bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Soil Salinity and Irrigation Water Quality of Chanchaga Irrigation Scheme I, Minna, Niger State
Authors: Kuti Ibrahim A , Adabembe Bolaji A , Musa John J , Adeoye Peter A , Animashaun Murtala , Aroboinosen Hillary , Akhare Michael E
Published: June 2020

The extent to which salinity is increasing in arid and semi-arid regions recently has become a concern in irrigation and non-irrigation land. In view of this, the study evaluated soil salinity and irrigation water quality at Chanchaga Irrigation Scheme I, Minna, Niger State with the aim of assessing the soil fertility status and irrigation water source of the scheme. The study took soil samples at 0 - 30cm depth from irrigated and non-irrigated plots and water was taken from the main point of the border irrigation system. Both soil and water sample collected were subjected to laboratory analysis. The study determined sodium absorption ratio and exchangeable sodium percentage of soil and water parameters analyzed in the laboratory. The Levene's test for equality of variances was performed on the concentration of the parameters analyzed in both soil (irrigated and non-irrigated plot) and water of the scheme. The study reveals that the sodium concentration was found higher in the irrigated plot than control plot and the EC and SAR values of the irrigated plot was classified as sodic. The SAR and other exchangeable values in both irrigated and non-irrigated plot have equal variances (> 0.10) with the exception of chlorine which is significant. The level of potassium in the water was higher and sodic in nature. The study concluded that the sodium hazard in both soil and water was higher than the desirable limits. It is important to take the soil sample of the whole plots so as to examine the salt variation in the scheme
Effect of Magnetic Treatment of Irrigation Water on Growth and Yield of Maize under different Water Deficit Conditions
Authors: Yusuf Kamorudeen O , Adeleye Anthony A
Published: June 2020

This study was conducted to determine the effect of magnetic treatment of irrigation water (MTW) on the growth and yield of maize under water deficit conditions. The maize was planted in a pot (2 stands per pot) in a transparent garden shed using Completely Randomized Design (CRD). A magnetic flux density of 443 gauss produced from electromagnet was used and measured inside the pipe using a gaussmeter Model GM-2 by Alpha Lab Inc. Water was allowed to flow through the magnetic field in a pipe for about 113 seconds. Four treatments used were 100 (2 litres at 100 %), 80, 60 and 50 % of water requirement labelled as T1, T2, T3 and T4, respectively and each treatment was replicated four times. A control experiment by non–magnetic treatment of water (NMTW) was also set up. The mean heights of maize plant with MTW at 29 days for T1, T2, T3 and T4 were 160, 184, 106, 103 mm while the yields after 86 days were 238.1, 281.6, 232.1 and 210.1 g/pot, respectively. The heights of maize plant with NMTW for T1, T2, T3 and T4 at 29 days were 124, 151, 91 and 90 mm while the yields after 86 days were 156.3, 209.6, 201.6 and 150.6 g/pot, respectively. The yield of maize from MTW compared to yield of maize from NMTW was statistically significant under the same water deficit condition by statistical pair t-test analysis.Keywords: Deficit irrigation, Magnetic treatment of water, Magnetically treated water, Maize
Design and Implementation of a Sequential Digital Display for a Nigerian University
Authors: Aribisala Adetoye , Martins Oluwaseun , Otenaike Adegboyega , Ajayi John
Published: June 2020

A sequential digital display is an electronic system that is used to display information to the public. It is a device that contains light emitting diodes that conveys messages by a programmable controller or mechanical processes, regardless of size. Sequential digital display is fast gaining acceptance and application in different spheres of life. In this work, a sequential digital display system was designed and implemented. The components used include transformer, diodes, voltage regulator, resistors (fixed and variable types), capacitors, NE 555 timer, IC4017, IC7432, light emitting diodes and transistors. The aim of the project was to carry out a cost effective design, therefore, the components of the design were readily available and relatively cheap. The light emitting diodes displayed a message written as: Welcome to NOUN Ado-Ekiti study center. The project was tested and commissioned and found to meet specified design requirements.Keywords—Integrated Circuit, Light Emitting Diodes, Sequential Digital Display, Transistor
Environmental Impact of Lumber Production using Life Cycle Assessment: A Case Study of the Production System in South-west Nigeria
Authors: Owofadeju Femi K , Agbaje Omeiza A , Ewemoje Temitayo A
Published: June 2020

