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The main objective of the present research is to investigate the benefits of using geogrid reinforcement in minimizing the rate of deterioration of ballasted rail track geometry resting on soft clay and to explore the effect of load amplitude, load frequency, presence of geogrid layer in ballast layer and ballast layer thickness on the behavior of track system. These variables are studied both experimentally and numerically. This paper examines the effect of geogrid reinforced ballast laying on a layer of clayey soil as a subgrade layer, where a half full scale railway tests are conducted as well as a theoretical analysis is performed.

The experimental tests work consists of laboratory model tests to investigate the reduction in the compressibility and stress distribution induced in soft clay under a ballast railway reinforced by geogrid reinforcement subjected to dynamic load. Experimental model based on an approximate half scale for general rail track engineering practice is adopted in this study which is used in Iraqi railways. The investigated parameters are load amplitude, load frequency and presence of geogrid reinforcement layer. A half full-scale railway was constructed for carrying out the tests, which consists of two rails 800 mm in length with three wooden sleepers (900 mm × 90 mm × 90 mm). The ballast was overlying 500 mm thick clay layer. The tests were carried out with and without geogrid reinforcement, the tests were carried out in a well tied steel box of 1.5 m length × 1 m width × 1 m height. A series of laboratory tests were conducted to investigate the response of the ballast and the clay layers where the ballast was reinforced by a geogrid. Settlement in ballast and clay, was measured in reinforced and unreinforced ballast cases. In addition to the laboratory tests, the application of numerical analysis was made by using the finite element program PLAXIS 3D 2013.

It was concluded that the settlement increased with increasing the simulated train load amplitude, there is a sharp increase in settlement up to the cycle 500 and after that, there is a gradual increase to level out between, 2,500 and 4,500 cycles depending on the load frequency. There is a little increase in the induced settlement when the load amplitude increased from 0.5 to 1 ton, but it is higher when the load amplitude increased to 2 ton, the increase in settlement depends on the geogrid existence and the other studied parameters. Both experimental and numerical results showed the same behavior. The effect of load frequency on the settlement ratio is almost constant after 500 cycles. In general, for reinforced cases, the effect of load frequency on the settlement ratio is very small ranging between 0.5 and 2% compared with the unreinforced case.

Increasing the ballast layer thickness from 20 cm to 30 cm leads to decrease the settlement by about 50%. This ascertains the efficiency of ballast in spreading the waves induced by the track.

As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous expansion of the application of AM materials, subtractive processing has become one of the necessary steps to improve the accuracy and performance of parts. In this paper, the processing process of AM materials is discussed in depth, and the surface integrity problem caused by it is discussed.

Firstly, we listed and analyzed the characterization parameters of metal surface integrity and its influence on the performance of parts and then introduced the application of integrated processing of metal adding and subtracting materials and the influence of different processing forms on the surface integrity of parts. The surface of the trial-cut material is detected and analyzed, and the surface of the integrated processing of adding and subtracting materials is compared with that of the pure processing of reducing materials, so that the corresponding conclusions are obtained.

In this process, we also found some surface integrity problems, such as knife marks, residual stress and thermal effects. These problems may have a potential negative impact on the performance of the final parts. In processing, we can try to use other integrated processing technologies of adding and subtracting materials, try to combine various integrated processing technologies of adding and subtracting materials, or consider exploring more efficient AM technology to improve processing efficiency. We can also consider adopting production process optimization measures to reduce the processing cost of adding and subtracting materials.

With the gradual improvement of the requirements for the surface quality of parts in the production process and the in-depth implementation of sustainable manufacturing, the demand for integrated processing of metal addition and subtraction materials is likely to continue to grow in the future. By deeply understanding and studying the problems of material reduction and surface integrity of AM materials, we can better meet the challenges in the manufacturing process and improve the quality and performance of parts. This research is very important for promoting the development of manufacturing technology and achieving success in practical application.

