The well-known Navier--Stokes--Fourier equations of fluid dynamics are, in general, not adequate for describing rarefied gas flows. Moreover, while the Stokes equations -- a simplified version of the Navier--Stokes--Fourier equations -- are effective in modeling slow and steady liquid flow past a sphere, they fail to yield a non-trivial solution to the problem of slow and steady liquid flow past an infinitely long cylinder (a two-dimensional problem essentially); this is referred to as Stokes' paradox. The paradox also arises when studying these problems for gases. In this paper, we present a way to obtain meaningful solutions for two-dimensional flows of rarefied gases around objects by circumventing Stokes' paradox. To this end, we adopt an extended hydrodynamic model, referred to as the CCR model, consisting of the balance equations for the mass, momentum and energy and closed with the coupled constitutive relations. We determine an analytic solution of the CCR model for the problem and compare it with a numerical solution based on the method of fundamental solutions. Apart from addressing flow past a circular cylinder, we aim to showcase the capabilities of the method of fundamental solutions to predict the flow past other objects in two dimensions for which analytic solutions do not exist or are difficult to determine. For that, we investigate the problem of rarefied gas flow past an infinitely long semicircular cylinder.

Response spectrum-based modal combination rules play an important role in the estimation of linear peak responses of multi-degree-of-freedom (MDOF) systems consistent with the seismic hazard specified through a set of elastic design spectra of different damping ratios. Most modal combination rules have assumed that the nonstationary peak factors relating the root-mean-square responses to the largest response peaks are identical for the modal and overall system responses. However, this assumption may significantly affect the response accuracy. This study considers the use of nonstationary peak factors specifically in a modal combination rule that has been formulated for the peak values of absolute floor acceleration responses in a lumped mass, classically damped, multistoried structure by using the hazard-consistent relative acceleration spectrum ordinates, and employs the hazard-consistent relative velocity spectrum ordinates to account for cross-correlation terms. The proposed formulation consists of the modeling of (1) the nonstationary peak factor for overall floor acceleration response as normalized by the nonstationary peak factor for ground acceleration, (2) the nonstationary peak factor for the relative acceleration response of a base-excited single-degree-of-freedom (SDOF) oscillator as normalized by the nonstationary peak factor for ground acceleration, and (3) the stationary peak factor for the relative displacement response of the SDOF oscillator as normalized by the stationary peak factor for ground acceleration. The proposed modal combination rule is illustrated with the help of five buildings and six earthquake excitations in comparison with the existing modal combination rules for absolute floor acceleration responses.

The dispersion of waves over a permeable seabed due to the presence of a vertically floating rigid circular cylinder is investigated under the assumptions of the linearized water wave theory and small-amplitude surface waves. Using the radiation condition and boundary conditions, the unknown potentials for the free-surface region and for the region covered by the cylinder are determined. The velocity potentials of the incident and scattered waves are expanded using the Bessel and Hankel functions for each region in the problem. The eigenfunction expansion technique is employed to solve the resulting boundary value problem. The effectiveness of the study is accessed by demonstrating the wave forces on the circular cylinder and the flow distribution along with the temporal simulation of the flow for different parameters. It is shown that the presence of a floating circular cylinder over the porous seabed reduces the amplitude of a surface wave on the leeside of the structure significantly. It is also illustrated that the radius and height of the cylinder play a significant role in reducing the wave forces on the cylinder and, hence, in creating a calm region in the leeside of the structure. The proposed setup has the potential to help design offshore structures that are capable of reducing the impact of the wave forces on the coastal structures, which can then safely be used for various marine operations.

