bluuebunny/crossref_metadata_2025 huggingface dataset:
Erratum: The Jiang–Su Absorption for Inclusions of Unital C*-algebras
Authors: Osaka Hiroyuki , Teruya Tamotsu
Published: June 2020

We correct an error in the statement in a proposition and a theorem in Jiang–Su absorption for inclusions of unital C*-algebras. Canad. J. Math. 70(2018), 400–425. This error was found by Dr. M. Ali Asadi-Vasfi and communicated to the authors by N. Christopher Phillips of the University of Oregon, who also suggested the outline for the following correct proofs.
Euler characteristics and their congruences in the positive rank setting
Authors: Ray Anwesh , Sujatha R.
Published: June 2020

The notion of the truncated Euler characteristic for Iwasawa modules is an extension of the notion of the usual Euler characteristic to the case when the homology groups are not finite. This article explores congruence relations between the truncated Euler characteristics for dual Selmer groups of elliptic curves with isomorphic residual representations, over admissiblep-adic Lie extensions. Our results extend earlier congruence results from the case of elliptic curves with rank zero to the case of higher rank elliptic curves. The results provide evidence for thep-adic Birch and Swinnerton-Dyer formula without assuming the main conjecture.
خطاب شجن الذات ما بين الآمال والآلام- قراءة نصية لنماذج من شعر امرئ القيْس
Authors: د. محمود سليم محمد هياجنه د. محمود سليم محمد هياجنه
Published: June 2020

حاولت الدراسة أن تكشف السجوف عن ظاهرة بدت جَليّة في مُقدِّمات امرئ القيس الطَلَلِيّة، وبعض قصائده، هذه الظاهرة هي ظاهرة شجن الذات ما بين الآمال والآلام؛ ولهذا فقد رُصِدتْ مُعطيات الاتساق في النصوص على ضوْء مرجعياته من الدّوال التي يَجْهر بها المشهد اللغوي؛ وبهذا فقد وجدتُ القراءة أن بناء المقدمات الطللية قد نُسِجَ على قواعد بَدتْ مشدودة في مُجْملها إلى قَلَقٍ وتَوَتُّرٍ تمَظْهر بشكل جلَيٍّ بين زمنين يتجاذبانه: الماضي والحاضر، وبين إحساسيْن يَعْتَوِرانه: الأمل والألم، مما خلق حالا من القلق اللائِب والتأزم النفسي لديه، مما أفضى إلى دلالات تعْتَمل في نفسِ الشاعر. إزاء ذلك؛ وقفتْ الدراسة عند هاتيك الظاهرة، محاولة تجليتها، قصْد الوقوف على مضامينها ومرجعياتها النفسية المؤسسة لمثل هذه الظاهرة، التي غَدَتْ نسقا خاصا في كثير من مقدماته الطللية وبعض قصائده.
التحولات الصرفية وأثرها الدلالي في شعر الأخطل دراسة نحوية دلالية
Authors: د. حســـين راضــي العايــدي د. حســـين راضــي العايــدي
Published: June 2020

تناولت هذه الدراسة التحولات الصرفية: اسم الفاعل، واسم المفعول، وصيغ المبالغة والصفة المشبهة في شعر الأخطل، الملقب بشاعر زمانه، وبينت الدراسة درجة شيوع هذه التحولات، كما وضحت الأثر الدلالي الناجم عن تلك التحولات من خلال السياق. وتلونت هذه التحولات دلالياً بعاطفة الشاعر، وانسجمت مع إيقاع قصائده ووزنها الشعري، ناهيك عن تماسكها مع قوافيه؛ لذا اكتسبت هذه الصيغ خصوصية في شعره،كما لوحظ دقة اختيارت هذا الشاعر لتلك الصيغ حيث ساهمت في رسم البنية الكلية في قصائده.
Analysis of the profitability of micro broiler enterprises in Calabar Metropolis, Cross River State
Authors: Ukpabuku Joseph Ugah , Ohen Susana Ben
Published: June 2020

This study was undertaken to evaluate the profitability micro broiler businesses in Calabar metropolis. The specific objectives of the study were to evaluate the profitability of micro broiler enterprises in Calabar metropolis, analyses selected factors which affects the profitability of micro broiler enterprises and to identify the constraints faced by micro broiler enterprises in Calabar metropolis. It made use of primary data obtained from a random sample of 112 micro broiler operators. The data were analyzed using descriptive statistics, profitability ratios, cost and return analysis and Ordinary Least Square Multiple regression approach. The cost and returns analysis showed that the total variable cost of production per cycle amounted to N45,931,670.00 with cost of feed contributing 60.11 percent to the total cost. Total production cost per bird was N1,213.77 and total revenue per bird was N1,862.39, showing a gross margin of  N684.96 and a net income of N648.62 per bird produced. The rate of return on sales (0.35), rate of return on investment (0.53), rate of return on variable cost (1.55) and operating ratio (0.63) all show that micro broiler business in Calabar metropolis was profitable. Output of broiler (flock size) (p<0.01), cost of day old chicks (p<0.05), and transportation fare (p<0.1) were significant to the variation in maximum variable profit. The most dominant constraints identified in the study included; inflationary/recessionary trends, high cost of inputs, poor access to credit, high competition and disease/pest in that order. The study recommended that micro broiler operators should organize themselves into cooperative societies to enable them enjoy the benefits of economies of size and credit facilities from lending agencies. 

