82 research outputs found
Energy Efficiency Technologies for Buildings: Potential for Energy, Cost, and Carbon Emission Savings
Buildings are a significant energy consumer and are responsible for an increasingly large percent of worldwide greenhouse gas emissions, currently between 30 and 40 percent. Energy efficiency presents unique opportunities for building owners to reduce their environmental footprint and add value through cost savings, tax deductions, and increased market value. An analysis of 183 samples of efficiency measures in seven technology categories found that 74% of efficiency investments had a positive net present value. Building automation system and chiller plant improvements had the highest mean energy and carbon dioxide savings per square foot. Additionally, building automation systems had, on average the highest return on investment, approximately $800 above the cost of implementation per one thousand square feet. Only building envelope modifications had a negative mean return on investment. Building automation system upgrades avoided an average of 350 pounds of CO2e for every dollar spent, reducing a building’s total carbon footprint by as much as 28%. The results suggest that a significant opportunity for cost, energy, and emission savings is available across all technology categories
Morphometric Analysis of some Species in the Genus Vigna (L.) Walp: Implication for Utilization for Genetic Improvement
The genus Vigna (L.) Walp is a large cosmopolitan leguminous genus comprising
both cultivated and wild species. Vigna unguiculata (L.) Walp. (Cowpea) is an
important food legume that is widely cultivated in the tropics, but its production and
storage are hampered by insect pests. The present study evaluated the intra-and
inter-specific morphological variabilities among 20 accessions of six Vigna species,
comprising wild and cultivated species. The species are Vigna unguiculata (L.)
Walp, V. vexillata (A. Richard), V. oblongifolia (A. Richard), V. ambacensis
(Baker), V. luteola (Jacq.) (Bentham) and V. racemosa (G. Don) (Hutch and
Dalziel). Thirty-one morphological characters involving qualitative and quantitative
vegetative and reproductive traits were used for the evaluation. Multivariate
analysis such as Pearson Correlation Coefficient (PCC), Principal Component
Analysis (PCA) and Cluster Analysis (CA) were employed to evaluate the intra and
inter specific variabilities. The paired-sample T test indicated significant differences
among the 20 accessions (p#0.000, df = 19) in their morphometric traits. The
relative significant correlation observed among some traits such as pod length,
number of locules per pod and number of seeds per pod indicated their closeness
and potential for genetic improvement of cowpea. The PCA showed that
reproductive traits such as days to 50% flowering (0.984), days to 50% ripe pod
(0.993), number of pods per peduncle (0.340) and 100-seed weight (0.132) are the
major traits that accounted for the variations among the species. The UPGMA using
the average (between groups) segregated the 20 accessions into two main clusters,
cluster I (comprising mainly wild Vigna species) and cluster II (comprising both
wild and cultivated species). The taxonomic affinities and genetic diversity among
the species are of great importance in the utilization of the species for food and
nutrition, fodder for ruminant animals, cover crop for rotational farming and more
importantly genetic improvement of cowpea
Preliminary Studies On Ethanol Production From Garcinia Kola (Bitter Kola) Pod: Effect Of Sacharification And Different Treatments On Ethanol Yield
A study on yeast fermentation of bitter kola pod( agricultural waste)
was carried out using dried active bakers' yeast ( Saccharomyces
cerevisiae )and brewer's yeast ( Saccharomyces carlsbergensis )
Effects of saccharification using Aspergillus niger and different
treatments on the waste as they relate to the optimization of the
ethanol production were investigated. The reducing sugar in the waste
was increased after 24-48 hours of sacharification using Aspergillus
niger, fresh bitter kola waste recorded 4.4 - 8.0g/100g of the waste,
while the partially fermented bitter kola waste gave the value in the
range of 5.6 - 6.8g/100g. Baker's yeast gave a higher ethanol yield
than Brewer's yeast. Different treatments of bitter kola pod revealed
that addition of nutrient supplement enhanced the ethanol yield;
however, 48 hours of saccharification significantly improved the
ethanol yield at p 64 0.05
Morphology and physicochemical properties of starch isolated from frozen cassava root
Spoilage of cassava root begins immediately after harvest, but its shelf-life could be enhanced by adopting
freezing as a storage method. This study investigated the physicochemical properties and morphology of starch
isolated from cassava roots frozen for 0, 7, 14, 21 and 28 days. Extracted starches can be categorized as compound
starches with most granules irregularly shaped, with some oval, round and truncated. The amylose
contents (22.05–26.41%) decreased with an increase in the freezing time, but the starches showed similar
crystallinity pattern (Type A). Fourier infrared transform spectroscopy showed a reduction in double-helical
order structure of starches from frozen cassava roots. Starches from the stored roots were generally less firm,
less sticky, more cohesive and had higher peak and trough viscosities compared to starch from freshly harvested
roots. Starch from frozen cassava starch may be suited for use in certain types of noodles, such as Japanese
noodles due to low amylose content. Future studies are however, required to explore the starches in food
applications
Effect of low BAP Levels on Multiple Shoots Induction in Indigenous Nigerian Pumpkin (Cucurbita pepo Linn.)
