Binding of Pb and Zn to Aluminium Oxide and Proton Stoichiometry

The interaction of Pb and Zn with Al2O3 in aqueous solution was studied as a function of pH and metal ion concentration. Results indicated the complexation of metal ions by oxide surfaces is strongly pH dependent; the extent of adsorption is a function of pH with an abrupt change within approximately 2 pH units. The adsorption of Pb and Zn on aluminium oxide can be interpreted in terms of a surface complexation formed by association with one surface AlOH group, thus releasing one bound hydrogen ion. -AlOH + M2+ = -AlOM+ + H+ . It is suggested that the major surface reaction is the formation of a monodentate inner-sphere complex

Impacts of Lake Victoria Level Fluctuations to Livelihoods Missungwi District Case Study

Lake Victoria experienced drastic levels changes in 2005 causing great inconveniences to lakeside communities. This study investigated effects of these changes on livelihoods through questionnaire surveys, focused group discussions, interviews and analysis of fish catches, diseases, crops, and lake levels data. Results indicate recession of levels had various socio-economic impacts. The changes caused severe water shortage due to drying up of shallow wells and a remarkable increase in prevalence of schistosomiasis because of increased utilization of lake water. There was no evidence for impact of level changes on malaria and diarrhea. Decline of water levels caused decline in fish catches due to retreat of water from breeding sites. However receding waters created a new land for cultivation which helped to boost Maize and sweet potatoes production. The results emphasize on ensuring stability of lake levels to avoid negative impacts on livelihoods and to maintain ecological integrity of the lake

Survival and growth of tree seedlings on reclaimed oil sands site in response to fertilizer and ground cover grass species

Non-Peer ReviewedEvery year, oil sands mining results in a significant area of degraded land which needs to be reclaimed. In reconstructed mine sites, ground cover is helpful to minimize soil erosion by stabilizing soil. Besides soil erosion control, ground cover may also influence the establishment success of tree seedlings by affecting soil nutrient and moisture availability. Barley (Hordeum vulgare L.) and oats (Avena sativa) are the ground cover species being recommended for oil sands reclamation operations, but interactions of the ground cover with planted tree seedlings are not fully understood. The objective of this study was to evaluate the effect of different fertilizer rates on survival and growth of trembling aspen (Populus tremuloides) and white spruce (Picea glauca) tree seedlings planted with two cover crops (barley and oats). To fulfill the objective a greenhouse bioassay experiment and a field experiment were conducted. Under greenhouse conditions, soil moisture significantly increased height, root collar diameter (RCD) and biomass yield of tree seedlings. Fertilizer application significantly increased height and RCD in greenhouse, but not under field conditions. Even without ground cover competition, tree seedlings responded poorly to NPK fertilizer. Furthermore, survival rates of tree seedlings were significantly decreased with increased fertilizer application rates, and no positive growth and yield responses were observed in the field. Vigorous growth of ground cover species with high fertilizer application rates largely controlled survival and growth responses of tree seedlings. Trembling aspen was more sensitive to ground cover competition and negatively affected by barley and oats with added fertilizer, whereas white spruce was unaffected. Therefore, adding fertilizer to these systems appears to be of little benefit to early establishment and growth of tree seedlings as well as for successful reclamation

Best-bet and best fit crop-ecology paradigm for sustainable intensification in ESA

United States Agency for International Developmen

The Effects of Gender Stereotyping on Career Choice among Secondary School Students in Tanzania

