Browse

1 - 10 of 302 items :

  • Business and Economics x
Clear All
Characteristics of Water Consumption in Cho-Cianów, Parchów and Pogorzeliska, Lower Silesia Province

Abstract

Water consumption is an amount characteristic to individual water sup-ply systems. It is described by values of the unitary consumption of water and unevenness coefficients. An analysis of consumption for the years 2009-2016 in two systems which are diverse in terms of the number of supplied recipients as well as the intended water use is presented. The values of unitary consumption indices as well as hourly and daily irregularity of consumption were calculated, and factors influencing the irregularity of consumption in different time frames indicated. Conclusions regarding the amount and irregularity of consumption were drawn and compared with guidelines and other analysed systems.

Open access
Effect of Cockele Shells on Mortars Performance in Extreme Conditions

Abstract

This paper studies the use of cockle shell as supplementary cementitious materials SCMs as substitute for cement. The cockle shells generally have a high CaO content which can alter the behavior and the properties of mortars and concrete. Cockle shell is used with weight ratios of 5, 10, 15 and 20% to formulate a mortar with cockle shell and a control mortar CM with 0% of cockle shell. The properties in the fresh state, the mechanical strength and the weight loss test as well as the depth of penetration of each mixture were carried out through the conducted experiments. Consistency and density of fresh mortars were determined, the results obtained showed that cockle shell have a significant influence on the properties of mortars in the fresh state.

The different results of hardened mortars show that the introduction of cockle shell tends to accelerate the development kinetics of strength at the young age but its ratio cannot be above of 5%. Mortar with 10% presented the lower depth penetration, the loss weight increased proportionally with the increasing of cockle shell amount.

Open access
Influence of the Static Loading of a Raft Unconnected to a Pile on the Pile Displacements Tested in Field Conditions

Abstract

We present the results of a static pile-raft interaction test in field conditions. The pile and the raft were unconnected. The static loading on the raft affected the displacements of the pile due to the skin friction. The displacements were also observed for another pile, placed at the 3-metre distance.

Open access
Investigation of Load Capacity of Steel Concrete Composite Columns Src Reinforced by IPE

Abstract

In this study, a column with section IPE and different lengths, completely embedded in concrete, is modelled by finite element software ABAQUS. Columns under different bi-axial loading were used and graphs of axial force-axial deformation, interaction axial force, and bending moment and column curve were mapped. The results show that the load capacity of the column, with increasing length and also increasing eccentricity of the axial load, will be reduced. With increasing length, the effect of an increased eccentricity of the reduced load capacity was increased. Equations for the design of the column are also presented. The results of the presented equations were compared with the values obtained from finite element and building national institute 10th topic.

Open access
Medical Waste Management in Al-Basheer State Hospital - Current Situation and Future Prospects

Abstract

In the Middle East and North Africa Jordan is considered as the top medical tourism due to the high level of medical specialized medical centers in the country. In Jordan Ministry of Health monitors, evaluate, enforces, and regulates requirements of medical waste management over medical waste instructions No. 1/2001. Al-Bashir Hospital is the largest hospital in Jordan. It is built on 156 acres and consists of 49 buildings and 80 departments. It has been reported that Al-Bashir Hospital has 1150 medical bed in 2019 and expected to increase to 1500. About 3200 employee and 1100 clean workers give the medical treatment and service for 7000 patient per day and 1.5 million patient per year. The present situation of medical waste management in Al-Bashir Hospital has many problems. The most important is the pressure imposed by heavy population around the incineration unit in the Hospital. Furthermore, the change from incineration to autoclave is faced by high cost of the autoclaves. The quantity of medical waste created by Al-Bashir Hospital is up to 703.8 ton which constitutes about 33% of the total medical waste in Jordan. The high cost of fuel resulted in wrong acts in Al-Bashir Hospital like mixing medical waste with household waste and incineration at lower temperature (about 600 °C). If the incineration unit in Al-Bashir Hospital is closed the expenses will range from US$ 400,000 to 2.5 million.

