Rivista e Edizione

Volume 16 (2021): Edizione 4 (December 2021)

Volume 16 (2021): Edizione 3 (September 2021)

Volume 16 (2021): Edizione 2 (June 2021)

Volume 16 (2021): Edizione 1 (March 2021)

Volume 15 (2019): Edizione 4 (December 2019)

Volume 15 (2019): Edizione 3 (September 2019)

Volume 15 (2019): Edizione 2 (June 2019)

Volume 15 (2019): Edizione 1 (March 2019)

Volume 14 (2018): Edizione 4 (December 2018)

Volume 14 (2018): Edizione 3 (September 2018)

Volume 14 (2018): Edizione 2 (June 2018)

Volume 14 (2018): Edizione 1 (March 2018)

Volume 13 (2017): Edizione 4 (December 2017)

Volume 13 (2017): Edizione 3 (September 2017)

Volume 13 (2017): Edizione 2 (June 2017)

Volume 13 (2017): Edizione 1 (March 2017)

Volume 12 (2016): Edizione 4 (December 2016)

Volume 12 (2016): Edizione 3 (September 2016)

Volume 12 (2016): Edizione 2 (June 2016)

Volume 12 (2016): Edizione 1 (March 2016)

Volume 11 (2015): Edizione 4 (December 2015)

Volume 11 (2015): Edizione 3 (September 2015)

Volume 11 (2015): Edizione 2 (May 2015)

Volume 11 (2015): Edizione 1 (March 2015)

Volume 10 (2014): Edizione 4 (December 2014)

Volume 10 (2014): Edizione 3 (September 2014)

Volume 10 (2014): Edizione 2 (June 2014)

Volume 10 (2014): Edizione 1 (March 2014)

Volume 9 (2013): Edizione 4 (December 2013)

Volume 9 (2013): Edizione 3 (September 2013)

Volume 9 (2013): Edizione 2 (June 2013)

Volume 9 (2013): Edizione 1 (March 2013)

Dettagli della rivista
Formato
Rivista
eISSN
2784-1391
Pubblicato per la prima volta
12 Apr 2013
Periodo di pubblicazione
4 volte all'anno
Lingue
Inglese

Cerca

Volume 10 (2014): Edizione 3 (September 2014)

Dettagli della rivista
Formato
Rivista
eISSN
2784-1391
Pubblicato per la prima volta
12 Apr 2013
Periodo di pubblicazione
4 volte all'anno
Lingue
Inglese

Cerca

6 Articoli
access type Accesso libero

High Stability and Low Emissions Burners Using Karlowitz Effect in Conical Burners

Pubblicato online: 30 Dec 2014
Pagine: 1 - 11

Astratto

Abstract

The conical tunnel burner is an improvement of the cylindrical tunnel burner because, by maintaining all its advantages by means of burning intensification, it may also insure the flame stabilization in a wide range of regulation with considerable diminished pressure losses. Technical applications for the conical furnace burner can vary due to the limited dimensions required by the system, as well as the important thermal loads, and also because of the burning stability characteristic that spreads over an important range of regulation. The low costs required by the burner, generated mainly by its simple construction, also raise the interest for this technical solution. A physical model is proposed for the ignition and flame front stabilization. The flame front stabilization contains different steps from the ignition moment to final flame front stabilization, with specific flame front geometries and specific locations along the burner axis. The installation realised by the authors allowed the experimental study of the burning process in conical furnaces, in order to determine the temperature fields and the flame profiles. The physical model developed for this new type of application and the experimental data sets obtained (along with their interpretation) make the subject of this paper.

Keywords

  • intensified burning process
  • stabilization
  • Karlowitz effect
  • conical burner
access type Accesso libero

Influence of Dynamic Analysis Methods on Seismic Response of a Buttress Dam

Pubblicato online: 30 Dec 2014
Pagine: 12 - 26

Astratto

Abstract

The seismic analysis of a buttress dam with 73.50 m height is performed by the spectral analysis method and the direct time integration method. An accelerogram with 0.1g maximum acceleration was applied horizontally, in the upstream - downstream direction, at the bottom of the dam-foundation finite element mesh. The hydrodynamic effect of the reservoir was considered according to the added mass procedure (Westergaard relation). ABAQUS software was used to make the analyses. The same type of finite element C3D20R was used for the mesh of the dam body and of the foundation. The comparison of the results is made on the displacements, the stress state and the sliding stability on the dam-foundation contact in the full reservoir hypothesis. The comprehensive analysis concluded that both methods had provided close results for the considered case study. The spectral analysis method revealed itself to be more conservative compared to the direct time integration method.

