Synthesis and characterization of a heterojunction rGO/ZrO₂/Ag₃PO₄ nanocomposite for degradation of organic contaminants

Anwer, Hassan,Park, Jae-Woo Elsevier 2018 Journal of hazardous materials Vol.358 No.-

<P><B>Abstract</B></P> <P>Synergy between surface adsorption and photocatalysis is key for effective contaminant degradation in the liquid phase. Herein, we report a heterojunction photocatalyst of reduced graphene oxide (rGO)/zirconium dioxide (ZrO<SUB>2</SUB>)/silver phosphate (Ag<SUB>3</SUB>PO<SUB>4</SUB>) that incorporates this synergy for 4-nitrophenol (PNP) removal. Compared with other photocatalyst combinations, ZrO<SUB>2</SUB> and Ag<SUB>3</SUB>PO<SUB>4</SUB> coupling generates reactive species with greater degradation potential. ZrO<SUB>2</SUB> and rGO were synthesized by a green approach using a one-step hydrothermal reaction in ethanol–water. The growth of rGO/ZrO<SUB>2</SUB> and Ag<SUB>3</SUB>PO<SUB>4</SUB> were accomplished and the functions of each part were well developed together. The rGO/ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB> composite exhibited enhanced light absorption and a low band gap energy (2.3 eV) owing to rGO and Ag<SUB>3</SUB>PO<SUB>4</SUB> integration. The composite’s photocatalytic activity was much higher than that of ZrO<SUB>2</SUB>, Ag<SUB>3</SUB>PO<SUB>4</SUB>, or ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB>. The maximal adsorption of PNP was 26.88 mg/g, and a pseudo-first-order model described the PNP degradation kinetics (k = 0.034 min<SUP>−1</SUP>). Synergy between the three components resulted in 97% PNP removal in 90 min, and even after five cycles, 94% PNP removal was obtained. The quantum yield of the system (7.31 × 10<SUP>−5</SUP> molecules/photon) was compared with those in previous reports to assess the photocatalytic performance and energy requirements.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel rGO/ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB> composite was synthesized via a green hydrothermal approach. </LI> <LI> Contaminant degradation by adsorption–photocatalysis synergy was confirmed. </LI> <LI> Optimal band-edge alignment of ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB> provided high photocatalytic performance. </LI> <LI> Structural stability and reusability of the composite favor practical applications. </LI> <LI> The quantum yield of this system exceeds previously reported values. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Determination of Semen Quality and Antibacterial Susceptibility Pattern of Bacteria Isolated from Semen of Iraqi Subjects

( Anwer Jaber Faisal ),( Hamzah Abdulrahman Salman ) 한국미생물 · 생명공학회 2021 한국미생물·생명공학회지 Vol.49 No.4

Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

Analogous crystal orientation for immobilizing rGO/ZrO₂/Ag₃PO₄ nanocomposite on a fluorine–doped tin oxide substrate

Anwer, Hassan,Park, Jae-Woo Elsevier 2019 Journal of hazardous materials Vol.369 No.-

<P><B>Abstract</B></P> <P>Immobilization of nanocomposites without compromising their photocatalytic performance is a challenging task. Here, we report a new method that utilizes analogous crystal orientations and similarities in interplanar spacings for photocatalyst immobilization. The photocatalyst rGO/ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB> was synthesized using a green hydrothermal method. A primary layer of ZrO<SUB>2</SUB> and a secondary layer of rGO/ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB> composite were deposited on a fluorine–doped tin oxide (FTO) substrate. The analogous crystal orientation and interplanar spacing of ZrO<SUB>2</SUB> between the two layers resulted in composite immobilization on the FTO substrate. X–ray diffraction analysis confirmed that ZrO<SUB>2</SUB> growth occurred along the same crystal planes in both layers. The film exhibited a low band gap energy (2.6 eV) and excellent light absorption. Photocatalytic performance achieved 92% para–nitrophenol degradation in 150 min. The degradation performance of this immobilization method was 43% higher than those of rGO/ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB> films deposited with conventional binder approaches. The quantum yield of the system was 3.46 × 10<SUP>–5</SUP> molecules·photon<SUP>–1</SUP>. Finally, a figure of merit based on different parameters was determined and compared with previous results to assess the practicality of this system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The rGO/ZrO<SUB>2</SUB>/Ag<SUB>3</SUB>PO<SUB>4</SUB> nanocomposite photocatalyst was immobilized on FTO glass. </LI> <LI> The composite film with a band gap of 2.63 eV showed good light absorbance. </LI> <LI> PNP degradation was 43% higher than for conventional binder-through approaches. </LI> <LI> The quantum yield and figure of merit were calculated to assess practicality. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effects of a Low Dose of Gamma Radiation on the Morphology, and the Optical and the Electrical Properties of an ITO Thin Film as an Electrode for Solar Cell Applications

Shaida Anwer Kakil,Barzan Nehmat Sabr,Lary Slewa Hana,Tariq Abdul-Hameed Abbas,Sarwin Yaseen Hussin 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.5

