Supervisory control for conventional unitary air conditioning system

The Supervisory control for conventional unitary air conditioning system is conceptually designed based on Programmable Logic Control (PLC) system. The advantage of PLC system is that it allows online monitoring continually and updates or modification can be performed interactively. This supervisory mode is applied to the conventional unitary air conditioner to avoid the frequent interruption or adjustment of the fan speed or temperature set point by users normal practice which has contributed to the surge of energy consumption due to the frequent on/off of the compressor. Three experiments have been performed at different control methods to simulate user’s daily practice. The first control method is the Variable Set point with high speed fan, the second control method is the Fixed Set point with high speed fan and the third control method is a Supervisory Control; a fixed set point with variable fan speed. The experiments have been conducted for eight (8) hours and the statistic data of accumulated energy consumption based on one unitary air conditioner with capacity of 1 Horse Power are acquired and sampled at the time interval of 30 minutes for the analysis. From these experiments, the supervisory control has consumed 4.2 kWh per day which is 82.35% compared to normal consumption of 5.1 kWh. This result translated into 0.9 kWh or 17.65% of total energy saving per day. The consistency of the air compressor operation in this control method has become a major factor in achieving indoor temperature steadiness whilst improving the energy savings

A hybrid quantum eraser scheme for characterization of free-space and fiber communication channels

We demonstrate a simple projective measurement based on the quantum eraser concept that can be used to characterize the disturbances of any communication channel. Quantum erasers are commonly implemented as spatially separated path interferometric schemes. Here we exploit the advantages of redefining the which-path information in terms of spatial modes, replacing physical paths with abstract paths of orbital angular momentum (OAM). Remarkably, vector modes (natural modes of free-space and fiber) have a non-separable feature of spin-orbit coupled states, equivalent to the description of two independently marked paths. We explore the effects of fiber perturbations by probing a step-index optical fiber channel with a vector mode, relevant to high-order spatial mode encoding of information for ultra-fast fiber communications.Comment: Published version, 6 pages, 5 figure

Combustible gaseous products from pyrolysis of combustible fractions of municipal solid waste

Municipal Solid Waste (MSW) sample was pyrolysed under inert atmosphere of nitrogen in a static bed pyrolysis reactor, heated at a controlled rate of 10°C min-1 to a final temperature of 700°C to recover combustible gaseous product. The yield of the combustible gaseous product was 23.01 wt%. Other pyrolysis products were 32.00 wt% char and 44.99 wt% oil. The combustible gaseous product evolved, analysed off line by gas chromatography to contain mainly CO2, CO, H2, CH4, C2H6 and C3H8 has relatively high calorific value of 18.0 MJ m-3, making the gas suitable for use as a fuel. The significance of this research is that the pyrolysis recovered combustible gas can now be stored conveniently and easily transported for various applications. This research, in addition to providing energy needs if implemented, has the capacity to stimulate regular collection of MSW to feed a pyrolysis plant thereby reducing accumulation of the waste in communities, especially in developing countries

Monitoring outcomes of climate smart agricultural options at multiple levels: understanding adoption, synergies and tradeoffs

This framework will support field practitioners in tracking over time, the progress and dynamic changes in adoption of CSA options and their related impacts at household and farm level

Characterization of Bambara Groundnut Landraces and Their Evaluation by Farmers in the Upper West Region of Ghana

departmental bulletin pape

Options for intensifying cereal-legume cropping systems in West Africa

United States Agency for International Developmen

Aflatoxin management in northern Ghana: current prevalence and priority strategies in maize (Zea mays L)

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