Life Cycle Assessment (LCA) is a decision support tool that can be used to evaluate the potential environmental impact of a product system. Environmental impact associated with the production of (0.0508×0.1524×3.6576) m lumber referred to as “2by6” in the primary wood industry was evaluated. This assessment is a cradle to gate system with boundaries spanning from the point of raw material extraction in Osun state, to transportation of the lumber product to wood market in Ibadan, Oyo state. The study compared four production scenarios by varying haulage distance and energy source during production at two sawmill facilities located in Ife and Ikire in Osun state. Data obtained from the production system were analysed using GaBi6 software to estimate and classify the emissions into five impact categories. Life Cycle Impact Assessment result (LCIA) showed that Acidification Potential (AP), Global Warming Potential (GWP) and Smog Potential (SP) were the most significant impact indicators observed in the four production scenarios. AP (2.883, 3.352, 3.483, 3.951) kg H+ mole-Equiv, GWP (13.25, 14.44, 15.45, 16.65) kg CO2-Equiv and SP (1.86, 2.15, 2.24, 2.53) kg O3-Equiv. Scenario 4 which involved a longer transportation distance and employed a diesel generator for the milling process showed the least environmental performance. Processes that contributed significant impact were wood waste disposal method employed and the secondary transportation processes during logging activities. In order to achieve a better production system, practices that encourage less waste generation and the use of renewable energy were recommended.Keywords— LCA, lumber production, environmental impact, wood waste
Wireless Sensor Network Based Health Monitoring System for Hypertensive In-Patients
Authors: Omodunbi Bolaji A , Esan Adebimpe O , Olaniyan Olatayo M , Adeyanju Ibrahim A , Raheem Waliyullah , Okoli Gabriel C , Badmus Taofeeq A
Published: June 2020

Hypertensive-patient monitoring is a continuous process of observing closely the situation of patient's blood pressure and alerting the appropriate personnel in case of any anomaly. It usually requires the use of non-invasive sensors that are hardwired to bedside monitors. Although, present systems allow continuous monitoring of patient vital signs and limit the patient to the bed, the readings are mostly stored on the system local memory over a period of time before it is assessed for analysis. Hence, the need for a real time hypertensive patients’ monitoring system which can meet up with immediate demands of emergency cases. This paper presents a Wireless Sensor Network (WSN)-based health monitoring system that addressed the aforementioned drawbacks for monitoring hypertensive in-patients. The design of the system comprises of hardware components such as blood pressure sensor, Bluetooth serial communication circuit, sensor node for base station interfaces and software components. Performance evaluation of the designed system gave an accuracy of 89.7% in blood pressure monitoring. The system is also cost effective, reliable and user friendly when compared with existing systems. Keywords— Blood Pressure, Health monitoring, Hypertension, Wireless Sensor Networks
Analysis of the Generalized Inverse Polynomial Scheme to Initial Value Problems
Authors: Abolarin Olusola E , Akingbade Samuel W
Published: June 2020

In this paper, we study the analysis of the generalized inverse polynomial scheme for the numerical solution of initial value problems of ordinary differential equation. At first, we generalize the scheme up to the fifth stage using the Binomial expansion and Taylor’s series method towards its derivation. The trend shows the generalization to the kth term. The analysis demonstrates the efficiency and the effectiveness of the generalized scheme.Keywords— Taylor’s Series, Initial Value Problem, Stability, Consistency, Convergence.
Probabilistic System Availability Model and Prevailing Factors for 33kV Primary Power Distribution Feeders in Nigeria
Authors: Melodi Adegoke O , Agare Efe K
Published: June 2020

Outage and complimentary load flow analyses of a selected 33kV primary distribution network in Ughelli Delta State, Nigeria, were carried out to depict feeder availability obtainable in the country. Outage and load flow analyses were carried out using parametric statistics and Newton-Raphson computation algorithm respectively. The results provide model distribution of monthly feeder availability, contributions of outage factors and normal load flow values. It was concluded that: monthly feeder availability represented using normal probability distribution function of; shows that overcurrent and earth faults contribute to outage duration, taking 5% to 12% of the month outage duration respectively; coupled with significant line losses and weak voltage profile. Recommendations proposed include: replacement of weak or failed elements and insulations in the systems with new and modern ones to mitigate especially earth faults in the short term; planning for immediate increase in system capacity to accommodate the power demand effectively for present and forecast periods to eliminate load shedding, overload events, and high technical losses; maintenance practice at the planning and execution stages to mitigate failure events and repair time. Keywords – fault, outage, probability, load flow, availability, distribution network.
Evaluation of Cement and Bitumen Emulsion on Strength Characteristics of Native South African Granular Soil as Base Course Material
Authors: Abiola Oladapo S , Wilson Reece , Barnard Anthony , Hattingh Shaun , Kupolati William K , Odunfa Simeon O
Published: June 2020

Pavement rehabilitation where the material in the existing pavement is recycled in-situ with bitumen will sustain the environment with conservation of natural aggregates, reduction in noise, dust emission and traffic disruption. This study investigate the effects of a native South African granular material stabilized with cement and bitumen emulsion as a base layer in pavement construction. The material stabilized with cement-bitumen emulsion (2-3%) was subjected to Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) tests for 1, 4, 7 and 28 days curing. The UCS and ITS requirement was evaluated with respect to a base layer for design traffic application of less than six million equivalent single axles. The results of UCS and ITS tests for the stabilized material showed improved strength and have the potential for use as a base course material for the design traffic. The result revealed that 2.5% cement and bitumen emulsion meets the minimum strength characteristics for the base layer. Relative to 2% cement and 2% bitumen emulsion, ITS obtained for 4 and 7 days of curing increased approximately by 24%, 41% and 24%, 53% respectively. Models for UCS in terms of ITS was developed for cement and bitumen emulsion which will make one test among the two sufficient to indicate the strength of cement and bitumen emulsion stabilized materials at the mix design level. Bitumen stabilization is a quick construction method, with lower cost than reconstruction and good for rehabilitation. Keywords— bitumen emulsion, cement, granular, indirect tensile strength unconfined compressive strength.
Microanalysis and Compactive Efforts Study of Black Cotton Soil Treated With Cement Kiln Dust
Authors: Salahudeen Anigilaje B , Eberemu Adrian O. , Osinubi Kolawole J.
Published: June 2020