The present study focuses on the in uence of gamma irradiation induced through the morphology effects on the modification of the optical and the electrical properties of transparent indium tin oxide (ITO) thin films. The prepared samples were exposed to low gamma radiation at room temperature with doses 3.90 Gy, 7.81Gy, 11.7 Gy, and 15.62 Gy from a Cs-137 radioisotope source. The surface structures before and after irradiation were analyzed. Atomic force microscopy was performed on two samples, one before and one after irradiation, to investigate any change in the morphology. The roughness parameters, such as Sz, Sv, Sc, and Sq, were found for the surface of the porous films after the gamma irradiation. As the dose of the irradiation was increased, the light absorption of the films increased, and the value of the optical energy gap changed from 3.83 to 3.73 eV while the refractive index changed from 1.9 to 2.05, as determined by using the Swanipol method. Electrical properties, such as the electrical sheet resistance, contact resistance, and current transfer length, were measured by using the four-point probe and the transmission line method (TLM). The determined electrical sheet resistance, contact resistance, and current transfer length were 14.54 , 0.235 , and 0.04 mm before gamma irradiation and 17.61 , 0.1316 , and 0.0025 mm after gamma irradiation. The decrease in the value of the contact resistance due to the irradiation led to a decrease in the current loss while the increase in the sheet resistance will cause the loss of some current through the film.

Dodecylbenzenesulfonic acid micelles assisted in situ preparation and enhanced thermoelectric performance of semiconducting polyaniline–zirconium oxide nanocomposites

Tarique Anwer,Faiz Mohammad,Mohd Omaish Ansari 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.5

Herein, we report in situ preparation of dodecylbenzenesulfonic acid (DBSA) micelles assisted polyaniline (Pani)/zirconium oxide (ZrO2) nanocomposites (Pani/ZrO2) by using K2S2O8 as an oxidizing agent. Thus prepared nanocomposites were characterized by SEM, FTIR, XRD and UV–vis spectropho-tometry. DBSA acted as dopant/surfactant, and the incorporation of ZrO2 nanoparticles improved the stability, electrical and thermal properties of nanocomposites. From the results of UV–vis absorbance it was observed that Pani/ZrO2 nanocomposite was more stabilized under UV light than Pani. DC electrical conductivity retention was studied by isothermal and cyclic ageing techniques and was observed to be better than Pani under ambient environmental conditions.

Corrosion inhibition performance and computational studies of pyridine and pyran derivatives for API X-65 steel in 6 M H2SO4

Kurls E. Anwer,Ahmed A. Farag,Eslam A. Mohamed,Eman M. Azmy,Galal H. Sayed 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

The present investigation aims to synthesize and explore the influence of pyridine and pyran derivativeson the API X-65 steel corrosion in a 6 M H2SO4 solution. The compound was examined at differentconcentrations to optimized the best concentration for the corrosion inhibition effect, weight lossmeasurements, potentiodynamic polarization measurement (PDP), electrochemical impedance spectroscopy(EIS), scanning electron microscopy (SEM) and theoretical methods were used to evaluating theinhibition efficiency. The obtained adsorption data achieved the model of Langmuir isotherm. Thepyridine derivatives showed higher inhibition than pyran derivatives. The PDP tests proposed thatpyridine and pyran derivatives are mixed-type inhibitors. The EIS parameters demonstrate that thedouble-layer capacitance (Cdl) decreases with the increase of inhibitor concentration, which implies areduces dielectric constant. It was observed from experimental data that the inhibition efficiency reached92.7%, 89.1, 94.7, and 85.2% for concentration 2.66 10 3M of I, II, III and IV, respectively indicating theinhibition order is III > I > II > IV. The parameters derived from the theoretical quantum chemicalcalculations were found adequately correlated with the obtained experimental results.

Design of a Fuzzy Logic-based MPPT Controller for a PV System Employing Sensorless Control of MRAS-based PMSM

Abbas Mahmood Oghor Anwer,Fuad Alhaj Omar,Ahmet Afsin Kulaksiz 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.11

The permanent magnet synchronous motors (PMSM) are widely employed in industrial, robotic, water pumping and HVAC applications due to their numerous benefits such as small size, high-energy efficiency, high performance, low inertia and the ability to operate in full load at low speeds. In case the PMSM drive system is supplied from photovoltaic (PV) modules, it can be a perfect match for water pumping or HVAC applications. In such a system, in order to extract full energy from PV modules, a maximum power point tracking (MPPT) algorithm must be employed. This article presents a PV system-fed PMSM drive system with sensorless speed control. The proposed system consists of two main parts. The first part deals with MPPT algorithm based on fuzzy logic controller and the second part deals with PMSM drive system with a sensorless speed estimator by using Model Reference Adaptive System (MRAS) approach to eliminate the use of an encoder. The operation of PMSM is accomplished by using the vector control method to obtain a similar dynamic of the DC motor. The overall system is modelled in Matlab/Simulink environment and simulation results are collected under various operating conditions.

