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Sample records for crater area ghana

  1. Area Handbook for Ghana.

    Science.gov (United States)

    Kaplan, Irving; And Others

    The dominant social, political, and economic aspects of Ghanaian society are described in this handbook. Changes and developments in Ghana in the past 10 years, highlighted by the 1966 overthrough and widespread repudiation of Kwame Nkrumah and his policies and practices, have created a need for this revision of the 1962 edition. The purpose of…

  2. Usability of small impact craters on small surface areas in crater count dating: Analysing examples from the Harmakhis Vallis outflow channel, Mars

    Science.gov (United States)

    Kukkonen, S.; Kostama, V.-P.

    2018-05-01

    The availability of very high-resolution images has made it possible to extend crater size-frequency distribution studies to small, deca/hectometer-scale craters. This has enabled the dating of small and young surface units, as well as recent, short-time and small-scale geologic processes that have occurred on the units. Usually, however, the higher the spatial resolution of space images is, the smaller area is covered by the images. Thus the use of single, very high-resolution images in crater count age determination may be debatable if the images do not cover the studied region entirely. Here we compare the crater count results for the floor of the Harmakhis Vallis outflow channel obtained from the images of the ConTeXt camera (CTX) and High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter (MRO). The CTX images enable crater counts for entire units on the Harmakhis Vallis main valley, whereas the coverage of the higher-resolution HiRISE images is limited and thus the images can only be used to date small parts of the units. Our case study shows that the crater count data based on small impact craters and small surface areas mainly correspond with the crater count data based on larger craters and more extensive counting areas on the same unit. If differences between the results were founded, they could usually be explained by the regional geology. Usually, these differences appeared when at least one cratering model age is missing from either of the crater datasets. On the other hand, we found only a few cases in which the cratering model ages were completely different. We conclude that the crater counts using small impact craters on small counting areas provide useful information about the geological processes which have modified the surface. However, it is important to remember that all the crater counts results obtained from a specific counting area always primarily represent the results from the counting area-not the whole

  3. Ghana.

    Science.gov (United States)

    1981-09-01

    The government of Ghana sees the country's population as a valuable natural resource and emphasizes national population policy as an important part of overall socioeconomic planning and development. A formal system of development planning has been in effect since 1951. Decennial censuses are conducted relatively regularly but vital registration is thought to be incomplete. The current population size is 11,679,000 and the current rate of natural increase (3.1%) is considered too high, constraining the achievement of socioeconomic development. The high rate of growth is taxing on employment and public services. High fertility rates are influenced both by regional norms, such as early and universal marriage, and demographic factors, i.e., an increasingly higher proportion of the population in the 0-14 age group. The government sponsors family planning services which can be obtained free or at subsidized rates and seeks to upgrade the health and living standards of the population. Sterilization is permitted for medical reasons only, and abortions are restricted. Crude death rates have declined steadily and are currently estimated at 21-23/1000 population. The infant mortality rate is approximately 125.7/1000 live births. These rates are considered unacceptable and budget allocations for curative and preventive services have continuously risen. Uneven regional distribution of services continues to be problematic. Efforts to curb immigration in 1969 are thought to have resulted in the current satisfactory situation. Restrictive measures to prevent the emigration of skilled personnel are in effect. 60-65% of the population are urban dwellers and the proportion is expected to increase. The current spatial distribution of the population is considered inappropriate, rapid urbanization is causing rural depopulation, overburdening urban services and accentuating rural-urban disparaties. 2 approaches to the problem have been implemented: the urban increase is accomodated by

  4. Ghana

    DEFF Research Database (Denmark)

    McKay, Andy; Pirttilä, Jukka; Tarp, Finn

    Ghana is relatively rare among Sub-Saharan African countries in having had sustained positive growth every year since the mid-1980s. This paper analyses the nature of the growth and then presents an analysis of the evolution of both consumption poverty and non-monetary poverty outcomes over...... this period, showing improvements in almost all indicators over this period. At the same time, inequality has risen over the past 20 years and spatial inequality, in both monetary and non-monetary outcomes, remains an important concern. This increase in inequality is one reason why growth has not led...

  5. Hydrochemical characterization of groundwater in the Akyem area, Ghana

    Science.gov (United States)

    Banoeng-Yakubo, B.; Yidana, S.M.; Anku, Y.; Akabzaa, T.; Asiedu, D.

    2008-01-01

    The Akyem area is a small farming community located in southeastern Ghana. Groundwater samples from wells in the area were analyzed for concentrations of the major ions, silica, electrical conductivity and pH. The objective was to determine the main controls on the hydrochemistry of ground-water. Mass balance modeling was used together with multivariate R-mode hierarchical cluster analysis to determine the significant sources of variation in the hydrochemistry. Two water types exist in this area. The first is influenced most by the weathering of silicate minerals from the underlying geology, and is thus rich in silica, sodium, calcium, bicarbonate, and magnesium ions. The second is water that has been influenced by the effects of fertilizers and other anthropogenic activities in the area. Mineral speciation and silicate mineral stability diagrams suggest that montmorillonite, probably derived from the incongruent dissolution of feldspars and micas, is the most stable silicate phase in the groundwaters. The apparent incongruent weathering of silicate minerals in the groundwater system has led to the enrichment of sodium, calcium, magnesium and bicarbonate ions as well as silica, leading to the supersaturation of calcite, aragonite, dolomite and quartz. Stability in the montmorillonite field suggests restricted flow conditions and a long groundwater residence time, leading to greater exposure of the rock to weathering. Cation exchange processes appear to play minor roles in the hydrochemistry of groundwater.

  6. Modelling of Malaria Risk Areas in Ghana by using Environmental ...

    African Journals Online (AJOL)

    Michael

    2015-12-02

    Dec 2, 2015 ... control in time and space to be prepared for outbreaks, which ... developing dynamic and area-specific risk maps to ... disease outbreaks including vaccination (Haydon et ... analyse malaria data against certain environmental.

  7. Drivers of land use change and carbon mapping in the savannah area of Ghana

    Directory of Open Access Journals (Sweden)

    Koranteng Addo

    2017-12-01

    Full Text Available Land-use and land-cover change in both forest reserves and off-reserves is a critical issue in sub Saharan Africa. Deforestation and conversion of forest land to agricultural land continue to be one of the major environmental problems in Africa, and for that matter, Ghana cannot be exceptional; and its resultant effect is the loss in the ecological integrity and the quality of forests, resulting in carbon loss and the resultant climate change effects (FAO 2016. The study area covers the Community Resource Management Areas (CREMA of the Mole National Park in Ghana, and this study reveals that the area is well endowed with a diverse composition and structure of woodland including dense, open and riverine stretches, which – under the national definition of forest – qualifies as forest. The results reveal that there had been an annual deforestation rate of 0.11% over the period of review. It was concluded from the study that woodland had high carbon stocks with an average carbon of 80 tC/ha, the highest being 194 tC/ha and the lowest being 7 tC/ha, which was recorded in the dense woodland and grassland respectively. The fluxes within the land sector in the study area are moderate and the potential of the area to qualify for as REDD+ is very high. However, the drivers of deforestation, especially bush fires and illegal timber harvesting, are challenges that need to be addressed.

  8. THE EFFECTS OF CLIMATIC VARIABLES AND CROP AREA ON MAIZE YIELD AND VARIABILITY IN GHANA

    Directory of Open Access Journals (Sweden)

    Henry De-Graft Acquah

    2012-10-01

    Full Text Available Climate change tends to have negative effects on crop yield through its influence on crop production. Understanding the relationship between climatic variables and crop area on the mean and variance of crop yield will facilitate development of appropriate policies to cope with climate change. This paper examines the effects of climatic variables and crop area on the mean and variance of maize yield in Ghana. The Just and Pope stochastic production function using the Cobb-Douglas functional form was employed. The results show that average maize yield is positively related to crop area and negatively related to rainfall and temperature. Furthermore, increase in crop area and temperature will enlarge maize yield variability while rainfall increase will decrease the variability in maize yield.

  9. Heavy metals concentration and distribution in soils and vegetation at Korle Lagoon area in Accra, Ghana

    DEFF Research Database (Denmark)

    Fosu-Mensah, Benedicta Yayra; Addae, Emmanuel; Yirenya-Tawiah, Dzidzo

    2017-01-01

    The call for reclamation of land around Korle Lagoon in Accra, Ghana, where burning of E-waste and cultivation of vegetables takes place, make risk assessment of heavy metal contaminations important. This study aimed at evaluating the levels and risk of heavy metal contamination in soils...... and vegetation around the Korle lagoon area in Accra. Geoaccumulation index, enrichment factor and pollution load index were determined to assess the risk of contamination. The levels and distribution of nine heavy metals (Pb, Hg, Cd, As, Zn, Sn, Ni, Cu and Cr) in soil (0 – 20 cm) and common vegetation (Panicum...... was significantly different (p burning of e-waste should be enforced and animals...

  10. Sachet drinking water in Ghana's Accra-Tema metropolitan area: past, present, and future.

    Science.gov (United States)

    Stoler, Justin; Weeks, John R; Fink, Günther

    2012-01-01

    Population growth in West Africa has outpaced local efforts to expand potable water services, and private sector sale of packaged drinking water has filled an important gap in household water security. Consumption of drinking water packaged in plastic sachets has soared in West Africa over the last decade, but the long-term implications of these changing consumption patterns remain unclear and unstudied. This paper reviews recent shifts in drinking water, drawing upon data from the 2003 and 2008 Demographic and Health Surveys, and provides an overview of the history, economics, quality, and regulation of sachet water in Ghana's Accra-Tema Metropolitan Area. Given the pros and cons of sachet water, we suggest that a more holistic understanding of the drinking water landscape is necessary for municipal planning and sustainable drinking water provision.

  11. MANAGING PHYSICAL DEVELOPMENT IN PERI-URBAN AREAS OF KUMASI, GHANA: A CASE OF ABUAKWA

    Directory of Open Access Journals (Sweden)

    Paul Amoateng

    2013-01-01

    Full Text Available A remarkable trait of the 21 st century has been the high rate of urbanization which has characterized the growth and development of cities especially in developing countries. This situation has fuelled rapid physical development and expansion of peri-urban areas as urban dwellers relocate to cities’ peripheries. Focusing on Abuakwa a peri-urban area in Kumasi, the second largest city in Ghana, this paper assesses the nature and extent of physical development in peri-urban areas, and identifies the factors contributing to the rapid development of peri-urban areas. The paper further examines the effects of the increasing physical growth on the development of peri-urban Abuakwa. Using a case study approach, both primary and secondary sources of data were collected from decentralized government institutions of Kumasi Metropolitan Assembly (KMA and Atwima Nwabiagya District Assembly (ANDA, as well as indigenes and relocated urban dwellers in Abuakwa. The paper reveals that the outward drift has manifested itself in an increased scramble for land for residential and commercial purposes in the peri-urban area. The resultant effect has been the fast and spontaneous physical development in the urban periphery which has significantly altered the peri-urban morphology. The paper recommends the establishment of Customary Land Secretariat (CLS to co-ordinate allocation of land, and the application of settlement growth management approaches to ensure the creation of a functional city and liveable peri-urban areas.

  12. Wildlife laws monitoring as an adaptive management tool in protected area management in Ghana: a case of Kakum Conservation Area.

    Science.gov (United States)

    Wiafe, Edward Debrah

    2016-01-01

    The wildlife laws of Ghana alienated the rural communities from forests and material well-being depended upon for their livelihood and this manifests itself in the progressive conflict between the park patrol staff and poachers from the fringes of the protected areas. The main aim of this study was to determine the impact of quantification of patrol efforts on indicators of illegal hunting activities that occur in rainforest protected areas, as a result of monitoring patrol operations and modifying the original plan. The specific objectives were to determine the optimal patrol efforts necessary to reduce illegal wildlife use to minimal; and the influence of the rainfall and seasonal activities on illegal wildlife use. The results indicated that as the patrol efforts increased the encounter with illegal wildlife use also increased until a certain point that the encounter rates started decreasing. Neither rainfall nor seasonal activities influenced the illegal activities and the patrol efforts. The protection staff of rainforest protected areas would work effectively to bring down illegal wildlife off-take to the barest minimum if monitored, quantified and provide feed-back. Illegal wildlife off-take can also be reduced by the protection staff if the original plans are made flexible to be adjusted. Recommendations for further studies have been made.

  13. Emerging feed markets for ruminant production in urban and peri-urban areas of Northern Ghana.

    Science.gov (United States)

    Konlan, S P; Ayantunde, A A; Addah, W; Dei, H K; Karbo, N

    2018-01-01

    Feed shortage in urban and peri-urban areas has triggered the emergence of feed markets in Northern Ghana. These markets were surveyed at three locations (Tamale, Bolgatanga, and Wa markets) to determine types and prices of feedstuffs sold across seasons; early dry (November-January), late dry (February-April), early wet (May-July), and main wet (August-October). Semi-structured questionnaire was used for data collection. Three samples of each feed type in the markets were bought from three different sellers per market in each season. The samples were oven dried to constant weight and price/kg DM of each feed determined. The total respondents were 169. Out of this number, 41% were feed sellers, 46% buyers, and 13% retailers. The feedstuffs found were crop residues (groundnut haulm and cowpea haulm), agro-industrial by-products (bran of maize, rice, and sorghum), fresh grasses (Rotteboellia cochinchinensis), and local browses (Ficus sp. and Pterocarpus erinaceous). Prices of feeds differed (P  0.05) in all seasons but that of crop residues were higher (P < 05) in early to late dry season than the wet season. Majority (90%) of respondents opined that the feed market will expand due to increasing number of livestock population in the peri-urban areas.

  14. Location of Farmers Warehouse at Adaklu Traditional Area, Volta Region, Ghana

    Directory of Open Access Journals (Sweden)

    Vincent Tulasi

    2016-01-01

    Full Text Available Postharvest loss is one major problem farmers in Adaklu Traditional Area that most Ghanaian farmers face. As a result, many farmers wallow in abject poverty. Warehouses are important facilities that help to reduce postharvest loss. In this research, Beresnev pseudo-Boolean Simple Plant Location Problem (SPLP model is used to locate a warehouse at Adaklu Traditional Area, Volta Region, Ghana. This model was used because it gives a straightforward computation and produces no iteration as compared with other models. The SPLP is a problem of selecting a site from candidate sites to locate a plant so that customers can be supplied from the plant at a minimum cost. The model is made up of fixed cost and transportation cost. Location index ordering matrix was developed from the transportation cost matrix and we used it with the fixed cost and differences between variable costs to formulate the Beresnev function. Linear term developed from the function which was partial is pegged to obtain a complete solution. Of the 14 notable communities considered, Adaklu Waya is found most suitable for the setting of the warehouse. The total cost involved is Gh₵ 78,180.00.

  15. Levels of cobalt and silver in water sources in a mining area in Ghana

    African Journals Online (AJOL)

    underground water and river water) from a mining community in Ghana. The water samples were treated in the laboratory by acid digestion and the concentration of silver and cobalt were analysed with Atomic Absorption Spectrophotometer.

  16. Particulate Matter and Black Carbon Concentration Levels in Ashaiman, a Semi-Urban Area of Ghana, 2008

    OpenAIRE

    Sam-Quarcoo Dotse; Joshua Kwame Asane; F.G. Ofosu

    2012-01-01

    Particulate matter and black carbon concentration levels in Ashaiman, a semi-urban area of Ghana was assessed. Using IVL PM2.5 and PM10 particle samplers, airborne particulate matter was sampled on Teflon filters for a period of three months. In addition to determination of particulate mass in the two fractions by gravimetrical method, aerosol filters were analyzed to determine Black Carbon (BC) concentration levels using the black smoke method. BC fractions in fine and coarse, together with ...

  17. Environment, wealth, inequality and the burden of disease in the Accra metropolitan area, Ghana.

    Science.gov (United States)

    Boadi, Kwasi Owusu; Kuitunen, Markku

    2005-06-01

    The study examines environmental problems and adverse impacts on the health of urban households in the Accra metropolitan area, Ghana. Accra is faced with severe inadequacy of urban infrastructure in the face of rapid population growth in the metropolis. More than half of the city's population do not have access to solid waste collection services. Only 39.8% of households have indoor pipe and over 35.0% of households depend on unsanitary public latrines whilst 2.5% do not have access to toilet facilities. Human excrement, garbage and wastewater are usually deposited in surface drains, open spaces and streams in poor neighbourhoods. The resultant poor sanitation has serious health impacts as more than half of reported diseases are related to poor environmental sanitation. The majority of households depend on solid fuels for cooking and this leads to indoor air pollution and high incidence of respiratory infections. Poor households bear a disproportionately large share of the burden of environmental health hazards than their wealthy counterparts, due to their particular vulnerability resulting from inadequate access to environmental health facilities and services.

  18. Hydrogeochemistry and Stable Isotope Studies of Groundwater in the Ga West Municipal Area, Ghana

    International Nuclear Information System (INIS)

    Saka, David

    2011-07-01

    This study assesses groundwater in the Ga West Municipal Area of Ghana using hydrogeochemistry and stable isotope approaches. High salinity groundwaters are obtained in the municipality which poses problems for current and future domestic water supply exploitation. The increase in salinity is related to the dissolution of minerals in the host rocks and the evaporative concentration of solutes. The dominant groundwater composition in both shallow and deep wells sampled is Na-Cl, with concentration increasing substantially with well depths. The mixing process between freshwater and saline water was observed in the shift from CaHCO3 facies to Ca-Cl facies. Schoeller diagrams showed that groundwater movement in the study area is mostly vertical, moving from the shallow groundwaters towards the deep groundwaters. There were however few exceptions where no relationship was established between the shallow and the deep groundwaters. The oxygen and hydrogen isotope compositions in the groundwater samples suggest that groundwater recharge is of meteoric origin, with few samples showing evidence of evaporation. An average deuterium excess of rainfall of 14.2‰ was observed, which indicates the significance of kinetic evaporation due to low humidity conditions prevalent in the study area. The d-excess also indicates modern recharge along the Akwapim-Togo Ranges. Groundwater analysis for trace metals indicates that 93% of the groundwaters have Iron concentration above recommended limits. However, Cu, Zn, Pb, Cd and Cr have values within the acceptable limits. Generally, about 40% of the groundwaters sampled are not suitable for drinking and domestic purposes based on comparison with international standards for drinking water. (au)

  19. Ghana - Transportation

    Data.gov (United States)

    Millennium Challenge Corporation — The Ghana Millennium Development Authority's (MiDA) Agriculture Project within the Government of Ghana's Compact with the Millennium Challenge Corporation is design...

  20. Buried Craters of Utopia

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-365, 19 May 2003Beneath the northern plains of Mars are numerous buried meteor impact craters. One of the most heavily-cratered areas, although buried, occurs in Utopia Planitia, as shown in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image. The history of Mars is complex; impact craters provide a tool by which to understand some of that history. In this case, a very ancient, cratered surface was thinly-buried by younger material that is not cratered at all. This area is near 48.1oN, 228.2oW; less than 180 km (112 mi) west of the Viking 2 lander site. Sunlight illuminates the scene from the lower left.

  1. Improving drug delivery strategies for lymphatic filariasis elimination in urban areas in Ghana.

    Directory of Open Access Journals (Sweden)

    Nana-Kwadwo Biritwum

    2017-05-01

    Full Text Available The Global Program to Eliminate Lymphatic Filariasis (GPELF advocates for the treatment of entire endemic communities, in order to achieve its elimination targets. LF is predominantly a rural disease, and achieving the required treatment coverage in these areas is much easier compared to urban areas that are more complex. In Ghana, parts of the Greater Accra Region with Accra as the capital city are also endemic for LF. Mass Drug Administration (MDA in Accra started in 2006. However, after four years of treatment, the coverage has always been far below the 65% epidemiologic coverage for interrupting transmission. As such, there was a need to identify the reasons for poor treatment coverage and design specific strategies to improve the delivery of MDA. This study therefore set out to identify the opportunities and barriers for implementing MDA in urban settings, and to develop appropriate strategies for MDA in these settings. An experimental, exploratory study was undertaken in three districts in the Greater Accra region. The study identified various types of non-rural settings, the social structures, stakeholders and resources that could be employed for MDA. Qualitative assessment such as in-depth interviews (IDIs and focus group discussions (FGDs with community leaders, community members, health providers, NGOs and other stakeholders in the community was undertaken. The study was carried out in three phases: pre-intervention, intervention and post-intervention phases, to assess the profile of the urban areas and identify reasons for poor treatment coverage using both qualitative and quantitative research methods. The outcomes from the study revealed that, knowledge, attitudes and practices of community members to MDA improved slightly from the pre-intervention phase to the post-intervention phase, in the districts where the interventions were readily implemented by health workers. Many factors such as adequate leadership, funding, planning and

  2. Rabbit Production in Selected Urban Areas of Southern Ghana: Status and Implications for Policy and Research

    Directory of Open Access Journals (Sweden)

    DY Osei

    2012-05-01

    Full Text Available A survey was conducted to elicit information on rabbit keeping in 26 urban areas of southern Ghana. The average age of the rabbit keepers was 44.3 years, and 95.5% of the keepers had formal education. Most of the producers got into rabbit keeping for money to meet urgent family needs, while household consumption was a major factor influencing the decision for rearing rabbits. Personal savings was the main source of income for the establishment of the rabbit enterprises. The major breeds of rabbits kept were the California White, New Zealand White and crossbreds of varied genetic variations. Backyard, small-scale and medium-scale commercial rabbit holdings were held by 18.2, 51.7 and 30.2% of the keepers respectively. The average rabbit population per farm was 77.8, with an average of 8.4 bucks, 21.6 does. Young rabbits formed 70.0% of the rabbit population. Owners of rabbitries usually cared for their animals as hired labour was expensive and often not available. High cost of feed was the most significant constraint to rabbit keeping, and mange was the most common disease affecting the rabbits. Marketing of rabbits was not organized, and this served as a disincentive to expanding the holdings. The rabbits were mostly sold either life or as fresh carcasses at the farm gate. To ensure a rapid growth of the rabbit industry, research should be undertaken to address the identified constraints to production while appropriate policies are put in place to enhance the growth of the industry. Keywords: rabbit keeping, socio-economic characteristics, farming technologies   Animal Production 14(2:131-139

  3. Spatio-temporal analysis of small-area intestinal parasites infections in Ghana

    NARCIS (Netherlands)

    Osei, F. B.; Stein, A.

    2017-01-01

    Intestinal parasites infection is a major public health burden in low and middle-income countries. In Ghana, it is amongst the top five morbidities. In order to optimize scarce resources, reliable information on its geographical distribution is needed to guide periodic mass drug administration to

  4. Experimental impact crater morphology

    Science.gov (United States)

    Dufresne, A.; Poelchau, M. H.; Hoerth, T.; Schaefer, F.; Thoma, K.; Deutsch, A.; Kenkmann, T.

    2012-04-01

    The research group MEMIN (Multidisciplinary Experimental and Impact Modelling Research Network) is conducting impact experiments into porous sandstones, examining, among other parameters, the influence of target pore-space saturation with water, and projectile velocity, density and mass, on the cratering process. The high-velocity (2.5-7.8 km/s) impact experiments were carried out at the two-stage light-gas gun facilities of the Fraunhofer Institute EMI (Germany) using steel, iron meteorite (Campo del Cielo IAB), and aluminium projectiles with Seeberg Sandstone as targets. The primary objectives of this study within MEMIN are to provide detailed morphometric data of the experimental craters, and to identify trends and characteristics specific to a given impact parameter. Generally, all craters, regardless of impact conditions, have an inner depression within a highly fragile, white-coloured centre, an outer spallation (i.e. tensile failure) zone, and areas of arrested spallation (i.e. spall fragments that were not completely dislodged from the target) at the crater rim. Within this general morphological framework, distinct trends and differences in crater dimensions and morphological characteristics are identified. With increasing impact velocity, the volume of craters in dry targets increases by a factor of ~4 when doubling velocity. At identical impact conditions (steel projectiles, ~5km/s), craters in dry and wet sandstone targets differ significantly in that "wet" craters are up to 76% larger in volume, have depth-diameter ratios generally below 0.19 (whereas dry craters are almost consistently above this value) at significantly larger diameters, and their spallation zone morphologies show very different characteristics. In dry craters, the spall zone surfaces dip evenly at 10-20° towards the crater centre. In wet craters, on the other hand, they consist of slightly convex slopes of 10-35° adjacent to the inner depression, and of sub-horizontal tensile

  5. Mapping irrigated areas of Ghana using fusion of 30 m and 250 m resolution remote-sensing data

    Science.gov (United States)

    Gumma, M.K.; Thenkabail, P.S.; Hideto, F.; Nelson, A.; Dheeravath, V.; Busia, D.; Rala, A.

    2011-01-01

    Maps of irrigated areas are essential for Ghana's agricultural development. The goal of this research was to map irrigated agricultural areas and explain methods and protocols using remote sensing. Landsat Enhanced Thematic Mapper (ETM+) data and time-series Moderate Resolution Imaging Spectroradiometer (MODIS) data were used to map irrigated agricultural areas as well as other land use/land cover (LULC) classes, for Ghana. Temporal variations in the normalized difference vegetation index (NDVI) pattern obtained in the LULC class were used to identify irrigated and non-irrigated areas. First, the temporal variations in NDVI pattern were found to be more consistent in long-duration irrigated crops than with short-duration rainfed crops due to more assured water supply for irrigated areas. Second, surface water availability for irrigated areas is dependent on shallow dug-wells (on river banks) and dug-outs (in river bottoms) that affect the timing of crop sowing and growth stages, which was in turn reflected in the seasonal NDVI pattern. A decision tree approach using Landsat 30 m one time data fusion with MODIS 250 m time-series data was adopted to classify, group, and label classes. Finally, classes were tested and verified using ground truth data and national statistics. Fuzzy classification accuracy assessment for the irrigated classes varied between 67 and 93%. An irrigated area derived from remote sensing (32,421 ha) was 20-57% higher than irrigated areas reported by Ghana's Irrigation Development Authority (GIDA). This was because of the uncertainties involved in factors such as: (a) absence of shallow irrigated area statistics in GIDA statistics, (b) non-clarity in the irrigated areas in its use, under-development, and potential for development in GIDA statistics, (c) errors of omissions and commissions in the remote sensing approach, and (d) comparison involving widely varying data types, methods, and approaches used in determining irrigated area statistics

  6. Mapping the expansion of galamsey gold mines in the cocoa growing area of Ghana using optical remote sensing

    Science.gov (United States)

    Snapir, B.; Simms, D. M.; Waine, T. W.

    2017-06-01

    Artisanal gold mining (galamsey) and cocoa farming are essential sources of income for local populations in Ghana. Unfortunately the former poses serious threats to the environment and human health, and conflicts with cocoa farming and other livelihoods. Timely and spatially referenced information on the extent of galamsey is needed to understand and limit the negative impacts of mining. To address this, we use multi-date UK-DMC2 satellite images to map the extent and expansion of galamsey from 2011 to 2015. We map the total area of galamsey in 2013 over the cocoa growing area, using k-means clustering on a cloud-free 2013 image with strong spectral contrast between galamsey and the surrounding vegetation. We also process a pair of hazy images from 2011 and 2015 with Multivariate Alteration Detection to map the 2011-2015 galamsey expansion in a subset, labelled the change area. We use a set of visually interpreted random sample points to compute bias-corrected area estimates. We also delineate an indicative impact zone of pollution proportional to the density of galamsey, assuming a maximum radius of 10 km. In the cocoa growing area of Ghana, the estimated total area of galamsey in 2013 is 27,839 ha with an impact zone of 551,496 ha. In the change area, galamsey has more than tripled between 2011 and 2015, resulting in 603 ha of direct encroachment into protected forest reserves. Assuming the same growth rate for the rest of the cocoa growing area, the total area of galamsey in 2015 is estimated at 43,879 ha. Galamsey is developing along most of the river network (Offin, Ankobra, Birim, Anum, Tano), with downstream pollution affecting both land and water.

  7. Crater in Utopia

    Science.gov (United States)

    2004-01-01

    23 March 2004 Craters of the martian northern plains tend to be somewhat shallow because material has filled them in. Their ejecta blankets, too, are often covered by younger materials. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an example--a crater in Utopia Planitia near 43.7oN, 227.3oW. Erosion has roughened some of the surfaces of the material that filled the crater and covered its ejecta deposit. The picture covers an area about 3 km (1.9 mi) across. Sunlight illuminates the scene from the lower left.

  8. Survey of Forest Elephants Loxodonta cyclotis (Matschie, 1900 (Mammalia: Proboscidea: Elephantidae in the Bia Conservation Area, Ghana

    Directory of Open Access Journals (Sweden)

    Emmanuel Danquah

    2014-10-01

    Full Text Available Information on elephant ranges and numbers is vital for effective conservation and management, especially in western Africa where elephant populations are small and scattered.  The Bia Conservation Area (BCA in southwestern Ghana is a priority site for the conservation of Forest Elephants in western Africa.  A dung count was conducted using a systematic segmented track line design to determine the density and distribution of the BCA elephant population.  The mean density of dung-piles was 452.15 per sq.km. and mean dung survival time was estimated to be 54.64 days (SD 2 days, leading to an estimate of 146 elephants (95% confidence interval 98-172 with a density of 0.48/km2 for the BCA. This estimate probably makes the Bia forest elephant population the largest in Ghana.  Records of BCA elephant activities were also made.  This study augments the Regional African Elephant Database and should facilitate strategic planning and management programmes.

  9. Assessment of atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana using epiphytic lichens

    Energy Technology Data Exchange (ETDEWEB)

    Boamponsem, L.K. [Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology, University Post Office, Kumasi (Ghana); Department of Laboratory Technology, School of Physical Sciences, University of Cape Coast, Cape Coast (Ghana); Adam, J.I. [Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology, University Post Office, Kumasi (Ghana); Dampare, S.B., E-mail: dampare@cc.okayama-u.ac.j [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon-Accra (Ghana); Department of Earth Sciences, Okayama University, 1-1, Tsushima-Naka 3-Chome, Okayama 700-8530 (Japan); Nyarko, B.J.B. [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon-Accra (Ghana); Essumang, D.K. [Department of Laboratory Technology, School of Physical Sciences, University of Cape Coast, Cape Coast (Ghana)

    2010-05-01

    In situ lichens (Parmelia sulcata) have been used to assess atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana. Total heavy metal concentrations obtained by instrumental neutron activation analysis (INAA) were processed by positive matrix factorization (PMF), principal component (PCA) and cluster (CA) analyses. The pollution index factor (PIF) and pollution load index (PLI) criteria revealed elevated levels of Sb, Mn, Cu, V, Al, Co, Hg, Cd and As in excess of the background values. The PCA and CA classified the examined elements into anthropogenic and natural sources, and PMF resolved three primary sources/factors: agricultural activities and other non-point anthropogenic origins, natural soil dust, and gold mining activities. Gold mining activities, which are characterized by dominant species of Sb, Th, As, Hg, Cd and Co, and significant contributions of Cu, Al, Mn and V, are the main contributors of heavy metals in the atmosphere of the study area.

  10. Assessment of atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana using epiphytic lichens

    International Nuclear Information System (INIS)

    Boamponsem, L.K.; Adam, J.I.; Dampare, S.B.; Nyarko, B.J.B.; Essumang, D.K.

    2010-01-01

    In situ lichens (Parmelia sulcata) have been used to assess atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana. Total heavy metal concentrations obtained by instrumental neutron activation analysis (INAA) were processed by positive matrix factorization (PMF), principal component (PCA) and cluster (CA) analyses. The pollution index factor (PIF) and pollution load index (PLI) criteria revealed elevated levels of Sb, Mn, Cu, V, Al, Co, Hg, Cd and As in excess of the background values. The PCA and CA classified the examined elements into anthropogenic and natural sources, and PMF resolved three primary sources/factors: agricultural activities and other non-point anthropogenic origins, natural soil dust, and gold mining activities. Gold mining activities, which are characterized by dominant species of Sb, Th, As, Hg, Cd and Co, and significant contributions of Cu, Al, Mn and V, are the main contributors of heavy metals in the atmosphere of the study area.

  11. Prioritization of strategies for protected area management with local people using the hybrid SWOT-AHP analysis: the case of Kakum conservation area, Ghana

    Directory of Open Access Journals (Sweden)

    Raphael Foli Fiagbomeh

    2015-05-01

    Full Text Available The contribution of protected areas towards conservation and protection of biodiversity cannot be over emphasized. Likewise, the dependence of local communities on forest and natural resources cannot be overlooked. Hence for the long term viability of forest reserves and wildlife protected area, the relationship of local people living close to these areas are of key importance if conflict of use can be mitigated. Admittedly, decision-making with respect to forest resource use and protection are complex due to the multiple interests of the major stakeholders. Stakeholder involvement in the planning, management and policy analysis can help resolve conflicts, and increase the commitment of local people to support conservation of protected areas. In this paper, we employ the SWOT-AHP methodology, with the aid of the Priority Estimation Tool (PriEsT, to evaluate and prioritize three management strategies for the Kakum conservation area in Ghana, as a means to facilitate conservation while ensuring benefits to local people. Considering the management objectives of the conservation area, seventeen SWOT sub-factors were identified and used in rating the three alternative management strategies. Among the strength sub-factors, enforcement of protection regulations (S4 is the most important. Similarly, limited funds for patrolling and outreach programs (W3, local people’s interest in alternative livelihood (O4 and the presence of illegal activities (T3 are the most important weakness, opportunity and threat sub-factors respectively. The management strategy “institute village committees to support monitoring and protection of resources” (A1 has the highest priority rating, indicating that management authorities must pay more attention to collaborative management. We propose that to improve on protected area management in Ghana, more management strategy studies must be conducted. However, these studies may apply the fuzzy AHP technique since it is

  12. Prevalence of peripheral blood parasitaemia, anaemia and low birthweight among pregnant women in a suburban area in coastal Ghana.

    Science.gov (United States)

    Stephens, Judith Koryo; Ofori, Michael F; Quakyi, Isabella Akyinbah; Wilson, Mark Lee; Akanmori, Bartholomew Dicky

    2014-01-01

    Malaria and anaemia have adverse effects in pregnant women and on the birth weight of infants in malaria endemic areas. P. falciparum malaria, the most virulent species continues to be a major health problem in sub-Saharan Africa. This study was carried out to establish the prevalence of pregnancy-associated malaria and its associated consequences including maternal anaemia and low birthweight (LBW) deliveries and placental malaria among pregnant women in a sub-urban area in coastal Ghana. A facility-based investigation was carried out among 320 pregnant women seeking antenatal care in a hospital in suburban coastal Ghana. Information on the use of Insecticide Treated Nets (ITNs) and Intermittent Preventive Treatment in pregnancy (IPTp) were collected using a structured questionnaire at enrollment. Venous blood was collected for microscopy and screening for Glucose 6-phosphate dehydrogenase (G6PD) deficiency. Haemoglobin concentration was obtained from an automatic blood analyzer. Placental smears and birth weight measurements were taken at delivery. The prevalence of Plasmodium falciparum parasitaemia was 5%. The mean haemoglobin (Hb) level at registration was 11.44 g/dL (95% CI 11.29 - 11.80). Placental blood parasitaemia and low birthweight were 2.5% and 3% respectively. ITN possession was 31.6% with 5.4% usage. The IPTp coverage was 55%. The prevalence of malaria and anaemia among the pregnant women were low at enrollment. Placental blood parasitaemia and LBW at delivery were also low. These are clear indications of the high coverage of the IPTp. Increase in ITN use will further improve birthweight outcomes and reduce placental malaria.

  13. Arsenic and mercury levels in human hairs and nails from gold mining areas in Wassa West District of Ghana

    International Nuclear Information System (INIS)

    Serfor-Armah, Y.; Samlafo, B.V.; Yeboah, P.O.

    2009-01-01

    Hair and nail samples obtained from inhabitants of Wassa District, a major gold mining area in Ghana, were analysed for arsenic (As) and mercury (Hg) using instrumental neutron activation analysis. The samples were irradiated at a thermal neutron flux of 5 x 10 11 n cm -2 s -1 using the Ghana Research Reactor. Concentration of Hg in the hairs ranged from 1.65 to 20.46 μg/g, which were below World Health Organization (WHO) recommended level of 50.00 μg/g for human hair. Mercury concentration in human nail samples ranged from 0.97 to 31.94 μg/g. Arsenic concentrations in human hairs ranged from 0.07 to 0.95 μg/g, while the levels in nail samples ranged from 0.08 to 3.90 μg/g. Generally, levels of As in the hair were less than WHO recommended value of 1.00 μg/g, however, the levels of As in 5 nail samples (FN 11 , FN 20 , FN 28 , TN 9 and TN 16 ) were above the maximum WHO value of 1.80μg/g. The measurement precision specified by the relative standard deviation was within ± 3 %. The accuracy of determination evaluated by analysing certified standard human reference material GBW 09101 was within ± 4 % of the certified value. The levels of As in hair and nail samples of the experimental group were generally higher as compared to the control subject. Similarly, Hg levels in the hair and nail samples in experimental group were also higher compared to the control subject. However, the levels of the toxic elements determined were all below WHO recommended values. (au)

  14. Extending the baseline of tropical dry forest loss in Ghana (1984–2015) reveals drivers of major deforestation inside a protected area

    OpenAIRE

    Janssen, T; Ametsisi, G; Collins, M; Adu-Bredu, S; Oliveras-Menor, I; Mitchard, ETA; Veenendaal, EM

    2017-01-01

    Abstract Tropical dry forests experience the highest deforestation rates on Earth, with major implications for the biodiversity of these ecosystems, as well as for its human occupants. Global remote sensing based forest cover data (2000 − 2012) point to the rapid loss of tropical dry forest in South America and Africa, also, if not foremost, inside formally protected areas. Here, we significantly extend the baseline of tropical dry forest loss inside a protected area in Ghana using a generali...

  15. Biomonitoring of trace-element air pollution in a gold mining area in Ghana using the generalized k0-standardization NAA method

    International Nuclear Information System (INIS)

    Nyarko, B.J.B.; Kyere, A.W.K.; Serfor-Armah, Y.; Akaho, E.H.K.

    2003-01-01

    Full text: Mining activities contribute immensely to trace element atmospheric pollution. In Ghana, air pollution due to gold mining is the least investigated. In order to obtain preliminary information on air quality in the mining areas, the generalized k o- Standardization neutron activation analysis (NAA) method for nuclides following '1/v' and non-'1/v' (n,γ) reactions was used to analyse lichen samples from Prestea, a gold mining area in Ghana. Using the computed EPI values of both the Hogdahl-convention and the modified Westcott-formalism with gold as comparator standard, the IAEA lichen 336 certified reference material (CRM) and the lichen samples were irradiated in the inner irradiation site of the Ghana Research Reactor-1 (GHARR-1) operating at a thermal neutron flux of 5.0x10 11 ns -1 cm -2 . Comparison of the results with samples obtained from a non-mining (control) area, indicates that values of some metal pollutants such as As, Cr, Sb, and V were found to be higher in the lichens from the mining area than those in the non-mining area (control area); signifying accumulation of these metal pollutant due to gold - mining activities. (author)

  16. Post-Closure Inspection and Monitoring Report for Corrective Action Unit 110: Area 3 WMD U-3ax/bl Crater, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office; Bechtel Nevada

    2006-08-01

    This Post-Closure Inspection and Monitoring Report provides the results and inspections and monitoring for Corrective Action Unit 110: Area 3 Waste Management Division U-3ax/bl Crater, Nevada Test Site, Nevada. This report includes an analysis and summary of the site inpsections, repairs and maintenance, meteorological information, and soil moisture monitoring data obtained at Corrective Action Unit 110, for the annual period July 2005 thrugh June 2006.

  17. Corrective Action Decision Document/Closure Report for Corrective Action Unit 367: Area 10 Sedan, Ess and Uncle Unit Craters Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Matthews

    2011-06-01

    Corrective Action Unit 367 comprises four corrective action sites (CASs): • 10-09-03, Mud Pit • 10-45-01, U-10h Crater (Sedan) • 10-45-02, Ess Crater Site • 10-45-03, Uncle Crater Site The purpose of this Corrective Action Decision Document/Closure Report is to provide justification and documentation of the corrective actions and site closure activities implemented at CAU 367. A corrective action of closure in place with use restrictions was completed at each of the three crater CASs (10-45-01, 10-45-02, and 10-45-03); corrective actions were not required at CAS 10-09-03. In addition, a limited soil removal corrective action was conducted at the location of a potential source material release. Based on completion of these correction actions, no additional corrective action is required at CAU 367, and site closure is considered complete. Corrective action investigation (CAI) activities were performed from February 2010 through March 2011, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 367: Area 10 Sedan, Ess and Uncle Unit Craters, Nevada Test Site, Nevada. The approach for the CAI was divided into two facets: investigation of the primary release of radionuclides, and investigation of non-test or other releases (e.g., migration in washes and potential source material). Based on the proximity of the Uncle, Ess, and Sedan craters, the impact of the Sedan test on the fallout deposited from the two earlier tests, and aerial radiological surveys, the CAU 367 investigation was designed to study the releases from the three crater CASs as one combined release (primary release). Corrective Action Site 10-09-03, Mud Pit, consists of two mud pits identified at CAU 367. The mud pits are considered non-test releases or other releases and were investigated independent of the three crater CASs. The purpose of the CAI was to fulfill data needs as defined during the data quality objective (DQO) process. The CAU 367 dataset of

  18. Determination of free cyanide and total cyanide concentrations in surface and underground waters in Bogoso and its surrounding areas in Ghana

    Directory of Open Access Journals (Sweden)

    S. Obiri

    2007-08-01

    Full Text Available Concentrations of free cyanide and total cyanide in water samples in Bogoso and its surrounding areas in Ghana have been measured in this study. Concentrations of free cyanide and total cyanide were found to be above the maximum permissible discharge limit of effluent from mining companies into natural waters set by Environmental Protection Agency, Ghana (GEPA. A comparison of the results obtained in this study with permissible levels set by US Environmental Protection Agency and the World Health Organization reveals that surface waters in the study areas are highly polluted with cyanide and it's not safe for human consumptions. This means that, the resident in and around Bogoso are at risk.

  19. Population studies of Lowe’s Monkey (Mammalia: Primates: Cercopithecidae: Cercopithecus lowei Thomas, 1923 in Kakum Conservation Area, Ghana

    Directory of Open Access Journals (Sweden)

    Edward Debrah Wiafe

    2016-02-01

    Full Text Available The status of Lowe’s Monkey Cercopithecus lowei was assessed during a survey in Kakum Conservation Area, Ghana.  Within the reserve logging and hunting was banned 20 years ago, and the forest underwent two decades of natural regeneration.  The main objectives of the study were to evaluate the impact of conservation measures on the local population of Lowe’s Monkey and assess its relationships with other primates and non-primate mammals.  Data on population status were collected during line transect surveys.  Comparing the present mean encounter rate of 1.03 (±0.03 groups/km to that recorded in 1993 (0.31±0.16 groups/km suggests an average population growth rate of 13.6% per annum.  Conservation measures such as banning illegal logging and hunting have likely contributed to the population increase.  Lowe’s monkeys were often observed in close proximity to other primates (e.g., Black and White Colobus and non-primate mammals (e.g., Maxwell’s Duiker, but neither socio-positive nor antagonistic interactions were observed.  Recommendations are made for further improvement and studies of the species elsewhere. 

  20. Private Sector Participation in Urban Water and Sanitation Provision in Ghana: Experiences from the Tamale Metropolitan Area (TMA)

    Science.gov (United States)

    Osumanu, Issaka Kanton

    2008-07-01

    African governments, like most countries in the developing world, face daunting tasks in their attempts to provide effective and equitable water and sanitation services for their ever increasing urban populations. Consequently, the past few years have witnessed increased private sector participation in urban water and sanitation provision, as many African governments strive to improve access to water and sanitation services for their citizens in line with Millennium Development Goal 7 (MDG7). Since the early 1990s, the government of Ghana and many local authorities have entered into various forms of public-private partnerships in urban water and sanitation provision. This article examines the outcome of such partnerships using the Tamale Metropolitan Area (TMA) as a case study with the aim of providing policy guidelines for the way forward. The article argues that the public-private arrangement for water supply and sanitation infrastructure management in the Tamale Metropolis has done nothing that an invigorated public sector could not have possibly achieved. It concludes that there can be no sustainable improvement in water and sanitation provision without political commitment, stakeholder ownership, and strong support for community driven initiatives.

  1. Centrifuge impact cratering experiment 5

    Science.gov (United States)

    1984-01-01

    Transient crates motions, cratering flow fields, crates dynamics, determining impact conditions from total crater welt, centrifuge quarter-space cratering, and impact cratering mechanics research is documented.

  2. Corrective Action Decision Document/Closure Report for Corrective Action Unit 372: Area 20 Cabriolet/Palanquin Unit Craters, Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick and Sloop, Christy

    2011-04-01

    This Corrective Action Decision Document (CADD)/Closure Report (CR) has been prepared for Corrective Action Unit (CAU) 372, Area 20 Cabriolet/Palanquin Unit Craters, located within Areas 18 and 20 at the Nevada National Security Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order (FFACO). Corrective Action Unit 372 comprises four corrective action sites (CASs): • 18-45-02, Little Feller I Surface Crater • 18-45-03, Little Feller II Surface Crater • 20-23-01, U-20k Contamination Area • 20-45-01, U-20L Crater (Cabriolet) The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation that no further corrective action is needed for CAU 372 based on the implementation of the corrective action of closure in place with administrative controls at all CASs. Corrective action investigation (CAI) activities were performed from November 9, 2009, through December 10, 2010, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 372: Area 20 Cabriolet/Palanquin Unit Craters. The approach for the CAI was divided into two facets: investigation of the primary release of radionuclides and investigation of other releases (migration in washes and chemical releases). The purpose of the CAI was to fulfill data needs as defined during the data quality objective (DQO) process. The CAU 372 dataset of investigation results was evaluated based on a data quality assessment. This assessment demonstrated the dataset is acceptable for use in fulfilling the DQO data needs. Investigation results were evaluated against final action levels (FALs) established in this document. A radiological dose FAL was established of 25 millirem per year based on the Remote Work Area exposure scenario (336 hours of annual exposure). Radiological doses exceeding the FAL were found to be present at all four CASs. It is assumed that radionuclide levels present within the Little Feller I and Cabriolet high

  3. Ghana Science Abstracts

    International Nuclear Information System (INIS)

    Entsua-Mensah, C.

    2004-01-01

    This issue of the Ghana Science Abstracts combines in one publication all the country's bibliographic output in science and technology. The objective is to provide a quick reference source to facilitate the work of information professionals, research scientists, lecturers and policy makers. It is meant to give users an idea of the depth and scope and results of the studies and projects carried out. The scope and coverage comprise research outputs, conference proceedings and periodical articles published in Ghana. It does not capture those that were published outside Ghana. Abstracts reported have been grouped under the following subject areas: Agriculture, Biochemistry, Biodiversity conservation, biological sciences, biotechnology, chemistry, dentistry, engineering, environmental management, forestry, information management, mathematics, medicine, physics, nuclear science, pharmacy, renewable energy and science education

  4. Seismic ground motion and hazard assessment of the Greater Accra Metropolitan Area, southeastern Ghana

    International Nuclear Information System (INIS)

    Amponsah, P.E.; Banoeng-Yakubo, B.K.; Asiedu, D.; Vaccari, F.; Panza, G.F.

    2008-08-01

    The seismic ground motion of the Greater Accra Metropolitan area has been computed and the hazard zones assessed using a deterministic hybrid approach based on the modal summation and finite difference methods. The seismic ground motion along four profiles located in the Greater Accra Metropolitan Area has been modelled using the 1939 earthquake of magnitude 6.5(M L ) as the scenario earthquake. Synthetic seismic waveforms from which parameters for engineering design such as peak ground acceleration, velocity and spectral amplifications have been produced along the geological cross sections. From the seismograms computed, the seismic hazard of the metropolis, expressed in terms of peak ground acceleration and peak ground velocity have been estimated. The peak ground acceleration estimated in the study ranges from 0.14 - 0.57 g and the peak ground velocity from 9.2 - 37.1cms -1 . The presence of low velocity sediments gave rise to high peak values and amplifications. The maximum peak ground accelerations estimated are located in areas with low velocity formations such as colluvium, continental and marine deposits. Areas in the metropolis underlain by unconsolidated sediments have been classified as the maximum damage potential zone and those underlain by highly consolidated geological materials are classified as low damage potential zone. The results of the numerical simulation have been extended to all areas in the metropolis with similar geological formation. (author)

  5. Cutting Craters

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 12 November 2003The rims of two old and degraded impact craters are intersected by a graben in this THEMIS image taken near Mangala Fossa. Yardangs and low-albedo wind streaks are observed at the top of the image as well as interesting small grooves on the crater floor. The origin of these enigmatic grooves may be the result of mud or lava and volatile interactions. Variable surface textures observed in the bottom crater floor are the result of different aged lava flows.Image information: VIS instrument. Latitude -15.2, Longitude 219.2 East (140.8 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  6. "Ghana faces ecological disaster".

    Science.gov (United States)

    Asmah, G F

    1990-05-01

    The rate of deforestation in Ghana is alarming and urgent steps need to be taken to reverse the trend, Robert D. Mann, a British tropical agriculturist, has warned. He says, "There will be further disintegration of the local climate, deterioration of soil fertility and reduced food-crop production, if the present trend of denudation by felling trees and uncontrolled bush fires is not halted and reversed." Mann, who has conducted research on "deforestation, drought and famine in Africa" was in Ghana recently to speak on the "role of the Church in West Africa in stimulating action to combat desertification". Representatives of protestant churches in Ghana, Togo, Liberia, Gambia, Nigeria, Cote d'Ivoire and Sierra Leone attended the 3-day conference which was organized by the Overseas Department of the British Methodist Church. It was to enable participants to share perspectives on the nature, scale and seriousness of the deforestation problem. Participants also exchanged experiences on village-based projects for promoting tree planting and agro-forestry, and developed strategies for the rural development programs. Robert Mann noted that Ghana was not only affected by its proximity to the Sahel, but also by its own deforestation. The situation in Ghana, once renowned for her extensive forests and woodland, has now drastically changed. By 1980/81 the area of closed forest had been reduced to 17,000 sq km from 47,9000 sq km in 1937/38. He said in 1939 the volume of wood exported from Ghana was 42,450 cubic meters but it rose to 1,471,600 cubic meters by 1987. Such activities, Mann said, put severe strain on the environment and affected both the economy and sociocultural basis of the country. full text

  7. Modeling the relationship between precipitation and malaria incidence in children from a holoendemic area in Ghana.

    Science.gov (United States)

    Krefis, Anne Caroline; Schwarz, Norbert Georg; Krüger, Andreas; Fobil, Julius; Nkrumah, Bernard; Acquah, Samuel; Loag, Wibke; Sarpong, Nimako; Adu-Sarkodie, Yaw; Ranft, Ulrich; May, Jürgen

    2011-02-01

    Climatic factors influence the incidence of vector-borne diseases such as malaria. They modify the abundance of mosquito populations, the length of the extrinsic parasite cycle in the mosquito, the malarial dynamics, and the emergence of epidemics in areas of low endemicity. The objective of this study was to investigate temporal associations between weekly malaria incidence in 1,993 children < 15 years of age and weekly rainfall. A time series analysis was conducted by using cross-correlation function and autoregressive modeling. The regression model showed that the level of rainfall predicted the malaria incidence after a time lag of 9 weeks (mean = 60 days) and after a time lag between one and two weeks. The analyses provide evidence that high-resolution precipitation data can directly predict malaria incidence in a highly endemic area. Such models might enable the development of early warning systems and support intervention measures.

  8. Key factors leading to reduced recruitment and retention of health professionals in remote areas of Ghana: a qualitative study and proposed policy solutions

    Directory of Open Access Journals (Sweden)

    Dzodzomenyo Mawuli

    2011-05-01

    Full Text Available Abstract Background The ability of many countries to achieve national health goals such as the Millennium Development Goals remains hindered by inadequate and poorly distributed health personnel, including doctors. The distribution of doctors in Ghana is highly skewed, with a majority serving in two major metropolitan areas (Accra and Kumasi, and inadequate numbers in remote and rural districts. Recent policies increasing health worker salaries have reduced migration of doctors out of Ghana, but made little difference to distribution within the country. This qualitative study was undertaken to understand how practicing doctors and medical leaders in Ghana describe the key factors reducing recruitment and retention of health professionals into remote areas, and to document their proposed policy solutions. Methods In-depth interviews were carried out with 84 doctors and medical leaders, including 17 regional medical directors and deputy directors from across Ghana, and 67 doctors currently practicing in 3 regions (Greater Accra, Brong Ahafo, and Upper West; these 3 regions were chosen to represent progressively more remote distances from the capital of Accra. Results and discussion All participants felt that rural postings must have special career or monetary incentives given the loss of locum (i.e. moonlighting income, the higher workload, and professional isolation of remote assignments. Career 'death' and prolonged rural appointments were a common fear, and proposed policy solutions focused considerably on career incentives, such as guaranteed promotion or a study opportunity after some fixed term of service in a remote or hardship area. There was considerable stress placed on the need for rural doctors to have periodic contact with mentors through rural rotation of specialists, or remote learning centers, and reliable terms of appointment with fixed end-points. Also raised, but given less emphasis, were concerns about the adequacy of clinical

  9. Maximizing microscopy as a diagnostic tool in peripheral health centres of BU endemic areas in Ghana.

    Science.gov (United States)

    Owusu, Enid; Newman, Mercy Jemima; Akumwena, Amos; Ofosu-Appiah, Lawrence; Pluschke, Gerd

    2015-09-01

    Buruli ulcer (BU) disease, a skin condition caused by Mycobacterium ulcerans (M. ulcerans) is endemic in remote rural areas. Disease diagnosis on clinical basis alone can be misleading, requiring definitive diagnosis based on laboratory tests. Resource constraints in BU endemic areas make microscopy for the detection of acid fast bacilli (AFB) an important and useful method. It is rapid, user-friendly, convenient and cheap. Despite its usefulness, its performance is relatively low. This study investigated modifications of the current method aimed at improving its performance. Forty (IS) 2404 polymerase chain reactions (PCR) positive BU samples were processed by eight physical (centrifugation and overnight sedimentation) and chemical (phenol ammonium sulphate and sodium hypochlorite) modifications of the current direct method. Assessments were based on standard AFB evaluation coupled with in house criteria; positivity (P), clarity and contrast (C) release of bacilli from specimen (R). Overall AFB positivity rate was 64% (409/640). Each protocol had 80 smears. The percentage positivity (P) for the conventional method was 58% (46/80) smears. The highest positivity rate of 57/80 (%) was by protocol 7 (5% phenol in 4% ammonium sulphate (PhAS) and concentrated by overnight gravitational sedimentation). The least positivity rate at 35% (28/80) was by protocol 1 (smears from direct application of swab tips). The differences in performance between the two chemical tested; 5% phenol in 4% ammonium sulphate (PhAS) and 3.5% NaHOCl was significant (p0.05). This study concluded that BU samples treated with a solution of 5% phenol in 4% ammonium sulphate and concentrated by either centrifugation or overnight sedimentation is useful for maximizing AFB detection by bright field microscopy. This can be useful in rural health facilities with resource constraints. Copyright © 2015 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  10. Maximizing microscopy as a diagnostic tool in peripheral health centres of BU endemic areas in Ghana

    Directory of Open Access Journals (Sweden)

    Enid Owusu

    2015-01-01

    Full Text Available Background: Buruli ulcer (BU disease, a skin condition caused by Mycobacterium ulcerans (M. ulcerans is endemic in remote rural areas. Disease diagnosis on clinical basis alone can be misleading, requiring definitive diagnosis based on laboratory tests. Resource constraints in BU endemic areas make microscopy for the detection of acid fast bacilli (AFB an important and useful method. It is rapid, user-friendly, convenient and cheap. Despite its usefulness, its performance is relatively low. This study investigated modifications of the current method aimed at improving its performance. Forty (IS 2404 polymerase chain reactions (PCR positive BU samples were processed by eight physical (centrifugation and overnight sedimentation and chemical (phenol ammonium sulphate and sodium hypochlorite modifications of the current direct method. Assessments were based on standard AFB evaluation coupled with in house criteria; positivity (P, clarity and contrast (C release of bacilli from specimen (R. Overall AFB positivity rate was 64% (409/640. Each protocol had 80 smears. The percentage positivity (P for the conventional method was 58% (46/80 smears. The highest positivity rate of 57/80 (% was by protocol 7 (5% phenol in 4% ammonium sulphate (PhAS and concentrated by overnight gravitational sedimentation. The least positivity rate at 35% (28/80 was by protocol 1 (smears from direct application of swab tips. The differences in performance between the two chemical tested; 5% phenol in 4% ammonium sulphate (PhAS and 3.5% NaHOCl was significant (p 0.05. This study concluded that BU samples treated with a solution of 5% phenol in 4% ammonium sulphate and concentrated by either centrifugation or overnight sedimentation is useful for maximizing AFB detection by bright field microscopy. This can be useful in rural health facilities with resource constraints.

  11. Stratigraphy and Age of Paleoproterozoic Birimian Volcaniclastic Sequence in the Cape Three Points area, Axim-Konongo (Ashanti) Belt, Southwest Ghana

    Science.gov (United States)

    Yoshimaru, S.; Kiyokawa, S.; Ito, T.; Ikehara, M.; Horie, K.; Takehara, M.; Sano, T.; Nyame, F. K.; Tetteh, G. M.

    2016-12-01

    This study investigated the depositional environments and bioactivities of well preserved volcaniclastic sequences in the Cape Three Points area in the Paleoproterozoic Axim-Konongo (Ashanti) belt in the Birimian of Ghana. Our current research outlines the stratigraphy, structure, approximate age and depositional setting of the volcaniclastic sequence in the Cape Three Points area in Ghana, West Africa.Axim-Konongo (Ashanti) belt is composed of mainly andesitic basalts, volcaniclastic rocks and belt type granitoids, which are unconformably overlain by Tarkwaian conglomerates and metasedimentary rocks. The rocks show NE-SW strike with maximum depositional age of overlying metasedimentary rocks of 2154±2 Ma (U-Pb zircon; Oberthür et al., 1998). The oldest age of an intrusive into Birimian volcanic rock near Sekondi is 2174±2 Ma (U-Pb zircon; Oberthür et al., 1998). Thick volcaniclastic succession over 4000 m thickness was reconstructed for 1000 m thickness after detailed field investigations. The succession shows approximately N-S strike mainly 60-80° dip to the east and generally upward sequence. The rocks were affected by greenschist facies metamorphism. TiO2/Al2O3 ratios of chromites and whole- rock trace elements compositions with low Nb concentration and high LREE concentration support deposition on mid-deep sea floor in a volcanic arc. New age data were obtained from foliated porphyritic dyke which occurs in the Cape Three Points area. Zircon grains, measured by SHRIMP at National Institute of Polar Research (NIPR), yielded a weighted mean 204Pb-corrected 207Pb/206Pb age of 2265.6±4.6 Ma (95% confidence). Thus, the volcaniclastic sequence was deposited before 2265.6±4.6 Ma and was deformed after 2265 Ma. 2260 Ma is the oldest age at which early volcanic activity in the Birimian terrane occurred (Loh and Hirdes, 1999). References Oberthür T et al. (1998) Precambrian Research 89: 129-143 Loh G and Hirdes W (1999) Exlplanatory Notes for the Geological Map

  12. Geology of Lofn Crater, Callisto

    Science.gov (United States)

    Greeley, Ronald; Heiner, Sarah; Klemaszewski, James E.

    2001-01-01

    Lofn crater is a 180-km-diameter impact structure in the southern cratered plains of Callisto and is among the youngest features seen on the surface. The Lofn area was imaged by the Galileo spacecraft at regional-scale resolutions (875 m/pixel), which enable the general geology to be investigated. The morphology of Lofn crater suggests that (1) it is a class of impact structure intermediate between complex craters and palimpsests or (2) it formed by the impact of a projectile which fragmented before reaching the surface, resulting in a shallow crater (even for Callisto). The asymmetric pattern of the rim and ejecta deposits suggests that the impactor entered at a low angle from the northwest. The albedo and other characteristics of the ejecta deposits from Lofn also provide insight into the properties of the icy lithosphere and subsurface configuration at the time of impact. The "target" for the Lofn impact is inferred to have included layered materials associated with the Adlinda multiring structure northwest of Loh and ejecta deposits from the Heimdall crater area to the southeast. The Lofn impact might have penetrated through these materials into a viscous substrate of ductile ice or possibly liquid water. This interpretation is consistent with models of the current interior of Callisto based on geophysical information obtained from the Galileo spacecraft.

  13. Surface water quality and isotopic study at a section of the Lower Volta River (Akuse to Sogakope area), Ghana

    International Nuclear Information System (INIS)

    Gampson, E. K.

    2012-01-01

    The water quality examination at a section of the Lower Volta River (Akuse to the Sogakope area), Ghana, was conducted by determining the physicochemical parameters at 38 sampling sites in September (2011) during the wet season and February (2012) during the dry season. Isotope analysis was also conducted during the same period. The ranges of physicochemical parameters analysed in the surface water were 6.45 to 7.26 for pH, -053 to -010 mV for Eh, 23.6 to 27 degrees celsius for temperature, 61.7 to 83.6 μS/cm for EC, 0% 0 for salinity, 29.7-39.4 mg/L for TDS, 0.63 to 2.28 mg/L for DO, 0 to 4 NTU for turbidity, 0 to 8mg/L for TSS, 36 to 108mg/L for total hardness, 0.8 to 5mg/L for BOD 5 , 23.16 to 46.33mg/L for HCO 3 - , 2.92 to 23.33mg/L for Mg 2+ , 7.8 to 11.0mg/L for Na + , 4.0 to 5.9mg/L for K + , 1.99 to 13.99mg/L for CI - , 3.2 to 14.4MG/L for Ca 2+ , 1.0 to 24.889mg/L for NO 3 - , 6.556 to 28.111mg/L for SO 4 2- and 1.333 to 11.667mg/L for PO 4 3- . While the results for dissolved metals (μg/L) were 32 to 348 for Fe, 12 to 278 for Mn, 16 to 84 for Cu, 4 to 38 for Pb, 20 to 162 for Ni, 12 to 32 for Cd and 12μg/L to 98 for Cd, Hg, Se, V and Zn were below detection limit. The river water will support agricultural activities. Except Cu which was low, about 37%, 89%, 29%, 33%, 8% and 29% of the sampled sites had Pb, Ni, Cd, Cr, Fe and Mn values respectively above the WHO (2004) standard for drinking water. Therefore, water quality monitoring and control of release of untreated anthropogenic wastes into the river is strongly needed. Stable isotope data of water (δ 2 H and δ 18 O) obtained showed stream waters are depleted and possibly recharge by rain and waters from the Akwapim Mountains than the isotopically heavy evaporated waters found within the Lower Volta River. (au)

  14. How old is Autolycus crater?

    Science.gov (United States)

    Hiesinger, Harald; Pasckert, Jan Henrik; van der Bogert, Carolyn H.; Robinson, Mark S.