An expansive clay, also known as Black cotton soil (BCS) was treated with up to 10 % cement kiln dust (CKD) using three different compactive efforts; British Standard light (BSL), West African Standard (WAS) and British Standard heavy (BSH) energies. Laboratory tests were performed on the natural soil and CKD treated soil samples in accordance with BS 1377 (1990) and BS 1924 (1990) respectively with the aim of improving the deficient soil to meet engineering requirements. Preliminary evaluations on the natural black cotton soil showed that it fell under A-7-6 (16) using AASHTO classification and CL according to Unified Soil Classification System (USCS). Results of laboratory tests carried out on soil specimens show that the properties of the soil generally improved with CKD treatment. Peak unconfined compressive strength (UCS) values of 357.07, 382.49 and 528.82 kN/m2 and California bearing ratio (CBR) of 7, 10 and 19 % as well as resistance to loss in strength of 44, 55 and 55 % were recorded at 10 % CKD treatment, respectively, for BSL, WAS and BSH compactive energies. Reduction in the particle sizes with curing period was observed when samples were viewed through the scanning electron microscope (SEM). The study showed that CKD can be beneficially used to improve the subgrade of lightly trafficked roads and as admixture in lime stabilization during construction of flexible pavements over expansive soil.Keywords: California bearing ratio; Cement kiln dust, Durability; Expansive soil; Microanalysis, Unconfined compressive strength; Scanning electron microscope.
Design of an Anaerobic Digester for Generation of Biogas Fired in a Burner and Lamp
Authors: Ozigi Idris I , Oodo Stephen O , Lawal Nasir M
Published: June 2020

This work presents design of an anaerobic digester for generation of biogas fired in a burner and in a gas mantle lamp. The methodology utilized equations to describe digester that stores slurry and biogas which were discharged according to designed orifices over a period. Models to predict volume of biogas generation over a period of retention, spent slurry discharge height from cylindrical digester to expansion chamber as well as energy delivered to the biogas burner and lamp were developed to promote scale and dimensions of digester systems. The anaerobic digester was determined to have a total plant volume of 10.5 m3. The volume of biogas generated over a period of 42 days retention shows a concave down curve of exponential polynomial equation, with highest rated daily gas production of about 5 m3 occurring between 15-25 days. The spent slurry flows towards expansion chamber as slurry level decreases in the digester and became much pronounced in day 15 of 42 days retention. The burner had specific firing rate of 0.256 m3/s/m2 and heat output per unit port area of 677 W/cm2 while the lamp light output was 1267 lm for an illumination area of 11.3 m2. The cumulative heat load of the burner and lamp reaches about 9.0 kW and 2.0 kW, respectively.Keywords: Anaerobic Digester; Biogas; Burner; Lamp; Models
E-Agriculture Reviewed: Theories, Concepts and Trends
Authors: Okediran Oladotun O , Ganiyu Rafiu A
Published: June 2020

One of the foremost sectors that have shaped the socioeconomic development of most countries is agriculture. Over the years, the benefits accruing from the widespread adoption and use of information and communication technologies (ICTs) in agriculture includes increasing people’s knowledge and practice of agricultural processes and hence improving agricultural production and linkages to remunerative markets, food security, national economies amongst many other benefits. A field of activity related to the use of modern information and communication tools and technologies that increase agricultural productivity and make available information that is relevant to agricultural research, planning, extension, production, monitoring, marketing and trade is referred to as e-agriculture. In this paper, we present a methodical review of theories, concepts and trends of e-agriculture. Keywords— Development, e-Agriculture, Globalization, Information and Communications Technology (ICT)
Engine Performance of a Gardener Compression Ignition Engine using Rapeseed Methyl Esther
Authors: Dandajeh Hamisu A , Ahmadu Talib O
Published: June 2020

This paper presents an experimental investigation on the influence of engine speed on the combustion characteristics of a Gardener compression ignition engine fueled with rapeseed methyl esther (RME). The engine has a maximum power of 14.4 kW and maximum speed of 1500 rpm. The experiment was carried out at speeds of 750 and 1250 rpm under loads of 4, 8, 12, 16 and 18 kg. Variations of cylinder pressure with crank angle degrees and cylinder volume have been examined. It was found that RME demonstrated short ignition delay primarily due to its high cetane number and leaner fuel properties (equivalence ratio (φ) = 0.22 at 4kg). An increase in thermal efficiency but decrease in volumetric efficiency was recorded due to increased brake loads. Variations in fuel mass flow rate, air mass flow rate, exhaust gas temperatures and equivalence ratio with respect to brake mean effective pressure at engine speeds of 750 and 1250 rpm were also demonstrated in this paper. Higher engine speed of 1250 rpm resulted in higher fuel and air mass flow rates, exhaust temperature, brake power and equivalent ratio but lower volumetric efficiency. Keywords— combustion characteristics, engine performance, engine speed, rapeseed methyl Esther
Development of an Automatic Body Mass Index Measurement Machine
Authors: Ewetumo Theophilus , Adedayo Kayode D , Lawal Yusuf B , Edun Abiodun T , Orokhe Joseph E
Published: June 2020

