oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 118 )

2018 ( 199 )

2017 ( 166 )

2016 ( 204 )

Custom range...

Search Results: 1 - 10 of 9339 matches for " Refaat Atalla Ahmed Abohassan "
All listed articles are free for downloading (OA Articles)
Page 1 /9339
Display every page Item
Perennial Biomass Production in Arid Mangrove Systems on the Red Sea Coast of Saudi Arabia
Refaat Atalla Ahmed Abohassan,Clement Akais Okia,Jacob Godfrey Agea,James Munga Kimondo,Morag M. McDonald
Environmental Research Journal , 2012, DOI: 10.3923/erj.2012.22.31
Abstract: Above and below biomass production were estimated in two Avicennia marina mangrove stands in Yanbu and Shuaiba regions on the Red sea coast of Saudi Arabia. Allometric equations were used to estimate above ground biomasses including stem, branches, leaves and total biomass while aerial and fine roots were estimated using ground plots and random coring, respectively. Linear relationships on log-log scale with tree DBH and height as predictor parameters best described the biomass variations. The total aboveground biomass in Shuaiba, (18.58 ha-1) was significantly higher than that of Yanbu (10.77 t ha-1) (p<0.05). Shuaiba also had significantly higher aerial and fine roots (23.7 and 96.42 t ha-1) than Yanbu (10.1 and 39.1 t ha-1, respectively) (p<0.05). Overall, aboveground biomass of the two sites was 14.77 t ha-1 while belowground fine roots was 67.8 t ha-1 and a shoot to root ratio of 0.22 indicating high biomass allocation to roots. These findings are the first reported for the Red sea mangroves and were comparable to estimates reported in other locations at similar extreme environmental conditions. In addition, these finding can serve as a baseline study for monitoring annual biomass increment as a function of site productivity and health.
Use and Management of Balanites aegyptiaca in Drylands of Uganda
Clement Akais Okia,Jacob Godfrey Agea,James Munga Kimondo,Refaat Atalla Ahmed Abohassan,Paul Okiror,Joseph Obua,Zewge Teklehaimanot
Research Journal of Biological Sciences , 2012, DOI: 10.3923/rjbsci.2011.15.24
Abstract: There is strong evidence across the drylands of Africa that local communities have utilized Indigenous Fruit Trees (IFTs) including Balanites for generations. IFTs have however, received limited recognition from research and development community. It is now widely accepted that IFTs research needs to embrace local knowledge since this can be a useful resource in solving local problems and contribute to meaningful development. This study explored local use and management of the Balanites aegyptiaca among two contrasting dryland communities in Uganda. A survey involving 150 respondents was conducted using a semi-structured questionnaire. Focus group discussions and key informant interviews were conducted to capture detailed information on various aspects of Balanites use and management. The results revealed a wealth of information on local use and management of B. aegyptiaca tree and its products. Besides being a market commodity, several uses of the tree products were reported, especially among women and children. Contrary to its early reference as famine food, B. aegyptiaca products were used by most households. The young leaves and ripe fruits were regarded as dependable dry season food sources in both years of food scarcity and plentiful harvest. However, institutional arrangements for management of Balanites and other IFTs are weak and trees are increasingly being cut for fuelwood. There is a need to build on the local peoples knowledge, especially on processing of products so as to realise increased contribution of Balanites to rural livelihoods in the drylands of Uganda and other areas where the species grows.
