Thermal degradation characteristic of Tetra Pak panel boards under inert atmosphere

Sabriye Piskin,Aysel Kantürk Figen,Evren Terzi,Nural Yilgör,Saip Nami Kartal 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.4

Thermal degradation characteristics of Tetra Pak panel boards (TPPB) can be useful to improve usage of such panels as an alternative to wood-based products such as plywood, fiberboard, and particleboard. In the study, samples from the TPBBs manufactured from waste Tetra Pak packages (WTPP) were heated in a nitrogen atmosphere at different heating rates (10, 15 and 20 oC/min) using a thermal analysis system. The Coats-Redfern kinetic model was applied to calculate kinetic parameters. The degradation rate equations were then established. In addition, the kinetic compensation effect (KCE) was used to correlate the pre-exponential factor (ko) with activation energy (Ea) and the existence of the KCE was accepted. TG-FT/IR analyses were applied to the TPPB degradation and then the FT-IR stack plot was used to analyze gas products (CO2, CH4, HCOOH, and CH3OH). Infrared vibrational frequencies and the micro,crystal structure of the TPPBs were investigated by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and X-Ray diffraction analysis (XRD), respectively.

Evaluation of the Isokinetic Calf Muscle Strength and the Range of Motion of Joint in C3 Chronic Venous Insufficiency

Sabriye Ercan,Cem Çetin,Turhan Yavuz,Hilmi Mustafa Demir,Yurdagül Baygül Atalay 대한혈관외과학회 2019 Vascular Specialist International Vol.35 No.2

Purpose: The present study aimed to compare the isokinetic muscle strength and range of motion (ROM) values of the ankle between patients diagnosed with C3 chronic venous insufficiency (group 1, n=57) and healthy individuals (group 2, n=30). Materials and Methods: After identifying the venous refilling time (VRT) of all participants, the active ROM of the ankle joint and plantar flexion (PF) and dorsiflexion (DF) muscle strength in the concentric/concentric mode at angular velocities of 60°/sec and 120°/sec were measured. Results: No statistically significant differences were found between the demographic data of groups 1 and 2 (P>0.05). In total, 102 lower extremities were included in group 1 and 60 lower extremities in group 2. The VRT of the patients in group 1 was 15.5±5.6 seconds, the PF ROM of the ankle joint was 39.3°±9.5°, and the DF ROM of the ankle joint was 27°±8°; in group 2, the VRT, PF ROM, and DF ROM were 36±8.1 seconds, 41°±6.2°, and 27.2°±7.5°, respectively. Statistically significant differences were found between the two groups in terms of VRT (P<0.05); however, no statistically significant difference was observed in terms of ankle ROM (P>0.05). Statistically significant difference was found in terms of all parameters of isokinetic muscle strength measurements, such as peak torque, peak torque/body weight, total work done, and ratio (DF/PF) in group 1 (P=0.001). Conclusion: The lower extremity muscle strength of patients with chronic venous insufficiency was low, and this weakness was prominent particularly in the direction of PF.

Synthesis, crystal structure and dehydration kinetics of NaB(OH)4·2H2O

Sabriye Piskin,Aysel Kanturk,Muge Sari 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.6

Sodium metaborate tetrahydrate (NaB(OH)4·2H2O) was synthesized by reaction of anhydrous borax (Na2O· 2B2O3) with sodium hydroxide (NaOH) under conditions at 90 oC for 150 min. The structure was characterized by Xray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and Thermogravimetric (TG) analyses. Moreover, dehydration kinetics of NaB(OH)4·2H2O was carried out under non-isothermal conditions and the Coats-Redfern method was applied to analyze the TG data for calculation of activation energies (Ea) and pre-exponential factors (ko) for different heating rates. It was determined that dehydration of sodium metaborate tetrahydrate occurred in five steps. According to the Coats-Redfern non-isothermal model, Ea and ko were calculated as 50.89 kJ/mol and 26×104 min−1 for region I, 18.51 kJ/mol and 0.87×103 min−1 for region II, 15.72 kJ/mol and 0.52× 103 min−1 for region III, 4.37 kJ/mol and 0.04×103 min−1 for region IV and 37.42 kJ/mol and 8.56×103 min−1 for region V, respectively.

Evaluation of Arabinofuranosidase and Xylanase Activities of Geobacillus spp. Isolated from Some Hot Springs in Turkey

( Canakci ),( Sabriye ),( Kadriye Inan ),( Murat Kacagan ),( Ali Osman Belduz ) 한국미생물생명공학회 2007 Journal of microbiology and biotechnology Vol.17 No.8

Assessment of liquefaction potential of the Erzincan, Eastern Turkey

Duman, Esra Subasi,Ikizler, Sabriye Banu,Angin, Zekai,Demir, Gokhan Techno-Press 2014 Geomechanics & engineering Vol.7 No.6

This study includes determination of liquefaction potential in Erzincan city center. Erzincan Province is situated within first-degree earthquake zone on earthquake map of Turkey. In this context, the earthquake scenarios were produced using the empirical expressions. Liquefaction potential for different earthquake magnitudes (6.0, 6.5, 7.0) were determined. Liquefaction potential was investigated using Standard Penetration Test (SPT). Liquefaction potential analyses are determined in two steps: geotechnical investigations and calculations. In the first steps, boreholes were drilled to obtain disturbed and undisturbed soil samples and SPT values were obtained. Laboratory tests were made to identify geotechnical properties of soil samples. In the second step, liquefaction potential analyses were examined using two methods, namely Seed and Idriss (1971), Iwasaki et al. (1981). The liquefaction potential broadly classified into three categories, namely non-liquefiable, marginally liquefiable and liquefiable regions. Additionally, the liquefaction potential index classified into four categories, namely non-liquefiable, low, high and very high liquefiable regions. In order to liquefaction analysis complete within a short time, MATLAB program were prepared. Following the analyses, liquefaction potential index is investigated by Iwasaki et al. (1982) methods. At the final stage of this study, liquefaction potential maps and liquefaction potential index maps of the all study area by using IDW (inverse distance weighted) interpolation method in Geostatistical Analyst Module of ArcGIS 10.0 Software were prepared for different earthquake magnitudes and different depths. The results of soil liquefaction potential were evaluated in ArcGIS to map the distributions of drillings with liquefaction potential. The maps showed that there is a spatial variability in the results obtained which made it difficult to clearly separate between regional areas of high or low potential to liquefy. However, this study indicates that the presence of ground water and sandy-silty soils increases the liquefaction potential with the seismic features of the region.

Assessment of swelling pressure of stabilized Bentonite

Angin, Zekai,Ikizler, Sabriye Banu Techno-Press 2018 Geomechanics & engineering Vol.15 No.6

In this study, a comprehensive laboratory experimental programme was conducted on expansive soil with a high swelling potential to study the influence of different additive materials on swelling pressure and index properties. Lime, sand, multifilament fiber and fibrillated fiber were used for stabilization of expansive soil. Lime, sand and fibers were respectively added to the expansive soil at 0-7%, 0-80%, 0-0.5%. On each mixture that was prepared by the proportions mentioned above, Atterberg limits, compaction, and swelling pressure tests were conducted. From the result of these experiments, the swelling pressure-time relation could be replaced by a rectangular hyperbola established to facilitate the prediction of ultimate percent swelling with a few initial data points. The best type of additive and its optimum ratio for engineering purposes could be estimated rapidly by this approach.

Use of rpoB Sequences and rep-PCR for Phylogenetic Study of Anoxybacillus Species

Kadriye Inan,Osman Belduz,Yusuf Bektas,Sabriye Canakci 한국미생물학회 2011 The journal of microbiology Vol.49 No.5

This study was conducted to investigate the applicability of rpoB, which encodes the β subunit of RNA polymerase, to be used as an alternative to 16S rRNA gene sequence similarity analysis in the thermophilic genus Anoxybacillus. Partial rpoB sequences were generated for the 14 type strains of Anoxybacillus species and 6 other strains of four Anoxybacillus species. The sequences and the phylogenetic tree of rpoB were compared with those obtained from 16S rRNA gene analysis. The rpoB gene was found to provide a better resolution for Anoxybacillus species, with lower interspecies sequence similarities. The rpoB sequence similarity analysis permitted a more accurate discrimination of the species within the Anoxybacillus genus than the more commonly used 16S rRNA gene. Furthermore, rapid and reproducible repetitive extragenic palindromic fingerprinting techniques (REP-, ERIC-, and BOX-PCR) were employed for the specimens of genus Anoxybacillus. Through comparison of the three methods, it was found that the BOX-PCR method generated more informative results than REP-PCR for the studied strains; BOX-PCR profiles were more distinct for the different strains, including a higher number of bands. Rapid and reproducible repetitive extragenic palindromic fingerprinting techniques (rep-PCR) constitute a suitable molecular approach for the validation and maintenance of taxonomy within the Anoxybacillus genus. The results of this study show that rpoB and rep-PCR provide rapid and reliable methods for molecular typing of Anoxybacillus species.

Determination and Characterization of Thermostable Esterolytic Activity from a Novel Thermophilic Bacterium Anoxybacillus gonensis A4

Faiz, Ozlem,Colak, Ahmet,Saglam, Nagihan,Canakci, Sabriye,Belduz, Ali Osman Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.4

A novel hot spring thermophile, Anoxybacillus gonensis A4 (A. gonensis A4) was investigated in terms of capability of tributyrin degradation and characterization of its thermostable esterase activity by the hydrolysis of p-nitrophenyl butyrate (PNPB). It was observed that A. gonensis A4 has an esterase with a molecular weight of 62 kDa. The extracellular crude preparation was characterized in terms of substrate specificity, pH and temperature optima and stability, kinetic parameters and inhibition/activation behaviour towards some chemicals and metal ions. Tributyrin agar assay showed that A. gonensis A4 secreted an esterase and $V_{max}$ and $K_m$ values of its activity were found to be 800 U/L and 176.5 ${\mu}M$, respectively in the presence of PNPB substrate. The optimum temperature and pH, for A. gonensis A4 esterase was $60-80^{\circ}C$ and 5.5, respectively. Although the enzyme activity was not significantly changed by incubating crude extract solution at $30-70^{\circ}C$ for 1 h, the enzyme activity was fully lost at $80^{\circ}C$ for same incubation period. The pH-stability profile showed that original crude esterase activity increased nearly 2-fold at pH 6.0. The effect of some chemicals on crude esterase activity indicated that A. gonensis A4 produce an esterase having serine residue in active site and -SH groups were essential for its activity.

Determination and Characterization of Thermostable Esterolytic Activity from a Novel Thermophiic Bacterium Anoxybacilus gonensis A4

( Ozlem Faiz ),( Ahmet Colak ),( Nagihan Saglam ),( Sabriye Canakci ),( Ali Osman Belduz ) 생화학분자생물학회 2007 BMB Reports Vol.40 No.4

The ATPase Activity of The G2alt Gene Encoding an Aluminium Tolerance Protein from Anoxybacillus gonensis G2

Fatih Saban Beris,Lina De Smet,Hakan Karaoglu,Sabriye Canakci,Jozef Van Beeumen,Ali Osman Belduz 한국미생물학회 2011 The journal of microbiology Vol.49 No.4

The G2ALT gene was cloned and sequenced from the thermophilic bacterium Anoxybacillus gonensis G2. The gene is 666 bp long and encodes a protein 221 amino acids in length. The gene was overexpressed in E. coli and purified to homogeneity and biochemically characterized. The enzyme has a molecular mass of 24.5 kDa and it could be classified as a member of the family of bacterial aluminium resistance proteins based on homology searches. When this fragment was expressed in E. coli, it endowed E. coli with Al tolerance to 500 μM. The purified G2ALT protein is active at a broad pH range (pH 4.0-10.0) and temperature range (25°C-80°C) with optima of 6.0 and the apparent optimal temperature of 73°C respectively. Under optimal conditions, G2ALT exhibited a low ATPase activity with K_(m-) and V_(max-) values of 10±0.55μM and 26.81±0.13 mg Pi released/min/mg enzyme, respectively. The ATPase activity of G2ALT requires Mg^(2+) and Na^+ ions, while Zn^(2+) and Al^(3+) stimulate the activity. Cd^(2+) and Ag^+ reduced the activity and Li^+,Cu^(2+), and Co^(2+) inhibited the activity. Known inhibitors of most ATPases, like such as β-mercaptoethanol and ouabain, also inhibited the activity of the G2ALT. These biochemical characterizations suggested that G2ALT belongs to the PP-loop ATPase superfamily and it can be responsible for aluminium tolerance in A. gonensis G2.