scholarly journals Feasibility of Pairing a Low-Cost Positive Displacement Pump With Low-Energy Pressure Compensating Drip Irrigation Emitters for Smallholder Farms in Africa

2019 ◽  
Author(s):  
Seiji Engelkemier ◽  
Fiona Grant ◽  
Jordan Landis ◽  
Carolyn Sheline ◽  
Hannah Varner ◽  
...  
Keyword(s):  
Low Income ◽  
Drip Irrigation ◽  
Control Algorithm ◽  
Smallholder Farmers ◽  
Low Cost ◽  
Low Income Countries ◽  
Irrigation Systems ◽  
Physical Relationship ◽  
Positive Displacement ◽  
Effective Manner

Abstract In low income countries, existing drip irrigation systems are cost prohibitive to many smallholder farmers. Companies are working to develop efficient, low-cost irrigation systems by using technologies such as positive displacement (PD) pumps and pressure compensating (PC) emitters. However, these two technologies have not been paired in an efficient and cost-effective manner. Here we describe a proof-of-concept pump control algorithm that demonstrates the feasibility of exploiting the physical relationship between the input electrical power to a PD pump and the hydraulic behavior of a system of PC emitters in order to determine the optimal pump operating point. The development and validation of this control algorithm was conducted in partnership with the Kenya-based irrigation company SunCulture. This control method is expected to reduce cost, improve system efficiency, and increase accessibility of irrigation systems to smallholder farmers.

scholarly journals Validation of an Analytical Model to Lower the Cost of Solar-Powered Drip Irrigation Systems for Smallholder Farmers in the Mena Region

2020 ◽  
Author(s):  
Fiona Grant ◽  
Carolyn Sheline ◽  
Susan Amrose ◽  
Elizabeth Brownell ◽  
Vinay Nangia ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Life Cycle Cost ◽  
Smallholder Farmers ◽  
Low Cost ◽  
Irrigation Schedule ◽  
Field Trials ◽  
Small Scale ◽  
Mena Region ◽  
Irrigation Systems ◽  
Solar Powered

Abstract Drip irrigation is a micro-irrigation technology that has been shown to conserve water and significantly increase crop yield. This technology could be particularly beneficial to the world’s estimated 500 million smallholder farmers, but drip systems tend to be financially inaccessible to this population. Drip systems require costly components including a pipe network, emitters, a pump and power system. Due to limited access to electricity, many smallholder farmers would require off-grid solutions. Designing reliable, low cost, off-grid drip irrigation systems for smallholder farms could significantly reduce the barrier to adoption. This paper builds on an integrated solar-powered drip irrigation model that was shown to improve upon an existing software. Field trials of the small-scale drip system were conducted on research farms in Jordan and Morocco for a full growing season. Data collected from these field trials are used to validate the hydraulics portion of the systems-level model. In addition, the insights gained from the field trials were formed into design requirements for future iterations of the model. These include optimizing for the system life cycle cost, as opposed to capital cost, the ability to simulate the system operation over a season, the capability to input a user’s irrigation schedule, incorporating locally-available components, and incorporating a system reliability constraint based on more detailed agronomic calculations.

scholarly journals Development of a System Model for Low-Cost, Solar-Powered Drip Irrigation Systems in the MENA Region

2018 ◽  
Author(s):  
Julia Sokol ◽  
Fiona Grant ◽  
Carolyn Sheline ◽  
Amos Winter
Keyword(s):  
Power System ◽  
Drip Irrigation ◽  
Smallholder Farmers ◽  
Low Cost ◽  
System Optimization ◽  
System Model ◽  
Solar Array ◽  
Optimization Scheme ◽  
Irrigation Systems ◽  
Solar Powered

Drip irrigation has the potential to conserve water and increase crop yields. However, existing drip irrigation systems often require high pumping power, making them financially inaccessible to smallholder farmers. Integrating a holistic system model with a cost-optimization scheme can enable the design and implementation of low-cost, solar-powered drip irrigations systems, ultimately making this technology more cost-effective for smallholder farmers. This paper describes the algorithms comprising an integrated model of solar-powered drip irrigation systems, consisting of agronomic, hydraulic, pump, and power system modules. It also introduces a preliminary optimization scheme for the power system, which uses the system hydraulics and pump curve to select an optimal solar array and energy storage configuration that minimizes capital cost. The system model and power system optimization is applied to three case studies, and the resulting power system configurations are compared to outputs from commercially-available software for sizing solar pumping systems. The results show that the model successfully captures the nuances in crop type, local weather patterns, and hydraulic system layout between different cases. This offers a greater level of flexibility than commercially available software, which tends to have broader applications and focuses on larger systems. Future model generations will add more variables to the optimization scheme — including pump selection, variable emitter flow rates and pipe geometries — to provide a versatile design tool for cost-optimized, solar-powered drip irrigation systems.

