Since anemia is one of the most skyrocketed public health problems worldwide, an investigation has thus been conducted to assess the prevalence and associated factors of anemia among the pregnant women receiving anten...Since anemia is one of the most skyrocketed public health problems worldwide, an investigation has thus been conducted to assess the prevalence and associated factors of anemia among the pregnant women receiving antenatal care (ANC) at Fatima Hospital in Jashore, Bangladesh. Facility-based cross-sectional study was carried out among 384 pregnant women at Fatima hospital, Bangladesh from February to April, 2019. Data were obtained using a structured questionnaire and participant’s current medical record card. Binary logistic regression analysis was used to identify factors associated with anemia and a P-value < 0.05 was considered as statistically significance. The overall prevalence of anemia among pregnant women was 58.9% (226/384). Out of 226 anemic pregnant mothers, 36.3% (82/226) were mildly anemic, 62.4% (141/226) were moderately anemic and 1.3% (3/384) was severely anemic. Binary logistic regression analysis revealed that the following variables were significantly associated with anemia: Monthly family income (11,000 - 20,000 Taka) [AOR (95% CI) = 0.45 (0.21 - 0.98)], Family size (joint) [AOR (95% CI) = 1.59 (1.03 - 2.45)], Gestational age (third trimester) [AOR (95% CI) = 2.18 (1.40 - 3.40)], birth spacing < 2 years [AOR (95% CI) = 2.87 (1.51 - 5.44)], Excessive blood loss during previous surgery (Yes) [AOR (95% CI) = 2.08 (1.14 - 4.17)], Food group eaten 24 hours (1 - 4 groups) [AOR (95% CI) = 3.43 (1.84 - 6.39)], Breakfast regularly (No) [AOR (95% CI) = 3.64 (1.36 - 9.75)]. The results obtained showed that the prevalence of anemia among pregnant women is severe at Fatima Hospital in Jashore, Bangladesh.展开更多
Metabolic changes together with cardiovascular and hepatic factors are related to the development of diseases like myocardial lipidosis,heart disease,and profound toxicity.The aim of this animal study is to determine ...Metabolic changes together with cardiovascular and hepatic factors are related to the development of diseases like myocardial lipidosis,heart disease,and profound toxicity.The aim of this animal study is to determine the effects of high erucic acid containing rapeseed oil(Brassica napus L.)varieties on liver,kidney and heart muscles in Wistar rats.Male Wistar rats were divided into three groups where each group containing four rats.Group A was considered as control diet group,while Group B rapeseed wild oil group and Group C rapeseed hybrid oil group were considered as experimental diet groups.The levels of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),creatine kinase-MB(CK-MB)and creatinine of two experimental groups were significantly elevated while compared to the control groups(p<0.05–0.001).Nevertheless,an increment in weight retardation(p<0.05)was also observed in rapeseed hybrid oil treated groups.No significant weight retardation found in other two groups(p>0.05).Noticeable tissue injury observed in this study is a sign of the relative toxicity of erucic acid containing rapeseed oil to mammalian species.The use of Brassica napus as a supplementary feed ingredient should be,therefore,thoroughly considered.展开更多
This study investigates the suction and magnetic field effects on the two-dimensional nanofluid flow through a stretching/shrinking sheet at the stagnation point in the porous medium with thermal radiation.The governi...This study investigates the suction and magnetic field effects on the two-dimensional nanofluid flow through a stretching/shrinking sheet at the stagnation point in the porous medium with thermal radiation.The governing partial differential equations(PDEs)are converted into ordinary differential equations(ODEs)using the similarity transformation.The resulting ODEs are then solved numerically by using the bvp4c solver in MATLAB software.It was found that dual solutions exist for the shrinking parameter values up to a certain range.The numerical results obtained are compared,and the comparison showed a good agreement with the existing results in the literature.The governing parameters’effect on the velocity,temperature and nanoparticle fraction fields as well as the skin friction coefficient,the local Nusselt number and the Sherwood number are represented graphically and analyzed.The variation of the velocity,temperature and concentration increase with the increase in the suction and magnetic field parameters.It seems that the thermal radiation effect has increased the local Sherwood number while the local Nusselt number is reduced with it.展开更多
Civil construction has high demand for new procedures and technologies capable of generating better results in numerous situations throughout the process.Nowadays,cavities in urban areas are commonly used due to the i...Civil construction has high demand for new procedures and technologies capable of generating better results in numerous situations throughout the process.Nowadays,cavities in urban areas are commonly used due to the implantation of commercial and residential developments with more than two floors,seeking a better use of the nobler areas of the big cities.In geotechnical terms,the filling of these cavities,with the local soil,especially in the Federal District,lateritic soils,can represent additional efforts for the structures and foundations and lead to a compromise of the technical and functional performance of the same,compromising the efficiency and the economy of the enterprise.In this sense,this research evaluates the mechanical behavior of the mixtures,using GEO5 Software,Containment Design and Verification Modules,presenting an alternative to fill cavities in urban regions,with a mixture of material with lower specific density in relation to the soil Natural.Proctor Normal compression tests,simple direct shear saturation and sample expansibility were performed.The results showed a reduction of 38%in the strength of the reinforced concrete curtain,as well as a 25%reduction in maximum bending moments and 31%in maximum shear forces,and a reduction of about 32%in the displacements of the structure to the soil with addition of expanded vermiculite for tests obtained in the saturated condition.For the compositions of cement soil,expanded vermiculite soil and soil cement and expanded vermiculite,the deformations were of the order of 0.3%,0.4%and 0.2%,respectively.展开更多
Plantain (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Musa spp</span></i><i><span style="...Plantain (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Musa spp</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">.) constitute</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> an essential food crop in both tropical and subtropical areas. The staple’s nutritional value and provitamin A carotenoid potential has attracted more interest and usage. </span><a name="_Hlk56239143"></a><span style="font-family:Verdana;">Plantain (</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></span></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Musa spp</span></i></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></i></span></i></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">.) optimization into food recipes has been identified to increase patronage and minimises food wastage, due to the fruit’s (pulp) high perishability nature. In this study, local over ripe plantain (</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></span></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Musa spp</span></i></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></i></span></i></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">.) was sampled and used in a beverage production. The beverage was processed from pureed ripe plantain, by three days fermentation of the pureed plantain mixture, boiling, and spicing, preservation with syrup, storage, and usage. The product’s processing was followed with a sensory evaluation of the new beverage on taste, appearance, color, flavour, and overall acceptability. Majority of the respondents indicated the new product was good and was well accepted. T</span></span><span style="font-family:Verdana;">he research sought to create food diversity, encourage more usage of the crop and to highlight the nutritional values of plantain (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Musa spp</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">.) which is particularly high in provitamin A carotenoid to address Vitamin A deficiency in low resource setting communities.展开更多