Despite the widespread use and application of resilience, much uncertainty about the conceptualization and operationalization in the context of tourism destinations still exists. The purpose of this paper is to provide a conceptual elaboration on destination resilience and to introduce a model for an improved understanding of the concept.

Taking a conceptual research approach, this paper seeks to untangle the fuzziness surrounding the destination and resilience concept by providing a new interpretation that synthesizes theories and concepts from various academic disciplines. It analyses the current debate to derive theoretic baselines and conceptual elements that subsequently inform the development of a new “Destination Resilience Model”.

The contribution advances the debate by proposing three key themes for future resilience conceptualizations: (1) the value of an actor-centered and agency-based resilience perspective; (2) the importance of the dynamic nature of resilience and the (mis)use of measurement approaches; (3) the adoption of a dualistic resilience perspective distinguishing specified and general resilience. Building on these propositions, we introduce a conceptual model that innovatively links elements central to the concepts of destination and risk and combines different narratives of resilience.

The contribution advances the debate surrounding destination resilience by critically examining the conceptualization and operationalization of destination resilience within previous research and by subsequently proposing a “Destination Resilience Model” that picks up central element of the three new frontiers identified in the conceptually driven review. The innovative integration strengthens the comprehension of the resilience concept at destination level and supports building future capacities to manage immediate adverse impacts as well as novel and systemic risks.

This study aims to assess the technological capability of Chinese internet platforms (BAT: Baidu, Alibaba, Tencent) compared to US ones (GAFA: Google, Amazon, Facebook, Apple). More specifically, this study explores Baidu’s technological catching-up process with Google by analyzing their patent textual information.

The authors retrieved 26,383 Google patents and 6,695 Baidu patents from PATSTAT 2019 Spring version. The collected patent documents were vectorized using the Word2Vec model first, and then K-means clustering was applied to visualize the technological space of two firms. Finally, novel indicators were proposed to capture the technological catching-up process between Baidu and Google.

The results show that Baidu follows a trend of US rather than Chinese technology which suggests Baidu is aggressively seeking to catch up with US players in the process of its technological development. At the same time, the impact index of Baidu patents increases over time, reflecting its upgrading of technological competitiveness.

This study proposed a new method to analyze technology mapping and evolution based on patent text information. As both US and China are crucial players in the internet industry, it is vital for policymakers in third countries to understand the technological capacity and competitiveness of both countries to develop strategic partnerships effectively.

The purpose of this review is to comprehensively consider the material properties and processing of additive titanium alloy and provide a new perspective for the robotic grinding and polishing of additive titanium alloy blades to ensure the surface integrity and machining accuracy of the blades.

At present, robot grinding and polishing are mainstream processing methods in blade automatic processing. This review systematically summarizes the processing characteristics and processing methods of additive manufacturing (AM) titanium alloy blades. On the one hand, the unique manufacturing process and thermal effect of AM have created the unique processing characteristics of additive titanium alloy blades. On the other hand, the robot grinding and polishing process needs to incorporate the material removal model into the traditional processing flow according to the processing characteristics of the additive titanium alloy.

Robot belt grinding can solve the processing problem of additive titanium alloy blades. The complex surface of the blade generates a robot grinding trajectory through trajectory planning. The trajectory planning of the robot profoundly affects the machining accuracy and surface quality of the blade. Subsequent research is needed to solve the problems of high machining accuracy of blade profiles, complex surface material removal models and uneven distribution of blade machining allowance. In the process parameters of the robot, the grinding parameters, trajectory planning and error compensation affect the surface quality of the blade through the material removal method, grinding force and grinding temperature. The machining accuracy of the blade surface is affected by robot vibration and stiffness.

This review systematically summarizes the processing characteristics and processing methods of aviation titanium alloy blades manufactured by AM. Combined with the material properties of additive titanium alloy, it provides a new idea for robot grinding and polishing of aviation titanium alloy blades manufactured by AM.

