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In this study, two different analytical models were developed to predict electrical conductivity of random and aligned nanofiber/polymer composites. Model-I calculated conductivity using micromechanics based analytical equation and model-II calculates effective conductivity by considering the composite as simplified fiber–fiber contact network based equivalent resistor model. The models incorporated the effect of filler geometry, concentration, orientation, interphase and percolation threshold. Electron tunneling along thin insulating layers between conductive fillers was considered as the major contributor of conductivity. The proposed models were validated with measured conductivity from random and electric field aligned CNF/epoxy composites of different concentrations. The models were further validated with literature data on the conductivity of random and aligned CNT and CNF/polymer composites. The proposed models can also be extended to predict electrical conductivity of nanocomposites with fillers with different geometry.

Introduction Health insurance is emerging fast as an important mechanism to finance health care needs of the people. Complexity of the health insurance industry has been much talked about and less understood in the Indian scenario. Hence, it is imperative to assess the level of awareness that the population has with respect to health insurance policies. Materials and methods Cross-sectional prospective study conducted over a period of 6 months, at the third-party administrator (TPA) desk of the hospital. The data was collected using a preformed close-ended questionnaire after obtaining consent from all the participants. Only patients admitted in the hospital availing cashless hospitalization were included in the study. The study was undertaken with the objective to determine the level of awareness about insurance policies and procedures among those insured and identify the problems faced by those insured when availing cashless treatment. Responses to the variables in the questionnaire were compiled and tabulated using Excel 2010. Results Response rate of 76% was observed. 56% of the study population were planned admissions and 44% were admitted through emergency department. The study showed that about 56% of the principal policy holders were between 30 and 50 years of age. The awareness regarding the terms and conditions of the health care insurance policy and the servicing TPA was found to be 70%. However, on interacting with patients it came to light that despite being appraised by their insurance agent, they faced challenges while availing health care benefits under health care insurance and were ignorant about the procedure involved. For the current admission, in 78% of the cases, the TPA responded within 24 hours of intimation; however, in 22% cases there were delays in response from the TPA mostly attributed to communication gap between the Insurance Company and the TPA. Preexisting disease was not covered in 14% cases. 82% cases had to wait for more than 2 hours for the final clearance from the TPA. Over the years, as ascertained in 2016 also, the scenario of insurance has not undergone significant change. Conclusion Strategies to optimize claims by bringing about a uniformity in the rates being charged by the hospitals for different procedures are needed to increase coverage. How to cite this article Jain K, Sinha SK, Jain D, Kumar R. Does Health Insurance give Us an Assurance? A Study on the Extent of Coverage of Health Insurance at a Tertiary Care Hospital in North India. Int J Res Foundation Hospc Health Adm 2016;4(1):25-30.

Despite the fact that the SU-8 is a useful material for micro-fabrication of MEMS devices using the photo- lithography process, its poor tribological properties restrict its wider applications. It was postulated in our previous study that adding perflouropolyether (PFPE) lubricant to SU-8 possibly promoted chemical reaction between the molecules and also formed the boundary lubrication, which enhanced the wear durability of SU-8 by more than four orders of magnitude. The same SU-8+PFPE composite were used to fabricate a stand-alone laminate film called “Lub-tape”, which has two layers of ∼90 μm thickness each. The top and bottom layers were made of SU-8+PFPE composite and pristine SU-8, respectively. The lub-tape has reduced the initial coefficient of friction by ∼7 times and increased wear life by more than five orders of magnitude of SU-8. It can also improve the tribology of any given surface. The Lub-tape can be used to protect all surfaces against friction and wear.

A novel method of carbon embedding (≤1 nm) is used as a surface modification technique to produce overcoat free media surfaces. The filtered cathodic vacuum arc technique at ion energy of 90 eV is used to embed carbon in the top surface of a ~25 nm iron/platinum (FePt) film. Transport of ions in matter (TRIM) simulations and X-ray photoelectron spectroscopy (XPS) are used to study carbon embedding profiles and surface chemical composition. XPS results show that carbon embedding is effective in improving the oxidation resistance of FePt. Conductive atomic force microscopy (CAFM) is done on samples after exposure to a 780 nm IR laser with an effective output power of 40 mW to study the thermal stability. No change in the conductivity is observed in the case of carbon embedded FePt surface. Ball-on-disk tribological tests are conducted at a contact pressure of 0.26 GPa on bare and modified FePt surfaces. It is observed that the coefficient of friction is reduced considerably from a value of approximately 0.8 to ~0.27 after the surface modification.