In the present seismic design philosophy, the structures are designed to remain within the specified displacement limits for multiple earthquake hazard levels expected during their design life. Accordingly, the estimation of maximum inelastic displacement demand in a structure consistent with a given hazard level is of primary importance. Considering the complexity and inconvenience associated with the nonlinear response history analyses for a suite of hazard-consistent ground motions, it is preferred to estimate the maximum inelastic displacement demand by using the scaling models available for the inelastic displacement ratio C$C$ in the single-degree-of-freedom (SDOF) structures. In this study, a new scaling model is developed for the inelastic displacement ratio CR(T)${C}_R(T)$ spectrum for a given response reduction factor R in the case of 5%-initial damping Bouc-Wen-Baber-Noori (BWBN) oscillators with stiffness and strength degradations and pinching. This model is based on the observed similarities between the CR(T)${C}_R(T)$ spectrum and the reciprocal of given displacement response SD(T$T$) spectrum in most cases, and thus, this indirectly accounts for the effects of seismological and site parameters. A new strong-motion duration definition is also proposed to identify shorter strong-motion segments of comparable relevance, and on using this definition, it is shown that the dependence of the mean CR(T)${C}_R(T)$ spectrum on strong-motion duration may be considered negligible. Accordingly, the regression parameters of the proposed scaling model for CR(T)${C}_R(T)$ spectrum are estimated as the exponential functions of only five governing BWBN parameters. The best-fit estimates of the regression coefficients of the resulting prediction equations are obtained for three values of R. The residual error spectra are also modeled to estimate the CR(T)${C}_R(T)$ spectrum for a given confidence level. The proposed scaling model can be applied to a wide range of existing reinforced concrete (RC) structures with 5% initial damping by using the input of the design displacement spectrum and BWBN parameters.

Drug development is a process that demands huge investment of resources and time with only 1 drug candidate successful in reaching market among 10,000 screened taking time duration of 10-15 years and millions of dollars. This high attrition rates discourage investors and researchers. The pharmaceutical industry is shifting its attention away from de novo drug research and towards discovering novel targets and indications for already-approved drugs. In order to accelerate the drug development process with reduced risk of failure and relatively lower costs, pharmaceutical companies have adopted drug repositioning as an alternative. Therefore, a good strategy for drug development would be drug repositioning or drug repurposing, which is to identify, investigate, and exploit new therapeutic uses of already-available, on-market drugs, as well as those that have been withdrawn due to toxicities or that remain on shelves in various stages of development. The outbreak of SARS-COV-19 shows that humanity is constantly vulnerable to epidemics and new microbial attacks and that there is no time to create disease-specific therapies. Consequently, it would seem advantageous to use what is already accessible. Novel therapeutic indications that have previously been approved by the market can reduce investment costs significantly in terms of money, resources, and most importantly, time, as long as they meet PKPD and toxicity standards. Sponsors and pharmaceutical corporations get enthusiastic about additional investments and initiatives related to drug development as a consequence. The upcoming therapeutic revolution, especially with the aid of artificial intelligence, is indicated by the successful applications of several already-available drugs against COVID-19 and the various phases of repurposed drugs against TB, colorectal cancer, Alzheimer’s disease, cervical cancer, and Parkinsonism.

Experimental and theoretical studies on millimetre-sized droplets suggest that at low Reynolds number the difference between the drag force on a circulating water droplet and that on a rigid sphere is very small (less than 1 %) (LeClair et al., J. Atmos. Sci., vol. 29, 1972, pp. 728-740). While the drag force on a spherical liquid droplet at high viscosity ratios (of the liquid to the gas), is approximately the same as that on a rigid sphere of the same size, the other quantities of interest (e.g. the temperature) in the case of a rarefied gas flow over a liquid droplet differ from the same quantities in the case of a rarefied gas flow over a rigid sphere. The goal of this article is to study the effects of internal motion within a spherical microdroplet/nanodroplet -- such that its diameter is comparable to the mean free path of the surrounding gas -- on the drag force and its overall dynamics. To this end, the problem of a slow rarefied gas flowing over an incompressible liquid droplet is investigated analytically by considering the internal motion of the liquid inside the droplet and also by accounting for kinetic effects in the gas. Detailed results for different values of the Knudsen number, the ratio of the thermal conductivities and the ratio of viscosities are presented for the pressure and temperature profiles inside and outside the liquid droplet. The results for the drag force obtained in the present work are in good agreement with the theoretical and experimental results existing in the literature.

