Fabrication and Excellent Dielectric Performance of Exfoliated Graphite Sheets

In the present investigation, exfoliated graphite sheets were obtained from the thermo-chemical treatment of natural graphite flakes. In this process, the graphite expands almost 300-350 times of its original volume and takes the shape of worms. These worms can be pressed or rolled into any desired shape without any binder. The exfoliated graphite sheets show excellent electrical properties i.e. high dielectric constant (ε = 6.374 ×107) and comparatively low dielectric loss (tanδ = 138) across the frequency in the range 50 Hz to 30 MHz and temperature in the range 40-300 °C. The products developed from exfoliated graphite can have very good sealing applications in industrial areas, especially for gaskets in the automobile industries

Fabrication and Excellent Dielectric Performance of Exfoliated Graphite Sheets

In the present investigation, exfoliated graphite sheets were obtained from the thermo-chemical treatment of natural graphite flakes. In this process, the graphite expands almost 300-350 times of its original volume and takes the shape of worms. These worms can be pressed or rolled into any desired shape without any binder. The exfoliated graphite sheets show excellent electrical properties i.e. high dielectric constant (ε = 6.374 ×107) and comparatively low dielectric loss (tanδ = 138) across the frequency in the range 50 Hz to 30 MHz and temperature in the range 40-300 °C. The products developed from exfoliated graphite can have very good sealing applications in industrial areas, especially for gaskets in the automobile industries

Taxonomical Description, Nativity and Endemism with Particular Reference to Threatened Ethnomedicinal Plants of Almora District of Western Himalaya

Out of 187 ethno-medicinal plants of Almora district (Kumari et. al. 2011), identifications, distribution, nativity and endemic/near endemic of 21 threatened ethno-medicinal plant species were studied. These 21 species of ethno medicinal plants belonging to 16 families were recorded. Of these, 2 species were trees, 1 shrub, 16 herbs and 2 climbers. The families Taxaceae, Ranunculaceae, Berberadaceae, Euphorbiaceae, Saxifragaceae,Verbenaceae,Bignonoaceae, Celastraceae, Costaceae, Dioscoreaceae, Hypoxidaceae, Valerianaceae and Gentianaceae having single species,  Lamiaceae, having two species and Orchidaceae, Liliaceae having three species were identified

Ultrasonic force microscopy on 'poly(vinyl alcohol)/SrTiO3' nano-perovskites hybrid films

Atomic Force Microscopy (AFM) and Ultrasonic Force Microscopy (UFM) have been applied to the characterization of composite samples formed by SrTiO 3 (STO) nanoparticles (NPs) and polyvinyl alcohol (PVA). The morphological features of the STO NPs were much better resolved in UFM than in contact-mode AFM topography. For high STO concentrations the individual STO NPs formed nanoclusters, which gathered in microaggregates. The STO aggregates, covered by PVA, exhibited no AFM frictional contrast, but were clearly distinguished from the PVA matrix using UFM. Similar aggregation was observed for NPs in the composite samples than for NPs deposited on top of a flat silicon substrate from a milliQ water solution in the absence of polymer. In the hybrid films, most STO nanoparticles typically presented a lower UFM contrast than the PVA matrix, even though stiffer sample regions such as STO should give rise to a higher UFM contrast. STO NPs with intermediate contrast were characterized by an UFM halo of lower contrast at the PVA/STO interface. The results may be explained by considering that ultrasound is effectively damped on the nanometer scale at PVA/ STO interfaces. According to our data, the nanoscale ultrasonic response at the PVA/STO interface plays a fundamental role in the UFM image contrast

Veterinary Ethnomedicinal Plants in Uttarakhand Himalayan Region, India

Drug research has enriched human life in many ways. The health care and resulting social and economic benefits of new drugs to society are most remarkable, are quite well recognized. Drug research has been the driving force for many basic scientific developments, such as that of many new synthetic methods, of the understanding of the physiology and pharmacology of biological systems and has contributed much too molecular recognition. The Uttarakhand Himalayas have a great wealth of medicinal plants and traditional medicinal knowledge. The medicinal plant that has been widely used as veterinary ethno-medicine in Uttarakhand region has been studied. These do not either occur elsewhere or have not so far been exploited commercially. Attempts have been made to explore the new possible species having medicinal importance especially for veterinary and to grow them in suitable areas so as to meet national industrial demands. The present paper deals with the traditional uses of 100 plant species employed in ethno-medicine and ethno-veterinary practice in Uttarakhand

Quantitative assessment and antibacterial activity of Origanum vulgare L.

