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Flow and Heat Transfer of a Dusty Williamson MHD Nanofluid Flow over a Permeable Cylinder in a Porous Medium

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Open Journal of Fluid Dynamics 2024年第2期14卷 100-122页

作者： Oluranti Adejoke Adekanmbi-Akinseye Olugbenga john Fenuga Hamzat Afe Isede Musibau Gbeminiyi sobamowo Department of Mathematics University of Lagos Lagos Nigeria Department of Mechanical Engineering University of Lagos Lagos Nigeria

This study investigates the flow and heat transfer of dusty Williamson (MHD) Nanofluid flow over a stretching permeable cylinder in a porous medium. Dusty Williamson Nanofluid was considered due to its thermal properties and potential benefits of increasing the heat transfer rate. Firstly, partial differential equations are transformed into coupled non-linear ordinary differential equations through a similarity variables transformation. The resulting set of dimensionless equations is solved analytically by using the Homogony Perturbation Method (HPM). The effects of the emerging parameters on the velocity and temperature profiles as well as skin-friction coefficient and Nusselt number are publicized through tables and graphs with appropriate discussions. The present result has been compared with published papers and found to be in agreement. To the best of author’s knowledge, there has been sparse research work in the literature that considers the effect of dust with Williamson Nanofluid and also solving the problem analytically. Therefore to the best of author’s knowledge, this is the first time analytical solution has been established for the problem. The results revealed that the fluid velocity of both the fluid and dust phases decreases as the Williamson parameter increases. Motivated by the above limitations and the gaps in past works, therefore, it is hoped that the present work will assist in providing accurate solutions to many practical problems in science, industry and engineering.

关键词： Williamson Dusty Particles Homotopy Perturbation Method (HPM) Magneto Hydrodynamic (MHD) Nanofluid Porous Medium stretching Cylinder

Effect of Tillage Practices on Hydro-Physical Properties of soils in a Rice-Grown Environment in North Central Nigeria

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Journal of Environmental Protection 2024年第5期15卷 527-536页

作者： Ebierni Akpoebidimiyen Otuaro john Jiya Musa Felix Oguche Abayomi Ibrahim Kuti Abubakar Ndaman Civil Engineering Department Maritime University Okerenkoko Nigeria Department of Agricultural and Bioresources Engineering Federal University of Technology Minna Nigeria Institute of Water and Environmental Management Faculty of Agricultural and Food Sciences and Environmental Management University of Debrecen Boszormenyi St Hungary

This study details soil’s physical and chemical properties in a rice-grown environment in Minna environs Niger state, Nigeria, under different soil and water conservation practices. soil samples were collected at 0 - 10 cm, 10 - 20 cm and 20 - 30 cm, respectively, using a soil auger to determine their physical and chemical properties such as moisture content, particle size, bulk density, particle density, porosity and organic matter. The textural classification determined the percentage dominance of the soil types in each study site location. The moisture content of site 1 ranged between 14.3% to 13.7%, site 2 ranged between 13.2% to 10.2%, site 3 ranged between 15.4% to 13.2%, site 4 ranged between 15.6% to 13.6% and site 5 ranged between 16.1% to 10.9%. The clay content of sites 3, 4 and 5 is higher than that of sites 1 and 2, while the silt contents of sites 1, 2 and 3 are higher than that of sites 4 and 5. The mean value of soil organic carbon from each study location was 2.37%, 2.03%, 2.43%, 2.07% and 2.17% for sites 1, 2, 3, 4, and 5, respectively. Therefore, site 1 is susceptible to erosion because of poor infiltration rate and well-ploughed or cultivated land by the tractor (harrowed). The particle sizes analysis indicated that the soil type in site 1 and site 2 is mainly sandy loam, while site 3 and site 5 are mainly loamy and predominantly clay loam in site 4.

关键词： Degradation Erosion Fertility Irrigation Management

Projected Changes in Extreme Event Indices for Alaska

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Atmospheric and Climate sciences 2024年第2期14卷 191-209页

作者： john E. Walsh Kyle Redilla Norman shippee Lukas Cheung David Bigelow Ronni Wilcock International Arctic Research Center University of Alaska Fairbanks Fairbanks USA stantec Ottawa Canada stantec Montreal Canada stantec Calgary Canada Two Bears Environmental Consulting Anchorage USA

