120 research outputs found
Developing models to predicting the effect of crises on construction projects using MLR technique
Most construction projects are exposed to multiple external and internal problems and obstacles that lead to a crisis within the construction project, which may lead to the failure of the construction project. It is also a source of concern for owners, stakeholders, and contractors alike due to its difficulty. As a result, a new approach to dealing with crises prior to their occurrence is required. Accurate construction project prediction concerns at the early stages of a construction project are critical factors in the success of a project. This study develops anticipatory models for construction project crises by identifying and categorizing the major different variables that affect construction project objectives and indicate time overrun, cost overrun, and poor quality for construction projects before crises occur. The most influential factors on the failure of construction projects in Iraq were identified in this study; some of these factors affect project implementation time, others affect project cost, and the remaining factors affect construction project quality. The independent variables measurement model is designed to collect accurate raw data from the site. This model is based on 53 data samples collected from various multi-story building projects, which were used to construct and test the model. From MLR multiple linear regression results, three equations were derived from calculating the percentage of overrun (time, cost and quality) because of the construction project being affected by crises. Found that the correlation coefficient of the above models is (99.8%, 98.6%, 96.5%), respectively
Determination a Reasonable Concession Period for (PPP) Projects
Public Private Partnership (PPP) are agreements where public bodies enter into long term contractual with private entities for construction or management the public sector facilities, or provision services to the community. Internal rate of return (IRR), pay back regime or tariff, and the concession period (CP) are essential items to success (PPP) projects. This research presents a systematic approach for a win-win partnership contract determined on a quantitative basis, by informing the partnership parties how long contract period should be made. Essence of the proposed methodology is that project completion time should allow a competent contractor to complete the project on schedule and operation period should be long enough to enable the concessionaire to achieve a reasonable return, but not too long such that concessionaire’s return is excessive and public sector’s interests are sacrificed. A case study of a PPP project in Mayoralty of Baghdad was conducted to evaluate performance of the developed mathematical models. The determined concession period (CP) has found to be approximately equal to actual concession period (CP) granted to the private sector. Evaluation shows the possibility to adopt the proposed approach to determine the concession period (CP) more effectively. Instead of opportunism policy, the proposed methodology enables local government of Baghdad province to enhance its policies of awarding the partnership projects to increase private sector participation in infrastructure development. Finally, the proposed method can be used by investment practitioners as a decision support tool for contract concession period (CP), and is worth popularizing to design the contracted concession period (CCP) for partnership projects in Iraq, and also can use as a methodology to assess the critical aspects which related to partnership projects in general
Learning organizations and knowledge management: Which one enhances another one more?
This paper presents an empirical investigation to detect whether knowledge management (KM) promotes learning organization (LO) or vice versa. The proposed study tries to find out the positive influences of KM components including knowledge acquisition, sharing, and utilization with different LOs dimensions. The study was performed among managers and members of societies of software and computer engineering field in city of Tehran, Iran. One time knowledge management processes were seen as independent variable and another time considered as dependent variables. Pearson correlation and regression analysis were used to test the hypothesis. The results show that KM promotes OLs more than OLs promotes KM
Comparative studies on the effect of environmental pollution on secondary metabolite contents and genotoxicity of two plants in Asir area, Saudi Arabia
Purpose: To investigate the phytochemical contents and genotoxic effects of Ficus carica and Schinus molle grown in healthy and polluted environments in Asir area, Saudi Arabia.Methods: Extracts of the aerial parts of the plants were screened for phytochemical constituents. Genotoxicity tests were carried out in mice using Comet assay, micronucleus test and chromosomal analysis.Results: Extracts of the two plants grown in polluted soil showed elevations in phytochemical and heavy metal contents, when compared with extracts from non-polluted sites. In genotoxicity tests, F. carica and S. molle extracts produced significant increases in the number of micro-nucleated cells in mice, compared to control. Cytotoxicity tests showed that extracts from plants grown in non-polluted environments did not decrease polychromatic erythrocytes (PCE) to normochromatic erythrocytes (NCE) ratio in bone marrow cells, relative to control. Mice in the vehicle control group showed some aberrant metaphases and a few aberrations per hundred metaphases.Conclusion: Pollution has significant effects on phenolic compounds, total flavonoids, and genotoxic potential of the two plants.Keywords: Ficus carica, Schinus molle, Pollution, Genotoxicity, Total phenolic compounds, Total flavonoid
Reducing Maintenance Costs for Government Projects in Iraq Using Performance Indicators