Extended-spectrum <i>β</i>-lactamase (ESBL) appeared some years after the introduction in hospital environment of unhydrolysable or extended-spectrum cephalosporins. Several studies have been reported on ...Extended-spectrum <i>β</i>-lactamase (ESBL) appeared some years after the introduction in hospital environment of unhydrolysable or extended-spectrum cephalosporins. Several studies have been reported on the blaTEM, blaCTX-M and blaSHV genes in ESBL producing Enterobacteria, however, very few studies reported in the literature were related to blaCTX-M subgroup blaTOHO. TOHO enzymes were responsible for healthcare-associated infections in hospitals and in the community. In Burkina Faso, data related to these types of enzymes were scarce. The purpose of this study was to detect TOHO enzymes in <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> in order to know the prevalence of infections related to bacterial resistance due to TOHO enzymes at Saint Camille Hospital of Ouagadougou (Burkina Faso). The study was conducted firstly by microbiological identification of ESBLs-producing by <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> using API 20 E gallery;secondly the antibiogram was performed by the diffusion method and finally the molecular characterization was made by conventional PCR to search for the blaTOHO gene. The visualization of the specific bands was made using the ultraviolet lamp (Gene Flash) for the photography of the gels. Data were entered and analyzed using Excel 2013 and EPI Info version 6.0 software. A p-value < 0.05 was considered as significant. We obtained at all 39 strains constituted by 21 (53.8%) <i>Escherichia coli</i> and 18 (46.2%) <i>Klebsiella pneumoniae</i>. Molecular characterization showed the presence of the blaTOHO gene in 25 bacterial strains (64.1%). It was therefore established in this study the existence of blaTOHO gene at Saint Camille Hospital in Ouagadougou in Burkina Faso. Our study made it possible to know the distribution of the blaTOHO gene in <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i>.展开更多
Polyamines(PAs) play diverse roles in plant growth and development,as well as responses to environmental stimuli.In this study,the effects of PAs on rice salt tolerance were investigated.Salt stress resulted in the al...Polyamines(PAs) play diverse roles in plant growth and development,as well as responses to environmental stimuli.In this study,the effects of PAs on rice salt tolerance were investigated.Salt stress resulted in the alteration of endogenous PAs levels in rice roots and leaves,where spermidine(Spd) and spermine(Spm) contents were increased,and putrescine(Put) content was decreased.RT-qPCR analysis revealed that PAs biosynthesis-related genes ADC1,ODC,and Arginase were significantly downregulated by salt treatment;however,SAMDC transcription was significantly upregulated.Exogenous Spm enhanced rice salt tolerance remarkably;however,exogenous Put and Spd undermined rice salt tolerance.Transgenic rice plants overexpressing SAMDC display a higher ratio of Spm/(Put+Spd) and enhanced salt tolerance.Salt stress also increased polyamine oxidase activities in rice,resulting in elevated reactive oxygen species(ROS) production.Our findings revealed that accumulation of Put and Spd substantially reduced salt tolerance in rice,likely by facilitating ROS production;whereas,conversion of Put and Spd to Spm contributes to rice salt tolerance.展开更多
Objective:To determine the lead bioactive compound in kernel extract of Mangifera pajang and its anti-cancer activity against human breast cancer cell lines with positive estrogen receptor(MCF-7).Methods:The methanoli...Objective:To determine the lead bioactive compound in kernel extract of Mangifera pajang and its anti-cancer activity against human breast cancer cell lines with positive estrogen receptor(MCF-7).Methods:The methanolic extract of dried powder kernel of Mangifera pajang was exposed to column chromatography for isolation.The structural elucidation of the isolated compound was characterized using infrared,nuclear magnetic resonance,mass spectrometry.Furthermore,cytotoxicity,morphological changes,flow cytometry and cell cycle arrest analyses were performed to examine the mechanism of anti-proliferation and apoptosis induced by methyl gallate against MCF-7.Results:One compound was isolated from the methanolic extract of Mangifera pajang kernel and identified as methyl gallate.The flow cytometric results demonstrated induction of apoptosis in MCF-7 cells by three concentrations of methyl gallate.The cell cycle arrest showed a significant(P<0.05)decrease in cell progression at G2/M phase of MCF-7 after treatment with 100μM of methyl gallate.The cell percentage of early and late apoptosis was significant at 10 and 100μM of methyl gallate.Also,methyl gallate treatment induced up-regulation of reactive oxygen species levels in MCF-7 cells with a reduction in superoxide dismutase levels.Conclusions:These findings indicate that isolated methyl gallate from Mangifera pajang kernel extracts induces growth inhibition and apoptosis in MCF-7 cells via up-regulating oxidative stress pathway.展开更多
<span style="font-family:Verdana;">This study investigates the economic benefits of energy efficiency to petroleum refineries regarding Tema Oil Refinery (TOR), Ghana. The study explores lessons relati...<span style="font-family:Verdana;">This study investigates the economic benefits of energy efficiency to petroleum refineries regarding Tema Oil Refinery (TOR), Ghana. The study explores lessons relating to the cost of production, energy recovery levels and economic fortunes of the refinery activities and designs a conceptual framework for improving the energy efficiency of Tema Oil Refinery (TOR). The study adopted a descriptive design using a quantitative approach to provide a statistical background to investigate the economic benefits of energy efficiency. A sample of 84 was adopted for study from a staff population of 520 working at Tema Oil refinery. In addition to primary data, secondary data on energy supply and consumption values from 2008 to 2019 was gathered. For the primary survey, 84 respondents were sampled from TOR and a structured questionnaire was used to retrieve information. A correlation analysis at P < 0.05 was conducted to test the relationship and significance of energy efficiency and economic benefits to the refinery. The study concludes that there is a linear trend between energy production (supply) and energy consumption. The energy generated in the entire economy of Ghana far exceeds the amount of energy consumed thus raising issues of waste or excesses that calls for better policies and management plan to improve EE. The study also identified that issues of lost energy are critical to the operations of the petroleum industry as the situation is compounded by the inability of the refineries to explore better ways to reduce and manage the waste. The study concludes that a significant and positive correlation between energy efficiency and the economic fortunes of Tema Oil Refinery is necessary for its economic fortunes. The supply of energy should have equivalence to the public consumption of energy.展开更多