This study aims to examine Musina municipality’s tourism development status and plans with existing documents and respondents’ responses on their envisaged implications on tourism development and sustainability initiatives in Vhembe District, Limpopo Province, South Africa.

Surveys, interviews and focus group discussions, supplemented by field observation and document reviews, gray literature alongside published literature, were applied. Subsequently, Microsoft Excel and cross-tabulation analysis orchestrated the analysis of the data.

The policy and strategy aspects contributing to the previous and actual tourism statuses in Musina municipality are defined. The study concludes that Musina Municipality has rich tourism possibilities but lacks a better tourism strategy to empower local communities. Nonetheless, it dwells in the most tourism-based landscape within the Vhembe District of Limpopo.

Musina Municipality is one of the driest areas in the north of Limpopo Province in South Africa. It is also marked by impoverished rural communities. Studies on sustainable tourism and development have increased in recent years. However, rare studies specialize in synergies within various forms of tourism. Also, significant resources to advance local communities in rural areas are not sufficiently appreciated.

This research aimed to capture undergraduate students' experiences in the transition from face-to-face (F2F) learning to online learning. This study explored their perceptions regarding the effectiveness of online learning in their academic lives, challenges encountered and suggestions for enhancing online learning in the post-COVID-19 era.

This study employed a concurrent mixed-methods research design and selected 118 undergraduate students using a multistage random sampling technique from four colleges in Assam. Standardized questionnaires and open-ended interview schedules were used.

Undergraduate students reported a positive attitude and satisfaction with online learning, valuing its adaptability to their schedules, its role as a motivating factor for self-learning, its effect on making them more technically proficient and enhancing their communication skills to articulate their thoughts. However, the challenges identified by the students have the potential to overshadow the promises of online learning. This research provided more constructive suggestions under the themes of “content delivery”, “systemic and infrastructural issues”, “pedagogy” and “capacity building” to enhance their experiences with online learning.

Our research findings would assist educational institutions in adopting innovative approaches for simpler and more efficient online learning experiences post-COVID-19 pandemic. Institutions should prepare themselves and design dual-mode courses for F2F and online learning.

The paper addressed a relevant topic in this era of online learning by examining undergraduate students’ viewpoints that added complementary information to the current body of literature on online learning in rural India. The insights gleaned from their experiences would be beneficial for the development of best practices for online learning in the coming decades.

Reynolds-averaged Navier–Stokes (RANS) models often perform poorly in shock/turbulence interaction regions, resulting in excessive wall heat load and incorrect representation of the separation length in shockwave/turbulent boundary layer interactions. The authors suggest that this can be traced back to inadequate numerical treatment of the inviscid fluxes. The purpose of this study is an extension to the well-known Harten, Lax, van Leer, Einfeldt (HLLE) Riemann solver to overcome this issue.

It explicitly takes into account the broadening of waves due to the averaging procedure, which adds numerical dissipation and reduces excessive turbulence production across shocks. The scheme is derived based on the HLLE equations, and it is tested against three numerical experiments.

Sod’s shock tube case shows that the scheme succeeds in reducing turbulence amplification across shocks. A shock-free turbulent flat plate boundary layer indicates that smooth flow at moderate turbulence intensity is largely unaffected by the scheme. A shock/turbulent boundary layer interaction case with higher turbulence intensity shows that the added numerical dissipation can, however, impair the wall heat flux distribution.

The proposed scheme is motivated by implicit large eddy simulations that use numerical dissipation as subgrid-scale model. Introducing physical aspects of turbulence into the numerical treatment for RANS simulations is a novel approach.

The metaverse is a virtual world where users can communicate with each other in a computer-generated environment. The use of metaverse technology has the potential to revolutionize the way businesses operate, interact with customers, and collaborate with employees. However, several obstacles must be addressed and overcome to ensure the successful implementation of metaverse technology. This study aims to examine the implementation of metaverse technology in the management of an organization's supply chain, with a focus on predicting potential barriers to provide suitable strategies.

