Amine functionalized silk fibroin functional hydrogel for metal ions and dyes removal in wastewater

( Chirag Batukbhai Godiya ),( Bum Jun Park ) 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.-

A Comprehensive Review of Verification and Validation Techniques Applied to Hydraulic Turbines

Chirag Trivedi,Ole Gunnar Dahlhaug 한국유체기계학회 2019 International journal of fluid machinery and syste Vol.12 No.4

The paper critically reviews the verification and validation (VV) techniques applied to investigate hydraulic turbines. Although there are well-established standards such as AIAA G-077-1998 and ERCOFTAC guide for turbulence modelling, majority of studies conducted on the turbines are lacking of systematic VV. Results without proper VV serve no purpose for safe and reliable designs of turbines. Available standards/guide are for general-purpose industrial applications and have limited scope. Customized VV procedure for the turbine applications is essential to create trust on the obtained results. The present review discusses how available standards/guide can be used to determine uncertainty/error and to demonstrate the credibility of results. The review includes several aspects of VV such as effect of discretization schemes, iterative error, convergence criteria, time-step sizing and impact of passage modeling approaches on the results. Further, how numerical results mislead the user and its implications are addressed. In the last, open questions on turbine modelling and recommendations on prospective numerical studies are discussed.

Microscopic varicocelectomy as a treatment option for patients with severe oligospermia

Chirag Gupta,Arun Chinchole,Rupin Shah,Hemant Pathak,Deepa Talreja,Ankit Kayal 대한비뇨의학회 2018 Investigative and Clinical Urology Vol.59 No.3

Purpose: Many studies have shown improved semen parameters after varicocele surgery; however, the benefit in terms of improved pregnancy rates and live births is still disputed in cases of severe oligoasthenozoospermia (OAS). The present study evaluated the outcome of microscopic subinguinal varicocelectomy in terms of the spontaneous pregnancy rate in patients with severe OAS. Materials and Methods: This was a retrospective, observational, analytic study of 56 men with OAS who underwent microscopic varicocelectomy at our center between 2008 and 2015. The subjects were followed for a mean period of 12.4 months. Outcome was compared among groups of men with mild (sperm concentration, 10.2–19 million/mL), moderate (5.7–9.5 million/mL), and severe (<5 million/mL) OAS who were operated on during the same period. Results: A total of 13 of 35 men (37.1%) with severe OAS achieved spontaneous pregnancy. Mean sperm density increased from 2.29 million/mL preoperatively to 14.09 million/mL postoperatively. The mean time to pregnancy from the date of surgery was 8.5 months. The spontaneous pregnancy rate in men with mild and moderate OAS was 62.5% and 46.2%, respectively. Conclusions: Although pregnancy rates after varicocele surgery are lower preoperatively in men with severe OAS than in men with mild or moderate OAS, the spontaneous pregnancy rate of 37.1% still compares very favorably with outcomes after a single attempt at in vitro fertilization.

Scrotal pain: Evaluation and management

Chirag G Gordhan,Hossein Sadeghi-Nejad 대한비뇨의학회 2015 Investigative and Clinical Urology Vol.56 No.1

Scrotal pain is a common complaint in a urological practice. Its diagnosis can prove challenging in both acute and chronic formsand requires a thorough and complete history and physical examination. This article discusses the evaluation and management ofseveral entities of scrotal pain, including testicular torsion, epididymitis, postvasectomy pain, varicocele, and chronic orchialgia.

Surgical and oncologic outcomes after robotic radical hysterectomy as compared to open radical hysterectomy in the treatment of early cervical cancer

Chirag A. Shah,Tiffany Beck,John B. Liao,Nadia V. Giannakopoulos,Dan Veljovich,Pam Paley 대한부인종양학회 2017 Journal of Gynecologic Oncology Vol.28 No.6

Objective: The use of robotic radical hysterectomy has greatly increased in the treatment of early stage cervical cancer. We sought to compare surgical and oncologic outcomes of women undergoing robotic radical hysterectomy compared to open radical hysterectomy. Methods: The clinic-pathologic, treatment, and recurrence data were abstracted through an Institutional Review Board-approved protocol at 2 separate large tertiary care centers in Seattle, Swedish Medical Center and the University of Washington. Data were collected from 2001–2012. Comparisons between the robotic and open cohorts were made for complications, recurrence, progression-free survival (PFS), and overall survival (OS). Results: In the study period, 109 robotic radical hysterectomies were performed. These were compared to 202 open radical hysterectomies. The groups were comparable in terms of age and body mass index (BMI). Length of stay (LOS) was considerably shorter in the robotic group (42.7 vs. 112.6 hours, p<0.001) as was estimated blood loss (EBL; 105.9 vs. 482.6 mL, p<0.001). There were more complications in the open radical hysterectomy group, 23.4% vs. 9.2% in the robotic group (p=0.002). The recurrence rate was comparable between the groups (10.1% vs. 10.4%, p=0.730). In multivariate adjusted analysis, robotic surgery was not a statistically significant predictor of PFS (p=0.230) or OS (0.85). Conclusion: Our study, one of the largest multi-institution cohorts of patients undergoing robotic radical hysterectomy, suggest robotic radical hysterectomy leads to comparable oncologic outcomes in the treatment of early stage cervical cancer with improved short-term surgical outcomes such as decreased LOS and EBL.

