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The purpose of this paper is to present experimental studies on the designed muffler which contains ceramic foam and has the integration function of purification and noise elimination.

Comparative tests were done on a diesel engine with no muffler, the original muffler and the purification muffler. The soot index (light absorption coefficient), A-weighted sound pressure level and fuel consumption rate, which were collected by the partial flow opacity method, the insertion loss measurement of spatial five points and the load characteristics tests, respectively, and the effects of purification and noise elimination were studied.

The results of this paper state that the purification muffler shows great improvement on exhaust soot purification and noise elimination. The variation in diesel fuel consumption rate was small, the sound pressure level of purification muffler was reduced by 6 to 10 dB, the insertion loss of the purification muffler was increased by 6.41 dB and the average light absorption coefficient decreased by 57.8 percent compared with the original muffler.

The value of this study is that it supplies a purification muffler which contains a ceramic foam. Under the prerequisite of little effect on the fuel economy of diesel engine, the purification muffler shows great improvement in exhaust soot purification and noise elimination.

One important study in the portfolio investment is the study of the optimal asset allocations. Markowitz is the pioneer of modern portfolio theory that analyses the performance of portfolio based on the mean (reward) and variance (risk). Motivated by the Markowitz's mean variance model, the purpose of this paper is to propose a new portfolio optimization model that takes into consideration both processes of purification and screening, which are key to constructing a Shariah-compliant portfolio. In practice, this paper introduces a stochastic purification variable and a probabilistic screening constraint into a portfolio model.

First, the authors study the stochastic nature of purification variable and apply it to both investment and dividend purification. Second, recognizing that the importance of on-going screening could adversely affect the portfolio strategy, the authors impose probabilistic constraints to control the risk of compliance change. They evaluate the proposed model by formulating the screening constraints at both asset and portfolio levels, together with three different financial screening divisors that are broadly used by the international Shariah boards. The authors also conduct an extensive empirical study using a sample of Shariah-compliant public companies listed on the Indonesia Stock Exchange.

Based on the empirical example presented in this paper, the authors found that the purification variable in the proposed model is closer to the practice in the Sharia capital market in terms of the nature of the non-constant data, and this variable reduces the total income of portfolio which has not been captured in the previous literature. The authors also have successfully derived the portfolio screening constraint to mitigate the risk of the asset change to be non-compliant in the future.

Based on the authors’ knowledge, this is the first paper that proposed the stochastic purification and the dynamic of screening processes into the Shariah portfolio model. This paper also examines the impact of non-short-selling, purification and screening policies to the performance of Shariah portfolio.

“Scale purification” – the process of eliminating items from multi-item scales – is widespread in empirical research, but studies that critically examine the implications of this process are scarce. The goals of this research are threefold: to discuss the methodological underpinning of scale purification, to critically analyze the current state of scale purification in supply chain management (SCM) research and to provide suggestions for advancing the scale-purification process.

A framework for making scale-purification decisions is developed and used to analyze and critically reflect on the application of scale purification in leading SCM journals.

This research highlights the need for rigorous scale-purification decisions based on both statistical and judgmental criteria. By applying the proposed framework to the SCM discipline, a lack of methodological rigor and coherence is identified when it comes to current purification practices in empirical SCM research. Suggestions for methodological improvements are provided.

The framework and additional suggestions will help to advance the knowledge about scale purification.

This paper demonstrates that the justification for scale purification needs to be driven by reliability, validity and parsimony considerations, and that this justification needs to be based on both statistical and judgmental criteria.

This paper aims to identify scale purification criteria for both uni- and multidimensional reflective scales and apply these criteria to an evaluation of the methodological status quo of the hospitality literature.

Based on a literature review, the authors develop a taxonomy of statistical and judgmental criteria across scale levels, from which best practices are derived. Recent publications in leading hospitality journals are then evaluated based on these scale purification steps.

The authors uncover a lack of transparency when reporting scale purification practices. Moreover, methodological steps are often entirely omitted or insufficiently followed, especially when it comes to judgmental scale purification practices.

The authors focus on reflective scales in the hospitality discipline. Methodological traditions in other fields might lead to different results if the chosen approach was to be repeated there.

The authors provide a set of suggestions that will help researchers in hospitality and adjacent disciplines to greater consensus and consistency of application regarding the methodological steps when carrying out scale purification in reflective scales.

Application of scale purification in hospitality research has been scarce. The authors extend existing research and provide the most comprehensive study so far of present and best scale purification practices, using both statistical and judgmental criteria.

This paper aims to propose a Shariah-compliant multi-period fuzzy portfolio optimization model that accounts for Shariah compliance through purification processes and incorporates various Shariah constraints, including sustainability constraints. This model aims to ensure both ethical alignment and robust portfolio management while navigating modern financial complexities and fostering responsible and sustainable investment practices.

The methodology involves a dynamic programming method to solve the proposed program, with returns of the assets assumed to be trapezoidal fuzzy variables. This approach allows for the quantification of portfolio return and risk by the possibilistic mean and semivariance of the fuzzy returns, respectively. A numerical study based on real stock market data tests the efficiency of the proposed algorithm.

The research showcases the model’s effectiveness in managing Shariah-compliant portfolios under financial uncertainties and supports the importance of incorporating ethical and sustainability constraints in investment decisions. It highlights the capability of the proposed model to offer a structured approach to ethical investing within the Islamic finance framework.

While the paper provides a solid foundation for Shariah-compliant portfolio optimization, it acknowledges the complexity and computational demands of the model. Future research could explore simplifying the model without compromising its ethical and Shariah-compliant principles.

