Tropical forests provide several ecosystem services and functions and support approximately two-thirds of the world’s biodiversity but are seriously threatened by deforestation.Approaches to counteract this menace ha...Tropical forests provide several ecosystem services and functions and support approximately two-thirds of the world’s biodiversity but are seriously threatened by deforestation.Approaches to counteract this menace have revolved around aff orestation with several or a single tree species.We thus investigated how plantation forests with either a single or several tree species infl uenced arthropod taxonomic and community composition using pitfall traps to sample selected groups of epigeal arthropods(Araneae,Coleoptera,Orthoptera and Hymenoptera)and with environmental variables assessed simultaneously.Our results revealed 54 taxonomic groups with signifi cantly higher taxonomic richness,activity density,and diversity in the mixed stands than in the monoculture stands.The significant differences in community composition were mainly driven by families including Lycosidae,Formicidae,Staphylinidae,Scotylidae,Hydrophilidae,Gryllidae and Scarabaeidae and were explained by distinct habitat characteristics(canopy openness,litter depth,deadwood volume,and tree height).While the diverse tree communities and heterogeneous vegetation structure off ered food and habitat resources for diverse arthropod groups,the allelopathic nature coupled with homogenous stand characteristics of the Tectona grandis stands in the monoculture suppressed the growth of understorey vegetation that could otherwise serve as food and habitat resources for arthropods,which might have led to limited activities and diversity of arthropods in the monoculture plantation stands.The fi ndings thus highlight the need to promote mixed tree plantations in degraded tropical areas,especially when restoring biodiversity is the prime management focus.展开更多
Honey is being used as a pure natural and as an ingredient in many foods, pharmaceuticals and cosmetics than ever before, so honey testing has become essential to maintain its healthful characteristics and protect pub...Honey is being used as a pure natural and as an ingredient in many foods, pharmaceuticals and cosmetics than ever before, so honey testing has become essential to maintain its healthful characteristics and protect public health. Tetracyclines （TCs） are used for the treatment or prevention of American and European foul broad in bee colonies which are caused especially by two species of bacteria--Paenibacillus larvae and Melissococcus pluton. The present study aimed to determine the tetracycline residues in different types of local and imported honey. The reversed-phase high performance liquid chromatography （HPLC） with ultraviolet detection （UV） was used. Tetracycline and oxytetracycline were extracted from honey with 0.01 M sodium succinate buffer. Of the examined samples, 31.25% and 12.50% had these oxytetracycline and tetracycline residues, respectively. It was observed that all the samples studied have been reported residues of tetracycline and oxytetracycline more than international standards of maximum residue limit （MRLs）.展开更多
The aim of this paper is to study the existence of integrable solutions of a nonlinear functional integral equation in the space of Lebesgue integrable functions on unbounded interval, L1(R+). As an application we ded...The aim of this paper is to study the existence of integrable solutions of a nonlinear functional integral equation in the space of Lebesgue integrable functions on unbounded interval, L1(R+). As an application we deduce the existence of solution of an initial value problem of fractional order that be studied only on a bounded interval. The main tools used are Schauder fixed point theorem, measure of weak noncompactness, superposition operator and fractional calculus.展开更多
The <strong><em>purpose</em></strong> of this research was to ascertain causes of Restocking Delays in a Distributor Company of Airtel Airtime (<em>AA</em>) that give justification ...The <strong><em>purpose</em></strong> of this research was to ascertain causes of Restocking Delays in a Distributor Company of Airtel Airtime (<em>AA</em>) that give justification for benefits of using Real Time Inventory Tracking (<em>R.T.I.T</em>) in an attempt to mitigate Restocking Delays. From a study out at the Private Marketing and Trading Services (<em>PMTS</em>) an Authorized Distributor of Airtel Products undertaken in 2017 evidenced by Airtime scratch card and Electronic, <strong><em>E-Recharge</em></strong> Airtime among other forms to encourage <em>R.T.I.T</em> among other products in Telecom Companies and other Business Enterprises. The research comprises of the following areas among which included a detailed focus on a <strong><em>Qualitative</em></strong> and <strong><em>Quantitative approach</em></strong> in obtaining different <strong><em>categories</em></strong> of Restocking Delays in form of <strong><em>Themes</em></strong> and <strong><em>Sub Themes</em></strong> encountered in the Distribution Supply Chain (<em>SC</em>) of <em>AA</em> that is contained in this paper. This research continues to capture an in-depth explanation of the <strong><em>Managerial</em></strong> and <strong><em>Operational</em></strong> causes of restocking delays in respect to <em>AA</em>. Similarly, fast consumer products and services other than <em>AA</em> require a solution to <strong><em>Restocking Delays</em></strong> through implementation of Real Time Inventory Tracking Model (<em>R.T.I.T.M</em>) of <em>AA</em> among Distributor Companies (<em>DCs</em>). This paper also elaborated on Literature, Methodology and Findings obtained