Vitex payos (Lour.) Merr Fruit Trees in the Drylands Areas of Eastern Kenya: Use, Marketing and Management
James Munga Kimondo,Jacob Godfrey Agea,Clement Akais Okia,Refaat Atalla Ahmed Abohassan,Jackson Mulatya,Zewge Teklehaimanot
Botany Research Journal , 2011, DOI: 10.3923/brj.2010.14.21
Abstract: This study explored the local use, marketing and management of Vitex payos in drylands areas of Eastern Kenya. Data were collected through household surveys using semi-structured questionnaires; transect walks, informal discussions and direct observations. Questionnaire responses were analyzed to generate descriptive statistics using Statistical Package for Social Sciences (SPSS) while graphs were generated using Excel. Vitex payos fruits were found to be used in >90% of the households and the management of the fruit trees was incidental rather than deliberate. A majority of farmers (>80%) pruned the Vitex payos trees found on the farm to reduce shading effects on the associated crop plants. Coppices from cut trees were managed to provide new crops. Some farmers smoked the flowering and fruiting trees to repel the flying insect pests while a few others sprinkled ash at the base of the tree to deter crawling insects. Besides the consumption of Vitex payos fruits as snacks and sale for income generation, fruits were used for treatment of diarrhoea. The trees were also used for placing of beehives while the leaves, bark and roots were used for making herbal medicine. The wood was used for timber, fuelwood and tool handles. The naturally ripe and fallen fruits were collected on the ground although a few gatherers harvested fruits by climbing and shaking the tree or branches to dislodge the fruits. Within households, the fruits were spread on mats under shade for 1-3 days before taking to the market. Traditionally, mature unripe fruits are placed in buckets and covered with wood ash to hasten ripening. Taste of the fruits was the main criteria used by consumers to select the best fruits. Farmers retained on their farmlands trees with high fruit productivity and those that produce sweet fruits. Ripe fruits were sold on farms, roadside stalls and local markets either by gatherers themselves or through fruit vendors. Gatherers and fruit vendors suffer heavy losses due to fruit damage during transportation to the markets. Lack of storage facilities and low market value lowers the overall income from the sales of the fruits. Small land sizes and lack of planting material negatively affected farmers planting of the trees. There is need to promote the fruits through initiating processing activities to improve on their shelf live and to add value to generate higher income at the farm level. Processing of fruits into high value products like fruit jam and juices should be explored. Increasing the accessibility and availability of good planting material should be explored through vegetative propagation techniques to capture desired traits such as taste, size and high tree productivity.
Wild and Semi-Wild Food Plants of Bunyoro-Kitara Kingdom of Uganda:Growth Forms, Collection Niches, Parts Consumed, Consumption Patterns, Main Gatherers and Consumers
Jacob Godfrey Agea,Clement Akais Okia,Refaat Atalla Ahmed Abohassan,James Munga Kimondo,Joseph Obua,John Hall,Zewge Teklehaimanot
Environmental Research Journal , 2012, DOI: 10.3923/erj.2011.74.86
Abstract: Numerous publications provide detailed knowledge of Wild and Semi-Wild Food Plants (WSWFPs) in specific locations in Africa. These studies reveal that WSWFPs are essential components of many Africans diets especially in periods of seasonal food shortage. In this study, researchers present the commonly consumed WSWFPs in Bunyoro-Kitara kingdom of Uganda; their growth forms, collection niches, parts mainly consumed, consumption patterns, main gatherers and the main consumers. A total 385 respondents sampled according to Krejcie and Morgan from two sub-countries (Mutunda and Kiryandongo) of Kibanda country in Bunyoro-Kitara Kingdom were administered with semi-structured questionnaires. Focus Group Discussions (FGDs) were also held to validate questionnaire responses and to characterise the commonly consumed WSWFPs in terms of their growth forms and life cycles. Excel spreadsheet and MINITAB statistical software were used to analyze the questionnaire responses. The outputs of FGDs were subjected to thorough content analysis. A total of 62 WSWFPs were reported as being consumed. The most frequently mentioned were Amaranthus dubius Mart. ex Thell (73.8%), Amaranthus spinosus L (71.4%), Tamarindus indica L (69.1%). Hibiscus sabdariffa L (51.9%) and Vitex doniana Sweet (50.1%). But in terms of botanical family, members of Solanaceae (9.7%) and Fabaceae (9.7%) families were the most commonly consumed followed by Amaranthaceace (8.1%), Malvaceae (8.1%) and Asteraceae (6.5%) families, respectively. Out of the 62 documented WSWFPs, herbs (51.6%) and shrubs (24.2%) constituted the highest the numbers. Trees, vines/climbers and graminoid were few. Fresh leaves and shoots (97.1%) and fruits (74.3%) were predominantly consumed plant parts in the study area. Most WSWFPs were largely consumed as the main sauce and side dishes after cooking, raw as snacks and as condiments (spices or appetizers). Their consumption as wine and porridge component, beverages, raw in salads, potash salts in other foods and as relishes were infrequent. Women (85.7%) and children (75.1%) were the main gatherers. Few men (10.4%) engaged in gathering activities. Majority (75.8%) of the respondents reported that the gathered plants are consumed nearly by entire household members. About 21% said women are the major consumers. Collection niches varied greatly from forests (forest gaps and margins) (77.8%), bushlands (woodlands) (65.7%), cultivated farmlands (63.2%) and grasslands (59.8%). Other niches included homegardens (homesteads), swampy areas (wetlands), abandoned homesteads and farmlands, wastelands, farm borders, roadsides (footpaths) and areas around animal enclosures/cattle corridors. There is a need for more research on the possibility of adapting, growing and intentionally managing the WSWFPs on farms since large proportion of them are still gathered from out-of-farm niches.
