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Recently, groove gap waveguides (GGWs) have shown significant potential in power handling and bandwidth enhancement compared to conventional waveguides. In this research work, we designed and developed an innovative mushroom-unit-cell-based groove gap waveguide (MGGW) that has shown improved bandwidth compared to conventional GGW structures. The dispersion characteristics of the MGGW were analyzed through the eigenmode solver feature of Microwave Studio CST, which showed that the bandwidth was improved by 8% compared to conventional unit cells in the microwave spectrum. To validate our proposed method for the physical dimensions of unit cell structures, we developed an MGGW structure for the S band, which shows similar trends aligning with the simulation results. The measurement results are promising as a reflection coefficient of less than −20 dB was achieved over the entire band for the WR284 Electronic Industries Alliance (EIA) standard waveguide adapter. The proposed MGGW structure with improved bandwidth will open new doors for researchers to develop ultra-wide bandwidth microwave applications, i.e., filters, transmission lines, resonators, attenuators, etc.

The study is aimed to investigate the impact of investor sentiment on returns of selected emerging equity markets i.e., Brazil, India, China, Russia, Indonesia, and Pakistan using non-linear predictive regression analysis. Principal Component Analysis is used to generate investor sentiment index. Investor sentiment has a significant impact on current market returns and this influence is continued in the short run in most of the sample countries. However, the impact of sentiment is not much pronounced in the longer run. Therefore, decision-makers cannot ignore sentiments in at least the short run. The findings of this study may be helpful for investors to better understand the market trends under the influence of sentiments and portfolio managers and risk professionals can devise their strategies accordingly. JEL: G02, G15, G24, M41

This study uses Non-linear Predictive Regression Analysis to analyze the effect of investor sentiment on the returns of the selected developing equity markets, including Brazil, South Africa, Indonesia, India, China, Russia, and Pakistan. The Principal Component Analysis is applied to construct an Investor Sentiment Index. In most selected countries, investor sentiment substantially affects contemporaneous market returns, and this effect remains persistent in the short term. However, it becomes less prominent over time. It suggests that stakeholders should give importance to the investors' sentiments while making investment decisions.

Abstract Gallium Nitride (GaN) remarkably shows high electron mobility, wide energy band gap, biocompatibility, and chemical stability. Wurtzite structure makes topmost Gallium atoms electropositive, hence high ligand binding ability especially to anions, making it usable as humidity sensor due to water self-ionization phenomenon. In this work, thin-film GaN based humidity sensor is fabricated through pulse modulated DC magnetron sputtering. Interdigitated electrodes (IDEs) with 100 μm width and spacing were inkjet printed on top of GaN sensing layer to further enhance sensor sensitivity. Impedance, capacitance, and current response were recorded for humidity and bio-sensing applications. The sensor shows approximate linear impedance response between 0 and 100% humidity range, the sensitivity of 8.53 nF/RH% and 79 kΩ/RH% for capacitance and impedance, and fast response (Tres) and recovery (Trec) time of 3.5 s and 9 s, respectively. The sensor shows little hysteresis of

This study examines extreme tail behavior in Asian currency markets for the period of 2005-2018. Value-at-Risk (VaR) is estimated through Extreme Value Theory (EVT) approach to forecast losses incurred in a day in Asian currencies. Initially EVT approach is used to estimate extreme losses on the left tail of the distribution. Then, the VaR estimation of this approach is back tested through traditional and advance back testing methods to ascertain the accuracy of the models used. Results indicate that the estimation of GPD static model is relevant for extreme risk forecasting in EVT approach at both 95% and 99% confidence intervals. The used method is recommended for use by market players.

Objective: To determine the association between maternal chronic apical periodontitis and low birth weight preterm birth. Method: The case-control study was conducted at the Gynaecology Ward of the Civil Hospital, Karachi, from September 2017 to April 2018, and comprised women aged 19-48 years with singleton pregnancy delivering spontaneously. The subjects were examined for the presence of periodontitis. The mothers who delivered low birth weight preterm babies were the cases in group A and those who delivered normal birth weight babies were the controls in group B. On the delivery day, after the subject having been moved to the room, data was collected through a questionnaire to record demographic details, history of pregnancy and information about the newborn. The radiographs were assessed for the presence of chronic apical periodontitis. The association between maternal chronic apical periodontitis and low birth weight preterm birth was subsequently determined. Data was analysed using SPSS 24. Results: Of the 200 subjects, 100(50%) were in group A with a mean age of 27.17±5.11 years, and 100(50%) were in group B with a mean age of 27.08±4.90 years. Low birth weight preterm birth was associated with education level and family size (p0.05). Conclusion: There was no association between maternal chronic apical periodontitis and low birth weight preterm birth. Key Words: Low birth weight infant, Periodontitis, Preterm birth, Adverse pregnancy outcomes, Chronic apical periodontitis. Continuous...

