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The purpose of the study is to design economical shock tube. It is an instrument used for experimental investigations not only related to shock phenomena but also for the behavior of the material when it is subjected to high-speed flow. The material used here in this shock tube is stainless steel ss304 and aluminum. A shock tube consists of two sections, namely, the driver and the driven. The gas in the driven and driver is filled with atmospheric air and nitrogen, respectively, under the predominant condition.

The focus of the study is on the design and fabrication of shock tubes. a shock tube is a research tool to make an aerodynamic test in the presence of high pressure and temperature by generating moving normal shock waves under controlled conditions.

The main necessity for instrumentation in the shock tube experiment is to know the velocity of the moving shock wave from which the other parameters can be calculated. the pressure transducers are located in the shock tube in various locations to measure aerodynamic parameters in terms of pressure.

The main objective of this project work is to make an experimental setup to produce supersonic velocity with the readily available material in the market in a highly safe manner.

The purpose of this paper is to generalize Yeh and Zhang's 2004 random threshold failure model for deteriorating systems.

An N‐policy was adopted by which the system was replaced after the Nth failure.

The model was found to have practical applications in warranty cost analysis.

By identifying the instance of a shock as the failure of the system and the threshold times as the warranty period offered and changing the definition of lethal shock (system failure in this case) as the occurrence of a shock within a threshold period in our generalized model, one can study the renewing warranty cost analysis.

Little is known about the quantitative impact of macro policies on disaggregated variables. This study investigates the effects of macroeconomic policies and cost/supply shocks on sectoral output growth.

We analyzed empirical evidence from Ghana using a Structural Vector Autoregression approach.

The results show that the transmission of various macro policies and supply/cost shocks is conditional on sectoral idiosyncrasies. Fiscal programs contribute the most to agricultural output growth and the least to industrial production. The downturn from rising costs and supply disruptions is more severe and lasting in the agriculture sector than in the service sector. The evidence shows that fiscal consolidation centered on government consumption cuts would not drag growth over the medium-term.

Our results show that the structural characteristics of a country may play an important role in understanding the output effects of macro policy changes. The empirical evidence shows that targeted policies are needed to complement countercyclical macroeconomic policies to facilitate broad-based economic recovery.

Research on the impact of macro policy shocks on the real economy has usually focused on the behavior of highly aggregated variables. In this research, we focus on disaggregated, sector-level variables to unveil the idiosyncrasies in the performance of disaggregated variables that are usually concealed when studying the behavior of aggregate variables. This study also contributes a different angle to the debate on supply shocks by examining how cost shocks are propagated through the various sectors of the economy.

The peer review history for this article is available at: https://publons.com/publon/10.1108/IJSE-11-2023-0876

In light of the recently experienced systemic shocks (the COVID-19 pandemic and the war in Ukraine), we investigate supply chain robustness. We aim to understand the potential consequences of uncertain events or adversary’s action on critical supplies in the Alliance.

We leverage a parsimonious supply chain model and investigate the relationship between upstream supplier concentration/diversification and the supply chain’s robustness (survival probability) in the presence of uncertain systemic shocks. In several scenarios of shock events, we simulate alternative input sourcing strategies in the presence of uncertainty.

A firm-level cost-focused optimisation may lead all upstream suppliers to concentrate in one location, which – when subsequently hit by a shock – would result in a disruption of the entire supply chain. A chain-level forward-looking optimisation diversifies the upstream supplier location and sourcing decisions. As a result, the supply chain’s survival probability is maximised, and critical supplies will continue even under the most demanding circumstances.

Our findings encourage political and military decision makers to enhance upstream supply chain robustness in critical and strategic sectors, such as the diversification of nitrocellulose supplies currently sourced almost exclusively from China by European gunpowder manufacturers.