This work introduces a novel integration of Shariah compliance with fuzzy portfolio optimization techniques, addressing the need for dynamic, ethical investment strategies in Islamic finance. The incorporation of purification processes and sustainability constraints into a fuzzy portfolio optimization model represents a unique contribution to the field.

In addition to agriculture, energy production, and industries, potable water plays a significant role in many fields, further increasing the demand for potable water. Purification and desalination play a major role in meeting the need for clean drinking water. Clean water is necessary in different areas, such as agriculture, industry, food industries, energy generation and in everyday chores.

The authors have used the different search engines like Google Scholar, Web of Science, Scopus and PubMed to find the relevant articles and prepared this mini review.

The various stages of water purification include coagulation and flocculation, coagulation, sedimentation and disinfection, which have been discussed in this mini review. Using nanotechnology in wastewater purification plants can minimize the cost of wastewater treatment plants by combining several conventional procedures into a single package.

In society, we need to avail clean water to meet our everyday, industrial and agricultural needs. Purification of grey water can meet the clean water scarcity and make the environment sustainable.

This mini review will encourage the researchers to find out ways in water remediation to meet the need of pure water in our planet and maintain sustainability.

This paper aims to add to the debate regarding the appropriate methodology to purify tainted components from shari’ah-compliant equities.

Based on the Qur’anical prohibition against riba and an analysis of the purification methodology recommended by Accounting and Auditing Organisation for Islamic Financial Institutions (AAOIFI) shari’ah Standard 21, this paper highlights the shortcomings in Standard 21 and references the corporate finance literature to argue for the need to also purify the interest tax shield from debt.

Purification is a pivotal element of the Islamic investment process, yet Standard 21 permits a loose interpretation which causes portfolios to be under-purified. Standard 21 also makes no mention of the interest tax shield from debt even though the benefits are at odds with the principles of social justice in Islam. That there is no mention of the interest tax shield from debt in the (limited) literature on the purification of Islamic equities is puzzling.

This paper has implications for the Islamic funds industry and for devout Muslim investors.

The specific contribution of this paper is the identification of the interest expense tax shield (well-established in the corporate finance literature) as a significant non-compliant riba-related component that needs to be considered in the purification process.

The main objective of the present investigation is to develop a novel efficient stochastic model for availability optimization of reverse osmosis machine system (ROMS) for water purification under the concepts of exponentially distributed decision variables and various redundancy strategies at the component level.

ROMS is a complex framework configured in a series structure using six subsystems. Initially, a state transition diagram is developed and Chapman–Kolmogorov differential-difference equations are derived using Markov birth death process. The steady-state availability of the ROMS is derived for a particular case. The impact of variation in failure and repair rates measured on availability. Furthermore, an effort is made to predict the optimal availability of the ROMS system using the metaheuristic algorithms, namely, dragonfly algorithm (DA), grasshopper optimization algorithm (GOA) and whale optimization algorithm (WOA).

It is observed that the ROMS system predicts optimal availability of 0.999926 after five iterations with a population size of 300 by the WOA. The findings of this study are significant for reliability engineers as well as for maintenance engineers to ensure the availability of ROMS for water purification.

In the present investigation, a novel stochastic model is developed for ROMS, and metaheuristics algorithms are applied to predict the optimal availability.

Cross-boundary cooperation with shared goals and values involving the poor has been argued as an indispensable means for inclusive business (IB) success. Cooperation may become dynamic, especially when exploratory and creative attempts with effective cooperative learning among partners can be realized. Even so, not many companies have reported successful in building the cooperation. One case, providing clean, affordable drinking water to the poor in Tanzanian rural villages, suggests that a delegated and grassroots-based approach in cooperation with a highly trustworthy local partner can successfully promote cooperative learning and transfer know-how in both operations and management. This approach also stimulates local and self-initiated activities for expanding water facilities and generating local businesses in an area where employment is scarce. Deviation from mainstream-institution-based operations and management is one example of institutional interconnections that enable the rural poor to self-manage projects and stimulate self-initiated business activities, consequently contributing to rural development and sustainable development goals.

To prepare and characterise vinyl ester (Bisphenol‐A‐glycidyldimethacrylate (BisGMA)) prepolymer via a new synthetic route involving the esterification of methacrylic acid and epoxy resin.

BisGMA prepolymer was synthesised from methacrylic acid and diglycidyl ether of bisphenol‐A‐type epoxy resin. The compound synthesised was then purified and characterised.

BisGMA prepolymer was synthesised from methacrylic acid and diglycidyl ether of bisphenol‐A‐type epoxy resin using triphenylphosphine as a catalyst and hydroxy toluene as a stabiliser. The synthesised compound was then purified by normal phase liquid chromatography and was analysed by proton NMR and reverse phase HPLC. The cure kinetics of the purified resin was investigated by differential scanning calorimetry (DSC) using NETZSCH thermo kinetics software.

The preparation, purification and kinetics study of the prepolymer described in the present investigation may be useful for preparation, purification and kinetics study of the other vinyl esters by a new synthetic route. Also, the polymer supports based on BisGMA have acceptable mechanical properties, chemical stability and are suitable for dental restoratives, fissure sealants, coatings, adhesives, moulding compounds, structural laminates, electrical applications and military/aerospace applications.

The method for the preparation, purification and kinetics study of the prepolymer is simple and provides a simple and practical solution for some other vinyl esters.

This is a novel method for synthesis and purification of BisGMA and may be useful for the synthesis and purification of other vinyl esters.