Athens journal of sciences最新文献

{"title":"Evaluation of Physicochemical Characteristics of Surface Water from Orashi River, Rivers State, Southern Nigeria","authors":"O. Edori, E. S. Edori","doi":"10.30958/AJS.8-2-2","DOIUrl":"https://doi.org/10.30958/AJS.8-2-2","url":null,"abstract":"Water samples were collected from four different stations bimonthly from the Orashi River for a period of one year. The samples were collected from the shores of selected communities along the Engenni axis of the river. The samples were treated and analyzed according to standard laboratory and analytical procedures for water physicochemical parameters. The parameters examined were pH, Salinity, chlorides (Cl-), Conductivity, total dissolved solids (TDS), total suspended solids (TSS) turbidity, temperature, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), nitrates (NO3-), sulphate (SO42-) and phosphates (PO43-). The results showed that the mean values of the evaluated parameters were; pH (6.91±0.11), salinity (9.79±0.27 mg/L), Cl (6.25±0.25 mg/L), conductivity (29.66±1.20 µS/cm), TDS (17.66±2.08 mg/L), TSS (16.83±1.15 mg/L), turbidity (11.84±1.50 mg/L), temperature (28.16±0.12 oC), DO (5.91±0.18 mg/L), BOD (7.30±0.60 mg/L), COD (9.41±0.70 mg/L), NO3- (3.42±0.27 mg/L), SO42- (1.15±0.56 mg/L) and PO43- (15.65±5.76 mg/L). The results of the different parameters showed that all of them fall within the WHO acceptable limit except turbidity, DO and BOD that were not within the recommended range, then COD and phosphates that were either within or above the recommended values at different instances. Based on the findings of this work, the water may not be particularly suitable for drinking purposes, but can be used for other household functions that do not require consumption and also for irrigation. Keywords: water, physicochemical property, human activity, environment, contamination","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47917237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical Analysis of the Implication of the Proposed Rise in the Retirement Age on the Unemployment Situation in Nigeria","authors":"C. Baptista, Natércia Santos, Manuel Rosa","doi":"10.30958/ajs.7-1-2","DOIUrl":"https://doi.org/10.30958/ajs.7-1-2","url":null,"abstract":"","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46945023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical Analysis of the Implication of the Proposed Rise in the Retirement Age on the Unemployment Situation in Nigeria","authors":"A. Ayoade, R. Folaranmi, T. Latunde","doi":"10.30958/ajs.7-1-3","DOIUrl":"https://doi.org/10.30958/ajs.7-1-3","url":null,"abstract":"","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44086330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Modified System of Nonlinear Fractional-Order Differential Equations in the Study of the Dynamics of Marital Relationships and their Behavioural Features","authors":"O. Odetunde, R. Odunaike, A. T. Talabi","doi":"10.30958/AJS.8-1-3","DOIUrl":"https://doi.org/10.30958/AJS.8-1-3","url":null,"abstract":"Urbanization and modernization have effects on marital relationships in Nigeria which led to high divorce rate among legitimate couples prompting unstable environment. This situation design and uses scientific means to study the dynamics of marital relationships and their behavioural features to check excesses in marriage and to promote stability. A modified system of nonlinear fractional-order differential equations was used to categorize people of different personalities and different Impact Factors of Memory, using different sets of parameters. The equations predict and interpret the features of the union of different individuals with external circumstance(s). Equations were adapted to a local environment where data collections were carried out to investigate factors affecting marriages. Data collected by the use of questionnaire validate the model. An Iterative Decomposition Method was adopted to solve the fractional system in which fractional derivatives were given in the Caputo sense; the obtained results were interpreted appropriately. The modified model shows the trajectory of the couple from the state of indifference and as the impact factor memory increases it affects their togetherness making the love between them to decay easily. Numerical simulation results were presented to show the effectiveness of the model and the accuracy of the statements established. Keywords: Differential model, dynamical system, impact factors of memory, iterative decomposition method, marital relationship","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48700125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Modified System of Nonlinear Fractional-Order Differential Equations in the Study of the Dynamics of Marital Relationships and their Behavioural Features","authors":"A. Avagyan","doi":"10.30958/AJS.8-1-4","DOIUrl":"https://doi.org/10.30958/AJS.8-1-4","url":null,"abstract":"Our theory includes generalized explanations of how nature works, confirmed by pieces of evidence, cover predictions for further technological developments towards economically and environmentally sustainable industrial processes as well as provides the role of bioenergy accumulation and transformation for improved understanding about evolution, influences of anthropogenic activity, decision-makers errors, technological choices, pandemics prevention and the necessary skills toward the innovation algae-based system. The possibility of origination and evolution of the landforms of life were the results of bioenergy accumulation by microalgae and at present, the contribution of algae remains dominant in reducing CO2 and maintaining O2 level in the atmosphere. Population growth stimulates the accumulation of air carbon and bioenergy. The production and application of fertilizers originated large GHG emissions and it is a big conceptual need to shift on organic agriculture including algae fertilization of soil to contribute long-term sustainability. The used technologies for 1G biofuels production, as well as microalgae to biofuel based on biomass phototrophic growth by the use of fertilizers, are induced aggressively increasing GHG emission instead of their mitigation. Microalgae biofuel has big potential in case the use of wastewaters and food waste for biomass growth. The priority strategy for dealing with future pandemics treats such as COVID-19, etc. must be increasing the stability of immunity system of humans and animals to infections and due to a high concentration of physiologically active compounds in microalgae they application can be the best decision. Analyses of the Kyoto Protocol, Paris Climate Agreement, etc. results provide that their application has many disadvantages. The New policy must be founded on the admitting of the Life Conserve industry