Neighboring Cage Fish Farming Affecting Water and Seabed Quality of the Jordanian Northern Gulf of Aqaba, Red Sea

Al-Zibdah Mohammad,Oqaily Firas,Al-Najjar Tariq,Manasrah Riyad1 한국해양과학기술원 2008 Ocean science journal Vol.43 No.1

Environmental qualities of coastal water and bottom sediment were assessed at Jordan’s northernmost tip of Gulf of Aqaba to evaluate possible impacts of the bordering fish pen cages in Eilat. Results showed significant differences between surface and bottom water in the chemical and physical variables in the different months of the year (2004-2005). Chlorophyll a was also significantly higher in bottom water when compared to that of the offshore water. Nitrate and ammonia were significantly higher in bottom water than the surface water at each individual station. The upper 2 cm of sediment sample recorded higher values of total phosphorus and organic matter. Seasonality affected the content of total phosphorus, organic matter, redox potential and color especially at the sediment layer below 3 cm of the sediment core. The present investigation showed slight modification of water and sediment qualities but no clear sign of eutrophication was observed. However, to maintain sustainability of healthy environmental conditions at the northern tip of Gulf of Aqaba potentials of any possible environmental risks arising from the fish farms or any other coastal investment should be carefully considered.

Ductility of carbon fiber-reinforced polymer (CFRP) strengthened reinforced concrete beams: Experimental investigation

Riyad S. Aboutaha,Sang Hun Kim 국제구조공학회 2004 Steel and Composite Structures, An International J Vol.4 No.5

Strength of reinforced concrete beams can easily be increased by the use of externally bonded CFRP composites. However, the mode of failure of CFRP strengthened beam is usually brittle due to tensionshear failure in the concrete substrate or bond failure near the CFRP-Concrete interface. In order to improve the ductility of CFRP strengthened concrete beams, critical variables need to be investigated. This experimental and analytical research focused on a series of reinforced concrete beams strengthened with CFRP composites to enhance the flexural capacity and ductility. The main variables were the amount of CFRP composites, the amount of longitudinal and shear reinforcement, and the effect of CFRP end diagonal anchorage system. Sixteen full-scale beams were investigated. A new design guideline was proposed according to the effects of the above-mentioned variables. The experimental and analytical results were found to be in good agreement.

Twist and Shout: A Clinical and Experimental Review of Testicular Torsion

Riyad T. Ellati,Parviz K. Kavoussi,Terry T. Turner,Jeffrey J. Lysiak 대한비뇨의학회 2009 Investigative and Clinical Urology Vol.50 No.12

Purpose: This review addresses different aspects of testicular torsion from the clinical perspective as well as the basic cellular and molecular events responsible for the post-torsion testicular changes and pathology, including tissue ischemia-reperfusion injury. Materials and Methods: A review of all published literature on testicular torsion was performed by use of two search engines. Results: Testicular torsion, or more correctly termed torsion of the spermatic cord, is a surgical emergency in order to salvage the testis. Its incidence is approximately 1 in 4,000 per annum. Testicular torsion must be treated promptly to avoid loss of the ipsilateral testis; however, even with torsion repair and gross testicular salvage, significant injury may still occur. Conclusions: The cellular and molecular mechanisms leading to ischemia- reperfusion injury are incompletely understood, and adjuncts to surgical treatment have received little attention. Understanding the cellular and molecular effects is important because 25% of males with a history of torsion may experience adult infertility. This review emphasizes current knowledge of basic science results and clinical outcomes of testicular torsion. Purpose: This review addresses different aspects of testicular torsion from the clinical perspective as well as the basic cellular and molecular events responsible for the post-torsion testicular changes and pathology, including tissue ischemia-reperfusion injury. Materials and Methods: A review of all published literature on testicular torsion was performed by use of two search engines. Results: Testicular torsion, or more correctly termed torsion of the spermatic cord, is a surgical emergency in order to salvage the testis. Its incidence is approximately 1 in 4,000 per annum. Testicular torsion must be treated promptly to avoid loss of the ipsilateral testis; however, even with torsion repair and gross testicular salvage, significant injury may still occur. Conclusions: The cellular and molecular mechanisms leading to ischemia- reperfusion injury are incompletely understood, and adjuncts to surgical treatment have received little attention. Understanding the cellular and molecular effects is important because 25% of males with a history of torsion may experience adult infertility. This review emphasizes current knowledge of basic science results and clinical outcomes of testicular torsion.