Harvesting and Processing of Balanites aegyptiaca Leaves and Fruits for Local Consumption by Rural Communities in Uganda
Clement Akais Okia,Jacob Godfrey Agea,James Munga Kimondo,Refaat Atalla Ahmed Abohassan,Joseph Obua,Zewge Teklehaimanot
Journal of Food Technology , 2013, DOI: 10.3923/jftech.2011.83.90
Abstract: Balanites aegyptiaca (L.) Del. commonly known as desert date is an important multipurpose tree found in most African countries. Like in many parts of dryland Africa, Balanites leaves and fruits provide livelihood support to many rural households in the drylands of Uganda where other options are limited. The young succulent leaves are a dependable dry season vegetable while the seed kernel obtained after cracking the nut is a valuable oil source. Local methods for harvesting and processing of Balanites products were examined as a step towards promoting their wide use and development of improved processing methods. Harvesting and preparation of Balanites leaves in Katakwi district and fruits/nuts collection and oil extraction in Adjumani district, Uganda were documented. The results revealed that Balanites leaf harvesting involves cutting the young branches and twigs and plucking leaves under the tree. Leaves are boiled within 24 h after collection to avoid loss of taste and to shorten boiling time. Boiled leaves have a shelf life of 2 days only. On the other hand, Balanites oil production starts from the fruits or nuts mainly collected from beneath the parent trees. Oil processing entails cracking the nuts to extract seed kernels followed by pounding and roasting of kernels and oil extraction by hot water floatation method. Cracking the hard nuts to obtain seed kernels is a major challenge in oil extraction process. Oil produced is too little to meet the demand. Processing of Balanites oil is a promising option for improving rural livelihoods in the dryland areas of Uganda where Balanites trees grow naturally and are abundant. However, appropriate tools for cracking the hard Balanites nuts are required to increase oil production. Ways of increasing the shelf life of processed Balanites leaves should also be explored.
Contribution of Wild and Semi-Wild Food Plants to Overall Household Diet in Bunyoro-Kitara Kingdom, Uganda
Jacob Godfrey Agea,James Munga Kimondo,Clement Akais Okia,Refaat Atalla Ahmed Abohassan,Joseph Obua,John Hall,Zewge Teklehaimanot
Agricultural Journal , 2013, DOI: 10.3923/aj.2011.134.144
Abstract: The contribution of Wild and Semi-wild Food Plants (WSWFPs) to overall household diet was assessed in Mutunda and Kiryandongo, sub-counties of Bunyoro-Kitara Kingdom, Uganda. The assessments were made using a combination of methods namely: household using semi-structured questionnaires and Focus Group Discussions (FGDs). A total of 385 households from the two sub-counties were selected for household survey following the method described by Krejcie and Morgan. Each informant was asked to list, the preferred WSWFPs consumed in the area and to estimate the amount harvested by members of his or her household in the previous 12 months period. In addition, they were asked to report whether or not WSWFPs were used by members of the household during the previous 12 months period. They were also asked to report whether or not the WSWFPs was given away and/or received by members of the household during the previous 12 months period. In addition, they were asked to estimate how long in a year their household members depend on WSWFPs. FGDs were held to construct seasonal calendar of availability of different WSWFPs consumed in the area. Contribution of WSWFPs to household diet was computed using two generic types of measures-mean per capita harvest and mean per capita use (consumption). The durations upon which households depend on WSWFPs was computed and presented in a chart. About 62 WSWFPs belonging to 31 botanical families were reported as commonly being consumed in the study area. Their consumption comprised a major part (7-9 months) of the dietary intake of the poor households. Many are almost available throughout the year for gathering with exception of a few species that are gathered mainly in the rainy or dry seasons. Mean per capita harvests varied substantially by species as high as 31.59 g day-1 in Amaranthus dubius to about 0.04 g day-1 as in Lantana camara. Like mean per capita harvest, mean per capita consumption also varied from one species to another. Mean per capita consumption of some the WSWFPs such as Hyptis spicigera (107.02 g day-1) and Borassus aethiopum (91.82 g