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This study aims to present a numerical model to investigate cavitation effects on oscillatory porous squeeze film. This effect is able to cause considerable damage to the lubrication mechanisms, mainly in the form of surface erosion. The erosion process is caused by surface spalling due to alternating positive and negative contact stresses imposed by bubble collapse. If the process continues uncontrolled, the performance of the contact will rapidly deteriorate.

The study is conducted numerically using Elrod–Adams model for the modified Reynolds equation coupled with the Darcy’s law for the lubricant flow through the porous medium. The governing equations are numerically discretized and iteratively solved.

The numerical results show that frequency, amplitude and permeability have a significant influence on the generation of cavitation. A comparison of the present numerical results against available literature experimental data in particular case proved a good agreement.

The present paper is to develop a more realistic and efficient model. Indeed, the consideration of cavitation phenomena in this model will lead to a more accurate prediction of the squeeze film characteristics. The results of this paper are based on original work and have practical value.

The purpose of this study is to present a theoretical investigation of the effects of cavitation and couple stress on the squeeze film behavior between an anisotropic poroelastic rigid disc and a sinusoidally oscillating rigid disc.

Based on the microcontinuum theory of Vijay Kumar Stokes and the Elrod–Adam algorithm, the non-Newtonian Reynolds equation coupled with modified Darcy's law for lubricant flow through the porous disc is derived. This numerical study includes the continuity of tangential velocity at the porous–fluid interface and the effects of percolation of the polar additives into the anisotropic porous disc.

The effects of couple stress, oscillating amplitude, percolation additives, permeability and anisotropic permeability on the squeeze film characteristics are discussed. It is found that both the percolation effect of the lubricant additives and the anisotropic structure of the porous surface reduce the flow in the porous disc, resulting in a decrease in pressure. It is also observed that cavitation effects are more pronounced for Newtonian fluids than couple stress fluids.

The results of this study can be used to design a variety of engineering applications such as bearings, wet clutches and non-contact mechanical seals.

This chapter offers a symbolic perspective on the Egyptian Revolution. It does so by analyzing the transformation of Khaled Said, a 28-year-old Egyptian man beaten to death by police on June 6, 2010, into a key visual injustice symbol. Activists were motivated by a horrifying cell phone photograph of Said taken by his family at the morgue and uploaded on the web. Although the postmortem photograph had a powerful emotional impact in itself, the transformation of Said from local/particular incident to injustice symbol with society-wide repercussions cannot be explained by its mere availability in the public sphere. The transformation required intervention and appropriation by activists who creatively and strategically universalized the case, linking it with existing injustice frames in Egypt. This chapter analyzes this interplay between photographs, activism, and society in two steps. The first provides an analysis of the genesis of the Said symbol and identifies three levels of agency in its formation. The second step analyzes the process through which Said was infused with injustice meanings by activists. Providing the first systematic analysis of Said from a social movement perspective, the chapter draws on several data sources that are subjected to interpretive analysis: visual material available on the internet, Facebook pages, and interviews with and accounts by key activists. And it calls for more attention to photographs and symbols in the analysis of activism and points to several historical and present cases with relevance for such an approach.

The purpose of this paper is to assess the level of pragmatic ambiguity (PA) lean culture has currently in the manufacturing and service literature.

A comprehensive systematic review of academic (journals, books and theses) and commercial literature was undertaken drawn from a six databases search of two keywords (“lean” and “culture”) and related citations.

A total sample of 1,066 references (678 academic papers, 121 books, 103 theses and 164 commercial documents) were analyzed. The authors found contributions from 67 countries but oddly, only two came from Japan. In total, 89 percent of citations were directly about lean culture. However, for 86 percent of them, lean culture was only discussed superficially. All four literature segments show an over 85 percent agreement on lean culture being an organizational aim. The authors encountered 103 definitions of organizational culture and found 13 definitions of lean culture. Issues of culture gap, leadership, human resource management, sustainability and innovation are found to amplify lean culture’s already high PA level.

Further research and development are needed to decrease lean culture’s PA level and improve understanding of lean from a cultural perspective.