Open access
Microscopic Evaluation of the Manholes in Selected Sewerage Pressure System

Abstract

The aim of the research was to determine changes in the elemental composition of concrete under the influence of exposure to hydrogen sulphide in the existing sewage system. The system operator pointed to significant problems with odours in this system. The research included a fragment of the pressure sewage system. The concentration of gases: hydrogen sulphide, ammonia and methane was measured in selected wells. High concentrations of hydrogen sulphide (over 200 ppm) were recorded in the studies. Concrete samples were taken from the internal walls of the well for testing. The samples were used for a microscopic analysis of their composition, using an electron microscope with an EDS attachment. Also, concrete samples from a new sewage well were tested to compare their elemental composition. Gas measurements confirmed the problem of odors, while the analysis of the elemental composition showed a significant proportion of sulphur (from 7.53% to 42.9%) on the surface of the well compared to the reference sample (0%).

Open access
The Role and Effectiveness of the MBT Installation in Poland Based on Selected Examples

Abstract

The paper presents examples of installations for the mechanical and biological treatment of municipal waste in Poland. Each of the presented installations is defined as a regional municipal waste treatment installation (RIPOK). Their technological solutions and work efficiency have been compared in this study. In addition, the loss of waste mass as a result of processes occurring in the biological part of individual installations was calculated in the research. The paper refers to the National Waste Management Plan (KPGO 2022) regarding the circular economy. As intended by the circular economy, MBP installations will be transformed into installations that will treat selectively collected municipal waste and become Regional Recycling Centers (RCR).

Open access
A Study on the Effect of Operating Parameters on the Efficiency of a Mercury Removal Unit from Natural Gas

Abstract

In this study, an industrial fixed-bed for mercury adsorption from natural gas, was evaluated by mathematical models. Equilibrium isotherms, kinetics equations, and adsorption models were applied to available data to evaluate sorbent characteristics, and then study bed’s performance under different case studies. Models solutions are evaluated by linear-regression and coefficient of determination. The study confirmed that the system is characterized by irreversible equilibrium. Examining of kinetics equations indicated the inclusion of chemisorption and intra-particle diffusion as ratelimiting steps. Bohart-Adams model was found the best fitting model with good match between model’s assumptions and available bed’s information. Model prediction for bed’s design-basis was examined and found good match with manufacturer’s data-sheet.

Open access
Vibration Control Devices for Building Structures and Installation Approach: A Review

Abstract

Retrofit and structural design with vibration control devices have been proven repeatedly to be feasible seismic hazard mitigation approach. To control the structural response; supplemental energy dissipation devices have been most commonly used for energy absorption. The passive control system has been successfully incorporated in mid to high rise buildings as an appropriate energy absorbing system to suppress seismic and wind-induced excitation. The considerable theses that are highlighted include vibration control devices, the dynamic behavior of devices; energy dissipation mechanism, devices installation approach and building guidelines for structural analysis and design employing vibration control devices also, design concern that is specific to building with vibration control devices. The following four types of supplemental damping devices have been investigated in this review: metallic devices, friction devices, viscous fluid devices, and viscoelastic devices. Although numerous devices installation techniques available, more precisely, devices installation approaches have been reviewed in this paper, including Analysis and Redesign approach (Lavan A/R), standard placement approach, simplified sequential search algorithm, and Takewaki approach.

Open access
Viscoelastic Material as Energy Dissipater Viscoelastic Damper for Building Structures to Mitigate the Seismic Vibration

Abstract

The supplemental energy dissipation system is a practical approach to attenuate the structural response under extreme loading. Viscoelastic damping used to reinforce the structure against the seismic vibration, Viscoelastic material (VEM) most commonly used in viscoelastic dampers (VEDs). In this paper, dynamic mechanical analysis (DMA) approach is used to investigate the performance index of VEM. It is demonstrated that the performance index, such as storage modulus, loss modulus, and loss factor decrease noticeably as the temperature increases, which reflects the low stiffness at high temperature. Excitation frequency also influenced the performance index, and the reaction has correspondence to temperature. As the temperature increases, the VEM dynamic properties decreases, which represents the rubbery region, and it is found that higher to low-temperature dynamic properties increases, which the glassy region is. DMA is a particularly flexible approach, and it characterizes the properties of VEM simultaneously at various conditions.

Open access