An unintended consequence of using “research expenditures” as a figure of merit for universities is to reduce the research output per dollar invested by discouraging the diffusion of superior, lower-cost, open-source scientific equipment.
e inconsistencies associated with the common simple method of evaluating the quality and stability of hydrogenated amorphous silicon (a-Si:H) materials for solar cell applications from just the magnitude of subgap absorption (a(E)) are addressed in this study. The approach taken in this study is to characterize the entire a(E) spectrum by its derivatives, d[a(E)]/dE. Results are presented and discussed for two a-Si:H thin film materials differing in deposition rate by an order of magnitude, w...
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 (UVA, VIS y parte del IR cercano) para el monitoreo solar en Cochabamba, Bolivia, conjuntamente con un sistema similar instalado en Ontario, Canadá. Los datos obtenidos en dos regiones con características geográficas muy distintas ayudaran en el estudio y optimización de materiales fotovoltaicos, para su implementación en diferent...
The use of lasers to weld polymer sheets provides a means of highly-adaptive and custom additive manufacturing for a wide array of industrial, medical, and end user/consumer applications. This paper provides an open source design for a laser polymer welding system, which can be fabricated with low-cost fused filament fabrication and off-the-shelf mechanical and electrical parts. The system is controlled with free and open source software and firmware. The operation of the machine is validated...
With the maturation of digital manufacturing technologies like 3-D printing, a new paradigm is emerging of distributed manufacturing in both scientific equipment and consumer goods. Hardware released under free licenses is known as free and open source hardware (FOSH). The availability of these FOSH designs has a large value to those with access to digital manufacturing methods and particularly for scientists with needs for highly-customized low-volume production products. It is challenging t...
A novel and simple chemical method based on sol-gel processing was proposed to deposit metastable orthorhombic tin oxide (SnOx) thin films on glass substrates at room temperature. The resultant samples are labeled according to the solvents used: ethanol (SnO-EtOH), isopropanol (SnO-IPA) and methanol (SnO-MeOH). The variations in the structural, morphological and optical properties of the thin films deposited using different solvents were characterized by X-ray diffraction, atomic force micros...
This paper describes a simple, low-temperature and cost effective chemical precipitation method in aqueous media to synthesis uniformly distributed zinc oxide (ZnO) microstructures for the fabrication of dye-sensitized solar cells (DSSCs). The size and morphology of the ZnO microstructures are systematically controlled by adjusting the concentration of the precursors, zinc acetate dihydrate and ammonium hydroxide. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used for the...
This study investigates ultra-thin transparent conducting oxides (TCO) of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO) and zinc oxide (ZnO) to determine their viability as candidate materials for use in plasmonic-enhanced thin-film amorphous silicon solar photovoltaic (PV) devices. First a sensitivity analysis of the optical absorption for the intrinsic layer of a nano-disk patterned thin-film amorphous silicon-based solar cell as a function of TCO thickness (10–50 nm) was perfor...
This study provides an in-depth investigation into low-cost and no-cost substrate release mechanisms that allow gas metal arc weld 3-D printed ER4043 aluminum and ER70S-6 steel parts to be removed from a reusable print substrate with minimal energy. Aluminum oxide, boron nitride, and titanium nitride coatings were evaluated as possible substrate release agents for aluminum printing. Additionally, the in situ formation of substrate release agents such as intermetallics and oxides were tested f...
Nitrate, the most oxidized form of nitrogen, is regulated to protect people and animals from harmful levels as there is a large over abundance due to anthropogenic factors. Widespread field testing for nitrate could begin to address the nitrate pollution problem, however, the Cadmium Reduction Method, the leading certified method to detect and quantify nitrate, demands the use of a toxic heavy metal. An alternative, the recently proposed Environmental Protection Agency Nitrate Reductase Nitra...
Metals in the plasmonic metamaterial absorbers for photovoltaics constitute undesired resistive heating. However, tailoring the geometric skin depth of metals can minimize resistive losses while maximizing the optical absorbance in the active semiconductors of the photovoltaic device. Considering experimental permittivity data for InxGa1-xN, absorbance in the semiconductor layers of the photovoltaic device can reach above 90%. The results here also provides guidance to compare the performance...
Limited material options, prohibitively expensive equipment, and high production costs currently limit the ability of small and medium enterprises to use 3D printing to prototype and manufacture metallic goods. A low-cost open-source 3D metal printer that utilizes gas metal arc welding technology has been developed that could make metal printing accessible to the average consumer. Unfortunately, this technology would demand access to expensive cutting tools for part removal from the substrate...
Two low-cost chemical methods of sol–gel and the hydrothermal process have been strategically combined to fabricate barium titanate (BaTiO3) nanopowders. This method was tested for various synthesis temperatures (100 °C to 250 °C) employing barium dichloride (BaCl2) and titanium tetrachloride (TiCl4) as precursors and sodium hydroxide (NaOH) as mineralizer for synthesis of BaTiO3 nanopowders. The as-prepared BaTiO3 powders were investigated for structural characteristics using x-ray diffr...
Ammonia synthesis is the most important step for nitrogen-fertilizer production and consumes approximately 1% of the world’s energy production and energy-related greenhouse gas emissions. In addition to the concomitant emissions caused by ammonia and nitrogen fertilizer synthesis, centrally produced fertilizer that must be distributed to farms also harms the environment because of the embodied energy of transportation. An environmentally-optimal nitrogen fertilizer system would be distribut...
As the number of prosumer printers has expanded rapidly, they now make up the majority of the 3-D printer market and of these printers those in the open-source lineage of the RepRap also have expanded to dominate. Although still primarily used for prototyping or hobbyist production of low-value products, the RepRap has the capacity to be used for high-value distributed manufacturing. A recent study found that RepRap printed parts printed in realistic environmental conditions can match and eve...