A new hybrid recommendation algorithm with privacy

Providing accurate and dependable recommendations efficiently while preserving privacy is essential for e‐commerce sites to recruit new customers and keep the existing ones. Such sites might be able to increase their sales and profits while customers can obtain precise and trustworthy predictions if they use appropriate collaborative filtering (CF) algorithms without deeply jeopardizing users' privacy. We propose a new recommendation algorithm, which is a hybrid‐memory and model‐based algorithm to generate truthful referrals efficiently. Moreover, we use randomization techniques to preserve users' privacy while still offering CF services with decent accuracy. We perform real data‐based trials and analyse our proposed schemes in terms of privacy, accuracy, and performance.     

Mixed model disassembly line balancing problem with fuzzy goals

The collection of used products is the driving force of remanufacturing systems and enterprises can gain significant economic, technical and social benefits from recycling. All products are disassembled up to some level in remanufacturing systems. The best way to disassemble returned products is valid by a well-balanced disassembly line. In this paper, a mixed integer programming (MIP) model is proposed for a mixed model disassembly line balancing (MMDLB) problem with multiple conflicting objectives: (1) minimising the cycle time, (2) minimising the number of disassembly workstations and (3) providing balanced workload per workstation. In most real world MMDLB problems, the targeted goals of decision makers are frequently imprecise or fuzzy because some information may be incomplete and/or unavailable over the planning horizon. This study is the first in the literature to offer the binary fuzzy goal programming (BFGP) and the fuzzy multi-objective programming (FMOP) approaches for the MMDLB problem in order to take into account the vague aspirations of decision makers. An illustrative example based on two industrial products is presented to demonstrate the validity of the proposed models and to compare the performances of the BFGP and the FMOP approaches.     

A randomized comparison of the 3 Papanicolaou smear collection methods

The purpose of this study was to compare the effectiveness of 3 cervical smear sampling devices for obtaining acceptable yields of endocervical cells in Papanicolaou smears. In a randomized, controlled clinical trial, we collected 346 smears over a 6-month period, 110 with the Cervex brush, 125 with the cotton swab plus Ayre spatula and 111 with the Cytobrush plus Ayre spatula. The Cytopathology Laboratory, blinded to the Papanicolaou smear method, screened the smears using the Bethesda system guidelines. Statistical analyses were performed using the Pearson X2 and analysis of variance tests. There was an increased detection of endocervical cells in the Cytobrush plus Ayre spatula and the Cervex brush methods, compared with the cotton swab plus Ayre spatula group (p = 2.39 x 10(-6), p = 4.49 x 10(-7) respectively). There was no statistically significant difference between the Cytobrush-Ayre spatula and the Cervex brush sampling methods were equally effective in obtaining endocervical cells in Papanicolaou smears.     

Synthesis and metal ions sorption properties of styrene‐based polymers

Atactic polystyrene (PS) was chemically modified with maleic (MAH), succinic (SAH), and phtalic (PhAH) anhydrides. Styrene was copolymerized with acrylic (AA) and methacrylic acids (MA). Amount of carboxyl groups (%) bound to polymers was determined in the range of 6.9–25.9. Different modified polystyrenes (MPS) and styrene copolymers were used in the experiments to study Cu(II) and Zn(II) ions adsorption probability and their comparison. Sorption capacity of the polymers for the metal ions were investigated in aqueous media containing different amounts of these ions (5–40 mg/L) and at different pH values (2.0–6.0). Adsorption behavior of heavy metal ions could be modeled using both the Langmuir and Freundlich isotherms. It was found that the adsorption capacity is highest at pH value of 6, whereas it decreases as the pH value decreases at temperature 25°C ± 1°C for 240 min. The results obtained from the adsorption capacity experiments for Cu(II) and Zn(II) ions were 3.47–5.45 and 5.42–6.85 mg/g, respectively. The affinity order of polymers for both metal ions was observed as follows: SMAC > SAAC > MPS with MAH > MPS with SAH > MPS with PhAH. The maximum adsorption capacities of SMAC were 6.85mg/g for Zn(II) and 5.45 mg/g for Cu(II). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Ion-Specific Interaction of Alumina Surfaces

There has been a long-standing question about the effect of the type of ionic species on the surface forces that is not considered in the classical Derjaguin–Landau–Vervey–Overbeek theory. Originating from the work of Hofmeister, the ion-specific interaction between particles has been known for a long time. Depending on the pH and oxide type, a direct or a reverse Hofmeister effect has been observed in colloidal suspensions at high salt concentrations. The origin of this effect is not well understood but is qualitatively taken into account in colloid science. From macroscopic behavior, it is predicted that alumina particles in LiCl solution attract each other more strongly than in CsCl solutions. If such an effect does exist, then force curves obtained using the colloid probe technique may detect the difference. Using chloride salts of the two end members of the Hofmeister series, namely Li⁺ and Cs⁺, stronger attraction in the LiCl electrolyte solution compared with the CsCl one was measured for the first time at the microlevel between alumina surfaces at pH=11.     

Modeling high-temperature stress-strain behavior of cast aluminum alloys

A modified two-state-variable unified constitutive model is presented to model the high-temperature stress-strain behavior of a 319 cast aluminum alloy with a T7 heat treatment. A systematic method is outlined, with which one can determine the material parameters used in the experimentally based model. The microstructural processes affecting the material behavior were identified using transmission electron microscopy and were consequently correlated to the model parameters. The stress-strain behavior was found to be dominated by the decomposition of the metastable θ′ precipitates within the dendrites and the subsequent coarsening of the θ phase, which was manifested through remarkable softening with cycling and time. The model was found to accurately simulate experimental stress-strain behavior such as strain-rate sensitivity, cyclic softening, aging effects, transient material behavior, and stress relaxation, in addition to capturing the main deformation mechanisms and microstructural changes as a function of temperature and inelastic strain rate.     

Energy efficiency in pumps

In this paper, “energy efficiency” studies, done in a big industrial facility’s pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data.

Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated.

The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems.     

The Effect of Pitching Rate on Fermentation and Flavour Compounds in High Gravity Brewing

The effect of pitching rate on fermentation and production of flavour compounds was studied in high gravity wort using a lager yeast. Fermentation performance was followed by monitoring the total sugar content and yeast growth. Volatile compounds were evaluated by analysing higher alcohols, esters and carbonyl compounds at the end of fermentation. Faster fermentation rates and higher yeast counts were observed with the higher pitching levels. Lower amounts of 2‐ and 3‐methyl‐1‐butanols and higher levels of 2‐methyl‐1‐propanol were found at the increased pitching rates. The concentration of isoamyl acetate was reduced with an increased pitching rate. Higher amounts of diacetyl and 2,3‐pentanedione were obtained at the lower pitching levels.     

Prussian Blue-Based Flexible Thin Film Nanoarchitectonics for Non-enzymatic Electrochemical Glucose Sensor

Journal of Inorganic and Organometallic Polymers and Materials - A facile and non-enzymatic electrochemical sensor is developed by the simple electrodeposition of Prussian Blue (PB) on conductive...