Adsorption of n-propyl mercaptan on Pb/LTA zeolites

In this study, we used Pb²⁺ cation exchanged zeolites as adsorbents due to their porous structure. Adsorption of n-propyl mercaptan on modified LTA and (3A, 4A) zeolites were studied by FTIR (Fourier Transform Infrared) Spectroscopy and AAS (Atomic Absorption Spectrometer) is used to measure the amount of metal cations on mentioned zeolites. SEM-EDX (Scanning Electron Microscope-Energy Dispersive X-Ray) graphics are used to monitor the differences on the surface. Cation modified zeolites change their characteristic properties for adsorption. LTA type zeolites when modified by Pb²⁺ cation tend to adsorb n-propyl mercaptan.     

Effect of γ-radiation on HfO2 based MOS capacitor

Radiation effects on Metal Oxide Semiconductor (MOS) capacitors with a HfO₂ gate insulator have been studied. Because HfO₂ is a promising high-k dielectric material for microelectronic applications, radiation effects on its performance in MOS devices is of interest. New results on radiation effects on HfO₂, particularly at low gamma radiation doses, are presented. The results are compared with other systems including those of Al₂O₃ plus silicon based Si MOS capacitors. Both devices with different gate thicknesses were irradiated with Co-60 gamma source for varying exposure time. The midgap and flatband voltage shifts in these devices were measured and analyzed. Results show that gamma radiation does not cause significant variations in the HfO₂ MOS especially at low doses.     

Impurities in hydride gases part 1: Investigation of trace moisture in the liquid and vapor phase of ultra-pure ammonia by FTIR spectroscopy

Trace moisture in ammonia is a critical impurity in the growth of epitaxial nitride films. Because moisture is very soluble in the liquid phase of ammonia, moisture in the vapor phase increases dramatically with cylinder use, and is often far higher than the nominal purity specification. A reliable method was developed for sampling and analyzing trace moisture in both liquid-and vaporphase ammonia using FTIR. Analysis of liquid-phase ammonia gives a stable and representative moisture value whereas gas-phase moisture levels strongly depend on sampling time, flow rate, temperature, mixing, and extent of cylinder use. The variation of vapor-phase moisture is discussed in terms of a variable vaporization model with applications to high flow.     

Oxidative degradations of reactive blue 4 dye by different advanced oxidation methods

The degradations of an anthraquinone dye, the reactive blue 4 (RB4), were studied by wet air oxidation (WAO), wet peroxide oxidation (WPO), photocatalytic oxidation, and electro-Fenton (EF) advanced oxidation. The RB4 oxidation was evaluated by the decrease in total organic carbon (TOC) content and concentration. The most efficient method for mineralization of RB4 was WPO, but in all methods TOC removal efficiency was above 75% after 60 min of treatment.     

Production and characterization of particleboards from cork-rich <Emphasis Type="Italic">Quercus cerris</Emphasis> bark

Single-layered particleboards were produced from granulated Quercus cerris bark containing cork and phloem granules using standard hot-press equipment and phenol–formaldehyde resin. The experimental boards were tested for thickness swelling, mechanical strength and thermal properties. Scanning electron microscopy observations were carried out to analyze the panel structure. The results showed that Q. cerris bark particleboards had low thickness swelling in water, high resistance to thermal degradation and high calorific values but their mechanical strength was below that of commercial wood particleboards. The produced Q. cerris bark particleboards were adequate for exterior applications where mechanical strength is not the key factor. Potential for process and feedstock optimization was acknowledged.     

Prevalence and Characterization of Salmonella Isolated from Chicken Meat in Turkey

This study was conducted in a Turkish province to investigate the presence of Salmonella spp. in 150 chicken meat samples using 2 phenotyping techniques: classic culture technique (CCT) and immunomagnetic separation (IMS). For the confirmation of the isolates at molecular levels, invA gene was detected in these isolates. The presence of invA, class 1 (Cls1) integrons, and integrase (Int1) genes was demonstrated by PCR assay; and the resistance of the isolated Salmonella spp. strains to antibiotics was determined by disk diffusion test. All the cultural and PCR results were evaluated together; Salmonella spp. were detected in a total of 64 (42.66%) chicken meat samples. Contamination rate was higher in carcasses (53.33%, n = 75) than in meat pieces (32%, n = 75). When results of standard culture were compared with IMS technique, IMS (n = 54) showed a clear superiority over the CCT (n = 38). A very high resistance rate (≥89.28%) to vancomycin, tetracycline, streptomycin, or nalidixic acid was found. Trimethoprim‐sulfamethoxazole resistance was present in 32.14%. Relatively lower incidence of resistance (≤8.33%) to gentamicin, chloramphenicol, ampicillin, and ceftriaxone was observed. Concurrent resistance to at least 4 antibiotics was detected in 92.85% of the isolates. Cls1 integrons and Int1 were positive in 80.95% and 95.23% of the isolates, respectively. However, Int1 alone was detected in 15.47% (n = 13). In conclusion, the high prevalence of Salmonella spp. in chicken meat may pose a potential public health risk, and the presence of antibiotic‐resistant Salmonella spp. isolate together with Cls1 integron and/or integrase might play an important role in horizontal antibiotic gene transfer.     

The prevalence of Escherichia coli O157 and O157:H7 in ground beef and raw meatball by immunomagnetic separation and the detection of virulence genes using multiplex PCR

The present study was conducted to investigate the presence of Escherichia coli O157 and O157:H7 strains and to detect the presence of the stx1, stx2, and eaeA genes in isolates derived from 200 samples (100 samples from fresh ground beef and 100 samples from raw meatball). The samples were purchased from the Samsun Province in Turkey, over a period of 1 year. Enrichment-based immunomagnetic separation and multiplex polymerase chain reaction were applied for these analyses. E. coli O157 was detected in five of the 200 (2.5%) samples tested (one isolated from ground beef and four from meatball samples), whereas E. coli O157: H7 was not detected in any sample. During the analysis, eight strains of E. coli O157 were obtained. The genes stx1, stx2, and eaeA were detected in two E. coli O157 isolates obtained from two meatball samples, whereas only the eaeA and the stx2 genes were detected in four E. coli O157 strains that were isolated from one meatball sample. None of the stx1, stx2, and eaeA was detected in the E. coli O157 isolates obtained from the ground beef and the one meatball samples.     

Far infrared and ultraviolet radiation as a combined method for surface pasteurization of black pepper seeds

This study presented the potential of far infrared (FIR) and ultraviolet (UVC) radiation for surface pasteurization of black pepper seeds. FIR treatment at different exposure times and temperatures was applied followed by constant UVC treatment with an intensity of 10.5 mW/cm² for 2 h. Then, the reduction on total mesophilic aerobic bacteria (TMAB) and mold-yeast contents were determined, and quality changes of the seeds were evaluated. TMAB of the seeds decreased to the target level of 10⁴ CFU/g after 4.7 and 3.5 min FIR treatment at 300 and 350 °C, respectively. Under given conditions, complete elimination for other microorganisms (TMY, Escherichia coli and Bacillus cereus) was also obtained while there were no significant changes in volatile oil and color. UVC however, alone or in combination with FIR, did not exhibit a significant reduction in TMAB content. Consequently, FIR treatment was suggested to be a promising method for the surface pasteurization of black pepper seeds.