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A Flash TDC with 2.6-4.2ps Resolution Using a Group of Unbalanced CMOS Arbiters

Research Authors
S. Komatsu, T. J. Yamaguchi, M. Abbas, N. Khanh, J. Tandon and K. Asada
Research Department
Research Journal
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Research Pages
pp.777-780
Research Rank
1
Research Vol
Vol.E97-A - No.3
Research Year
2014

Prediction of axial compressive strength of reinforced concrete circular short columns confined with carbon fiber reinforced polymer wrapping sheets

Research Abstract
External confinement of concrete columns by means of carbon fiber reinforced polymer (CFRP) sheets can be considered as an efficient technique for their structural strengthening. An experimental research program including 18 circular short column specimens were tested under axial compression load, to investigate the gain strength of reinforced concrete (RC) columns confined with CFRP sheets. The parameters studied were both the volume and configurations of CFRP sheets, the size of cross-section, the percentage of main reinforcement, and the volume of internal stirrups. On the basis of the obtained results, mathematical models (Egyptian code and American Concrete Institute code) proposed to predict the axial compressive strength of non-slender RC column strengthened by means of CFRP sheets are evaluated. These codes showed an underestimation in predicting the axial compressive strength of RC strengthened columns. This, from the authors’ point of view, is attributed mainly to the fact that the proposed models overlooked the amount of internal stirrups when calculating the strength of strengthened columns. Therefore, modifications in the studied models were considered. The modifications take the effective lateral confining pressure due to presence of internal steel stirrups into account. The modified codes showed an acceptable approach to the experimental results
Research Authors
Omar Ahmed Farghal and Hesham Mohamed Ahmed Diab
Research Department
Research Journal
Journal of Reinforced Plastics and Composites
Research Member
Research Pages
1406–1418
Research Publisher
SAGE
Research Rank
1
Research Vol
32 -19
Research Year
2013

Prediction of axial compressive strength of reinforced concrete circular short columns confined with carbon fiber reinforced polymer wrapping sheets

Research Abstract
External confinement of concrete columns by means of carbon fiber reinforced polymer (CFRP) sheets can be considered as an efficient technique for their structural strengthening. An experimental research program including 18 circular short column specimens were tested under axial compression load, to investigate the gain strength of reinforced concrete (RC) columns confined with CFRP sheets. The parameters studied were both the volume and configurations of CFRP sheets, the size of cross-section, the percentage of main reinforcement, and the volume of internal stirrups. On the basis of the obtained results, mathematical models (Egyptian code and American Concrete Institute code) proposed to predict the axial compressive strength of non-slender RC column strengthened by means of CFRP sheets are evaluated. These codes showed an underestimation in predicting the axial compressive strength of RC strengthened columns. This, from the authors’ point of view, is attributed mainly to the fact that the proposed models overlooked the amount of internal stirrups when calculating the strength of strengthened columns. Therefore, modifications in the studied models were considered. The modifications take the effective lateral confining pressure due to presence of internal steel stirrups into account. The modified codes showed an acceptable approach to the experimental results
Research Authors
Omar Ahmed Farghal and Hesham Mohamed Ahmed Diab
Research Department
Research Journal
Journal of Reinforced Plastics and Composites
Research Member
Research Pages
1406–1418
Research Publisher
SAGE
Research Rank
1
Research Vol
32 -19
Research Year
2013

Bond strength and effective bond length of FRP sheets/plates bonded to concrete considering the type of adhesive layer

Research Abstract
Recent experimental results of the FRP–concrete bonded joint using flexible adhesive showed that the most popular analytical models available in the literature underestimate the bond strength and the effective bond length of these experiments. Most of these existing models need to be modified to consider the type of adhesive layer. Consequently, the bond strength model proposed by Chen and Teng (2001) has been modified to consider the type of adhesive layer. An extensive database consisting of about 100 test results of FRP–concrete joint has been assembled to examine the validity of the proposed model taking the type of adhesive layer into consideration. The modified bond strength model is accurately capable of predicting the bond strength and the effective bond length.
Research Authors
د./ هشام محمد أحمد دياب- كلية الهندسة - جامعة اسيوط
د./ عمر احمد فرغل - استاذ مساعد - كلية الهندسة - جامعة اسيوط
Research Department
Research Journal
Composites Part B: Engineering, Elsevier, science Direct Vol.58, 2014
Research Member
Research Publisher
Elsevier, science Direct
Research Rank
1
Research Vol
58
Research Year
2014

Bond strength and effective bond length of FRP sheets/plates bonded to concrete considering the type of adhesive layer