Keywords: Profitability, enterprises, micro, broiler, cost and returns
Geophysical investigation of foundation failure at Medina Estate, Lagos, Southwestern Nigeria
Authors: Oladunjoye M.A. , Adejato K.O. , Ogunkoya A.O.
Published: June 2020

Integrated geophysical investigation involving Ground Penetrating Radar (GPR) and Electrical Resistivity methods were carried out at Medina Estate, Lagos southwestern Nigeria to map the subsurface lithology in order to delineate its peat stratigraphy that has been causing foundation failure in the area. Twenty-one traverses (varying from 35-880 m in length) of Ground Penetrating Radar (GPR) survey were conducted along the streets of Medina trending NE-SW and NW-SE directions using the Mala 250 MHZ bi-static shielded antenna. Thirty-six Vertical Electrical Soundings (VES) were carried out using Schlumberger electrode array at some selected points along the established traverses within the area. The GPR data were processed into radar section using Rad Explorer software. The VES data were interpreted quantitatively using the partial curve matching method and 1-D forward modeling with Win Resist Software. Available litho-logs from boreholes drilled within the area were compared with the geophysical results.  Results of the GPR survey delineated three geologic layers which include the topsoil with high amplitude, parallel to sub parallel, horizontal reflections, with thickness varying from 1 to 2 m across the entire profiles and composed of lateritic clay; peat layer with low amplitude, parallel sinuous/wavy reflections with depth of occurrence ranging from 2.0 to 8 m and clay with low amplitude, planar, horizontal, sub-parallel reflections underlying the peat layer. Vertical Electrical Sounding results revealed the presence of three geological layers which are the topsoil, peat and clay and sandy clay with layer resistivity values ranging from 20- 225 Ωm, 5 – 90 Ωm and 36 to 366 Ωm and thickness values ranging from 0.5 – 2 m, 4.0-29.0 m and infinity respectively. Borehole information confirms the occurrence of shallow peat with depth ranging from 1.5 to 9 m and clay layer with depth ranging from 9 to 21 m beneath the area. The GPR survey results correlates with the well logs acquired in the study area. Based on the correlation of the geophysical results with the well logs, the GPR gives better information about the peat layer compared to the Electrical ResistivityMethod. The information obtained from this study shows that the soils at shallow depth are organic soils which are difficult foundation materials because they exhibit very high compressibility, as such making shallow foundation impossible except some form of soil improvement is carried out. The alternative approach is the adoption of deep foundations in form of piles.

Keywords: Foundation Failure, Geophysical Investigation, Ground Penetrating Radar, Vertical Electrical Sounding, Peat.
The influence of media on political knowledge amongst undergraduate students in Ibadan, Nigeria
Authors: Oluwatosin Olaniru , Olusoji Olatunji s. , Olusola Ayandele , Popoola Olugbenga A.
Published: June 2020

Knowledge about politics and government activities increases due to the socialization and enlightenment functions of the mass  media. Youths and students are the largest bloc of voters in Nigeria but seemingly least political informed. This study examines the frequency of the forms of media accessed and level of political knowledge among Nigerian students. It also assessed the relationships between political knowledge and access to  radio, television, newspaper, and social media. Moreover, it investigated the predictive influence of the frequency of media access on Nigerian  students’ political knowledge. The study adopted Uses and Gratification Theory (UGT) to explain how media is used to the advantage of people. Using cross-sectional survey research design, a structured questionnaire was used to collect information on students’ demographic, frequency of  media access and knowledge of Nigerian politics from 246 randomly selected students of the Polytechnic, Ibadan (Mean age is 25.07 years, SD = 6.23). Descriptive and inferential statistics were used to analyze the data. Findings identified social media as the most frequently use media,  followed by radio, television and newspaper.31% of the respondents had very high political knowledge while 3% had no political knowledge. Access to radio is the only significant correlate (r = 0.42, p<0.05) and independent predictor (β= 0.43, t=-3.98, p<0.05) of political knowledge although access  to radio, television, newspaper and social media are significant joint predictors of political knowledge (R2= .18, F (4, 241) = 4.32). Therefore, the study concludes that radio is the foremost source of political knowledge amongst undergraduate students in Ibadan, Nigeria. It recommends that various  media institutions and political analysts should take advantage of the social media to make more audience politically knowledgeable.

Keywords: Political knowledge; Mass media; Social media;  Traditional media; Nigerian students.
COVID-2019 – lessons to learn in Africa (Short Communication) A critical review on the potential effect of COVID-2019 on Africa and lessons to be learnt
Authors: Williams Victor
Published: June 2020

No abstract.
Effet de la terre des termitières sur la croissance de trois cultivars de la morelle noire (Solanum nigrum L. : Solanaceae) cultivée à Brazzaville (Congo)
Authors: Kpangba Thierry Placide Médard Kingo , Mpika Joseph , Makoundou Alaric , Bita Mercier Alain , Attibayéba Attibayéba
Published: June 2020

La productivité de la morelle noire est faible sur les sols surexploités dans les zones périurbaines de Brazzaville. L’objectif était d’évaluer l’apport de la terre des termitières sur la croissance végétale de trois cultivars de la morelle noire. Les termitières collectées ont été broyées, tamisées et amendées les planches de 3 m x 1,2 m. Une planche ayant reçu 0 kg, 2 kg, 4 kg et 6 kg de terre des termitières, 60 plants d’un cultivar ont été repiqués aux écartements 20 x 20 cm selon un schéma bi factoriel complet 4 x 3 logé dans un dispositif en bloc complètement randomisé. Les traitements ont été répétés trois fois. Les résultats ont révélé une meilleure croissance en hauteur et en diamètre ainsi qu’un meilleur développement foliaire des plants amendés avec les doses de la terre des termitières en comparaison de ceux n’en ayant pas reçu. L’apport de 6 kg de terre des termitières montre une influence positive sur le développement racinaire de plants des trois cultivars. L’apport 2 kg, 4 kg et 6 kg de terre de termitières améliore la croissance végétative et le rendement en biomasses aérienne et souterraine de trois cultivars de morelle noire cultivés au Congo.

