The Architecture, Engineering, and Construction (AEC) industry is one of the most dangerous industries due to its unique nature. Safety is a critical issue in developed and developing countries. The ...main objective of this paper was to identify and classify the barriers that hinder the implementation of safety in projects and ways to improve safety performance. The method used in this paper includes a heavy review of many sources related to the safety barriers in the AEC industry, including a process of identification and classification of these barriers, after which we discuss the most popular methods between them, based on the appearance of it in the sources which were reviewed. Then, the ways to improve safety performance were viewed in AEC industry. Based on that, it was found that there are the following 4 categories associated with safety barriers: (1) Behavior Barriers; (2) Management Barriers; (3) Awareness Barriers; and (4) Culture Barriers. At the same time, the most popular barriers are based on appearance in sources: lack of safety training, lack of commitment, work pressure is high when deadlines are approaching, and low level education, lack of experience, and lack of knowledge. The many ways to improve safety performance are illustrated in the end of this paper. The results of this paper show the importance of safety and that the actual safety of the projects should be focused on in order to reduce injuries, accidents, and reduce barriers of applying safety, which will enhance the sustainability and development of safe environments within in AEC industry.
Ti Schottky contact (SC) metal with 50 nm and 100 nm thickness on n-GaAs substrate was sputtered by DC magnetron into vacuum unite. It was checked whether the diode parameters changed with SC metal ...thickness and measurement temperature. As a result of measurements, the potential barrier values decreased while ideality factors remained unchanged with the increasing metal thickness. The results showed that the Ti film thickness has a considerable effect on the barrier potential value. The potential barrier value of the device with thickness of 50 nm was found to be 0.92 and 0.63 eV, and that of 100 nm thickness to be 0.80 and 0.56 eV at 300 and 60 K, respectively. That is, a different of 0.12 eV for the barrier potential was obtained depending on metal thickness at 300 K.
We developed β-Ga 2 O 3 trench MOS-type Schottky barrier diodes (MOSSBDs) for the first time. A Sidoped Ga 2 O 3 layer was grown via halide vapor phase epitaxy on a single-crystal Sn-doped β-Ga 2 O 3 ...(001) substrate. The trench structure was fabricated using dry etching and photolithography. HfO 2 film was used as the dielectric film of the trench MOS structure. The specific on-resistances (RON,SP) of the normal SBD and trench MOSSBD were about 2.3 and 2.9 mΩcm 2 , respectively. The reason the RON,SP of MOSSBD was a little higher than that of the Schottky barrier diodes (SBD) is that the current path decrease as a result of forming the trench MOS structure. The normal SBD had a large reverse leakage current due to the large electric field at the anode metal/semiconductorinterface. On the other hand, the trench MOSSBD had several orders of magnitude smaller leakage current. We, thus, demonstrated that incorporating the trench MOS structure in Ga 2 O 3 is highly effective for decreasing the reverse leakage current.
This study draws on contributions from Social Cognitive Career Theory and Conservation of Resources theory to investigate how configurations of career barriers associated with gender and ethnicity ...influence the development of perceived employability. Our study with graduates surveyed before and two years after completing their degrees, shows that groups of graduates perceiving higher career barriers experience a significant decline in perceived employability during the early stage of their careers. In contrast, those perceiving fewer career hurdles report a more stable employability trajectory and have higher perceived employability two years after graduating. Our study contributes to the literature by showing that perceived employability does not necessarily increase with labor market experience but can instead remain stable or even decline depending on perceived career hindrances.
•This study explores how graduates' perceived employability develops over time as a result of perceiving career barriers.•Four career barriers profiles were identified ranging from multiple strong to weak gender and ethnic barriers.•Graduates perceiving low barriers experience stable perceived employability trajectories.•In contrast, those perceiving high barriers report declining perceived employability trajectories.
•The study appraises empirical literature on factors associated with export barriers.•Four explicit- and two implicit- theories capture the discourse.•Thirty-six independent variables and four ...primary export barrier groupings are identified.•Vote counting collates the relationship between the independent variables and export barriers.•Conclusions, implications, and directions for future studies are underlined.