    2016-04-01

    Accurately determining the lunar cratering chronology is prerequisite for deriving absolute model ages (AMAs) across the lunar surface and throughout the Solar System [e.g., 1]. However, the lunar chronology is only constrained by a few data points over the last 1 Ga and there are no calibration data available between 1 and 3 Ga and beyond 3.9 Ga [2]. Rays from Autolycus and Aristillus cross the Apollo 15 landing site and presumably transported material to this location [3]. [4] proposed that at the Apollo 15 landing site about 32% of any exotic material would come from Autolycus crater and 25% would come from Aristillus crater. [5,6] proposed that the 39Ar-40Ar age of 2.1 Ga derived from three petrologically distinct, shocked Apollo 15 KREEP basalt samples, date Autolycus crater. Grier et al. [7] reported that the optical maturity (OMAT) characteristics of these craters are indistinguishable from the background values despite the fact that both craters exhibit rays that were used to infer relatively young, i.e., Copernican ages [8,9]. Thus, both OMAT characteristics and radiometric ages of 2.1 Ga and 1.29 Ga for Autolycus and Aristillus, respectively, suggest that these two craters are not Copernican in age. [10] interpreted newer U-Pb ages of 1.4 and 1.9 Ga from sample 15405 as the formation ages of Aristillus and Autolycus. If Autolycus is indeed the source of the dated exotic material collected at the Apollo 15 landing site, than performing crater size frequency distribution (CSFD) measurements for Autolycus offers the possibility to add a new calibration point to the lunar chronology, particularly in an age range that was previously unconstrained. We used calibrated and map-projected LRO NAC images to perform CSFD measurements within ArcGIS, using CraterTools [11]. CSFDs were then plotted with CraterStats [12], using the production and chronology functions of [13]. We determined ages of 3.72 and 3.85 Ga for the interior (Ai1) and ejecta area Ae3, which we

  15. Malnutrition in Pre-school Children across Different Geographic Areas and Socio-Demographic Groups in Ghana.

    Science.gov (United States)

    Ewusie, J E; Beyene, J; Ahiadeke, C; Hamid, J S

    2017-04-01

    Objective Malnutrition in children pervades all aspects of their health, growth, cognitive and social development and can lead to irreversible and lifelong effects. We examine the prevalence and determinants of malnutrition in children under 5 in the Ghanaian population. Methods Using data from the latest available Ghana Demographic and Health Survey (GDHS), we estimated and compared prevalence of malnutrition in children among the different subgroups of the population. We used multivariable logistic regression to identify potential factors associated with childhood malnutrition in Ghana. Results Overall, 35.6 % (95 % CI: 33.6, 37.6) of Ghanaian children under 5 years of age suffer from some form of malnutrition. Specifically, 27.5 % (95 % CI: 25.1, 28.7), 13.8 % (95 % CI: 12.5, 15.3), 8.9 % (95 % CI: 7.8, 10.2) were stunted, underweight and wasted, respectively. Results from the logistic regression indicate that gender and age of the child, educational and nutritional status of the mother, and financial status of the household are risk factors associated with childhood malnutrition in Ghana. Conclusions for Practice In view of the observed high rate of malnutrition among Ghanaian children despite the interventions that have been in place since the 1990s, there is a need for increased awareness and improved targeted interventions as well as knowledge translation tools including extensive education on infant and young child feeding practices.

  16. Ghana Journal of Science

    African Journals Online (AJOL)

    The GHANA JOURNAL OF SCIENCE is published jointly by the Council for Scientific and Industrial Research of Ghana and the Ghana Science Association. It is open to all ... the authors belong. The topics need not be related to West Africa.

  17. OF GHANA

    African Journals Online (AJOL)

    porting rural livelihoods in Ghana, especially in the severe food ... moded methods of manufacturing and organization” (Beeh- .... there are certain productive activities that are jointly undertaken by .... Type of food Apatanga Adaboya Bongo-Soc Total ..... fulfilment of household needs and maintenance and the critical issue of ...

  18. A Tale of 3 Craters

    Science.gov (United States)

    2004-01-01

    11 November 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image captures some of the complexity of the martian upper crust. Mars does not simply have an impact-cratered surface, it's upper crust is a cratered volume. Over time, older craters on Mars have been eroded, filled, buried, and in some cases exhumed and re-exposed at the martian surface. The crust of Mars is layered to depths of 10 or more kilometers, and mixed in with the layered bedrock are a variety of ancient craters with diameters ranging from a few tens of meters (a few tens of yards) to several hundred kilometers (more than one or two hundred miles). The picture shown here captures some of the essence of the layered, cratered volume of the upper crust of Mars in a very simple form. The image shows three distinct circular features. The smallest, in the lower right quarter of the image, is a meteor crater surrounded by a mound of material. This small crater formed within a layer of bedrock that once covered the entire scene, but today is found only in this small remnant adjacent to the crater. The intermediate-sized crater, west (left) of the small one, formed either in the next layer down--that is, below the layer in which the small crater formed--or it formed in some layers that are now removed, but was big enough to penetrate deeply into the rock that is near the surface today. The largest circular feature in the image, in the upper right quarter of the image, is still largely buried. It formed in layers of rock that are below the present surface. Erosion has brought traces of its rim back to the surface of Mars. This picture is located near 50.0oS, 77.8oW, and covers an area approximately 3 km (1.9 mi) across. Sunlight illuminates this October 2004 image from the upper left.

  19. Surface temperature monitoring by integrating satellite data and ground thermal camera network on Solfatara Crater in Campi Flegrei volcanic area (Italy)

    Science.gov (United States)

    Buongiorno, M. F.; Musacchio, M.; Silvestri, M.; Vilardo, G.; Sansivero, F.; caPUTO, T.; bellucci Sessa, E.; Pieri, D. C.

    2017-12-01

    Current satellite missions providing imagery in the TIR region at high spatial resolution offer the possibility to estimate the surface temperature in volcanic area contributing in understanding the ongoing phenomena to mitigate the volcanic risk when population are exposed. The Campi Flegrei volcanic area (Italy) is part of the Napolitan volcanic district and its monitored by INGV ground networks including thermal cameras. TIRS on LANDSAT and ASTER on NASA-TERRA provide thermal IR channels to monitor the evolution of the surface temperatures on Campi Flegrei area. The spatial resolution of the TIR data is 100 m for LANDSAT8 and 90 m for ASTER, temporal resolution is 16 days for both satellites. TIRNet network has been developed by INGV for long-term volcanic surveillance of the Flegrei Fields through the acquisition of thermal infrared images. The system is currently comprised of 5 permanent stations equipped with FLIR A645SC thermo cameras with a 640x480 resolution IR sensor. To improve the systematic use of satellite data in the monitor procedures of Volcanic Observatories a suitable integration and validation strategy is needed, also considering that current satellite missions do not provide TIR data with optimal characteristics to observe small thermal anomalies that may indicate changes in the volcanic activity. The presented procedure has been applied to the analysis of Solfatara Crater and is based on 2 different steps: 1) parallel processing chains to produce ground temperature data both from satellite and ground cameras; 2) data integration and comparison. The ground cameras images generally correspond to views of portion of the crater slopes characterized by significant thermal anomalies due to fumarole fields. In order to compare the satellite and ground cameras it has been necessary to take into account the observation geometries. All thermal images of the TIRNet have been georeferenced to the UTM WGS84 system, a regular grid of 30x30 meters has been

  20. Dome craters on Ganymede

    International Nuclear Information System (INIS)

    Moore, J.M.; Malin, M.C.

    1987-01-01

    Voyager observations reveal impact craters on Ganymede that are characterized by the presence of broad, high albedo, topographic domes situated within a central pit. Fifty-seven craters with central domes were identified in images covering approx. 50% of the surface. Owing to limitations in resolution, and viewing and illumination angles, the features identified are most likely a subset of dome craters. The sample appears to be sufficiently large to infer statistically meaningful trends. Dome craters appear to fall into two distinct populations on plots of the ratio of dome diameter to crater rim diameter, large-dome craters and small-dome craters. The two classes are morphologically distinct from one another. In general, large dome craters show little relief and their constituent landforms appear subdued with respect to fresh craters. The physical attributes of small-dome craters are more sharply defined, a characteristic they share with young impact craters of comparable size observed elsewhere in the solar system. Both types of dome craters exhibit central pits in which the dome is located. As it is difficult to produce domes by impact and/or erosional processes, an endogenic origin for the domes is reasonably inferred. Several hypotheses for their origin are proposed. These hypotheses are briefly reviewed

  1. Willingness to work in rural areas and the role of intrinsic versus extrinsic professional motivations - a survey of medical students in Ghana

    Science.gov (United States)

    2011-01-01

    Background Retaining health workers in rural areas is challenging for a number of reasons, ranging from personal preferences to difficult work conditions and low remuneration. This paper assesses the influence of intrinsic and extrinsic motivation on willingness to accept postings to deprived areas among medical students in Ghana. Methods A computer-based survey involving 302 fourth year medical students was conducted from May-August 2009. Logistic regression was used to assess the association between students' willingness to accept rural postings and their professional motivations, rural exposure and family parental professional and educational status (PPES). Results Over 85% of students were born in urban areas and 57% came from affluent backgrounds. Nearly two-thirds of students reported strong intrinsic motivation to study medicine. After controlling for demographic characteristics and rural exposure, motivational factors did not influence willingness to practice in rural areas. High family PPES was consistently associated with lower willingness to work in rural areas. Conclusions Although most Ghanaian medical students are motivated to study medicine by the desire to help others, this does not translate into willingness to work in rural areas. Efforts should be made to build on intrinsic motivation during medical training and in designing rural postings, as well as favour lower PPES students for admission. PMID:21827698

  2. Willingness to work in rural areas and the role of intrinsic versus extrinsic professional motivations - a survey of medical students in Ghana

    Directory of Open Access Journals (Sweden)

    Dzodzomenyo Mawuli

    2011-08-01

    Full Text Available Abstract Background Retaining health workers in rural areas is challenging for a number of reasons, ranging from personal preferences to difficult work conditions and low remuneration. This paper assesses the influence of intrinsic and extrinsic motivation on willingness to accept postings to deprived areas among medical students in Ghana. Methods A computer-based survey involving 302 fourth year medical students was conducted from May-August 2009. Logistic regression was used to assess the association between students' willingness to accept rural postings and their professional motivations, rural exposure and family parental professional and educational status (PPES. Results Over 85% of students were born in urban areas and 57% came from affluent backgrounds. Nearly two-thirds of students reported strong intrinsic motivation to study medicine. After controlling for demographic characteristics and rural exposure, motivational factors did not influence willingness to practice in rural areas. High family PPES was consistently associated with lower willingness to work in rural areas. Conclusions Although most Ghanaian medical students are motivated to study medicine by the desire to help others, this does not translate into willingness to work in rural areas. Efforts should be made to build on intrinsic motivation during medical training and in designing rural postings, as well as favour lower PPES students for admission.

  3. Willingness to work in rural areas and the role of intrinsic versus extrinsic professional motivations - a survey of medical students in Ghana.

    Science.gov (United States)

    Agyei-Baffour, Peter; Kotha, S Rani; Johnson, Jennifer C; Gyakobo, Mawuli; Asabir, Kwesi; Kwansah, Janet; Nakua, Emmanuel; Dzodzomenyo, Mawuli; Snow, Rachel C; Kruk, Margaret E

    2011-08-09

    Retaining health workers in rural areas is challenging for a number of reasons, ranging from personal preferences to difficult work conditions and low remuneration. This paper assesses the influence of intrinsic and extrinsic motivation on willingness to accept postings to deprived areas among medical students in Ghana. A computer-based survey involving 302 fourth year medical students was conducted from May-August 2009. Logistic regression was used to assess the association between students' willingness to accept rural postings and their professional motivations, rural exposure and family parental professional and educational status (PPES). Over 85% of students were born in urban areas and 57% came from affluent backgrounds. Nearly two-thirds of students reported strong intrinsic motivation to study medicine. After controlling for demographic characteristics and rural exposure, motivational factors did not influence willingness to practice in rural areas. High family PPES was consistently associated with lower willingness to work in rural areas. Although most Ghanaian medical students are motivated to study medicine by the desire to help others, this does not translate into willingness to work in rural areas. Efforts should be made to build on intrinsic motivation during medical training and in designing rural postings, as well as favour lower PPES students for admission.

  4. Drainage systems of Lonar Crater, India: Contributions to Lonar Lake hydrology and crater degradation

    Science.gov (United States)

    Komatsu, Goro; Senthil Kumar, P.; Goto, Kazuhisa; Sekine, Yasuhito; Giri, Chaitanya; Matsui, Takafumi

    2014-05-01

    Lonar, a 1.8-km-diameter impact crater in India, is a rare example of terrestrial impact craters formed in basaltic bedrock. The estimated age of the crater ranges widely from less than 12 ka to over 600 ka, but the crater preserves a relatively pristine morphology. We conducted a study of various drainage systems of Lonar Crater. The crater floor hosts a shallow 5-m-deep lake, which fluctuates seasonally. Our investigation reveals that the lake level is influenced by surface runoff that is active during the monsoon and groundwater input effective during both the rainy and the dry seasons. The groundwater discharge is observed as springs on the inner rim walls corresponding to weathered vesicular basalt and/or proximal ejecta, which are underlain by thick massive basalt layers. This observation indicates that groundwater movement is lithologically controlled: it passes preferentially through permeable vesicular basalt or proximal ejecta but is hindered in less permeable massive basalt. It is hypothesized that groundwater is also structurally controlled by dipping of basalt layers, interconnectivity of the permeable lithologic units through fractures, and preferential pathways such as fractures within the permeable lithologic units. Investigation on hydrological processes at Lonar Crater and its lake could provide useful insights into purported paleo-crater lakes presumably formed in the basaltic crust of Mars. The Lonar Crater interior shows signs of degradation in the forms of gullies and debris flows, and the Dhar valley incising in the rim leading to form a fan delta. The ejecta surface is characterized by the presence of channels, originating from the rim area and extending radially away from the crater center. The channels probably resulted from surface runoff, and its erosion contributes to the removal of the ejecta. Lonar Crater is a valuable analog site for studying degradation processes with potential application to impact craters occurring on

  5. Degraded Crater Rim

    Science.gov (United States)

    2002-01-01

    (Released 3 May 2002) The Science The eastern rim of this unnamed crater in Southern Arabia Terra is very degraded (beaten up). This indicates that this crater is very ancient and has been subjected to erosion and subsequent bombardment from other impactors such as asteroids and comets. One of these later (younger) craters is seen in the upper right of this image superimposed upon the older crater rim material. Note that this smaller younger crater rim is sharper and more intact than the older crater rim. This region is also mantled with a blanket of dust. This dust mantle causes the underlying topography to take on a more subdued appearance. The Story When you think of Arabia, you probably think of hot deserts and a lot of profitable oil reserves. On Mars, however, Southern Arabia Terra is a cold place of cratered terrain. This almost frothy-looking image is the badly battered edge of an ancient crater, which has suffered both erosion and bombardment from asteroids, comets, or other impacting bodies over the long course of its existence. A blanket of dust has also settled over the region, which gives the otherwise rugged landscape a soft and more subdued appearance. The small, round crater (upper left) seems almost gemlike in its setting against the larger crater ring. But this companionship is no easy romance. Whatever formed the small crater clearly whammed into the larger crater rim at some point, obliterating part of its edge. You can tell the small crater was formed after the first and more devastating impact, because it is laid over the other larger crater. How much younger is the small one? Well, its rim is also much sharper and more intact, which gives a sense that it is probably far more youthful than the very degraded, ancient crater.

  6. Crater Highlands, Tanzania

    Science.gov (United States)

    2006-01-01

    The Shuttle Radar Topography Mission (SRTM), flown aboard Space Shuttle Endeavour in February 2000, acquired elevation measurements for nearly all of Earth's landmass between 60oN and 56oS latitudes. For many areas of the world SRTM data provide the first detailed three-dimensional observation of landforms at regional scales. SRTM data were used to generate this view of the Crater Highlands along the East African Rift in Tanzania. Landforms are depicted with colored height and shaded relief, using a vertical exaggeration of 2X and a southwestwardly look direction. Lake Eyasi is depicted in blue at the top of the image, and a smaller lake occurs in Ngorongoro Crater. Near the image center, elevations peak at 3648 meters (11,968 feet) at Mount Loolmalasin, which is south of Ela Naibori Crater. Kitumbeine (left) and Gelai (right) are the two broad mountains rising from the rift lowlands. Mount Longido is seen in the lower left, and the Meto Hills are in the right foreground. Tectonics, volcanism, landslides, erosion and deposition -- and their interactions -- are all very evident in this view. The East African Rift is a zone of spreading between the African (on the west) and Somali (on the east) crustal plates. Two branches of the rift intersect here in Tanzania, resulting in distinctive and prominent landforms. One branch trends nearly parallel the view and includes Lake Eyasi and the very wide Ngorongoro Crater. The other branch is well defined by the lowlands that trend left-right across the image (below center, in green). Volcanoes are often associated with spreading zones where magma, rising to fill the gaps, reaches the surface and builds cones. Craters form if a volcano explodes or collapses. Later spreading can fracture the volcanoes, which is especially evident on Kitumbeine and Gelai Mountains (left and right, respectively, lower center). The Crater Highlands rise far above the adjacent savannas, capture moisture from passing air masses, and host rain

  7. Mental health research in Ghana: A literature review | Read | Ghana ...

    African Journals Online (AJOL)

    Context/Background: Mental health is a neglected area in health care in Ghana. With few clinicians and trained researchers in the field, research has been limited both in quantity and quality. Method: A search of the available literature revealed 98 articles published between 1955 and 2009. Sixty-six are reviewed in this ...

  8. Crater Constellation

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    (the Cup; abbrev. Crt, gen. Crateris; area 282 sq. deg.) A southern constellation which lies to the south-west of Virgo, and culminates at midnight in mid-March. It represents the cup of the god Apollo in Greek mythology (see Corvus). Its brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest....

  9. Investigations of Ceres's Craters with Straightened Rim

    Science.gov (United States)

    Frigeri, A.; De Sanctis, M. C.; Ammannito, E.; Raponi, A.; Formisano, M.; Ciarniello, M.; Magni, G.; Combe, J. P.; Marchi, S.; Raymond, C. A.; Schwartz, S. J.

    2017-12-01

    Dwarf planet Ceres hosts some geological features that are unique in the solar system because its composition, rich in aqueously-altered silicates, is usually found on full-size planets, whereas its mean radius is smaller than most natural satellites in the solar system. For example, the local high-albedo, carbonate-rich areas or faculaeare specific to Ceres; also, the absence of big impact crater structures is key to understand the overall mechanical behaviour of the Cerean crust. After the first findings of water ice occurring in the shadowed areas of craters on Ceres by the NASA/Dawn mission (1, 2), we analyzed the morphology of craters looking for features similar to the ones where the water ice composition has been detected analyzing the data from the VIR spectrometer (3). These craters fall outside of the family of polygonal craters which are mainly related to regional or global scale tectonics (4). We analyzed the morphology on the base of the global mosaic, the digital terrain model derived by using the stereo photogrammetry method and the single data frames of the Framing Camera. Our investigation started from crater Juling, which is characterized by a portion of the rim which forms a straight segment instead of a portion of a circle. This linear crater wall is also steep enough that it forms a cliff that is in the shadowed area in all images acquired by Dawn. Very smooth and bright deposits lay at the foot of this crater-wall cliff. Then, we identified several other craters, relatively fresh, with radius of 2 to 10 kilometers, showing one or two sectors of the crater-rim being truncated by a mass-wasting process, probably a rockfall. Our first analysis show that in the selected craters, the truncated sectors are always in the north-eastern sector of the rim for the craters in the southern hemisphere. Conversely, the craters on the northern hemisphere exhibit a truncated rim in their south-eastern sector. Although a more detailed analysis is mandatory

  10. Time and Change in Ghana

    Science.gov (United States)

    Hodge, Peter

    1969-01-01

    The disastrous state of Ghanaian finances immediately before and after the coup against Nkrumah has had the effect of virtually eliminating community development and health services, particularly in non-urban areas of Ghana. It is hoped that new regional and district structure and improved staff morale can now bring about more effective programs.…

  11. Meteor Crater, AZ

    Science.gov (United States)

    2002-01-01

    The Barringer Meteorite Crater (also known as 'Meteor Crater') is a gigantic hole in the middle of the arid sandstone of the Arizona desert. A rim of smashed and jumbled boulders, some of them the size of small houses, rises 50 m above the level of the surrounding plain. The crater itself is nearly a 1500 m wide, and 180 m deep. When Europeans first discovered the crater, the plain around it was covered with chunks of meteoritic iron - over 30 tons of it, scattered over an area 12 to 15 km in diameter. Scientists now believe that the crater was created approximately 50,000 years ago. The meteorite which made it was composed almost entirely of nickel-iron, suggesting that it may have originated in the interior of a small planet. It was 50 m across, weighed roughly 300,000 tons, and was traveling at a speed of 65,000 km per hour. This ASTER 3-D perspective view was created by draping an ASTER bands 3-2-1image over a digital elevation model from the US Geological Survey National Elevation Dataset.This image was acquired on May 17, 2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The Terra mission is part of NASA's Earth Science Enterprise, along

  12. Polygons near Lyot Crater

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-564, 4 December 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows patterned ground, arranged in the form of polygons, on the undulating plains associated with ejecta from the Lyot impact crater on the martian northern plains. This picture was acquired in October 2003 and shows that the polygon margins are ridges with large boulders--shown here as dark dots--on them. On Earth, polygon patterns like this are created in arctic and antarctic regions where there is ice in the ground. The seasonal and longer-term cycles of freezing and thawing of the ice-rich ground cause these features to form over time. Whether the same is true for Mars is unknown. The polygons are located near 54.6oN, 326.6oW. The image covers an area 3 km (1.9 mi) wide and is illuminated from the lower left.

  13. Corrective Action Decision Document/Closure Report for Corrective Action Unit 375: Area 30 Buggy Unit Craters, Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Matthews

    2011-08-01

    Corrective Action Unit 375 comprises three corrective action sites (CASs): (1) 25-23-22, Contaminated Soils Site; (2) 25-34-06, Test Cell A Bunker; and (3) 30-45-01, U-30a, b, c, d, e Craters. The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation that no further corrective action is needed for CAU 375 based on the implementation of corrective action of closure in place with administrative controls at CAS 25-23-22, no further action at CAS 25-34-06, and closure in place with administrative controls and removal of potential source material (PSM) at CAS 30-45-01. Corrective action investigation (CAI) activities were performed from July 28, 2010, through April 4, 2011, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 375: Area 30 Buggy Unit Craters. The approach for the CAI was divided into two facets: investigation of the primary release of radionuclides, and investigation of other releases (migration in washes and chemical releases). The purpose of the CAI was to fulfill data needs as defined during the data quality objective (DQO) process. The CAU 375 dataset of investigation results was evaluated based on the data quality assessment. This assessment demonstrated the dataset is acceptable for use in fulfilling the DQO data needs. Investigation results were evaluated against final action levels (FALs) established in this document. A radiological dose FAL of 25 millirem per year was established based on the Remote Work Area exposure scenario (336 hours of annual exposure). Radiological doses exceeding the FAL were assumed to be present within the default contamination boundaries at CASs 25-23-22 and 30-45-01. No contaminants were identified at CAS 25-34-06, and no corrective action is necessary. Potential source material in the form of lead plate, lead-acid batteries, and oil within an abandoned transformer were identified at CAS 30-45-01, and corrective actions were undertaken that

  14. Application of Quantitative Microbial Risk Assessment to analyze the public health risk from poor drinking water quality in a low income area in Accra, Ghana.

    Science.gov (United States)

    Machdar, E; van der Steen, N P; Raschid-Sally, L; Lens, P N L

    2013-04-01

    In Accra, Ghana, a majority of inhabitants lives in over-crowded areas with limited access to piped water supply, which is often also intermittent. This study assessed in a densely populated area the risk from microbial contamination of various sources of drinking water, by conducting a Quantitative Microbiological Risk Assessment (QMRA) to estimate the risk to human health from microorganism exposure and dose-response relationships. Furthermore the cost-effectiveness in reducing the disease burden through targeted interventions was evaluated. Five risk pathways for drinking water were identified through a survey (110 families), namely household storage, private yard taps, communal taps, communal wells and water sachets. Samples from each source were analyzed for Escherichia coli and Ascaris contamination. Published ratios between E. coli and other pathogens were used for the QMRA and disease burden calculations. The major part of the burden of disease originated from E. coli O157:H7 (78%) and the least important contributor was Cryptosporidium (0.01%). Other pathogens contributed 16% (Campylobacter), 5% (Rotavirus) and 0.3% (Ascaris). The sum of the disease burden of these pathogens was 0.5 DALYs per person per year, which is much higher than the WHO reference level. The major contamination pathway was found to be household storage. Disinfection of water at household level was the most cost-effective intervention (Water supply network improvements were significantly less cost-effective. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Post-Closure Inspection and Monitoring Report for Corrective Action Unit 110: Area 3 WMD U-3ax/bl Crater, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2006-08-01

    This Post-Closure Inspection and Monitoring Report (PCIMR) provides the results of inspections and monitoring for Corrective Action Unit (CAU) 110, Area 3 WMD [Waste Management Division] U-3ax/bl Crater. This PCIMR includes an analysis and summary of the site inspections, repairs and maintenance, meteorological information, and soil moisture monitoring data obtained at CAU 110, for the annual period July 2005 through June 2006. Site inspections of the cover were performed quarterly to identify any significant changes to the site requiring action. The overall condition of the cover, cover vegetation, perimeter fence, and UR warning signs was good. Settling was observed that exceeded the action level as specified in Section VILB.7 of the Hazardous Waste Permit Number NEV HW009 (Nevada Division of Environmental Protection, 2000). This permit states that cracks or settling greater than 15 centimeters (6 inches) deep that extend 1.0 meter (m) (3 feet [ft]) or more on the cover will be evaluated and repaired within 60 days of detection. Along the east edge of the cover (repaired previously in August 2003, December 2003, May 2004, October 2004), an area of settling was observed during the December 2005 inspection to again be above the action level, and required repair. This area and two other areas of settling on the cover that were first observed during the December 2005 inspection were repaired in February 2006. The semiannual subsidence surveys were done in September 2005 and March 2006. No significant subsidence was observed in the survey data. Monument 5 shows the greatest amount of subsidence (-0.015 m [-0.05 ft] compared to the baseline survey of 2000). This amount is negligible and near the resolution of the survey instruments; it does not indicate that subsidence is occurring on the cover. Soil moisture results obtained to date indicate that the CAU 110 cover is performing as expected. Time Domain Reflectometry (TDR) data indicated an increase in soil moisture (1

  16. Post-Closure Inspection and Monitoring Report for Corrective Action Unit 110: Area 3 WMD U-3ax/bl Crater, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    NSTec Environmental Restoration

    2006-01-01

    This Post-Closure Inspection and Monitoring Report (PCIMR) provides the results of inspections and monitoring for Corrective Action Unit (CAU) 110, Area 3 WMD [Waste Management Division] U-3ax/bl Crater. This PCIMR includes an analysis and summary of the site inspections, repairs and maintenance, meteorological information, and soil moisture monitoring data obtained at CAU 110, for the annual period July 2005 through June 2006. Site inspections of the cover were performed quarterly to identify any significant changes to the site requiring action. The overall condition of the cover, cover vegetation, perimeter fence, and UR warning signs was good. Settling was observed that exceeded the action level as specified in Section VILB.7 of the Hazardous Waste Permit Number NEV HW009 (Nevada Division of Environmental Protection, 2000). This permit states that cracks or settling greater than 15 centimeters (6 inches) deep that extend 1.0 meter (m) (3 feet [ft]) or more on the cover will be evaluated and repaired within 60 days of detection. Along the east edge of the cover (repaired previously in August 2003, December 2003, May 2004, October 2004), an area of settling was observed during the December 2005 inspection to again be above the action level, and required repair. This area and two other areas of settling on the cover that were first observed during the December 2005 inspection were repaired in February 2006. The semiannual subsidence surveys were done in September 2005 and March 2006. No significant subsidence was observed in the survey data. Monument 5 shows the greatest amount of subsidence (-0.015 m [-0.05 ft] compared to the baseline survey of 2000). This amount is negligible and near the resolution of the survey instruments; it does not indicate that subsidence is occurring on the cover. Soil moisture results obtained to date indicate that the CAU 110 cover is performing as expected. Time Domain Reflectometry (TDR) data indicated an increase in soil moisture (1

  17. SMALL CRATERS AND THEIR DIAGNOSTIC POTENTIAL

    Directory of Open Access Journals (Sweden)

    R. Bugiolacchi

    2017-07-01

    Full Text Available I analysed and compared the size-frequency distributions of craters in the Apollo 17 landing region, comprising of six mare terrains with varying morphologies and cratering characteristics, along with three other regions allegedly affected by the same secondary event (Tycho secondary surge. I propose that for the smaller crater sizes (in this work 9–30 m, a] an exponential curve of power −0.18D can approximate Nkm−2 crater densities in a regime of equilibrium, while b] a power function D−3 closely describes the factorised representation of craters by size (1 m. The saturation level within the Central Area suggests that c] either the modelled rates of crater erosion on the Moon should be revised, or that the Tycho event occurred much earlier in time than the current estimate. We propose that d] the size-frequency distribution of small secondary craters may bear the signature (in terms of size-frequency distribution of debris/surge of the source impact and that this observation should be tested further.

  18. Using High Resolution Commercial Satellite Imagery to Quantify Spatial Features of Urban Areas and their Relationship to Quality of Life Indicators in Accra, Ghana

    Science.gov (United States)

    Sandborn, A.; Engstrom, R.; Yu, Q.

    2014-12-01

    Mapping urban areas via satellite imagery is an important task for detecting and anticipating land cover and land use change at multiple scales. As developing countries experience substantial urban growth and expansion, remotely sensed based estimates of population and quality of life indicators can provide timely and spatially explicit information to researchers and planners working to determine how cities are changing. In this study, we use commercial high spatial resolution satellite imagery in combination with fine resolution census data to determine the ability of using remotely sensed data to reveal the spatial patterns of quality of life in Accra, Ghana. Traditionally, spectral characteristics are used on a per-pixel basis to determine land cover; however, in this study, we test a new methodology that quantifies spatial characteristics using a variety of spatial features observed in the imagery to determine the properties of an urban area. The spatial characteristics used in this study include histograms of oriented gradients, PanTex, Fourier transform, and line support regions. These spatial features focus on extracting structural and textural patterns of built-up areas, such as homogeneous building orientations and straight line indices. Information derived from aggregating the descriptive statistics of the spatial features at both the fine-resolution census unit and the larger neighborhood level are then compared to census derived quality of life indicators including information about housing, education, and population estimates. Preliminary results indicate that there are correlations between straight line indices and census data including available electricity and literacy rates. Results from this study will be used to determine if this methodology provides a new and improved way to measure a city structure in developing cities and differentiate between residential and commercial land use zones, as well as formal versus informal housing areas.

  19. Centrifuge Impact Cratering Experiments

    Science.gov (United States)

    Schmidt, R. M.; Housen, K. R.; Bjorkman, M. D.

    1985-01-01

    The kinematics of crater growth, impact induced target flow fields and the generation of impact melt were determined. The feasibility of using scaling relationships for impact melt and crater dimensions to determine impactor size and velocity was studied. It is concluded that a coupling parameter determines both the quantity of melt and the crater dimensions for impact velocities greater than 10km/s. As a result impactor radius, a, or velocity, U cannot be determined individually, but only as a product in the form of a coupling parameter, delta U micron. The melt volume and crater volume scaling relations were applied to Brent crater. The transport of melt and the validity of the melt volume scaling relations are examined.

  20. Rock spatial densities on the rims of the Tycho secondary craters in Mare Nectaris

    Science.gov (United States)

    Basilevsky, A. T.; Michael, G. G.; Kozlova, N. A.

    2018-04-01

    The aim of this work is to check whether the technique of estimation of age of small lunar craters based on spatial density of rock boulders on their rims described in Basilevsky et al. (2013, 2015b) and Li et al. (2017) for the craters rock counts on the rims of four craters having diameters 1000, 1100, 1240 and 1400 m located in Mare Nectaris. These craters are secondaries of the primary crater Tycho, whose age was found to be 109 ± 4 Ma (Stoffler and Ryder, 2001) so this may be taken as the age of the four craters, too. Using the dependence of the rock spatial densities at the crater rims on the crater age for the case of mare craters (Li et al., 2017) our measured rock densities correspond to ages from ∼100 to 130 Ma. These estimates are reasonably close to the given age of the primary crater Tycho. This, in turn, suggests that this technique of crater age estimation is applicable to craters up to ∼1.5 km in diameter. For the four considered craters we also measured their depth/diameter ratios and the maximum angles of the crater inner slopes. For the considered craters it was found that with increasing crater diameter, the depth/diameter ratios and maximum angles of internal slopes increase, but the values of these parameters for specific craters may deviate significantly from the general trends. The deviations probably result from some dissimilarities in the primary crater geometries, that may be due to crater to crater differences in characteristics of impactors (e.g., in their bulk densities) and/or differences in the mechanical properties of the target. It may be possible to find secondaries of crater Tycho in the South pole area and, if so, they may be studied to check the specifics and rates of the rock boulder degradation in the lunar polar environment.

  1. Problems and Prospects of Millennium Development Goals in Ghana

    Directory of Open Access Journals (Sweden)

    Olusola Olasupo

    2016-12-01

    Full Text Available Ghana, like other developing nations, was not left behind in embracing the eight time-bound Millennium Development Goals (MDGs in September 2000. The millennium development goals aimed towards peace and good standards of living have been faced with series of problems in its attainment in Ghana. These problems have undermined the extent to which Ghana could achieve the MDGs. The study adopting qualitative research method shows that Ghana is faced with difficulty in achieving these eight millennium development goals in certain portions of the nation most especially in the rural communities due to lack of infrastructure. The study therefore recommends that Ghana should focus more on improving the standard of living of the rural dwellers by increasing the public services in the area.  The need for Ghana to focus more on solving these problems is strategic for a better result in this new era of Sustainable Development Goals.

  2. Biophysical and Socioeconomic State and Links of Deltaic Areas Vulnerable to Climate Change: Volta (Ghana, Mahanadi (India and Ganges-Brahmaputra-Meghna (India and Bangladesh

    Directory of Open Access Journals (Sweden)

    Ignacio Cazcarro

    2018-03-01

    Full Text Available We examine the similarities and differences of specific deltaic areas in parallel, under the project DEltas, vulnerability and Climate Change: Migration and Adaptation (DECCMA. The main reason for studying Deltas is their potential vulnerability to climate change and sea level rise, which generates important challenges for livelihoods. We provide insights into the current socioeconomic and biophysical states of the Volta Delta (Ghana, Mahanadi Delta (India and Ganges-Brahmaputra-Meghna (India and Bangladesh. Hybrid methods of input-output (IO construction are used to develop environmentally extended IO models for comparing the economic characteristics of these delta regions with the rest of the country. The main sources of data for regionalization were country level census data, statistics and economic surveys and data on consumption, trade, agricultural production and fishing harvests. The Leontief demand-driven model is used to analyze land use in the agricultural sector of the Delta and to track the links with final demand. In addition, the Hypothetical Extraction Method is used to evaluate the importance of the hypothetical disappearance of a sector (e.g., agriculture. The results show that, in the case of the Indian deltas, more than 60% of the cropland and pasture land is devoted to satisfying demands from regions outside the delta. While in the case of the Bangladeshi and Ghanaian deltas, close to 70% of the area harvested is linked to internal demand. The results also indicate that the services, trade and transportation sectors represent 50% of the GDP in the deltas. Still, agriculture, an activity directly exposed to climate change, plays a relevant role in the deltas’ economies—we have estimated that the complete disappearance of this activity would entail GDP losses ranging from 18 to 32%.

  3. Polygons on Crater Floor

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-357, 11 May 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a pattern of polygons on the floor of a northern plains impact crater. These landforms are common on crater floors at high latitudes on Mars. Similar polygons occur in the arctic and antarctic regions of Earth, where they indicate the presence and freeze-thaw cycling of ground ice. Whether the polygons on Mars also indicate water ice in the ground is uncertain. The image is located in a crater at 64.8oN, 292.7oW. Sunlight illuminates the scene from the lower left.

  4. Fresh Impact Crater and Rays in Tharsis

    Science.gov (United States)

    2002-01-01

    The Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) Extended Mission has included dozens of opportunities to point the spacecraft directly at features of interest so that pictures of things not seen during the earlier Mapping Mission can be obtained. The example shown here is a small meteorite impact crater in northern Tharsis near 17.2oN, 113.8oW. Viking Orbiter images from the late 1970's showed at this location what appeared to be a dark patch with dark rays emanating from a brighter center. The MOC team surmised that the dark rays may be indicating the location of afresh crater formed by impact sometime in the past few centuries (since dark ray are quickly covered by dust falling out of the martian atmosphere). All through MOC's Mapping Mission in 1999 and 2000, attempts were made to image the crater as predictions indicated that the spacecraft would pass over the site, but the crater was never seen. Finally, in June 2001, Extended Mission operations allowed the MOC team to point the spacecraft (and hence the camera, which is fixed to the spacecraft)directly at the center of the dark rays, where we expected to find the crater.The picture on the left (above, A) is a mosaic of three MOC high resolution images and one much lower-resolution Viking image. From left to right, the images used in the mosaic are: Viking 1 516A55, MOC E05-01904, MOCM21-00272, and MOC M08-03697. Image E05-01904 is the one taken in June 2001 by pointing the spacecraft. It captured the impact crater responsible for the rays. A close-up of the crater, which is only 130 meters (427 ft)across, is shown on the right (above, B). This crater is only one-tenth the size of the famous Meteor Crater in northern Arizona.The June 2001 MOC image reveals many surprises about this feature. For one, the crater is not located at the center of the bright area from which the dark rays radiate. The rays point to the center of this bright area, not the crater. Further, the dark material ejected from the

  5. Environmental and occupational exposures to mercury among indigenous people in Dunkwa-On-Offin, a small scale gold mining area in the South-West of Ghana.

    Science.gov (United States)

    Kwaansa-Ansah, E E; Basu, N; Nriagu, J O

    2010-11-01

    Total mercury concentrations in human hair and urine samples were determined to ascertain the extent of environmental and occupational mercury exposure in Dunkwa-On-Offin, a small scale gold mining area of the central-west region of Ghana. In all ninety-four (94) hair and urine samples comprising of forty (40) small scale miners and fifty-four (54) farmers were collected and analyzed for their total mercury levels using the cold vapour atomic absorption spectrometry. The hair total mercury concentrations ranged from 0.63 to 7.19 ug/g with a mean of 2.35 ± 1.58 ug/g for the farmers and 0.57-6.07 ug/g with a mean of 2.14 ± 1.53 ug/g for the small scale gold miners. There was no significant correlation between the total mercury concentration and the average weekly fish diet. The total mercury concentrations in urine of the miners were higher than those of the farmers and ranged from 0.32 to 3.62 ug/L with a mean of 1.23 ± 0.86 ug/L. The urine concentrations of farmers ranged from 0.075 to 2.31 ug/L with a mean of 0.69 ± 0.39 ug/L. Although the results indicate elevated internal dose of mercury the current levels of exposures do not appear to pose a significant health threat to the people.

  6. Mercury's Densely Cratered Surface

    Science.gov (United States)

    1974-01-01

    Mariner 10 took this picture (FDS 27465) of the densely cratered surface of Mercury when the spacecraft was 18,200 kilometers (8085 miles) from the planet on March 29. The dark line across top of picture is a 'dropout' of a few TV lines of data. At lower left, a portion of a 61 kilometer (38 mile) crater shows a flow front extending across the crater floor and filling more than half of the crater. The smaller, fresh crater at center is about 25 kilometers (15 miles) in diameter. Craters as small as one kilometer (about one-half mile) across are visible in the picture.The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.Image Credit: NASA/JPL/Northwestern University

  7. Multivariate analyses of crater parameters and the classification of craters

    Science.gov (United States)

    Siegal, B. S.; Griffiths, J. C.

    1974-01-01

    Multivariate analyses were performed on certain linear dimensions of six genetic types of craters. A total of 320 craters, consisting of laboratory fluidization craters, craters formed by chemical and nuclear explosives, terrestrial maars and other volcanic craters, and terrestrial meteorite impact craters, authenticated and probable, were analyzed in the first data set in terms of their mean rim crest diameter, mean interior relief, rim height, and mean exterior rim width. The second data set contained an additional 91 terrestrial craters of which 19 were of experimental percussive impact and 28 of volcanic collapse origin, and which was analyzed in terms of mean rim crest diameter, mean interior relief, and rim height. Principal component analyses were performed on the six genetic types of craters. Ninety per cent of the variation in the variables can be accounted for by two components. Ninety-nine per cent of the variation in the craters formed by chemical and nuclear explosives is explained by the first component alone.

  8. Ghana Space Science and Technology Institute (GSSTI),Ghana Atomic Energy Commission: Annual Report 2013/2014

    International Nuclear Information System (INIS)

    2014-01-01

    The report presents the structure as well as the research projects of the newly established Ghana Space Science and Technology Institute of the Ghana Atomic Energy Commission from January to December 2014. Research projects listed are in the areas of Astronomy and Astrophysics; Remote Sensing; Electronics and Instrumentation; and Satellite Communication.

  9. Levels of some heavy metals and nutritional compositions of cocoa beans from selected cocoa- growing areas in Ashanti and Western regions of Ghana

    International Nuclear Information System (INIS)

    Asante, Nnuro William

    2013-03-01

    In this study, the levels of six heavy metals namely: cadmium, lead, copper, manganese, iron and zinc were determined in cocoa beans from some cocoa-growing areas in the Western and Ashanti Regions of Ghana using atomic absorption spectroscopy. The metal levels in the cocoa beans from the Western Region, expressed in mg/ kg varied from 0.045 to 0.066 with mean value of 0.054 for cadmium, from 0.013 to 0.030 with mean value of 0.020 for lead, from 46.47 to 55.17 with mean value of 51.98 for copper, from 48.36 to 64.65 with mean value of 55.18 for manganese, from 43.80 to 53.11 with the mean value of 47.51 iron and from 43.04 to 52.06 with the mean value of 48.29 for zinc. Those of Ashanti Region ranged from 0.050 to 0.065 with the mean value of 0.056 for cadmium, from 0.014 to 0.020 with the mean value of 0.017 for lead, from 47.43 to 54.17 with the mean value of 49.10 for copper, from 47.15 to 57.34 with the mean value of 54.62 for manganese, from 50.23 to 63.87 with the mean value of 54.63 for iron and from 53.02 to 58.71 with the mean value of 56.49 for zinc. Upon proximate analyses of four of the samples chosen at random (two samples from each region), it was found that all the samples were of high fat and carbohydrate content. The percentages of fat were 45.52%, 43.85%, 45.57% and 36.72% in samples from Kasapen, Asampaneye, Bekwai and Juaso respectively. Those of carbohydrates were 32.56%, 32.08%, 31.62% and 42.88% in cocoa samples from Kasapen, Asempaneye, Bekwai and Juaso respectively. Levels of proteins were 14.34%, 13.97%, 13.74% and 13.91% in the samples from the towns as listed in the order above. The samples from Kasapen in the Western Region gave 3.15%, 3.40% and 1.03% for moisture, ash and fibre contents respectively. The moisture, ash and fibre content in samples from Asempaneye also in the Western Region were 4.39%, 3.69% and 1.02% respectively. Samples from Bekwai in the Ashanti Region gave 4.46%, 3.52% and1.09% for moisture, ash and fibre contents

  10. Mineralogy, provenance, and diagenesis of a potassic basaltic sandstone on Mars: CheMin X-ray diffraction of the Windjana sample (Kimberley area, Gale Crater)

    International Nuclear Information System (INIS)

    Treiman, Allan H.; Bish, David L.; Chipera, Steve J.; Blake, David F.

    2015-01-01

    The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X-ray diffraction (XRD) in the MSL Curiosity rover. From Rietveld refinements of its XRD pattern, Windjana contains the following: sanidine (21% weight, ~Or 95 ); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (~25%); and percent levels of others including ilmenite, fluorapatite, and bassanite. From mass balance on the Alpha Proton X-ray Spectrometer (APXS) chemical analysis, the amorphous material is Fe rich with nearly no other cations—like ferrihydrite. The Windjana sample shows little alteration and was likely cemented by its magnetite and ferrihydrite. From ChemCam Laser-Induced Breakdown Spectrometer (LIBS) chemical analyses, Windjana is representative of the Dillinger and Mount Remarkable members of the Kimberley formation. LIBS data suggest that the Kimberley sediments include at least three chemical components. The most K-rich targets have 5.6% K 2 O, ~1.8 times that of Windjana, implying a sediment component with >40% sanidine, e.g., a trachyte. A second component is rich in mafic minerals, with little feldspar (like a shergottite). A third component is richer in plagioclase and in Na 2 O, and is likely to be basaltic. The K-rich sediment component is consistent with APXS and ChemCam observations of K-rich rocks elsewhere in Gale Crater. The source of this sediment component was likely volcanic. Finally, the presence of sediment from many igneous sources, in concert with Curiosity's identifications of other igneous materials (e.g., mugearite), implies that the northern rim of Gale Crater exposes a diverse igneous complex, at least as diverse as that found in similar-age terranes on Earth.

  11. Characteristics of ejecta and alluvial deposits at Meteor Crater, Arizona and Odessa Craters, Texas: Results from ground penetrating radar

    Science.gov (United States)

    Grant, J. A.; Schultz, P. H.

    1991-01-01

    Previous ground penetrating radar (GRP) studies around 50,000 year old Meteor Crater revealed the potential for rapid, inexpensive, and non-destructive sub-surface investigations for deep reflectors (generally greater than 10 m). New GRP results are summarized focusing the shallow sub-surfaces (1-2 m) around Meteor Crater and the main crater at Odessa. The following subject areas are covered: (1) the thickness, distribution, and nature of the contact between surrounding alluvial deposits and distal ejecta; and (2) stratigraphic relationships between both the ejecta and alluvium derived from both pre and post crater drainages. These results support previous conclusions indicating limited vertical lowering (less than 1 m) of the distal ejecta at Meteor Crater and allow initial assessment of the gradational state if the Odessa craters.

  12. Craters on comets

    Science.gov (United States)

    Vincent, J.; Oklay, N.; Marchi, S.; Höfner, S.; Sierks, H.

    2014-07-01

    This paper reviews the observations of crater-like features on cometary nuclei. ''Pits'' have been observed on almost all cometary nuclei but their origin is not fully understood [1,2,3,4]. It is currently assumed that they are created mainly by the cometary activity with a pocket of volatiles erupting under a dust crust, leaving a hole behind. There are, however, other features which cannot be explained in this way and are interpreted alternatively as remnants of impact craters. This work focusses on the second type of pit features: impact craters. We present an in-depth review of what has been observed previously and conclude that two main types of crater morphologies can be observed: ''pit-halo'' and ''sharp pit''. We extend this review by a series of analysis of impact craters on cometary nuclei through different approaches [5]: (1) Probability of impact: We discuss the chances that a Jupiter Family Comet like 9P/Tempel 1 or the target of Rosetta 67P/Churyumov-Gerasimenko can experience an impact, taking into account the most recent work on the size distribution of small objects in the asteroid Main Belt [6]. (2) Crater morphology from scaling laws: We present the status of scaling laws for impact craters on cometary nuclei [7] and discuss their strengths and limitations when modeling what happens when a rocky projectile hits a very porous material. (3) Numerical experiments: We extend the work on scaling laws by a series of hydrocode impact simulations, using the iSALE shock physics code [8,9,10] for varying surface porosity and impactor velocity (see Figure). (4) Surface processes and evolution: We discuss finally the fate of the projectile and the effects of the impact-induced surface compaction on the activity of the nucleus. To summarize, we find that comets do undergo impacts although the rapid evolution of the surface erases most of the features and make craters difficult to detect. In the case of a collision between a rocky body and a highly porous

  13. Ghana : Accounting and Auditing

    OpenAIRE

    World Bank

    2004-01-01

    This report provides an assessment of accounting and auditing practices within the context of the Ghana institutional framework to ensure the quality of corporate financial reporting. The accounting and auditing practices in Ghana suffer from institutional weaknesses in regulation, compliance, and enforcement of standards and rules. Various weaknesses were identified in the laws and regula...

  14. Ghana Medical Journal

    African Journals Online (AJOL)

    The Ghana Medical Journal is a peer-reviewed, open access journal published by the Ghana Medical Association. It was established in 1962 It publishes quality manuscripts in in all aspects of health, health care and the medical sciences. The full text of published articles are available online at this website and at African ...

  15. Ghana Mining Journal: Contact

    African Journals Online (AJOL)

    Principal Contact. Professor Daniel Mireku-Gyimah Editor-in-Chief University of Mines & Technology Ghana Mining Journal University of Mines & Technology P. O. BOX 237 Tarkwa Ghana Phone: +233 362 20280/20324. Fax: +233 362 20306. Email: dm.gyimah@umat.edu.gh ...

  16. Geologic map of Tooting crater, Amazonis Planitia region of Mars

    Science.gov (United States)

    Mouginis-Mark, Peter J.

    2015-01-01

    Tooting crater has a diameter of 27.2 km, and formed on virtually flat lava flows within Amazonis Planitia ~1,300 km west of the summit of Olympus Mons volcano, where there appear to have been no other major topographic features prior to the impact. The crater formed in an area ~185 x 135 km that is at an elevation between −3,870 m and −3,874 m relative to the Mars Orbiter Laser Altimeter (MOLA) Mars datum. This fortuitous situation (for example, a bland, horizontal target) allows the geometry of the crater and the thickness of the ejecta blanket to be accurately determined by subtracting the appropriate elevation of the surrounding landscape (−3,872 m) from the individual MOLA measurements across the crater. Thus, for the first time, it is possible to determine the radial decrease of ejecta thickness as a function of distance away from the rim crest. On the basis of the four discrete ejecta layers surrounding the crater cavity, Tooting crater is classified as a Multiple-Layered Ejecta (MLE) crater. By virtue of the asymmetric distribution of secondary craters and the greater thickness of ejecta to the northeast, Morris and others (2010) proposed that Tooting crater formed by an oblique impact from the southwest. The maximum range of blocks that produced identifiable secondary craters is ~500 km (~36.0 crater radii) from the northeast rim crest. In contrast, secondary craters are only identifiable ~215 km (15.8 radii) to the southeast and 225 km (16.5 radii) to the west.

  17. Determining long-term regional erosion rates using impact craters

    Science.gov (United States)

    Hergarten, Stefan; Kenkmann, Thomas

    2015-04-01

    More than 300,000 impact craters have been found on Mars, while the surface of Moon's highlands is even saturated with craters. In contrast, only 184 impact craters have been confirmed on Earth so far with only 125 of them exposed at the surface. The spatial distribution of these impact craters is highly inhomogeneous. Beside the large variation in the age of the crust, consumption of craters by erosion and burial by sediments are the main actors being responsible for the quite small and inhomogeneous crater record. In this study we present a novel approach to infer long-term average erosion rates at regional scales from the terrestrial crater inventory. The basic idea behind this approach is a dynamic equilibrium between the production of new craters and their consumption by erosion. It is assumed that each crater remains detectable until the total erosion after the impact exceeds a characteristic depth depending on the crater's diameter. Combining this model with the terrestrial crater production rate, i.e., the number of craters per unit area and time as a function of their diameter, allows for a prediction of the expected number of craters in a given region as a function of the erosion rate. Using the real crater inventory, this relationship can be inverted to determine the regional long-term erosion rate and its statistical uncertainty. A limitation by the finite age of the crust can also be taken into account. Applying the method to the Colorado Plateau and the Deccan Traps, both being regions with a distinct geological history, yields erosion rates in excellent agreement with those obtained by other, more laborious methods. However, these rates are formally exposed to large statistical uncertainties due to the small number of impact craters. As higher crater densities are related to lower erosion rates, smaller statistical errors can be expected when large regions in old parts of the crust are considered. Very low long-term erosion rates of less than 4

  18. Optimizing laser crater enhanced Raman scattering spectroscopy

    Science.gov (United States)

    Lednev, V. N.; Sdvizhenskii, P. A.; Grishin, M. Ya.; Fedorov, A. N.; Khokhlova, O. V.; Oshurko, V. B.; Pershin, S. M.

    2018-05-01

    The laser crater enhanced Raman scattering (LCERS) spectroscopy technique has been systematically studied for chosen sampling strategy and influence of powder material properties on spectra intensity enhancement. The same nanosecond pulsed solid state Nd:YAG laser (532 nm, 10 ns, 0.1-1.5 mJ/pulse) was used for laser crater production and Raman scattering experiments for L-aspartic acid powder. Increased sampling area inside crater cavity is the key factor for Raman signal improvement for the LCERS technique, thus Raman signal enhancement was studied as a function of numerous experimental parameters including lens-to-sample distance, wavelength (532 and 1064 nm) and laser pulse energy utilized for crater production. Combining laser pulses of 1064 and 532 nm wavelengths for crater ablation was shown to be an effective way for additional LCERS signal improvement. Powder material properties (particle size distribution, powder compactness) were demonstrated to affect LCERS measurements with better results achieved for smaller particles and lower compactness.

  19. Fluids, evaporation and precipitates at Gale Crater

    OpenAIRE

    Schwenzer, S. P.; Bridges, J. C.; Leveille, R.; Wiens, R. C.; Mangold, N.; McAdam, A.; Conrad, P.; Kelley, S. P.; Westall, F.; Martín-Torres, F.; Zorzano, M.-P.

    2015-01-01

    The Mars Science Laboratory (MSL) mission landed in Gale Crater, Mars, on 6th August 2012, and has explored the Yellowknife Bay area. The detailed mineralogical and sedimentological studies provide a unique opportunity to characterise the secondary fluids associated with this habitable environment.

  20. Hypervelocity impact cratering calculations

    Science.gov (United States)

    Maxwell, D. E.; Moises, H.

    1971-01-01

    A summary is presented of prediction calculations on the mechanisms involved in hypervelocity impact cratering and response of earth media. Considered are: (1) a one-gram lithium-magnesium alloys impacting basalt normally at 6.4 km/sec, and (2) a large terrestrial impact corresponding to that of Sierra Madera.

  1. Cratering Equations for Zinc Orthotitanate Coated Aluminum

    Science.gov (United States)

    Hyde, James; Christiansen, Eric; Liou, Jer-Chyi; Ryan, Shannon

    2009-01-01

    The final STS-125 servicing mission (SM4) to the Hubble Space Telescope (HST) in May of 2009 saw the return of the 2nd Wide Field Planetary Camera (WFPC2) aboard the shuttle Discovery. This hardware had been in service on HST since it was installed during the SM1 mission in December of 1993 yielding one of the longest low Earth orbit exposure times (15.4 years) of any returned space hardware. The WFPC2 is equipped with a 0.8 x 2.2 m radiator for thermal control of the camera electronics (Figure 1). The space facing surface of the 4.1 mm thick aluminum radiator is coated with Z93 zinc orthotitanate thermal control paint with a nominal thickness of 0.1 0.2 mm. Post flight inspections of the radiator panel revealed hundreds of micrometeoroid/orbital debris (MMOD) impact craters ranging in size from less than 300 to nearly 1000 microns in diameter. The Z93 paint exhibited large spall areas around the larger impact sites (Figure 2) and the craters observed in the 6061-T651 aluminum had a different shape than those observed in uncoated aluminum. Typical hypervelocity impact craters in aluminum have raised lips around the impact site. The craters in the HST radiator panel had suppressed crater lips, and in some cases multiple craters were present instead of a single individual crater. Humes and Kinard observed similar behavior after the WFPC1 post flight inspection and assumed the Z93 coating was acting like a bumper in a Whipple shield. Similar paint behavior (spall) was also observed by Bland2 during post flight inspection of the International Space Station (ISS) S-Band Antenna Structural Assembly (SASA) in 2008. The SASA, with similar Z93 coated aluminum, was inspected after nearly 4 years of exposure on the ISS. The multi-crater phenomena could be a function of the density, composition, or impact obliquity angle of the impacting particle. For instance, a micrometeoroid particle consisting of loosely bound grains of material could be responsible for creating the

  2. Ghana Chemical Society eleventh national annual conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    The publication contains the programme and abstracts of the eleventh annual conference of the Ghana Chemical Society. The aim of the conference was to examine the role of chemistry and the strategic role of chemistry practitioners in the overall development of Ghana in the twenty first century. Abstracts presented have been grouped in the following order: welcome address, professional lecture on the future direction of the Ghana Chemical Society, conference programme, plenary lectures on the role of chemistry in the critical areas of the economy such as energy, environment, education, health, agriculture, special seminar on chemistry and society highlighting the role of chemistry in fire prevention, crime detection, water quality, customs operations, scientific papers and selected industrial processes. A total of twenty five abstracts have been presented. (E.A.A)

  3. Ghana Chemical Society eleventh national annual conference

    International Nuclear Information System (INIS)

    1998-01-01

    The publication contains the programme and abstracts of the eleventh annual conference of the Ghana Chemical Society. The aim of the conference was to examine the role of chemistry and the strategic role of chemistry practitioners in the overall development of Ghana in the twenty first century. Abstracts presented have been grouped in the following order: welcome address, professional lecture on the future direction of the Ghana Chemical Society, conference programme, plenary lectures on the role of chemistry in the critical areas of the economy such as energy, environment, education, health, agriculture, special seminar on chemistry and society highlighting the role of chemistry in fire prevention, crime detection, water quality, customs operations, scientific papers and selected industrial processes. A total of twenty five abstracts have been presented. (E.A.A)

  4. Prediction of gamma exposure rates in large nuclear craters

    Energy Technology Data Exchange (ETDEWEB)

    Tami, Thomas M; Day, Walter C [U.S. Army Engineer Nuclear Cratering Group, Lawrence Radiation Laboratory, Livermore, CA (United States)

    1970-05-15

    In many civil engineering applications of nuclear explosives there is the need to reenter the crater and lip area as soon as possible after the detonation to carry out conventional construction activities. These construction activities, however, must be delayed until the gamma dose rate, or exposure rate, in and around the crater decays to acceptable levels. To estimate the time of reentry for post-detonation construction activities, the exposure rate in the crater and lip areas must be predicted as a function of time after detonation. An accurate prediction permits a project planner to effectively schedule post-detonation activities.

  5. Ghana Medical Journal: Submissions

    African Journals Online (AJOL)

    Journal Home > About the Journal > Ghana Medical Journal: Submissions ... Works publishable under this section include original work of suitable standard. ... interest statement of all types of manuscript should be submitted as a separate file.

  6. Ghana Mining Journal

    African Journals Online (AJOL)

    ... in the Ghana mining journal: Geology and Mineral Exploration, Mining, Quarrying, Geomechanics, Groundwater Studies, Hydrocarbon Development, Mineral Processing, Metallurgy, Material Science, Mineral Management Policies, Mineral Economics, Environmental Aspects, Computer Applications and Mining Education.

  7. Ghana's nuclear programme

    International Nuclear Information System (INIS)

    Ahafia, Albert K.

    1988-01-01

    The Paper gives the purpose of Ghana's Nuclear Programme and describes some specific research activities and peaceful applications of atomic energy in agriculture, medicine and industry. A discussion of some of the problem facing the programme concludes the Paper. (author)

  8. African Journals Online: Ghana

    African Journals Online (AJOL)

    Items 1 - 27 of 27 ... African Journal of Educational Studies in Mathematics and Sciences .... The Ghana Medical Journal is a peer-reviewed, open access journal ... The Journal of Business Research (JBR) is an International journal published by ...

  9. IDRC in Ghana

    International Development Research Centre (IDRC) Digital Library (Canada)

    ting up the Canada-Ghana Research and. Science Council ... major reform in the country's national health insurance ... helped spread the use of insecticide- coated mosquito nets throughout Africa. These nets are a ... effects of climate change.

  10. Improving the first-line treatment of febrile illnesses in Ghana: willingness to pay for malaria rapid diagnostic tests at licensed chemical shops in the Kintampo area.

    Science.gov (United States)

    Tawiah, Theresa; Malam, Keziah; Kwarteng, Anthony; Bart-Plange, Constance; Febir, Lawrence; Aubyn, Vivian; Obermann, Konrad; Owusu-Agyei, Seth; Asante, Kwaku Poku

    2018-01-01

    Use of malaria rapid diagnostic test (mRDT) enhances patient management and reduces costs associated with the inappropriate use of antimalarials. Despite its proven clinical effectiveness, mRDT is not readily available at licensed chemical shops in Ghana. Therefore, in order to improve the use of mRDT, there is the need to understand the willingness to pay for and sell mRDT. This study assessed patients' willingness to pay and licensed chemical operators' (LCS) willingness to sell mRDTs. The study was a cross-sectional survey conducted in Kintampo North Municipality and Kintampo South District of Ghana. Contingent valuation method using the dichotomous approach was applied to explore patient's willingness to pay. In-depth interviews (IDIs) were used to obtain information from licensed chemical operators' willingness to sell. Majority 161 (97%) of the customers were willing to pay for mRDT while 100% of licensed chemical operators were also willing to sell mRDT. The average lowest amount respondents were willing to pay was Ghana cedis (GH¢) 1.1 (US$ 0.26) and an average highest amount of GH¢ 2.1 (US$ 0.49). LCS operators were willing to sell the test kit at an average lowest price of GH¢1 (US$ 0.23) and average highest price of GH¢2 (US$ 0.47). Community members were willing to pay for mRDT and LCS operators are willing to sell mRDTs. However, the high cost of the mRDT is likely to prevent the widespread use of mRDT. There is a clear need to find system-compatible ways to subsidize the use of mRDT via National Health Insurance scheme.

  11. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Measurement and errors of crater statistics. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    Planetary imagery techniques, errors in measurement or degradation assignment, and statistical formulas are presented with respect to cratering data. Base map photograph preparation, measurement of crater diameters and sampled area, and instruments used are discussed. Possible uncertainties, such as Sun angle, scale factors, degradation classification, and biases in crater recognition are discussed. The mathematical formulas used in crater statistics are presented.

  12. Entrepreneurship training in Ghana

    DEFF Research Database (Denmark)

    Schmidt, Leila Kæmsgaard Pagh

    2017-01-01

    is that adding a focus on means, attitude and enterprising behaviour skills will increase the value of entrepreneurship training. The study is a design-based research undertaken in collaboration with the local NGO, Youth Empowerment for Life (YEfL). It builds on relevant theory and involves qualitative...... and quantitative research in Northern Ghana. The study reveals the five most crucial constraints for young entrepreneurs in Northern Ghana. Moreover, it proposes a new entrepreneurship model and training manual....

  13. Ghana's high forests

    OpenAIRE

    Oduro, K.A.

    2016-01-01

    Deforestation and forest degradation in the tropics have been receiving both scientific and political attention in recent decades due to its impacts on the environment and on human livelihoods. In Ghana, the continuous decline of forest resources and the high demand for timber have raised stakeholders concerns about the future timber production prospects in the country. The principal drivers of deforestation and forest degradation in Ghana are agricultural expansion (50%), wood harvesting (35...

  14. Bank service management in Ghana

    DEFF Research Database (Denmark)

    Kuada, John; Narteh, Bedman

    2011-01-01

    This article reports a study of the determinants of effective management of of retail banking services in Ghana......This article reports a study of the determinants of effective management of of retail banking services in Ghana...

  15. Snow-avalanche impact craters in southern Norway: Their morphology and dynamics compared with small terrestrial meteorite craters

    Science.gov (United States)

    Matthews, John A.; Owen, Geraint; McEwen, Lindsey J.; Shakesby, Richard A.; Hill, Jennifer L.; Vater, Amber E.; Ratcliffe, Anna C.