from the study. The <strong><em>results</em></strong> were obtained from <strong><em>regression analysis</em></strong> by using the Statistical Package for Social Sciences (<em>SPSS</em>) that showed a higher significance of <strong><em>Stock Turnover Period</em></strong> and<strong><em> Airtime Denomination</em></strong> as a contributor to Restocking Delays whereas <strong><em>Messages from Airtel</em></strong> Head office to the Distributor had a non-significant contribution to restocking Delays as in Figure 9. The research recommends a Model for <em>R.T.I.T</em> in Telecom Distribution <em>SC</em> of <em>AA </em>and Omnichannel Inventory Management (<em>OIM</em>) as a significant contributor to timely reliable inventory restocking and promotes higher sales among <em>DCs</em> and retailers through minimized Restocking Delays. It shows that the forces of Demand and Supply change over time with different tastes and preferences of customers. The imbalance in <em>AA</em> stock levels changes at given times due to unforeseen forces of consumer demand experienced by <em>DCs</em>, explained by the “<strong><em>Bullwhip Effect</em></strong>” due to information distortion in the Supply Chain (<em>SC</em>).展开更多
The present study is devoted to understanding the evolution of the Upper Jurassic Sab'atayn Formation in the Marib-Shabwa Basin,Yemen,through a sequence stratigraphic analysis based on integrating datasets of sedi...The present study is devoted to understanding the evolution of the Upper Jurassic Sab'atayn Formation in the Marib-Shabwa Basin,Yemen,through a sequence stratigraphic analysis based on integrating datasets of sedimentology,seismic sections,and well logs.The Sab'atayn Formation(Tithonian age)is represented by a series of clastic and evaporites that were deposited under fluvio-deltaic to prodeltaic settings.It is divided into four members including Yah(at the base),upwards to Seen,Alif,and Safir at the top.Two third-order depositional sequences were determined for the Tithonian succession which were separated by three sequence boundaries.These sequences were classified into their systems tracts signifying several sedimentation patterns of progradational,aggradational,and retrogradational parasequence sets.The first depositional sequence corresponds to the early-middle Tithonian Yah and Seen units that can be classified into lowstand,transgressive,and highstand systems tracts.The second sequence comprises the late Tithonian Alif unit that can be subdivided into transgressive and highstand systems tracts.The sandy deposits of the Alif Member(highstand deposits)represent the most productive hydrocarbon reservoir in the basin.The Upper Jurassic sediments in the study area were resulted from a combination of eustatic and tectonic effects.展开更多
This study aimed to determine the amount of total polluting matter emitted into the atmosphere from heating and industrial-based emissions and the total pollution bulk of Tokat city center. The annual cycles of some h...This study aimed to determine the amount of total polluting matter emitted into the atmosphere from heating and industrial-based emissions and the total pollution bulk of Tokat city center. The annual cycles of some heavy metal in particulate matters have been investigated at this area in order to elucidate temporal variations as well as major sources processes responsible for their formation. Air particulate samples were collected from three different locations situated around Tokat. These samples were determined for heavy metals by using Flame or graphite-furnace Atomic absorption spectroscopy. Particulate matter concentrations up to 52.43μg/m^3 were observed in sampling area. The initial results of the chemical analysis showed that concentration values of heavy metals in air particles observed were higher than the World Health Organization （WHO） guideline limit values.展开更多
The aim of this paper is to approximate the solution of system of fractional delay differential equations. Our technique relies on the use of suitable spline functions of polynomial form. We introduce the description ...The aim of this paper is to approximate the solution of system of fractional delay differential equations. Our technique relies on the use of suitable spline functions of polynomial form. We introduce the description of the proposed approximation method. The error analysis and stability of the method are theoretically investigated. Numerical example is given to illustrate the applicability, accuracy and stability of the proposed method.展开更多
The aim of this study was to fabricate multi-layered recycled α-Fe<sub>2</sub>O<sub>3</sub>/OPEFB fiber/PCL composites for microwave absorbing applications in the 1 - 4 GHz frequency range. Th...The aim of this study was to fabricate multi-layered recycled α-Fe<sub>2</sub>O<sub>3</sub>/OPEFB fiber/PCL composites for microwave absorbing applications in the 1 - 4 GHz frequency range. The multi-layered composites were 6 mm thick and each consisted of a 2 mm thick layer of recycled α-Fe<sub>2</sub>O<sub>3</sub>/PCL composites at various loadings (5 wt% - 25 wt%) of 16.2 nm recycled α-Fe<sub>2</sub>O<sub>3</sub> nanofiller, placed between two layers of 2 mm thick OPEFB fiber/PCL composites blended at a fixed ratio of 7:3. The real (ε') and imaginary (ε") components of the relative complex permittivity were measured using the open-ended coaxial probe technique and the values obtained were applied as inputs for the Finite Element Method to calculate the reflection coefficient magnitudes from which the reflection loss (RL) properties were determined. Both ε' and ε" increased linearly with recycled α-Fe<sub>2</sub>O<sub>3</sub> nanofiller content and the values of ε' varied between 3.0 and 3.9 while the ε" values ranged between 0.26 and 0.64 within 1 - 4 GHz. The RL (dB) showed the most prominent values within the 1.38 - 1.46 GHz band with a minimum of -38 dB attained by the 25 wt% composite. Another batch of minimum values occurred in the 2.39 - 3.49 GHz range with the lowest of -25 dB at 2.8 GHz. The recycled α-Fe<sub>2</sub>O<sub>3</sub>/OPEFB fiber/PCL multi-layered composites are promising materials that can be engineered for solving noise problems in the 1 - 4 GHz range.展开更多
