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1 – 10 of 20Hakan Hafizoglu, Huseyin Emrah Konokman, Latif Kesemen and Ali Kursat Atay
This paper aims to investigate the effects of fragment impacts to shaped charge warheads in terms of shaped charge jet formation geometries and penetration performances.
Abstract
Purpose
This paper aims to investigate the effects of fragment impacts to shaped charge warheads in terms of shaped charge jet formation geometries and penetration performances.
Design/methodology/approach
In experimental process, a fragment was accelerated to a shaped charge warhead by means of a powder gun to a velocity more than 1,000 m/s, and this impact led to conical damage in the explosive of the warhead. Deformation on the warhead was visualized using X-ray technique to observe holes generated during fragment impact. Penetration test was performed against AISI 1040 steel plates with the damaged shaped charge warhead. Penetration performance of shaped charge jet, which deviated from the symmetry axis, was simulated by using SPEED software with 3-D Eulerian method to validate the numerical modelling method by comparing penetration test and simulation results of damaged warhead.
Findings
Simulation and test results showed good correlation for the warhead in terms of penetration depth and hole geometry at the impact surface of steel plates. In addition, the effects of the numbers and the geometries of fragment holes on shaped charge jet penetration performances were investigated with validated numerical methods. Simulation results showed that the increase in the number of fragment holes in the explosive of the warhead led to particulation of shaped charge jet that diminished penetration depth in the target plate. Additionally, simulation results also showed that the fragment hole geometry in the explosive after different fragment impact angles affected the amount of jet deviation from the symmetry axis as well as penetration depth in the target plate.
Practical implications
The results obtained from the current study revealed that fragment impact angle and different number of fragment impact reduced the penetration performance of shaped charge warhead by influencing the symmetry of shaped charge jet negatively.
Originality/value
The current study fulfils the need to investigate how fragment impact on the shaped charge warhead affect the formation symmetry of shaped charge jet as well as penetration performance by experimental and numerical methods. Penetration performance result of asymmetric jet is compared by experimental and numerical studies. A detailed methodology on numerically modelling of the effect of fragment impact angle and number of fragment impact on shaped charge jet performance is given in this study.
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Fatma Hilal Ergen Keleş and Emrah Keleş
This study aims to examine whether social capital contributes to service firms' resilience during crisis.
Abstract
Purpose
This study aims to examine whether social capital contributes to service firms' resilience during crisis.
Design/methodology/approach
This study measures social capital via environmental and social (ES) ratings and firm performance via buy-and-hold-abnormal returns derived from Refinitiv ESG and CRSP databases. Using a sample of 404 US service firms, this study runs cross-sectional regressions to estimate the effect of social capital on service firms' crisis returns.
Findings
This study finds that high-social capital service firms outperformed in the first quarter of 2020. The crisis response is heterogeneous among service sub-sectors and diverges (i.e. calming or deepening) over time depending on social capital. Service sub-sector analysis notably posits that social capital impact is positively related to returns of Health- and Business Services and firms with utilitarian nature. The study also indicates that ES commitments targeting internal stakeholders contribute more to resilience. Overall, social capital might be a relevant value driver, generate real impact and provide insurance-like protection for service firms during turmoil.
Originality/value
The service industry is one of the most severely hit industries during COVID-19. However, there is limited knowledge about whether and when social capital creates value in the service industry during crises. This study makes two main contributions: first, it extends to the continuous efforts toward the role of social capital in firm performance, and second, it provides important insights related to the resilience search for service firms.
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Decision-making, reinforced by artificial intelligence (AI), is predicted to become potent tool within the domain of supply chain management. Considering the importance of this…
Abstract
Purpose
Decision-making, reinforced by artificial intelligence (AI), is predicted to become potent tool within the domain of supply chain management. Considering the importance of this subject, the purpose of this study is to explore the triggers and technological inhibitors affecting the adoption of AI. This study also aims to identify three-dimensional triggers, notably those linked to environmental, social, and governance (ESG), as well as technological inhibitors.
Design/methodology/approach
Drawing upon a six-step systematic review following the preferred reporting items for systematic reviews and meta analysis (PRISMA) guidelines, a broad range of journal publications was recognized, with a thematic analysis under the lens of the ESG framework, offering a unique perspective on factors triggering and inhibiting AI adoption in the supply chain.
