The two-dimensional axisymmetric magnetohydrodynamic boundary layer flow with heat transfer of Newtonian fluid over a stretching and non-stretching bullet-shaped object has been investigated. Therefore, fluid flow and heat transfer have been investigated in two types of flow geometries such as the thicker surface and the thinner surface of the bullet-shaped object. The present analysis also focuses on the physical relevance and accurate trends of the boundary layer profiles which are adequate in the laminar boundary layer flow. The novelty of this current work is to discuss the effect of shape and size (surface thickness parameter s) and the stretching factor of the bullet-shaped object on the fluid velocity and temperature profiles within the boundary layer region also develop the relationship between the dependent and independent parameters by the correlation coefficient. The partial differential equations of momentum and energy have been reduced to a system of non-linear ordinary differential equations along with the transformed boundary conditions by applying the local similarity transformations. These coupled non‐linear ordinary differential equations’ governing the flow field has been solved by the Spectral Quasi-Linearization Method (SQLM). The numerical analysis of the SQLM has been carried out with MATLAB for investigating the effect of various controlling parameters on the flow fields. The residual error infinity norms have been analyzed to determine the speed of convergence and accuracy of the method. The numerical results have been displayed graphically and in tabular form and the physical behavior of the problem also discussed. The investigation shows that in the case of a thicker bullet-shaped object the velocity profile does not approach the ambient condition asymptotically but intersects the axis with a steep angle and the boundary layer structure has no definite shape whereas in the case of a thinner bullet-shaped object the velocity profile converge the ambient condition asymptotically and the boundary layer structure has a definite shape. It is also noticed that thinner bullet-shaped object acts as good cooling conductor compared to thicker bullet-shaped object and the wall friction can be reduced much when thinner bullet-shaped object is used rather than the thicker bullet-shaped object in both types of non-stretching or stretching bullet-shaped object . Keywords: forced convection, correlation coefficient, multiple regression, MHD, stretching
{"title":"Numerical Analysis of Boundary Layer Flow and Heat Transfer over a Stretching and Non-Stretching Bullet-Shaped Object","authors":"M. Ali, M. A. Alim","doi":"10.30958/ajs.8-4-3","DOIUrl":"https://doi.org/10.30958/ajs.8-4-3","url":null,"abstract":"The two-dimensional axisymmetric magnetohydrodynamic boundary layer flow with heat transfer of Newtonian fluid over a stretching and non-stretching bullet-shaped object has been investigated. Therefore, fluid flow and heat transfer have been investigated in two types of flow geometries such as the thicker surface and the thinner surface of the bullet-shaped object. The present analysis also focuses on the physical relevance and accurate trends of the boundary layer profiles which are adequate in the laminar boundary layer flow. The novelty of this current work is to discuss the effect of shape and size (surface thickness parameter s) and the stretching factor of the bullet-shaped object on the fluid velocity and temperature profiles within the boundary layer region also develop the relationship between the dependent and independent parameters by the correlation coefficient. The partial differential equations of momentum and energy have been reduced to a system of non-linear ordinary differential equations along with the transformed boundary conditions by applying the local similarity transformations. These coupled non‐linear ordinary differential equations’ governing the flow field has been solved by the Spectral Quasi-Linearization Method (SQLM). The numerical analysis of the SQLM has been carried out with MATLAB for investigating the effect of various controlling parameters on the flow fields. The residual error infinity norms have been analyzed to determine the speed of convergence and accuracy of the method. The numerical results have been displayed graphically and in tabular form and the physical behavior of the problem also discussed. The investigation shows that in the case of a thicker bullet-shaped object the velocity profile does not approach the ambient condition