    2017-11-01

    This regional inventory and study of a globally uncommon landform type reveals similarities in form and process between craters produced by snow-avalanche and meteorite impacts. Fifty-two snow-avalanche impact craters (mean diameter 85 m, range 10-185 m) were investigated through field research, aerial photographic interpretation and analysis of topographic maps. The craters are sited on valley bottoms or lake margins at the foot of steep avalanche paths (α = 28-59°), generally with an easterly aspect, where the slope of the final 200 m of the avalanche path (β) typically exceeds 15°. Crater diameter correlates with the area of the avalanche start zone, which points to snow-avalanche volume as the main control on crater size. Proximal erosional scars ('blast zones') up to 40 m high indicate up-range ejection of material from the crater, assisted by air-launch of the avalanches and impulse waves generated by their impact into water-filled craters. Formation of distal mounds up to 12 m high of variable shape is favoured by more dispersed down-range deposition of ejecta. Key to the development of snow-avalanche impact craters is the repeated occurrence of topographically-focused snow avalanches that impact with a steep angle on unconsolidated sediment. Secondary craters or pits, a few metres in diameter, are attributed to the impact of individual boulders or smaller bodies of snow ejected from the main avalanche. The process of crater formation by low-density, low-velocity, large-volume snow flows occurring as multiple events is broadly comparable with cratering by single-event, high-density, high-velocity, small-volume projectiles such as small meteorites. Simple comparative modelling of snow-avalanche events associated with a crater of average size (diameter 85 m) indicates that the kinetic energy of a single snow-avalanche impact event is two orders of magnitude less than that of a single meteorite-impact event capable of producing a crater of similar size

  16. Noachian and more recent phyllosilicates in impact craters on Mars.

    Science.gov (United States)

    Fairén, Alberto G; Chevrier, Vincent; Abramov, Oleg; Marzo, Giuseppe A; Gavin, Patricia; Davila, Alfonso F; Tornabene, Livio L; Bishop, Janice L; Roush, Ted L; Gross, Christoph; Kneissl, Thomas; Uceda, Esther R; Dohm, James M; Schulze-Makuch, Dirk; Rodríguez, J Alexis P; Amils, Ricardo; McKay, Christopher P

    2010-07-06

    Hundreds of impact craters on Mars contain diverse phyllosilicates, interpreted as excavation products of preexisting subsurface deposits following impact and crater formation. This has been used to argue that the conditions conducive to phyllosilicate synthesis, which require the presence of abundant and long-lasting liquid water, were only met early in the history of the planet, during the Noachian period (> 3.6 Gy ago), and that aqueous environments were widespread then. Here we test this hypothesis by examining the excavation process of hydrated minerals by impact events on Mars and analyzing the stability of phyllosilicates against the impact-induced thermal shock. To do so, we first compare the infrared spectra of thermally altered phyllosilicates with those of hydrated minerals known to occur in craters on Mars and then analyze the postshock temperatures reached during impact crater excavation. Our results show that phyllosilicates can resist the postshock temperatures almost everywhere in the crater, except under particular conditions in a central area in and near the point of impact. We conclude that most phyllosilicates detected inside impact craters on Mars are consistent with excavated preexisting sediments, supporting the hypothesis of a primeval and long-lasting global aqueous environment. When our analyses are applied to specific impact craters on Mars, we are able to identify both pre- and postimpact phyllosilicates, therefore extending the time of local phyllosilicate synthesis to post-Noachian times.

  17. Geological mapping of lunar highland crater Lalande: Topographic configuration, morphology and cratering process

    Science.gov (United States)

    Li, Bo; Ling, Zongcheng; Zhang, Jiang; Chen, Jian; Liu, ChangQing; Bi, Xiangyu

    2018-02-01

    Highland crater Lalande (4.45°S, 8.63°W; D = 23.4 km) is located on the PKT area of the lunar near side, southeast of the Mare Insularum. It is a complex crater in Copernican era and has three distinguishing features: high silicic anomaly, the highest Th abundance and special landforms on its floor. There are some low-relief bulges on the left of Lalande's floor with regular circle or ellipse shapes. They are ∼250-680 m wide and ∼30-91 m high with maximum flank slopes >20°. There are two possible scenarios for the formation of these low-relief bulges which are impact melt products or young silicic volcanic eruptions. We estimated the absolute model ages of the ejecta deposits, several melt ponds and the hummocky floor and determined the ratio of diameter and depth of the crater Lalande. In addition, we found some similar bugle features within other Copernican-aged craters and there were no volcanic source vents on Lalande's floor. Thus, we hypothesized that these low-relief bulges were most consistent with an origin of impact melts during the crater formation instead of small and young volcanic activities occurring on the floor. Based on Kaguya Terrain Camera (TC) ortho-mosaic and Digital Terrain Model (DTM) data produced by TC imagery in stereo, geological units and some linear features on the floor and wall of Lalande have been mapped. Eight geological units are organized by crater floor units: hummocky floor, central peak and low-relief bulges; and crater wall units: terraced walls, channeled and veneered walls, interior walls, mass wasting areas, blocky areas, and melt ponds. These geological units and linear features provided us a chance to understand some details of the cratering process and elevation differences on the floor. We proposed that subsidence due to melt cooling, late-stage wall collapse and rocks uplifted from beneath the surface could be the possible causes of the observed elevation differences on Lalande's floor.

  18. Polygons and Craters

    Science.gov (United States)

    2005-01-01

    3 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows polygons enhanced by subliming seasonal frost in the martian south polar region. Polygons similar to these occur in frozen ground at high latitudes on Earth, suggesting that perhaps their presence on Mars is also a sign that there is or once was ice in the shallow subsurface. The circular features are degraded meteor impact craters. Location near: 72.2oS, 310.3oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  19. Gully formation in terrestrial simple craters: Meteor Crater, USA and Lonar Crater, India

    Science.gov (United States)

    Kumar, P.; Head, J. W.; Kring, D. A.

    2007-12-01

    Geomorphic features such as gullies, valley networks, and channels on Mars have been used as a proxy to understand the climate and landscape evolution of Mars. Terrestrial analogues provide significant insight as to how the various exogenic and endogenic processes might contribute to the evolution of these martian landscapes. We describe here a terrestrial example from Meteor Crater, which shows a spectacular development of gullies throughout the inner wall in response to rainwater precipitation, snow melting and groundwater discharge. As liquid water has been envisaged as one of the important agents of landscape sculpturing, Meteor Crater remains a useful landmark, where planetary geologists can learn some lessons. We also show here how the lithology and structural framework of this crater controls the gully distribution. Like many martian impact craters, it was emplaced in layered sedimentary rocks with an exceptionally well-developed centripetal drainage pattern consisting of individual alcoves, channels and fans. Some of the gullies originate from the rim crest and others from the middle crater wall, where a lithologic transition occurs. Deeply incised alcoves are well-developed on the soft sandstones of the Coconino Formation exposed on the middle crater wall, beneath overlying dolomite. In general, the gully locations are along crater wall radial fractures and faults, which are favorable locales of groundwater flow and discharge; these structural discontinuities are also the locales where the surface runoff from rain precipitation and snow melting can preferentially flow, causing degradation. Like martian craters, channels are well developed on the talus deposits and alluvial fans on the periphery of the crater floor. In addition, lake sediments on the crater floor provide significant evidence of a past pluvial climate, when groundwater seeped from springs on the crater wall. Caves exposed on the lower crater level may point to percolation of surface runoff

  20. Entrepreneurship training in Ghana

    DEFF Research Database (Denmark)

    Schmidt, Leila Kæmsgaard Pagh

    2017-01-01

    Abstract Due to the very high youth unemployment in Northern Ghana, there is a huge need for enterprising skills among young people. A natural focus in recent years has therefore been entrepreneurship training, focusing on training young Ghanaians to start-up businesses. Unfortunately, the young...... is that adding a focus on the young entrepreneur’s means, attitude and enterprising behaviour skills to the existing focus on starting up businesses, will increase the value of the Entrepreneurship training and support the overcoming of constraints. The paper build on a design-based research project...... in collaboration with the local NGO YEfL. Based on relevant theory, a qualitative field research in Northern Ghana and a quantitative baseline survey a new Entrepreneurship Model has been designed. The new model was tested in autumn 2016 at three Entrepreneurship boot camps in Northern Ghana. The study has...

  1. Aqueous alteration detection in Tikhonravov crater, Mars

    Science.gov (United States)

    Mancarella, F.; Fonti, S.; Alemanno, G.; Orofino, V.; Blanco, A.

    2018-03-01

    The existence of a wet period lasting long enough to allow the development of elementary forms of life on Mars has always been a very interesting issue. Given this perspective, the research for geological markers of such occurrences has been continually pursued. Once a favorable site is detected, effort should be spent to get as much information as possible aimed at a precise assessment of the genesis and evolution of the areas showing the selected markers. In this work, we discuss the recent finding of possible deposits pointing to the past existence of liquid water in Tikhonravov crater located in Arabia Terra. Comparison of CRISM spectra and those of laboratory minerals formed by aqueous alteration has led us to the conclusion that the studied areas within the impact crater host phyllosilicates deposits. In addition, analysis of the CRISM spectra has resulted in the tentative identification of carbonates mixed with phyllosilicates.

  2. Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 4: Flow Ejecta Crater Distribution

    Science.gov (United States)

    Parker, T. J.; Pieri, D. C.

    1985-01-01

    Flow ejecta craters - craters surrounded by lobate ejecta blankets - are found throughout the study area. The ratio of the crater's diameter to that of the flow ejecta in this region is approximately 40 to 45%. Flow ejecta craters are dominantly sharply defined craters, with slightly degraded craters being somewhat less common. This is probably indicative of the ejecta's relatively low resistence to weathering and susceptibility to burial. Flow ejecta craters here seem to occur within a narrow range of crater sizes - the smallest being about 4km in diameter and the largest being about 27km in diameter. Ejecta blankets of craters at 4km are easily seen and those of smaller craters are simply not seen even in images with better than average resolution for the region. This may be due to the depth of excavation of small impacting bodies being insufficient to reach volatile-rich material. Flow ejecta craters above 24km are rare, and those craters above 27km do not display flow ejecta blankets. This may be a result of an excavation depth so great that the volatile content of the ejecta is insufficient to form a fluid ejecta blanket. The geomorphic/geologic unit appears also to play an important role in the formation of flow ejecta craters. Given the typical size range for the occurrence of flow ejecta craters for most units, it can be seen that the percentage of flow ejecta craters to the total number of craters within this size range varies significantly from one unit to the next. The wide variance in flow ejecta crater density over this relatively small geographical area argues strongly for a lithologic control of their distribution.

  3. Corrective Action Decision Document/Closure Report for Corrective Action Unit 374: Area 20 Schooner Unit Crater, Nevada National Security Site, Nevada with ROTC 1 and 2, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick

    2011-07-01

    Corrective Action Unit 374 comprises five corrective action sites (CASs): • 18-22-05, Drum • 18-22-06, Drums (20) • 18-22-08, Drum • 18-23-01, Danny Boy Contamination Area • 20-45-03, U-20u Crater (Schooner) The purpose of this Corrective Action Decision Document/Closure Report is to provide justification and documentation supporting the recommendation that no further corrective action is needed for CAU 374 based on the implementation of corrective actions. The corrective action of closure in place with administrative controls was implemented at CASs 18-23-01 and 20-45-03, and a corrective action of removing potential source material (PSM) was conducted at CAS 20-45-03. The other CASs require no further action; however, best management practices of removing PSM and drums at CAS 18-22-06, and removing drums at CAS 18-22-08 were performed. Corrective action investigation (CAI) activities were performed from May 4 through October 6, 2010, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 374: Area 20 Schooner Unit Crater, Nevada Test Site, Nevada. The approach for the CAI was divided into two facets: investigating the primary release of radionuclides and investigating other releases (migration in washes and chemical releases). The purpose of the CAI was to fulfill data needs as defined during the data quality objective (DQO) process. The CAU 374 dataset of investigation results was evaluated based on the data quality indicator parameters. This evaluation demonstrated the dataset is acceptable for use in fulfilling the DQO data needs. Analytes detected during the CAI were evaluated against final action levels (FALs) established in this document. Radiological doses exceeding the FAL of 25 millirem per year were found to be present in the surface soil that was sampled. It is assumed that radionuclide levels present in subsurface media within the craters and ejecta fields (default contamination boundaries) at the Danny Boy and

  4. Characterization of malaria transmission by vector populations for improved interventions during the dry season in the Kpone-on-Sea area of coastal Ghana

    Directory of Open Access Journals (Sweden)

    Tchouassi David P

    2012-09-01

    Full Text Available Abstract Background Malaria is a major public health problem in Ghana. We present a site-specific entomological study of malaria vectors and transmission indices as part of an effort to develop a site for the testing of improved control strategies including possible vaccine trials. Methods Pyrethrum spray catches (PSC, and indoor and outdoor human landing collections of adult female anopheline mosquitoes were carried out over a six-month period (November 2005 - April 2006 at Kpone-on-Sea, a fishing village in southern Ghana. These were morphologically identified to species level and sibling species of the Anopheles gambiae complex further characterized by the polymerase chain reaction (PCR. Enzyme-linked immunosorbent assay was used to detect Plasmodium falciparum mosquito infectivity and host blood meal sources. Parity rate was examined based on dilatation of ovarian tracheoles following dissection. Results Of the 1233 Anopheles mosquitoes collected, An. gambiae s.l. was predominant (99.5%, followed by An. funestus (0.4% and An. pharoensis (0.1%. All An. gambiae s.l. examined (480 were identified as An. gambiae s.s. with a majority of M molecular form (98.2% and only 1.8% S form with no record of M/S hybrid. A significantly higher proportion of anophelines were observed outdoors relative to indoors (χ2 = 159.34, df = 1, p An. gambiae M molecular form contributed to transmission with a high degree of anthropophily, parity rate and an estimated entomological inoculation rate (EIR of 62.1 infective bites/person/year. The Majority of the infective bites occurred outdoors after 09.00 pm reaching peaks between 12.00-01.00 am and 03.00-04.00 am. Conclusion Anopheles gambiae M molecular form is responsible for maintaining the status quo of malaria in the surveyed site during the study period. The findings provide a baseline for evidence-based planning and implementation of improved malaria interventions. The plasticity observed in

  5. Ghana - Land Tenure Facilitation Impact Evaluation

    Data.gov (United States)

    Millennium Challenge Corporation — The MCC-supported Land Title Facilitation Activity (LTF) in Ghana was designed to increase investment and productivity by strengthening property rights. In Ghana,...

  6. Ghana Journal of Geography

    African Journals Online (AJOL)

    Effects of Spatial Location and Household Wealth on the Utilisation of Skilled Birth Attendants at Delivery Among Women in Rural Ghana · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Hubert Amu, Dickson Kwamena Sekyi, 58-77 ...

  7. Ghana's high forests

    NARCIS (Netherlands)

    Oduro, K.A.

    2016-01-01

    Deforestation and forest degradation in the tropics have been receiving both scientific and political attention in recent decades due to its impacts on the environment and on human livelihoods. In Ghana, the continuous decline of forest resources and the high demand for timber have raised

  8. POST CLOSURE INSPECTION AND MONITORING REPORT FOR CORRECTIVE ACTION UNIT 110: AREA 3 WMD U-3AX/BL CRATER, NEVADA TEST SITE, NEVADA FOR THE PERIOD JULY 2004 - JUNE 2005

    Energy Technology Data Exchange (ETDEWEB)

    BECHTEL NEVADA

    2005-08-01

    This Post-Closure Inspection and Monitoring report provides the results of inspections and monitoring for Corrective Action Unit (CAU) 110, Area 3 Waste Management Division (WMD) U-3ax/bl Crater. This report includes an analysis and summary of the site inspections, repairs and maintenance, meteorological information, and soil moisture monitoring data obtained at CAU 110, for the annual period July 2004 through June 2005. Site inspections of the cover were performed quarterly to identify any significant changes to the site requiring action. The overall condition of the cover, cover vegetation, perimeter fence, and use restriction warning signs was good. Settling was observed that exceeded the action level as specified in Section VII.B.7 of the Hazardous Waste Permit Number NEV HW009 (Nevada Division of Environmental Protection, 2000). This permit states that cracks or settling greater than 15 centimeters (cm) (6 inches [in]) deep that extend 1.0 meter (m) (3 feet [ft]) or more on the cover will be evaluated and repaired within 60 days of detection.

  9. Assessing the Effectiveness of Limestone from Oterkpolu Area in the Eastern region of Ghana as a Suitable Adsorbent for Water Defluoridation

    International Nuclear Information System (INIS)

    Droepenu, Eric Kwabena

    2016-07-01

    Fluoride-contamination of groundwater [above the World Health Organization (WHO) recommended limit of 1.5 mg/L] in the Upper East and Northern regions of Ghana is a well-known problem. Fluoride is, however, beneficial to humans if present in drinking water at levels between 0.7 – 1.5 mg/L. Although, there are some efficient methods for defluoridation of drinking water using various adsorbents, the magnitude of the problem has made it imperative to develop economically viable water defluoridation techniques using readily available natural resource as adsorbent. This will complement the existing defluoridation techniques in order to alleviate the difficulty faced by inhabitants of the affected communities. In addition, a method which is cost effective, easy to use by a layman, does not add other contaminants to water, and efficient in the long term is highly desirable. In this study, the effectiveness of readily available limestone from Oterkpolu (Yilo-Krobo district, Eastern region of Ghana) as fluoride adsorbent was assessed. A drinking water defluoridation technique was subsequently developed using the limestone with various grain sizes (i.e., 500 – 1000 μm, 1000 – 2000 μm and 2000 – 6350 μm) through Batch Adsorption Experiment (using NaF solution concentrations of 1, 5 and 10 mgF"-/L), followed by Column Adsorption Experiment using fluoride contaminated groundwater water samples from Bongo district. This was achieved through the geochemical and mineralogical characterization of Oterkpolu limestone using X-ray Powder Diffraction (XRD) and Petrographic Thin Section (PTS). In addition, the radiological risk associated with the use of the limestone for water defluoridation was assessed through the determination of the activity concentration of the Naturally-Occurring Radioactive Materials (NORMs) using a High-Purity Germanium (HPGe) γ-ray detector [γ-ray spectrometry], and computed Annual Effective Dose (AED). The study also evaluated the fluoride

  10. Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks

    Science.gov (United States)

    Bortey-Sam, Nesta; Nakayama, Shouta M. M.; Akoto, Osei; Ikenaka, Yoshinori; Fobil, Julius N.; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

    2015-01-01

    This study was carried out to assess the extent of heavy metals and metalloid accumulation from agricultural soils to foodstuffs (viz, M. esculenta (cassava) and Musa paradisiaca (plantain)) around thirteen neighboring communities within Tarkwa, Ghana; and to estimate the human health risk associated with consumption of these foodstuffs. Concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, and Zn were measured with an inductively coupled plasma–mass spectrometer and mercury analysis was done using a mercury analyzer. From the results, 30% of cassava samples collected, contained higher concentrations of Pb when compared to Codex Alimentarius Commission standard values. Bioconcentration factor indicated that Ni had higher capacity of absorption into food crops from soil than the other heavy metals. For both children and adults, the target hazard quotient (THQ) of Pb in cassava in communities such as Techiman, Wangarakrom, Samahu, and Tebe (only children) were greater than 1, which is defined as an acceptable risk value. This indicated that residents could be exposed to significant health risks associated with cassava consumption. PMID:26225988

  11. Mobile phone-based interactive voice response as a tool for improving access to healthcare in remote areas in Ghana - an evaluation of user experiences.

    Science.gov (United States)

    Brinkel, J; May, J; Krumkamp, R; Lamshöft, M; Kreuels, B; Owusu-Dabo, E; Mohammed, A; Bonacic Marinovic, A; Dako-Gyeke, P; Krämer, A; Fobil, J N

    2017-05-01

    To investigate and determine the factors that enhanced or constituted barriers to the acceptance of an mHealth system which was piloted in Asante-Akim North District of Ghana to support healthcare of children. Four semi-structured focus group discussions were conducted with a total of 37 mothers. Participants were selected from a study population of mothers who subscribed to a pilot mHealth system which used an interactive voice response (IVR) for its operations. Data were evaluated using qualitative content analysis methods. In addition, a short quantitative questionnaire assessed system's usability (SUS). Results revealed 10 categories of factors that facilitated user acceptance of the IVR system including quality-of-care experience, health education and empowerment of women. The eight categories of factors identified as barriers to user acceptance included the lack of human interaction, lack of update and training on the electronic advices provided and lack of social integration of the system into the community. The usability (SUS median: 79.3; range: 65-97.5) of the system was rated acceptable. The principles of the tested mHealth system could be of interest during infectious disease outbreaks, such as Ebola or Lassa fever, when there might be a special need for disease-specific health information within populations. © 2017 John Wiley & Sons Ltd.

  12. Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks

    Directory of Open Access Journals (Sweden)

    Nesta Bortey-Sam

    2015-07-01

    Full Text Available This study was carried out to assess the extent of heavy metals and metalloid accumulation from agricultural soils to foodstuffs (viz, M. esculenta (cassava and Musa paradisiaca (plantain around thirteen neighboring communities within Tarkwa, Ghana; and to estimate the human health risk associated with consumption of these foodstuffs. Concentrations of As, Cd, Co, Cr, Cu, Ni, Pb, and Zn were measured with an inductively coupled plasma–mass spectrometer and mercury analysis was done using a mercury analyzer. From the results, 30% of cassava samples collected, contained higher concentrations of Pb when compared to Codex Alimentarius Commission standard values. Bioconcentration factor indicated that Ni had higher capacity of absorption into food crops from soil than the other heavy metals. For both children and adults, the target hazard quotient (THQ of Pb in cassava in communities such as Techiman, Wangarakrom, Samahu, and Tebe (only children were greater than 1, which is defined as an acceptable risk value. This indicated that residents could be exposed to significant health risks associated with cassava consumption.

  13. Morphometry and Morphology of Fresh Craters on Titan

    Science.gov (United States)

    Kirk, R. L.; Wood, C. A.; Neish, C.; Lucas, A.; Hayes, A. G.; Cassini Radar Team

    2011-12-01

    Cassini RADAR imagery obtained on Titan flyby T77 revealed a 40-km diameter fresh impact crater at 11.6° N 44.6° W. This is only the 8th crater identified with high confidence (Wood et al., 2010, Icarus 206, 334), and the 3rd (after Sinlap D=79 km and Ksa D=30 km) for which the depth can be estimated by comparing the foreshortening of the near and far walls. This "autostereo" technique yields an estimated depth of 680 m. The T77 image forms a stereo pair with the T17 discovery image of Ksa from which we estimate the depth of Ksa at 750-800 m, in close agreement with SARTopo data. The depth of Sinlap is 760 m based on SARTopo. Depth-diameter ratios for these craters thus range from 0.01 to 0.025 and the depths are comparable to but 200-400 m shallower than fresh craters of the same size on Ganymede (Bray et al., 2008, Met. Planet Sci. 43, 1979). The depth differences could be explained by initial crater morphometry, by relaxation in a different thermal environment, or (perhaps most plausibly given the bland floors of even the freshest Titan craters) to sedimentary infill. In contrast, the 18x36 km elliptical depression at Sotra Facula is much deeper than Ganymede craters of similar size (d=1500 m from stereo), supporting the conclusion that it is not an impact crater. All three craters exhibit a relatively radar-bright annulus around the outer edge of the floor, possibly as the result of mass wasting of blocky materials from the crater walls. The central part of each crater is darker. The central darker floor of the new crater is symmetrical and featureless, whereas Ksa has a bright central ring 7 km in diameter. Stereo spot heights indicate the ring is 350±100 m above the outer floor. This height is in close agreement with the scaling for Ganymede crater central peaks from Bray et al. (2008). The darker floor area of Sinlap is substantially asymmetrical with a small bright central spot whose elevation is unknown. The new crater has continuous, radar

  14. The Stratigraphy and Lithofacies of the Paleoproterozoic Volcaniclastic Sequences in the Cape Three Points Area- Akodda section of the Southern in Ashanti Belt in the Birimian of southwest Ghana

    Science.gov (United States)

    Yoshimaru, S.; Kiyokawa, S.; Ito, T.; Ikehara, M.; Nyame, F. K.; Tetteh, G. M.

    2015-12-01

    The Paleoproterozoic Era is thought to have experienced one of the most significant changes in earth's environment during earth history. Early continents started to diverge and collide accompanied by first major oxidation of the atmosphere-oceanic system known as the Great Oxidation Environment (GOE). Due to their well-preserved oceanic sedimentary sequences, Paleoproterozoic belts are usually good targets for studies on the history of earth's past environment. In addition, these belts provide great help to understand the nature of the Paleoproterozoic deeper oceanic environments. Birimian greenstone belt in southwestern Ghana is likely to have made up of subduction of oceanic basin to form a volcanic island arc. Birimian rocks are separated by nonconformity from the Tarkwaian Group which is a younger paleoplacer deposit (Perrouty et al., 2012). The Birimian is made up of island-arc volcanic rocks; foreland basin made up of shale, sandstone, quartzite and turbidities derived from 2.17 Ga granite intrusions during Birimian volcanism. In this study, we focused on the coastal area around Cape Three Points at the southernmost part of the Ashanti (Axim-Konongo) belt in Ghana. In the eastern part of the area, excellently preserved Paleoprotorozoic deeper oceanic sedimentary sequences extensively outcrop for over 4km stretch. This volcano-sedimentary sequence has been affected by greenschist facies metamorphism. Structurally, this region preserves S1 cleavage and asymmetrical synform with west vergence and S0 younging to the east. Provisional stratigraphy is very continuous up to more than 2000m thick and, in addition, suggests at least four different fining upward sequences in the area to the east and west of Atwepo, west of Kwetakora and Akodda. These sub-sequences are mainly composed of volcaniclasitc, sandstone, black shale and rare volcanics such as pillow basalt or massive volcanic lava. In other words, this continuous sequence suggests distal submarine

  15. MINING RELATED ARSENIC PROBLEMS IN GHANA

    OpenAIRE

    Kofi Bempah, Crentsil

    2015-01-01

    Ghana is Africa's second-largest gold producing country after South Africa. Most mining areas particularly in Ashanti Region (Obuasi) and Western Region (Tarkwa), until the introduction of the bio-oxidation (BIOX) technology of extracting gold, the processing of the ore for gold involved the crushing and grinding of ore to fine powder followed by dissolution and precipitation of free gold. During the ore preparation by roasting, sulphur dioxide and As trioxide were released into terrestrial a...

  16. Heavy Cratering near Callisto's South Pole

    Science.gov (United States)

    1997-01-01

    Images from NASA's Galileo spacecraft provide new insights into this region near Callisto's south pole. This two frame mosaic shows a heavily cratered surface with smooth plains in the areas between craters. North is to the top of the image. The smoothness of the plains appears to increase toward the south pole, approximately 480 kilometers (293 miles) south of the bottom of the image. This smoothness of Callisto's surface was not evident in images taken during the 1979 flyby of NASA's Voyager spacecraft because the resolution was insufficient to show the effect. This smooth surface, and the process(es) that cause it, are among the most intriguing aspects of Callisto. Although not fully understood, the process(es) responsible for this smoothing could include erosion by tiny meteorites and energetic ions. Some craters, such as Keelut, the 47 kilometer (29 mile) crater in the lower right corner, have sharp, well defined rims. Keelut contains an inner ring surrounding a central depression about 17 kilometers (11 miles) in diameter. Keelut, and the more irregularly shaped, degraded Reginleif, the 32 kilometer (19.5 mile) crater in the top center of the image, are very shallow and have flat floors. Crater forms can be seen down to less than 2 kilometers (1.2 miles) in diameter in the image. Each picture element (pixel) in this image is approximately 0.68 kilometers (0.41 miles) across.This image which was taken by the Galileo spacecraft's solid state imaging (CCD) system during its eighth orbit around Jupiter, on May 6th, 1997. The center of the image is located at 71.3 degrees south latitude, 97.6 degrees west longitude, and was taken when the spacecraft was approximately 35,470 kilometers (21,637 miles) from Callisto.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http

  17. Seroprevalence of Antibodies against Plasmodium falciparum Sporozoite Antigens as Predictive Disease Transmission Markers in an Area of Ghana with Seasonal Malaria Transmission.

    Directory of Open Access Journals (Sweden)

    Kwadwo A Kusi

    Full Text Available As an increasing number of malaria-endemic countries approach the disease elimination phase, sustenance of control efforts and effective monitoring are necessary to ensure success. Mathematical models that estimate anti-parasite antibody seroconversion rates are gaining relevance as more sensitive transmission intensity estimation tools. Models however estimate yearly seroconversion and seroreversion rates and usually predict long term changes in transmission, occurring years before the time of sampling. Another challenge is the identification of appropriate antigen targets since specific antibody levels must directly reflect changes in transmission patterns. We therefore investigated the potential of antibodies to sporozoite and blood stage antigens for detecting short term differences in malaria transmission in two communities in Northern Ghana with marked, seasonal transmission.Cross-sectional surveys were conducted during the rainy and dry seasons in two communities, one in close proximity to an irrigation dam and the other at least 20 Km away from the dam. Antibodies against the sporozoite-specific antigens circumsporozoite protein (CSP and Cell traversal for ookinetes and sporozoites (CelTOS and the classical blood stage antigen apical membrane antigen 1 (AMA1 were measured by indirect ELISA. Antibody levels and seroprevalence were compared between surveys and between study communities. Antibody seroprevalence data were fitted to a modified reversible catalytic model to estimate the seroconversion and seroreversion rates.Changes in sporozoite-specific antibody levels and seroprevalence directly reflected differences in parasite prevalence between the rainy and dry seasons and hence the extent of malaria transmission. Seroconversion rate estimates from modelled seroprevalence data did not however support the above observation.The data confirms the potential utility of sporozoite-specific antigens as useful markers for monitoring short term

  18. Ejecta from single-charge cratering explosions

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, R H

    1970-05-15

    The objective was to obtain experimental data tracing the location of ejecta to its origin within the crater region. The experiment included ten high-explosive spherical charges weighing from 8 to 1000 pounds and detonated in a playa dry lake soil on the Tonopah Test Range. Each event included from 24 to 40 locations of distinctly different tracer material embedded in a plane in the expected crater region. Tracers consisted of glass, ceramic and bugle beads, chopped metal, and plastic wire. Results of this experiment yielded data on tracer dispersion as a function of charge weight, charge burial depth and tracer emplacement position. Tracer pattern parameters such as center-of-tracer mass, range to center-of-tracer mass, and angle to center-of-tracer mass were determined. There is a clear tendency for range (to center-of-tracer mass) and the size of the dispersion pattern to decrease as tracer emplacement depth increases. Increasing tracer emplacement depth and range tends to decrease the area over which tracers are dispersed on the ground surface. Tracers at the same scaled position relative to the charge were deposited closer to the crater (on a scaled basis) as charge weight was increased. (author)

  19. Oblique view of crater Theophilus at northwest edge of Sea of Nectar

    Science.gov (United States)

    1969-01-01

    An Apollo 11 oblique view of the large crater Theophilus located at the northwest edge of the Sea of Nectar on the lunar nearside. Theophilus is about 60 statute miles in diameter. the smooth area is Mare Nectaris. The smaller crater Madler, about 14 statute miles in diameter, is located to the east of Theophilus. Visible in the background are the large crater Fracastorius and the smaller crater Beaumont. The coordinates of the center of this photograph are 29 degrees east longitude and 11 degrees south latitude.

  20. Bioenergy from agricultural residues in Ghana

    DEFF Research Database (Denmark)

    Thomsen, Sune Tjalfe

    and biomethane under Ghanaian conditions. Detailed characterisations of thirteen of the most common agricultural residues in Ghana are presented, enabling estimations of theoretical bioenergy potentials and identifying specific residues for future biorefinery applications. When aiming at residue-based ethanol...... to pursue increased implementation of anaerobic digestion in Ghana, as the first bioenergy option, since anaerobic digestion is more flexible than ethanol production with regard to both feedstock and scale of production. If possible, the available manure and municipal liquid waste should be utilised first....... A novel model for estimating BMP from compositional data of lignocellulosic biomasses is derived. The model is based on a statistical method not previously used in this area of research and the best prediction of BMP is: BMP = 347 xC+H+R – 438 xL + 63 DA , where xC+H+R is the combined content of cellulose...

  1. Ghana's Integrated Nuclear Security Support Plan

    International Nuclear Information System (INIS)

    Dahlstrom, Danielle

    2013-01-01

    recently reviewed to identify additional areas for improvement. Based on IAEA nuclear security guidance, it is designed to identify those actions required to ensure that Ghana's national nuclear security regime is effective and can be implemented over a period of time to ensure sustainability. The main objectives of an INSSP are to identify and consolidate the nuclear security needs of an individual State into an integrated document. But it is more than a document; it is nuclear security in action. Joseph Gdadago, Manager of the National Nuclear Research Institute at the Ghana Atomic Energy Commission (GAEC), explains, ''Nuclear security is very important. This reactor uses highly enriched uranium. We put all necessary security measures in place to protect this and prevent any sabotage or theft of any kind.''

  2. Ghana Mining Journal: Editorial Policies

    African Journals Online (AJOL)

    Focus and Scope. The Ghana Mining Journal (GMJ) is a publication which focuses on the exchange of ideas, dissemination of information and promotion of knowledge arising out of research pertinent to the effective and sustainable exploitation of mineral resources in Ghana and elsewhere. Original contributions in the ...

  3. Ghana Journal of Development Studies

    African Journals Online (AJOL)

    Ghana Journal of Development Studies (GJDS) is a multi-, trans- and an ... The Political Economy of Decentralisation and the Challenge of Improved Service Delivery ... Tax Collection in Northern Ghana during British Colonail Rule (1898 – 1950) ... District of South Africa · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  4. 100 New Impact Crater Sites Found on Mars

    Science.gov (United States)

    Kennedy, M. R.; Malin, M. C.

    2009-12-01

    Recent observations constrain the formation of 100 new impact sites on Mars over the past decade; 19 of these were found using the Mars Global Surveyor Mars Orbiter Camera (MOC), and the other 81 have been identified since 2006 using the Mars Reconnaissance Orbiter Context Camera (CTX). Every 6 meter/pixel CTX image is examined upon receipt and, where they overlap images of 0.3-240 m/pixel scale acquired by the same or other Mars-orbiting spacecraft, we look for features that may have changed. New impact sites are initially identified by the presence of a new dark spot or cluster of dark spots in a CTX image. Such spots may be new impact craters, or result from the effect of impact blasts on the dusty surface. In some (generally rare) cases, the crater is sufficiently large to be resolved in the CTX image. In most cases, however, the crater(s) cannot be seen. These are tentatively designated as “candidate” new impact sites, and the CTX team then creates an opportunity for the MRO spacecraft to point its cameras off-nadir and requests that the High Resolution Imaging Science Experiment (HiRISE) team obtain an image of ~0.3 m/pixel to confirm whether a crater or crater cluster is present. It is clear even from cursory examination that the CTX observations are areographically biased to dusty, higher albedo areas on Mars. All but 3 of the 100 new impact sites occur on surfaces with Lambert albedo values in excess of 23.5%. Our initial study of MOC images greatly benefited from the initial global observations made in one month in 1999, creating a baseline date from which we could start counting new craters. The global coverage by MRO Mars Color Imager is more than a factor of 4 poorer in resolution than the MOC Wide Angle camera and does not offer the opportunity for global analysis. Instead, we must rely on partial global coverage and global coverage that has taken years to accumulate; thus we can only treat impact rates statistically. We subdivide the total data

  5. Enhancing Magnetic Interpretation Towards Meteorite Impact Crater at Bukit Bunuh, Perak, Malaysia

    Science.gov (United States)

    Nur Amalina, M. K. A.; Nordiana, M. M.; Saad, Rosli; Saidin, Mokhtar

    2017-04-01

    Bukit Bunuh is the most popular area of suspected meteorite impact crater. In the history of meteorite impact hitting the earth, Bukit Bunuh has complex crater of a rebound zone of positive magnetic anomaly value. This study area was located at Lenggong, Perak of peninsular Malaysia. The crater rim extended 5 km outwards with a clear subdued zone and immediately surround by a positive magnetic residual crater rim zone. A recent study was done to enhance the magnetic interpretation towards meteorite impact crater on this study area. The result obtained is being correlated with boreholes data to determine the range of local magnetic value. For the magnetic survey, the equipment used is Geometric G-856 Proton Precision magnetometers with the aids of other tools such as compass and GPS. In advance, the using of proton precision magnetometer causes it able in measures the magnetic fields separately within interval of second. Also, 18 boreholes are accumulated at study area to enhance the interpretation. The additional boreholes data had successfully described the structure of the impact crater at Bukit Bunuh in detailed where it is an eroded impact crater. Correlations with borehole records enlighten the results acquired from magnetic methods to be more reliable. A better insight of magnetic interpretation of Bukit Bunuh impact crater was done with the aid of geotechnical methods.

  6. Hydrokinetic power for energy access in rural Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Veronica B.; Schaefer, Laura A. [Energy Systems Laboratory, Department of Mechanical Engineering and Materials Science, Mascaro Center for Sustainable Innovation, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA (United States); Ramde, Emmanuel W. [Department of Mechanical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi (Ghana); Gradoville, Robert T. Jr. [Sustainability and Green Design, Department of Civil and Environmental Engineering, Mascaro Center for Sustainable Innovation, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA (United States)

    2011-02-15

    Approximately half of Ghana's overall population has access to electricity and, of this, much of it is in urban areas. Often in regions where modern energy is not available, kerosene lamps, for example, are used for indoor lighting. This produces harmful emissions, leading to poor respiratory effects. Implementation of hydrokinetic power (HKP) within nearby streams can provide low impact, robust energy to rural communities. Such a system lends itself to a simple design with ease of maintenance, which can be used as a stand alone power system (SAPS). With Ghana's renewable energy policies coming to fruition, it is sought to establish the economic viability and sustainability of this technology. This paper discusses site selection and the HKP technology in rural areas of Ghana. (author)

  7. Cratering Studies in Thin Plastic Films

    Science.gov (United States)

    Shu, A. J.; Bugiel, S.; Gruen, E.; Hillier, J.; Horanyi, M.; Munsat, T. L.; Srama, R.

    2013-12-01

    Thin plastic films, such as Polyvinylidene Fluoride (PVDF), have been used as protective coatings or dust detectors on a number of missions including the Dust Counter and Mass Analyzer (DUCMA) instrument on Vega 1 and 2, the High Rate Detector (HRD) on the Cassini Mission, and the Student Dust Counter (SDC) on New Horizons. These types of detectors can be used on the lunar surface or in lunar orbit to detect dust grain size distributions and velocities. Due to their low power requirements and light weight, large surface area detectors can be built for observing low dust fluxes. The SDC dust detector is made up of a permanently polarized layer of PVDF coated on both sides with a thin layer (≈ 1000 Å) of aluminum nickel. The operation principle is that a micrometeorite impact removes a portion of the metal surface layer exposing the permanently polarized PVDF underneath. This causes a local potential near the crater changing the surface charge of the metal layer. The dimensions and shape of the crater determine the strength of the potential and thus the signal generated by the PVDF. The theoretical basis for signal interpretation uses a crater diameter scaling law which was not intended for use with PVDF. In this work, a crater size scaling law has been experimentally determined, and further simulation work is being done to enhance our understanding of the mechanisms of crater formation. LS-Dyna, a smoothed particle hydrodynamics (SPH) code from the Livermore Software Technology Corp. was chosen to simulate micrometeorite impacts. SPH is known to be well suited to the large deformities found in hypervelocity impacts. It is capable of incorporating key physics phenomena, including fracture, heat transfer, melting, etc. Furthermore, unlike Eulerian methods, SPH is gridless allowing large deformities without the inclusion of unphysical erosion algorithms. Material properties are accounted for using the Grüneisen Equation of State. The results of the SPH model can

  8. East Part of Sapas Mons with Flooded Crater

    Science.gov (United States)

    1991-01-01

    This Magellan image centered near 9.6 degrees north latitude, 189.5 degrees east longitude of an area 140 kilometers (87 miles) by 110 kilometers (68 miles) covers part of the eastern flank of the volcano Sapas Mons on the western edge of Atla Regio. The bright lobate features along the southern and the western part of the image, oriented in northeast to southwest directions, are lava flows that are rough at the 12.6 centimeter wavelength of the radar. These flows range in width from 5 kilometers to 25 kilometers (3 to 16 miles) with lengths of 50 kilometers to 100 kilometers (31 to 62 miles), extending off the area shown here. Additional radar-dark (smooth) flows are also present. The radar-bright linear structures in the northwest part of the image are interpreted to be faults and fractures possibly associated with the emplacement of magma in the subsurface. Located near the center of the image is a 20 kilometer (12 mile) diameter impact crater. This crater is superimposed on a northeast/southwest trending fracture while the southern part of the crater's ejecta blanket is covered by a 6 kilometer (4 mile) wide radar-bright lava flow. These relations indicate that the crater post dates an episode of fracturing and is older than the lava flows covering its southern edge. This is one of only a few places on Venus in which an impact crater is seen to be covered by volcanic deposits.

  9. A comprehensive review of biomass resources and biofuels potential in Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Duku, Moses Hensley [School of Engineering Sciences, University of Southampton, Southampton, S017 1BJ (United Kingdom); Institute of Industrial Research, Council for Scientific and Industrial Research, P. Box LG 576, Legon (Ghana); Gu, Sai [School of Engineering Sciences, University of Southampton, Southampton, S017 1BJ (United Kingdom); Hagan, Essel Ben [Institute of Industrial Research, Council for Scientific and Industrial Research, P. Box LG 576, Legon (Ghana)

    2011-01-15

    Biomass is the major energy source in Ghana contributing about 64% of Ghana's primary energy supply. In this paper, an assessment of biomass resources and biofuels production potential in Ghana is given. The broad areas of energy crops, agricultural crop residues, forest products residues, urban wastes and animal wastes are included. Animal wastes are limited to those produced by domesticated livestock. Agricultural residues included those generated from sugarcane, maize, rice, cocoa, oil palm, coconut, sorghum and millet processing. The urban category is subdivided into municipal solid waste, food waste, sewage sludge or bio-solids and waste grease. The availability of these types of biomass, together with a brief description of possible biomass conversion routes, sustainability measures, and current research and development activities in Ghana is given. It is concluded that a large availability of biomass in Ghana gives a great potential for biofuels production from these biomass resources. (author)

  10. Stability of nuclear crater slopes in rock

    International Nuclear Information System (INIS)

    Fleming, Robert W.; Frandsen, Alton D.; LaFrenz, Robert L.

    1970-01-01

    The United States Army Engineer Nuclear Cratering Group was established in 1962 to participate with the Atomic Energy Commission in a joint research and development program to develop nuclear engineering and construction technology. A major part of this research effort has been devoted to studies of the engineering properties of craters. The program to date has included field investigations of crater properties in various media over a broad range of chemical and nuclear explosive yields, studies of man-made and natural slopes, and studies directed toward the development of analytical and empirical methods of crater stability analysis. From this background, a general understanding has been developed of the effects of a cratering explosion on the surrounding medium and of physical nature of the various crater zones which are produced. The stability of nuclear crater slopes has been a subject of prime interest in the feasibility study being conducted for an Atlantic-Pacific sea-level canal. Based on experimental evidence assembled to date, nuclear crater slopes in dry dock and dry alluvium have an initially stable configuration. There have been five nuclear craters produced to date with yields of 0.4 kt or more on which observations are based and the initial configurations of these craters have remained stable for over seven years. The medium, yield, crater dimensions, and date of event for these craters are summarized. It is interesting to note that the Sedan Crater has been subjected to strong seismic motions from nearby detonations without adverse effects

  11. Stability of nuclear crater slopes in rock

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Robert W; Frandsen, Alton D; LaFrenz, Robert L [U.S. Army Engineer Nuclear Cratering Group, Lawrence Radiation Laboratory, Livermore, CA (United States)

    1970-05-15

    The United States Army Engineer Nuclear Cratering Group was established in 1962 to participate with the Atomic Energy Commission in a joint research and development program to develop nuclear engineering and construction technology. A major part of this research effort has been devoted to studies of the engineering properties of craters. The program to date has included field investigations of crater properties in various media over a broad range of chemical and nuclear explosive yields, studies of man-made and natural slopes, and studies directed toward the development of analytical and empirical methods of crater stability analysis. From this background, a general understanding has been developed of the effects of a cratering explosion on the surrounding medium and of physical nature of the various crater zones which are produced. The stability of nuclear crater slopes has been a subject of prime interest in the feasibility study being conducted for an Atlantic-Pacific sea-level canal. Based on experimental evidence assembled to date, nuclear crater slopes in dry dock and dry alluvium have an initially stable configuration. There have been five nuclear craters produced to date with yields of 0.4 kt or more on which observations are based and the initial configurations of these craters have remained stable for over seven years. The medium, yield, crater dimensions, and date of event for these craters are summarized. It is interesting to note that the Sedan Crater has been subjected to strong seismic motions from nearby detonations without adverse effects.

  12. Ghana energy abstracts

    International Nuclear Information System (INIS)

    Entsua-Mensah, Clement

    1994-01-01

    Ghana Energy Abstracts 1994 is the first issue of an annual publication of the Energy information Centre. The aim is to combine in one publication the country' s bibliographic output on energy so as to provide a valuable source of reference for policy makers, planners,and researchers. It covers the broad spectrum of energy including; energy conservation, energy resource management, petroleum and renewable energy resources.The documents listed comprise research reports, baseline studies,conference proceedings, periodical articles dissertations and theses. Keywords and author indexes have been provided to facilitate easy reference. (C.E.M)

  13. Inadequate housing in Ghana

    Directory of Open Access Journals (Sweden)

    Franklin Obeng-Odoom

    2011-01-01

    Full Text Available Two themes are evident in housing research in Ghana. One involves the study of how to increase the number of dwellings to correct the overall housing deficit, and the other focuses on how to improve housing for slum dwellers. Between these two extremes, there is relatively little research on why the existing buildings are poorly maintained. This paper is based on a review of existing studies on inadequate housing. It synthesises the evidence on the possible reasons for this neglect, makes a case for better maintenance and analyses possible ways of reversing the problem of inadequate housing.

  14. Moon - 'Ghost' craters formed during Mare filling.

    Science.gov (United States)

    Cruikshank, D. P.; Hartmann, W. K.; Wood, C. A.

    1973-01-01

    This paper discusses formation of 'pathological' cases of crater morphology due to interaction of craters with molten lavas. Terrestrial observations of such a process are discussed. In lunar maria, a number of small impact craters (D less than 10 km) may have been covered by thin layers of fluid lavas, or formed in molten lava. Some specific lunar examples are discussed, including unusual shallow rings resembling experimental craters deformed by isostatic filling.

  15. Meteor Crater (Barringer Meteorite Crater), Arizona: Summary of Impact Conditions

    Science.gov (United States)

    Roddy, D. J.; Shoemaker, E. M.

    1995-09-01

    Meteor Crater in northern Arizona represents the most abundant type of impact feature in our Solar System, i.e., the simple bowl-shaped crater. Excellent exposures and preservation of this large crater and its ejecta blanket have made it a critical data set in both terrestrial and planetary cratering research. Recognition of the value of the crater was initiated in the early 1900's by Daniel Moreau Barringer, whose 27 years of exploration championed its impact origin [1]. In 1960, Shoemaker presented information that conclusively demonstrated that Meteor Crater was formed by hypervelocity impact [2]. This led the U.S. Geological Survey to use the crater extensively in the 1960-70's as a prime training site for the Apollo astronauts. Today, Meteor Crater continues to serve as an important research site for the international science community, as well as an educational site for over 300,000 visitors per year. Since the late 1950's, studies of this crater have presented an increasingly clearer view of this impact and its effects and have provided an improved view of impact cratering in general. To expand on this data set, we are preparing an upgraded summary on the Meteor Crater event following the format in [3], including information and interpretations on: 1) Inferred origin and age of the impacting body, 2) Inferred ablation and deceleration history in Earth's atmosphere, 3) Estimated speed, trajectory, angle of impact, and bow shock conditions, 4) Estimated coherence, density, size, and mass of impacting body, 5) Composition of impacting body (Canyon Diablo meteorite), 6) Estimated kinetic energy coupled to target rocks and atmosphere, 7) Terrain conditions at time of impact and age of impact, 8) Estimated impact dynamics, such as pressures in air, meteorite, and rocks, 9) Inferred and estimated material partitioning into vapor, melt, and fragments, 10) Crater and near-field ejecta parameters, 11) Rock unit distributions in ejecta blanket, 12) Estimated far

  16. Ghana Journal of Agricultural Science - Vol 42, No 1-2 (2009)

    African Journals Online (AJOL)

    Economics of backyard poultry production in Akure South Local Government Area of ... production in the northern Guinea Savanna agroecological zone of Ghana ... Causes of differences in seed quality among cowpea (Vigna unguiculata (L.) ...

  17. Quality of Sachet Water Produced at Tarkwa, Ghana | Ndur | Ghana ...

    African Journals Online (AJOL)

    Ghana Mining Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2015) >. Log in or Register to get access to full text downloads.

  18. Malaria among the pastoral communities of the Ngorongoro Crater ...

    African Journals Online (AJOL)

    Malaria among the pastoral communities of the Ngorongoro Crater Area, northern Tanzania. L.E.G Mboera, R.C Malima, P.E Mangesho, K.P Senkoro, V Mwingira. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  19. Post-Closure Inspection and Monitoring Report for Corrective Action Unit 110: Area 3 WMD U-3ax/bl Crater, Nevada Test Site, Nevada, For the Period July 2007-June 2008

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2008-08-01

    This Post-Closure Inspection and Monitoring Report (PCIMR) provides the results of inspections and monitoring for Corrective Action Unit (CAU) 110, Area 3 WMD [Waste Management Division] U-3ax/bl Crater. This PCIMR includes an analysis and summary of the site inspections, repairs and maintenance, meteorological information, and soil moisture monitoring data obtained at CAU 110 for the period July 2007 through June 2008. Site inspections of the cover were performed quarterly to identify any significant changes to the site requiring action. The overall condition of the cover, perimeter fence, and use restriction (UR) warning signs was good. However, settling was observed that exceeded the action level as specified in Section VII.B.7 of the Hazardous Waste Permit Number NEV HW021 (Nevada Division of Environmental Protection, 2005). This permit states that cracks or settling greater than 15 centimeters (6 inches) deep that extend 1.0 meter (m) (3 feet [ft]) or more on the cover will be evaluated and repaired within 60 days of detection. Two areas of settling and cracks were observed on the south and east edges of the cover during the September 2007 inspection that exceeded the action level and required repair. The areas were repaired in October 2007. Additional settling and cracks were observed along the east side of the cover during the December 2007 inspection that exceeded the action level, and the area was repaired in January 2008. Significant animal burrows were also observed during the March 2008 inspection, and small mammal trapping and relocation was performed in April 2008. The semiannual subsidence surveys were performed in September 2007 and March 2008. No significant subsidence was observed in the survey data. Monument 5 shows the greatest amount of subsidence (-0.02 m [-0.08 ft] compared to the baseline survey of 2000). This amount is negligible and near the resolution of the survey instruments; it does not indicate that subsidence is occurring overall on

  20. Stratigraphy of the crater Copernicus

    Science.gov (United States)

    Paquette, R.

    1984-01-01

    The stratigraphy of copernicus based on its olivine absorption bands is presented. Earth based spectral data are used to develop models that also employ cratering mechanics to devise theories for Copernican geomorphology. General geologic information, spectral information, upper and lower stratigraphic units and a chart for model comparison are included in the stratigraphic analysis.

  1. Kayayei: the women head porters of southern Ghana | Opare ...

    African Journals Online (AJOL)

    It was found that most of the woman porters hail from the savanna zones of northern Ghana and adjoining areas of Burkina Faso and Togo. They move down south to work and save money for various forms of investment. The paper attributes the push factor, poverty, to the interplay of natural phenomena and human agency.

  2. North-South Migration and Remittances in Ghana

    African Journals Online (AJOL)

    mobility and high rates of rural-urban migration and in recent times child migration .... after the migrant settles at the place of destination and his income profile starts rising .... the rural areas of Northern Ghana had little or no education. ... The poor educational infrastructure, lack of schools and teachers, high dropout rates.

  3. Biotechnology and the food industry: some potentials for Ghana | Klu ...

    African Journals Online (AJOL)

    Biotechnology has played a major role in the traditional food and agriculture industry particularly in the areas of food fermentation, biological control of pests, and conventional animal vaccine production. The need to augment food production to meet the increasing population in Ghana requires that modern techniques be ...

  4. Marketing in Southern Ghana: towards a planning typology

    NARCIS (Netherlands)

    D.M. Dunham (David)

    1974-01-01

    textabstractThere are a number of strong historical and practical grounds for a regional planner operating in Southern Ghana to study marketing structures. The recent history of the area confirms an important axiom of regional theory, namely that the organisation of marketing has a considerable

  5. Inside Back Cover | Chief | Ghana Journal of Linguistics

    African Journals Online (AJOL)

    All areas of linguistics are invited – the journal is not limited to articles on languages of or in Ghana or Africa. ALL CONTRIBUTIONS must be submitted in English (except for special issues reserved for African languages), in electronic format to the current Editor-in-Chief, via our website at https://gjl.laghana.org. Authors ...

  6. Repositioning Ghana Schools as English Language Learner Schools

    Science.gov (United States)

    Taylor, Mark

    2016-01-01

    Although English has traditionally been the only language of instruction in Ghana, most young children do not speak English at home. This paper argues that students' academic performance might be improved if their native languages were also used in school. Such an approach offers benefits in areas such as classroom participation, engagement in…

  7. Ghana Journal of Agricultural Science - Vol 38, No 2 (2005)

    African Journals Online (AJOL)

    Productivity of soils of areas climatically suitable for oil palm cultivation in Ghana ... diets containing cocoa-cake-with-shell and dried cocoa husk · EMAIL FULL TEXT .... Reduction of spread of Cape St Paul wilt disease (CSPWD) of coconut by ...

  8. Slum upgrading in developing countries: lessons from Ghana and ...

    African Journals Online (AJOL)

    The proliferation of slums in many cities of the developing countries has ... slum upgrading in Ghana and Kenya as model examples to make a case for .... improvement in housing, and still others, infrastructural development. ..... Class Summer Research Report), City and Regional Planning: International and Area Studies.

  9. Nankana West District of Ghana

    African Journals Online (AJOL)

    Agribotix GCS 077

    Local governments in Ghana play very important roles with actors in the ... Metropolitan, Municipal and District Chief Executives (MMDCEs), the .... District Budget Officer, District Finance Officer, Presiding Member, members of the Works Sub-.

  10. Rainfall erosivity map for Ghana

    International Nuclear Information System (INIS)

    Oduro Afriyie, K.

    1995-10-01

    Monthly rainfall data, spanning over a period of more than thirty years, were used to compute rainfall erosivity indices for various stations in Ghana, using the Fournier index, c, defined as p 2 /P, where p is the rainfall amount in the wettest month and P is the annual rainfall amount. Values of the rainfall erosivity indices ranged from 24.5 mm at Sunyani in the mid-portion of Ghana to 180.9 mm at Axim in the south western coastal portion. The indices were used to construct a rainfall erosivity map for the country. The map revealed that Ghana may be broadly divided into five major erosion risk zones. The middle sector of Ghana is generally in the low erosion risk zone; the northern sector is in the moderate to severe erosion risk zone, while the coastal sector is in the severe to extreme severe erosion risk zone. (author). 11 refs, 1 fig., 1 tab

  11. Assessment of PCBs and exposure risk to infants in breast milk of primiparae and multiparae mothers in an electronic waste hot spot and non-hot spot areas in Ghana.

    Science.gov (United States)

    Asamoah, Anita; Essumang, David Kofi; Muff, Jens; Kucheryavskiy, Sergey V; Søgaard, Erik Gydesen

    2018-01-15

    The aim of the study was to assess the levels of PCBs in the breast milk of some Ghanaian women at suspected hotspot and relatively non-hotspot areas and to find out if the levels of these PCBs pose any risk to the breastfed infants. A total of 128 individual human breast milk were sampled from both primiparae and multiparae mothers. The levels of PCBs in the milk samples were compared. Some of these mothers (105 individuals) work or reside in and around Agbogbloshie (hot-spot), the largest electric and electronic waste dump and recycling site in Accra, Ghana. Others (23 donor mothers) also reside in and around Kwabenya (non-hotspot) which is a mainly residential area without any industrial activities. Samples were analyzed using GC-MS/MS. The total mean levels and range of Σ 7 PCBs were 3.64ng/glipidwt and ˂LOD-29.20ng/glipidwt, respectively. Mean concentrations from Agbogbloshie (hot-spot area) and Kwabenya (non-hotspot areas) were 4.43ng/glipidwt and 0.03ng/glipidwt, respectively. PCB-28 contributed the highest of 29.5% of the total PCBs in the milk samples, and PCB-101 contributed the lowest of 1.74%. The estimated daily intake of PCBs and total PCBs concentrations in this work were found to be lower as compared to similar studies across the world. The estimated hazard quotient using Health Canada's guidelines threshold limit of 1μg/kgbw/day showed no potential health risk to babies. However, considering minimum tolerable value of 0.03μg/kgbw/day defined by the Agency for Toxic Substances and Disease Registry (ATSDR), the values of some mothers were found to be at the threshold limit. This may indicate a potential health risk to their babies. Mothers with values at the threshold levels of the minimum tolerable limits are those who work or reside in and around the Agbogbloshie e-waste site. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Testing models for the formation of the equatorial ridge on Iapetus via crater counting

    Science.gov (United States)

    Damptz, Amanda L.; Dombard, Andrew J.; Kirchoff, Michelle R.

    2018-03-01

    Iapetus's equatorial ridge, visible in global views of the moon, is unique in the Solar System. The formation of this feature is likely attributed to a key event in the evolution of Iapetus, and various models have been proposed as the source of the ridge. By surveying imagery from the Cassini and Voyager missions, this study aims to compile a database of the impact crater population on and around Iapetus's equatorial ridge, assess the relative age of the ridge from differences in cratering between on ridge and off ridge, and test the various models of ridge formation. This work presents a database that contains 7748 craters ranging from 0.83 km to 591 km in diameter. The database includes the study area in which the crater is located, the latitude and longitude of the crater, the major and minor axis lengths, and the azimuthal angle of orientation of the major axis. Analysis of crater orientation over the entire study area reveals that there is no preference for long-axis orientation, particularly in the area with the highest resolution. Comparison of the crater size-frequency distributions show that the crater distribution on the ridge appears to be depleted in craters larger than 16 km with an abruptly enhanced crater population less than 16 km in diameter up to saturation. One possible interpretation is that the ridge is a relatively younger surface with an enhanced small impactor population. Finally, the compiled results are used to examine each ridge formation hypothesis. Based on these results, a model of ridge formation via a tidally disrupted sub-satellite appears most consistent with our interpretation of a younger ridge with an enhanced small impactor population.

  13. Adopting Internet Banking in Ghana

    OpenAIRE

    G.O. Ofori-Dwumfuo; Betty A. Dankwah

    2013-01-01

    This study looks at the benefits, challenges and barriers in adopting Internet banking at a major bank in Ghana. The development of the Internet is changing the way financial services are provided in Ghana. The Internet banking facility has resulted in new ways of delivering banking services. The research is a case study based on the staffs that has worked with the bank for more than three years. In evaluating benefits, challenges and barriers to the bank in adopting Internet banking, intervi...

  14. Characteristics of small young lunar impact craters focusing on current production and degradation on the Moon

    Science.gov (United States)

    Kereszturi, Akos; Steinmann, Vilmos

    2017-11-01

    Analysing the size-frequency distribution of very small lunar craters (sized below 100 m including ones below 10 m) using LROC images, spatial density and related age estimations were calculated for mare and terra terrains. Altogether 1.55 km2 area was surveyed composed of 0.1-0.2 km2 units, counting 2784 craters. The maximal areal density was present at the 4-8 m diameter range at every analysed terrain suggesting the bombardment is areally relatively homogeneous. Analysing the similarities and differences between various areas, the mare terrains look about two times older than the terra terrains using ages ranged between 13 and 20 Ma for mare, 4-6 Ma for terra terrains. Substantial fluctuation (min: 936 craters/km2, max: 2495 craters/km2) was observed without obvious source of nearby secondaries or fresh ejecta blanket produced fresh crater. Randomness analysis and visual inspection also suggested no secondary craters or ejecta blanket from fresh impact could contribute substantially in the observed heterogeneity of the areal distribution of small craters - thus distant secondaries or even other, poorly known resurfacing processes should be considered in the future. The difference between the terra/mare ages might come only partly from the easier identification of small craters on smooth mare terrains, as the differences were observed for larger (30-60 m diameter) craters too. Difference in the target hardness could more contribute in this effect. It was possible to separate two groups of small craters based on their appearance: a rimmed thus less eroded, and a rimless thus more eroded one. As the separate usage of different morphology groups of craters for age estimation at the same area is not justifiable, this was used only for comparison. The SFD curves of these two groups showed characteristic differences: the steepness of the fresh craters' SFD curves are similar to each other and were larger than the isochrones. The eroded craters' SFD curves also resemble

  15. Lomonosov Crater, Day and Night

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 16 June 2004 This pair of images shows part of Lomonosov Crater. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude 64.9, Longitude 350.7 East (9.3 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

  16. Blocky craters: implications about the lunar megaregolith

    International Nuclear Information System (INIS)

    Thompson, T.W.; Roberts, W.J.; Hartmann, W.K.; Shorthill, R.W.; Zisk, S.H.

    1979-01-01

    Radar, infrared, and photogeologic properties of lunar craters have been studied to determine whether there is a systematic difference in blocky craters between the maria and terrae and whether this difference may be due to a deep megaregolith of pulverized material forming the terra surface, as opposed to a layer of semi-coherent basalt flows forming the mare surface. Some 1310 craters from about 4 to 100 km diameter have been catalogued as radar and/or infrared anomalies. In addition, a study of Apollo Orbital Photography confirmed that the radar and infrared anomalies are correlated with blocky rubble around the crater. Analysis of the radar and infrared data indicated systematic terra-mare differences. Fresh terra craters smaller than 12 km were less likely to be infrared and radar anomalies than comparable mare craters: but terra and mare craters larger than 12 km had similar infrared and radar signatures. Also, there are many terra craters which are radar bright but not infrared anomalies. The authors interpretation of these data is that while the maria are rock layers (basaltic flow units) where craters eject boulder fields, the terrae are covered by relatively pulverized megaregolith at least 2 km deep, where craters eject less rocky rubble. Blocky rubble, either in the form of actual rocks or partly consolidated blocks, contributes to the radar and infrared signatures of the crater. However, aging by impacts rapidly destroys these effects, possibly through burial by secondary debris or by disintegration of the blocks themselves, especially in terra regions. (Auth.)

  17. Origin of the outer layer of martian low-aspect ratio layered ejecta craters

    Science.gov (United States)

    Boyce, Joseph M.; Wilson, Lionel; Barlow, Nadine G.

    2015-01-01

    Low-aspect ratio layered ejecta (LARLE) craters are one of the most enigmatic types of martian layered ejecta craters. We propose that the extensive outer layer of these craters is produced through the same base surge mechanism as that which produced the base surge deposits generated by near-surface, buried nuclear and high-explosive detonations. However, the LARLE layers have higher aspect ratios compared with base surge deposits from explosion craters, a result of differences in thicknesses of these layers. This characteristics is probably caused by the addition of large amounts of small particles of dust and ice derived from climate-related mantles of snow, ice and dust in the areas where LARLE craters form. These deposits are likely to be quickly stabilized (order of a few days to a few years) from eolian erosion by formation of duricrust produced by diffusion of water vapor out of the deposits.

  18. Lunar Bouguer gravity anomalies - Imbrian age craters

    Science.gov (United States)

    Dvorak, J.; Phillips, R. J.

    1978-01-01

    The Bouguer gravity of mass anomalies associated with four Imbrian age craters, analyzed in the present paper, are found to differ considerably from the values of the mass anomalies associated with some young lunar craters. Of the Imbrian age craters, only Piccolomini exhibits a negative gravity anomaly (i.e., a low density region) which is characteristic of the young craters studied. The Bouguer gravity anomalies are zero for each of the remaining Imbrian age craters. Since, Piccolomini is younger, or at least less modified, than the other Imbrian age craters, it is suggested that the processes responsible for the post-impact modification of the Imbrian age craters may also be responsible for removing the negative mass anomalies initially associated with these features.

  19. Ghana Journal of Development Studies: Submissions

    African Journals Online (AJOL)

    University for Development Studies P. O. Box 520 ... A Book by a Corporate Author University for Development Studies (2003). Strategic plan (2003-2008). Tamale, Ghana: ... Accra, Ghana: National Development Planning Commission.

  20. Archives: Journal of Science and Technology (Ghana)

    African Journals Online (AJOL)

    Items 1 - 38 of 38 ... Archives: Journal of Science and Technology (Ghana). Journal Home > Archives: Journal of Science and Technology (Ghana). Log in or Register to get access to full text downloads.

  1. Crater Lake Controls on Volcano Stability: Insights From White Island, New Zealand

    Science.gov (United States)

    Hamling, Ian J.