As climate has warmed in recent decades, Alaska has experienced a variety of high-impact extreme events that include heat waves, wildfires, coastal storms and freezing rain. Because the warming is projected to continue, it is essential to consider future changes when planning adaptation actions and building resilience. In this study, we synthesize information on future changes in extreme events in Alaska from an ensemble of regional climate model simulations performed as part of Arctic-CORDEX (Coordinated Regional Climate Downscaling Experiment). A set of 13 extreme event indices, based on those developed by the World Climate Research Programme’s Expert Team on Climate Change Detection and Indices (ETCCDI), are evaluated from the Arctic-CORDEX output for Alaska. Of the 13 indices, six pertain to temperature, five to total precipitation, one to wind and one to snow. The results for locations in seven different climate zones of Alaska include large increases (5˚C - 10˚C) in the temperature thresholds for the five hottest and coldest days of the year, and large increases in warm spell duration and decreases in cold spell duration. Changes in the cold day temperature threshold are generally larger than the changes in the hot day temperature threshold, consistent with the projections of a stronger warming in winter than in summer in Alaska yearly maximum 1-day and 5-day precipitation amounts as well as the yearly number of consecutive wet days are projected to increase at all locations. The indices for heavy snow days and high-wind days show mixed changes, although the results indicate increases in heavy snow days at the more northern locations and increases in windy days at coastal locations. The changes in the extreme event indices continue through 2100 under the higher-emission (RCP 8.5) emission scenario, while the changes generally stabilize under the lower-emission (RCP 4.5) scenario. .

关键词： Extreme Events Temperature Precipitation Alaska Climate

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手捧空花盆的孩子

空中英语教室（初级版．大家说英语） 2024年第2期 25-27,52,53页

作者： john Telfer 不详

找找看国王给了每个孩子什么东西?从前,有一位非常有智慧的国王。他的年纪很大了,而且没有子女。他下令让他的子民把他们的孩子都带到王宫来。“现在是选择下一任国王的时候了,”他说,“我会从这些孩子当中选出一个人。”人们非常兴奋,... 详细信息

找找看国王给了每个孩子什么东西?从前,有一位非常有智慧的国王。他的年纪很大了,而且没有子女。他下令让他的子民把他们的孩子都带到王宫来。“现在是选择下一任国王的时候了,”他说,“我会从这些孩子当中选出一个人。”人们非常兴奋,他们带着孩子来到了王宫。

关键词：子民花盆国王

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夏季奥运会

空中英语教室（初级版．大家说英语） 2024年第7期 45-47,56页

作者： john Telfer 不详

你看奥运会吗?选手们在众多竞赛中跑步、跳跃和游泳。最棒的选手会赢得奖牌,金牌是最高的荣誉。今年的夏季奥运会是在法国巴黎举行。届时将会有1500万人前往巴黎观看比赛,其他人则将在电视上观看奥运会转播。

关键词：夏季奥运会观看比赛跑步奖牌游泳选手

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如何跳绳

空中英语教室（初级版．大家说英语） 2024年第1期 14-15,51页

作者： john Telfer 不详

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如何包饺子

空中英语教室（初级版．大家说英语） 2024年第2期 12-13,50页

作者： john Telfer 不详

一、准备饺子馅料和饺子皮。二、在饺子皮内放一些馅料。三、在饺子皮的边缘蘸一点儿水。四、将饺子皮对折把馅料包起来,把边缘捏起来。五、在锅里装水。六、把水煮开,然后把饺子放进水里。七、再度把水煮开,加一碗冷水。八、重复第七... 详细信息

一、准备饺子馅料和饺子皮。二、在饺子皮内放一些馅料。三、在饺子皮的边缘蘸一点儿水。四、将饺子皮对折把馅料包起来,把边缘捏起来。五、在锅里装水。六、把水煮开,然后把饺子放进水里。七、再度把水煮开,加一碗冷水。八、重复第七步。九、饺子浮上水面。十、把饺子捞出,放在盘子里,好好享用吧。

关键词：馅料饺子皮包饺子冷水边缘饺子馅

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如何做仰卧起坐

空中英语教室（初级版．大家说英语） 2024年第4期 25-26,53页

作者： john Telfer 不详

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伊索寓言

空中英语教室（初级版．大家说英语） 2024年第4期 12-14,51页

作者： john Telfer 不详

一头老狮子住在一个洞穴里。它的动作已经变得迟缓,所以很难抓到食物。“我该怎么办?”它心想,“我已经没办法又跑又跳了,再过不久一定会饿死。”它想了又想。“我知道了!可以让食物接近我啊。我会假装生病,这样其他动物就会来看我,然... 详细信息

一头老狮子住在一个洞穴里。它的动作已经变得迟缓,所以很难抓到食物。“我该怎么办?”它心想,“我已经没办法又跑又跳了,再过不久一定会饿死。”它想了又想。“我知道了!可以让食物接近我啊。我会假装生病,这样其他动物就会来看我,然后我再吃掉它们!”一开始,它的计划进行得很顺利,它躺在它的洞穴里哭泣。动物们听到它的声音,都感到很担心,就进去看它。狮子邀请它们进入洞穴之后,就会把它们吃了!有一天,一只狐狸从洞穴旁边经过。它听到一个声音,是老狮子在洞穴里哭。狐狸站在外面。“你还好吗?”它问狮子。

关键词：伊索寓言洞穴狐狸狮子声音食物生病动物