A novel microtribometer is developed to characterize microelectromechanical systems (MEMS) sidewall friction with high resolution. The design is based on a rotational grating displacement sensing mechanism, with which 1.2-nm sensing sensitivity can be achieved. Employing it, the adhesion force (1.85 μN) and the coefficients of static (0.801) and kinetic (0.363) frictions on the sidewall of an as-fabricated MEMS device have been measured. Besides these, the whole process of stick-slip associated with the movement under friction, including the transition between static and kinetic frictional states, has also been clearly revealed. To reduce friction, a localized lubrication method is developed, with which liquid lubricant can be applied directly onto the desired region without affecting other components on the same device. From the experimental results, reduced values in adhesion force (1.23 μN ) and coefficients of friction (0.262 for static and 0.183 for kinetic) are obtained in the same MEMS device after lubrication treatment, demonstrating improved frictional performance.

In the present study, we have investigated the thickness dependence of mechanical properties of the Black Diamond™ (SiOC:H, BD, Low-k) films, which are of great interest in current Cu/low-k Back End of the Line (BEOL) interconnect/packaging technologies. For this investigation the BD thin films of six different thicknesses 100, 300, 500, 700, 1,000 and 1,200 nm were deposited on the 8″ Si wafer by using plasma enhanced chemical vapor deposition (PECVD) technique. Nanoindentation and nanoscratch tests of the BD films were performed by using the Nano Indenter® XP (MTS Corp. USA). In nanoindentation testing of the BD films, significant differences in the elastic modulus of the BD films were observed. In nanoscratch testing, it is found that the critical load (Lc) and scratch width increases as the thickness of the film increases. Cross-sectional analysis of residual nanoindentation impressions was carried out using atomic force microscopy (AFM) to study the deformation behavior. The nanoindentation and nanoscratch responses of the BD thin films of six different thicknesses are different and they are expected mainly due to the molecular reorganization in thin/ultra thin films.

Liquid lubrication may provide a solution to the problem of high friction and wear in micro-electro-mechanical systems. Although the effectiveness of this approach has been demonstrated in laboratory-based friction tests, practical constraints prevent it from being applied in commercial devices. The main problem is how to position the lubricant on a silicon surface in order to limit spreading and evaporation. This paper describes two techniques to address this issue. First, low concentrations of additives are used to promote autophobic behaviour. Tests’ results show that certain concentrations of both multiply alkylated cyclopentane and amine additives are effective in halting the spread of hexadecane on silicon, and, in the latter case, cause the hexadecane drop to subsequently retract. The second approach involves applying a micro-contact printing technique previously used on gold surfaces. Here, silicon surfaces are coated with octadecyltrichlorosilane mono-layers that are then selectively removed, using oxygen plasma, to leave regions of contrasting surface energy. Results from spin tests show that surfaces treated in this way can anchor 1 μl drops of hexadecane and water when forces of up to 22 and 230 μN, respectively, are applied.

In the present study, magnesium composites with sub-micron size silicon carbide (SiC) particulate reinforcements were successfully synthesized using an innovative Disintegrated Melt Deposition technique followed by hot extrusion. The extruded materials were characterized for their microstructural, thermal and mechanical properties. Systematic investigations on the microstructure of the extruded samples revealed a fairly uniform distribution of SiC particulates with limited clustering. Good SiC/Mg interfacial integrity and limited porosity was observed for all the samples. The results of the properties characterization revealed that SiC in sub-micron length scale are more effective in lowering CTE, and enhancing hardness, 0.2% yield strength, and ultimate tensile strength when compared to SiC particulates in micron length scale. Subsequently, isothermal heat treatment at 150 °C for 5 h was carried out for the composite samples. The results of tensile testing revealed that the heat treated samples showed an improvement of 0.2% YS, UTS and ductility. Particular emphasis is placed in this study to investigate the effect of heat treatment at the recrystallization temperature on the tensile properties of magnesium.

