In most industrial environments, it is usually considered that machines are accessible throughout the planning horizon, but in real situation, machines may be unavailable due to a scheduled preventive maintenance where the periods of unavailability are known in advance. The main idea of this paper is to consider different preventive maintenance policies on machines regarding open shop scheduling problem (OSSP) with sequence dependent setup times (SDST) using immune algorithm. The preventive maintenance (PM) policies are planned for maximizing availability of machines or keeping minimum level of reliability through the production horizon. The objective function of the paper is to minimize makespan. In total, the proposed algorithm extensively is compared with six adaptations of existing heuristic and meta-heuristic methods for the problem through data sets from benchmarks based on Taillard’s instances with some adjustments. The results show that the proposed algorithm outperforms other algorithms for this problem.

In this study an integrated model is proposed for the location inventory routing problem under uncertainty. This problem involves determining the location of distribution centers (DCs) in a three echelon supply chain. The DCs receive orders from the customer and according to a continuous review inventory replenishment policy place orders to the supplier. The products are directly shipped from the supplier to the DCs. The vehicles start from the DCs to fulfill the demands of the customers. Determining the routing of the vehicles is one of the decisions involved in this problem. The demands of customers are stochastically distributed and the capacity of DCs are limited. If one of the DCs undergo a disruption and is unable to fulfill the demands of the customers, shortage may occur. Moreover in the proposed model the shortage is considered as partial backlogging. This means that if shortage occurs, some of the orders result in lost sales and other orders are fulfilled in the next period. In order to optimally solve the proposed model a nonlinear integer programming (INLP) model is developed. However, since the problem is NP-hard, the mathematical formulation cannot be efficiently solved for large sized instances of the problem. Therefore an outer approximation method is developed to solve the problem more efficiently. The computational results show the efficiency of the proposed method.

Agricultural tractor selection is vital for farms, farmers or other agricultural companies in terms
of success and competitiveness in the global market. This selection may be assumed as a
MCDM (Multi Criteria Decision Making) problem involving qualitative and quantitative
factors that must be simultaneously integrated into the selection process. At the same time there
are many agricultural tractor alternatives in the market when purchasing an agricultural tractor.
This paper deals with the agricultural tractor selection problem using TOPSIS method. This
problem is also solved with two other MCDM methods; COPRAS (COmplex PRoportional
ASsessment) and EVAMIX (EVAluation of MIXed Data) to rank the tractors alternatives.
Lastly Borda and Copeland methods are used to aggregate all three ranking results.

Machining of hardened work materials with appropriate levels of process parameters is still a burning issue in manufacturing sectors and challenging. It is because of pressing demand of surface quality which adversely affected by evolution of tool wear. Therefore the present investigation is undertaken to make a decision on parametric optimization of multi-responses such as flank wear and surface roughness during machining hardened AISI 52100 steel (55±1) steel using mixed ceramic insert under dry environment through grey relational analysis combined with Taguchi approach. Also predicted mathematical models of 1st and 2nd order have been developed for responses and checked for its accuracy. Second order mathematical model presented higher R2 value and represents best fit of the model and adequate compared to first order model. Model indicates good correlations between the experimental and predicted results. The proposed grey-based Taguchi methodology has been proved to be efficient for solving multi-attribute decision making problem as a case study in hard machining environment.

The utilization of bis(isonicotinic acid)phthalocyaninatocobalt (II) [CoPc(isa)2] incorporated on TiO2 has been studied as a photocatalyst to degrade benzene vapor under fluorescent lamp (indoor light) conditions. The photocatalytic activity of [CoPc(isa)2]-TiO2 compared to TiO2 showed an increase in the extent of degradation. The axial isonicotinic acid ligand attached to CoPc improved the degradation rate of benzene as compared with unligated CoPc-TiO2 which may be attributed to the enhancement of electronic structure in the complex due to the additional isonicotinic acid ligand and its possible attachment to the TiO2 surface through the carboxylic acid moiety. Therefore, covalently-linked CoPc(isa)2 to TiO2 can enhance the extent of photodegradation of benzene and other common volatile organic compounds under indoor lighting conditions.

A simple, efficient and general method for the synthesis of 4H-pyrans is established through a multi component cyclocondensation of aromatic aldehydes, malononitrile and ethyl acetoacetate or acetyl acetone using snail shell as a natural catalyst. In this method the snail shell was used as green and reusable natural catalyst. Excellent yields, short reaction times and availability of the catalyst are the advantages of this method.

A series of semicarbazones, thiosemicarbazones, 1,3,4-oxadiazoles/thiadiazoles bearing pyrazole scaffold were designed and synthesized. All the synthesized new compounds were characterized by 1H NMR, 13C NMR, MS and elemental analysis. The synthesized compounds were screened to probe their in vitro antimicrobial activity against bacteria and fungi species. The structure-activity relationship of the synthesized compounds was studied. The compounds displayed good to excellent potency against tested microorganisms. The in vitro antioxidant activities of the 1,3,4-oxadiazoles/thiadiazoles were evaluated by DPPH, hydroxyl and nitric oxide radical scavenging assay. Among the tested compounds, compound with chloro substitution showed good antioxidant potential.

Preliminary experiments shows, that [3+2] cycloadditions reactions proceeds with full regioselectivity and high stereoselectivity. In consequence, 3,4-trans-2-methyl-3-(3,4,5-trimethoxyphenyl)-4-halo-4-nitroisoxazolidines are forming as predominantly (or sole) products. Additionally, prognosis for the synthesized compounds to be potential ingredients of drugs is good.

A simple, efficient protocol for one pot synthesis of bis(indolyl)methanes from primary alcohols is investigated with N-bromosuccinimde as a catalyst under ultrasound irradiation. Alcohols can be converted into carbonyl compounds by removal of hydrogen in presence of N-bromosuccinimde as an oxidant and can react in situ with indole to give desired bis(indolyl)methanes. In the reported one pot multicomponent condensation reaction N-bromosuccinimde promotes the oxidation of alcohol to aldehyde, facilitating the subsequent condensation with indole to afford bis(indolyl) methanes in good to excellent yields. The inexpensiveness and easy handling are some of important feature of N-bromosuccinimde. The by-product N-succinimide can be easily recovered and recycled to N-bromosuccinimide.

The present study endeavors to show an application of the multi objective optimization on the basis of ratio analysis (MOORA) method and technique for order performance by similarity to ideal solution (TOPSIS) method to select optimal process parameters in sheet hydroforming process. The right choice of the process parameters is critical to produce a final part with proper quality. In order to meet this characteristic, the important properties are the cup final thickness (FT), required forming force (FF) and radial stress (RS) at cup wall region. Nine alternatives for selecting the process parameters were taken into consideration based on Taguchi L9 orthogonal array. The limit drawing ratio (LDR), maximum pressure and prebulge pressure were selected as input variables. To solve the problem of process parameters’ selection, the two mentioned methods were used. A compromised weighting approach composed of Entropy and analytic hierarchy process (AHP) methods were used to weight all criteria. The alternatives ranking were performed using MOORA and TOPSIS methods and then the results were compared. The results achieved in both of the assessment represent that the alternative number 3, leads to the best multi performance features of the process among the 9 experiments. In this experiment LDR is 1.81, maximum pressure and prebulge pressure are 37 MPa and 15 MPa, respectively.