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The fused filament fabrication (FFF) process is an additive manufacturing technique used in engineering design. The mechanical properties of parts manufactured by FFF are influenced by the printing parameters. The mechanical properties of rigid thermoplastics for FFF are well defined, while thermoplastic elastomers (TPE) are uncommonly investigated. The purpose of this paper is to investigate the influence of extruder temperature, bed temperature and printing speed on the mechanical properties of a thermoplastic elastomer.

Regression models predicting mechanical properties as a function of extruder temperature, bed temperature and printing speed were developed. Tensile specimens were tested according to ASTM D638. A 3×3 full factorial analysis, consisting of 81 experiments and 27 printing conditions was performed, and models were developed in Minitab. Tensile tests verifying the models were conducted at two selected printing conditions to assess predictive capability.

Each mechanical property was significantly affected by at least two of the investigated FFF parameters, where printing speed and extruder temperature terms influenced all mechanical properties (p < 0.05). Notably, tensile modulus could be increased by 21%, from 200 to 244 MPa. Verification prints exhibited properties within 10% of the predictions. Not all properties could be maximized together, emphasizing the importance of understanding FFF parameter effects on mechanical properties when making design decisions.

This work developed a model to assess FFF parameter influence on mechanical properties of a previously unstudied thermoplastic elastomer and made property predictions within 10% accuracy.

The great value of offline identification of machine parameters is when the machine manufacturer does not provide its parameters. Most machine control strategies require parameter values, and some circumstances in the industrial sector only require offline identification. This paper aims to present a new offline method for estimating induction motor parameters based on least squares and a salp swarm algorithm (SSA).

The central concept is to use the classic least squares (LS) method to acquire the majority of induction machine (IM) constant parameters, followed by the SSA method to obtain all parameters and minimize errors.

The obtained results showed that the LS method gives good results in simulation based on the assumption that the measurements are noise-free. However, unlike in simulations, the LS method is unable to accurately identify the machine’s parameters during the experimental test. On the contrary, the SSA method proves higher efficiency and more precision for IM parameter estimation in both simulations and experimental tests.

After performing a primary identification using the technique of least squares, the initial intention of this study was to apply the SSA for the purpose of identifying all of the machine’s parameters and minimizing errors. These two approaches use the same measurement from a simple running test of an IM, and they offer a quick processing time. Therefore, this combined offline strategy provides a reliable model based on the identified parameters.

This paper aims to characterize and develop a new ecological lightweight concrete reinforced by addition of palm plant fibers (from vegetal waste) to be used in the thermal and acoustical insulation of local constructions. The date palm plant fibers are characterized by their low sensitivity to chemical reactions, low cost and large availability in local regions. Therefore, the newly obtained lightweight concrete may suggest a great interest, as it seems to be able to achieve good solutions for local construction problems, technically, economically and ecologically.

The experimental program focused on developing the composition of palm-fiber-reinforced concrete, by studying the effect of the length of the fibers (10, 20, 30 and 40 mm) and their mass percentage (0.5%, 1%, 1.5% and 2%), on the mechanical and acoustical properties of the composite. The main measured parameters were the compressive strength and flexural strength, sound absorption coefficient, noise reduction coefficient (NRC), etc. These tests were also borne out by the measure of density and water absorption, as well as microstructure analyses. To fully appreciate the behavior of the material, visualizations under optical microscope and scanning electron microscope analyses were carried out.

The addition of plant fibers to concrete made it possible to formulate a new lightweight concrete having interesting properties. The addition of date palm fibers significantly decreased the density of the concrete and consequently reduced its mechanical strength, particularly in compression. Acceptable compressive strength values were possible, according to the fibers content, while better values have been obtained in flexion. On the other hand, good acoustical performances were obtained: a considerable increase in the sound absorption coefficient and the NRC was recorded, according to the content and length of fibers. Even the rheological behavior has been improved with the addition of fibers, but with short fibers only.

Over the recent decades, many studies have attempted to search for more sustainable and environmentally friendly building materials. Therefore, this work aims to study the possibility of using waste from date palm trees as fibers in concrete instead of the conventionally used fibers. Although many researches have already been conducted on the effect of palm plant fibers on the mechanical/physical properties of concrete, no information is available neither on the formulation of this type of concrete nor on its acoustical properties. Indeed, due to the scarcity of raw materials and the excessive consumption of energy, the trend of plant fibers as resources, which are natural and renewable, is very attractive. It is therefore a major recycling project of waste and recovery of local materials.

