Fabrication of a Novel Biocompatible Magnetic Biomaterial with Hyperthermia Potential

Preparation and characterization of a novel biocompatible magnetic biomaterial having hyperthermia potential is reported in this study. Fe³⁺ and Ni²⁺ (2:1) cosubstituted hydroxyapatite nanoparticles were synthesized by simple wet precipitation method followed by freeze‐drying which on heat treatment at 1150°C yielded the above mentioned biocompatible magnetic biomaterial composed of hydroxyapatite and β‐tricalcium phosphate along with nickel ferrite. The product was characterized by X‐ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscope along with composition analysis. The magnetic behavior was analyzed by vibrating sample magnetometer and biocompatibility was assessed by testing the toxicity on Hela cells using MTT assay. The hyperthermia potential of the material was studied using induction heating. The prepared material has the potential to generate sufficient heat that could be easily controlled by magnetic field parameters and amount of sample. Hence, it can be a potential candidate for making implantable thermoseed for hyperthermia treatment.     

Effect of octene content on peroxide crosslinking of ethylene–octene copolymers

Various ethylene–octene copolymers were crosslinked by dicumyl peroxide. Octene content was 16, 20, 30, 35 and 38 wt% and melt flow index was 1 or 3 g/10 min. The concentration of dicumyl peroxide was 0.3, 0.5 and 0.7 wt%. Crosslinking was analyzed by a rubber process analyzer in the temperature range 150–200 °C. Cross‐linkability was evaluated from the real part modulus s'_max versus peroxide level plots as the slope of the line. With decreasing octene content and increasing melt flow index the crosslinkability increased. This was confirmed also by tan δ analysis. The network density was measured by the gel content. A higher gel content was found for melt flow index 3 and low octene content. The melting points T_m and the crystallinities were evaluated by DSC. © 2012 Society of Chemical Industry     

Nanoporous well‐defined reversible addition–fragmentation chain transfer polymer of N‐acrylamido‐l‐tryptophan: synthesis and characterization

A nanoporous polymer with a chiral pendant chain of N‐acrylamido‐l ‐tryptophan was synthesized through a reversible addition–fragmentation chain transfer polymerization process using a dithiobenzoate derivative as chain transfer agent. The polymerization exhibited the usual characteristics of living processes, though slow polymerization rate and low percentage conversion for a chain extension experiment were observed. Depending on the monomer/chain transfer agent ratio, poly(N‐acrylamido‐l ‐tryptophan) with number‐average molecular weights between 640 and 4340 g mol^?1 and molar mass dispersities between 1.10 and 1.24 was obtained, as evidenced from gel permeation chromatography. Scanning electron microscopy images indicated that the polymer was porous. Nitrogen adsorption analysis of the polymer evidenced the presence of mesopores (2–19 nm) associated with micropores (0.45–2 nm) according to the Barrett–Joyner–Halenda method with a specific Brunauer–Emmett–Teller surface area of 22.98 m² g^?1. © 2013 Society of Chemical Industry     

Raman Scattering and Backscattering Studies of Silicon Nanocrystals Formed Using Sequential Ion Implantation

Silicon nanocrystals were produced using a two-stage gold ion implantation technique. The first stage implantation using low energy ions led to the formation of an amorphous Si (a-Si) layer. A subsequent high energy Au irradiation in the second stage was found to produce strained Si NCs. An annealing step at a temperature as low as 500 °C was seen to result in strain free NCs. Higher temperature annealing of the samples was found to result in a growth in size from recrystallization of the a-Si matrix. Raman Scattering, X-Ray diffraction and Rutherford Backscattering Spectrometry have been used to study the effect of annealing on the samples and the size of the Si NCs formed. The data can be well explained using a phonon confinement model with an extremely narrow size distribution. The XRD results are in line with the Raman analysis.     

Bridging two-liquid theory with molecular simulations for electrolytes: An investigation of aqueous NaCl solution

We reexamine the theoretical framework of electrolyte nonrandom two-liquid model and formulate the binary interaction parameters as functions of species diameter ( σ ), effective interaction strength ( ɛ ), the domain radius around the center species ( R ), and the nonrandomness factor ( α ). We show that these quantities can be directly obtained from molecular simulations using aqueous NaCl as the model system. The binary interaction parameters determined from the simulations are consistent with those obtained from regression of experimental data. Our work provides a molecular interpretation of the classical thermodynamic model and shows a way to predict from molecular simulations the binary interaction parameters for use in process industries. © 2019 American Institute of Chemical Engineers AIChE J, 65: 1315–1324, 2019     

Graft copolymerization of 2‐acrylamido‐2‐methyl‐1‐propanesulphonic acid onto carboxymethylcellulose (sodium salt) using bromate/thiourea redox pair

Unreported graft copolymer of 2‐acrylamido‐2‐methyl‐1‐propanesulphonic acid (AMPS) with sodium carboxymethylcellulose (Na‐CMC) was synthesized and reaction conditions were optimized using a bromate/thiourea redox pair under an inert atmosphere at 40°C. Grafting ratio, add on, and conversion increase as the concentration of thiourea and [H⁺] increases up to 3.6 × 10^?3 and 0.6 × 10^?2 mol dm^?3, respectively, while on increasing the concentration of bromate ion and Na‐CMC, grafting ratio, add on, and conversion decrease. The samples of Na‐CMC and grafted Na‐CMC with AMPS were subjected to thermogravimetric analysis, with the objective of studying the effect of grafting of AMPS on the thermal stability of graft copolymer. The graft copolymer was found to be more thermally stable than pure Na‐CMC. Comparing the IR spectra of pure with grafted Na‐CMC confirm the evidence of grafting. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 100: 26–34, 2006     

