Reflection of piezothermoelastic waves from the charge and stress free boundary of a transversely isotropic half space

The present paper concentrates on the study of propagation and reflection characteristics of waves from the stress free, thermally insulated/isothermal boundary of a piezothermoelastic half space. The non-classical (generalized) theories of linear piezo-thermoelasticity have been employed to investigate the problem. In the two-dimensional model of the transversely isotropic piezothermoelastic medium, there are three types of plane waves quasi-longitudinal (QL), quasi-transverse (QT) and thermal wave (T-mode), whose velocities depend on the angle of incidence and frequency. These waves are dispersive in character and are also affected by piezoelectric as well as pyroelectric properties of the materials. The low and high frequency approximations for the speeds of propagation and the attenuation coefficients of these waves have been obtained. The quasi-longitudinal (QL), quasi-transverse (QT) and thermal wave (T-mode) incident cases at the stress free, thermally insulated or isothermal open circuit boundary of a transversely isotropic piezothermoelastic half space are considered to discuss the reflection characteristics of various waves. The amplitude ratios of reflected waves to that of incident one in each case have been obtained. The special cases of normal and grazing incidence are also derived and discussed. Finally, the numerical computations of reflection coefficients are carried out for cadmium Selenide (CdSe) material by using Gauss elimination procedure. In addition the phase velocities and attenuation coefficients are also computed along various directions of wave propagation. The obtained results in each case are presented graphically.     

Novel stereo controlled glycosylation of 1,2,3,4,6-penta-o-acetyl-β-d-glucopyranoside using MgO–ZrO2 as an environmentally benign catalyst

Glycosylation reactions are most commonly encountered in nature. Synthetically, glycosylations are carried out with Lewis acid catalysts or mineral acids. However an environmental threat associated with catalysts has encouraged process modification by alternative development of solid catalysts based glycosylation reactions, which are commercially viable as well. In this contribution comparative study of glycosidic bond formation of 1,2,3,4,6-penta-o-acetyl-β-d-glucopyranoside with various alcohols over variety of reaction promoters/catalyst like p-toluene sulphonic acid, HCl, H₂SO₄ and MgO–ZrO₂ were taken up to evaluate the performance of this potential promoter/catalysts systems. The best catalyst for the selective synthesis of alkyl-β-d-glucopyranosides was MgO–ZrO₂ which remains active upto three runs. This replacement of homogeneous acid catalysts by heterogeneous base catalyst shows alkyl-β-d-glucopyranoside as major product at comparatively low temperature range. The effects of variety of parameters were studied in a batch reactor. The mechanism of the reaction over basic mixed metal oxide at 363 K is put forth.     

Close-packed noncircular nanodevice pattern generation by self-limiting ion-mill process

We describe a self-limiting, low-energy argon-ion-milling process that enables noncircular device patterns, such as squares or hexagons, to be formed using precursor arrays of uniform circular openings in poly(methyl methacrylate) defined using electron beam lithography. The proposed patterning technique is of particular interest for bit-patterned magnetic recording medium fabrication, where square magnetic bits result in improved recording system performance. Bit-patterned magnetic medium is among the primary candidates for the next generation magnetic recording technologies and is expected to extend the areal bit density limits far beyond 1 Tbit/in(2). The proposed patterning technology can be applied either for direct medium prototyping or for manufacturing of nanoimprint lithography templates or ion beam lithography stencil masks that can be utilized in mass production.     

Galectin‐3‐Binding Glycomimetics that Strongly Reduce Bleomycin‐Induced Lung Fibrosis and Modulate Intracellular Glycan Recognition

Discovery of glycan‐competitive galectin‐3‐binding compounds that attenuate lung fibrosis in a murine model and that block intracellular galectin‐3 accumulation at damaged vesicles, hence revealing galectin‐3–glycan interactions involved in fibrosis progression and in intracellular galectin‐3 activities, is reported. 3,3′‐Bis‐(4‐aryltriazol‐1‐yl)thiodigalactosides were synthesized and evaluated as antagonists of galectin‐1, ‐2, ‐3, and ‐4 N‐terminal, ‐4 C‐terminal, ‐7 and ‐8 N‐terminal, ‐9 N‐terminal, and ‐9 C‐terminal domains. Compounds displaying low‐nanomolar affinities for galectins‐1 and ‐3 were identified in a competitive fluorescence anisotropy assay. X‐ray structural analysis of selected compounds in complex with galectin‐3, together with galectin‐3 mutant binding experiments, revealed that both the aryltriazolyl moieties and fluoro substituents on the compounds are involved in key interactions responsible for exceptional affinities towards galectin‐3. The most potent galectin‐3 antagonist was demonstrated to act in an assay monitoring galectin‐3 accumulation upon amitriptyline‐induced vesicle damage, visualizing a biochemically/medically relevant intracellular lectin–carbohydrate binding event and that it can be blocked by a small molecule. The same antagonist administered intratracheally attenuated bleomycin‐induced pulmonary fibrosis in a mouse model with a dose/response profile comparing favorably with that of oral administration of the marketed antifibrotic compound pirfenidone.     