asymptotically but intersects the axis with a steep angle and the boundary layer structure has no definite shape whereas in the case of a thinner bullet-shaped object the velocity profile converge the ambient condition asymptotically and the boundary layer structure has a definite shape. It is also noticed that thinner bullet-shaped object acts as good cooling conductor compared to thicker bullet-shaped object and the wall friction can be reduced much when thinner bullet-shaped object is used rather than the thicker bullet-shaped object in both types of non-stretching or stretching bullet-shaped object . Keywords: forced convection, correlation coefficient, multiple regression, MHD, stretching","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46586399","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}
Yusuf Alapata Ahmed, Nathaniel Bayode Eniolorunda, Yakubu Fakai Musa, Samuel Igra
This study assessed the nature of solid waste generation, its spatio-temporal pattern and existing management strategies in Sokoto metropolis. The greatest challenges facing cities in the developing world are; paucity of solid waste management and control. In the Nigeria context, solid waste management is characterized by inefficient collection, insufficient coverage of the collection system and improper disposal methods. In Sokoto metropolis, increase in population has resulted into accelerated of solid waste generation with pollution of all categories, and the consequent is dearth of modern management. The study used; selection of different wastes for observation, sampling-up four sub-soils at 0-30cm at random from each of the waste dump sites to determine not only for heavy metal concentrations but also for fertility supplement in comparison with the National Environmental Standard and Regulation Enforcement Agency (NESREA). Also, fifty scheduled questionnaires were administered each on selected residents around dumped sites and to the staff of Town Planning Board to solicit for relevant information on government and its agencies effectiveness in disposal and management of waste. Landsat data was also used to map out the waste sites for spatio-temporal analysis from 1999 to 2016. Results are expected to inform major decisions makers and urban planners in order to promote a sustainable urban development for Sokoto metropolis and its environs. Keywords: developing world, protection agencies, Metropolis, urban planners, Sokoto
{"title":"Waste Management and Control Problems in Sokoto Metropolis: Projected Mitigation on the Syndrome","authors":"Yusuf Alapata Ahmed, Nathaniel Bayode Eniolorunda, Yakubu Fakai Musa, Samuel Igra","doi":"10.30958/ajs.8-4-1","DOIUrl":"https://doi.org/10.30958/ajs.8-4-1","url":null,"abstract":"This study assessed the nature of solid waste generation, its spatio-temporal pattern and existing management strategies in Sokoto metropolis. The greatest challenges facing cities in the developing world are; paucity of solid waste management and control. In the Nigeria context, solid waste management is characterized by inefficient collection, insufficient coverage of the collection system and improper disposal methods. In Sokoto metropolis, increase in population has resulted into accelerated of solid waste generation with pollution of all categories, and the consequent is dearth of modern management. The study used; selection of different wastes for observation, sampling-up four sub-soils at 0-30cm at random from each of the waste dump sites to determine not only for heavy metal concentrations but also for fertility supplement in comparison with the National Environmental Standard and Regulation Enforcement Agency (NESREA). Also, fifty scheduled questionnaires were administered each on selected residents around dumped sites and to the staff of Town Planning Board to solicit for relevant information on government and its agencies effectiveness in disposal and management of waste. Landsat data was also used to map out the waste sites for spatio-temporal analysis from 1999 to 2016. Results are expected to inform major decisions makers and urban planners in order to promote a sustainable urban development for Sokoto metropolis and its environs. Keywords: developing world, protection agencies, Metropolis, urban planners, Sokoto","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45955138","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}
Efosa Michael Ogbeide, Joseph Erunmwosa Osemwenkhae