The potential occurrence of certain illnesses can be easily diagnosed through measurements of some health indicators. One of such parameters is the Body Mass Index (BMI). BMI is simply the ratio of mass (kg) of a body to the square of its height (m2). This research presents the design and construction of an automated BMI measurement machine for medical purposes. It consists of three major units: the weighing unit (5 – 200 kg); height-measuring unit (0.02 – 2 m) and the processing unit. The weighing unit is made up of load button cell and load cell amplifier while the height-measuring unit consists of ultrasonic sensor. The analog differential output voltage from load cell is connected to arduino microcontroller via a Programmable Gain Amplifier (PGA) integrated with Analogue-to-Digital Converter (ADC). The two units are connected to an open source arduino uno which computes mass-to-body ratio and sends the output results (mass, height and BMI) to the liquid crystal display (LCD). The weighing system was calibrated against a precision digital weighing system and it gave a correlation of 0.99. The height measurement was also compared with manual height measurement using a tape rule which gave a correlation of 0.97. The developed Instrument is cost effective and has high positive correlation with the standards (weighing scale and tape rule), it is therefore recommended for the measurement of weight, height and BMI. Keywords— load button cell, load cell amplifier, ultrasonic, body mass index, arduino uno
Tribological and mechanical behaviours of nanostructured aluminium alloys and nanocomposites at elevated temperatures: A short review
Authors: Ajibola Olawale , Owa Adebayo , Adebayo Abdullahi , Borisade Sunday , Adigun Oluwole
Published: June 2020

Aluminium alloys demonstrate exceptional properties such as high strength-weight ratio and corrosion resistance are used for general engineering applications, automobile, automotives and in aerospace industries. However, they suffer some limitations as wear and creep at high temperatures. With the trending developments from nanometallurgy, diverse nano-particle compounds of mono and heterogeneous compositions have been used in reinforcing aluminium and its alloys as widely reported in the public domains. This paper reviews some of the vast literature on the enhancement of nanostructured aluminium alloys and reinforced aluminium nanocomposites. Importance is laid on the tribological and mechanical behaviours of the manufactured composites and nano-composites with respect to their production methods and applications at elevated (high) and cryogenic (low) temperatures. Keywords— Tribology; mechanical behaviours; nanostructure; aluminium alloys; nano-composites; elevated temperatures
Comparative Analysis of XML Schema Languages for Improved Entropy Metric
Authors: Sotonwa Kehinde A
Published: June 2020

The eXtensible Markup Language (XML) is a data set to represent data in a format that is both human readable and machine readable. For XML documents to provide understanding about data exchange between applications, XML schema documents should be validated against the schema language. Most existing schema metrics were implemented differently in Document Type Definition (DTD), XML Schema Definition (XSD) and Regular Language for Next Generation (RNG) but never compare XML schema languages on any metric. Hence this paper compared three different schema languages on Improved Entropy Metric (IEM) using the Number of Attributes (NA), Number of Equivalence Class (NEC), Frequency Occurrence of Class (FOCi) and Number of Elements (NE). The proposed metric was applied on real schemas documents data are acquired from Web Service Description Language (WSDL) and implemented in DTD, XSD and RNG. The result showed that RNG reduce complexity of class elements, reflect strong support for class elements to appear in any order which showed more reusability and flexibility traits and overall understanding of the schema documents becomes much easier because RNG can be algorithmically converted and partner with other schema languages therefore this reduces maintenance effort. Keywords— XML Schema Language, Schema Documents, Schema Metrics
Determination of an Annual Groundwater Recharge and Demand in Oke-Ero LGA, Kwara State, Nigeria
Authors: Agboola Akeem A , Adeogun Babatunde K , Ajibike Morufu A
Published: June 2020

Efficient groundwater management, water consumption rate and quantitative determination of the amount of rainfall that recharges groundwater naturally is essential for a place like Oke-Ero LGA where  the people in Oke-Ero depend mainly on groundwater as the only source of water supply. In this work, an attempt has been made to evaluate the amount of rainfall that recharges aquifers using Krishna model with a view to knowing the groundwater potential of the area and determine the water consumption rate. This study established that Oke-Ero LGA has 65.7 million cubic meters (MCM) groundwater potential annually, from the survey output the average daily water demand in Oke-Ero is 75 l/c/d. The total water demands across the LGA based on 2016 population estimate is 2.11 MCM/year with anticipated increase of 4.34 MCM/year by 2040 and expected water demand increase rate of 3.2% annually. This work has ascertained that the available water is sufficient to take care of the water demand of the people in Oke-Ero LGA and it also shows that there is more water for other activities such as industrial purposes. Keywords - Groundwater potential, Groundwater recharge, Oke-Ero LGA, Water demand.
An Efficient Seven-Step Block Method for Numerical Solution of SIR and Growth Model
Authors: Abolarin Olusola E , Ogunware Gbenga B , Akinola Lukman S
Published: June 2020

