The performance evaluation of a cassava pelletizer

This paper reports on the development and performance evaluation of a machine for cottage level production of pellets from cassava mash. Cassava flour was produced by peeling, grating and drying freshly harvested cassava tubers. Experiments were conducted to determine the physical properties, such as moisture content, particle size distribution and bulk density and the chemical composition of the flour. The flour was mixed with water at different blend ratios to form cassava mash of different moisture contents. A cassava pelletizer was then developed incorporating relevant properties of the flour. The pelletizer consists of a barreled screw auger, which compresses cassava mash against a perforated end plate, through which the pellets are extruded. The barrel is encased in a co-axial counter flow heat exchanger to provide cooling for the system. The performance of the pelletizer was evaluated in terms of the density, durability, crushing strength and cyanide content of the pellets, and the throughput of the machine, against the moisture content of the mash (18, 20 and 22 % w.b.), die size (4, 6 and 8 mm) and the auger speed (90, 100 and 120 rpm). Test results showed that the bulk density and the durability of pellets decreased while the moisture content increased significantly (p<0.05) and separately with increasing die size and moisture content of cassava mash. The pellets with the best quality attributes were obtained from cassava mash at 18% moisture content (w.b.) extruded through the 4 mm die at 90 rpm and a maximum throughput of 54 kg/hr. The pellets exhibited a bulk density of 635 kg/m3 , 15% moisture content (w.b.) crushing strength of 34.24 MPa and a high durability (85.7%). The machine, thus, provides a significant leverage in the utilization of cassava as pelletized animal feed

Determinants of Households’ Food Security in Akure South Local Government Area of Ondo State, Nigeria

The study examined the determinants of households’ food security in Akure South Local Government Area of Ondo State, Nigeria. The study used a multi-stage sampling procedure to select eighty respondents with the aid of a structured questionnaire. Data were collected randomly from four communities and analyzed using a combination of descriptive statistics, food security index and probit regression model. The results revealed that food secure households had an average daily per capita calorie consumption of 3854.46Kcal while the households that were food insecure had an average daily per capita calorie consumption of 1564.3Kcal. The results of probit regression revealed that, household size, level of education, household head’s income and number of income earners were significant determinants of food security among households. Level of education, household head’s income and number of income earners influenced food security positively while household size affected it negatively. Based on the findings of the study, it was therefore recommended that households should diversify their sources of income and register with cooperative societies which may be necessary for them to access funds and also there should be limit in population size through integrated health and education services. Keywords: Determinants, Food Security, Households, Probit Model DOI: 10.7176/JESD/12-22-04 Publication date: November 30th 202

Design, fabrication and testing of a cassava pelletizer

This paper reports on the design of fabrication and testing of a machine for cottage level production of pellets from cassava mash. The pelletizer consists of a barreled screw auger which compresses cassava mash against perforated end plate, through which the pellets are pelletized. The result derived from the calculated design parameters (shaft diameter, tensile stress, torque, screw length, volumetric capacity mass flow rate and power rating) were used for the fabrication. The testing of the pelletizer was determined in terms of throughput of the machine, against the moisture content of the mash (18, 20 and 22% wb), die size (4, 6 and 8 mm) and the auger speed (90, 100 and 120 rpm). Test results showed that the pellets with the best quality attributes were obtained from cassava mash at 18% moisture content (wb) through the 4 mm die at 90 rpm and a maximum throughput of 54 kg/h

Education and Adolescent Fertility: A Multilevel Cross-Sectional Analysis

The steady decline in global adolescent fertility rate masks poor performance in many countries and regions. High levels of adolescent fertility rate still persist in many Sub-Saharan Africa countries. This study examines the effects of education on adolescent fertility across regions and over selected periods of time. The main objective of the study is to ascertain if the effect of education on adolescent fertility varies with regions and time. The simple econometric analysis conducted using global, SSA and OECD countries’ data in 2000, 2010 and 2014, revealed remarkable results. The three data sets employed shows different but consistent effects of education on adolescent fertility over the three different periods. Education had a negative and significant effect on adolescent fertility in all the estimations. However, the effect of education was found to be highest in Sub-Saharan Africa region. In view of the fact that female secondary education is still very low in the region, policies that promote girl child education up to secondary school level will go a long way in addressing the challenge of high adolescent fertility rate in Sub-Sahara Afric

