138 research outputs found
Moisture Adsorption Characteristics of Ginger (Zingiber officinale) Powders
The adsorption equilibrium moisture content of the powders of peeled ginger (PGP) and unpeeled ginger (UGP) at 20, 30, 40 and 50 °C were investigated using static gravimetric method. The data were fitted to various sorption models. The thermodynamics of water vapour adsorption of the powders was also investigated at moisture contents in the range of 8 to 20 g H2O/100 g solid. Both powders exhibited the type II isotherms. The equilibrium moisture content of the powder decreased with increasing temperature and increased with water activity. The monolayer moisture content also decreased with an increase in temperature. The powder of peeled ginger was less hygroscopic than that of unpeeled ginger and is therefore more shelf- stable. The GAB, Henderson and Oswin equations accurately fitted experimental sorption data (RMS < 10 %); however, the GAB model gave the best fit. The net isosteric heats (ΔHst) of sorption generally decreased with increasing moisture content. The ΔHst of UGP was generally higher than that of PGP. The isosteric heat of the first molecule (ΔHo) of UGP was also higher (72.042 kJ/mol) than that of the PGP (59.695 kJ/mol). On the other hand, the characteristic moisture content (Mch) of UGP was lower (4.058 g H2O/100g solid) than its equivalent for PGP (4.155 g H2O/100 g solid). The values of ΔHo and Mch indicated the relative low moisture affinity of UGP compared to PGP. The enthalpies of sorption for PGP were lower than UGP. Conversely, the entropy of sorption of UGP was higher (6.233 to 158.180 J/mol-K) than that of PGP (2.496 to 125.721 J/mol-K)
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Investigating the Impact of Learners Emotions on Academic Performance and Motivation using Ethnography
Researches has shown that students experience a
wide range of emotions in class and while doing test and this
thus have consequences on learning and achievement. This
research therefore tried to find out the effect of achievement
pressure and expectation of failure on students’. Students’
motivation and academic performance were examined with a
sample of twenty-four students of Computer Science in 200 level.
The results of the investigation revealed that students'
motivation and action are settings to consider when
investigating the different types of emotions students experience
while in class and doing test. The results also revealed that there
is significant difference between class-related emotions and
test-related emotions on students’ hypotheses for patterns
within and between domains
Occupational Stress among Academic Staff in Private University: Empirical Evidence from Covenant University, Nigeria.
The study examined occupational stress among Academic Staff in Private University in Nigeria. The objectives of the study were to ascertain whether work overload has impact on the quality of graduates produced by private University, to examine the relationship between university policy and the loyalty of academic staff of a private University, to justify the extent to which resource inadequacy affects the quality of research and publications produced by the academic staff of a private University and to highlight the effect of job dissatisfaction on the academic excellence of academic staff in a private University. The simple random sampling technique was used in this study to determine occupational stress among academic staff in a private University. A sample of 150 academic staff of Covenant University, Ota, was drawn for this study with response rate of 92%. The data were analyzed using simple frequency tables; regression and Pearson's product moment correlation were used for the four hypotheses proposed for this study. The results of the hypotheses showed that a negative relationship exists between university policy and the loyalty of academic staff, that resource inadequacy to a large extent affects the quality of research and publications produced by academic staff of a private University, that job dissatisfaction affects the academic excellence of academic staff in a private University and that there is a negative relationship between workload and quality of graduate produced by a private university. Research indicates that academics are experiencing higher level of strain compared to other occupational group and that occupational stress affects employees in several ways and is a major source of employee's turnover in many institutions. With this study, the general agreement is that occupational stress will have a negative effect on the academic staff of a private University. Therefore, an institution that emphasizes quality, performance and accountability must work towards reducing and managing occupational stress among its staff
Morphological Diversity and Cytological Studies in Some Accessions of Vigna vexillata (L.) A. Richard
Aim: The objectives of this study were to characterize and evaluate intraspecific relationship among
twenty-six accessions of Vigna vexillata (L.) and work out interrelationship among the morphological
traits which could be used for genetic improvement of cowpea, V. unguiculata (L.) Walp.
Study Design: Field experiment was laid out in blocks of five buckets per accession in a row giving
a total of 260 plants.
Place and Duration of Study: At the experimental field of the Department of Biological Sciences,
Covenant University, Ota, Ogun state, Nigeria, during the dry planting season (September –
December, 2012). Methodology: A total of 26 traits comprising 18 quantitative and 8 qualitative traits of the
vegetative, floral, pod and seed were evaluated using descriptive statistics, Pearson Correlation
Coefficient (PCC), Principal Component Analysis (PCA) and Cluster Analysis (CA). Mitotic
chromosome counts and meiotic behaviour were studied using root tip cells and pollen mother cells
from young flower buds.
Results: The analysis of variance showed that all quantitative morphological characters were
significantly different among the accessions (P = 0.01) except stipule length and width. There were
significant correlations among characters such as calyx lobe length, standard petal length and width,
peduncle length, days to 50% flowering, days to 50% pod maturity, pod length and width, number of
locules per pod, number of seeds per pod, and 100-seed weight which could be used for breeding
and conservation purposes. The first six principal components accounted for 89.84% of the total
variance. The cluster analysis segregated the 26 accessions into three main clusters; cluster I (15
accessions), cluster II (10 accessions) and cluster III (1 accession). Mitotic chromosome counts of
2n = 22 were recorded for all the accessions and meiosis was observed to be normal with the
formation of eleven bivalents (n = 11).