We determined the sequence of mitochondrial Cytochrome oxidase subunit I （CO1） in two Drosophila melanogaster strains originating at ＂Evolution Canyon＂, Israel. CO1 nucleotide sequences from two iso-female strains...We determined the sequence of mitochondrial Cytochrome oxidase subunit I （CO1） in two Drosophila melanogaster strains originating at ＂Evolution Canyon＂, Israel. CO1 nucleotide sequences from two iso-female strains, 2-1 and 6-1, were 1,534 and 1,543 base-pairs, respectively. In each strain, ATAA was used in initiation of translation. Exchange rates for nucleotide and amino acid sequences were larger in the 6-1 strain than in the 2-1 strain when Oregon-R was used as the standard. Non-synonymous exchange rate was larger than synonymous exchange rate among the three strains.展开更多
<span style="font-family:Verdana;">Plank quantum and classical string energy relations seem to be uncorrelated. This work correlated them. The relativistic energy-momentum relation has been used togeth...<span style="font-family:Verdana;">Plank quantum and classical string energy relations seem to be uncorrelated. This work correlated them. The relativistic energy-momentum relation has been used together with plank and de Brogglie hypothesis to prove that the wave group velocity is equal to the particle velocity in both ordinary and curved space. The plank energy relation is shown also to be related to the classical energy relation of an oscillating string. Starting from plank energy relation for n photons and performing integration, the expression of classical string energy was obtained. This means that one can treat electromagnetic waves as a collection of continuous photons having frequencies ranging from zero to w. Conversely, starting from classical string energy relation by differentiating it with respect to angular frequency, the plank quantum energy for n photons has been found. This means that the quanta results from separation of electromagnetic waves to single isolated waves. Each wave consists of n photons or quanta.</span>展开更多
The nature and origin of the photon and elementary rest masses are some of the challeng-ing problems that physics face. The approaches used to solve these problems are complex and time-consuming. Specifically, the pho...The nature and origin of the photon and elementary rest masses are some of the challeng-ing problems that physics face. The approaches used to solve these problems are complex and time-consuming. Specifically, the photon rest mass pays attention to theoretical physi-cists. Many experimental works show that the photon rest mass is non zero. This problem can be solved using generalized potential dependent special relativity, which has been de-rived using simple arguments, and Maxwell’s equations, besides the conventional Einstein energy-momentum relation. The results obtained show that the rest mass of photons and elementary particles are strongly dependent on the vacuum energy and a universal con-stant. This result conforms with the models that predict time decaying vacuum energy as-sociated with production of smaller rest mass particles followed by larger masses. The two potential dependent mass expressions conform with the cosmological models that suggest the photon is generated first by assuming the universe consisting of total constant vacuum with decaying cosmological part and mass generating part. Using Maxwell’s equations, beside plank and De Broglie hypothesis together with special relativity energy-momentum relation the photon rest mass is estimated. It was shown that the photon rest mass is ex-tremely small compared to the electron mass.展开更多
Organic microporous materials based on spiroketal and spirothioketal polymers were synthesized through 1,3- dioxol-forming polymerization reaction between pentaerythritol or pentaerythritol tetrathiol and different ty...Organic microporous materials based on spiroketal and spirothioketal polymers were synthesized through 1,3- dioxol-forming polymerization reaction between pentaerythritol or pentaerythritol tetrathiol and different types of cyclohexa- 1,4-dione derivatives. The structure of the prepared polymers was confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers show a large amount of nitrogen adsorbed at low relative pressure indicating microporosity. These polymers have Brunauer Emmitt and Teller （BET） surface areas in the range from 492 （m^2g^-1） to 685 （m^2 g^-1）. The prepared polymers were found to be useful for pervaporation separation of methanol-toluene mixture with a separation factor up to 12.5 and fluxes, varying between 6.7×10-3 kg/（m^2 h） and 13.4 × 10^-3 kg/（m^2 h）.展开更多
Genetic diversity in natural populations has been explored through evolutionary analysis,and patterns of microscale biodiversity have been studied in populations at“Evolution Canyon”,Israel.A total of 2,000 eggs fro...Genetic diversity in natural populations has been explored through evolutionary analysis,and patterns of microscale biodiversity have been studied in populations at“Evolution Canyon”,Israel.A total of 2,000 eggs from each of iso-female Drosophila melanogaster line 2-1 from the north-facing slope(NFS)and line 6-1 from the south-facing slope(SFS)were placed in 20 vials and evaluated.Egg-to-adult viability was 0.89 and 0.75 in lines 2-1 and 6-1,respectively,and the difference was statistically significant by t-test.Genetic diversity was higher on the harsher SFS than on the milder NFS.Inter-slope genetic differences corroborated the effect of stochastic climate selection pressures to viability polygenes in populations at“Evolution Canyon”,Israel.展开更多