Some phenomena pertaining to rarefied gases are beyond the reach of traditional fluid dynamics described, e.g., by the Euler or Navier-Stokes-Fourier equations. Therefore we adopt a recently developed model-referred to as the CCR model-to investigate thermally-induced transport in rarefied gases. To this end, the method of fundamental solutions is employed on the CCR model to investigate two problems: (i) a rarefied gas flow confined between two coaxial cylinders having different temperatures with the inner cylinder being circular while the outer being elliptical, and (ii) evaporation/condensation process in a rarefied vapor confined between two coaxial cylinders, again with the inner cylinder being circular and the outer being elliptical. Through a comprehensive analysis, the efficiency of the method of fundamental solutions is assessed. The work contributes toward a better understanding of thermally-induced confined rarefied gas flows.

The inability of the Navier-Stokes-Fourier equations to capture rarefaction effects motivates us to adopt the extended hydrodynamic equations. In the present work, a hydrodynamic model, which consists of the conservation laws closed with the recently propounded coupled constitutive relations (CCR), is utilized. This model is referred to as the CCR model and is adequate for describing moderately rarefied gas flows. A numerical framework based on the method of fundamental solutions is developed to solve the CCR model for rarefied gas flow problems in quasi two dimensions. To this end, the fundamental solutions of the linearized CCR model are derived in two dimensions. The significance of deriving the two-dimensional fundamental solutions is that they cannot be deduced from their three-dimensional counterparts that do exist in literature. As applications, the developed numerical framework based on the derived fundamental solutions is used to simulate (i) a rarefied gas flow between two coaxial cylinders with evaporating walls and (ii) a temperature-driven rarefied gas flow between two non-coaxial cylinders. The results for both problems have been validated against those obtained with the other classical approaches. Through this, it is shown that the method of fundamental solutions is an efficient tool for addressing quasi two-dimensional multiphase microscale gas flow problems at a low computational cost. Moreover, the findings also show that the CCR model solved with the method of fundamental solutions is able to describe rarefaction effects, like transpiration flows and thermal stress, generally well.

In estimating the damage to a single‐degree‐of‐freedom (SDOF) structure due to multiple earthquake events, it may be convenient to use a frequency‐based approach, in which the anticipated ground motions are characterized through power spectral density functions (PSDFs) compatible with the specified design spectra for those motions. Since a spectrum‐compatible PSDF corresponds to a fictitious stationary ground motion process of a specified duration, the duration of this process should preferably be same as the length of the stationary segment in the actual ground acceleration process for a meaningful computation of the stochastic response. On assuming the strong‐motion segment of a given ground motion to represent its stationary segment, the nonstationarity of the strong‐motion segment is evaluated for the existing strong‐motion duration definitions. It is found that the Trifunac‐Brady definition is the most reasonable strong‐motion duration definition in respect of consistently giving the longest strong‐motion segment with least nonstationarity. Further, a spectrum‐compatible PSDF can be used for estimating the stochastic response of a linear system, provided the system has the same damping ratio as that of the design spectrum from which the PSDF has been computed. This causes errors in estimating the peak response of an equivalent linear system due to its damping ratio being higher than the initial damping ratio of the nonlinear system. To address this, an empirical expression is developed for the modified damping ratio of a linear system, which would lead to the correct peak response of the system on using the PSDF obtained from the 5%‐damping design spectrum.

The current earthquake design philosophy based on only the most critical earthquake may prove inadequate when the smaller events occurring before this event cause significant damage to the structure and repairs become infeasible. The design force levels may therefore be raised using the modified design force ratio, defined as the ratio of the yield force level for a specified damage level under all the seismic events to the yield force level for the same damage level under only the most critical event. This study considers the updating of the existing frequency-based approach, using the power spectral density function (PSDF)-based characterization of design ground motion, for the estimation of modified design force ratio spectrum. First, an empirical expression developed in the companion paper for modifying the damping of the equivalent linear oscillator is used such that the use of the PSDF compatible with 5%-damping response spectrum leads to correct peak response, even when the equivalent damping ratio exceeds 5%. Next, the frequency-domain design force ratio estimates are benchmarked in the case of steel and reinforced concrete oscillators by comparing those with the time-domain estimates of equivalent Bouc-Wen oscillators over various sequences of events and by suitably adjusting the stiffness degradation parameter. It is shown in the case of a hypothetical seismic scenario that the optimal values of this parameter as 2.0 and 1.7 work well for the steel structures and reinforced concrete structures with high stiffness degradation respectively. Also, the proposed approach needs to be improved further for applicability in the case of reinforced concrete structures exhibiting significant pinching behavior. The frequency-domain DFR estimates are benchmarked in the case of steel and reinforced concrete oscillators by comparing those with the time-domain estimates of equivalent Bouc-Wen oscillators over various sequences of events and by suitably adjusting the stiffness degradation parameter. image

