Natural & Applied Sciences

Research Papers/Topics Natural & Applied Sciences

Overcoming Technical Constraints for Obtaining Sustainable Development with Open Source Appropriate Technology

Open source appropriate technology (OSAT) refers to technologies that provide for sustainable development while being designed in the same fashion as free and open-source software. Facilitated by advances in information technology software and hardware, new ways to disseminate information such as wikis and Internet-enabled mobile phones, the global development of OSAT has emerged as a reality. This paper shows the sharing of design processes, appropriate tools, and technical information is en...

Overcoming Language Challenges of Open Source Appropriate Technology for Sustainable Development in Africa

Despite enormous efforts over the course of several decades, sustainable development on the African continent remains incompletely realized. Top-down methodologies have largely failed and many sustainable development organizations now support small-scale direct approaches, which provide the tools and knowledge necessary for people to help themselves. The new approach to sustainable development of open source appropriate technology (OSAT) builds on these successes. OSAT is a development method...

Open Design-Based Strategies to Enhance Appropriate Technology Development

The appropriate technology (AT) movement is being driven by inventors and innovators who are interested in designing technologies that are culturally, environmentally, and economically appropriate, and feasible to construct and use for people anywhere in the world. This paper examines how open sharing of designs, specifications, and technical information can enhance effectiveness, widespread use, and innovation of AT. This commons-based open design method has been highly successful for softwa...

Hybrid Virtual- and Field Work-based Service Learning with Green Information Technology and Systems Projects

Traditional engineering service learning (SL) projects can be classified as: 1) collaborations with a community group or non-profit organization to provide specific engineering around a community need, or 2) an internship-like experience with industry to address work requested by a client. The limitation of both traditional SL approaches is that they do not prepare students to implement unprescribed projects. In contrast, here students chose both the project and the partner for a self-directe...

Viability of Small-Scale Arsenic-Contaminated Water Purification Technologies for Sustainable Development in Pakistan

Drinking arsenic-contaminated water leads to a series of health problems that has limited development for the largely poor rural people of Pakistan who are unable to afford bottled water, centralized treatment plants, or expensive water filter systems. This paper reviews the available appropriate technologies for the removal of arsenic in drinking water to assist in just sustainable development in Pakistan. Several technologies were found to be both technically- and economically- viable and s...

Barriers to Appropriate Technology Growth in Sustainable Development

Given the urgency of development problems world-wide, as well as the opportunities of open source appropriate technology (OSAT) to help expedite sustainable development goals, a better understanding of the barriers limiting the scaling of OSAT is needed. In this study, key organizations and researchers working in the field of appropriate technology (AT) were interviewed to identify barriers to OSAT. The data was analyzed via pattern coding and content analysis. Results reveal that among the m...

Effects of Substrate Temperature on Indium Gallium Nitride Nanocolumn Crystal Growth

Indium gallium nitride films with nanocolumnar microstructure were deposited with varying indium content and substrate temperatures using plasma-enhanced evaporation on amorphous SiO2 substrates. FESEM and XRD results are presented, showing that more crystalline nanocolumnar microstructures can be engineered at lower indium compositions. Nanocolumn diameter and packing factor (void fraction) was found to be highly dependent on substrate temperature, with thinner and more closely packed nanoco...

Analytical Model for the Optical Functions of Indium Gallium Nitride with Application to Thin Film Solar Photovoltaic Cells

This paper presents the preliminary results of optical characterization using spectroscopic ellipsometry of wurtzite indium gallium nitride (InxGa1-xN) thin films with medium indium content (0.38

Effects on Amorphous Silicon Photovoltaic Performance from High-temperature Annealing Pulses in Photovoltaic Thermal Hybrid Devices

There is a renewed interest in photovoltaic solar thermal (PVT) hybrid systems, which harvest solar energy for heat and electricity. Typically, a main focus of a PVT system is to cool the photovoltaic (PV) cells to improve the electrical performance, however, this causes the thermal component to under-perform compared to a solar thermal collector. The low temperature coefficients of amorphous silicon (a-Si:H) allow for the PV cells to be operated at higher temperatures and are a potential can...

The Case for Open Source Appropriate Technology

Much of the widespread poverty, environmental desecration, and waste of human life seen around the globe could be prevented by known (to humanity as a whole) technologies, many of which are simply not available to those that need it. This lack of access to critical information for sustainable development is directly responsible for a morally and ethically unacceptable level of human suffering and death. A solution to this general problem is the concept of open source appropriate technology or...

Optimizing the solar water disinfection (SODIS) method by decreasing turbidity with NaCl

Solar water disinfection (SODIS) has proven to be effective at reducing diarrheal incidence in epidemiological intervention studies. However, the SODIS method is limited to waters of low turbidity (

DESARROLLO DE UN SISTEMA DE MONITOREO DE RADIACIÓN SOLAR BASADO EN UN ESPECTRÓMETRO DE AMPLIO ESPECTRO

RESUMEN La eficiencia cuántica de materiales fotovoltaicos depende de la longitud de onda de la radiación incidente, el espectro solar influye en la producción de energía producida por estos sistemas. En el presente trabajo, se diseñó y construyó un prototipo funcional de un sistema de medición de radiación solar (global y difusa) basado en un espectrómetro de amplio espectro para el monitoreo solar en Cochabamba, Bolivia, conjuntamente con un sistema similar instalado en Kingston, Ontario.

The Effect of Hybrid Photovoltaic Thermal Device Operating Conditions on Intrinsic Layer Thickness Optimization of Hydrogenated Amorphous Silicon Solar Cells

Historically, the design of hybrid solar photovoltaic thermal (PVT) systems has focused on cooling crystalline silicon (c-Si)-based photovoltaic (PV) devices to avoid temperature-related losses. This approach neglects the associated performance losses in the thermal system and leads to a decrease in the overall exergy of the system. Consequently, this paper explores the use of hydrogenated amorphous silicon (a-Si:H) as an absorber material for PVT in an effort to maintain higher and more favo...

Prediction of Energy Effects on Photovoltaic Systems due to Snowfall Events

The accurate prediction of yields from photovoltaic systems (PV) is critical for their proper operation and financing, and in northern latitudes the effects of snowfall on yield can become significant. This work provides methods for identifying snowfall effects from commonly collected performance data, and recommends a model to allow for prediction of these effects based solely on meteorological time series. The model was validated with data from two large-scale (>8MW) operational PV plants. ...


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