© 2020 International Formulae Group. All rights reserved.

Mots clés: Congo, fertilisation, termitières champignons, croissance végétative, Solanum nigrum L.

English Title: Effect of the termite mounds on the vegetative production of three cultivars of black nightshade (Solanum nigrum L.: Solanaceae) grown in Brazzaville, Congo

English Abstract

The productivity of black nightshade is low on the overexploited soils in the suburban areas of Brazzaville. The objective was to evaluate the contribution of termite mound on the plant growth of three black nightshade cultivars. The termite mounds were collected, crushed, sieved and amended the planks of 3m x 1.2m. A board having received 0 kg, 2 kg, 4 kg and 6 kg of termite mounds, 60 plants of a cultivar were transplanted at 20 x 20 cm intervals according to a complete 4 x 3 bi-factorial diagram housed in a block plan completely randomized. The treatments were repeated three times. The results showed better growth in height and diameter, as well as better foliar development of seedlings amended with termite mounds compared to those that did not. The contribution of 6 kg of termite mound had a positive influence on the root development of the three cultivars. The contribution of 2 kg, 4 kg and 6 kg of termite mound improved vegetative growth and yield in aboveground and belowground biomass of three black nightshade cultivars grown in Congo.

© 2020 International Formulae Group. All rights reserved.

Keywords: Congo, cultivar, fertility, Termite fungi, vegetative production, Solanum nigrum L.
Biopesticide Plants species of the mining area of Tokpli (South-Togo) effects on Okra (Abelmoschus esculentus) protection against Aphtona spp.
Authors: Toundou Outéndé , Palanga Koffi Kibalou , Simalou Oudjaniyobi , Abalo Mabafei , Woglo Iréné , Tozo Koffi
Published: June 2020

Pest management is among the many challenges confronting African farmers today. In Togo, pest attack has been seen as a challenge posed on many vegetable crops producers. In pursuit to contribute to effective vegetables crops protection using local Biopesticide plants, an ethnobotanical survey conducted in the District of Tokpli to collect data from the local population identified five biopesticide plants. Among these plants, Chromolaena odorata, Morinda lucida, Azadirachta indica, and Ludwigia decurrens pure leaves extract significantly reduced the number of Aphtona spp. attacking Okra (Abelmoschus esculentus) plants in the field. Treatment Efficiency of the pure aqueous extract from mixture of leaves of these four plants, applied at the interval of 1 day and 2 days of 14 days were respectively 90% and 81% and were significantly higher than the result obtained with the chemical insecticide LAMBDA POWER applied following the recommendations of the manufacturer which was 79%.

© 2020 International Formulae Group. All rights reserved.

Keywords: Biopesticide, crops protection, Chromolaena odorata, Morinda lucida, Azadirachta indica, Ludwigia decurrens
Development and validation of a UV-Visible method for the determination of the active principle Efavirenz in tablets
Authors: Tittikpina Nassifatou Koko , Wane Thierno Mouhamed , Diouf Diery , Thiam Khadidiatou , Diop Amadou , Fall Djibril , Diop Yerim Mbagnick , Sarr Serigne Omar
Published: June 2020

Methods proposed by pharmacopeias to control the quality of Efavirenz, an antiretroviral drug used in the treatment of AIDS are based on expensive equipment which are most of the time not available in African countries. To solve this issue, using UV-visible spectrophotometry, a cheap and easy-to-use device available in many laboratories on the African continent; a sensitive, reliable, simple and rapid method has been validated for the determination of the active substance Evafirenz in Efavirenz tablets, to control their quality by checking its dosage. The accuracy profile approach was adopted. The response function gave a correlation coefficient R2 = 0.9987. The detection and quantification limits were 0.15625 μg / mL and 0.515625 μg / mL, respectively. The acceptability limit has been set at 15%. The tolerance limits for the different concentration levels (80, 100 and 120%) are represented respectively as follows: lower limits 86.2; 90.3 and 96.1%; upper limits 100.2; 106.3 and 113.7%. The tolerance limits are within the acceptability limits for values around 100% concentration (7 μg / mL). Therefore, the method was declared valid and reliable for the analysis of Efavirenz in Efavirenz tablets and could routinely be used in laboratories for the quality control of EFAVIRENZ drug.

© 2020 International Formulae Group. All rights reserved.

Keywords: Efavirenz, accuracy profile, spectrophotometry, pharmaceutical formulation
Etude de l’effet de Cercospora oryzae Miyake sur la qualite des grains du riz et le developpement de la ternissure
Authors: Soura Hervé B. , Gnancadja-Andre Simplice L. , Zandjanakou-Tachin Martine , Gandonou Christophe , Baba-Moussa Farid A.K.
Published: June 2020

La cercosporiose due à Cercospora oryzae est un champignon pouvant causer des pertes allant jusqu'à 60%. Elle est de plus en plus fréquente en Afrique de l'Ouest. Les premières prospections réalisées au sud du Bénin ont indiqué que Cercospora oryzae a une contribution large puisqu’elle a affectée 85% des champs de riz des trois zones agroécologiques du sud Bénin. Cette étude vise principalement à contribuer à la connaissance détaillée des effets de Cercospora oryzae sur les grains afin d’optimiser la conservation, la commercialisation et la production. Elle a consistée a : i) évaluer les effets de Cercospora oryzae sur le pouvoir germinatif des grains, ii) évaluer les effets de Cercospora oryzae sur le développement de la ternissure. L’étude a combiné des outils physiologiques et phytiatriques. Au terme des travaux, les variétés testées ont enregistré une bonne teneur en eau pour un minimum de 6%, ainsi qu’un bon taux de germination. A la fin de l’étude nous avons pu constater que Cerocpora oryzae entrainait une baisse du pouvoir germinatif des grains, une altération de la graine blanche et une décoloration de l’enveloppe. Ces résultats constituent une étape d’un travail de recherche approfondi sur la caractérisation (agronomique et génétique) de Cercospora oryzae afin de proposer des méthodes de luttes.