This study sought to explore the influence of gender stereotyping on career choices among secondary school students in Moshi rural district. Specifically, the study sought to examine the knowledge of career requirements among secondary school students, assess gender differences in career choice among secondary school students and examine the extent to which gender stereotyping beliefs influence career choices among secondary school students Moshi rural district. A total number of 299 students participated in the study. Data were collected using questionnaire. Data were analyzed quantitatively using the Statistical Package for the Social Sciences (SPSS). Frequencies and percentage were used to determine the level of career information and knowledge. Chi squire was used in determining the association among the variables of the study. (T-test) was conducted to compare means scores of stereotyping of career of sex and subject specialization. The study revealed that students had better knowledge on different types of careers available in the world of work. It was revealed that, teachers, parents, relatives, books, television, career role models, radio and the internet were sources of career information among secondary school students. In addition, the results showed a significant difference between re-categorized career and sex with a large effect size of, χ2 (1, n = 299) = 36.821, p =< .005, phi =.-351). Similarly, there was a statistical significant difference between re categorized career and subject specialization with a large effects size of; χ2 (1, n = 299) = 17.753, p =< .005, phi =.-255). In addition to that, findings revealed that there was significant difference between re categorized career and school with a large effect size of; χ2 (4, n = 299) =23.812, p =< .005, cramer\u27s v =.282). it was also revealed that, there is statistically significant difference between males (M= 39.22, SD= 5.79) and females (M= 36.4, SD=5.82; t (297) = 4.17, p

Survival and growth of tree seedlings on reclaimed oil sand site in response to fertilizer and ground cover grass species

Non-Peer ReviewedEvery year, oil sands mining results in a significant area of degraded land which needs to be reclaimed. In reconstructed mine sites, ground cover is helpful to minimize soil erosion by stabilizing soil. Besides soil erosion control, ground cover may also influence the establishment success of tree seedlings by affecting soil nutrient and moisture availability. Barley (Hordeum vulgare L.) and oats (Avena sativa) are the ground cover species being recommended for oil sands reclamation operations, but interactions of the ground cover with planted tree seedlings are not fully understood. The objective of this study was to evaluate the effect of different fertilizer rates on survival and growth of trembling aspen (Populus tremuloides) and white spruce (Picea glauca) tree seedlings planted with two cover crops (barley and oats). To fulfill the objective a greenhouse bioassay experiment and a field experiment were conducted. Under greenhouse conditions, soil moisture significantly increased height, root collar diameter (RCD) and biomass yield of tree seedlings. Fertilizer application significantly increased height and RCD in greenhouse, but not under field conditions. Even without ground cover competition, tree seedlings responded poorly to NPK fertilizer. Furthermore, survival rates of tree seedlings were significantly decreased with increased fertilizer application rates, and no positive growth and yield responses were observed in the field. Vigorous growth of ground cover species with high fertilizer application rates largely controlled survival and growth responses of tree seedlings. Trembling aspen was more sensitive to ground cover competition and negatively affected by barley and oats with added fertilizer, whereas white spruce was unaffected. Therefore, adding fertilizer to these systems appears to be of little benefit to early establishment and growth of tree seedlings as well as for successful reclamation

The role of short rotation coppice technology in fuelwood supply in Rungwe district, Tanzania

The roles of Short Rotation Coppice (SRC) Technology in fuelwood supply and offsetting CO2 emissions in the Tanzania and most African countries remain poorly understood. This study was carried in Rungwe District, Mbeya region in Tanzania, to determine trends, extent and drivers of adoption of SRC; identify various sources of household energy and assess the contribution of SRC to the total household fuelwood needs, and trees and shrub species used as sources of fuelwood. Data were collected using reconnaissance, field and social surveys and was analyzed using the Statistical Package for Social Sciences (SPSS). Results revealed that, 97.5% of local community adopted the SRC technology since 1960s. Eucalyptus spp. are mostly planted in woodlots and field boundaries while Persea americana and Leucaena leucocephala are intercropped in farmlands. The survey indicated that out of 176 tons of fuelwood used annually, 73% comes from SRC technology, 25% from non-SRC technology, and only 2% is purchased to supplement household fuelwood shortage. Local communities depend heavily on biomass energy from woodlots and farmlands where tree species like Eucalyptus spp. plays a key role in meeting the energy demand. This study demonstrates that SRC technologies like woodlots, boundary planting, and intercropping in farmland hold high promise to meet the household energy demand. If promoted and backed with strong policies and supportive land tenure, these technologies may reduce the harvesting pressure on native forests for energy demand and contribute to climate change mitigation and adaptation.Int. J. Agril. Res. Innov. &amp; Tech. 6 (1): 41-46, June, 201

Landscape natural resources management with soil and water conservation practices

United States Agency for International Developmen