The inability to achieve the target of universal access to electricity is influenced by several factors including funding limitations, the use of obsolete equipment, power theft, and system losses confronting the elec...The inability to achieve the target of universal access to electricity is influenced by several factors including funding limitations, the use of obsolete equipment, power theft, and system losses confronting the electricity distribution services of the Electricity Company of Ghana Limited (ECG). The study assessed the components of system losses within the ECG by determining and computing the percentage of system losses within ECG, examining the causes of both commercial and technical losses in ECG, and determining ways to improve energy efficiency by reducing system losses in the most cost-efficient manner. The study adopted deductive reasoning and a quantitative approach to guide data collection and analysis of the research output. A sample of 345 technical and non-technical staff of ECG in the Greater Accra Metropolis was selected from a population of 2500. Purposive, simple random, and cluster sampling techniques were used in identifying and accessing respondents for the study. Descriptive statistics were applied to measure central tendency and degrees of dispersion and the Relative Importance Index (RII) to predict criterion and predictor variables. The impact of low voltage network losses can adversely contribute to technical losses (20%) and reduce energy efficiency in power or electricity distribution companies. Non-technical losses are mainly caused by illegal connections, meter problems, and billing problems. Each of the non-technical losses contributes a maximum of 10% to system losses. Contributors to system losses at ECG are ranked first for power theft and least for lack of incentives. System losses at ECG include metering inaccuracies, bad workmanship, unmetered supply, and lengthy distribution lines, each recording a mean value of above 3.5. Measures to improve monitoring of the networks and systems at ECG and discourage power theft should include an extensive quantification, patrolling, and inspection of the entire network to assess the extent of the network and conditions relevant for the placement of systematically planned maintenance programmes.展开更多
In this paper, SLAM systems are introduced using monocular and stereo visual sensors. The SLAM solutions are implemented in both indoor and outdoor. The SLAM samples have been taken in different modes, such as a strai...In this paper, SLAM systems are introduced using monocular and stereo visual sensors. The SLAM solutions are implemented in both indoor and outdoor. The SLAM samples have been taken in different modes, such as a straight line that enables us to measure the drift, in addition to the loop sample that is used to test the loop closure and its corresponding trajectory deformation. In order to verify the trajectory scale, a baseline method has been used. In addition, a ground truth has been captured for both indoor and outdoor samples to measure the biases and drifts caused by the SLAM solution. Both monocular and stereo SLAM data have been captured with the same visual sensors which in the stereo situation had a baseline of 20.00 cm. It has been shown that, the stereo SLAM localization results are 75% higher precision than the monocular SLAM solution. In addition, the indoor results of the monocular SLAM are more precise than the outdoor. However, the outdoor results of the stereo SLAM are more precise than the indoor results by 30%, which is a result of the small stereo baseline cameras. In the vertical SLAM localization component, the stereo SLAM generally shows 60% higher precision than the monocular SLAM results.展开更多
Investments in the exploitation of the continent’s raw material reserves have resulted in little (positive) impact on the energy security situation within Africa. This paper attempts to explore factors influencing th...Investments in the exploitation of the continent’s raw material reserves have resulted in little (positive) impact on the energy security situation within Africa. This paper attempts to explore factors influencing the level of energy security of Small Medium Enterprises (SMEs) in the Greater Accra Region of Ghana, and from the dimension of availability, affordability, economic efficiency and environmental stewardship or sustainability of energy. The cross-sectional survey design was employed as the design for the collection and analysis of data. The study applied a quantitative research method in examining the indicators of energy security for SMEs in Accra Metropolis in the Greater Accra Region of Ghana. The population covered about 500 SMEs who have about 100 employees and total revenue of $1 million or the equivalence in Ghana Cedis. A sample of 246 was selected through a cluster and simple random sampling. The analysis adopted statistical techniques to conduct descriptive, exploratory and inferential analysis of the data collected. Factors that influence the level of energy security of SMEs are broadly categorized into the environment and economic change, political factors, physical disruptions and market conditions. Ge- nerally, the level of energy security under the availability dimension is medium among the SMEs. Issues of affordability, economic efficiency and environmental stewardship provide high medium interventions on energy security for SMEs. It is recommended that managers of Ghana’s energy sector should ensure prudent management of the country’s energy resources since the disruption of supply lines or sources form the key conditions that influence the energy security level of SMEs. SMEs should adopt energy efficiency measures to ensure that energy is conserved for future use.展开更多
Absorption chillers are cooling units usually powered by renewable energy or waste heat.Their performance generally depends on the temperatures of the heat source,the ambient and the medium to be cooled.The present wo...Absorption chillers are cooling units usually powered by renewable energy or waste heat.Their performance generally depends on the temperatures of the heat source,the ambient and the medium to be cooled.The present work deals with the thermodynamic study of a 10 kW NH3/H2O absorption machine in order to find the COP(coefficient of performance).The first and second laws of thermodynamics were used for the operating conditions.The thermodynamic properties of the NH3/H2O mixture were determined using the EES(Engineering Equation Solver)software.The results of the simulation of the machine were validated with the results of the literature.After validation,the program was used to simulate a 10-kW NH3/H2O absorption machine for milk conservation/cold storage in northern Senegal.The simulation results of the 10-kW ammonia-water absorption machine give an acceptable COP of 0.521 with a milk storage temperature of 4°C.展开更多
