A combination of electrically tunable lens with a microscope objective lens (MO) for multifocal plane imaging capability is proposed. The method aims at extending the depth of focus of the MO by ...changing its axial range and field of view. The combination is implemented in a common path off-axis digital holographic microscopy configuration experimentally and it achieves an axial scanning range of 363.5 μm. It utilizes image plane holography to obtain in-focus images throughout the axial range. The proposed method demonstrates its application in quantitative phase imaging of the USAF 1951 test chart and flowing red blood cells at different axial depths. An axial depth variation of 0.76 μm-0.81 μm is obtained between two consecutive focused planes. The results validate and postulate the advantage of the proposed method over traditional extended depth-of-focus algorithms. The quantitative and qualitative results exploit the possibility of using the proposed method further for localization and tracking of flowing microscopic samples.
The physicochemical analysis of collected effluent sample for different parameters shown results as pH (pH 5.6 ± 0.11) slightly acidic, high conductivity (1563.34 ± 176 μs cm
−1
), total dissolved ...solids (920.34 ± 137 mg L
−1
), high BOD (7253.34 ± 1022 mg L
−1
), and COD (756.67 ± 1124 mg L
−1
) in the effluent sample. The results of heavy metals concentration are viz. as Cu (1.98–2.56), Co (0.26–0.53), Cd (0.10–0.50), Ni (0.04–0.07), Pb (0.58–1.2), Mn (0.58–1.05), Cr (1.47–1.51), Zn (2.61–3.5), Fe (1.72–2.13), As (0.05–0.09), and Hg (0.003–0.006). Results revealed the higher concentration of BOD, COD, TDS, and conductivity and also the concentration of lead. Results of GC–MS also confirmed the high levels of organic pollutants in effluent. Further the effluent toxicity was evaluated by employing genotoxocity assays with the use of
Allium cepa
L. (onion) root tip cells. Genotoxicity measured mitotic index (MI) and chromosomal aberrations (CAs) in root tip cells obtained after treatment with effluent of 6.25, 12.5, and 25% concentration (v/v). The results of root growth test showed that inhibition of root growth occurred at effluent concentration ≥ 50% (v/v). The lowest MI was recorded (MI = 9.6%) in 25% of effluent concentration, showing a significant reduction in mitotic index compared with control which MI = 64.1%. Further, the chromosomal aberration was investigated in root tip cell after treating with different concentration ranges of effluent exhibiting various CA, viz. c-mitosis, chromosome loss, chromosome break, micronucleated cells, etc. The result suggests that the effluent contained toxic constituents, which imposed cytotoxic and genotoxic hazard.
PurposeThe authors examine the impacts of corporate announcements on stock returns during the pandemic stress.Design/methodology/approachThe authors employ the event study methodology with the market ...model on a sample of 90 events (announcement and ex-date).FindingsThe authors find that all the corporate announcements do not impact the stock returns in a similar pattern. While the bonus announcement, ex-bonus and ex-split events led to positive significant abnormal returns on the event date, the rights issue and stock-split announcements failed to influence the stock returns. The findings suggest that before making such announcements, the corporates should wait until the market recovers because even the positively impacting events result in negative market responses during pandemic stress.Practical implicationsThis study will guide the policymakers to stimulate share prices during such pandemics with the help of various corporate announcements. The investors will be assisted in understanding the stock market mechanism and making wise decisions before reacting to corporate actions during a pandemic or emergency period. While the policymakers are concerned with influencing the share prices, the investors are concerned with the composition of the risk-return parameters in their portfolio. This study will act as an essential investment tool for both.Originality/valueTo the best of the authors’ knowledge, the authors conduct the first-ever study to examine the impacts of corporate announcements during a pandemic stress period that significantly contributes to the literature. The authors examine the announcement effects in India and accurately anticipate that this study will be a pioneer in this field. This study also paves the way for future researches in this area.
Artificial Intelligence (AI) is a concept of recent origin and is accepted for banking activities such as customer service, detection of fraudulent activities, and suspicious transactions. For the ...successful implementation of AI in the Indian context, a deep understanding is required in terms of its need and importance compared to the traditional banking system. To date, this outlook of AI has been less focused by industry practitioners and experts for the smooth flow of operational procedures in banks for developing countries, for example, India. This study aims to unearth factors and establish a relationship among the identified factors through the decision-making trial and evaluation laboratory (DEMATEL) approach to categorize the factors and frame the cause-and-effect relationships. Fifteen factors are identified through a literature review of existing studies, and ten experts were solicited to express their outlook on this subject. The result indicated that 'Transparency of information,' 'Perceived security of AI-based technology,' 'Social influence on customer,' 'Government regulation of AI in banks,' 'Awareness level of AI,' 'Efficiency of AI system,' 'Technical requirement,' and 'Cost of AI-based technology' were causative factors that support customer acceptance and penetration of AI in banks. The study presents a unique approach to customer acceptability towards AI in banks in developing countries using the DEMATEL technique. This study also discusses the possible area for the adaption of AI in Indian banks. The findings will support policymakers and practitioners in executing AI-based technologies in the banking sector in emerging nations.