A practical logMAR near reference table for low vision practitioners: Design and applications

LogMAR  charts  are  particularly  useful  for visual acuity (VA) measurement for low vision patients  as  they  simplify  conversion  of  non-standard  viewing  distance  visual  acuities  to standard values. Also, the process of predicting various  quantities  involved  in  the  prescrip-tion of optical devices for patients are greatly facilitated.  However, the processes involved in the use of this logMAR principle require series of multiplication and division by the logMAR ratio  of  1.2589.   A  table  computed  and  pre-sented in this article provides easy reference for the conversions and predictions needed for the various quantities at near.  The table (Table 1) is computed using the logMAR scale of 1.2589 in logMAR, M and N notations. The table con-tains VA values between logMAR 1.4 (10M or 80 point) and logMAR 0.18 (1.3M or10 point) in steps of 1.2589 for reduced (non-standard) viewing distances  ranging from 31.8 cm (0.32 m)  to  3.2  cm  (0.03M).    The  table  contains values  which  can  be  used  to  convert  visual acuity values measured at reduced near view-ing distances to standard visual acuity values.  The values also can be used to represent any of  the  quantities  involved  in  the  prescription of optical devices for low vision patients. The use of the table for converting reduced distance VA values to standard values and for predict-ing optical powers and visual performance of low vision patients are discussed with relevant examples. Like all principles based on the log-MAR principles, the table is quite versatile in VA  conversion  and  prediction  of  the  various quantities  such  as  print  size  that  can  be  read by  the  low  vision  patient  when  factors  such as  viewing  distance    or  power  are  varied

ECONOMIC ANALYSIS OF BUSHMEAT TRADE IN ABEOKUTA, OGUN STATE

This paper examines bushmeat trade in Abeokuta comprising of Abeokuta north and south LG areas of Ogun State. Forty-five (45) respondents were accidentally selected across the two local government areas. The respondents were involved in bushmeat trade at three different levels. There were hunters (31%), ethno-medicine sellers (49%) and bushmeat sellers (20%). The result of the study revealed that majority (69%) of the traders were female. Also, 87% of the respondents had poor education. Therefore respondents could not keep record of their transactions, but from qualitative and quantitative analysis of the profitability of the business, the trade may be described as profitable (89%). An estimate of average annual profit of the trade in the study area was N453,004.  Other benefit though insignificant is that of protein supplement of the family (8%) derived from the trade. Major constraint of the business is the seasonal fluctuation of supply (85%) which affects income of respondents. However, a total of  11 common species of wild animals were traded, therefore it is recommended that conservation policy in terms of educational programme that target hunters and sellers, in order to sensitize them on the danger of indiscriminate harvesting of the animals must be put in place along with improved domestication effort.Â

ECONOMIC CONTRIBUTION OF WILDLIFE TO BUSHMEAT MARKETS IN IBADAN, OYO STATE

This paper examined the economic contribution of wild animals to bushmeat trade in Ibadan, Oyo State, Nigeria. Five prominent bush meat markets in Ibadan and its suburb were used for the study. The selection was based on the high intensity of bush meat marketing operations identified with the markets. All sellers in each market visited were interviewed which sum up to forty four respondents. Data were collected using structured questionnaire. Budgetary analysis was done to calculate costs and return of the bushmeat sellers. Income on mammals had the highest (₦5,755,600) per annum followed by the income on birds (₦858,000) per annum and reptiles (₦182,000). In the same pattern, percentage contribution indicates that mammals contributed 84% of the total income, while wild birds contributed 12% of the total income and reptile 3%. The net profit realized from the sales of mammals was ₦4,979,000 and ₦180,900 for wild birds. Cost and return analysis showed that sale of bushmeat is a profitable venture. In addition, mammals contributed more to the economy of the market than other two classes of animal found in the bushmeat market