In this article, a new implicit continuous block method is developed using the interpolation and collocation techniques via Power series as the basis function. A constant step length within a seven-step interval of integration was adopted. The selected grid points were evaluated to get a continuous linear multistep method. The evaluation of the continuous method at the non-interpolation points produces the discrete schemes which form the block. The basic properties of the block method were investigated and found to be consistent, zero stable and hence convergent. The new method was tested on real life problems namely: SIR and Growth model. The results were found to compare favourably with the existing methods in terms of accuracy and efficiency.  Keywords: Block method, Growth Model, implicit, power series and SIR model.
Uso de servicios de salud por los adultos mayores en el Hospital Regional Hermilio Valdizán Medrano
Authors: Ramos-Alania Abner
Published: June 2020

La investigación tuvo el objetivo de describir el uso de los servicios de salud por los adultos mayores usuarios del Hospital Regional Hermilio Valdizán Medrano, 2019. Fue un estudio descriptivo, transversal y correlacional, cuya muestra probabilística la conformaron 138 adultos maduros. Se utilizó una guía de entrevista y una ficha de registro del uso de servicios de salud, previamente validada y confiables. Se aplicaron las consideraciones éticas para la investigación. Se realizó el análisis descriptivo y las hipótesis se contrastaron mediante la X2 para p≤0,05. Según los resultados, la mayoría de los adultos mayores eran continuadores [71.7%(99)], el principal motivo de consulta fue la enfermedad crónica de tipo degenerativa [37.0%(17), seguido de infecciones [28.3%(39)]. En 17.4% (24), la principal causa de hospitalizaron en el último episodio fue la Infección Respiratoria Aguda, en 15.2%(21) la diabetes mellitus y problemas cardiovasculares. Respecto a la utilización de los servicios de salud según características sociodemográficas, 26.1% (36) de los adultos masculinos utilizaban de forma continua, y en 39.1% (54) de las féminas fue discontinua. Un 19.6% (27) de los que tuvieron entre 70-79 años de edad; 37.0% (51) y 13.0% (18) de quienes no tenían nivel educativo y nivel primario respectivamente, 32.6% (45) cuyos ingresos fueron entre 500-799 soles y 30.4% (42) de ingresos ≤ 499 soles, utilizaban los servicios continuamente. Estas correlaciones fueron significativas (p ≤0.05) y se concluye que las variables sociodemográficas guardan relación con el uso de los servicios de salud por adultos mayores en el Hermilio Valdizán Medrano Regional Hospital.
A juventude na formação de professores do campo
Authors: Janata Natacha Eugenia
Published: June 2020

Apresentamos resultados de uma investigação em que analisamos a inserção no trabalho docente e na militância de egressos da Licenciatura em Educação do Campo da UFSC, com análise permeada por estudos sobre a juventude que tomam como base a psicologia histórico-cultural. Caracterizamos o curso, com seu histórico, organização curricular, turmas ofertadas, bem como os formados até o ano de 2017. Estabelecemos o recorte para a turma concluída em 2016, da qual entrevistamos 11 egressos. Problematizamos sobre determinantes e contradições de suas inserções no trabalho docente e na militância e a formação da juventude do campo, considerando as peculiaridades da região em que ocorreu a licenciatura, bem como as questões mais gerais que atravessam a vida de todos sob as relações sociais de produção capitalistas. Concluímos pelo potencial formativo da consciência de classe da juventude, evidenciando a importância de abordá-la na formação de professores do campo, tendo a apropriação dos conceitos científicos, artísticos e filosóficos, bem como a inserção nas lutas sociais como horizonte.
Jogos de linguagem e jogos de movimento: deslocamentos lúdicos na aula de língua italiana
Authors: Bunn Daniela
Published: June 2020

O objetivo deste estudo é socializar duas atividades lúdicas de ensino de língua italiana que podem ser adaptadas para outros contextos de ensino. As dinâmicas baseiam-se, principalmente, em jogos linguísticos e jogos de movimento que permitem ao aluno deslocar-se em sala de aula, como, por exemplo, na atividade de desenvolvimento oral Caccia al tesoro (Caça ao tesouro), na qual o aluno deve movimentar-se pela sala em busca de colegas que preencham requisitos orientado por uma série de perguntas lúdicas e nonsense. Atividades de movimento como essa estimulam, além do uso da língua oral e da aquisição de vocabulário, possibilidades de entrosamento e (re)conhecimento de pares no microuniverso da sala de aula. A outra proposta é denominada Il sasso nello stagno (A pedra no pântano) e configura-se como a produção criativa de acrósticos. Essas práticas lúdicas são direcionadas a crianças a partir do Ensino Fundamental II e também a adultos, e se baseiam nos preceitos da Gramática da fantasia (Grammatica della fantasia, 1973), de Gianni Rodari. São jogos que promovem o estranhamento e estimulam a criatividade. Os alunos interagem, refletem sobre a língua, brincam, apre(e)ndem e as propostas didáticas fluem de uma maneira mais espontânea.
Quantifying sources of Brazil's CH4 emissions between 2010 and 2018 from satellite data
Authors: Tunnicliffe Rachel L. , Ganesan Anita L. , Parker Robert J. , Boesch Hartmut , Gedney Nicola , Poulter Benjamin , Zhang Zhen , Lavrič Jošt V. , Walter David , Rigby Matthew , Henne Stephan , Young Dickon , O'Doherty Simon
Published: June 2020

