Utility Impact Assessment of Road Projects in the State of Qatar

Qatar has been blessed with large reserves of natural gas and since the past 20 years its leaders have been busy formulating its path to modernization. Henceforth, the sovereign state has been and is still going through tremendous development phase to meet the 2030 vision of making Qatar a world class country and giving its citizens a very high standard of living. This is to be achieved with development in key sectors namely economic, social, environmental and more importantly human development. Moreover, in 2010 Qatar was awarded to host the 2022 FIFA World Cup, which increased the country’s pipeline of projects such as stadia, hotels, metro and ports (air and sea). This also led to fast tracking of its stockpile of existing infrastructure projects to meet 2022 deadlines. Accordingly, significant portion of these projects will be constructed within the right of way or road reserve. Although the current practice of road construction and utility installation in Qatar is in-line with world best practices, but such practices were not followed stringently in the past. Moreover, Qatar’s cities have gone through an excessive urban densification, which meant that the service providers had to provide greater number of utilities and road authorities had to design and construct complex road networks that involved tunnels, bridges, underpasses and overpasses. These challenges are further compounded by the fact that there are narrow right of ways for the installation of all these utilities in the urban areas. In tackling these challenges, the Ministry of Municipality and Environment (MME) along with road authorities and utility providers have gone through robust review and modification of their practices. As a result, actions were taken and in particular MME developed a process namely, utility impact assessment process that guides the road designers to collaborate with utility designers to achieve a more value engineered outcome

The effect of visual inspection reliability on risk-based inspection

Bridge inspection has come a long way from its inception as a component level practice following the Silver Bridge collapse in 1967 to the most recent advancement enacted by the Moving Ahead for Progress in the 21st Century (MAP-21) legislation to determine the inspection interval using risk-based inspection (RBI) and mandated element-level data collection for all the states. RBI, a well-researched topic in other fields is new to the bridge inspection practice and element-level bridge inspection provides data for RBI condition attributes. The first objective of the research was to determine how inspection variability in condition state (CS) assignment and defect quantification affect the attributes in RBI practice. Based on the data collected from Indiana and Michigan, about 9 [percent] of the inspectors incorrectly assigned the bridges' elements to CS 4 (RBI screening attribute), and 18 [percent] of the inspectors incorrectly assigned the bridges' elements to CS 2 (low ranking score). The conclusion was made assuming that if most of the inspectors assign the same CS for a bridge's element, it is the correct CS assignment. The second objective was to determine how the inspection data variability affects the deterioration models (Markov chain, Kaplan-Meier, and Weibull). Based on the National Bridge Inventory (NBI) data from the seven states, it was shown that the NBI data do not fit the Weibull distribution and the variability in NBI data on Kaplan-Meier either extends or shortens the median time in condition rating (TICR) for a bridge component. Build on the details of the second objective, the Markov chain was proposed to calculate the probability of failure (POF) for the RBI occurrence factor (OF)

Design of cyclic prefix characteristic-based OFDM system for WiMAX technology

Worldwide interoperability for microwave access (WiMAX) offers the wireless connectivity using orthogonal frequency division multiplexing (OFDM) modulation is a proficient wireless technology that capacities high-speed data transmission facilities. The existing WiMAX techniques have the problem of increase in inter-symbol interference (ISI) and bit error rate (BER) at reduced power spectrum that degrades the performance of WiMAX system due to high data rate transmission. The utilization of different adaptive modulation techniques seen as a potential solution to reduce the ISI and BER for high data rate transmission. In this paper, OFDM is adapted using advanced modulation technique for WiMAX system. The technique proposes the cyclic prefix (CP) is utilized that include supplementary bits at the stage of the transmitter. The proposed technique offers minimization of ISI and improvement in BER. It is defined that performance of the existing CP system is equated with the designed single cyclic prefix (SCP) and double cyclic prefix (DCP) and non-cyclic prefix (NCP). BER, probability of error, and power spectral density are utilized to analyse the performance of the designed system. The OFDM based SCP and DCP and NCP for WiMAX are demonstrated for modulation techniques such as; QPSK, BPSK, and QAM. It is determined that BPSK has the smallest BER when compared to QPSK, 16-QAM, and 64-QAM modulations. It is also demonstrated that QPSK is also very competent, however, it has a higher BER as compared to BPSK modulation. It is also observed that 16-QAM and 64-QAM are less efficient in terms of BER compared to QPSK and BPKS modulations. 64-QAM offers the high data rates, and due to high SNR ratio. The designed system is tested for under AWGN and Rayleigh fading channel, and effect power spectral density of signal to noise ratio on OFDM for rayleigh fading channel are demonstrated for SCP and DCP and NCP. It is determined that the OFDM transmitter with proposed DCP for random signals is efficiently reducing the BER and ISI for WiMAX system

