Hallmark professionalism in probabilistic analysis is to quantify the uncertainties involved in construction materials subject to intrinsic randomness in its physical and mechanical properties and is now gaining popularity in civil engineering arena. As well, knowledge of behaviour of materials is continuously evolving and its statistical descriptors are also changing when more and more data collected or even data updated and hence reliability analysis has to be carried out with the updated data as a continuous process. As per the committee report ACI 544.2R, it is found that there is no attempt made for probabilistic relation between cube compressive strength and cylinder compressive strength for fiber reinforced concrete. In consequence of this report, a robust relation between cube and cylinder of experimentally conducted compressive strength was established by Monte-Carlo simulation technique for different types of fibrous concrete like steel, alkali resistant glass and polyester fibrous concrete before and after thermoshock considering various uncertainties. Nevertheless simulated probabilistic modals, characteristic modals, optimized factor of safety and allowable designed cylinder compressive strength have been developed from the drawn probability of failure graph, which exhibits robust performance in realistic Civil Engineering materials and structures.
The problem of poor quality of traffic accident data assembled in national databases has been addressed in European project InDeV. Vulnerable road users (pedestrians, cyclists, motorcyclists and moped riders) are especially affected by underreporting of accidents and misreporting of injury severity. Analyses of data from the European CARE database shows differences between countries in accident number trends as well as in fatality and injury rates which are difficult to explain. A survey of InDeV project partners from 7 EU countries helped to identify differences in their countries in accident and injury definitions as well as in reporting and data checking procedures. Measures to improve the quality of accident data are proposed such as including pedestrian falls in accident statistics, precisely defining minimum injury and combining police accident records with hospital data.
Underground spaces having features such as stability, resistance, and being undetected can play a key role in reducing vulnerability by relocating infrastructures and manpower. In recent years, the competitive business environment and limited resources have mostly focused on the importance of project management in order to achieve its objectives. In this research, in order to find the best balance among cost, time, and quality related to construction projects using reinforced concrete in underground structures, a multi-objective mathematical model is proposed. Several executive approaches have been considered for project activities and these approaches are analyzed via several factors. It is assumed that cost, time, and quality of activities in every defined approach can vary between compact and normal values, and the goal is to find the best execution for activities, achieving minimum cost and the maximum quality for the project. To solve the proposed multi-objective model, the genetic algorithm NSGA-II is used.
Varistors are commonly used elements which protect power supply networks against high-voltage surges or lightning. Therefore, quality and endurance of these elements is important to avoid losses when an expensive laboratory equipment would not be protected from random overvoltages. Additionally, excessive leakage currents generate serious costs due to high energy consumption. The paper presents shortly properties of varistors that comprized different ZnO grain types and can have various quality which changes continuously during exploitation (due to exposition to overheating and overvoltage pulses). Therefore, it is important to monitor varistors during their ageing (causing changes within their microstructures). A few methods of varistor property diagnosis were considered and compared with the methods currently applied in laboratory or industry applications. A new measurement (diagnostic) system that can monitor varistors during ageing and can be widely applied in power networks is presented. The proposed system fulfills requirements of the industrial customers which demand various methods for power line protection. The proposed system can be simply developed into a more advanced wireless diagnostic system of long power supply lines.
We discuss waste, fuels, and air quality with Prof. Czesława Rosik-Dulewska from the PAS Institute of Environmental Engineering and the Department of Land Protection at the University of Opole.
Air quality and climate change, as two crucial environmental emergencies confronting our societies, are still generally viewed as separate problems requiring different research and policy frameworks. However, they should rightfully be viewed as two sides of the same coin. What we truly need to seek, therefore, are “win-win” solutions.
Wonji Shoa Sugar Estate (WSSE), located in the flood plain of the Awash River (Ethiopia), has been under long-term (>60 years) irrigation, industrial activities and agro-chemical usage. In this study, the hydrochemical properties of ground-water bodies available at WSSE have been characterized for quality compositions. Water samples were collected from groundwater monitoring piezometers distributed in the sugarcane plantation and then analysed for physico-chemical quality parameters (pH, EC,major cations and anions) following standard procedures. Other chemical indices (e.g., total dissolved solids (TDS),total hardness(TH),magnesium absorption ratio(MAR), base exchange (r1), meteoric genesis(r2)) were de-rived from the measured water quality parameters. The compositional variability and groundwater classification has been presented using the Box and Piper plots. The potential sources of minerals were suggested for each of the considered water sources based on their quality characteristics. Both trilinear Piper plot and meteoric genesis index revealed that groundwaterof the area is shallow meteoric water percolation type with a changing of hydrochemical facies and mixing trend. Ground-water of the area, is group 1 (Ca-Mg-HCO3) type, with no dominant cations and HCO3 are the dominant anions. Overall, the study result elucidates that the chemical composition of GW of the area showed spatial variability depending upon the variations in hydrochemical inputs from natural processes and/or anthropogenic activities within the region. The local an-thropogenic processes could be discharges from sugar factory, domestic sewage and agricultural activities.
The physicochemical and bacteriological quality of groundwater was assessed to show the impact of the agriculture and human activities in the Triffa Plain located in North-East of Morocco. The current levels of contamination of the groundwater were estimated by analysing electrical conductivity, nitrate, nitrite, ammonia, orthophosphate, and indicators of faecal pollution content.