Spatial and Seasonal Variations of Sea Level in the Red Sea, 1958-2001

Riyad Manasrah,H.M. Hasanean,Saber Al-Rousan 한국해양과학기술원 2009 Ocean science journal Vol.44 No.3

The present study investigated the variability of monthly mean sea level data and discussed its relation with climatic events in the Red Sea during 1958-2001. The data were obtained from Simple Ocean Data Assimilation (SODA), for three different locations (north, central and south) in the Red Sea. Spatial and temporal variability as well as trends and periodicity of sea level time series records in the three locations was investigated using One-way ANOVA test, weighted running mean filter and autocorrelation spectral analysis. Results revealed that mean sea level in the northern Red Sea was permanently lower than its central and southern parts. Moreover, the mean sea level during winter and spring in the three locations was significantly higher than summer and autumn seasons. Increasing and decreasing of sea level trends with respect to time were also observed. Inter-decadal variations in sea level including a fairly regular quasi 2.5-2.7 year oscillation in all seasons were detected, although its amplitude varied among different cycles. Studying the cyclicity in the hydroclimatic record can resolve some of the complexities of the hydroclimate system. The sign of Quasi Biennial Oscillation, El Niño Southern Oscillation and sunspots events may have an important influence in sea level variations of the Red Sea.

Seasonal Changes of Water Properties and Current in the Nothernmost Gulf of Aqaba, Red Sea

Riyad Manasrah,Mohammad Zibdah,Firas Al-Ougaily,Najim Yusuf,Tariq Al-Najjar 한국해양과학기술원 2007 Ocean science journal Vol.42 No.2

Seasonal changes of tide signal(s), temperature, salinity and current were studied during the years 2004-2005 in the northernmost Gulf of Aqaba, which is under developmental activities, to obtain scientific bases for best management and sustainability. Spectrum analysis revealed permanent signals of tide measurements during all seasons, which represented semidiurnal and diurnal barotropic tides. The other signal periods of 8.13, 6.10-6.32, 4.16 and 1.02-1.05 h were not detected in all seasons, which were related to shallow water compound and overtides of principle solar and lunar constituent and to seiches generated in the Red Sea and the Gulf of Aqaba. Spatial and temporal distribution of temperature, salinity and density showed significant differences between months in the coastal and offshore region and no significant differences among the coastal sites, between the surface and bottom waters and between coastal and offshore waters. Therefore, the temporal and spatial variation of water properties in the northernmost Gulf of Aqaba behave similarly compared to other parts. The coastal current below 12 m depth was weak (3-6 cms-1) and fluctuated from east-northeastward to west-southwestward (parallel to the shoreline), which may be related to the effect of bottom topography and/or current density due to differential cooling between eastern and western parts in the study area, and wind-induced upwelling and downwelling in the eastern and western side, respectively. The prevailing northerly winds and stratification conditions during summer were the main causes of the southward current at 6 and 12 m depths with average speed of 28 and 12 cms-1, respectively.

Seasonal Changes of Water Properties and Current in the Northernmost Gulf of Aqaba, Red Sea

Manasrah, Riyad,Zibdah, Mohammad,Al-Ougaily, Firas,Yusuf, Najim,Al-Najjar, Tariq The Korean Society of Oceanography 2007 Ocean science journal Vol.42 No.2

Seasonal changes of tide signal(s), temperature, salinity and current were studied during the years 2004-2005 in the northernmost Gulf of Aqaba, which is under developmental activities, to obtain scientific bases for best management and sustainability. Spectrum analysis revealed permanent signals of tide measurements during all seasons, which represented semidiurnal and diurnal barotropic tides. The other signal periods of 8.13, 6.10-6.32, 4.16 and 1.02-1.05 h were not detected in all seasons, which were related to shallow water compound and overtides of principle solar and lunar constituent and to seiches generated in the Red Sea and the Gulf of Aqaba. Spatial and temporal distribution of temperature, salinity and density showed significant differences between months in the coastal and offshore region and no significant differences among the coastal sites, between the surface and bottom waters and between coastal and offshore waters. Therefore, the temporal and spatial variation of water properties in the northernmost Gulf of Aqaba behave similarly compared to other parts. The coastal current below 12 m depth was weak $(3-6\;cms^{-1})$ and fluctuated from east-northeastward to west-southwestward (parallel to the shoreline), which may be related to the effect of bottom topography and/or current density due to differential cooling between eastern and western parts in the study area, and wind-induced upwelling and downwelling in the eastern and western side, respectively. The prevailing northerly winds and stratification conditions during summer were the main causes of the southward current at 6 and 12 m depths with average speed of 28 and $12cms^{-1}$ respectively.

