Estimation of Compressional Wave Speed in Marine Sediments using Biot Stoll Model and Buckinghams Grain shearing Model

Acoustic properties of seafloor sediments can be estimated using theoretical models by giving geophysical properties of sediments as inputs to the respective models. Empirical relations connecting the geophysical and geoacoustic properties are available in literature. In this study an experimental assessment of two such theoretical models viz., Biot-Stoll model (BSM), a poro-elastic model and the Buckingham’s grain shearing (GS) model, a visco-elastic model is done by estimating the compressional wave speed. Compressional wave speed is measured using in-house developed sediment velocimeter and is compared with the speed estimated using both the models and a regression analysis was done. It was observed that the Coefficient of determination R2 for BSM and GS model are 0.769 and 0.729, respectively. It shows that once the constants used in GS model are evaluated for the Indian waters, then it can be used to estimate the acoustic properties of sediments

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Production of Bacterial Cellulose from Acetobacter Species and Its Applications – A Review

Bacterial cellulose (BC) is a natural polymer secreted as a protective cell covering of certain bacterial species. In contrary to plant cellulose, BC possesses some unique features like high moisture-holding capacity, high durability, high liquid absorbing capabilities, biostability, and biodegradability, makes BC an excellent raw material in wide-ranging areas like biomedical, food, agriculture, paper, textile industries and electronics. The main objective of this review is to discuss various aspects of BC production (different sources for bacterial strain isolation, culture media and, its alternatives also major culture techniques). In addition, various applications of BC are also reviewed

Controlled assembly and solution observation of a 2.6 nm polyoxometalate super tetrahedron cluster: [KFe₁₂(OH)₁₈(-1,2,3-P₂W₁₅O₅₆)₄]²⁹–

A nanoscale Fe<sup>III</sup>-substituted polyoxotungstate [KFe<sub>12</sub>(OH)<sub>18</sub>(-1,2,3-P<sub>2</sub>W<sub>15</sub>O<sub>56</sub>)<sub>4</sub>]<sup>29</sup>– is synthesized starting from the trilacunary {P<sub>2</sub>W<sub>15</sub>} Dawson cluster and [Fe<sub>3</sub>(µ<sub>3</sub>-O)(CH<sub>2</sub>CHCOO)<sub>6</sub>(H<sub>2</sub>O)<sub>3</sub>]<sup>1+</sup> to give a 2.6 nm tetrahedral cluster species and the 16 kDa cluster can be directly observed in solution as revealed by mass spectrometry studies

Organic-soluble lacunary {M-2(P2W15)(2)} polyoxometalate sandwiches showing a previously unseen alpha beta beta alpha isomerism

New polyoxometalate `sandwiches' have been formed where two P2W15O56](12-)lacunary Dawson clusters encapsulate two transition metal ions to give clusters with the general formula M-2(II)(P2W15O56)(2)](20-) (where M = Mn, Co, and Ni respectively), Fe-2(III)(P2W15O56)(2)](18-), and Cu-4(II)(P2W15O56)2](16-). The Mn, Co, and Ni clusters exhibit a hitherto unseen alpha beta beta alpha isomeric geometry and all five compounds are associated with tetrabutylammonium cations which allow for their dissolution in non-aqueous solvent

Amphiphilic properties of dumbbell-shaped inorganic–organic–inorganic molecular hybrid materials in solution and at an interface

Five novel dumbbell-shaped polyoxometalate (POM)-based inorganic-organic-inorganic molecular hybrids are investigated both in polar solvents and at interfaces for potential amphiphilic properties, which are compared with those of conventional surfactants. These hybrids with the general formula {P(2)V(3)W(15)}(2)-bis(TRIS)-linker are formed by linking two Wells Dawson-type clusters, [P(2)V(3)W(15)O(62)](9-), with different linear bis(TRIS) linker ligands between the two TRIS moieties. Laser light scattering (LLS) studies reveal the presence of self-assembled vesicular structures in water/acetone mixed solvents, and the vesicle size increases with increasing acetone content, suggesting a charge-regulated process. The elastic constants, which are used to calculate the bending energy during vesicle formation, reveal that the organic ligands play an important role in determining the self-assembly process and that the hybrids do demonstrate amphiphilic behavior at the water/air interface. Furthermore, it is shown that some of the hybrids form monolayers at the interface, with an average molecular area that can be correlated with their organic linkers, as determined from their pi-A isotherms. Finally, the hybrids not only display amphiphilic behavior akin to that of a surfactant but also exhibit an unusually high entropy contribution to vesicle formation as a result of their unique large, polar head groups, complex organic linkers, and their special molecular architectures as well as because of the involvement of the amphiphilic tetrabutylammonium (TBA) counterions

Assembly of modular asymmetric organic-inorganic polyoxometalate hybrids into anisotropic nanostructures

Three organic-inorganic hybrid Mn-Anderson polyoxometalates (POMs), with both symmetrical and asymmetrical appended groups, have been synthesized, identified using electrospray mass spectrometry, and isolated using an approach that allows the three AA, BB, and AB compounds to be structurally characterized. Investigation of the self-assembly of the hybrids on hydrophilic surfaces reveals the formation of nanofibres with characteristics that reflect the nature of the substitution of the POM yielding a route to the programmed assembly of anisotropic hybrid nanostructure

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Not AvailableParasites of the genus Perkinsus predominantly infect bivalves, and two species among them, P. olseni and P. marinus, are notifiable to OIE. P. olseni infections are known to cause extensive damage to wild as well as farmed bivalves globally with enormous implications to its fishery. Consequent to the initiation of a surveillance programme for aquatic animal diseases in India, Perkinsus infections were observed in many species of bivalves. The present paper describes P. olseni infections in the short neck yellow clam, Paphia malabarica from the southwest coast of India. Diagnosis of the parasite was carried out using Ray's Fluid Thioglycollate Medium culture, histology, in-situ hybridisation and molecular taxonomy. Pathology of infection and development of zoospores is also described. This forms the first report of a P. olseni infection in P. malabarica. High prevalence and intensity of infection of Perkinsus in clams raises concerns, as clam reserves in this geographical area sustain fisheries and the livelihoods of local fishing communitiesNot Availabl