Abstract. Brazil's CH4 emissions over the period 2010–2018 were derived for the three main sectors of activity: anthropogenic, wetland and biomass burning. Our inverse modelling estimates were derived from GOSAT satellite measurements of XCH4 combined with surface data from Ragged Point, Barbados and the high-resolution regional atmospheric transport model NAME. We find that Brazil's mean emissions over 2010–2018 are 33.6 ± 3.6 Tg/yr, which are comprised of 19.0 ± 2.6 Tg/yr from anthropogenic (primarily related to agriculture and waste), 13.0 ± 1.9 Tg/yr from wetlands and 1.7 ± 0.3 Tg/yr from biomass burning sources. In addition, between the 2011–2013 and 2014–2018 periods, Brazil's mean emissions rose by 6.9 ± 5.3 Tg/yr and this increase may have contributed to the accelerated global methane growth rate observed during the latter period. We find that wetland emissions from the Western Amazon increased during the start of the 2015–16 El Nino by 3.7 ± 2.7 Tg/yr and this is likely driven by increased surface temperatures. We also find that our estimates of anthropogenic emissions are consistent with those reported by Brazil to the United Framework Convention on Climate Change. We show that satellite data is beneficial for constraining national-scale CH4 emissions, and, through a series of sensitivity studies and validation experiments using data not assimilated in the inversion, we demonstrate that calibrated ground-based data are important to include alongside satellite data in a regional inversion, and that inversions must account for any offsets between the two data streams and their representations by models.
Warmer winter causes deepening and intensification of summer
subsurface bloom in the Black Sea: the role of convection and self-shading
mechanism
Authors: Kubryakova Elena A. , Kubryakov Arseny A.
Published: June 2020

Abstract. Large differences in the vertical distribution of chlorophyll-a concentration (Chl) in a year with cold and warm winter are observed in the Black Sea on the base of Bio-Argo data. Stronger winter nutrient flux from deeper isopycnal layer in cold 2017 caused an increase of Chl in the upper 40-meter layer observed throughout the whole year – from February to October, with a maximum exceeding 1.3 mg/m3 in February-May of 2017. In warm 2016 with weaker winter convection maximum of Chl during winter-spring in this layer was only about 0.8–0.9 mg/m3. However, the increase of Chl in 2017 led to strong light attenuation in the upper layer and a decrease of euphotic layer depth due to the self-shading mechanism. In 2016 with weaker bloom irradiance penetrated to a 40–70 m layer, below the maximum winter mixed layer depth (40–50 m) and reached the upper layer of nitroclyne, which was not affected by winter mixing. As a result, in warm 2016 the subsurface chlorophyll maximum deepens and Chl in deeper layers was on 0.2–0.6 mg/m3 higher than in 2017. The maximum difference (0.6 mg/m3) was observed during a summer seasonal peak of irradiance due to the largest increase of light attenuation in 2017. As a result, the column-averaged yearly values of Chl in warm 2016 and cold 2017 were comparable. These results demonstrate that the effect of self-shading largely compensates the role of winter convective entrainment of nutrients and causes the deepening of Chl subsurface maximum in warmer years.
Experimental investigation of aerodynamic characteristics of bat carcasses after collision with a wind turbine
Authors: Prakash Shivendra , Markfort Corey D.
Published: June 2020

Abstract. A large number of bat fatalities have been reported in
wind energy facilities in different regions globally. Wind farm operators
are required to monitor bat fatalities by conducting carcass surveys at wind
farms. A previous study implemented the ballistics model to characterize the
carcass fall zone distributions after a bat is struck by turbine blades. The ballistics
model considers the aerodynamic drag force term, which is dependent upon
the carcass drag coefficient. The bat carcass drag coefficient is highly
uncertain; no measurement of it is available. This paper
introduces a methodology for bat carcass drag coefficient estimation. Field
investigation at Macksburg wind farm resulted in the discovery of three bat
species: the hoary bat (Lasiurus cinereus), eastern red bat (Lasiurus borealis), and evening bat (Nycticeius humeralis). Carcass drop
experiments were performed from a dropping platform at finite height, and
carcass position time series data were recorded using a high-speed
camera. Falling carcasses were subjected to aerodynamic drag and
gravitational forces. Carcasses were observed to undergo rotation, often
rotating around multiple axes simultaneously, as well as lateral
translation. The complex fall dynamics, along with drop from a limited height,
prohibit the carcasses from attaining terminal velocity. Under this
limitation, the drag coefficient is estimated by fitting a ballistics model to
the measured velocity. Multivariable optimization was performed to fit the
ballistics model to the measured velocity resulting, in an optimized estimate of
the drag coefficient. A sensitivity analysis demonstrated significant variation
in the drag coefficient with a small change in initial position, highlighting the
chaotic nature of carcass fall dynamics. Based on the limited sample, the
bat carcass drag coefficient and terminal velocity were found to be between
0.70–1.23 and 6.63–17.57 m s−1, respectively. The maximum distance
carcasses are predicted to fall after impact with a typical utility-scale
onshore wind turbine was computed using a 2-D ballistics model. Based on
the range of drag coefficients found in this study, hoary and evening bats
are estimated to fall within the rotor plane up to a maximum distance of 92 and 62 m, respectively, from the wind turbine tower. The ballistics model of
carcasses after being struck by wind turbine blades can be used to obtain fall
distributions for bats, guide carcass survey efforts, and correct survey
data for limited or unsearched areas.
Presidential Address, 2006 Comparative Education in Changing Times: A View with a Southern Exposure
Authors: De Pass Cecille
Published: June 2020