Density estimation is an important aspect of statistics. Statistical inference often requires the knowledge of observed data density. A common method of density estimation is the kernel density estimation (KDE). It is a nonparametric estimation approach which requires a kernel function and a window size (smoothing parameter H). It aids density estimation and pattern recognition. So, this work focuses on the use of a modified intersection of confidence intervals (MICIH) approach in estimating density. The Nigerian crime rate data reported to the Police as reported by the National Bureau of Statistics was used to demonstrate this new approach. This approach in the multivariate kernel density estimation is based on the data. The main way to improve density estimation is to obtain a reduced mean squared error (MSE), the errors for this approach was evaluated. Some improvements were seen. The aim is to achieve adaptive kernel density estimation. This was achieved under a sufficiently smoothing technique. This adaptive approach was based on the bandwidths selection. The quality of the estimates obtained of the MICIH approach when applied, showed some improvements over the existing methods. The MICIH approach has reduced mean squared error and relative faster rate of convergence compared to some other approaches. The approach of MICIH has reduced points of discontinuities in the graphical densities the datasets. This will help to correct points of discontinuities and display adaptive density. Keywords: approach, bandwidth, estimate, error, kernel density
{"title":"On the Use of a Modified Intersection of Confidence Intervals (MICIH) Kernel Density Estimation Approach","authors":"Efosa Michael Ogbeide, Joseph Erunmwosa Osemwenkhae","doi":"10.30958/ajs.8-4-4","DOIUrl":"https://doi.org/10.30958/ajs.8-4-4","url":null,"abstract":"Density estimation is an important aspect of statistics. Statistical inference often requires the knowledge of observed data density. A common method of density estimation is the kernel density estimation (KDE). It is a nonparametric estimation approach which requires a kernel function and a window size (smoothing parameter H). It aids density estimation and pattern recognition. So, this work focuses on the use of a modified intersection of confidence intervals (MICIH) approach in estimating density. The Nigerian crime rate data reported to the Police as reported by the National Bureau of Statistics was used to demonstrate this new approach. This approach in the multivariate kernel density estimation is based on the data. The main way to improve density estimation is to obtain a reduced mean squared error (MSE), the errors for this approach was evaluated. Some improvements were seen. The aim is to achieve adaptive kernel density estimation. This was achieved under a sufficiently smoothing technique. This adaptive approach was based on the bandwidths selection. The quality of the estimates obtained of the MICIH approach when applied, showed some improvements over the existing methods. The MICIH approach has reduced mean squared error and relative faster rate of convergence compared to some other approaches. The approach of MICIH has reduced points of discontinuities in the graphical densities the datasets. This will help to correct points of discontinuities and display adaptive density. Keywords: approach, bandwidth, estimate, error, kernel density","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48594847","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}
The main goal of the presented exploration was to estimate potential for mineralization in the Mawat ophiolitic massif in Kurdistan, Iraq. The aim of the study was to explore existing copper mineralization and assessor elements gold, platinoids and chromium. Geological exploration detected two types of Cu occurrence a) secondary Cu carbonates (malachite) and b) Cu sulfides (chalcopyrite-pyrite). The Mawat region is mostly built of ultrabasic and basic rocks: peridotites, gabbros, serpentinites and basalts which are heavily deformed, with faults mostly oriented NNW-SSE, and NE-SW. The first phase of exploration comprised digital processing of ASTER and QuickBird satellite images, with appropriate geometrical and radiometric corrections and transformation into coordinate system. Color composite images were produced in different scales. They served to define lithological composition, tectonic settings, location of the points of interest etc. The field work was designed to check satellite data in situ, with focus on perspective rock formations, which might host copper mineralization, and other