Sugar is important in daily food intake since it is used as food preservative and sweetener.Therefore,is important to analyze the influence of sugar on the spectroscopic properties of the sample.Terahertz spectroscopy...Sugar is important in daily food intake since it is used as food preservative and sweetener.Therefore,is important to analyze the influence of sugar on the spectroscopic properties of the sample.Terahertz spectroscopy is proven to be useful and an efficient method for sugar detection as well as for future food quality industry.However,the lack of detection sensitivity in Terahertz Spectroscopy has prevented it from being used in a widespread spectroscopic analysis technology.In this paper,Frequency Selective Surface(FSS)using the Terahertz Spectroscopy Time Domain Spectrum(THz-TDS)which operates at terahertz frequency range has been demonstrated for application of sugar detection.The FSS is designed with a circle slot structure and has been optimized in line with the molecular resonance of glucose and fructose at different level concentration at 1.98 THz and 1.80 THz,respectively.Transmission magnitude of glucose and sucrose is inversely proportional with the level of sugar concentrations.The realization of the FSS structure is using electron beam lithography and wet etching technique.Results show that the FSS performance for glucose and sucrose reveal fair shifts in measured transmission magnitude from its original in CST by approximately 30%.The use of fabricated FSS with circle structure indicates that the concentration can be improved averagely at 25%for glucose and 13%for sucrose.Thus,it shows that the FSS circle structure combined with THz-TDS has the potential to become an alternative method for food sensing technology in the future.展开更多
Catalyst-free InGaAs nanowires grown by selective area epitaxy are promising building blocks for future optoelectronic devices in the infrared spectral region.Despite progress,the role of pattern geometry and growth p...Catalyst-free InGaAs nanowires grown by selective area epitaxy are promising building blocks for future optoelectronic devices in the infrared spectral region.Despite progress,the role of pattern geometry and growth parameters on the composition,microstructure,and optical properties of InGaAs nanowires is still unresolved.Here,we present an optimised growth parameter window to achieve highly uniform In1-xGaxAs nanowire arrays on GaAs(111)B substrate over an extensive range of Ga concentrations,from 0.1 to 0.91,by selective-area metal-organic vapor-phase epitaxy.We observe that the Ga content always increases with decreasing In/(Ga+In)precursor ratio and group V flow rate and increasing growth temperature.The increase in Ga content is supported by a blue shift in the photoluminescence peak emission.The geometry of the nanowire arrays also plays an important role in the resulting composition.Notably,increasing the nanowire pitch size from 0.6 to 2μm in a patterned array shifts the photoluminescence peak emission by up to 120 meV.Irrespective of these growth and geometry parameters,the Ga content determines the crystal structure,resulting in a predominantly wurtzite structure for xGa≤0.3 and a predominantly zinc blende phase for xGa≥0.65.These insights on the factors controlling the composition of InGaAs nanowires grown by a scalable catalyst-free approach provide directions for engineering nanowires as functional components of future optoelectronic devices.展开更多
<span style="font-family:Verdana;">Technologies for gas conversion have attracted more serious attention, but energy efficiency, supply deficiencies, as well as other risks undermining the gas supply i...<span style="font-family:Verdana;">Technologies for gas conversion have attracted more serious attention, but energy efficiency, supply deficiencies, as well as other risks undermining the gas supply industry</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> make it difficult to achieve sustainability in gas supply in Ghana. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">This study </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">explored strategies for improving supplies for sustainable power generation in Ghana. Specifically, the study investigates the risks associated with the gas supply industry and also investigates strategies for improving gas supplies in Ghana. A descriptive study that applied both qualitative and quantitative tools was applied to data collection and analysis to allow for an in-depth analysis of the findings of the research. The population was concentrated on the regulators (Energy Commission) and consumers (VRA and Sunon Asogli, and GNGC/Eni in the supply domains. In all, 357 population w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> targeted with a sample of 151. Probability (simple random sampling) and non-probability (purposive) sampling approaches were applied to source participants for the study. Statistical inferential tools that guided the analysis included means, standard deviation, Relative Importance Index (RII). The study identified issues of power sector debt due to the weak financial background of the gas supply sector, poor infrastructure, issues of corruption created by delays, poor transparency and weak regulatory framework as key risk factors in the gas supply industry in Ghana. The study also concluded that strategies to support the drive to achieve sustainability in the gas supply industry should involve a planned action towards providing regular and improved infrastructure in transportation and gas supply pipelines to enhance the visibility of the local gas industry and to also meet both domestic and industrial demand for gas products. Again, there should be the establishment and maintenance of functional gas-related policies and regulators, as well as an emergency supply plan to address any shocks that may tend to impact the gas supply industry in Ghana.</span></span></span>展开更多
Background:Indoor air quality(IAQ)is a concern in kindergartens as children spend much of their time there.Yet,there is a shortage of biological indicators needed for assessing IAQ.Thus,this study evaluated IAQ using ...Background:Indoor air quality(IAQ)is a concern in kindergartens as children spend much of their time there.Yet,there is a shortage of biological indicators needed for assessing IAQ.Thus,this study evaluated IAQ using transplanted lichen Usnea misaminensis as a biological indicator.Methods:Lichen samples,collected from Bukit Larut,Perak,Malaysia,were exposed to indoor and outdoor environments in an urban area(Ummi Aiman Kindergarten)and a rural area(Ummi Qaseh Pelangi Kindergarten)for 2 months during August 15 to October 14,2019.The concentrations of 12 selected elements and the vitality of the lichens were then evaluated.Results:Increased concentrations of eleven of the twelve elements deposited in the lichen samples in both urban and rural areas were observed.For both areas,the element concentrations in the samples from the indoor environment was lower than those from the outdoor environment,and those in the rural area were lower than those from in the urban area,suggesting the impacts of traffic emissions.The vitality of the lichens showed no significant change in indoor environment,compared to that in outdoor environment,indicating that even exposed to indoor environment,the lichens remained effective biological indicators as same as they were in the outdoor environment.Conclusions:Lichens are effective biological indicators for both outdoor and indoor environments.Furthermore,outdoor emissions could influence IAQ,which could be problematic in densely populated areas such as kindergartens.Mitigation measures should be taken.展开更多
The Editors-in-Chief have retracted this article because it contains material that substantially overlaps with the fol-lowing article(Paoli et al.2019).