This paper presents data from topographical and tribo-chemical measurements that were carried out after wear tests on perfluoropolyether (PFPE) films dip-coated on diamond-like-carbon (DLC). The wear experiments were carried out using a glass ball slider sliding on PFPE lubricated (/spl sim/2 nm) magnetic hard disks under a normal load of 20 mN and at different sliding speeds. The test conditions were maintained such that only the PFPE film was worn and no wear of either the DLC or the magnetic layer of the disk was observed. After the wear test, the worn PFPE films were analyzed in two ways. The first analysis focused on the changes in the chemical compositions of the film due to sliding operation. The analytical test was carried out using X-ray photoemission spectroscopy. The second analysis observed the topographical changes in the wear zone due to sliding operations. The topography was measured using an ellipsometer. Furthermore, a surface reflectivity analyzer was used to quantitatively compare the features of the worn and unworn zones on the film. From these observations we conclude that contact sliding removes the PFPE film causing some chemical compositional changes which might be related to tribo-chemistry of the surface. On the topography, there is a large roughening of the PFPE film due to sliding. This increased roughness of the film is stable even after leaving the sample for several weeks. Annealed and as-lubricated samples have different effects on the topographical changes.

In a previous work, we have developed a perflouropolyether (PFPE) lubricant droplet-filled SU-8 composite which promotes bonding between the molecules of SU-8 and PFPE and provides excellent boundary lubrication. The SU-8 + PFPE composite has enhanced the wear durability of SU-8 by more than four orders of magnitude. In this work, the same SU-8 + PFPE composite was used to fabricate a stand-alone laminate film called “Lube-tape”. It has integrated two layers of approximately 90 microns thickness each, the top layer is made of SU-8 + PFPE composite and the bottom layer of pristine SU-8. Thus, a single tape can have drastically contrasting high friction and low friction properties on its two surfaces. The composite side has the initial coefficient of friction ~7 times lower and the wear life more than four orders of magnitude than those of the pristine SU-8 side. This lube tape can be used on any load bearing surface to improve the tribological performance by simply pasting the pristine SU-8 side onto the substrate.

This paper presents results obtained from the scratching of an ultrahigh molecular weight polyethylene (UHMWPE) and a polycarbonate (PC). The data are used to obtain various surface mechanical properties such as the hardness and also the prevailing deformation mechanisms. Scratch results are reported for the case of rigid conical indenters for various tip included angles, bulk temperatures, scratch velocities, and applied normal loads. Scanning electron microscopy (SEM) and laser profilometry data are used to study the surface deformation and damage mechanisms, and to assess the topography of the surfaces after scratching. Deformation maps are provided for these polymers under different experimental conditions, which describe the various deformation characteristics. In general, these polymers show both increasing and decreasing trends for the scratch hardness values with variation of cone angle, (4qW/ηd 2 ; where W is the normal load, d the width of the residual scratch, and q is a characteristic contact parameter, which ranges between 1 and 2). The scratch velocity, which governs the imposed strain rate, imparts an increasing effect on the hardness values, whereas a higher bulk temperature of the material decreases the scratch hardness. The measured responses of the surface properties of these polymers are shown to greatly depend upon the kind of deformation mechanism prevalent during the scratching and associated material removal processes.

A compression moulded Kevlar-phenolic resin composite consisting of 30 wt% continuous fibres was slid against a steel disc such that the fibre axis was normal to the sliding plane. The sliding experiments were conducted in a normal pressure range of 0.47–4.27 MPa and at a sliding speed of 0.5 ms–1. The initial sliding interaction is abrasive. With further sliding, as patches of polymer transfer film develop on the polymer pin and counterface, the interaction becomes adhesive and steady-state friction is established. The wear resistance of the polymer was found to be related to the stability of this film.

We study squalane and heptamethylnonane (HMN) confined between a conducting atomic force microscope tip and a graphite surface. Solvation layering occurs for both liquids but marked differences in the squeeze out mechanics are observed for ordered or disordered monolayers. The squalane monolayer at 25 degrees C is an ordered solid, as verified by direct imaging, and the squeeze out can be modeled using elastic continuum mechanics. HMN is in a disordered state at 25 degrees C and cannot be modeled as a single elastic asperity even in solid-solid contact because HMN liquid is trapped in the contact zone.

The paper describes an experimental study of the normal and scratch hardnesses of a poly(methylmethacrylate). The deformations have been introduced using hard steel cones of a range of included cone angles. The influence of the state of interfacial lubrication is examined and rationalized. The observed time dependence of the two types of computed hardness data is compared and the nature of the correlations between these data is evaluated. It is observed that when the imposed strains are modest, say less than 0.2, the scratch hardness and normal hardness deformations produce self consistent data using first order and rather indiscriminate analyses for both types of deformations. At higher levels of imposed strain, a more critical appraisal of the nature of the deformation produced in the two cases is necessary in order to provide mutually consistent hardness values and hence unequivocal rheological characteristics for this polymer.