day-1) were higher than the reported vegetable and fruit per capita consumption of 79.45 g day-1 in sub-Saharan Africa although, much although much lower than the world average of 205.48 g consumed per person per day. There is a need for policy-makers and technocrats both at the local (counties, sub-counties, parishes, villages) and national levels (e.g., Ministry of Agriculture, Animal Industry and Fisheries) to create policies by-laws or any other avenues for mainstreaming, the management of some of the WSWFPs with high per capita harvest and per capita consumption rates into the existing, the farming systems and/or any the programs (e.g., Plan for Modernisation of Agriculture) aimed at addressing household poverty and food insecurity. While wild foods cannot entirely bridge, the existing supply and demand gaps of poor household food requirements without them, the gaps woul
Estimating Fruit Yield from Vitex payos (Lour) Merr. in Semi-arid Eastern Province of Kenya: Application of Allometric Equations
James Munga Kimondo,Clement Akais Okia,Jacob Godfrey Agea,Refaat Atalla Ahmed Abohassan,Jackson Mulatya,Zewge Teklehaimanot
Research Journal of Applied Sciences , 2012, DOI: 10.3923/rjasci.2011.153.162
Abstract: Vitex payos (Lour) Merr. is a common species in the semiarid areas of Eastern Kenya. It is a favoured species and is frequently maintained in homestead plots and arable fields in an agroforestry situation. Although, the abundance and popularity of Vitex payos has led to the commercialisation of its fruits, their quantities to sustainability support cottage industries in the rural areas has not been considered. Vitex payos trees were surveyed during fruit season and the quantity of fruits for 120 trees distributed on farm lands and bushlands in three districts counted per tree. Mean fruit yield was significantly higher from farm trees (>6145 fruits per tree) than trees in bushlands areas (<4154 fruits per tree), even after accounting for differences in tree size. Few cases of trees with over 21000 fruits were also recorded from both land uses. Although, the majority of the trees produce <5000 fruits per tree per year, through purposeful selection of germplasm in its wide natural range, production could be increased up to four fold. A fairly accurate prediction of fruits per tree and consequently the quantity available from the farms could be achieved through use of a combined logarithmic and inverse transformation equations using the crown diameter and the tree height. However, considering that the Vitex payos grows in more diverse dryland areas in Kenya including the Eastern, Coastal and Central regions, it is prudent to collect more data from all these areas and test the validity of the equation developed in this study for wide-scale application as a management tool.
The Impacts of Land Use and Forest Activities on Tree Species Composition and Structure on the Edges of Budongo Forest Reserve, Uganda
Jacob Godfrey Agea,Clement Akais Okia,Refaat Atalla Ahmed Abohassan,James Munga Kimondo,Susan B. Tumwebaze,Peter Ndemere,Patrick Buyinza,Joseph Obua
Botany Research Journal , 2011, DOI: 10.3923/brj.2010.7.13
Abstract: The impact of land use activities on tree species composition, structure and diversity in and around Budongo Forest Reserve was assessed in August and September 2000. Forty plots measuring 50x50 m were laid at 100 m intervals along 1,000 m transects originating from each land use type activity and the number, species, diameter at breast height (dbh) and height of trees ≥10 cm recorded. The land use/forest activities considered were farming, settlement, charcoal production and harvesting of timber, firewood and building poles. One way ANOVA, Kruskal-Wallis test and Shannon-Weaner diversity index were used to analyse the data. It was found that different land use activities have affected forest tree species abundance (H = 24.77, p = 0.001), composition (F = 2.87, p = 0.047) and structure (dbh: F = 3.82, p = 0.018 and height: F = 1.63, p = 0.039). Timber harvesting had the least negative effect on tree species diversity (H = 2.8016) and the highest negative effect on forest structure (average dbh = 33.06 cm; average height = 22.06 m). Farming had the highest negative effect on tree species diversity (H = 2.57) and the lowest negative effect on forest structure (average dbh = 39.11 cm; average height = 25.18 m). It is recommended that the effect of land use practices on the forest fringes should be monitored and a methodology for an integrated land use-forest management plan developed.