Oil and gas operators worldwide are expecting service companies to deliver integrated techniques to minimize,if not prevent,drilling problems.Drilling fluids perform vital functions to ensure the success of drilling o...Oil and gas operators worldwide are expecting service companies to deliver integrated techniques to minimize,if not prevent,drilling problems.Drilling fluids perform vital functions to ensure the success of drilling operations.The technical challenges often associated with water-based drilling fluids are loss of critical properties,such as fluid loss control and rheology,under demanding conditions,such as in drilling deeper,high-temperature and high-pressure wells.Fluid loss during drilling operations has a very significant effect in both reservoir formation damage and monetary terms.The use of durian rind(DR)as a new additive in controlling lost circulation would provide another opportunity to reduce waste and avoid pollution.Therefore,DR was used to improve the rheological properties of water-based mud,and it was prepared for use as a fluid loss additive.For a better understanding of the influence of pectin on drilling mud properties,the rheological evaluation of untreated DR was compared to that of mud samples containing treated DR.The pectin in DR was extracted using four different solvents,namely,ethanol,methanol,sodium hydroxide and hydrogen peroxide,and the most effective solvent to remove the pectin was then determined.The Fourier transform infrared spectroscopy(FTIR)results showed that NaOH was the best solvent for removing pectin from DR.Thermogravimetric analysis(TGA)was used to determine the thermal stability of DR before and after treatments.The TGA results demonstrated that the treated DR had improved thermal stability compared to untreated DR.The sizes of DR used were coarse,medium,and fine.The untreated DR presented better rheological properties than the treated DR.The experimental investigation showed that a concentration of 20 lb/bbl of intermediate-sized DR was the best concentration among the tested samples.展开更多
文摘Since anemia is one of the most skyrocketed public health problems worldwide, an investigation has thus been conducted to assess the prevalence and associated factors of anemia among the pregnant women receiving antenatal care (ANC) at Fatima Hospital in Jashore, Bangladesh. Facility-based cross-sectional study was carried out among 384 pregnant women at Fatima hospital, Bangladesh from February to April, 2019. Data were obtained using a structured questionnaire and participant’s current medical record card. Binary logistic regression analysis was used to identify factors associated with anemia and a P-value < 0.05 was considered as statistically significance. The overall prevalence of anemia among pregnant women was 58.9% (226/384). Out of 226 anemic pregnant mothers, 36.3% (82/226) were mildly anemic, 62.4% (141/226) were moderately anemic and 1.3% (3/384) was severely anemic. Binary logistic regression analysis revealed that the following variables were significantly associated with anemia: Monthly family income (11,000 - 20,000 Taka) [AOR (95% CI) = 0.45 (0.21 - 0.98)], Family size (joint) [AOR (95% CI) = 1.59 (1.03 - 2.45)], Gestational age (third trimester) [AOR (95% CI) = 2.18 (1.40 - 3.40)], birth spacing < 2 years [AOR (95% CI) = 2.87 (1.51 - 5.44)], Excessive blood loss during previous surgery (Yes) [AOR (95% CI) = 2.08 (1.14 - 4.17)], Food group eaten 24 hours (1 - 4 groups) [AOR (95% CI) = 3.43 (1.84 - 6.39)], Breakfast regularly (No) [AOR (95% CI) = 3.64 (1.36 - 9.75)]. The results obtained showed that the prevalence of anemia among pregnant women is severe at Fatima Hospital in Jashore, Bangladesh.
基金This research received funding from Department of Biotechnology and Genetic Engineering,Faculty of Applied Science and Technology,Islamic University,Kushtia,7003,Bangladesh.The authors would like to thank Dr.Jahangir Alam and Professor Dr.Md.Anwarul Haque who helped with sample collection,analysis and critical revision of the manuscript.
文摘Metabolic changes together with cardiovascular and hepatic factors are related to the development of diseases like myocardial lipidosis,heart disease,and profound toxicity.The aim of this animal study is to determine the effects of high erucic acid containing rapeseed oil(Brassica napus L.)varieties on liver,kidney and heart muscles in Wistar rats.Male Wistar rats were divided into three groups where each group containing four rats.Group A was considered as control diet group,while Group B rapeseed wild oil group and Group C rapeseed hybrid oil group were considered as experimental diet groups.The levels of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),creatine kinase-MB(CK-MB)and creatinine of two experimental groups were significantly elevated while compared to the control groups(p<0.05–0.001).Nevertheless,an increment in weight retardation(p<0.05)was also observed in rapeseed hybrid oil treated groups.No significant weight retardation found in other two groups(p>0.05).Noticeable tissue injury observed in this study is a sign of the relative toxicity of erucic acid containing rapeseed oil to mammalian species.The use of Brassica napus as a supplementary feed ingredient should be,therefore,thoroughly considered.
基金the Fundamental Research Grant Scheme(FRGS)under a grant number of FRGS/1/2018/STG06/UNIMAP/02/3 from the Ministry of Education Malaysia。
文摘This study investigates the suction and magnetic field effects on the two-dimensional nanofluid flow through a stretching/shrinking sheet at the stagnation point in the porous medium with thermal radiation.The governing partial differential equations(PDEs)are converted into ordinary differential equations(ODEs)using the similarity transformation.The resulting ODEs are then solved numerically by using the bvp4c solver in MATLAB software.It was found that dual solutions exist for the shrinking parameter values up to a certain range.The numerical results obtained are compared,and the comparison showed a good agreement with the existing results in the literature.The governing parameters’effect on the velocity,temperature and nanoparticle fraction fields as well as the skin friction coefficient,the local Nusselt number and the Sherwood number are represented graphically and analyzed.The variation of the velocity,temperature and concentration increase with the increase in the suction and magnetic field parameters.It seems that the thermal radiation effect has increased the local Sherwood number while the local Nusselt number is reduced with it.
文摘Civil construction has high demand for new procedures and technologies capable of generating better results in numerous situations throughout the process.Nowadays,cavities in urban areas are commonly used due to the implantation of commercial and residential developments with more than two floors,seeking a better use of the nobler areas of the big cities.In geotechnical terms,the filling of these cavities,with the local soil,especially in the Federal District,lateritic soils,can represent additional efforts for the structures and foundations and lead to a compromise of the technical and functional performance of the same,compromising the efficiency and the economy of the enterprise.In this sense,this research evaluates the mechanical behavior of the mixtures,using GEO5 Software,Containment Design and Verification Modules,presenting an alternative to fill cavities in urban regions,with a mixture of material with lower specific density in relation to the soil Natural.Proctor Normal compression tests,simple direct shear saturation and sample expansibility were performed.The results showed a reduction of 38%in the strength of the reinforced concrete curtain,as well as a 25%reduction in maximum bending moments and 31%in maximum shear forces,and a reduction of about 32%in the displacements of the structure to the soil with addition of expanded vermiculite for tests obtained in the saturated condition.For the compositions of cement soil,expanded vermiculite soil and soil cement and expanded vermiculite,the deformations were of the order of 0.3%,0.4%and 0.2%,respectively.
