We report ammonium metavanadate catalyzed one-pot synthesis of 3,4-dihydropyrano[3,2-c]chromenes, from aldehydes, active methylene compounds malononitrile and 4-hydroxycoumarin in water:ethanol(1:1) under reflux. The attractive features of this process are mild reaction conditions, short reaction times, easy isolation of products, and excellent yields.

This paper presents a survey on the effect of corporate dividend payout policy on stock price volatility. The primary objective of this study is to examine the impact of dividend payout ratio on the stock price volatility in Pakistan Stock Exchange. A sample of 15 firms from PSX is considered and the study covers the historical data over the period 2011-2015. Stock Price volatility is the dependent variable in this study and dividend payout ratio is the main independent variable. For this purpose, some other independent variables are also included such as Earnings Volatility, Size of the firm, Leverage and Assets Growth. The study has determined a positive relationship between stock price volatility and dividend payout ratio. In addition, our results show that earnings volatility and leverage had negative relationship with stock price volatility. Other independent variables including assets growth and size have maintained positive relationship with stock price volatility.

A convenient, highly efficient and time economic method has been described for the chemo- and regioselective synthesis of 5-aryloyl-1,3,7,9-tetraalkyl-2,8-dithioxo-2,3,8,9-tetrahydro-1H-pyrano[2,3-d:6,5-dˊ]dipyrimidine-4,6(5H,7H)-diones derivatives by one-pot two-component reaction of 1,3-diethyl-2-thiobarbituric acid or 1,3-dimethyl-2-thiobarbituric acid with substituted arylglyoxalmonohydrates using commercially available zirconium (IV) oxydichloride octahydrate (ZrOCl2.8H2O) as green Lewis acid catalyst. This method is associated with some attractive characteristics such as good selectivity, very short reaction time, high yield of products, cleaner reaction profile, no harmful by-product, cheap and environmental benign catalyst, simple experimental and work-up procedure. This procedure does not require solvent separation and purification steps such as column chromatography.

This research includes an extensive review of the studies associated with Corporate Governance. The study uses Scopus database as a primary search engine to collect the necessary data and collects 333 records over the period 2010-2018.The purpose of this research is to investigate the structured study of research activities carried out around the subject of corporate governance which have been published in international, well-known and credible magazines, books and sites. For this purpose, the study searches the phrase corporate governance on Scopus site and detects around 7200 documents and 2000 of highly cited documents are selected for the purpose of the investigation accomplished by a bibliometrics tool. The study limits the survey on published articles over the period 1993-2009 and detects 806 documents among 2000 documents from Scopus. The results indicate that papers published by researchers in United States have received the highest citations (8669), followed by United Kingdom (2094) and Australia with 1557 citations.

This paper summarizes the reaction of DABCO with the enol tosylate derivatives made from (L-Ser-L-Ser) and (L-Phe-L-Ser) diketopiperazines (DKP’s). The reaction between DABCO and EE-di-tosylate (L-Ser-L-Ser) DKP (2), results in the isomerization of the serine di-tosylate from EE-2 to ZZ-2. This is the first direct example of the utility of DABCO as a reagent demonstrating the successful isomerization in a DKP derivative. The E-enol tosylate of (L-Phe-L-Ser) DKP (4) upon reaction with DABCO provided a unique bis-ylidiene product (5).

A four-component reaction of phenylhydrazines, ethyl acetoacetate, aldehydes and β-naphthol has been achieved in the presence of FeCl3/SiO2 nanoparticles as a highly effective heterogeneous catalyst to produce 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones in good to excellent yields, short reaction times, mild reaction conditions and the employment of a cost-effective catalyst.

Efficient and stable performance of the banking system underpins sustainable growth of any economy. Of late, several economic reforms have been initiated in India for facilitating growth and withstanding dynamics of global economy. In this context, the current study compares the performance of the selected private and public sector banks in India on a five year time horizon in order to discern any changes in the performance over a period of time. First, the performance of the selected banks are examined in terms of management efficiency perspective using a Multi-Criteria Decision Making (MCDM) technique such as Combinative Distance-based Assessment (CODAS) when an Entropy method is also employed for determining criteria weight. The study also applies k-Means Clustering for checking consistency of performance based ranking with asset management efficiency. Finally, the paper delves into the relationship between financial and market performance. The study has found consistent results and observed private sector banks perform better than the public sector.

Pirochromite (MgCr2O4) nanoparticles were successfully prepared in this study. During synthesis of the pirochromite nanoparticles, a sol-gel was prepared by using magnesium acetate and potassium dichromate as magnesium and chromium sources and by using stearic acid as the network. Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used for the elemental analysis, and diffuse reflectance spectroscopy (DRS) and vibrating sample magnetometer (VSM) were used in order to identify, provide a fuzzy diagnosis, and determine the size and morphology of the particles, as well as to analyze the optical and magnetic properties of the particles. The particle size of MgCr2O4 nanoparticles was observed to fall within a range of 39 nm–71 nm.

This study aims to investigate the relationship among performance risk, safety risk, social risk, psychological risk, satisfaction, and intention to use Grab in Vietnam. Validated measurements were identified from a literature review. A convenience sample of 276 respondents was collected through online and offline survey. It was then analyzed by using SPSS and AMOS software. A reliability test, EFA, CFA and SEM were implemented. The results of this study indicate a negative relationship between safety risk and satisfaction and intention to use Grab cars. In addition, passengers’ satisfaction influenced intentions to use Grab cars. However, performance risk and social risk show no effect on satisfaction and intentions to use Grab service. The main contribution of this study is to create a framework of the effect of perceived risk types on intention to use Grab cars. The users care about their own safety and information security. In addition, the issue of said psychological risk is important because consumers are concerned about health and infectious diseases.

Emergency department (ED) overcrowding is a common issue in emergency medicine of Canada. Previous studies indicate that adding a physician in triage (PIT) can increase accuracy and efficiency in the initial process of patient evaluations. However, the PIT concept should be thoroughly researched before its widespread implementation can be recommended. This paper introduces the evaluation of impact of PIT on ED patient wait times and length of stay (LOS) using simulation modeling. A discrete-event simulation model of ED is built to simulate and predict the effect of PIT intervention. The model performance is validated using current-state ED flow metrics to quantitatively test multiple alternatives for ED improvements. Results show that the PIT implementation can reduce the ED patient LOS by an average of 34% and Waiting to be Seen time by 49% across all scenarios studied. The proposed method can be applied to improve the operation efficiency of healthcare systems in the current pandemic, COVID -19.