Numerical solutions of nonlinear evolution equations using variational iteration method

AbstractThe variational iteration method is used to solve three kinds of nonlinear partial differential equations, coupled nonlinear reaction diffusion equations, Hirota–Satsuma coupled KdV system and Drinefel’d–Sokolov–Wilson equations. Numerical solutions obtained by the variational iteration method are compared with the exact solutions, revealing that the obtained solutions are of high accuracy. He's variational iteration method is introduced to overcome the difficulty arising in calculating Adomian polynomial in Adomian method. The method is straightforward and concise, and it can also be applied to other nonlinear evolution equations in mathematical physics

Utilization of Used Vegetable Oil as a Biodiesel Fuel

In this study the reusing of vegetable oil as an alternative substitute for biodiesel was investigated. The used vegetable oil (UVO) was obtained from Baraka Factory – Potato chips line, Wad Madani, Sudan. The biodiesel is produced from used vegetable oil by alkali transesterification. The kinematic viscosity of biodiesel (at 40ºC), flash point, density (at 15ºC), and calorific value were 5.35cSt, 119ºC, 0.881gm/ml, and 41.9MJ/kg respectively. The results showed that the used vegetable oil is suitable for biodiesel productio

Modèle de régression optimale des traits de conformation et de la production laitière des troupeaux bovins de race kouri élevés à la station de Sayam du Niger.

Objectif : évaluer en station, la pertinence des traits de conformation traditionnellement privilégiés par les éleveurs kouri, pour l’identification des meilleures vaches laitières.Méthodologie et résultats : La production laitière et treize traits biométriques ont été évalués sur 54 vaches, de septembre 2015 à février 2016, au Centre de Multiplication de Bétail de Sayam, après six (6) mois de contrôle laitier. Il est constaté que la production laitière journalière était positivement corrélée aux traits de conformation du bassin (largeur aux ischions (r = 0.35**) et la largeur aux trochanters (r = 0.36**)), à la profondeur de poitrine (r = 0.27*), à la largeur aux poitrines (r = 0.29*) et au rapport de la largeur aux poitrines sur la largeur aux hanches (r = 0.28*). Le modèle de régression optimale de la production laitière qui s’est bien ajusté de façon hautement significative (p = 0.004) est un modèle utilisant la largeur-Trochanters et le rapport largeur- Poitrine/Largeur-hanche comme indices prévisionnels. La valeur du R carrée ajusté du modèle et de l’erreur standard des résidus étaient respectivement 0.16 et 0.43.Conclusion et perspectives : les traits biométriques intéressants, identifiés comme promoteurs dans cette étude, peuvent être inclus dans le développement de mécanismes de sélection qui peut encore être couplé à des techniques modernes de sélection. Le modèle ainsi obtenu, pourrait être utilisé pour prédire la production de lait des vaches kouri ou à des fins de sélection.Mots clés : Corrélation, modélisation, traits de conformation, production laitière, kour

Perceptions de la variabilité climati que et stratégies d’adaptation dans le système oasien de Gouré (Sud-est Niger)

Les savoirs liés au temps et à l’espace, et l’identification des stratégies paysannes pour affronter les problèmes climatiques sont indispensables pour toute compréhension des questions climatiques. Pour mieux apprécier les perceptions de la variabilité climatique et les stratégies d’adaptation utilisées, une enquête semi structuré qui a concerné 60 personnes repartie dans 4 villages du département de Gouré, situé dans l’Est du Niger est conduite selon une approche qualitative et quantitative. Les effets de la variabilité climatique ressentis par les agriculteurs sont l’aridité du climat, l’augmentation de la température et le caractère aléatoire des pluies. Les éleveurs la perçoivent de façon indirecte à travers la réduction du fourrage et de la disponibilité d’eau. Ces effets ont poussé ces populations à adopter des stratégies d’adaptation comme la recherche de nouvelles variétés à cycle court et supportant les poches de sécheresse, la pratique des techniques de fixation des dunes pour la restauration du couvert herbacé, l’utilisation de la fumure organique, la modification des dates de semis, le stockage de fourrage, le déstockage des animaux pendant la soudure, les prières collectives de demande de pluies. Elles sont toutefois insuffisantes du fait de la persistance des effets négatifs de la variabilité climatiques au Niger.Mots clés: Variabilité climatique, perception, stratégies d’adaptation, Gouré, NigerEnglish Title: Farmers perception and adaptation strategies to climate change in the oasis system of Goure (Southeast Niger)English AbstractKnowledge related to the perception of time and space, and identification of farmers’ strategies for dealing with climate change is a perequisite for a good understanding of climate issues. Farmers’ climate variability perceptions and adaptation strategies was studied using a survey conducted with sixty (60) farmers in the department of Gouré, located in eastern Niger. Results showed that farmers directly experience changes in  climate variability through temperature increase, frequent drought and erratic rainfall. By contrast, herders sense the effects of climate change indirectly through fodder reduction and scarce water availability. These effects have prompted farmers to adopt coping strategies such as the use of improved varieties, early and drought tolerant, sand dune stabilization and land reclamation, use of organic manure, changing of planting dates, storage of fodder, the destocking of animals during drought periods, collective prayers for rain. These strategies, however, appear to be insufficient for addressing the negative effects of climate change in this part of Niger.Keywords: climate variability, perception, strategies of adaptation, Goure, Nige