文摘Plantain (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Musa spp</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">.) constitute</span><span style="font-family:Verdana;">s</span><span style="font-family:""><span style="font-family:Verdana;"> an essential food crop in both tropical and subtropical areas. The staple’s nutritional value and provitamin A carotenoid potential has attracted more interest and usage. </span><a name="_Hlk56239143"></a><span style="font-family:Verdana;">Plantain (</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></span></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Musa spp</span></i></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></i></span></i></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">.) optimization into food recipes has been identified to increase patronage and minimises food wastage, due to the fruit’s (pulp) high perishability nature. In this study, local over ripe plantain (</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i></span></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">Musa spp</span></i></span><span style="font-family:Verdana;"><i><span style="font-family:Verdana;"></i></span></i></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">.) was sampled and used in a beverage production. The beverage was processed from pureed ripe plantain, by three days fermentation of the pureed plantain mixture, boiling, and spicing, preservation with syrup, storage, and usage. The product’s processing was followed with a sensory evaluation of the new beverage on taste, appearance, color, flavour, and overall acceptability. Majority of the respondents indicated the new product was good and was well accepted. T</span></span><span style="font-family:Verdana;">he research sought to create food diversity, encourage more usage of the crop and to highlight the nutritional values of plantain (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Musa spp</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">.) which is particularly high in provitamin A carotenoid to address Vitamin A deficiency in low resource setting communities.
文摘Extended-spectrum <i>β</i>-lactamase (ESBL) appeared some years after the introduction in hospital environment of unhydrolysable or extended-spectrum cephalosporins. Several studies have been reported on the blaTEM, blaCTX-M and blaSHV genes in ESBL producing Enterobacteria, however, very few studies reported in the literature were related to blaCTX-M subgroup blaTOHO. TOHO enzymes were responsible for healthcare-associated infections in hospitals and in the community. In Burkina Faso, data related to these types of enzymes were scarce. The purpose of this study was to detect TOHO enzymes in <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> in order to know the prevalence of infections related to bacterial resistance due to TOHO enzymes at Saint Camille Hospital of Ouagadougou (Burkina Faso). The study was conducted firstly by microbiological identification of ESBLs-producing by <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> using API 20 E gallery;secondly the antibiogram was performed by the diffusion method and finally the molecular characterization was made by conventional PCR to search for the blaTOHO gene. The visualization of the specific bands was made using the ultraviolet lamp (Gene Flash) for the photography of the gels. Data were entered and analyzed using Excel 2013 and EPI Info version 6.0 software. A p-value < 0.05 was considered as significant. We obtained at all 39 strains constituted by 21 (53.8%) <i>Escherichia coli</i> and 18 (46.2%) <i>Klebsiella pneumoniae</i>. Molecular characterization showed the presence of the blaTOHO gene in 25 bacterial strains (64.1%). It was therefore established in this study the existence of blaTOHO gene at Saint Camille Hospital in Ouagadougou in Burkina Faso. Our study made it possible to know the distribution of the blaTOHO gene in <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i>.
基金supported by the National Key R&D Program(2017YFD0200900)the Natural Science Foundation of China(31570252 and 31601629)the Chinese Academy of Sciences(CAS)and the World Academy of Sciences(TWAS)Presidents Fellowship for supporting Md Azizul Islam as a doctoral student(2015CTF068)
文摘Polyamines(PAs) play diverse roles in plant growth and development,as well as responses to environmental stimuli.In this study,the effects of PAs on rice salt tolerance were investigated.Salt stress resulted in the alteration of endogenous PAs levels in rice roots and leaves,where spermidine(Spd) and spermine(Spm) contents were increased,and putrescine(Put) content was decreased.RT-qPCR analysis revealed that PAs biosynthesis-related genes ADC1,ODC,and Arginase were significantly downregulated by salt treatment;however,SAMDC transcription was significantly upregulated.Exogenous Spm enhanced rice salt tolerance remarkably;however,exogenous Put and Spd undermined rice salt tolerance.Transgenic rice plants overexpressing SAMDC display a higher ratio of Spm/(Put+Spd) and enhanced salt tolerance.Salt stress also increased polyamine oxidase activities in rice,resulting in elevated reactive oxygen species(ROS) production.Our findings revealed that accumulation of Put and Spd substantially reduced salt tolerance in rice,likely by facilitating ROS production;whereas,conversion of Put and Spd to Spm contributes to rice salt tolerance.
基金funded by Fundamental Research Grant Scheme(FRGS Vot 1560)Universiti Tun Hussein Onn Malaysia Contract grant(H277&U688)。
文摘Objective:To determine the lead bioactive compound in kernel extract of Mangifera pajang and its anti-cancer activity against human breast cancer cell lines with positive estrogen receptor(MCF-7).Methods:The methanolic extract of dried powder kernel of Mangifera pajang was exposed to column chromatography for isolation.The structural elucidation of the isolated compound was characterized using infrared,nuclear magnetic resonance,mass spectrometry.Furthermore,cytotoxicity,morphological changes,flow cytometry and cell cycle arrest analyses were performed to examine the mechanism of anti-proliferation and apoptosis induced by methyl gallate against MCF-7.Results:One compound was isolated from the methanolic extract of Mangifera pajang kernel and identified as methyl gallate.The flow cytometric results demonstrated induction of apoptosis in MCF-7 cells by three concentrations of methyl gallate.The cell cycle arrest showed a significant(P<0.05)decrease in cell progression at G2/M phase of MCF-7 after treatment with 100μM of methyl gallate.The cell percentage of early and late apoptosis was significant at 10 and 100μM of methyl gallate.Also,methyl gallate treatment induced up-regulation of reactive oxygen species levels in MCF-7 cells with a reduction in superoxide dismutase levels.Conclusions:These findings indicate that isolated methyl gallate from Mangifera pajang kernel extracts induces growth inhibition and apoptosis in MCF-7 cells via up-regulating oxidative stress pathway.
文摘<span style="font-family:Verdana;">This study investigates the economic benefits of energy efficiency to petroleum refineries regarding Tema Oil Refinery (TOR), Ghana. The study explores lessons relating to the cost of production, energy recovery levels and economic fortunes of the refinery activities and designs a conceptual framework for improving the energy efficiency of Tema Oil Refinery (TOR). The study adopted a descriptive design using a quantitative approach to provide a statistical background to investigate the economic benefits of energy efficiency. A sample of 84 was adopted for study from a staff population of 520 working at Tema Oil refinery. In addition to primary data, secondary data on energy supply and consumption values from 2008 to 2019 was gathered. For the primary survey, 84 respondents were sampled from TOR and a structured questionnaire was used to retrieve information. A correlation analysis at P < 0.05 was conducted to test the relationship and significance of energy efficiency and economic benefits to the refinery. The study concludes that there is a linear trend between energy production (supply) and energy consumption. The energy generated in the entire economy of Ghana far exceeds the amount of energy consumed thus raising issues of waste or excesses that calls for better policies and management plan to improve EE. The study also identified that issues of lost energy are critical to the operations of the petroleum industry as the situation is compounded by the inability of the refineries to explore better ways to reduce and manage the waste. The study concludes that a significant and positive correlation between energy efficiency and the economic fortunes of Tema Oil Refinery is necessary for its economic fortunes. The supply of energy should have equivalence to the public consumption of energy.
