Pre-selection of suppliers through an integrated fuzzy analytic hierarchy process and max-min methodology

There are a variety of analytical models for supplier selection ranging from simple weighted techniques to complex mathematical programming approaches. However, these models are specifically aimed at supporting a decision maker in a single phase, especially in the final selection phase and they have failed to consider the supplier selection process from a holistic point of view. Although the methodology presented in this paper primarily focused on the prequalification of potential suppliers, the outputs of the previous phases, namely problem definition and formulation of criteria, are used as inputs in this methodology. The methodology utilises a fuzzy analytic hierarchy process (AHP) method to determine the weights of the pre-selected decision criteria, a max-min approach to maximise and minimise the supplier performances against these weighted criteria, and a non-parametric statistical test to identify an effective supplier set. This information supports decision makers in making the final selection with effective alternative choices. Potential application of the proposed methodology is demonstrated in Audio Electronics in Turkey's electronics industry.     

Acid Activation and Bleaching Performance of Turkish (Somas) Bentonite in Crude Soybean Oil

In this work, a bentonite clay from Turkey (Somas bentonite) was activated with different concentrations of H₂SO₄ and HCl at 70°–90°C and 5–8 h. Under these conditions several cations were removed from natural bentonite (Al, Mg, and Fe) and DTA-TGA and FT-IR curves of the solids obtained after acid treatment were examined. Treatment time and acid concentration increased the degree of destruction of the bentonite structure, which was determined by ICP. The specific surface area (S) and mesopore size distribution (PSD) of the samples were determined. Activated samples were tested in order to verify their capacity to bleach soybean oil and compared to standard commercial bleaching clays. The experimental results indicate that samples treated with H₂SO₄ show the same efficiency in bleaching crude soybean oil with the standards, and the sample treated with HCl is more efficient in bleaching than the commercial products. PSD values are mainly distributed between 7 and 60 Å, similar to standard commercial bleaching clays.     

Boron nitride stamp for ultra-violet nanoimprinting lithography fabricated by focused ion beam lithography

Cubic boron nitride (c-BN) is one of the hardest known materials (second after diamond). It has a high level of chemical resistance and high UV transmittance. In this study, a stamp for ultra-violet nanoimprint lithography (UV-NIL) was fabricated using a bi-layered BN film deposited on a quartz substrate. Deposition of the BN was done using RF magnetron sputtering. A hexagonal boron nitride (h-BN) layer was deposited for 30?min before c-BN was deposited for 30?min. The thickness of the film was measured as 160?nm. The phase of the c-BN layer was investigated using Fourier transform infrared (FTIR) spectrometry, and it was found that the c-BN layer has a 40% cubic phase. The deposited film was patterned using focused ion beam (FIB) lithography for use as a UV-NIL stamp. Line patterns were fabricated with the line width and line distance set at 150 and 150?nm, respectively. The patterning process was performed by applying different currents to observe the effect of the current value on the pattern profile. The fabricated patterns were investigated using AFM, and it was found that the pattern fabricated by applying a current value of 50?picoamperes (pA) has a better profile with a 65?nm line depth. The UV transmittance of the 160?nm thick film was measured to be 70-86%. The hardness and modulus of the BN was measured to be 12 and 150?GPa, respectively. The water contact angle of the stamp surface was measured at 75°. The stamp was applied to UV-NIL without coating with an anti-adhesion layer. Successful imprinting was proved via scanning electron microscope (SEM) images of the imprinted resin.     

Criticality and burnup analyses of a PBMR-400 full core using Monte Carlo calculation method

In this study, the criticality and burnup analyses have been performed for full core model of Pebble Bed Modular Reactors, such as PBMR-400, using the computer codes MCNP5.1.4 and MONTEBURNS 2.0. Three different pebble distributions, namely; Body Centered Cubic (BCC) (packing fraction = 68%), Random Packing (RP) (packing fraction = 61%) and Simple Cubic (SC) (packing fraction = 52%) were selected for the analyses. The calculated core effective multiplication factor, k_eff, for BCC, RP and SC came to be 1.2395, 1.2357 and 1.2223, respectively. The core life for these distributions were calculated as ～1200, 1000, and 800 Effective Full Power Days (EFPDs), whereas, the corresponding burnups came out to be ～99,000, ～92,000 and ～86,000 MWD/T, respectively, for end of life k_eff set equal to 1.02.     

EFFECTS OF DIFFERENT SALT CONTENTS ON SOME QUALITY CHARACTERISTICS DURING PROCESSING OF DRY‐CURED TURKISH PASTIRMA

ABSTRACT

This study examined the effects of different salt contents (3, 6 and 9%) during process stages on physicochemical, lipid oxidation and microbial quality of a dry‐cured meat product, past?rma, throughout 21 days of processing. Significant changes in moisture content, NaCl content, pH and water activity (a_w) were observed in past?rma after the third drying and pasting stages. There were significant decreases (P < 0.05) in objective color characteristics (L*, a* and b*) between raw material and final product for all past?rma samples. However, no significant effect of salt level (P > 0.05) was detected on L* and a*. Salt level significantly (P < 0.05) affected thiobarbituric acid‐reactive substances (TBARS) formation, which was lower in low‐salt past?rma samples, while the combination of salting, drying and pressing stages increased TBARS values in high‐salt past?rma samples. Higher salt content (6% and 9%) and last drying resulted in reduction of microbial count.