Mots clés : Pouvoir germinatif, décoloration, altération, Cercospora oryzae, riz.

 

English Title: Study of the effect of Cercospora oryzae Miyake on the quality of rice grains and the development of tarnishSigatoka caused by Cercospora oryzae is a fungus that can cause losses up to 60%. It is more and more frequent in West Africa. The first surveys carried out in the south of Benin indicated that Cercospora oryzae has a large contribution since affected 85% of the rice fields of the three agroecological zones of southern Benin. The main objective of this study is to contribute to detailed knowledge of the effects of Cercospora oryzae on grains in order to optimize conservation, marketing and production. It consisted in: i) evaluating the effects of Cercospora oryzae on the germination power of the grains, ii) evaluating the effects of Cercospora oryzae on the development of tarnish. The study combined physiological and phytiatric tools. At the end of the work, the varieties tested recorded a good water content for a minimum of 6%, as well as a good germination rate. At the end of the study we could see that Cerocpora oryzae did not cause a drop in the germinative power of the grains but rather resulted in an alteration of the white seed and a discoloration of the envelope. These results constitute a stage of an in-depth research work on the characterization (agronomic and genetic) of Cercospora oryzae in order to propose methods of struggle.Keywords: Germination, discoloration, deterioration, Cercospora oryzae, rice.
Inventory of refuge plants of Recilia mica Kramer (Homoptera, Cicadellidae), blast disease vector in oil palm nursery (Elaeis guineensis Jacq.
Authors: Anougba Bossoma Danielle , N'guessan Assiénin Hauverset , Konan Kla , Hala N’Klo François , Yeo Kolo
Published: June 2020

Blast is the most important disease in nursery of palm tree in West Africa. The mycoplasm responsible of this disease is transmitted by the vector Recilia mica KRAMER (Homoptera, Cicadellidae). The aim of this study was to determine R. mica KRAMER plants reservoirs. To achieve this objective, an inventory of the flora frequented by this insect was carried out around two selected plots including a palm tree nursery and a plantation. In total, 14 plants were identified around the nursery and 15 plants around the plantation. Some plants have been registered in both environments. Plants considered refuges for R. mica in this study were Digitaria horizontalis, Pueraria phaseoloides, Panicum maximum, Oldemlandia herbacea, Ageratum conyzoides, Ipomea eriocarpa, Eleusine indica. Furthermore, this study showed that the Recilia mica frequents more plants of the Poaceae family compared to other plant families. This study should be continued to study the reproductive biology of R. micaKeywords: Oil Palm tree, Blast disease, Recilia mica, refuge plants.
Variation of essential oil composition of fruits of Zanthoxylum leprieurii Guill. et Perr (Rutaceae) from different sample locations and during their maturation period
Authors: Tine Yoro , Diallo Alioune , Diatta William , Ndoye Idrissa , Guèye Rokhya Sylla , Baldé Mamadou , Diédhiou Adama , Fall Djibril , Seck Matar , Desjobert Jean-Marie , Costa Jean , Wélé Alassane , Paolini Julien
Published: June 2020

The fruits of Zanthoxylum leprieurii Guill. & Perr. (Rutaceae) are traditionally used in Africa, particularly in Cameroon, as a spice and in the treatment of sickle cell anaemia. The objective of this study was to investigate the fruit essential oils from different sample locations and during their maturation period by using GC and GC-MS. Except for one sample collected in Aniak which consisted mainly of oxygenated monoterpenes, the volatile composition of Z. leprieurii fruits exhibited relative high amounts of monoterpene hydrocarbons (61.1-90.9%) such as (E)-β-ocimene (13.4-75.2%) and a-pinene (1.1-40.7%). The influence of the maturity stage on the chemical composition of the essential oils has resulted in an increase of oil yield and variations in the content of volatile compounds (a-pinene 13.3-75.6; (E)-β-ocimene 2.9-64.0%).

Keywords: Senegal, Zanthoxylum leprieurii fruits, essential oil, chemical variability, stage of maturity and GC-MS.
Automated university lecture timetable using Heuristic Approach
Authors: Hambali A.M. , Olasupo Y.A. , Dalhatu M.
Published: June 2020

There are different approaches used in automating course timetabling problem in tertiary institution. This paper present a combination of genetic algorithm (GA) and simulated annealing (SA) to have a heuristic approach (HA) for solving course timetabling problem in Federal University Wukari (FUW). The heuristic approach was implemented considering the soft and hard constraints and the survival for the fittest. The period and space complexity was observed. This helps in matching the number of rooms with the number of courses.