Polyethyleneimine Integrated Sodium Alginate Hydrogel for Effective Uptake of Toxic Metallic Ions and Catalysis in Effluents

Chirag Godiya,Bum Jun Park 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.1

Sodium alginate-based functional hydrogel for efficient and fast elimination of cationic dyes in effluents

( Chirag Batukbhai Godiya ),박범준 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.1

Application of extraction chromatographic techniques for separation and purification of emerging radiometals 44/47Sc and 64/67Cu

Chirag K. Vyas,박정훈,양승대 대한방사성의약품학회 2016 Journal of radiopharmaceuticals and molecular prob Vol.2 No.2

Considerably increasing interest in using the theranostic isotopes/ isotope pairs of radiometals like 44/47Sc and 64/67Cu for diagnosis and/or therapeutic applications in the nuclear medicine procedures necessitates its reliable production and supply. Separation and purification of no-carrier-added (NCA) isotopes from macro quantitates of the irradiated target matrix along with other impurities is a cardinal procedure amongst several other steps involved in its production. Multitudinous methods including but not limited to liquid-liquid (solvent) extraction, extraction chromatography (EXC), ion exchange, electrodeposition and sublimation are routinely applied either solitarily or in combination for the separation and purification of radioisotopes depending on their production routes, radioisotope of interest and impurities involved. However, application of EXC though has shown promises towards the numerous separation techniques have not received much attention as far as its application prospects in the field of nuclear medicine are concerned. Advances in the recent past for application of the EXC resins in separation and purification of the several medically important radioisotopes at ultra-high purity have shown promising behavior with respect to their operation simplicity, acidic and radiolytic stability, separation efficiencies and speedy procedures with the enhanced and excellent extraction abilities. In this mini review we will be talking about the recent developments in the application and the use of EXC techniques for the separation and purification of 44/47Sc and 64/67Cu for medical applications. Furthermore, we will also discuss the scientific and practical aspects of EXC in the view of separation of the NCA trace amount of radionuclides. J Radiopharm Mol Probes 2(2):84-95, 2016

Bismuth zinc borate- Polyacrylonitrile nanofibers for photo-piezocatalysis

Chirag Porwal,Sahil Verma,Vishal Singh Chauhan,Rahul Vaish 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

This study investigates the use of an electrospun membrane composed of Bi2ZnB2O7 - Polyacrylonitrile(BBZO-PAN) for the degradation of Methylene blue (MB) dye. The membrane was fabricated using theelectrospinning technique, and its structural and morphological properties were analyzed using X-raydiffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy(FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). The membrane’schemical states before and after encapsulation of BBZO in PAN matrix were analyzed using X-ray photoemissionspectroscopy (XPS). The optical studies revealed that the band gap of the BBZO-PAN membranewas 2.92 eV, which is lower than that of the PAN membrane (4.06 eV), due to the presence of BBZO in thePAN matrix. The prepared membrane demonstrated the capability to degrade dye under visible light irradiationvia photocatalysis, piezocatalysis, and photo-piezocatalysis. The highest achieved degradationand kinetic rate constant were 82% and 8.8*10-3 min1, respectively. The active species responsible fordegradation were identified using scavenger tests for all catalytic processes. These results demonstratethe potential of the BBZO-PAN membrane for use in wastewater treatment and other environmentalapplications.

Optical Properties and Phase Transition in VO2 and Ti:ZnO/VO2 Thin Films

Chirag Saharan,Pawan S Rana,Manish Kumar 한국진공학회 2023 Applied Science and Convergence Technology Vol.32 No.4

Energy saving methods/materials are becoming increasingly important for meeting society’s energy demands. Smart windows made of thermochromic materials show great promise in reducing the energy consumption of buildings. Thermochromic vanadium dioxide (VO2) is a potential candidate for smart window applications; however, its commercial usage is limited by its low visible light transmittance. To address this issue, we integrated a VO2 layer with an antireflecting Ti-doped ZnO (TZO) layer. Single-layer VO2 and bilayer TZO/ VO2 thin films were fabricated on c-Al2O3 substrates using radio frequency sputtering, and their structural, morphological, and optical properties were investigated. The single-phase growth of the VO2 and TZO layers in single and bilayer samples was confirmed through room-temperature X-ray diffraction (XRD) measurements. Temperature-dependent grazing incidence XRD measurements during the heating and cooling cycle were performed in a synchrotron to explore the structural changes in the VO2 and TZO/VO2 thin-film samples. The structural phase transition curves were modified in the TZO/VO2 thin-film sample. The increase in visible light transmittance was examined using ultraviolet-visible spectroscopy in the transmittance mode at room temperature. The enhanced visible light transmittance of the TZO/VO2 bilayer shows promise for realizing more effective smart windows.