Tissue segregation plays a crucial role in the measurement of breast density in breast magnetic resonance (MR) images. This paper proposes a mathematical analysis of the new distribution mixture ...model for the intensity spectrum of breast MR images using Gamma and Gaussian distribution for fibro-glandular and adipose tissues, respectively. The thorough regression analysis and mapping presented in this paper clearly indicate that the distribution of Gamma is best suited to the spectrum of fibro-glandular tissue intensities relative to the standard Gaussian distribution. Moreover, Gamma distribution can represent both symmetric and non-symmetric (skewed) intensity distributions in a more efficient way, leading to a more accurate segmentation of fibro-glandular and adipose tissues. The efficiency of the segmentation is quantified by measuring the standard performance appraisal steps : Dice similarity coefficient, Jaccard index and dissimilarity index. The whole mathematical analysis is performed on a data set of 200 patients with 160 axial slices per subject with various breast sizes and densities. The Gamma Gaussian mixture model (GaGMM’s) assessment metrics indicate an improvement of 39.4 %, 46.8 % and 54.9 %, respectively, in relation to the Gaussian mixture model.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PurposeThis study examines the impact of the Russia–Ukraine war on the constituent firms of the leading stock market indices of the G7 countries to provide insights into the vulnerability of firms to ...war events.Design/methodology/approachThis study employs the event study method on a sample of 531 firms covering the period from 02 March 2021 to 08 March 2022 and conducts a cross-sectional analysis of cumulative abnormal returns and country- and firm-specific variables.FindingsRisk exposure and trade dependence trigger invasion-generated negative abnormal returns. The authors demonstrate that stock prices are fragile to geopolitical risks and trade dependence. Consistent with previous literature, the authors find evidence of a size anomaly and high risk associated with a higher book-to-market ratio.Research limitations/implicationsThis study has implications for policymakers identifying the firm-specific variables driving event-induced returns. While providing insights into the geographical diversification of funds, this study shows the heterogeneous characteristics of firms operating in these countries.Originality/valuePrevious studies on the Russia–Ukraine war have been limited to analyzing the behavior of leading stock market indices without examining firm-level variations triggered by the war. This study fills this gap and contributes to the growing literature on the Russia–Ukraine crisis in two ways: first, it provides firm-level evidence from the G7 countries in addition to how global stock market indices have reacted to the invasion and second, it uses cross-sectional analysis to provide evidence of the characteristics that make firms resilient to wars.HighlightsWe are the first to report firm-level evidence of the Russia–Ukraine war effectsFirms in France and the United States are unaffectedStock prices are fragile to geopolitical risks and considerable dependence on tradeHigher book-to-market exposes the firms to the risk of exogenous shocksSmaller firms outperform large firms in the G7 stock markets
This study examines the market reaction to the 2022 Russian invasion of Ukraine on the leading European Union stock market indices employing the event study method, cross-sectional and network ...analysis We find adverse event day impact on the stock market indices. Further, Poland, Denmark, and Portugal exhibit positive cumulative abnormal returns post-event. A few developed nations are insignificant to the war event. The findings are attributable to the geographic proximity to the war zone and the market efficiency. While the developed markets and NATO nations exhibit positive returns, the economic sanctions and the fear of reduced exports negatively drive abnormal returns during the post-event windows. Contrary to previous studies, stronger past returns negatively drive the returns during the post-event windows. Additional analysis on the mapping of financial networks provides relevant insights into systemic integration between EU stock markets, especially during the war.
•No negative impact on Belgium, Denmark, Luxembourg, Netherlands and Spain.•Denmark, Poland, and Portugal exhibit more substantial positive impacts post-event.•Developed markets and NATO nations exhibit positive returns during the event window.•Economic sanctions and fear of reduced exports negatively drive the abnormal returns.•The financial network of the EU stock markets changes significantly during war.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Impact of the Russian invasion of Ukraine on global stock market indices.•Developed markets more heavily and negatively impacted than emerging markets.•Exceptionally, US markets positively impacted ...by the war on the event day.•War has not affected Asian markets.•Trade-to-GDP negatively associated with abnormal returns during the war.
Using an event study methodology to examine the impact of the 2022 Russian invasion of Ukraine, we find that this invasion generated negative cumulative abnormal returns for global stock market indices, but with heterogeneous effects. Cross-sectional analysis reveals that economic globalization as measured by GDP-scaled trade is negatively associated with event-day and post-event returns. Consistent with the expected economic stimulus of military preparedness, markets of NATO countries exhibited higher returns. Results are consistent with markets of more globalized economies being more vulnerable to international conflicts, with, however, notable heterogeneities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
With a sample of 332 dividend announcements from January 2019 to December 2020, using the event study methodology with the market model, we provide evidence that the dividend announcements failed to ...influence the stock prices under the pandemic stress. Although the pre-pandemic period announcements significantly impacted the stock returns, the pandemic period dividend announcements failed to generate significant abnormal returns even for an increase in dividend over the previous year. The pre-pandemic period results are consistent with previous literature with significant returns for constant, increase, and decrease in dividends. During the pre-pandemic period, we also find the possibility of information leakage in the Indian stock market as the pre-announcement period is marked with positive significant abnormal returns while the post-announcement period seems to be profit booking. The industry-wise analysis reveals the presence of positive returns in the Information Technology, Media and Telecommunication sector. However, the rest of the results are in line with the previous analysis. The findings suggest that before making such announcements, the companies should wait for the market to recover; else, the positively impacting dividend announcement will fail to influence the stock prices when the market is already under pandemic stress. We conduct the first-ever study to examine the impacts of dividend announcements during a pandemic stress period with also comparing the impacts during the pre-pandemic period.
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CEKLJ, FFLJ, GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, ODKLJ, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This work presents the design of a modified Vivaldi antenna, a metamaterial structure and their combined utilization for tuning the gain. Two triangular shaped conducting patches are used to form a ...(5 mm × 5 mm) unit metamaterial structure, which is used on the Vivaldi antenna to enhance the bandwidth and the gain. The proposed antenna has a −10 dB bandwidth of 17.36 GHz ranging from 3.3 to 21.6 GHz. The absorption capability of the metamaterial structure is observed for multiple polarization angles and the corresponding losses are also measured. The metamaterial surface, made up of periodic arrays of the proposed structure, is further implemented to tune the gain of the antenna, to make an application-independent near-field microwave imaging instrument.
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