Keywords: Heuristic approach (HA), Genetic algorithm (GA), Course Timetabling, Space Complexity.
Design and analysis of displacement models for modular horizontal wind turbine blade structure
Authors: Etuk E.M. , Ikpe A.E. , Adoh U.A.
Published: June 2020

This study examined the normal, radial, axial and tangential loading cycles undergone by wind turbine rotor blades and their effects on the  displacement of the blade structure. The rotor blade was modelled using Q Blade finite element sub module, which evaluated the loading cycles in  terms of the forces induced on the blade at various frequencies through several complete revolution cycles (360o each cycle). At frequencies of 5 HZ, 23 Hz, 60 Hz, 124 Hz and 200 Hz, maximum strain deformation of 0.004, 0.04, 0.08, 0.14 and 0.24 were obtained, and geometry of the deformed blades were characterized by twisting and bending configuration. Maximum deflections from tangential loading increased from -0.55-1.2 mm,  -0.39-1.6 mm from axial loading, -0.28-1.8 mmfrom radial loading and -0.01-2.3 mm from normal loading. From these deflection values, normal loading cycle would cause the highest level of structural damage on the rotor blade followed by radial, axial and tangential loading. Moreover, the  strain deformations and deflections of the blade structure increased as the cycles of frequency increased.

Keywords: Loading cycle, Wind turbine, Rotor blade, Frequency, Strain deformations, Deflections.
Pressure behaviour of a horizontal well sandwiched between two parallel sealing faults
Authors: Ogbamikhumi A.V. , Adewole E.S.
Published: June 2020

Generally, reservoir fluid flow is governed by diffusivity equation and solution to this equation helps to investigate pressure behaviour under certain reservoir and wellbore boundary conditions. In this paper however, the analytical solution method of Green and Source function is deployed to determine the performance of a horizontal well located between two parallel sealing faults, assuming simple rectangular reservoir geometry. Also, the dimensionless pressure and derivative approach is applied for all computations as it prevents the problem of unit conversions, reduces longer expressions and it helps to handle numerical values. The pressure expression derived from this work reveals that a maximum of two flow periods occur for the stated reservoir model. It was found out that an inverse relationship exists between dimensionless pressure and dimensionless length while pressure increased with thickness. Also high vertical permeability shortens the effect of the early radial flow period experienced by the horizontal well, thereby increasing productivity index. Finally, it was discovered that increased perforation length reduces the production potential of the horizontal well.

Keywords: Dimensionless pressure, pressure derivatives, heterogeneity, pressure performance, reservoir and wellbore characterization.
Modeling and simulation of the effect of moisture content and ambient temperature on gas turbine power plant performance in Ughelli, Nigeria
Authors: Onoroh F. , Ogbonnaya M. , Onochie U.P.
Published: June 2020

The influence of ambient temperature and moisture content on the performance of Transcorp Power Plant, Ughelli, Delta State, Nigeria was investigated with the aid of a digital psychrometer. The simulation was done using codes developed on MATLAB R2017a and the results show that compressor power consumption increased by 1.65% for 0.7% rise in temperature, and 0.50% for 71.4% rise in moisture content. The specific fuel consumption also increased with increase in temperature where a 1.71% rise in ambient temperature resulted in a 0.15% rise in specific fuel consumption but it decreased by 0.49% for a 41.7% rise in moisture content. A 1.62% rise in temperature led to a 0.13% drop in net power output and a 29.4% rise in moisture content resulted in a 0.48% drop in net power output. Thus gas turbine plant operates optimally in areas with low ambient temperatures and high moisture content.

Keywords: Work ratio, net power, efficiency, moisture content, specific fuel consumption, heat rate.
A study of ferroresonance in underground distribution network for 15MVA, 33/11 kV injection substation
Authors: Koledowo S.O. , Ashigwuike E.C. , Bawa A.
Published: June 2020

This provides an overview of ferroresonance phenomena, modeling aspects and practical experience in recognizing and mitigating the effect of  ferroresonance in the power network. In particular, we will present symptoms of ferroresonance. In this study, ferroresonance phenomenon are investigated under the modelling of the underground cable of 15 MVA, 33/11/0.415 kV with four feeders supply over 31 distribution transformers of  Garki 1 service unit, Abuja, conducted using MATLAB/SIMSCAPE software package. The network is subjected to switching resulting in the formation of a series LC combination prone to ferroresonance. The waveforms and total harmonic distortion charts obtained are observed, analyzed and then  used to design Harmonic filters which have been implemented to mitigate ferroresonance in the network. The simulated ferroresonance  phenomenon was suppressed using Shunt Active Harmonic Filter connected in parallel to the network. A reduced harmonic content and dampened event when compared to a non-filtered event was observed. Application of Shunt Active Harmonic filter reduces ferroresonance effect by 67.743%.

Keywords: Ferroresonance, Transformer, MATLAB/Simscape, Harmonic Distortion, Power system Modelling, Saturable inductor, Capacitance
Model prediction and climatology of aerosol optical depth (τ550) and angstrom exponent (α470-660) over three aerosol robotic network stations in Sub-Saharan Africa using moderate resolution imaging spectroradiometer data
Authors: Sharafa S.B. , Aliyu R. , Ibrahim B.B. , Tijjani B.I. , Darma T.H. , Gana U.M. , Ayedun F. , Sulu H.T.
Published: June 2020

