Evaluating the Catalytic Effects of Carbon Materials on the Photocatalytic Reduction and Oxidation Reactions of TiO₂

Khan, Gulzar,Kim, Young Kwang,Choi, Sung Kyu,Han, Dong Suk,Abdel-Wahab, Ahmed,Park, Hyunwoong Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.4

$TiO_2$ composites with seven different carbon materials (activated carbons, graphite, carbon fibers, single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene oxides, and reduced graphene oxides) that are virgin or treated with nitric acid are prepared through an evaporation method. The photocatalytic activities of the as-prepared samples are evaluated in terms of $H_2$ production from aqueous methanol solution (photo-catalytic reduction: PCR) and degradation of aqueous pollutants (phenol, methylene blue, and rhodamine B) (photocatalytic oxidation: PCO) under AM 1.5-light irradiation. Despite varying effects depending on the kinds of carbon materials and their surface treatment, composites typically show enhanced PCR activity with maximum 50 times higher $H_2$ production as compared to bare $TiO_2$. Conversely, the carbon-induced synergy effects on PCO activities are insignificant for all three substrates. Colorimetric quantification of hydroxyl radicals supports the absence of carbon effects. However, platinum deposition on the binary composites displays the enhanced effect on both PCR and PCO reactions. These differing effects of carbon materials on PCR and PCO reactions of $TiO_2$ are discussed in terms of physicochemical properties of carbon materials, coupling states of $TiO_2$/carbon composites, interfacial charge transfers. Various surface characterizations of composites (UV-Vis diffuse reflectance, SEM, FTIR, surface area, electrical conductivity, and photoluminescence) are performed to gain insight on their photocatalytic redox behaviors.

Evaluating the Catalytic Effects of Carbon Materials on the Photocatalytic Reduction and Oxidation Reactions of TiO2

Gulzar Khan,Young Kwang Kim,최성규,한동석,Ahmed Abdel-Wahab,박현웅 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.4

TiO2 composites with seven different carbon materials (activated carbons, graphite, carbon fibers, singlewalled carbon nanotubes, multi-walled carbon nanotubes, graphene oxides, and reduced graphene oxides) that are virgin or treated with nitric acid are prepared through an evaporation method. The photocatalytic activities of the as-prepared samples are evaluated in terms of H2 production from aqueous methanol solution (photocatalytic reduction: PCR) and degradation of aqueous pollutants (phenol, methylene blue, and rhodamine B) (photocatalytic oxidation: PCO) under AM 1.5-light irradiation. Despite varying effects depending on the kinds of carbon materials and their surface treatment, composites typically show enhanced PCR activity with maximum 50 times higher H2 production as compared to bare TiO2. Conversely, the carbon-induced synergy effects on PCO activities are insignificant for all three substrates. Colorimetric quantification of hydroxyl radicals supports the absence of carbon effects. However, platinum deposition on the binary composites displays the enhanced effect on both PCR and PCO reactions. These differing effects of carbon materials on PCR and PCO reactions of TiO2 are discussed in terms of physicochemical properties of carbon materials, coupling states of TiO2/carbon composites, interfacial charge transfers. Various surface characterizations of composites (UV-Vis diffuse reflectance, SEM, FTIR, surface area, electrical conductivity, and photoluminescence) are performed to gain insight on their photocatalytic redox behaviors.

Effects of Various Mechanical and Chemical Treatments of Rapeseed Meal on the Performance of Broilers

Khan, M.Z.,Mahmood, S.,Sarwar, M.,Nisa, M.,Gulzar, F. Asian Australasian Association of Animal Productio 1998 Animal Bioscience Vol.11 No.6

One hundred and eighty, 1-day old broiler chicks, randomly divided into 15 replicates of 10 brids each were employed to six treatment rations (A, B, C, D, E and F). Rapeseed meal (RSM) with or without treatment was incorporated in the rations at 20 percent level in lieu of soybean meal. The birds in group A were fed soybean based ration and those in group B, C, D, E and F were given ration containing untreated, solvent extracted, water treated, autoclaved and ferrous sulphate treated RSM, respectively. Presence of RSM in the rations whether untreated or treated, significantly reduced weight gain and feed consumption of the birds compared with those of control group but efficiency of feed utilization, dressed weight, dressing percentage and weights of internal organs amongst the groups remained unaffected. The size of thyroid galnds of the broilers using the meal was significantly larger than those having ration without RSM. The only exception was that the birds having solvent extracted meal had similar thyroid gland relative weight as those of control group indicating reduced antinutritional effect of isothiocyanates content due to solvent extraction of the meal.