scholarly journals Evaluation of a Low-Cost Commercial Actigraph and Its Potential Use in Detecting Cultural Variations in Physical Activity and Sleep

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3774
Author(s):  
Pavlos Topalidis ◽  
Cristina Florea ◽  
Esther-Sevil Eigl ◽  
Anton Kurapov ◽  
Carlos Alberto Beltran Leon ◽  
...  
Keyword(s):  
Physical Activity ◽  
Low Income ◽  
Large Scale ◽  
Low Cost ◽  
Low Income Countries ◽  
Time Data ◽  
Cultural Variations ◽  
Step Counts ◽  
Scale Step ◽  
Potential Use

The purpose of the present study was to evaluate the performance of a low-cost commercial smartwatch, the Xiaomi Mi Band (MB), in extracting physical activity and sleep-related measures and show its potential use in addressing questions that require large-scale real-time data and/or intercultural data including low-income countries. We evaluated physical activity and sleep-related measures and discussed the potential application of such devices for large-scale step and sleep data acquisition. To that end, we conducted two separate studies. In Study 1, we evaluated the performance of MB by comparing it to the GT3X (ActiGraph, wGT3X-BT), a scientific actigraph used in research, as well as subjective sleep reports. In Study 2, we distributed the MB across four countries (Austria, Germany, Cuba, and Ukraine) and investigated physical activity and sleep among these countries. The results of Study 1 indicated that MB step counts correlated highly with the scientific GT3X device, but did display biases. In addition, the MB-derived wake-up and total-sleep-times showed high agreement with subjective reports, but partly deviated from GT3X predictions. Study 2 revealed similar MB step counts across countries, but significant later wake-up and bedtimes for Ukraine than the other countries. We hope that our studies will stimulate future large-scale sensor-based physical activity and sleep research studies, including various cultures.

scholarly journals Adaptation and validation for Colombia of the WHO safe childbirth checklist

2018 ◽  
Vol 49 (3) ◽  
pp. 201-212
Author(s):  
Ana Carolina Amaya Arias ◽  
Óscar Zuluaga ◽  
Douglas Idárraga ◽  
Javier Hernando Eslava Schmalbach
Keyword(s):  
Low Income ◽  
Health Workers ◽  
Low Cost ◽  
Neonatal Morbidity ◽  
Neonatal Care ◽  
World Health ◽  
Low Income Countries ◽  
Safe Childbirth Checklist ◽  
Health Organization ◽  
Safe Childbirth

Introduction: Most maternal deaths that occur in developing countries are considered unfair and can be avoided. In 2008, The World Health Organization (WHO) proposed a checklist for childbirth care, in order to assess whether a simple, low-cost intervention had an impact on maternal and neonatal mortality in low-income countries. Objective: To translate, adapt and validate the content of the WHO Safe Childbirth Checklist (SCC) for its use in Colombia Methods: The checklist was translated and adapted to the Colombian context. It was subsequently validated by a panel of experts composed of 17 health workers with experience in maternal and neonatal care and safety. Reliability among judges was estimated (Rwg) and items were modified or added to each section of the list according to the results. Results: Modifications were made to 28 items, while 19 new items were added, and none was removed. The most important modifications were made to the management guidelines included in each item, and the items added refer to risks inherent to our environment. Conclusion: The Colombian version of the SCC will be a useful tool to improve maternal and neonatal care and thereby contribute to reducing maternal and neonatal morbidity and mortality in our country.

Access and Adoption of Hybrid Seeds: Evidence from Uganda

2019 ◽  
Vol 29 (3) ◽  
pp. 215-235
Author(s):  
Nikolaus Axmann ◽  
Torben Fischer ◽  
Kevin Keller ◽  
Kevin Leiby ◽  
Daniel Stein ◽  
...  
Keyword(s):  
Low Income ◽  
Smallholder Farmers ◽  
Low Income Countries ◽  
Control Group ◽  
Maize Seeds ◽  
Percentage Points ◽  
Female Farmers ◽  
Hybrid Seeds ◽  
Plant Hybrid ◽  
Hybrid Maize