as the new part of the production. Keywords: bioenergy, biofuel, environmental policy evaluation, evolution, climate change, Malthusian theory, microalgae, agriculture, pandemics, waste","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42205634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behaviour of Temperature Variations in Subsurface Layers in the South-Eastern Mediterranean Sea","authors":"T. El-Geziry, Ibrahim A. Maiyza, M. Kamel","doi":"10.30958/AJS.8-1-1","DOIUrl":"https://doi.org/10.30958/AJS.8-1-1","url":null,"abstract":"The present work is a qualitative research, which aims at drawing the general behaviour of variations in the subsurface seawater temperatures within three distinctive subsurface layers in the south-eastern Mediterranean region. The work is based on hydrographic data collected over 65 years (1948–2012). The investigated layers are the subsurface, the intermediate and the deep water layers. The general trend of the mean annual temperature anomaly (MATA) was examined using the linear and quadratic regressions. Results revealed that the MATA over the water column in the south-eastern Mediterranean has the same trend, regardless of the place (layer) of investigation. Linearly, all MATA have increasing trends with different rates, with the exception of the 75 m level, which has a decreasing trend following that previously concluded for the surface water in the region. Also, the quadratic approach reflects the same trend of MATA over the water column, with different years of minimum occurrence. These same trends from the surface to deep can be attributed to the vertical convection processes in this region, and to the expanded impact of solar radiation which may reach more than 30 m depth. Keywords: South-eastern Mediterranean Sea, seawater temperature, linear regression, quadratic regression, cyclic trend","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47094306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drying of Okra by Different Drying Methods: Comparison of Drying time, Product Color Quality, Energy Consumption and Rehydration","authors":"O. Ismail, A. Kipcak, I. Doymaz","doi":"10.30958/ajs.6-3-1","DOIUrl":"https://doi.org/10.30958/ajs.6-3-1","url":null,"abstract":"In this study, okra was dried and modelled with using five different drying methods exist in literature. In the methods of vacuum and hot air drying, the drying temperature of 50°C was selected, while the powers of microwave and infrared were set as 90 W and 83 W, respectively. The results were evaluated in terms of drying time, product color quality, energy consumption and rehydration. The minimum drying time was obtained by microwave drying method. Also, the energy efficiency increased with the microwave drying method. In terms of color criteria the best value was obtained by the hot-air drying method. Rehydration content of dried okra samples with hot air was higher than that of other drying methods. From the results of this study, the most efficient drying methods were determined as microwave and hot-air drying.","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42494882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Practical Model of Godel–Planck–Hubble–Birch Universe","authors":"U. Seshavatharam, S. Lakshminarayana","doi":"10.30958/ajs.6-3-4","DOIUrl":"https://doi.org/10.30958/ajs.6-3-4","url":null,"abstract":"By considering ‘Planck mass’ as a characteristic massive seed and by replacing big bang with a growing Planck ball, an evolving model of quantum cosmology can be developed. With reference to increasing support for large scale cosmic anisotropy, preferred directions, quantum mechanical demand of cosmic spin and by considering a decreasing trend of angular velocity, from the beginning of Planck scale, we have developed a procedure for estimating the trend of all cosmic physical parameters. From and about the baby universe, in all directions, cosmic acceleration can be understood with increasing expansion velocity and decreasing total matter density ratio. We would like suggest that, from the beginning of Planck scale, 1) Dark matter can be considered as a kind of cosmic foam responsible for formation of galaxies. 2) Cosmic angular velocity decreases with square of the decreasing cosmic temperature. 3) Increasing ratio of Hubble parameter to angular velocity plays a crucial role in estimating increasing cosmic expansion velocity and decreasing total matter density ratio. 4) There is no need to consider dark energy for understanding cosmic acceleration. With further study, cosmological nucleosynthesis and dark matter synthesis along with mass generation mechanism can be reviewed in a quantum cosmological approach.","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46325883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dry Ports Development: A Pivot Strategy to Enhance Sustainable Transit Traffic via West African Corridors","authors":"Sewodo Augustin Degbe, Bingliang Song","doi":"10.30958/ajs.6-3-3","DOIUrl":"https://doi.org/10.30958/ajs.6-3-3","url":null,"abstract":"West Africa like many other regions in Africa, is enjoying a period of rapid growth in the past decade and within this period, its international trade has grown significantly. However, the region lacks sufficient dry ports, which can enhance a sustainable transportation of transit cargoes via the various corridors as well as relieving pressures on the seaports. The essence of this paper is to select an optimum location for the development of a dry port in West Africa based on specific factors relevant the research objective. The center of gravity location model was applied at the landside in order to ascertain the transportation cost of goods from selected coastal ports to the hinterland markets as well selecting an optimum location for the development of a dry port with a cost minimization objective. A simple forecast of demand throughput for West African landlocked countries was also applied using time series regression analysis in order to access the traffic growth rate as well as the associated capacity constraints that the ports might experience in the nearest future. Finally, SWOT analysis was used to analyze the endogenous and exogenous factors, which are deemed crucial to the development of dry port in Cote d‟Ivoire.","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44405952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentation Processes in the Black Sea during the Last Glacial Period Deduced from Grain Size Analyses on Gravity Core MSM 33/54-3 from the Eastern Anatolian Continental Margin","authors":"C. Neugebauer","doi":"10.30958/ajs.6-3-2","DOIUrl":"https://doi.org/10.30958/ajs.6-3-2","url":null,"abstract":"","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45792809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}