Hybrid Variable Neighborhood Search for Solving School Bus-Driver Problem with Resource Constraints

The School Bus-Driver Problem with Resource Constraints (SBDP-RC) is an optimization problem with many practical applications. In the problem, the number of vehicles is prepared to pick a number of pupils, in which the total resource of all vehicles is less than a predefined value. The aim is to find a tour minimizing the sum of pupils’ waiting times. The problem is NP-hard in the general case. In many cases, reaching a feasible solution becomes an NP-hard problem. To solve the large-sized problem, a metaheuristic approach is a suitable approach. The first phase creates an initial solution by the construction heuristic based on Insertion Heuristic. After that, the post phase improves the solution by the General Variable Neighborhood Search (GVNS) with Random Neighborhood Search combined with Shaking Technique. The hybridization ensures the balance between exploitation and exploration. Therefore, the proposed algorithm can escape from local optimal solutions. The proposed metaheuristic algorithm is tested on a benchmark to show the efficiency of the algorithm. The results show that the algorithm receives good feasible solutions fast. Additionally, in many cases, better solutions can be found in comparison with the previous metaheuristic algorithms

The Impacts of Task-Based Activities on Learners’ Grammatical Acquisition and Motivation at Dong Nai Technology University

The study aims to measure the effect of Task-based language teaching on grammatical achievement and the motivation of EFL learners at Dong Nai Technology University. The research will conduct a quick grammar test to administer 48 students at the school to achieve this goal. After sitting the test, the learners will undergo a 6-week course applying task-based language teaching. Before the treatment, one certified instructor-made grammar test about the learning units will be encompassed as the pre-test. Furthermore, a motivation questionnaire will be carried out in this group at the research's beginning and end. Afterward, the learners will learn through the treatment, which is learning through the implementation of Task-based language teaching. After six weeks of treatment, the group will take the same teacher-made grammar test as the post-test. After that, the writer will analyze the data through paired sample t-test. The results demonstrated a significant difference between the pre-test and post-test in the student’s performance on grammar acquisition and the enhancement in learners’ motivation. Based on the findings of this research, it is believed that task-based language teaching can be used in English classes to enhance learners’ grammar achievements and motivation among Vietnamese university learners

Advanced Method for Motion Control of a 3 DOFs Lower Limb Rehabilitation Robot

This paper presents two motion control methods for a lower limb rehabilitation robot based on compensate gravity proportional-derivative and inverse dynamic proportional-derivative (PD) control algorithms. The Robot’s mechanism is comprised of three active joints: hip joint, knee joint and ankle joint, which are driven by DC motors. Firstly, based on Robot’s mechanism, a dynamic model of the Robot is built. Then, based on Robot’s model, motion control systems for Robot are designed. Simulation results show good performances and workability of these proposed controllers. Finally, the calculation of the joint angle errors and toque of each controller is performed. The comparison of simulation results between proposed controllers and the adaptive fuzzy controller allows to choice suitable motion control methods for Robot that can meet the requirements of a 3 DOFs lower limb rehabilitation robot for post-stroke patient

USING EXPERIMENTAL PLANNING TO OPTIMIZE THE HYDROLYSIS OF SUGAR CANE BAGASSE INTO FERMENTABLE SUGARS FOR BIOETHANOL PRODUCTION BY FUNGAL ENZYME MIXTURE

