244 research outputs found
Wave-packet dynamics in slowly perturbed crystals: Gradient corrections and Berry-phase effects
We present a unified theory for wave-packet dynamics of electrons in crystals
subject to perturbations varying slowly in space and time. We derive the
wave-packet energy up to the first order gradient correction and obtain all
kinds of Berry-phase terms for the semiclassical dynamics and the quantization
rule. For electromagnetic perturbations, we recover the orbital magnetization
energy and the anomalous velocity purely within a single-band picture without
invoking inter-band couplings. For deformations in crystals, besides a
deformation potential, we obtain a Berry-phase term in the Lagrangian due to
lattice tracking, which gives rise to new terms in the expressions for the
wave-packet velocity and the semiclassical force. For multiple-valued
displacement fields surrounding dislocations, this term manifests as a Berry
phase, which we show to be proportional to the Burgers vector around each
dislocation.Comment: 12 pages, RevTe
Investigation on the mechanical properties of ramie/kenaf fibers under various parameters using GRA and TOPSIS methods
This work aims to optimize the mechanical performance of ramie and kenaf fibers
in epoxy composites developed using the hand layup technique. Fiber reinforcement at 0–10 wt% and benzoyl chloride treatment at 0–5 wt% were incorporated
with this composites. Taguchi-based grey relational analysis (GRA) and technique
for order preference by similarity to ideal solution (TOPSIS) methods were used to
determine the optimized conditions for overall mechanical properties of the developed composites. Optimization techniques concluded that 10 wt% ramie (R)/10 wt
% kenaf (K) with 5 wt% benzoyl chloride treatment (T) based epoxy composites
observed good mechanical properties with ultimate tensile strength of 37.39 MPa,
ultimate flexural strength of 63.53 MPa, and impact strength of 70.36 J/m due to
hybridization and the reduction in hydrophilic nature by the surface treatment process. The optimized GRA and TOPSIS combination with 10 wt% R/10 wt% K/5 wt
% of T observed reduced water absorption nature with a contact angle of 64.72
Catalytic N-oxidation of tertiary amines on RuO(2)NPs anchored graphene nanoplatelets
Ultrafine ruthenium oxide nanoparticles (RuO2NPs) with an average diameter of 1.3 nm were anchored on graphene nanoplatelets (GNPs) using a Ru(acac)3 precursor by a very simple dry synthesis method. The resultant material (GNPs–RuO2NPs) was used as a heterogeneous catalyst for the N-oxidation of tertiary amines for the first time. The transmission electron microscopy (TEM) images of the GNPs–RuO2NPs showed the excellent attachment of RuO2NPs on GNPs. The loading of Ru in GNPs–RuO2NPs was 2.68 wt%, as confirmed by scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). The X-ray photoelectron spectrum (XPS) and the X-ray diffraction pattern (XRD) of GNPs–RuO2NPs revealed that the chemical state of Ru on GNPs was +4. After the optimization of reaction conditions for N-oxidation of triethylamine, the scope of the reaction was extended to various aliphatic, alicyclic and aromatic tertiary amines. The GNPs–RuO2NPs showed excellent catalytic activity in terms of yields even at a very low amount of Ru catalyst (0.13 mol%). The GNPs–RuO2NPs was heterogeneous in nature, chemically as well as physically, very stable and could be reused up to 5 times.ArticleCATALYSIS SCIENCE & TECHNOLOGY. 4(7):2099-2106 (2014)journal articl
COMPARATIVE CYTOTOXIC EFFECT OF COMMERCIAL MOUTHWASH AND GREEN TEA PAPAYA FORMULATION BASED MOUTHWASH - AN IN VITRO STUDY
INTRODUCTION : An ideal mouthwash is one that doesn\u27t cause allergies, doesn\u27t discolor teeth or the oral mucosa, has anti-plaque and antibacterial qualities, doesn\u27t have a lot of cytotoxic effects on cells, is environmentally friendly, and tastes good. The aim of the present study is to compare the cytotoxic effect of commercial mouthwash and green tea and papaya formulation based mouthwash. MATERIALS AND METHODS : The study was conducted in the month of August 2022 in Saveetha dental college and Hospitals. Papaya and green tea samples were collected and the samples were boiled, filtered and concentrated to prepare the extract. Both the extract were mixed together and 0.3g sucrose, 0.01 g SLS agent and sodium benzoate was added and mouthwash was prepared. Cytotoxic activity was compared with commercial chlorhexidine mouthwash using brine shrimp lethality assay. Salt water was prepared. 6 ELISA plates were taken with different concentrations and 10-12 ml of saline water was filled. To that 10 nauplii were slowly added to each well Then the nanoparticles were added according to the concentration level. The plates were incubated for 24 hours, the ELISA plates were observed and noted for the number of live nauplii present and calculated by using formula. The results were then tabulated and represented graphicallyRESULTS : The cytotoxic activity of commercial mouthwash and green tea and papaya formulated mouthwash was compared. The number of live nauplii present in commercial mouthwash and papaya and green tea formulated mouthwash decreased on increasing the concentrations. But compared to commercial mouthwash, green tea and papaya formulated mouthwash had a higher number of nauplii present. CONCLUSION : From the present study it was concluded that the papaya green tea formulated mouthwash showed lower cytotoxicity than commercial mouthwash
