STUDY ON THE EFFECT OF THE SELF-ATTENUATION COEFFICIENT ON γ-RAY DETECTOR EFFICIENCY CALCULATED AT LOW AND HIGH ENERGY REGIONS

El-Khatib, Ahmed M.,Thabet, Abouzeid A.,Elzaher, Mohamed A.,Badawi, Mohamed S.,Salem, Bohaysa A. Korean Nuclear Society 2014 Nuclear Engineering and Technology Vol.46 No.2

The present work used the efficiency transfer method used to calculate the full energy peak efficiency (FEPE) curves of the (2"*2" & 3"*3") NaI (Tl) detectors based on the effective solid angle subtended between the source and the detector. The study covered the effect of the self attenuation coefficient of the source matrix (with a radius greater than the detector's radius) on the detector efficiency. $^{152}$ An Eu aqueous radioactive source covering the energy range from 121.78 keV up to 1408.01 keV was used. In this study an empirical formula was deduced to calculate the difference between the measured and the calculated efficiencies [without self attenuation] at low and high energy regions. A proper balance between the measured and calculated efficiencies [with self attenuation] was achieved with discrepancies less than 3%, while reaching 39% for calculating values [without self attenuation] due to working with large sources, or for low photon energies.

One-Pot Robust Dyeing of Cotton Fabrics with Multifunctional Chamomile Flower Dyes

Manal M. El-Zawahry,Hala S. El Khatib,Gehan M. Shokry,Hager Gamal Rashad 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

Our study focused on the extraction of biologically active compounds in the form of eco-friendly dyes from driedchamomile flower (CF) powder using three different solvents, as well as the development of an approach to the simultaneousdyeing and finishing of cationized cotton fabrics, a process which can impart multifunctional properties. These extracted dyeswere successfully used as reducing and stabilizing agents in the synthesis of silver nanoparticles (AgNPs), whichfunctionalized both the dye and the fabric. This green, value-added dyeing approach is needed for the production ofbiomedical textiles, especially in the healthcare sector. Our results revealed that the total phenolic content (TPC) and totalflavonoid content (TFC) were significantly higher in dyes extracted using ethanol and methanol than those extracted using anaqueous solution. Furthermore, cotton fabrics dyed with these three dyes exhibited a wide range of colors with good washingfastness, excellent UV protection, and antioxidant properties. The simultaneous dyeing and finishing of cotton fabrics via thein situ green synthesis CF extracts/AgNPs dyes enhanced the K/S values and the antimicrobial, antifungal, and antioxidantactivity of the fabrics while still providing adequate UV protection. This process also improved the washing fastness anddurability, which is important for biomedical applications.

Study on the Effect of the Self-Attenuation Coefficient on γ-ray Detector Efficiency Calculated at Low and High Energy Regions

Ahmed. M. El-Khatib,ABOUZEID. A. THABET,MOHAMED. A. ELZAHER,MOHAMED. S. BADAWI,BOHAYSA. A. SALEM 한국원자력학회 2014 Nuclear Engineering and Technology Vol.46 No.2

The present work used the efficiency transfer method used to calculate the full energy peak efficiency (FEPE) curves ofthe (2"*2" & 3"*3") NaI (Tl) detectors based on the effective solid angle subtended between the source and the detector. Thestudy covered the effect of the self attenuation coefficient of the source matrix (with a radius greater than the detector's radius)on the detector efficiency. 152 An Eu aqueous radioactive source covering the energy range from 121.78 keV up to 1408.01keV was used. In this study an empirical formula was deduced to calculate the difference between the measured and thecalculated efficiencies [without self attenuation] at low and high energy regions. A proper balance between the measured andcalculated efficiencies [with self attenuation] was achieved with discrepancies less than 3%, while reaching 39% forcalculating values [without self attenuation] due to working with large sources, or for low photon energies.