EFFECT OF MINERAL FERTILIZATION AND CUTTING NUMBERS ON GROWTH AND PRODUCTIVITY OF GUAR PLANT I. EFFECT ON VEGETATIVE GROWTH PARAMETERS

This work was carried out during the two successive growing seasons of 2019 and 2020 at the farm of Animal Industrial Feeding Factory at Shosha Village, Production Sector, Agricultural Research Centre, Ministry of Agriculture, and Laboratory of Floriculture, Faculty of Agriculture, Minia University, to study the effect of mineral fertilization and number of cuts on the vegetative growth of guar (Cyamopsis tetragonoloba, (L.) Taub.) plants. Data revealed that increasing mineral NPK level led to a significant increase in plant height, number of branches and herb fresh and dry weights as compared with control. While, without cut treatment (control) was superior to other cutting treatments (one, two and three cuts) on increasing all studied previous parameters except number of branches.It can be noticed that the highest level of NPK mineral fertilization (500 kg/fed comprised of 200 kg ammonium sulfate + 200 kg calcium supper phosphate + 100 kg potassium sulfate) in combination with applying three cuts led to the greatest branch numbe

EFFECT OF MINERAL FERTILIZATION AND CUTTING NUMBERS ON GROWTH AND PRODUCTIVITY OF GUAR PLANT II. EFFECT ON YIELD OF GREEN FOLIAGE, SEED, GUARAN YIELD AND PROTEIN

This work was carried out during the two successive growing seasons of 2019 and 2020 at the farm of Animal Industrial Feeding Factory, Shosha Village, which belongs to Production Sector, Agricultural Research Centre, Ministry of Agriculture, and Laboratory of Floriculture, Faculty of Agriculture, Minia University, to study the effect of NPK fertilization and number of cuts on the foliage, seed and guaran yield as well as protein content of guar (Cyamopsis tetragonoloba, L. Taub.) plant. Data revealed that increasing mineral NPK level led to significant increase all studied parameters (fresh and dry green foliage/fed/year, seed and guaran yield/plant and /fed/year and protein content) comparing with control. The results showed that increasing number of cuts significantly increased fresh and dry green foliage/fed/year and, protein content while significantly decreased seed and guaran yield/plant and /fed as compared with non-cut plants. The interaction treatment of high level of NPK in combination with three cuts was the best interaction treatment to obtain the highest green foliage/plant and /fed/year and protein content. For obtaining good productivity of seeds and guaran, it should be fertilizing plants with a high level of NPK (200:200:100 kg/fed) without cutting. Meanwhile, when green leaf yield is the primary goal, it is suggested to supply plants with the high level of NPK (200:200:100 kg/fed) and cutting plants three times. In the case of search for a good yield of seed, guaran and foliage, it could be recommended to fertilize guar plants with the high level of NPK and cutting plants just one tim

Exploration of the equilibrium operating space for NSTX-Upgrade

This paper explores a range of high-performance equilibrium scenarios available in the NSTX-Upgrade device [J.E. Menard, submitted for publication to Nuclear Fusion]. NSTX-Upgrade is a substantial upgrade to the existing NSTX device [M. Ono, et al., Nuclear Fusion 40, 557 (2000)], with significantly higher toroidal field and solenoid capabilities, and three additional neutral beam sources with significantly larger current drive efficiency. Equilibria are computed with freeboundary TRANSP, allowing a self consistent calculation of the non-inductive current drive sources, the plasma equilibrium, and poloidal field coil current, using the realistic device geometry. The thermal profiles are taken from a variety of existing NSTX discharges, and different assumptions for the thermal confinement scalings are utilized. The no-wall and idealwall n=1 stability limits are computed with the DCON code. The central and minimum safety factors are quite sensitive to many parameters: they generally increases with large outer plasmawall gaps and higher density, but can have either trend with the confinement enhancement factor. In scenarios with strong central beam current drive, the inclusion of non-classical fast ion diffusion raises qmin, decreases the pressure peaking, and generally improves the global stability, at the expense of a reduction in the non-inductive current drive fraction; cases with less beam current drive are largely insensitive to additional fast ion diffusion. The non-inductive current level is quite sensitive to the underlying confinement and profile assumptions. For instance, for BT=1.0 T and Pinj=12.6 MW, the non-inductive current level varies from 875 kA with ITER-98y,2 thermal confinement scaling and narrow thermal profiles to 1325 kA for an ST specific scaling expression and broad profiles. This sensitivity should facilitate the determination of the correct scaling of transport with current and field to use for future fully non-inductive ST devices. Scenarios are presented which can be sustained for 8-10 seconds, or (20-30)τCR, at βN=3.8-4.5, facilitating, for instance, the study of disruption avoidance for very long pulse. Scenarios have been documented which can operate with βT~25% and equilibrated qmin>1. The value of qmin can be controlled at either fixed non-inductive fraction of 100% or fixed plasma current, by varying which beam sources are used, opening the possibility for feedback qmin control. In terms of quantities like collisionality, neutron emission, non-inductive fraction, or stored energy, these scenarios represent a significant performance extension compared to NSTX and other present spherical torii

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries