Covalent modification of reduced graphene oxide with piperazine as a novel nanoadsorbent for removal of H2S gas

In the present research, piperazine grafted-reduced graphene oxide RGO-N-(piperazine) was synthesized through a three-step reaction and employed as a highly efficient nanoadsorbent for H2S gas removal. Temperature optimization within the range of 30–90 °C was set which significantly improved the adsorption capacity of the nanoadsorbent. The operational conditions including the initial concentration of H2S (60,000 ppm) with CH4 (15 vol%), H2O (10 vol%), O2 (3 vol%) and the rest by helium gas and gas hour space velocity (GHSV) 4000–6000 h−1 were examined on adsorption capacity. The results of the removal of H2S after 180 min by RGO-N-(piperazine), reduced graphene oxide (RGO), and graphene oxide (GO) were reported as 99.71, 99.18, and 99.38, respectively. Also, the output concentration of H2S after 180 min by RGO-N-(piperazine), RGO, and GO was found to be 170, 488, and 369 ppm, respectively. Both chemisorption and physisorption are suggested as mechanism in which the chemisorption is based on an acid–base reaction between H2S and amine, epoxy, hydroxyl functional groups on the surface of RGO-N-(piperazine), GO, and RGO. The piperazine augmentation of removal percentage can be attributed to the presence of amine functional groups in the case of RGO-N-(piperazine) versus RGO and GO. Finally, analyses of the equilibrium models used to describe the experimental data showed that the three-parameter isotherm equations Toth and Sips provided slightly better fits compared to the three-parameter isotherms

Evaluation of Moving Average Window Technique as Low-pass Filter in Microprocessor-Based Protecting Relays

Over the last decades, with the increase in the use of harmonic source devices, the filtering process has received more attention than ever before. Digital relays operate according to accurate thresholds and precise setting values. In signal flow graphs of relays, the low-pass filter plays a crucial role in pre-filtering and purifying waveforms performance estimating techniques to estimate the expected impedances, currents, voltage etc. The main process is conducted in the CPU through methods such as Man and Morrison, Fourier, Walsh-based techniques, least-square methods etc. To purify waveforms polluted with low-order harmonics, it is necessary to design and embed cutting frequency in a narrow band which would be costly. In this article, a technique is presented which is able to eliminate specified harmonics, noise and DC offset, attenuate whole harmonic order and hand low-pass filtered signals to CPU. The proposed method is evaluated by eight case studies and compared with first and second order low-pass filter

Removal of Trichloroethylene by Clay Modified with Cationic Surfactant in Aqueous Solutions: Equilibrium, Kinetic, and Thermodynamic Study

Trichloroethylene (TCE) is commonly found in ground water, and it may serve as a major source of many types of cancers such as kidney, liver, lymphatic glands, and spinal cord. In the present research, TCE uptake from aqueous media by montmorillonite (Mt) modified by tetradecyl trimethyl ammonium bromide (TTAB) surfactant was explored. Firstly, the characteristics of raw and modified montmorillonite (raw-Mt and TTAB-Mt) were analyzed by SEM, FTIR, XRD, and XRF instruments. Then, the sorption process was evaluated as a function of different factors such as surfactant loading rate, pH, ionic strength, contact time, sorbent dosage, TCE concentration, temperature, and regeneration agent. The maximum TCE sorption by the modified clay was obtained at surfactant loading rate of 120 cation exchange capacity of the clay. The maximum removal efficiency of TCE by the modified clay was 99.6 at pH 5 and 30 min contact time. The findings also exhibited that the isotherm and kinetic sorption followed the Freundlich and pseudo-second-order models, respectively. It can be concluded that TTAB-Mt, as a cheap, abundant, non-toxic, and environmental friendly adsorbent can be considered to remove TCE in aqueous phase

McGill Quality of Life Questionnaire: Reliability and validity of the Persian version in Iranian patients with advanced cancer

Objectives: McGill Quality of Life Questionnaire (MQOL) is an instrument specifically designed to evaluate quality of life (QOL) in patients with advanced diseases. The primary objective of this study was to translate this questionnaire into Persian and assess its reliability and validity in Iranian patients suffering from an advanced cancer. The report also includes the correlations between patients' characteristics and their QOL scores. Methods: MQOL was translated into Persian using a forward-backward method and administered to 62 patients with cancer at two hospitals in Tehran. Statistical analysis was performed to test reliability and validity of the questionnaire and to assess relationships between patients' characteristics and MQOL scores. Results: In general, MQOL-Persian is a valid and reliable questionnaire to assess QOL in Iranian patients with advanced cancer. Test-retest reliability of the whole questionnaire is highly favorable for a questionnaire of this type (Pearson correlation = 0.87). Except for the existential subscale, all MQOL scores are internally consistent. There was no significant correlation between MQOL scores and patients' extent of knowledge about their disease. Conclusion: The Persian version of MQOL is, for the most part, a valid, reliable instrument in this setting. Because of cultural differences, the existential subscale may require adaptation. Further studies are needed to explore other aspects of QOL in Iranian patients with cancer. © 2008 Mary Ann Liebert, Inc

Synthesis, Characterization and Epoxidation of cis-Enriched New Polycarbonates Catalyzed by Efficient Organotin Compound

Presence of active functional groups on polymer chain is a suitable aspect of polymer structure which allows performing next favourite reactions on polymer molecule. In this research a novel aromatic derivative of cis-but-2-endiol was synthesized as monomer. The synthesized monomer was polymerized using diphenyl carbonate and 1,4-butandiol as second and third monomer along with organotin catalyst. Polymerization reaction performed by using melt-phase transesterification process to produce a new terpolymer of polycarbonate. During the reaction the double bonds are preserved on polymer chain and epoxidized by m-chloroperbenzoic acid (MCBPA) in good yield to demonstrate the reactivity and possibility of performing further reactions on double bonds of polymer

Mutations in hepatitis-B X-gene region: Chronic hepatitis-B versus cirrhosis

Introduction: Specific mutations in Hepatitis-B Virus (HBV) genome would proceed the development of chronic hepatitis B to more serious consequences like cirrhosis and end-stage liver disease. Aim: This study was designed to detect deletion and insertion mutational patterns in the X-gene region in a population of chronic HBV and related cirrhosis patients. Materials and Methods: Sixty eight chronic HBV patients and 34 HBV-related cirrhotics were recruited from the eligible cases (N=50) referred to the academic hospitals of Gorgan city, Northeast of Iran, between Jan 2011 to Dec 2013. The HBx region was amplified by semi-nested PCR using serum samples and analyzed by sequencing. Results: Our findings showed deletions and insertions in the C-terminal of HBx of the cirrhotic group and 8 bp found in two chronic HBV cases (2.9). We detected 15 types of deletions in cirrhotic cases such as 1762-1768, 1763-1770, 1769-1773 and T1771/A1775. Conclusion: Considering the proposed role for some of these mutations in severe liver disease, further investigations are needed to clarify the importance of them in the early stages of hepatitis B infection. © 2017, Journal of Clinical and Diagnostic Research. All rights reserved

A New Variation of Omohyoid Muscle: A Case Report

BACKGROUND AND OBJECTIVE: The omohyoid muscle is one of the muscles among the infrahyoid muscles. Due to the connections and proximity of this muscle to the brachial plexus, carotid sheath, phrenic nerve and sternocleidomastoid muscle, it is very important to be aware of all possible variations of this muscle in terms of anatomic, clinical and surgical factors. CASE REPORT: During the dissection of posterior carotid triangle on the left side of the neck of a 55-year-old male cadaver (who had been purchased about two years ago from Tehran University of Medical Sciences) for master's students of anatomy in the dissection room of Babol University of Medical Sciences, it was observed that instead of passing under the sternocleidomastoid muscle, the intermediate tendon of the omohyoid muscle passes through its two origins connected to the sternum and the clavicle. CONCLUSION: This type of variation of the omohyoid muscle can be very important due to the proximity of this muscle to the surrounding elements and its effect on the large vessels of the carotid sheath and surrounding tissues

Mutations in Hepatitis-B X-Gene Region: Chronic Hepatitis-B versus Cirrhosis.

INTRODUCTION: Specific mutations in Hepatitis-B Virus (HBV) genome would proceed the development of chronic hepatitis B to more serious consequences like cirrhosis and end-stage liver disease. AIM: This study was designed to detect deletion and insertion mutational patterns in the X-gene region in a population of chronic HBV and related cirrhosis patients. MATERIALS AND METHODS: Sixty eight chronic HBV patients and 34 HBV-related cirrhotics were recruited from the eligible cases (N=50) referred to the academic hospitals of Gorgan city, Northeast of Iran, between Jan 2011 to Dec 2013. The HBx region was amplified by semi-nested PCR using serum samples and analyzed by sequencing. RESULTS: Our findings showed deletions and insertions in the C-terminal of HBx of the cirrhotic group and 8 bp found in two chronic HBV cases (2.9%). We detected 15 types of deletions in cirrhotic cases such as 1762-1768, 1763-1770, 1769-1773 and T1771/A1775. CONCLUSION: We found that the frequencies of deletion and insertion mutations in C-terminal of X-gene were more seen in cirrhotic patients comparing to chronic HBV cases in our area of study