Study of molar properties of GO after doping with transition metals for photodegradation of fluorescent dyes.

We synthesized graphene oxide (GO) doped with transition metal ions and characterized it using XPS, FT-IR, TGA/DTG, XRD, SEM, AFM, ICP-OES, UV/vis, and Raman spectroscopy. An intrinsic viscosity [η] of 0.002-0.012 g% @ 0.002 aq-GO was determined for viscosity average molecular weight (M v) of GO at 288.15, 298.15, and 308.15 K. Mark-Houwink (M-H) constants k (cm3 g-1) and a (cm3 mol g-2) were calculated for 5-15 mg/100 mL polyvinylpyrrolidone (PVP), using 29, 40, 55 kg mol-1 as markers for calculating M v by fitting the [η] to the Mark-Houwink-Sakurada equation (MHSE). We obtained 48 134.19 g mol-1 M v at 298.15 K, and the apparent molar (V ϕ m , cm3 mol-1), limiting molar volumes (V 0 GO)GO⃑0, enthalpy (ΔH m, J mol-1), entropy (ΔS m, J mol-1 K-1), viscosity (η m, mPa s mol-1), surface tension (γ m, mN m-1 mol-1), friccohesity (σ m, scm-1 mol-1), fractional volume (ϕ m, cm3 mol-1), isentropic compressibility (K sϕ,m, 10-4 cm s2 g-1 mol), infer GO molar consistency throughout the chemical processes. Molar properties (MPs) infer a GO monodispersion producing negative electrons (e-) and positive holes (h+) under sunlight. The transition metal ions (Fe2+, Mn2+, Ni2+, Cr3+, TMI) doped onto GO (TMI-GO), can photodegrade methylene blue (MB) in 60 min compared with 120 min using GO alone. The 4011 C atoms, 688 hexagonal sheets, 222 π-conjugations, and 4011 FE were calculated from the 48 134.19 g mol-1. The functional edges are the negative and positive holes generating centres of the GO 2D sheets.

Monte Carlo Processing on a Chip (MCoaC)-preliminary experiments toward the realization of optimal-hardware for TOPAS/Geant4 to drive discovery.

Amongst the scientific frameworks powered by the Monte Carlo (MC) toolkit Geant4 (Agostinelli et al., 2003), the TOPAS (Tool for Particle Simulation) (Perl et al., 2012) is one. TOPAS focuses on providing ease of use, and has significant implementation in the radiation oncology space at present. TOPAS functionality extends across the full capacity of Geant4, is freely available to non-profit users, and is being extended into radiobiology via TOPAS-nBIO (Ramos-Mendez et al., 2018). A current "grand problem" in cancer therapy is to convert the dose of treatment from physical dose to biological dose, optimized ultimately to the individual context of administration of treatment. Biology MC calculations are some of the most complex and require significant computational resources. In order to enhance TOPAS's ability to become a critical tool to explore the definition and application of biological dose in radiation therapy, we chose to explore the use of Field Programmable Gate Array (FPGA) chips to speedup the Geant4 calculations at the heart of TOPAS, because this approach called "Reconfigurable Computing" (RC), has proven able to produce significant (around 90x) (Sajish et al., 2012) speed increases in scientific computing. Here, we describe initial steps to port Geant4 and TOPAS to be used on FPGA. We provide performance analysis of the current TOPAS/Geant4 code from an RC implementation perspective. Baseline benchmarks are presented. Achievable performance figures of the subsections of the code on optimal hardware are presented; Aspects of practical implementation of "Monte Carlo on a chip" are also discussed.

Catalytic Regioselective γ-Methylenation of α,ß-Unsaturated Aldehydes Using Formaldehyde via Vinylogous Aldol Condensation.

The first vinylogous aldol condensation of α,ß-unsaturated aldehydes using aqueous formaldehyde is developed under mild reaction conditions to form the γ-methylenated products with excellent regioselectivity. Using this methodology, a short synthesis of α-triticene, an antifungal compound, is achieved in two steps. The practicality of this methodology is demonstrated by the gram-scale synthesis. Formation of the unusual double γ-functionalized products from crotonaldehyde and a direct asymmetric vinylogous aldol product from phenylglyoxal is also described.

Evaluation of positional accuracy of the Varian's exact-arm and retractable-arm support electronic portal imaging device using intensity-modulated radiotherapy graticule phantom.

PURPOSE: The aim of the present study was to compare the positional accuracy of varian's exact-arm (E-arm) and retractable-arm (R-arm) supporting electronic portal imaging device (EPID) systems (amorphous silicon flat-panel detector) using the intensity-modulated radiotherapy (IMRT) graticule phantom. MATERIALS AND METHODS: The known shifts of 0.5, 1.0, and 1.5 cm were introduced to the given phantom in longitudinal, lateral, and vertical directions, respectively, with respect to treatment couch of medical linear accelerator. The experiment was repeated for different gantry angle and varying source to imager distances (SIDs). The images were acquired for each shift at varying SIDs and beam orientations for both EPID supporting systems. The corresponding shifts obtained from treatment planning system (TPS) were recorded and compared. RESULTS: The known (expected) and observed (recorded from TPS) shifts obtained for different beam angles (namely, 0°, 90°, 180°, and 270° for anterior, left lateral, posterior, and right-lateral portal images, respectively) in the longitudinal, lateral, and vertical direction at varying SID were compared. The maximum shift in the observed value from the expected one was 3 and 2 mm, respectively, out of the all beam configuration for R-arm and E-arm. These shifts were randomly observed for all imager position and beam orientation. CONCLUSION: The IMRT graticule phantom is an effective tool to check the mechanical characteristic and consistency of different EPID supporting arms. The effect of EPID sag due to gravity (gantry and treatment couch) was not significant for detection of shift in patient's position. The E-arm support EPID has better mechanical stability and accuracy in detection of patient's position than that of R-arm.