Modelling the effects of cutting parameters on residual stresses in hard turning of AISI H11 tool steel

In the present study, an attempt has been made to model the effect of cutting parameters (cutting speed, feed, depth of cut and nose radius) on residual stresses in hard turning of AISI H11 tool steel using ceramic tools. The machining experiments were conducted based on response surface methodology and using the Box–Behnken design of experiments. Residual stresses were determined using the X-ray diffraction technique, and the experimental results were investigated using analysis of variance. The results indicated that the feed and depth of cut are the main influencing factor on residual stresses whereas cutting speed and nose radius are having mild impact on residual stresses. The results show that it is possible to produce tailor-made residual stress levels by controlling the tool geometry and cutting parameters. The aim of this paper is to introduce an original approach for the prediction of residual stresses.     

Calcium carbonate (CaCO3) nanoparticle filled polypropylene: Effect of particle surface treatment on mechanical,thermal, and morphological performance of composites

The present study was aimed to see the effect of surface treatment on nanocomposites with different fatty acids (stearic acid and oleic acid) having two different coupling agents (titanate and silane). Nanocomposites were prepared via melt mixing in Haake 90 twin screw extruder. The characterization of nanocomposites had been carried out using various advance analytical techniques such as dynamic mechanical analysis, thermogravimetric analysis, heat distortion temperature, melt flow index, and scanning electron microscopy. The strength and stiffness were also improved with the incorporation of maleic‐anhydride grafted ethylene propylene rubber in PP/Nano‐CaCO₃ nanocomposites. The tensile, flexural, and impact strength properties of PP/MA‐g‐EPR/treated‐CaCO₃ and untreated nanocomposites were determined. These studies revealed that stearic acid treated nanofiller filled composites had better properties than those of untreated and oleic acid treated nanofiller filled composites. The SEM studies demonstrated that the dispersion and distribution of Nano‐CaCO₃ (nCaCO₃) particles within the polypropylene matrix were dependent on the nature of surface treating agents. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Factors associated with body temperature of healthy Holstein dairy cows during the first 10 days in milk

In this prospective observational study rectal and vaginal temperature of 82 (26 primiparous, 56 multiparous) early post-partum healthy dairy cows that calved without intervention within 3 months and did not show clinical signs of infectious and metabolic diseases were continuously measured and evaluated for associations with plausible factors during the first 10 days in milk (DIM). During May, June and July mean (±SD) temperature humidity index (THI) was 60·1±5; 66·8±5·6 and 74·2±4·3, respectively. Environmental conditions had a negligible effect on body temperature (BT) during May (P<0·05). During June and July, however, the ambient temperature and THI influenced BT (P<0·05). Furthermore, plausible factors like parity, DIM, months and time of day had an effect on BT (P<0·05). Overall, primiparous cows demonstrated 0·2°C greater BT during the first 10 DIM than multiparous cows. The effect of parity, however, on BT varied between DIM according to month (P<0·001). During this 3-month study period all cows demonstrated BT rhythms; however, the amplitude of BT increased from May to July (0·3 to 0·7°C). A greater proportion of the vaginal temperature measurements exceeded a threshold tested (≥39·5°C) during July (46·8%) than in June (33·9%) and May (19·3%). Overall the percentage of BT values above a threshold of ≥39·5°C was lower during the period 6.00-10.00 compared with the remaining 20 h (P<0·05). Therefore this study concluded that the BT of healthy post-partum dairy cows during the period 1-10 DIM post partum is greater compared with the reference range of 38·6 to 39·5°C reported by others and is influenced by parity, DIM, time of day and THI. When the association between BT and THI increased the reliability of threshold levels of BT (≥39·5°C) decreased.     