Adopting a wide angle lens to photograph selected educational vistas, the address also focuses on specificities associated with intractable challenges in comparative education. The paper offers a three part approach to discuss concomitant complexities: the first approach represents a well established historical tradition; the second, emphasizing interdependence, usually depicts the dominant mainstream perspective. In contrast, the third approach embedded in social justice, critical pedagogy, and opposition, demands significant structural changes. Understandably, the latter is the least likely to be adopted at regional, national and international levels.
Se servant d’un objectif à grande ouverture pour photographier les vues choisies de l’ éducation, ce rapport présidentiel se centre aussi autour des spécificités associées avec les défis complexes de l’ éducation comparée. Il offre trois approches différentes pour discuter des complexités concomitantes: la première approche représente une tradition historique bien établie; la seconde, soulignant l’interdépendance, décrit souvent la perspective de la tendance dominante. En contraste, la troisième approche, se plantant dans la justice sociale, la pédagogie critique, et l’opposition, exige des changements structuraux significatifs. On comprend bien que cette dernière approche est la moindre à être adoptée aux trois niveaux régional, national et international.
Comparing Connecticut and Finland: Teacher Friendly Policies in an Age of Accountability
Authors: Larsen Marianne
Published: June 2020

Educational policy makers across a wide array of settings have made concerted efforts to improve their educational systems by paying close attention to their teaching profession. The state of Connecticut in the north-eastern U.S.A. and the northern European country of Finland are two such jurisdictions. However, unlike most other settings, where low-trust, accountability based policies have been imposed on the teaching profession, Finland and Connecticut’s policies can be considered teacher-friendly. This paper compares the teacher policies implemented in those two settings over the past fifteen years. Given the well-documented link between teacher quality and student achievement, it is worth considering these teacher friendly policies, which shift the focus from high-stakes accountability to improving teachers’ working conditions and the overall prestige of the profession within a supportive policy framework.﻿
Les responsables des politiques de l’enseignement public, à travers une rangée étendue de milieux, ont fait conjointement des efforts pour améliorer leurs systèmes d’enseignement en prêtant plus d’attention à la profession de l’enseignement. L’ état de Connecticut dans le Nord-est des États-Unis et la Finlande, pays nordique de l’Europe sont deux de telles juridictions. Cependant, à l’opposé des autres milieux, où une confiance peu élevée et une politique ayant pour base la responsabilité scrutateuse se sont imposées sur la profession de l’enseignement, la Finlande et le Connecticut ont adopté une politique que l’on peut dire amicale envers les enseignants et enseignantes. Cet article compare ces politiques qui ont été mises en cours dans ces deux milieux pendant les quinze dernières années. Etant donné la corrélation bien documentée entre la qualité des instituteurs et institutrices et le résultat accompli des éléves, il vaut bien l’effort de considérer ces politiques amicales aux enseignants et enseignantes. Ces politiques ont remplacé le centre d’attention sur une responsabilité sévère par l’amélioration des conditions de travail des enseignants et ont rétabli le prestige de la profession dans le cadre d’une politique de soutien et d’appui.
Chinese Graduate Students at North American Universities: Learning Challenges and Coping Strategies
Authors: Huang Jinyan , Klinger Don
Published: June 2020

The paper investigated four Chinese graduate students’ perceptions of the challenges they face and the coping strategies they use in their English academic learning at two North American universities. They reported experiencing the following seven major challenges in their academic learning: 1) financial difficulties; 2) problems in using English for academic purposes; 3) frustrations in becoming a permanent resident; 4) difficulty in adapting to the classroom learning environment; 5) lack of critical thinking skills; 6) acculturation problems; and 7) loneliness and academic anxiety. For each of the seven challenges they have developed corresponding coping strategies.
Cet article examine la perception des défis auxquels devaient faire face quatre étudiants chinois et les stratégies qu’ils employaient pour survivre dans le milieu d’apprentissage académique anglais de deux universités en Amérique du nord. Ils ont éprouvé, disaient-ils dans leurs récits, les sept défis importants suivants: 1) des difficultés financières; 2) des problèmes sur l’usage de l’anglais pour des fins académiques; 3) des frustrations dans leurs applications pour la résidence permanente; 4) des difficultés d’adaptation au milieu d’apprentissage de leurs classes; 5) un manque d'aptitude d’esprit crituque; 6) des problèmes d’acculturation; et 7) la solitude et l'anxiété académique. Pour chacun de ces défis, ils ont développé des stratégies de survie correspondantes.
L’interculturel en environnement : Rencontre de la justice sociale et de la justice environnementale
Authors: Thésée Gina , Carr Paul
Published: June 2020

