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This study aims to investigate the factors responsible for substrate cracking reliability problem in through-glass vias (TGVs), which are critical components for glass-based 2.5 D integration.

Numerical models were used to examine the driving force for substrate cracking in glass interposers due to stress coupling during heating. An analytical solution was used to demonstrate how the energy release rate (ERR) for the glass substrate cracking is affected by the via design and the mismatch in thermal strain. Then, the numerical models were implemented to investigate the design factors effects, such as the pitch distance, via diameter, via pattern, via design, effect from a stress buffer layer and the interposer materials selection on the susceptibility to substrate cracking.

ERR for substrate cracking was found to be directly proportional to the via diameter and the thermal mismatch strain. When a via pattern is implemented for high-density integration, a coupling in the stress fields was identified. This coupling effect was found to depend on the pitch distance, the position of the vias, and the via arrangement, suggesting a via pattern-dependent reliability behavior for glass interposers. Changing the design of the via to an annular shape or a substrate-cored via was found to be a promising approach to reduce the susceptibility to substrate cracking compared to a fully filled solid via. Also, the use of a stress buffer layer, an encouraging design prospect presented for the first time for TGVs in this study, was found to significantly reduce cracking. Finally, alternative via and substrate materials showed lower tendency for substrate cracking, indicating that the reliability of glass interposers can be further enhanced with the implementation of such new materials.

This study signifies the first attempt to comprehensively evaluate the susceptibility to crack formation in glass interposers during heating. Therefore, this study provides new perspectives on how to achieve a significant potential reliability improvement for TGVs.

The purpose of this paper is to investigate the effect of process parameters of fused deposition modelling (FDM) 3D printing process on viscoelastic responses (creep compliance and recoverable compliance) of FDM built parts using a novel experimental design technique.

As part of the process characterization, a recently developed class of three-level design methodology – definitive screening design (DSD) – was used in this study to fit a second-order polynomial regression model. Artificial neural network (ANN) was also used to determine the optimal process parameters to improve creep compliance and recoverable compliance. The relationship between layer thickness, air gap, raster angle, build orientation, road width, number of contours and creep performance of FDM fabricated part was thereafter established empirically. Scanning electron microscope (SEM) is used to examine and characterize the morphology of the structures for some samples.

This study found that the creep resistance of FDM-manufactured part is significantly influenced by layer thickness, air gap, raster angle and number of contours and it can be improved by optimizing the settings of the selected parameters. The relationship between FDM process parameters and creep properties was determined, with the best creep performance observed by using 0.127 mm of layer thickness, zero air gap, zero raster angle, build orientation of 17.188°, road width of 0.4572 mm and 10 contours. Finally, the result is verified by confirmation experiments. The results prove that a DSD is a very effective design in characterizing the influence of process parameters on creep properties of FDM-built part at the lowest cost.

The originality of this paper lies in characterizing and optimizing the effect of process parameters on creep performance of FDM manufactured part that has not been studied in all previous studies. The paper highlights, for the first time, how the application of DSD can overcome most of the limitations encountered in the conventional techniques. This study can be used as a guide to the different additive manufacturing users of various industries and the results provide a good technical database on how FDM process parameters influence the creep performance of manufactured parts.

Fused deposition modeling (FDM) has become an increasingly important process among the available additive manufacturing technologies in various industries. Although there are many advantages of FDM process, a downside of its industrial application is the attainable dimensional accuracy with tight tolerance without compromising the mechanical performance. This paper aims to study the effects of six FDM operating parameters on two conflicting responses, namely, dynamic stiffness and dimensional stability of FDM produced PC-ABS parts. This study also aims to determine the optimal process settings using graphical optimization that satisfy the dynamic mechanical properties without compromising the dimensional accuracy.

The regression models based upon IV-optimal response surface methodology are developed to study the variation of dimensional accuracy and dynamic mechanical properties with changes in process parameter settings. Statistical analysis was conducted to establish the relationships between process variables and dimensional accuracy and dynamic stiffness. Analysis of variance is used to define the level of significance of the FDM operating parameters. Scanning electron microscope and Leica MZ6 optical microscope are used to examine and characterize the morphology of the structures for some specimens.

Experimental results highlight the individual and interaction effects of processing conditions on the dynamic stiffness and part accuracy. The results showed that layer thickness (slice height), raster-to-raster air gap and number of outlines have the largest effect on the dynamic stiffness and dimensional accuracy. The results also showed an interesting phenomenon of the effect of number of contours and the influence of other process parameters. The optimal process conditions for highest mechanical performance and part accuracy are obtained.