A previous study on the tribological performance of a compression-moulded aramid fibre-phenolic resin composite, containing 30% continuous fibre, showed that this composite provides a reasonable combination of the friction coefficient and wear rate to be used as a friction component, such as a brake shoe. In the present work, the effect of sliding speed on the friction and wear behaviour of this composite has been investigated. The sliding experiments were conducted in a speed range of 0.1-6 m s(-1) at two normal pressure levels of 1.0 and 4.9 MPa. The coefficient of friction was found to be stable over a wide range of sliding speeds and normal pressures. The wear of the composite was found to be insensitive to changes in the speed in the higher speed range. The results have been supplemented with scanning electron micrographs to help understand possible friction and wear mechanisms.

Micro-Electro-Mechanical-Systems (MEMS) are built at micro/nano-scales. At these scales, the interfacial forces are extremely strong. These forces adversely affect the smooth operation and cause wear resulting in the drastic reduction in wear life (useful operating lifetime) of actuator-based devices. In this paper, we present a surface chemical modification method that reduces friction and significantly extends the wear life of the two most popular MEMS structural materials namely, silicon and SU-8 polymer. The method includes surface chemical treatment using ethanolamine-sodium phosphate buffer, followed by coating of perfluoropolyether (PFPE) nanolubricant on (i) silicon coated with SU-8 thin films (500 nm) and (ii) MEMS process treated SU-8 thick films (50 μm). After the surface chemical modification, it was observed that the steady-state coefficient of friction of the materials reduced by 4 to 5 times and simultaneously their wear durability increased by more than three orders of magnitude (> 1000 times). The significant reduction in the friction coefficients is due to the lubrication effect of PFPE nanolubricant, while the exceptional increase in their wear life is attributed to the bonding between the -OH functional group of ethanolamine treated SU-8 thin/thick films and the -OH functional group of PFPE. The surface chemical modification method acts as a common route to enhance the performance of both silicon and SU-8 polymer. It is time-effective (process time ≤ 11 min), cost-effective and can be readily integrated into MEMS fabrication/assembly processes. It can also work for any kind of structural material from which the miniaturized devices are/can be made.

The paper describes an experimental and analytical study of the normal and scratch hardnesses of a model soft rigid-plastic solid. The material known as ‘Plasticine’, a mixture of dry particles and a mineral oil, has been deformed with a range of rigid conical indentors with included angles of between 30° and 170°. The sliding velocity dependence of the computed scratch hardness and friction has been examined in the velocity range 0.19 mm/s to 7.3 m/s. Data are also described for the time dependence of the normal hardness and also the estimated rate dependence of the intrinsic flow stress. The latter values were estimated from data obtained during the upsetting of right cylinders. Three major conclusions are drawn from these data and the associated analysis. (1) A first-order account of the scratching force may be provided by adopting a model which sums the computed plastic deformation and interfacial sliding contributions to the total sliding work. This is tantamount to the adoption of the two-term non-interacting model of friction. (2) For this system during sliding, at high sliding velocities at least, the interface shear stress which defines the boundary condition is not directly related to the bulk shear stress. The interface rheological characteristics indicate an appreciable dependence on the imposed strain or strain rate. In particular, the relative contributions of the slip and stick boundary conditions appear to be a function of the imposed sliding velocity. (3) The computed normal and scratch hardness values are not simply interrelated primarily because of the evolving boundary conditions which appear to exist in the scratching experiments.

Previous work involving the squeeze-film flow of a model paste substance, a mixture of clay particles and mineral oil commonly known as ‘Plasticine’, has suggested that it behaves as a simple Herschel-Bulkley fluid which exhibits little strain history. However, tensile measurements, which are naturally limited to small strains by the onset of necking, indicate that this material shows strain hardening. A two roll-mill is employed here to investigate the influence of larger extensional strains. The data are analysed using an available first order engineering plasticity solution. The results confirm that this material exhibits both extensional strain and strain rate hardening. This observed strain hardening effect, which is not observed in the squeeze-film experiments, is attributed, in part, to the more homogeneous deformation fields induced during rolling and tensile extension.