Current lean culture’s high PA level has positive and negative effects on lean implementation. Taking lean implementation from a cultural perspective may facilitate an organization’s lean transformation journey.

This is the first systematic literature review on lean culture using a broad and inductive approach. An original evidence-based definition of organizational culture is proposed.

This paper aims at contributing to our understanding of how self-settled Syrian refugees (registered and non-registered) use informal practices to forge their non-political agency and how this agency could be considered as political acts.

This paper was conducted per the qualitative data analysis (in-depth interviews and participant observation), attributed to the critical ethnographic approach, through which refugees’ everyday struggle is explored, additionally, that was incorporated with the analysis of Syrians’ Facebook groups and formal sources.

The research paper concluded that everyday struggle strategies are considered as political acts by acquiring rights that many self-settled Syrian refugees are stripped of by international humanitarian agencies and host government. Hence, registered and unregistered refugees equally forge what is called “informal citizenship” through their presence via a blend of agency forms ranging from hidden agency to explicit one and via their incorporating into the informal contexts, leading them to carve a position of semi-legality that help them to circumvent the formal structural hardship.

This paper endeavors to study how urban refugees as change agents can convert their illegal presence to “probably refugeeness” to unsettle the prominent recognition of them as illegal non-citizens in southern cities.

The purpose of this study is to examine the direct impact of social intelligence and collective self- efficacy on two components of service providers’ performance: extra-role performance and intra-role one. The study also investigates the indirect effect of social intelligence on service providers’ performance and its components via the mediating role of collective self-efficacy.

This study was undertaken to develop a conceptual framework that integrates social intelligence, collective self-efficacy and service provider’s performance constructs in one framework. Data was collected from 220 physicians in the Egyptian governmental hospitals. Confirmatory factor analysis explored the latent structure of the research constructs. The current study used structural equation modelling to test the research model hypotheses.

The study finds that social intelligence was positively associated with service providers’ performance. The results also support the significant effect of social intelligence on the two main dimensions of service provider’s performance: extra-role (contextual) performance and intra-role (task) performance. Moreover, the results indicate that social intelligence competences provide a basis for collective self-efficacy and service providers’ performance for physicians in the Egyptian governmental hospitals.

This study collected data based on a cross-sectional design, so further studies could test the theoretical model by using longitudinal studies’ data, which give the study results more accuracy of results and support generalizing the results. This study considers the synergistic effects between social intelligence and collective self-efficacy on service providers’ performance and sheds new light on bringing new drivers for developing extra- and intra-role dimensions of service provider performance in service literature.

This study is one of the first studies that integrate social intelligence and collective self-efficacy with service providers’ performance and its dimensions in one framework. This study contributes to knowledge by integrating the social exchange theory with the cognitive theory in one study.

The purpose of this paper is to identify the key drivers and challenges to supply chain collaboration in the humanitarian sector; to appraise the relationships between international non-governmental organizations (INGOs) and local non-governmental organizations (LNGOs) during disaster relief; and to explore the humanitarian context in regard to supply chain collaboration.

Literature from both the commercial and humanitarian sectors is discussed in the context of vertical partnerships. A Jordanian study spanning a network of 26 international and LNGOs is explored via semi-structured interviews.

The research provides valuable insights on the challenges facing LNGOs and INGOs when developing partnerships. Contextual factors, including host governmental policies and the social-economic setting of a disaster directly affect the motivations for supply chain collaboration between LNGOs and INGOs.

The research is built on interviewees with 30 humanitarian professionals working in one country during an extended crisis. The majority of the empirical data are only from one actor’s perspective, thus further research into dyadic and network relationships is required. Approaches to addressing the diverse cultural and decision-making perspectives of LNGOs and INGOs warrant further investigation.

Recognizing the motives and challenges to vertical partnerships between LNGOs and INGOs will assist the managers, both at the strategic and operational levels, to find solutions and evolve strategies to build effective partnerships. Compromise and consideration for partner’s drivers and cultural views are essential for effective joint humanitarian relief initiatives.