Differential Flotation of Some Egyptian Feldspars for Separation of Both Silica and Iron Oxides Contaminants  [PDF]
Tawfik Refaat Boulos, Suzan Sami Ibrahim, Ahmed Yehia
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2015, DOI: 10.4236/jmmce.2015.36046
Abstract: An anionic-cationic flotation of two Egyptian feldspar samples, representing Road Ashaab locality of the Eastern Desert of Egypt, was investigated on both laboratory and pilot plant scales. The pegmatites belong to the alkali feldspar granite type, mostly microcline and orthoclase, KAL Si3O8 coarse grained rocks. Quartz, as the main gangue mineral, occurs in two forms as either free grains or as veins intercalating the feldspar crystals or, sometimes, intermingled with them. Iron, on the other hand, is found in three different forms as free magnetite embedded in the feldspar crystals, as microcrystalline crystals, or as magnetite filling cracks in the feldspar. Dissolution of magnetite to hematite is, sometimes, observed. Grinding of the feldspar samples to less than 0.25 mm followed by desliming was optimized in the laboratory, using a ball mill in closed circuit with the screen. Anionic flotation of the iron oxide impurity from the -0.25 + 0.03 mm ground product was successfully conducted using locally produced dodecyl benzene sulphonic acid—rice bran oil/kerosene promoter at pH 3. Cationic flotation of feldspar from this product was then carried out employing a locally produced quaternary ammonium salt in presence of HF acid, as a silica depressant and a feldspar activator at pH 3. Feldspar final concentrates assaying 80.8% - 89.5% feldspar mineral, 0.119% - 0.127% Fe2O3 and 16.84% - 18.65% Al2O3, were obtained at the optimum operating conditions that satisfy the requirements of the ceramic industry. Continuous 200 kg/h pilot plant runs were conducted using the appropriate equipment, based upon the laboratory findings to produce feldspar concentrates assaying 16.38% - 18.13% Al2O3, and 0.13% - 0.15% Fe2O3. Materials’ metallurgical balance and complete chemical analyses were shown.
The Art of Talc Flotation for Different Industrial Applications  [PDF]
Tawfik Refaat Boulos, Suzan Sami Ibrahim, Ahmed Yehia
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2016, DOI: 10.4236/jmmce.2016.43020
Abstract: Talc has found a steadily increasing number of uses such as cosmetics, steatite and cordierite ceramics, for pitch control in the paper industry and as a reinforcing filler in rubber, etc. In this research, the amenability of some Egyptian carboniferous finely disseminated talc ores to beneficiation by flotation was investigated on laboratory scale. The original talc sample is characterized by low MgO content (25.40%), low SiO2 (45.71%), high CaO content (6.32%) and high L.O.I. (11.35%), indicating its low grade. Attrition scrubbing of the crushed ores was found to be an unconventional process, not only for fine talc production, but also for proper separation of the harder carbonaceous gangue. Talc pre-concentrates, less than 0.074 μm, were prepared by attrition scrubbing in the laboratory having 8.40% L.O.I. with a yield reaching 74.70%. Cleaner talc concentrate with L.O.I. content averaging 6.70% was obtained by flotation in the presence of Aerofroth 71 with a yield reaching 64.71%. This was relatively improved by the use of a selective (quaternary amine) talc collector and in presence of a selective carbonate depressant (soda ash). Flotation of the fine ground talc (less than 22 μm) produced a talc concentrate assaying 6.90% L.O.I. with a yield recovery of 62.91%. However, different talc concentrates obtained by just natural floatability or by the use of small dose of Aerofroth 71, or by the application of quaternary amine in presence of carbonate depressant, satisfy the requirement of paper coating, ceramics production, functional filler, and pharmaceuticals applications. Tailings could also be used in carpets, roofs, and tiles production industries.
Page 1 /9339
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.