The spatial and temporal variations of aerosol optical depth at 550 nm (τ550) and Angstrom exponent derived from 470 and 660 nm (α470-660) over Nairobi (NAI), Skukuza (SKU) and Ilorin (ILO) Aerosol Robotic Network (AERONET) stations in sub-Saharan Africa, as recorded by Moderate Resolution Imaging Spectroradiometer (MODIS) satellites for fifteen years (2000-2015), were examined in relation to their climatologies and prediction. The MODIS measurements of τ550 and α470-660 from aqua (MYD04) and terra (MOD04) satellites were used in this study. Retrievals of τ550 for both satellites were validated with AERONET τ550 for the same period. The validation results showed that they compare favourably over the three stations, but MOD04 performed better than MYD04 data in NAI and ILO for τ550. This shows that the τ550 of NAI and ILO are best captured using the MOD04 data while that of SKU is best with MYD04. It was also discovered that MODIS underestimated AERONET τ550 data over NAI and SKU. The most polluted station is ILO while the least polluted one is NAI. Similarly, the station with the highest concentration of absorbing aerosols is NAI and the least was observed in ILO. The aerosol climatology shows that the most polluted months in NAI, SKU and ILO are October, June and March respectively. On the other hand, February, November and March has the highest amount of scattering aerosols in the atmosphere for NAI, SKU and ILO respectively. The highest amount of absorbing aerosols was found, respectively, in the months of June, June and August. The generated time series (TS) models are all good, though a general underestimation of the parameters by the models was also observed.

Keywords: Aerosol optical depth, Angstrom exponent, MODIS, Time series, sub-Saharan Africa
Estimation and comparison of reference evapotranspiration within Kaduna Central District, Nigeria, using four different methods
Authors: Onwuegbunam N. E. , Onwuegbunam D.O. , Dare A.
Published: June 2020

The reference evapotranspiration (ETo) within Kaduna Central District, Nigeria was estimated from a 30-year climatological data using four different methods namely, Penman-Monteith (PM), Blaney Criddle (BC), Hargreaves (HGRV) and Piche evaporimeter (PiEv) (atmometer) methods. The study shows that the highest ETo values obtained from PM, BC and PiEv were 6.43 mm/day, 7.58 mm/day and 8.63 mm/day, respectively, and these occurred in February, except for HGRV which estimated its highest ETo (3.73 mm/day) in March. The lowest ETo values were obtained in August for all the methods. By means of the confidence index (c), agreement or concordance index (d) and correlation coefficients (r) statistics the BC, HGRV and PiEv ETo values were correlated with that of PM, as the standard. Results showed that BC, HGRV and PiEv gave c-values of 0.88, 0.48 and 0.67, respectively. Hence, BC-PM, HGRV-PM and PiEv-PM correlations were adjudged as excellent, bad and good, respectively, on the basis of criteria for interpretation of the performance of methods of ETo estimations. Blaney-Criddle reference evapotranspiration method gave the best estimate in comparison to the Penman-Monteith standard in the study area. Hence, the Blaney-Criddle ETo can be calibrated with the Penman-Monteith ETo and used effectively within the Kaduna Central District conditions for irrigation water management decisions.

Keywords: Estimation and comparison, Reference evapotranspiration,  Methods, Kaduna Central District, Nigeria.
A taxonomy of building collapse causes in Lagos State Nigeria
Authors: Imafidon M.O. , Ogbu C.P.
Published: June 2020

This Lagos-based study provides an unsupervised grouping of the causes of building collapse in Lagos State Nigeria using purposively obtained data from construction professionals (n=34) in the state. Hierarchical cluster analysis technique and mean scores were used for the analyses. Findings show that the causes of building collapse in Lagos State can be statistically grouped into design and construction-related, policy-related and quality-related causes. The most important causes of building collapse under each of these groups are respectively: poor maintenance culture, change of use of building and use of substandard materials in construction. Government needs to strengthen efforts at monitoring both the design and construction of buildings, starting with fine-tuning building related policies. A holistic approach should be adopted in addressing building material counterfeiting and circulation of substandard construction materials in the study area.

Keywords: Building Approval, Building Collapse, Building Failure, Cluster Analysis, Lagos State.
Predicting the split tensile strength of Saw Dust Ash - Fine aggregate concrete
Authors: Oba K.M. , Ugwu O.O. , Okafor F.O.
Published: June 2020

The industrial waste, Saw Dust Ash (SDA), has played a key role in concrete mix research. It has served as an alternative or complementary material to some of the traditional materials of concrete. In this study, SDA was used to replace 5% of the fine aggregate (sand), as the other three ingredients, cement, granite, and water remained constant. Scheffe’s simplex lattice was used for five mix ratios in a {5,2} component mix, which resulted in additional ten mix ratios. Additional fifteen mix ratios were generated for verification and testing. The thirty concrete mix ratios were subjected to laboratory experiments to determine the 28 days Split Tensile Strengths. The results of the first fifteen Split Tensile strengths were used for the calibration of the model constant coefficients using Scheffe’s simplex approach, while those from the second fifteen were used for the model verification. A mathematical regression model was derived from the experimental results, with which the Split Tensile Strengths were predicted. The derived model was subjected to a two-tailed t-test with 5% significance, which ascertained the model to be adequate with an R2 value of 0.8099. The study revealed that SDA can replace 5% of fine aggregate and promote sustainability, without compromising the 28 days Split Tensile Strength.

