Analysis of the implementation of fire protection measures in civil buildings |
Author : Conf.univ.dr.ing. Aurel Trofin, Drd.ing. Mihai Ciprian Mitrea |
Abstract | Full Text |
Abstract :Implementing the fire protection measures in the context of current legislation,
involves the identification of a set of legislative measures and technical rules specific to
the field of activity and standardized implementation in all stages of design, execution,
commissioning and operation of civil buildings. At the same time, the decision makers for
each stage listed above are responsible for the implementation of technical rules and
measures necessary to ensure fire safety of all workers and users of civil buildings. |
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Influence of illumination and tracers on Particle Image Velocimetry measurements on open flow channels |
Author : Ilinca Nastase, Mihnea Sandu, Marius Iliescu, Amjed Albaiyati |
Abstract | Full Text |
Abstract :Within the study of free surface flows, measurements in the vertical planes of
the flow are desired. Using Particle Image Velocimetry, usually measurements are
performed with the laser sheet through the bottom of the channel in order to avoid the
optical perturbations on the laser light sheet, generating light scattering and
measurement artefacts. There are however a number of cases where this is not possible
since the transparence of the bottom cannot be ensured. In the present study we wanted to
check the influence of the illumination on the velocity fields distribution, through the
bottom of the channel or through the free surface, on a very simple flow on a plane plate
placed on the bottom of a circular channel. We also checked the influence on using
conventional silver hollow glass spheres and fluorescent particles.
The results allowed us to conclude that in the cases where the study is focused on the
boundary layer close to the solid surface and the observed perturbations of the free
surface are not important, top illumination of the open channel might be considered as an
option if perturbations of the free surface are not observed. |
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Theoretical aspects regarding energy efficiency in foods refrigeration and freezing |
Author : Alina GIRIP , Razvan CALOTA , Madalina NICHITA , Anica ILIE |
Abstract | Full Text |
Abstract :This paper presents a technical study on energy consumption and performance of a
refrigeration system used for food products refrigeration and congelation. The authors
compared the two-stage refrigeration system with the cascade refrigeration system. The
analysis was based on the thermodynamic cycles corresponding to each one of the proposed
solutions. For the booster system several refrigerants were considered in the analysis for
the upper loop, respectively R717, R404A, R407C and R417A. Based on the total energy
consumption of the installation (compressor, fans, recirculation pumps), the overall
performance coefficient of the installation was determined. The study showed that the
lowest electrical energy consumption corresponds to the cascade refrigeration system with
R717-R744 and the two-stage compression refrigeration system with R717. The difference
between the 2 optimal variants is only 4.6%. Therefore, it is recommended that the choice
of the final scheme to be made on the basis of an LCC (Life cycle cost) analyze, which
takes into account the refrigerant charge, the initial investment cost, the operating costs and
the electricity cost. |
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Steady heat transfer by natural (free) convection and radiation, for a horizontal circular pipe surrounded by air, using the Mathcad® software |
Author : Gelu-Adrian CHISALITA, Raluca MOLDOVAN |
Abstract | Full Text |
Abstract :The paper presents a study on the heat transfer in steady state, by natural
convection and radiation, from a circular pipe to the surrounding air. Using the Mathcad®
software application, the calculation procedure for the average heat transfer coefficient on
the surface by convection, radiation and combined was implemented on the computer, as
well as the determination of the heat flux density (the rate of heat transfer per unit time per
unit length) taking into account various values of the outer surface temperature of the pipe.