In this study, the unpretreated sugar cane bagasse was milled to a particle size of 0.5 – 1 mm and be used as material for bioconversion into fermentable sugars by using an enzyme cocktail acted synergistically. Experimental planning was used to optimize the enzyme conversion through assessment and analysis of individual parameter. As the result, the optimal condition for enzymatic conversion of sugar cane bagasse into reducing sugar product are at pH = 5, 400C, and 48 h incubation in rate of enzyme (Cell/Xyl, AltFAE, XpoAE) and substrate (bagasse meal) is 3.1. From the above application, the mathematical model is found to describe equation of the bioconversion of bagasse into reducing sugars: = 206.946 + 29.954x1 + 5.501x2 + 7.323x3 + 2.288x2x3 – 7.011; and using flexible algorithm of nonlinear planning to identify optimal conditions of enzyme mixture of conversion into reducing sugars that the reaction reached max = 251.86 mg per gram bagasse with x1 = 1.215, x2 = 1.215, x3 = 1.215 or Cell/Xyl = 1 ml (100U), AltFAE = 0.5 ml (7.56U), XpoAE = 0.4 ml (10.8U) on the test range. Experimental verification has the same result in constant conditons and reached total reducing sugars of 260.2 mg per gram substrate.In this study, the unpretreated sugar cane bagasse was milled to a particle size of 0.5 – 1 mm and be used as material for bioconversion into fermentable sugars by using an enzyme cocktail acted synergistically. Experimental planning was used to optimize the enzyme conversion through assessment and analysis of individual parameter. As the result, the optimal condition for enzymatic conversion of sugar cane bagasse into reducing sugar product are at               pH = 5, 40 oC, and 48 h incubation in rate of enzyme (Cell/Xyl, AltFAE, XpoAE) and substrate (bagasse meal) is 3.1. From the above application, the mathematical model is found to describe equation of the bioconversion of bagasse into reducing sugars: = 206.946 + 29.954x1 + 5.501x2 + 7.323x3 + 2.288x2x3 – 7.011; and using flexible algorithm of nonlinear planning to identify optimal conditions of enzyme mixture of conversion into reducing sugars that the reaction reached max = 251.86 mg per gram bagasse with x1 = 1.215, x2 = 1.215, x3 = 1.215 or Cell/Xyl = 1 ml (100U), AltFAE = 0.5 ml (7.56U), XpoAE = 0.4 ml (10.8U) on the test range. Experimental verification has the same result in constant conditons and reached total reducing sugars of 260.2 mg per gram substrate

Microwave-assisted direct synthesis of some 5-alkyl-2-amino-1,3,4-thiadiazoles.

Some 5-alkyl-2-amino-1,3,4-thiadiazoles have been synthesized by the MW-mediated solvent-free method. The reaction mixture is consisted of aliphatic acid, thiosemicarbazide and concentrated sulfuric acid (98%). Molar ratio of thiosemicarbazide and carboxylic acid was 1:2, reaction time was shortened (20 houres vs. 30 minutes). The structures of these aminothiadiazoles were confirmed by spectrospcopic methods (IR and 1H-NMR)

Approche par la théorie du calcul à la rupture du dimensionnement au feu de panneaux de grande hauteur

Principalement utilisés dans les bâtiments industriels, les panneaux de grande hauteur constitués de bandeaux horizontaux sont des ouvrages en béton armé pour lesquels l’analyse de leur comportement au feu requiert des traitements plus sophistiqués que les ouvrages courants. En effet, outre la détérioration des propriétés mécaniques des matériaux, et notamment de leur résistance, le feu induit des déformations thermiques susceptibles de provoquer des changements de géométrie non négligeables en raison des grandes dimensions de ces ouvrages. Dans le but de modéliser correctement le problème et d’examiner les points particuliers sur lesquels il convient de focaliser l’étude, une approche de type calcul à la rupture a été choisie. Ce type de méthode présente l’avantage de conduire de façon rigoureuse à la détermination des charges limites sans prise en compte de l’histoire de chargement, c’est-à-dire en s’affranchissant des difficultés liées à l’utilisation de lois de comportement non linéaires de type plasticité ou endommagement. Présentant l’originalité d’associer la prise en compte de la dégradation des caractéristiques mécaniques en conditions d’incendie au raisonnement du calcul à la rupture, des critères de rupture spécifiques aux plaques en béton armé soumises à des efforts membranaires et de flexion sont développés. Ceux-ci sont ensuite appliqués à la géométrie déformée de la structure étudiée afin de prendre en compte les effets du changement de géométrie. Afin d’évaluer la pertinence de la démarche, les résultats obtenus sont alors confrontés soit à ceux issus de modélisations de type calcul de béton armé classique, soit à des résultats expérimentaux disponibles dans la littérature. Cette contribution présentera et mettra en œuvre l’ensemble de la démarche décrite ci-dessus sur l’exemple simplifié d’un panneau de grande hauteur soumis à son poids propre et à un chargement thermique de type incendie, modélisé comme une poutre élancée

Influence of alloying elements on the corrosion of fine art bronze in the strong corrosive environment