Design and optimization of color lookup tables on a simplex topology

An important computational problem in color imaging is the design of color transforms that map color between devices or from a device-dependent space (e.g., RGB/CMYK) to a device-independent space (e.g., CIELAB) and vice versa. Real-time processing constraints entail that such nonlinear color transforms be implemented using multidimensional lookup tables (LUTs). Furthermore, relatively sparse LUTs (with efficient interpolation) are employed in practice because of storage and memory constraints. This paper presents a principled design methodology rooted in constrained convex optimization to design color LUTs on a simplex topology. The use of n simplexes, i.e., simplexes in n dimensions, as opposed to traditional lattices, recently has been of great interest in color LUT design for simplex topologies that allow both more analytically tractable formulations and greater efficiency in the LUT. In this framework of n-simplex interpolation, our central contribution is to develop an elegant iterative algorithm that jointly optimizes the placement of nodes of the color LUT and the output values at those nodes to minimize interpolation error in an expected sense. This is in contrast to existing work, which exclusively designs either node locations or the output values. We also develop new analytical results for the problem of node location optimization, which reduces to constrained optimization of a large but sparse interpolation matrix in our framework. We evaluate our n -simplex color LUTs against the state-of-the-art lattice (e.g., International Color Consortium profiles) and simplex-based techniques for approximating two representative multidimensional color transforms that characterize a CMYK xerographic printer and an RGB scanner, respectively. The results show that color LUTs designed on simplexes offer very significant benefits over traditional lattice-based alternatives in improving color transform accuracy even with a much smaller number of nodes.     

Antidyslipidemic and Antioxidant Effects of Novel Lupeol-Derived Chalcones

A series of Lupeol-based chalcones have been synthesized aiming to enhance the therapeutic efficacy of parent compound, the novel compounds were evaluated for their antidyslipidemic activity in triton-WR 1339 induced hyperlipidemic rats. Among the ten synthesized chalcones, the most active K4, K8, and K9 reversed the plasma levels of TC by (24, 25, 27 %), phospholipid by (25, 26, 25 %) and triacylglycerol by (27, 24, 24 %) respectively. In addition, the compounds showed significant in vitro antioxidant activity. The lipid lowering activity of these compounds were mediated through lipoprotein lipase activation (12–21 %) and enhanced post-heparin lipolytic activity (15–16 %). The compounds also displayed noteworthy inhibitory effect on 3-hydroxy-3-methyl-glutaryl reductase activity (in vitro). The in vitro effect of the most active compounds on MDI-induced adipogenesis using 3T3-L1 preadipocytes at 10 and 20 μM concentrations showed significant inhibition (20–32 %) of adipogenesis.     

Screening and optimization through response surface methodology for synthesis of pH,temperature and salt‐sensitive Aloe vera–acrylic acid‐based biodegradable hydrogel: Its evaluation as dye adsorbent

A pH‐, temperature‐, and salt‐sensitive hydrogel was synthesized using acrylic acid (AA) as monomer, natural polysaccharide Aloe vera as backbone, ammonium persulfate–N,N‐methylene‐bis‐acrylamide as an initiator–crosslinker system via free‐radical grafting method. Different parameters such as treatment time, temperature, amount of solvent, pH, concentration of initiator, crosslinker and monomer were screened using Plackett–Burman design (PBD). The PBD showed that pH, monomer, and crosslinker were taken as the most important variables, which highly impact the swelling behavior of the synthesized hydrogel as compared to the rest of the variables. The half normality plot was used to find the significant parameters regarding the swelling capacity of the hydrogel. The center composite design was used for further optimizing the important variables like pH, monomer, and crosslinker. The pH and monomer interaction on percentage swelling (Ps) was studied through the analysis of variance model. Synthesized hydrogel Av‐cl‐poly(AA) was characterized by different techniques such as Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction, and scanning electron microscopy (SEM). The effect of different chloride salt solutions like KCl, NaCl, BaCl₂, FeCl₃, and CoCl₃·6H₂O on Ps of synthesized Av‐cl‐poly(AA)‐based hydrogel was also studied. Biodegradation studies of the synthesized polymer were also carried out using soil burial and vermicompositing methods. Biodegradation of semi interpenetrating polymer network (SIPN) was confirmed by SEM and FTIR techniques. Synthesized SIPN was also used as a device for the removal of dye and was found very effective as an adsorbent. POLYM. ENG. SCI., 59:2323–2334, 2019. © 2019 Society of Plastics Engineers