    2017-11-01

    Many volcanoes around the world host summit crater lakes but their influence on the overall stability of the edifice remains poorly understood. Here I use satellite radar data acquired by TerraSAR-X from early 2015 to July 2017 over White Island, New Zealand, to investigate the interaction of the crater lake and deformation of the surrounding edifice. An eruption in April 2016 was preceded by a period of uplift within the crater floor and drop in the lake level. Modeling of the uplift indicates a shallow source located at ˜100 m depth in the vicinity of the crater lake, likely coinciding with the shallow hydrothermal system. In addition to the drop in the lake level, stress changes induced by the inflation suggest that the pressurization of the shallow hydrothermal system helped promote failure along the edge of the crater lake which collapsed during the eruption. After the eruption, and almost complete removal of the crater lake, large areas of the crater wall and lake edge began moving downslope at rates approaching 400 mm/yr. The coincidence between the rapid increase in the displacement rates and removal of the crater lake suggests that the lake provides a physical control on the stability of the surrounding edifice.

  2. Crater Degradation on Mercury: A Global Perspective

    Science.gov (United States)

    Kinczyk, M. J.; Byrne, P. K.; Prockter, L. M.; Susorney, H. C. M.; Chapman, C. R.; Barnouin, O. S.

    2017-12-01

    On geologic timescales, initially fresh craters are subjected to many weathering mechanisms. Whereas water and wind are, or were, effective erosive mechanisms such as on Earth and Mars, micrometeorite bombardment and modification due to subsequent impacts are the dominant processes that degrade craters and crater rays on airless bodies like the Moon and Mercury. Classifying craters based on their state of degradation can help determine the relative ages of landforms proximal to, and crosscut by, these craters. However, this method is most effective when used together with statistical analysis of crater distributions. Pre-MESSENGER degradation classification schemes lacked sufficient detail to be consistently applied to craters of various sizes and morphological types—despite evidence suggesting that the ejecta deposits of large basins persist much longer than those of smaller craters, for instance—yet broad assumptions have been made regarding the correlation of crater class to the planet's time-stratigraphic sequence. Moreover, previous efforts to categorize craters by degradation state have either been restricted to regional study sites or applied only to a subset of crater age or size. As a result, numerous interpretations of crater degradation state persist for Mercury, challenging a complete understanding of this process on the innermost planet. We report on the first global survey of crater degradation on Mercury. By modifying an established 5-class scheme, we have systematically applied a rigorous set of criteria to all craters ≥40 km in diameter on the planet. These criteria include the state and morphology of crater deposits separately (e.g., rim, floor, wall, ejecta) and degradation classes were assigned as the collection of these individual attributes. This approach yields a consistent classification of craters of different sizes. Our results provide the first comprehensive assessment of how craters of various states of degradation are distributed

  3. Nuclear Power for Electricity Generation in Ghana: Issues and Challenges

    International Nuclear Information System (INIS)

    Nyarko, B.J.B.; Akaho, E.H.K.; Ennison, I.

    2011-01-01

    Ghana's electricity demand has been estimated to be growing at a high rate of about 7% per annum over the last ten years. This is due to the relatively high population growth, economic aspiration of the country and the extension of electricity to rural areas. Electricity supply, on the contrary, has been unable to meet the demand due to high dependency on rain-fed hydropower plants, which started operating in 1965 and currently account for about 68% of the total installed capacity. Within the last 28 years, climatic changes and draughts have caused the nation to experience three major power crises. These climate changes resulted in low inflows and thus reduced power generation from hydropower systems. To complement the hydropower systems, the Government in 1997 installed thermal plants based on light crude oil. However, due to the high crude oil prices on the international market in recent times have made the operation of these plants very expensive. Ghana's crude oil find can boost its energy supply when the oil exploration begins somewhere in 2010. For rural cooking, domestic biomass is employed. Ghana has no domestic coal resources. The Government of Ghana is concerned with: limited further growth potential of domestic hydro; high cost of imported oil and gas and environmental issues associated with use of imported coal. Small Solar and wind generation exist in some sectors, but potential large-scale development is not envisioned for the near future. With these in mind, the President of Ghana set up a Committee involving Stakeholder Institutions to formulate the Nuclear Power Policy and develop the basic elements of Nuclear Infrastructure and to assess the viability of introducing the nuclear power option in Ghana's energy mix. Cabinet took a decision to include the nuclear power for electricity generation after the Committee submitted his report to the President in 2008. (author)

  4. Assessment of wind power generation along the coast of Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Adaramola, Muyiwa S., E-mail: muyiwa.adaramola@umb.no [Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Ås (Norway); Agelin-Chaab, Martin [Department of Automotive, Mechanical and Manufacturing Engineering, University of Ontario Institute of Technology, Oshawa, ON (Canada); Paul, Samuel S. [REHAU Industries, Winnipeg, Manitoba (Canada)

    2014-01-15

    Highlights: • The wind energy and its economic viability along the coastal region of Ghana are examined. • Wind resource along the coastal region of Ghana fall into Class 2 or less wind resource. • Wind turbine with rated speed from 9 to 11 m/s is suggested for wind power development. • The unit cost of wind generated electricity is found be between 0.0732 GH¢/kW h and 0.2905 GH¢/kW h. - Abstract: This study examined the wind energy potential and the economic viability of using wind turbine for electricity generation in selected locations along the coastal region of Ghana. The two-parameter Weibull probability density function was employed to analyze the wind speed data obtained from the Ghana Energy Commission. The energy output and unit cost of electricity generated from medium size commercial wind turbine models with rated powers ranging from 50 kW to 250 kW were determined. It was found that the wind resource along the coastal region of Ghana can be classified into Class 2 or less wind resource which indicate that this resource in this area is marginally suitable for large scale wind energy development or suitable for small scale applications and be useful as part of hybrid energy system. It was further observed that wind turbine with designed cut-in wind speed of less than 3 m/s and moderate rated wind speed between 9 and 11 m/s is more suitable for wind energy development along the coastal region of Ghana. Based on the selected wind turbine and assumptions used in this study, it was estimated that the unit cost of electricity varied between 0.0695 GH¢/kW h and 0.2817 GH¢/kW h.

  5. Assessment of wind power generation along the coast of Ghana

    International Nuclear Information System (INIS)

    Adaramola, Muyiwa S.; Agelin-Chaab, Martin; Paul, Samuel S.

    2014-01-01

    Highlights: • The wind energy and its economic viability along the coastal region of Ghana are examined. • Wind resource along the coastal region of Ghana fall into Class 2 or less wind resource. • Wind turbine with rated speed from 9 to 11 m/s is suggested for wind power development. • The unit cost of wind generated electricity is found be between 0.0732 GH¢/kW h and 0.2905 GH¢/kW h. - Abstract: This study examined the wind energy potential and the economic viability of using wind turbine for electricity generation in selected locations along the coastal region of Ghana. The two-parameter Weibull probability density function was employed to analyze the wind speed data obtained from the Ghana Energy Commission. The energy output and unit cost of electricity generated from medium size commercial wind turbine models with rated powers ranging from 50 kW to 250 kW were determined. It was found that the wind resource along the coastal region of Ghana can be classified into Class 2 or less wind resource which indicate that this resource in this area is marginally suitable for large scale wind energy development or suitable for small scale applications and be useful as part of hybrid energy system. It was further observed that wind turbine with designed cut-in wind speed of less than 3 m/s and moderate rated wind speed between 9 and 11 m/s is more suitable for wind energy development along the coastal region of Ghana. Based on the selected wind turbine and assumptions used in this study, it was estimated that the unit cost of electricity varied between 0.0695 GH¢/kW h and 0.2817 GH¢/kW h

  6. Ghana | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    Our funds sponsored Ghana Health Service research to improve the country's ... Major reforms extended health care to the aged, the poor, and children under 18. ... Researchers in Ghana found innovative ways to use information technology to ... enhance the quality of climate change science at the University of Ghana ...

  7. Journal of the Ghana Science Association

    African Journals Online (AJOL)

    The Journal of the Ghana Science Association publishes scholarly articles in all disciplines of science and technology and will normally be published three times in a year. Articles are accepted from Ghana and elsewhere and the topic need not be related to Ghana or West Africa. The contents of the issues focus primarily on ...

  8. Chemical hazards from acid crater lakes

    Science.gov (United States)

    van Bergen, M. J.; Sumarti, S.; Heikens, A.; Bogaard, T. A.; Hartiyatun, S.

    2003-04-01

    Acid crater lakes, which are hosted by a considerable number of active volcanoes, form a potential threat for local ecosystems and human health, as they commonly contain large amounts of dissolved chemicals. Subsurface seepage or overflow can lead to severe deterioration of the water quality of rivers and wells, as observations around several of these volcanoes have shown. The Ijen crater lake in East Java (Indonesia) is a striking example, as this reservoir of hyperacid (pHfluoride-rich water is the source of a ca. 50 km long acid river that transports substantial quantities of potentially toxic elements. A downstream trend of increasing pH from fluoride levels pose some of the most severe environmental threats. Its concentration decreases from ca. 1300 mg/kg in the lake to ca. 10 mg/kg in a coastal area downstream, where virtually all of the river water is used for irrigating rice fields and other cropland. Apart from serious problems for agriculture, our survey of 55 drinking water wells in the irrigation area shows that 50% contain fluoride above the 1.5 ppm WHO limit, in line with the observation that dental fluorosis is widespread among the ca. 100,000 residents of the area. A conspicuous spatial correlation between fluoride concentrations and the irrigation system suggest that long-term (century) infiltration of irrigation water may have affected the quality of groundwater. Fluorosis is also a problem in some villages within the caldera, where well water sources may have a more direct subsurface connection with the lake system. From our observations we conclude that water-quality monitoring is especially needed for health reasons in volcanic areas where volatile elements, derived from passively degassing magma, are intercepted by (sub) surface water bodies.

  9. Policy talk: incentives for rural service among nurses in Ghana.

    Science.gov (United States)

    Kwansah, Janet; Dzodzomenyo, Mawuli; Mutumba, Massy; Asabir, Kwesi; Koomson, Elizabeth; Gyakobo, Mawuli; Agyei-Baffour, Peter; Kruk, Margaret E; Snow, Rachel C

    2012-12-01

    Like many countries in sub-Saharan Africa, Ghana is faced with the simultaneous challenges of increasing its health workforce, retaining them in country and promoting a rational distribution of staff in remote or deprived areas of the country. Recent increases in both public-sector doctor and nurse salaries have contributed to a decline in international out-migration, but problems of geographic mal-distribution remain. As part of a research project on human resources in the Ghanaian health sector, this study was conducted to elicit in-depth views from nursing leaders and practicing nurses in rural and urban Ghana on motivations for urban vs rural practice, job satisfaction and potential rural incentives. In-depth interviews were conducted with 115 nurses selected using a stratified sample of public, private and Christian Health Association of Ghana (CHAG) facilities in three regions of the country (Greater Accra, Brong Ahafo and Upper West), and among 13 nurse managers from across Ghana. Many respondents reported low satisfaction with rural practice. This was influenced by the high workload and difficult working conditions, perception of being 'forgotten' in rural areas by the Ministry of Health (MOH), lack of professional advancement and the lack of formal learning or structured mentoring. Older nurses without academic degrees who were posted to remote areas were especially frustrated, citing a lack of opportunities to upgrade their skills. Nursing leaders echoed these themes, emphasizing the need to bring learning and communication technologies to rural areas. Proposed solutions included clearer terms of contract detailing length of stay at a post, and transparent procedures for transfer and promotion; career opportunities for all cadres of nursing; and benefits such as better on-the-job housing, better mentoring and more recognition from leaders. An integrated set of recruitment and retention policies focusing on career development may improve job satisfaction

  10. Imaging the Buried Chicxulub Crater with Gravity Gradients and Cenotes

    Science.gov (United States)

    Hildebrand, A. R.; Pilkington, M.; Halpenny, J. F.; Ortiz-Aleman, C.; Chavez, R. E.; Urrutia-Fucugauchi, J.; Connors, M.; Graniel-Castro, E.; Camara-Zi, A.; Vasquez, J.

    1995-09-01

    Differing interpretations of the Bouguer gravity anomaly over the Chicxulub crater, Yucatan Peninsula, Mexico, have yielded diameter estimates of 170 to 320 km. Knowing the crater's size is necessary to quantify the lethal perturbations to the Cretaceous environment associated with its formation. The crater's size (and internal structure) is revealed by the horizontal gradient of the Bouguer gravity anomaly over the structure, and by mapping the karst features of the Yucatan region. To improve our resolution of the crater's gravity signature we collected additional gravity measurements primarily along radial profiles, but also to fill in previously unsurveyed areas. Horizontal gradient analysis of Bouguer gravity data objectively highlights the lateral density contrasts of the impact lithologies and suppresses regional anomalies which may obscure the gravity signature of the Chicxulub crater lithologies. This gradient technique yields a striking circular structure with at least 6 concentric gradient features between 25 and 85 km radius. These features are most distinct in the southwest probably because of denser sampling of the gravity field. Our detailed profiles detected an additional feature and steeper gradients (up to 5 mGal/km) than the original survey. We interpret the outer four gradient maxima to represent concentric faults in the crater's zone of slumping as is also revealed by seismic reflection data. The inner two probably represent the margin of the central uplift and the peak ring and or collapsed transient cavity. Radial gradients in the SW quadrant over the inferred ~40 km-diameter central uplift (4) may represent structural "puckering" as revealed at eroded terrestrial craters. Gradient features related to regional gravity highs and lows are visible outside the crater, but no concentric gradient features are apparent at distances > 90 km radius. The marginal gradient features may be modelled by slump faults as observed in large complex craters on

  11. Irregular and incomplete primary schooling in rural Ghana. A case-study of late enrolment and early drop-out in the eastern region

    OpenAIRE

    Oduro, Beth Cathrine Fagerlid

    2014-01-01

    This study takes a closer look at the issue of late enrolment and early drop out in a rural area in Eastern Region in Ghana. Children enrolling in school later than the recommended age of six, is a persistent problem in Ghana in spite of a fee free public school. Using qualitative methodology through household interviews in two villages, interviews with teachers and staff at Ghana Educational Service, a registration scheme and diaries the study seeks to unravel some of the stor...

  12. Table of Contents | Editor | Ghana Journal of Linguistics

    African Journals Online (AJOL)

    2016. Editorial Committee: Ọbádélé Kambon (Editor-in-Chief; University of Ghana). E. Kweku Osam (Consulting Editor; University of Ghana). Gordon S. Adika (University of Ghana). Nana Aba A. Amfo (University of Ghana). Jemima A. Anderson (University of Ghana). Charles O. Marfo (Kwame Nkrumah University of Science ...

  13. Culture and the environment in Ghana

    Science.gov (United States)

    Dyasi, Hubert M.

    1985-03-01

    The traditional culture of Ghana stressed a strong relationship with the environment, and a culturally acceptable environmental management resulted from strictures and taboos related to the land. Following its independence in 1957, Ghana has enacted laws that reflect an enlightened environmental policy. These are especially important because of the difficulties Ghana has had in its economic development using Western technology that has damaged the fragile tropical ecosystem. A key aspect of Ghana's policy is the attempt to marry scientific knowledge and traditional beliefs for environmentally sound management of Ghana's resources.

  14. Facts about Nuclear Waste Safety - How the issue is being treated in Ghana

    International Nuclear Information System (INIS)

    Glover, E.T.; Fletcher, J.J.

    2001-01-01

    The fear of radioactive discharges and releases particularly from severe nuclear accidents and radioactive waste is central to public concern about nuclear activities. This fear was witnessed when Ghana began to suffer shortage in electricity supply from the hydroelectric power station at Akosombo and debates began on Ghana's energy mix and alternate options. As in every country, dependable and continuous supply of electricity is a prerequisite for ensuring sustainable development. The Ghana Atomic Energy Commission was confronted at that time more than ever with the problem of public education on nuclear power safety to enhance public acceptance. This paper presents what the Ghana Atomic Energy Commission is doing to communicate facts and education about nuclear waste safety to the Ghanaian public and to facilitate the comparison of risk from nuclear reactors and disposal facilities with risks from other forms of technology. The paper also tells of the usefulness of and difficulties in using Jos Draiger and John Lakey's manual on Radiation and Radiation Protection to educate pupils in the Ghana Atomic Energy Commission Preparatory School. The difficulties in communication of facts about nuclear, radiation and waste safety in Ghana, because of the different languages and dialects used by Ghanaians in the rural areas of Ghana. As a large number of factors influence decision making in the energy sector. To assist energy planners, the Ghana Atomic Energy Commission carried out assessments of alternative energy sources, covering a broad range of technical, economic and environmental factors. Cost-benefit and risk-benefit analyses place the nuclear power option on a scale comparable to the other electricity generating technologies. How come then that nuclear power option has so much negative publicity? The conclusion is drawn that literacy in nuclear radiation and waste safety is needed at all levels of the Ghanaian society. As inadequate perception of radiation risk

  15. Cardiothoracic surgical experience in Ghana.

    Science.gov (United States)

    Tettey, Mark; Tamatey, Martin; Edwin, Frank

    2016-10-01

    Ghana is one of the few low-to-middle-income countries in sub-Saharan Africa able to consistently sustain a cardiothoracic program with locally trained staff for more than two decades. Cardiothoracic surgery practice in Ghana started in 1964 but faltered from a combination of political and the economic problems. In 1989, Dr. Kwabena Frimpong-Boateng, a Ghanaian cardiothoracic surgeon trained in Hannover, rekindled interest in cardiothoracic surgery and in establishing a National Cardiothoracic Centre. His vision and leadership has brought cardiothoracic surgery practice in Ghana to its current high level. As a result, the medical landscape of what is achievable locally in both pediatric and adult patients has changed substantially: outbound medical travel that used to be common among Ghanaian cardiovascular patients has been reduced drastically. Ghana's National Cardiothoracic Center (NCTC), the only tertiary center in the country for cardiothoracic surgical pathology manages all such patients that were previously referred abroad. The NCTC has become a medical/surgical hub in the West African sub-region providing service, training, and research opportunities to neighboring countries. The Centre is accredited by the West African College of Surgeons as a center of excellence for training specialists in cardiothoracic surgery. Expectedly, practicing cardiothoracic surgery in such a resource-poor setting has peculiar challenges. This review focuses on the history, practice, successes, and challenges of cardiovascular and thoracic surgery in Ghana.

  16. Neurogenomics: Challenges and opportunities for Ghana

    Directory of Open Access Journals (Sweden)

    Thomas K. Karikari

    2015-06-01

    Full Text Available The application of genomic tools and technologies has shown the potential to help improve healthcare and our understanding of disease mechanisms. While genomic tools are increasingly being applied to research on infectious diseases, malaria and neglected tropical diseases in Africa, an area that has seen little application of genomic approaches on this continent is neuroscience. In this article, we examined the prospects of developing neurogenomics research and its clinical use in Ghana, one of the African countries actively involved in genomics research. We noted that established international research funding sources and foundations in genomic research such as H3ABioNet nodes established at a couple of research centres in Ghana provide excellent platforms for extending the usage of genomic tools and techniques to neuroscience-related research areas. However, existing challenges such as the (i lack of degree programmes in neuroscience, genomics and bioinformatics; (ii low availability of infrastructure and appropriately-trained scientists; and (iii lack of local research funding opportunities, need to be addressed. To promote and safeguard the long-term sustainability of neurogenomics research in the country, the impact of the existing challenges and possible ways of addressing them have been discussed.

  17. Herbage productivity of the Winneba plains of Ghana | Fleischer ...

    African Journals Online (AJOL)

    The biomass productivity of the Winneba plains of Ghana was measured between January 1990 and February 1992. Ten sampling sites were chosen for the study. An area of 5.0 m W 5.0 m was demarcated and within it an area of 1.0 m W 1.0 m was harvested at monthly intervals, clipped by means of sickle at 5 cm above ...

  18. Institutional analysis of biofuel production in Northern Ghana

    OpenAIRE

    Kwoyiga, Lydia

    2013-01-01

    The thesis studied the nature of institutional arrangement around biofuel production and how this arrangement has shaped the production outcome of biofuel companies and community development. The study was conducted in two communities of the Yendi Municipal Assembly of the Northern Region of Ghana. In this area, a biofuel company called Biofuel Africa Limited has acquired areas of land and cultivated Jatropha plantations. A total of 32 informants were interviewed to arrive at information ne...

  19. Geologic Map of Mount Mazama and Crater Lake Caldera, Oregon

    Science.gov (United States)

    Bacon, Charles R.

    2008-01-01

    Crater Lake partly fills one of the most spectacular calderas of the world, an 8-by-10-km basin more than 1 km deep formed by collapse of the volcano known as Mount Mazama (fig. 1) during a rapid series of explosive eruptions about 7,700 years ago. Having a maximum depth of 594 m, Crater Lake is the deepest lake in the United States. Crater Lake National Park, dedicated in 1902, encompasses 645 km2 of pristine forested and alpine terrain, including the lake itself, virtually all of Mount Mazama, and most of the area of the geologic map. The geology of the area was first described in detail by Diller and Patton (1902) and later by Williams (1942), whose vivid account led to international recognition of Crater Lake as the classic collapse caldera. Because of excellent preservation and access, Mount Mazama, Crater Lake caldera, and the deposits formed by the climactic eruption constitute a natural laboratory for study of volcanic and magmatic processes. For example, the climactic ejecta are renowned among volcanologists as evidence for systematic compositional zonation within a subterranean magma chamber. Mount Mazama's climactic eruption also is important as the source of the widespread Mazama ash, a useful Holocene stratigraphic marker throughout the Pacific Northwest, adjacent Canada, and offshore. A detailed bathymetric survey of the floor of Crater Lake in 2000 (Bacon and others, 2002) provides a unique record of postcaldera eruptions, the interplay between volcanism and filling of the lake, and sediment transport within this closed basin. Knowledge of the geology and eruptive history of the Mount Mazama edifice, greatly enhanced by the caldera wall exposures, gives exceptional insight into how large volcanoes of magmatic arcs grow and evolve. Lastly, the many smaller volcanoes of the High Cascades beyond the limits of Mount Mazama are a source of information on the flux of mantle-derived magma through the region. General principles of magmatic and eruptive

  20. Genetic diversity affects testicular morphology in free-ranging lions (Panthera leo) of the Serengeti Plains and Ngorongoro Crater.

    Science.gov (United States)

    Munson, L; Brown, J L; Bush, M; Packer, C; Janssen, D; Reiziss, S M; Wildt, D E

    1996-09-01

    Reduced genetic variability is known to adversely affect ejaculate quality in inbred lions (Panthera leo) physically isolated in the Ngorongoro Crater compared with outbred lions inhabiting the adjacent Serengeti Plains in East Africa. This study compared the histomorphology of testicular biopsies from these two lion populations. Ngorongoro Crater lions had fewer (P 0.05) between populations. Interstitial areas were greater (P < 0.05) in Crater than in Plains lions, but no qualitative differences were evident, suggesting that proportionately less testicular area was occupied by seminiferous tubules in Crater lions. None of the lions in either population had evidence of testicular degeneration. Overall results suggest that inbred Crater lions have reduced spermiogenesis and less total seminiferous tubular area per testis. These data further support the premise that genetic homogeneity compromises reproductive traits in free-living, male African lions.

  1. Size-Frequency Distribution of Small Lunar Craters: Widening with Degradation and Crater Lifetime

    Science.gov (United States)

    Ivanov, B. A.

    2018-01-01

    The review and new measurements are presented for depth/diameter ratio and slope angle evolution during small ( D model. The uncertainty of crater retention age due to crater degradational widening is estimated. The collected and analyzed data are discussed to be used in the future updating of mechanical models for lunar crater aging.

  2. All projects related to Ghana | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Home · What we do / Regions and countries / Ghana ... Integrated Climate Smart Flood Management for Accra, Ghana ... by scaling up enhanced information and communication technology-enabled (ICT) extension service models in Ghana.

  3. The Creation of Districts and Constituencies in Ghana: Some ...

    African Journals Online (AJOL)

    The Regions of Ghana. Ghana is presently divided into ten political regions which are subdivided ..... errors to which attention was drawn (Ghana 1972b:) ... national interest has been the driving force behind the creation of districts some of ...

  4. Predictors of Contraceptive use Among Female Adolescents in Ghana

    African Journals Online (AJOL)

    Predictors of Contraceptive use Among Female Adolescents in Ghana. ... contraceptive use amongst adolescent girls in Ghana using the 2008 Ghana Demographic and Health Survey (GDHS). ... (Afr J Reprod Health 2014; 18[1]: 102-109).

  5. Nuclear medicine in Ghana

    International Nuclear Information System (INIS)

    Affram, R.K.; Kyere, K.; Amuasi, J.

    1991-01-01

    The background to the introduction and application of radioisotopes in medicine culminating in the establishment of the nuclear Medicine Unit at the Korle Bu Teaching Hospital, Ghana, has been examined. The Unit has been involved in important clinical researches since early 1970s but routine application in patient management has not always been possible because of cost per test and lack of continuous availability of convertible currency for the purchase of radioisotopes which are not presently produced by the National Nuclear Research Institute at Kwabenya. The capabilities and potentials of the Unit are highlighted and a comparison of Nuclear Medicine techniques to other medical diagnostic and imaging methods have been made. There is no organised instruction in the principles of medical imaging and diagnostic methods at both undergraduate and postgraduate levels in Korle Bu Teaching Hospital which has not promoted the use of Nuclear Medicine techniques. The development of a comprehensive medical diagnostic and imaging services is urgently needed. (author). 18 refs., 3 tabs

  6. Investigation of Secondary Craters in the Saturnian System

    Science.gov (United States)

    Hoogenboom, T.; Schenk, P.; White, O. L.

    2012-03-01

    To derive accurate ages using impact craters, the impact source must be determined. We investigate secondary crater size, frequency, distribution, formation, and crater chain formation on icy satellites throughout the Jupiter and Saturn systems.

  7. Martian Low-Aspect-Ratio Layered Ejecta (LARLE) craters: Distribution, characteristics, and relationship to pedestal craters

    Science.gov (United States)

    Barlow, Nadine G.; Boyce, Joseph M.; Cornwall, Carin

    2014-09-01

    Low-Aspect-Ratio Layered Ejecta (LARLE) craters are a unique landform found on Mars. LARLE craters are characterized by a crater and normal layered ejecta pattern surrounded by an extensive but thin outer deposit which terminates in a sinuous, almost flame-like morphology. We have conducted a survey to identify all LARLE craters ⩾1-km-diameter within the ±75° latitude zone and to determine their morphologic and morphometric characteristics. The survey reveals 140 LARLE craters, with the majority (91%) located poleward of 40°S and 35°N and all occurring within thick mantles of fine-grained deposits which are likely ice-rich. LARLE craters range in diameter from the cut-off limit of 1 km up to 12.2 km, with 83% being smaller than 5 km. The radius of the outer LARLE deposit displays a linear trend with the crater radius and is greatest at higher polar latitudes. The LARLE deposit ranges in length between 2.56 and 14.81 crater radii in average extent, with maximum length extending up to 21.4 crater radii. The LARLE layer is very sinuous, with lobateness values ranging between 1.45 and 4.35. LARLE craters display a number of characteristics in common with pedestal craters and we propose that pedestal craters are eroded versions of LARLE craters. The distribution and characteristics of the LARLE craters lead us to propose that impact excavation into ice-rich fine-grained deposits produces a dusty base surge cloud (like those produced by explosion craters) that deposits dust and ice particles to create the LARLE layers. Salts emplaced by upward migration of water through the LARLE deposit produce a surficial duricrust layer which protects the deposit from immediate removal by eolian processes.

  8. Turbulent flow over craters on Mars: Vorticity dynamics reveal aeolian excavation mechanism

    Science.gov (United States)

    Anderson, William; Day, Mackenzie

    2017-10-01

    Impact craters are scattered across Mars. These craters exhibit geometric self-similarity over a spectrum of diameters, ranging from tens to thousands of kilometers. The late Noachian-early Hesperian boundary marks a dramatic shift in the role of mid-latitude craters, from depocenter sedimentary basins to aeolian source areas. At present day, many craters contain prominent layered sedimentary mounds with maximum elevations comparable to the rim height. The mounds are remnants of Noachian deposition and are surrounded by a radial moat. Large-eddy simulation has been used to model turbulent flows over synthetic craterlike geometries. Geometric attributes of the craters and the aloft flow have been carefully matched to resemble ambient conditions in the atmospheric boundary layer of Mars. Vorticity dynamics analysis within the crater basin reveals the presence of counterrotating helical vortices, verifying the efficacy of deflationary models put forth recently by Bennett and Bell [K. Bennett and J. Bell, Icarus 264, 331 (2016)], 10.1016/j.icarus.2015.09.041 and Day et al. [M. Day et al., Geophys. Res. Lett. 43, 2473 (2016)], 10.1002/2016GL068011. We show how these helical counterrotating vortices spiral around the outer rim, gradually deflating the moat and carving the mound; excavation occurs faster on the upwind side, explaining the radial eccentricity of the mounds relative to the surrounding crater basin.

  9. Impact ejecta and carbonate sequence in the eastern sector of the Chicxulub crater

    Science.gov (United States)

    Urrutia-Fucugauchi, Jaime; Chavez-Aguirre, Jose Maria; Pérez-Cruz, Ligia; De la Rosa, Jose Luis

    2008-12-01

    The Chicxulub 200 km diameter crater located in the Yucatan platform of the Gulf of Mexico formed 65 Myr ago and has since been covered by Tertiary post-impact carbonates. The sediment cover and absence of significant volcanic and tectonic activity in the carbonate platform have protected the crater from erosion and deformation, making Chicxulub the only large multi-ring crater in which ejecta is well preserved. Ejecta deposits have been studied by drilling/coring in the southern crater sector and at outcrops in Belize, Quintana Roo and Campeche; little information is available from other sectors. Here, we report on the drilling/coring of a section of ˜34 m of carbonate breccias at 250 m depth in the Valladolid area (120 km away from crater center), which are interpreted as Chicxulub proximal ejecta deposits. The Valladolid breccias correlate with the carbonate breccias cored in the Peto and Tekax boreholes to the south and at similar radial distance. This constitutes the first report of breccias in the eastern sector close to the crater rim. Thickness of the Valladolid breccias is less than that at the other sites, which may indicate erosion of the ejecta deposits before reestablishment of carbonate deposition. The region east of the crater rim appears different from regions to the south and west, characterized by high density and scattered distribution of sinkholes.

  10. Turbulent flow over craters on Mars: Vorticity dynamics reveal aeolian excavation mechanism.

    Science.gov (United States)

    Anderson, William; Day, Mackenzie

    2017-10-01

    Impact craters are scattered across Mars. These craters exhibit geometric self-similarity over a spectrum of diameters, ranging from tens to thousands of kilometers. The late Noachian-early Hesperian boundary marks a dramatic shift in the role of mid-latitude craters, from depocenter sedimentary basins to aeolian source areas. At present day, many craters contain prominent layered sedimentary mounds with maximum elevations comparable to the rim height. The mounds are remnants of Noachian deposition and are surrounded by a radial moat. Large-eddy simulation has been used to model turbulent flows over synthetic craterlike geometries. Geometric attributes of the craters and the aloft flow have been carefully matched to resemble ambient conditions in the atmospheric boundary layer of Mars. Vorticity dynamics analysis within the crater basin reveals the presence of counterrotating helical vortices, verifying the efficacy of deflationary models put forth recently by Bennett and Bell [K. Bennett and J. Bell, Icarus 264, 331 (2016)]ICRSA50019-103510.1016/j.icarus.2015.09.041 and Day et al. [M. Day et al., Geophys. Res. Lett. 43, 2473 (2016)]GPRLAJ0094-827610.1002/2016GL068011. We show how these helical counterrotating vortices spiral around the outer rim, gradually deflating the moat and carving the mound; excavation occurs faster on the upwind side, explaining the radial eccentricity of the mounds relative to the surrounding crater basin.

  11. Climate Change and Variability in Ghana: Stocktaking

    Directory of Open Access Journals (Sweden)

    Felix A. Asante

    2014-12-01

    Full Text Available This paper provides a holistic literature review of climate change and variability in Ghana by examining the impact and projections of climate change and variability in various sectors (agricultural, health and energy and its implication on ecology, land use, poverty and welfare. The findings suggest that there is a projected high temperature and low rainfall in the years 2020, 2050 and 2080, and desertification is estimated to be proceeding at a rate of 20,000 hectares per annum. Sea-surface temperatures will increase in Ghana’s waters and this will have drastic effects on fishery. There will be a reduction in the suitability of weather within the current cocoa-growing areas in Ghana by 2050 and an increase evapotranspiration of the cocoa trees. Furthermore, rice and rooted crops (especially cassava production are expected to be low. Hydropower generation is also at risk and there will be an increase in the incidence rate of measles, diarrheal cases, guinea worm infestation, malaria, cholera, cerebro-spinal meningitis and other water related diseases due to the current climate projections and variability. These negative impacts of climate change and variability worsens the plight of the poor, who are mostly women and children.

  12. What Really Happened to Earth's Older Craters?

    Science.gov (United States)

    Bottke, William; Mazrouei, Sara; Ghent, Rebecca; Parker, Alex

    2017-10-01

    Most assume the Earth’s crater record is heavily biased, with erosion/tectonics destroying older craters. This matches expectations, but is it actually true? To test this idea, we compared Earth’s crater record, where nearly all D ≥ 20 km craters are pick out from older craters with eroded fragments. Moreover, an inverse relationship between rock abundance (RA) and crater age exists. Using measured RA values, we computed ages for 111 rocky craters with D ≥ 10 km that formed between 80°N and 80°S over the last 1 Gyr.We found several surprising results. First, the production rate of D ≥ 10 km lunar craters increased by a factor of 2.2 [-0.9, +4.4; 95% confidence limits] over the past 250 Myr compared to the previous 750 Myr. Thus, the NEO population is higher now than it has been for the last billion years. Second, the size and age distributions of lunar and terrestrial craters for D ≥ 20 km over the last 650 Myr have similar shapes. This implies that crater erasure must be limited on stable terrestrial terrains; in an average sense, for a given region, the Earth either keeps all or loses all of its D ≥ 20 craters at the same rate, independent of size. It also implies the observed deficit of large terrestrial craters between 250-650 Myr is not preservation bias but rather reflects a distinctly lower impact flux. We predict 355 ± 86 D ≥ 20 km craters formed on Earth over the last 650 Myr. Only 38 ± 6 are known, so the ratio, 10.7 ± 3.1%, is a measure of the Earth’s surface that is reasonably stable to large crater formation over 650 Myr. If erosion had dominated, the age distribution of terrestrial craters would be strongly skewed toward younger ages, which is not observed. We predict Chicxulub-type impacts were rare over the last Gyr, with the event 66 Ma a probable byproduct of the current high terrestrial impact flux.

  13. Machine cataloging of impact craters on Mars

    Science.gov (United States)

    Stepinski, Tomasz F.; Mendenhall, Michael P.; Bue, Brian D.

    2009-09-01

    This study presents an automated system for cataloging impact craters using the MOLA 128 pixels/degree digital elevation model of Mars. Craters are detected by a two-step algorithm that first identifies round and symmetric topographic depressions as crater candidates and then selects craters using a machine-learning technique. The system is robust with respect to surface types; craters are identified with similar accuracy from all different types of martian surfaces without adjusting input parameters. By using a large training set in its final selection step, the system produces virtually no false detections. Finally, the system provides a seamless integration of crater detection with its characterization. Of particular interest is the ability of our algorithm to calculate crater depths. The system is described and its application is demonstrated on eight large sites representing all major types of martian surfaces. An evaluation of its performance and prospects for its utilization for global surveys are given by means of detailed comparison of obtained results to the manually-derived Catalog of Large Martian Impact Craters. We use the results from the test sites to construct local depth-diameter relationships based on a large number of craters. In general, obtained relationships are in agreement with what was inferred on the basis of manual measurements. However, we have found that, in Terra Cimmeria, the depth/diameter ratio has an abrupt decrease at ˜38°S regardless of crater size. If shallowing of craters is attributed to presence of sub-surface ice, a sudden change in its spatial distribution is suggested by our findings.

  14. Problems of Frafra potato production in Ghana | Tetteh | Ghana ...

    African Journals Online (AJOL)

    A survey of the production of Frafra potato (Solenostemum rotundifolius Poir) in Ghana was conducted to collect baseline data on the crop and to identify constraints to production. In all, 100 farmers who were randomly selected from 16 villages and towns in five districts in the Upper East Region and Upper West Region ...

  15. Quality of Sachet Water Produced at Tarkwa, Ghana | Ndur | Ghana ...

    African Journals Online (AJOL)

    Cholera outbreak in some cities and towns in Ghana in early 2011 necessitated a sachet water quality study in Tarkwa to determine their wholesomeness. The study was conducted in four phases in August 2011, December 2011, August 2012 and December, 2013. Most of the physico-chemical parameters analysed were ...

  16. Breast cancer in Kumasi, Ghana | Adjei | Ghana Medical Journal

    African Journals Online (AJOL)

    Background: Breast cancer is the leading cause of cancer deaths in Ghanaian women. Objective: To describes the characteristics of breast cancer patients attending the Komfo Anokye Teaching Hospital in Kumasi, Ghana. Method: The study was conducted at the Komfo Anokye Teaching Hospital. Between July 1st 2004 ...

  17. Towards a culture of maps appreciation in Ghana | Kofie | Ghana ...

    African Journals Online (AJOL)

    Ghana Journal of Geography. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 5 (2013) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load here ...

  18. Insect succession on three coffee types in Ghana | Padi | Ghana ...

    African Journals Online (AJOL)

    Insect succession on three coffee types in Ghana. B Padi, E Ampomah. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

  19. Impact craters in South America

    CERN Document Server

    Acevedo, Rogelio Daniel; Ponce, Juan Federico; Stinco, Sergio G

    2015-01-01

    A complete and updated catalogue of impact craters and structures in South America from 2014 is presented here. Approximately eighty proven, suspected and disproven structures have been identified by several sources in this continent. All the impact sites of this large continent have been exhaustively reviewed: the proved ones, the possible ones and some very doubtful. Many sites remain without a clear geological ""in situ"" confirmation and some of them could be even rejected. Argentina and Brazil are leading the list containing almost everything detected. In Bolivia, Chile, Colombia, Guyana,

  20. Martian Cratering 7: The Role of Impact Gardening

    Science.gov (United States)

    Hartmann, William K.; Anguita, Jorge; de la Casa, Miguel A.; Berman, Daniel C.; Ryan, Eileen V.

    2001-01-01

    Viking-era researchers concluded that impact craters of diameter Dduricrust at Viking and Pathfinder sites demonstrates the cementing process. These results affect lander/rover searches for intact ancient deposits. The upper tens of meters of exposed Noachian units cannot survive today in a pristine state. Intact Noachian deposits might best be found in cliffside strata, or in recently exhumed regions. The hematite-rich areas found in Terra Meridiani by the Mars Global Surveyor are probably examples of the latter.

  1. Ghana integrated to the world economy : focus on Ghana-UK-Germany trade linkage model

    OpenAIRE

    Sarpong, Daniel Bruce

    1998-01-01

    In this study of Ghana integrated to the world economy, we focus primarily on Ghana-UK-Germany trade axis partly because of Ghana?s relative dependence on the EU for her international trade. The study employs ?representative? country macroeconometric models of these economies, using data over 1970-1991, including bilateral trade links among them and with the USA and Japan, to quantitatively analyze and draw policy inference of the international transmission mechanism of macroeconomic disturba...

  2. Toward universal electrification in Ghana

    DEFF Research Database (Denmark)

    Kemausuor, Francis; Ackom, Emmanuel

    2017-01-01

    sector in Ghana, negatively impacting all sectors of the economy and leading to economic losses. The low generation capacity is partly due to poor fuel supply to existing thermal power plants, meaning that installed capacity is often not available for use. This is coupled with low investment...

  3. Technical problems and future cratering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Knox, J B [Lawrence Radiation Laboratory, Livermore, CA (United States)

    1969-07-01

    This paper reviews some of the key technical problems that remain to be solved in nuclear cratering technology. These include: (1) developing a broader understanding of the effects that material properties and water content of the earth materials around the shot have on cratering behavior, (2) extending the experimental investigation of retarc formation to include intermediate yields and various materials, and (3) improving our ability to predict the escape of radioactive material to the atmosphere to form the cloud source responsible for fallout. The formation processes of ejecta craters, retarcs, and subsidence craters are described in the light of our present understanding, and the major gaps in our understanding are indicated. Methods of calculating crater and retarc formation are discussed, with particular reference to the input information needed. Methods for calculating fallout are presented, and their shortcomings are discussed. A preliminary analysis of the safety factors associated with the presently proposed nuclear excavation concepts is presented. (author)

  4. Technical problems and future cratering experiments

    International Nuclear Information System (INIS)

    Knox, J.B.

    1969-01-01

    This paper reviews some of the key technical problems that remain to be solved in nuclear cratering technology. These include: (1) developing a broader understanding of the effects that material properties and water content of the earth materials around the shot have on cratering behavior, (2) extending the experimental investigation of retarc formation to include intermediate yields and various materials, and (3) improving our ability to predict the escape of radioactive material to the atmosphere to form the cloud source responsible for fallout. The formation processes of ejecta craters, retarcs, and subsidence craters are described in the light of our present understanding, and the major gaps in our understanding are indicated. Methods of calculating crater and retarc formation are discussed, with particular reference to the input information needed. Methods for calculating fallout are presented, and their shortcomings are discussed. A preliminary analysis of the safety factors associated with the presently proposed nuclear excavation concepts is presented. (author)

  5. Asteroid families from cratering: Detection and models

    Science.gov (United States)

    Milani, A.; Cellino, A.; Knežević, Z.; Novaković, B.; Spoto, F.; Paolicchi, P.

    2014-07-01

    A new asteroid families classification, more efficient in the inclusion of smaller family members, shows how relevant the cratering impacts are on large asteroids. These do not disrupt the target, but just form families with the ejecta from large craters. Of the 12 largest asteroids, 8 have cratering families: number (2), (4), (5), (10), (87), (15), (3), and (31). At least another 7 cratering families can be identified. Of the cratering families identified so far, 7 have >1000 members. This imposes a remarkable change from the focus on fragmentation families of previous classifications. Such a large dataset of asteroids believed to be crater ejecta opens a new challenge: to model the crater and family forming event(s) generating them. The first problem is to identify which cratering families, found by the similarity of proper elements, can be formed at once, with a single collision. We have identified as a likely outcome of multiple collisions the families of (4), (10), (15), and (20). Of the ejecta generated by cratering, only a fraction reaches the escape velocity from the surviving parent body. The distribution of velocities at infinity, giving to the resulting family an initial position and shape in the proper elements space, is highly asymmetric with respect to the parent body. This shape is deformed by the Yarkovsky effect and by the interaction with resonances. All the largest asteroids have been subjected to large cratering events, thus the lack of a family needs to be interpreted. The most interesting case is (1) Ceres, which is not the parent body of the nearby family of (93). Two possible interpretations of the low family forming efficiency are based on either the composition of Ceres with a significant fraction of ice, protected by a thin crust, or with the larger escape velocity of ~500 m/s.

  6. Next steps towards a Climate Innovation Centre in Ghana. Discussion Paper

    International Nuclear Information System (INIS)

    De Coninck, H.C.; Wuertenberger, L.; Akon-Yamga, G.

    2011-03-01

    A climate innovation centre is an institution aimed at enabling development through catalysing climate technology research, development, market creation and policy. This discussion paper discusses the possibilities, considerations and next steps for a Climate Innovation Centre (CIC) in Ghana based on new insights within the government of Ghana, a mapping of climate innovation in Ghana, new developments in the international climate negotiations and other multilateral processes, and analysis conducted by ECN. The conclusion is that a Climate Innovation Centre can fill significant gaps in climate resilient development in Ghana. It seems important that a Ghana CIC does not become yet another institution that focuses on basic research in the area of climate change. Rather, it should connect the dots of the Ghanaian climate innovation system and act as a knowledge facilitator, also for the private sector. Various models of climate innovation centres exist. Before choices are made for a model or a combination of models for Ghana, it is recommended to allow for a broad stakeholder process. The World Bank's infoDev programme could be a model for such a process. Such stakeholder engagement should be aligned with other policymaking processes on adaptation and low-carbon development, as well as related policy arenas, such as agriculture, transport, waste and energy.

  7. Next steps towards a Climate Innovation Centre in Ghana. Discussion Paper

    Energy Technology Data Exchange (ETDEWEB)

    De Coninck, H.C.; Wuertenberger, L. [ECN Policy Studies, Petten (Netherlands); Akon-Yamga, G. [Science and Technology Policy Research Institute STEPRI, Accra (Guinea)

    2011-03-15

    A climate innovation centre is an institution aimed at enabling development through catalysing climate technology research, development, market creation and policy. This discussion paper discusses the possibilities, considerations and next steps for a Climate Innovation Centre (CIC) in Ghana based on new insights within the government of Ghana, a mapping of climate innovation in Ghana, new developments in the international climate negotiations and other multilateral processes, and analysis conducted by ECN. The conclusion is that a Climate Innovation Centre can fill significant gaps in climate resilient development in Ghana. It seems important that a Ghana CIC does not become yet another institution that focuses on basic research in the area of climate change. Rather, it should connect the dots of the Ghanaian climate innovation system and act as a knowledge facilitator, also for the private sector. Various models of climate innovation centres exist. Before choices are made for a model or a combination of models for Ghana, it is recommended to allow for a broad stakeholder process. The World Bank's infoDev programme could be a model for such a process. Such stakeholder engagement should be aligned with other policymaking processes on adaptation and low-carbon development, as well as related policy arenas, such as agriculture, transport, waste and energy.

  8. Females in the Agricultural Labour Force and Non-Formal Education for Rural Development in Ghana

    NARCIS (Netherlands)

    M. Greenstreet (Miranda)

    1981-01-01

    textabstractGhana is an agricultural country where most of the people live in rural areas, the proportion of women being greater than men. Life in the rural areas is difficult, but despite the much talked about drift of people to the urban areas, it is almost certain that for many decades, a large

  9. Leakage Identification Of Volcanic Product Pollutant Of ijen Crater Using Natural Isotop Deuterium And Oxiren-18

    International Nuclear Information System (INIS)

    Susiati, Heni; Sjarmufni, A.; S.B.S, Yarianto; Suprijadi; Wibagyo

    2001-01-01

    Community surrounding the Asembagus Sugar Fabric guess that the factory has polluted water body of Banyuputih River. Leakage detection of the pollutant has been to prove that guess using variation of natural isotop composition of Deuterium and Oxygen-18. Sampling was carried out at Ijen crater area, Banyupahit River and surrounding the sugar factory and also Belawan Fresh water source. Isotop analysis was done-by mass spectrometer. Based on analysis result have been gotten information that each location have vary of isotop value, Isotop concentration at Ijen crater was relative high so isotop concentration of Banyupahit river was also relative high although rather lower than lien Crater. Based on another interpretation, there are correlation at isotope concentration between Ijen crater and Banyupahit River

  10. Experience of modeling relief of impact lunar crater Aitken based on high-resolution orbital images

    Science.gov (United States)

    Mukhametshin, Ch R.; Semenov, A. A.; Shpekin, M. I.

    2018-05-01

    The paper presents the author’s results of modeling the relief of lunar Aitken crater on the basis of high-resolution orbital images. The images were taken in the frame of the “Apollo” program in 1971-1972 and delivered to the Earth by crews of “Apollo-15” and “Apollo-17”. The authors used the images obtained by metric and panoramic cameras. The main result is the careful study of the unusual features of Aitken crater on models created by the authors with the computer program, developed by “Agisoft Photoscan”. The paper shows what possibilities are opened with 3D models in the study of the structure of impact craters on the Moon. In particular, for the first time, the authors managed to show the structure of the glacier-like tongue in Aitken crater, which is regarded as one of the promising areas of the Moon for the forthcoming expeditions.

  11. Mining, Pollution and Agricultural Productivity: Evidence from Ghana

    OpenAIRE

    Fernando Aragon; Juan Pablo Rud

    2012-01-01

    Most modern mines in the developing world are located in rural areas, where agriculture is the main source of livelihood. This creates the potential of negative spillovers to farmers through competition for key inputs (such as land) and environmental pollution. To explore this issue, we examine the case of gold mining in Ghana. Through the estimation of an agricultural production function using household level data, we find that mining has reduced agricultural productivity by almost 40%. This...

  12. Evidence for rapid topographic evolution and crater degradation on Mercury from simple crater morphometry

    Science.gov (United States)

    Fassett, Caleb I.; Crowley, Malinda C.; Leight, Clarissa; Dyar, M. Darby; Minton, David A.; Hirabayashi, Masatoshi; Thomson, Bradley J.; Watters, Wesley A.

    2017-06-01

    Examining the topography of impact craters and their evolution with time is useful for assessing how fast planetary surfaces evolve. Here, new measurements of depth/diameter (d/D) ratios for 204 craters of 2.5 to 5 km in diameter superposed on Mercury's smooth plains are reported. The median d/D is 0.13, much lower than expected for newly formed simple craters ( 0.21). In comparison, lunar craters that postdate the maria are much less modified, and the median crater in the same size range has a d/D ratio that is nearly indistinguishable from the fresh value. This difference in crater degradation is remarkable given that Mercury's smooth plains and the lunar maria likely have ages that are comparable, if not identical. Applying a topographic diffusion model, these results imply that crater degradation is faster by a factor of approximately two on Mercury than on the Moon, suggesting more rapid landform evolution on Mercury at all scales.Plain Language SummaryMercury and the Moon are both airless bodies that have experienced numerous impact events over billions of years. These impacts form craters in a geologic instant. The question examined in this manuscript is how fast these craters erode after their formation. To simplify the problem, we examined craters of a particular size (2.5 to 5 km in diameter) on a particular geologic terrain type (volcanic smooth plains) on both the Moon and Mercury. We then measured the topography of hundreds of craters on both bodies that met these criteria. Our results suggest that craters on Mercury become shallower much more quickly than craters on the Moon. We estimate that Mercury's topography erodes at a rate at least a factor of two faster than the Moon's.

  13. Geology of drill hole USW VH-2, and structure of Crater Flat, southwestern Nevada

    International Nuclear Information System (INIS)

    Carr, W.J.; Parrish, L.D.

    1985-01-01

    A 1219 meter (4000 ft) drill hole in Crater Flat shows the absence of buried Pliocene or Quaternary volcanic rocks, and penetrates a section of Timber Mountain, Paintbrush, and the upper part of the Crater Flat Tuffs, similar to that exposed adjacent to Crater Flat. A prominent negative aeromagnetic anomaly between the drill hole and Bare Mountain is attributed to a westward thickening section of a reversely magnetized Miocene basalt. The relatively shallow depth of this basalt in the west-central part of Crater Flat indicates that no large amount of tectonic movement has occurred in approximately the last 10 m.y. Massive brecciated wedges of Paleozoic rocks are penetrated in two stratigraphic intervals in the drill hole; the older one, between the Tiva Canyon Member of the Paintbrush Tuff and the Rainier Mesa Member of the Timber Mountain Tuff, correlates with the time of maximum faulting east of Crater Flat in the Yucca Mountain area. The younger slide masses are correlated with a large slide block of probable late Miocene age exposed along the southwestern rim of Crater Flat. The structural pattern and style buried beneath central and western Crater Flat is deduced to be similar to that exposed at Yucca Mountain, but less developed. The major fault system controlling the steep east face of Bare Mountain, though probably still active, is believed to have developed mainly as a result of caldera collapse between 13 and 14 m.y. ago. Relations between faulting and four episodes of basalt eruption in the Crater Flat area strongly suggest contemporaneity of the two processes. 17 refs., 2 figs., 3 tabs

  14. Saying Goodbye to 'Bonneville' Crater

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Annotated Image NASA's Mars Exploration Rover Spirit took this panoramic camera image on sol 86 (March 31, 2004) before driving 36 meters (118 feet) on sol 87 toward its future destination, the Columbia Hills. This is probably the last panoramic camera image that Spirit will take from the high rim of 'Bonneville' crater, and provides an excellent view of the ejecta-covered path the rover has journeyed thus far. The lander can be seen toward the upper right of the frame and is approximately 321 meters (1060 feet) away from Spirit's current location. The large hill on the horizon is Grissom Hill. The Colombia Hills, located to the left, are not visible in this image.

  15. Sands at Gusev Crater, Mars

    Science.gov (United States)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth E.; Knoll, Andrew H.; Farmer, Jack D.; Arvidson, Raymond E.; Grin, E.A.; Li, Ron; Fenton, Lori; Cohen, B.; Bell, J.F.; Yingst, R. Aileen

    2014-01-01

    Processes, environments, and the energy associated with the transport and deposition of sand at Gusev Crater are characterized at the microscopic scale through the comparison of statistical moments for particle size and shape distributions. Bivariate and factor analyses define distinct textural groups at 51 sites along the traverse completed by the Spirit rover as it crossed the plains and went into the Columbia Hills. Fine-to-medium sand is ubiquitous in ripples and wind drifts. Most distributions show excess fine material, consistent with a predominance of wind erosion over the last 3.8 billion years. Negative skewness at West Valley is explained by the removal of fine sand during active erosion, or alternatively, by excess accumulation of coarse sand from a local source. The coarse to very coarse sand particles of ripple armors in the basaltic plains have a unique combination of size and shape. Their distribution display significant changes in their statistical moments within the ~400 m that separate the Columbia Memorial Station from Bonneville Crater. Results are consistent with aeolian and/or impact deposition, while the elongated and rounded shape of the grains forming the ripples, as well as their direction of origin, could point to Ma'adim Vallis as a possible source. For smaller particles on the traverse, our findings confirm that aeolian processes have dominated over impact and other processes to produce sands with the observed size and shape patterns across a spectrum of geologic (e.g., ripples and plains soils) and aerographic settings (e.g., wind shadows).

  16. Aboriginal oral traditions of Australian impact craters

    Science.gov (United States)

    Hamacher, Duane W.; Goldsmith, John

    2013-11-01

    In this paper we explore Aboriginal oral traditions that relate to Australian meteorite craters. Using the literature, first-hand ethnographic records and field trip data, we identify oral traditions and artworks associated with four impact sites: Gosses Bluff, Henbury, Liverpool and Wolfe Creek. Oral traditions describe impact origins for Gosses Bluff, Henbury and Wolfe Creek Craters, and non-impact origins for Liverpool Crater, with Henbury and Wolfe Creek stories having both impact and non-impact origins. Three impact sites that are believed to have been formed during human habitation of Australia -- Dalgaranga, Veevers, and Boxhole -- do not have associated oral traditions that are reported in the literature.

  17. Cratering statistics on asteroids: Methods and perspectives

    Science.gov (United States)

    Chapman, C.

    2014-07-01

    Crater size-frequency distributions (SFDs) on the surfaces of solid-surfaced bodies in the solar system have provided valuable insights about planetary surface processes and about impactor populations since the first spacecraft images were obtained in the 1960s. They can be used to determine relative age differences between surficial units, to obtain absolute model ages if the impactor flux and scaling laws are understood, to assess various endogenic planetary or asteroidal processes that degrade craters or resurface units, as well as assess changes in impactor populations across the solar system and/or with time. The first asteroid SFDs were measured from Galileo images of Gaspra and Ida (cf., Chapman 2002). Despite the superficial simplicity of these studies, they are fraught with many difficulties, including confusion by secondary and/or endogenic cratering and poorly understood aspects of varying target properties (including regoliths, ejecta blankets, and nearly-zero-g rubble piles), widely varying attributes of impactors, and a host of methodological problems including recognizability of degraded craters, which is affected by illumination angle and by the ''personal equations'' of analysts. Indeed, controlled studies (Robbins et al. 2014) demonstrate crater-density differences of a factor of two or more between experienced crater counters. These inherent difficulties have been especially apparent in divergent results for Vesta from different members of the Dawn Science Team (cf. Russell et al. 2013). Indeed, they have been exacerbated by misuse of a widely available tool (Craterstats: hrscview.fu- berlin.de/craterstats.html), which incorrectly computes error bars for proper interpretation of cumulative SFDs, resulting in derived model ages specified to three significant figures and interpretations of statistically insignificant kinks. They are further exacerbated, and for other small-body crater SFDs analyzed by the Berlin group, by stubbornly adopting

  18. Decade of inclusive education in Ghana: perspectives of special educators

    Directory of Open Access Journals (Sweden)

    Maxwell Peprah Opoku

    2017-09-01

    Full Text Available The development of inclusive education systems has been recognized as the process for orchestrating educational quality and equity. Inclusive education systems reflect growing awareness of the imperatives of 21st century societies to make quality education available to all students. This article contributes to developing area of inclusive education by exploring the perspectives of Ghanaian special educators on the progress and achievements of inclusive education. The data in this paper emerged from case study involving special educators from two regions in Ghana. Findings show an uncoordinated attempt to pilot inclusive education across the country because of different agencies funding the project. The authors argue that there is the need for a holistic review of the programme to ground the policy within the education system of Ghana.

  19. Care Services in Periurban Ghana

    Directory of Open Access Journals (Sweden)

    Paa Kobina Turkson

    2011-01-01

    Full Text Available The study used logistic regression modelling to determine predictors of satisfaction with delivery of animal health care services for 889 clients (livestock and poultry keepers in periurban Ghana. Of the 15 indicators tested as predictors of satisfaction in this study, 8 were included in the best fit model. These were accessibility, availability of services, service charge, effectiveness, efficiency, quality of services, meeting client needs, and getting help. Efficiency and effectiveness were perceived by the respondents to be synonymous, as were service quality and effectiveness, as suggested by ORs>10 when cross tabulated. Therefore, one or the other could be used in future studies but not both to avoid collinearity. The identified predictors could be targeted for improvement in quality of service delivery to livestock and poultry keepers in Ghana.

  20. Ghana's cocoa frontier in transition

    DEFF Research Database (Denmark)

    Knudsen, Michael Helt; Agergaard, Jytte

    2015-01-01

    Since the first commercial planting of cocoa in Ghana more than a century ago, the production of cocoa has been a key factor in the redistribution of migrants and has played a pivotal role in the development of both sending and receiving communities. This process has been acknowledged...... Region, this article aims to examine how immigration and frontier dynamics in the Western region are contributing to livelihood transitions and small town development, and how this process is gradually becoming delinked from the production of cocoa. The article focuses on how migration dynamics interlink...... in the literature for decades. However, how migration flows have changed in response to changing livelihoods dynamics of the frontier and how this has impacted on the development of the frontier has only attracted limited attention. Based on a study of immigration to Ghana's current cocoa frontier in the Western...

  1. Child witch hunts in contemporary Ghana.

    Science.gov (United States)

    Adinkrah, Mensah

    2011-09-01

    The persecution of children as witches has received widespread reportage in the international mass media. In recent years, hundreds of children have been killed, maimed and abandoned across Africa based on individual and village-level accusations of witchcraft. Despite the media focus, to date, very little systematic study has investigated the phenomenon. In this case study, the persecution of child witches in Ghana is studied to explore the nature and patterns of witch hunts against children in the West African nation. There are no reliable national data on child abuse related to witchcraft accusations in Ghana. For this study, 13 cases of child witch hunts appearing in the local media during 1994-2009 were analyzed. Case summaries were constructed for each incident to help identify the socio-demographic characteristics of assailants and victims, victim-offender relationships, the methods of attacks, the spatial characteristics, as well as the motivations for the attacks. Children branded as witches ranged in age from 1-month-old to 17-years-old, were primarily from poor backgrounds, and lived in rural areas of the country. Accusations of witchcraft and witch assaults were lodged by close family members often through the encouragement of, or in concert with Christian clergymen and fetish priests. Accused witches were physically brutalized, tortured, neglected, and in two cases, murdered. For school-aged children, imputations of witchcraft contributed to stigmatization in both the community and at school, resulting in dropping out. The most frequently expressed reason for persecution of the child was suspicion that the child had used witchcraft to cause the death or illness of family relations or someone in the community. Another reason was suspicion that the child was responsible for the business failure or financial difficulties of a perceived victim. The results of this research are consistent with findings in the witchcraft literature suggesting that seemingly

  2. JOICFP included in GII mission to Ghana. Global Issues Initiative.

    Science.gov (United States)

    1996-03-01

    Among countries in West Africa, Ghana is the main focus of the Global Issues Initiative (GII) on Population and AIDS and one of twelve priority countries selected for official development assistance (ODA) under the program. A ten-member project formulation mission sent to Ghana by the Ministry of Foreign Affairs (MOFA) of Japan was in the country during January 10-18. This mission was the first of its kind to be sent to Africa. It was led by the director of the Third Project Formulation Study Division, Project Formulation Study Department, Japan International Cooperation Agency (JICA), and included representatives of MOFA, JICA, and the Ministry of Health and Welfare, and an observer from UNAIDS. The mission's chief objective was to explore possibilities for Japanese cooperation in the areas of population, child health, and HIV/AIDS in line with the Mid-Term Health Strategy (MTHS) formulated in 1995 by the government of Ghana. The mission also explored the possibility of collaboration with major donors, international organizations, international agencies, and NGOs. The mission met with representatives of NGOs from population, women, AIDS, and health-related areas on January 13, who were then briefed upon Japan's Grant Assistance for Grassroots Project for local NGOs. Views were exchanged upon NGO activities.

  3. Estimating solar radiation in Ghana

    International Nuclear Information System (INIS)

    Anane-Fenin, K.

    1986-04-01

    The estimates of global radiation on a horizontal surface for 9 towns in Ghana, West Africa, are deduced from their sunshine data using two methods developed by Angstrom and Sabbagh. An appropriate regional parameter is determined with the first method and used to predict solar irradiation in all the 9 stations with an accuracy better than 15%. Estimation of diffuse solar irradiation by Page, Lin and Jordan and three other authors' correlation are performed and the results examined. (author)

  4. Underwater research methods for study of nuclear bomb craters, Enewetak, Marshall Islands

    Science.gov (United States)

    Shinn, E.A.; Halley, R.B.; Kindinger, J.L.; Hudson, J.H.; Slate, R.A.

    1990-01-01

    Three craters, created by the explosion of nuclear fusion devices, were mapped, sampled, core drilled and excavated with airlifts at Enewetak Atoll in the Marshall Islands by using scuba and a research submersible. The craters studied were Mike, Oak, and Koa. Tests took place near sea level at the transition between lithified reef flat and unlithified lagoonal sediments, where water depth ranged from 1 to 4 m. Craters produced by the blasts ranged from 30 to 60 m in depth. The purpose of our study was to determine crater diameter and depth immediately after detonation. Observations of submerged roadways and testing structures and upturned crater rims similar to those characteristic of meteor impacts indicate that the initial, or transient, craters were smaller than their present size. At some later time, while the area was too radioactive for direct examination, the sides of the craters slumped owing to dewatering of under lying pulverized rock. Core drilling of crater margins with a diver-operated hydraulic coring device provided additional data. On the seaward margin of the atoll, opposite Mike, a large portion of the atoll rim approximately the size of a city block had slumped into the deep ocean, leaving a clean vertical rock section more than 400m high. An abundance of aggressive grey reef sharks displaying classic territorial behavior prevented use of scuba at the Mike slump site. The two-person submersible R.V. Delta provided protection and allowed observations down to 300 m. During the 6-week period of study, we made more than 300 scuba and 275 submersible dives. Mapping was with side scan sonar and continuous video sweeps supplemented by tape-recorded verbal descriptions made from within the submersible. A mini-ranger navigation system linked to the submersible allowed plotting of bottom features, depth and sediment type with spatial accuracy to within 2 m.

  5. Topography of the Martian Impact Crater Tooting

    Science.gov (United States)

    Mouginis-Mark, P. J.; Garbeil, H.; Boyce, J. M.

    2009-01-01

    Tooting crater is approx.29 km in diameter, is located at 23.4degN, 207.5degE, and is classified as a multi-layered ejecta crater [1]. Our mapping last year identified several challenges that can now be addressed with HiRISE and CTX images, but specifically the third dimension of units. To address the distribution of ponded sediments, lobate flows, and volatile-bearing units within the crater cavity, we have focused this year on creating digital elevation models (DEMs) for the crater and ejecta blanket from stereo CTX and HiRISE images. These DEMs have a spatial resolution of approx.50 m for CTX data, and 2 m for HiRISE data. Each DEM is referenced to all of the available individual MOLA data points within an image, which number approx.5,000 and 800 respectively for the two data types

  6. mics in Modern Day Ghana 1

    African Journals Online (AJOL)

    Studies in Gender and Development in Afiica, I (200 7): September. THE WOMBAS TARGET: .... countries. The purpose of this historical contextualization of HIV/AIDS policy cur- rently in Ghana is to ..... product development from a distance. ..... environmental disintegration and poverty in Nordiem Ghana.” In response to the.