Abstract Adoption of hybrid seeds remains low in many low-income countries. We conduct a field-experiment designed to measure the effect of offering hybrid maize seeds for purchase during a time when potential customers have high liquidity. Working with a large buyer of agricultural commodities in Northern Uganda, we randomly offer smallholder farmers the opportunity to purchase certified hybrid maize seeds at the same time as they visit the buyers’ stores to sell crops from a previous harvest. 16% of those offered purchase hybrid seeds, and average adoption of hybrid maize among those offered increases by 8 percentage points compared to a control group who does not receive the offer. Among those who accept the offer, we see an increase in the propensity to plant hybrid maize of 50 percentage points. This effect is more pronounced for female farmers than for their male counterparts. Our findings suggest that providing access to certified agricultural inputs at the place and time of post-harvest sales is a promising strategy to increase input usage.

scholarly journals Fe0/H2O Filtration Systems for Decentralized Safe Drinking Water: Where to from Here?

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 429 ◽  
Author(s):  
Charles Nanseu-Njiki ◽  
Willis Gwenzi ◽  
Martin Pengou ◽  
Mohammad Rahman ◽  
Chicgoua Noubactep
Keyword(s):  
Drinking Water ◽  
Low Income ◽  
Universal Access ◽  
Low Cost ◽  
Low Income Countries ◽  
Future Research ◽  
Systematic Research ◽  
Safe Drinking Water ◽  
Iron Corrosion ◽  
Small Communities

Inadequate access to safe drinking water is one of the most pervasive problems currently afflicting the developing world. Scientists and engineers are called to present affordable but efficient solutions, particularly applicable to small communities. Filtration systems based on metallic iron (Fe0) are discussed in the literature as one such viable solution, whether as a stand-alone system or as a complement to slow sand filters (SSFs). Fe0 filters can also be improved by incorporating biochar to form Fe0-biochar filtration systems with potentially higher contaminant removal efficiencies than those based on Fe0 or biochar alone. These three low-cost and chemical-free systems (Fe0, biochar, SSFs) have the potential to provide universal access to safe drinking water. However, a well-structured systematic research is needed to design robust and efficient water treatment systems based on these affordable filter materials. This communication highlights the technology being developed to use Fe0-based systems for decentralized safe drinking water provision. Future research directions for the design of the next generation Fe0-based systems are highlighted. It is shown that Fe0 enhances the efficiency of SSFs, while biochar has the potential to alleviate the loss of porosity and uncertainties arising from the non-linear kinetics of iron corrosion. Fe0-based systems are an affordable and applicable technology for small communities in low-income countries, which could contribute to attaining self-reliance in clean water supply and universal public health.

Development of improved low-cost ceramic water filters for viral removal in the Haitian context

2014 ◽  
Vol 5 (1) ◽  
pp. 28-38 ◽  
Author(s):  
L. Guerrero-Latorre ◽  
M. Rusiñol ◽  
A. Hundesa ◽  
M. Garcia-Valles ◽  
S. Martinez ◽  
...  
Keyword(s):  
Low Income ◽  
Low Cost ◽  
World Health ◽  
Low Income Countries ◽  
Virus Removal ◽  
Ceramic Water Filters ◽  
Removal Efficiencies ◽  
Reductive Atmosphere ◽  
Health Organization ◽  
Water Filters

Household-based water treatment (HWT) is increasingly being promoted to improve water quality and, therefore, health status in low-income countries. Ceramic water filters (CWFs) are used in many regions as sustainable HWT and have been proven to meet World Health Organization (WHO) microbiological performance targets for bacterial removal (2–4 log); however, the described viral removal efficiencies are insufficient to significantly reduce the associated risk of viral infection. With the objective of improving the viral removal efficiencies of ceramic water filters, new prototypes with different oxide compositions and firing atmospheres have been developed and evaluated. For removal efficiencies human adenoviruses, MS2 bacteriophage and Escherichia coli were quantified in all prototypes. A new model of CWF that was fired in a reductive atmosphere presented virus and bacteria removal efficiencies greater than 3.0 log and 2.5 log, respectively, which would fulfill the viral targets that are recommended by the WHO. Ceramic characterization of the selected filters, which were fired in a reductive atmosphere, showed that a larger specific surface area than those of control filters and higher fraction of a positive Z-potential fraction are the most likely explanations for this increase in virus removal.

scholarly journals The reversible adjustable coupling: A lightweight and low-cost alignment component for the lower limb prosthesis