Those medicines which are having same efficacy as that of their branded and expensive counterparts are known as Generic medicines. Compare to branded medicines, generic medicines have similar route of administration, indication, side effects, strength. Contrary to lower price and affordability the generic medicines are not so popular among healthcare professionals. The objective of this study is to analyse, knowledge and experience on use of generic medicines among healthcare professionals. A pilot study was conducted at Institute of Medical Sciences (IMS) Banaras Hindu University Varanasi India. This was a questionnaire-based cross-sectional study. The participants were doctors, nurses, pharmacists and others (research scholars and PG students). Chi square test used to find out p value. The overall response rate was 84.61 percent (55/65). Among all participants 12.7 percent did not “heard about Pradhan Mantri Jan Aushadhi Pariyojana Kendra”. Among all participants only 40 percent were not aware about Pradhan Mantri Jan Aushadhi Pariyojana Kendra situated in their area. Among all participants 72.73% aware about safe generic medicines, while among participant groups 60% of participating doctors, all nursing and pharmacy professionals and 72% of others accepted that generic medicines are safe as like branded medicines. A variation observed in respect of knowledge, and experience on generic medicines among participants. 40% (percent) of participating doctors did not believe in generic medicines and opted that the generic medicines are not safe as like branded medicines. Therefore, need for more training/awareness programmes on generic medicine arises. Need for building trust among healthcare professionals on generic medicines required.

Displacement-based design has gained importance due to the emergence of the performance-based engineering, and it has now become desirable to estimate maximum (inelastic) displacements of structures for different levels of seismic hazard. Being closely related to damage, displacement (or drift) has become an important parameter necessary to meet various performance goals. It is considered convenient to estimate the inelastic displacement demand in a structure by multiplying the elastic displacement demand of the structure with a ratio called the inelastic displacement ratio. A comprehensive study is conducted for the parametric dependence of the inelastic displacement ratio in single-degree-of-freedom (SDOF) systems with known relative lateral strengths, on strong motion duration, earthquake magnitude, epicentral distance, and geological site conditions. This study is different from the earlier studies of similar types in that other governing parameters are kept fixed while the effects of variations in any particular parameter are studied. This study is based on the generation of ensembles of synthetic accelerograms from a database of 1274 accelerograms recorded in western USA for the pseudospectral acceleration (PSA) spectra of given source and site parameters. It is found that strong motion duration may influence the inelastic displacement ratios, depending on the hysteretic properties of the oscillator, in the case of durations not much longer than 10 s. Earthquake magnitude has a significant influence on these ratios for the SDOF systems of most periods, while site geology appears to be important for the stiff oscillators. A scaling model is also proposed in this study for estimating the inelastic displacement ratio spectrum from a normalized relative velocity spectrum of the ground motion. The proposed model indirectly includes the effects of various governing parameters and is shown to preserve the trends available from the direct study. A comprehensive study is conducted for the parametric dependence of the inelastic displacement ratio in single-degree-of-freedom (SDOF) systems with known relative lateral strengths, on strong motion duration, earthquake magnitude, epicentral distance, and geological site conditions. This study is different from the earlier studies of similar types in that other governing parameters are kept fixed while the effects of variations in any particular parameter are studied. A scaling model is also proposed in this study for estimating the inelastic displacement ratio spectrum from a normalized relative velocity spectrum of the ground motion. image

This study describes the designing steps of the proposed self-cleaning system for the photovoltaic (PV) system and experimentally investigates the effectiveness of the proposed self-cleaning PV sliding system for solar power plants under all Indian climate conditions. To investigate the performance of the proposed self-cleaning PV sliding system, we used three PV panels of 20 W with a sliding structure and another set of three PV panels of 20 W with a traditional (fixed) technique, and recorded the output power for the period of December 2019 to April 2021. The experimental results show that the proposed self-cleaning PV sliding system improved efficiency by 18.3%, 13.3% and 6.4%, respectively, in the summer, winter and post-monsoon seasons when compared to the fixed PV system. The results also revealed that energy consumption was very low when compared to the amount of energy gained. The proposed system not only cleans the PV system, but also protects it from hailstorms. The results of this study show that there is a significant improvement in PV efficiency and thus an increase in electricity production under all climate conditions.