Our findings have direct recommendations to supply chain downstream decision makers and to the government’s policy choices. Since global supply chain (GSC) disruptions in critical sectors may have catastrophic impacts on social welfare and the probability of shocks such as COVID-19 and Russia’s war may not be known even approximately, robust decision rules seem to be the appropriate tools for policymaking in critical and strategic sectors such as energy supplies, food and water, communication and defence. A robust supply chain is one in which the survival probability is maximised, which we show in a central planner strategy’s simulations.

The paper shows formally why a market-based global input sourcing strategy may be efficient from an individual firm’s perspective but may be suboptimal from a societal resilience perspective.

UK regional data on GDP and the GDP deflator are analysed to extract information on underlying demand and supply shocks as well as aggregate demand and supply shocks. Identification is achieved using long run restrictions, based on a theoretical model. The main results are that the supply shocks are almost completely symmetric across UK regions and that there is no evidence of these shocks being propagated slowly across the regions.

This study aims to investigate the amount and direction of economic policy uncertainty (EPU) spillover among six emerging market economies (EMEs), and to also ascertain arguments on the increased volatilities of uncertainty in most EMEs.

This study adopts a recent methodology developed by Baruník and Krehlík’s (2018) methodology to measure pairwise, composite and net spillover. This methodology helps investigate the size and direction of EPU spillover in EMEs. The unique feature of this methodology is its ability to capture frequency domain as well as time-frequency dynamics.

Inter-country static spillover connectedness among the EPU of the selected EMEs show that Korea-EPU is the main transmitter and recipient of spillover shocks among the EMEs across all frequency bands. The findings from this study also show evidence of spillover between EPU, GDP and SPX across the EMEs. The time-varying total spillover index analysis shows evidence of overall connectedness across the selected EMEs. Overall connectedness is highest in the short term. We document that global economic and financial events intensify the volatility of the total spillover across the selected EMEs.

This study extends the literature on studies conducted on EMEs as studies on EPU spillover has mainly focused on advanced economies. To address the limitation of previous empirical studies that were unable to address the amount and direction of spillover from a country to other countries, this study offers new insight on country-specific spillover amounts and causal patterns “to” and “from” the selected EMEs. The findings throw more light on the network connectedness across EMEs and hence aids investors to undertake precise investment decisions and intelligently plan their portfolio diversification strategies. We then introduce two new variables to the analysis and record evidence of high connectedness between EPU, gross domestic product and share price index in all the frequency bands.

We examine the twin deficits and the direction of its movement for the case of Bolivia, a natural resource-dependent country, using the database of (Kehoe et al., 2019) from 1960 to 2019.

We combine a structural vector autoregression (SVAR) model with a dynamic stochastic general equilibrium (DSGE) model to understand the transmission mechanisms.

Our results suggest the existence of twin deficits in Bolivia; however, causality in the Mundell-Fleming sense does not hold. While fiscal policy shocks explain current account deficits, current account shocks have a stronger effect over fiscal deficit. In fact, only 23% of the variance of current account forecast errors is explained by fiscal policy shocks; in contrast, 45% of the variance of the fiscal deficit is explained by current account shocks.

The study is for a specific case, which is a limitation; however, other country samples can be included.

Based on the results of the work, policies can be recommended and designed to cushion the effects of external shocks.

According to the literature available for the Bolivian case, our work constitutes a significant contribution and, therefore, is original for this specific case.

This paper aims to investigate the effect of economic policy uncertainty (EPU) shocks on Indian equity market sectors. The effect of domestic (Indian) and foreign (USA) EPU shocks is examined on ten major Bombay Stock Exchange sectors.

The study uses data covering the period from September 2005 to July 2023 and uses the methodology of quantile regression to investigate the heterogenous response of stock market sectors under diverse market conditions explained through the analysis of conditional quantiles distribution.

The results demonstrate that domestic and foreign EPU shocks negatively affect most of the sectors in bearish market conditions. Industrials, commodities, utilities, consumer discretionary and financial services are the most affected sectors by domestic EPU. However, the information technology sector is found to be immune to domestic EPU shocks but negatively affected by foreign EPU shocks. On the other hand, energy, financial services and fast-moving consumer goods sectors are found to be immune to foreign EPU shocks but are negatively affected by domestic EPU shocks.

