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Two-dimensional flexural backstripping and thermal modelling (assuming laterally variable stretching) is applied along regional depth-converted interpreted seismic profiles from the Laxmi Basin in the Arabian Sea. Results from reverse post-rift flexural modelling reveal considerable basin-wide subsidence in response to the crustal geodynamics during and after the last extensional phase. Unloading of the stratigraphy allows us to estimate the degree of laterally varying extension, assuming thermal subsidence and pure shear. High degrees of extension in the basin centre predict considerable water depths at the time of rift cessation, consistent with deep drilling data. We suggest that regional extension prior to Paleocene time could have fuelled variable subsidence in the Laxmi Basin but that extension is less than seen in typical oceanic lithosphere. Volcanic loading by the seamounts shortly after extension has flexed the basin and implies an effective elastic thickness (Te) at that time of ∼6 km. Reconstruction of the seamount top near sea level at the end of emplacement indicates no major transient uplift potentially linked to the Deccan mantle plume activity. Backstripping of post-rift sediments from interpreted seismic profiles supports the presence of a hyper-thinned crust underneath the Laxmi Basin, with β factors reaching >7 in the basin centre and ∼3 across much of the basin width. Computations of decompacted sediment accumulation rates in light of new results from IODP Expedition 355 show that basin sedimentation peaked during early–middle Miocene time, possibly coeval with uplift and erosion of the Himalayan–Tibetan Plateau driven by strong summer monsoon rains.
2016+112 was observed simultaneously with the European VLBI Network (EVN) and MERLIN arrays during the May 1993 joint EVN-MERLIN session at λ18 cm. Common elements to both arrays included the Jodrell Bank 76-m Lovell and 32-m Cambridge telescopes. In order to simultaneously map the entire 4 arcsec2 field of view, various wide-field mapping techniques were employed (see Garrett et al. 1994b).
A high gain ZnO nanowire (NW) based photodetector was fabricated, which was sensitive to photoexcitation at or below 370 nm corresponding to the band-edge of ZnO. At an incident wavelength of 370 nm and a bias field of 5 kV/cm, the maximum responsivity was over 105 A/W corresponding to an extremely high photoconductive gain of the order of 106. Through this work we provide experimental evidence of the role of surface and defects in carrier dynamics, resulting in enhanced photoresponse. Using intensity and temperature dependence of the rise and decay rates of photocurrent, we present a detailed analysis that provides an estimate of the activation energies of carrier trapping mechanisms.
The thyroid gland is removed en bloc during laryngectomy. There are no objective criteria for deciding the extent of thyroid gland resection in primary hypopharyngeal cancer cases. The present study aimed to determine the incidence of thyroid gland involvement in hypopharyngeal cancer and identify the various predictors of this involvement.
This paper reports a retrospective analysis of 358 patients with hypopharyngeal cancer, who underwent total laryngectomy with partial or total pharyngectomy at Tata Memorial Hospital, Mumbai between 2004 and 2010.
The mean age of this population was 61 years. The pyriform sinus was the most common hypopharyngeal subsite involved (in 89 per cent of cases). Most patients underwent hemi-thyroidectomy as part of their surgery. The thyroid gland was involved in only 13 per cent of cases.
Thyroid gland involvement is not common in hypopharyngeal cancer. Cases that involved the post-cricoid area, subglottic extension, extralaryngeal spread or prior tracheostomy were associated with a higher risk of thyroid gland involvement. Ipsilateral thyroidectomy is sufficient in most patients undergoing surgery (laryngectomy with partial or total pharyngectomy) for hypopharyngeal cancers.
Morinda reticulata Gamble and Morinda umbellata Linn. (Rubiaceae) are medicinally important climbers distributed as a mixed population in southern Western Ghats of India. A close morphological resemblance of these two species misleads the harvester in the identification of plant parts for preparation of herbal medicines. Though both species contain anthraquinone derivatives and share common medicinal properties for treating stomach disorders, each of these species has unique curative properties for treating selective diseases. Conventional methods are not reliable for identification of these species due to similarities in morphology. Thus, misidentification often leads to the deterioration of the quality of medicines. Thus, authentication utilizing conserved gene sequences in the chloroplast genome of these two Morinda spp. has been attempted for precise identification. Here we report the use of two barcoding genes (maturase kinase and ribulose 1,5-bisphosphate carboxylase large subunit) to distinguish M. reticulata and M. umbellata based on single nucleotide polymorphism. The present findings can be used for authenticating leaf samples of M. reticulata and M. umbellata.