elements. The host rocks of the ore occurrences are primarily gabbros and metagabbros intersected by diabase dykes, epidote and quartz veins. Secondary mineralization is the product of surficial weathering and it is represented by malachite and limonite. The geophysical survey was very useful in the detection of area with elevated induced polarization and low resistivity. Three perspective areas have been selected for detailed explorations: Waraz, Mirava-Chenara and Konjirin-Kuradawi. The concentration of copper varies highly in very wide ranges; the maximum measured concentration of Cu was determined in Waraz area 6.7%. Some rock samples also show concentration of gold from 0.36 to 2.59 ppm Au. Keywords: Mawat ophiolitic massif, geologic-geophysical explorations, copper mineralization, Kurdistan-Iraq
{"title":"Mineral Exploration in Mawat Region, Kurdistan-Iraq, Based on Satellite Data and Terrain Prospection","authors":"M. Oluić, S. Romandic, R. Vasiljević","doi":"10.30958/ajs.8-4-2","DOIUrl":"https://doi.org/10.30958/ajs.8-4-2","url":null,"abstract":"The main goal of the presented exploration was to estimate potential for mineralization in the Mawat ophiolitic massif in Kurdistan, Iraq. The aim of the study was to explore existing copper mineralization and assessor elements gold, platinoids and chromium. Geological exploration detected two types of Cu occurrence a) secondary Cu carbonates (malachite) and b) Cu sulfides (chalcopyrite-pyrite). The Mawat region is mostly built of ultrabasic and basic rocks: peridotites, gabbros, serpentinites and basalts which are heavily deformed, with faults mostly oriented NNW-SSE, and NE-SW. The first phase of exploration comprised digital processing of ASTER and QuickBird satellite images, with appropriate geometrical and radiometric corrections and transformation into coordinate system. Color composite images were produced in different scales. They served to define lithological composition, tectonic settings, location of the points of interest etc. The field work was designed to check satellite data in situ, with focus on perspective rock formations, which might host copper mineralization, and other elements. The host rocks of the ore occurrences are primarily gabbros and metagabbros intersected by diabase dykes, epidote and quartz veins. Secondary mineralization is the product of surficial weathering and it is represented by malachite and limonite. The geophysical survey was very useful in the detection of area with elevated induced polarization and low resistivity. Three perspective areas have been selected for detailed explorations: Waraz, Mirava-Chenara and Konjirin-Kuradawi. The concentration of copper varies highly in very wide ranges; the maximum measured concentration of Cu was determined in Waraz area 6.7%. Some rock samples also show concentration of gold from 0.36 to 2.59 ppm Au. Keywords: Mawat ophiolitic massif, geologic-geophysical explorations, copper mineralization, Kurdistan-Iraq","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43949343","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}
Science, Technology, Engineering and Mathematics (STEM) programs that attract and sustain student interest feature learning that is experiential, investigative, hands-on, personally significant to both students and faculty, connected to other inquiries, and suggestive of practical application to students’ lives. Such learning flourishes in a community in which faculty are committed equally to teaching, to maintaining their own intellectual vitality, and to partnering with students in learning, and in which institutional support for such a community exists. The Creative Scientific Inquiry Experience (CSIE) Program at Eastern Michigan University (EMU) is involved in retaining and increasing the number of STEM graduates by including faculty professional development, student connectedness to the sciences and mathematics through academic service-learning, and curricular reform. In this conference paper we report on the success of the CSIE program, including course development, student engagement, student success, especially among underserved students, and sustainability. This work is important because it offers insight into the development, sustainability, and scalability into faculty-driven STEM education reform spanning 15 years. Keywords: STEM education, retention strategies, undergraduate STEM, majors/non-majors
