Examination of pipeline planning in terms of hydraulic criteria |
Author : Prof. Dr. Necati Gülbahar |
Abstract | Full Text |
Abstract :Transportation of materials with pipelines has a long history. It is a historical fact that materials were transported through pipelines by Chinese and Romans. Presently, this issue has become multidimensional sub ject such as engineering, industry ,economy, security,environment and foreign policy.Therefore, a pipeline cons truction should be evaluated in all aspects. In terms of economy and security, pipelines are more economical and reliable than other types of transport. As Turkey is located at the crossroads of energy lines, it should pay special attention to the design of pipelines. In this article, this issue is considered from an engineering pers pective. However, this will also have an impact on the other fields. These issues are discussed in this article and suggestions are presented. |
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Study on the impact of thermal rehabilitation on energy consumption of schools in Romania |
Author : Tiberiu Catalina, Marian Grigore, Alexandra Ene |
Abstract | Full Text |
Abstract :The thermal rehabilitation of educational buildings is very important from many points of view: increased thermal comfort, reducing energy consumption and especially reducing carbon dioxide emissions. The study shows successufel cases where energy efficiency has been considerable. The second part of this article presents new and interesting information on the energy analysis of 13 educational buildings where major thermal rehabilitation measures have been proposed, from thermal envelope to the installation of photovoltaic solar panels. It has been found that the largest energy consumer is heating with more than 80% of the total energy and the lighting with approx. 15%. By applying the energy efficiency measures an average reduction of 63% was achieved. Based on the statistical data on the total area of educational buildings, we have a value of 17.4 million m2 which, if fully renovated, would achieve savings of 172 million € / year and an emission level of 131 022 tonnes / year. At the current renovation costs, we estimate that thre return on the investment on the full renovation of the entire buildings park would be between 18-28 years. If, however, the return time of the investment is not a small one, it should nevertheless be taken into account that CO2 emissions, and thus the beneficial effect on the environment, will be very low. |
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Particularities relating bananas refrigeration in mobile transport means using freon R449A |
Author : Lector. dr. ing. Razvan CALOTA, ing. Andrei LUPU |
Abstract | Full Text |
Abstract :Refrigeration of vegetables and fruits is done to extend their consumption period, or for a period of time before the controlled ripening process, followed by putting products on the consumer market.
If their metabolic processes (respiration) are major, then refrigeration will be done in an accelerated manner. The banana transport temperature should be kept between 13-14°C because at this temperature bananas close their pores and the process of ripening can no longer take place naturally during transport.
The article presents a method for determining the refrigeration load of the refrigeration plant for a banana refrigeration container operating with a low environmental impact refrigerant, R449A. |
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System for the use of renewable sources for heating a residential building. Method of assessing energy performance. Energy analysis |
Author : Prof. dr. ing. Florin Iordache, Drd. Ing. Mugurel Talpiga |
Abstract | Full Text |
Abstract :This paper presents an unconventional system using energy renewable sources, consisting from two unconventional components: the solar loop and the heat pump, both of which being coupled to use only the solar energy source. The heat pump raises the thermal potential of the captured solar power and increases its value with a relatively small proportion. This type of system has been investigated energetically if there is the possibility of prolonging the period of use of the solar energy from the transition period to the winter period. In this paper is a description of the proposed system and the corresponding heat transfer processes equation modeling. Also presented is the actual working procedure to investigate energy performance on a case study. The results obtained are graphical displayed but also listed in a table and comments are made on the sustainability of such systems. |
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Assessing the effectiveness of dune sand as a mineral addition to produce ultra-high performance fiber reinforced concretes |
Author : Farida Ait Medjber, Mohammed Saidi, Brahim Safi, Hamza Mechakra |
Abstract | Full Text |
Abstract :In order to valorize our natural resources especially dune sand, the strength development and characterization of ultra-high performance fiber concrete based on local mineral additions, have been studied in this present work. The experimental study was carried out on various concretes made from finely ground dune sand and reinforced with metal fibers (at different percentages) compared to others concretes manufactured with cementitious materials (silica fume and pozzolan). The studied concretes were made from Portland cement (PC), dune sand (DS), pozzolan (PZ), fine sand (FS), metal fibers (MF) and super plasticizing admixture (SP). The results obtained show the possibility to producing a more performant fiber concrete having 34 MPa for flexural tensile and 136 MPa for compressive strength. SEM-images of studied concretes showed the beneficial effect of the crushed dune sand on cementitious hydration products giving of new hydration products from the pozzolanic reaction between crushed dune sand and portlandite (Ca(OH)2) released from hydration of cement. To manufacture a concrete based on local raw materials having good mechanical characteristics, can lead to saving the consumption of cement. |
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Influence of the acoustic insulation position on the reverberation time and noise level in a large classroom |
Author : Catalin Bailescu, Vlad Iordache |
Abstract | Full Text |
Abstract :Acoustic comfort is a requirement of major importance during the design of
a classroom, conference room or cinema hall. This study is focused on the acoustic comfort parameters called reverberation time and sound pressure level. The aim of this study is to determine the placement influence of the sound absorption material upon the reverberation time for a classroom. In this study the reverberation time was determined using Sabine; Eyring, Arau Puchades and dedicated software of architecture modelling- Sketch-up and acoustic modelling- Odeon. Using these software, we have simulated various locations of the acoustic insulation and determined the most effective placement for sound absorption material to reduce the reverberation time and to maintain a good uniformity of sound pressure level inside the classroom. |
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Space and time variations of the effect of the urban heat island; Case study for the city of Bucharest |
Author : Florinela Ardelean |
Abstract | Full Text |
Abstract :The relationship between the city and the climate is reciprocal. The climate influences the way the city’s space is used, being an essential element in designing, execution and exploitation of buildings. The city, through its specific activities and arrangement, modifies regional climate conditions. This paper analyzes the urban heat island (UHI), as a result of this interaction. The indicator, which describes UHI, is the temperature difference between the city’s downtown and outskirts. Using the average monthly temperatures of the lower troposphere as well as other meteorological parameters, the values obtained by processing data corresponding to the 2005 – 2013 interval, appreciations could be made on the metropolitan area of Bucharest. |
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Optimizing systems for the use of solar energy for space heating and hot water preparation in buildings |
Author : Drd. ing. Mugurel Talpiga, Drd. ing. Eugen Mandric, Prof. dr. Ing. Florin Iordache |
Abstract | Full Text |
Abstract :Aim of this paper is energetic study of solar equipments used in heating and daily hot water of residential and commercial buildings. Identified most important unconventional system parameters have direct influence of the energetic performances.
Hydraulic drawings of the system are presented and obtained results will be graphically plotted for heating and daily hot water preparation. Auxiliary source contain a classical thermal heating unit which provide necessary accumulated heat inside heat exchanger for heating thermal agent or daily hot water. |
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