Indigenous Nigerian pumpkin is a cucurbitaceous plant primarily grown in Southwestern
Nigeria for its young leaves, which are relished as pleasant-tasting vegetable. In spite of its nutritional
value, the plant is scarcely available compared to other vegetables. As a result, development of a rapid in
vitro regeneration procedure is imperative to ensure all year round availability. The influence of 6-
Benzylaminopurine (BAP) and 2,4-dichlorophenoxyacetic acid on multiple shoots induction from
cotyledonary node explant of indigenous Nigerian pumpkin has been previously reported. However, the
concentrations of BAP used may have been high, hence the inhibition of shoots formation on medium
amended with plant growth regulators (PGRs). Can low concentrations of BAP alone elicit multiple
shoots from cotyledonary node explant of indigenous Nigerian pumpkin? To ascertain this, we cultured
cotyledonary node explants derived from 3-week-old in vitro grown seedlings for 8 weeks on Murashige
and Skoog (MS) basal medium fortified with 0.35, 0.45 and 0.55 mg/L BAP. Medium without BAP (0.00
mg/L) was used as control. Mean number of shoots per explant was not statistically significant (P≤0.05)
among the BAP concentrations employed except for control and medium augmented with 0.45 mg/L
BAP. Medium fortified with 0.45 mg/L of BAP gave 3.25±0.921 shoots per explant and was therefore
most effective for multiple shoots induction. The result showed that low levels of BAP were capable of
inducing shoots formation from cotyledonary node explant of indigenous Nigerian pumpkin.
Nevertheless, much lower BAP concentration than used in the present study should be investigated for
the likelihood to elicit higher shoot responses
Performance Evaluation of Kernel-Based Feature Extraction Techniques for Face Recognition System
Face recognition is considered to be one of the most reliable biometrics where security issues are of concerned. Feature extraction which is a functional block of a face recognition system becomes a critical problem when there is need to obtain the best feature with minimum classification error and low running time. Most existing face recognition systems have adopted different non-linear feature extraction techniques for face recognition but identification of the most suitable non-linear kernel variants for these systems remain an open problem. Hence, this research work analyzed the performance of three kernel feature extraction technique (Kernel Principal Component Analysis, Kernel Linear Discriminant Analysis and Kernel Independent Component Analysis) for face recognition system. A database of 360 face images was created by obtaining facial images from LAUTECH Biometric Research Group consisting of six facial expressions of 60 persons. Images were preprocessed (gray scaling, cropping and histogram equalization) and the kernel variants were used to extract distinctive features and reduce the dimensionality of each of the images from 600x800 pixels to four smaller dimensions: 50x50, 100x100, 150x150 and 200x200 pixels. Euclidean Distance similarity measure was used for classification. The performance of the three kernel variants was evaluated for face recognition system using 180 images for training and 180 images for testing using the following metrics: Recognition Accuracy (RA) and Recognition Time (RT). Empirical result indicate that KLDA performs best for face recognition system with an average accuracy of 94.52%. The larger image dimension also results in better recognition performance. We intend to experiment on other classifiers for face recognition system in our future work. Keywords— Biometrics, Face, Feature extraction, Kernel, KICA, KPCA, KLDA, Linear, Non-linear
Establishing the psychometric properties of constructs from the conceptual 'settlement services literacy' framework and their relationship with migrants' acculturative stress in Australia
Background: Effective migration often requires supports for new arrivals, referred to as settlement services. Settlement services literacy (SSL) is key to ensuring new migrants have the capability to access and utilise the information and services designed to support the resettlement process and achieve positive settlement outcomes. To date, however, no research has sought to empirically validate measures of SSL or to assess individual migrants' levels of SSL. The aim of this study was to establish the psychometric properties of constructs from the conceptual SSL framework. Design Using a snowball sampling approach, trained multilingual research assistants collected data on 653 participants. The total sample was randomly divided into two split-half samples: one for the exploratory factor analysis (EFA; N = 324) and the other for the confirmatory factor analysis (CFA; N = 329) and scale validation. The final SSL scale included 30 questions. The full data set was used to test the nomological validity of the scale regarding whether the components of SSL impact on migrants' level of acculturative stress. Results: The EFA yielded five factors: knowledge (eight items, α = 0.88), empowerment (five items, α = 0.89), competence (four items, α = 0.86), community influence (four items, α = 0.82), and political (two