Conclusion: The intraspecific variabilities indicates plasticity in the genomes of the studied
accessions, with high correlations among the morphological characters which are common to all
accessions, thus justifying their grouping as a species. The morphological and reproductive
attributes displayed by accessions TVnu93 and TVnu97 in terms of plant vigour, early flowering and
pod maturity, longer pods and relatively high 100-seed weight made them good potential candidates
in breeding for host plant resistance in cowpea
Economic growth, air pollution and health outcomes in Nigeria: A moderated mediation model
The third of the sustainable development goals is to ensure healthy living
and promote well-being for all by 2030. The Nigerian government has made several
efforts at achieving this goal. Economic experts have projected that the Nigerian
economy must grow at a minimum rate of 6–8% yearly to catch up with global
development and contribute positively to goals set by nations of the world.
However, the attainment of high levels of economic growth could have implications
for the attainment of other development objectives in the economy. One of such
implications is pollution of the environment caused through productive activities. In
carrying out productive activities, a cycle from production to consumption occurs to
affect the release of emissions into the atmosphere and environment which in turn
hampers health stability. In order to assess the cyclical effects of these economic
relationships, this study adopted the use of a moderated mediation model. The
model helped in the explanation of interactions among economic growth, air pollution
and health performance. The interactions were analyzed with PROCESS
macro, an analytical tool developed by Hayes. The study found air pollution and
government expenditure on health as a significant interaction that affects health
performance in Nigeria. Consequently, efforts by the government to ensure
Beneficial effects of omega-3 fatty acid on dyslipidemia in organs of alloxan-induced diabetic rats
Diabetes Mellitus is one of the heterogeneous metabolic disorders associated with dyslipidemia, a major risk factor
contributing to cardiovascular disease. This metabolic abnormality affects virtually all organs. Over the years,
antidiabetic drugs which majorly aim at the hyperglycemic aspect of the disease have been used. Therefore, to
address this dyslipidemia, omega-3 fatty acid (O3FA) supplement was employed. Its effects on lipid metabolism in
the organs (heart, liver, kidney, pancreas, spleen and brain) of alloxan-induced (150mg/kg body weight,
intraperitoneally) diabetic male rats were investigated. O3FA (0.4g/kg b.wt/day) was administered as pre- and posttreatment
for 2 weeks. The lipid levels were significantly increased (p<0.05) in diabetic rats. O3FA administration
significantly reduced (p<0.05) the levels of cholesterol, phospholipids, triacylglycerol by varying extents, in the
examined organs without affecting hyperglycemia in the diabetic rats. The ratio of HMG CoA/mevalonate decreased
in the liver of the diabetic rats by 28% indicating increased activity of HMG-CoA reductase. This diabetes-induced
dyslipidemia was accompanied by a 28% increase in the activity of hepatic HMG-CoA reductase. Administration of
O3FA to the diabetic rats however resulted in 10% and 17% decrease in the activity of this enzyme in the pre- and
post-treated groups respectively. Also, lipid peroxidation was significantly reduced (p<0.05) by O3FA suggesting
that it has protective effect against oxidative damage. This study reveals that O3FAsupplement has beneficial effects
in attenuating dyslipidemia observed in diabetes mellitus and could be beneficial as an adjunct in the management
of diabetes mellitus
Dementia incidence declined in African-Americans but not in Yoruba
INTRODUCTION:
To compare dementia incidence of African-American and Yoruba cohorts aged ≥70 years enrolled in 1992 and 2001.
METHODS:
African-Americans residing in Indianapolis and Yoruba in Ibadan, Nigeria without dementia were enrolled in 1992 and 2001 and evaluated every 2-3 years until 2009. The cohorts consist of 1440 African-Americans, 1774 Yoruba in 1992 and 1835 African-Americans and 1895 Yoruba in the 2001 cohorts aged ≥70 years.
RESULTS:
In African-Americans, dementia and Alzheimer's disease (AD) incidence rates were significantly lower in 2001 than 1992 for all age groups except the oldest group. The overall standardized annual dementia incidence rates were 3.6% (95% confidence interval [CI], 3.2%-4.1%) in the 1992 cohort and 1.4% (95% CI, 1.2%-1.7%) in the 2001 cohort. There was no significant difference in dementia or AD incidence between the Yoruba cohorts.
DISCUSSION:
Future research is needed to explore the reasons for the differential changes in incidence rates in these two populations
A Bibliometric Analysis of Recycled Concrete Research (1978–2019)
ArticlePurpose – The use of recycled concrete (RC) can reduce the greenhouse emissions associated with the
production of cement, which is one of the primary materials used for the execution of construction projects.
This research aims to review the state of knowledge in the field of RC research. An understanding of the state of
the art in the RC domain justifies future research in this field.
Design/methodology/approach – A systematic and comprehensive search of RC-related literature was
conducted using the Scopus database. In this research, the bibliometrix R-package was used for the analysis of
bibliometric information of the selected papers. The software was used to create a map, which highlights the
trends and gaps in the RC knowledge domain.
Findings – The results reveal the research themes, clusters, collaboration networks and advancement of
knowledge in the field of RC research. The study integrates the literature focussed on RC research and provides
a platform for progression of knowledge in this field.
Originality/value – The study contributes to the growing body of knowledge by providing an up-to-date RC
knowledge map based on an analysis of bibliographic data. Information gleaned from previous studies
suggests that bibliometric review can strengthen and complement the findings emerging from other forms of
literature reviews. The study reported here is one of the first studies to provide insights into the evolution of RC
research
The Association Between Cognition and Histamine-2 Receptor Antagonists in African Americans: H2 ANTAGONIST-COGNITION
To evaluate the association between histamine-2 receptor antagonist (H2A) exposure and incident cognitive impairment in a community-based sample of African Americans
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