Pseudohalogenation of methyl 9-hydroxy-cis-12-and 12-hydroxy-cis-9-octadecenoate

Pseudohalogenation of methyl 9-hydroxy-cis-12-octadecenoate (I) and methyl 12-hydroxy-cis-9-octadecenoate (II) has been carried out with N,N-dibromobenzenesulfonamide (NNDBS). Compounds I and II, on reaction with NNDBS, formed four and three products, respectively. The interesting feature of these reactions was the formation of 1,4-epoxy compounds. The structures of individual compounds were established with the help of elemental and spectral analysis.     

Suicide risk assessment in a college student population.

A group of 211 students at a midwestern university completed the Suicidal Behaviors Questionnaire (M. M. Linehan & S. L. Nielsen, 1981), Adult Suicidal Ideation Questionnaire (W. M. Reynolds, 1991a), Multi-Attitude Suicide Tendency Scale (I. Orbach et al., 1991), Beck Helplessness Scale (A. T. Beck, A. Weissman, D. Lester, & L. Trexler, 1974), and the Reasons for Living Inventory (M. M. Linehan, L. J. Goodstein, S. L. Nielsen, & J. A. Chiles, 1983) to determine if this group of commonly used self-report measures can distinguish between individuals with high and low levels of suicidal ideation and history of self-harmful behaviors. Exploratory principal-axis factor analysis resulted in an interpretable 2-factor solution accounting for 36.2% of the variance in suicidality. Support for convergent validity of the chosen measures was also found. It appears that rapid, accurate assessment of university student suicide risk is possible. Implications for reduction of suicide risk in this segment of the population are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of hydrostatic pressure on the electrical properties of unvulcanized FEF-loaded SBR

Styrene butadience rubber (SBR-1502) loaded with different concentrations of FEF carbon black was tested to find out the effect of pressure on its electrical properties during vulcanization. Using the thermodynamically calculated values of the pressure coefficient (K), the thermoelastic coefficient (L = ?T/?P) was also estimated and compared with that obtained by other workers. The thermoelastic coefficient was found to be strongly dependent on the carbon black concentration.     

Performance of joint multilevel/AES‐LDPCC‐CPFSK schemes over wireless sensor networks

In wireless sensor networks, data encryption and channel coding are considered together for ensuring secure and robust communication. In order to achieve this purpose, we introduce a new joint scheme, namely ‘Multilevel/Advanced Encryption Standard‐Low Density Parity Check Coded‐Continuous Phase Frequency Shift Keying (ML/AES‐LDPCC‐CPFSK)’. AES algorithm is the most powerful and widely used symmetric key cryptography in providing secure data transmission. LDPC codes have very large Euclidean distance and use iterative decoding algorithms. In this study, we have increased error performance employing multilevel structure to AES and LDPC. In all communications systems, phase discontinuities of modulated signals result in extra bandwidth requirements. CPFSK, which is a special type of continuous phase modulation, is a powerful solution for this problem. In this paper, we simulate error performance of ML/AES‐LDPCC‐CPFSK for regular LDPC codes. Simulation results are drawn for 4CPFSK, 8CPFSK and 16CPFSK over wireless cooperative sensor networks. Using this scheme, we are able to improve bit error performance, channel throughput, security level of communication and reduction in complexity compared with related schemes such as various turbo code structures. Copyright © 2009 John Wiley & Sons, Ltd.     

Negative capacitance peculiarities in a-Si:H/c-Si rectifier structure

Nontrivial negative capacitance (NC) effect, observed in a-Si:H/c-Si heterostructure devices, is discussed emphasizing the theoretical interpretation of experimental data. To explain NC effect, we have performed dark current voltage (I-V) and admittance measurements (C-V, G-V, C-f and G-f). The calculated values of series resistance (R_s) and barrier height (Φ_Bo) have the values from 100 to 114.7 Ω and 0.94 to 0.83 eV, respectively. Also, below 50% helium dilution rate, diode ideality factor (n) becomes bigger than 2, because tunneling at junction interface plays a major role. The measured room temperature (294 K) dark I-V result has been used during the fitting process for suggested capacitance model (Eq. (18)). The measured NC values exhibit strongly voltage depended behavior. This unexpected behavior is attributed to the presence of inductively coupled space charge region which might possibly be stemmed from the helium diluted a-Si:H material. It is seen that the measured NC values are well fitted with suggested capacitance model (Eq. (18)). Application of suggested correction formula on to experimental C-V data yields satisfactory results. It is shown that the calculated inductance values of the investigated device range from 10 to 42 μH and after correction, NC values are no longer observed in the C_d-V data.     