진동열교환기에서 다양한 충진율에 따른 압력및 진동특성에 관한 연구

리야드(Md.Riyad Tanshen),김영식(Young-Sik Kim),이대철(Dae-chul Lee),정한식(Han-Shik Chung),정효민(Hyo-Min Jeong) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7

The article focuses on pressure characteristics inside single loop oscillating heat pipe (OHP) that is of 4.5 ㎜ inner diameter copper tube with the length of 440 ㎜. The system consists of evaporator, condenser and adiabatic section at middle of heat pipe. Distilled water is used as working fluid inside the OHP with different filling ratios of 40%, 60%, 80% of total volume. Experimental results shows that thermal characteristics are significantly inter-related with pressure fluctuations as well as pressure frequency. And the pressure frequency also depends upon the evaporator temperature which has been maintained from 60oC to 96oC. The Investigation shows 60% filling ratio gives the highest magnitude of inside pressure and highest pressure frequency at any of setting evaporator temperature. Piezoresistive absolute pressure sensor (Model-Kistler 4045A5) has been used to take data.

Experimental Investigations on the Temperature Characteristics of Loop Heat Pipe

리야드(Md.Riyad Tanshen),이광성(Kwangsung Lee),정효민(HyoMin Jeong),정한식(Hanshik Chung) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

Loop heat pipes (LHPs) are temperature tools having a mighty thermo-hydrodynamic coupling ruling the thermal performance. In this paper, heat pipe is experimentally studied thereby providing vital information on the parameter dependency of their thermal performance. The impact depiction has been done for the variation of tube model of the device. LHPs are constructed of copper capillary tubes of outer diameter 6.25 ㎜, inner diameter 4 ㎜ heated by constant temperature water bath cooled by ambient temperature. Using four type of LHPs of copper capillary tubes is length of 1500 ㎜ and 650㎜ inside tubes working fluid is R-22 Pressure 2 bar and mass 34g,32g,28g,16g. The results show an impact of four different types of (LHPs) used. These data collected using thermocouple and data logger connected with computer. The results indicate a strong influence of filling ratio on the performance.

Review of design parameters for FRP-RC members detailed according to ACI 440.1R-06

Fares Jnaid,Riyad Aboutaha 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.2

This paper investigates the parameters that control the design of Fiber Reinforced Polymer (FRP) reinforced concrete flexural members proportioned following the ACI 440.1R-06. It investigates the critical parameters that control the flexural design, such as the deflection limits, crack limits, flexural capacity,concrete compressive strength, beam span and cross section, and bar diameter, at various Mean-Ambient Temperatures (MAT). The results of this research suggest that the deflection and cracking requirements are the two most controlling limits for FRP reinforced concrete flexural members.

Finite element analysis of carbon fiber-reinforced\r\npolymer (CFRP) strengthened reinforced concrete beams

SangHun Kim,Riyad S. Aboutaha 한국계산역학회 2004 Computers and Concrete, An International Journal Vol.1 No.4

This paper presents investigation of a three-dimensional (3-D) nonlinear finite element model analysis to examine the behavior of reinforced concrete beams strengthened with Carbon Fiber Reinforced Polymer (CFRP) composites to enhance the flexural capacity and ductility of the beams. Three-dimensional nonlinear finite element models were developed between the internal reinforcement and concrete using a smeared relationship. In addition, bond models between the concrete surface and CFRP composite were developed using a smeared bond for general analyses and a contact bond for sensitivity analyses. The results of the FEA were compared with the experimental data on full-scale members. The results of two finite-element bonding models showed good agreement with those of the experimental tests.