文摘The inability to achieve the target of universal access to electricity is influenced by several factors including funding limitations, the use of obsolete equipment, power theft, and system losses confronting the electricity distribution services of the Electricity Company of Ghana Limited (ECG). The study assessed the components of system losses within the ECG by determining and computing the percentage of system losses within ECG, examining the causes of both commercial and technical losses in ECG, and determining ways to improve energy efficiency by reducing system losses in the most cost-efficient manner. The study adopted deductive reasoning and a quantitative approach to guide data collection and analysis of the research output. A sample of 345 technical and non-technical staff of ECG in the Greater Accra Metropolis was selected from a population of 2500. Purposive, simple random, and cluster sampling techniques were used in identifying and accessing respondents for the study. Descriptive statistics were applied to measure central tendency and degrees of dispersion and the Relative Importance Index (RII) to predict criterion and predictor variables. The impact of low voltage network losses can adversely contribute to technical losses (20%) and reduce energy efficiency in power or electricity distribution companies. Non-technical losses are mainly caused by illegal connections, meter problems, and billing problems. Each of the non-technical losses contributes a maximum of 10% to system losses. Contributors to system losses at ECG are ranked first for power theft and least for lack of incentives. System losses at ECG include metering inaccuracies, bad workmanship, unmetered supply, and lengthy distribution lines, each recording a mean value of above 3.5. Measures to improve monitoring of the networks and systems at ECG and discourage power theft should include an extensive quantification, patrolling, and inspection of the entire network to assess the extent of the network and conditions relevant for the placement of systematically planned maintenance programmes.
文摘In this paper, SLAM systems are introduced using monocular and stereo visual sensors. The SLAM solutions are implemented in both indoor and outdoor. The SLAM samples have been taken in different modes, such as a straight line that enables us to measure the drift, in addition to the loop sample that is used to test the loop closure and its corresponding trajectory deformation. In order to verify the trajectory scale, a baseline method has been used. In addition, a ground truth has been captured for both indoor and outdoor samples to measure the biases and drifts caused by the SLAM solution. Both monocular and stereo SLAM data have been captured with the same visual sensors which in the stereo situation had a baseline of 20.00 cm. It has been shown that, the stereo SLAM localization results are 75% higher precision than the monocular SLAM solution. In addition, the indoor results of the monocular SLAM are more precise than the outdoor. However, the outdoor results of the stereo SLAM are more precise than the indoor results by 30%, which is a result of the small stereo baseline cameras. In the vertical SLAM localization component, the stereo SLAM generally shows 60% higher precision than the monocular SLAM results.
文摘Investments in the exploitation of the continent’s raw material reserves have resulted in little (positive) impact on the energy security situation within Africa. This paper attempts to explore factors influencing the level of energy security of Small Medium Enterprises (SMEs) in the Greater Accra Region of Ghana, and from the dimension of availability, affordability, economic efficiency and environmental stewardship or sustainability of energy. The cross-sectional survey design was employed as the design for the collection and analysis of data. The study applied a quantitative research method in examining the indicators of energy security for SMEs in Accra Metropolis in the Greater Accra Region of Ghana. The population covered about 500 SMEs who have about 100 employees and total revenue of $1 million or the equivalence in Ghana Cedis. A sample of 246 was selected through a cluster and simple random sampling. The analysis adopted statistical techniques to conduct descriptive, exploratory and inferential analysis of the data collected. Factors that influence the level of energy security of SMEs are broadly categorized into the environment and economic change, political factors, physical disruptions and market conditions. Ge- nerally, the level of energy security under the availability dimension is medium among the SMEs. Issues of affordability, economic efficiency and environmental stewardship provide high medium interventions on energy security for SMEs. It is recommended that managers of Ghana’s energy sector should ensure prudent management of the country’s energy resources since the disruption of supply lines or sources form the key conditions that influence the energy security level of SMEs. SMEs should adopt energy efficiency measures to ensure that energy is conserved for future use.
文摘Absorption chillers are cooling units usually powered by renewable energy or waste heat.Their performance generally depends on the temperatures of the heat source,the ambient and the medium to be cooled.The present work deals with the thermodynamic study of a 10 kW NH3/H2O absorption machine in order to find the COP(coefficient of performance).The first and second laws of thermodynamics were used for the operating conditions.The thermodynamic properties of the NH3/H2O mixture were determined using the EES(Engineering Equation Solver)software.The results of the simulation of the machine were validated with the results of the literature.After validation,the program was used to simulate a 10-kW NH3/H2O absorption machine for milk conservation/cold storage in northern Senegal.The simulation results of the 10-kW ammonia-water absorption machine give an acceptable COP of 0.521 with a milk storage temperature of 4°C.
基金This research was supported by Ministry of Higher Education Malaysia(MOHE)through Fundamental Research Grant Scheme,FRGS/1/2017/TK04/UTHM/02/13Postgraduate Research Scheme,GPPS VOT H026.
文摘Sugar is important in daily food intake since it is used as food preservative and sweetener.Therefore,is important to analyze the influence of sugar on the spectroscopic properties of the sample.Terahertz spectroscopy is proven to be useful and an efficient method for sugar detection as well as for future food quality industry.However,the lack of detection sensitivity in Terahertz Spectroscopy has prevented it from being used in a widespread spectroscopic analysis technology.In this paper,Frequency Selective Surface(FSS)using the Terahertz Spectroscopy Time Domain Spectrum(THz-TDS)which operates at terahertz frequency range has been demonstrated for application of sugar detection.The FSS is designed with a circle slot structure and has been optimized in line with the molecular resonance of glucose and fructose at different level concentration at 1.98 THz and 1.80 THz,respectively.Transmission magnitude of glucose and sucrose is inversely proportional with the level of sugar concentrations.The realization of the FSS structure is using electron beam lithography and wet etching technique.Results show that the FSS performance for glucose and sucrose reveal fair shifts in measured transmission magnitude from its original in CST by approximately 30%.The use of fabricated FSS with circle structure indicates that the concentration can be improved averagely at 25%for glucose and 13%for sucrose.Thus,it shows that the FSS circle structure combined with THz-TDS has the potential to become an alternative method for food sensing technology in the future.