Keywords: Saw Dust Ash, Scheffe’s simplex lattice, Split Tensile Strength of concrete.
Digestible lysine effects on gene expression by Japanese quails in the pre-laying phase
Authors: Santana T.P. , Gasparino E , Bastos M.S. , Lima A.S. , Pinto A.P.G. , Oliveira Junior G.M. , Brito C.O. , Barbosa L.T. , Del Vesco A.P.
Published: June 2020

This study aimed to determine the effects of digestible lysine levels in the diets of Japanese quail (Coturnix coturnix japonica) on performance, blood parameters and the expression of insulin-like growth factor I, and growth hormone receptor (GHR), apolipoprotein A-I (APOA-I), acetyl-CoA-carboxylase (ACC), and fatty acid synthase (FAS) genes. A total of 288 seven-day-old female Japanese quails were randomly assigned to one of three diets that contained 0.8%, 1.10%, or 1.40% digestible lysine. The birds were slaughtered at 42 days old, and relative gene expression was evaluated in the liver by qRT-PCR using the 2-ΔCT method. Lysine supplementation had no effect on weight gain and feed conversion. Abdominal fat was lower in birds supplemented with 0.8% digestible lysine than those supplemented with 1.10% and 1.40%. Increased total cholesterol and triglycerides were elevated in quails that received supplementation of 1.10% digestible lysine compared with the other diets. High density lipoproteins were decreased in birds that received 0.8% digestible lysine. Quails fed with 1.40% digestible lysine had greater expression of GHR and APOA-I than quails fed diets with 0.8 and 1.10% (P <0.05). The greatest expressions of ACC and FAS were observed in the liver of quails fed with 0.8% digestible lysine. The current results suggest that lysine supplementation in the pre-laying phase allows birds to deposit muscle mass to reach the optimal conformation and body fatness that provides an energetic reserve for the productive phase by modulating the expression of genes related to growth and lipid metabolism.

Keywords: Coturnix coturnix japonica, growth, growth hormone, lipid synthesis, lipid metabolism
Effects of Lavender (Lavandula angustifolia) augmentation of alfalfa silages
Authors: Duru A.A.
Published: June 2020

The aim of this study was to determine the chemical, fermentation, and microbiological properties of alfalfa silages that were augmented with lavender (Lavandula angustifolia) and to appraise their in vitro organic matter digestibility (IVOMD), metabolizable energy (ME), and net energy for lactation (NEL) contents. Lavender flowers were added to alfalfa silages at 0.5, 1.0, 1.5, and 2.0% of the weight of alfalfa. An unaugmented alfalfa silage was also evaluated. After 75 day of ensiling, pH, dry matter, NDF and ADF contents of alfalfa silages had decreased and OMD had increased with the addition of lavender. No significant differences in crude protein, ash, ether extract, lactic acid, acetic acid, propionic acid, lactic acid bacteria number, ME and NEL contents were detected. No butyric acid, Enterobacteriaceae, Listeria spp, sulphide reducing anaerobes, and yeasts were found in the alfalfa silages. Mould content decreased with the addition of lavender. Thus, the addition of lavender flowers to alfalfa silages may improve their quality.

Keywords: essential oil, fermentation, nutritional value, supplement
Effect of controlled breeding on performance of beef cattle in Central Bushveld bioregion
Authors: Grobler S.M. , Scholtz M.M. , Neser F.W.C. , Greyling J.P.C. , Morey L
Published: June 2020

In most extensive beef production systems in South Africa, calves are weaned at specific dates. This implies that cows that calve late in the season wean younger and lighter calves. In the current study, Bonsmara cows were mated naturally after synchronization over six years (2009 - 2014) in an extensive production system on natural veld in the Central Bushveld bioregion. Within the herd, 50% of cows were synchronized prior to the commencement of the summer breeding season and they were mated naturally for 90 days. The results indicated that calving rate did not differ significantly between cows that were synchronized and non- synchronized. However, there was a significant difference between years in calving rate. Oestrous synchronization prior to natural breeding influenced the average days to conception. The difference in percentage of cows that calved within 293 days of the onset of the breeding season between those that were oestrous synchronized and non-synchronized was 15% in favour of the synchronized cows. Although calves from synchronized cows achieved higher average weaning weights, the cost implications of synchronization offset the benefit of higher calf weights.

Keywords: calving rate, oestrous synchronization, natural breeding
Genetic diversity and differentiation among Korean-Holstein, Hanwoo, and Uganda-Holstein breeds
Authors: Bigirwa G , Kim D , Acai O , Na C , Oh J , Song K
Published: June 2020

The aim of this research was to assess genetic diversity of Korean-Holstein, Korean Hanwoo, and Ugandan-Holstein dairy cattle. DNA was extracted from either blood or hair of Korean-Holstein (n=74), Korean-Hanwoo (n=75) and Ugandan-Holstein (N=77) using AccuPrep® PCR purification kit. The DNA samples were amplified by multiplex polymerase chain reaction, using GeneTrackTM Hanwoo genotyping kit and assayed using ABI genetic analyser 3130XL. Number of alleles, expected heterozygosity (He), observed heterozygosity (Ho), and the polymorphism information content (PIC) were estimated from 10 microsatellite loci in the three breeds. In addition, F-statistics for each of the 10 microsatellites in the three cattle breeds were estimated using fstat version 2.9.3.2 computer program. GENETIX (v.4.02) was used to perform factorial correspondence analysis (FCA) from the allele frequencies and multi-locus clustering was done using STRUCTURE analyses. A total of 124 alleles were detected. The number of alleles per locus varied from eight (TGLA126) to 22 (TGLA122), with an overall mean of 12.2. Expected heterozygosity ranged from 0.617 (SPS115) to 0.854 (TGLA53) and averaged 0.761. Observed heterozygosity ranged from 0.6 (SPS115) to 0.859 (TGLA53); and averaged 0.761. The mean PIC was 0.723; and means of the F-statistics FIT, FST and FIS were 0.077, 0.076 and 0.001 respectively. Although FCA revealed clear differentiation of Uganda-Holstein, Korean-Holstein, and Hanwoo, clustering assignments showed genetic admixture between Ugandan dairy cattle (Uganda-Holstein) and Hanwoo. In conclusion, the allelic variation present at the 10 loci was sufficient to categorize these cattle into distinct breed groups.