{"title":"Sustaining Solutions in Undergraduate STEM Education","authors":"E. T. Contis, Batoul Y. Abdallah","doi":"10.30958/ajs.8-3-3","DOIUrl":"https://doi.org/10.30958/ajs.8-3-3","url":null,"abstract":"Science, Technology, Engineering and Mathematics (STEM) programs that attract and sustain student interest feature learning that is experiential, investigative, hands-on, personally significant to both students and faculty, connected to other inquiries, and suggestive of practical application to students’ lives. Such learning flourishes in a community in which faculty are committed equally to teaching, to maintaining their own intellectual vitality, and to partnering with students in learning, and in which institutional support for such a community exists. The Creative Scientific Inquiry Experience (CSIE) Program at Eastern Michigan University (EMU) is involved in retaining and increasing the number of STEM graduates by including faculty professional development, student connectedness to the sciences and mathematics through academic service-learning, and curricular reform. In this conference paper we report on the success of the CSIE program, including course development, student engagement, student success, especially among underserved students, and sustainability. This work is important because it offers insight into the development, sustainability, and scalability into faculty-driven STEM education reform spanning 15 years. Keywords: STEM education, retention strategies, undergraduate STEM, majors/non-majors","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44580130","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}
The aim of this paper is to describe the research results on multiple intelligences in mathematics learning, using a descriptive approach. It also ascertains the influence of various learning models on mathematics learning outcomes based on students’ multiple intelligences. Student Teams-Achievement Divisions (STAD) and Team Games Tournament (TGT) learning models improved learning outcomes for students possessing logical-mathematical, kinesthetic, and interpersonal intelligences. Furthermore, Group Investigation (GI) and Numbered Head Together (NHT) learning models improved student learning outcomes with logical-mathematical intelligence. Two Stay Two Stray (TSTS) learning model with peer tutors improved student learning outcomes with linguistic, logical-mathematical, and interpersonal intelligences. Team Assisted Individualization (TAI) and Jigsaw learning improved student learning outcomes with linguistic intelligence. Also, TSTS and NHT learning models improved student learning outcomes with logical-mathematical, and interpersonal intelligences. Keywords: compound intelligence, learning model, mathematics
{"title":"The Effect of Various Learning Approaches on Mathematical Learning Outcomes based on the Multiple Intelligences of Students","authors":"Y. Yerizon, A. A. Putra","doi":"10.30958/ajs.8-3-4","DOIUrl":"https://doi.org/10.30958/ajs.8-3-4","url":null,"abstract":"The aim of this paper is to describe the research results on multiple intelligences in mathematics learning, using a descriptive approach. It also ascertains the influence of various learning models on mathematics learning outcomes based on students’ multiple intelligences. Student Teams-Achievement Divisions (STAD) and Team Games Tournament (TGT) learning models improved learning outcomes for students possessing logical-mathematical, kinesthetic, and interpersonal intelligences. Furthermore, Group Investigation (GI) and Numbered Head Together (NHT) learning models improved student learning outcomes with logical-mathematical intelligence. Two Stay Two Stray (TSTS) learning model with peer tutors improved student learning outcomes with linguistic, logical-mathematical, and interpersonal intelligences. Team Assisted Individualization (TAI) and Jigsaw learning improved student learning outcomes with linguistic intelligence. Also, TSTS and NHT learning models improved student learning outcomes with logical-mathematical, and interpersonal intelligences. Keywords: compound intelligence, learning model, mathematics","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43417539","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}
