Proactive environmental strategy in a supply chain context: the mediating role of investments

There is a growing body of knowledge on the link between environmental management and supply chain management, but there is contradicting evidence on the impact of a proactive environmental strategy on environmental performance. Therefore, this paper investigates the impact of proactive environmental strategy on environmental performance as mediated by environmental investments. We also consider the antecedents of the adoption of proactive environmental strategy. We develop and test hypotheses, using data collected from 96 Turkish manufacturers through an online questionnaire. The model was tested using partial least squares (PLS), a structural equation modelling method. The results show that a proactive environmental strategy leads to higher environmental investments; both internally and externally in collaboration with suppliers. Our findings support our hypothesis that environmental investments act as a mediating variable between proactive environmental strategy and environmental performance. The results also show that customer pressure and, particularly, organisational commitment positively impact the extent to which firms adopt a proactive environmental strategy.     

Polypyrrole–vinyl aniline modified cyclohexanone formaldehyde resin copolymers: a comparative study of the resin preparation

In this study, the synthesis of polypyrrole‐b‐vinyl aniline modified cyclohexanone formaldehyde resin (PPy‐b‐CFVAnR) block copolymers by a combination of condensation polymerization and chemical oxidative polymerization processes was examined. First, a cyclohexanone formaldehyde resin containing vinyl aniline units [4‐ vinyl aniline modified cycl?ohexanone formaldehyde resin (CFVAnR)] was prepared by a direct condensation reaction of 4‐vinyl aniline and cyclohexanone with formaldehyde in an in situ modification reaction. CFVAnR and pyrrole (Py) were then used with a conventional method of in situ chemical oxidative polymerization. The reactions were carried out with heat‐activated potassium persulfate salt in the presence of p‐toluene sulfonic acid in a dimethyl sulfoxide–water binary solvent system; this led to the formation of desired block copolymers. The effects of the oxidant–monomer molar ratio, dopant existence, addition order of the reactants, and reaction temperature on the yield, conductivity, and morphology of the resulting products were investigated. PPy‐b‐CFVAnR copolymers prepared with a resin‐to‐Py molar ratio of 1:40 showed conductivity in the range 3.7 × 10^?1 to 3.8 × 10^?2 S/cm. Oxidant‐to‐Py molar ratios of 0.5 and 1.0 were proposed to be the optimum stoichiometries for higher conductivity and yield, respectively, of the copolymer. The morphology of the copolymer (PPy‐b‐CFVAnR) was investigated with environmental scanning electron microscopy analyses. The results indicate that the surface of the copolymer was composed of well‐distributed nanospheres with average particle diameters of 60–85 nm. Also, the synthesized PPy‐b‐CFVAnR had a higher thermal stability than the pure CFVAnR. The chemical composition and structure of the PPy‐b‐CFVAnR copolymers were characterized by Fourier transform infrared spectroscopy and measurement. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42841.     

Calculation from the current-voltage and capacitance-voltage measurements of characteristics parameters of Cd/CdS/n-Si/Au-Sb structure with CdS interface layer grown on n-Si substrate by SILAR method

The CdS thin film has been directly formed on n-type Si substrate to form an interfacial layer between cadmium (Cd) and n-type Si with Successive Ionic Layer Adsorption and Reaction (SILAR) method. An Au-Sb electrode has been used as an ohmic contact. The Cd/CdS/n-Si/Au-Sb structure has demonstrated clearly rectifying behaviour by the current-voltage (I-V) curves studied at room temperature. The characteristics parameters such as barrier height, ideality factor and series resistance of Cd/CdS/n-Si/Au-Sb structure have been calculated from the forward bias I-V and reverse bias C⁻²-V characteristics. The diode ideality factor and the barrier height have been calculated as n = 2.06 and Φ_b = 0.92 eV by applying a thermionic emission theory, respectively. The diode shows non-ideal I-V behaviour with an ideality factor greater than unity that can be ascribed to the interfacial layer, the interface states and the series resistance. At high current densities in the forward direction, the series resistance (R_s) effect has been observed. The values of R_s obtained from dV/d(lnI)-I and H(I)-I plots are near to each others (R_s = 182.24 Ω and R_s = 186.04 Ω, respectively). This case shows the consistency of the Cheung′s approach. In the same way, the barrier height calculated from C⁻² -V characteristics varied from 0.698 to 0.743 eV. Furthermore, the density distribution of interface states (N_ss) of the device has been obtained from the forward bias I-V characteristics. It has been seen that, the N_ss has almost an exponential rise with bias from the mid gap toward the bottom of conduction band.     