This paper extends supply chain collaboration to a humanitarian context. Overcoming the challenges facing collaborative efforts and complementary nature of the drivers provide a means to achieve effective partnerships. Despite the uniqueness of the humanitarian context, such as the secondary nature of cost and dynamic demand, the core principles of collaboration still hold.

The purpose of this paper is to draw a map of the general features of epistemological and critical concerns in contemporary Islamic philosophy. This study will not be confined to the domain of academic philosophy or to those who are professionals in the field of philosophy.

The paper adopted the critical rational approach in dealing with contemporary Islamic philosophy in the Arab world. The scope will include scholars from different fields of epistemology who tried to present a “vision” of the attitude that should be adopted in facing the challenges of the age and the problems of the nation on the epistemological level or the political, economic and social levels.

There is a need for a philosophy of action and progress rather than a philosophy that is based on abstract ideas and theories and of words/rhetoric. The ethics required to accomplish this ought to identify the attributes of the citizen who can reach self-actualization through legitimate means based on a progress agenda with theoretical and philosophical foundations.

Because a critical rational approach can be dealt with from different perspectives, this paper will adopt the classification of the principal intellectual trends: the reformist, secular and liberal.

This paper covers a long time span to determine whether the philosophical projects have been effective.

This paper, which criticizes the philosophic projects that are theoretically unsound and that do not address real social problems (like poverty), argues the need for a philosophy of progress and action. This will lead to devising an agenda that addresses the challenges the society is facing and to finding alternative and creative solutions resulting in development.

The present research aims to explore the relationship between the university's new identity and its architectural design, and to investigate the impact of COVID-19 pandemic on this model. It also aims to analyze the declared identity of the new Egyptian universities.

To formulate the hypothesis of the relational model, the research started with the literature related to physical and nonphysical variables of university's identity (organizational and visual identity) and the impact of the pandemic on its identity. Secondly, an online questionnaire targeting academic leaders was conducted to identify the relative importance of the selected variables of university's identity pre- and post-pandemic. Thirdly, a content analysis of the new Egyptian universities' identity was used to track the correlation between the selected variables based on information accessible on universities' websites. Finally, the results of the content analysis and the questionnaire were compared to test the hypothesis.

The study reveals the most important physical variable of university's new identity pre- and post-pandemic is technological infrastructure and flexible design, while the least important is university's unique design. The results highlight that the universities need to revisit the declared identity to reflect the new challenges posed by COVID-19.

This study is considered one of the first researches that links the physical and nonphysical variables of university's new identity. The current study contributes to analyzing the impact of COVID-19 on university identity and architecture.

The purpose of this paper is to fall light on the possibility of using the biopolymer chitosan in gamma dose monitoring.

The chitosan films were irradiated to gamma rays in the range starting from 10 to 120 kGy at a dose rate of 1.4 kGy/h using ⁶⁰Co gamma source. The ultra violet and visible (UV/Vis) spectrophotometry were used to examine the optical properties of chitosan film. Also, Fourier transform infrared (FTIR) analysis was used to detect and trace any change in structural bands that may take place upon irradiation.

Increase in optical density of the chitosan film was recorded at 298 nm that correlated with increasing in the absorbed doses. Change in color of the film from pale yellow to denser yellow was detected upon increasing the absorbed doses. The close investigation for UV/Vis and FTIR analysis nominates the chitosan film to be used as a label-dosimeter in the range of 10–120 kGy depending on chitosan concentrations. The chitosan film has an excellent stability in different environmental conditions with ±3.7% uncertainty in measurements (2σ, approximately equal to a 95% confidence level).

Chitosan film may be used as a medium and high-dose monitor with an acceptable overall uncertainty in routine radiation processing

The useful dose range from 10 to 80 kGy was detected for different concentrations of chitosan (0.5, 1, 1.5 Wt%) that correlated with increasing the absorbed dose, which is assigned to the linear parts in the target response curves. For the dose range 10–120 kGy, the film may be used as label dosimeter with detected color change from pale yellow to dense yellow.