Findings
In the environmental dimension, triggers include product waste reduction and greenhouse gas emissions reduction, highlighting the potential of AI in promoting sustainability and environmental responsibility. In the social dimension, triggers encompass product security and quality, as well as social well-being, indicating how AI can contribute to ensuring safe and high-quality products and enhancing societal welfare. In the governance dimension, triggers involve agile and lean practices, cost reduction, sustainable supplier selection, circular economy initiatives, supply chain risk management, knowledge sharing and the synergy between supply and demand. The inhibitors in the technological category present challenges, encompassing the lack of regulations and rules, data security and privacy concerns, responsible and ethical AI considerations, performance and ethical assessment difficulties, poor data quality, group bias and the need to achieve synergy between AI and human decision-makers.
Research limitations/implications
Despite the use of PRISMA guidelines to ensure a comprehensive search and screening process, it is possible that some relevant studies in other databases and industry reports may have been missed. In light of this, the selected studies may not have fully captured the diversity of triggers and technological inhibitors. The extraction of themes from the selected papers is subjective in nature and relies on the interpretation of researchers, which may introduce bias.
Originality/value
The research contributes to the field by conducting a comprehensive analysis of the diverse factors that trigger or inhibit AI adoption, providing valuable insights into their impact. By incorporating the ESG protocol, the study offers a holistic evaluation of the dimensions associated with AI adoption in the supply chain, presenting valuable implications for both industry professionals and researchers. The originality lies in its in-depth examination of the multifaceted aspects of AI adoption, making it a valuable resource for advancing knowledge in this area.
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Safak Kaya, Esref Arac, Fethiye Akgul, Senol Comoglu, Sehmuz Kaya, Songul Araç, Yesim Yildiz, Seyit Ali Buyuktuna, Bircan Kayaaslan, Emine Parlak, Birol Baysal, Faruk Karakecili, Elif Zelal Balik, Ali Akkoç, Kevser Ozdemir, Seyhmus Kavak, Suat Ali Dogan, Emrah Günay, Semsi Nur Karabela, Mehmet Cabalak, Yasemin Cag, Veli Avci, Yasemin Durdu, Zehra Kaya, Damla Kilic, Halis Yerlikaya, Hüseyin Tarakçı, Osman Mentes, Ayse Sağmak Tartar, Adem Kose, Omer Faruk Alakus, Ulas Aktas, Halil Komek and Selcuk Aksoz
This paper aims to determine the knowledge and attitudes of the physicians regarding human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), to emphasize…
Abstract
Purpose
This paper aims to determine the knowledge and attitudes of the physicians regarding human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), to emphasize that these patients exist and they will exist in the future and to raise awareness so as to prevent that their rights to treatment are revoked.
Design/methodology/approach
The survey was conducted via a link sent through an online system. Random physicians from 81 cities of the country were invited to the survey. The survey has 41 questions regarding knowledge and attitudes in total, including epidemiological information such as age, gender and title.
Findings
A total of 3,107 physicians has voluntarily participated in the study. In total, 2,195 (70.7%) are internal physicians and 912 (29.3%) are surgical physicians among the participant physicians. In total, 1,452 (46.7%) of the participants are specialist physicians, 608 (19.6%) of the participants are practising physician and the rest of it is physician assistants, academicians and dentists, respectively.
Originality/value
In this study, it has been found out that the physicians have a lack of knowledge on HIV/AIDS and they adopt a discriminatory attitude towards HIV-positive persons. HIV-positive patients who are exposed to discrimination and scared of being uncovered refrain from applying to hospitals for treatment, which puts public health into jeopardy due to the high viral load and these patients are faced with difficulties in coping with both medical and emotional load of the disease.
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Emrah Keskin, Ozgur Yayla, Nevres Sezen and Bekir Bora Dedeoğlu
Gastronomic festivals are important events to bring people together around food-themed activities. This study aimed at determining the relationships between festival quality…
Abstract
Purpose
Gastronomic festivals are important events to bring people together around food-themed activities. This study aimed at determining the relationships between festival quality, memorable food experience, loyalty, behavioral intention, hedonic well-being, and eudaimonic well-being. In this study, festival quality is the independent variable that affects the memorable food experience, the memorable food experience is the independent variable that affects loyalty, and loyalty is the independent variable that affects behavioral intent. Hedonic well-being and eudaimonic well-being are moderating variables. Behavioral intention is the dependent variable, while memorable food experience and loyalty are both dependent and independent variables.
Design/methodology/approach
The population consisted of local tourists visiting Orange Blossom Carnival held in Adana, Turkey. The survey technique and the convenience sampling method were preferred and 545 data were obtained.
Findings
The analysis results showed that all dimensions of the memorable food experience are strongly affected by festival quality. Plus, superior service approach and high value perception dimensions of the memorable food experience have significant effects on loyalty. Furthermore, destination loyalty was found to have a strong effect on behavioral intentions. Moreover, higher levels of Hedonic well-being (HWB) and Eudomenic well-being (EWB) were found to increase the effect of loyalty on behavioral intention; accordingly, the moderator roles of HWB and EWB were determined.