  7. Constructivism and mathematics education in Ghana | Fletcher ...

    African Journals Online (AJOL)

    Mathematics is a subject found in every school Curriculum in almost every country. Here in Ghana, mathematics is a compulsory subject in both the basic education (i.e. primary and junior secondary) and senior secondary curricula. This paper argues that in spite of the desire of mathematics educators in Ghana to pursue a ...

  8. Challenges of decentralisation in Ghana: district assembly's ...

    African Journals Online (AJOL)

    The 1992 Constitution of the Republic of Ghana and the various legislations on decentralisation articulate the explicit objectives of the policy which includes responsiveness to community needs. The rationale behind Ghana's decentralisation programme and the functions of the District Assemblies (DAs) therefore provide a ...

  9. Ghana Journal of Linguistics: Editorial Policies

    African Journals Online (AJOL)

    Focus and Scope. The Ghana Journal of Linguistics is a peer-reviewed scholarly journal appearing twice a year, published by the Linguistics Association of Ghana. Beginning with Volume 2 (2013) it is published in electronic format only, open access, at www.ajol.info. However print-on-demand copies can be made ...

  10. Management of mutual health organizations in Ghana.

    NARCIS (Netherlands)

    Baltussen, R.M.P.M.; Bruce, E.; Rhodes, G.; Narh-Bana, S.A.; Agyepong, I.

    2006-01-01

    OBJECTIVE: Mutual Health Organizations (MHO) emerged in Ghana in the mid-1990s. The organizational structure and financial management of private and public MHO hold important lessons for the development of national health insurance in Ghana, but there is little evidence to date on their features.

  11. Leakage of active crater lake brine through the north flank at Rincon de la Vieja volcano, northwest Costa Rica, and implications for crater collapse

    Science.gov (United States)

    Kempter, K.A.; Rowe, G.L.

    2000-01-01

    de la Vieja. The distribution of thermal water types at Rincon de la Vieja strongly indicates that formation of the north-flank ACS waters is not due to mixing of shallow, steam-heated AS water with deep-seated NC water. More likely, hyper-acidic brines formed in the Active Crater area are migrating through permeable zones in the volcanic strata that make up the Active Crater's north flank. Dissolution and shallow subsurface alteration of north-flank volcanoclastic material by interaction with acidic lake brine, particularly in the more permeable tephra units, could weaken the already oversteepened north flank of the Active Crater. Sector collapse of the Active Crater, with or without a volcanic eruption, represents a potential threat to human lives, property, and ecosystems at Rincon de la Vieja volcano.

  12. Crater Mound Formation by Wind Erosion on Mars

    Science.gov (United States)

    Steele, L. J.; Kite, E. S.; Michaels, T. I.

    2018-01-01

    Most of Mars' ancient sedimentary rocks by volume are in wind-eroded sedimentary mounds within impact craters and canyons, but the connections between mound form and wind erosion are unclear. We perform mesoscale simulations of different crater and mound morphologies to understand the formation of sedimentary mounds. As crater depth increases, slope winds produce increased erosion near the base of the crater wall, forming mounds. Peak erosion rates occur when the crater depth is ˜2 km. Mound evolution depends on the size of the host crater. In smaller craters mounds preferentially erode at the top, becoming more squat, while in larger craters mounds become steeper sided. This agrees with observations where smaller craters tend to have proportionally shorter mounds and larger craters have mounds encircled by moats. If a large-scale sedimentary layer blankets a crater, then as the layer recedes across the crater it will erode more toward the edges of the crater, resulting in a crescent-shaped moat. When a 160 km diameter mound-hosting crater is subject to a prevailing wind, the surface wind stress is stronger on the leeward side than on the windward side. This results in the center of the mound appearing to "march upwind" over time and forming a "bat-wing" shape, as is observed for Mount Sharp in Gale crater.

  13. A content analysis of outdoor non-alcoholic beverage advertisements in Ghana

    OpenAIRE

    Bragg, Marie A; Hardoby, Tamara; Pandit, Natasha G; Raji, Yemi R; Ogedegbe, Gbenga

    2017-01-01

    Objectives This was a two-part descriptive study designed to (1) assess the marketing themes and sugar content of beverages promoted in outdoor advertisements (ads) within a portion of Accra, Ghana and (2) quantify the types of ads that appeared along the Accra-Cape Coast Highway. Setting A 4.7 km2 area of Accra, Ghana and a 151 km region along the highway represented the target areas for collecting photos of outdoor beverage ads. Primary and secondary outcome measures Number and types of bev...

  14. Nuclear cratering on a digital computer

    Energy Technology Data Exchange (ETDEWEB)

    Terhune, R W; Stubbs, T F; Cherry, J T [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Computer programs based on the artificial viscosity method are applied to developing an understanding of the physics of cratering, with emphasis on cratering by nuclear explosives. Two established codes, SOC (spherical symmetry) and TENSOR (cylindrical symmetry), are used to illustrate the effects of variations in the material properties of various media on the cratering processes, namely shock, spall, and gas acceleration. Water content is found to be the most important material property, followed by strength, porosity, and compressibility. Crater profile calculations are presented for Pre-Gondola Charley (20-ton nitromethane detonation in shale) and Sedan (100-kt nuclear detonation in alluvium). Calculations also are presented for three 1-Mt yields in saturated Divide basalt and 1-Mt yield in dry Buckboard basalt, to show crater geometry as a function of the burial depth for large explosive yields. The calculations show, for megaton-level yields, that gas acceleration is the dominate mechanism in determining crater size and depends in turn on the water content in the medium. (author)

  15. Nuclear cratering on a digital computer

    International Nuclear Information System (INIS)

    Terhune, R.W.; Stubbs, T.F.; Cherry, J.T.

    1970-01-01

    Computer programs based on the artificial viscosity method are applied to developing an understanding of the physics of cratering, with emphasis on cratering by nuclear explosives. Two established codes, SOC (spherical symmetry) and TENSOR (cylindrical symmetry), are used to illustrate the effects of variations in the material properties of various media on the cratering processes, namely shock, spall, and gas acceleration. Water content is found to be the most important material property, followed by strength, porosity, and compressibility. Crater profile calculations are presented for Pre-Gondola Charley (20-ton nitromethane detonation in shale) and Sedan (100-kt nuclear detonation in alluvium). Calculations also are presented for three 1-Mt yields in saturated Divide basalt and 1-Mt yield in dry Buckboard basalt, to show crater geometry as a function of the burial depth for large explosive yields. The calculations show, for megaton-level yields, that gas acceleration is the dominate mechanism in determining crater size and depends in turn on the water content in the medium. (author)

  16. Map Coordinate Referencing and the use of GPS Datasets in Ghana ...

    African Journals Online (AJOL)

    Map Coordinate Referencing and the use of GPS Datasets in Ghana. ... Journal of Science and Technology (Ghana) ... systems used in Ghana (the Ghana war office system and also the Clarke1880 system) using the Bursa-Wolf model.

  17. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Estimated thickness of ejecta deposits compared to to crater rim heights. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    The area of the continuous ejecta deposits on mercury was calculated to vary from 2.24 to 0.64 times the crater's area for those of diameter 40 km to 300 km. Because crater boundaries on the geologic map include the detectable continuous ejecta blanket, plains exterior to these deposits must consist of farther-flung ejecta (of that or other craters), or volcanic deposits flooding the intervening areas. Ejecta models are explored.

  18. What Influences Where They Give Birth? Determinants of Place of Delivery among Women in Rural Ghana

    Directory of Open Access Journals (Sweden)

    Kwamena Sekyi Dickson

    2016-01-01

    Full Text Available Background. There is a paucity of empirical literature in Ghana on rural areas and their utilisation of health facilities. The study examined the effects of the sociodemographics of rural women on place of delivery in the country. Methods. The paper made use of data from the 2014 Ghana Demographic and Health Survey. Women from rural areas who had given birth within five years prior to the survey were included in the analysis. Descriptive analyses and binary logistic regression were used to analyse the data. Results. Wealth, maternal education, ecological zone, getting money for treatment, ethnicity, partner’s education, parity, and distance to a health facility were found as the determinants of place of delivery among women in rural Ghana. Women in the richest wealth quintile were three times (OR = 3.04, 95% CI = 0.35–26.4 more likely to deliver at a health facility than the poorest women. Conclusions. It behoves the relevant stakeholders including the Ghana Health Service and the Ministry of Health to pay attention to the wealth status, maternal education, ecological zone, ethnicity, partner’s education, parity, and distance in their planning regarding delivery care in rural Ghana.

  19. Are pre-crater mounds gas-inflated?

    Science.gov (United States)

    Leibman, Marina; Kizyakov, Alexandr; Khomutov, Artem; Dvornikov, Yury; Babkina, Elena; Arefiev, Stanislav; Khairullin, Rustam

    2017-04-01

    Gas-emission craters (GEC) on Yamal peninsula, which occupied minds of researches for the last couple of years since first discovered in 2014, appeared to form on the place of specifically shaped mounds. There was a number of hypotheses involving pingo as an origin of these mounds. This arouse an interest in mapping pingo thus marking the areas of GEC formation risk. Our field research allows us to suggest that remote-sensing-based mapping of pingo may result in mix up of mounds of various origin. Thus, we started with classification of the mounds based on remote-sensing, field observations and survey from helicopter. Then we compared indicators of mounds of various classes to the properties of pre-crater mounds to conclude on their origin. Summarizing field experience, there are three main mound types on Yamal. (1) Outliers (remnant hills), separated from the main geomorphic landform by erosion. Often these mounds comprise polygonal blocks, kind of "baydzherakh". Their indicators are asymmetry (short gentle slope towards the main landform, and steep slope often descending into a small pond of thermokarst-nivation origin), often quadrangle or conic shape, and large size. (2) Pingo, appear within the khasyrei (drain lake basin); often are characterized by open cracks resulting from expansion of polygonal network formed when re-freezing of lake talik prior to pingo formation; old pingo may bear traces of collapse on the top, with depression which differs from the GEC by absence of parapet. (3) Frost-heave mounds (excluding pingo) may form on deep active layer, reducing due to moss-peat formation and forming ice lenses from an active layer water, usually they appear in the drainage hollows, valley bottoms, drain-lake basins periphery. These features are smaller than the first two types of mounds. Their tops as a rule are well vegetated. We were unable to find a single or a set of indicators unequivocally defining any specific mound type, thus indicators of pre-crater

  20. Preliminary results of soil radon gas survey of the Lake Bosomtwi impact crater

    International Nuclear Information System (INIS)

    Preko, S.; Danuor, S.K.; Menyeh, A.

    2004-01-01

    Soil radon gas survey was carried out in the Lake Bosomtwi impact crater area on eight profiles, which ran rapidly toward the end of the crater. One thousand soil samples, each weighing about 100g were acquired at a depth of 20 cm and at regular intervals of 10 m. The radon gas decay rate of the soil samples was then determined in the laboratory using the RDA-200 Radon detector and RDU-200 Degassing unit. It was found that generally areas south and east of the crater, which are severally sheared, faulted and fractured recorded high radon gas decay rates of the order of 800 counts/min whilst relatively undisturbed zones west of the crater recorded lower rates of the order of 20 counts/min. the cause of fracturing, shearing and faulting have been attributed to the effect of the meteorite impact in the Bosomtwi area, and therefore the results indicate that the soil radon gas survey could serve as a useful tool in mapping the impact-related structural characteristics of the crater. (author)

  1. El'gygytgyn impact crater, Chukotka, Arctic Russia: Impact cratering aspects of the 2009 ICDP drilling project

    Science.gov (United States)

    Koeberl, Christian; Pittarello, Lidia; Reimold, Wolf Uwe; Raschke, Ulli; Brigham-Grette, Julie; Melles, Martin; Minyuk, Pavel; Spray, John

    2013-01-01

    this rather thin fallback impactite sequence may be the location of the drill core on an elevated part of the central uplift. A general lack of large coherent melt bodies is evident, similar to that found at the similarly sized Bosumtwi impact crater in Ghana that, however, was formed in a target composed of a thin layer of sediment above crystalline rocks. PMID:26074719

  2. Facipulation and Elite Formation: Community Resource Management in Southwestern Ghana

    Directory of Open Access Journals (Sweden)

    Manali Baruah

    2017-01-01

    Full Text Available Despite their stated commitment to democratic processes, the Government of Ghana and international authorities presume the accountability and ability of NGOs to represent local interests in forest resource management. This article scrutinises elite formation and elite capture through the case of a Community Resource Management Area (CREMA in western Ghana. NGOs and the forestry department promotes commercial tree planting on farmlands at this CREMA site. This article shows how institutional mandates, technical and managerial priorities are used by higher-level authorities to rationalise the omission of accountability and representation in CREMA activities. Disregard for democratic processes thus centralise decision making and render political processes apolitical at the cost of effective local participation and control over forest resources. Also, the legal and administrative framework of the CREMA tended to empower the traditional elites. In addition, the recognition of a local NGO by state authorities to oversee natural resource management infringed upon the CREMA's mandate and encouraged the formation of new elites. Further, the higher-level authorities' promotion of tree-tenure privatisation reduced public engagement by enclosing and thus discounting the public forest domain. The combination of these factors compromise the accountability and equitable sharing of benefits in CREMAs. Nevertheless, the CREMAs have been endorsed by the government as an innovative institutional structure for implementing REDD+ projects in Ghana.

  3. Predictors of contraceptive use among female adolescents in Ghana.

    Science.gov (United States)

    Marrone, Gaetano; Abdul-Rahman, Lutuf; De Coninck, Zaake; Johansson, Annika

    2014-03-01

    Adolescent girls in Ghana still face a number of challenges accessing reproductive/sexual health services despite efforts to improve their accessibility. This paper explores the key socio-demographic factors associated with contraceptive use amongst adolescent girls in Ghana using the 2008 Ghana Demographic and Health Survey (GDHS). Data from the 2008 GDHS was analyzed. Socio-demographic variables were selected to assess their interaction with contraceptive use. Multivariable regression analyses were performed. Odds ratios and confidence intervals were computed. Place of residence and marital status were the most important predictors of contraceptive use among sexually active adolescents. Rural residents were less likely to use contraceptives compared to urban residents (OR 0.32, CI 0.12-0.84, p = 0.021) as well as married respondents compared to their unmarried peers (OR 0.27, 95% CI 0.11-0.67, p = 0.005). The accessibility of reproductive/sexual health services needs to be improved and promoted in rural areas and among married adolescent women.

  4. Mafic Materials in Scott Crater? A Test for Lunar Reconnaissance Orbiter

    Science.gov (United States)

    Cooper, Bonnie L.

    2007-01-01

    Clementine 750 nm and multispectral ratio data, along with Lunar Orbiter and radar data, were used to study the crater Scott in the lunar south polar region. The multispectral data provide evidence for mafic materials, impact melts, anorthositic materials, and a small pyroclastic deposit. High-resolution radar data and Lunar Orbiter photography for this area show differences in color and surface texture that correspond with the locations of the hypothesized mafic and anorthositic areas on the crater floor. This region provides a test case for the upcoming Lunar Reconnaissance Orbiter. Verification of the existence of a mafic deposit at this location is relevant to future lunar resource utilization planning.

  5. Pancam Peek into 'Victoria Crater' (Stereo)

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Left-eye view of a stereo pair for PIA08776 [figure removed for brevity, see original site] Right-eye view of a stereo pair for PIA08776 A drive of about 60 meters (about 200 feet) on the 943rd Martian day, or sol, of Opportunity's exploration of Mars' Meridiani Planum region (Sept. 18, 2006) brought the NASA rover to within about 50 meters (about 160 feet) of the rim of 'Victoria Crater.' This crater has been the mission's long-term destination for the past 21 Earth months. Opportunity reached a location from which the cameras on top of the rover's mast could begin to see into the interior of Victoria. This stereo anaglyph was made from frames taken on sol 943 by the panoramic camera (Pancam) to offer a three-dimensional view when seen through red-blue glasses. It shows the upper portion of interior crater walls facing toward Opportunity from up to about 850 meters (half a mile) away. The amount of vertical relief visible at the top of the interior walls from this angle is about 15 meters (about 50 feet). The exposures were taken through a Pancam filter selecting wavelengths centered on 750 nanometers. Victoria Crater is about five times wider than 'Endurance Crater,' which Opportunity spent six months examining in 2004, and about 40 times wider than 'Eagle Crater,' where Opportunity first landed. The great lure of Victoria is the expectation that a thick stack of geological layers will be exposed in the crater walls, potentially several times the thickness that was previously studied at Endurance and therefore, potentially preserving several times the historical record.

  6. A Tale of Two Craters

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] In western Acidalia, two craters of similar size (a few km's) dramatically display the effects of geologic activity. The younger one on the left has been left relatively well preserved, retaining a sharp rim crest, a classic bowl shape, and a clearly defined ejecta blanket. The older one on the right likely has experienced a flood of lava that covered over the ejecta and filled in the bowl (note the breach in the rim). Its rim crest has been worn down by a multitude of subsequent impacts.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude 35.9, Longitude 311.1 East (48.9 West). 19 meter/pixel resolution.

  7. The Global Contribution of Secondary Craters on the Icy Satellites

    Science.gov (United States)

    Hoogenboom, T.; Johnson, K. E.; Schenk, P.

    2014-12-01

    At present, surface ages of bodies in the Outer Solar System are determined only from crater size-frequency distributions (a method dependent on an understanding of the projectile populations responsible for impact craters in these planetary systems). To derive accurate ages using impact craters, the impactor population must be understood. Impact craters in the Outer Solar System can be primary, secondary or sesquinary. The contribution of secondary craters to the overall population has recently become a "topic of interest." Our objective is to better understand the contribution of dispersed secondary craters to the small crater populations, and ultimately that of small comets to the projectile flux on icy satellites in general. We measure the diameters of obvious secondary craters (determined by e.g. irregular crater shape, small size, clustering) formed by all primary craters on Ganymede for which we have sufficiently high resolution data to map secondary craters. Primary craters mapped range from approximately 40 km to 210 km. Image resolution ranges from 45 to 440 m/pixel. Bright terrain on Ganymede is our primary focus. These resurfaced terrains have relatively low crater densities and serve as a basis for characterizing secondary populations as a function of primary size on an icy body for the first time. Although focusing on Ganymede, we also investigate secondary crater size, frequency, distribution, and formation, as well as secondary crater chain formation on icy satellites throughout the Saturnian and Jovian systems principally Rhea. We compare our results to similar studies of secondary cratering on the Moon and Mercury. Using Galileo and Voyager data, we have identified approximately 3,400 secondary craters on Ganymede. In some cases, we measured crater density as a function of distance from a primary crater. Because of the limitations of the Galileo data, it is necessary to extrapolate from small data sets to the global population of secondary craters

  8. Closure plan for Corrective Action Unit 109: U-2bu subsidence crater, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    1999-03-01

    The U-2bu subsidence crater, Corrective Action Unit 109, will be closed in accordance with the Resource Conservation and Recovery Act, the Nevada Division of Environmental Protection operational permit, and the Federal Facility Agreement and Consent Order. The U-2bu subsidence crater is located in Area 2 of the Nevada Test Site. It was created in 1971 by an underground nuclear test with the name Miniata. The crater has a diameter of 288 meters (944 feet) and an approximate depth of 35 meters (115 feet). Based on the results of the analyses reported in the site characterization report, the only constituents of concern in the U-2bu subsidence crater include leachable lead and total petroleum hydrocarbons. Closure activities will include the excavation and disposal of impacted soil from the top of the crater. Upon completion of excavation, verification samples will be collected to show that the leachable lead has been removed to concentrations below the regulatory action level. After sample results show that the lead has been removed, the excavated area will be backfilled and a soil flood diversion berm will be constructed as a best management practice. An independent registered professional engineer will certify the site was closed following the approved Closure Plan. Post-closure care is not warranted for this site because closure activities will involve removal of the Resource Conservation and Recovery Act constituents of concern

  9. RCRA Part A permit characterization plan for the U-2bu subsidence crater. Revision 1

    International Nuclear Information System (INIS)

    1998-04-01

    This plan presents the characterization strategy for Corrective Action Unit (CAU) 109, U-2bu Subsidence Crater (referred to as U-2bu) in Area 2 at the Nevada Test Site (NTS). The objective of the planned activities is to obtain sufficient characterization data for the crater soils and observed wastes under the conditions of the current Resource Conservation and Recovery Act (RCRA) Part A permit. The scope of the characterization plan includes collecting surface and subsurface soil samples with hand augers and for the purpose of site characterization. The sampling strategy is to characterize the study area soils and look for RCRA constituents. Observable waste soils and surrounding crater soils will be analyzed and evaluated according to RCRA closure criteria. Because of the status of the crater a RCRA Part A permit site, acquired radionuclide analyses will only be evaluated in regards to the health and safety of site workers and the disposition of wastes generated during site characterization. The U-2bu Subsidence Crater was created in 1971 by a Lawrence Livermore National Laboratory underground nuclear test, event name Miniata, and was used as a land-disposal unit for radioactive and hazardous waste from 1973 to 1988

  10. Closure Plan for Corrective Action Unit 109: U-2bu Subsidence Crater Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Shannon Parsons

    1999-03-01

    The U-2bu subsidence crater, Corrective Action Unit 109, will be closed in accordance with the Resource Conservation and Recovery Act, the Nevada Division of Environmental Protection operational permit, and the Federal Facilities Agreement and Consent Order. The U-2bu subsidence crater is located in Area 2 of the Nevada Test Site. It was created in 1971 by an underground nuclear test with the name Miniata. The crater has a diameter of 288 meters (944 feet) and an approximate depth of 35 meters (115 feet). The subsidence crater was used as a land disposal unit for radioactive and hazardous waste from 1973 to 1988. Site disposal history is supported by memorandums, letters, and personnel who worked at the Nevada Test Site at the time of active disposal. Closure activities will include the excavation and disposal of impacted soil form the tip of the crater. Upon completion of excavation, verification samples will be collected to show that lead has been removed to concentrations be low regulatory action level. The area will then be backfilled and a soil flood diversion berm will be constructed, and certified by an independent professional engineer as to having followed the approved Closure Plan.

  11. Closure plan for Corrective Action Unit 109: U-2bu subsidence crater, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The U-2bu subsidence crater, Corrective Action Unit 109, will be closed in accordance with the Resource Conservation and Recovery Act, the Nevada Division of Environmental Protection operational permit, and the Federal Facility Agreement and Consent Order. The U-2bu subsidence crater is located in Area 2 of the Nevada Test Site. It was created in 1971 by an underground nuclear test with the name Miniata. The crater has a diameter of 288 meters (944 feet) and an approximate depth of 35 meters (115 feet). Based on the results of the analyses reported in the site characterization report, the only constituents of concern in the U-2bu subsidence crater include leachable lead and total petroleum hydrocarbons. Closure activities will include the excavation and disposal of impacted soil from the top of the crater. Upon completion of excavation, verification samples will be collected to show that the leachable lead has been removed to concentrations below the regulatory action level. After sample results show that the lead has been removed, the excavated area will be backfilled and a soil flood diversion berm will be constructed as a best management practice. An independent registered professional engineer will certify the site was closed following the approved Closure Plan. Post-closure care is not warranted for this site because closure activities will involve removal of the Resource Conservation and Recovery Act constituents of concern.

  12. Attitudes towards English in Ghana

    Directory of Open Access Journals (Sweden)

    Kari Dako

    2017-05-01

    Full Text Available The paper considers official and individual attitudes towards bilingualism in English and a Ghanaian language. We ask whether bilingualism in English and Ghanaian languages is a social handicap, without merit, or an important indicator of ethnic identity. Ghana has about 50 non-mutually intelligible languages, yet there are no statistics on who speaks what language(s where in the country. We consider attitudes to English against the current Ghanaian language policy in education as practised in the school system. Our data reveal that parents believe early exposure to English enhances academic performance; English is therefore becoming the language of the home.

  13. Combined analysis of 2-D electrical resistivity, seismic refraction and geotechnical investigations for Bukit Bunuh complex crater

    International Nuclear Information System (INIS)

    Azwin, I N; Saad, Rosli; Nordiana, M M; Bery, Andy Anderson; Hidayah, I N E; Saidin, Mokhtar

    2015-01-01

    Interest in studying impact crater on earth has increased tremendously due to its importance in geologic events, earth inhabitant history as well as economic value. The existences of few shock metamorphism and crater morphology evidences are discovered in Bukit Bunuh, Malaysia thus detailed studies are performed using geophysical and geotechnical methods to verify the type of the crater and characteristics accordingly. This paper presents the combined analysis of 2-D electrical resistivity, seismic refraction, geotechnical SPT N value, moisture content and RQD within the study area. Three stages of data acquisition are made starting with regional study followed by detailed study on West side and East side. Bulk resistivity and p-wave seismic velocity were digitized from 2-D resistivity and seismic sections at specific distance and depth for corresponding boreholes and samples taken. Generally, Bukit Bunuh shows the complex crater characteristics. Standard table of bulk resistivity and p-wave seismic velocity against SPT N value, moisture content and RQD are produce according to geological classifications of impact crater; inside crater, rim/slumped terrace and outside crater

  14. Combined analysis of 2-D electrical resistivity, seismic refraction and geotechnical investigations for Bukit Bunuh complex crater

    Science.gov (United States)

    Azwin, I. N.; Saad, Rosli; Saidin, Mokhtar; Nordiana, M. M.; Anderson Bery, Andy; Hidayah, I. N. E.

    2015-01-01

    Interest in studying impact crater on earth has increased tremendously due to its importance in geologic events, earth inhabitant history as well as economic value. The existences of few shock metamorphism and crater morphology evidences are discovered in Bukit Bunuh, Malaysia thus detailed studies are performed using geophysical and geotechnical methods to verify the type of the crater and characteristics accordingly. This paper presents the combined analysis of 2-D electrical resistivity, seismic refraction, geotechnical SPT N value, moisture content and RQD within the study area. Three stages of data acquisition are made starting with regional study followed by detailed study on West side and East side. Bulk resistivity and p-wave seismic velocity were digitized from 2-D resistivity and seismic sections at specific distance and depth for corresponding boreholes and samples taken. Generally, Bukit Bunuh shows the complex crater characteristics. Standard table of bulk resistivity and p-wave seismic velocity against SPT N value, moisture content and RQD are produce according to geological classifications of impact crater; inside crater, rim/slumped terrace and outside crater.

  15. NORTHERN REGION OF GHANA

    African Journals Online (AJOL)

    2004-12-02

    Dec 2, 2004 ... the use of Cl and stable isotopes (2H and 18O), Sharma and Hughes. (1985) observed that ... able to adapt to the harsh environmental conditions of the area. Dur- ing the dry ... December 2004. 3.4 Geology and hydrogeology.

  16. 1995 annual report. Ghana Atomic Energy Commission : using nuclear energy and techniques to alleviate hunger, diseases and control of environmental pollution

    International Nuclear Information System (INIS)

    1996-01-01

    The 1995 annual report reflects the activities of the Ghana Atomic Energy Commission (GAEC) on an institutional basis. It provides an overview of the outcomes achieved and the current activities of the GAEC grouped under its core nuclear science areas

  17. Geochemical monitoring of volcanic lakes. A generalized box model for active crater lakes

    Directory of Open Access Journals (Sweden)

    Franco Tassi

    2011-06-01

    Full Text Available

    In the past, variations in the chemical contents (SO42−, Cl−, cations of crater lake water have not systematically demonstrated any relationships with eruptive activity. Intensive parameters (i.e., concentrations, temperature, pH, salinity should be converted into extensive parameters (i.e., fluxes, changes with time of mass and solutes, taking into account all the internal and external chemical–physical factors that affect the crater lake system. This study presents a generalized box model approach that can be useful for geochemical monitoring of active crater lakes, as highly dynamic natural systems. The mass budget of a lake is based on observations of physical variations over a certain period of time: lake volume (level, surface area, lake water temperature, meteorological precipitation, air humidity, wind velocity, input of spring water, and overflow of the lake. This first approach leads to quantification of the input and output fluxes that contribute to the actual crater lake volume. Estimating the input flux of the "volcanic" fluid (Qf- kg/s –– an unmeasurable subsurface parameter –– and tracing its variations with time is the major focus during crater lake monitoring. Through expanding the mass budget into an isotope and chemical budget of the lake, the box model helps to qualitatively characterize the fluids involved. The (calculated Cl− content and dD ratio of the rising "volcanic" fluid defines its origin. With reference to continuous monitoring of crater lakes, the present study provides tips that allow better calculation of Qf in the future. At present, this study offers the most comprehensive and up-to-date literature review on active crater lakes.

  18. Ghana Science Association. 21st biennial conference. Program and abstracts book

    International Nuclear Information System (INIS)

    1999-08-01

    The publication covers the program and abstracts of papers presented during the 21st biennial conference of the Ghana Science Association. The conference was held at the University of Ghana, Legon from 8th to 13th August 1999. The theme of the conference was S ustainable food Industry in Ghana in the 21st Century . The first part of the publication covers membership of various committees, list of sponsors and conference program among others. The second part is devoted to abstracts of papers presented during various scientific sessions. Papers have been grouped under the following subject areas: Biological and Medical Science, Physical Sciences, Food and Agriculture, Social Science Education and Policy Research and Poster Presentations. (E.A.)

  19. The Environmental Effect of Land Use in the Tenure Systems in Ghana

    Directory of Open Access Journals (Sweden)

    Libor Grega

    2016-01-01

    Full Text Available This paper examines the land tenure system in Ghana and its impact on the environment. The main forms of land tenure systems are explained and the positive and negative impacts of each of these forms on the environment analysed. Specific attention is devoted to deforestation and soil depletion. The complex problems of land acquisition in Ghana, and the inherent insecurity effects on farming, which is considered to be the most important economic activity in the rural areas are examined. The analyses and the result proved that the insecurity of land tenure system has a direct relationship with the environment. Cross-sectional data analyses establishes that traditional forms of land acquisitions, ownership and land use form part of the main causes of environmental degradation in Ghana.

  20. A concise biogas plant construction suitable for Ghana and other tropical countries

    Energy Technology Data Exchange (ETDEWEB)

    Gbagbo, J.K.N.

    1997-04-01

    This report is intended to be used by people in the field of biogas for workshops, technicians, teachers to educate as well as to carry out hands on constructions in Ghana and other tropical countries. Chapter 1, discusses the biogas technology, what a biogas plant is, and how it functions. Chapter 2, describes the entire process. Chapter 3, discusses the necessary conditions for fermentation. Chapter 4, the measuring parameters for monitoring the system. Chapter 5, describes the various types of biogas plants suitable for tropical countries. Chapter 6, describes a planning guide for Ghana and other tropical countries. Chapter 7, discusses digester sizing and finally, Chapter 8, describes a concise biogas plant construction suitable for the rural areas of Ghana and other tropical countries. (au)

  1. Qualitative Interpretation Of Aerogravity And Aeromagnetic Survey Data Over The South Western Part Of The Volta River Basin Of Ghana

    OpenAIRE

    George Hinson; Aboagye Menyeh; David Dotse Wemegah

    2015-01-01

    Abstract The study area South western part of Volta River Basin of Ghana covering an area of 8570 km2 which is one-eleventh the area of the Volta River basin of Ghana has been subjected to numerous academic research works but geophysical survey works because of virtual perceptive reasons. It is now believed to overly mineral-rich geological structures hence the use of magnetic and gravity survey methods to bring out these mineral-rich geological structures.Geographically it study area is loca...

  2. The effects of vehicle congestion on the environment – an EIA in the Ngorongoro crater. The Environmental Impact Statement

    OpenAIRE

    Nyahongo, Julius; Lowassa, Asanterabi; Malugu, Lucas; Nkya, Hassan; Mwakalebe, Grayson; Thomassen, Jørn; Kaltenborn, Bjørn Petter; Lyamuya, Richard; Marealle, Wilfred; Keyyu, Julius; Stokke, Sigbjørn; Røskaft, Eivin

    2007-01-01

    Nyahongo, J., Lowassa, A., Malugu, L., Nkya, H., Mwakalebe, G., Thomassen, J., Kaltenborn, B. P., Lyamuya, R., Marealle, W., Keyyu, J., Stokke, S. & Røskaft, E. 2007. The effects of vehicle congestion on the environment – an EIA in the Ngorongoro crater. The Environmental Impact Statement – NINA Report 258. 83 pp. The Ngorongoro Conservation Area Authority (NCAA) faces a great challenge in managing the vehicle congestion in the Ngorongoro crater. They are in need for an assessment of the pres...

  3. Two-dimensional computer simulation of hypervelocity impact cratering: some preliminary results for Meteor Crater, Arizona

    International Nuclear Information System (INIS)

    Bryan, J.B.; Burton, D.E.; Cunningham, M.E.; Lettis, L.A. Jr.

    1978-06-01

    A computational approach used for subsurface explosion cratering was extended to hypervelocity impact cratering. Meteor (Barringer) Crater, Arizona, was selected for the first computer simulation because it is one of the most thoroughly studied craters. It is also an excellent example of a simple, bowl-shaped crater and is one of the youngest terrestrial impact craters. Initial conditions for this calculation included a meteorite impact velocity of 15 km/s, meteorite mass of 1.67 x 10 8 kg, with a corresponding kinetic energy of 1.88 x 10 16 J (4.5 megatons). A two-dimensional Eulerian finite difference code called SOIL was used for this simulation of a cylindrical iron projectile impacting at normal incidence into a limestone target. For this initial calculation, a Tillotson equation-of-state description for iron and limestone was used with no shear strength. Results obtained for this preliminary calculation of the formation of Meteor Crater are in good agreement with field measurements. A color movie based on this calculation was produced using computer-generated graphics. 19 figures, 5 tables, 63 references

  4. Two-dimensional computer simulation of hypervelocity impact cratering: some preliminary results for Meteor Crater, Arizona

    International Nuclear Information System (INIS)

    Bryan, J.B.; Burton, D.E.; Cunningham, M.E.; Lettis, L.A. Jr.

    1978-04-01

    A computational approach used for subsurface explosion cratering has been extended to hypervelocity impact cratering. Meteor (Barringer) Crater, Arizona, was selected for our first computer simulation because it was the most thoroughly studied. It is also an excellent example of a simple, bowl-shaped crater and is one of the youngest terrestrial impact craters. Shoemaker estimates that the impact occurred about 20,000 to 30,000 years ago [Roddy (1977)]. Initial conditions for this calculation included a meteorite impact velocity of 15 km/s. meteorite mass of 1.57E + 08 kg, with a corresponding kinetic energy of 1.88E + 16 J (4.5 megatons). A two-dimensional Eulerian finite difference code called SOIL was used for this simulation of a cylindrical iron projectile impacting at normal incidence into a limestone target. For this initial calculation a Tillotson equation-of-state description for iron and limestone was used with no shear strength. A color movie based on this calculation was produced using computer-generated graphics. Results obtained for this preliminary calculation of the formation of Meteor Crater, Arizona, are in good agreement with Meteor Crater Measurements

  5. Two-dimensional computer simulation of hypervelocity impact cratering: some preliminary results for Meteor Crater, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, J.B.; Burton, D.E.; Cunningham, M.E.; Lettis, L.A. Jr.

    1978-06-01

    A computational approach used for subsurface explosion cratering was extended to hypervelocity impact cratering. Meteor (Barringer) Crater, Arizona, was selected for the first computer simulation because it is one of the most thoroughly studied craters. It is also an excellent example of a simple, bowl-shaped crater and is one of the youngest terrestrial impact craters. Initial conditions for this calculation included a meteorite impact velocity of 15 km/s, meteorite mass of 1.67 x 10/sup 8/ kg, with a corresponding kinetic energy of 1.88 x 10/sup 16/ J (4.5 megatons). A two-dimensional Eulerian finite difference code called SOIL was used for this simulation of a cylindrical iron projectile impacting at normal incidence into a limestone target. For this initial calculation, a Tillotson equation-of-state description for iron and limestone was used with no shear strength. Results obtained for this preliminary calculation of the formation of Meteor Crater are in good agreement with field measurements. A color movie based on this calculation was produced using computer-generated graphics. 19 figures, 5 tables, 63 references.

  6. Experimental investigation of crater growth dynamics

    Science.gov (United States)

    Schmidt, R. M.; Housen, K. R.; Bjorkman, M. D.; Holsapple, K. A.

    1985-01-01

    This work is a continuation of an ongoing program whose objective is to perform experiments and to develop scaling relationships for large-body impacts onto planetary surfaces. The centrifuge technique is used to provide experimental data for actual target materials of interest. With both power and gas guns mounted on the rotor arm, it is possible to match various dimensionless similarity parameters, which have been shown to govern the behavior of large-scale impacts. The development of the centrifuge technique has been poineered by the present investigators and is documented by numerous publications, the most recent of which are listed below. Understanding the dependence of crater size upon gravity has been shown to be key to the complete determination of the dynamic and kinematic behavior of crater formation as well as ejecta phenomena. Three unique time regimes in the formation of an impact crater have been identified.

  7. Crater monitoring through social media observations

    Science.gov (United States)

    Gialampoukidis, I.; Vrochidis, S.; Kompatsiaris, I.

    2017-09-01

    We have collected more than one lunar image per two days from social media observations. Each one of the collected images has been clustered into two main groups of lunar images and an additional cluster is provided (noise) with pictures that have not been assigned to any cluster. The proposed lunar image clustering process provides two classes of lunar pictures, at different zoom levels; the first showing a clear view of craters grouped into one cluster and the second demonstrating a complete view of the Moon at various phases that are correlated with the crawling date. The clustering stage is unsupervised, so new topics can be detected on-the-fly. We have provided additional sources of planetary images using crowdsourcing information, which is associated with metadata such as time, text, location, links to other users and other related posts. This content has crater information that can be fused with other planetary data to enhance crater monitoring.

  8. Physics of soft impact and cratering

    CERN Document Server

    Katsuragi, Hiroaki

    2016-01-01

    This book focuses on the impact dynamics and cratering of soft matter to describe its importance, difficulty, and wide applicability to planetary-related problems. A comprehensive introduction to the dimensional analysis and constitutive laws that are necessary to discuss impact mechanics and cratering is first provided. Then, particular coverage is given to the impact of granular matter, which is one of the most crucial constituents for geophysics. While granular matter shows both solid-like and fluid-like behaviors, neither solid nor fluid dynamics is sufficient to fully understand the physics of granular matter. In order to reveal its fundamental properties, extensive impact tests have been carried out recently. The author reveals the findings of these recent studies as well as what remains unsolved in terms of impact dynamics. Impact crater morphology with various soft matter impacts also is discussed intensively. Various experimental and observational results up to the recent Itokawa asteroid’s terrain...

  9. A concept of row crater enhancement

    International Nuclear Information System (INIS)

    Redpath, B.B.

    1970-01-01

    Linear craters formed by the simultaneous detonation of a row of buried explosives will probably have a wider application than single charges in the explosive excavation of engineering structures. Most cratering experience to date has been with single charges, and an analytical procedure for the design of a row of charges to excavate a crater with a specified configuration has been lacking. There are no digital computer codes having direct application to a row of charges as there are for single charges. This paper derives a simple relationship which can be used to design row charges with some assurance of achieving the desired result and with considerable flexibility in the choice of explosive yield of the individual charges

  10. Goat paddock cryptoexplosion crater, Western Australia

    Science.gov (United States)

    Harms, J.E.; Milton, D.J.; Ferguson, J.; Gilbert, D.J.; Harris, W.K.; Goleby, B.

    1980-01-01

    Goat Paddock, a crater slightly over 5 km in diameter (18??20??? S, 126??40???E), lies at the north edge of the King Leopold Range/Mueller Range junction in the Kimberley district, Western Australia (Fig. 1). It was noted as a geological anomaly in 1964 during regional mapping by the Bureau of Mineral Resources, Geology and Geophysics and the Geological Survey of Western Australia. The possibility of its being a meteorite impact crater has been discussed1, although this suggestion was subsequently ignored2. Two holes were drilled by a mining corporation in 1972 to test whether kimberlite underlay the structure. Here we report the findings of five days of reconnaissance in August 1979 which established that Goat Paddock is a cryptoexplosion crater containing shocked rocks and an unusually well exposed set of structural features. ?? 1980 Nature Publishing Group.

  11. Optimizing laser crater enhanced Raman spectroscopy.

    Science.gov (United States)

    Lednev, V N; Sdvizhenskii, P A; Grishin, M Ya; Filichkina, V A; Shchegolikhin, A N; Pershin, S M

    2018-03-20

    Raman signal enhancement by laser crater production was systematically studied for 785 nm continuous wave laser pumping. Laser craters were produced in L-aspartic acid powder by a nanosecond pulsed solid state neodymium-doped yttrium aluminum garnet laser (532 nm, 8 ns, 1 mJ/pulse), while Raman spectra were then acquired by using a commercial spectrometer with 785 nm laser beam pumping. The Raman signal enhancement effect was studied in terms of the number of ablating pulses used, the lens-to-sample distance, and the crater-center-laser-spot offset. The influence of the experiment parameters on Raman signal enhancement was studied for different powder materials. Maximum Raman signal enhancement reached 11 fold for loose powders but decreased twice for pressed tablets. Raman signal enhancement was demonstrated for several diverse powder materials like gypsum or ammonium nitrate with better results achieved for the samples tending to give narrow and deep craters upon the laser ablation stage. Alternative ways of cavity production (steel needle tapping and hole drilling) were compared with the laser cratering technique in terms of Raman signal enhancement. Drilling was found to give the poorest enhancement of the Raman signal, while both laser ablation and steel needle tapping provided comparable results. Here, we have demonstrated for the first time, to the best of our knowledge, that a Raman signal can be enhanced 10 fold with the aid of simple cavity production by steel needle tapping in rough highly reflective materials. Though laser crater enhancement Raman spectroscopy requires an additional pulsed laser, this technique is more appropriate for automatization compared to the needle tapping approach.

  12. CERN servers donated to Ghana

    CERN Multimedia

    CERN Bulletin

    2012-01-01

    Cutting-edge research requires a constantly high performance of the computing equipment. At the CERN Computing Centre, computers typically need to be replaced after about four years of use. However, while servers may be withdrawn from cutting-edge use, they are still good for other uses elsewhere. This week, 220 servers and 30 routers were donated to the Kwame Nkrumah University of Science and Technology (KNUST) in Ghana.   “KNUST will provide a good home for these computers. The university has also developed a plan for using them to develop scientific collaboration with CERN,” said John Ellis, a professor at King’s College London and a visiting professor in CERN’s Theory Group.  John Ellis was heavily involved in building the relationship with Ghana, which started in 2006 when a Ghanaian participated in the CERN openlab student programme. Since 2007 CERN has hosted Ghanaians especially from KNUST in the framework of the CERN Summer Student Progr...

  13. Breast cancer in Kumasi, Ghana

    International Nuclear Information System (INIS)

    Ohene-Yeboah, M.; Adjei, E.

    2012-01-01

    Breast cancer is the leading cause of cancer deaths in Ghanaian women.To describes the characteristics of breast cancer patients attending the Komfo Anokye Teaching Hospital in Kumasi, Ghana.The study was conducted at the Komfo Anokye Teaching Hospital. Between July 1st 2004 and June 30th 2009 patients presenting with breast lumps were assessed by clinical examination, imaging studies and pathological examination. Relevant clinical and pathological were recorded prospectively data on all patients with microscopically proven breast cancer. The cancers were graded according to the modified Bloom-Richardson system. Tissue immunoperoxidase stains for oestrogen, progesterone receptors and c-erb2 oncogene were performed with commercially prepared antigens and reagents.Nineteen thousand four hundred and twenty – three (19,423) patients were seen during the study period. There were 330 (1.7%) patients with histologically proven breast cancer. The mean age was 49.1 years. A palpable breast lump was detected in 248 patients (75.2%). Two hundred and eighty –one patients (85.2%) presented with Stages III and IV , 271 (82.1%) invasive and 230 ( 85.2%) high grade carcinomas. Oestrogen and progesterone receptors were positive in 32 and 9 cases respectively. Her2 protein was positive in 11 cases. In Kumasi, as in other parts of Ghana, breast cancer affects mostly young pre-menopausal who present with advanced disease. The cancers have unfavourable prognostic features and are unlikely to respond to hormonal therapy. (au)

  14. Laboratory and Field Investigations of Small Crater Repair Technologies

    National Research Council Canada - National Science Library

    Priddy, Lucy P; Tingle, Jeb S; McCaffrey, Timothy J; Rollings, Ray S

    2007-01-01

    .... This airfield damage repair (ADR) investigation consisted of laboratory testing of selected crater fill and capping materials, as well as full-scale field testing of small crater repairs to evaluate field mixing methods, installation...

  15. Pesticide residues in fish from the Densu River Basin in Ghana ...

    African Journals Online (AJOL)

    The Densu River is a typical river flowing through agricultural areas in Southern Ghana. Six fish species from different locations in the river were sampled and analyzed for residues of pesticides and metabolites using GC with ECD/FID. The results of the study indicate that all the detected residues and metabolites in fish ...

  16. TIMSS 2011 Science Assessment Results: A Review of Ghana's Performance

    Science.gov (United States)

    Buabeng, Isaac; Owusu, Kofi Acheaw; Ntow, Forster Danso

    2014-01-01

    This paper reviews Ghana's performance in the TIMSS 2011 survey in comparison with other African and some high performing countries which participated in the TIMSS assessment. Students' achievement in the science content areas assessed were summarized and teacher preparation constructs of teachers of the students who took part in the assessment…

  17. Structural barriers to coping with Type 1 Diabetes Mellitus in Ghana ...

    African Journals Online (AJOL)

    Structural barriers to coping with Type 1 Diabetes Mellitus in Ghana: Experiences of diabetic youth and their families. ... Methods: Qualitative study conducted with families with a child with T1DM, receiving care in the greater Accra area. Total of 17 individuals ... Social support networks need to be explored and strengthened.

  18. Where do overweight women in Ghana live? Answers from exploratory spatial data analysis

    Directory of Open Access Journals (Sweden)

    Fidelia A.A. Dake

    2012-03-01

    Full Text Available Contextual influence on health outcomes is increasingly becoming an important area of research. Analytical techniques such as spatial analysis help explain the variations and dynamics in health inequalities across different context and among different population groups. This paper explores spatial clustering in body mass index among Ghanaian women by analysing data from the 2008 Ghana Demographic and Health Survey using exploratory spatial data analysis techniques. Overweight was a more common occurrence in urban areas than in rural areas. Close to a quarter of the clusters in Ghana, mostly those in the southern sector contained women who were overweight. Women who lived in clusters where the women were overweight were more likely to live around other clusters where the women were also overweight. The results suggest that the urban environment could be a potential contributing factor to the high levels of obesity in urban areas of Ghana. There is the need for researchers to include a spatial dimension to obesity research in Ghana paying particular attention the urban environment.

  19. Fire in Ghana's dry forest: Causes, frequency, effects and management interventions

    Science.gov (United States)

    Sandra Opoku Agyemang; Michael Muller; Victor Rex Barnes

    2015-01-01

    This paper describes the number of fires, area burned, causes and seasonality of fires over a ten year period from 2002-2012 and investigates different fire management strategies and their effectiveness in the Afram headwaters forest reserve in Ghana. Data were collected from interviews of stakeholders in two communities adjacent to the reserve, and from 2002-2012 fire...

  20. Groundwater Exploration for Rural Communities in Ghana, West Africa

    Science.gov (United States)

    McKay, W. A.

    2001-05-01

    Exploration for potable water in developing countries continues to be a major activity, as there are more than one billion people without access to safe drinking water. Exploration for groundwater becomes more critical in regions where groundwater movement and occurrence is controlled by secondary features such as fractures and faults. Drilling success rates in such geological settings are generally very low, but can be improved by integrating geological, hydrogeological, aerial photo interpretation with land-based geophysical technology in the selection of drilling sites. To help alleviate water supply problems in West Africa, the Conrad N. Hilton Foundation and other donors, since 1990, have funded the World Vision Ghana Rural Water Project (GRWP) to drill wells for potable water supplies in the Greater Afram Plains (GAP) of Ghana. During the first two years of the program, drilling success rates using traditional methods ranged from 35 to 80 percent, depending on the area. The average drilling success rate for the program was approximately 50 percent. In an effort to increase the efficiency of drilling operations, the Desert Research Institute evaluated and developed techniques for application to well-siting strategies in the GAP area of Ghana. A critical project element was developing technical capabilities of in-country staff to independently implement the new strategies. Simple cost-benefit relationships were then used to evaluate the economic advantages of developing water resources using advanced siting methods. The application of advanced methods in the GAP area reveal an increase of 10 to 15 percent in the success rate over traditional methods. Aerial photography has been found to be the most useful of the imagery products covering the GAP area. An effective approach to geophysical exploration for groundwater has been the combined use of EM and resistivity methods. Economic analyses showed that the use of advanced methods is cost-effective when success

  1. Science for Development: Failure in Ghana

    African Journals Online (AJOL)

    kofimereku

    Next to follow was the Ghana Atomic Energy Commission, established at .... notion of science education and the predictions made by the model of science ..... banks, production and consumption armies, serve as a god for those who have.

  2. Gender, Migration and Remittances in Ghana

    African Journals Online (AJOL)

    to strengthen social ties and networks of responsibility and affection. Indeed .... undocumented evidence in Ghana of the construction of second cycle schools, health .... business/financial operations, administration/secretarial and elementary ...

  3. EXPERIENCES OF FEMALE ACADEMICS IN GHANA ...

    African Journals Online (AJOL)

    The implications of the research for social work practice are discussed. .... to female academics' rise to the top of their careers in Ghana. ... Saleebey (1996) identifies resilience, empowerment and membership as the key principles of the ...

  4. Journal of the Ghana Institution of Engineers

    African Journals Online (AJOL)

    ... of topical issues on all aspects of engineering practice in Ghana and abroad ... Computer Aided Synthesis of a Four-Bar Mechanism For Soil Tilling ... Development Of An Agricultural Land Drainage And Reclamation Design Software.

  5. Experience on domestic waste segregation in Ghana

    OpenAIRE

    Osei Bonsu Patterson

    2013-01-01

    Pollution from domestic wastes is a major environmental challenge in Ghana and many developing countries. Most of these countries depend almost entirely on landfills for waste management, which has proved to be expensive, inefficient and unsustainable. A sustainable solution to this problem is productive use of waste such as recycling. The main challenge that may limit recycling in Ghana and some of these countries is that a chunk of the wastes are littered on the environment, and the rest is...

  6. Crater ejecta scaling laws: fundamental forms based on dimensional analysis

    International Nuclear Information System (INIS)

    Housen, K.R.; Schmidt, R.M.; Holsapple, K.A.

    1983-01-01

    A model of crater ejecta is constructed using dimensional analysis and a recently developed theory of energy and momentum coupling in cratering events. General relations are derived that provide a rationale for scaling laboratory measurements of ejecta to larger events. Specific expressions are presented for ejection velocities and ejecta blanket profiles in two limiting regimes of crater formation: the so-called gravity and strength regimes. In the gravity regime, ejectra velocities at geometrically similar launch points within craters vary as the square root of the product of crater radius and gravity. This relation implies geometric similarity of ejecta blankets. That is, the thickness of an ejecta blanket as a function of distance from the crater center is the same for all sizes of craters if the thickness and range are expressed in terms of crater radii. In the strength regime, ejecta velocities are independent of crater size. Consequently, ejecta blankets are not geometrically similar in this regime. For points away from the crater rim the expressions for ejecta velocities and thickness take the form of power laws. The exponents in these power laws are functions of an exponent, α, that appears in crater radius scaling relations. Thus experimental studies of the dependence of crater radius on impact conditions determine scaling relations for ejecta. Predicted ejection velocities and ejecta-blanket profiles, based on measured values of α, are compared to existing measurements of velocities and debris profiles

  7. Coesite from Wabar crater, near Al Hadida, Arabia

    Science.gov (United States)

    Chao, E.C.T.; Fahey, J.J.; Littler, J.

    1961-01-01

    The third natural occurrence of coesite, the high pressure polymorph of silica, is found at the Wabar meteorite crater, Arabia. The Wabar crater is about 300 feet in diameter and about 40 feet deep. It is the smallest of three craters where coesite has been found.

  8. 3D structure of the Gusev Crater region

    NARCIS (Netherlands)

    van Kan - Parker, M.; Zegers, T.E.; kneissl, T.; Ivanov, B.; Neukum, G.; Foing, B.

    2010-01-01

    Gusev Crater lies within the Aeolis Quadrangle of Mars at the boundary between the northern lowlands and southern highlands. The ancient valley Ma'adim Vallis dissects the highlands south of Gusev Crater and is thought to have fed the crater with sediments.High Resolution Stereo Camera data and

  9. Cratering on Small Bodies: Lessons from Eros

    Science.gov (United States)

    Chapman, C. R.

    2003-01-01

    Cratering and regolith processes on small bodies happen continuously as interplanetary debris rains down on asteroids, comets, and planetary satellites. Butthey are very poorly observed and not well understood. On the one hand, we have laboratory experimentation at small scales and we have examination of large impact craters (e.g. Meteor Crater on Earth and imaging of abundant craters on terrestrial planets and outer planet moons). Understanding cratering on bodies of intermediate scales, tens of meters to hundreds of km in size, involves either extrapolation from our understanding of cratering phenomena at very different scales or reliance on very preliminary, incomplete examination of the observational data we now have for a few small bodies. I review the latter information here. It has been generally understood that the role of gravity is greatly diminished for smaller bodies, so a lot of cratering phenomena studied for larger bodies is less applicable. But it would be a mistake to imagine that laboratory experiments on gravitationless rocks (usually at 1 g) are directly applicable, except perhaps to those monolithic Near Earth Asteroids (NEAs) some tens of meters in size that spin very rapidly and can be assumed to be "large bare rocks" with "negative gravity". Whereas it had once been assumed that asteroids smaller than some tens of km diameter would retain little regolith, it is increasingly apparent that regolith and megoregolith processes extend down to bodies only hundreds of meters in size, perhaps smaller. Yet these processes are very different from those that pertain to the Moon, which is our chief prototype of regolith processes. The NEAR Shoemaker spacecraft's studies of Eros provide the best evidence to date about small-body cratering processes, as well as a warning that our theoretical understanding requires anchoring by direct observations. Eros: "Ponds", Paucity of Small Craters, and Other Mysteries. Although Eros is currently largely detached

  10. Medical physics practice and training in Ghana.

    Science.gov (United States)

    Amuasi, John H; Kyere, Augustine K; Schandorf, Cyril; Fletcher, John J; Boadu, Mary; Addison, Eric K; Hasford, Francis; Sosu, Edem K; Sackey, Theophilus A; Tagoe, Samuel N A; Inkoom, Stephen; Serfor-Armah, Yaw

    2016-06-01

    Medical physics has been an indispensable and strategic stakeholder in the delivery of radiological services to the healthcare system of Ghana. The practice has immensely supported radiation oncology and medical imaging facilities over the years, while the locally established training programme continues to produce human resource to feed these facilities. The training programme has grown to receive students from other African countries in addition to local students. Ghana has been recognised by the International Atomic Energy Agency as Regional Designated Centre for Academic Training of Medical Physicists in Africa. The Ghana Society for Medical Physics collaborates with the School of Nuclear and Allied Sciences of the University of Ghana to ensure that training offered to medical physicists meet international standards, making them clinically qualified. The Society has also worked together with other bodies for the passage of the Health Profession's Regulatory Bodies Act, giving legal backing to the practice of medical physics and other allied health professions in Ghana. The country has participated in a number of International Atomic Energy Agency's projects on medical physics and has benefited from its training courses, fellowships and workshops, as well as those of other agencies such as International Organization for Medical Physics. This has placed Ghana's medical physicists in good position to practice competently and improve healthcare. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  11. Moon Zoo: Making the public part of a crater survey algorithm

    Science.gov (United States)

    Gay, P. L.; Brown, S.; Huang, D.; Daus, C.; Lehan, C.; Robbins, S.

    2011-10-01

    The Moon Zoo citizen science website launched in May 2010 and invited the public to annotate images from the Lunar Reconnaissance Orbiter's Narrow Angle Camera (NAC). Tasks included marking the edges of craters with an ellipse tool, indicating where linear features (e.g. scarps) and special types of craters (e.g. dark haloed) are located with a box, and rating the number of boulders in an image. The goal of this project is to create crater and feature catalogues for large areas of the moon. In addition to doing science, Moon Zoo also seeks to educate its audience through educational content, to engage them through social media, and to understand them through research into their motivations and behaviors.

  12. Sanitation investments in Ghana

    DEFF Research Database (Denmark)

    Awunyo-Akaba, Y.; Awunyo-Akaba, J.; Gyapong, M.

    2016-01-01

    with people’s willingness and ability to invest in household sanitation across all communities. The status of being a stranger i.e. migrant in the area left some populations without rights over the land they occupied and with low incentives to invest in sanitation, while indigenous communities were challenged......Background: Ghana’s low investment in household sanitation is evident from the low rates of improved sanitation. This study analysed how land ownership, tenancy security and livelihood patterns are related to sanitation investments in three adjacent rural and peri-urban communities in a district...... communities were triangulated with multiple interview material and contextual knowledge on social structures, history of settlement, land use, livelihoods, and access to and perceptions about sanitation. Results: This study shows that the history of settlement and land ownership issues are highly correlated...

  13. Nature of mango anthracnose in Ghana: Implications for the control ...

    African Journals Online (AJOL)

    Nature of mango anthracnose in Ghana: Implications for the control of the disease. ... Mango anthracnose is a major disease hampering the production of quality fruits for export in Ghana. The nature of the disease and ... HOW TO USE AJOL.

  14. Non-communicable diseases among children in Ghana: health and ...

    African Journals Online (AJOL)

    the health and social concerns of parents/caregivers on in-patient care for children with NCDs in Ghana. Methods: This ..... givers influence health seeking behaviours and medical .... among older adults in China, Ghana, Mexico, India, Rus-.

  15. Globalization and male sex trade in Ghana: Modernity or Immorality ...

    African Journals Online (AJOL)

    Globalization and male sex trade in Ghana: Modernity or Immorality? ... apolitical and less hypocritical way of discussing the issue devoid of criminalization, in the ... Key words: Globalization, homosexuality, male sex trade, sex culture, Ghana.

  16. Providers of antenatal care services in Ghana: evidence from Ghana demographic and health surveys 1988-2014.

    Science.gov (United States)

    Dickson, Kwamena Sekyi; Darteh, Eugene Kofuor Maafo; Kumi-Kyereme, Akwasi

    2017-03-14

    Antenatal care is one of the three most essential care - antenatal, delivery and post-natal, given to women during pregnancy and has the potential to contribute towards the achievement of the Sustainable Development Goal (SDG) target 3.1- reducing the global maternal mortality ratio to less than 70 per 100,000 and target 3.8 - achieve universal health coverage. The main objective is to examine the contribution of the various providers of antenatal care services in Ghana from 1988 to 2014. The study uses data from all the six rounds of the Ghana Demographic and Health Survey (GDHS). Binary logistic regression models were applied to examine the association between background characteristics of respondents and providers of antenatal care services. The results show that majority of antenatal care services were provided by nurses over the period under review. The proportion of women who received antenatal care services from nurses improved over the period from 55% in 1988 to 89.5% in 2014. Moreover, there was a decline in antenatal care services provided by traditional birth attendants and women who did not receive antenatal care services from any service provider over the years under review. It was observed that women from rural areas were more likely to utilise antenatal care services provided by traditional birth attendants, whilst those from urban areas were more likely to utilise antenatal care from doctors and nurses. To further improve access to and utilisation of antenatal care services provided by nurses and doctors it is recommended that the Ghana Health Service and the Ministry of Health should put in place systems aimed at improving on the quality of care given such as regular training workshops for health personnel and assessment of patient's satisfaction with services provided. Also, they should encourage women in rural areas especially those from the savannah zone to utilise antenatal care services from skilled providers through social and behaviour

  17. Geologic field trip guide to Mount Mazama and Crater Lake Caldera, Oregon

    Science.gov (United States)

    Bacon, Charles R.; Wright, Heather M.

    2017-08-08

    Crater Lake partly fills one of the most spectacular calderas of the world—an 8 by 10 kilometer (km) basin more than 1 km deep formed by collapse of the Mount Mazama volcano during a rapid series of explosive eruptions ~7,700 years ago. Having a maximum depth of 594 meters (m), Crater Lake is the deepest lake in the United States. Crater Lake National Park, dedicated in 1902, encompasses 645 square kilometers (km2) of pristine forested and alpine terrain, including the lake itself, and virtually all of Mount Mazama. The geology of the area was first described in detail by Diller and Patton (1902) and later by Williams (1942), whose vivid account led to international recognition of Crater Lake as the classic collapse caldera. Because of excellent preservation and access, Mount Mazama, Crater Lake caldera, and the deposits formed by the climactic eruption constitute a natural laboratory for study of volcanic and magmatic processes. For example, the climactic ejecta are renowned among volcanologists as evidence for systematic compositional zonation within a subterranean magma chamber. Mount Mazama’s climactic eruption also is important as the source of the widespread Mazama ash, a useful Holocene stratigraphic marker throughout the Pacific Northwest United States, adjacent Canada, and offshore. A detailed bathymetric survey of the floor of Crater Lake in 2000 (Bacon and others, 2002) provides a unique record of postcaldera eruptions, the interplay between volcanism and filling of the lake, and sediment transport within this closed basin. Knowledge of the geology and eruptive history of the Mount Mazama edifice, enhanced by the caldera wall exposures, gives exceptional insight into how large volcanoes of magmatic arcs grow and evolve. In addition, many smaller volcanoes of the High Cascades beyond the limits of Mount Mazama provide information on the flux of mantle-derived magma through the region. General principles of magmatic and eruptive processes revealed by

  18. Summary of results of cratering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Toman, J [Lawrence Radiation Laboratory, Livermore, CA (United States)

    1969-07-01

    The use of nuclear excavation as a construction technique for producing harbors, canals, highway cuts, and other large excavations requires a high assurance that the yield and depth of burst selected for the explosive will produce the desired configuration within an acceptable degree of tolerance. Nuclear excavation technology advanced significantly during 1968 as a result of the successful execution of Projects Cabriolet, Buggy, and Schooner. Until these experiments were conducted, the only nuclear data available for designing large excavations were derived from Sedan (100 kt in alluvium), Danny Boy (0.42 kt in basalt), and Sulky (0.090 kt in basalt). Applicable experience has now been extended to include two additional rock types: tuff and porphyritic trachyte, non-homogeneous formations with severe geologic layering, and a nuclear row in hard rock. The continued development of cratering calculations using in situ geophysical measurements and high-pressure test data have provided a means for predicting the cratering characteristics of untested materials. Chemical explosive cratering experiments conducted in the pre-Gondola series during the past several years have been directed toward determining the behavior of weak, wet clay shales. This material is important to nuclear excavation because of potential long-term stability problems which may affect the cratered slopes. (author)

  19. Inclement Weather Crater Repair Tool Kit

    Science.gov (United States)

    2017-11-30

    9. Corrugated steel quadcons. ....................................................................................................... 14 Figure 10...Saw cutting around crater upheaval. ERDC/GSL TR-17-26 6 The excavation team is responsible for breaking up the damaged portland cement ...in the table located on Sheet 2 in Appendix A. The corrugated steel quadcons (Item 1) are equipped with double swing doors on both ends of the

  20. Summary of results of cratering experiments

    International Nuclear Information System (INIS)

    Toman, J.

    1969-01-01

    The use of nuclear excavation as a construction technique for producing harbors, canals, highway cuts, and other large excavations requires a high assurance that the yield and depth of burst selected for the explosive will produce the desired configuration within an acceptable degree of tolerance. Nuclear excavation technology advanced significantly during 1968 as a result of the successful execution of Projects Cabriolet, Buggy, and Schooner. Until these experiments were conducted, the only nuclear data available for designing large excavations were derived from Sedan (100 kt in alluvium), Danny Boy (0.42 kt in basalt), and Sulky (0.090 kt in basalt). Applicable experience has now been extended to include two additional rock types: tuff and porphyritic trachyte, non-homogeneous formations with severe geologic layering, and a nuclear row in hard rock. The continued development of cratering calculations using in situ geophysical measurements and high-pressure test data have provided a means for predicting the cratering characteristics of untested materials. Chemical explosive cratering experiments conducted in the pre-Gondola series during the past several years have been directed toward determining the behavior of weak, wet clay shales. This material is important to nuclear excavation because of potential long-term stability problems which may affect the cratered slopes. (author)

  1. Some Studies of Terrestrial Impact Cratering Rate

    Directory of Open Access Journals (Sweden)

    Jetsu L.