Departing from Turkish national debates around Islam, national belonging, and homosexuality during 2008–2011, this paper shows how “LGBT rights” discourses ultimately worked to position Muslim headscarf activists as against LGBT activists by rendering complex positions that do not follow easy “for vs. against” LGBT rights political formulas as “homophobic.” In return, this foreclosed potential solidarities differently injured citizens could have formed against increasing neoliberal state violence. I show that the multitude of Muslim women’s positions on the issue of LGBT rights complicates easy religious/secular binaries and illuminates how it is not only human rights discourses but also their “Western” critiques that travel transnationally. This story also contributes to current debates on postsecularism by illustrating how the same national context can house both liberal rights frameworks that can be used against pious Muslim subjects, and a monopolization of a definition of Islam for state power. Finally, I offer “politics of cruelty” and “right to sin” as alternative frameworks for imagining social justice outside of liberal rights-based politics.

This paper examines the time-varying return connectedness between renewable energy, oil, precious metals, the Gulf Council Cooperation region and the United States stock markets during two successive crises: the pandemic Covid-19 and the 2022 Russo-Ukrainian war. The main objective is to investigate the effect of the Covid-19 pandemic and the Russo-Ukrainian war on the connectedness between the considered stock markets.

This paper uses the time-varying parameter vector autoregression approach, which represents an extension of the Spillover approach (Diebold and Yilmaz, 2009, 2012, 2014), to examine the time-varying connectedness among stock markets.

This paper reflects the effect of the two crises on the stock markets in terms of shock transmission degree. We find that the United States and renewable energy stock markets are the main net emitters of shocks during the global period and not just during the two considered crises sub-periods. Oil stock market is both an emitter and a receiver of shocks against Gulf Council Cooperation region and United States markets during the full sample period, which may be due to price fluctuation especially during the two crises sub-periods, which suggests that the future is for renewable energy.

This paper examines the effect of the two recent and successive crises, the Covid-19 pandemic and the 2022 Russo-Ukrainian war, on the connectedness among traditional stock markets (the United States and Gulf Council Cooperation region) and commodities stock markets (renewable energy, oil and precious metals).

Given the competitiveness of the business environment globally, environmental, social and governance (ESG), which represents a sustainable development framework that integrates environmental, social and corporate governance factors, has become an increasingly recognized concept in emerging markets. In the case of Ghana, its implementation is influenced by several factors, including leadership.

Drawing on the resource-based view theory, higher-order theory and stakeholder theory, we developed and evaluated a serial mediation model to explain how ESG performance and corporate reputation can connect transformational leadership to enhance competitive advantage. Utilizing the Process Macro model 6 in SPSS, data were collected from 340 senior managers/executives and middle-level managers from European multinational firms operating in Ghana.

The results indicate that transformational leadership positively affects ESG performance. Enhanced ESG performance, in turn, leads to improved corporate reputation, which subsequently results in a stronger competitive advantage.

This study is limited to European multinational firms operating in Ghana, which may restrict the generalizability of the findings to other contexts or regions.

The findings suggest that organizations aiming to strengthen their competitive advantage should prioritize transformational leadership practices that foster ESG initiatives, as these are critical drivers of corporate reputation and market positioning.

This study provides new insights into the interwovenness between ESG performance and leadership in enhancing corporate reputation and competitive advantage within the context of emerging markets.

The objective of this study is to investigate further the interplay between corporate governance and firm performance with special focus on a situation expected to bring larger agency costs to the firm, that is, when voting rights of the dominant shareholder exceed his/her cash flow rights.

The research is conducted in Canada over a four‐year period from 2002 to 2005 and uses a balanced sample of 130 firms or 520 firm‐year observations. Corporate governance is measured based on the ROB corporate governance index published by The Globe and Mail.

The results clearly show a positive and significant relationship between the ROB governance scores and Tobin's Q, when there is a separation between voting and cash flow rights. In the absence of any excess voting rights, no significant relation is found between governance and performance.