PRACTICAL APPLICATIONS

Salt (NaCl) is an important agent in inhibiting microbial growth, reducing water activity and imparting a salty taste to dry‐cured meat products such as ham and past?rma. Salt content in past?rma varies from 5% to 10% in the final product and has an impact on product quality parameters. The effects of different NaCl contents (3, 6 and 9%) and processing stages on pH, water activity (a_w), color parameters, lipid oxidation and microbial count were studied during processing of past?rma. Low‐salt concentration had some negative impacts on past?rma characteristics, giving high a_w, pH and microbial count, but low Thiobarbituric acid‐reactive substances value and NaCl content. Drying, pressing and pasting with çemen mixture during past?rma processing had a positive impact on reduction of moisture, a_w and microbial count.

     

Synthesis and characterization of novel graft copolymers by radiation‐induced grafting

The radiation‐induced graft copolymerization of N‐vinyl‐2‐pyrrolidone (NVP), 4‐vinyl pyridine (4VP), and 2‐vinyl pyridine (2VP) monomers onto poly (ethylene‐alt‐tetrafluoroethylene) (ETFE) was investigated. The influence of synthesis conditions particularly the solvent was studied. Various solvents, such as n‐propanol, isoproponol, benzyl alcohol, methanol, ethanol, cyclohexanone, tetrahydrofuran (THF), nitromethane, 1,4‐dioxane, and n‐heptane were examined for this purpose. Graft copolymers were characterized by Fourier transform infrared (FTIR) spectroscopy, dynamic mechanical analysis (DMA), and scanning electron microscopy‐energy dispersive spectroscopy (SEM‐EDAX). It was found that the nature of the solvent had profound influence over the grafting reaction. Cyclohexanone, n‐propanol, and isoproponol for 4VP/ETFE grafting, THF and 1,4‐dioxane for NVP/ETFE grafting, and benzyl alcohol and methanol for 2VP/ETFE grafting were found to be the suitable solvents yielding highest graft levels. Isoproponol and n‐propanol are promising in terms of both graft level and mechanical properties for 4VP/ETFE. Grafting of NVP, 4VP, and 2VP onto ETFE were verified through FTIR spectroscopy. Storage modulus and glass transition temperature of the copolymers were found to increase as graft level increased. Surface profile of representative films was also investigated by viewing the distribution of elemental nitrogen using SEM‐EDAX. Results indicated that copolymers of 4VP, NVP, and 2VP are considerably different from each other. 4VP‐based copolymers exhibited relatively more homogenous grafting over the surface compared with NVP‐ and 2VP‐based copolymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Electrostatic self‐assembly dyeing of cotton fabrics

A new approach to the dyeing of cotton fabrics using an electrostatic self‐assembly method was evaluated. Cotton fabrics were pretreated with 2,3‐epoxypropyltrimethylammonuium chloride and cationic charges were produced on the fabric surfaces. For the dyeing of cotton fabric, reactive and acid dyes were used. Oppositely charged anionic reactive/acid dyes and cationic poly(diallyldimethylammonium chloride) were alternately deposited on the surface of cationised cotton fabrics. Ten multilayer films of dye/poly(diallyldimethylammonium chloride) were deposited on the cotton fabric surfaces using a padder. The build‐up of the multilayer films and the level of colour strength (K/S) achieved are discussed. Samples of cotton fabrics were also dyed with the same dyes, but using the exhaust method, and both types of dyed samples were compared. The washing, rubbing and light fastness properties were evaluated for the dyed fabrics.     

Determination of drying rates of different timber kinds

In this study, the drying rate of poplar, pine, and oak timbers is estimated using an adaptive neuro-fuzzy inference system (ANFIS). Experimental data were used for training and testing networks. The R² value obtained when unknown data were applied to the networks was 0.99982 for the drying rate of poplar timbers, 0.999028 for the drying rate of pine timbers, and 0.999968 for the drying rate of oak timbers, which is very satisfactory. The method proposed offers more flexibility and therefore drying analysis of different timber kinds is fairly simplified.     

An efficient interface model to develop scalable methodology of melt processing of polypropylene with graphene oxide produced by an improved and eco-friendly electrochemical exfoliation

This study developed a scalable and straightforward adaptation methodology for melt processing of polypropylene (PP) to provide a high degree of exfoliation of multilayer graphene oxide (GO) by using a high-shear mixer. GO was first produced by an improved and eco-friendly electrochemical exfoliation by using an environmentally friendly aqueous methanesulfonic acid (MSA) and a sodium sulfate salt system to minimize the environmental impact. The produced GOs then were melt blended with PP and their mechanical, thermal, and morphological properties were investigated under different GO loadings to attain ideal configuration and increase interfacial interactions between polymer matrix and reinforcer. Comparisons were made by producing different PP composites using two different GO types produced in salt and acid environments. Additionally, by applying different voltages to salt system, the effect of applied voltage on the properties of both GO material and the composites were discussed. The characterization results indicated that GO obtained in MSA solution caused a 71% increase in flexural modulus and 46% in flexural strength with the addition of 1 wt% GO. The rheological characterization also showed that dispersion and viscosity improved with lower GO loadings compared to neat polymer by providing cost-effective and scalable graphene manufacturing.