Mean daily variability of latent heat (E), sensible heat (H), net long wave (Lwnet), net short wave, and net flux of surface heat balance were estimated from hourly sea surface water temperature (SST) and meteorological time series obtained for three months during summer season (2019) in Alexandria Eastern Harbor (AEH), Egypt. Latent and sensible heat were not in phase and had their maximum 181.12 W/m2 (5:00 PM), 16.5 W/m2 (5:00 AM) and minimum 103.64 W/m2 (8:00 AM), -12.14 W/m2 (3:00 PM), resulting in Bowen ration of -0.11 and 0.09, respectively. The loss of heat by evaporation therefore predominates than sensible heat utilized to warm surface atmosphere. The instability of the atmosphere was existing nearly most of the time period, rising exchange coefficients of sensible and latent heat flux by about 24.26% over estimated neutral values (from 1.15 × 10−3 to 1.43 × 10−3). Mean Lwnet changed from 165.63 at early morning to 173.52 W/m2 at late afternoon, point out its significant importance in the total balance of heat flux of eastern harbor surface. Latent heat flux and Lwnet were positive (energy losing from eastern harbor), throughout the day. The daily average of net energy budget (S) was 38.52 W/m2; daytime gain exceeded nighttime loss, with consequent heating the eastern harbor. Qualitatively, daily variations of net energy budget (S) were nearly consistent with time delay to the variability of sea surface temperature, indicating the predominant role of the heat budget of the surface layer in modulating surface temperatures of the Eastern Harbor. Keywords: heat flux, shortwave, long wave, latent heat, sensible heat, Eastern Harbor
{"title":"Mean Daily Variability of Energy Fluxes Above Alexandria Eastern Harbor","authors":"M. M. Hussein","doi":"10.30958/ajs.8-3-2","DOIUrl":"https://doi.org/10.30958/ajs.8-3-2","url":null,"abstract":"Mean daily variability of latent heat (E), sensible heat (H), net long wave (Lwnet), net short wave, and net flux of surface heat balance were estimated from hourly sea surface water temperature (SST) and meteorological time series obtained for three months during summer season (2019) in Alexandria Eastern Harbor (AEH), Egypt. Latent and sensible heat were not in phase and had their maximum 181.12 W/m2 (5:00 PM), 16.5 W/m2 (5:00 AM) and minimum 103.64 W/m2 (8:00 AM), -12.14 W/m2 (3:00 PM), resulting in Bowen ration of -0.11 and 0.09, respectively. The loss of heat by evaporation therefore predominates than sensible heat utilized to warm surface atmosphere. The instability of the atmosphere was existing nearly most of the time period, rising exchange coefficients of sensible and latent heat flux by about 24.26% over estimated neutral values (from 1.15 × 10−3 to 1.43 × 10−3). Mean Lwnet changed from 165.63 at early morning to 173.52 W/m2 at late afternoon, point out its significant importance in the total balance of heat flux of eastern harbor surface. Latent heat flux and Lwnet were positive (energy losing from eastern harbor), throughout the day. The daily average of net energy budget (S) was 38.52 W/m2; daytime gain exceeded nighttime loss, with consequent heating the eastern harbor. Qualitatively, daily variations of net energy budget (S) were nearly consistent with time delay to the variability of sea surface temperature, indicating the predominant role of the heat budget of the surface layer in modulating surface temperatures of the Eastern Harbor. Keywords: heat flux, shortwave, long wave, latent heat, sensible heat, Eastern Harbor","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46965889","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}
The present study is aimed at quantifying and comparing the net aerial primary productivity (NAPP) of two alfalfa varieties (Medical sativa L.) by determining the Radiation Use Efficiency (Ɛ) for each variety, estimating the NAPP though the Red Vegetation Index and relating it to the quantified NAPP. Significant differences between the individual NAPP of each variety were not found: G969 = 1564 g dm m-2 and M901 = 1636 g dm m-2 (T = 0.92; p>0.05). The Ɛ of the G969 was 0.56 g Mj-1 while that of M901 was 0.58 g Mj-1. Significant direct relationships between the quantified NAPP and that calculated using the Red Vegetation Index were found. The models obtained were: NAPPG969 = 506.06x – 343.25 (R2 = 0.88; p<0.001) and NAPPM901 = 420.28x + 37.82 (R2 = 0.98; p<0.001). The Ɛ values of the alfalfa varieties under study, determined at local level, reduce uncertainty when generating predictive models of productivity. The NAPP of alfalfa varieties can be non-destructively predicted using the Red Vegetation Index obtained by a reflex RGB digital camera. Keywords: radiation use efficiency, digital camera, canopy reflectance, RGB indices
