Dynamics of vortices with magnetic impurities

We investigate the dynamics of BPS vortices in the presence of magnetic impurities taking the form of axially-symmetric localised lumps and delta-functions. We present numerical results for vortices on flat space, as well as exact results for vortices on hyperbolic space in the presence of delta-function impurities. In fact, delta-function impurities of appropriate strength can be captured within the moduli space approximation by keeping one or more of the vortices fixed. We also show that previous work on vortices on the 2-sphere extends naturally to the inclusion of delta-function impurities

Environmental and Gender Impacts of Land Tenure Regularization in Africa

Although recent developments greatly increased interest in African land tenure, few models to address these issues at the required scale have been identified or evaluated. Rwanda.s nation-wide land tenure regularization programme is of great interest. A discontinuity design with spatial fixed effects that is used to evaluate the pilot for this programme points to three main effects; namely, (i) improved land access for legally married women and better recordation of inheritance rights; (ii) significant and large investment impacts that are particularly pronounced for women; and (iii) a reduction in land market activity rather than distress sales. Implications for programme design and policy are discussed.gender, agricultural investment, land administration, Rwanda

Do overlapping property rights reduce agricultural investment ? evidence from Uganda

The need for land-related investment to ensure sustainable land management and increase productivity of land use is widely recognized. However, there is little rigorous evidence on the effects of property rights for increasing agricultural productivity and contributing toward poverty reduction in Africa. Whether and by how much overlapping property rights reduce investment incentives, and the scope for policies to counter such disincentives, are thus important policy issues. Using information on parcels under ownership and usufruct by the same household from a nationally representative survey in Uganda, the authors find significant disincentives associated with overlapping property rights on short and long-term investments. The paper combines this result with information on crop productivity to obtain a rough estimate of the magnitudes involved. The authors make suggestions on ways to eliminate such inefficiencies.Wetlands,Labor Policies,Common Property Resource Development,,Municipal Housing and Land

Productivity effects of land rental markets in Ethiopia : Evidence from a matched tenant-landlord sample

As countries increasingly strive to transform their economies from agriculture-based into a diversified one, land rental will become of greater importance. It will thus be critical to complement research on the efficiency of specific land rental arrangements -- such as sharecropping -- with an inquiry into the broader productivity impacts of the land rental market. Plot-level data for a matched landlord-tenant sample in an environment where sharecropping dominates allows this paper to explore both issues. The authors find that pure output sharing leads to significantly lower levels of efficiency that can be attenuated by monitoring while the inefficiency disappears if inputs are shared as well. Rentals transfer land to more productive producers but realization of this productivity advantage is prevented by the inefficiency of contractual arrangements, suggesting changes that would prompt adoption of different contractual arrangements could have significant benefits.Labor Policies,Municipal Housing and Land,Economic Theory&Research,Land and Real Estate Development,Real Estate Development

Review of Soil Fertility Improvement and Crop Responses to Application of Fertilizers in the Southern Ethiopia

Soil fertility is declining most rapidly and resulted in low crop yields and livestock numbers that led to reduced food security and increased poverty in the highlands of Southern Ethiopia, which are characterized by high population, high rainfall and sloppy lands. Improving soil fertility and productivity can be achieved through applications of manure, other organic materials, inorganic fertilizers, lime and the inclusion of legumes and crop rotations in the cropping systems, or a combination of these. There are a number of site and crop specific fertilizer recommendations made for different crops being grown in southern nations nationalities and people’s region (SNNPR). However, they are not collected together in such a way that the extension workers and end users can easily access them. Collecting together and documenting these technologies can greatly help both the distributers and the end users in using the technologies to increase crop production and productivity. Therefore, this review work was conducted to assemble fertilizer recommendations made on different crops in SNNPR for making accessible for disseminators. Fertilizers recommendations made for different crops including teff, maize, sorghum, barley, wheat, haricot bean, potato, enset and sweet potato in various areas of the region were collected from different literatures and summarized. Keywords: Fertilizer recommendation, Soil fertility, Manure, Productivity, Respons

Effects of different levels of inorganic fertilizers applications on the production of Enset (Ensete ventricosum (Welw) Cheesman)