The effect of FDM processing parameters on the properties under dynamic and cyclic loading conditions has not been studied in the previous published work. Furthermore, simultaneous optimization of dynamic mechanical properties without compromising the dimensional accuracy has also been investigated. On the basis of experimental findings, it is possible to provide practical suggestions to set the optimal FDM process parameters in relation to dynamic mechanical performance, as well as the dimensional accuracy.

Glass is a promising interposer substrate for 2.5 D integration; yet detailed analysis of the interfacial reliability of through-glass vias (TGVs) has been lacking. The purpose of this paper is to investigate the design and material factors responsible for the interfacial delamination in TGVs and identify methods to improve reliability.

The interfacial reliability of TGVs is studied both analytically and numerically. An analytical solution is presented to show the dependence of the energy release rate (ERR) for interfacial delamination on the via design and the thermal mismatch strain. Then, finite element analysis (FEA) is used to investigate the influence of detailed design and material factors, including the pitch distance, via aspect ratio, via geometry and the glass and via materials, on the susceptibility to interfacial delamination.

ERR for interfacial delamination is directly proportional to the via diameter and the thermal mismatch strain. Thinner wafers with smaller aspect ratios show larger ERRs. Changing the via geometry from a fully filled via to an annular via leads to lower ERR. FEA results also show that certain material combinations have lower thermal mismatch strains, thus less prone to delamination.

The results and approach presented in this paper can guide the design and development of more reliable 2.5 D glass interposers.

This paper represents the first attempt to comprehensively evaluate the impact of design and material selection on the interfacial reliability of TGVs.

The purpose of this paper is to assess the impacts on production of five fruit crops from 1961 to 2018 of energy use, CO₂ emissions, farming areas and the labor force in China.

This analysis applied the autoregressive distributed lag-bound testing (ARDL) approach, Granger causality method and Johansen co-integration test to predict long-term co-integration and relation between variables. Four machine learning methods are used for prediction of the accuracy of climate effect on fruit production.

The Johansen test findings have shown that the fruit crop growth, energy use, CO₂ emissions, harvested land and labor force have a long-term co-integration relation. The outcome of the long-term use of CO₂ emission and rural population has a negative influence on fruit crops. The energy consumption, harvested area, total fruit yield and agriculture labor force have a positive influence on six fruit crops. The long-run relationships reveal that a 1% increase in rural population and CO₂ will decrease fruit crop production by −0.59 and −1.97. The energy consumption, fruit harvested area, total fruit yield and agriculture labor force will increase fruit crop production by 0.17%, 1.52%, 1.80% and 4.33%, respectively. Furthermore, uni-directional causality is correlated with the growth of fruit crops and energy consumption. Also, the results indicate that the bi-directional causality impact varies from CO₂ emissions to agricultural areas to fruit crops.

This study also fills the literature gap in implementing ARDL for agricultural fruits of China, used machine learning methods to examine the impact of climate change and to explore this important issue.

The purpose of the study would typically involve investigating how the ongoing COVID-19 pandemic has impacted the learning abilities of university students. The study could encompass various factors that may influence students' ability to learn, such as their academic performance, motivation, engagement, mental health, access to resources and learning environment.

1. A cross-sectional design, collecting data at a specific point in time to capture the impact of the COVID-19 pandemic on students' learning abilities. 2. A structured questionnaire will be developed based on relevant literature and research objectives. 3. The questionnaire could be administered to the targeted sample of university students through online surveys, email or other appropriate methods. 4. Descriptive statistics could be used to summarize the demographic characteristics and other relevant variables of the sample. Factor analysis could be performed to identify underlying factors. The Mann–Whitney test, a non-parametric test, could be used to compare the differences between groups.

The results of the data analysis would be interpreted and discussed in the context of the research objectives and relevant literature. The findings could provide insights into the factors that significantly affect learning abilities during the COVID-19 pandemic and highlight any differences among groups. Limitations of the study, such as sample size or potential biases, would also be discussed.

The study would provide a comprehensive overview of the impact of the COVID-19 pandemic on university students' learning abilities, highlight the existing literature in the field and establish the need for further research to investigate the factors influencing students' learning abilities during the pandemic. The study can provide a solid framework for similar studies.

The learning outcomes of this paper are as follows: to assess the extent to which a new business concept or entrepreneurial idea represents a commercial success or practical failure, to estimate the complexities associated with the management of a partnership-based venture in the context of emerging markets, to demonstrate understanding of entrepreneurial action and strategic adaptation under the condition of uncontrollable external shocks (e.g. COVID-19) and to evaluate the pros and cons of different strategic options and provide viable recommendations for the future.