Characterization & evaluation of Al7075 MMCs reinforced with ceramic particulates and influence of age hardening on their tensile behavior

Aluminium has a massive demand in the areas of automobile, aerospace and diverse engineering applications in order to furnish the requirement in those fields. But this technological evolution needs something more than aluminium. Materialogists are struggling hard to find out a material which owns sound mechanical and thermal properties and also superior than aluminium in each extent. Metal matrix composite (MMC) is a solution. Generally, metal matrix composites contain a low density material, i.e. aluminium or magnesium, reinforced with fibers or particulate of a ceramic material, i.e. silicon carbide or graphite. They show greater specific strength, high stiffness, elevated operating temperature, and superior wear resistance, along with the possibility to customize these properties for a specific use. In this study, Al 7075 is taken as a base matrix material, whereas ceramic materials like SiC, Al₂O₃, B4C and TiB₂ are used as reinforcements. There are different methods available for fabricating metal matrix composite materials and in this work, stir casting technique, which is a liquid state process, is used. Four different MMC specimens were produced with 15 % SiC, 15 % Al₂O₃, 15 % B4C and 15 % TiB₂. Mechanical properties i.e. tensile strength, hardness, and impact strength were studied for the prepared specimens. The results were charted and presented graphically to describe these materials characteristics.     

Discrete Wavelet Transform Based Measurement of Inner Race Defect Width in Taper Roller Bearing

Local bearing defect monitoring and measurement has been a challenging area of research for profitable use of motion. A technique based on decomposition using Symlet wavelet is implemented for measuring inner race defect width in a taper roller bearing. It is difficult to estimate the defect width in inner race because defect moves continuously with respect to accelerometer. The bursts are selected from the signal for measuring the defect width on the basis of their amplitude. The degree of ambiguity in detecting the entry point in the groove gets reduced by using Symlet5 wavelet based decomposition which is almost linear phase nature and hence, sharpness in the signal gets maintained even in case of sudden change induced in raw signal. The technique has been successfully implemented for measuring defect width ranging from 0.4714 to 1.8145 mm. The measurement of defect width has also been verified by image analysis. Maximum difference in measurements has been found to be 6.68 % for the defect width of 0.4714 mm at no load condition and this gets reduced to 1.21 % with increase in load. This method has also potential in dimension measurement of surfaces having dissimilar and uneven surface characteristics.     

Service Delivery Strategy: Trends in Mining Industries

Mine operators are increasingly outsourcing non-core business processes. Often, the maintenance issue is treated as a non-core business by the mining industry. In today's business environment, many industrial operators/users are interested in buying performance rather than physical products. It is a common practice for an original equipment manufacturer (OEM)/supplier of a product to own, operate, maintain, and support his product. Product performance in general is defined in a negotiated agreement. Even in a conventional product scenario a user/mine operator often prefers to outsource maintenance to OEMs or contractors in order to focus on core business goals. This paper reviews the recent trends in delivery of product support within segments of the mining industry. In this paper, we advocate the adoption of 'solution-selling' and 'total care solutions' into the mining industry. There appears to be a strong likelihood that these concepts can benefit the mining industry. Solution selling and total care solutions are seen as applicable to the mining industry because the product/equipment utilised in this industry are specialised and often expensive. The strategies addressed in this paper support a mine operator's option to buy processes instead of physical products, and the increasing demand for a total solution.     

Inhalable liposomes of Glycyrrhiza glabra extract for use in tuberculosis: formulation,in vitro characterization,in vivo lung deposition,and in vivo pharmacodynamic studies

Objective: The current study involves the development of liposomal dry powder for inhalation (LDPI) containing licorice extract (LE) for use in tuberculosis.

Significance: The current epidemiology of tuberculosis along with the increasing emergence of resistant forms of tuberculosis necessitates the need for developing alternative efficacious medicines for treatment. Licorice is a medicinal herb with reported activity against Mycobacterium tuberculosis.

Methods: Liposomes with LE were prepared by thin film hydration technique and freeze dried to obtain LDPI. The comprehensive in vitro and in vivo characterization of the LDPI formulation was carried out.

Results: The particle size of liposomes was around 210?nm with drug entrapment of almost 75%. Transmission electron microscopy revealed spherical shape of liposome vesicles. The flow properties of the LDPI were within acceptable limits. Anderson Cascade Impactor studies showed the mean median aerodynamic diameter, geometric standard deviation and fine particle fraction of the LDPI to be 4.29?µm, 1.23, and 54.68%, respectively. In vivo lung deposition studies of LDPI in mice showed that almost 46% of the drug administered reaches the lungs and 16% of administered drug is retained in the lungs after 24?hours of administration. The in vivo pharmacodynamic evaluation of the LDPI showed significant reduction in bacterial counts in lungs as well as spleen of TB-infected mice.

Conclusions: LE LDPI thus has a promising potential to be explored as an effective anti-tubercular medicine or as an adjunct to existing anti-tubercular drugs.