Abstract This study examines the impact of family control on the dividend policy of firms in Pakistan, covering the period from 2009 to 2016. It also investigates whether family control moderates the impact of firm-specific factors on the dividend policy. The GMM model for panel data estimation is used. The mean difference univariate analysis shows that family firms differ from nonfamily firms based on financial characteristics. The multivariate analysis shows that family firms pay lower dividends than nonfamily firms. Besides, firm size inversely affects the dividend policy, whereas tangibility positively affects it. Moreover, family control does not moderate the impact of all firm-specific factors on the dividend policy. Overall, family control, size, and tangibility are found to be the main determinants of the dividend policy in Pakistan.

Objective: To report the caries frequency of proximal surfaces of permanent first molars. Study Design: Descriptive study. Place and Duration of the Study: Department of Operative Dentistry, Dow Dental College, Dow University of Health Sciences Karachi. One month from 1 October 2015 to 31 October 2015. Materials and Methods: The study was conducted on retrospective data of 374 patients presenting to the department of Operative Dentistry, Dow University of Health Sciences. Diagnosis of dental caries was made on selected periapical radiographs using criteria provided by Senel. Caries data and other independent variables e.g. age; gender, arch and side were analyzed with SPSS for windows version 17. Chi square test was used to measure association between proximal caries and qualitative variables such as gender, age group and tooth group. Results: There were more mesial proximal lesions (56.4%) than distal lesions (43.6) in all age groups except for 41-50 years and above 50 years (p=0.109). When maxillary and mandibular teeth were compared with proximal surfaces, mesial surface of maxillary first molar was found to be more carious statistically (p=0.000326) Conclusion: Mesial surface of maxillary permanent first molar was associated with increased risk for dental caries.

This paper investigates the effect of bank competition and financial stability on economic growth by examining panel-data from 38 European countries over 2001 to 2017. Bank competition is measured with the Boone indicator, and bank stability with Z-scores and non-performing loan ratios, all at the country level. This study employs a fixed-effect estimator, as well as a system generalized method of moment (GMM) estimator to control unobserved heterogeneity, endogeneity, the dynamic effect of economic growth, and reverse causality in its estimation. Results show that bank stability significantly contributes to economic growth in Europe. Economic growth falls during crisis periods (both the global financial crisis and the local banking crisis), highlighting the importance of a resilient banking system during crisis periods. Moreover, empirical outcomes show that lower banking competition supports economic growth and increases financial stability. This study provides a framework for banks and regulators to boost economic growth through the channel of banking stability.

This study examines long term and short term inter-linkage between liquidity dimensions and equity returns in oil and gas sector of an emerging stock market for the time period 2009-2015.Conventional liquidity ratio and Amihud ratio are used to capture Price impact. Roll estimator is employed to quantify the effective spread and transaction cost aspect of liquidity. The depth of market is measured through volume and turnover rate. Pedroni cointegration, Granger causality and vector error correction model have been applied in panel data setting. The Pedroni cointegration analysis provides evidence about the existence of long term interaction between liquidity indicators and the equity returns. The VECM reports that liquidity influences equity returns in short run and speed of adjustment is high. Moreover, bi directional casualty is observed between liquidity and equity returns. The results suggest that local market liquidity is an important driver of expected returns. The study further implies that liquidity is vital for asset pricing. Average liquidity is priced and liquidity also predicts future returns. Moreover liquidity shocks are positively correlated with return shocks. Therefore, investors must be vigilant about liquidity trends while making investment decisions.

