Istrazivanja i projektovanja za privredu
Latest Publications


TOTAL DOCUMENTS

710
(FIVE YEARS 347)

H-INDEX

9
(FIVE YEARS 4)

Published By Centre For Evaluation In Education And Science

1821-3197, 1451-4117

Author(s):  
Jenan Abu qadourah ◽  
Ala’a Al-Falahat ◽  
Saad Alrwashdeh

This paper evaluates and compares the embodied energy and embodied carbon using a Life Cycle Assessment (LCA) approach for three different intermediate floor structures, all of which use prefabricated materials—cross-laminated timber (CLT), precast hollow-core concrete, and solid concrete—to decide which floor construction materials have less environmental impact for use in the construction of a semi-detached house in the UK. The Inventory of Carbon & Energy (ICE) and the Carbon Calculator tool were used to calculate the carbon footprint from “cradle to grave” to determine whether the use of a CLT solution provides improved environmental performance over the traditional concrete solutions. The carbon footprint results indicate that the use of a hollow-core precast concrete floor system emits less carbon than the other two systems, although the concrete requires more fossil fuel input than the timber during the manufacturing process, so based on this, the footprint from cradle to gate for the timber was expected to be the less than that of the concrete. However, the results show the opposite; this is because of the differences in the material quantities needed in each system.


Author(s):  
Tampanatu Parengkuan Fransiscus Sompie

Good infrastructure and transportation facilities move people and goods take place safely and economically in terms of time and cost. The trips made by people on weekdays or weekends affect environmental conditions in the area. The purpose of this paper is to find out the influence of socioeconomic status on modes choice of transportation both on weekdays and weekends. The study location is in Manado Municipality. There are 3 (three) modes of transportation reviewed, i.e. private cars, motorcycles, and public transportation. Indicators of socioeconomics status of transportation users are age, education, occupation, income, number of family members, and vehicle ownership. Data regarding the modes of transportation and socioeconomic status of travelers were obtained through questionnaire surveys. SEM-AMOS was used to measure the validity and reliability of the data. The probability of the mode choice on weekdays and weekends was analyzed using multinomial logistic regression analysis. The results showed that the socioeconomic status of the traveler has an influence on the mode choice of transportation by 49.2% on weekends and 49.5% on weekdays. Furthermore, the probability of transportation mode choice on weekends is the car by 88.4%, and on weekdays is motorcycles by 71.6%.


Author(s):  
Faisal Estu Yulianto ◽  
Noor Endah Mochtar ◽  
M. Ma'ruf Amin

Peat is a type of soil with high organic content, very low bearing capacity, and high uneven settlement. Some methods to improve soil have been applied to peat in order to make it strong enough for civilization-building foundation situated on it. Peat stabilization is a method that is continuously developed considering that the cost it needs is lower and this approach is more environmentally friendly compared to other methods. The admixture of lime (CaCO3) and Rice husk ash, a new ecofriendly stabilizer material, has been applied to peat soil and showed a good result. However, in studies conducted previously, the effect of water infiltration from surrounding areas of soil was stabilized was not involved as variable influencing the change of parameter. Based on that, this laboratory study was carried out to model the real condition in the field when the stabilization is performed and to identify the physical and engineering changes of peat soil in the 10th, 20th, and 30th days of stabilization in its border and middle parts, with the percentage of material stabilizer 5%, 10%, 15% and 20% of the unit weight of the initial condition of peat. The result of laboratory test shows that the addition of admixture of lime (CaCO3) and rice husk ash can improve the physical and engineering properties of peat soil are stabilized. Water infiltration occurred on peat soil is stabilized has not affected the physical and engineering properties of the soil. It can be seen from the physical and engineering properties of the border and central parts of peat soil is stabilized that still have a similar value. It is assumed to be caused by CaSiO3 gel formed still needs a longer duration to become stable gel. However, in this initial study it was known that the more stabilizers added, made the better the parameters of the stabilized peat soil.


Author(s):  
Alexey Tikhonov

Until recently, the high rates of aircraft engine engineering’s development were ensured by the technological solutions improvement and the desire to approximate as much as possible the ideal thermodynamic cycle of turbojet engines. The traditional fuel for turbojet engines is an aviation kerosene – Jet-A fuel group and their regional analogies. The traditional way of aircraft engines efficiency increasing is a raising of a temperature in front of the high-pressure turbine. New alloys and technologies allow to increase the aircraft engines efficiency to a certain level. Raising the temperature in the combustion chamber by 50 degrees increases the efficiency, which leads to a 5% reduction in fuel consumption. However, this approach is technology limited and does not provide innovative solutions. The aircraft engine engineering’s development tempo in the 21st century continues to accelerate. The main driver of such processes in recent years is the tightening of economic and environmental requirements. Many aircraft manufacturers are actively looking for ways to reach a new qualitative level in terms of turbojet engines economic efficiency and meeting strict environmental requirements. The paper considers the feasibility of using new cryogenic fuels in aircraft turbojet engines, and possible ways for aircraft industry successful development.