Institutions and companies are looking to reduce spending on buildings and services according to scientific methods, provided they reach the same purpose but at a lower cost. On this basis, this paper proposes a model to measure and reduce maintenance costs in one of the public sector institutions in Iraq by using performance indicators that fit the nature of the work of this institution and the available data. The paper relied on studying the nature of the institution’s work in the maintenance field and looking at the type of data available to know the type and number of appropriate indicators to create the model. Maintenance data were collected for the previous six years by reviewing the maintenance and financial department records. On this basis, three performance indicators are proposed in creating the model. The result is a model to reduce maintenance costs based on three indicators; each indicator contains a baseline value and a target value. If this model is applied, it will significantly help measure, track, control, and reduce maintenance costs in government institutions
Detection of equid herpesviruses among different Arabian horse populations in Egypt
Equid herpesviruses (EHVs) threaten equine health and can cause significant economic losses to the equine industry worldwide. Different equid herpesviruses, EHV‐1, EHV‐2, EHV‐4 and EHV5 are regularly detected among horse populations. In Egypt, monitoring is sporadic but EHV‐1 or EHV‐4 have been reported to circulate in the horse population. However, there is a lack of reports related to infection and health status of horses, likely due to the absence of regular diagnostic procedures. In the current study, the circulation of four infectious equid herpesviruses (EHV‐1, EHV‐2, EHV‐4 and EHV‐5) among different Arabian horse populations and donkeys residing the same farm was monitored. Different samples were collected and DNA was extracted and subjected to quantitative (q)‐PCR to detect the four equid herpesviruses using specific primers and probes. Antibody titres against EHV‐1 and EHV‐4 were tested using virus neutralization test and type‐specific ELISA. The results showed that EHV‐1, EHV‐2, EHV‐4 and EHV‐5 are endemic and can be a continuous threat for horses in the absence of vaccination programs and frequent virus reactivation. There is an urgent need for introduction of active regular surveillance measures to investigate the presence of different equid herpesviruses, and other equine viral pathogens, in various horse populations around Egypt and to establish a standardized cataloguing of equine health status
COMPARATIVE PROFILING OF BIOMARKER PSORALEN IN ANTIOXIDANT ACTIVE EXTRACTS OF DIFFERENT SPECIES OF GENUS FICUS BY VALIDATED HPTLC METHOD
Background: A simple but sensitive HPTLC method was developed for the comparative evaluation of psoralen in antioxidant active extracts of leaves of five different species of genus Ficus (Ficus carica, Ficus nitida, Ficus ingens, Ficus palmata and Ficus vasta).
Materials and Methods: HPTLC studies were carried out using CAMAG HPTLC system on Glass-backed silica gel 60F254 HPTLC pre-coated plates using selected mobile phase toluene: methanol (9:1). The antioxidant activity was carried out, using DPPH free radical method.
Results: Among all the five species of genus Ficus, F. palmata and F. carica exhibited comparatively good antioxidant activity in DPPH assay. The developed HPTLC method was found to give a compact spot for psoralen (Rf = 0.55±0.001) at 305 nm. The regression equation and r2 for psoralen was found to be Y= 4.516X+35.894 and 0.998. The quantification result revealed the presence of psoralen in only two species, F. carica (0.24%, w/w) and F. palmata (1.88%, w/w) which supported their supremacy for anti-oxidant potential over other species. The statistical analysis proved that the developed method was reproducible and selective.
Conclusion: The developed method can be used as an important tool to assure the therapeutic dose of active ingredients in herbal formulations as well as for standardization and quality control of bulk drugs and in-process formulations. This method can also be employed for the further study of degradation kinetics and determination of psoralen in plasma and other biological fluids
Antigenotoxic Studies of Different Substances to Reduce the DNA Damage Induced by Aflatoxin B1 and Ochratoxin A
Mycotoxins are produced mainly by the mycelial structure of filamentous fungi, or more specifically, molds. These secondary metabolites are synthesized during the end of the exponential growth phase and appear to have no biochemical significance in fungal growth and development. The contamination of foods and feeds with mycotoxins is a significant problem for the adverse effects on humans, animals, and crops that result in illnesses and economic losses. The toxic effect of the ingestion of mycotoxins in humans and animals depends on a number of factors including intake levels, duration of exposure, toxin species, mechanisms of action, metabolism, and defense mechanisms. In general, the consumption of contaminated food and feed with mycotoxin induces to neurotoxic, immunosuppressive, teratogenic, mutagenic, and carcinogenic effect in humans and/or animals. The most significant mycotoxins in terms of public health and agronomic perspective include the aflatoxins, ochratoxin A (OTA), trichothecenes, fumonisins, patulin, and the ergot alkaloids. Due to the detrimental effects of these mycotoxins, several strategies have been developed in order to reduce the risk of exposure. These include the degradation, destruction, inactivation or removal of mycotoxins through chemical, physical and biological methods. However, the results obtained with these methods have not been optimal, because they may change the organoleptic characteristics and nutritional values of food. Another alternative strategy to prevent or reduce the toxic effects of mycotoxins is by applying antimutagenic agents. These substances act according to several extra- or intracellular mechanisms, their main goal being to avoid the interaction of mycotoxins with DNA; as a consequence of their action, these agents would inhibit mutagenesis and carcinogenesis. This article reviews the main strategies used to control AFB1 and ochratoxin A and contains an analysis of some antigenotoxic substances that reduce the DNA damage caused by these mycotoxins
- …