231 research outputs found

    The Key Criteria in Deciding to Tender for Construction Projects

    Get PDF
    Planning for a construction project is a formidable task which involves a huge investment with multiple stakeholders such as clients, consultants, and contractors. A tender is a submission of a technical, administrative, and contractual material made by a potential contractor in response to an invitation to tender by the project client. Established contractors normally realise the importance of doing initial research before committing themselves to enter the tender. Normally, tender pre-qualification is a strict process. A low-quality tender submitted due to problems such as insufficient time and incomplete tender documents normally lead to tender rejection by the client. Thus, this research aimed to provide a strategy to help the contractors in deciding whether they should or should not submit a tender at the initial tendering decision phase. The literature review was focused on the key factors identified in influencing the decision-making process and in the final part, the initial conceptual model was establishe

    Experimental Stand for Investigations of Insulator Degradation and Electrode Erosion in High-current Breaker

    Get PDF
    An experimental stand for studies of electric arc, electrode erosion and insulator degradation processes in high-current circuit breakers and some preliminary experimental data is described. The setup includes a discharge chamber, a capacitive energy storage with capacitance of 0.11 F, voltage up to 10 kV, and all necessary diagnostic techniques. The stand is designed for modeling current pulse with amplitude of 3–150 kA and duration of the first half period of 1.0–3.0  ms during the process of disconnecting the ring and the pin contacts. The arc is cooled by transverse gas blowing at pressure in the chamber of 0.5–3 MPa. Acquired experimental data can be used for verification of the modelling results of the heat transfer processes in the discharge chamber. At the stand, advanced composite materials based on carbon and iron-copper pseudoalloy are studied

    Peri-Adolescent Ethanol Vapor Exposure Produces Reductions in Hippocampal Volume that are Correlated with Deficits in Prepulse Inhibition of the Startle

    Get PDF
    Epidemiological studies suggest that excessive alcohol consumption is prevalent among adolescents and may have lasting neurobehavioral consequences. The use of animal models allows for the separation of the effects of adolescent ethanol exposure from genetic background and other environmental insults. In the present study the effects of moderate ethanol vapor exposure, during adolescence, on structural diffusion tensor imaging (DTI) and behavioral measures were evaluated in adulthood

    The European Language Resources and Technologies Forum: Shaping the Future of the Multilingual Digital Europe

    Get PDF
    Proceedings of the 1st FLaReNet Forum on the European Language Resources and Technologies, held in Vienna, at the Austrian Academy of Science, on 12-13 February 2009

    Fixatives increase the efficacy of gel formulations containing Piper aduncum linnaeus (Piperales: Piperaceae) essential oil as repellenty

    Get PDF
    Piper aduncum essential oil exhibit repellency activity and has a potential to be use as an alternative for synthetic repellent such as N,N-diethyl-3- methylbenzamide, (DEET). However, the volatility properties of the essential oil decrease their persistence as a topical repellent. Study has shown that formulation of the essential oil with some fixatives may increase their effectiveness. Therefore, this study was conduct to evaluate the effectiveness of gel formulation containing P. aduncum essential oil with two fixative; vanillin and paraffin oil. Gel formulations containing P. aduncum essential oil with 5% and 10% vanillin and 6% paraffin oil was prepared and tested against Aedes aegypti in laboratory using Standards and Industrial Research Institute of Malaysia (SIRIM) bioassay method. After 240 minute post-application, formulation containing 5% and 10% vanillin was able to provide >70% repellency percentage against mosquito while formulation containing 6% paraffin oil gives <30% repellency percentage. As conclusion, P. aduncum based repellent gel containing 5% and 10% vanillin was able to prolong the effect of P. aduncum essential oil as repellent against dengue vector in laboratory

    The origin of large molecules in primordial autocatalytic reaction networks

    Get PDF
    Large molecules such as proteins and nucleic acids are crucial for life, yet their primordial origin remains a major puzzle. The production of large molecules, as we know it today, requires good catalysts, and the only good catalysts we know that can accomplish this task consist of large molecules. Thus the origin of large molecules is a chicken and egg problem in chemistry. Here we present a mechanism, based on autocatalytic sets (ACSs), that is a possible solution to this problem. We discuss a mathematical model describing the population dynamics of molecules in a stylized but prebiotically plausible chemistry. Large molecules can be produced in this chemistry by the coalescing of smaller ones, with the smallest molecules, the `food set', being buffered. Some of the reactions can be catalyzed by molecules within the chemistry with varying catalytic strengths. Normally the concentrations of large molecules in such a scenario are very small, diminishing exponentially with their size. ACSs, if present in the catalytic network, can focus the resources of the system into a sparse set of molecules. ACSs can produce a bistability in the population dynamics and, in particular, steady states wherein the ACS molecules dominate the population. However to reach these steady states from initial conditions that contain only the food set typically requires very large catalytic strengths, growing exponentially with the size of the catalyst molecule. We present a solution to this problem by studying `nested ACSs', a structure in which a small ACS is connected to a larger one and reinforces it. We show that when the network contains a cascade of nested ACSs with the catalytic strengths of molecules increasing gradually with their size (e.g., as a power law), a sparse subset of molecules including some very large molecules can come to dominate the system.Comment: 49 pages, 17 figures including supporting informatio

    The Global Brain Health Survey: Development of a Multi-Language Survey of Public Views on Brain Health.

    Get PDF
    Background: Brain health is a multi-faceted concept used to describe brain physiology, cognitive function, mental health and well-being. Diseases of the brain account for one third of the global burden of disease and are becoming more prevalent as populations age. Diet, social interaction as well as physical and cognitive activity are lifestyle factors that can potentially influence facets of brain health. Yet, there is limited knowledge about the population's awareness of brain health and willingness to change lifestyle to maintain a healthy brain. This paper introduces the Global Brain Health Survey protocol, designed to assess people's perceptions of brain health and factors influencing brain health. Methods: The Global Brain Health Survey is an anonymous online questionnaire available in 14 languages to anyone above the age of 18 years. Questions focus on (1) willingness and motivation to maintain or improve brain health, (2) interest in learning more about individual brain health using standardized tests, and (3) interest in receiving individualized support to take care of own brain health. The survey questions were developed based on results from a qualitative interview study investigating brain health perceptions among participants in brain research studies. The survey includes 28 questions and takes 15-20 min to complete. Participants provide electronically informed consent prior to participation. The current survey wave was launched on June 4, 2019 and will close on August 31, 2020. We will provide descriptive statistics of samples distributions including analyses of differences as a function of age, gender, education, country of residence, and we will examine associations between items. The European Union funded Lifebrain project leads the survey in collaboration with national brain councils in Norway, Germany, and Belgium, Brain Foundations in the Netherlands and Sweden, the National University of Ostroh Academy and the Women's Brain Project. Discussion: Results from this survey will provide new insights in peoples' views on brain health, in particular, the extent to which the adoption of positive behaviors can be encouraged. The results will contribute to the development of policy recommendations for supporting population brain health, including measures tailored to individual needs, knowledge, motivations and life situations
    corecore