Engineering

Research Papers/Topics Engineering

Evaluation de la réponse du maïs (Zea mays L.) installé entre les haies de Tithonia diversifolia à Lubumbashi, R.D. Congo

Assessment of the response of maize (Zea mays L.) planted between hedgerows of Tithonia diversifolia in Lubumbashi, DR Congo Objective: Two trials were carried out over time at the Centre de Recherche Agroalimentaire (CRAA) and aimed at evaluating the behavior of maize cultivation in hedgerows of Tithonia diversifolia (Mexican sunflower). Methodology and results: The experimentation design was a completely randomized, the distances from maize planting lines to the T. diversifolia hedge ar...

DESIGN AND CONSTRUCTION OF A MELON DEHUSKING MACHINE

Abstract: Melon dehusking is often associated with lots of manual labour and stresses. In order to reduce the stress and boredom usually involved in manual dehusking of melon process, a melon dehusking and separation machine was designed, constructed and tested for operation as presented in this paper. The melon dehusking machine operates on the principle of attrition/friction as opposed to the use of an impact force in the dehusking chamber for shelling of melon seeds. This principle resu...

DESIGN AND CONSTRUCTION OF RESTAURANT ORDER SYSTEM

ABSTRACT This project deals with the design and development of restaurant order meal system, in order to reduce the number of staff. In meal ordering project, you can request for any kind of food or drinks available in the restaurant which contains the menu embedded in each button. Microcontroller is the central processing unit CPU of this project and it also consists of Bluetooth it is said to be the main component used in this project. Microcontroller gets the coordinates from the Bluetooth...

Isolation and characterization of PGPR from the rhizopheres of selected vegetables in Ogun state

ABSTRACT Beneficial bacteria that colonize the root of plants and are capable of stimulating the growth of plants directly or indirectly are called plant-growth promoting rhizobacteria. The objective of this study was to isolate and characterize plant-growth promoting rhizobacteria from the rhizosphere of some selected vegetables collected at different locations in Ago-iwoye, Oru and Ijebu-Igbo in Ijebu-North local Government Area of Ogun state, using general microbiological and biochemical t...

Design and Construction of a 20-m Distance Remotely Controlled Metal Detector Using Arduino

   Abstract The project DESIGN AND CONSTRUCTION OF A 20-METRE DISTANCE REMOTELY  CONTROLLED METAL DETECTOR is used for detecting metallic objects such as phones,  bombs, and other metallic objects that are hidden from view. The design is based on the principle  of the Resonant Frequency Oscillator (RFO) metal detectors in which oscillation is a function of  parallel connection of an inductor and a capacitor operating in resonance. The project is divided  into two sections. The transmit...

Microstructurally Engineered p-layers for Obtaining High Open-Circuit Voltages in a-Si:H n-i-p Solar Cells

A study was carded out with the goal of obtaining high open circuit voltages (Voc) in a-Si:H n-i-p solar cells, taking into account the evolutionary nature of the microstructure of the p-layers during growth. It is found that cells with players in the protocrystalline Si:H growth regime give the highest values of Voc not those with microcrystalline Si:H p-layers. Evidence for this conclusion is presented whereby Voc is related directly to the microstructure of the p-layers, as characterized u...

Maximization of the open circuit voltage for a-Si:H n-i-p solar cells by incorporation of protocrystalline Si:H p-type layers

In studies of hydrogenated amorphous silicon (a-Si:H) n–i–p solar cells fabricated by rf plasma-enhanced chemical vapor deposition (PECVD), we have found that the maximum open circuit voltage (Voc) is obtained by incorporating p-type doped Si:H layers that are protocrystalline in nature. Specifically, these optimum p layers are prepared by PECVD in the a-Si:H growth regime using the maximum hydrogen-to-silane flow ratio possible without crossing the thickness-dependent transition into the...

Correlation of Light-Induced Changes in a-Si:H Films with Characteristics of Corresponding Solar Cells

For the first time direct correlations are obtained between the light induced changes under 1 sun illumination in the properties of a-Si:H and those in the characteristics of p-i-n cells incorporating identically-prepared i-layers. These correlations were obtained after account was taken of the effects that the location of the electron and hole quasi-Fermi levels have on the carrier recombination that occurs through the different gap states. The changes in midgap state density, as measured on...

Photovoltaics — a path to sustainable futures

As both population and energy use per capita increase, modern society is approaching physical limits to its continued fossil fuel consumption. The immediate limits are set by the planet’s ability to adapt to a changing atmospheric chemical composition, not the availability of resources. In order for a future society to be sustainable while operating at or above our current standard of living a shift away from carbon based energy sources must occur. An overview of the current state of active...

Absence of carrier recombination associated with the defect pool model in a-Si:H i-layers: Evidence from current-voltage characteristics on p-i-n and n-i-p solar cells

Forward bias current–voltage characteristics (JD–V) were studied for both p–i–n (superstrate) and n–i–p (substrate) (a-SiC:H p)/(a-Si:H i) solar-cell structures having different p/i interface layers and different thickness i-layers. Contributions of the p/i interfaces to the JD–V characteristics were separated, and the dependence on the thickness of the i-layers was established. Equivalence was observed in a comparison of the characteristics of p–i–n and n–i–p cells....

Light Induced Defect States in Hydrogenated Amorphous Silicon Centered Around 1.05 and 1.2eV from the Conduction Band Edge

To take into account the presence of multiple light-induced defect states in hydrogenated amorphous silicon (a-Si:H) the evolution of the entire spectra of photoconductive subgap absorption, α(hν), has been analyzed. Using this approach two distinctly different light-induced defect states centered around 1.0 and 1.2 eV from the conduction band edge are clearly identified. Results are presented on their evolution and respective effects on carrier recombination that clearly point to the impor...

Carrier Transport and Recombination In A-SI: H PIN Solar Cells in Dark and Under Illumination

Abstract A study has been carried out on the forward bias dark current and the short circuit current-open circuit voltage characteristics of a-Si: H pin solar cells over wide range of illumination intensities. Results are presented with superposition of these characteristics over extended current voltage regimes. This and the observed separation between these characteristics are consistent with the arguments presented based on first principle arguments.

Numerical Simulation of the Direct Application of Compound Parabolic Concentrators to a Single Effect Basin Solar Still

As regional shortages of fresh water become more prevalent, solar distillation using a single-effect basin holds promise as a method to bring low-cost, clean, and ecologically-responsible water to remote area dwellers. Compound parabolic concentrators (CPCs) can be used to direct more light onto the still increasing the throughput and efficiency of these passive solar devices. A computer program has been developed that uses the properties of materials and the solar energy characteristics of t...

3D-mapping optimization of embodied energy of transportation

Resources Conservation and Recycling, Jan 1, 2007 The recent development of Google Earth, an information service that provides imagery and three dimensional data depicting the entire Earth, provides an opportunity to use a new method of navigating information to save energy in the real world. Google Earth uses Keyhole Markup Language (KML) for modeling and storing geographic features and information for display in the Google Earth Client. This paper will analyze the potential of this novel an...

Reducing greenhouse gas emissions by inducing energy conservation and distributed generation from elimination of electric utility customer charges

This paper quantifies the increased green house gas emissions and negative effect on energy conservation (or “efficiency penalty”) due to electric rate structures that employ an unavoidable customer charge. First the extent of customer charges was determined from a nationwide survey of U.S. electric tariffs. To eliminate the customer charge nationally while maintaining a fixed sum for electric companies for a given amount of electricity, an increase of 7.12% in the residential electrical ...


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