Mechanical Properties of Ceramic Based Functionally Graded Dental Crowns Produced by Additive Manufacturing

All-ceramic dental crowns present a higher incidence of fracture and chipping when supported by dental implants as opposed to natural teeth. This study attempted to replicate the graded structural design of a natural tooth in an implant-supported all-ceramic crown to improve its fracture resistance by using additive manufacturing (AM). The purpose of this in vitro study was to compare the fracture resistance and ultimate compressive strength of implant-supported milled zirconia (MZr), milled lithium disilicate (MLD), AM zirconia (AMZr) and AM graded structural (AMGS) crowns. A maxillary cast with a dental implant replacing the right second bicuspid was obtained. Custom abutments and full-contour crowns were digitally designed. The STL files were used to mill 40 zirconia abutments and fabricate 10 crowns for each of the aforementioned 4 groups: MZr, MLD, AMZr and AMGS. The crowns were cemented to implant supported zirconia abutments in accordance with the manufacturer’s guidelines and mounted onto polyurethane foam blocks. The fracture resistance and ultimate compressive strength were determined for all the groups by vertical force application using a computer controlled universal testing machine at a crosshead speed of 2mm/min. Kruskal-Wallis test (α=0.05) was used to analyze the data and the mode of failure was determined for all the groups. Based on the experimental design, MZr revealed the highest mean value for fracture resistance (1330±111 N) and ultimate compressive strength, followed by MLD (1257±169 N), AMZr (1179±247 N) and AMGS (1169±163 N). However statistical analysis showed no significant differences in fracture resistance and ultimate compressive strength between the groups (p>0.05). All the samples fractured at the implant-abutment interface. Within the limitations of this in vitro study, it can be concluded that AM crowns demonstrated similar strengths to milled crowns, when cemented to implant supported zirconia abutments

Supply chain collaboration within the Iranian construction industry

Collaboration is an important factor to succeed and increase the sustainability in project management and construction, especially in a construction supply chain (CSC) that includes multiple partners. Although, in recent decades, many changes have occurred in the construction industry, there are still many problems in this area. Therefore, research in this area becomes vital because collaboration is one of the best approaches to improve CSC performance. In this study, collaborative relationship has been found to be affected by three main factors: managerial, financial and structural. However, application of collaboration in Iran is still in its inception. This comprehensive research study focuses on suitable context for implementing the collaboration method. The methodology of this research is based on interviews and a review of previous research, which identifies critical factors and positive results of use in relation to collaboration. Results of this study improve our knowledge about the role of collaboration in a CSC’s performance. Analysis of data shows that managerial factors have the most positive effects on the implementation of collaboration networks in CSCs, followed by financial factors and organizational factors

A review of brain death protocols across the globe and need for brain death guideline for Pakistan.

