Non-linear bending and stress analysis of a transversely loaded isotropic plates material using 3-D plate theory

This paper presents the bending stress analysis of anisotropic plate material under transverse loading using a three-dimensional (3-D) plate theory. The static elastic theory was used to formulate the total energy expression of the plate thereafter, transformed into a compatibility equation through general variation to get the slope and deflection relationship. The solution of equations of the equilibrium gave rise to the exact polynomial deflection function while the coefficient of deflection and shear deformation of the plate was gotten from the governing equation through the direct variation method. These solutions were used to obtain the characteristic expression for analyzing the displacement and stresses of the rectangular plate. This formula was used for the solution of the bending problem of the rectangular plate that is clamped at the first-two edge and the other edges simply supported (CCSS). The result of the deflection and stresses decrease as the span-thickness ratio increases. More so, the aspect ratio effect of the shear stress of isotropic plates is investigated and discussed after a comparative analysis between the present work and previous studies. The result shows that the present study differs from that refined plate theory (RPT) of assumed deflection by 5.5% whereas exact 2-D RPT by 5.3%. This shows the efficacy of the exact 3-D plate theory for flexural characteristics of CCSS isotropic rectangular thick plate

Static Elastic Bending Analysis of a Three-Dimensional Clamped Thick Rectangular Plate using Energy Method

Analytical formulations and solutions for the thick rectangular plate static analysis with clamped support based on a three-dimensional (3-D) elasticity theory is developed using the energy method. The theoretical model, whose formulation is based on the static elastic principle as already reported in the literature, is presented herein to obviate the shear correction coefficients while considering shear deformation effect and transverse normal strain/stress in the analysis. The equilibrium equations are obtained using 3-D kinematic and constitutive relations. The deflection and rotation functions, which are the solutions of the equilibrium equation, are obtained in closed form using a general variational technique for solving the boundary value problem. The minimization energy equation yields the general equation which was used to obtain the theoretical model for the deflection and stresses of the plate. The results are compared with the available literature and the results-computed trigonometric displacement function shows that this 3-D predicts the vertical displacement and the stresses more accurately than previous studies considered in this paper. The result showed that the percentage difference between the present work and those of 2-D Mindlin FSDT, 2-D numeric analysis, and 2-D HSDT of polynomial shape functions was about 3.02%, 0.62%, and 0.33%, respectively. It is concluded that the 3-D trigonometric model gives an exact solution, unlike other 2-D theories, and can be used for clamped-supported thick plate analysis. Doi: 10.28991/HIJ-2022-03-03-03 Full Text: PD

Differentials in the Cassava Seed System among Entrepreneurs in Southern Nigeria: A Gender Situation Analyses

The study analysed gender differentials in the cassava seed system among entrepreneurs in southern Nigeria to proffer policies for growth and sustainable cassava seed systems. A multi-stage and purposive sampling technique was used to select respondents for the study. Village seed entrepreneurs (VSEs) and cassava farmers in the cassava seed network of the BASICS project in 4 States were sampled in the first stage. Data were collected with interview schedules for individual interviews and Focus Group Discussions (FGD). The results show that the different gender groups compliment each other in the roles they play. Among the most important drivers of seed demand include; big roots size/ yield (67.56%) and (60.97%) for the male and female cassava farmers respectively), among the male was income generation (17.14%) and yield good gari quality for the female (31.70%), followed by high starch content (17.14%) for male and female (22.85). The profitability analyses show that for every N1.00 spent in cassava seed production, about N0.92 (male) and N0.90 (female) were generated, while N1.50 (male) and N1.32 (female) were generated for root production. The seed flow system shows that both male and female cassava farmers receive seed from various channels but at varying levels. The results call for policy issues targeted at increasing cassava production by advocating for more involvement of the women in seed production and increased access to and control of finance. There is also need to mitigate important constraints militating against cassava seed production for increased participation and production of cassava seed

Implementation of an Intelligent Course Advisory Expert System

Academic advising of students is an expert task that requires a lot of time, and intellectual investments from the human agent saddled with such a responsibility. In addition, good quality academic advising is subject to availability of experienced and committed personnel to undertake the task. However, there are instances when there is paucity of capable human adviser, or where qualified persons are not readily available because of other pressing commitments, which will make system-based decision support desirable, and useful. In this work, we present the design, implementation, of an intelligent Course Advisory Expert System (CAES) that uses a combination of rule based reasoning (RBR), and case based reasoning (CBR) to recommend courses that a student should register in a specific semester by making recommendation based on the student’s academic history. The evaluation CAES yielded satisfactory performance in terms of credibility of its recommendations, and usability