    2011-06-01

    Full Text Available In 1984, a 28.4 Myr periodicity was detected in the ages of terrestrial impact craters and a 26 Myr periodicity in the epochs of mass extinctions of species. Periodic comet showers from the Oort cloud seemed to cause catastrophic events linked to mass extinctions of species. Our first study revealed that the only significant detected periodicity is the “human signal” caused by the rounding of these data into integer numbers. The second study confirmed that the original 28.4 Myr periodicity detection was not significant. The third study revealed that the quality and the quantity of the currently available data would allow detection of real periodicity only if all impacts have been periodic, which cannot be the case. The detection of a periodic signal, if present, requires that more craters should be discovered and the accuracy of age estimates improved. If we sometimes will be able to find the difference between the craters caused by asteroid and comet impacts, the aperiodic component could be removed. The lunar impact craters may eventually provide the required supplementary data.

  2. The Carancas meteorite impact crater, Peru: Geologic surveying and modeling of crater formation and atmospheric passage

    Science.gov (United States)

    Kenkmann, T.; Artemieva, N. A.; Wünnemann, K.; Poelchau, M. H.; Elbeshausen, D.; Núñez Del Prado, H.

    2009-08-01

    The recent Carancas meteorite impact event caused a worldwide sensation. An H4-5 chondrite struck the Earth south of Lake Titicaca in Peru on September 15, 2007, and formed a crater 14.2 m across. It is the smallest, youngest, and one of two eye-witnessed impact crater events on Earth. The impact violated the hitherto existing view that stony meteorites below a size of 100 m undergo major disruption and deceleration during their passage through the atmosphere and are not capable of producing craters. Fragmentation occurs if the strength of the meteoroid is less than the aerodynamic stresses that occur in flight. The small fragments that result from a breakup rain down at terminal velocity and are not capable of producing impact craters. The Carancas cratering event, however, demonstrates that meter-sized stony meteoroids indeed can survive the atmospheric passage under specific circumstances. We present results of a detailed geologic survey of the crater and its ejecta. To constrain the possible range of impact parameters we carried out numerical models of crater formation with the iSALE hydrocode in two and three dimensions. Depending on the strength properties of the target, the impact energies range between approximately 100-1000 MJ (0.024- 0.24 t TNT). By modeling the atmospheric traverse we demonstrate that low cosmic velocities (12- 14 kms-1) and shallow entry angles (<20°) are prerequisites to keep aerodynamic stresses low (<10 MPa) and thus to prevent fragmentation of stony meteoroids with standard strength properties. This scenario results in a strong meteoroid deceleration, a deflection of the trajectory to a steeper impact angle (40-60°), and an impact velocity of 350-600 ms-1, which is insufficient to produce a shock wave and significant shock effects in target minerals. Aerodynamic and crater modeling are consistent with field data and our microscopic inspection. However, these data are in conflict with trajectories inferred from the analysis of

  3. On the crypto-explosive crater and its relation with gold mineralization in larma Au-U deposit

    International Nuclear Information System (INIS)

    Chen Guohua; Jing Hongxiang; Huang Shutao

    1998-01-01

    A new type of gold mineralization-controlling structure-hydrothermal crypto-explosive crater was identified at the Larma gold-uranium deposit in the border regions between Gansu and Sichuan provinces, western China. The hydrothermal crypto-explosive crater is ellipse-shaped at the surface, while funnel-like in profile. A silica-cap composed of hydrothermal siliceous breccia is distributed at the top of the crater, while hydrothermal crypto-explosive breccia are in the centre. The configuration of the crater is roughly consistent with the distribution of gold ore bodies. The formation mechanism of the crater is: first, a silica cap composed of hydrothermal siliceous metasomatic rock was formed at the contact area between the siliceous rock and the slate, and blocked the movement of hydrothermal fluid and resulted in the appearance of over-pressed geothermal environment. Then, at 49.5 Ma, the rejuvenation of the EW-striking faults in larma area resulted in the breaking of the brittle silica cap, followed by the crypto-explosion of hydrothermal fluid. In Larma gold-uranium deposit, the hydrothermal crypto-explosion gave rise to the precipitation of gold from the hydrothermal fluid, while the crypto-explosive crater provided the space for gold mineralization

  4. Euthanasia, assisted dying and the right to die in Ghana: a socio-legal analysis.

    Science.gov (United States)

    Owusu-Dapaa, Ernest

    2013-12-01

    There is unanimity among states to protect the continuation of life of the individual as a safeguard against their collective extinction. The right to life is accordingly guaranteed but its antithesis, the right to die is the subject of an unending debate. The controversy over the right to die is deepened by rapid advances in medicine, creating the capability for prolongation of life beyond the span which one's natural strength can endure. Ghana's supreme law explicitly guarantees the right to life but remains ambiguous on right to die, particularly euthanasia and assisted dying. Thus, some of the other rights, such as the right to dignity and not to be tortured, can creatively be exploited to justify some instances of euthanasia. Ghana's criminal code largely proscribes euthanasia. Notwithstanding, proscription of euthanasia and assisted dying by the law, in Ghana's empirical work undertaken in some of the communities in Ghana, suggests that euthanasia is quietly practisedin health facilities and private homes, especially in the rural areas. Contrary to the popular reasons assigned in the literature of the Western world, with respect to the practice or quest for legalization of euthanasia as being a necessity for providing relief from pain or hopeless quality of life, empirical data from social and anthropological studies conducted in Ghana reveal that poverty is the motivation for informal euthanasia practice in Ghana rather than genuine desire on part of patients to die or their relatives to see to their accelerated death. Apart from poverty, traditional cultural values of African societies consider non-natural death as a taboo and ignominy to the victim and his family. Thus, any move by the government to legalize euthanasia will need to be informed by widely held consultations and a possible referendum; otherwise the law may be just a mere transplant of Western models of legislation on euthanasia without reflecting the ethos of the African people.

  5. Nuclear Power for Future Electricity Generation in Ghana: Issues and Challenges

    International Nuclear Information System (INIS)

    Nyarko, B.J.B.; Akaho, E.H.K.; Ennison, I.

    2011-01-01

    Ghana's electricity demand has been estimated to be growing at a high rate of about 7% per annum over the last ten years. This is due to the relatively high population growth, economic aspiration of the country and the extension of electricity to rural areas. Electricity supply, on the contrary, has been unable to meet the demand due to high dependency on rain-fed hydropower plants, which started operating in 1965 and currently account for about 68% of the total installed capacity. Within the last 28 years, climatic changes and draughts have caused the nation to experience three major power crises. These climate changes resulted in low inflows and thus reduced power generation from hydropower systems. To complement the hydropower systems, the Government in 1997 installed thermal plants based on light crude oil. However, due to the high crude oil prices on the international market in recent times have made the operation of these plants very expensive. Ghana's crude oil find can boost its energy supply when the oil exploration begins somewhere in 2010. For rural cooking, domestic biomass is employed. Ghana has no domestic coal resources. The Government of Ghana is concerned with: limited further growth potential of domestic hydro; high cost of imported oil and gas and environmental issues associated with use of imported coal. Small Solar and wind generation exist in some sectors, but potential large-scale development is not envisioned for the near future. With these in mind, the President of Ghana set up a Committee involving Stakeholder Institutions to formulate the Nuclear Power Policy and develop the basic elements of Nuclear Infrastructure and to assess the viability of introducing the nuclear power option in Ghana's energy mix. Cabinet took a decision to include the nuclear power for electricity generation after the Committee submitted his report to the President in 2008. (author)

  6. Preliminary Results from Initial Investigations of Ceres' Cratering Record from Dawn Imaging Data

    Science.gov (United States)

    Schmedemann, Nico; Michael, Gregory; Ivanov, Boris A.; Kneissl, Thomas; Neesemann, Adrian; Hiesinger, Harald; Jaumann, Ralf; Raymond, Carol A.; Russell, Christopher T.

    2015-04-01

    The highly successful Dawn mission [1] finished data collection at Vesta in 2012 and is now on its way to the dwarf planet Ceres. According to the current Ceres approach timeline of the Dawn mission, the ground resolution of the Dawn FC camera [2] will be about 10 times better than Hubble data [3] at the time of the presentation of this work. This may allow for identification of craters about 15 km in diameter. Initial mapping of sample areas may provide enough information of the cratering record in order to compare it with the theoretical Ceres crater production function we present at the 46th LPSC conference (March 16-20, 2015, The Woodlands, Texas) [4]. Our preliminary crater production function for Ceres is derived from the assumption of an icy crust just below a thin surface layer of dust [5], and a projectile population that is very similar to the one that impacted the Moon [6]. In order to scale the lunar cratering record to Ceres we use the Ivanov scaling laws [7], which allow for crater scaling based on parameters that can be derived from observations. The lunar-like approach gave reasonable good results for the crater production function on the asteroids Vesta, Ida, Lutetia and Gaspra [8]. Since the lunar surface is of basaltic composition, the correct scaling between the different materials is challenging. One crucial parameter is the transition diameter from simple to complex craters. Based on the simple to complex transition diameter on Iapetus, an icy satellite of Saturn, we expect this transition at about 12 km crater size at Ceres. This value may be slightly different due to the different temperatures at Ceres and Iapetus. If the simple to complex transition is observed at much larger diameters, the reason could be a substantial fraction of rock in the shallow subsurface of Ceres. In an ice-rich surface material high relaxation rates may also be expected that could change the shape of the crater production function. A thorough geological mapping

  7. Plant genetic resources management in Ghana: Some challenges in ...

    African Journals Online (AJOL)

    Plant genetic resources management in Ghana: Some challenges in legumes. ... Ghana Journal of Agricultural Science ... The Plant Genetic Resources Research Institute, serving as the national gene bank of Ghana, together with other stakeholders, had made strenuous efforts in managing the legume genetic resources in ...

  8. Revising The Standards For Financial Reporting In Ghana | Appiah ...

    African Journals Online (AJOL)

    The need to strengthen financial reporting through standard setting in Ghana has been examined. The roles of the Institute of Chartered Accountants (Ghana) and Ghana National Accounting Standards Board were found not to be addressing the revision and updating of the standards, and bringing the procedures and ...

  9. Institutional Support : Institute of Economic Affairs (IEA-Ghana ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The Institute of Economic Affairs in Ghana (IEA-Ghana) was founded in 1989 during the twilight of the military dictatorship. At that time there were no independent policy centres in the country and hence little public policy dialogue. Still, IEA-Ghana succeeded in creating a platform for debate and made a strong case for major ...

  10. Crater Ejecta by Day and Night

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 24 June 2004 This pair of images shows a crater and its ejecta. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -9, Longitude 164.2 East (195.8 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

  11. Meridiani Crater in Day and Night

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 14 June 2004 This pair of images shows crater ejecta in the Terra Meridiani region. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -1.6, Longitude 4.1 East (355.9 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in

  12. Gusev Crater by Day and Night

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 23 June 2004 This pair of images shows part of Gusev Crater. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -14.5, Longitude 175.5 East (184.5 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

  13. Experimental simulation of impact cratering on icy satellites

    Science.gov (United States)

    Greeley, R.; Fink, J. H.; Gault, D. E.; Guest, J. E.

    1982-01-01

    Cratering processes on icy satellites were simulated in a series of 102 laboratory impact experiments involving a wide range of target materials. For impacts into homogeneous clay slurries with impact energies ranging from five million to ten billion ergs, target yield strengths ranged from 100 to 38 Pa, and apparent viscosities ranged from 8 to 200 Pa s. Bowl-shaped craters, flat-floored craters, central peak craters with high or little relief, and craters with no relief were observed. Crater diameters increased steadily as energies were raised. A similar sequence was seen for experiment in which impact energy was held constant but target viscosity and strength progressively decreases. The experiments suggest that the physical properties of the target media relative to the gravitationally induced stresses determined the final crater morphology. Crater palimpsests could form by prompt collapse of large central peak craters formed in low target strength materials. Ages estimated from crater size-frequency distributions that include these large craters may give values that are too high.

  14. Shallow and deep fresh impact craters in Hesperia Planum, Mars

    Science.gov (United States)

    Mouginis-Mark, Peter J.; Hayashi, Joan N.

    1993-01-01

    The depths of 109 impact craters about 2-16 km in diameter, located on the ridged plains materials of Hesperia Planum, Mars, have been measured from their shadow lengths using digital Viking Orbiter images (orbit numbers 417S-419S) and the PICS computer software. On the basis of their pristine morphology (very fresh lobate ejecta blankets, well preserved rim crests, and lack of superposed impact craters), 57 of these craters have been selected for detailed analysis of their spatial distribution and geometry. We find that south of 30 deg S, craters less than 6.0 km in diameter are markedly shallower than similar-sized craters equatorward of this latitude. No comparable relationship is observed for morphologically fresh craters greater than 6.0 km diameter. We also find that two populations exist for older craters less than 6.0 km diameter. When craters that lack ejecta blankets are grouped on the basis of depth/diameter ratio, the deeper craters also typically lie equatorward of 30 S. We interpret the spatial variation in crater depth/diameter ratios as most likely due to a poleward increase in volatiles within the top 400 m of the surface at the times these craters were formed.

  15. Demographic patterns and sustainable development in Ghana.

    Science.gov (United States)

    Tawiah, E O

    1995-01-01

    There is a growing recognition that the present demographic patterns in sub-Saharan Africa, including Ghana, do not augur well for the achievement of sustainable development. Ghana is characterized by a youthful population, rapid population growth, uneven population distribution, high fertility, and rural-urban migration which has brought human numbers into collision with resources to sustain them. It is submitted that the issues discussed are equally applicable to the subregion as well. The estimated population in 1993 was about 16.4 million. The population of Ghana increased from 1970 to 1984 at a rate of growth of 2.6% per annum. The proliferation of small settlements has serious implications for sustainable development. Urban centers comprised about 12.9% of the total population in 1948, 23% in 1960, 28.3% in 1970, and 31.3% in 1984. The average woman in Ghana still has more than six children. The 1988 Ghana Demographic and Health Survey (GDHS) indicated that the median age at first marriage for women was 16.5 years. Contraceptive use is low in sub-Sahara Africa. Currently married women (15-49) currently using any modern method ranged from 1% in Burundi (1987) and Mali (1987) to 36% in Zimbabwe (1988/89). The rapid population growth in Ghana, coupled with the concentration of infrastructural facilities and job opportunities in the urban centers, has resulted in a massive rural-urban migration. Basic social facilities like health, water, housing, and electricity have been stretched to their breakpoints. The Government of Ghana initiated a major effort to put environmental issues on the priority agenda in March 1988. This led to the preparation of an Environmental Action Plan (EAP) in 1991 to address issues relating to the protection of the environment, but the need is still urgent to adopt relevant population policies as a basic strategy in sustainable development.

  16. Introduction of Nuclear Power in Ghana

    International Nuclear Information System (INIS)

    Aboh, K.; Dzobo, M

    2010-01-01

    Ghana depends mainly on hydro-systems for electricity generation. In 1984, 1998, 2003 and 2007, there was drastic shortfalls in hydro-generation due to severe droughts. In 2007, the shortfall in generation was compounded by high prices of light crude oil. In May 2007, the government set-up a 7-man Presidential Committee on feasibility of a Nuclear Power Programme. Ghana’s electricity demand was projected to increase at 7.7% p.a. between 2004 and 2030. Per capita electricity demand is expected to increase from 253 kWh in 2004 to 1120 kWh in 2030. Peak electricity demand was expected to increase from 1095 MW in 2004 to 6700 MW in 2030. Ghana received IAEA assistance to undertake a national TCP GHA/0/011: “Evaluating the role of Nuclear Power in Future Generation Mix”. Under the national TCP GHA/0/011, a proposal for establishing NEPIO – (an Inter-ministerial Steering Committee to be chaired by the Minister of Energy) based on IAEA recommendations was submitted to the Minister of Energy. Ghana Atomic Energy Commission in partnership with other stakeholders and support from the IAEA did prepared a draft nuclear bill. The draft Ghana Nuclear Bill also proposed the establishment of an independent Ghana Nuclear Regulatory Authority. The Authority is mandated to license and regulate all nuclear installations including power plants. No potential sites for nuclear power plant and waste disposal had been identified yet for evaluation. Potential sites for nuclear power plants and waste disposal were identified and assessed under the IAEA national TCP GHA/0/011. Ghana Atomic Energy Commission (i.e. GAEC) and the University of Ghana with support from the IAEA have established the Graduate School of Nuclear and Allied Sciences (i.e. SNAS) for training nuclear expert

  17. Wrinkle Ridges and Young Fresh Crater

    Science.gov (United States)

    2002-01-01

    (Released 10 May 2002) The Science Wrinkle ridges are a very common landform on Mars, Mercury, Venus, and the Moon. These ridges are linear to arcuate asymmetric topographic highs commonly found on smooth plains. The origin of wrinkle ridges is not certain and two leading hypotheses have been put forth by scientists over the past 40 years. The volcanic model calls for the extrusion of high viscosity lavas along linear conduits. This thick lava accumulated over these conduits and formed the ridges. The other model is tectonic and advocates that the ridges are formed by compressional faulting and folding. Today's THEMIS image is of the ridged plains of Lunae Planum located between Kasei Valles and Valles Marineris in the northern hemisphere of the planet. Wrinkle ridges are found mostly along the eastern side of the image. The broadest wrinkle ridges in this image are up to 2 km wide. A 3 km diameter young fresh crater is located near the bottom of the image. The crater's ejecta blanket is also clearly seen surrounding the sharp well-defined crater rim. These features are indicative of a very young crater that has not been subjected to erosional processes. The Story The great thing about the solar system is that planets are both alike and different. They're all foreign enough to be mysterious and intriguing, and yet familiar enough to be seen as planetary 'cousins.' By comparing them, we can learn a lot about how planets form and then evolve geologically over time. Crinkled over smooth plains, the long, wavy raised landforms seen here are called 'wrinkle ridges,' and they've been found on Mars, Mercury, Venus, and the Moon - that is, on rocky bodies that are a part of our inner solar system. We know from this observation that planets (and large-enough moons) follow similar processes. What we don't know for sure is HOW these processes work. Scientists have been trying to understand how wrinkle ridges form for 40 years, and they still haven't reached a conclusion. That

  18. Hailar crater - A possible impact structure in Inner Mongolia, China

    Science.gov (United States)

    Xiao, Zhiyong; Chen, Zhaoxu; Pu, Jiang; Xiao, Xiao; Wang, Yichen; Huang, Jun

    2018-04-01

    Hailar crater, a probable impact structure, is a circular depression about 300 m diameter in Inner Mongolia, northeast China. With broad elevated rims, the present rim-to-floor depth is 8-20 m. Regional geological background and geomorphological comparison suggest that this feature is likely not formed by surface processes such as salt diapir, karst, aeolian, glacial, or volcanic activity. Its unique occurrence in this region and well-preserved morphology are most consistent with it being a Cenozoic impact crater. Two field expeditions in 2016 and 2017 investigated the origin of this structure, recognizing that (1) no additional craters were identified around Hailar crater in the centimeter-scale digital topography models that were constructed using a drone imaging system and stereo photogrammetry; (2) no bedrock exposures are visible within or adjacent to the crater because of thick regolith coverage, and only small pieces of angular unconsolidated rocks are present on the crater wall and the gently-sloped crater rim, suggesting recent energetic formation of the crater; (3) most samples collected from the crater have identical lithology and petrographic characteristics with the background terrain, but some crater samples contain more abundant clasts and silicate hydrothermal veins, indicating that rocks from depths have been exposed by the crater; (4) no shock metamorphic features were found in the samples after thin section examinations; and (5) a systematic sample survey and iron detector scan within and outside of the crater found no iron-rich meteorites larger than 2 cm in size in a depth of 30 cm. Although no conclusive evidence for an impact origin is found yet, Hailar crater was most likely formed by an impact based on its unique occurrence and comparative geomorphologic study. We suggest that drilling in the crater center is required to verify the impact origin, where hypothesized melt-bearing impactites may be encountered.

  19. Pesticide exposures in a malarious and predominantly farming area ...

    African Journals Online (AJOL)

    Asayah

    Received 6 April, 2015; Accepted 10 July, 2015. In areas where ... the Kintampo Health and Demographic Surveillance System area of Ghana to estimate the prevalence of pesticide .... A cross-sectional survey was conducted among heads of.

  20. Wind-Eroded Crater Floors and Intercrater Plains, Terra Sabaea, Mars

    Science.gov (United States)

    Irwin, Rossman P.; Wray, James J.; Mest, Scott C.; Maxwell, Ted A.

    2018-02-01

    Ancient impact craters with wind-eroded layering on their floors provide a record of resurfacing materials and processes on early Mars. In a 54 km Noachian crater in Terra Sabaea (20.2°S, 42.6°E), eolian deflation of a friable, dark-toned layer up to tens of meters thick has exposed more resistant, underlying light-toned material. These layers differ significantly from strata of similar tone described in other regions of Mars. The light-toned material has no apparent internal stratification, and visible/near-infrared spectral analysis suggests that it is rich in feldspar. Its origin is ambiguous, as we cannot confidently reject igneous, pyroclastic, or clastic alternatives. The overlying dark-toned layer is probably a basaltic siltstone or sandstone that was emplaced mostly by wind, although its weak cementation and inverted fluvial paleochannels indicate some modification by water. Negative-relief channels are not found on the crater floor, and fluvial erosion is otherwise weakly expressed in the study area. Small impacts onto this crater's floor have exposed deeper friable materials that appear to contain goethite. Bedrock outcrops on the crater walls are phyllosilicate bearing. The intercrater plains contain remnants of a post-Noachian thin, widespread, likely eolian mantle with an indurated surface. Plains near Hellas-concentric escarpments to the north are more consistent with volcanic resurfacing. A 48 km crater nearby contains similar dark-over-light outcrops but no paleochannels. Our findings indicate that dark-over-light stratigraphy has diverse origins across Mars and that some dark-toned plains with mafic mineralogy are not of igneous origin.

  1. Abraded Target on Rock 'Champagne' in Gusev Crater

    Science.gov (United States)

    2005-01-01

    NASA's Mars Exploration Rover Spirit took this microscopic image of a target called 'Bubbles' on a rock called 'Champagne' after using its rock abrasion tool to grind a hole through the rock's outer surface. The circular area where the rock's interior is exposed is about 5 centimeters (2 inches) across. This rock is different from rocks out on the plains of Gusev Crater but is similar to other rocks in this area of the 'Columbia Hills' in that it rich in phosphorus. Plagioclase, a mineral commonly found in igneous rocks, is also present in these rocks, according to analysis with Spirit's miniature thermal emission spectrometer. By using the rover's alpha particle X-ray spectrometer to collect data for multiple martian days, or sols, scientists are also beginning to get measurements of trace elements in the rocks. Spirit took the images that are combined into this mosaic on sol 358 (Jan. 3, 2005).

  2. Brushed Target on Rock 'Champagne' in Gusev Crater

    Science.gov (United States)

    2005-01-01

    NASA's Mars Exploration Rover Spirit took this microscopic image of a target called 'Bubbles' on a rock called 'Champagne' after using its rock abrasion tool to brush away a coating of dust. The circular brushed area is about 5 centimeters (2 inches) across. This rock is different from rocks out on the plains of Gusev Crater but is similar to other rocks in this area of the 'Columbia Hills' in that it has higher levels of phosphorus. Plagioclase, a mineral commonly found in igneous rocks, is also present in these rocks, according to analysis with the minature thermal emission spectrometer. By using the alpha particle X-ray spectrometer to collect data over multiple martian days, or sols, scientists are also beginning to get measurements of trace elements in these rocks. Spirit took the images that are combined into this mosaic on sol 354 (Dec. 30, 2004).

  3. Geologic Structures in Crater Walls on Vesta

    Science.gov (United States)

    Mittlefehldt, David W.; Beck, A. W.; Ammannito, E.; Carsenty, U.; DeSanctis, M. C.; LeCorre, L.; McCoy, T. J.; Reddy, V.; Schroeder, S. E.

    2012-01-01

    The Framing Camera (FC) on the Dawn spacecraft has imaged most of the illuminated surface of Vesta with a resolution of apporpx. 20 m/pixel through different wavelength filters that allow for identification of lithologic units. The Visible and Infrared Mapping Spectrometer (VIR) has imaged the surface at lower spatial resolution but high spectral resolution from 0.25 to 5 micron that allows for detailed mineralogical interpretation. The FC has imaged geologic structures in the walls of fresh craters and on scarps on the margin of the Rheasilvia basin that consist of cliff-forming, competent units, either as blocks or semi-continuous layers, hundreds of m to km below the rims. Different units have different albedos, FC color ratios and VIR spectral characteristics, and different units can be juxtaposed in individual craters. We will describe different examples of these competent units and present preliminary interpretations of the structures. A common occurrence is of blocks several hundred m in size of high albedo (bright) and low albedo (dark) materials protruding from crater walls. In many examples, dark material deposits lie below coherent bright material blocks. In FC Clementine color ratios, bright material is green indicating deeper 1 m pyroxene absorption band. VIR spectra show these to have deeper and wider 1 and 2 micron pyroxene absorption bands than the average vestan surface. The associated dark material has subdued pyroxene absorption features compared to the average vestan surface. Some dark material deposits are consistent with mixtures of HED materials with carbonaceous chondrites. This would indicate that some dark material deposits in crater walls are megabreccia blocks. The same would hold for bright material blocks found above them. Thus, these are not intact crustal units. Marcia crater is atypical in that the dark material forms a semi-continuous, thin layer immediately below bright material. Bright material occurs as one or more layers. In

  4. Monturaqui meteorite impact crater, Chile: A field test of the utility of satellite-based mapping of ejecta at small craters

    Science.gov (United States)

    Rathbun, K.; Ukstins, I.; Drop, S.

    2017-12-01

    Monturaqui Crater is a small ( 350 m diameter), simple meteorite impact crater located in the Atacama Desert of northern Chile that was emplaced in Ordovician granite overlain by discontinuous Pliocene ignimbrite. Ejecta deposits are granite and ignimbrite, with lesser amounts of dark impact melt and rare tektites and iron shale. The impact restructured existing drainage systems in the area that have subsequently eroded through the ejecta. Satellite-based mapping and modeling, including a synthesis of photographic satellite imagery and ASTER thermal infrared imagery in ArcGIS, were used to construct a basic geological interpretation of the site with special emphasis on understanding ejecta distribution patterns. This was combined with field-based mapping to construct a high-resolution geologic map of the crater and its ejecta blanket and field check the satellite-based geologic interpretation. The satellite- and modeling-based interpretation suggests a well-preserved crater with an intact, heterogeneous ejecta blanket that has been subjected to moderate erosion. In contrast, field mapping shows that the crater has a heavily-eroded rim and ejecta blanket, and the ejecta is more heterogeneous than previously thought. In addition, the erosion rate at Monturaqui is much higher than erosion rates reported elsewhere in the Atacama Desert. The bulk compositions of the target rocks at Monturaqui are similar and the ejecta deposits are highly heterogeneous, so distinguishing between them with remote sensing is less effective than with direct field observations. In particular, the resolution of available imagery for the site is too low to resolve critical details that are readily apparent in the field on the scale of 10s of cm, and which significantly alter the geologic interpretation. The limiting factors for effective remote interpretation at Monturaqui are its target composition and crater size relative to the resolution of the remote sensing methods employed. This

  5. Ghana and the nuclear power option

    International Nuclear Information System (INIS)

    Fletcher, J.J.; Ennison, I.

    2000-01-01

    For every country, dependable and continuous supply of electricity is a prerequisite for ensuring sustainable development. In Ghana, Ghanaians have currently known the consequences of disrupted and inadequate supply of electricity. Globally too the call of ''Agenda 21'' of the Rio de Janeiro Conference (Earth Summit) to engage in the development and supply of electricity in a sustainable manner imposes on us certain limitations in our choice of energy option to utilise. Taking into account the high economic and population growths with the subsequent increase in demand for electricity in the 21st century, the fact that Ghana has no coal and imports oil which will be in dwindling supply in the 21st century and that the total hydro supply in Ghana will not be sufficient for our electricity demand in the next century, this paper proposes that Ghana starts now to plan for the introduction of the nuclear option so that in the long term we may have in place an environmentally friendly, dependable and reliable supply of energy. The paper also highlights the economic competitiveness of nuclear power over the other energy options in Ghana and addresses the apprehension and misunderstanding surrounding the nuclear power option. (author)

  6. Generating Impact Maps from Automatically Detected Bomb Craters in Aerial Wartime Images Using Marked Point Processes

    Science.gov (United States)

    Kruse, Christian; Rottensteiner, Franz; Hoberg, Thorsten; Ziems, Marcel; Rebke, Julia; Heipke, Christian

    2018-04-01

    The aftermath of wartime attacks is often felt long after the war ended, as numerous unexploded bombs may still exist in the ground. Typically, such areas are documented in so-called impact maps which are based on the detection of bomb craters. This paper proposes a method for the automatic detection of bomb craters in aerial wartime images that were taken during the Second World War. The object model for the bomb craters is represented by ellipses. A probabilistic approach based on marked point processes determines the most likely configuration of objects within the scene. Adding and removing new objects to and from the current configuration, respectively, changing their positions and modifying the ellipse parameters randomly creates new object configurations. Each configuration is evaluated using an energy function. High gradient magnitudes along the border of the ellipse are favored and overlapping ellipses are penalized. Reversible Jump Markov Chain Monte Carlo sampling in combination with simulated annealing provides the global energy optimum, which describes the conformance with a predefined model. For generating the impact map a probability map is defined which is created from the automatic detections via kernel density estimation. By setting a threshold, areas around the detections are classified as contaminated or uncontaminated sites, respectively. Our results show the general potential of the method for the automatic detection of bomb craters and its automated generation of an impact map in a heterogeneous image stock.

  7. Layers of 'Cabo Frio' in 'Victoria Crater'

    Science.gov (United States)

    2006-01-01

    This view of 'Victoria crater' is looking southeast from 'Duck Bay' towards the dramatic promontory called 'Cabo Frio.' The small crater in the right foreground, informally known as 'Sputnik,' is about 20 meters (about 65 feet) away from the rover, the tip of the spectacular, layered, Cabo Frio promontory itself is about 200 meters (about 650 feet) away from the rover, and the exposed rock layers are about 15 meters (about 50 feet) tall. This is an approximately true color rendering of images taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity during the rover's 952nd sol, or Martian day, (Sept. 28, 2006) using the camera's 750-nanometer, 530-nanometer and 430-nanometer filters.

  8. Impact cratering experiments in Bingham materials and the morphology of craters on Mars and Ganymede

    Science.gov (United States)

    Fink, J. H.; Greeley, R.; Gault, D. E.

    1982-01-01

    Results from a series of laboratory impacts into clay slurry targets are compared with photographs of impact craters on Mars and Ganymede. The interior and ejecta lobe morphology of rampart-type craters, as well as the progression of crater forms seen with increasing diameter on both Mars and Ganymede, are equalitatively explained by a model for impact into Bingham materials. For increasing impact energies and constant target rheology, laboratory craters exhibit a morphologic progression from bowl-shaped forms that are typical of dry planetary surfaces to craters with ejecta flow lobes and decreasing interior relief, characteristic of more volatile-rich planets. A similar sequence is seen for uniform impact energy in slurries of decreasing yield strength. The planetary progressions are explained by assuming that volatile-rich or icy planetary surfaces behave locally in the same way as Bingham materials and produce ejecta slurries with yield strenghs and viscosities comparable to terrestrial debris flows. Hypothetical impact into Mars and Ganymede are compared, and it is concluded that less ejecta would be produced on Ganymede owing to its lower gravitational acceleration, surface temperature, and density of surface materials.

  9. Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

    International Nuclear Information System (INIS)

    Yang, Changyi; Wu, Yiyong; Lv, Gang; Rubanov, Sergey; Jamieson, David N.

    2015-01-01

    Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

  10. Hypervelocity dust impact craters on photovoltaic devices imaged by ion beam induced charge

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Changyi [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Wu, Yiyong; Lv, Gang [National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environments, Harbin Institute of Technology, Harbin (China); Rubanov, Sergey [Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC 3010 (Australia); Jamieson, David N., E-mail: d.jamieson@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2015-04-01

    Hypervelocity dust has a speed of greater than 5 km/s and is a significant problem for equipment deployed in space such as satellites because of impacts that damage vulnerable components. Photovoltaic (PV) arrays are especially vulnerable because of their large surface area and the performance can be degraded owing to the disruption of the structure of the junction in the cells making up the array. Satellite PV arrays returned to Earth after service in orbit reveal a large number of craters larger than 5 μm in diameter arising from hypervelocity dust impacts. Extensive prior work has been done on the analysis of the morphology of craters in PV cells to understand the origin of the micrometeoroid that caused the crater and to study the corresponding mechanical damage to the structure of the cell. Generally, about half the craters arise from natural micrometeoroids, about one third from artificial Al-rich debris, probably from solid rocket exhausts, and the remainder from miscellaneous sources both known and unknown. However to date there has not been a microscopic study of the degradation of the electrical characteristics of PV cells exposed to hypervelocity dust impacts. Here we present an ion beam induced charge (IBIC) pilot study by a 2 MeV He microbeam of craters induced on a Hamamatsu PIN diode exposed to artificial hypervelocity Al dust from a dust accelerator. Numerous 5–30 μm diameter craters were identified and the charge collection efficiency of the crater and surrounds mapped with IBIC with bias voltages between 0 and 20 V. At highest bias, it was found the efficiency of the crater had been degraded by about 20% compared to the surrounding material. The speed distribution achieved in the Al dust accelerator was peaked at about 4 km/s compared to 11–68 km/s for dust encountered in low Earth orbit. We are able to extrapolate the charge collection efficiency degradation rate of unbiased cells in space based on our current measurements and the

  11. Low-velocity impact cratering experiments in granular slopes

    Science.gov (United States)

    Hayashi, Kosuke; Sumita, Ikuro

    2017-07-01

    Low-velocity impact cratering experiments are conducted in sloped granular targets to study the effect of the slope angle θ on the crater shape and its scales. We use two types of granular matter, sand and glass beads, former of which has a larger friction coefficient μs = tanθr , where θr is the angle of repose. Experiments show that as θ increases, the crater becomes shallower and elongated in the direction of the slope. Furthermore the crater floor steepens in the upslope side and a thick rim forms in the downslope side, thus forming an asymmetric profile. High-speed images show that these features are results of ejecta being dispersed farther towards the downslope side and the subsequent avalanche which buries much of the crater floor. Such asymmetric ejecta dispersal can be explained by combining the Z-model and a ballistic model. Using the topographic maps of the craters, we classify crater shape regimes I-III, which transition with increasing θ : a full-rim crater (I), a broken-rim crater (II), and a depression (III). The critical θ for the regime transitions are larger for sand compared to glass beads, but collapse to close values when we use a normalized slope θ^ = tanθ / tanθr . Similarly we derive θ^-dependences of the scaled crater depth, length, width and their ratios which collapse the results for different targets and impact energies. We compare the crater profiles formed in our experiments with deep craters on asteroid Vesta and find that some of the scaled profiles nearly overlap and many have similar depth / length ratios. This suggests that these Vestan craters may also have formed in the gravity regime and that the formation process can be approximated by a granular flow with a similar effective friction coefficient.

  12. The isostatic state of Mead crater

    Science.gov (United States)

    Banerdt, W. B.; Konopliv, A. S.; Rappaport, N. J.; Sjogren, W. L.; Grimm, R. E.; Ford, P. G.

    1994-01-01

    We have analyzed high-resolution Magellan Doppler tracking data over Mead crater, using both line-of-sight and spherical harmonic methods, and have found a negative gravity anomaly of about 4-5 mgal (at spacecraft altitude, 182 km). This is consistent with no isostatic compensation of the present topography; the uncertainty in the analysis allows perhaps as much as 30% compensation at shallow dpeths (approximately 25 km). This is similar to observations of large craters on Earth, which are not generally compensated, but contrasts with at least some lunar basins which are inferred to have large Moho uplifts and corresponding positive Bouguer anomalies. An uncompensated load of this size requires a lithosphere with an effective elastic lithosphere thickness greater than 30 km. In order for the crust-mantle boundary not to have participated in the deformation associated with the collapse of the transient cavity during the creation of the crater, the yield strength near the top of the mantle must have been significantly higher on Earth and Venus than on the Moon at the time of basin formation. This might be due to increased strength against frictional sliding at the higher confining pressures within the larger planets. Alternatively, the thinner crusts of Earth and Venus compared to that of the Moon may result in higher creep strength of the upper mantle at shallower depths.

  13. The central uplift of Ritchey crater, Mars

    Science.gov (United States)

    Ding, Ning; Bray, Veronica J.; McEwen, Alfred S.; Mattson, Sarah S.; Okubo, Chris H.; Chojnacki, Matthew; Tornabene, Livio L.

    2015-01-01

    Ritchey crater is a ∼79 km diameter complex crater near the boundary between Hesperian ridged plains and Noachian highland terrain on Mars (28.8°S, 309.0°E) that formed after the Noachian. High Resolution Imaging Science Experiment (HiRISE) images of the central peak reveal fractured massive bedrock and megabreccia with large clasts. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral analysis reveals low calcium pyroxene (LCP), olivine (OL), hydrated silicates (phyllosilicates) and a possible identification of plagioclase bedrock. We mapped the Ritchey crater central uplift into ten units, with 4 main groups from oldest and originally deepest to youngest: (1) megabreccia with large clasts rich in LCP and OL, and with alteration to phyllosilicates; (2) massive bedrock with bright and dark regions rich in LCP or OL, respectively; (3) LCP and OL-rich impactites draped over the central uplift; and (4) aeolian deposits. We interpret the primitive martian crust as igneous rocks rich in LCP, OL, and probably plagioclase, as previously observed in eastern Valles Marineris. We do not observe high-calcium pyroxene (HCP) rich bedrock as seen in Argyre or western Valles Marineris. The association of phyllosilicates with deep megabreccia could be from impact-induced alteration, either as a result of the Richey impact, or alteration of pre-existing impactites from Argyre basin and other large impacts that preceded the Ritchey impact, or both.

  14. The central uplift of Ritchey crater, Mars

    Science.gov (United States)

    Ding, Ning; Bray, Veronica J.; McEwen, Alfred S.; Mattson, Sarah S.; Okubo, Chris H.; Chojnacki, Matthew; Tornabene, Livio L.

    2015-05-01

    Ritchey crater is a ∼79 km diameter complex crater near the boundary between Hesperian ridged plains and Noachian highland terrain on Mars (28.8°S, 309.0°E) that formed after the Noachian. High Resolution Imaging Science Experiment (HiRISE) images of the central peak reveal fractured massive bedrock and megabreccia with large clasts. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral analysis reveals low calcium pyroxene (LCP), olivine (OL), hydrated silicates (phyllosilicates) and a possible identification of plagioclase bedrock. We mapped the Ritchey crater central uplift into ten units, with 4 main groups from oldest and originally deepest to youngest: (1) megabreccia with large clasts rich in LCP and OL, and with alteration to phyllosilicates; (2) massive bedrock with bright and dark regions rich in LCP or OL, respectively; (3) LCP and OL-rich impactites draped over the central uplift; and (4) aeolian deposits. We interpret the primitive martian crust as igneous rocks rich in LCP, OL, and probably plagioclase, as previously observed in eastern Valles Marineris. We do not observe high-calcium pyroxene (HCP) rich bedrock as seen in Argyre or western Valles Marineris. The association of phyllosilicates with deep megabreccia could be from impact-induced alteration, either as a result of the Richey impact, or alteration of pre-existing impactites from Argyre basin and other large impacts that preceded the Ritchey impact, or both.

  15. National waste management infrastructure in Ghana

    International Nuclear Information System (INIS)

    Darko, E.O.; Fletcher, J.J.

    1998-01-01

    Radioactive materials have been used in Ghana for more than four decades. Radioactive waste generated from their applications in various fields has been managed without adequate infrastructure and any legal framework to control and regulate them. The expanded use of nuclear facilities and radiation sources in Ghana with the concomitant exposure to human population necessitates effective infrastructure to deal with the increasing problems of waste. The Ghana Atomic Energy Act 204 (1963) and the Radiation Protection Instrument LI 1559 (1993) made inadequate provision for the management of waste. With the amendment of the Atomic Energy Act, PNDCL 308, a radioactive waste management centre has been established to take care of all waste in the country. To achieve the set objectives for an effective waste management regime, a waste management regulation has been drafted and relevant codes of practice are being developed to guide generators of waste, operators of waste management facilities and the regulatory authority. (author)

  16. Analysis of the Proposed Ghana Broadband Strategy

    DEFF Research Database (Denmark)

    Williams, Idongesit; Botwe, Yvonne

    This project studied the Ghana Broadband Strategy with the aim of evaluating the recommendations in the strategy side by side the broadband development in Ghana. The researchers conducted interviews both officially and unofficially with ICT stakeholders, made observations, studied Government...... intervention policies recommended in the Ghana broadband policy is used to evaluate the broadband market to find out whether the strategy consolidates with the Strengths and opportunities of the market and whether it corrects the anomalies that necessitate the weaknesses and threats to the market....... The strategy did address some threats and weaknesses of the broadband market. It also consolidated on some strengths and opportunities of the broadband market. The researchers also discovered that a market can actually grow without a policy. But a market will grow faster if a well implemented policy is guiding...

  17. Safe management of radioactive waste in Ghana

    International Nuclear Information System (INIS)

    Glover, E.T.; Fletcher, J.J.

    2000-01-01

    The Ghana Atomic Energy Commission was established in 1963 by an Act of Parliament, Act 204 for the Promotion, Development and Peaceful Application of Nuclear Techniques for the Benefit of Ghana. As in many developing countries the use of nuclear application is growing considerably in importance within the national economy. The Radiation Protection Board was established as the national regulatory authority and empowered by the Radiation Protection Instrument LI 1559 (1993). The above regulations, Act 204 and LI 1559 provided a minimum legal basis for regulatory control of radioactive waste management as it deals with waste management issues in a very general way and is of limited practical use to the waste producer. Hence the National Radioactive Waste Management Centre was established in July 1995 to carry out waste safety operations in Ghana. This paper highlights steps that have been taken to develop a systemic approach for the safe management of radioactive waste in the future and those already in existence. (author)

  18. Education and Health Care Policies in Ghana

    Directory of Open Access Journals (Sweden)

    Ziblim Abukari

    2015-10-01

    Full Text Available Education and health care policies in Ghana since independence have been universalist in approach providing free universal health care and free basic and tertiary education until the early 1980s. Precipitated primarily by a severe drought, stagnant economic growth, mismanagement, and political instability, Ghana undertook major economic reforms with prodding from the World Bank and International Monetary Fund in a bid to salvage the economy. These economic measures included cost recovery and cutback spending in education and health sectors. However, in recent years, purposive targeted interventions have been pursued to address inequalities in education and health care. These new programs include the Education Capitation Grant, school feeding program, and the National Health Insurance Scheme (NHIS, which are propelling Ghana toward the achievement of the Millennium Development Goals. The prospects of these programs in addressing disparities in access to education and health care in the country and recommendations for improved delivery are discussed.

  19. Dietary diversity and child malnutrition in Ghana

    Directory of Open Access Journals (Sweden)

    Raymond Boadi Frempong

    2017-05-01

    Full Text Available The health of children in Ghana has improved in recent years. However, the current prevalence rates of malnutrition remain above internationally acceptable levels. This study, therefore, revisits the determinants of child health by using Ghana’s Multiple Indicator Cluster Survey to investigate the effect of infant feeding practices on child health. We used the World Health Organization’s Infant and Young Children Feeding guidelines to measure dietary quality. The econometric analyses show that dietary diversity may cause improvement in children’s health in Ghana. This suggests that educational campaigns on proper infant feeding and complementary dieting could be an effective means of improving the health of children in Ghana.

  20. CORPORATE SOCIAL RESPONSIBILITY IN GHANA: A COMPARATIVE ANALYSIS AND BUSINESS IMPERATIVE

    Directory of Open Access Journals (Sweden)

    Martin Owusu Ansah

    2013-10-01

    Full Text Available The grounds underpinning companies resorting to different Corporate Social Responsibility (CSR practices are not obvious. Rationally, the profit making motive is at the front position of the companies’ goals as well as other factors which are hidden. This has led to a keen interest in promoting CSR among companies in Ghana than it was before. Through observations, document analysis and conduction of interviews of managers among the selected organizations, this paper sought to examine the CSR policies of five companies in Ghana and the associated benefits enjoyed by Ghanaians. Specifically, the paper aimed at determining the nature and impact – present and potential - of the selected companies’ CSR policies in Ghana and examined the assumptions behind the practice of CSR among the chosen companies. The methods used comprised primary data and secondary data sources. Convenient sampling technique was used for the study. The data were collected, collated and analyzed using charts and diagrams for easy interpretation. It was revealed from the research that, CSR programmes were community-focus initiatives, programmes on education as well as programmes in developing communities. It was therefore concluded that, there should be a law on CSR in Ghana and a course on CSR to train experts in that area.

  1. National health insurance subscription and maternal healthcare utilisation across mothers' wealth status in Ghana.

    Science.gov (United States)

    Ameyaw, Edward Kwabena; Kofinti, Raymond Elikplim; Appiah, Francis

    2017-12-01

    This study is against the backdrop that despite the forty-nine percent decline in Maternal Mortality Rate in Ghana, the situation still remains high averaging 319 per 100,000 live births between 2011 and 2015. To examine the relationship between National Health Insurance and maternal healthcare utilisation across three main wealth quintiles (Poor, Middle and Rich). The study employed data from the 2014 Ghana Demographic and Health Survey. Both descriptive analysis and binary logistic regression were conducted. Descriptively, rich women had high antenatal attendance and health facility deliveries represented by 96.5% and 95.6% respectively. However, the binary logistic regression results revealed that poor women owning NHIS are 7% (CI = 1.76-2.87) more likely to make at least four antenatal care visits compared to women in the middle wealth quintile (5%, CI = 2.12-4.76) and rich women (2%, CI = 1.14-4.14). Similarly, poor women who owned the NHIS are 14% (CI = 1.42-2.13) likely to deliver in health facility than women in the middle and rich wealth quintile. The study has vindicated the claim that NHIS Scheme is pro-poor in Ghana. The Ministry of Health should target women in the rural area to be enrolled on the NHIS to improve maternal healthcare utilisation since poverty is principally a rural phenomenon in Ghana.

  2. The Effects of Biofuel Feedstock Production on Farmers’ Livelihoods in Ghana: The Case of Jatropha curcas

    Directory of Open Access Journals (Sweden)

    Emmanuel Acheampong

    2014-07-01

    Full Text Available The widespread acquisition of land for large-scale/commercial production of biofuel crops in Ghana has raised concerns from civil society organizations, local communities and other parties, regarding the impact of these investments on local livelihoods. This paper assessed the effect of large-scale acquisition of land for production of Jatropha curcas on farmers’ livelihoods in Ghana. The study was conducted in 11 communities spanning the major agro-ecological zones and political divisions across Ghana. Methods of data collection included questionnaire survey, interviews and focus group discussions. Results show that several households have lost their land to Jatropha plantations leading, in some cases, to violent conflicts between biofuel investors, traditional authorities and the local communities. Most people reported that, contrary to the belief that Jatropha does well on marginal lands, the lands acquired by the Jatropha Companies were productive lands. Loss of rights over land has affected households’ food production and security, as many households have resorted to reducing the area they have under cultivation, leading to shortening fallow periods and declining crop yields. In addition, although the cultivation of Jatropha led to the creation of jobs in the communities where they were started, such jobs were merely transient. The paper contends that, even though the impact of Jatropha feedstock production on local livelihoods in Ghana is largely negative, the burgeoning industry could be developed in ways that could support local livelihoods.

  3. Fostering repeat donations in Ghana.

    Science.gov (United States)

    Owusu-Ofori, S; Asenso-Mensah, K; Boateng, P; Sarkodie, F; Allain, J-P

    2010-01-01

    Most African countries are challenged in recruiting and retaining voluntary blood donors by cost and other complexities and in establishing and implementing national blood policies. The availability of replacement donors who are a cheaper source of blood has not enhanced repeat voluntary donor initiatives. An overview of activities for recruiting and retaining voluntary blood donors was carried out. Donor records from mobile sessions were reviewed from 2002 to 2008. A total of 71,701 blood donations; 45,515 (63.5%) being voluntary donations with 11,680 (25%) repeat donations were collected during the study period. Donations from schools and colleges contributed a steady 60% of total voluntary whilst radio station blood drives increased contribution from 10 to 27%. Though Muslim population is less than 20%, blood collection was above the 30-donation cost-effectiveness threshold with a repeat donation trend reaching 60%. In contrast Christian worshippers provided donations. Repeat donation trends amongst school donors and radio blood drives were 20% and 70% respectively. Repeat donations rates have been variable amongst different blood donor groups in Kumasi, Ghana. The impact of community leaders in propagating altruism cannot be overemphasized. Programs aiming at motivating replacement donors to be repeat donors should be developed and assessed. Copyright 2009 The International Association for Biologicals. All rights reserved.

  4. Morphological Indicators of a Mascon Beneath Ceres's Largest Crater, Kerwan

    Science.gov (United States)

    Bland, M. T.; Ermakov, A. I.; Raymond, C. A.; Williams, D. A.; Bowling, T. J.; Preusker, F.; Park, R. S.; Marchi, S.; Castillo-Rogez, J. C.; Fu, R. R.; Russell, C. T.

    2018-02-01

    Gravity data of Ceres returned by the National Aeronautics and Space Administration's Dawn spacecraft is consistent with a lower density crust of variable thickness overlying a higher density mantle. Crustal thickness variations can affect the long-term, postimpact modification of impact craters on Ceres. Here we show that the unusual morphology of the 280 km diameter crater Kerwan may result from viscous relaxation in an outer layer that thins substantially beneath the crater floor. We propose that such a structure is consistent with either impact-induced uplift of the high-density mantle beneath the crater or from volatile loss during the impact event. In either case, the subsurface structure inferred from the crater morphology is superisostatic, and the mass excess would result in a positive Bouguer anomaly beneath the crater, consistent with the highest-degree gravity data from Dawn. Ceres joins the Moon, Mars, and Mercury in having basin-associated gravity anomalies, although their origin may differ substantially.

  5. A schematic model of crater modification by gravity

    Science.gov (United States)

    Melosh, H. J.

    1982-01-01

    The morphology of craters found on planets and moons of the solar system is examined and a development model which can account for the observed crater characteristics is discussed. The prompt collapse of craters to form flat floors, terraced walls, and central peak structures is considered to be the result of an approximate Bingham plastic rheology of the material surrounding the crater. This rheology is induced dynamically by the strong incoherent acoustic 'noise' accompanying excavation of the crater. Central pits, peak rings, and other multiple symmetric-profile rings originate by oscillation of this fluid. Large craters with transient depths comparable to the lithosphere thickness are subject to collapse by fragmentation of the lithosphere as well as fluidization. The considered concepts are developed mathematically. A model emerges which appears capable of explaining most of the qualitative features of large impact structures.

  6. Impact spacecraft imagery and comparative morphology of craters

    International Nuclear Information System (INIS)

    Moutsoulas, M.; Piteri, S.

    1979-01-01

    The use of hard-landing 'simple' missions for wide-scale planetary exploration is considered. As an example of their imagery potentialities, Ranger VII data are used for the study of the morphological characteristics of 16 Mare Cognitum craters. The morphological patterns of lunar craters, expressed in terms of the Depth/Diameter ratios appear to be in most cases independent of the crater location or size. (Auth.)

  7. Crater populations in the early history of Mercury

    International Nuclear Information System (INIS)

    Guest, J.E.; Gault, D.E.

    1976-01-01

    Crater populations on two major geologic units of Mercury have been classified into three morphologic types which characterize their state of degradation. The results indicate that one or more processes either prior to or contemporary with the formation of the 1300 km diameter Caloris Planitia reduced the population of fresh craters smaller than 70--80 km diameter and totally erased the population of fresh craters smaller than 20--30 km

  8. Delineating Bukit Bunuh impact crater boundary by geophysical and geotechnical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Azwin, I. N., E-mail: nurazwinismail@yahoo.com; Rosli, S.; Nordiana, M. M.; Ragu, R. R.; Mark, J. [Geophysics Section, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Mokhtar, S. [Centre for Global Archaeological Research Malaysia, 11800 USM, Penang (Malaysia)

    2015-03-30

    Evidences of crater morphology and shock metamorphism in Bukit Bunuh, Lenggong, Malaysia were found during the archaeological research conducted by the Centre for Global Archaeological Research Malaysia, Universiti Sains Malaysia. In order to register Bukit Bunuh as one of the world meteorite impact site, detailed studies are needed to verify the boundary of the crater accordingly. Geophysical study was conducted utilising the seismic refraction and 2-D electrical resistivity method. Seismic refraction survey was done using ABEM MK8 24 channel seismograph with 14Hz geophones and 40kg weight drop while 2-D electrical resistivity survey was performed using ABEM SAS4000 Terrameter and ES10-64C electrode selector with pole-dipole array. Bedrock depths were digitized from the sections obtained. The produced bedrock topography map shows that there is low bedrock level circulated by high elevated bedrock and interpreted as crater and rim respectively with diameter approximately 8km. There are also few spots of high elevated bedrock appear at the centre of the crater which interpreted as rebounds zone. Generally, the research area is divided into two layers where the first layer with velocity 400-1100 m/s and resistivity value of 10-800 Om predominantly consists of alluvium mix with gravel and boulders. Second layer represents granitic bedrock with depth of 5-50m having velocity >2100 m/s and resistivity value of >1500 Om. This research is strengthen by good correlation between geophysical data and geotechnical borehole records executed inside and outside of the crater, on the rim, as well as at the rebound area.

  9. Strontium isotopes in carbonate deposits at Crater Flat, Nevada

    International Nuclear Information System (INIS)

    Marshall, B.D.; Futa, K.; Peterman, Z.E.; Stuckless, J.S.

    1991-01-01

    Strontium isotope studies of carbonates from soils, veins, eolian dust and Paleozoic basement sampled near Crater Flat, southwest of Yucca Mountain, provide evidence for the origins of these materials. Vein and soil carbonates have nearly identical ranges of 87 Sr/ 86 Sr, and eolian material has 87 Sr/ 86 Sr ratios at the lower end of the pedogenic range. The average 87 Sr/ 86 Sr of Paleozoic basement from Black Marble Hill is similar to the 87 Sr/ 86 Sr in the eolian dust, perhaps indicating a local source for this material. Possible spring deposits have generally higher 87 Sr/ 86 Sr than the other carbonates. These data are compared with similar data from areas east of Yucca Mountain

  10. Huygens Crater: Insights into Noachian Volcanism, Stratigraphy, and Aqueous Processes

    Science.gov (United States)

    Ackiss, S. E.; Wray, J. J.; Seelos, K. D.; Niles, P. B.

    2015-01-01

    Huygens crater is a well preserved peak ring structure on Mars centered at 13.5 deg S, 55.5 deg E in the Noachian highlands between Terras Tyrrhena and Sabaea near the NW rim of Hellas basin. With a diameter of approximately 470 km, it uplifted and exhumed pre-Noachian crustal materials from depths greater than 25 km, penetrating below the thick, ubiquitous layer of Hellas ejecta. In addition, Huygens served as a basin for subsequent aqueous activity, including erosion/deposition by fluvial valley networks and subsurface alteration that is now exposed by smaller impacts. Younger mafic-bearing plains that partially cover the basin floor and surrounding intercrater areas were likely emplaced by later volcanism.

  11. Strontium isotopes in carbonate deposits at Crater Flat, Nevada

    International Nuclear Information System (INIS)

    Marshall, B.D.; Futa, K.; Peterman, Z.E.; Stuckless, J.S.

    1991-01-01

    Strontium isotope studies of carbonates from soils, veins, eolian dust and Paleozoic basement samples near Crater Flat, southwest of Yucca Mountain, provide evidence for the origins of these materials. Vein and soil carbonates have nearly identical ranges of 87 Sr/ 86 Sr ratios at the lower end of the pedogenic range. The average 87 Sr/ 86 Sr of Paleozoic basement from Black Marble Hill is similar to the 87 Sr/ 86 Sr in the eolian dust, perhaps indicating a local source for this material. Possible spring deposits have generally higher 87 Sr/ 86 Sr than the other carbonates. These data are compared with similar data from areas east of Yucca Mountain. 7 refs., 5 figs

  12. Computer simulations of large asteroid impacts into oceanic and continental sites--preliminary results on atmospheric, cratering and ejecta dynamics

    Science.gov (United States)

    Roddy, D.J.; Schuster, S.H.; Rosenblatt, M.; Grant, L.B.; Hassig, P.J.; Kreyenhagen, K.N.

    1987-01-01

    Computer simulations have been completed that describe passage of a 10-km-diameter asteroid through the Earth's atmosphere and the subsequent cratering and ejecta dynamics caused by impact of the asteroid into both oceanic and continental sites. The asteroid was modeled as a spherical body moving vertically at 20 km/s with a kinetic energy of 2.6 ?? 1030 ergs (6.2 ?? 107 Mt ). Detailed material modeling of the asteroid, ocean, crustal units, sedimentary unit, and mantle included effects of strength and fracturing, generic asteroid and rock properties, porosity, saturation, lithostatic stresses, and geothermal contributions, each selected to simulate impact and geologic conditions that were as realistic as possible. Calculation of the passage of the asteroid through a U.S. Standard Atmosphere showed development of a strong bow shock wave followed by a highly shock compressed and heated air mass. Rapid expansion of this shocked air created a large low-density region that also expanded away from the impact area. Shock temperatures in air reached ???20,000 K near the surface of the uplifting crater rim and were as high as ???2000 K at more than 30 km range and 10 km altitude. Calculations to 30 s showed that the shock fronts in the air and in most of the expanding shocked air mass preceded the formation of the crater, ejecta, and rim uplift and did not interact with them. As cratering developed, uplifted rim and target material were ejected into the very low density, shock-heated air immediately above the forming crater, and complex interactions could be expected. Calculations of the impact events showed equally dramatic effects on the oceanic and continental targets through an interval of 120 s. Despite geologic differences in the targets, both cratering events developed comparable dynamic flow fields and by ???29 s had formed similar-sized transient craters ???39 km deep and ???62 km across. Transient-rim uplift of ocean and crust reached a maximum altitude of nearly

  13. Floor-Fractured Craters through Machine Learning Methods

    Science.gov (United States)

    Thorey, C.

    2015-12-01

    Floor-fractured craters are impact craters that have undergone post impact deformations. They are characterized by shallow floors with a plate-like or convex appearance, wide floor moats, and radial, concentric, and polygonal floor-fractures. While the origin of these deformations has long been debated, it is now generally accepted that they are the result of the emplacement of shallow magmatic intrusions below their floor. These craters thus constitute an efficient tool to probe the importance of intrusive magmatism from the lunar surface. The most recent catalog of lunar-floor fractured craters references about 200 of them, mainly located around the lunar maria Herein, we will discuss the possibility of using machine learning algorithms to try to detect new floor-fractured craters on the Moon among the 60000 craters referenced in the most recent catalogs. In particular, we will use the gravity field provided by the Gravity Recovery and Interior Laboratory (GRAIL) mission, and the topographic dataset obtained from the Lunar Orbiter Laser Altimeter (LOLA) instrument to design a set of representative features for each crater. We will then discuss the possibility to design a binary supervised classifier, based on these features, to discriminate between the presence or absence of crater-centered intrusion below a specific crater. First predictions from different classifier in terms of their accuracy and uncertainty will be presented.

  14. Surface age of venus: use of the terrestrial cratering record

    International Nuclear Information System (INIS)

    Schaber, G.G.; Shoemaker, E.M.; Kozak, R.C.

    1987-01-01

    The average crater age of Venus' northern hemisphere may be less than 250 m.y. assuming equivalence between the recent terrestrial cratering rate and that on Venus for craters ≥ 20 km in diameter. For craters larger than this threshold size, below which crater production is significantly affected by the Venusian atmosphere, there are fairly strong observational grounds for concluding that such an equivalence in cratering rates on Venus and Earth may exist. However, given the uncertainties in the role of both active and inactive comet nuclei in the cratering history of Earth, we conclude that the age of the observed surface in the northern hemisphere of Venus could be as great as the 450-m.y. mean age of the Earth's crust. The observed surface of Venus might be even older, but no evidence from the crater observations supports an age as great as 1 b.y. If the age of the observed Venusian surface were 1 b.y., it probably should bear the impact scars of a half dozen or more large comet nuclei that penetrated the atmosphere and formed craters well over 100 km in diameter. Venera 15/16 mapped only about 25% of Venus; the remaining 75% may tell us a completely different story

  15. The Gale Crater Mound in a Regional Geologic Setting: Comparison Study of Wind Erosion in Gale Crater and Within a 1000 KM Radius

    Science.gov (United States)

    Dapremont. A.; Allen, C.; Runyon, C.

    2014-01-01

    Gale is a Late Noachian/Early Hesperian impact crater located on the dichotomy boundary separating the southern highlands and the northern lowlands of Mars. NASA's Curiosity Rover is currently exploring Gale, searching for evidence of habitability early in Mars history. With an approximate diameter of 155 km, and a approx. 5 km central mound informally titled Mt. Sharp, Gale represents a region of geologic interest due to the abundance of knowledge that can be derived, through its sedimentary deposits, pertaining to the environmental evolution of Mars. This study was undertaken to compare wind erosional features in Gale Crater and within sediments in a 1000 km radial area. The ultimate objective of this comparison was to determine if or how Gale relates to the surrounding region.

  16. Does the operations of the National Health Insurance Scheme (NHIS) in Ghana align with the goals of Primary Health Care? Perspectives of key stakeholders in northern Ghana.

    Science.gov (United States)

    Awoonor-Williams, John Koku; Tindana, Paulina; Dalinjong, Philip Ayizem; Nartey, Harry; Akazili, James

    2016-09-05

    In 2005, the World Health Assembly (WHA) of the World Health Organization (WHO) urged member states to aim at achieving affordable universal coverage and access to key promotive, preventive, curative, rehabilitative and palliative health interventions for all their citizens on the basis of equity and solidarity. Since then, some African countries, including Ghana, have taken steps to introduce national health insurance reforms as one of the key strategies towards achieving universal health coverage (UHC). The aim of this study was to get a better understanding of how Ghana's health insurance institutions interact with stakeholders and other health sector programmes in promoting primary health care (PHC). Specifically, the study identified the key areas of misalignment between the operations of the NHIS and that of PHC. Using qualitative and survey methods, this study involved interviews with various stakeholders in six selected districts in the Upper East region of Ghana. The key stakeholders included the National Health Insurance Authority (NHIA), district coordinators of the National Health Insurance Schemes (NHIS), the Ghana Health Service (GHS) and District Health Management Teams (DHMTs) who supervise the district hospitals, health centers/clinics and the Community-based Health and Planning Services (CHPS) compounds as well as other public and private PHC providers. A stakeholders' workshop was organized to validate the preliminary results which provided a platform for stakeholders to deliberate on the key areas of misalignment especially, and to elicit additional information, ideas and responses, comments and recommendations from respondents for the achievement of the goals of UHC and PHC. The key areas of misalignments identified during this pilot study included: delays in reimbursements of claims for services provided by health care providers, which serves as a disincentive for service providers to support the NHIS; inadequate coordination among

  17. Social capital and active membership in the Ghana National Health Insurance Scheme - a mixed method study.

    Science.gov (United States)

    Fenenga, Christine J; Nketiah-Amponsah, Edward; Ogink, Alice; Arhinful, Daniel K; Poortinga, Wouter; Hutter, Inge

    2015-11-02

    People's decision to enroll in a health insurance scheme is determined by socio-cultural and socio-economic factors. On request of the National health Insurance Authority (NHIA) in Ghana, our study explores the influence of social relationships on people's perceptions, behavior and decision making to enroll in the National Health Insurance Scheme. This social scheme, initiated in 2003, aims to realize accessible quality healthcare services for the entire population of Ghana. We look at relationships of trust and reciprocity between individuals in the communities (so called horizontal social capital) and between individuals and formal health institutions (called vertical social capital) in order to determine whether these two forms of social capital inhibit or facilitate enrolment of clients in the scheme. Results can support the NHIA in exploiting social capital to reach their objective and strengthen their policy and practice. We conducted 20 individual- and seven key-informant interviews, 22 focus group discussions, two stakeholder meetings and a household survey, using a random sample of 1903 households from the catchment area of 64 primary healthcare facilities. The study took place in Greater Accra Region and Western Regions in Ghana between June 2011 and March 2012. While social developments and increased heterogeneity seem to reduce community solidarity in Ghana, social networks remain common in Ghana and are valued for their multiple benefits (i.e. reciprocal trust and support, information sharing, motivation, risk sharing). Trusting relations with healthcare and insurance providers are, according healthcare clients, based on providers' clear communication, attitude, devotion, encouragement and reliability of services. Active membership of the NHIS is positive associated with community trust, trust in healthcare providers and trust in the NHIS (p-values are .009, .000 and .000 respectively). Social capital can motivate clients to enroll in health insurance

  18. Effects of occupational stress and coping mechanisms adopted by radiographers in Ghana

    International Nuclear Information System (INIS)

    Ashong, G.G.N.A.; Rogers, H.; Botwe, B.O.; Anim-Sampong, S.