Keywords

  • dams
  • earthquakes
  • dynamic analyses
  • stress
access type Accesso libero

Simulation of Two High Pressure Distribution Network Operation in one-Network Connection

Pubblicato online: 30 Dec 2014
Pagine: 27 - 35

Astratto

Abstract

The programs developed by the water supply system operators in view of metering the branches and reducing the potable water losses from the distribution network pipes lead to the performance reassessment of these networks. As a result the energetic consumption of the pumping stations should meet the accepted limits. An essential role in the evaluation of the operation parameters of the network performance is played by hydraulic modeling, by means of which the network performance simulation can be done in different scenarios. The present article describes the concept of two high-pressure network coupling. These networks are supplied by two repumping stations, in which the water flows were drastically reduced due to the present situation

Parole chiave

  • network distribution
  • pumping stations
  • numerical model
  • EPANET
access type Accesso libero

Update of the P100-1 Concrete Provisions

Pubblicato online: 30 Dec 2014
Pagine: 36 - 47

Astratto

Abstract

In an effort to improve the harmonization of the Romanian design codes with the Eurocodes, the revision of the Seismic Design Code, P100-1, started in April 2010 and ended in September 2013. The main issues addressed during the revision process are presented in this paper. They include re-outlining the fundamental requirements for seismic design, revision of the seismic action, improvement of the specific provisions for the design of reinforced concrete, steel, composite, wood and masonry structures and non-structural components. This paper focuses on the specific provisions for reinforced concrete structures but general information about the fundamental requirements and the seismic action are presented as well.

Keywords

  • seismic
  • code
  • Eurocode
  • reinforced
  • concrete
  • performance
  • goals
access type Accesso libero

Determination of Wheel-Rail Contact Characteristics by Creating a Special Program for Calculation

Pubblicato online: 30 Dec 2014
Pagine: 48 - 59

Astratto

Abstract

The authors in this paper describe the steps of creating a special program in GUI tool in Matlab. The program is designed to calculate the main properties of wheel-rail contact zone, such as: contact ellipse dimensions, normal stress and friction coefficients. All the relevant equations, which were introduced by different researchers, are firstly presented and modified to be applicable to the programming environment, and then the program was built. In the end, the program working quality is discussed and some expected future developments on this program are suggested. The proposed program can make the comparison between theoretical and experimental results, when they are available, easier and faster.

Keywords

  • Matlab
  • GUI
  • railway
  • friction
  • contact ellipse
  • Kalker
access type Accesso libero

Thermal Comfort Analyses in Naturally Ventilated Buildings

Pubblicato online: 30 Dec 2014
Pagine: 60 - 66

Astratto

Abstract

Global current requirement is to increase thermal comfort in residential and non residential buildings. A field survey was accomplished in a naturally ventilated university classroom in Bucharest, Romania, in winter and spring. Comfort parameters were measured and comfort questionnaires were distributed to the students. Questions were related to thermal sensation of the occupants. This paper compares the experimental results with the occupant’s response. It analyzes the variation of Predicted Mean Vote (PMV) and Predicted Percent of Dissatisfied (PPD) with temperature. It is made a comparison between PMV and thermal sensation vote. The results show PMV values different from Thermal Sensation Vote (TSV) values which means there is a poor approximation of indoor comfort. In conclusion the comfort parameters should be reviewed and should be proposed other evaluation methods. Possible explanations are discussed in relation with thermal regime of the buildings.

Keywords

  • thermal comfort
  • university classroom
  • PMV
  • PPD
6 Articoli
access type Accesso libero

High Stability and Low Emissions Burners Using Karlowitz Effect in Conical Burners

Pubblicato online: 30 Dec 2014
Pagine: 1 - 11

Astratto

Abstract

The conical tunnel burner is an improvement of the cylindrical tunnel burner because, by maintaining all its advantages by means of burning intensification, it may also insure the flame stabilization in a wide range of regulation with considerable diminished pressure losses. Technical applications for the conical furnace burner can vary due to the limited dimensions required by the system, as well as the important thermal loads, and also because of the burning stability characteristic that spreads over an important range of regulation. The low costs required by the burner, generated mainly by its simple construction, also raise the interest for this technical solution. A physical model is proposed for the ignition and flame front stabilization. The flame front stabilization contains different steps from the ignition moment to final flame front stabilization, with specific flame front geometries and specific locations along the burner axis. The installation realised by the authors allowed the experimental study of the burning process in conical furnaces, in order to determine the temperature fields and the flame profiles. The physical model developed for this new type of application and the experimental data sets obtained (along with their interpretation) make the subject of this paper.

