Physico-chemical Properties of Black Pepper Starch

Unusually small-sized (2 - 2.5 μ) starch granules were isolated from black pepper (Piper nigrum) in 25 – 38% yield. The granules having an amylose content of 18% were non-ionic in nature and exhibited low solubility and low swelling power in water, but high solubility in DMSO. The amylogram peak viscosity of the starch was about 530 B. U. with a very little set back (∼ 550 B. U.) on cooling, indicating a stable linear molecule very strongly associated with amylopectin. X-ray power pattern revealed the starch granules to be of A-type.     

Scanning Electron Microscopy of Enzyme-digested Starch Granules

The study deals with comparison of the susceptibility to fungal glucoamylase and salivary α-amylase of starch granules from navane, panivaragu, black pepper and black gram. The crude glucoamylase was purified by fractionation and column chromatography to give two pure fractions of which one was used. The rate of amylolysis was followed by estimating the amount of glucose and maltose released. The type and extent of damage of the starch granules were observed by scanning electron microscopy which revealed characteristic degradation patterns in navane and panivaragu, whereas black gram granules were resistant to the attack. Very small-sized black pepper starch granules did not exhibit any obvious signs of amylolytic attack.     

A Review of the Common Neurodegenerative Disorders: Current Therapeutic Approaches and the Potential Role of Nanotherapeutics

Neurodegenerative disorders are primarily characterized by neuron loss. The most common neurodegenerative disorders include Alzheimer’s and Parkinson’s disease. Although there are several medicines currently approved for managing neurodegenerative disorders, a large majority of them only help with associated symptoms. This lack of pathogenesis-targeting therapies is primarily due to the restrictive effects of the blood–brain barrier (BBB), which keeps close to 99% of all “foreign substances” out of the brain. Since their discovery, nanoparticles have been successfully used for targeted delivery into many organs, including the brain. This review briefly describes the pathophysiology of Alzheimer’s, Parkinson’s disease, and amyotrophic lateral sclerosis, and their current management approaches. We then highlight the major challenges of brain-drug delivery, followed by the role of nanotherapeutics for the diagnosis and treatment of various neurological disorders.     

Variability of waste copper slag concrete and its effect on the seismic safety of reinforced concrete building: A case study

Proven research output on the behavior of structures made of waste copper slag concrete can improve its utilization in the construction industry and thereby help to develop a sustainable built environment. Although numerous studies on waste copper slag concrete can be found in the published literature, no research has focused on the structural application of this type of concrete. In particular, the variability in the strength properties of waste copper slag concrete, which is required for various structural applications, such as limit state design formulation, reliability-based structural analysis, etc., has so far not attracted the attention of researchers. This paper quantifies the uncertainty associated with the compressive-, flexural- and split tensile strength of hardened concrete with different dosages of waste copper slag as fine aggregate. Best-fit probability distribution models are proposed based on statistical analyses of strength data generated from laboratory experiments. In addition, the paper presents a reliability-based seismic risk assessment of a typical waste copper slag incorporated reinforced concrete framed building, considering the proposed distribution model. The results show that waste copper slag can be safely used for seismic resistant structures as it results in an identical probability of failure and dispersion in the drift demand when compared with a conventional concrete building made of natural sand.     

Design and test of a Pareto optimal flat pad aerostatic bearing

This paper discusses the design and assessment of a Pareto optimal aerostatic flat pad bearing. The design of such bearings is a multi-variable, multi-criteria problem. The criteria used were load capacity, flow rate and stiffness. The design technique does not rely on weighting the criteria at the outset but allows a final design to be selected from the Pareto set. The final design was assessed using an automated experimental rig to obtain load/deflection data, mass flow rates, and film pressure profiles for a range of gap heights. The experimental performance of the Pareto optimal bearing is shown to compare well with the theoretical prediction at lower gap heights.     

Experimental analysis of the thermal properties of fused quartz-reinforced Al-6061alloy matrix composites using RSM approach

Journal of Mechanical Science and Technology - This study investigates the thermal property of fused quartz-reinforced aluminum 6061 alloy metal matrix composites for three different chill material...     