Biodiversity, which twenty years ago was considered unimportant by most ecologists, has now been shown to impact significantly upon many aspects of ecosystem functioning. Diversity must now be added to the list of factors — including species composition, disturbance regime, soil type and climate — that influence ecosystem functioning. The recent knowledge of the importance of biodiversity highlights an under-appreciated truth — although society is dependent on natural and managed ecosystems for goods and services that are essential for human survival, we know all too little about how ecosystems work. Origanum vulgare L. is one of the important ethno medicinal plants, are found spread over to sub-temperate forest zone. They are of Ayurvedic importance and have trade value as well. Due to over exploitation and habitat degradation they are now turning into a rare species. Threat assessments of this species revealed that they are vulnerable in study area under reference. Their dominance too was found less as compare to other species. Their diversity profile in study areas also went down. Origanum vulgare L. has antimicrobial activities but Becillus subtillis, Pseudomonas aereuguinosa, Staphylococcus aureus and Escherchia coli bacteria were shown to be proactive. Due to fast growing urbanization of life, people are being attracted towards use of natural products and as such utility of such plants are gaining ground. Thus the need is to protect, promote and conserve such natural resources to have advantage of biodiversity conservation.Â

Photosensitivity of Graphene Quantum Dots Dispersed Polyvinyl Butyral Nanocomposites

775-778The development of optically active polymer composites continues to be the research interest in the field of applied science. A polymer composite composed of polyvinyl butyral (PVB)/ Graphene Quantum Dots (GQD) that demonstrated significant photosensitivity has been studied in this work. A systematic influence of GQD on the photosensitivity to bandgap variation is observed. The surface morphology of loaded nano entities in the composites and their surface roughness was examined by TEM and AFM analysis

Photosensitivity of Graphene Quantum Dots Dispersed Polyvinyl Butyral Nanocomposites

The development of optically active polymer composites continues to be the research interest in the field of applied science. A polymer composite composed of polyvinyl butyral (PVB)/ Graphene Quantum Dots (GQD) that demonstrated significant photosensitivity has been studied in this work. A systematic influence of GQD on the photosensitivity to bandgap variation is observed. The surface morphology of loaded nano entities in the composites and their surface roughness was examined by TEM and AFM analysis

A spectroscopic analysis of the chemically peculiar star HD207561

In this paper we present a high-resolution spectroscopic analysis of the chemically peculiar star HD207561. During a survey programme to search for new roAp stars in the Northern hemisphere, Joshi et al. (2006) observed significant photometric variability on two consecutive nights in the year 2000. The amplitude spectra of the light curves obtained on these two nights showed oscillations with a frequency of 2.79 mHz [P~6-min]. However, subsequent follow-up observations could not confirm any rapid variability. In order to determine the spectroscopic nature of HD207561, high-resolution spectroscopic and spectro-polarimetric observations were carried out. A reasonable fit of the calculated Hbeta line profile to the observed one yields the effective temperature (Teff) and surface gravity (log g) as 7300 K and 3.7 dex, respectively. The derived projected rotational velocity (vsin i) for HD207561 is 74 km/sec indicative of a relatively fast rotator. The position of HD207561 in the H-R diagram implies that this is slightly evolved from the main-sequence and located well within the delta-Scuti instability strip. The abundance analysis indicates the star has slight under-abundances of Ca and Sc and mild over-abundances of iron-peak elements. The spectro-polarimetric study of HD207561 shows that the effective magnetic field is within the observational error of 100 gauss (G). The spectroscopic analysis revealed that the star has most of the characteristics similar to an Am star, rather than an Ap star, and that it lies in the delta-Scuti instability strip; hence roAp pulsations are not expected in HD207561, but low-overtone modes might be excited.Comment: 8 pages, 7 figures, 3 tables. Accepted for pubblication in MNRA

Pain management after elective craniotomy: A systematic review with procedure-specific postoperative pain management (PROSPECT) recommendations.

BACKGROUND Pain after craniotomy can be intense and its management is often suboptimal. OBJECTIVES We aimed to evaluate the available literature and develop recommendations for optimal pain management after craniotomy. DESIGN A systematic review using procedure-specific postoperative pain management (PROSPECT) methodology was undertaken. DATA SOURCES Randomised controlled trials and systematic reviews published in English from 1 January 2010 to 30 June 2021 assessing pain after craniotomy using analgesic, anaesthetic or surgical interventions were identified from MEDLINE, Embase and Cochrane Databases. ELIGIBILITY CRITERIA Each randomised controlled trial (RCT) and systematic review was critically evaluated and included only if met the PROSPECT requirements. Included studies were evaluated for clinically relevant differences in pain scores, use of nonopioid analgesics, such as paracetamol and NSAIDs, and current clinical relevance. RESULTS Out of 126 eligible studies identified, 53 RCTs and seven systematic review or meta-analyses met the inclusion criteria. Pre-operative and intra-operative interventions that improved postoperative pain were paracetamol, NSAIDs, intravenous dexmedetomidine infusion, regional analgesia techniques, including incision-site infiltration, scalp nerve block and acupuncture. Limited evidence was found for flupirtine, intra-operative magnesium sulphate infusion, intra-operative lidocaine infusion, infiltration adjuvants (hyaluronidase, dexamethasone and α-adrenergic agonist added to local anaesthetic solution). No evidence was found for metamizole, postoperative subcutaneous sumatriptan, pre-operative oral vitamin D, bilateral maxillary block or superficial cervical plexus block. CONCLUSIONS The analgesic regimen for craniotomy should include paracetamol, NSAIDs, intravenous dexmedetomidine infusion and a regional analgesic technique (either incision-site infiltration or scalp nerve block), with opioids as rescue analgesics. Further RCTs are required to confirm the influence of the recommended analgesic regimen on postoperative pain relief