Photocatalytic Degradation of Organic Pollutant using Reduced Graphene Oxide

A simple eco friendly preparation of reduced graphene oxide from graphene oxide using strawberry extract is reported. As prepared reduced graphene oxide were characterized by X-Ray Diffraction, UV-Vis spectroscopy, Scaning electron microscopy and degradation performane of MB. The reduced graphene oxide was effectively degradation of MB.

Estudio de pastas cerámicas del centro-oeste argentino (Mendoza, Argentina): microscopía óptica y QEMSCAN

En este trabajo se integran resultados de dos técnicas analíticas utilizadas para el estudio de pastas cerámicas: microscopio petrográfico y Quantitative Evaluation of Minerals by Scaning Electron Microscopy (QEMSCAN), el cual se presenta como una innovación para el estudio de pastas. El objetivo consistió en explorar el potencial de complementariedad entre ambas técnicas. Para ello, se aplicaron análisis de QEMSCAN a muestras de material cerámico arqueológico provenientes del Noroeste de la provincia de Mendoza, en el Centro Oeste Argentino, que fueron estudiadas previamente en microscopio de polarización óptica. La información obtenida mediante QEMSCAN resultó coherente con los resultados del análisis por microscopio de polarización y permitió profundizar las observaciones realizadas a partir de los estudios petrográficos. Los análisis de QEMSCAN detectaron minerales de tamaños muy finos que componen la arcilla, cuya identificación presenta dificultades en el microscopio petrográfico, mientras que los estudios petrográficos permitieron interpretar los resultados obtenidos por el análisis automatizado. La aplicación conjunta de ambos análisis permitió caracterizar y discriminar pastas de procedencia diversa y vincular su composición con marcos geológicos locales y extraregionales. Consideramos que los análisis realizados mediante microscopio de polarización y QEMSCAN, brindan información complementaria, y su aplicación combinada guarda potencial para estudiar proveniencia de materiales cerámicos y manufactura de pastas.

Study of Nanostructured Cu Al Ni Alloy Produced by High Energy Mechanical Milling

Some years ago a new process was developed for the elaboration of alloys in order to overcome drawbacks observed in samples produced by conventional casting. In the present work are shown the results obtained by high energy mechanical milling for Cu-Al-Ni. the mechanical alloying powder Cu84Al12Ni4 (W%) was fabricated in high energy planetary ball milling at a speed of 250 r/min for various milling times (10 20 30 40 50 60 hours) the weight ratio of the balls of powder was 15 to 1. this mechanical alloying process is significantly modifying the characteristic of the powder, the recovered grains are ultimately compacted. The means used to study the different evolution are SEM Scaning Electron Microscopy, Differential thermal analysis DTA, X-ray Diffraction analysis and DRX in situ.

VIBRATION EFFECTS ON THE FABRICATION AND THE INTERFACE OF Al–SiC COMPOSITE PRODUCED BY THE PRESSURELESS INFILTRATION METHOD

In this study, an infiltrated Al/SiC composite was fabricated by the pressureless vibration method. Porous silicon carbide preforms with the pore size of 10, 20 and 30[Formula: see text]ppi were used as the reinforcement. The molten aluminum–magnesium alloy was infiltrated into the preforms at 650[Formula: see text]C and 850[Formula: see text]C. The investigation showed complete infiltration at 650[Formula: see text]C, but infiltration at 850[Formula: see text]C broke the oxidation layer and improved the composite quality. Scaning electron microscopy (SEM) micrographs showed the creation of a good interface and connection between the matrix and the reinforcement. EDS analysis also showed spinel phase (MgAl2O[Formula: see text] had been formed in the interface. This phase was formed due to a reaction against Al2O3 in the reinforcements and MgO. The possibility of the formation of MgAl2O4 phase and the wettability between the metal matrix and ceramic reinforcement was enhanced with increasing the temperature.

MICROMORPHOLOGY OF POLLEN GRAINS FROM BISEXUAL AND FUNCTIONAL MALE FLOWERS OF POMEGRANATE

Modern taxonomy uses pollen grain morphology as an important tool due to itsspecific and diverse features. Pomegranate is an andromonoecious species havingtwo type flowers on the same plant, in other words, hermaphrodite flowers(bisexual) and male flowers (functional male flowers) that develop on the sameplant. The length of polar axis (P) and the equatorial diameter (E) as well as P/Eratio of pollen grains, collected from both bisexual and functionally male flowersof the cultivar ‘Caner I’, were analyzed using scaning electron microscopy (SEM).The length of polar axis (P), the equatorial diameter (E), and P/E ratio wascompared between the two grain. The sculpturing pattern of the exine of both typeflowers was striate, with more parallel longitudinal ridges Pollen from bothbisexual and functional male flower types is similar in size (≈21 μm). In contrast tothe divergent pistil development observed between bisexual and functional malepomegranate flowers, no differences in pollen morphology were detected. Thepollens had prolate shape (P\E=1.65 vs 1.59) in both types of flowers.

PENGARUH PENAMBAHAN BENTONIT TERMODIFIKASI SEBAGAI PENGISI TERHADAP SIFAT MEKANIK DAN PENYERAPAN AIR KOMPOSIT EPOKSI

Research about the application of modified bentonite as filler in epoxy has been done for the purpose of getting the best composition of modified bentonite as filler at epoxy composite to obtain the best mechanical properties such as tensile strength, impact strength and the water absorption. In this research, epoxy resin mixed with bentonite which have been modified using cetyltrimethylammonium bromide (CTAB) surfactant with various concentrations of 0,05M, 0,1M, and 0,15M. Modified bentonite filler and TiO2 then mixed with epoxy resin with various concentration of 5%, 10%, 15%, and 20% of filler from the total mass of the composite and then the composite was produced with hand lay-up method. The result of FTIR characterization showed that the bond between matrix and the filler produced was only interfacial bonding. The result of the mechanical properties test indicated that 5% of filler composition with 0,1M of surfactant concentration obtained the maximum value of tensile strength and mechanical strength respectively 33,667 MPa and 12564,9 J/m2. The result of mechanical properties test was supported by analysis of Scaning Electron Microscopy (SEM). On the test of water absorption, the water absorption capacity increased along with the increased of filler composition.

Preparation and Nonlinear Optical Properties of Poly(2,3-Dimethylaniline) Grafted Reduced Graphene Oxide

Poly (2,3-dimethylaniline) synthesized by a novel polymerization technique, is covalently grafted to reduced graphene oxide layers. Amide linkages formed between Poly (2,3-dimethylaniline) and reduced graphene oxide is confirmed with FTIR and Raman spectroscopy. Morphology was studied by scaning electron microscopy. The hybrid showed improved nonlinear optical properties compared to the graphene oxide precursor and the pristine poly (2, 3-dimethylaniline).

Microstructure and Mechanical Properties of Welded Joints of Cr18Ni30Mo2Al3Nb Alloy

In this present study, A comparative research on the mechanical properties of the dissimilar welded joints of 800H and Cr18Ni30Mo2Al3Nb was investigated. Butt joints were made using argon tungsten-arc welding (TIG). The TIG joint was made using well established welding parameters (i.e., current ampere of 110~120A, welding rate of 105~115mm/min, argon flow 8~10L/min and voltage of 12V). Mechanical behavior of joints was evaluated by room temperature and high temperature (650°C) tensile testing, and hardness testing, respectively. The microstructure of joint was characterized via optical microscopy, and the morphology of tensile fracture was observed by scaning electron microscopy. As can be seen from the experimental results, clearly shown that Cr18Ni30Mo2Al3Nb has better mechanical performance of welded joint than 800H.