The study assesses the quality of hand dug wells in relation to distance from soakaway septic tanks in three selected peri-urban communities in the Ga West Municipality near Accra, Ghana. Water quality analyses of bio...The study assesses the quality of hand dug wells in relation to distance from soakaway septic tanks in three selected peri-urban communities in the Ga West Municipality near Accra, Ghana. Water quality analyses of bio-physico-chemical variables (pH, Temperature, EC, turbidity, DO, BOD, TSS, TDS, sodium, potassium, nitrate, nitrite, ammonia, sulphate, chloride, salinity, total alkalinity, total coliform, fecal coliforms and isolation of <i>E. coli</i>) were determined. Concentrations of the major nutrient anion sulphate, nitrate, phosphate, and chlorides in water samples at distances between 0</span><span style="font-family:""> </span><span style="font-family:"">-</span><span style="font-family:""> </span><span style="font-family:"">30 m radial distances from the septic tank were above the WHO permissible limit of drinking water compared to the control. All the water samples had high fecal and total coliform counts that exceeded the international standard of 0 per 100 mL of potable water with counts ranging from 0</span><span style="font-family:""> - </span><span style="font-family:"">143</span><span style="font-family:""> </span><span style="font-family:"">cfu/100</span><span style="font-family:""> </span><span style="font-family:"">ml and 53</span><span style="font-family:""> </span><span style="font-family:"">-</span><span style="font-family:""> </span><span style="font-family:"">463/100</span><span style="font-family:""> </span><span style="font-family:"">ml for FC and TC respectively. High fecal coliform and detection of <i>E. coli</i> in most samples is an indication of fecal pollution possibly from their close proximity to soak away septic sewage. The high nutrient levels detected in samples at distances between 0</span><span style="font-family:""> </span><span style="font-family:"">-</span><span style="font-family:""> </span><span style="font-family:"">30</span><span style="font-family:""> </span><span style="font-family:"">m as compared to the controls may also be attributed to its close proximity to septic tanks. This study, therefore, accentuates the need for the owners of the water points to site their water source at least 30m away </span><span style="font-family:"">from </span><span style="font-family:"">localized sources of pollution as well as treatment of groundwater before use.展开更多
The study was conducted to assess the effects of small-scale (artisanal) gold mining and its social and economic implications on the people in Amansie West District of Ghana. The artisanal gold mining communities were...The study was conducted to assess the effects of small-scale (artisanal) gold mining and its social and economic implications on the people in Amansie West District of Ghana. The artisanal gold mining communities were studied using secondary data from scholarly articles and journals, books, conference papers, research reports, policy documents, working papers, and briefs. Descriptive and systematic analyses were conducted. The result indicated that youth aged between 21 - 30 were most likely to engage in illegal mining operations in the selected study areas. The study revealed that farmland had been destroyed, making farming difficult for the inhabitants. It is evident from the review that dug-out pits from mining serve as breeding grounds for mosquitoes and death traps for humans. The study, therefore, accentuates the need for illegal small-scale gold mining to be formalised and strategic interventions and policies proposed for the protection of Ghana’s Natural resources. Furthermore, community members should be involved in policy-making and environmental protection issues to help control the menace of landscape destruction. Although the ban on illegal gold mining activity by the government has caused more people to lose their jobs leading to livelihood challenges in mining communities, it is a step in the right direction, as the ban seeks to halt and check the illegal small-scale mining sector. The study recommended alternative livelihood and income-generating projects such as beekeeping, mushroom culture, grasscutter rearing, and agroforestry technologies including the growth of economic fruit trees as alternative livelihood ventures.展开更多
Traditional methods for proportioning of high-performance concrete(HPC)have certain shortcomings,such as high costs,usage constraints,and nonlinear relationships.Implementing a strategy to optimize the mixtures of HPC...Traditional methods for proportioning of high-performance concrete(HPC)have certain shortcomings,such as high costs,usage constraints,and nonlinear relationships.Implementing a strategy to optimize the mixtures of HPC can minimize design expenses,time spent,and material wastage in the construction sector.Due to HPC’s exceptional qualities,such as high strength(HS),fluidity and resilience,it has been broadly used in construction projects.In this study,we employed Generalized Regression Neural Network(GRNN),Nonlinear AutoRegressive with exogenous inputs(NARX neural network),and Random Forest(RF)models to estimate the Compressive Strength(CS)of HPC in the first scenario.In contrast,the