文摘Catalyst-free InGaAs nanowires grown by selective area epitaxy are promising building blocks for future optoelectronic devices in the infrared spectral region.Despite progress,the role of pattern geometry and growth parameters on the composition,microstructure,and optical properties of InGaAs nanowires is still unresolved.Here,we present an optimised growth parameter window to achieve highly uniform In1-xGaxAs nanowire arrays on GaAs(111)B substrate over an extensive range of Ga concentrations,from 0.1 to 0.91,by selective-area metal-organic vapor-phase epitaxy.We observe that the Ga content always increases with decreasing In/(Ga+In)precursor ratio and group V flow rate and increasing growth temperature.The increase in Ga content is supported by a blue shift in the photoluminescence peak emission.The geometry of the nanowire arrays also plays an important role in the resulting composition.Notably,increasing the nanowire pitch size from 0.6 to 2μm in a patterned array shifts the photoluminescence peak emission by up to 120 meV.Irrespective of these growth and geometry parameters,the Ga content determines the crystal structure,resulting in a predominantly wurtzite structure for xGa≤0.3 and a predominantly zinc blende phase for xGa≥0.65.These insights on the factors controlling the composition of InGaAs nanowires grown by a scalable catalyst-free approach provide directions for engineering nanowires as functional components of future optoelectronic devices.
文摘<span style="font-family:Verdana;">Technologies for gas conversion have attracted more serious attention, but energy efficiency, supply deficiencies, as well as other risks undermining the gas supply industry</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> make it difficult to achieve sustainability in gas supply in Ghana. </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">This study </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">explored strategies for improving supplies for sustainable power generation in Ghana. Specifically, the study investigates the risks associated with the gas supply industry and also investigates strategies for improving gas supplies in Ghana. A descriptive study that applied both qualitative and quantitative tools was applied to data collection and analysis to allow for an in-depth analysis of the findings of the research. The population was concentrated on the regulators (Energy Commission) and consumers (VRA and Sunon Asogli, and GNGC/Eni in the supply domains. In all, 357 population w</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">as</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> targeted with a sample of 151. Probability (simple random sampling) and non-probability (purposive) sampling approaches were applied to source participants for the study. Statistical inferential tools that guided the analysis included means, standard deviation, Relative Importance Index (RII). The study identified issues of power sector debt due to the weak financial background of the gas supply sector, poor infrastructure, issues of corruption created by delays, poor transparency and weak regulatory framework as key risk factors in the gas supply industry in Ghana. The study also concluded that strategies to support the drive to achieve sustainability in the gas supply industry should involve a planned action towards providing regular and improved infrastructure in transportation and gas supply pipelines to enhance the visibility of the local gas industry and to also meet both domestic and industrial demand for gas products. Again, there should be the establishment and maintenance of functional gas-related policies and regulators, as well as an emergency supply plan to address any shocks that may tend to impact the gas supply industry in Ghana.</span></span></span>
基金supported by Universiti Kebangsaan Malaysia through a research grant(GUP-2018-032).
文摘Background:Indoor air quality(IAQ)is a concern in kindergartens as children spend much of their time there.Yet,there is a shortage of biological indicators needed for assessing IAQ.Thus,this study evaluated IAQ using transplanted lichen Usnea misaminensis as a biological indicator.Methods:Lichen samples,collected from Bukit Larut,Perak,Malaysia,were exposed to indoor and outdoor environments in an urban area(Ummi Aiman Kindergarten)and a rural area(Ummi Qaseh Pelangi Kindergarten)for 2 months during August 15 to October 14,2019.The concentrations of 12 selected elements and the vitality of the lichens were then evaluated.Results:Increased concentrations of eleven of the twelve elements deposited in the lichen samples in both urban and rural areas were observed.For both areas,the element concentrations in the samples from the indoor environment was lower than those from the outdoor environment,and those in the rural area were lower than those from in the urban area,suggesting the impacts of traffic emissions.The vitality of the lichens showed no significant change in indoor environment,compared to that in outdoor environment,indicating that even exposed to indoor environment,the lichens remained effective biological indicators as same as they were in the outdoor environment.Conclusions:Lichens are effective biological indicators for both outdoor and indoor environments.Furthermore,outdoor emissions could influence IAQ,which could be problematic in densely populated areas such as kindergartens.Mitigation measures should be taken.
文摘The Editors-in-Chief have retracted this article because it contains material that substantially overlaps with the fol-lowing article(Paoli et al.2019).
文摘Oil and gas operators worldwide are expecting service companies to deliver integrated techniques to minimize,if not prevent,drilling problems.Drilling fluids perform vital functions to ensure the success of drilling operations.The technical challenges often associated with water-based drilling fluids are loss of critical properties,such as fluid loss control and rheology,under demanding conditions,such as in drilling deeper,high-temperature and high-pressure wells.Fluid loss during drilling operations has a very significant effect in both reservoir formation damage and monetary terms.The use of durian rind(DR)as a new additive in controlling lost circulation would provide another opportunity to reduce waste and avoid pollution.Therefore,DR was used to improve the rheological properties of water-based mud,and it was prepared for use as a fluid loss additive.For a better understanding of the influence of pectin on drilling mud properties,the rheological evaluation of untreated DR was compared to that of mud samples containing treated DR.The pectin in DR was extracted using four different solvents,namely,ethanol,methanol,sodium hydroxide and hydrogen peroxide,and the most effective solvent to remove the pectin was then determined.The Fourier transform infrared spectroscopy(FTIR)results showed that NaOH was the best solvent for removing pectin from DR.Thermogravimetric analysis(TGA)was used to determine the thermal stability of DR before and after treatments.The TGA results demonstrated that the treated DR had improved thermal stability compared to untreated DR.The sizes of DR used were coarse,medium,and fine.The untreated DR presented better rheological properties than the treated DR.The experimental investigation showed that a concentration of 20 lb/bbl of intermediate-sized DR was the best concentration among the tested samples.
