Agricultural tractor selection: A hybrid and multi-attribute approach

Usually, agricultural tractor investments are assessed using traditional economic techniques that only involve financial attributes, resulting in reductionist evaluations. However, tractors have qualitative and quantitative attributes that must be simultaneously integrated into the evaluation process. This article reports a hybrid and multi-attribute approach to assessing a set of agricultural tractors based on AHP-TOPSIS. To identify the attributes in the model, a survey including eighteen attributes was given to agricultural machinery salesmen and farmers for determining their importance. The list of attributes was presented to a decision group for a case of study, and their importance was estimated using AHP and integrated into the TOPSIS technique. In this case, one tractor was selected from a set of six alternatives, integrating six attributes in the model: Initial cost, annual maintenance cost, liters of diesel per hour, safety of the operator, maintainability and after-sale customer service offered by the supplier. Based on the results obtained, the model can be considered easy to apply and to have good acceptance among farmers and salesmen, as there are no special software requirements for the application. © 2016 by the authors

New product development and innovation in the maquiladora industry: A causal model

Companies seek to stand out from their competitors and react to other competitive threats. Making a difference means doing things differently in order to create a product that other companies cannot provide. This can be achieved through an innovation process. This article analyses, by means of a structural equation model, the current situation of Mexican maquiladora companies, which face the constant challenge of product innovation. The model associates three success factors for new product development (product, organization, and production process characteristics as independent latent variables) with benefits gained by customers and companies (dependent latent variables). Results show that, in the Mexican maquiladora sector, organizational characteristics and production processes characteristics explain only 31% of the variability (R2 = 0.31), and it seems necessary to integrate other aspects. The relationship between customer benefits and company benefits explains 58% of the variability, the largest proportion in the model (R2 = 0.58). © 2016 by the authors; licensee MDPI, Basel, Switzerland

Poly (acrylonitrile-co-methyl methacrylate) nanoparticles: I. Preparation and characterization

This work concerns the preparation and characterization of poly (acrylonitrile-co-methyl methacrylate) Copolymer, P(AN-co-MMA), nano-particles using precipitation polymerization technique. Potassium per-sulfate redox initiation system was used to perform polymerization process in an alcoholic aqueous system. The impact of different polymerization conditions such as comonomer concentration and ratio, polymerization time, polymerization temperatures, initiator concentration and co-solvent composition on the polymerization yield and particle size was studied. Maximum polymerization yield, 70%, was obtained with MMA:AN (90%:10%) comonomer composition. Particle sizes ranging from 16 nm to 1483 nm were obtained and controlled by variation of polymerization conditions. The co-polymerization process was approved by FT-IR and TGA analysis. The copolymer composition was investigated by nitrogen content analysis. Copolymers with a progressive percentage of PAN show thermal stabilities close to PAN Homopolymer. SEM photographs prove spherical structure of the produced copolymers. The investigated system shows promising future in the preparation of nanoparticles from comonomers without using emulsifiers or dispersive agents