    2016-01-01

    Background: Studies have shown that population of radiography staff within various hospitals in Ghana decreased by 30% in the last decade due to several reasons. One of such reasons understood to be related to stress and job satisfaction which affect work output. Purpose: To investigate the effects of occupational stress and the coping mechanisms adopted by radiographers in Ghana. Method: A descriptive survey using a five-point Likert-scale questionnaire with pre-coded responses was administered via email to respondents. Purposive sampling method was used to select 190 radiographers who work in hospitals in Ghana. Descriptive statistics was mainly used to analyse the data using SPSS Version 20. Results: Of a total 190 questionnaires sent, 122 were completed and returned giving a 64.3% response rate. Majority 78 (64%) of respondents were males and the predominant area of work was conventional radiography. Most radiographers revealed they were stressed with 63% indicating high/very high levels of stress. The consequent effects of stress on radiographers were sick absence, depression and job dissatisfaction. Most of the radiographers used primary interventions to cope with stress. Conclusion: This study has demonstrated that most radiographers in Ghana are stressed. However, they cope well with problem-solving mechanisms. This suggests that the decrease in number of radiographers within various facilities in Ghana by 30% may not necessarily be caused by stress but other factors which need to be investigated. Nevertheless, occupational stress has an effect on radiographers' quality of working life and may directly impact on their behaviour during service delivery. - Highlights: • There is high level of occupational stress among Ghanaian Radiographers. • Some sources and causes of occupational stress among Ghanaian Radiographers were workload, poor pay and shortage of staff. • Job dissatisfaction, depression and sick absence were effects of occupational

  19. Journal of the Ghana Science Association: Submissions

    African Journals Online (AJOL)

    Unless otherwise stated, the first named author of a joint publication will be taken as ... be sent to The Editor, Journal of Ghana Science Association, P.O. Box 7, Legon. ... Copyright for articles published in this journal is retained by the journal.

  20. Ghana Mining Journal - Vol 9 (2007)

    African Journals Online (AJOL)

    Evaluating the Acid Mine Drainage Potential at Abosso Goldfields Limited (AGL), Ghana. JS Kuma, DN Asamoah. http://dx.doi.org/10.4314/gm.v9i1.42604 ... Application of Virtual Reality for Visual Presentation in the Mineral Industry. AA Mensah, PA Eshun. http://dx.doi.org/10.4314/gm.v9i1.42611 ...

  1. Assessing the Implementation of Ghana's Patient Charter

    Science.gov (United States)

    Abekah-Nkrumah, Gordon; Manu, Abubakar; Atinga, Roger Ayimbillah

    2010-01-01

    Purpose: This paper seeks to assess the implementation of Ghana's Patients' Charter by investigating the level of awareness and knowledge of the Charter's content, some socio-demographic factors that may influence awareness and knowledge of the Charter and how providers have discharged their responsibilities under the Charter.…

  2. Small Scale Foundries in Ghana: The challenges

    Directory of Open Access Journals (Sweden)

    Anthony ANDREWS

    2012-08-01

    Full Text Available Small Scale Foundries (SSFs have been in existence for several years in Ghana. The industry has created several jobs for the people of Ghana and has minimized the burden on government to find ways of disposing scrap metals generated within the country. While scrap metals are still being exported, the quantity exported has decreased as a result of recycling by foundrymen in producing various parts. The government of Ghana has not paid special attention to this industry. Nevertheless, individuals and private investors are heavily involved in producing several thousands of tonnes of castings annually generating revenue for the government through taxation as well as helping with metal waste disposal. Metal cast products are sold both locally and internationally to neighbouring countries. The industry is however faced with numerous challenges. These include quality issues due to lack of technical know-how, access to funding from both government and private financial institutions and foundry waste management. To promote this industry, government and private financial institutions must be encouraged to come on board. Policies must be established and proper training programme developed to improve and promote this technology. This could go a long way in reducing the high unemployment rate in Ghana.

  3. Ghana Atomic Energy Commission: Annual Report 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This report covers the activities and research progams of the Ghana Atomic Energy Commission for the year 2001. The research programs and associated publications have been grouped under the three main institutes of the Commission namely National Nuclear Research Institute, Radiation Protection Institute and Biotechnology and Nuclear Agricultre Research Institute.

  4. Ghana Library Journal - Vol 14 (2002)

    African Journals Online (AJOL)

    Services, resources and benefits of the Internet available to academics in Ghana · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Evelyn D Markwei, 21-30. http://dx.doi.org/10.4314/glj.v14i1.33946 ...

  5. Ghana Atomic Energy Commission: Annual Report 2001

    International Nuclear Information System (INIS)

    2002-01-01

    This report covers the activities and research progams of the Ghana Atomic Energy Commission for the year 2001. The research programs and associated publications have been grouped under the three main institutes of the Commission namely National Nuclear Research Institute, Radiation Protection Institute and Biotechnology and Nuclear Agricultre Research Institute

  6. Determinants of Antenatal Care Use in Ghana

    NARCIS (Netherlands)

    Overbosch, G.B.; Nsowah-Nuamah, N.N.N.; van den Boom, G.J.M.; Damnyag, L.

    2004-01-01

    The paper investigates the determinants of antenatal care use in Ghana. In particular, we study how economic factors affect the demand for antenatal care and the probability that the number of visits falls below the recommended number of four. Estimation results from a nested three-level multinomial

  7. Agricultural and Food Science Journal of Ghana

    African Journals Online (AJOL)

    The Agricultural and Food Science Journal of Ghana publishes papers describing research, observational or experimental and critical reviews in Agriculture and Food Science. Vol 10, No 1 (2017). DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Table of Contents. Articles ...

  8. Mobile rural youth in northern Ghana

    DEFF Research Database (Denmark)

    Gough, Katherine; Birch-Thomsen, Torben

    2016-01-01

    , followed by structural adjustment programmes and neoliberalism, have all contributed to increasing the inequality between the north and the south. Although Ghana has now joined the ranks of lower middle-income countries, its northern part lags behind, with 22.2% of the population living below the poverty...

  9. Internationalisation of SMEs in Ghana in Retrospect

    DEFF Research Database (Denmark)

    Sørensen, Olav Jull; Kuada, John

    2006-01-01

    The aim of the conference paper is to collide the research on internationalisation of companies from a developing country, Ghana. The paper is based on more than 30 research projects conducted over the period 1996-2006. It is found that Ghanaian companies are poorly integrated into the global eco...

  10. ANALYSING INBOUND TOURISTS' PERCEPTIONS OF GHANA

    African Journals Online (AJOL)

    be created (either by official sources or by a marketing agency). and secondly ... that revenue from I Iotcls and Restaurants Customers' tax grew from GI I. 24 million in ..... market-driven specific tourism products in tandem with the various market ... strategy for Ghana· s tourism industry: A focus on the African-American market ...

  11. Intersectoral labor mobility and deforestation in Ghana

    NARCIS (Netherlands)

    Owusu, V.; Yerfi Fosu, K.; Burger, C.P.J.

    2012-01-01

    This paper quantifies the effects of the determinants of intersectoral labor mobility and the effect of intersectoral labor mobility on deforestation in Ghana over the period 1970–2008. A cointegration and error correction modeling approach is employed. The empirical results show that labor mobility

  12. Mothers education and childhood mortality in Ghana.

    NARCIS (Netherlands)

    Buor, D.

    2003-01-01

    The significant extent to which maternal education affects child health has been advanced in several sociodemographic-medical literature, but not much has been done in analysing the spatial dimension of the problem; and also using graphic and linear regression models of representation. In Ghana,

  13. Controlling human oesophagostomiasis in northern Ghana

    NARCIS (Netherlands)

    Ziem, Juventus Benogle

    2006-01-01

    This thesis describes aspects of the epidemiology and attempts to control infection and pathology due to the nematode parasite Oesophagostomum bifurcum . In northern Ghana and Togo O. bifurcum is an important parasite of humans; elsewhere it is predominantly seen as a parasite of non-human primates.

  14. A model for the dynamics of crater-centered intrusion: Application to lunar floor-fractured craters

    Science.gov (United States)

    Thorey, Clément; Michaut, Chloé

    2014-01-01

    Lunar floor-fractured craters are a class of craters modified by post-impact mechanisms. They are defined by distinctive shallow floors that are convex or plate-like, sometimes with a wide floor moat bordering the wall region. Radial, concentric, and polygonal floor fractures suggest an endogenous process of modification. Two mechanisms have been proposed to account for such deformations: viscous relaxation and spreading of a magma intrusion at depth below the crater. To test the second assumption and bring more constraints on the intrusion process, we develop a model for the dynamics of magma spreading below an elastic overlying layer with a crater-like topography. As predicted in earlier more qualitative studies, the increase in lithostatic pressure at the crater wall zone prevents the intrusion from spreading laterally, leading to the thickening of the intrusion. Additionally, our model shows that the final crater floor appearance after the uplift, which can be convex or flat, with or without a circular moat bordering the wall zone, depends on the elastic thickness of the layer overlying the intrusion and on the crater size. Our model provides a simple formula to derive the elastic thickness of the overlying layer hence a minimum estimate for the intrusion depth. Finally, our model suggests that crust redistribution by cratering must have controlled magma ascent below most of these craters.

  15. Establishing a central waste processing and storage facility in Ghana

    International Nuclear Information System (INIS)

    Glover, E.T.; Fletcher, J.J.; Darko, E.O.

    2001-01-01

    Radioactive waste and spent sealed sources in Ghana are generated from various nuclear applications - diagnostic and therapeutic procedures in medicine, measurement and processing techniques in industry, irradiation techniques for food preservation and sterilization of medical products and a research reactor for research and teaching. Statistics available indicate that over 15 institutions in Ghana are authorized to handle radiation sources. At present radioactive waste and spent sealed sources are collected and stored in the interim facility without conditioning. With the increasing use of radioactive sources in the industry, medicine for diagnostic and therapeutic purpose and research and teaching, the volume of waste is expected to increase. The radioactive waste expected include spent ion exchange resins from the nuclear reactor water purification system, incompactible solid waste from mechanical filter, liquid and organic waste and spent sealed sources. It is estimated that four 200L drums will be needed annually to condition the waste to be generated. The National Radioactive Waste Management Centre (NRWMC) was therefore established to carry radioactive waste safety operations in Ghana and research to ensure that each waste type is managed in the most appropriate manner. Its main task includes development and establishment of the radioactive waste management infrastructure with a capacity considering the future nuclear technology development in Ghana. The first phase covers the establishment of administrative structure, development of basic regulations and construction of the radioactive waste processing and storage facility. The Ghana Radioactive Waste Management regulation has been presented to the Parliament of Ghana for consideration. The initial draft was reviewed by the RPB. A 3-day national seminar on the Understanding and Implementation of the Regulation on Radioactive Waste Management in Ghana was held to discuss and educate the general public on the

  16. Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 2: Crater Size-frequency Distribution Curves and Geomorphic Unit Ages

    Science.gov (United States)

    Parker, T. J.; Pieri, D. C.

    1985-01-01

    In assessing the relative ages of the geomorphic/geologic units, crater counts of the entire unit or nearly the entire unit were made and summed in order to get a more accurate value than obtainable by counts of isolated sections of each unit. Cumulative size-frequency counts show some interesting relationships. Most of the units show two distinct crater populations with a flattening out of the distribution curve at and below 10 km diameter craters. Above this crater size the curves for the different units diverge most notably. In general, the variance may reflect the relative ages of these units. At times, however, in the larger crater size range, these curves can overlap and cross on another. Also the error bars at these larger sizes are broader (and thus more suspect), since counts of larger craters show more scatter, whereas the unit areas remain constant. Occasional clusters of relatively large craters within a given unit, particularly one of limited areal extent, can affect the curve so that the unit might seem to be older than units which it overlies or cuts.

  17. Cratering record in the inner solar system: Implications for earth

    International Nuclear Information System (INIS)

    Barlow, N.G.

    1988-01-01

    Internal and external processes have reworked the Earth's surface throughout its history. In particular, the effect of meteorite impacts on the early history of the earth is lost due to fluvial, aeolian, volcanic and plate tectonic action. The cratering record on other inner solar system bodies often provides the only clue to the relative cratering rates and intensities that the earth has experienced throughout its history. Of the five major bodies within the inner solar system, Mercury, Mars, and the Moon retain scars of an early episode of high impact rates. The heavily cratered regions on Mercury, Mars, and the Moon show crater size-frequency distribution curves similar in shape and crater density, whereas the lightly cratered plains on the Moon and Mars show distribution curves which, although similar to each other, are statistically different in shape and density from the more heavily cratered units. The similarities among crater size-frequency distribution curves for the Moon, Mercury, and Mars suggest that the entire inner solar system was subjected to the two populations of impacting objects but Earth and Venus have lost their record of heavy bombardment impactors. Thus, based on the cratering record on the Moon, Mercury, and Mars, it can be inferred that the Earth experienced a period of high crater rates and basin formation prior to about 3.8 BY ago. Recent studies have linked mass extinctions to large terrestrial impacts, so life forms were unable to establish themselves until impact rates decreased substantially and terrestrial conditions became more benign. The possible periodicity of mass extinctions has led to the theory of fluctuating impact rates due to comet showers in the post heavy bombardment period. The active erosional environment on the Earth complicates attempts to verify these showers by erasing geological evidence of older impact craters

  18. EFFECTS OF WEATHER-INDEX INSURANCE: THE CASE OF SMALLHOLDER MAIZE FARMERS IN NORTHERN GHANA

    Directory of Open Access Journals (Sweden)

    Bashiru Haruna

    2017-07-01

    Full Text Available The study investigates the effect of weather-index insurance on intensity of fertilizer use and yields among 230 smallholder maize farmers in Northern Region of Ghana. Out of the total sample of selected farmers, about 35% purchased the insurance. Using an endogenous treatment regression model, the study showed that weather-index insurance purchase increased the intensity of fertilizer use but did not have a significant effect on maize yield. Past experience of crop failure due to drought, livestock ownership as well as the total area of land owned explained weather-index insurance purchase in the study area. Based on the results of this study, the Government of Ghana can use weather-index insurance as a policy tool to increase the use of fertilizer by smallholder maize farmers.

  19. Observational constraints on the identification of shallow lunar magmatism : insights from floor-fractured craters

    OpenAIRE

    Jozwiak, Lauren; Head, James; Neumann, G. A.; Wilson, Lionel

    2017-01-01

    Floor-fractured craters are a class of lunar crater hypothesized to form in response to the emplacement of a shallow magmatic intrusion beneath the crater floor. The emplacement of a shallow magmatic body should result in a positive Bouguer anomaly relative to unaltered complex craters, a signal which is observed for the average Bouguer anomaly interior to the crater walls. We observe the Bouguer anomaly of floor-fractured craters on an individual basis using the unfiltered Bouguer gravity so...

  20. Detection of lunar floor-fractured craters using machine learning methods

    Science.gov (United States)

    Thorey, C.

    2015-10-01

    About 200 Floor Fractured Craters (FFCs) have been identified by Schultz (1976) on the Moon, mainly around the lunar maria. These craters are a class of impact craters that are distinguished by having radi-ally and concentric floor-fractured networks and ab-normally shallow floors. In some cases, the uplift of the crater floor can be as large as 50% of the initial crater depth. These impact craters are interpreted to have undergone endogenous deformations after their formation.

  1. Early Warning System Ghana: how to successfully implement a disaster early warning system in a data scarce region

    Science.gov (United States)

    Udo, Job; Jungermann, Nicole

    2016-04-01

    Ghana is a country frequently struck by natural disasters like floods and droughts. Timely warning or detection of such disasters will mitigate the negative impact on lives and property. However, local data and monitoring systems necessary to provide such a warning are hardly available. The availability and improvement of internet, mobile phones and satellites has provided new possibilities for disaster warning systems in data scarce regions such as Ghana. Our presentation describes the development of an early warning system (EWS) in Ghana completely based on satellite based open data. The EWS provides a flood or drought hazard warning on sub-catchment level and links the warning to a more detailed flood or drought risk map, to enable the disaster coordinator to send warnings or relieve more efficiently to areas that have the highest risk. This is especially relevant because some areas for which the system is implemented are very remote. The system is developed and tested to be robust and operational especially in remote areas. This means that the necessary information is also available under limited internet conditions and not dependent on local computer facilities. In many rural areas in Ghana communities rely on indigenous knowledge when it comes to flood or drought disaster forecasting. The EWS has a feature that allows indigenous knowledge indicators to be taken into account in the warning and makes easy comparison possible with the satellite based warnings.

  2. Assessing Worker and Environmental Chemical Exposure Risks at an e-Waste Recycling and Disposal Site in Accra, Ghana

    Directory of Open Access Journals (Sweden)

    Jack Caravanos

    2011-01-01

    Conclusions. The Agbogbloshie e-waste recycling/disposal site in Accra, Ghana revealed an area with extensive lead contamination in both ambient air and topsoil. Given the urban nature of this site e as well as the large adjacent food distribution market, the potential for human health impact is substantial both to workers and local residents.

  3. Crater lake and post-eruption hydrothermal activity, El Chichón Volcano, Mexico

    Science.gov (United States)

    Casadevall, Thomas J.; De la Cruz-Reyna, Servando; Rose, William I.; Bagley, Susan; Finnegan, David L.; Zoller, William H.

    1984-01-01

    Explosive eruptions of Volcán El Chichón in Chiapas, Mexico on March 28 and April 3–4, 1982 removed 0.2 km3 of rock to form a 1-km-wide 300-m-deep summit crater. By late April 1982 a lake had begun to form on the crater floor, and by November 1982 it attained a maximum surface area of 1.4 × 105 m2 and a volume of 5 × 106 m3. Accumulation of 4–5 m of rainfall between July and October 1982 largely formed the lake. In January 1983, temperatures of fumaroles on the crater floor and lower crater walls ranged from 98 to 115°C; by October 1983 the maximum temperature of fumarole emissions was 99°C. In January 1983 fumarole gas emissions were greater than 99 vol. % H2O with traces of CO2, SO2, and H2S. The water of the lake was a hot (T = 52–58°C), acidic (pH = 0.5), dilute solution (34,046 mg L−1 dissolved solids; Cl/S = 20.5). Sediment from the lake contains the same silicate minerals as the rocks of the 1982 pyroclastic deposits, together with less than 1% of elemental sulfur. The composition and temperature of the lake water is attributed to: (1) solution of fumarole emissions; (2) reaction of lake water with hot rocks beneath the lake level; (3) sediments washed into the lake from the crater walls; (4) hydrothermal fluids leaching sediments and formational waters in sedimentary rocks of the basement; (5) evaporation; and (6) precipitation.

  4. Ghana Space Science and Technology Institute (GSSTI) - Annual Report 2015

    International Nuclear Information System (INIS)

    2015-01-01

    The Ghana Space Science and Technology Institute (GSSTI) of the Ghana Atomic Energy Commission was established to exploit space science and technology for socio-economic development of Ghana. The report gives the structure of GSSTI and the detailed activities of the year. Various activities include: training and seminars, projects and workshops. Publications and their abstracts are also listed. The report also highlights some of the challenges, provides some recommendations and points to some expectation for the following year.

  5. Cardiovascular diseases in Ghana within the context of globalization.

    Science.gov (United States)

    Ofori-Asenso, Richard; Garcia, Daireen

    2016-02-01

    This paper discusses how globalization and its elements are influencing health dynamics and in particular Cardiovascular diseases (CVDs) in Ghana. It assesses the growing burden of CVDs and its relationship with globalization. It further describes the conceptual framework on which to view the impact of globalization on CVDs in Ghana. It also set out the dimensions of the relationship between CVD risk factors and globalization. The paper concludes with a discussion on strategies for tackling the growing burden of CVDs in Ghana.

  6. Program and book of abstracts of the 23rd biennial conference of the Ghana Science Association

    International Nuclear Information System (INIS)

    2003-08-01

    The twenty-third biennial conference of the Ghana Science Association was held on 4-7 August, 2003 in Kumasi. The theme of the conference was-The HIV/AIDS pandemic: challenges for the Ghanaian scientists. This publication contains the program, and about 200 abstracts of papers presented at the conference including poster sessions. The abstracts have been arranged under the following broad subject areas: Biomedical, Agriculture, Food and Nutrition, Physical and General (E.A.A.)

  7. Analysis of hybrid energy systems for application in southern Ghana

    International Nuclear Information System (INIS)

    Adaramola, Muyiwa S.; Agelin-Chaab, Martin; Paul, Samuel S.

    2014-01-01

    Highlights: • The option of using hybrid energy for electricity in remote areas of Ghana is examined. • The cost of electricity produced by the hybrid system is found to be $0.281/kW h. • The levelized cost of electricity increase by 9% when the PV price is increased from $3000/kW to $7500/kW. - Abstract: Due to advances in renewable energy technologies and increase in oil price, hybrid renewable energy systems are becoming increasingly attractive for power generation applications in remote areas. This paper presents an economic analysis of the feasibility of utilizing a hybrid energy system consisting of solar, wind and diesel generators for application in remote areas of southern Ghana using levelized cost of electricity (LCOE) and net present cost of the system. The annual daily average solar global radiation at the selected site is 5.4 kW h/m 2 /day and the annual mean wind speed is 5.11 m/s. The National Renewable Energy Laboratory’s Hybrid Optimization Model for Electric Renewable (HOMER) software was employed to carry out the present study. Both wind data and the actual load data have been used in the simulation model. It was found that a PV array of 80 kW, a 100 kW wind turbine, two generators with combined capacity of 100 kW, a 60 kW converter/inverter and a 60 Surrette 4KS25P battery produced a mix of 791.1 MW h of electricity annually. The cost of electricity for this hybrid system is found to be $0.281/kW h. Sensitivity analysis on the effect of changes in wind speed, solar global radiation and diesel price on the optimal energy was investigated and the impact of solar PV price on the LCOE for a selected hybrid energy system was also presented

  8. Lower Expression of TLR2 and SOCS-3 Is Associated with Schistosoma haematobium Infection and with Lower Risk for Allergic Reactivity in Children Living in a Rural Area in Ghana

    NARCIS (Netherlands)

    Hartgers, Franca C.; Obeng, Benedicta B.; Kruize, Yvonne C. M.; Duijvestein, Marjolijn; de Breij, Anna; Amoah, Abena; Larbi, Irene A.; van Ree, Ronald; Wilson, Michael D.; Rodrigues, Laura C.; Boakye, Daniel A.; Yazdanbakhsh, Maria

    2008-01-01

    Background: Helminth infections are prevalent in rural areas of developing countries and have in some studies been negatively associated with allergic disorders and atopy. In this context little is known of the molecular mechanisms of modulation involved. We have characterized the innate immune

  9. The Age of Lunar South Circumpolar Craters Haworth, Shoemaker, Faustini, and Shackleton: Implications for Regional Geology, Surface Processes, and Volatile Sequestration

    Science.gov (United States)

    Tye, A. R.; Fassett, C. I.; Head, J. W.; Mazarico, E.; Basilevsky, A. T.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

    2015-01-01

    The interiors of the lunar south circumpolar craters Haworth, Shoemaker, Faustini, and Shackleton contain permanently shadowed regions (PSRs) and have been interpreted to contain sequestered volatiles including water ice. Altimetry data from the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter provide a new means of examining the permanently shadowed interiors of these craters in unprecedented detail. In this study, we used extremely high-resolution gridded LOLA data of Haworth, Shoemaker, Faustini, and Shackleton to determine the size-frequency distributions and the spatial density of craters superposing their rims, inner slopes, and floors. Based on their population of superposed D greater than or equal to 2 km craters, Haworth, Shoemaker, and Faustini have pre-Nectarian formation ages. Shackleton is interpreted as having a Late Imbrian age on the basis of craters with diameter D greater than or equal to 0.5 km superposed on its rim. The local density of craters with sub-km diameters across our study area is strongly dependent on slope; because of its steep interior slopes, the lifetime of craters on the interior of Shackleton is limited. The slope-dependence of the small crater population implies that the population in this size range is controlled primarily by the rate at which craters are destroyed. This is consistent with the hypothesis that crater removal and resurfacing is a result of slopedependent processes such as diffusive mass wasting and seismic shaking, linked to micrometeorite and meteorite bombardment. Epithermal neutron flux data and UV albedo data show that these circumpolar PSRs, particularly Shoemaker, may have approximately 1-2% water ice by mass in their highly porous surface regolith, and that Shoemaker may have approximately 5% or more water ice by mass in the near subsurface. The ancient formation ages of Shoemaker, Faustini and Haworth, and the Late Imbrian (approximately 3.5 Ga) crater retention ages of their

  10. Impact cratering on porous targets in the strength regime

    Science.gov (United States)

    Nakamura, Akiko M.

    2017-12-01

    Cratering on small bodies is crucial for the collision cascade and also contributes to the ejection of dust particles into interplanetary space. A crater cavity forms against the mechanical strength of the surface, gravitational acceleration, or both. The formation of moderately sized craters that are sufficiently larger than the thickness of the regolith on small bodies, in which mechanical strength plays the dominant role rather than gravitational acceleration, is in the strength regime. The formation of microcraters on blocks on the surface is also within the strength regime. On the other hand, the formation of a crater of a size comparable to the thickness of the regolith is affected by both gravitational acceleration and cohesion between regolith particles. In this short review, we compile data from the literature pertaining to impact cratering experiments on porous targets, and summarize the ratio of spall diameter to pit diameter, the depth, diameter, and volume of the crater cavity, and the ratio of depth to diameter. Among targets with various porosities studied in the laboratory to date, based on conventional scaling laws (Holsapple and Schmidt, J. Geophys. Res., 87, 1849-1870, 1982) the cratering efficiency obtained for porous sedimentary rocks (Suzuki et al., J. Geophys. Res. 117, E08012, 2012) is intermediate. A comparison with microcraters formed on a glass target with impact velocities up to 14 km s-1 indicates a different dependence of cratering efficiency and depth-to-diameter ratio on impact velocity.

  11. Evolution of Occator Crater on (1) Ceres

    Energy Technology Data Exchange (ETDEWEB)

    Nathues, A.; Platz, T.; Thangjam, G.; Hoffmann, M.; Corre, L. Le; Reddy, V.; Kallisch, J. [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Goettingen (Germany); Mengel, K. [IELF, TU Clausthal, Adolph-Roemer-Straße 2A, 38678 Clausthal-Zellerfeld (Germany); Cloutis, E. A. [University of Winnipeg, Winnipeg, MB R3B 2E (Canada); Crown, D. A., E-mail: nathues@mps.mpg.de, E-mail: platz@mps.mpg.de, E-mail: thangjam@mps.mpg.de, E-mail: hoffmann@mps.mpg.de, E-mail: kallisch@mps.mpg.de, E-mail: gkmengel@t-online.de, E-mail: e.cloutis@uwinnipeg.ca, E-mail: lecorre@psi.edu, E-mail: reddy@psi.edu, E-mail: crown@psi.edu [Planetary Science Institute, 1700 East Fort Lowell Rd, Suite 106, Tucson, AZ 85719-2395 (United States)

    2017-03-01

    The dwarf planet Ceres (diameter 939 km) is the largest object in the main asteroid belt. Recent investigations suggest that Ceres is a thermally evolved, volatile-rich body with potential geological activity, a body which was never completely molten but possibly differentiated into a rocky core, an ice-rich mantle, and which may contain remnant internal liquid water. Thermal alteration and exogenic material infall contribute to producing a (dark) carbonaceous chondritic-like surface containing ammoniated phyllosilicates. Here we report imaging and spectroscopic analyses of Occator crater derived from the Framing Camera and the Visible and Infrared Spectrometer onboard Dawn. We found that the central bright spot (Cerealia Facula) of Occator is ∼30 Myr younger than the crater itself. The central spot is located in a central pit which contains a dome that is spectrally homogenous, exhibiting absorption features that are consistent with carbonates. Multiple radial fractures across the dome indicate an extrusive formation process. Our results lead us to conclude that the floor region was subject to past endogenic activity. Dome and bright material in its vicinity formed likely due to a long-lasting, periodic, or episodic ascent of bright material from a subsurface reservoir rich in carbonates. Originally triggered by an impact event, gases, possibly dissolved from a subsurface water/brine layer, enabled material rich in carbonates to ascend through fractures and be deposited onto the surface.

  12. Theory and experiments on centrifuge cratering

    International Nuclear Information System (INIS)

    Schmidt, R.M.; Holsapple, K.A.

    1980-01-01

    Centrifuge experimental techniques provide possibilities for laboratory simulation of ground motion and cratering effects due to explosive loadings. The results of a similarity analysis for the thermomechanical response of a continuun show that increased gravity is a necessary condition for subscale testing when identical materials for both model and prototype are being used. The general similarity requirements for this type of subscale testing are examined both theoretically and experimentally. The similarity analysis is used to derive the necessary and sufficient requirements due to the general balance and jump equations and gives relations among all the scale factors for size, density, stress, body forces, internal energy, heat supply, heat conduction, heat of detonation, and time. Additional constraints due to specific choices of material constitutive equations are evaluated separately. The class of consitutive equations that add no further requirements is identified. For this class of materials, direct simulation of large-scale cratering events at small scale on the centrifuge is possible and independent of the actual constitutive equations. For a rare-independent soil it is shown that a small experiment at gravity g and energy E is similar to a large event at 1 G but with energy equal to g 3 E. Consequently, experiments at 500 G with 8 grams of explosives can be used to

  13. An Analysis of Emergency Healthcare Delivery in Ghana: Lessons ...

    African Journals Online (AJOL)

    Ghana medical emergencies usually result from road traffic accidents, during which ..... electrocardiography, intravenous therapy, administration of medications, drugs and solutions, use of adjunctive medical devices and trauma care.

  14. Mass movement on Vesta at steep scarps and crater rims

    Science.gov (United States)

    Krohn, K.; Jaumann, R.; Otto, K.; Hoogenboom, T.; Wagner, R.; Buczkowski, D. L.; Garry, B.; Williams, D. A.; Yingst, R. A.; Scully, J.; De Sanctis, M. C.; Kneissl, T.; Schmedemann, N.; Kersten, E.; Stephan, K.; Matz, K.-D.; Pieters, C. M.; Preusker, F.; Roatsch, T.; Schenk, P.; Russell, C. T.; Raymond, C. A.

    2014-12-01

    The Quadrangles Av-11 and Av-12 on Vesta are located at the northern rim of the giant Rheasilvia south polar impact basin. The primary geologic units in Av-11 and Av-12 include material from the Rheasilvia impact basin formation, smooth material and different types of impact crater structures (such as bimodal craters, dark and bright crater ray material and dark ejecta material). Av-11 and Av-12 exhibit almost the full range of mass wasting features observed on Vesta, such as slump blocks, spur-and-gully morphologies and landslides within craters. Processes of collapse, slope instability and seismically triggered events force material to slump down crater walls or scarps and produce landslides or rotational slump blocks. The spur-and-gully morphology that is known to form on Mars is also observed on Vesta; however, on Vesta this morphology formed under dry conditions.

  15. Mass Movement on Vesta at Steep Scarps and Crater Rims

    Science.gov (United States)

    Krohn, K.; Jaumann, R.; Otto, K.; Hoogenboom, T.; Wagner, R.; Buczkowski, D. L.; Garry, B.; Williams, D. A.; Yingst, R. A.; Scully, J.; hide

    2014-01-01

    The Quadrangles Av-11 and Av-12 on Vesta are located at the northern rim of the giant Rheasilvia south polar impact basin. The primary geologic units in Av-11 and Av-12 include material from the Rheasilvia impact basin formation, smooth material and different types of impact crater structures (such as bimodal craters, dark and bright crater ray material and dark ejecta material). Av-11 and Av-12 exhibit almost the full range of mass wasting features observed on Vesta, such as slump blocks, spur-and-gully morphologies and landslides within craters. Processes of collapse, slope instability and seismically triggered events force material to slump down crater walls or scarps and produce landslides or rotational slump blocks. The spur-and-gully morphology that is known to form on Mars is also observed on Vesta; however, on Vesta this morphology formed under dry conditions.

  16. Postshot distribution and movement of radionuclides in nuclear crater ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Koranda, John J; Martin, John R; Wikkerink, Robert; Stuart, Marshall [Bio-Medical Division, Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    The distribution and postshot movement of radionuclides in nuclear crater ejecta are discussed in this report. Continuing studies of tritium movement in ejecta at SEDAN crater demonstrate that variations in tritium concentration are correlated with seasonal rainfall and soil water movements. Losses of 27 mCi H{sup 3}/ft{sup 2} are evident on SEDAN crater lip at the end of a three year period of measurements in -which an unusually large flux of rain was received. The distribution of gamma emitting radionuclides and tritium is described in the recently created SCHOONER crater ejecta field. The specific activity of radionuclides in the SCHOONER ejecta continuum is shown for ejecta collected from the crater lip to 17 miles from GZ. The movement of W{sup 181} and tritium into the sub-ejecta preshot soil is described at a site 3000 feet from GZ. (author)

  17. Acoustic fluidization and the scale dependence of impact crater morphology

    Science.gov (United States)

    Melosh, H. J.; Gaffney, E. S.

    1983-01-01

    A phenomenological Bingham plastic model has previously been shown to provide an adequate description of the collapse of impact craters. This paper demonstrates that the Bingham parameters may be derived from a model in which acoustic energy generated during excavation fluidizes the rock debris surrounding the crater. Experimental support for the theoretical flow law is presented. Although the Bingham yield stress cannot be computed without detailed knowledge of the initial acoustic field, the Bingham viscosity is derived from a simple argument which shows that it increases as the 3/2 power of crater diameter, consistent with observation. Crater collapse may occur in material with internal dissipation Q as low as 100, comparable to laboratory observations of dissipation in granular materials. Crater collapse thus does not require that the acoustic field be regenerated during flow.

  18. Comparative Analysis of Households Solid Waste Management in Rural and Urban Ghana

    Directory of Open Access Journals (Sweden)

    Simon Boateng

    2016-01-01

    Full Text Available The comparative analysis of solid waste management between rural and urban Ghana is largely lacking. This study investigated the solid waste situation and the organisation of solid waste management in both urban and rural settings from the perspective of households. The study employed cross-sectional survey covering both rural and urban districts in the Ashanti and Greater Accra Regions of Ghana. The study systematically sampled houses from which 400 households and respondents were randomly selected. Pearson’s Chi square test was used to compare demographic and socioeconomic variables in rural and urban areas. Multivariate Test, Tests of Between-Subjects Effects, and Pair-Wise Comparisons were performed through one-way MANOVA to determine whether or not solid waste situations in rural and urban areas are significantly different. The results revealed that location significantly affects solid waste management in Ghana. Urban communities had lower mean scores than rural communities for poor solid waste situation in homes. However, urban communities had higher mean scores than rural communities for poor solid waste situation in principal streets and dumping sites. The study recommends that the local government authorities implement very comprehensive policies (sanitary inspection, infrastructure development, and community participation that will take into consideration the specific solid waste management needs of both urban and rural areas.

  19. Comparative Analysis of Households Solid Waste Management in Rural and Urban Ghana

    Science.gov (United States)

    Appiah, Divine Odame; Poku, Adjoa Afriyie; Garsonu, Emmanuel Kofi

    2016-01-01

    The comparative analysis of solid waste management between rural and urban Ghana is largely lacking. This study investigated the solid waste situation and the organisation of solid waste management in both urban and rural settings from the perspective of households. The study employed cross-sectional survey covering both rural and urban districts in the Ashanti and Greater Accra Regions of Ghana. The study systematically sampled houses from which 400 households and respondents were randomly selected. Pearson's Chi square test was used to compare demographic and socioeconomic variables in rural and urban areas. Multivariate Test, Tests of Between-Subjects Effects, and Pair-Wise Comparisons were performed through one-way MANOVA to determine whether or not solid waste situations in rural and urban areas are significantly different. The results revealed that location significantly affects solid waste management in Ghana. Urban communities had lower mean scores than rural communities for poor solid waste situation in homes. However, urban communities had higher mean scores than rural communities for poor solid waste situation in principal streets and dumping sites. The study recommends that the local government authorities implement very comprehensive policies (sanitary inspection, infrastructure development, and community participation) that will take into consideration the specific solid waste management needs of both urban and rural areas. PMID:27807453

  20. Comparative Analysis of Households Solid Waste Management in Rural and Urban Ghana.

    Science.gov (United States)

    Boateng, Simon; Amoako, Prince; Appiah, Divine Odame; Poku, Adjoa Afriyie; Garsonu, Emmanuel Kofi

    2016-01-01

    The comparative analysis of solid waste management between rural and urban Ghana is largely lacking. This study investigated the solid waste situation and the organisation of solid waste management in both urban and rural settings from the perspective of households. The study employed cross-sectional survey covering both rural and urban districts in the Ashanti and Greater Accra Regions of Ghana. The study systematically sampled houses from which 400 households and respondents were randomly selected. Pearson's Chi square test was used to compare demographic and socioeconomic variables in rural and urban areas. Multivariate Test, Tests of Between-Subjects Effects, and Pair-Wise Comparisons were performed through one-way MANOVA to determine whether or not solid waste situations in rural and urban areas are significantly different. The results revealed that location significantly affects solid waste management in Ghana. Urban communities had lower mean scores than rural communities for poor solid waste situation in homes. However, urban communities had higher mean scores than rural communities for poor solid waste situation in principal streets and dumping sites. The study recommends that the local government authorities implement very comprehensive policies (sanitary inspection, infrastructure development, and community participation) that will take into consideration the specific solid waste management needs of both urban and rural areas.

  1. Control of the geomorphic evolution of an active crater: Popocatpetl (Mexico) 1994-2003.

    Science.gov (United States)

    Andrés, N.; Zamorano, J. J.; Palacios, D.; Macias, J. L.; Sanjosé, J. J.

    2009-04-01

    Volcanic activity often causes intense and successive geomorphic changes to occur inside a crater. In terms of hazard mitigation, it is important to understand the cause of these changes whether they be exterior lava spills, sequences of explosions or massive glacier melt. Access to an active crater, however, is very difficult and dangerous, so analytical approaches involving remote study must substitute actual fieldwork. Several studies done at Popocatepetl volcano during its most recent eruptive phase that began in December 1994, use remote techniques and are described in Cruz-Reyna et al. (1998), Wright et al. (2002), Martín-Del Pozo et al. (2003), Tanarro et al. (2005), Matiella et al. (2008), and Zamorano et al. (1996,1998), among others. The compendium of results reveals that recent volcanic activity on Popocatépetl is characterized by successive dome growth and destruction inside the crater. Macias and Siebe (2005) even suggest that the walls of the crater may no longer withstand future dome growth. The purpose of this study is to understand the morphologic evolution of the interior of the crater during the most active period of the present eruptive phase on Popocatepetl from 1994 to 2003. The methodology is based on photogrammetry techniques that have been used successfully at volcanic sites by Donnadieu et al. (2003), and on a GIS to organize information, draft maps and 3-D images, and to calculate spatial variations in landforms (Procter et al., 2006; Schilling et al., 2006). Traditional aerial photo interpretation was used for 22 triplets selected from a collection of photos taken by the Mexican Highway and Transport Secretariat, from 1982 to 2003, and enabled us to draft geomorphic maps of the interior of the crater. The photos and maps were rectified and georeferenced with ArcGis software, and then the maps were digitized. The areas containing morphologic units associated with a date (exterior crater walls, colluvial ramps and recent volcanic complex

  2. Simple Impact Crater Shapes From Shadows - The Sequel

    Science.gov (United States)

    Chappelow, J. E.

    2008-12-01

    At the last LPSC meeting I presented the outline of a method for determining simple impact crater shapes from shadows. In theory the shadow cast within a simple crater provides enough information to derive its cross-sectional shape from shadow measurements, at least to the maximum depth to which the shadow extends. Under certain simple assumptions, this can be done analytically. If the crater is conic-section - shaped, then it can be shown that the down-sun bound of any shadow cast within it is elliptical, with one axis along the direction of illumination and the other (perpendicular to it) of semi-length D/2 (where D is diameter). The properties of this shadow-ellipse can be related to the parameters of the crater shape conic-section, thus measurements of the shadow-ellipse yield not only crater depth and diameter but also the approximate crater shape, in terms of conic sections. The method also does not depend upon the shadow crossing near the crater center, which avoids a pitfall of older shadow measurement methods. The technique is also amenable to computer implementation, which has already been largely completed. Once computerized, crater measurements can be made rapidly and repeatably. The program reads in an image, its resolution, and the solar elevation and azimuth. The user then defines the crater rim by 'clicking' on three points, and the shadow ellipse by clicking on two more. The program calculates and outputs the diameter, the depth, and parameters describing the crater's approximating conic-section. It is highly applicable to situations where only single-image photography is available, for example MESSENGER flybys of Mercury. At the meeting I will present the finished math for this method and give some examples of its use.

  3. LU60645GT and MA132843GT Catalogues of Lunar and Martian Impact Craters Developed Using a Crater Shape-based Interpolation Crater Detection Algorithm for Topography Data

    Science.gov (United States)

    Salamuniccar, Goran; Loncaric, Sven; Mazarico, Erwan Matias

    2012-01-01

    For Mars, 57,633 craters from the manually assembled catalogues and 72,668 additional craters identified using several crater detection algorithms (CDAs) have been merged into the MA130301GT catalogue. By contrast, for the Moon the most complete previous catalogue contains only 14,923 craters. Two recent missions provided higher-quality digital elevation maps (DEMs): SELENE (in 1/16° resolution) and Lunar Reconnaissance Orbiter (we used up to 1/512°). This was the main motivation for work on the new Crater Shape-based interpolation module, which improves previous CDA as follows: (1) it decreases the number of false-detections for the required number of true detections; (2) it improves detection capabilities for very small craters; and (3) it provides more accurate automated measurements of craters' properties. The results are: (1) LU60645GT, which is currently the most complete (up to D>=8 km) catalogue of Lunar craters; and (2) MA132843GT catalogue of Martian craters complete up to D>=2 km, which is the extension of the previous MA130301GT catalogue. As previously achieved for Mars, LU60645GT provides all properties that were provided by the previous Lunar catalogues, plus: (1) correlation between morphological descriptors from used catalogues; (2) correlation between manually assigned attributes and automated measurements; (3) average errors and their standard deviations for manually and automatically assigned attributes such as position coordinates, diameter, depth/diameter ratio, etc; and (4) a review of positional accuracy of used datasets. Additionally, surface dating could potentially be improved with the exhaustiveness of this new catalogue. The accompanying results are: (1) the possibility of comparing a large number of Lunar and Martian craters, of e.g. depth/diameter ratio and 2D profiles; (2) utilisation of a method for re-projection of datasets and catalogues, which is very useful for craters that are very close to poles; and (3) the extension of the

  4. PUBLIC EXPOSURE TO MULTIPLE RF SOURCES IN GHANA.

    Science.gov (United States)

    Deatanyah, P; Abavare, E K K; Menyeh, A; Amoako, J K

    2018-03-16

    This paper describes an effort to respond to the suggestion in World Health Organization (WHO) research agenda to better quantify potential exposure levels from a range of radiofrequency (RF) sources at 200 public access locations in Ghana. Wide-band measurements were performed-with a spectrum analyser and a log-periodic antenna using three-point spatial averaging method. The overall results represented a maximum of 0.19% of the ICNIRP reference levels for public exposure. These results were generally lower than found in some previous but were 58% (2.0 dB) greater, than found in similar work conducted in the USA. Major contributing sources of RF fields were identified to be FM broadcast and mobile base station sites. Three locations with the greatest measured RF fields could represent potential areas for epidemiological studies.

  5. Creation of High Resolution Terrain Models of Barringer Meteorite Crater (Meteor Crater) Using Photogrammetry and Terrestrial Laser Scanning Methods

    Science.gov (United States)

    Brown, Richard B.; Navard, Andrew R.; Holland, Donald E.; McKellip, Rodney D.; Brannon, David P.

    2010-01-01

    Barringer Meteorite Crater or Meteor Crater, AZ, has been a site of high interest for lunar and Mars analog crater and terrain studies since the early days of the Apollo-Saturn program. It continues to be a site of exceptional interest to lunar, Mars, and other planetary crater and impact analog studies because of its relatively young age (est. 50 thousand years) and well-preserved structure. High resolution (2 meter to 1 decimeter) digital terrain models of Meteor Crater in whole or in part were created at NASA Stennis Space Center to support several lunar surface analog modeling activities using photogrammetric and ground based laser scanning techniques. The dataset created by this activity provides new and highly accurate 3D models of the inside slope of the crater as well as the downslope rock distribution of the western ejecta field. The data are presented to the science community for possible use in furthering studies of Meteor Crater and impact craters in general as well as its current near term lunar exploration use in providing a beneficial test model for lunar surface analog modeling and surface operation studies.

  6. Ethics-sensitivity of the Ghana national integrated strategic response plan for pandemic influenza.

    Science.gov (United States)

    Laar, Amos; DeBruin, Debra

    2015-05-07

    Many commentators call for a more ethical approach to planning for influenza pandemics. In the developed world, some pandemic preparedness plans have already been examined from an ethical viewpoint. This paper assesses the attention given to ethics issues by the Ghana National Integrated Strategic Plan for Pandemic Influenza (NISPPI). We critically analyzed the Ghana NISPPI's sensitivity to ethics issues to determine how well it reflects ethical commitments and principles identified in our review of global pandemic preparedness literature, existing pandemic plans, and relevant ethics frameworks. This paper reveals that important ethical issues have not been addressed in the Ghana NISPPI. Several important ethical issues are unanticipated, unacknowledged, and unplanned for. These include guidelines on allocation of scarce resources, the duties of healthcare workers, ethics-sensitive operational guidelines/protocols, and compensation programs. The NISPPI also pays scant attention to use of vaccines and antivirals, border issues and cooperation with neighboring countries, justification for delineated actions, and outbreak simulations. Feedback and communication plans are nebulous, while leadership, coordination, and budgeting are quite detailed. With respect to presentation, the NISPPI's text is organized around five thematic areas. While each area implicates ethical issues, NISPPI treatment of these areas consistently fails to address them. Our analysis reveals a lack of consideration of ethics by the NISPPI. We contend that, while the plan's content and fundamental assumptions provide support for implementation of the delineated public health actions, its consideration of ethical issues is poor. Deficiencies include a failure to incorporate guidelines that ensure fair distribution of scarce resources and a lack of justification for delineated procedures. Until these deficiencies are recognized and addressed, Ghana runs the risk of rolling out unjust and ethically

  7. High Resolution Digital Elevation Models of Pristine Explosion Craters

    Science.gov (United States)

    Farr, T. G.; Krabill, W.; Garvin, J. B.

    2004-01-01

    In order to effectively capture a realistic terrain applicable to studies of cratering processes and landing hazards on Mars, we have obtained high resolution digital elevation models of several pristine explosion craters at the Nevada Test Site. We used the Airborne Terrain Mapper (ATM), operated by NASA's Wallops Flight Facility to obtain DEMs with 1 m spacing and 10 cm vertical errors of 4 main craters and many other craters and collapse pits. The main craters that were mapped are Sedan, Scooter, Schooner, and Danny Boy. The 370 m diameter Sedan crater, located on Yucca Flat, is the largest and freshest explosion crater on Earth that was formed under conditions similar to hypervelocity impact cratering. As such, it is effectively pristine, having been formed in 1962 as a result of a controlled detonation of a 100 kiloton thermonuclear device, buried at the appropriate equivalent depth of burst required to make a simple crater. Sedan was formed in alluvium of mixed lithology and subsequently studied using a variety of field-based methods. Nearby secondary craters were also formed at the time and were also mapped by ATM. Adjacent to Sedan and also in alluvium is Scooter, about 90 m in diameter and formed by a high-explosive event. Schooner (240 m) and Danny Boy (80 m) craters were also important targets for ATM as they were excavated in hard basalt and therefore have much rougher ejecta. This will allow study of ejecta patterns in hard rock as well as engineering tests of crater and rock avoidance and rover trafficability. In addition to the high resolution DEMs, crater geometric characteristics, RMS roughness maps, and other higher-order derived data products will be generated using these data. These will provide constraints for models of landing hazards on Mars and for rover trafficability. Other planned studies will include ejecta size-frequency distribution at the resolution of the DEM and at finer resolution through air photography and field measurements

  8. Distribution of Early, Middle, and Late Noachian cratered surfaces in the Martian highlands: Implications for resurfacing events and processes

    Science.gov (United States)

    Irwin, Rossman P.; Tanaka, Kenneth L.; Robbins, Stuart J.

    2013-02-01

    Most of the geomorphic changes on Mars occurred during the Noachian Period, when the rates of impact crater degradation and valley network incision were highest. Fluvial erosion around the Noachian/Hesperian transition is better constrained than the longer-term landscape evolution throughout the Noachian Period, when the highland intercrater geomorphic surfaces developed. We interpret highland resurfacing events and processes using a new global geologic map of Mars (at 1:20,000,000 scale), a crater data set that is complete down to 1 km in diameter, and Mars Orbiter Laser Altimeter topography. The Early Noachian highland (eNh) unit is nearly saturated with craters of 32-128 km diameter, the Middle Noachian highland (mNh) unit has a resurfacing age of ~4 Ga, and the Late Noachian highland unit (lNh) includes younger composite surfaces of basin fill and partially buried cratered terrain. These units have statistically distinct ages, and their distribution varies with elevation. The eNh unit is concentrated in the high-standing Hellas basin annulus and in highland terrain that was thinly mantled by basin ejecta near 180° longitude. The mNh unit includes most of Arabia Terra, the Argyre vicinity, highland plateau areas between eNh outcrops, and the Thaumasia range. The lNh unit mostly occurs within highland basins. Crater depth/diameter ratios do not vary strongly between the eNh and mNh units, although crater losses to Noachian resurfacing appear greater in lower lying areas. Noachian resurfacing was spatially non-uniform, long-lived, and gravity-driven, more consistent with arid-zone fluvial and aeolian erosion and volcanism than with air fall mantling or mass wasting.

  9. Advancing obstetric and neonatal care in a regional hospital in Ghana via continuous quality improvement.

    Science.gov (United States)

    Srofenyoh, Emmanuel; Ivester, Thomas; Engmann, Cyril; Olufolabi, Adeyemi; Bookman, Laurel; Owen, Medge

    2012-01-01

    To reduce maternal and neonatal death at a large regional hospital through the use of quality improvement methodologies. In 2007, Kybele and the Ghana Health Service formed a partnership to analyze systems and patient care processes at a regional hospital in Accra, Ghana. A model encompassing continuous assessment, implementation, advocacy, outputs, and outcomes was designed. Key areas for improvement were grouped into "bundles" based on personnel, systems management, and service quality. Primary outcomes included maternal and perinatal mortality, and case fatality rates for hemorrhage and hypertensive disorders. Implementation and outcomes were evaluated tri-annually between 2007 and 2009. During the study period, there was a 34% decrease in maternal mortality despite a 36% increase in patient admission. Case fatality rates for pre-eclampsia and hemorrhage decreased from 3.1% to 1.1% (Pcontinuous quality improvement were developed and employed. Copyright © 2011 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  10. The Relationship between On-Farm Shade Trees and Cocoa Yields in Ghana

    DEFF Research Database (Denmark)

    Asare, Richard

    Cocoa (Theobroma cacao L.) is a crop that is widely cultivated across West Africa with Côte d’Ivoire, Cameroon, Ghana and Nigeria contributing about 70% of the global production. In Ghana cocoa contributes significantly to the national economy as over 20% of the world’s cocoa production comes from...... the country, making it the world’s second largest producer with an annual production level of over 700,000 metric tons, and an estimated cultivation area of ca. 1.6 million ha. Cocoa is mostly cultivated by smallholder farmers either as a monocrop or in association with other food crops, tree crops and under...... the cover of shade trees – cocoa agroforestry. This thesis hypothesizes that canopy cover of shade trees in low input (low-to-no fertilizer application) cocoa growing systems can contribute to cocoa yield improvements. The main theme deals with shade trees diversity and its effects on cocoa production...

  11. Assessment of radiofrequency radiation within the vicinity of some GSM base stations in Ghana

    International Nuclear Information System (INIS)

    Deatanyah, P.; Amoako, J. K.; Fletcher, J. J.; Asiedu, G. O.; Adjei, D. N.; Dwapanyin, G. O.; Amoatey, E. A.

    2012-01-01

    A radiofrequency (RF) electromagnetic radiation safety survey had been carried out at public access points in 46 towns with 76 Global Systems for Mobile communication cell sites in two major cities in Ghana. The objective was to determine the levels of RF field in residential areas, schools and market places, and compare the measured results with the guidelines set by the International Commission of Non-Ionising Radiation (ICNIRP). Measurements were made with log-periodic antenna coupled with spectrum analyzer. The results varied from 0.85 to 1.07 mW m -2 and 0.78 to 1.19 mW m -2 for the transmission frequencies of 900 and 1800 MHz, respectively. The result generally shows a compliance with the ICNIRP limit of 0.024 % but was 108 times higher than a similar survey carried out in Ghana 2 y ago. (authors)

  12. The Journey Towards Africanising Psychology in Ghana

    Directory of Open Access Journals (Sweden)

    Seth Oppong

    2016-04-01

    Full Text Available Psychology has come a long way since its origin in Africa and Ghana in particular. In this paper, an attempt is made to explore the current state of psychological knowledge in Ghana as well as the associated problems in the application of such knowledge. It was concluded that the approach to the study and application of psychological knowledge and tests has been too Eurocentric and westernized. As a result, it limits the applicability of the approach to the African setting, and yet, Western theorists may expect African psychologists to apply the theories to Africans. On the basis of this criticism, the scope of Pan-African psychology is defined and suggestions for pursuing an Africanisation project are presented. It is expected that the strategies that this paper advocates for indigenizing psychology in Africa can equally be useful to psychologists in other developing regions of the world.

  13. Two worlds apart: experiential learning in Ghana.

    Science.gov (United States)

    Ware, Sharon Douglass; Winters-Moorhead, Carol

    2009-07-01

    As our society becomes more diverse, it is important for nursing students to become culturally competent and to view the world from a global perspective. Traveling abroad enlightens the senses and expands the worldview. Traveling for study abroad is more than taking a vacation; it affords students the opportunity to learn experientially and it can be a transforming encounter that influences the way an evolving nurse will practice. Nursing students at North Carolina Central University in Durham, North Carolina, had the opportunity to bridge two worlds, urban life at the university and village life in Dodowa, Ghana, West Africa. The purpose of this article is to explore the role that studying abroad has in nurturing experiential learning. The experiences of students from a southern historically Black university that were enrolled concurrently in two summer independent study courses focusing on global healthcare in Ghana, West Africa, are described.

  14. Test of solar dryers in Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Oestergaard Jensen, S. [Teknologisk Institut. SolEnergiCentret, Taastrup (Denmark); Floejgaard Kristensen, E. [Danmarks JordbrugsForskning, Tjele (Denmark); Agyei, F. [FAGOD Ltd. (Ghana); Larsen, T. [Clipper Design Ltd. (Ghana); Nketiah, K.S. [FORIG (Ghana)

    2002-06-01

    The report describes the tests carried out in Ghana on three solar dryers as part of the project 'Test and Research Project into the Drying of Food and Wood Products with Solar Heat' financed by DANIDA. The main objective of the project was to develop and test solar dryers for crop, fish and wood in Ghana. Three dryers were erected: 1. Solar crop dryer: The solar crop dryer was erected at Silwood Farms at Pokuase about 30 km north of Accra. Silwood Farms grows primarily maize for seed and pineapples, 2. Solar fish dryer: The solar fish dryer was erected at Elite Enterprise Ltd. at Tema about 35 km east-north-east of Accra. Elite Enterprise Ltd. buys and dries fish, 3. Solar wood dryer: The solar wood dryers were erected at Clipper Design Ltd. at Mankoadze about 65 km west-south-west of Accra. Clipper Design Ltd. produces mainly doors. (BA)

  15. Ghana: an emerging oil-rich democracy

    International Nuclear Information System (INIS)

    Pellerin, Mathieu

    2011-12-01

    After an indication of the main economic and social indicators of Ghana, and an overview of the historical evolution of Ghana towards democracy since its independence in 1960, a discussion of its advances and limitations in this respect as this country is starting oil production (support of investors, obstacles and difficulties related to institutional limits, decentralisation process, land tenure regime and tradition), the author discusses the possible consequences of this oil wind fall on the democratic dynamics, notably regarding the legal framework (issues of fragility of the institutional and legal systems). In a third part, the author discusses the capacity of the Ghanaian system to face the oil challenge while exorcising the generally occurring curse associated with oil resources

  16. Management Strategies and Economic Development in Ghana

    DEFF Research Database (Denmark)

    Kuada, John

    2014-01-01

    as number 2 on the World Bank’s world economic growth list. It has also scored high on measures of civil liberty, political rights and political stability among other nations on the West African sub-continent. But Ghana still faces serious economic and social challenges and is, therefore, in search of new......Ghana has experienced a tumultuous political and economic history since its independence in 1957. But today it is among the handful of African nations that showcase the dreams and aspirations of Sub-Sahara Africa. In 2011 it achieved an impressive economic growth rate of 14.6 per cent and ranked...... to provides illustrations of the usefulness of the human capability development framework presented in volume one as a foundation for sustainable and inclusive economic development in SSA. It also highlights the challenges that the country continues to grapple with and provides some directions for further...

  17. National health insurance scheme enrolment and antenatal care among women in Ghana: is there any relationship?

    Science.gov (United States)

    Dixon, Jenna; Tenkorang, Eric Y; Luginaah, Isaac N; Kuuire, Vincent Z; Boateng, Godfred O

    2014-01-01

    The objective of this study was to examine whether enrolment in the National Health Insurance Scheme (NHIS) affects the likelihood and timing of utilising antenatal care among women in Ghana. Data were drawn from the Ghana Demographic and Health Survey, a nationally representative survey collected in 2008. The study used a cross-sectional design to examine the independent effects of NHIS enrolment on two dependent variables (frequency and timing of antenatal visits) among 1610 Ghanaian women. Negative binomial and logit models were fitted given that count and categorical variables were employed as outcome measures, respectively. Regardless of socio-economic and demographic factors, women enrolled in the NHIS make more antenatal visits compared with those not enrolled; however, there was no statistical association with the timing of the crucial first visit. Women who are educated, living in urban areas and are wealthy were more likely to attend antenatal care than those living in rural areas, uneducated and from poorer households. The NHIS should be strengthened and resourced as it may act as an important tool for increasing antenatal care attendance among women in Ghana. © 2013 John Wiley & Sons Ltd.

  18. Beyond dualism: Multisegmented labor markets in Ghana

    OpenAIRE

    James Heintz; Fabian Slonimczyk

    2007-01-01

    Using estimates of earnings functions in Ghana, this paper examines patterns of labor market segmentation with regard to formal and informal employment. Persistent earnings differentials are used as indicators of limited mobility across segments of the employed labor force. We find evidence of labor market segmentation between formal and informal employment and between different categories of informal employment which cannot be fully explained by human capital, physical asset, or credit marke...

  19. PRIVATE SECTOR DEVELOPMENT AND COMPETITIVENESS IN GHANA

    OpenAIRE

    Wolf, Susanna

    2003-01-01

    Ghana has a relatively good international reputation with respect to political stability and macroeconomic reforms. However, its success with developing the private sector and attracting investment has at best been mixed. Therefore the new government that came into power in 2001 proclaimed a "Golden Age of Business". Competitiveness and private sector development are closely interlinked. On the one hand the factors that influence the competitiveness of a country are a precondition for private...

  20. Social Factors Influencing Child Health in Ghana.

    Directory of Open Access Journals (Sweden)

    Emmanuel Quansah

    Full Text Available Social factors have profound effects on health. Children are especially vulnerable to social influences, particularly in their early years. Adverse social exposures in childhood can lead to chronic disorders later in life. Here, we sought to identify and evaluate the impact of social factors on child health in Ghana. As Ghana is unlikely to achieve the Millennium Development Goals' target of reducing child mortality by two-thirds between 1990 and 2015, we deemed it necessary to identify social determinants that might have contributed to the non-realisation of this goal.ScienceDirect, PubMed, MEDLINE via EBSCO and Google Scholar were searched for published articles reporting on the influence of social factors on child health in Ghana. After screening the 98 articles identified, 34 of them that met our inclusion criteria were selected for qualitative review.Major social factors influencing child health in the country include maternal education, rural-urban disparities (place of residence, family income (wealth/poverty and high dependency (multiparousity. These factors are associated with child mortality, nutritional status of children, completion of immunisation programmes, health-seeking behaviour and hygiene practices.Several social factors influence child health outcomes in Ghana. Developing more effective responses to these social determinants would require sustainable efforts from all stakeholders including the Government, healthcare providers and families. We recommend the development of interventions that would support families through direct social support initiatives aimed at alleviating poverty and inequality, and indirect approaches targeted at eliminating the dependence of poor health outcomes on social factors. Importantly, the expansion of quality free education interventions to improve would-be-mother's health knowledge is emphasised.

  1. Ancient aqueous environments at Endeavour crater, Mars

    Science.gov (United States)

    Arvidson, R. E.; Squyres, S. W.; Bell, J.F.; Catalano, J.G.; Clark, B. C.; Crumpler, L.S.; de Souza, P.A.; Fairén, A.G.; Farrand, W. H.; Fox, V.K.; Gellert, Ralf; Ghosh, A.; Golombeck, M.P.; Grotzinger, J.P.; Guinness, E.A.; Herkenhoff, Kenneth E.; Jolliff, B.L.; Knoll, A.H.; Li, R.; McLennan, S.M.; Ming, D. W.; Mittlefehldt, D. W.; Moore, Johnnie N.; Morris, R.V.; Murchie, S.L.; Parker, T.J.; Paulsen, G.; Rice, J.W.; Ruff, S.W.; Smith, M.D.; Wolff, M.J.

    2014-01-01

    Opportunity has investigated in detail rocks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures indicate the presence of Fe+3-rich smectites. The signatures are associated with fine-grained, layered rocks containing spherules of diagenetic or impact origin. The layered rocks are overlain by breccias, and both units are cut by calcium sulfate veins precipitated from fluids that circulated after the Endeavour impact. Compositional data for fractures in the layered rocks suggest formation of Al-rich smectites by aqueous leaching. Evidence is thus preserved for water-rock interactions before and after the impact, with aqueous environments of slightly acidic to circum-neutral pH that would have been more favorable for prebiotic chemistry and microorganisms than those recorded by younger sulfate-rich rocks at Meridiani Planum.