The results of the study show that neglecting the heat transfer by thermal radiation, even
for low temperatures with values in the range of 40°C...90°C, can lead to relatively high
technical errors in estimating the heat loss of pipes. In these situations, is necessary to take
into account the combined heat transfer by natural convection and thermal radiation. |
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Software programs used in designing of low voltage electrical distribution panels |
Author : Cristina Gabriela Saracin, Diana Paraipan |
Abstract | Full Text |
Abstract :This paper presents the ABB Doc and Schrack Design programs used in the design of
voltage electrical distribution panels. The consumers power supply depends on the correct choice
of the protection and switching equipment and the correct size of the distribution panel. Therefore,
the paper exemplifies and compares these software applications used successfully in the size of
distribution cabinets. Therefore, the paper exemplifies and compares these software applications
used successfully in the size of distribution cabinets. Dimensions of the switchboard are obtained
by choosing and correctly positioning the electrical equipment in the switchboard. Schrack Design
program allows the manufacturing of electrical panels without calculating the necessary
parameters choices of protection and switching equipment. The choice of electrical equipment and
electrical distribution panels is made exclusively by the user. It can make component selections
from the manufacturers database or add electrical equipment from other companies to this
database. Once the options have been selected, the program generates the single-wire or multi-wire circuit diagram. The validation of the chosen solutions involves the thermal calculation of the
electrical distribution panels which is done with the help of the Schrack Design program. |
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In-situ and Laboratory Analysis of Treated Marine Soil by Consolidation Methods |
Author : Houssam KHELALFA |
Abstract | Full Text |
Abstract :The methods of improvement of vibroflotation (VF), dynamic compaction (DC) and the
preloading took a scale in Algeria these last years, they are applied at the port of
DjenDjen in Jijel province, object of our study, in the framework of its extension and its
development, in order to improve the support soil which will receive the foundations of
the protections structures and the container terminal in caissons. The main objective is to
understand and apprehend these techniques, as well as the sensitivity of the intervening
factors on its realization, and their effect on the behavior of the soil during and after its
implementation. In addition, this treatment to minimize the risk of liquefaction and
instability of the protective structure, However, the advantage of speed of execution and
reasonable cost compared to the importance of the project, thus no negative effects have
been reported on the environment. The effectiveness of these soil treatment methods has
been demonstrated by the results of the available in-situ tests, in particular the SPT tests
which made it possible to check the capacity of the support soil before and after its
completion, as well as the settlement surveys confirm the efficiency of these techniques
in terms of improving the bearing capacity of the seabed. |
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Modeling the Drying Shrinkage of Structural Concretes |
Author : Abderraouf Kebir, Abdelmalek Brahma |
Abstract | Full Text |
Abstract :Shrinkage in hydraulic materials is a complex time-dependent process. For
standard concretes, one of the most significant parts of shrinkage is drying shrinkage. In
fact, to predict deformations of concrete due to shrinkage, various predictive models have
been developed; most of them use many numbers of factors that can affect shrinkage such
as concrete strength, concrete age at loading, curing conditions type, ambient conditions,
type of cement and aggregates, water to cement ratio, concrete mix, member shape and
size, loading duration and type. A such number of parameters increases the complexity of
using these models lead to some prediction imperfections; thence a new simplified model
is needed. The main target of the current paper is to formulate a novel and simplified model
with a minimum of factors that affect drying shrinkage behaviour as like as relative
humidity and volume to area ratio of the concrete element (V/S). To achieve this goal, we
had developed a prediction model based on probability density function and a small
number of parameters that influence shrinkage like relative humidity and volume to surface
ratio of the element. A huge database has been used to calibrate our models parameters
using the most recent studies and researches to validate the model. |
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A Review Regarding the Heat Recovery from Wastewater |
Author : Amjed Albaiyati |
Abstract | Full Text |
Abstract :One of the main challenges in the world today is reducing energy consumption
and CO2 footprint in existing buildings without major construction work. Many of these
buildings represent heritage buildings and the intervention constraints on the original
building are much more restrictive for these particular cases. The building sector is one
of the worlds largest energy consumers, so it is important to seek out and use recovery
energies for individual consumers. The main component of energy consumption in
buildings is heating, but the demand for the domestic hot water is also very high,
especially when daily consumption is high and especially for specific applications ( hotels
or laundries for example) This is why the implementation of technologies using
renewable energy and recovery sources for water heating[1] has become very important
and one of these technologies involves the recovery of the thermal energy from
wastewater. Usually, heat recovery from wastewater is designed to recover residual
energy from the hot drainage water and this recovered energy is used to preheat
incoming cold water or to heat pumps. |
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Expansion of glass waste by the double effect of liquid and solid foaming agents for manufacturing the cellular glass gravel (CGG) in a 10 kW-microwave oven |
Author : Lucian Paunescu, Sorin Mircea Axinte, Marius Florin Dragoescu, Bogdan Valentin Paunescu |
Abstract | Full Text |
Abstract :An industrially manufacturing recipe of cellular glass gravel (CGG) from
glass waste by an original unconventional heating technique using simultaneously a liquid and solid foaming agent (glycerol and calcium carbonate) was tested on a 10 kWmicrowave oven. Using a large silicon carbide ceramic crucible, inside which a metal
mold containing the finely ground pressed raw material mixture was inserted, a much
higher amount of foamed product was produced. The characteristics of CGG samples
were bulk density of 0.20-0.25 g/cm3
, thermal conductivity of 0.062-0.070 W/m?K and
compressive strength of 7.1-7.4 MPa. |
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Effective microwave heating method for manufacturing glass foam from glass waste |
Author : Lucian Paunescu, Sorin Mircea Axinte, Marius Florin Dragoescu, Bogdan Valentin Paunescu |
Abstract | Full Text |
Abstract :An original technique for manufacturing glass foam by high temperature
sintering of glass waste due to the microwave heating is presented in the paper. The
heating of the raw material is performed predominantly direct and partially indirect by
using a SiC ceramic tube with an optimal wall thickness of 2.5 mm. This method contributes to the significant reduction of the specific energy consumption, the heating
rate and the process duration compared to the conventional heating techniques. The
characteristics of glass foam are similar to those of conventionally manufactured foams
and can be used as replacements for existing building materials |
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