Making Big Data Small: Strategies to Expand Urban and Geographical Research Using Social Media

While exciting, Big Data (particularly geotagged social media data) has proven difficult for many urbanists and social science researchers to use. As a partial solution, we propose a strategy that enables the fast extracting of only relevant data from large sets of geosocial data. While contrary to many Big Data approaches—in which analysis is done on the entire dataset—much productive social science work can use smaller datasets—around the same size as census or survey data—within standard methodological frameworks. The approach we outline in this paper—including the example of a fully operating system—offers a solution for urban researchers interested in these types of data but reluctant to personally build data science skills.     

Al-6013-T6 and Al-7075-T7351 alloy anodes for aluminium-air battery

This study is aimed to determine the appropriate anode material (pure Al, 6013-T6; Al1 and 7075-T7351; Al2) for Al-air batteries. Electrochemical Measurements, Galvanostatic Anodic Dissolution Test and Surface Characterization are performed. The corrosion rate and the hydrogen gas evolution rate are calculated. Anodic dissolution test is carried out at the current density of 10–50 mA cm^?2. The weight loss measurements were performed. The anode utilization (Ua%) and capacity density are calculated. The surface morphology of electrodes is investigated by scanning electron microscope (SEM) and mapping imagines are taken. The surface analysis also is performed by energy dispersive X-ray spectrometer (EDS) and contact angles are determined by Young–Laplace Contact Angle method. As a result, it is seen that alloy elements change the surface characteristics during discharging of the battery and the battery performance is positively affected. Especially, copper shows surprisingly synergistic effect with aluminium on the alloy surface.     

Resource recovery as a sustainable perspective for the remediation of mining wastes: rehabilitation of the CMC mining waste site in Northern Cyprus

Bulletin of Engineering Geology and the Environment - This paper highlights resource recovery and stabilization as the novel approach adopted in the rehabilitation strategy of the abandoned copper...     

Enhanced corrosion resistance and surface characterization of anodized 7075 Al

Protection of Metals and Physical Chemistry of Surfaces - In this study, we aim to enhance physical and chemical properties of 7075 aluminum via anodizing. For this purpose, convenient potential,...     

On the quality variation impact of returns in remanufacturing

This study considers a two-class production system that is subject to operational and quality failures. A generalized example for such systems is the remanufacturing processes where new and used parts are handled by the same machines. Here the impurities of used parts bring additional load to machines that are shared by new and used parts. In order to analyze the process first the single machine operation is modeled as a Continuous Time Markov Chain. Then based on the single machine model, a model for a two-machine-one-buffer-system is constructed. Here in order to attain computational tractability for systems with larger buffers state aggregation and randomized part type sequencing is considered for both machines. Then using this model the impact of the remanufacturing ratio on the effective throughput rate of the system is numerically analyzed.     

A comprehensive assessment of measurement equivalence in operations management

This paper provides a comprehensive framework for treating equivalence both prior to data collection and during subsequent analyses, and assesses the extent to which equivalence is considered in survey research in six leading empirical Operations Management (OM) journals (Decision Sciences, International Journal of Operations & Production Management, International Journal of Production Research, Journal of Operations Management, Management Science and Production and Operations Management). Measurement equivalence of latent variables in survey data is an important condition that should be met in order to meaningfully pool and/or compare data stemming from apparently heterogeneous sub-groups. We assess 465 survey articles from a six-year period from 2006 to 2011 and document these articles in relation to the four main stages of our comprehensive framework: identifying sources of heterogeneity; maximising equivalence prior to data collection; testing measurement equivalence after data collection; and dealing with partial and non-equivalence. We conclude that pooling of data from heterogeneous sub-groups is common practice in OM, but that awareness and testing of equivalence remains limited. Given these findings, we further elaborate the best practices detected in those few OM studies that do address equivalence in some way. We conclude that to improve the quality of OM survey research, authors, editors and reviewers should pay greater attention to equivalence, and we provide a pragmatic checklist of measurement equivalence issues across the four stages.