second scenario involved the development of an ensemble model using the Radial Basis Function Neural Network(RBFNN)to detect inferior performance of standalone model combinations.The output variable was the 28 Days CS in MPa,while the input variables included slump(S),water-binder ratio(W/B)%,water content(W)kg/m^(3),fine aggregate ratio(S/a)%,silica fume(SF)%,and superplasticizer(SP)kg/m^(3).An RF model was developed by using R Studio;GRNN and NARX-NN models were developed by using the MATLAB 2019a toolkit;and the pre-and post-processing of data was carried out by using E-Views 12.0.The results indicate that in the first scenario,the Combination M1 of the RF model outperformed other models,with greater prediction accuracy,yielding a PCC of 0.854 and MAPE of 4.349 during the calibration phase.In the second scenario,the ensemble of RF models surpassed all other models,achieving a PCC of 0.961 and MAPE of 0.952 during the calibration phase.Overall,the proposed models demonstrate significant value in predicting the CS of HPC.展开更多
The endoplasmic reticulum(ER)is a cellular organelle responsible for protein synthesis and folding.When its protein folding capacity is exceeded,unfolded or misfolded proteins accumulate,causing ER stress and triggeri...The endoplasmic reticulum(ER)is a cellular organelle responsible for protein synthesis and folding.When its protein folding capacity is exceeded,unfolded or misfolded proteins accumulate,causing ER stress and triggering the unfolded protein response(UPR)to restore ER proteostasis.Although UPR gene expression in plants follows a diel cycle,the mechanisms by which the circadian clock regulates these genes remain unclear.Here,we demonstrate that sensitivity to ER stress in root growth exhibits time-of-day phases and that the circadian clock regulates UPR target gene expression during ER stress.Notably,mutations in the core morning clock component CIRCADIAN CLOCK ASSOCIATED 1(CCA1)impair ER stress recovery.CCA1 forms a complex with the UPR modulator basic leucine zipper 28(bZIP28)and acts as an upstream regulator of ER stress recovery.Upon ER stress,CCA1 is stabilized and associates with bZIP28 at the ER stress response element within the BiP3 promoter,enhancing the ER stress response.Thus,CCA1 and bZIP28 coordinate a time-dependent adaptive response to ER stress to maintain ER proteostasis.Our re-sults suggest that the circadian clock primes the timing and levels of ER chaperone expression to enhance ER stress tolerance.展开更多
文摘Tropical forests provide several ecosystem services and functions and support approximately two-thirds of the world’s biodiversity but are seriously threatened by deforestation.Approaches to counteract this menace have revolved around aff orestation with several or a single tree species.We thus investigated how plantation forests with either a single or several tree species infl uenced arthropod taxonomic and community composition using pitfall traps to sample selected groups of epigeal arthropods(Araneae,Coleoptera,Orthoptera and Hymenoptera)and with environmental variables assessed simultaneously.Our results revealed 54 taxonomic groups with signifi cantly higher taxonomic richness,activity density,and diversity in the mixed stands than in the monoculture stands.The significant differences in community composition were mainly driven by families including Lycosidae,Formicidae,Staphylinidae,Scotylidae,Hydrophilidae,Gryllidae and Scarabaeidae and were explained by distinct habitat characteristics(canopy openness,litter depth,deadwood volume,and tree height).While the diverse tree communities and heterogeneous vegetation structure off ered food and habitat resources for diverse arthropod groups,the allelopathic nature coupled with homogenous stand characteristics of the Tectona grandis stands in the monoculture suppressed the growth of understorey vegetation that could otherwise serve as food and habitat resources for arthropods,which might have led to limited activities and diversity of arthropods in the monoculture plantation stands.The fi ndings thus highlight the need to promote mixed tree plantations in degraded tropical areas,especially when restoring biodiversity is the prime management focus.
文摘Honey is being used as a pure natural and as an ingredient in many foods, pharmaceuticals and cosmetics than ever before, so honey testing has become essential to maintain its healthful characteristics and protect public health. Tetracyclines （TCs） are used for the treatment or prevention of American and European foul broad in bee colonies which are caused especially by two species of bacteria--Paenibacillus larvae and Melissococcus pluton. The present study aimed to determine the tetracycline residues in different types of local and imported honey. The reversed-phase high performance liquid chromatography （HPLC） with ultraviolet detection （UV） was used. Tetracycline and oxytetracycline were extracted from honey with 0.01 M sodium succinate buffer. Of the examined samples, 31.25% and 12.50% had these oxytetracycline and tetracycline residues, respectively. It was observed that all the samples studied have been reported residues of tetracycline and oxytetracycline more than international standards of maximum residue limit （MRLs）.
文摘The aim of this paper is to study the existence of integrable solutions of a nonlinear functional integral equation in the space of Lebesgue integrable functions on unbounded interval, L1(R+). As an application we deduce the existence of solution of an initial value problem of fractional order that be studied only on a bounded interval. The main tools used are Schauder fixed point theorem, measure of weak noncompactness, superposition operator and fractional calculus.