Biosynthesis and antimicrobial activity of pseudodesmin and viscosinamide cyclic lipopeptides produced by pseudomonads associated with the cocoyam rhizosphere

Pseudomonascyclic lipopeptides (CLPs) are encoded non-ribosomally by biosynthetic gene clusters (BGCs) and possess diverse biological activities. In this study, we conducted chemical structure and BGC analyses with antimicrobial activity assays for two CLPs produced byPseudomonasstrains isolated from the cocoyam rhizosphere in Cameroon and Nigeria. LC-MS and NMR analyses showed that thePseudomonassp. COR52 and A2W4.9 produce pseudodesmin and viscosinamide, respectively. These CLPs belong to the Viscosin group characterized by a nonapeptidic moiety with a 7-membered macrocycle. Similar to other Viscosin-group CLPs, the initiatory non-ribosomal peptide synthetase (NRPS) gene of the viscosinamide BGC is situated remotely from the other two NRPS genes. In contrast, the pseudodesmin genes are all clustered in a single genomic locus. Nano- to micromolar levels of pseudodesmin and viscosinamide led to the hyphal distortion and/or disintegration ofRhizoctonia solaniAG2-2 andPythium myriotylumCMR1, whereas similar levels of White Line-Inducing Principle (WLIP), another member of the Viscosin group, resulted in complete lysis of both soil-borne phytopathogens. In addition to the identification of the biosynthetic genes of these two CLPs and the demonstration of their interaction with soil-borne pathogens, this study provides further insights regarding evolutionary divergence within the Viscosin group

Cyclic lipopeptide‐producing Pseudomonas koreensis group strains dominate the cocoyam rhizosphere of a Pythium root rot suppressive soil contrasting with P. putida prominence in conducive soils

Pseudomonas isolates from tropical environments have been underexplored and may form an untapped reservoir of interesting secondary metabolites. In this study, we compared Pseudomonas and cyclic lipopeptide (CLP) diversity in the rhizosphere of a cocoyam root rot disease (CRRD) suppressive soil in Boteva, Cameroon with those from four conducive soils in Cameroon and Nigeria. Compared with other soils, Boteva andosols were characterized by high silt, organic matter, nitrogen and calcium. Besides, the cocoyam rhizosphere at Boteva was characterized by strains belonging mainly to the P . koreensis and P . putida (sub)groups, with representations in the P . fluorescens , P . chlororaphis , P . jessenii and P . asplenii (sub)groups. In contrast, P . putida isolates were prominent in conducive soils. Regarding CLP diversity, Boteva was characterized by strains producing 11 different CLP types with cocoyamide A producers, belonging to the P . koreensis group, being the most abundant. However, putisolvin III‐V producers were the most dominant in the rhizosphere of conducive soils in both Cameroon and Nigeria. Furthermore, we elucidated the chemical structure of putisolvin derivatives—putisolvin III‐V, and described its biosynthetic gene cluster. We show that high Pseudomonas and metabolic diversity may be driven by microbial competition, which likely contributes to soil suppressiveness to CRRD

Effect of the Golden Liquid from Honeybees and Refined Granulated Sugar on the Blood Glucose and Serum Iron Levels of Albino Rats.