Solar photovoltaic (PV) technology can be considered a suitable option for fossil fuels because of its free availability and ease of use. The deprivation of power generation from PV systems due to environmental factors shows a major flaw in solar PV systems. As a result, they are unreliable in deserts or remote locations. The accumulation of dust in solar PV systems is a major problem. Solar PV energy prediction is a critical factor in future ecological and reliable energy sources for system stability. Real-time observing systems are essential in a remote PV system for collecting all the parameters needed to evaluate and optimize system performance. Many existing studies use costly and difficult-to-use wired data acquisition systems that run on LABVIEW licensed software. PV panels must be cleaned on a regular basis to achieve maximum efficiency. Most existing cleaning methods require water for cleaning the PV system. In this study, a wireless data acquisition system and a method of self-cleaning the PV panels are developed and tested. The proposed cleaning system not only cleans the PV system but also protects it from hailstorms. We investigate the performance of a 106 W PV system under Jaipur weather conditions over a one-year period using a proposed wireless data acquisition and monitoring system. The results revealed that the exposure of 12 months of 106 W PV panels under different seasons in Jaipur reduced the PV system's efficiency by 24.5% in summer, by 15.6% in winter, by 5.14% in post-monsoon and by 1.95% in monsoon. The PV panels' maximum efficiency is reached at a panel temperature of 41 degrees C in the summer and 48 degrees C in the winter. We observed that the proposed data acquisition system is applicable, durable, efficient, and appropriate for severe outdoor conditions for observing and collecting operational information about the PV system. The efficiency of a fixed PV system with daily manual cleaning was compared to that of a proposed cleaning PV system for a month and the proposed cleaning PV system's efficiency was only 1.13% lower. The result shows that the proposed cleaning PV system performs well even in semi-arid environments.

Aftershocks have the potential to cause collapse of a structure damaged by the preceding main shock and thus the conventional single event-based seismic design may not guarantee the desired safety against earthquake ground motions. A systematic investigation is carried out in this study on the relative contribution of aftershock ground motions to cumulative structural damage in the case of three Indian code-designed reinforced concrete bare frames having different fundamental periods. Assuming that the response spectrum and time-frequency characteristics of the aftershock motions may be related to these characteristics of the main shock motion, a variety of seismic scenarios (in terms of earthquake magnitude, representative distance, focal depth and soil type), and response spectrum and time-frequency characteristics of the anticipated main shock motion are considered, and corresponding main shock and aftershock ground motions are generated. The damage analysis shows that short-period structures are more vulnerable to the aftershock-induced damage compared to the long-period structures, unless the main shock motion has a significant long period component or is associated with relatively shallower aftershocks. Further, the severity of aftershock events (in comparison with that of the main shock event) increases significantly for the longer main shock and shallower aftershock events, and for the high-frequency main shock motions in the case of short-period structures. It is also found that the relative aftershock severity can be estimated in terms of the relative ground motion parameters like the ratios of duration and spectral ordinates for the aftershock to those for the main shock.

This study introduces the design and performance of a three-axis solar tracker system. The primary objective of evolving a three-axis solar tracker is to follow the sun's location and remove shading caused by obstacles. High-rise objects, such as upcoming buildings, trees, or shading caused by the preceding row of PV modules due to the sun's changing latitudes during the winter and summer, could be obstacles. To overcome these challenges, a third axis is included to allow the height of the solar panel to be adjusted so that it is not shaded. Existing solar tracking systems attempt to generate maximum output power but are unable to eliminate 100% shading on the solar panel's surface, resulting in lower received output power. If the PV module is kept vertical to the sun's radiation, the PV system will produce the most power. With this addition to the tracker, the solar panel stays perpendicular to the rays of sunlight with this addition to the tracker, allowing it to collect the most solar radiation at sunset and sunrise, which is difficult to achieve with static solar panels and a two-axis tracker system. Test outcomes reveal that the developed system generates more output power by up to 181% and 19% as compared to the static solar panels and dual-axis (active type) solar tracker systems, respectively. Thus, the main ideology of this technology is to obtain maximum solar radiation from sunrise to sunset, regardless of the sun's changing positions (summer and winter).

