383 research outputs found
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Design of a Dual Operating Mode Sheet Folding Machine.
No full textResearch PaperA sheet folding machine that can be operated through hydraulics by two hydraulic cylinders or
manually (with the cylinders disengaged) was designed. The design need emanated from the
strained national electrical grid system that has recently seen industrialists and households in
Zimbabwe experiencing major power cuts. The machine enables manufacturers to schedule
heavier jobs during periods when power supply is up and lighter jobs during power cut periods
hence run their workshops throughout the daily production shifts. The two hydraulic cylinders
can be disengaged from the machine?s folding beam so that manual operation can be done
through a manual clamping lever system. The folding force at full capacity is 294.6 KN (29.46
Ton), total bending length of 1.8 m and working height of 1 m. The folding force decreases
significantly in manual operating mode to 500 N, considering that on average an operate can
manually exert that force. A student version of Simulation X 3.5 was used to simulate the hydraulic
operation of the machine
Open Access in Summary
No full textPresented as part of the Open Access Activities at National University of Lesotho, 22 October 2013
Open Access: Prospectors Wanted!
No full textPresented as part of the Activities of the International Open Access Week at National University of Lesotho, 22 October 201
Occurrence of pesticides used in tobacco farming in edible vegetables and environmental samples
No full textConference Proceeding. 6th SETAC Africa Conference, Lusaka Zambia September, 2013.A method was developed and validated for the analysis of chlorothalonil (CT), dimethoate (DM) and triadimenol (TD) in soil, surface water and edible green vegetables. In method development, A range of solvents were evaluated, and ethyl acetate was observed to be the best extracting solvent in soil and vegetable samples, while acetonitrile was the best extracting solvent in water samples. The effect of solvent type, solvent volume and extraction time on recovery of pesticides was studied. Analysis was carried on HPLC-UV a C18 column using a mobile phase comprising CH3CN/water (50:50, v/v) with a flow rate of 1.0ml/min in isocratic mode. The pesticides were extracted by ultrasonication and obtained recoveries in water, soil and vegetables ranged from 65-91 %. Furthermore, the detection limit in water, soil and vegetables was 0.01 ?g/L, 2.8 ?g/kg and 0.005 ?g/kg, respectively. Limits of quantification ranged from 0.25-1.25?g/kg for vegetables, 1.35-2.3?g/kg and 0.02-0.05?g/l. Precision was measured in terms of the RSD, and values were less than 10%. The method was successfully applied to the analysis of incurred vegetable, soil and water samples from 3 farms from Bromley A2 agricultural area near Marondera, Zimbabwe. About 1.6?g/kg of CT was detected at one farm in soil samples, DM (0.025?g/l) was detected at another farm in well water. However, TD was not detected in all samples and no pesticides were detected in vegetable samples
Assessing the Impact of Vaccination on Controlling the Spread of Human Scabies
No full textThis is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Scabies is among the infestations almost forgotten due to its association with poor communities. We formulate a deterministic
model to assess the possible impact vaccination will have on scabies control.The Descartes?s rule of signs is used to show the nature
of the endemic equilibria. Analysis of the reproduction number and numerical simulations suggest that vaccination in addition to
treatment will help greatly in reducing the spread of scabies infestation.This suggests there is a strong need for researchers to come
up with a possible vaccine in that order to effectively control scabies especially among the disadvantaged communities
Assessing the Impact of Vaccination on Controlling the Spread of Human Scabies
No full textScabies is among the infestations almost forgotten due to its association with poor communities. We formulate a deterministic
model to assess the possible impact vaccination will have on scabies control.The Descartes?s rule of signs is used to show the nature
of the endemic equilibria. Analysis of the reproduction number and numerical simulations suggest that vaccination in addition to
treatment will help greatly in reducing the spread of scabies infestation.This suggests there is a strong need for researchers to come
up with a possible vaccine in that order to effectively control scabies especially among the disadvantaged communities
Improving productivity and profitability through Ergonomics, Occupational Health and Safety
No full textPublished in The Chronicle Newspaper of 2013 on the productivity column.The year 2013 has started with many organizations aspiring for improved performance
from what transpired in the previous year. This ambition is on the shoulders of
management together with their workforce. It is important to highlight those that reported
for duty on the first working day wish to do so for as long as they are employed.
However, it is possible that their reporting for duty may be stopped if they are injured or
killed at work. It is for this reason that the author sees it fit to discuss issues of
Occupational Health and Safety as they affect both production and productivity. It thus
becomes important for all stakeholders to observe high standards of occupational health
and safety standards
Modelling the Subsurface Geology and Groundwater Occurrence of the Matsheumhlope Low Yielding Aquifer in Bulawayo Urban, Zimbabwe
No full textThis is an open-access article distributed under the terms and conditions of the Creative Commons Attribution
license (http://creativecommons.org/licenses/by/3.0/)This study is focused on determining the nature, extend and spatial variation of the subsurface and groundwater
in the Matsheumhlope low yielding aquifer so as to improve the understanding of groundwater occurrence within
Bulawayo Metropolitan area. The abstraction and utilisation of groundwater from crystalline basement
complexes have often been hampered by the high rate of borehole failure. For instance, borehole failure in the
Matsheumhlope wellfield that characterises the greater part of Bulawayo City, Zimbabwe, is often ascribed to
many factors which are yet to be investigated locally and regionally. The electrical resistivity method was used
to establish the depth, thickness and sequence of geological units in the low yielding aquifer. Satellite data were
used to delineate the lineaments and assess the topographic features of the area. Geological samples obtained
from boreholes were correlated with the geophysical pseudo sections to give a better view of the subsurface and
groundwater occurrence in the area. Geographic Information Systems (GIS) was used to model the geophysical
characteristics of the subsurface giving the potential groundwater occurrence in the area. The study confirmed
that the Matsheumhlope aquifer is a heterogeneous unconfined aquifer with a shallow depth to the basement rock
in highlands of the study area. The results also showed high spatial variation of subsurface formations and
groundwater potential over short distances, thereby indicating the complex nature of mapping basement aquifers.
Borehole failure in the area was attributed to the occurrence of shallow depth of the bedrock underlying some
parts of the aquifer. Therefore the results of the study recommended that the structural and geodynamic analysis
of the fractures of the whole Matsheumhlope aquifer should be done using both structural mapping and
geophysical methods