文摘The <strong><em>purpose</em></strong> of this research was to ascertain causes of Restocking Delays in a Distributor Company of Airtel Airtime (<em>AA</em>) that give justification for benefits of using Real Time Inventory Tracking (<em>R.T.I.T</em>) in an attempt to mitigate Restocking Delays. From a study out at the Private Marketing and Trading Services (<em>PMTS</em>) an Authorized Distributor of Airtel Products undertaken in 2017 evidenced by Airtime scratch card and Electronic, <strong><em>E-Recharge</em></strong> Airtime among other forms to encourage <em>R.T.I.T</em> among other products in Telecom Companies and other Business Enterprises. The research comprises of the following areas among which included a detailed focus on a <strong><em>Qualitative</em></strong> and <strong><em>Quantitative approach</em></strong> in obtaining different <strong><em>categories</em></strong> of Restocking Delays in form of <strong><em>Themes</em></strong> and <strong><em>Sub Themes</em></strong> encountered in the Distribution Supply Chain (<em>SC</em>) of <em>AA</em> that is contained in this paper. This research continues to capture an in-depth explanation of the <strong><em>Managerial</em></strong> and <strong><em>Operational</em></strong> causes of restocking delays in respect to <em>AA</em>. Similarly, fast consumer products and services other than <em>AA</em> require a solution to <strong><em>Restocking Delays</em></strong> through implementation of Real Time Inventory Tracking Model (<em>R.T.I.T.M</em>) of <em>AA</em> among Distributor Companies (<em>DCs</em>). This paper also elaborated on Literature, Methodology and Findings obtained from the study. The <strong><em>results</em></strong> were obtained from <strong><em>regression analysis</em></strong> by using the Statistical Package for Social Sciences (<em>SPSS</em>) that showed a higher significance of <strong><em>Stock Turnover Period</em></strong> and<strong><em> Airtime Denomination</em></strong> as a contributor to Restocking Delays whereas <strong><em>Messages from Airtel</em></strong> Head office to the Distributor had a non-significant contribution to restocking Delays as in Figure 9. The research recommends a Model for <em>R.T.I.T</em> in Telecom Distribution <em>SC</em> of <em>AA </em>and Omnichannel Inventory Management (<em>OIM</em>) as a significant contributor to timely reliable inventory restocking and promotes higher sales among <em>DCs</em> and retailers through minimized Restocking Delays. It shows that the forces of Demand and Supply change over time with different tastes and preferences of customers. The imbalance in <em>AA</em> stock levels changes at given times due to unforeseen forces of consumer demand experienced by <em>DCs</em>, explained by the “<strong><em>Bullwhip Effect</em></strong>” due to information distortion in the Supply Chain (<em>SC</em>).
文摘The present study is devoted to understanding the evolution of the Upper Jurassic Sab'atayn Formation in the Marib-Shabwa Basin,Yemen,through a sequence stratigraphic analysis based on integrating datasets of sedimentology,seismic sections,and well logs.The Sab'atayn Formation(Tithonian age)is represented by a series of clastic and evaporites that were deposited under fluvio-deltaic to prodeltaic settings.It is divided into four members including Yah(at the base),upwards to Seen,Alif,and Safir at the top.Two third-order depositional sequences were determined for the Tithonian succession which were separated by three sequence boundaries.These sequences were classified into their systems tracts signifying several sedimentation patterns of progradational,aggradational,and retrogradational parasequence sets.The first depositional sequence corresponds to the early-middle Tithonian Yah and Seen units that can be classified into lowstand,transgressive,and highstand systems tracts.The second sequence comprises the late Tithonian Alif unit that can be subdivided into transgressive and highstand systems tracts.The sandy deposits of the Alif Member(highstand deposits)represent the most productive hydrocarbon reservoir in the basin.The Upper Jurassic sediments in the study area were resulted from a combination of eustatic and tectonic effects.
文摘This study aimed to determine the amount of total polluting matter emitted into the atmosphere from heating and industrial-based emissions and the total pollution bulk of Tokat city center. The annual cycles of some heavy metal in particulate matters have been investigated at this area in order to elucidate temporal variations as well as major sources processes responsible for their formation. Air particulate samples were collected from three different locations situated around Tokat. These samples were determined for heavy metals by using Flame or graphite-furnace Atomic absorption spectroscopy. Particulate matter concentrations up to 52.43μg/m^3 were observed in sampling area. The initial results of the chemical analysis showed that concentration values of heavy metals in air particles observed were higher than the World Health Organization （WHO） guideline limit values.
文摘The aim of this paper is to approximate the solution of system of fractional delay differential equations. Our technique relies on the use of suitable spline functions of polynomial form. We introduce the description of the proposed approximation method. The error analysis and stability of the method are theoretically investigated. Numerical example is given to illustrate the applicability, accuracy and stability of the proposed method.
文摘The aim of this study was to fabricate multi-layered recycled α-Fe<sub>2</sub>O<sub>3</sub>/OPEFB fiber/PCL composites for microwave absorbing applications in the 1 - 4 GHz frequency range. The multi-layered composites were 6 mm thick and each consisted of a 2 mm thick layer of recycled α-Fe<sub>2</sub>O<sub>3</sub>/PCL composites at various loadings (5 wt% - 25 wt%) of 16.2 nm recycled α-Fe<sub>2</sub>O<sub>3</sub> nanofiller, placed between two layers of 2 mm thick OPEFB fiber/PCL composites blended at a fixed ratio of 7:3. The real (ε') and imaginary (ε") components of the relative complex permittivity were measured using the open-ended coaxial probe technique and the values obtained were applied as inputs for the Finite Element Method to calculate the reflection coefficient magnitudes from which the reflection loss (RL) properties were determined. Both ε' and ε" increased linearly with recycled α-Fe<sub>2</sub>O<sub>3</sub> nanofiller content and the values of ε' varied between 3.0 and 3.9 while the ε" values ranged between 0.26 and 0.64 within 1 - 4 GHz. The RL (dB) showed the most prominent values within the 1.38 - 1.46 GHz band with a minimum of -38 dB attained by the 25 wt% composite. Another batch of minimum values occurred in the 2.39 - 3.49 GHz range with the lowest of -25 dB at 2.8 GHz. The recycled α-Fe<sub>2</sub>O<sub>3</sub>/OPEFB fiber/PCL multi-layered composites are promising materials that can be engineered for solving noise problems in the 1 - 4 GHz range.