Research Abstract
Recent experimental results of the FRP–concrete bonded joint using flexible adhesive showed that the most popular analytical models available in the literature underestimate the bond strength and the effective bond length of these experiments. Most of these existing models need to be modified to consider the type of adhesive layer. Consequently, the bond strength model proposed by Chen and Teng (2001) has been modified to consider the type of adhesive layer. An extensive database consisting of about 100 test results of FRP–concrete joint has been assembled to examine the validity of the proposed model taking the type of adhesive layer into consideration. The modified bond strength model is accurately capable of predicting the bond strength and the effective bond length.
Research Authors
د./ هشام محمد أحمد دياب- كلية الهندسة - جامعة اسيوط
د./ عمر احمد فرغل - استاذ مساعد - كلية الهندسة - جامعة اسيوط
Research Department
Research Journal
Composites Part B: Engineering, Elsevier, science Direct Vol.58, 2014
Research Member
Research Publisher
Elsevier, science Direct
Research Rank
1
Research Vol
58
Research Year
2014

Parametric investigation of solar chimney with new cooling tower
integrated in a single room for New Assiut city, Egypt climate

Research Abstract
Houses in Egypt are often designed without taking the climate into account sufficiently. Consequently, new houses often have a poor indoor climate, which affects comfort, health and building efficiency. In hot and arid climates, passive cooling system employs non-mechanical procedures to maintain suitable indoor temperature. Thus, they have been increasing the influence of the traditional cooling concepts but with new technology. Therefore, these conditions encourage such a concept to enhance natural ventilation with evaporative cooling and save energy in the New Assiut city. In the present study, the effect of solar chimney parameters on wind tower parameters was numerically investigated as a second phase of the new integrated model. All the detailed mathematical equations and system description are presented in phase one. A numerical simulation is implemented in Transient systems simulation program-Conjunction of multizone infiltration specialists program softwares. The parametric studies of the integrated system in phase two were studied to achieve high performance with new compact small design especially for the hottest days in the summer season. The temperature and airflow rates are predicted iteratively taking into account the zone pressure and the pressure drop in the evaporative cooler component. The result shows that the system achieves nearly at least close to 80 % acceptable comfort range according to Adaptive Comfort Standard of American Society of Heating, Refrigerating and Air-Conditioning Engineers with optimum ventilation rate 414 m3/h for the hottest day. The findings show that the system achieves high performance in the hottest day with small solar chimney dimension and is easy to integrate in the building envelope than the proposed system before parametric studies in phase one.
Research Authors
Amr Sayed Hassan Abdallah
• Yoshino Hiroshi
•Tomonobu Goto
• Napoleon Enteria
•Magdy M. Radwan
• M. Abdelsamei Eid
Research Journal
International Journal of Energy and Environmental Engineering, Springer
Research Publisher
Springer
Research Rank
1
Research Vol
5:92
Research Website
http://link.springer.com/article/10.1007/s40095-014-0092-6
Research Year
2014

Parametric investigation of solar chimney with new cooling tower
integrated in a single room for New Assiut city, Egypt climate

Research Abstract
Houses in Egypt are often designed without taking the climate into account sufficiently. Consequently, new houses often have a poor indoor climate, which affects comfort, health and building efficiency. In hot and arid climates, passive cooling system employs non-mechanical procedures to maintain suitable indoor temperature. Thus, they have been increasing the influence of the traditional cooling concepts but with new technology. Therefore, these conditions encourage such a concept to enhance natural ventilation with evaporative cooling and save energy in the New Assiut city. In the present study, the effect of solar chimney parameters on wind tower parameters was numerically investigated as a second phase of the new integrated model. All the detailed mathematical equations and system description are presented in phase one. A numerical simulation is implemented in Transient systems simulation program-Conjunction of multizone infiltration specialists program softwares. The parametric studies of the integrated system in phase two were studied to achieve high performance with new compact small design especially for the hottest days in the summer season. The temperature and airflow rates are predicted iteratively taking into account the zone pressure and the pressure drop in the evaporative cooler component. The result shows that the system achieves nearly at least close to 80 % acceptable comfort range according to Adaptive Comfort Standard of American Society of Heating, Refrigerating and Air-Conditioning Engineers with optimum ventilation rate 414 m3/h for the hottest day. The findings show that the system achieves high performance in the hottest day with small solar chimney dimension and is easy to integrate in the building envelope than the proposed system before parametric studies in phase one.
Research Authors
Amr Sayed Hassan Abdallah
• Yoshino Hiroshi
•Tomonobu Goto
• Napoleon Enteria
•Magdy M. Radwan
• M. Abdelsamei Eid
Research Journal
International Journal of Energy and Environmental Engineering, Springer
Research Member
Research Publisher
Springer
Research Rank
1
Research Vol
5:92
Research Website
http://link.springer.com/article/10.1007/s40095-014-0092-6
Research Year
2014
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