Keywords

  • intensified burning process
  • stabilization
  • Karlowitz effect
  • conical burner
access type Accesso libero

Influence of Dynamic Analysis Methods on Seismic Response of a Buttress Dam

Pubblicato online: 30 Dec 2014
Pagine: 12 - 26

Astratto

Abstract

The seismic analysis of a buttress dam with 73.50 m height is performed by the spectral analysis method and the direct time integration method. An accelerogram with 0.1g maximum acceleration was applied horizontally, in the upstream - downstream direction, at the bottom of the dam-foundation finite element mesh. The hydrodynamic effect of the reservoir was considered according to the added mass procedure (Westergaard relation). ABAQUS software was used to make the analyses. The same type of finite element C3D20R was used for the mesh of the dam body and of the foundation. The comparison of the results is made on the displacements, the stress state and the sliding stability on the dam-foundation contact in the full reservoir hypothesis. The comprehensive analysis concluded that both methods had provided close results for the considered case study. The spectral analysis method revealed itself to be more conservative compared to the direct time integration method.

Keywords

  • dams
  • earthquakes
  • dynamic analyses
  • stress
access type Accesso libero

Simulation of Two High Pressure Distribution Network Operation in one-Network Connection

Pubblicato online: 30 Dec 2014
Pagine: 27 - 35

Astratto

Abstract

The programs developed by the water supply system operators in view of metering the branches and reducing the potable water losses from the distribution network pipes lead to the performance reassessment of these networks. As a result the energetic consumption of the pumping stations should meet the accepted limits. An essential role in the evaluation of the operation parameters of the network performance is played by hydraulic modeling, by means of which the network performance simulation can be done in different scenarios. The present article describes the concept of two high-pressure network coupling. These networks are supplied by two repumping stations, in which the water flows were drastically reduced due to the present situation

Parole chiave

  • network distribution
  • pumping stations
  • numerical model
  • EPANET
access type Accesso libero

Update of the P100-1 Concrete Provisions

Pubblicato online: 30 Dec 2014
Pagine: 36 - 47

Astratto

Abstract

In an effort to improve the harmonization of the Romanian design codes with the Eurocodes, the revision of the Seismic Design Code, P100-1, started in April 2010 and ended in September 2013. The main issues addressed during the revision process are presented in this paper. They include re-outlining the fundamental requirements for seismic design, revision of the seismic action, improvement of the specific provisions for the design of reinforced concrete, steel, composite, wood and masonry structures and non-structural components. This paper focuses on the specific provisions for reinforced concrete structures but general information about the fundamental requirements and the seismic action are presented as well.

Keywords

  • seismic
  • code
  • Eurocode
  • reinforced
  • concrete
  • performance
  • goals
access type Accesso libero

Determination of Wheel-Rail Contact Characteristics by Creating a Special Program for Calculation

Pubblicato online: 30 Dec 2014
Pagine: 48 - 59

Astratto

Abstract

The authors in this paper describe the steps of creating a special program in GUI tool in Matlab. The program is designed to calculate the main properties of wheel-rail contact zone, such as: contact ellipse dimensions, normal stress and friction coefficients. All the relevant equations, which were introduced by different researchers, are firstly presented and modified to be applicable to the programming environment, and then the program was built. In the end, the program working quality is discussed and some expected future developments on this program are suggested. The proposed program can make the comparison between theoretical and experimental results, when they are available, easier and faster.

Keywords

  • Matlab
  • GUI
  • railway
  • friction
  • contact ellipse
  • Kalker
access type Accesso libero

Thermal Comfort Analyses in Naturally Ventilated Buildings

Pubblicato online: 30 Dec 2014
Pagine: 60 - 66

Astratto

Abstract

Global current requirement is to increase thermal comfort in residential and non residential buildings. A field survey was accomplished in a naturally ventilated university classroom in Bucharest, Romania, in winter and spring. Comfort parameters were measured and comfort questionnaires were distributed to the students. Questions were related to thermal sensation of the occupants. This paper compares the experimental results with the occupant’s response. It analyzes the variation of Predicted Mean Vote (PMV) and Predicted Percent of Dissatisfied (PPD) with temperature. It is made a comparison between PMV and thermal sensation vote. The results show PMV values different from Thermal Sensation Vote (TSV) values which means there is a poor approximation of indoor comfort. In conclusion the comfort parameters should be reviewed and should be proposed other evaluation methods. Possible explanations are discussed in relation with thermal regime of the buildings.

Keywords

  • thermal comfort
  • university classroom
  • PMV
  • PPD

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