Enset is one of the major food crops supporting many people in Southern Nations, Nationalities and People’s Regional State. The crop requires intensive management and high amount of nutrients; however, only limited research has been conducted on fertilizer requirement of the crop. An experiment was conducted to determine rate and frequency of N and P fertilizers application for enset production at Areka, Wolaita, in Southern Ethiopia. Three levels of N (46, 92 and 138 kg/ha), three levels of P (20, 40 and 60 kg/ha), two levels of frequency of application (one time and two times), and absolute control treatment were arranged in factorial experiment with randomized complete block design replicated three times. Phosphorus was applied as DAP and N was applied as Urea and DAP. Data on plant height, pseudo stem height, pseudo stem circumference, leaf sheath number, corm weight, central shoot, bula weight, unsqueezed and squeezed kocho were collected and analyzed. The result indicated that application of N and P increased enset production at Areka. Application of 138 kg N and 20 kg P/ha per year two times in the life of the crop gave the highest enset production in all the above parameters. Beside increasing enset production, application of 138 kg N and 20 kg P/ha per year for two consecutive years enabled the enset to mature three years earlier as compared to the farmers experience in the area, which takes five years to mature. In conclusion, application of N and P more than one time in the life of enset is important to increase its production and reduce its maturity period. Therefore, application of 138 kg N and 20 kg P/ha per year for two consecutive years is recommended for better production of enset at Areka. Keywords: Enset, Banana, Maturity, Bulla, Fertilize

The Influence of Applying Lime and NPK Fertilizers on Yield of Maize and Soil Properties on Acid Soil of Areka, Southern Region of Ethiopia

Soil acidity is one of the major soil problems that limit agricultural productivity in the mid andhighlands of Ethiopia. For its strong acid neutralizing effect, liming is the most frequently usedpractice to treat acid soils. This study was conducted to know the effect of lime and NPK nutrients onthe yield of maize and soil chemical properties on acid soils of Areka. Five levels of NPK (Check,NP, NK, PK, NPK) and three levels of lime (0, half and full dose of the required amount) werearranged in a factorial experiment using randomized complete block design (RCBD) with threereplications. Urea, TSP, and Potassium chloride were used as the sources of NPK, respectively,whereas calcitic limestone was used as the source of lime. The lime was applied one month beforeplanting of the test crop. Nitrogen was applied in split, half at planting and half at knee height (45 daysafter planting). The whole doses of TSP and KCl were applied at planting time. Soil samples werecollected from 0-30 cm before planting (one composite sample from the experimental site) and atharvest (from each treatment plot) to evaluate different soil chemical properties and analyzed usingstandard laboratory procedures. Crop data such as plant height, biomass yield and grain yield werecollected and analysed using SAS program. Application of full dose lime (1800 kg/ha) with 69 kg Nand 20 kg P/ha gave significantly higher result than the control and the plot that received onlyfertilizer (without lime). Application of NP + full dose lime significantly increased maize productionover the NK and PK treatments whether NK and PK are applied alone or with both doses of lime.Application of lime alone did not influence maize production at Areka. Application of NP significantlyincreased maize production over the control and lime alone treatments both in the first and secondyears of the experiment. Application of NK either alone or with half dose of lime did not increasemaize production over the non-fertilized treatment (control). But it increased maize productionsignificantly over the control treatment when integrated with full dose of lime. Soil analysis indicatedthat pH, P, Ca and CEC were increased with application of lime. In conclusion, enough amount ofNP should be applied with the required amount of lime for better production of maize at acidic soil ofAreka. Therefore, 69 kg N/ha and 20 kg P/ha with 1800 kg lime/ha are recommended for betterproduction of maize at Areka.Keywords: Lime, NPK fertilizers, Residual effec

Optimization of Tekniikka elämää palvelemaan (TEP) ry's box-type solar cooker : Insulation Improvement

The purpose of this thesis was to evaluate the cooking performance of an existing, field tested box-type solar cooker by studying computer plotted rates of temperature change in the cooking chamber and to suggest improvement ideas. The solar cooker was originally designed by Maria Telkes, a Hungarian-American scientist and inventor who worked on solar technologies, and its design was modified by Kari Silfverberg, an architect doing volunteer work for a Finnish non-governmental association called Technology For Life, Finland (Tekniikka elämää palvelemaan or TEP in short), which distributes free solar cookers to countries in the developing world. Thermal simulations in Solidworks software, researches on different types of solar cookers and the results of actual performance tests on kari Silvferberg’s box-type solar cooker and its modified version named Metropolia 1 made in Metropolia’s Environmental Engineering Laboratory were used to devise design modifications for the different parts of the solar cooker that can improve the cooking performance. An improved version of the conventional box-type solar cooker incorporating the design modifications was made and experimentally investigated for its insulation. The results obtained suggest that the improved version has a better insulation than TEP ry’s box-type solar cooker. The experimental and thermal simulation results showed that, the insulation of TEP ry’s box-type solar cooker can be improved by adding an additional insulation layer of polyurethane to its existing stone wool insulation and by using double-paned glazing in place of the existing single pane glazing. Thermal simulations in SolidWorks software and computer plots of the temperature versus time for the inside of a solar cooker that is heated to 100°C and left at room temperature for 5 hours were made for the TEP and Metropolia version-1 solar cookers and compared. It was observed from these plots and thermal simulations that the rate of temperature change for Metropolia 1 was lesser, which suggests that the design of Metropolia 1 can be taken as one improvement option to that of the TEP solar cooker