Effects of starter cultures and additives on the quality of Turkish style sausage (sucuk)

The effects of starter cultures and additives on the quality of Turkish style sausage (sucuk) were investigated during ripening and storage. Total aerobic plate counts (aerobic bacteria), mould and yeast counts, pH, thiobarbituric acid (TBA) value and biogenic amine formation were followed. Aerobic bacteria increased (P<0.05) during the first 10 days of ripening to 9.26 log CFU/g and they decreased (P<0.05) to 5.70 at the end of the storage. Larger reductions (P<0.05) were observed in sausages made with high levels of potassium sorbate, nitrite and nitrate than in those containing low levels of additives and those without additives at the end of storage. During the first 3 days of ripening, the pH values of all sausages decreased (P<0.05) from 5.98 to about 4.53. Later, the pH values increased slowly, due to decomposition of acids to an approximately constant value of about 5.20. TBA values were higher (P<0.05) in the sausages made without additives than in the others. Sausages prepared using high concentration of additives had lower (P<0.05) concentrations of biogenic amines than the others. Addition of starter culture with high concentration of additives (nitrite, nitrate, α-tocopherol, ascorbic acid, potassium sorbate, potassium pyrophosphate and di-potassium hydrogenphosphate) decreased the formation of biogenic amine.     

Lactic acid bacteria profiles and tyramine and tryptamine contents of Turkish tulum cheeses

Tulum cheese, commonly produced in Turkey, is a traditional Turkish dairy product made from raw milk. In this research, 20 samples of tulum cheese were purchased from different markets in Isparta and Ankara (Turkey) and the populations of lactic acid bacteria (LAB) and contents of biogenic amines of Turkish tulum cheeses were investigated. The mean counts of LAB (as log10 cfu/g) were 7.22±0.67 on MRS agar, 6.93±1.77 on M17 agar, 7.28±0.72 on APT agar and 5.98±2.20 on ADA agar. Isolates of LAB obtained from 20 tulum cheeses were characterised as lactobacilli (48.5%), enterococci (32.7%), lactococci (15.8%) and streptococci (3.0%). Lactobacillus paracasei ssp. paracasei, Lactobacillus bifermentans and Enterococcus faecium predominated among the LAB in the samples of tulum cheeses; these organisms represented 30.2% of the isolates. As amino acids, tyrosine and tryptophan were determined in tulum cheeses. Tyramine and tryptamine, biogenic amines, were found at 0.00–329.00 and 0.32–40.44 mg/kg, respectively.     

Characterization of protein functionality and texture of tumbled squid,octopus and cuttlefish muscles

The aim of this study was to investigate the effects of tumbling on the physicochemical and textural characteristics of squid (Loligo vulgaris), octopus (Octopus vulgaris) and cuttlefish (Sepia officinalis) muscles. Before tumbling the cephalopod samples were placed in plastic bags and 0.5 M NaCl was added. Tumbling process was performed continuously in three different tumbling times (2, 4, and 6 h). The results of the analyses showed that tumbling affected the physicochemical properties of cephalopod muscles. The increase in the time of tumbling resulted in the tenderness of the cephalopod muscles. The total soluble protein, the total free amino acid, and pH values increased with the increase of the tumbling time. The water holding capacity decreased and the cooking loss increased. The squid and octopus hardness and shear force values decreased after tumbling, according to instrumental and sensorial texture measurements. As a result, tumbling was found to be an effective method for tenderizing of squid and octopus muscle, but not for cuttlefish.     

Characterisation and Assessment of the Role of Barley Malt Endoproteases During Malting and Mashing1

Barley malt endoproteases (EC.3.4.21) develop as multiple isoforms mainly during grain germination and pass through kilning almost intact. Thermostability, under simulated mashing conditions, varied from low to high depending on the substrate used in the assay. This suggests that individual enzymes respond differently to heat exposure and to protein substrates. The optimal pH with haemoglobin was pH 3.5, with hordein pH 4 and with glutelin pH 5. The optimal temperature with hordein was 40°C, with glutelin 50°C and with haemoglobin 60°C. These differences suggest that it is not possible to comprehensively characterise all malt endoproteases under one set of assay conditions. In brewing, most of the barley protein degradation (> 70 %) occurs during malting. But some proteinases remain active during mashing and contribute to wort soluble proteins and free amino nitrogen. Their contribution to all malt EBC mash total free amino nitrogen was 25 % in Schooner (Australian) and 30 % in Morex (USA). The importance of proteolytic activity during mashing and the possibility that the levels may not be adequate, at high solid adjunct ratios, are acknowledged.     

A comparative prediction for tensile properties of ternary blended open-end rotor yarns using regression and neural network models

This study focused on predicting tensile properties of PES/CV/PAN blended Open-End Rotor yarns. The effective factors were fiber blend ratios (six stages from 0 to 100%), linear density (three count levels), mixing method (carding machine and drawframe), and number of passages in drawframe (one and two times) as production parameters. We performed a stepwise multiple linear regression (MLR) analysis and established an artificial neural network (ANN) model that trained with backpropagation rule as Levenberg–Marquardt. Then, we conducted a comparative analysis for both models in terms of prediction performance. As a result, ANN has given a slightly better prediction values than MLR for breaking strength but significantly better prediction values for breaking elongation.