Equations of dynamic systems in droplet distribution at high pressure and boundary value flows in the swirl chamber of a swirl nozzle were used in conjunction with momentum equations of forces on moving curved vanes t...Equations of dynamic systems in droplet distribution at high pressure and boundary value flows in the swirl chamber of a swirl nozzle were used in conjunction with momentum equations of forces on moving curved vanes to develop mathematical models.A computer program in C++language was developed and used to simulate the effect of some flow and geometric parameters,including flow rate,pressure and swirl chamber diameter,on the spray performance of a high pressure agro-forestry swirl nozzle.Each of the three performance parameters of axial flow rate,spray cone angle and output discharge(or performance)coefficient were studied as a function of any two combinations of the nozzle supply pressure,exit orifice diameter and swirl chamber diameter.The study established that the spray cone angle of the discharge flow pattern varied from the minimum value of 40°for a swirl chamber diameter of 90 mm to 220°for 40 mm as the exit orifice diameter varied from the minimum value of 0.5 mm to 4.0 mm.The simulated nozzle output discharge coefficient could be varied from 0.98,when the nozzle supply pressure was 400 kPa to the minimum value of 0.001 at any of the other six simulated nozzle supply pressure values of 200,250,300,350,450 and 500 kPa by varying the exit orifice diameter from 0.5 mm to 4.0 mm.The pattern of variation of the simulated nozzle discharge coefficient values were similar to those obtained by measurement during the validation exercise in the laboratory although their sensitivities to the independent variables were different.The results indicated that the range of nozzle discharge coefficient of 0.80 to 0.98 required for a well designed high pressure agro-forestry swirl nozzle has been simulated.With the successful development of the C++computer program,a useful tool that will cut down on the rigor encountered and time spent by nozzle designers and evaluators during nozzle development process has been developed in the study.展开更多
This paper develops an information theoretic estimator of wage and employment shifts that provides quantification of and inference about type of employment (full time, part time, seasonal, unemployed) and industry sha...This paper develops an information theoretic estimator of wage and employment shifts that provides quantification of and inference about type of employment (full time, part time, seasonal, unemployed) and industry share of employment. It is applied to determine the effects of two United States Agency for International Development (USAID) projects on employment in villages in the Tambacounda and Kedougou provinces in Senegal. The projects support the development of local forest-based production and processing industries. The results demonstrate statistically significant and positive effects on employment and the industry composition of employment.展开更多
Kyabwanswa Rural Integrated Farming Systems(KRIFS)is a Community Based Organization(CBO)with its Head Office in Kitagwenda Town Council.KRIFS quartet model involves emphasis of integrating four agricultural activities...Kyabwanswa Rural Integrated Farming Systems(KRIFS)is a Community Based Organization(CBO)with its Head Office in Kitagwenda Town Council.KRIFS quartet model involves emphasis of integrating four agricultural activities namely:Apiculture,agro-forestry,coffee and at least one type of livestock.The paper utilizes data obtained from January 2017 surveys,interviews,focus group discussions and observations by the authors.The authors observe that the four activities are symbiotic income generating enterprises.The quartet model has greatly contributed in reducing poverty,increasing agricultural productivity,facilitating value addition,conserving the environment,halting biodiversity loss and mitigating climate change.The model is strongly hinged on training of farmers in organized groups more especially the youth and the women.The involvement of KRIFS in integrated farming that involves introducing new innovations to improve production and productivity in agriculture through improved breeds of livestock and crops as well as environmental conservation being pivotal in its operations,has culminated to agro-tourism in the district.The authors recommend that the model be implemented in the whole of Uganda.Apiculture should be included in the priority commodity list for the parish model.Agro-tourism is yet another economic activity that should be exploited to reduce unemployment,conserve the environment and reduce effects of climate change.展开更多
文摘Equations of dynamic systems in droplet distribution at high pressure and boundary value flows in the swirl chamber of a swirl nozzle were used in conjunction with momentum equations of forces on moving curved vanes to develop mathematical models.A computer program in C++language was developed and used to simulate the effect of some flow and geometric parameters,including flow rate,pressure and swirl chamber diameter,on the spray performance of a high pressure agro-forestry swirl nozzle.Each of the three performance parameters of axial flow rate,spray cone angle and output discharge(or performance)coefficient were studied as a function of any two combinations of the nozzle supply pressure,exit orifice diameter and swirl chamber diameter.The study established that the spray cone angle of the discharge flow pattern varied from the minimum value of 40°for a swirl chamber diameter of 90 mm to 220°for 40 mm as the exit orifice diameter varied from the minimum value of 0.5 mm to 4.0 mm.The simulated nozzle output discharge coefficient could be varied from 0.98,when the nozzle supply pressure was 400 kPa to the minimum value of 0.001 at any of the other six simulated nozzle supply pressure values of 200,250,300,350,450 and 500 kPa by varying the exit orifice diameter from 0.5 mm to 4.0 mm.The pattern of variation of the simulated nozzle discharge coefficient values were similar to those obtained by measurement during the validation exercise in the laboratory although their sensitivities to the independent variables were different.The results indicated that the range of nozzle discharge coefficient of 0.80 to 0.98 required for a well designed high pressure agro-forestry swirl nozzle has been simulated.With the successful development of the C++computer program,a useful tool that will cut down on the rigor encountered and time spent by nozzle designers and evaluators during nozzle development process has been developed in the study.
文摘This paper develops an information theoretic estimator of wage and employment shifts that provides quantification of and inference about type of employment (full time, part time, seasonal, unemployed) and industry share of employment. It is applied to determine the effects of two United States Agency for International Development (USAID) projects on employment in villages in the Tambacounda and Kedougou provinces in Senegal. The projects support the development of local forest-based production and processing industries. The results demonstrate statistically significant and positive effects on employment and the industry composition of employment.
基金Thanks to SIDA through the BREAD project that funded the survey for the primary data collection in 2017Special thanks go to Uganda Geographical Association(UGA)that funded the authors to attend the 1st International Conference on Geographical Science for Resilient Communities,Ecosystems and Livelihoods under Global Environmental Change(GORILLA).
文摘Kyabwanswa Rural Integrated Farming Systems(KRIFS)is a Community Based Organization(CBO)with its Head Office in Kitagwenda Town Council.KRIFS quartet model involves emphasis of integrating four agricultural activities namely:Apiculture,agro-forestry,coffee and at least one type of livestock.The paper utilizes data obtained from January 2017 surveys,interviews,focus group discussions and observations by the authors.The authors observe that the four activities are symbiotic income generating enterprises.The quartet model has greatly contributed in reducing poverty,increasing agricultural productivity,facilitating value addition,conserving the environment,halting biodiversity loss and mitigating climate change.The model is strongly hinged on training of farmers in organized groups more especially the youth and the women.The involvement of KRIFS in integrated farming that involves introducing new innovations to improve production and productivity in agriculture through improved breeds of livestock and crops as well as environmental conservation being pivotal in its operations,has culminated to agro-tourism in the district.The authors recommend that the model be implemented in the whole of Uganda.Apiculture should be included in the priority commodity list for the parish model.Agro-tourism is yet another economic activity that should be exploited to reduce unemployment,conserve the environment and reduce effects of climate change.