文摘We determined the sequence of mitochondrial Cytochrome oxidase subunit I （CO1） in two Drosophila melanogaster strains originating at ＂Evolution Canyon＂, Israel. CO1 nucleotide sequences from two iso-female strains, 2-1 and 6-1, were 1,534 and 1,543 base-pairs, respectively. In each strain, ATAA was used in initiation of translation. Exchange rates for nucleotide and amino acid sequences were larger in the 6-1 strain than in the 2-1 strain when Oregon-R was used as the standard. Non-synonymous exchange rate was larger than synonymous exchange rate among the three strains.
文摘<span style="font-family:Verdana;">Plank quantum and classical string energy relations seem to be uncorrelated. This work correlated them. The relativistic energy-momentum relation has been used together with plank and de Brogglie hypothesis to prove that the wave group velocity is equal to the particle velocity in both ordinary and curved space. The plank energy relation is shown also to be related to the classical energy relation of an oscillating string. Starting from plank energy relation for n photons and performing integration, the expression of classical string energy was obtained. This means that one can treat electromagnetic waves as a collection of continuous photons having frequencies ranging from zero to w. Conversely, starting from classical string energy relation by differentiating it with respect to angular frequency, the plank quantum energy for n photons has been found. This means that the quanta results from separation of electromagnetic waves to single isolated waves. Each wave consists of n photons or quanta.</span>
文摘The nature and origin of the photon and elementary rest masses are some of the challeng-ing problems that physics face. The approaches used to solve these problems are complex and time-consuming. Specifically, the photon rest mass pays attention to theoretical physi-cists. Many experimental works show that the photon rest mass is non zero. This problem can be solved using generalized potential dependent special relativity, which has been de-rived using simple arguments, and Maxwell’s equations, besides the conventional Einstein energy-momentum relation. The results obtained show that the rest mass of photons and elementary particles are strongly dependent on the vacuum energy and a universal con-stant. This result conforms with the models that predict time decaying vacuum energy as-sociated with production of smaller rest mass particles followed by larger masses. The two potential dependent mass expressions conform with the cosmological models that suggest the photon is generated first by assuming the universe consisting of total constant vacuum with decaying cosmological part and mass generating part. Using Maxwell’s equations, beside plank and De Broglie hypothesis together with special relativity energy-momentum relation the photon rest mass is estimated. It was shown that the photon rest mass is ex-tremely small compared to the electron mass.
文摘Organic microporous materials based on spiroketal and spirothioketal polymers were synthesized through 1,3- dioxol-forming polymerization reaction between pentaerythritol or pentaerythritol tetrathiol and different types of cyclohexa- 1,4-dione derivatives. The structure of the prepared polymers was confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers show a large amount of nitrogen adsorbed at low relative pressure indicating microporosity. These polymers have Brunauer Emmitt and Teller （BET） surface areas in the range from 492 （m^2g^-1） to 685 （m^2 g^-1）. The prepared polymers were found to be useful for pervaporation separation of methanol-toluene mixture with a separation factor up to 12.5 and fluxes, varying between 6.7×10-3 kg/（m^2 h） and 13.4 × 10^-3 kg/（m^2 h）.
文摘Genetic diversity in natural populations has been explored through evolutionary analysis,and patterns of microscale biodiversity have been studied in populations at“Evolution Canyon”,Israel.A total of 2,000 eggs from each of iso-female Drosophila melanogaster line 2-1 from the north-facing slope(NFS)and line 6-1 from the south-facing slope(SFS)were placed in 20 vials and evaluated.Egg-to-adult viability was 0.89 and 0.75 in lines 2-1 and 6-1,respectively,and the difference was statistically significant by t-test.Genetic diversity was higher on the harsher SFS than on the milder NFS.Inter-slope genetic differences corroborated the effect of stochastic climate selection pressures to viability polygenes in populations at“Evolution Canyon”,Israel.
文摘The study assesses the quality of hand dug wells in relation to distance from soakaway septic tanks in three selected peri-urban communities in the Ga West Municipality near Accra, Ghana. Water quality analyses of bio-physico-chemical variables (pH, Temperature, EC, turbidity, DO, BOD, TSS, TDS, sodium, potassium, nitrate, nitrite, ammonia, sulphate, chloride, salinity, total alkalinity, total coliform, fecal coliforms and isolation of <i>E. coli</i>) were determined. Concentrations of the major nutrient anion sulphate, nitrate, phosphate, and chlorides in water samples at distances between 0</span><span style="font-family:""> </span><span style="font-family:"">-</span><span style="font-family:""> </span><span style="font-family:"">30 m radial distances from the septic tank were above the WHO permissible limit of drinking water compared to the control. All the water samples had high fecal and total coliform counts that exceeded the international standard of 0 per 100 mL of potable water with counts ranging from 0</span><span style="font-family:""> - </span><span style="font-family:"">143</span><span style="font-family:""> </span><span style="font-family:"">cfu/100</span><span style="font-family:""> </span><span style="font-family:"">ml and 53</span><span style="font-family:""> </span><span style="font-family:"">-</span><span style="font-family:""> </span><span style="font-family:"">463/100</span><span style="font-family:""> </span><span style="font-family:"">ml for FC and TC respectively. High fecal coliform and detection of <i>E. coli</i> in most samples is an indication of fecal pollution possibly from their close proximity to soak away septic sewage. The high nutrient levels detected in samples at distances between 0</span><span style="font-family:""> </span><span style="font-family:"">-</span><span style="font-family:""> </span><span style="font-family:"">30</span><span style="font-family:""> </span><span style="font-family:"">m as compared to the controls may also be attributed to its close proximity to septic tanks. This study, therefore, accentuates the need for the owners of the water points to site their water source at least 30m away </span><span style="font-family:"">from </span><span style="font-family:"">localized sources of pollution as well as treatment of groundwater before use.