Although research on export barriers spans five decades, no single prior study has systematically reviewed findings in this field. This study enriches the discourse on internationalization through a systematic review of the factors associated with export barriers, the theories underpinning this, and the exact nature of the relationships. Findings indicate the bulk of empirical studies focus on drivers of export barriers. The study identifies thirty-six such variables, falling in the categories of firm demographics, export venture characteristics, managerial factors, environmental and operational factors, and international trading environment. Smaller sub-streams of research investigate export barriers as predictors, mediators, and moderators. A vote counting approach dissects the associations (i.e. positive, negative, and weak) between the various factors and export barriers. Moreover, the study identifies four explicit (i.e. resource-based view, incremental internationalization, network, and institutional theories) and two implicit (i.e. attribution and rationalization) theories underlying the associations. Concerning research design and methodology, the study highlights the underrepresentation of emerging markets, longitudinal studies, cross-national comparisons, and advanced multivariate analytical tools. Finally, the study draws key implications for managers, policymakers, and educators, before setting an agenda for future research.
This study critically appraises employing chitosan as a composite with bentonite, biochar, or both materials as an alternative to conventional barrier materials. A comprehensive literature review was ...conducted to identify the studies reporting chitosan-bentonite composite (CBC), chitosan amended biochar (CAB), and chitosan-bentonite-biochar composite (CBBC) for effective removal of various contaminants. The study aims to review the synthesis of these composites, identify fundamental properties affecting their adsorption capacities, and examine how these properties affect or enhance the removal abilities of other materials within the composite. Notably, CBC composites have the advantage of adsorbing both cationic and anionic species, such as heavy metals and dyes, due to the cationic nature of chitosan and the anionic nature of montmorillonite, along with the increased accessible surface area due to the clay. CAB composites have the unique advantage of being low-cost sorbents with high specific surface area, affinity for a wide range of contaminants owing to the high surface area and microporosity of biochar, and abundant available functional groups from the chitosan. Limited studies have reported the utilization of CBBC composites to remove various contaminants. These composites can be prepared by combining the steps employed in preparing CBC and CAB composites. They can benefit from the favorable adsorption properties of all three materials while also satisfying the mechanical requirements of a barrier material. This study serves as a knowledge base for future research to develop novel composite barrier materials by incorporating chitosan and biochar as amendments to bentonite.
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•Chitosan with highly reactive functional groups is effective for contaminant removal.•Bentonite is a desirable composite constituent for contaminant removal due to its surface area and anionic nature.•Biochar in the composite increases surface area for contaminant adsorption.•Composite synthesis procedures vary depending on the application.•Contaminant removal by composites varied widely due to the variability in materials.
The Schottky barrier height and the S-parameter of the semipolar $\left( {11\bar 22} \right)$ n-type GaN grown on m-plane sapphire substrate were investigated by using Schottky diodes fabricated with ...the different work functions of metals including Cu, Pd, and Pt. The Barrier inhomogeneity model applied to temperature dependent current a voltage characteristics of Schottky diodes revealed the mean barrier heights of 0.86, 0.77, and 0.82 eV for the Cu, Pd, and Pt contact, respectively. The extracted S-parameter was nearly zero, indicating a pinning of the surface Fermi level at approximately 0.8 eV below the conduction band. This could be attributed to the substantial crystallographic defects of semipolar GaN as verified from the atomic force microscope and x-ray diffraction measurements.
Despite the promised benefits of MOOCs (Massive Open Online Courses) to address the digital divide and promote equity in educational opportunities, the use of MOOCs is still lagging especially in ...developing countries. The purpose of this study is to investigate the barriers underlying the adoption of MOOCs in the context of a developing country. Drawing from the theoretical framework of innovation resistance theory, this study conducted focus group discussions with 69 college students in China, a major developing country in Asia. It was found that innovation resistance theory is plausible to explain the barriers to adopting MOOCs. Our results showed that the main barriers in the adoption of MOOCs encountered by students in a developing country are usage barrier, value barrier, and tradition barrier. Furthermore, to complement the perspective of innovation resistance theory, this study also conducted an inductive analysis to identify other types of obstacles hindering students' use of MOOCs. It was found that individual factors (e.g., self-control and attitude) as well as the environment (e.g., promotion and economical circumstance) are also barriers to the use of MOOCs. Implications and suggestions for practice are also discussed.
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