  2. Martian Fluvial Conglomerates at Gale Crater

    Science.gov (United States)

    Williams, R. M. E.; Grotzinger, J. P.; Dietrich, W. E.; Gupta, S.; Sumner, D. Y.; Wiens, R. C.; Mangold, N.; Malin, M. C.; Edgett, K. S.; Maurice, S.; Forni, O.; Gasnault, O.; Ollila, A.; Newsom, H. E.; Dromart, G.; Palucis, M. C.; Yingst, R. A.; Anderson, R. B.; Herkenhoff, K. E.; Le Mouélic, S.; Goetz, W.; Madsen, M. B.; Koefoed, A.; Jensen, J. K.; Bridges, J. C.; Schwenzer, S. P.; Lewis, K. W.; Stack, K. M.; Rubin, D.; Kah, L. C.; Bell, J. F.; Farmer, J. D.; Sullivan, R.; Van Beek, T.; Blaney, D. L.; Pariser, O.; Deen, R. G.; Kemppinen, Osku; Bridges, Nathan; Johnson, Jeffrey R.; Minitti, Michelle; Cremers, David; Edgar, Lauren; Godber, Austin; Wadhwa, Meenakshi; Wellington, Danika; McEwan, Ian; Newman, Claire; Richardson, Mark; Charpentier, Antoine; Peret, Laurent; King, Penelope; Blank, Jennifer; Weigle, Gerald; Schmidt, Mariek; Li, Shuai; Milliken, Ralph; Robertson, Kevin; Sun, Vivian; Baker, Michael; Edwards, Christopher; Ehlmann, Bethany; Farley, Kenneth; Griffes, Jennifer; Miller, Hayden; Newcombe, Megan; Pilorget, Cedric; Rice, Melissa; Siebach, Kirsten; Stolper, Edward; Brunet, Claude; Hipkin, Victoria; Léveillé, Richard; Marchand, Geneviève; Sobrón Sánchez, Pablo; Favot, Laurent; Cody, George; Steele, Andrew; Flückiger, Lorenzo; Lees, David; Nefian, Ara; Martin, Mildred; Gailhanou, Marc; Westall, Frances; Israël, Guy; Agard, Christophe; Baroukh, Julien; Donny, Christophe; Gaboriaud, Alain; Guillemot, Philippe; Lafaille, Vivian; Lorigny, Eric; Paillet, Alexis; Pérez, René; Saccoccio, Muriel; Yana, Charles; Aparicio, Carlos Armiens; Caride Rodríguez, Javier; Carrasco Blázquez, Isaías; Gómez Gómez, Felipe; Elvira, Javier Gómez; Hettrich, Sebastian; Lepinette Malvitte, Alain; Marín Jiménez, Mercedes; Frías, Jesús Martínez; Soler, Javier Martín; Torres, F. Javier Martín; Molina Jurado, Antonio; Sotomayor, Luis Mora; Muñoz Caro, Guillermo; Navarro López, Sara; González, Verónica Peinado; García, Jorge Pla; Rodriguez Manfredi, José Antonio; Planelló, Julio José Romeral; Alejandra Sans Fuentes, Sara; Sebastian Martinez, Eduardo; Torres Redondo, Josefina; O'Callaghan, Roser Urqui; Zorzano Mier, María-Paz; Chipera, Steve; Lacour, Jean-Luc; Mauchien, Patrick; Sirven, Jean-Baptiste; Manning, Heidi; Fairén, Alberto; Hayes, Alexander; Joseph, Jonathan; Squyres, Steven; Thomas, Peter; Dupont, Audrey; Lundberg, Angela; Melikechi, Noureddine; Mezzacappa, Alissa; DeMarines, Julia; Grinspoon, David; Reitz, Günther; Prats, Benito; Atlaskin, Evgeny; Genzer, Maria; Harri, Ari-Matti; Haukka, Harri; Kahanpää, Henrik; Kauhanen, Janne; Paton, Mark; Polkko, Jouni; Schmidt, Walter; Siili, Tero; Fabre, Cécile; Wray, James; Wilhelm, Mary Beth; Poitrasson, Franck; Patel, Kiran; Gorevan, Stephen; Indyk, Stephen; Paulsen, Gale; Bish, David; Schieber, Juergen; Gondet, Brigitte; Langevin, Yves; Geffroy, Claude; Baratoux, David; Berger, Gilles; Cros, Alain; Uston, Claude d.; Lasue, Jérémie; Lee, Qiu-Mei; Meslin, Pierre-Yves; Pallier, Etienne; Parot, Yann; Pinet, Patrick; Schröder, Susanne; Toplis, Mike; Lewin, Éric; Brunner, Will; Heydari, Ezat; Achilles, Cherie; Oehler, Dorothy; Sutter, Brad; Cabane, Michel; Coscia, David; Szopa, Cyril; Robert, François; Sautter, Violaine; Nachon, Marion; Buch, Arnaud; Stalport, Fabien; Coll, Patrice; François, Pascaline; Raulin, François; Teinturier, Samuel; Cameron, James; Clegg, Sam; Cousin, Agnès; DeLapp, Dorothea; Dingler, Robert; Jackson, Ryan Steele; Johnstone, Stephen; Lanza, Nina; Little, Cynthia; Nelson, Tony; Williams, Richard B.; Jones, Andrea; Kirkland, Laurel; Treiman, Allan; Baker, Burt; Cantor, Bruce; Caplinger, Michael; Davis, Scott; Duston, Brian; Fay, Donald; Hardgrove, Craig; Harker, David; Herrera, Paul; Jensen, Elsa; Kennedy, Megan R.; Krezoski, Gillian; Krysak, Daniel; Lipkaman, Leslie; McCartney, Elaina; McNair, Sean; Nixon, Brian; Posiolova, Liliya; Ravine, Michael; Salamon, Andrew; Saper, Lee; Stoiber, Kevin; Supulver, Kimberley; Van Beek, Jason; Zimdar, Robert; French, Katherine Louise; Iagnemma, Karl; Miller, Kristen; Summons, Roger; Goesmann, Fred; Hviid, Stubbe; Johnson, Micah; Lefavor, Matthew; Lyness, Eric; Breves, Elly; Dyar, M. Darby; Fassett, Caleb; Blake, David F.; Bristow, Thomas; DesMarais, David; Edwards, Laurence; Haberle, Robert; Hoehler, Tori; Hollingsworth, Jeff; Kahre, Melinda; Keely, Leslie; McKay, Christopher; Bleacher, Lora; Brinckerhoff, William; Choi, David; Conrad, Pamela; Dworkin, Jason P.; Eigenbrode, Jennifer; Floyd, Melissa; Freissinet, Caroline; Garvin, James; Glavin, Daniel; Harpold, Daniel; Mahaffy, Paul; Martin, David K.; McAdam, Amy; Pavlov, Alexander; Raaen, Eric; Smith, Michael D.; Stern, Jennifer; Tan, Florence; Trainer, Melissa; Meyer, Michael; Posner, Arik; Voytek, Mary; Anderson, Robert C.; Aubrey, Andrew; Beegle, Luther W.; Behar, Alberto; Brinza, David; Calef, Fred; Christensen, Lance; Crisp, Joy A.; DeFlores, Lauren; Feldman, Jason; Feldman, Sabrina; Flesch, Gregory; Hurowitz, Joel; Jun, Insoo; Keymeulen, Didier; Maki, Justin; Mischna, Michael; Morookian, John Michael; Parker, Timothy; Pavri, Betina; Schoppers, Marcel; Sengstacken, Aaron; Simmonds, John J.; Spanovich, Nicole; de la Torre Juarez, Manuel; Vasavada, Ashwin R.; Webster, Christopher R.; Yen, Albert; Archer, Paul Douglas; Cucinotta, Francis; Jones, John H.; Ming, Douglas; Morris, Richard V.; Niles, Paul; Rampe, Elizabeth; Nolan, Thomas; Fisk, Martin; Radziemski, Leon; Barraclough, Bruce; Bender, Steve; Berman, Daniel; Dobrea, Eldar Noe; Tokar, Robert; Vaniman, David; Leshin, Laurie; Cleghorn, Timothy; Huntress, Wesley; Manhès, Gérard; Hudgins, Judy; Olson, Timothy; Stewart, Noel; Sarrazin, Philippe; Grant, John; Vicenzi, Edward; Wilson, Sharon A.; Bullock, Mark; Ehresmann, Bent; Hamilton, Victoria; Hassler, Donald; Peterson, Joseph; Rafkin, Scot; Zeitlin, Cary; Fedosov, Fedor; Golovin, Dmitry; Karpushkina, Natalya; Kozyrev, Alexander; Litvak, Maxim; Malakhov, Alexey; Mitrofanov, Igor; Mokrousov, Maxim; Nikiforov, Sergey; Prokhorov, Vasily; Sanin, Anton; Tretyakov, Vladislav; Varenikov, Alexey; Vostrukhin, Andrey; Kuzmin, Ruslan; Clark, Benton; Wolff, Michael; McLennan, Scott; Botta, Oliver; Drake, Darrell; Bean, Keri; Lemmon, Mark; Lee, Ella Mae; Sucharski, Robert; Hernández, Miguel Ángel de Pablo; Blanco Ávalos, Juan José; Ramos, Miguel; Kim, Myung-Hee; Malespin, Charles; Plante, Ianik; Muller, Jan-Peter; González, Rafael Navarro; Ewing, Ryan; Boynton, William; Downs, Robert; Fitzgibbon, Mike; Harshman, Karl; Morrison, Shaunna; Kortmann, Onno; Williams, Amy; Lugmair, Günter; Wilson, Michael A.; Jakosky, Bruce; Zunic, Tonci Balic; Frydenvang, Jens; Kinch, Kjartan; Stipp, Susan Louise Svane; Boyd, Nick; Campbell, John L.; Gellert, Ralf; Perrett, Glynis; Pradler, Irina; VanBommel, Scott; Jacob, Samantha; Owen, Tobias; Rowland, Scott; Savijärvi, Hannu; Boehm, Eckart; Böttcher, Stephan; Burmeister, Sönke; Guo, Jingnan; Köhler, Jan; García, César Martín; Mellin, Reinhold Mueller; Schweingruber, Robert Wimmer; McConnochie, Timothy; Benna, Mehdi; Franz, Heather; Bower, Hannah; Brunner, Anna; Blau, Hannah; Boucher, Thomas; Carmosino, Marco; Atreya, Sushil; Elliott, Harvey; Halleaux, Douglas; Rennó, Nilton; Wong, Michael; Pepin, Robert; Elliott, Beverley; Spray, John; Thompson, Lucy; Gordon, Suzanne; Williams, Joshua; Vasconcelos, Paulo; Bentz, Jennifer; Nealson, Kenneth; Popa, Radu; Moersch, Jeffrey; Tate, Christopher; Day, Mackenzie; Kocurek, Gary; Hallet, Bernard; Sletten, Ronald; Francis, Raymond; McCullough, Emily; Cloutis, Ed; ten Kate, Inge Loes; Arvidson, Raymond; Fraeman, Abigail; Scholes, Daniel; Slavney, Susan; Stein, Thomas; Ward, Jennifer; Berger, Jeffrey; Moores, John E.

    2013-05-01

    Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic composition, consistent with minimal aqueous alteration of sediments. Sediment was mobilized in ancient water flows that likely exceeded the threshold conditions (depth 0.03 to 0.9 meter, average velocity 0.20 to 0.75 meter per second) required to transport the pebbles. Climate conditions at the time sediment was transported must have differed substantially from the cold, hyper-arid modern environment to permit aqueous flows across several kilometers.

  3. The Microstructure of Lunar Micrometeorite Impact Craters

    Science.gov (United States)

    Noble, S. K.; Keller, L. P.; Christoffersen, R.; Rahman, Z.

    2016-01-01

    The peak of the mass flux of impactors striking the lunar surface is made up of objects approximately 200 micrometers in diameter that erode rocks, comminute regolith grains, and produce agglutinates. The effects of these micro-scale impacts are still not fully understood. Much effort has focused on evaluating the physical and optical effects of micrometeorite impacts on lunar and meteoritic material using pulsed lasers to simulate the energy deposited into a substrate in a typical hypervelocity impact. Here we characterize the physical and chemical changes that accompany natural micrometeorite impacts into lunar rocks with long surface exposure to the space environment (12075 and 76015). Transmission electron microscope (TEM) observations were obtained from cross-sections of approximately 10-20 micrometers diameter craters that revealed important micro-structural details of micrometeorite impact processes, including the creation of npFe (sup 0) in the melt, and extensive deformation around the impact site.

  4. Slope activity in Gale crater, Mars

    Science.gov (United States)

    Dundas, Colin M.; McEwen, Alfred S.

    2015-01-01

    High-resolution repeat imaging of Aeolis Mons, the central mound in Gale crater, reveals active slope processes within tens of kilometers of the Curiosity rover. At one location near the base of northeastern Aeolis Mons, dozens of transient narrow lineae were observed, resembling features (Recurring Slope Lineae) that are potentially due to liquid water. However, the lineae faded and have not recurred in subsequent Mars years. Other small-scale slope activity is common, but has different spatial and temporal characteristics. We have not identified confirmed RSL, which Rummel et al. (Rummel, J.D. et al. [2014]. Astrobiology 14, 887–968) recommended be treated as potential special regions for planetary protection. Repeat images acquired as Curiosity approaches the base of Aeolis Mons could detect changes due to active slope processes, which could enable the rover to examine recently exposed material.

  5. Crater Topography on Titan: Implications for Landscape Evolution

    Science.gov (United States)

    Neish, Catherine D.; Kirk, R.L.; Lorenz, R. D.; Bray, V. J.; Schenk, P.; Stiles, B. W.; Turtle, E.; Mitchell, K.; Hayes, A.

    2013-01-01

    We present a comprehensive review of available crater topography measurements for Saturn's moon Titan. In general, the depths of Titan's craters are within the range of depths observed for similarly sized fresh craters on Ganymede, but several hundreds of meters shallower than Ganymede's average depth vs. diameter trend. Depth-to-diameter ratios are between 0.0012 +/- 0.0003 (for the largest crater studied, Menrva, D approximately 425 km) and 0.017 +/- 0.004 (for the smallest crater studied, Ksa, D approximately 39 km). When we evaluate the Anderson-Darling goodness-of-fit parameter, we find that there is less than a 10% probability that Titan's craters have a current depth distribution that is consistent with the depth distribution of fresh craters on Ganymede. There is, however, a much higher probability that the relative depths are uniformly distributed between 0 (fresh) and 1 (completely infilled). This distribution is consistent with an infilling process that is relatively constant with time, such as aeolian deposition. Assuming that Ganymede represents a close 'airless' analogue to Titan, the difference in depths represents the first quantitative measure of the amount of modification that has shaped Titan's surface, the only body in the outer Solar System with extensive surface-atmosphere exchange.

  6. Nevada Test Site craters used for astronaut training

    Science.gov (United States)

    Moore, H. J.

    1977-01-01

    Craters produced by chemical and nuclear explosives at the Nevada Test Site were used to train astronauts before their lunar missions. The craters have characteristics suitable for reconnaissance-type field investigations. The Schooner test produced a crater about 300 m across and excavated more than 72 m of stratigraphic section deposited in a fairly regular fashion so that systematic observations yield systematic results. Other features common on the moon, such as secondary craters and glass-coated rocks, are present at Schooner crater. Smaller explosive tests on Buckboard Mesa excavated rocks from three horizontal alteration zones within basalt flows so that the original sequence of the zones could be determined. One crater illustrated the characteristics of craters formed across vertical boundaries between rock units. Although the exercises at the Nevada Test Site were only a small part of the training of the astronauts, voice transcripts of Apollo missions 14, 16, and 17 show that the exercises contributed to astronaut performance on the moon.

  7. The Morphology of Craters on Mercury: Results from MESSENGER Flybys

    Science.gov (United States)

    Barnouin, Oliver S.; Zuber, Maria T.; Smith, David E.; Neumann, Gregory A.; Herrick, Robert R.; Chappelow, John E.; Murchie, Scott L.; Prockter, Louise M.

    2012-01-01

    Topographic data measured from the Mercury Laser Altimeter (MLA) and the Mercury Dual Imaging System (MDIS) aboard the MESSENGER spacecraft were used for investigations of the relationship between depth and diameter for impact craters on Mercury. Results using data from the MESSENGER flybys of the innermost planet indicate that most of the craters measured with MLA are shallower than those previously measured by using Mariner 10 images. MDIS images of these same MLA-measured craters show that they have been modified. The use of shadow measurement techniques, which were found to be accurate relative to the MLA results, indicate that both small bowl-shaped and large complex craters that are fresh possess depth-to-diameter ratios that are in good agreement with those measured from Mariner 10 images. The preliminary data also show that the depths of modified craters are shallower relative to fresh ones, and might provide quantitative estimates of crater in-filling by subsequent volcanic or impact processes. The diameter that defines the transition from simple to complex craters on Mercury based on MESSENGER data is consistent with that reported from Mariner 10 data.

  8. Science-based health innovation in Ghana: health entrepreneurs point the way to a new development path.

    Science.gov (United States)

    Al-Bader, Sara; Daar, Abdallah S; Singer, Peter A

    2010-12-13

    Science, technology and innovation have long played a role in Ghana's vision for development, including in improving its health outcomes. However, so far little research has been conducted on Ghana's capacity for health innovation to address local diseases. This research aims to fill that gap, mapping out the key actors involved, highlighting examples of indigenous innovation, setting out the challenges ahead and outlining recommendations for strengthening Ghana's health innovation system. Case study research methodology was used. Data were collected through reviews of academic literature and policy documents and through open-ended, face-to-face interviews with 48 people from across the science-based health innovation system. Data was collected over three visits to Ghana from February 2007 to August 2008, and stakeholders engaged subsequently. Ghana has strengths which could underpin science-based health innovation in the future, including health and biosciences research institutions with strong foreign linkages and donor support; a relatively strong regulatory system which is building capacity in other West African countries; the beginnings of new funding forms such as venture capital; and the return of professionals from the diaspora, bringing expertise and contacts. Some health products and services are already being developed in Ghana by individual entrepreneurs, which are innovative in the sense of being new to the country and, in some cases, the continent. They include essential medicines, raw pharmaceutical materials, new formulations for pediatric use and plant medicines at various stages of development. While Ghana has many institutions concerned with health research and its commercialization, their ability to work together to address clear health goals is low. If Ghana is to capitalize on its assets, including political and macroeconomic stability which underpin investment in health enterprises, it needs to improve the health innovation environment

  9. Assessment of the structural shielding integrity of some selected computed tomography facilities in the Greater Accra Region of Ghana

    International Nuclear Information System (INIS)

    Nkansah, A.

    2010-01-01

    The structural shielding integrity was assessed for four of the CT facilities at Trust Hospital, Korle-Bu Teaching Hospital, the 37 Military Hospital and Medical Imaging Ghana Ltd. in the Greater Accra Region of Ghana. From the shielding calculations, the concrete wall thickness computed are 120, 145, 140 and 155mm, for Medical Imaging Ghana Ltd. 37 Military, Trust Hospital and Korle-Bu Teaching Hospital respectively using Default DLP values. The wall thickness using Derived DLP values are 110, 110, 120 and 168mm for Medical Imaging Ghana Ltd, 37 Military Hospital, Trust Hospital and Korle-Bu Teaching Hospital respectively. These values are within the accepted standard concrete thickness of 102- 152mm prescribed by the National Council of Radiological Protection and measurement. The ultrasonic pulse testing indicated that all the sandcrete walls are of good quality and free of voids since pulse velocities estimated were approximately equal to 3.45km/s. an average dose rate measurement for supervised areas is 3.4 μSv/wk and controlled areas is 18.0 μSv/wk. These dose rates were below the acceptable levels of 100 μSv per week for the occupationally exposed and 20 μSv per week for members of the public provided by the ICRU. The results mean that the structural shielding thickness are adequate to protect members of the public and occupationally exposed workers (au).

  10. Ethics, culture and nursing practice in Ghana.

    Science.gov (United States)

    Donkor, N T; Andrews, L D

    2011-03-01

    This paper describes how nurses in Ghana approach ethical problems. The International Council of Nurses' (ICN) Code for Nurses (2006) that serves as the model for professional code of ethics worldwide also acknowledges respect for healthy cultural values. Using the ICN's Code and universal ethical principles as a benchmark, a survey was conducted in 2009 to ascertain how nurses in Ghana respond to ethical and cultural issues in their practice. The study was qualitative with 200 participant nurses. Data were obtained through anonymous self-administered questionnaires. Descriptive statistics were used to analyze the data. Nurses' approaches to ethical problems in Ghana do not always meet expectations of the ICN Code for Nurses. They are also informed by local ethical practices related to the institutional setting and cultural environment in the country. While some cultural values complemented the ICN's Code and universal ethical principles, others conflicted with them. These data can assist nurses to provide culturally competent solutions to ethical dilemmas in their practice. Dynamic communication between nurses and patients/clients, intentional study of local cultural beliefs, and the development of ethics education will improve the conformity between universal ethical standards and local cultural values. © 2011 The Authors. International Nursing Review © 2011 International Council of Nurses.

  11. Financing public healthcare institutions in Ghana.

    Science.gov (United States)

    Akortsu, Mercy Akosua; Abor, Patience Aseweh

    2011-01-01

    The financing of healthcare services has been of a major concern to all governments in the face of increasing healthcare costs. For developing countries, where good health is considered a poverty reduction strategy, it is imperative that the hospitals used in the delivery of healthcare services are well financed to accomplish their tasks. The purpose of this paper is to examine how public hospitals in Ghana are financed, and the challenges facing the financing modes adopted. To achieve the objectives of the study, one major public healthcare institution in Ghana became the main focus. The findings of the study revealed that the main sources of financing the public healthcare institution are government subvention, internally-generated funds and donor-pooled funds. Of these sources, the internally generated fund was regarded as the most reliable, and the least reliable was the donor-pooled funds. Several challenges associated with the various financing sources were identified. These include delay in receipt of government subvention, delay in the reimbursement of services provided to subscribers of health insurance schemes, influence of government in setting user fees, and the specifications to which donor funds are put. The findings of this study have important implications for improving the financing of public healthcare institutions in Ghana. A number of recommendations are provided in this regard.

  12. E-waste interventions in Ghana.

    Science.gov (United States)

    Asante, Kwadwo Ansong; Pwamang, John A; Amoyaw-Osei, Yaw; Ampofo, Joseph Addo

    2016-03-01

    Electrical and electronic waste (e-waste) has become an emerging environmental and human health problem in the world in the 21st century. Recently, the developing nations of West Africa (e.g. Ghana and Nigeria) have become a major destination for e-waste worldwide. In Ghana, the e-waste recyclers use primitive methods (mechanical shredding and open burning) to remove plastic insulation from copper cables. This technique can release highly toxic chemicals and severely affect the environment and human health if improperly managed. It is as a result of the adverse impact on human health that some interventions are being made in Ghana to reduce exposure. The present mode of recycling/dismantling, which happens at Agbogbloshie must be replaced by official receiving/recycling centers to be established. Currently, equipment to strip both large and small cables are available in the country via the Blacksmith Institute (USA) and it is expected that the e-waste workers will embrace the use of these machines. This technology will go a long way to help prevent the burning of e-waste and will be replicated in other smaller e-waste centers in the country.

  13. Gale Crater - Why are We There and What do We Hope to Learn?

    Science.gov (United States)

    Allen, Carlton C.

    2012-01-01

    The Mars Science Laboratory Rover Curiosity is commencing a two-year investigation of Gale crater and Mt. Sharp, the craters prominent central mound. Gale is a 155 km, late Noachian/early Hesperian impact crater located near the dichotomy boundary separating the southern highlands from the northern plains. The central mound is composed of layered sedimentary rock, with upper and lower mound units separated by a prominent erosional unconformity. The lower mound is of particular interest, as it contains secondary minerals indicative of a striking shift from water-rich to water-poor conditions on early Mars. A key unknown in the history of Gale is the relationship between the sedimentary units in the mound and sedimentary sequences in the surrounding region. We employed orbital remote sensing data to determine if areas within a 1,000 km radius of Gale match the characteristics of sedimentary units in Mt. Sharp. Regions of interest were defined based on: the mound s inferred age, altitude range, and THEMIS nighttime brightness (a proxy for thermal inertia). Using orbital CTX, MOC and HiRISE images we examined all areas within our regions of interest for analogous geomorphic units in the same altitude ranges as the corresponding units in Mt. Sharp. The results are consistent with the hypothesis that sedimentary units in both the upper and lower sections of the Gale mound are related to nearby regional units located along the dichotomy boundary. This relationship supports an inferred geologic history that includes several episodes of widespread sedimentary deposition and erosion in the martian mid-latitudes. In this model Mt. Sharp is the remnant of regional sedimentary deposits that partially or completely filled the crater, became lithified, and were subsequently deeply eroded. Key questions that will be addressed by Curiosity include the compositions of the sediments, the modes of deposition, the mechanisms of lithification, and the nature of the erosion.

  14. Conflicts in Northern Ghana: Search for Solutions, Stakeholders and ...

    African Journals Online (AJOL)

    in Northern Ghana that have drawn national attention, most of which were/are violent. It ... analysis of four case studies on the northern Ghana conflicts. ...... It will also be necessary to consider sponsorship of research and studies in ... more important to keep communications flows and avoid the creation of suspicion and.

  15. Utilisation of rice residues for decentralised electricity generation in Ghana

    DEFF Research Database (Denmark)

    Ramamurthi, Pooja Vijay; Fernandes, Maria Cristina; Nielsen, Per Sieverts

    2016-01-01

    Developing countries, especially in Sub-Saharan Africa, face large challenges to achieve universal electrification. Using the case of Ghana, this study explores the role that rice residues can play to help developing countries meet their electrification needs. In Ghana, Levelised Electricity Costs...

  16. All projects related to Ghana | Page 4 | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Climate change constitutes a real threat to the livelihood and well-being of the Ghanaian population. ... HEALTH STATISTICS, STATISTICAL DATA, STATISTICAL ANALYSIS ... Impact of Foreign Direct Investment Flows on Poverty in Ghana. Project. Ghana will need considerable external assistance to achieve its Poverty ...

  17. Determinants of propensity of tertiary agricultural students in Ghana ...

    African Journals Online (AJOL)

    The study aimed to identify factors that affect the decision of tertiary agricultural students in Ghana to enter agribusiness as a self-employment venture after graduation. The results showed that tertiary agricultural students in Ghana were predominantly males with little or no farming background. They had a rather moderate ...

  18. Ghana Medical Journal - Vol 51, No 1 (2017)

    African Journals Online (AJOL)

    Ghana Medical Journal. ... Breast cancer screening in a resource poor country: Ultrasound versus mammography · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Review of errors in the issue of medical certificates of cause of death in a tertiary hospital in Ghana · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  19. Diagnosis of tuberculosis in Ghana: The role of laboratory training ...

    African Journals Online (AJOL)

    Objectives: The laboratory is considered the cornerstone of tuberculosis (TB) control programme. International review of Ghana's programme in the late nineties identified the laboratory services as the weakest component. Sputum smear microscopy (SSM) being the main method of diagnosing pulmonary TB in Ghana, the ...

  20. Trade Policy and Pro Poor Growth in Ghana | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    As in other sub-Saharan countries, small-scale subsistence farming constitutes the predominant source of livelihood in Ghana. This grant will allow the Institute of Statistical, Social and Economic Research (ISSER) at the University of Ghana to assess the linkages between international trade and poverty with special ...

  1. Barriers to Sustainable MVA Supply in Ghana: Challenges for the ...

    African Journals Online (AJOL)

    Multiple studies have demonstrated that manual vacuum aspiration (MVA) is ideal for surgical uterine evacuation in low-resource settings such as Ghana, but developing a sustainable supply to MVA has been challenging. In 2007 a situational analysis was conducted in Ghana to identify barriers to sustainable MVA supply.

  2. Understanding the health and nutritional status of children in Ghana

    NARCIS (Netherlands)

    Asenso-Okyere, W.K.; Asante, F.A.; Nube, M.

    1997-01-01

    The data set of the Ghana Living Standards Survey (GLSS, round 1, 1987/1988) was utilized to analyse the principal determinants (publicly and privately) of health and nutrition of children under five in Ghana. While in most health and nutrition studies the emphasis is either on health-related

  3. Innovation platform: A tool for sustainable rice production in Ghana ...

    African Journals Online (AJOL)

    Agriculture plays a key role in Ghana's economy and that of sub Saharan Africa. Transforming agriculture in Ghana is key to increasing farm output, reducing poverty, ensuring environmental sustainability and reducing food insecurity. Linear transfer of technology addressing productivity, marketing and policy underlies the ...

  4. Prostate cancer screening in Ghana - a clinical benefit? | Arthur ...

    African Journals Online (AJOL)

    In Ghana and most African countries, prostate cancer is the most common cancer in males after hepatocellular carcinoma. Whereas in the advanced countries, screening for prostate specific antigen (PSA) has led to early detection and management of the disease, screening has been very low in Ghana, thus leading to low ...

  5. Syphilis screening practices in blood transfusion facilities in Ghana

    DEFF Research Database (Denmark)

    Sarkodie, Francis; Hassall, Oliver; Owusu-Dabo, Ellis

    2016-01-01

    OBJECTIVES: The primary objective of this study was to compare laboratory practices for screening blood donors for syphilis at blood transfusion facilities in Ghana with the recommendations of the World Health Organization and the National Blood Service, Ghana (NBSG). The prevalence of syphilis a...

  6. The appraisal of mathematics teachers in Ghana | Fletcher | African ...

    African Journals Online (AJOL)

    This study examined the nature and existing methods of teacher appraisal in Ghana. 441 secondary mathematics teachers participated, of whom 193 teach the subject at the junior secondary level and 248 teach it at the senior secondary level. In addition, 44 Ghana Education Service Officials and 6 Heads of secondary ...

  7. The Management of Chieftaincy Records in Ghana: An Overview ...

    African Journals Online (AJOL)

    In many developing countries like Ghana, the chieftaincy institution serves both administrative and advisory role to the government in community affairs. Using data obtained through a survey, the study examined the management of chieftaincy records in Ghana. The study revealed that chieftaincy records serve as source ...

  8. Disaster Management in Academic Libraries in Ghana | Akussah ...

    African Journals Online (AJOL)

    The article presents the findings of a survey of the management of disasters in academic libraries in Ghana. In the 12 academic libraries surveyed, the findings revealed varying levels of unpreparedness of most academic libraries for disasters in Ghana. The absence of purpose of recovery after disasters, the lack of disaster ...

  9. Abortion Care in Ghana: A Critical Review of the Literature ...

    African Journals Online (AJOL)

    The Government of Ghana has taken important steps to mitigate the impact of unsafe abortion. However, the expected decline in maternal deaths is yet to be realized. This literature review aims to present findings from empirical research directly related to abortion provision in Ghana and identify gaps for future research.

  10. Ghana Journal of Development Studies - Vol 6, No 2 (2009)

    African Journals Online (AJOL)

    Community-based Tourism and Rural Development: The Case of the Wechiau Hippo Sanctuary in the Wa West District of Ghana · EMAIL FREE FULL TEXT EMAIL FREE FULL ... Teacher Migration and the Quality of Basic Education in the Upper West Region of Ghana · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  11. Artisanal Mining of Gold with Mercury in Ghana

    African Journals Online (AJOL)

    USER

    ³Department of Chemistry, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon, Ghana ... The paper examines the environmental impact of artisanal mining of gold ... numerous deaths resulting from the eating of Hg-contaminated fish or .... The improper use and handling of mercury can also lead to potential health.

  12. Utilisation of rice residues for decentralised electricity generation in Ghana

    DEFF Research Database (Denmark)

    Ramamurthi, Pooja Vijay; Fernandes, Maria Cristina; Nielsen, Per Sieverts

    2016-01-01

    the average LEC of grid extension diesel mini-grids and off-grid solar systems for remote communities in Ghana. Electricity produced from husk gasification has the potential to cater to 7% of the needs of un-electrified communities in Ghana. The methodology and analysis of this study can support policymakers...

  13. Floodplain hydrodynamic modelling of the Lower Volta River in Ghana

    Directory of Open Access Journals (Sweden)

    Frederick Yaw Logah

    2017-12-01

    Full Text Available The impacts of dam releases from re-operation scenarios of the Akosombo and Kpong hydropower facilities on downstream communities along the Lower Volta River were examined through hydrodynamic modelling using the HEC-RAS hydraulic model. The model was used to simulate surface water elevation along the river reach for specified discharge hydrographs from proposed re-operation dam release scenarios. The morphology of the river and its flood plains together with cross-sectional profiles at selected river sections were mapped and used in the hydrodynamic modelling. In addition, both suspended and bed-load sediment were sampled and analysed to determine the current sediment load of the river and its potential to carry more sediment. The modelling results indicate that large areas downstream of the dam including its flood plains would be inundated if dam releases came close to or exceeded 2300 m3/s. It is therefore recommended to relocate communities along the banks and in the flood plains of the Lower Volta River when dam releases are to exceed 2300 m3/s. Suspended sediment transport was found to be very low in the Lower Volta River and the predominant soil type in the river banks and bed is sandy soil. Thus, the geomorphology of the river can be expected to change considerably with time, particularly for sustained high releases from the Akosombo and Kpong dams. The results obtained from this study form a basis for assessing future sedimentation problems in the Lower Volta River and for underpinning the development of sediment control and management strategies for river basins in Ghana. Keywords: Geomorphology, HEC-RAS model, Dam release, Floodplain, Lower Volta River, Ghana

  14. Research focus and trends in nuclear science and technology in Ghana: a bibliometric study based on the INIS database

    International Nuclear Information System (INIS)

    Agyeman, E. A.; Bilson, A.

    2015-01-01

    The peaceful application of atomic energy was introduced into Ghana about fifty years ago. This is the first bibliometric study of nuclear science and technology research publications originating from Ghana and listed in the International Nuclear Information System (INIS) Database. The purpose was to use the simple document counting method to determine the geographical distribution, annual growth and the subject areas of the publications as well as communication channels, key journals and authorship trends. The main findings of the study were that, a greater number of the nuclear science and technology records listed in the Database were published in Ghana (598 or 56.57% against 459 or 43.43% published outside Ghana). There has been a steady growth in the number of publications over the years with the most productive year being 2012. The main focus of research has been in the area of applied life sciences, comprising plant cultivation & breeding, pest & disease control, food protection and preservation, human nutrition and animal husbandry; followed by chemistry; environmental sciences; radiation protection; nuclear reactors; physics; energy; and radiology and nuclear medicine. The area with the least number of publications was safeguards and physical protection. The main channel of communicating research results was peer reviewed journals and a greater number of the journal articles were published in Ghana followed by the United Kingdom, Hungary and the Netherlands. The core journals identified in this study were Journal of Applied Science and Technology; Journal of Radioanalytical and Nuclear Chemistry; Journal of the Ghana Science Association; Radiation Protection Dosimetry; Journal of the Kumasi University of Science and Technology; West African Journal of Applied Ecology; Ghana Journal of Science; Applied Radiation and Isotopes; Annals of Nuclear Energy, IOP Conference Series (Earth and Environmental Science) and Radiation Physics and Chemistry. Eighty percent

  15. Geomorphology of crater and basin deposits - Emplacement of the Fra Mauro formation

    Science.gov (United States)

    Morrison, R. H.; Oberbeck, V. R.

    1975-01-01

    Characteristics of continuous deposits near lunar craters larger than about 1 km wide are considered, and it is concluded that (1) concentric dunes, radial ridges, and braided lineations result from deposition of the collision products of ejecta from adjacent pairs of similarly oriented secondary-crater chains and are, therefore, concentrations of secondary-crater ejecta; (2) intracrater ridges are produced within preexisting craters surrounding a fresh primary crater by ricocheting and focusing of secondary-crater ejecta from the preexisting craters' walls; and (3) secondary cratering has produced many of the structures of the continuous deposits of relatively small lunar craters and is the dominant process for emplacement of most of the radial facies of the continuous deposits of large lunar craters and basins. The percentages of Imbrium ejecta in deposits and the nature of Imbrium sculpturing are investigated.

  16. Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

    Science.gov (United States)

    Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

    2015-01-01

    The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

  17. Human Resource Local Content in Ghana's Upstream Petroleum Industry

    Science.gov (United States)

    Benin, Papa

    Enactment of Ghana's Petroleum (Local Content and Local Participation) Regulations, 2013 (L.I. 2204) was intended to regulate the percentage of local products, personnel, financing, and goods and services rendered within Ghana's upstream petroleum industry value chain. Five years after the inception of Ghana's upstream oil and gas industry, a gap is evident between the requirements of L.I. 2204 and professional practice. Drawing on Lewin's change theory, a cross-sectional study was conducted to examine the extent of differences between the prevailing human resource local content and the requirements of L.I. 2204 in Ghana's upstream petroleum industry. The extent to which training acquired by indigenous Ghanaians seeking jobs in Ghana's oil fields affects the prevalent local content in its upstream petroleum industry was also examined. Survey data were collected from 97 management, technical, and other staff in 2 multinational petroleum companies whose oil and gas development plans have been approved by the Petroleum Commission of Ghana. To answer the research questions and test their hypotheses, one-way ANOVA was performed with staff category (management, technical, and other) as the independent variable and prevalent local content as the dependent variable. Results indicated that prevailing local content in Ghana's upstream petroleum industry meets the requirements of L.I. 2204. Further, training acquired by indigenous Ghanaians seeking jobs in Ghana's oil fields affects the prevalent local content in its offshore petroleum industry. Findings may encourage leaders within multinational oil companies and the Petroleum Commission of Ghana to organize educational seminars that equip indigenous Ghanaians with specialized skills for working in Ghana's upstream petroleum industry.

  18. Analytical results, geology, and sample locality map of mercury-sulfur-gypsum mineralization at Crater, Inyo County, California

    Science.gov (United States)

    Erickson, M.S.; Marsh, S.P.; Roemer, T.A.

    1984-01-01

    The Crater mercury-su l fur-gypsum ~ineral ized area is located in east-central California along the crest of the Last Chance Range, west of the north end of Death Valley (fig. 1). The area is in the northwest quarter of the Last Chance Range 15-minute quadrangle and occupies the area between 117 39 and 117 45 longitude and 37 10 and 37 15 latitudP.. The area studied lies between 5000 ( 1525 m) and 6000 ( 1830 m) feet above sea level. Relief isgenerally moderate but can be extreme in some places, as at Hanging Rock Canyon (plate 1). The climate is arid, and there are no active streams in the area. The range fronts east and west of the area are precipitous and incised by many steep canyons, whereas the range crest has relatively low relief. The old abandoned town and mine site of Crater 1 ie in this area of low relief. Access to the Crater area is by paved and dirt roads from Big Pine to the west or from the north end of the Death Valley National Monument to the southeast.

  19. Waste electrical and electronic Equipment (E-Wastes) management in Ghana: environmental impacts at Agbogbloshie, Accra Ghana

    International Nuclear Information System (INIS)

    Manukure, Sampson Atiemo

    2016-07-01

    Ghana has relatively large volumes of e-wastes but inefficient recycling methods adopted by the informal sector causes both environmental contamination and potential loss of scarce metals. The control of pollution and management of e-wastes are twin challenges confronted by Ghana. The main objective of the study is to assess the extent to which the current methods employed in e-waste management in Ghana promote sound environmental management. Interviews and field observations were used to collect and collate data from key stakeholders on sustainable e-wastes management in Ghana. Soil samples were collected and analysed using Energy Dispersive X-ray fluorescence technique (EDXRF) and neutron activation analysis (NAA). The results of the field survey revealed that there were three main method of getting e-waste into the yard; house-to-house collection, business-to-business collection and e-waste from dump sites. Majority of the scrap dealers (72%) have not received any form of training in the handling of the hazardous fractions hence do not use any personal protection equipment (PPE). There is poor awareness on the association between disease symptoms and e-waste activity however, 46% of the workers associated symptoms such as headaches, fever, stomach ache and vomiting to e-wastes activities. The challenges of the scrap dealers identified include; rampant arrests and beatings of collectors, fluctuating prices of general scraps, transportation costs, lack of access to working capital as well as ethnic, political and religious difference among the scrap dealers. The results of the elemental analysis revealed that generally the different sampling locations in the study area exhibited an overall metallic dominance pattern of SC > RD > VG > MS > CS > RS > DS > SG > BS. Lead levels registered in the in the soil samples analyzed ranged from 14.2 mg/kg to 7,020.0 mg/kg while Cd was found to be in the range of DS>SG>RS>MS>RD>CS>VF>SC. All the sampling sites showed very high

  20. Crater topography on Titan: Implications for landscape evolution

    Science.gov (United States)

    Neish, C.; Kirk, R.; Lorenz, R.; Bray, V.; Schenk, P.; Stiles, B.; Turtle, E.; Cassini Radar Team

    2012-04-01

    Unique among the icy satellites, Titan’s surface shows evidence for extensive modification by fluvial and aeolian erosion, which act to change the topography of its surface over time. Quantifying the extent of this landscape evolution is difficult, since the original, ‘non-eroded’ surface topography is generally unknown. However, fresh craters on icy satellites have a well-known shape and morphology, which has been determined from extensive studies on the airless worlds of the outer solar system (Schenk et al., 2004). By comparing the topography of craters on Titan to similarly sized, pristine analogues on airless bodies, we can obtain one of the few direct measures of the amount of erosion that has occurred on Titan. Cassini RADAR has imaged >30% of the surface of Titan, and more than 60 potential craters have been identified in this data set (Wood et al., 2010; Neish and Lorenz, 2012). Topographic information for these craters can be obtained from a technique known as ‘SARTopo’, which estimates surface heights by comparing the calibration of overlapping synthetic aperture radar (SAR) beams (Stiles et al., 2009). We present topography data for several craters on Titan, and compare the data to similarly sized craters on Ganymede, for which topography has been extracted from stereo-derived digital elevation models (Bray et al., 2012). We find that the depths of craters on Titan are generally within the range of depths observed on Ganymede, but several hundreds of meters shallower than the average (Fig. 1). A statistical comparison between the two data sets suggests that it is extremely unlikely that Titan’s craters were selected from the depth distribution of fresh craters on Ganymede, and that is it much more probable that the relative depths of Titan are uniformly distributed between ‘fresh’ and ‘completely infilled’. This is consistent with an infilling process that varies linearly with time, such as aeolian infilling. Figure 1: Depth of

  1. Vegetation damage and recovery after Chiginagak Volcano Crater drainage event

    Data.gov (United States)

    Department of the Interior — From August 20 — 23, 2006, I revisited Chiginigak volcano to document vegetation recovery after the crater drainage event that severely damaged vegetation in May of...

  2. LRO MOON CRATER EDR RAWDATA VERSION 1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set comprises the raw binary data from from the LRO Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument. The data consists of the...

  3. Mars Climate History: Insights From Impact Crater Wall Slope Statistics

    Science.gov (United States)

    Kreslavsky, Mikhail A.; Head, James W.

    2018-02-01

    We use the global distribution of the steepest slopes on crater walls derived from Mars Orbiter Laser Altimeter profile data to assess the magnitudes of degradational processes with latitude, altitude, and time. We independently confirm that Amazonian polar/high-latitude crater slope modification is substantial, but that craters in the low latitudes have essentially escaped significant slope modification since the Early Hesperian. We find that the total amount of crater wall degradation in the Late Noachian is very small in comparison to the circumpolar regions in the Late Amazonian, an observation that we interpret to mean that the Late Noachian climate was not characterized by persistent and continuous warm and wet conditions. A confirmed elevational zonality in degradation in the Early Hesperian is interpreted to mean that the atmosphere was denser than today.

  4. Extreme Access & Lunar Ice Mining in Permanently Shadowed Craters

    Data.gov (United States)

    National Aeronautics and Space Administration — Results from the recent NASA Lunar CRater Observation and Sensing Satellite, or LCROSS, mission in 2010, indicate that water (H2O), ice and other useful volatiles...

  5. Collective familial decision-making in times of trouble: intergenerational solidarity in Ghana.

    Science.gov (United States)

    McGadney-Douglass, Brenda F; Douglass, Richard L

    2008-06-01

    In post-colonial populations the retention of the nuclear family concept of collectivism as the basis for decision-making is associated with familial and cultural survival. Collectivism within familial contexts provides intergenerational access to experience, information, resources, and sound decision making during times of conflict or dealing with the consequences of poverty. In contemporary Ghana inter-ethnic wars and conflict have marginalized minority groups, causing substantial internal displacement of people. Poverty and cultural issues have caused a persistently high level of child malnutrition and mortality in all areas of Ghana, including urban centers where appropriate food is in abundance. In each of these circumstances the senior women, particularly the grandmothers, have been found to be essential for child survival, protecting the family from dissolution, and ensuring intergenerational cultural transmission. This paper discusses the place of collective decision-making processes of older African women in two studies in Ghana that assessed the: (1) indigenous methods used for understanding and arresting violent ethnic conflict by internally displaced women who survived the 1994/95 Guinea Fowl War; and (2) parenting and grandparenting strategies from families who insured the survival of children suffering from kwashiorkor, a severe form of childhood malnutrition. In this paper, findings from qualitative interview data will include narratives and illustrative cases.

  6. Conducting an audit to improve the facilitation of emergency maternal and newborn referral in northern Ghana.

    Science.gov (United States)

    Awoonor-Williams, John Koku; Bailey, Patricia E; Yeji, Francis; Adongo, Ayire Emmanuel; Baffoe, Peter; Williams, Afua; Mercer, Sarah

    2015-10-01

    Ghana Health Service conducted an audit to strengthen the referral system for pregnant or recently pregnant women and newborns in northern Ghana. The audit took place in 16 facilities with two 3-month cycles of data collection in 2011. Midwife-led teams tracked 446 referred women until they received definitive treatment. Between the two audit cycles, teams identified and implemented interventions to address gaps in referral services. During this time period, we observed important increases in facilitating referral mechanisms, including a decrease in the dependence on taxis in favour of national or facility ambulances/vehicles; an increase in health workers escorting referrals to the appropriate receiving facility; greater use of referral slips and calling ahead to alert receiving facilities and higher feedback rates. As referral systems require attention from multiple levels of engagement, on the provider end we found that regional managers increasingly resolved staffing shortages; district management addressed the costliness and lack of transport and increased midwives' ability to communicate with pregnant women and drivers; and that facility staff increasingly adhered to guidelines and facilitating mechanisms. By conducting an audit of maternal and newborn referrals, the Ghana Health Service identified areas for improvement that service providers and management at multiple levels addressed, demonstrating a platform for problem solving that could be a model elsewhere.

  7. 3D reconstruction and characterization of laser induced craters by in situ optical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Casal, A.; Cerrato, R.; Mateo, M.P.; Nicolas, G., E-mail: gines@udc.es

    2016-06-30

    Highlights: • Evolution of the laser induced crater and ablation features by in situ homemade optical microscope. • Performance comparison between confocal microscope for material characterization and homemade optical microscope. • Coupled system of laser ablation setup with a low cost optical microscope. - Abstract: A low-cost optical microscope was developed and coupled to an irradiation system in order to study the induced effects on material during a multipulse regime by an in situ visual inspection of the surface, in particular of the spot generated at different pulses. In the case of laser ablation, a reconstruction of the crater in 3D was made from the images of the sample surface taken during the irradiation process, and the subsequent profiles of ablated material were extracted. The implementation of this homemade optical device gives an added value to the irradiation system, providing information about morphology evolution of irradiated area when successive pulses are applied. In particular, the determination of ablation rates in real time can be especially useful for a better understanding and controlling of the ablation process in applications where removal of material is involved, such as laser cleaning and in-depth characterization of multilayered samples and diffusion processes. The validation of the developed microscope was made by a comparison with a commercial confocal microscope configured for the characterization of materials where similar results of crater depth and diameter were obtained for both systems.

  8. Mars Reconnaissance Orbiter and Opportunity observations of the Burns formation: crater hopping at Meridiani Planum

    Science.gov (United States)

    R.E. Arvidson,; Bell, J.F.; Catalano, J.G.; Clark, B. C.; Fox, V.K.; Gellert, Ralf; Grotzinger, J.P.; Guinness, E.A.; Herkenhoff, Kenneth E.; Knoll, A.H.; Lapotre, M.G.A.; McLennan, S.M.; Ming, D. W.; Morris, R.V.; Murchie, S.L.; Powell, K. E.; Smith, M.D.; Squyres, S. W.; Wolff, M.J.; J.J. Wray,

    2015-01-01

    Compact Reconnaissance Imaging Spectrometer for Mars hyperspectral (1.0–2.65 µm) along-track oversampled observations covering Victoria, Santa Maria, Endeavour, and Ada craters were processed to 6 m/pixel and used in combination with Opportunity observations to detect and map hydrated Mg and Ca sulfate minerals in the Burns formation. The strongest spectral absorption features were found to be associated with outcrops that are relatively young and fresh (Ada) or preferentially scoured of dust, soil, and coatings by prevailing winds. At Victoria and Santa Maria, the scoured areas are on the southeastern rims and walls, opposite to the sides where wind-blown sands extend out of the craters. At Endeavour, the deepest absorptions are in Botany Bay, a subdued and buried rim segment that exhibits high thermal inertias, extensive outcrops, and is interpreted to be a region of enhanced wind scour extending up and out of the crater. Ada, Victoria, and Santa Maria outcrops expose the upper portion of the preserved Burns formation and show spectral evidence for the presence of kieserite. In contrast, gypsum is pervasive spectrally in the Botany Bay exposures. Gypsum, a relatively insoluble evaporative mineral, is interpreted to have formed close to the contact with the Noachian crust as rising groundwaters brought brines close to and onto the surface, either as a direct precipitate or during later diagenesis. The presence of kieserite at the top of the section is hypothesized to reflect precipitation from evaporatively concentrated brines or dehydration of polyhydrated sulfates

  9. Constraints on early events in Martian history as derived from the cratering record

    International Nuclear Information System (INIS)

    Barlow, N.G.

    1990-01-01

    The shapes and densities of crater size-frequency distribution curves are used to constrain two major events early in Martian history: termination of high obliteration rates and viability of the multiple impact origin of the crustal dichotomy. Distribution curves of fresh craters superposed on uplands, intercrater plains, and ridged plains display shapes and densities indicative of formation prior to the end of heavy bombardment. This observation correlates with other geologic evidence, suggesting a major change in the erosional regime following the last major basin size impact (i.e., Argrye). In addition, the multisloped nature of the curves supports the idea that the downturn in the crater size-frequency distribution curves reflects the size-frequency distribution of the impactors rather than being the result of erosion. The crustal dichotomy formed prior to the heavy bombardment intermediate epoch based on distribution curves of knobby terrain; if the dichotomy resulted from a single gigantic impact, this observation places constraints on when this event happened. An alternate theory for dichotomy formation, the multiple-impact basin idea, is questioned: since distribution curves of large basins as well as heavy bombardment era units are not represented by a -3 differential power law function, this study finds fewer basins missing on Mars compare to the Moon and Mercury than previously reported. The area covered by these missing basins is less than that covered the northern plains

  10. Deformed barchans under alternating flows: Flume experiments and comparison with barchan dunes within Proctor Crater, Mars

    Science.gov (United States)

    Taniguchi, Keisuke; Endo, Noritaka

    2007-10-01

    It is generally considered that barchans, isolated crescentic-shaped dunes, develop where wind is unidirectional and the available sand is insufficient to cover the entire dune field; however, Bishop [Bishop, M.A., 2001. Seasonal variation of crescentic dune morphology and morphometry, Strzelecki Simpson desert, Australia. Earth Surface Process and Landforms 26, 783 791.] observed barchans that developed in areas where winds blow seasonally in opposite directions and described a peculiar deformation feature, the “rear slipface,” that is not found in ordinary barchans. Barchans under such bidirectional flows are poorly understood, and it is necessary to study barchans that formed under many different flow conditions. We conducted flume experiments to investigate the deformation of barchans under alternating water flow, and observed new deformation features in addition to rear slipfaces. We conclude that the deformation of barchans can be categorized into four types, one of which shows morphologies similar to barchans within Proctor Crater, Mars. The deformation type depends on the strength of the reverse flow relative to the forward flow and the absolute velocity of the forward flow. Comparison of our results with barchan dunes within Proctor Crater enable us to qualitatively estimate the wind strength and direction related to dune formation on Mars. These results are in agreement with those of Fenton et al. [Fenton, L.K., Toigo, A.D., Richardson, M.I., 2005. Aeolian processes in Proctor Crater on Mars: Mesoscale modeling of dune-forming winds. Journal of Geophysical Research 110 (E6), E06005.].

  11. 3D reconstruction and characterization of laser induced craters by in situ optical microscopy

    International Nuclear Information System (INIS)

    Casal, A.; Cerrato, R.; Mateo, M.P.; Nicolas, G.

    2016-01-01

    Highlights: • Evolution of the laser induced crater and ablation features by in situ homemade optical microscope. • Performance comparison between confocal microscope for material characterization and homemade optical microscope. • Coupled system of laser ablation setup with a low cost optical microscope. - Abstract: A low-cost optical microscope was developed and coupled to an irradiation system in order to study the induced effects on material during a multipulse regime by an in situ visual inspection of the surface, in particular of the spot generated at different pulses. In the case of laser ablation, a reconstruction of the crater in 3D was made from the images of the sample surface taken during the irradiation process, and the subsequent profiles of ablated material were extracted. The implementation of this homemade optical device gives an added value to the irradiation system, providing information about morphology evolution of irradiated area when successive pulses are applied. In particular, the determination of ablation rates in real time can be especially useful for a better understanding and controlling of the ablation process in applications where removal of material is involved, such as laser cleaning and in-depth characterization of multilayered samples and diffusion processes. The validation of the developed microscope was made by a comparison with a commercial confocal microscope configured for the characterization of materials where similar results of crater depth and diameter were obtained for both systems.

  12. The adaptive capacity of smallholder farmers to climate change in the Northern Region of Ghana

    Directory of Open Access Journals (Sweden)

    Majeed Abdul-Razak

    2017-01-01

    Full Text Available Climate change is expected to adversely affect agricultural production, particularly in sub-Saharan Africa where the agricultural sector forms the backbone of most countries’ economies. This thus holds true for the agriculture sector of the Northern Region of Ghana which is largely rain-fed and dominated by smallholder farmers with minimal livelihood alternatives. The main research question of this paper is how the adaptive capacity to climate change of smallholder farmers in the Northern Region of Ghana can be characterised? The paper proposes an indicator-based framework for assessing the adaptive capacity of smallholder farmers in the Northern Region of Ghana along six main determinants of adaptive capacity: economic resources, social capital, awareness and training, technology, infrastructure and institutions. Based on a thorough literature review and qualitative interviews with experts for rural livelihoods and agriculture in the study region, the determinants were ranked and three to five indicators per determinant were selected. The results of the expert interviews show that economic resources, awareness and training as well as technological capacities seem most relevant for smallholder farmers’ adaptive capacity while infrastructure, social capital, and institutions were ranked least important. The study operationalized the indicators in a standardized survey questionnaire and tested it in two agrarian communities in the Northern Region of Ghana. The survey results show the aggregate adaptive capacity of respondents is low. However, disparities in adaptive capacity were recorded among respondents in terms of gender and education. Differentiating between the determinants women farmer show significantly lower capacities in fields of economic resources, technology and knowledge and awareness. This paper recommends resilience building interventions in the study area that target individuals with low adaptive capacities, especially women

  13. Spatial and socio-demographic determinants of contraceptive use in the Upper East region of Ghana.

    Science.gov (United States)

    Achana, Fabian Sebastian; Bawah, Ayaga A; Jackson, Elizabeth F; Welaga, Paul; Awine, Timothy; Asuo-Mante, Eric; Oduro, Abraham; Awoonor-Williams, John Koku; Phillips, James F

    2015-04-02

    This paper presents results of baseline data on the determinants of contraceptive use in 7 districts in northern Ghana where there is an ongoing integrated primary health care systems strengthening projectknown as the Ghana Essential Health Intervention Project (GEHIP). We used a household survey data conducted within 66 randomly sampled census enumeration areas in seven rural districts of the Upper East Region of northern Ghana where health systems strengthening interventions are currently ongoing in three of the districts with four of the districts serving as comparison districts. This survey was conducted prior to the introduction of interventions. Data was collected on various indices included geographic information systems (GIS) and contraceptive use. The data was analyzed using survey design techniques that accounts for correct variance estimation. Categorical variables were summarized as proportions and associations between these variables and contraceptive use tested using Chi-square test. Uni-variable and multivariable logistic regression techniques were used to assess the effects of the selected covariates on contraceptive use. All tests were deemed to be statistically significant at 5% level statistical significance. Results show that contraceptive use is generally low (about 13 per cent) and use is nearly evenly for spacing and stopping purposes. Factors associated with the use of contraceptives include exposure to integrated primary healthcare services, the level of education, and socioeconomic status, couple fertility preference, marital status, and parity. For instance, the odds of contraceptive use among 15-45 year old women who live 2 km or more from a CHPS compound is 0.74 compared to women who live less than 2 km from a CHPS compound (p-value = 0.035). The findings suggest that rapid scale up of the Community based Health Planning and Services (CHPS) program accompanied with improved door-to-door health services would kindle uptake of modern

  14. Site characterization requirements for nuclear-cratering design

    International Nuclear Information System (INIS)

    Terhune, R.W.; Carlson, R.C.

    1977-01-01

    A material properties measurement program for the design of large engineering nuclear-excavation projects by computer calculation is presented. Material properties of the site and their relative effect on crater size are analyzed and ordered in relation to their importance in determining the overall cratering efficiency. The measurement program includes both in situ logging and laboratory measurement of core samples, together with the reason for each measurement and its use in the calculations

  15. A global catalogue of Ceres impact craters ≥ 1 km and preliminary analysis

    Science.gov (United States)

    Gou, Sheng; Yue, Zongyu; Di, Kaichang; Liu, Zhaoqin

    2018-03-01

    The orbital data products of Ceres, including global LAMO image mosaic and global HAMO DTM with a resolution of 35 m/pixel and 135 m/pixel respectively, are utilized in this research to create a global catalogue of impact craters with diameter ≥ 1 km, and their morphometric parameters are calculated. Statistics shows: (1) There are 29,219 craters in the catalogue, and the craters have a various morphologies, e.g., polygonal crater, floor fractured crater, complex crater with central peak, etc.; (2) The identifiable smallest crater size is extended to 1 km and the crater numbers have been updated when compared with the crater catalogue (D ≥ 20 km) released by the Dawn Science Team; (3) The d/D ratios for fresh simple craters, obviously degraded simple crater and polygonal simple crater are 0.11 ± 0.04, 0.05 ± 0.04 and 0.14 ± 0.02 respectively. (4) The d/D ratios for non-polygonal complex crater and polygonal complex crater are 0.08 ± 0.04 and 0.09 ± 0.03. The global crater catalogue created in this work can be further applied to many other scientific researches, such as comparing d/D with other bodies, inferring subsurface properties, determining surface age, and estimating average erosion rate.

  16. Morphological indicators of a mascon beneath Ceres' largest crater, Kerwan

    Science.gov (United States)

    Bland, Michael T.; Ermakov, Anton; Raymond, Carol A.; Williams, David A.; Bowling, Tim J.; Preusker, F.; Park, Ryan S.; Marchi, Simone; Castillo-Rogez, Julie C.; Fu, R.R.; Russell, Christopher T.

    2018-01-01

    Gravity data of Ceres returned by the National Aeronautics and Space Administration's Dawn spacecraft is consistent with a lower density crust of variable thickness overlying a higher density mantle. Crustal thickness variations can affect the long‐term, postimpact modification of impact craters on Ceres. Here we show that the unusual morphology of the 280 km diameter crater Kerwan may result from viscous relaxation in an outer layer that thins substantially beneath the crater floor. We propose that such a structure is consistent with either impact‐induced uplift of the high‐density mantle beneath the crater or from volatile loss during the impact event. In either case, the subsurface structure inferred from the crater morphology is superisostatic, and the mass excess would result in a positive Bouguer anomaly beneath the crater, consistent with the highest‐degree gravity data from Dawn. Ceres joins the Moon, Mars, and Mercury in having basin‐associated gravity anomalies, although their origin may differ substantially.

  17. Telecom Policy Innovation: the Role of Free Spectrum and Telecommunication Development in Rural Ghana

    Directory of Open Access Journals (Sweden)

    Idongesit Williams

    2011-08-01

    Full Text Available Every nation wants to achieve Universal Access of telecommunication services due to its importance to the economy and national life. Unfortunately in sub-Saharan Africa, telecommunication services are either scarce or non-existent in rural areas. However, previous telecommunication policies have enabled the provision of various network technologies in Africa. What type of policy is needed to push these telecommunication services into rural areas? This paper discusses the importance of issuing a using Free Spectrum policy to as an incentive to small telecom network operators in Africa. Ghana is used as a test case.

  18. Regulatory frameworks and Implementation patterns for Mobile Money in Africa: The case of Kenya, Ghana and Nigeria

    DEFF Research Database (Denmark)

    Williams, Idongesit

    This paper discusses the potentials of an adaptation of the Internet café business model adopted for Internet access in African cities to improve rural Internet access through a partnership between the public and private sectors. The rural areas in most developing countries e lack of Internet...... are replicated in the rural areas. A study is carried out in Ghana, where the market players in the Internet café operations to ascertain the potential viability of public –private partnership in the provisioning of internet access in the rural areas in Ghana. A new business model in the form of Public Private...... connectivity due to commercial unviability of such investment by the private sector alone. The modernization theory is used to support the concept that the availability of Internet services in rural can be catalyzed if an Adaptation of the Internet cafés business model incorporating the public participation...

  19. Geological Mapping of Impact Melt Deposits at Lunar Complex Craters: New Insights into Morphological Diversity, Distribution and the Cratering Process

    Science.gov (United States)

    Dhingra, D.; Head, J. W., III; Pieters, C. M.

    2014-12-01

    We have completed high resolution geological mapping of impact melt deposits at the young lunar complex craters (wall and rim impact melt units and their relation to floor units have also been mapped. Among the distinctive features of these impact melt deposits are: 1) Impact Melt Wave Fronts: These are extensive (sometimes several kilometers in length) and we have documented their occurrence and distribution in different parts of the crater floor at Jackson and Tycho. These features emphasize melt mobility and style of emplacement during the modification stage of the craters. 2) Variations in Floor Elevations: Spatially extensive and coherent sections of crater floors have different elevations at all the three craters. The observed elevation differences could be caused by subsidence due to cooling of melt and/or structural failure, together with a contribution from regional slope. 3) Melt-Covered Megablocks: We also observe large blocks/rock-fragments (megablocks) covered in impact melt, which could be sections of collapsed wall or in some cases, subdued sections of central peaks. 4) Melt-Covered Central Peaks: Impact melt has also been mapped on the central peaks but varies in spatial extent among the craters. The presence of melt on peaks must be taken into account when interpreting peak mineralogy as exposures of deeper crust. 5) Boulder Distribution: Interesting trends are observed in the distribution of boulder units of various sizes; some impact melt units have spatially extensive boulders, while boulder distribution is very scarce in other units on the floor. We interpret these distributions to be influenced by a) the differential collapse of the crater walls during the modification stage, and b) the amount of relative melt volume retained in different parts of the crater floor. These observations provide important documentation of the morphological diversity and better understanding of the emplacement and final distribution of impact melt deposits.

  20. Temperature profiles from Pos Crater Lake

    Science.gov (United States)

    Neshyba, Steve; Fernandez, Walter; Diaz-Andrade, José

    In 1984, we took part in an expedition to measure the temperature field and bathymetry of the acid lake (Figure 1) that has formed in the crater of Poás volcano, Costa Rica, since its last eruption in 1953. Obtaining these data was the first step in a long-range study planned by researchers at the Center for Geophysical Research, University of Costa Rica (San Jose, Costa Rica), and the College of Oceanography, Oregon State University (Corvallis). The study will eventually consider all aspects of fluid behavior in a volcanic lake that is heated or otherwise convectively driven by energy injected at the lake bottom.Evidence of convection is clearly visible on the surface of the Poás lake most of the time. Fumarole activity has been continuous since 1953. Phreatic explosions are quite frequent, varying from weak to strong, and the height of the ejected column varies from 1 to more than 500 m. One immediately useful result of the research would be an estimate of the heat transfer from sources within the conduit to the overlying water column. As far as geophysical fluid behavior goes, we are interested in the turbulent and diffusive processes by which heat and chemical species are transferred. We are especially interested in the impact on the density stratification of the density changes that occur as particulates settle downward through the fluid column. The stratification would otherwise be controlled by the turbulent and diffusive processes driven by thermochemical factors.