Theoretical and Experimental Insight into the Mechanism for Spontaneous Vertical Growth of ReS2 Nanosheets

Rhenium disulfide (ReS₂) differs fundamentally from other group‐VI transition metal dichalcogenides (TMDs) due to its low structural symmetry, which results in its optical and electrical anisotropy. Although vertical growth is observed in some TMDs under special growth conditions, vertical growth in ReS₂ is very different in that it is highly spontaneous and substrate‐independent. In this study, the mechanism that underpins the thermodynamically favorable vertical growth mode of ReS₂ is uncovered. It is found that the governing mechanism for ReS₂ growth involves two distinct stages. In the first stage, ReS₂ grows parallel to the growth substrate, consistent with conventional TMD growth. However, subsequent vertical growth is nucleated at points on the lattice where Re atoms are “pinched” together. At such sites, an additional Re atom binds with the cluster of pinched Re atoms, leaving an under‐coordinated S atom protruding out of the ReS₂ plane. This under‐coordinated S is “reactive” and binds to free Re and S atoms, initiating growth in a direction perpendicular to the ReS₂ surface. The utility of such vertical ReS₂ arrays in applications where high surface‐to‐volume ratio and electric‐field enhancement are essential, such as surface enhanced Raman spectroscopy, field emission, and solar‐based disinfection of bacteria, is demonstrated.     

Optical,DC and AC electrical investigations of 4-hydroxy coumarin molecule as an organic Schottky diode

The current–voltage (I–V) and optical characteristics of 4-hydroxy coumarin Schottky diode were investigated. The conventional methods related with device were used to extract the various diode parameters. From dielectric study low dielectric constant and loss was observed. From its optical study, an indirect allowed transition is shown by this compound. The optical band gap (E _g ) was found to be around 3.78 eV. The observed properties shown by this molecule give a bright opportunity to explore its application for different organic devices.     

Applications of Polymer Matrix Syntactic Foams

A collection of applications of polymer matrix syntactic foams is presented in this article. Syntactic foams are lightweight porous composites that found their early applications in marine structures due to their naturally buoyant behavior and low moisture absorption. Their light weight has been beneficial in weight sensitive aerospace structures. Syntactic foams have pushed the performance boundaries for composites and have enabled the development of vehicles for traveling to the deepest parts of the ocean and to other planets. The high volume fraction of porosity in syntactic foams also enabled their applications in thermal insulation of pipelines in oil and gas industry. The possibility of tailoring the mechanical and thermal properties of syntactic foams through a combination of material selection, hollow particle volume fraction, and hollow particle wall thickness has helped in rapidly growing these applications. The low coefficient of thermal expansion and dimensional stability at high temperatures are now leading their use in electronic packaging, composite tooling, and thermoforming plug assists. Methods have been developed to tailor the mechanical and thermal properties of syntactic foams independent of each other over a wide range, which is a significant advantage over other traditional particulate and fibrous composites.     

Fabrication, characterization and invitro bioactivity evaluation of QPSU/TiO2 composite membranes

Quaternized Polysulfone (QPSU) is a widely investigated material in the industry because of its unique properties such as resistance to corrosion and high mechanical properties. The ionic nature of the compound can be exploited for medical applications such as in haemodialysis, drug delivery and tissue engineering. In this study, composite membranes of QPSU with varying concentrations of Titanium oxide (TiO₂) were prepared and characterized using FT-IR, ¹H-NMR, XRD, TGA and SEM. The bioactivity of the membranes was studied by immersing them in simulated body fluid (SBF) for 7 days and subsequently observing under SEM for the formation of calcium-phosphate (Ca–PO₄) layer on the surface of the membranes. The formation of Ca–PO₄ on the samples was confirmed using FT-IR and EDAX. The results were compared with those obtained for QPSU membranes and the effect of TiO₂ concentration on the membrane properties was analyzed. It was observed that the percentage crystallinity of the composites increased upto a filler concentration of 5 wt% beyond which it decreased. TGA studies revealed an increase in the thermal stability of the composites with increasing filler concentrations. While optimum bioactivity was observed in the samples containing 5 wt% of TiO₂, higher filler content resulted in the formation of denser calcium—phosphate layer on the surface of the composites. The study shows that quaternized polysulphone/TiO₂ composites are promising bio composites having great potential for application in health care.