The findings suggest that regulators need to exercise caution before deciding whether or not to recommend or impose corporate governance rules for all firms, since the benefits of these rules may vary among the firms.

The study contributes to explaining mixed international evidence on the governance‐performance relationship, while directing attention to the moderating effect of the deviation from the one share‐one vote principle. To the best of the authors' knowledge, no other study using corporate governance indices has taken into account the impact of excess voting rights despite the widespread use of that practice outside the USA.

The purpose of this paper is to develop an approach for implementing business excellence (BE) based on prevailing corporate culture and to propose relevant gates to monitor the corporate culture in the way to excellence.

This research demonstrates a culture-based perspective of implementing BE. After an exhaustive review of literature, the relation between BE and corporate culture was clarified and a methodology was developed, which describes how BE projects can be performed successfully in the context of an existing culture instead of adapting the culture.

The outcome of this research is the main concept for culture-based implementation of BE. Furthermore, five culture gates were designed to control the effect of BE measures on the corporate culture in long period of time. The findings indicate how BE can be implemented without considerable efforts to change the culture.

The findings of this study are relevant to all different sized organizations in different sectors and industries for achieving outstanding results and maintain this capability permanently in the organization.

This paper presents a unique approach for implementing BE in the light of prevailing corporate culture; such an approach has not been addressed in previous publications.

The purpose of this paper is to investigate the effect of the replacement of natural coarse aggregate (NCA) with different percentages of recycled coarse aggregate (RCA) on properties of low calcium fly ash (FA)-based geopolymer concrete (GPC) cured at oven temperature. Further, this paper aims to study the effect of partial replacement of FA by ground granulated blast slag (GGBS) in GPC made with both NCA and RCA cured under ambient temperature curing.

M25 grade of ordinary Portland cement (OPC) concrete was designed according to IS: 10262-2019 with 100% NCA as control concrete. Since no standard guidelines are available in the literature for GPC, the same mix proportion was adopted for the GPC by replacing the OPC with 100% FA and W/C ratio by alkalinity/binder ratio. All FA-based GPC mixes were prepared with 12 M of sodium hydroxide (NaOH) and an alkalinity ratio, i.e. sodium hydroxide to sodium silicate (NaOH:Na₂SiO₃) of 1:1.5, subjected to 90^°C temperature for 48 h of curing. The NCA were replaced with 50% and 100% RCA in both OPC and GPC mixes. Further, FA was partially replaced with 15% GGBS in GPC made with the above percentages of NCA and RCA, and they were given ambient temperature curing with the same molarity of NaOH and alkalinity ratio.

The workability, compressive strength, split tensile strength, flexural strength, water absorption, density, volume of voids and rebound hammer value of all the mixes were studied. Further, the relationship between compressive strength and other mechanical properties of GPC mixes were established and compared with the well-established relationships available for conventional concrete. From the experimental results, it is found that the compressive strength of GPC under ambient curing condition at 28 days with 100% NCA, 50% RCA and 100% RCA were, respectively, 14.8%, 12.85% and 17.76% higher than those of OPC concrete. Further, it is found that 85% FA and 15% GGBS-based GPC with RCA under ambient curing shown superior performance than OPC concrete and FA-based GPC cured under oven curing.

The scope of the present paper is limited to replace the FA by 15% GGBS. Further, only 50% and 100% RCA are used in place of natural aggregate. However, in future study, the replacement of FA by different amounts of GGBS (20%, 25%, 30% and 35%) may be tried to decide the optimum utilisation of GGBS so that the applications of GPC can be widely used in cast in situ applications, i.e. under ambient curing condition. Further, in the present study, the natural aggregate is replaced with only 50% and 100% RCA in GPC. However, further investigations may be carried out by considering different percentages between 50 and 100 with the optimum compositions of FA and GGBS to enhance the use of RCA in GPC applications. The present study is further limited to only the mechanical properties and a few other properties of GPC. For wider use of GPC under ambient curing conditions, the structural performance of GPC needs to be understood. Therefore, the structural performance of GPC subjected to different loadings under ambient curing with RCA to be investigated in future study.

The replacement percentage of natural aggregate by RCA may be further enhanced to 50% in GPC under ambient curing condition without compromising on the mechanical properties of concrete. This may be a good alternative for OPC and natural aggregate to reduce pollution and leads sustainability in the construction.