Startup entrepreneurship constitutes the backbone of the socioeconomic activity of any nation and a driver of innovation, industrial diversification and wealth generation, particularly in emerging market settings. Drawing upon narrative storytelling techniques, this case study immerses the reader into the intricacies of entrepreneurial venture creation within the dynamic startup ecosystem in the Middle East. It follows the story of a young serial entrepreneur, Omar, who decided to launch a business in the creative industry of arts in the United Arab Emirates in partnership with his friend, Ahmed. Their common venture, Mont8, showcased and promoted the artwork of budding and well-known Arab talents and was on track to become a recognizable brand in the Middle Eastern business of arts until the COVID-19 crisis shook the world taking everyone by surprise. In an attempt to build a successful post-pandemic future, Omar was convinced that Mont8 needed to fast-track its digital transformation. He envisioned an e-commerce marketplace that would empower Arab artists, designers and photographers to create customized virtual galleries on their own web-stores through the Mont8’s digital platform. Yet, Omar’s vision diverged drastically from the very conservative mindset of Ahmed, who did not want to disrupt tradition and argued in favor of a back-to-business-as-usual approach. It remains unclear whose option would be selected and whether the two partners would stay in this makeover together or rather part ways.

Upper-level undergraduate courses.

Teaching notes are available for educators only.

CSS 3: Entrepreneurship.

Al-Qaeda is conventionally portrayed as a monolithic, hierarchical organization whose activities – coordinated by the network's leader Osama bin Laden – are the source of international terrorism today. Al-Qaeda is considered a radical tendency within the broader Islamist Salafi movement, legitimizing its terrorist operations as a global Islamist jihad against Western civilization. Al-Qaeda's terrorist activity today is considered, “blowback” from long finished CIA and western covert operations in Afghanistan.

The conventional wisdom is demonstrably false. After the Cold War, Western connections with al-Qaeda proliferated around the world, challenging mainstream conceptions of al-Qaeda's identity. Western covert operations and military – intelligence connections in strategic regions show that “al-Qaeda” is a network whose raison d’etre and modus operandi are inextricably embedded in a disturbing conglomerate of international Western diplomatic, financial, military and intelligence policies today. US, British, and Western power routinely manipulates al-Qaeda through a complex network of state-regional and human nodes. Such manipulation extended directly to the 9-11 hijackers, and thus to the events of 9-11 itself.11This paper advances an original argument based partially on research in Ahmed (2005), supplemented here with significant new data and analysis. Also see Ahmed (2002).

Children diagnosed with autism spectrum disorder (ASD) and their families especially their mothers face numerous and pervasive challenges. Difficulties to access quality care, financial burden, issues of adulthood and their child’s behaviors may produce significant stressors to mothers. This study aims to assess perceived stress among mothers of children with ASD in Egypt.

A cross-sectional study was conducted in Mansoura University Hospital, Egypt on 94 mothers of children with ASD using a structured questionnaire of the socio-demographic and clinical features of the studied mothers and their children and the perceived stress scale (PSS).

The mean total PSS score of mothers was 31.97 ± 12.39 and the level of autism had a statistically significant relation with stress perceived by the studied mothers.

The findings in this study were based on caregivers’ self-reporting. As such, inaccurate reporting might have biased the findings. The main limitations of this study include non-participation and dropout. During data collection, some mothers declined to participate in the study. Also, the current study was conducted in one hospital. This represents a loss of valuable information and may weaken the generalizability of the current study findings. Another limitation is the use of a convenience sample in the study. With the use of convenience sampling, there is an increased risk of bias, as study participants may not accurately reflect the characteristics of the total population.

Caregivers’ education programs through media and press should be developed for mothers of children with ASD to help those who experience levels of stress by presenting knowledge about ASD and treatment and training on adaptive coping methods and teaching communication and problem-solving. Recognizing levels of stress and parent counseling may be a useful strategy. Regular periodic meetings should be conducted between mothers and hospital personnel to promote proper communication. One key policy implication, this paper can derive from this study is the need for cooperation between the Ministry of Health, social welfare and other relevant governmental and non-governmental organizations to provide support for families of individuals with ASD such as financial aids. It is also recommended that future study would benefit a larger sample to enhance external validity. As well, future qualitative research is recommended to more fully understand the lived experience of mothers of children with ASD.

This study provides evidence that mothers of children with ASD experienced high perceived stress. Caregivers’ education programs through media and press should be developed in Egypt for mothers of children with ASD.