The concept of brain death was first formally presented in United States of America in 1968 (Ad Hoc Committee of the Harvard Medical School to examine the definition of Brain Death, 1968) in part to facilitate organ donation. It is a widely accepted term in most countries but some like Japan do not consider it as death. According toAAN, brain death is defined as death due to irreversible loss of function of the entire brain — comparable to circulatory death, which is defined as irreversible loss of function of the circulatory system. The purpose of our study is to review brain death protocols from various parts of the world to ultimately formulate a concise brain death protocol for Pakistan

Virtual reality as pedagogical tool to enhance experiential learning: A systematic literature review

Since half of the century, technology has dominated the modern era. The rapid advancement of technology has reached generating artificial intelligence and artificial realities. So, virtual reality is an emerging technology and is applicable in education as well. Virtual reality is a computer-generated simulation, where people can interact within an artificial environment. Moreover, in an educational setting, such an environment provides students with a chance to get experiential learning. This paper has a systematic literature review on emerging technologies, such as virtual reality as a pedagogical tool for enhancing students’ experiential learning. This review aims to explore and understand the effect of virtual reality on students’ experiential learning by reviewing twenty-six selected articles. The selected studies have followed various methodologies and are from different contexts. This review study aims to present a systematic literature review for understanding and exploring the effect of virtual reality as a pedagogical tool for enhancing students’ experiential learning. Nine themes were identified, which are (a) virtual reality as pedagogical tool, (b) virtual reality as emerging educational technology tool, (c) virtual reality as digital transformation, (d) virtual reality as teaching learning model, (e) virtual reality as architectural pedagogy, (f ) virtual reality for communication skills, (g) virtual reality for reading and writing skills, (h) virtual reality for social learning, and (i) virtual reality for experiential learning. Thus, it is found that virtual reality is used as a pedagogical tool for various subject areas for encouraging involvement. It is helpful in medical, engineering, language, and social learning, as it provides a chance to get first-hand experience of the environment. Also, it helps learners to engage in a presented virtual environment and experience the sense of presence in it and enhances students’ experiential learning. Therefore, this review found virtual reality as an essential pedagogical tool for strengthening students’ experiential learning

Communicative language teaching in public universities in Afghanistan: perceptions and challenges

While Communicative Language Teaching (CLT) has been advocated in Afghanistan, little is known about the perception of Afghan EFL (English as a Foreign Language) teachers on CLT. This study aims to investigate the perceptions and challenges of CLT in Afghan public universities from the perspectives of EFL teachers. The study employed a mixed-method approach comprising survey questionnaires and a qualitative interview. A sample of sixty-two Afghan EFL teachers was selected to participate in a survey questionnaire, while five were interviewed. Findings from the questionnaires and interview showed that Afghan EFL teachers have positive perceptions regarding CLT. The results also showed that the education system is one of the significant challenges for CLT implementation in Afghan public universities. The current study is valuable for policymakers, teachers, and students for improvement of EFL classes in Afghanistan

Association of vitamin D deficiency and VDBP gene polymorphism with the risk of AMI in a Pakistani population

OBJECTIVE: To investigate the relationship of vitamin D deficiency and risk of AMI in a Pakistani population, and to find out any associationbetween vitamin D binding protein (VDBP) genotypes and risk of AMI in this population.METHODS: In a comparative cross-sectional study, 246 patients (age: 20-70 years; 171 males and 75 females) with first AMI were enrolled with informed consent. Similarly, 345 healthy adults (230 males and 115 females) were enrolled as controls. Their fasting serum samples were analyzed for 25 (OH) vitamin D, lipids and other biomarkers using kit methods, while DNA was analyzed for VDBP genotypes using PCR-RFLP based methods. Chi-squared test and logistic regression were used for association of vitamin D deficiency and VDBP genotypes with AMI.RESULTS: Mean serum concentration of 25(OH) vitamin D was significantly lower in AMI patients compared to healthy subjects (p=0.015) and percent vitamin D deficiency was higher in AMI patients compared to healthy subjects (p=0.003). VDBP IF-IF genotype was positively associated with the risk of AMI in subject above 45 years after adjusting for potential confounders [OR = 9.86; 95% CI=1.16 to 83.43].CONCLUSION: Vitamin D deficiency and VDBP IF-IF genotype are associated with AMI in Pakistani adults