The influence of Sn, Zn, and Pb on the corrosion of fine art bronze in strong corrosive environment were investigated. The value of loss mass and the potential of the specimens were determined in the artificial sea-water environment. Corrosion of specimens was compared each to other to find the effect of the elements. The corrosion products were determined with the XRD/SEM/EDS analyses. The results shown that, Sn decreases the corrosion rate of the bronze alloy in marine environment while Zn increases it. The corrosion rates and potential curves showed that the corrosion rate of the bronzes reduced with immersion time. Alloy containing 0.7% Pb; 1.6% Zn; 9.7 % Sn; 88% Cu (in %wt.) has the corrosion rate as lowest. Keywords. Corrosion, strong corrosive environments, fine art bronze, Sn, Pb, Zn

Influence of biofertilizer produced using drumstick (Moringa oleifera L.) unused parts on the growth performance of two leafy vegetables

The non-edible parts of Moringa oleifera, such as stems, branches or leaf petioles, have often been discarded while the leaves are consumed as a vegetable or are used to produce organic fertilizer. This study aimed to determine the optimal conditions for producing Moringa organic fertilizer (MOF) from previously unused parts and to compare these fertilizers with cow manure and bio-organic fertilizer. Seventy kilograms of the unused Moringa parts were blended with fifty kilograms of manure, 0.2 kilogram of Trichoderma-based product and two kilograms of superphosphate. The mixture was incubated at different intervals, including 5, 7 or 9 weeks. Next, the effects of MOF on the growth, yield, ascorbic acid content and Brix of lettuce and mustard spinach were also determined and compared with other organic fertilizers (cow manure and bio-organic fertilizer). Results of the study revealed that 25 tons per ha of MOF were significantly superior to those treated with cow manure and bio-organic fertilizer in the case of vegetable yields. Further, 7 weeks of MOF incubation was found suitable to produce an optimal yield during the various incubation period. These results suggested that the Moringa non-edible parts can make organic fertilizer and enhance growth, yield, and leafy vegetable production

Anti–inflammatory and antioxidant properties of the ethanol extract of Clerodendrum cyrtophyllum turcz in copper sulfate‐induced inflammation in zebrafish

Oxidative stress and inflammation are commonly present in many chronic diseases. These responses are closely related to pathophysiological processes. The inflammatory process can induce oxidative stress and vice versa through the activation of multiple pathways. Therefore, agents with antioxidant and/or anti-inflammatory activities are very useful in the treatment of many pathologies. Clerodendrum cyrthophyllum Turcz, a plant belonging to the Verbenaceae family, is used in Vietnamese traditional medicine for treating migraine, hypertension, inflammation of the throat, and rheumatic arthritis. Despite its usefulness, studies on its biological properties are still scarce. In this study, ethanol extract (EE) of leaves of C. cyrtophyllum showed protective activity against CuSO4 toxicity. The protective activity was proven to relate to antioxidant and anti-inflammatory properties. EE exhibited relatively high antioxidant activity (IC50 of 16.45 µg/mL) as measured by DPPH assay. In an in vivo anti-antioxidant test, three days post fertilization (dpf) zebrafish larvae were treated with different concentrations of EE for 1 h and then exposed to 10 µM CuSO4 for 20 min to induce oxidative stress. Fluorescent probes were used to detect and quantify oxidative stress by measuring the fluorescent intensity (FI) in larvae. FI significantly decreased in the presence of EE at 5 and 20 µg/mL, demonstrating EE’s profound antioxidant effects, reducing or preventing oxidative stress from CuSO4. Moreover, the co-administration of EE also protected zebrafish larvae against oxidative damage from CuSO4 through down-regulation of hsp70 and gadd45bb expression and upregulation of sod. Due to copper accumulation in zebrafish tissues, the damage and oxidative stress were exacerbated overtime, resulting in the upregulation of genes related to inflammatory processes such as cox-2, pla2, c3a, mpo, and pro- and anti-inflammatory cytokines (il-1ß, il-8, tnf-α, and il-10, respectively). However, the association of CuSO4 with EE significantly decreased the expression of cox-2, pla2, c3a, mpo, il-8, and il-1ß. Taken together, the results suggest that EE has potent antioxidant and anti-inflammatory activities and may be useful in the treatment of various inflammatory diseases