This study presents an experimental investigation of the proposed waterless photovoltaic (PV) cleaning mechanism in a semi-desert environment. The goal of this research is to improve the efficiency of the solar photovoltaic systems while reducing cleaning costs and avoiding the use of water, ensuring effectiveness and adaptability. In this paper, the effectiveness of the suggested waterless PV cleaning technique has been evaluated by considering a variety of factors, such as cleaning performance, cost, energy consumption, and land use. In the post-monsoon, winter, and summer seasons, the overall gain in energy generation is 1.64%, 4.34%, and 7.76% higher than that of the PV system without the cleaning technique, respectively. The efficiency of a conventional PV system using weekly cleaning was reduced by 1.92%, 2.01%, 1.62%, and 2% after the first, second, third, and fourth weeks, respectively, whereas the PV system's efficiency with the suggested waterless cleaning method was reduced by 0.67%, 0.67%, 0.42%, and 0.25%. A conventional PV system that involves cleaning every day (using water and cloth) was compared to a suggested waterless cleaning PV system for 30 days, and it was noted that the average efficiency of the suggested waterless PV cleaning system was 0.56% less than the average efficiency of the daily manual cleaning PV system. In the event of a hailstorm, there is no way to protect PV panels. The proposed system both cleans up the dust and shields the PV system from hail.

It is convenient to synthesize the Fourier spectra of the rocking ground motions at a station from the recorded translational motions at the same station. The conventional models in this approach assume (1) the seismic source to be a point source, (2) the medium to be a horizontally stratified elastic half-space, and (3) the translational motions to be caused primarily by the planar wavefronts of the body waves. An improved 'planar wavefront' model is proposed under this approach such that (1) the model applies also to near the epicenter, with the hypocentral distance of the station assumed to be much larger than the wavelengths of the incident waves, (2) the information on the underlying focal mechanism is accounted for, and (3) both in-plane and out-of-plane rocking spectra can be estimated. The proposed model assumes the material properties of the stratified medium to vary smoothly with depth. Further, it considers the spatial variations of both the amplitudes and the incidence angles of the incoming waves. The spatial variation of the amplitudes is formulated by considering the physics of (1) the radiation of body waves emitted by a kinematic shear dislocation point source and (2) the propagation of those waves through the stratified medium. A numerical study shows that the proposed model leads to more accurate rocking spectra over a large range of fault parameters and frequencies. Further, a few example nearepicenter records of translational ground motions illustrate the disparities between the time-domain estimates of the proposed model with those of the conventional models as well as between the responses of simple structures subjected to the two sets of motions.

Abstract Determining physically admissible boundary conditions for higher moments in an extended continuum model is recognised as a major obstacle. Boundary conditions for the regularised 26-moment (R26) equations obtained using Maxwell's accommodation model do exist in the literature; however, we show in this article that these boundary conditions violate the second law of thermodynamics and the Onsager reciprocity relations for certain boundary value problems, and, hence, are not physically admissible. We further prove that the linearised R26 (LR26) equations possess a proper $H$-theorem (second-law inequality) by determining a quadratic form without cross-product terms for the entropy density. The establishment of the $H$-theorem for the LR26 equations in turn leads to a complete set of boundary conditions that are physically admissible for all processes and comply with the Onsager reciprocity relations. As an application, the problem of a slow rarefied gas flow past a spherical droplet with and without evaporation is considered and solved analytically. The results are compared with the numerical solution of the linearised Boltzmann equation, experimental results from the literature and/or other macroscopic theories to show that the LR26 theory with the physically admissible boundary conditions provides an excellent prediction up to Knudsen number $\lesssim 1$ and, consequently, provides transpicuous insights into intriguing effects, such as thermal polarisation. In particular, the analytic results for the drag force obtained in the present work are in an excellent agreement with experimental results even for very large values of the Knudsen number.