3,569 research outputs found
Causative factors of construction and demolition waste generation in Iraq Construction Industry
The construction industry has hurt the environment from the waste generated during
construction activities. Thus, it calls for serious measures to determine the causative
factors of construction waste generated. There are limited studies on factors causing
construction, and demolition (C&D) waste generation, and these limited studies only
focused on the quantification of construction waste. This study took the opportunity to
identify the causative factors for the C&D waste generation and also to determine the
risk level of each causal factor, and the most important minimization methods to
avoiding generating waste. This study was carried out based on the quantitative
approach. A total of 39 factors that causes construction waste generation that has been
identified from the literature review were considered which were then clustered into 4
groups. Improved questionnaire surveys by 38 construction experts (consultants,
contractors and clients) during the pilot study. The actual survey was conducted with
a total of 380 questionnaires, received with a response rate of 83.3%. Data analysis
was performed using SPSS software. Ranking analysis using the mean score approach
found the five most significant causative factors which are poor site management, poor
planning, lack of experience, rework and poor controlling. The result also indicated
that the majority of the identified factors having a high-risk level, in addition, the better
minimization method is environmental awareness. A structural model was developed
based on the 4 groups of causative factors using the Partial Least Squared-Structural
Equation Modelling (PLS-SEM) technique. It was found that the model fits due to the
goodness of fit (GOF ≥ 0.36= 0.658, substantial). Based on the outcome of this study,
39 factors were relevant to the generation of construction and demolition waste in Iraq.
These groups of factors should be avoided during construction works to reduce the
waste generated. The findings of this study are helpful to authorities and stakeholders
in formulating laws and regulations. Furthermore, it provides opportunities for future
researchers to conduct additional research’s on the factors that contribute to
construction waste generation
Neurophysiological defects in temperature-sensitive paralytic mutants of Drosophila melanogaster
A new temperature-sensitive paralytic mutant of Drosophila, comatose, is compared behaviorally and physiologically with the previously known types, para and shi. All three have different properties with respect to kinetics of paralysis at high temperature and recovery from paralysis; com is hypersensitive to paralysis by cooling. Neurophysiological experiments indicate different mechanisms for paralysis in each of the mutants
A Robust Continuous Time Fixed Lag Smoother for Nonlinear Uncertain Systems
This paper presents a robust fixed lag smoother for a class of nonlinear
uncertain systems. A unified scheme, which combines a nonlinear robust
estimator with a stable fixed lag smoother, is presented to improve the error
covariance of the estimation. The robust fixed lag smoother is based on the use
of Integral Quadratic Constraints and minimax LQG control. The state estimator
uses a copy of the system nonlinearity in the estimator and combines an
approximate model of the delayed states to produce a smoothed signal. In order
to see the effectiveness of the method, it is applied to a quantum optical
phase estimation problem. Results show significant improvement in the error
covariance of the estimator using fixed lag smoother in the presence of
nonlinear uncertainty.Comment: 8 pages, will be presented in 52nd Conference on Decision and Contro
Identifying the relevance of personal values to e-government portals' success: insights from a Delphi study
Most governments around the world have put considerable financial resources into the development of e-government systems. They have been making significant efforts to provide information and services online. However, previous research shows that the rate of adoption and success of e-government systems vary significantly across countries. It is argued here that culture can be an important factor affecting e- government success. This paper aims to explore the relevance of personal values to the e-government success from an individual user’s perspective. The ten basic values identified by Schwartz were used. A Delphi study was carried out with a group of experts to identify the most relevant personal values to the e-government success from an individual’s point of view. The findings suggest that four of the ten values, namely Self-direction, Security, Stimulation, and Tradition, most likely affect the success. The findings provide a basis for developing a comprehensive e-government evaluation framework to be validated using a large scale survey in Saudi Arabia
Non-adherence to cardiovascular pharmacotherapy in Iraq assessed using 8-items Morisky questionnaire and analysis of dried blood spot samples
open access journalThe study evaluated the non-adherence to selected cardiovascular medications, atenolol, atorvastatin, bisoprolol, diltiazem, lisinopril, simvastatin and valsartan in Iraqi patients by applying a standardized Morisky questionnaire (8-MMAS) and by measuring therapeutic drug concentrations in dried blood spots (DBS) analyzed by liquid chromatography - high resolution mass spectrometry (LC-HRMS). Sixty-nine patients, on continued use of one or more of the selected drugs, were evaluated. The questionnaire showed that 21.7% of participants were non-adherent whereas DBS analysis showed that 49.3% were non-adherent to their medications. No significant correlation between medication non-adherence and gender was detected, but adherence was negatively correlated with the number of medications in the regimen. The 8-items questionnaire was unable to differentiate non-adherence to multiple medications in the prescribed pharmacotherapy regimens. DBS is an alternative to conventional methods to monitor non-adherence objectively. Agreement between the two approaches was weak (Kappa =0.269, p-value 0.05)
Influence of Hydrolytic and Chemical Treatment on the Mechanical Properties of Aramid and Copolyaramid Fibers
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Commercial PPTA fibers ( Kevlar 49® and Twaron 1055®) and copolyaramid fibers (Trevar®) are subjected to various hydrolytic and chemical treatments. Tensile mod ulus, tensile strength, and elongation at break are measured, and mechanical property deterioration is compared. Copolyaramid fibers show improved hydrolytic stability and chemical resistance compared to PPTA fibers. The time dependence of degradation pro cesses can be described by two decreasing exponential functions. WAXS measurements detect only slight differences in the crystalline structure and superstructure of the treated fibers. Thus, the main origin of mechanical degradation is the destruction of intercrys talline links such as tie molecules or tie crystallites
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