本研究旨在通过确定两个苜蓿品种（Medical sativa L.）的辐射利用效率（Ɛ），通过红色植被指数估计NAPP，并将其与量化的NAPP联系起来，来量化和比较两个紫花苜蓿品种的净地上初级生产力（NAPP）。各品种的NAPP差异不显著：G969=1564 g dm m-2和M901=1636 g dm m-1（T=0.92；p>0.05）。量化的NAPP与使用红色植被指数计算的NAPP之间存在显著的直接关系。所获得的模型为：NAPPG969=506.06x–343.25（R2=0.88；p<0.001）和NAPPM901=420.28x+37.82（R2=0.98；p>0.001）。在地方一级确定的所研究苜蓿品种的Ɛ值在生成生产力预测模型时降低了不确定性。苜蓿品种的NAPP可以使用反射RGB数码相机获得的红色植被指数进行无损预测。关键词：辐射利用效率，数码相机，冠层反射率，RGB指数
{"title":"Net Aerial Primary Productivity Models for Alfalfa Varieties (Medicago sativa L.) Derived from the Red Vegetation Index","authors":"J. Tiedemann","doi":"10.30958/ajs.8-3-1","DOIUrl":"https://doi.org/10.30958/ajs.8-3-1","url":null,"abstract":"The present study is aimed at quantifying and comparing the net aerial primary productivity (NAPP) of two alfalfa varieties (Medical sativa L.) by determining the Radiation Use Efficiency (Ɛ) for each variety, estimating the NAPP though the Red Vegetation Index and relating it to the quantified NAPP. Significant differences between the individual NAPP of each variety were not found: G969 = 1564 g dm m-2 and M901 = 1636 g dm m-2 (T = 0.92; p>0.05). The Ɛ of the G969 was 0.56 g Mj-1 while that of M901 was 0.58 g Mj-1. Significant direct relationships between the quantified NAPP and that calculated using the Red Vegetation Index were found. The models obtained were: NAPPG969 = 506.06x – 343.25 (R2 = 0.88; p<0.001) and NAPPM901 = 420.28x + 37.82 (R2 = 0.98; p<0.001). The Ɛ values of the alfalfa varieties under study, determined at local level, reduce uncertainty when generating predictive models of productivity. The NAPP of alfalfa varieties can be non-destructively predicted using the Red Vegetation Index obtained by a reflex RGB digital camera. Keywords: radiation use efficiency, digital camera, canopy reflectance, RGB indices","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49131017","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}
Pedro Mena, L. Kerby, Derick Nielson, K. Wilsdon, P. Gilbreath, Connie Hill, Konner Casanova, Kyle Massey
The goal of improving cost efficiencies is a constant endeavor of all organizations. This is especially true for governments, where public perception often has the ability to affect budget allocations. The data used in this analysis consisted of publically available state expenditures from 2018 and 2019 for the state of Idaho. The dataset contains the record of over 2 million state expenditures across all state agencies. The data analysis was performed using Python and the Pandas library. Visualizations were created using the Matplotlib package. The data exploration showed that Idaho’s Departments of Health and Welfare, Education and Transportation spent the most in this time period. The analysis also determined which Summary Objects, Sub-Object and Vendors experienced the greatest changes between the two years. Comparisons were also done using publicly available data on reported budget allocations by the states of Arkansas, California, Texas and Montana to see how spending differs between Idaho and these states based on percentage and per capita. Finally, suggestions for improvement in the areas of health care and employee transportation were given. These include methods of improving competition in health care, reducing travel through expanded teleconferencing and providing incentives to employees for reduced travel cost. Keywords: data science, budget analysis, python, pandas, government spending
{"title":"Government Expenditure Data Exploration & Analysis Using Python","authors":"Pedro Mena, L. Kerby, Derick Nielson, K. Wilsdon, P. Gilbreath, Connie Hill, Konner Casanova, Kyle Massey","doi":"10.30958/AJS.8-2-3","DOIUrl":"https://doi.org/10.30958/AJS.8-2-3","url":null,"abstract":"The goal of improving cost efficiencies is a constant endeavor of all organizations. This is especially true for governments, where public perception often has the ability to affect budget allocations. The data used in this analysis consisted of publically available state expenditures from 2018 and 2019 for the state of Idaho. The dataset contains the record of over 2 million state expenditures across all state agencies. The data analysis was performed using Python and the Pandas library. Visualizations were created using the Matplotlib package. The data exploration showed that Idaho’s Departments of Health and Welfare, Education and Transportation spent the most in this time period. The analysis also determined which Summary Objects, Sub-Object and Vendors experienced the greatest changes between the two years. Comparisons were also done using publicly available data on reported budget allocations by the states of Arkansas, California, Texas and Montana to see how spending differs between Idaho and these states based on percentage and per capita. Finally, suggestions for improvement in the areas of health care and employee transportation were given. These include methods of improving competition in health care, reducing travel through expanded teleconferencing and providing incentives to employees for reduced travel cost. Keywords: data science, budget analysis, python, pandas, government spending","PeriodicalId":91843,"journal":{"name":"Athens journal of sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41515076","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}