Author(s):  
LAKHDAR Abdelghani ◽  
Aziz Moumen ◽  
Khalifa MANSOURI

With the increase in plastic waste, recycling becomes an urgent necessity to reduce and revalue it. PVC is one of the most widely used types of plastic in the world, and indeed it is among the most recycled. The effect of recycling on PVC or any other type of material is to reduce these characteristics, which also depends on the method by which it is recycled. Finding a way to increase the recyclability number of PVC by improving the mechanical characteristics will be an addition at the level of scientific research as well as at the industrial level. The addition of a bio-loading in the form of cow horns, coconut or chicken feathers on the rigid and flexible PVC with an experimental study of the results obtained allow to deduce the most adequate bio-loaded material to improve the mechanical characteristics after recycling. The experiments carried out on rigid and flexible PVC demonstrated the evolutions brought to PVC with and without loading after recycling The results obtained showed an improvement in the mechanical properties of rigid and flexible PVC with a natural bio-loading with the three fibers of coconut, cow horns and chicken feathers which enhance the environment, are very light and can be collected. directly from the waste with a large amount.


Author(s):  
Ambróz Hájnik ◽  
Alica Kalašová ◽  
Veronika Harantová ◽  
Ján Beňuš ◽  
Stanislav Kubaľák

In our paper, we have analyzed and compared fixed and actuated control at a chosen intersection, where we pointed out the importance of actuated control and its benefits. We have used traffic data from sensors in the roadway. The intersection was modelled in Aimsun, where we performed simulations. The research focused mainly on the impact of actuated control on the basic characteristics of the traffic flow, delay time and emissions. The outputs of simulations showed positive results of actuated control in all compared values. The environmental pollution topic is up-to-date and road transport has a significant impact on it. Furthermore, we want to continue with our research to investigate the impact of speed changes on emission production and the smoothness of the traffic flow under fixed and actuated control.


Author(s):  
Sriyati Ramadhani ◽  
Ahmad Rifa'i ◽  
Wahyu Wilopo

Poboya area has many geological structures that result in distribution of strength and stress of rocks not evenly distributed, as a result, the rock mass strength becomes disturbed and slopes become unstable. The objective of the study was to determine the geological structure effect on slope stability and tunnel conditions on metamorphic rocks at the Poboya gold mine. The study was conducted in the Mantikulore sub-district, Palu, Central Sulawesi. Lithology composing study area is metamorphic rocks consisting of gneiss and schist, therefore, the analysis was carried out on both locations which have many geological structures. Numerical analysis was performed applying the finite element method with the RS2 program assistance. The findings show that the safety factor value of the existing slope at gneiss and schist location under static loading is 4.6 and 2.72, if there is an earthquake it becomes 1.07 and 0.77. The safety factor value under static loading with the joint is 4.58 and 2.03, while under dynamic loading with joint, it becomes 0.94 and 0.64. The geological structure effect which represented by the joint gave a big impact with a decrease of safety factor at gneiss about 0.43% under static loading and 80% under dynamic loading. Meanwhile, at schist, safety factor decreased 25% under static loading and 76% under dynamic loading. For tunnel stability, the existence of joint will increase the displacement of 65% at gneiss under static loading and 84% under dynamic loading, while at schist, it increases 25% under static loading and 54% under dynamic loading. This illustrates that geological structures under dynamic loading affect significantly slope stability of Poboya gold mine.


Author(s):  
Vitaliy Zhmakin ◽  
Victor Budnikov

This article discusses the problems of transmission of liquefied natural gas through a non-pressure pipeline from a stationary storage facility to a transport cryogenic tank and ways to solve them. Theoretical studies have been carried out, including mathematical modeling of thermal and hydrodynamic processes during the transmission of liquefied natural gas through a pipeline by a non-pressure method.


Author(s):  
Gigih Priyandoko

Many vibration isolators, for instance, passive vehicle mounting device, have fixed stiffness. This article presents the development of the adjustable stiffness engine mounting magnetorheological elastomers (MREs) based to reduce vibration. The development of MREs vibration isolator is to design of engine mounting first step, for next step is to simulate the electromagnetic circuit. The housing material selection and MREs thickness were considered to equip sufficient, uniform magnetic fields to change the stiffness. The innovative magnetic circuit design includes the type and size of the wire and the number of the coil turns to obtain the best magnetic fields to eliminate vibration. Finite Element Method Magnetics (FEMM) software was utilized to show the effectiveness of the electromagnetic circuit in generating magnetic fields through the MREs. Finally, various current input influence to the MREs vibration isolator is investigated. The higher current input is more useful to eliminate vibration using MREs isolator system.


Author(s):  
Ksenia Olegovna Dubrakova ◽  
Viacheslav Aseev ◽  
Aleksey Bulgakov

The research aimed to study methods for calculating wood-concrete beams of rectangular cross-section when testing building structures according to the ultimate limit state. The article focuses on the comparison of theoretical methods for calculating structures and considers several methods of fastening the samples of a typical wood-concrete beam. There were obtained experimental data of the ultimate limit state for each sample and carried out a comparative analysis of the most advantageous scheme of fastening the sample parts. The scientific novelty is in the development of an algorithm for calculating composite wood-concrete beams of rectangular cross-sections. As a result, numerical comparison of the values for calculating a typical wood-concrete beam using two of the methods under consideration was given, experimental studies were carried out, as well as a comparative analysis of the obtained theoretical and experimental results.


Sign in / Sign up

Export Citation Format

Share Document