Synthesis of Quaternary,Long-Chain N-Alkyl Amides and Their Corrosion Inhibition in Acidic Media

New cationic surfactants were synthesized by the quaternization of a number of straight-chain amide derivatives with triethylamine or pyridine. The corrosion inhibition tests of the surface-active compounds were performed at room temperature for 24 h on carbon steel coupons in acidic media using the gravimetric method. The acidic media used were 1.5 M HCl and 1.5 M H₂SO₄. Almost all of the synthesized cationic surfactants showed efficient inhibition of corrosion in the test. To establish the inhibition efficiencies of the inhibitors, surface characterization studies (contact angle measurements, SEM analysis and optical profilometer images) of the metal coupons used were performed.     

Identifying the factors affecting the willingness to pay for fuel-efficient vehicles in Turkey: A case of hybrids

This paper aims to determine the factors that have an impact on the consumers’ willingness to pay a premium for hybrid automobiles in Turkey. A web-based random survey was conducted in different regions of Turkey. A questionnaire was administered to 1983 participants in January–March of 2009. The questionnaire was prepared by taking the issues raised in various sources into account. An ordered Probit model was used to meet the objective. Results show that variables such as income, gender, education, concerns about global warming, number of automobiles, importance of automobile performance, risk preference, attitude toward the alternative energy sources have an impact on the consumers’ willingness to pay a premium for hybrids. Findings suggest that consumers who have high income, higher educational level, and concerns about the global warming are more likely to pay a premium for hybrids. This study is expected to make important contributions to the current literature related to the consumers’ willingness to pay for hybrids by providing a research study from a developing country’s perspective. Results of this study also make important contributions to the policy and decision makers, environmental groups and automotive industry.     

Design and economic optimization of shell and tube heat exchangers using Artificial Bee Colony (ABC) algorithm

In this study, a new shell and tube heat exchanger optimization design approach is developed. Artificial Bee Colony (ABC) has been applied to minimize the total cost of the equipment including capital investment and the sum of discounted annual energy expenditures related to pumping of shell and tube heat exchanger by varying various design variables such as tube length, tube outer diameter, pitch size, baffle spacing, etc. Finally, the results are compared to those obtained by literature approaches. The obtained results indicate that Artificial Bee Colony (ABC) algorithm can be successfully applied for optimal design of shell and tube heat exchangers.     

The effect of using an exopolysaccharide‐producing culture on the physicochemical properties of low‐fat and reduced‐fat Kasar cheeses

A mixed starter culture containing exopolysaccharide (EPS)‐producing strains of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was combined with Lactobacillus helveticus LH301 and used in the manufacture of low‐fat and reduced‐fat Kasar cheeses. For comparison, low‐fat (C10) and reduced‐fat (C20) cheeses were made using EPS‐producing (EPS⁺) starter strain and EPS‐non‐producing (EPS^?) starter strain. The physicochemical properties of the cheeses were assessed in terms of chemical composition, texture, microstructure and microbial content over 90 days. Cheeses made with EPS‐producing culture (EPS10 and EPS20) had lower protein contents than control cheeses with 10% and 20% fat in dry basis (C10 and C20). Scanning electron microscopy images showed that using EPS‐producing culture resulted in a less compact protein matrix and sponge‐like structure in the cheese samples. In general, cheeses made using EPS‐producing culture had lower total viable counts. This could be related to the reduced survivability of EPS‐producing cells in the cheese matrix during ripening due to autolysis ability.     

Robust and accurate regression-based techniques for period inference in real-time systems

Real-Time Systems - With the growth in complexity of real-time embedded systems, there is an increasing need for tools and techniques to understand and compare the observed runtime behavior of a...     

Effect of Messaging Model on the Reliable Data Transfer Latency in a Fog System

Journal of Network and Systems Management - IoT applications have become a pillar for enhancing the quality of life. However, the increasing amount of data generated by IoT devices places pressure...     

Neutronic study on the effect of first wall material thickness on tritium production and material damage in a fusion reactor

In this study, the effects of changing first wall materials and their thicknesses on a reactor were investigated to determine the displacement per atom（DPA） and gas production（helium and hydrogen） in the first wall, as well as the tritium breeding ratio（TBR） in the coolant and tritium breeding zones. Therefore, the modeling of the magnetic fusion reactor was determined based on the blanket parameters of the International Thermonuclear Experimental Reactor（ITER）. Stainless steel（SS 316 LNIG）, Oxi...     

Temperature Dependent Current Transport Mechanism of Photopolymer Based Al/NOA60/p-Si MPS Device

A photopolymer based Al/Norland Optical Adhesive 60 (NOA60)/p-Si MPS (metal-polymer-semiconductor) device was fabricated by a combination of vacuum evaporation and smear technique. The current transport properties of the device were investigated by using the forward bias current–voltage (I-V) characteristic in the temperature range of 80–300 K. The cross-sectional structure of polymer/semiconductor was revealed by the scanning electron microscope (SEM) image and it was seen that the NOA60 photopolymer was tidily coated on the p-Si surface. According to the I-V measurements at room temperature, the MPS device exhibits a good rectification ratio of 8140 at?±?1 V. The temperature-dependent I-V measurements (I-V-T) were analyzed based on the thermionic emission (TE) theory and an abnormal increase in zero-bias barrier height (BH) and a decrease in ideality factor (n) was observed with increasing temperature. Additionally, two different linear regions with distinct values from the theoretical value of the Richardson constant (A*) were observed in the conventional Richardson plot. Such deviations from the ideal TE theory have been attributed to the effect of BH inhomogeneities. Gaussian distribution (GD) of the BH model has applied the I-V-T results and the double GD BH with mean values of 0.75?±?0.08 eV (80–140 K) and 1.02?±?0.11 eV (140–300 K) were calculated. Moreover, the A* value of 31.4 A/cm²K² was calculated close to the known value of p-Si from the modified Richardson plot. Thus, it has been concluded that the current transport of the Al/NOA60/p-Si MPS device can be explained by TE with a double GD BH model for a wide temperature region.