Silymarin, a flavonoid antioxidant, protects streptozotocin-induced lipid peroxidation and β-Cell damage in rat pancreas

Sharma, Manju,Anwer, Tarique,Pillai, K K,Haque, Syed Ehtaishamul,Najmi, A K,Sultana, Yasmin Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.2

The present study is aimed at finding the influence of silymarin (a flavonoid) (25 mg/kg & 50 mg/kg) in streptozotocin (STZ)-induced diabetic rats. Type 2 diabetes was induced by single intraperitoneal injection of STZ (100 mg/kg) to 3 days old rat pups. Silymarin was administered for 15 days after the animals were confirmed diabetic (75 days after STZ injection). Blood glucose, glycosylated hemoglobin ($HbA_{1c}$), lipid peroxides (LPO) levels and reduced glutathione (GSH) contents in pancreas and liver were estimated following the established procedures. Biochemical observations were further substantiated with histological examination of pancreas. Blood glucose and $HbA_{1c}$ levels, which were elevated by STZ, were lowered to physiological levels by the administration of silymarin. The levels of LPO were significantly increased in STZ-induced diabetic rats. Silymarin reduced the LPO levels in both pancreas and liver. GSH contents which were reduced significantly in pancreas and liver of STZ-induced diabetic rats were brought back to near normal levels by silymarin treatment. Multifocal necrotic and degenerative changes of pancreas in STZ-diabetic rats were minimized to near normal morphology by administration of silymarin as evident by histopathological examination. Silymarin showed a dose dependent protective effect on STZ-induced $\beta$-cell damage. It could be attributed to the antioxidative and free radicals scavenging properties of the flavonoid. Thus, it may be considered as a natural antioxidant with potential therapeutic application in the treatment of type 2 diabetes.

Field Study on the Mycotoxin Binding Effects of Clay in Oreochromis niloticus Feeds and Their Impacts on the Performance as Well as the Health Status throughout the Culture Season

Abdelaziz, Mohamed,Anwer, Wael,Abdelrazek, Abeer Hamada Korean Society for Bioinformatics 2010 Interdisciplinary Bio Central (IBC) Vol.2 No.4

Total aflatoxin and ochratoxin were detected in 3 naturally contaminated fish feed samples using immune-affinity method. The results revealed that the average levels of aflatoxins in the 3 examined samples were (15, 22 and $12\;{\mu}g/kg$) respectively while the average levels of ochratoxins were (15, 6 and $6\;{\mu}g/kg$). The results of determination of the effects of clay as a mycotoxin binder on the health status and performance of Oreochromis niloticus in comparing with a control group revealed that the survival rate in control group was 81% after the end of the culture season. The results also revealed that the survival rate in group 2 which received clay treated feed was 86%. The results of regular parasitological examination revealed the identification of trichodina as external protozoa in Oreochromis niloticus from both ponds but without manifestation of disease signs. The results of bacteriological examination revealed the isolation and identification of Pseudomonas flouresence from some moribund Oreochromis niloticus. Higher performance parameters were recorded in group 2 that received feeds treated with clay which reflected in the total production which reaches 1646.47 kg while in the control pond, the total production was1308.36 kg.

The combination of canagliflozin and omega-3 fatty acid ameliorates insulin resistance and cardiac biomarkers via modulation of inflammatory cytokines in type 2 diabetic rats

Mohammed Mohsen Safhi,Tarique Anwer,Gyas Khan,Rahimullah Siddiqui,Sivagurunathan Moni Sivakumar,Mohammad Firoz Alam 대한생리학회-대한약리학회 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.5

The present study was carried out with the hypothesis that combination of canagliflozin and omega-3 fatty acid may have potential effect on insulin level, insulin resistance, cardiac biomarkers, inflammatory cytokines and histological studies in type 2 diabetes mellitus (DM). Type 2 DM was induced by injecting nicotinamide (120 mg/kg, i.p.) 15 min before STZ (60 mg/kg) injection. Canagliflozin (5 and 10 mg/ kg) and omega-3 fatty acid (300 mg/kg) were given for 28 days after confirmation of diabetes. Biochemical estimations revealed elevated levels of glucose, insulin, HOMA-R and inflammatory cytokines in diabetic group. Daily dosing of alone canagliflozin and omega-3 fatty acid slightly reduced elevated levels of glucose, insulin, HOMA-R and inflammatory cytokines (IL-1β, IL-2, and TNFα), whereas canagliflozin and omega-3 fatty acid combination has reduced these biochemical parameters significantly when compared with diabetic group. Similarly in diabetic group the levels of cardiac biomarkers such as lipid profile, LDH, CKMB and troponin were significantly increased. Elevated levels of cardiac biomarkers were significantly reduced after daily dosing of alone canagliflozin and omega-3 fatty acid. Canagliflozin and omega-3 fatty acid combination has offered better improvement in cardiac biomarkers compared to alone canagliflozin and omega-3 fatty acid. Histopathological analysis also supported the above hypothesis that combination therapy (canagliflozin and omega-3 fatty acid) offered better protection against degenerative changes in β-cells of pancreas as compared to alone treatment with these drugs. Thus the present study revealed that canagliflozin and omega-3 fatty acid can be used as potential combination therapy in type 2 DM along with cardiac complication.