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Coconut shell waste as an alternative lightweight aggregate in concrete- A review
Muhammad ,Aslam,Waqas, Aziz,M. Jahanzaib, Khalil,M. Jahanzaib, Ali,Muhammad, Raheel,Aayzaz, Ahmed,Muhammad Fahad, Ejaz Techno-Press 2022 Advances in materials research Vol.11 No.4
This review article highlights the physical, mechanical, and chemical properties of coconut shells, and the fresh and hardened properties of the coconut shell concrete are summarized and were compared with other types of aggregates. Furthermore, the structural behavior in terms of flexural, shear, and torsion was also highlighted, with other properties including shrinkage, elastic modulus, and permeability of the coconut shell concrete. Based on the reviewed literature, concrete containing coconut shell as coarse aggregate with normal sand as fine showed the 28-day compressive strength between 2 and 36 MPa with the dried density range of 1865 to 2300 kg/m<sup>3</sup>. Coconut shell concretes showed a 28-day modulus of rupture and splitting tensile strength values in the ranges of 2.59 to 8.45 MPa and 0.8 to 3.70 MPa, respectively, and these values were in the range of 5-20% of the compressive strength. The flexural behavior of CSC was found similar to other types of lightweight concrete. There were no horizontal cracks on beams which indicate no bond failure. Whereas, the diagonal shear failure was prominent in beams with no shear reinforcements while flexural failure mode was seen in beams having shear reinforcement. Under torsion, CSC beams behave like conventional concrete. Finally, future recommendations are also suggested in this study to investigate the innovative lightweight aggregate concrete based on the environmental and financial design factors.
Winner-Loser Effect: Empirical Evidence from Pakistan
Muhammad Sahid RASHEED,Muhammad Fayyaz SHEIKH,Jahanzaib SULTAN,Qamar ALI,Aamir Inam BHUTTA 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.10
The study examines the behavior of stock prices after large price changes. It further examines the effect of firm size on stock returns, and the presence of the disposition effect. The study employs the event study methodology using daily price data from Pakistan Stock Exchange (PSX) for the period January 2001 to July 2012. Furthermore, to examine the factors that explain stock price behavior after large price movements, the study employs a two-way fixed-effect model that allows for the analysis of unobservable company and time fixed effects that explain market reversals or continuation. The findings suggest that winners perform better than losers after experiencing large price shocks thus showing a momentum behavior. In addition, the winners remain the winner, while the losers continue to lose more. This suggests that most of the investors in PSX behave rationally. Further, the study finds no evidence of disposition effect in PSX. The investors underreact to new information and the prices continue to move in the direction of initial change. The pooled regression estimates show that firm size is positively related to post-event abnormal returns while the fixed-effect model reveals the presence of unobservable firm-specific and time-specific effects that account for price continuation.
A Review of Large-Scale Hydropower Project in Public Sector of Pakistan
Umair, Muhammad,Choudhary, Muhammad Abbas,Jahanzaib, Mirza Korea Institute of Construction Engineering and Ma 2014 Journal of construction engineering and project ma Vol.4 No.4
Client organization inadequate project planning before awarding the contract and insufficient monitoring and control system among the parties involved create severe problems. Ultimately, large-scale projects go beyond the expected cost and time control limits. This paper discusses the major issues involved with a large-scale Hydropower Project in Pakistan Public Sector environment. The latest approved Baseline Plan of project was reviewed and analyzed using Variance Analysis and Trend Analysis techniques in Primavera project management software to assess the efforts made of the parties involved. It was found that Project is 202% Cost overrun and 25% time delays from original contract award. After analysis of baseline plan and quantification of various variance issues in impacted activities, the questionnaire survey was conducted to identify the impact of causative factors. There were almost 17 most significant causative factors identified among 60 identified factors and responsibilities are assigned accordingly. At the end recommendations are made for strategic decisions as lessons learned during project evaluation.
CEO Compensation and Unobserved Firm Performance in Pakistan
Muhammad Fayyaz SHEIKH,Aamir Inam BHUTTA,Jahanzaib SULTAN 한국유통과학회 2019 The Journal of Asian Finance, Economics and Busine Vol.6 No.3
The study examines whether higher CEO compensation is related to unobserved future firm performance in an emerging market, Pakistan. Further, it extends its scope to analyzing the impact of group affiliation and ownership concentration on the relationship between CEO compensation and future firm performance. The study uses an unbalanced panel data consisting of 1508 firm-year observations from 225 non-financial listed companies in Pakistan Stock Exchange (PSX) for period 2005 to 2012. The multiple regression models adjusted to heteroskedasticity and autocorrelation in error terms are used. The study finds that, in general, CEO compensation is positively associated with future operating performance. However, higher CEO compensation leads to lower operating performance in firms that have lower ownership concentration and are affiliated with business groups. When firms are not affiliated with any group and have high ownership concentration, the relationship between excessive CEO compensation and future operating performance becomes insignificant. Given that efficient compensation packages may lead to long term value creation to shareholders and reduce agency problems, this study highlights an important moderating role of ownership concentration and group affiliation of the firms in emerging markets.