Effect of optical defocus on colour perception

Daily experience shows that colour  of a very distant object cannot be accurately determined.  It is assumed that visual acuity (VA) loss is one of the factors at play in this case.  The effects of reduced VA as a result of refractive error or optical defocus on colour vision have not been examined.  Such study will dictate the need or otherwise for optical correction before assessment of colour vision.  The purpose of this study therefore, was to investigate the effects of optical defocus on colour vision in individuals with normal colour vision.  Twenty nine young adult subjects (11 male and 18 females) were included in this study. Their ages ranged from 11 to 29 years with a mean of 22.1 ± 3.4 years.  All subjects had VA of 6/6 or better and normal colour vision.  The colour vision was evaluated with the Farnsworth panel D-15 (desaturated). Each subject was optically defocused to VA of 6/24, 6/60 and 1/60(6/360) at 6 meters respectively and colour vision was assessed at each reduced VA.  At VA of 6/24, colour vision was not affected in all subjects. When the VA was reduced to 6/60, however, 15 (51%) of the subjects failed the colour vision test. When the VA was further reduced to 1/60 by optical defocus, 24 (83%) of the subjects failed the colour vision test.  It was concluded that optical defocus and reduced VA can adversely affect colour vision test findings. While VA reduction to 6/24 may not affect the colour vision results, VA of 6/60 can.  It is therefore, recommended that in clinical colour vision  testing and colour vision screening, VA should first be assessed andcompensated, especially if uncorrected VA is 6/24 or worse

Assessment of Tree Species Diversity, Family Composition and Diameter Size Class of Tree Species in Igbo-Olua Sacred Groove, Ondo State, Nigeria

This study was carried out to assess the tree species diversity, family composition and diameter size distribution of the tree species in Igbo-Olua sacred groove, Ondo state, Nigeria using appropriate standard techniques. A total of 34 tree species distributed in 23 families were recorded.&nbsp; Sterculiaceae family (66) had the highest number of individual stem per ha while Moraceae family had the highest number in terms of tree species per hectare (7). The distribution of the diameter structure is typical of the natural forest type with high number of tree species in the smaller size classes or interval (12.5) and the number of tree species decreases with increasing size class or interval. Diversity measures obtained included Shannon-Weiner index (3.09), Evenness (0.64) and Margalef index (6.36). Awakening the consciousness of people towards the protection of sacred groves has practical implications on their survival. Hence government and other allied institutions should gear efforts towards grove conservation

A review of the role of oxidative stress in the pathogenesis of eye diseases

Free radicals, referred to as oxidants are molecules in the body with unpaired electrons, hence are unstable and ready to bond with other molecules with unpaired electrons.  They include Reactive Oxygen Species (ROS) such as superoxide anion radicals (·O¯), hydrogen peroxide (H202), and hydroxyl free radicals (·OH).  Endogenous sources of ROS include metabolic and other organic processes, while exogenous sources include ultraviolet radiation and environmental toxins such as smoke.  Antioxidants (oxidant scavengers) such as ascorbate, alpha-tocopherol and glutathione as well as various enzymatic compounds such as superoxide dismutase (SOD), catalase and glutathione reductase are also present in the body and in manyfoods or food supplements.  An imbalance between oxidants and antioxidants in favour of oxidantsis termed oxidative stress and can lead to cell or tissue damage and aging. Oxidative stress has been implicated in the pathogenesis of many serious systemic diseases such as diabetes, cancer and neurological disorders.  Also, laboratory and epidemiological studies have implicated oxidative stress in the pathogenesis of the majority of common serious eye diseases such as cataract, primary open angle glaucoma and age-related macular degeneration. In this article, we reviewed the current information on the roles of oxidative stress in the pathogenesis of various eye diseases and the probable roles of antioxidants.  Eye care practitioners will find this article useful as it provides information on the pathogenesis of common eye diseases. (S Afr Optom 2011 70(4) 182-190