Understanding the heterogeneous response of different sectors to EPU shocks could help investors and portfolio managers identify portfolio diversification opportunities.

This study makes an inaugural attempt to examine the responses of Indian stock market sectors to domestic and foreign EPU shocks using the approach of quantile regression and unveils the previously unexamined diverse reactions of Indian stock market sectors to EPU shocks originating from both India and USA.

This paper aims to investigate whether negative and positive monetary policy (MP) shocks have asymmetric impacts on corporate firms’ investment decisions in Pakistan using firm-level panel data set. Moreover, the authors emphasized on symmetric effects of MP; the authors examine whether high-leverage and low-leverage firms respond differently to negative and positive unanticipated shocks in MP instruments.

In contrast to the conventional framework of VAR, it uses an alternative methodology of Taylor rule to estimate unanticipated MP shocks. The two-step system-generalized method of movement (GMM) estimation method is applied to examine the effect of MP shocks on firm investment through leverage-based asymmetry.

The two-step system-GMM estimation results indicate that unanticipated negative changes (unfavorable shocks) in MP instruments have negative, significant effects on investment. In contrast, unanticipated positive changes (favorable shocks) have statistically insignificant impacts on firm investment. The results also reveal that firm leverage has a significant role in establishing the effect of unanticipated negative changes in MP instruments on investments. Finally, the results indicate that high-leverage firms respond more to negative changes than low-leverage firms. Yet, the results show that only low-leverage firms positively respond to unanticipated positive shocks in MP.

The findings of the paper suggest that MP authorities should pay due attention to the asymmetric effects of MP shocks on firm investment while designing MP. Because firm leverage has a significant influence on the effects of MP shocks, firm managers should take into account such role of leverage while deciding capital structure of their firms.

First, unlike “Keynesian asymmetry” and most of published empirical research work, the authors use both unanticipated negative and positive MP shocks simultaneously. Departing from the conventional empirical literature, the authors differentiate between unanticipated positive and negative shocks in MP using the backward-looking Taylor rule. Second, the authors contribute to the existing literature by investigating the differential effects of positive and negative unanticipated MP shocks on firms’ investment decisions. Unlike the published studies that have emphasized on the symmetric effects of MP, the authors examine whether high-leverage and low-leverage firms respond differently to negative and positive unanticipated shocks in MP instruments.

This study aims to evaluate the structural oil shocks effect on stock returns of Indian renewable energy companies across market conditions.

This study applies the structural vector autoregression model to estimate sources of oil shocks such as oil supply shock, aggregate demand shock and oil price-specific demand shock. In the next step, the panel quantile regression model estimates the effect of these oil shocks on stock return across market conditions. Monthly data are collected from January 2009 to December 2019. All renewable energy companies listed on the National Stock Exchange of India are considered for the analysis.

In the whole sample analysis, this study finds that oil shocks negatively affect stock returns in most of the market conditions except oil price-specific demand shock. In sub-groups, oil shocks driven by supply and aggregate demand also negatively affect stock return in most market conditions. This study finds the positive interaction of oil price-specific demand shock. A majority of these positive interactions happen in bearish market conditions. In the whole sample, the asymmetric effects of shocks driven from oil supply and oil price-specific demand are seen in most quantiles or market conditions. At the same time, aggregate demand shock does not affect asymmetrically. In the sub-group analysis, standalone renewable energy companies stock returns are least asymmetrically affected by these oil shocks. The asymmetries of oil supply-driven shock on stock returns of the renewable energy sub-group companies are found in most quantiles.

First, this is a company-level study of the stock returns response to the structural oil shocks in the renewable energy sector. Second, to the best of the authors’ knowledge, this type of study is the first in the Indian context. Third using panel quantile regression model along with capital asset pricing model framework, the authors investigate these effects across market conditions.