Covariance-based structural equation modeling (CB-SEM) was used to test the model. In addition, artificial neural network modeling (ANN) was also performed.

The CB-SEM results revealed that a firm's technological limitations are among the most significant barriers to implementing metaverse technology in the supply chain management (SCM). The ANN results further highlighted that the firm's technological limitations are the most crucial input factors, followed by a lack of governance and standardization, integration challenges, poor diffusion through the network, traditional organizational culture, lack of stakeholder commitment, lack of collaboration and low perception of value by customers.

Because metaverse technology has the potential to provide organizations with a competitive advantage, increase productivity, improve customer experience and stimulate creativity, it is crucial to discuss and develop solutions to implementation challenges in the business world. Companies can position themselves for success in this fascinating and quickly changing technological landscape by conquering these challenges.

This study provides insights to metaverse technology developers and supply chain practitioners for successful implementation in SCM, as well as theoretical contributions for supply chain managers aiming to implement such environments.

The aim of this article is to highlight the major part played by executives in the escalation of corporate social irresponsibility (CSI). Based on the upper echelons theory, the authors developed a model which shows the essential role of CEOs in explaining CSI. The authors proposed that the key personality traits of CEOs—narcissism—, as well as their power, could explain the degree of CSI.

Due to the significant methodological challenges when investigating CSI, the authors explored a novel method for measuring CSI in order to assess the degree of irresponsible behaviors. The authors build a CSI scale based on the perceptions of key informants, i.e. experts with diverse professional backgrounds. The authors apply CSI scale in a sample of 84 Spanish companies that were involved in CSI.

The results of the authors’ empirical study show the positive and significant influence of CEO narcissism and CEO power on the degree of CSI.

On the one hand, corporate irresponsibility scandals have relevant social consequences and practical implications. On the other hand, narcissism is a natural feature of managers in top positions that is increasing in societies.

The authors’ findings may help CEOs, TMTs and corporate boards to acknowledge potential sources of CSI decreasing its likelihood through counterbalancing CEO's power and considering the dark side of narcissism.

On the one hand, corporate scandals have relevant social and practical implications. On the other hand, narcissism is a natural feature of managers in top positions that is increasing in societies.

In this paper, the authors highlight the role of CEOs characteristics and their firms as the key actors for explaining and understanding the degree of CSI.

本研究擬強調行政主管在加劇企業無社會責任感上所扮演的主要角色。我們根據高層梯隊理論, 開發了一個模型, 來顯示執行長如何在解釋企業無社會責任感上所起的關鍵作用。我們提出一個見解, 就是: 執行長的主要人格特質-自戀和其權力-或許能解釋企業無社會責任感的程度。

由於面對在關於企業無社會責任感的研究法上的重大挑戰, 我們探索了一個估量企業無社會責任感的新穎方法, 以能對企業無社會責任感行為的程度進行評估。我們根據主要的資訊提供者的觀念和看法, 制定了一個企業無社會責任感的等級 (這些主要的資訊提供者均為具有不同專業背景的專家), 我們在84間西班牙公司的樣本裡, 使用了這企業無社會責任感等級, 而這些公司均涉及企業無社會責任感的。

我們這實證研究的結果顯示, 執行長的自戀和其權力, 對企業無社會責任感的程度, 起著正面和顯著的影響。

在本學術論文裡, 我們強調了執行長的特徵和他們的公司, 是瞭解和解釋企業無社會責任感的程度的關鍵行為者。

一方面, 企業無社會責任感的醜聞會帶來相關的社會後果和實務方面的影響;而另一方面, 自戀是高層主管的自然特徵, 而這些特徵, 在我們的社會裡不斷增強。本研究的結果, 或許可幫助執行長、高層管理團隊和公司董事會去承認企業無社會責任感的潛在原因, 並以透過平衡執行長的權力和考慮自戀的陰暗面而減低企業無社會責任感產生的可能。