Keywords: dairy cattle, genetic differentiation, F-statistics, heterozygosity, microsatellite
Performance of sheep grazing Panicum maximum cv. Massai and supplemented with protein sources during the dry season
Authors: Fernandes L.S. , Difante G.S. , Neto J.V. Emerenciano , Araújo I.M.M. , Veras E.L.L. , Costa M.G.
Published: June 2020

The low quality of tropical grasses in the dry season justifies the use of dietary supplements to meet the nutritional needs of sheep. The objective of this study was to evaluate the effect of supplementation with high-protein feed on mutton sheep performance and yield in Massai grass pastures during the dry season. The treatments corresponded to four supplements, namely Leucaena leucocephala leaf hay, Gliricidia sepium leaf hay, soybean meal, and a treatment that received only multiple mixture (protein salt) ad libitum. The pasture was evaluated for canopy height, forage supply, and chemical composition of leaf blade, stem and dead material. Average daily gain, weight gain per area, and the stocking rate were also evaluated. There were four grazing cycles because the grazing method was rotational stocking with seven days of occupation and 35 days of rest. The interaction between supplements and grazing cycles was not significant, and no effects of the supplements were found for any of the variables. The highest forage and leaf blade offerings were observed in the first grazing cycle. The highest levels of crude protein and lower neutral detergent fibre and lignin of pasture components were observed in cycles 3 and 4. The highest average daily gains per animal and per area were observed in cycles 1 and 2. Protein supplementation of sheep in Massai grass pastures promotes satisfactory gains during the dry season, and Leucaena and Gliricidia hays can be used as protein sources instead of soybean meal.

Keywords: Gliricidia sepium, leguminous, Leucaena leucocephala, pasture
Effects of soil type on density of trees and nutritive value of tree leaves in selected communal areas of South Africa
Authors: Ravhuhali K.E. , Mlambo V , Beyene T.S. , Palamuleni L.G.
Published: June 2020

This study aimed to describe the distribution and nutritive value of woody species growing in clay-loamy and red-brown sand from selected localities of North West, South Africa. Three 2.2 km transects, radiating from homesteads, which served as replicates, were established at each of four selected grazing areas. Nine 10 × 10 m homogenous vegetation units (HVU), 20 m apart, were marked in each transect. Woody plant density, height and canopy cover (CC), were recorded, and chemical properties and degradability via in vitro ruminal fermentation of harvested leaves were measured. Raisin bush (Grewia flava), Buffalo thorn (Ziziphus mucronata) and Camel thorn (Vachellia erioloba) were the common species across both soil types. Soil type influenced (P <0.05) plant density, CC, total tree equivalent (TTE) and plant height. Areas with red-brown sandy soil had higher (P <0.05) total plant density (827.7 plant/ha), CC (9.6%) and TTE (2886.4 TTE/ha) than those with clay-loamy soil. Vachellia erioloba leaves in clay-loamy soil had the highest (P <0.05) crude protein content (151.2 g/kg DM). Leaves of Searsia lancea species that were harvested from both the clay-loamy and red-brown sandy soils had the highest (P <0.05) amounts of condensed tannins (0.915 AU550/200 mg and 0.917 AU550/200 mg, respectively). Searsia lancea leaves had the lowest (P <0.05) in vitro ruminal nitrogen degradability values in both soil types. The leaves of Z. mucronata and G. flava leaves have potential as protein supplements for ruminants owing to their higher crude protein content and in vitro ruminal N degradability.

Keywords: canopy cover, feeding value, plant height, semi-arid, species diversity, tree equivalent
Chemical, nutritive, fermentation profile and gas production of citrus pulp silages, alone or combined with maize silage
Authors: Ülger İ , Beyzi S.B. , Kaliber M , Konca Y
Published: June 2020

Quality attributes of citrus pulp silages that were ensiled alone and combined with maize silage were determined. Fresh samples of lemon, orange and tangerine pulps, maize plants and their combinations were fermented in glass jars for 90 days at about 20 - 25 °C. Treatments included i) 100% maize silage as control (MS); ii) 100% lemon pulp silage (LPS); iii) 100% orange pulp silage (OPS); iv) 100% tangerine pulp silage (TPS); v) 50% LPS and 50% maize silage (LPS + MS); vi) 50% OPS and 50% MS; and vii) 50% TPS and 50% maize silage (TPS + MS). The pH differed among treatment groups. The highest and lowest pH values were recorded for MS group and the OPS + MS group, respectively (3.84 vs. 3.51). The highest dry matter (DM), crude fibre (CF), neutral detergent fibre (NDF), acid detergent fibre (ADF) and hemicellulose (HEM) were observed for MS (P <0.01). Citrus pulp silages alone had significantly greater total digestible nutrients (TDN), organic matter (OM) and non-fibre carbohydrate (NFC) values than MS and the combined silages (P <0.01). Maize silage had higher lactic acid (LA) (101.2 g/kg DM) and acetic acid (AA) (49.3 g/kg DM) concentrations than the citrus groups (P <0.05). In vitro gas production (TG), methane (CH4), metabolizable energy (ME) and organic matter digestibility (OMD) of the silages were similar (P >0.05). Thus, citrus pulps can be ensiled in spite of their moisture content. However, to increased DM and nutrient content, the citrus pulps should be ensiled with 50% maize.

Keywords: fermentation metabolites, methane production, organic matter digestibility