In this paper, we examine whether jumps matter in both equity market returns and integrated volatility. For this purpose, we use the swap variance (SwV) approach to identify monthly jumps and estimated realized volatility in prices for both developed and emerging markets from February 2001 to February 2020. We find that jumps arise in all equity markets; however, emerging markets have more jumps relative to developed markets, and positive jumps are more frequent than negative jumps. In emerging markets, the markets with average volatility earn higher returns during jump periods; however, highly volatile markets earn higher returns during jump periods in developed markets. Furthermore, markets with low continuous returns and high volatility are more adversely affected during periods of negative jumps. The average ratio of jump variations to total variation shows considerable variations due to jumps. Integrated volatility is high during periods of negative jumps, and this pattern is consistent in both developed and emerging markets. Moreover, the peak volatility of stock markets is observed during periods of crises. The implication of this study is useful in the asset pricing model, risk management, and for individual investors and portfolio managers for both developed and emerging markets.

This is a pioneering study on total accrual reversals, i.e. long-term reversals and their role in company performance in an emerging market. This study observes the impact of total accrual reversals on company performance more exclusively. The sample consists of 100 non-financial companies listed on the Pakistan Stock Exchange (PSE). The purpose is to examine the role of long-term reversals in the performance of companies by observing the impact of total accrual reversals for the current period as well as the previous period on the earnings as it is used as a proxy for company performance. The Pooled OLS Robust method with Driscoll-Kraay standard errors is used. The result indicates that total accrual reversals of the previous and current period affect the earnings of companies positively. This result rejects the perception that accrual reversal does not predict the earnings in the long-term perspective. The study concludes that the role of reversals of total accruals in the performance of companies is positive, which is beneficial for growing companies in an emerging market. Hence, companies should increase the total accrual reversals to enhance their performance and attract foreign investors.

This study aimed to investigate the association between corporate governance characteristics, shariah governance characteristics, and the credit rating of Asian Islamic banks. To do so, we collected data from 22 banks during the 2006–2018 period. In total, we observed 286 data points. Credit rating was measured through an adaption of the credit rating scale that measured the long term credit of Islamic banks on an ordinal scale. From these data, 19 scores (Aaa) were considered high credit ratings and 1 score (C) was considered a low credit rating. Descriptive statistics, correlations, and the ordered logit regression model were applied in a panel setting. We found that the board interlock, board independence, CEO duality, and board foreign directorship negatively affected credit ratings. We also found that the board size, board accounting, finance knowledge, presence of women on the board, shariah board size, presence of supervisory shariah board, the shariah board interlock, and presence of female shariah scholars all were positively associated with credit ratings. This study suggests that Islamic banks can access more funds with higher shariah compliance. As such, we concluded that evaluating organizations’ credit ratings must consider shariah governance attributes as determinants of the credit rating of Islamic banks.

The dependence of various stock markets plays a vital role in diversification while selecting securities in an investor’s portfolio. This study examines interdependence among the East Asian stock markets in relation to the Karachi Stock Exchange. Monthly data ranging from 2000 to 2010 is included and tested in this paper. This relationship is tested by using descriptive statistics and correlation matrix. Data stationarity is ensured by Unit Root Test. Evidence from Granger Causality and Impulse Response Test prove no relationship between KSE and stock markets of the East Asian countries while there exists certain level of unidirectional relationship from Japan to China and from Japan to Pakistan.

In this paper, a compact microstrip feed inset patch sensor is proposed for measuring the salinities in seawater. The working principle of the proposed sensor depends on the fact that different salinities in liquid have different relative permittivities and cause different resonance frequencies. The proposed sensor can obtain better sensitivity to salinity changes than common sensors using conductivity change, since the relative permittivity change to salinity is 2.5 times more sensitive than the conductivity change. The patch and ground plane of the proposed sensor are fabricated by conductive copper spray coating on the masks made by 3D printer. The fabricated patch and the ground plane are bonded to a commercial silicon substrate and then attached to 5 mm-high chamber made by 3D printer so that it contains only 1 mL seawater. For easy fabrication and testing, the maximum resonance frequency was selected under 3 GHz and to cover salinities in real seawater, it was assumed that the salinity changes from 20 to 35 ppt. The sensor was designed by the finite element method-based ANSYS high-frequency structure simulator (HFSS), and it can detect the salinity with 0.01 ppt resolution. The designed sensor has a resonance frequency separation of 37.9 kHz and reflection coefficients under −20 dB at the resonant frequencies. The fabricated sensor showed better performance with average frequency separation of 48 kHz and maximum reflection coefficient of −35 dB. By comparing with the existing sensors, the proposed compact and low-cost sensor showed a better detection capability. Therefore, the proposed patch sensor can be utilized in radio frequency (RF) tunable sensors for salinity determination.