items, α = 0.81). In the CFA, the initial model demonstrated a poor to marginal fit model. Its re-specification by examining modification indices resulted in a good model fit: CMIN/DF = 3.07, comparative fit index = 0.92, root mean square error of approximation = 0.08 and standardised root mean square residual = 0.07, which are consistent with recommendations. All the path coefficients between the second-order construct (SSL) and its five dimensions (knowledge, empowerment, competence, community influence and political) were significant at an α = .05 level, giving evidence for the validity of different SSL dimensions. We found that SSL is significantly related to migrants' acculturative stress (β = - 0.39, p < 0.05) in the nomological model. Conclusions The study provides evidence of the construct validity and reliability of the SSL tool. It provides the basis for integrating the measures of SSL into evaluation of settlement services. This will allow for more effective decision-making in designing and implementing settlement services as well as funding and service agreements to address any deficiencies
An evaluation of biosecurity compliance levels and assessment of associated risk factors for highly pathogenic avian influenza H5N1 infection of live-bird-markets, Nigeria and Egypt
Live bird market (LBM) is integral component in the perpetuation of HPAI H5N1, while biosecurity is crucial and key to the prevention and control of infectious diseases. Biosecurity compliance level and risk factor assessments in 155LBMs was evaluated in Nigeria and Egypt through the administration of a 68-item biosecurity checklist, scored based on the modifications of previous qualitative data, and analysed for degree of compliance. LBMs were scored as "complied with a biosecurity item" if they had good-very good scores (4). All scores were coded and analysed using descriptive statistics and risk or protective factors were determined using univariable and multivariable logistic regression at p≤0.05. Trading of wild birds and other animal in the LBMs (Odd Ratio (OR)=34.90; p=0.01) and claims of hand disinfection after slaughter (OR=31.16; p=0.03) were significant risk factors while mandatory routine disinfection of markets (OR=0.13; p≤0.00), fencing and gates for live bird market (OR=0.02; p≤0.01) and hand washing after slaughter (OR=0.41; p≤0.05) were protective factors for and against the infection of Nigerian and Egyptian LBMs with the HPAI H5N1 virus. Almost all the LBMs complied poorly with most of the variables in the checklist (p≤0.05), but pathways to improved biosecurity in the LBMs existed. We concluded that the LBM operators play a critical role in the disruption of transmission of H5N1 virus infection through improved biosecurity and participatory epidemiology and multidisciplinary approach is needed.http://www.elsevier.com/locate/actatropica2017-12-31hb2017Veterinary Tropical Disease
Evaluation analysis of a developed solar refrigerator using conventional refrigerant for rural and medical applications
This paper study the performance evaluation of a refrigeration system that operates on
solar energy as alternative source of power to enhance the refrigerating effect,
coefficient of performance (COP), preservation of perishable items and short time
drug such as vaccine, to remote communities and parts of the urban settlement around
the developing nations where there is no access to modern electrical source. The
system was made from locally sourced materials using a conventional refrigerant
HFC134a as working fluid to improve thermal efficiency and stability of the vapour
compression refrigeration system. The COP of the system was enhanced by 8.67%
when working with solar and with energy reduction of 2.38% respectively. In case the
weather is cloudy or during the night hour when the energy generation is low, the
refrigerator can work on battery for an average of 12 hours if fully charge during the
day to avoid idle time of the refrigeration syste
Effect of Fins spacing on the Performance Evaluation of a Refrigeration System using LPG as Refrigerant
In this paper, experimental analysis was carried out on a vapour compression system by
varying the parallel tube condenser fins spacing under the same atmospheric condition in
a selected Refrigeration and Air-conditioning laboratory to examine the performance
characteristics of the refrigeration system. The fins spacing were 2, 4 and 6 mm using
Liquefied petroleum gas (LPG) as working fluid with a mixture proportion of 17.2%
isobutene, 56.4% butane, 24.4% propane. The result shows that the coefficient of
performance of the system when working with condenser fins spacing of 2 mm was 28.8
and 35.9% higher compared to when the system worked with the fins spacing of 4 and
6 mm respectively. Energy consumed by the single hermetic compressor when the system
worked with condenser fins spacing of 2 mm reduced by 16.4 and 18.7% compared to
when the refrigerator worked with fins spacing of 4 and 6 mm respectively. The pull down
time of the cooling system was attained in 2 hours 45 minute with minimum evaporator
temperature of -13 ℃ while working with 30 g mass charge of LP
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