Preparation of pure boehmite, alpha-Al2O3 and their mixtures by hydrothermal oxidation of aluminium metal

A hydrothermal oxidation process for preparing pure boehmite, alpha-Al2O3, and their mixtures by oxidation of pure aluminum metal is described, and the reaction mechanisms involved are identified. SEM images are presented which show distinct morphologies of boehmite, alpha-Al2O3, and boehmite + alpha-Al2O3 phases. Near sperical shapes of alpha-Al2O3 powder phases are obtained at 550 C with 30 percent volume of fill

Electromechanical and Dynamic Characterization of In-House-Fabricated Amplified Piezo Actuator

A diamond-shaped amplified piezo actuator (APA) fabricated using six multilayered piezo stacks with maximum displacement of 173 μm at 175V and the amplification factor of 4.3. The dynamic characterization of the actuator was carried out at different frequencies (100 Hz–1 kHz) and at different AC voltages (20V–40V). The actuator response over this frequency range was found neat, without attenuation of the signal. Numerical modeling of multilayered stack actuator was carried out using empirical equations, and the electromechanical analysis was carried out using ABAQUS software. The block force of the APA was 81 N, calculated by electromechanical analysis. This is similar to that calculated by dynamic characterization method

Comparative assessment of air pollution tolerance index (APTI) in the industrial (Rourkela) and non industrial area (Aizawl) of India: An ecomanagement approach

Science for phyto-technologies has got immense application in air pollution science. The present study focuses on the determination of air pollution tolerance indices (APTI) from six common road side plant species growing along industrial (Rourkela) and non industrial area (Aizawl), India. The APTI was determined by synthesizing the four different physiological and biochemical parameters, that is, leaf relative water content (RWC), ascorbic acid content (AA), total leaf chlorophyll (TCh) and pH of leaf extract. The plant species selected for the study were Ficus bengalensis, Mangifera indica, Bougainvillea spectabilis, Psidium guajava, Hibiscus rosa-sinensis and Lantana camara. Reduction in total chlorophyll content and pH was found in the leaf samples of all selected plants collected from Industrial site (Rourkela) when compared with samples from non industrial site (Aizawl) whereas APTI, ascorbic acid and RWC were found to be higher in the plant samples of Industrial site (Rourkela) as compared to non industrial site (Aizawl). On the basis of APTI, F. bengalensis was found to be tolerant (8.64) in industrial site (Rourkela) and M. indica (7.95) in non industrial site (Aizawl). Plant species such as M. indica and B. spectabilis, showing minimum difference in their APTI values may be considered as tolerant for both (industrial and non industrial) sites.Key words: Air pollution tolerance indices (APTI), biochemical parameters, Ficus bengalensis, roadside plants

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Cordyceps spp.: A Review on Its Immune-Stimulatory and Other Biological Potentials

In recent decades, interest in the Cordyceps genus has amplified due to its immunostimulatory potential. Cordyceps species, its extracts, and bioactive constituents have been related with cytokine production such as interleukin (IL)-1ß, IL-2, IL-6, IL-8, IL-10, IL-12, and tumor necrosis factor (TNF)-a, phagocytosis stimulation of immune cells, nitric oxide production by increasing inducible nitric oxide synthase activity, and stimulation of inflammatory response via mitogen-activated protein kinase pathway. Other pharmacological activities like antioxidant, anti-cancer, antihyperlipidemic, anti-diabetic, anti-fatigue, anti-aging, hypocholesterolemic, hypotensive, vasorelaxation, anti-depressant, aphrodisiac, and kidney protection, has been reported in pre-clinical studies. These biological activities are correlated with the bioactive compounds present in Cordyceps including nucleosides, sterols, flavonoids, cyclic peptides, phenolic, bioxanthracenes, polyketides, and alkaloids, being the cyclic peptides compounds the most studied. An organized review of the existing literature was executed by surveying several databanks like PubMed, Scopus, etc. using keywords like Cordyceps, cordycepin, immune system, immunostimulation, immunomodulatory, pharmacology, anti-cancer, anti-viral, clinical trials, ethnomedicine, pharmacology, phytochemical analysis, and different species names. This review collects and analyzes state-of-the-art about the properties of Cordyceps species along with ethnopharmacological properties, application in food, chemical compounds, extraction of bioactive compounds, and various pharmacological properties with a special focus on the stimulatory properties of immunity.This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1G1A1004667), Republic of Korea

Lead-free piezoelectric K0.5Bi0.5TiO3–Bi(Mg0.5Ti0.5)O3 ceramics with depolarisation temperatures up to ~220 C

The properties of K0.5Bi0.5TiO3-rich ceramic solid solutions in the system (1 - x)K0.5Bi0.5TiO3– xBi(Mg0.5Ti0.5)O3 are reported. The highest values of piezoelectric charge coefficient, d33, and field-induced strains are found in compositions located close to a compositional boundary between single-phase tetragonal and mixed tetragonal ? cubic perovskite phases. Maximum d33 values were *150 pC/N for x = 0.03, with positive strains of *0.25 %; the x = 0.04 composition had a d33 * 133 pC/N and strain of 0.35 % (bipolar electric field, 50 kV/ cm, 1 Hz). Depolarisation temperature Td is an important selection criterion for any lead-free piezoelectric for actuator or sensor applications. A Td of *220 C for x = 0.03 is *100 C higher than for the widely reported Na0.5Bi0.5TiO3–BaTiO3 system, yet d33 values and strains are similar, suggesting the new material is worthy of further attention as a lead-free piezoceramic for elevated temperature applications

Origin of the Spin-Orbital Liquid State in a Nearly J=0 Iridate Ba3ZnIr2O9

We show using detailed magnetic and thermodynamic studies and theoretical calculations that the ground state of Ba3ZnIr2O9 is a realization of a novel spin-orbital liquid state. Our results reveal that Ba3ZnIr2O9 with Ir5+ (5d(4)) ions and strong spin-orbit coupling (SOC) arrives very close to the elusive J = 0 state but each Ir ion still possesses a weak moment. Ab initio density functional calculations indicate that this moment is developed due to superexchange, mediated by a strong intradimer hopping mechanism. While the Ir spins within the structural Ir2O9 dimer are expected to form a spin-orbit singlet state (SOS) with no resultant moment, substantial frustration arising from interdimer exchange interactions induce quantum fluctuations in these possible SOS states favoring a spin-orbital liquid phase down to at least 100 mK