Practical implications
This article provides information that the memorable dining experiences of festival visitors who attend the Orange Blossom Carnival in Adana affect the quality of the festival and their intentions to loyalty. In addition, in the study, it was found that the well-being of carnival visitors had a moderating role in the effect of their loyalty on their behavioral intentions. Therefore, this article provides information on how the food experiences and well-being of the visitors at the gastronomy festival will affect which factors.
Originality/value
According to the findings, gastronomy-based events may affect tourists’ experiences, and tourists’ psychological well-being affects loyalty and behavioral intentions. Destination management organizations can learn about gastronomy-based festivals. The results of the study include a number of theoretical and practical findings for destination management organizations, festival managers, policy makers and academics working in the literature.
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Oguzhan Kazanci, Serdar Ulubeyli and Emrah Dogan
This study aims to present the financial performance of companies and investment areas in the real estate investment trust (REIT) industry.
Abstract
Purpose
This study aims to present the financial performance of companies and investment areas in the real estate investment trust (REIT) industry.
Design/methodology/approach
A fuzzy model for financial performance measurement (FM-FPM) was proposed through the collaboration of fuzzy axiomatic design (FAD) and fuzzy entropy weighting (FEW). For the data, financial ratios were used, and their importance and functional requirements were collected via a questionnaire survey.
Findings
The FM-FPM is a beneficial model to be used for a REIT industry based on the structured procedures of FAD and FEW techniques. It can be suitable to regularly evaluate the performance of REITs and their investment areas in financial means, especially in today’s turbulent business environment. The Turkish market that was considered to show the practical applicability of the FM-FPM demonstrated specifically that diversified real estate was found to rank first, followed by mixed-buildings, warehouses, shopping malls and hotels, respectively.
Research limitations/implications
The FM-FPM can be employed for REIT industries in other countries and adapted to different industries. However, more respondents or a different set of criteria might lead to different outputs.
Practical implications
The FM-FPM may guide REIT managers and investors while making their decisions and controlling the performance of REITs and investment areas.
Social implications
The FM-FPM may encourage low- and middle-income investors to make good use of their savings.
Originality/value
The research is first (1) to offer a FPM model in order to determine investable areas in a REIT industry and (2) to employ multiple criteria decision-making tools in order to measure the financial performance of individual companies and investment areas in a REIT industry.
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Samet Güner, Halil Ibrahim Cebeci and Emrah Aydemir
Social media is widely used to capture citizens' opinions and topics deemed important. The importance or interest social media users attribute to a topic is traditionally measured…
Abstract
Purpose
Social media is widely used to capture citizens' opinions and topics deemed important. The importance or interest social media users attribute to a topic is traditionally measured by tweet frequency. This approach is practical but overlooks other user engagement tools such as retweets, likes, quotes, and replies. As a result, it may lead to a misinterpretation of social media signals. This paper aims to propose a method that considers all user engagement indicators and ranks the topics based on the interest attributed by social media users.
Design/methodology/approach
A multi-criteria decision-making framework was proposed, which calculates the relative importance of user engagement tools using objective (information entropy) and subjective (Bayesian Best-Worst Method) methods. The results of the two methods are aggregated with a combinative method. Then, topics are ranked based on their user engagement levels using Multi-Objective Optimization by Ratio Analysis.
Findings
The proposed approach was used to determine citizens' priorities in transport policy, and the findings are compared with those obtained solely based on tweet frequency. The results revealed that the proposed multi-criteria decision-making framework generated more comprehensive and robust results.
Practical implications
The proposed method provides a systematic way to interpret social media signals and guide institutions in making better policies, hence ensuring that the demands of users/society are properly addressed.
Originality/value
This study presents a systematic method to prioritize user preferences in social media. It is the first in the literature to discuss the necessity of considering all user engagement indicators and proposes a reliable method that calculates their relative importance.
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Emrah Köksal Sezgin, Abdullah Tanrısevdi and Ahu Sezgin
The study aims to examine the mediating effects of escapism (ESC) and ethnic food experience (EFE) in the relationship between diversity (DIV) and behavioral intentions (BI) of…
Abstract
Purpose
The study aims to examine the mediating effects of escapism (ESC) and ethnic food experience (EFE) in the relationship between diversity (DIV) and behavioral intentions (BI) of visitors attending Hoi An International Food Festival held in Vietnam.