2017 ◽  
Vol 4 ◽  
pp. 205566831770642
Author(s):  
Kazuhiko Sasaki ◽  
Jutamat Pinitlertsakun ◽  
Pakwan Nualnim ◽  
Gary Guerra ◽  
Yuttapichai Sansook ◽  
...  
Keyword(s):  
Low Income ◽  
Lower Limb ◽  
External Rotation ◽  
Low Cost ◽  
Low Income Countries ◽  
Strength Tests ◽  
Lower Limb Prosthesis ◽  
Repetitive Loading ◽  
Limb Prosthesis ◽  
Anterior Posterior

Background The alignment of the lower limb prosthesis is an integral part of the prosthetic fitting. A properly aligned prosthesis contributes to optimal gait and overall function of the patient. The current offering of alignment componentry is expensive for low-income countries. The purpose of this study was to develop a lightweight and low-cost alignment coupler for the lower limb prosthesis. Methods An alignment coupler called the reversible adjustable coupling was designed and manufactured. Measurements of total anterior/posterior and medial/lateral and rotation in prostheses were recorded and mechanical testing performed. Swiftness and difficulty of use was also recorded. Results The reversible adjustable coupling permitted acceptable ranges of anterior/posterior and medial/lateral translation and 30° of internal and external rotation of prosthetic componentry. Repetitive loading of the coupling at a speed of 1 Hz under 1.28 kN load for 2000 cycles was successful, as were static and strength tests. Discussion The coupler provided acceptable ranges of anterior/posterior and medial/lateral and rotation adjustment and is acceptable for potential use in the alignment of both exoskeletal and endoskeletal prosthesis. The final weight of the component was 166 g and cost of $55.00 USD is affordable for low-income countries for use in clinical and educational settings.

scholarly journals Performance Evaluation of a low cost integrated collector storage solar water heater with independent plane reflectors

2015 ◽  
Vol 49 (3) ◽  
pp. 147-154
Author(s):  
Zakariya Kaneesamkandi
Keyword(s):  
Low Income ◽  
Storage Systems ◽  
Low Cost ◽  
Heating System ◽  
Low Income Countries ◽  
Water Heating ◽  
Water Heater ◽  
Beam Radiation ◽  
Solar Water Heating ◽  
Solar Water

High initial cost is one of the reasons why consumers think twice before investing on the conventional solar water heating systems, especially in low income countries. Integrated collector storage systems are available at a lesser cost, but with a penalty of decreased efficiency. In this paper, yet another attempt to reduce cost of solar water heating system has been made by using independent plane reflectors along with an insulated storage tank provided with a heat absorbing aperture. With no tracking arrangement, this system uses only the intense beam radiation available from 9:00 AM to 3:00 PM with a concentration factor of 10. A theoretical study was conducted using commercial computational fluid dynamics software which was followed by an experimental validation of the results. The theoretical results were in agreement with the experimental results. The efficiency of this system was less than collector storage systems reported in the literature by about 10-15%. Maximum average tank temperature of 350 K and efficiency of 0.61 was obtained. Overall loss coefficient was identical with that of existing integrated collector storage systems. DOI: http://dx.doi.org/10.3329/bjsir.v49i3.22128 Bangladesh J. Sci. Ind. Res. 49(3), 147-154, 2014

scholarly journals Right use of Screening Pulse Oximetry test for early detection of Critical Congenital Heart Diseases

2018 ◽  
Vol 1 (5) ◽  
pp. 7-11
Author(s):  
Andreas Petropoulos
Keyword(s):  
Early Detection ◽  
Pulse Oximetry ◽  
Low Income ◽  
Screening Test ◽  
Congenital Heart ◽  
Heart Diseases ◽  
Low Cost ◽  
Health Care Systems ◽  
Low Income Countries ◽  
High Morbidity

Introduction: Preventive medicine is the ideal way in dealing with frequent and fatal diseases. Congenital heart disease (CHD) is responsible for the largest proportion of mortality caused by birth defects in the first year of life. Actual numbers and mortality from CHD is increasing. In the developed world the treatment of CHD has escalating costs for health care systems and private covered patients, while in low-income countries the resources are minimal. Prevention/early detection is urgently needed to tackle the increasing needs. Aim: To justify why pulse oximetry (pox) is the best available, early detecting postnatal screening test currently. Conclusion: Although CHD’s are both frequent and carry a high morbidity and mortality, we still lack a single, easy to apply, non-invasive and low-cost screening test, worldwide. The most advantageous method for minimizing CHD deaths worldwide seems to be currently, the combination of clinical assessment with pox. Original publication: https://crimsonpublishers.com/ojchd/pdf/OJCHD.000510.pdf Open Journal of Cardiology and Heart Diseases.

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