Le sur-développement des pays du Nord fait planer sur le monde entier des menaces sans précédent. Les changements climatiques sont les signes avant-coureurs, à long, moyen ou court terme, de ces menaces. Aux prises directement avec les premiers impacts, les populations du Sud voient leurs multiples vulnérabilités s’accentuer. Si l’approche écologiste, après des décennies de combat, a finalement reçu l’attention des mondes politique et économique à propos des défis environnementaux, ces derniers ont adroitement opéré un virage conceptuel significatif : l’environnement et l’éducation relative à l’environnement (ERE) ont cédé la place au développement durable et à l’éducation au développement durable (EDD). Or, dans cette refonte conceptuelle, le modèle hégémonique du développement à l’occidental n’est pas remis en question. Il poursuit, entre autres, ses visées impérialistes en muselant toujours les cultures qu’il domine, tout en invalidant les savoirs dont elles sont porteuses. Il y a tout lieu de parler ici d’un racisme épistémologique. Ce texte propose quelques pistes de réflexion pour une rencontre des cultures en environnement où la justice sociale et la justice environnementale se conjuguent.
Unprecedented threats hover over the entire world as a result of overdevelopment of Northern countries. Climate changes are the long-, medium-, and short-term forerunners of these threats. In direct grip of the first impact of the problems, the people of the South witness an increase of their multiple vulnerabilities. After decades of struggles, if the ecological approach has finally received the attention of the political and economical world authorities regarding the environmental challenges, these latter have skilfully created a significant conceptual change of policy: the environment and education related to environment (ERE) have been replaced by sustainable development and education for sustainable development (ESD). However, in this conceptual remake, the hegemony of the Occidental development model was not challenged. So this model pursues, among other things, its imperialist designs by always silencing other cultures under its domination, while invalidating the knowledges embedded in these cultures. One can speak of an epistemological racism. This paper proposes some means of reflexion to create a meeting place between cultures on the environment where social justice and environmental justice can be of the same mind.
Globalization and Post-Secondary Education Policy in Canada:A Review of Trends
Authors: Kirby Dale
Published: June 2020

In 2005, provincial governments in Ontario and Newfoundland and Labrador each commissioned comprehensive public post-secondary education and training system reviews. While there are considerable differences between the systems and policy approaches in these jurisdictions, the final reports of each of these reviews provide an interesting repository of current post-secondary policy tendencies in Canada. The principal arguments and recommendations put forward in the review reports demonstrate the pervasive influence of economic globalization and the continuing shift to a more utilitarian and market-oriented ideological outlook on post-secondary education’s raison d'être. The policies advocated by both reviews illustrate, to varying extents, the impact of dominant influences on modern post-secondary policies including workforce training, privatization, marketization, internationalization and quality assessment mechanisms.
En 2005, les gouvernements provinciaux de l'Ontario et de Terre-Neuve et Labrador ont commandé séparément des comptes-rendus détaillés sur les systèmes publiques d'enseignement et de formation au niveau post- secondaire. Quoiqu'il y ait bien des différences entre les systèmes et les approches politiques des deux provinces, chacun des comptes-rendus finals devient un répertoire intéressant des tendances en cours de la politique de l’éducation post-secondaire. Les recommendations et arguments principaux présentés dans ces comptes-rendus démontrent l'influence envahissante de la mondialisation économique et le changement continu vers une perspective idéologique plus utilitaire et plus orientée vers la commercialisation sur la raison d'être de l'enseignement post-secondaire. Les recommandations de ces deux comptes-rendus démontrent l'effet des influences dominantes sur la politique de l’éducation post-secondaire moderne pour y incorporer la formation de la main-d'œuvre; la privatisation et la commercialisation et les mécanismes d'évaluation de la qualité.
Educational Reform Via School Councils: Comparing Saskatchewan’s School Community Councils to an International Precedent
Authors: Preston Jane
Published: June 2020

A variety of school governance reform movements directly affected community participation within schools globally during the 1980s and 1990s. This article highlights some of the economic, social, and political undercurrents at the core of this trend. Utilizing historical information as a comparative and dialectic backdrop, the societal and political intricacies interwoven into the recent inception of School Community Councils in Saskatchewan, Canada are explicated. Throughout this article, an overview of the purpose and responsibilities of Saskatchewan’s School Community Councils are compared to and contrasted with the governing persuasion and power of a number of international school councils.
Une série de mouvements de réforme de la gouvernance scolaire a directement touché la participation globale des communautés dans les écoles pendant les années 1980 et 1990. Cet article met en évidence certains facteurs économiques, sociaux, et politiques sous-jacents au coeur de cette tendance. Utilisant les informations historiques comme toile de fond comparative et dialectique, les complexités sociales et politiques entrelacées dans la récente création des conseils de la communauté scolaire en Saskatchewan, au Canada, sont développées. Tout au long de l’article, une vue d’ensemble des buts et responsabilités des conseils de la communauté scolaire en Saskatchewan est comparée et mise en contraste avec la persuasion et le pouvoir régissant d’un certain nombre de conseils scolaires internationaux.