Culture and Development in Egypt

Mohamed Fathalah El Khatib 경남대학교 극동문제연구소 1994 CULTURE & DEVELOPMENT Vol.- No.-

Kinetics of Base Hydrolysis of Some Chromen-2-one Indicator Dyes in Different Solvents at Different Temperatures

Abu-Gharib, Ezz A.,EL-Khatib, Rafat M.,Nassr, Lobna A.E.,Abu-Dief, Ahmed M. Korean Chemical Society 2011 대한화학회지 Vol.55 No.3

7-hydroxy-2H-chromen-2-one(HC)와 7-hydroxy-2H-chromen-2-one-4-acetic acid(HCA)의 염기성 가수분해반응을 aqueous-methanol과 aqueous-acetone 혼합물에서 283 K에서 313 K의 온도 범위에서 속도론적으로 연구하였다. 반응의 활성화 파라미터를 구하고 토의하였다. 게다가, 물, 물-에탄올, 물-아세톤 혼합물 내에서 화합물들에 대한 활성화 에너지 장벽의 변화를 속도론적 데이터로부터 추정하였다. 활성화 장벽의 변화는 HC and HCA의 가수분해 반응과 거의 같았다. HC와 HCA의 염기성 가수분해는 $k_{obs}=k_2[OH^-]$와 같은 속도법칙을 따른다. 메탄올 또는 아세톤의 비가 증가함에 따라 HC 와 HCA의 속도 상수들이 감소하는 것은 $OH^-$ 이온이 불안정해지기 때문이다. 활성화 엔트로피가 큰 음의 값을 갖는 다는 것은 반응이 중간 착물의 형성을 경유하며 진행된다는 것을 의미하며, 또한 중간 착물이 경직성과 안정도를 갖는다는 것을 의미한다. 그러므로, 중간 착물의 고리 열림이 속도 조절 단계가 될 것이다. Base hydrolysis of 7-hydroxy-2H-chromen-2-one (HC) and 7-hydroxy-2H-chromen-2-one-4-acetic acid (HCA) in aqueous-methanol and aqueous-acetone mixtures were studied kinetically at temperature range from 283 to 313 K. The activation parameters of the reactions were evaluated and discussed. Moreover, the change in the activation energy barrier of the investigated compounds from water to water-methanol and water-acetone mixtures was estimated from the kinetic data. It is observed that the change in activation barriers is more or less the same for the hydrolysis of HC and HCA. Base hydrolysis of HC and HCA follows a rate law with $k_{obs}=k_2[OH^-]$. The decrease in the rate constants of HC and HCA as the proportion of methanol or acetone increases is due to the destabilization of $OH^-$ ion. The high negative values of entropy of activation support the proposal mechanism, i.e. the investigated reaction takes place via the formation of an intermediate complex. Moreover, these values refer to the rigidity and stability of the intermediate complex. Thus, the ring opening of the intermediate complex would be the rate controlling step.

Development of electroless Ni–P modified aluminum substrates in a simulated fuel cell environment

Amani E. Fetohi,K.M. El-Khatib,R.M. Abdel Hameed 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.30 No.-

The corrosion resistance of electroless Ni–P coating on pure Al, Al 6061, Al 3004 and Al 1050 is examinedin an environment simulated to PEM fuel cell. Potentiodynamic polarization techniques, Interfacialcontact resistance, surface morphology, chemical composition of coated substrates and EISmeasurements have been investigated. Modified Al 1050 showed reduction in its corrosion currentdensity by 44.69 times. It also showed the best stability of all modified Al substrates. The formed Ni–Player on Al 1050 is thicker by about 3 times, relative to that on Al 6061 and has higher Ea value of135.68 kJ mol 1 supporting its lower corrosion rate.

Implementation of waste silicate glass into composition of ordinary cement for radiation shielding applications

Mohanad S. Eid,I.I. Bondouk,Hosam M. Saleh,Khaled M. Omar,M.I. Sayyed,Ahmed M. El-Khatib,Mohamed Elsafi 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4

The aim of this work is to study the radiation shielding properties of cement samples with waste glassincortated into its composition. The mass attenuation coefficient (MAC) of the samples were experimentally determined to evaluate their radiation shielding ability. The experimental coefficient wasevaluated using NaI detector for gamma energies between 59.53 keV and 1408.01 keV using differentradioactive point sources Am-241, Eu-152, Co-60, and Cs-137, and the gamma transmission parametershalf-value layer, mean free path, and transmission factor were calculated. The theoretical coefficient ofthe composites was determined using Geant4 and XCOM software. The results were also comparedagainst Geant4 and XCOM simulations by calculating the relative deviation between the values todetermine the accuracy of the results. In addition the mechanical properties (including Compressive andporosity) as well as the thermogravimetric analysis were tested for the present samples. Overall, it wasconcluded that the cement sample with 50% waste glass has the greatest shielding potential for radiationshielding applications and is a useful way to reuse waste glass.