Aguh Akeh Nug, C. E. Suh, J. Boman, Godwin Sendze Yinda
Air quality progressively deteriorates as urbanization, motorization and economic activities increase. Aerosol particles smaller than 2.5µm (PM2.5), a widespread form of pollution is an emergent threat to human health, the environment, quality of life, and the world’s climate. The composition of these particles is an important aspect of interest not only related to possible health and environmental effects of the elemental content but the elemental determination which also adds valuable information for source apportionment. This study investigates and evaluates the level of PM2.5 in Douala, Cameroon. Particles were collected using a cyclone that separates the PM2.5 from the air stream and impacts them on polycarbonate filters which were changed every 24-hour sampling period. Samples were analyzed for particulate mass concentration, black carbon (BC) and trace elements. Trace element analysis was done by EDXRF (energy dispersive x-ray fluorescence spectroscopy). Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, Sr, and Pb were identified and quantified for samples. Local meteorology was used to study variations in PM2.5 mass concentrations. Possible sources for the pollutants were also investigated. The mean particle mass concentration was 252 ± 130μg/m3 while BC attained a maximum of 6.993μg/m3. The influence of leaded gasoline was inferred while combustion and road traffic were identified as the major anthropogenic sources. Trends in meteorological parameters were influenced by thunderstorms. Sea spray was identified as another major contributor to aerosol PM. This study highlights high pollution levels in Douala. Keywords: PM2.5, air quality, aerosol, mass concentration, source identification
{"title":"Monitoring Particulate Matter Air Pollution in Urban Centers: New Insights from Douala, Cameroon","authors":"Aguh Akeh Nug, C. E. Suh, J. Boman, Godwin Sendze Yinda","doi":"10.30958/AJS.8-2-1","DOIUrl":"https://doi.org/10.30958/AJS.8-2-1","url":null,"abstract":"Air quality progressively deteriorates as urbanization, motorization and economic activities increase. Aerosol particles smaller than 2.5µm (PM2.5), a widespread form of pollution is an emergent threat to human health, the environment, quality of life, and the world’s climate. The composition of these particles is an important aspect of interest not only related to possible health and environmental effects of the elemental content but the elemental determination which also adds valuable information for source apportionment. This study investigates and evaluates the level of PM2.5 in Douala, Cameroon. Particles were collected using a cyclone that separates the PM2.5 from the air stream and impacts them on polycarbonate filters which were changed every 24-hour sampling period. Samples were analyzed for particulate mass concentration, black carbon (BC) and trace elements. Trace element analysis was done by EDXRF (energy dispersive x-ray fluorescence spectroscopy). Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, Sr, and Pb were identified and quantified for samples. Local meteorology was used to study variations in PM2.5 mass concentrations. Possible sources for the pollutants were also investigated. The mean particle mass concentration was 252 ± 130μg/m3 while BC attained a maximum of 6.993μg/m3. The influence of leaded gasoline was inferred while combustion and road traffic were identified as the major anthropogenic sources. Trends in meteorological parameters were influenced by thunderstorms. Sea spray was identified as another major contributor to aerosol PM. This study highlights high pollution levels in Douala. Keywords: PM2.5, air quality, aerosol, mass concentration, source identification","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":"42501738","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}
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