Highly dispersed metal oxide/molecular sieve catalysts can be prepared through modification of metallosilicate molecular sieves. The resulting materials have been shown to exhibit enhanced catalytic activities for selected reactions. The metallosilicates examined include the gallosilicates, iron (ferri-) silicates and cobalt silicates. The size of the metal oxide particles as well as their location (in the pores or on the surface) can be controlled through post-synthesis methods. Thermal or mild hydrothermal treatment of the metallosilicate produces a highly dispersed metal oxide phase, while higher temperatures or longer treatment causes the metal oxide to migrate and form larger agglomerates of the metal oxide phase. The size of these agglomerates are strongly dependent on the conditions of hydrothermal treatment. Dispersion, location and agglomeration of the metal oxide phase have been characterized for the iron silicates using both physical and catalytic techniques. The magnetic properties of the iron silicates are described.
Contrary to existing models, strengths need not be a strong function of porosity for intermediate density, brittle materials. Flaw sizes can remain small (<50μm) if the void space is distributed uniformly in minimum dimension pores. For RBSN, fracture toughness decreases linearly with porosity for 0< porosity <40%. Strains to failure and specific strengths of these materials are higher than fully dense counterparts.
Previously we reported on a theoretical treatment of the influence on freezing rate of sudden changes in translation rate in the Bridgman-Stockbarger technique . This has now been extended to consideration of a linear ramped translation rate and an oscillatory freezing rate. Oscillations above a few hertz are found to be highly damped in smalldiameter apparatus.
An experimental test was made of the theoretical predictions for a sudden change of translation rate. MnBi-Bi eutectic was solidified with current induced interface demarcation.The experimental results correspond reasonably well with theory if the silica ampoule wall is assumed either (1) to contribute only a resistance to heat exchange of sample with the furnace wall, or (2) to transmit heat effectively in the axial direction by radiation.
In an attempt to explain the fact that a finer microstructure is obtained in space, MnBi-Bi microstructure is being determined when the freezing rate is rapidly increased or decreased. Preliminary results indicate that fiber branching does not occur as readily as does fiber termination.
Selenium thin films (350 nm) deposited from a 0.01 M solution of Na2SeSO3 of pH 4.5 maintained at 10 °C for 13 h, have been used as a source of selenium vapour for reaction with vacuum deposited Ag thin film on chemically deposited Sb2S3+Ag layers. When a stack of Sb2S3+Ag is heated in contact with Se film, AgSbSe2 is formed through solid state reaction of Sb2S3 and Ag2Se. The latter is formed at 80°C through the reaction of Ag-film in Se-vapour. This thin film is photoconductive and p-type. The optical band gap is nearly 1 eV and dark conductivity, 10-3 Ω-1cm-1. This thin film has been incorporated to form a photovoltaic structure, SnO2:F-(n)CdS:In-(i)Sb2S3-(p)AgSbSe2-silver print. Voc> 400 mV and Jsc>12 mA/cm2 have been observed in this under an illumination intensity of 1 kWm-2.
Hydroxyapatite formed from low temperature setting calcium phosphate cements (CPC) are currently been used for various orthopaedic applications. CPCs are attractive candidates for the development of scaffolds for bone tissue engineering, since they are moldable, resorbable, set at physiological temperature without the use of toxic chemicals, and can be processed in an operating room setting. However they may have mechanical disadvantages which seriously limit them to non-load bearing orthopaedic applications. The aim of the present study was to develop composites from polyphosphazenes and calcium deficient hydroxyapatite precursors to form poorly crystalline hydroxyapatite-polymer composites. Composites were formed from calcium deficient hydroxyapatite precursors (Ca/P – 1.5, 1.6) and biodegradable polyphosphazenes, poly[bis(ethyl alanato)phosphazene] (PNEA) and poly[(50%ethyl alanato) (50%methyl phenoxy)phosphazene] (PNEA50mPh50) at physiological temperature. The results demonstrated that poorly crystalline hydroxyapatite that resembled the mineral component of bone was formed in the presence of biodegradable polyphosphazenes. The surface morphology of all the four composites was identical with a porous microstructure. The composites supported the adhesion and proliferation of osteoblast like MC3T3-E1 cells making them potential candidates for bone tissue engineering.