SWNTs-catalyzed solar hydrogen production

Kim, Young Kwang,Khan, Gulzar,Jeong, Hye Won,Park, Hyunwoong Korean Society of Photoscience 2014 Rapid communication in photoscience Vol.3 No.3

Single-walled carbon nanotubes (SWNTs) catalyzed hydrogen production from water containing various electron donors under visible light (${\lambda}$ > 420 nm). As-received SWNTs were effective for hydrogen production, yet the effect vanished when they underwent surface chemical treatments. Upon coupling with CdSe particles, however, the surface treated SWNTs were far superior to non-treated SWNTs by a factor of ~30 for hydrogen production.

Some folded issues related to over-shielded and unplanned rooms for medical linear accelerators - A case study

Muhammad, Wazir,Ullah, Asad,Hussain, Amjad,Ali, Nawab,Alam, Khan,Khan, Gulzar,Matiullah,,Maeng, Seongjin,Lee, Sang Hoon 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.

Some Folded Issues Related to Over-shielded and Unplanned Rooms for Medical Linear Accelerators - A Case Study

Wazir Muhammad,Asad Ullah,Amjad Hussain,Nawab Ali,Khan Alam,Gulzar Khan,Matiullah,뱅수진,이상훈 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.3

A medical linear accelerator (LINAC) room must be properly shielded to limit the outside radiation exposure to an acceptable safe level defined by individual state and international regulations. However, along with this prime objective, some additional issues are also important. The current case-study was designed to unfold the issues related to over-shielded and unplanned treatment rooms for LINACs. In this connection, an apparently unplanned and over-shielded treatment room of 610 × 610 cm2 in size was compared with a properly designed treatment room of 762 × 762 cm2 in size (i.e., by following the procedures and recommendations of the IAEA Safety Reports Series No. 47 and NCRP 151). Evaluation of the unplanned room indicated that it was over-shielded and that its size was not suitable for total body irradiation (TBI), although the license for such a treatment facility had been acquired for the installed machine. An overall 14.96% reduction in the total shielding volume (i.e., concrete) for an optimally planned room as compared to a non-planned room was estimated. Furthermore, the inner room’s dimensions were increased by 25%, in order to accommodate TBI patients. These results show that planning and design of the treatment rooms are imperative to avoid extra financial burden to the hospitals and to provide enough space for easy and safe handling of the patients. A spacious room is ideal for storing treatment accessories and facilitates TBI treatment.

Endoscopic Yield, Appropriateness, and Complications of Pediatric Upper Gastrointestinal Endoscopy in an Adult Suite: A Retrospective Study of 822 Children

Manzoor Ahmad Wani,Showkat Ali Zargar,Ghulam Nabi Yatoo,Inaamul Haq,Altaf Shah,Jaswinder Singh Sodhi,Ghulam Mohammad Gulzar,Mushtaq Khan 대한소화기내시경학회 2020 Clinical Endoscopy Vol.53 No.4

Background/Aims: This study aimed to study the endoscopic yield, appropriateness, and complications of pediatric endoscopyperformed by adult gastroenterologists in an adult endoscopic suite. Methods: This a retrospective study in which records of all the patients less than 18 years of age who underwent endoscopy in the last5 years were studied. The indications of endoscopy in children were categorized as appropriate or inappropriate per the latest guidelinesby American Society for Gastrointestinal Endoscopy and North American Society for Pediatric Gastroenterology, Hepatology andNutrition. Positive endoscopic yield was defined as the presence of any abnormality on endoscopy. Results: Among the total of 822 children (age <18 years), the most common indications were variceal surveillance/eradication in 157(19.1%), followed by dyspepsia in 143 (17.4%), upper gastrointestinal (UGI) bleeding in 136 (16.5%), recurrent abdominal pain in 94(11.4%), unexplained anemia in 74 (9%), recurrent vomiting in 50 (6.08%), chronic refractory gastroesophageal reflux disease in 34 (4.1%)and others; 780 out of 822 endoscopic procedures (94.9%) done in children were appropriate as per the guidelines. The endoscopicyield was 45.8%, highest in patients with UGI bleeding (71.3%), followed by variceal surveillance (54.8%), recurrent vomiting (38%),dyspepsia (37.8%), and recurrent abdominal pain (36%). Minor adverse events occurred in 7.3% of children. Conclusions: Pediatric endoscopy performed by an experienced adult gastroenterologist may be acceptable if done in cooperation witha pediatrician.