Honey is a naturally sweet substance produced by honeybees from water, pollen, and nectar. Due to its unique nutritional and therapeutic benefits, which are ascribed to the interaction of the various chemical groups it contains, natural honey is one of the most popular consumed products. Modern-day individuals consume a lot of refined granulated sugar, either directly through foods or indirectly from other sources. The consumption of large amounts of refined granulated sugar alters hematological and physiological changes in the body. According to several scientific studies, honey can be a healthier alternative to refined granulated sugar because it does not threaten human health. Consuming natural honey raises serum iron levels and red blood cell counts since it is known that the iron in honey serves as a precursor to hemoglobin. Overconsumption of refined granulated sugar has been identified as a risk factor for metabolic disorders such as obesity, cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. This study, therefore, investigated the effect of the golden liquid from honeybees (natural honey) and refined granulated sugar on the blood glucose and serum iron levels of 25 Wistar albino rats. The experimental animals used in this study were grouped into five treatments based on the dose of natural honey and refined granulated sugar administered namely: T1 (1.02 g of honey /kg BW), T2 (1.40g of honey /kg BW), T3 (1.02 g of refined granulated sugar /kg BW), T4 (1.40g of refined granulated sugar /kg BW), rats in T5 were not administered honey, and refined granulated sugar served as the control. The blood glucose concentration of the albino rats was measured using the glucose strips with a glucometer while the serum iron analysis was conducted using Atomic Absorption Spectrophotometer. The result revealed that the mean blood glucose level of the rats was highest in T3 (112.95mg/dl), followed by T5 (92.20mg/dl) while the least value was recorded in T2 (74.86mg/dl). There was a significant difference in the blood glucose levels of albino rats orally administered natural honey and refined granulated sugar at varying levels (P0.05) among treatments. It was found that the highest serum iron level was recorded in T5 (1.31±0.395 ppm) followed by T2 (1.22± 0.115 ppm), while the least serum iron level was recorded in T1 (0.88±1.319ppm). It was observed that there were no significant differences in the serum iron levels of the albino rats (p\u3e0.05) among treatments The use of natural honey is recommended since albino rats orally administered honey at varying doses had lower blood glucose levels than those given refined granulated sugar. This work will be a useful tool for understanding the role of honey over granulated sugars, especially among prediabetic and diabetic patients in order to control their sugar levels using diet as a source. This implies that the consumption of natural honey did not significantly increase blood glucose levels. It was therefore recommended that physicians and dietitians should advocate for natural honey use over refined granulated sugar which could be safe for consumption by diabetic patients

Adapting clonally propagated crops to climatic changes: a global approach for taro (Colocasia esculenta (L.) Schott)

Clonally propagated crop species are less adaptable to environmental changes than those propagating sexually. DNA studies have shown that in all countries where taro (Colocasia esculenta (L.) Schott) has been introduced clonally its genetic base is narrow. As genetic variation is the most important source of adaptive potential, it appears interesting to attempt to increase genetic and phenotypic diversity to strengthen smallholders’ capacity to adapt to climatic changes. A global experiment, involving 14 countries from America, Africa, Asia and the Pacific was conducted to test this approach. Every country received a set of 50 indexed genotypes in vitro assembling significant genetic diversity. After onstation agronomic evaluation trials, the best genotypes were distributed to farmers for participatory on-farm evaluation. Results indicated that hybrids tolerant to taro leaf blight (TLB, Phytophthora colocasiae Raciborski), developed by Hawaii, Papua New Guinea and Samoa breeding programmes outperformed local cultivars in most locations. However, several elite cultivars from SE Asia, also tolerant to TLB, outperformed improved hybrids in four countries and in one country none of the introductions performed better than the local cultivars. Introduced genotypes were successfully crossed (controlled crossing) with local cultivars and new hybrids were produced. For the first time in the history of Aroids research, seeds were exchanged internationally injecting tremendous allelic diversity in different countries. If climatic changes are going to cause the problems envisaged, then breeding crops with wide genetic diversity appears to be an appropriate approach to overcome the disasters that will otherwise ensue.This research was financially supported by the Europe-Aid project ‘‘Adapting clonally propagated crops to climatic and commercial changes’’ (Grant No. DCI-FOOD/ 2010/230-267 SPC). Thanks are due to the 14 different countries technicians working on research stations and to farmers and their families for their enthusiastic contributioninfo:eu-repo/semantics/publishedVersio

Chromogenic detection of yam mosaic virus by closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP)

A closed-tube reverse transcription loop-mediated isothermal amplification (CT-RT-LAMP) assay was developed for the detection of yam mosaic virus (YMV, genus Potyvirus) infecting yam (Dioscorea spp.). The assay uses a set of six oligonucleotide primers targeting the YMV coat protein region, and the amplification products in YMV-positive samples are visualized by chromogenic detection with SYBR Green I dye. The CT-RT-LAMP assay detected YMV in leaf and tuber tissues of infected plants. The assay is 100 times more sensitive in detecting YMV than standard RT-PCR, while maintaining the same specificity