Antimony sulfide thin films (300 nm) have been deposited on glass substrates at 1–10°C from chemical bath. When heated these become crystalline and photoconductive with optical band gap (direct) of 1.7 eV. Thin films formed from chemical baths containing SbCl3 and sodium selenosulfate are of mixed phase Sb2O3/Sb2Se3, which when heated in the presence of Se-vapor converts to single phase Sb2Se3 film with optical band gap of 1.1 eV. Such films possess dark conductivity of 10-8 ohm-1cm-1 and show photosensitivity of two orders. Reaction of Sb2S3-CuS in nitrogen at 400°C produces crystalline, photoconductive p-type CuSbS2 with optical band gap (direct) of 1.5 eV. By controlling the deposition and heating condition, (i)Sb2S3-(p)CuSbS2 layer is formed, which is utilized in a photovoltaic structure, (n)CdS:In-(i)Sb2S3-(p)CuSbS2, with a Voc of 345 mV and Jsc 0.18 mA/cm2 under 1 kW m-2 tungsten halogen illumination. In the case of a structure, CdS:Cl-Sb2S3-Cu2-xSe, Voc of 350 mV and Jsc of 0.5 mA/cm2 are observed.
We have previously demonstrated that blending biodegradable glycine co-substituted polyphosphazenes with poly(lactide-co-glycolide) (PLAGA) results in novel biomaterials with versatile properties. The study showed that the degradation rate of polyphosphazene/PLAGA blends can be effectively controlled by varying the blend composition while at the same time the degradation products of polyphosphazenes effectively neutralized the acidic degradation products of PLAGA. In the present study, novel blends of hydrophobic, biodegradable polyphosphazene, poly[bis(ethyl alanato) phosphazene] (PNEA) and PLAGA (LA: GA; 85:15) were developed as candidates for bone tissue engineering applications. Two different blend compositions were developed by blending PNEA and PLAGA having weight ratios of 25:75 (Blend-1) and 50:50 (Blend-2) by the mutual solvent technique using dichloromethane as the solvent. The miscibility of the blends was determined using differential scanning calorimetry (DSC), fourier transform-infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Surface analysis of the blends by SEM revealed a smooth uniform surface for Blend-1, whereas Blend-2 showed evidence of phase separation. PNEA is not completely miscible with PLAGA, as evidenced from DSC and FT-IR measurements. The osteocompatibilities of Blend-1 and Blend-2 were compared to those of parent polymers by following the adhesion and proliferation of primary rat osteoblast cells on two dimensional (2-D) polymer and blend films over a 21 day period in culture. Blend films showed significantly higher cell numbers on the surface compared to PLAGA and PNEA films.
The term “microfabrication” has been used primarily as an acronym for silicon-based device fabrication. Recent developments in ceramic processing technology have resulted in cost-effective, scalable options of ceramic microfabrication that offer the potential for fabrication of devices with a number of advantages over silicon-based microdevices for specific applications. These advantages include the ability to fabricate devices with three-dimensional architecture, high-temperature operation up to 1200°C, porous layers for gas diffusion, and textured substrate properties for specific applications through wider materials selection. Processing routes for these ceramic microdevices with three-dimensional architecture include established processes such as tape casting, laser machining, lamination and sintering, or new processes such as reaction bonding and lost-mold techniques. The ability to fabricate three-dimensional feature geometries allows the application of these ceramic microfabrication techniques for device fabrication targeted at a number of applications such as point-of-use high purity gas generation, microchannel devices, microreactors, fiber-optic connectors and heat-pipes for microelectronics.
High fluences of low energy Ge+ ions were implanted into Si matrix. We have also deposited Ge and SiO2 composite films by using the Atom beam sputtering (ABS). The as implanted/as-deposited films were irradiated by Swift Heavy Ions (SHI) with various energies and fluences. These pristine and irradiated samples were subsequently characterized by XRD and Raman to understand the crystallization behavior. Raman studies of the films indicate the formation of Ge crystallites as a result of SHI irradiation. Glancing angle X-ray diffraction results also confirm the presence of Ge crystallites in the irradiated samples. Moreover, the crystalline nature of Ge improves with an increase in fluence. Rutherford back scattering was used to quantify the concentration of Ge in SiO2 matrix and the film thickness. These detailed results have been discussed and compared with the ones available in literature. The basic mechanism for crystallization induced by SHI in these films will be presented.