Photodegradation of dyes by a novel TiO2/u-RuO2/GNS nanocatalyst derived from Ru/GNS after its use as catalyst in aerial oxidation of primary alcohols (GNS = Graphene NanoSheets)
Ruthenium nanoparticles (RuNPs) supported on graphene nanosheets (GNS), a composite (Ru/GNS), were prepared by a dry synthesis method and were used as nanocatalysts for the aerial oxidation of various primary alcohols. Ru/GNS was highly efficient, selective, stable and heterogeneous in nature. Owing to the high stability of the used catalyst (u-Ru/GNS), it was further applied in a different catalytic system viz photocatalytic degradation, after suitable modifications. We have obtained a novel TiO2/u-RuO2/GNS catalyst from u-Ru/GNS by the sol-gel method. The catalytic activity of TiO2/u-RuO2/GNS toward the photodegradation of methyl orange (MO) and acridine orange (AO) was found to be excellent. Overall, the sustainable use of these recyclable materials (Ru/GNS and TiO2/u-RuO2/GNS) could lead to economic and environmental benefits.Reaction Kinetics, Mechanisms and Catalysis. 115(2):759-772 (2015)journal articl
Inorganic Capping Layers in RDL Technologies: Process Advantages and Reliability
The authors would like to express their gratitude to the different imec teams involved in this study. Contributions from imec's 3D IIAP program are deeply acknowledged. Special thanks for the numerous FIB cross-section requests handled by Dr. Olivier Richard and Ms. Chris Drijbooms. Sincere thanks should go to JSR Corporation and JSR Micro N.V. for providing the photosensitive polymer used in this study. The support of A. Hiro and H. Noda is deeply recognized
Screening of recombinant inbred lines for resistance to bacterial leaf blight pathotypes in rice (Oryza sativa L.)
In the present investigation 16 recombinant inbred lines (RIL’s) developed from the intra-specific cross between YH3 and AKDRMS 21-54 through Marker Assisted Pedigree Breeding Method were screened along with their parents and the checks, namely, BPT 5204, TN1 and Improved Samba Mahsuri (ISM) against IxoPt-20 pathotype at the ICAR-Indian Institute of Rice Research, Hyderabad during Rabi 2021-22 and a new pathotype of Xanthomonas oryzae pv. oryzae causing Bacterial Leaf Blight disease in rice at Regional Agricultural Research Station, Maruteru during Kharif 2022 to identify pathotype specific resistant sources. Morpho-Molecular screening was adopted to evaluate the recombinant inbred lines over two locations in the consecutive seasons of Rabi 2021-22 and Kharif 2022. Based on per cent diseased leaf area, the genotypes were scored and categorised as per the Standard Evaluation System (SES) scale provided by International Rice Research Institute (IRRI). The results revealed all 16 RIL’s to be either resistant (10) or moderately resistant (6) to IxoPt-20 pathotype. However, only five RIL’s were found to be resistant, while four RIL’s were moderately resistant for the new virulent pathotype. Seven RIL’s with resistant to moderately resistant reaction for IxoPt-20 pathotype, showed moderately susceptible reaction for the new virulent pathotype. Among the resistant RIL’s identified for each pathotype, BPT-1901-72-10-6, BPT-1901-108-4-1 and BPT-1901-111-3-2 were found to be uniformly resistant, while, BPT-1901-45-8-6 and BPT-1901-163-1-18 were uniformly moderately resistant to both IXoPt-20 and the new virulent pathotype at Hyderabad and Maruteru, respectively, indicating their potential as genetic stocks for development of new cultivars resistant to bacterial leaf blight disease
Catalytic N-oxidation of tertiary amines on RuO(2)NPs anchored graphene nanoplatelets
Ultrafine ruthenium oxide nanoparticles (RuO2NPs) with an average diameter of 1.3 nm were anchored on graphene nanoplatelets (GNPs) using a Ru(acac)3 precursor by a very simple dry synthesis method. The resultant material (GNPs–RuO2NPs) was used as a heterogeneous catalyst for the N-oxidation of tertiary amines for the first time. The transmission electron microscopy (TEM) images of the GNPs–RuO2NPs showed the excellent attachment of RuO2NPs on GNPs. The loading of Ru in GNPs–RuO2NPs was 2.68 wt%, as confirmed by scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). The X-ray photoelectron spectrum (XPS) and the X-ray diffraction pattern (XRD) of GNPs–RuO2NPs revealed that the chemical state of Ru on GNPs was +4. After the optimization of reaction conditions for N-oxidation of triethylamine, the scope of the reaction was extended to various aliphatic, alicyclic and aromatic tertiary amines. The GNPs–RuO2NPs showed excellent catalytic activity in terms of yields even at a very low amount of Ru catalyst (0.13 mol%). The GNPs–RuO2NPs was heterogeneous in nature, chemically as well as physically, very stable and could be reused up to 5 times.ArticleCATALYSIS SCIENCE & TECHNOLOGY. 4(7):2099-2106 (2014)journal articl
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