Design/methodology/approach
The research takes a predictive and explanatory approach rather than theory confirmation. Partial least squares (PLS) algorithm was used to analyze multiple mediation. The data were collected from 323 attendees through a self-administered questionnaire.
Findings
The research highlights that escapism and EFE have positive and significant mediating effects on the relationship between DIV and BI. Furthermore, while EFE is the most important predictor of BI, escapism has emerged as an antecedent variable that deserves to be given the highest importance. Finally, visitors who are participating in their first international food festival do not seem to consider the nexus between DIV and ESC as much as repeaters.
Research limitations/implications
The study's limitations include the collection of data from a single festival and the fact that the analyses are only quantitative. The results contribute to festival organizers by revealing the importance of multiple mediation roles.
Originality/value
This study contributes novel insights to the literature on festival and event management, extending previous studies and filling a gap by proposing ESC and EFE as multiple mediators in the nexus between DIV and BI. The present study provides a comprehensive examination of the influence of individual variables previously analyzed separately on festival-goers' experiences. This facilitated the identification of crucial aspects of the circumstance, thereby reducing any ambiguity.
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Jiongyi Yan, Emrah Demirci and Andrew Gleadall
Extrusion width, the width of printed filaments, affects multiple critical aspects in mechanical properties in material extrusion additive manufacturing: filament geometry…
Abstract
Purpose
Extrusion width, the width of printed filaments, affects multiple critical aspects in mechanical properties in material extrusion additive manufacturing: filament geometry, interlayer load-bearing bonded area and fibre orientation for fibre-reinforced composites. However, this study aims to understand the effects of extrusion width on 3D printed composites, which has never been studied systematically.
Design/methodology/approach
Four polymers with and without short-fibre reinforcement were 3D printed into single-filament-wide specimens. Tensile properties, mechanical anisotropy and fracture mechanisms were evaluated along the direction of extruded filaments (F) and normal to the interlayer bond (Z). Extrusion width, nozzle temperature and layer height were studied separately via single-variable control. The extrusion width was controlled by adjusting polymer flow in the manufacturing procedure (gcode), where optimisation can be achieved with software/structure design as opposed to hardware.
Findings
Increasing extrusion width caused a transition from brittle to ductile fracture, and greatly reduced directional anisotropy for strength and ductility. For all short fibre composites, increasing width led to an increase in strain-at-break and decreased strength and stiffness in the F direction. In the Z direction, increasing width led to increased strength and strain-at-break, and stiffness decreased for less ductile materials but increased for more ductile materials.
Originality/value
The transformable fracture reveals the important role of extrusion width in processing-structure-property correlation. This study reveals a new direction for future research and industrial practice in controlling anisotropy in additive manufacturing. Increasing extrusion width may be the simplest way to reduce anisotropy while improving printing time and quality in additive manufacturing.
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Jiongyi Yan, Emrah Demirci and Andrew Gleadall
This study/paper aims to develop fundamental understanding of mechanical properties for multiple fibre-reinforced materials by using a single-filament-wide tensile-testing…
Abstract
Purpose
This study/paper aims to develop fundamental understanding of mechanical properties for multiple fibre-reinforced materials by using a single-filament-wide tensile-testing approach.
Design/methodology/approach
In this study, recently validated single-filament-wide tensile-testing specimens were used for four polymers with and without short-fibre reinforcement. Critically, this specimen construct facilitates filament orientation control, for representative longitudinal and transverse composite directions, and enables measurement of interlayer bonded area, which is impossible with “slicing” software but essential in effective property measurement. Tensile properties were studied along the direction of extruded filaments (F) and normal to the interlayer bond (Z) both experimentally and theoretically via the Kelly–Tyson model, bridging model and Halpin–Tsai model.
Findings
Even though the four matrix-material properties varied hugely (1,440% difference in ductility), consistent material-independent trends were identified when adding fibres: ductility reduced in both F- and Z-directions; stiffness and strength increased in F but decreased or remained similar in Z; Z:F strength anisotropy and stiffness anisotropy ratios increased. Z:F strain-at-break anisotropy ratio decreased; stiffness and strain-at-break anisotropy were most affected by changes to F properties, whereas strength anisotropy was most affected by changes to Z properties.
Originality/value
To the best of the authors’ knowledge, this is the first study to assess interlayer bond strength of composite materials based on measured interlayer bond areas, and consistent fibre-induced properties and anisotropy were found. The results demonstrate the critical influence of mesostructure and microstructure for three-dimensional printed composites. The authors encourage future studies to use specimens with a similar level of control to eliminate structural defects (inter-filament voids and non-uniform filament orientation).
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