文摘The study was conducted to assess the effects of small-scale (artisanal) gold mining and its social and economic implications on the people in Amansie West District of Ghana. The artisanal gold mining communities were studied using secondary data from scholarly articles and journals, books, conference papers, research reports, policy documents, working papers, and briefs. Descriptive and systematic analyses were conducted. The result indicated that youth aged between 21 - 30 were most likely to engage in illegal mining operations in the selected study areas. The study revealed that farmland had been destroyed, making farming difficult for the inhabitants. It is evident from the review that dug-out pits from mining serve as breeding grounds for mosquitoes and death traps for humans. The study, therefore, accentuates the need for illegal small-scale gold mining to be formalised and strategic interventions and policies proposed for the protection of Ghana’s Natural resources. Furthermore, community members should be involved in policy-making and environmental protection issues to help control the menace of landscape destruction. Although the ban on illegal gold mining activity by the government has caused more people to lose their jobs leading to livelihood challenges in mining communities, it is a step in the right direction, as the ban seeks to halt and check the illegal small-scale mining sector. The study recommended alternative livelihood and income-generating projects such as beekeeping, mushroom culture, grasscutter rearing, and agroforestry technologies including the growth of economic fruit trees as alternative livelihood ventures.
文摘Traditional methods for proportioning of high-performance concrete(HPC)have certain shortcomings,such as high costs,usage constraints,and nonlinear relationships.Implementing a strategy to optimize the mixtures of HPC can minimize design expenses,time spent,and material wastage in the construction sector.Due to HPC’s exceptional qualities,such as high strength(HS),fluidity and resilience,it has been broadly used in construction projects.In this study,we employed Generalized Regression Neural Network(GRNN),Nonlinear AutoRegressive with exogenous inputs(NARX neural network),and Random Forest(RF)models to estimate the Compressive Strength(CS)of HPC in the first scenario.In contrast,the second scenario involved the development of an ensemble model using the Radial Basis Function Neural Network(RBFNN)to detect inferior performance of standalone model combinations.The output variable was the 28 Days CS in MPa,while the input variables included slump(S),water-binder ratio(W/B)%,water content(W)kg/m^(3),fine aggregate ratio(S/a)%,silica fume(SF)%,and superplasticizer(SP)kg/m^(3).An RF model was developed by using R Studio;GRNN and NARX-NN models were developed by using the MATLAB 2019a toolkit;and the pre-and post-processing of data was carried out by using E-Views 12.0.The results indicate that in the first scenario,the Combination M1 of the RF model outperformed other models,with greater prediction accuracy,yielding a PCC of 0.854 and MAPE of 4.349 during the calibration phase.In the second scenario,the ensemble of RF models surpassed all other models,achieving a PCC of 0.961 and MAPE of 0.952 during the calibration phase.Overall,the proposed models demonstrate significant value in predicting the CS of HPC.
基金supported by National Research Foundation of Korea(NRF)grants funded by the Korean government(RS-2020-NR049332 and RS-2022-NR070837 to W.-Y.K.and RS-2024-00358746 to G.A.).
文摘The endoplasmic reticulum(ER)is a cellular organelle responsible for protein synthesis and folding.When its protein folding capacity is exceeded,unfolded or misfolded proteins accumulate,causing ER stress and triggering the unfolded protein response(UPR)to restore ER proteostasis.Although UPR gene expression in plants follows a diel cycle,the mechanisms by which the circadian clock regulates these genes remain unclear.Here,we demonstrate that sensitivity to ER stress in root growth exhibits time-of-day phases and that the circadian clock regulates UPR target gene expression during ER stress.Notably,mutations in the core morning clock component CIRCADIAN CLOCK ASSOCIATED 1(CCA1)impair ER stress recovery.CCA1 forms a complex with the UPR modulator basic leucine zipper 28(bZIP28)and acts as an upstream regulator of ER stress recovery.Upon ER stress,CCA1 is stabilized and associates with bZIP28 at the ER stress response element within the BiP3 promoter,enhancing the ER stress response.Thus,CCA1 and bZIP28 coordinate a time-dependent adaptive response to ER stress to maintain ER proteostasis.Our re-sults suggest that the circadian clock primes the timing and levels of ER chaperone expression to enhance ER stress tolerance.