Water samples from 55 locations were collected during two period of time, the wet and the dry season of the year 2016. Result obtained indicated that most samples are highly contaminated. The electrical conductivity varied from 800 to 9 100 μS∙cm–1. Nitrate levels ranged from 25 to 216 mgꞏdm–3, with 78% of samples exceeding the critical level value set at 50 mgꞏdm–3. Nitrate concentrations are slightly higher during the wet period in 73% of studied cases. Nitrite rarely exceeded the normal rate fixed by World Health Organization and reached 0.90 mgꞏdm–3. Ammonia and orthophosphate contents do not exceed these norms.
The study revealed a wide contamination of groundwater by microbial agents such as, total coliforms, faecal coliforms and faecal streptococci, with content ranged from 0 to 14 000, 0 to 5 000 and 0 to 5 000 CFUꞏ(100 cm3)–1 respectively, con-firming the impact of septic tanks, wastewater discharge into rivers without treatment, and the use of animal waste on the ground water vulnerability.Samplings and measurements were carried out according to the international standard ISO 13395, ISO 11732 and ISO 15681-2 for chemical compounds and ISO 9308-1 and ISO 7899-2 for microbiological numerations.
The surfacing technologies are used for constitution of protection layer against wear and is destined for obtaining coating with high
hardness. Among many weldings methods currently used to obtain the hard surface layer one of the most effective way of hardfacing is
using flux cored arc welding. This additional material gives more possibilities to make expected hard surface layer.
Chemical composition, property and economic factors obtained in flux cored wire are much richer in comparison to these obtained with
other additional materials. This is the reason why flux cored wires give possibilities of application this kind of material for improving
surface in different sectors of industry.
In the present paper the imperfection in the layers was used for hardfacing process in different situations to show the possible application
in the surface layer. The work presents studies of imperfection of the welds, contains the picture of microstructures, macrostructures and
shows the results of checking by visual and penetrant testing methods.
The paper shows a study on the relationship between noise measures and sound quality (SQ) features that
are related to annoyance caused by the traffic noise. First, a methodology to perform analyses related to
the traffic noise annoyance is described including references to parameters of the assessment of road noise
sources. Next, the measurement setup, location and results are presented along with the derived sound quality
features. Then, statistical analyses are performed to compare the measurement results and sound quality
features. The included conclusions are focused on showing that the obtained loudness values, regardless of
the used system, are similar in a statistical sense. Contrarily, sharpness, roughness and fluctuation strength
values differ for the tools employed.
In the age of Information and Communication Technology (ICT), Web and the Internet have changed significantly the way applications are developed, deployed and used. One of recent trends is modern design of web-applications based on SOA. This process is based on the composition of existing web services into a single scenario from the point of view of a particular user or client. This allows IT companies to shorten the product-time to market process. On the other hand, it raises questions about the quality of the application, trade-offs between quality factors and attributes and measurements of these. Services are usually hosted and executed in an environment managed by its provider that assures the quality attributes such as availability or throughput. Therefore, in this paper an attempt has been made to perform quality measurements towards the creation of efficient, dependable and user-oriented Web applications. First, the process of designing service-based applications is described. Next, metrics for subsequent measurements of efficiency, dependability and usability of distributed applications are presented. These metrics will assess the efforts and trade-offs in a Web-based application development. As examples, we describe a pair of multimedia applications which we have developed in our department and executed in a cluster-based environment. One of them runs in the BeesyCluster middleware and the second one in the Kaskada platform. For these applications we present results of measurements and conclude about relations between quality attributes in the presented application development model. This knowledge can be used to reason about such relations for new similar applications and be used in rapid and quality development of the latter.
This study presents the hydrochemical composition of groundwater under long-term irrigation of Wonji plain (Ethiopia) and its quality status for drinking purpose. Groundwater samples were collected from 30 groundwater monitoring tube wells installed at different parts of the sugarcane plantation and then analysed for the major physico-chemical quality parameters (pH, EC, major cations and anions) following standard test procedures. The status of groundwater for drinking was compared with WHO and other quality standards. Analytical analysis results indicated that majority of the considered quality parameters are rated above the prescribed tolerable limits for drinking set by WHO. About 97% of the water sample has water quality index in the range of very poor to unfit for drinking. The contamination index is in the ranges of low (–1.0) to high (3.6). In general, the groundwater of the area is unsuitable for human consumption without proper treatment such as boiling, chlorination, filtering, distillation, desalinaization, defluoridation, deionization, demineralization (ionexchange) and membrane processes. Since the TDS concentration is relatively small (<2000 ppm), demineralization process alone can be sufficient to bring the water to an acceptable level.
Paper presents the results of quality assessment of speech and music signals transmitted via DAB+ system with the use of Single Frequency Network (SFN). The musical signals were evaluated in overall quality domain. The subjective research was provided with the use of Absolute Category Rating procedure according to the ITU recommendation and the results have been presented as the MOS values for various bit rates. The speech signals were additionally examined with PESQ method. The results have shown that the assumed quality of 4 MOS, for this kind of broadcasting could be achieved at 48 kb/s for speech and 64 kb/s for music. This fact was confirmed by both: subjective and objective research. The comparison between the results obtained for SFN broadcasting with three emitters with singleemitter broadcast was presented.
The work presents a comparison of some sound attributes perceived at a multichannel and stereo playback of musical recordings. The width of the virtual source, coherence impression, total size of sound scene, general quality and balance were the subjects of interest after the format reduction in accordance with the ITU recommendation. The results showed that evaluation of these attributes depends on the way the original audiosphere has been created in the surround system, for example, for a narrow virtual source the mix-down process causes only a small change in its size but for a broad source the observed degradation is significant. In addition, different ways of conversion from the multichannel to stereo format have been tested for compatibility.