د. احمدالحاج

قسم الفيزياء كلية العلوم

الاسم الكامل

د. احمد محمد احمد الحاج

المؤهل العلمي

دكتوراة

الدرجة العلمية

استاذ مساعد

ملخص

احمد الحاج هو احد اعضاء هيئة التدريس بقسم الفيزياء بكلية العلوم. يعمل السيد احمد الحاج بجامعة طرابلس كـمحاضر منذ وله العديد من المنشورات العلمية في مجال تخصصه

تنزيل السيرة الذاتية

معلومات الاتصال

روابط التواصل

الإستشهادات

الكل منذ 2017
الإستشهادات
h-index
i10-index

المؤهلات

دكتوراة

فيزياء اشعاعية
جامعة الاسكندرية
8 ,2011

ماجستير

فيزياء نووية
جامعة طرابلس
6 ,1997

بكالوريوس

فيزياء
جامعة سبها
10 ,1988

الخبرة

التدريس - التعليم المتوسط والعالى

I have been teacher from 1989 to 1991 at secondary school , Sebha I have been lecturer from 1992 to 1996 at Intermediate Industrial Institute I have been teacher from 1997 to 2003 at Intermediate electronic Institute I have been lecturer from 2003 to 2006 at Ejfara University And from 2012 – up to now I have been lecturer at Tripoli University
1989 - 2022

المنشورات

Tissue Injury Monitoring During X-Ray Irradiation Using Bioimpedance Spectroscopy

The effects of X-irradiation on electrical properties of rat liver, kidney and muscle tissues are studied. Multiple frequency bioelectrical impedance analysis (MFBIA) method is used to describe change in electrical properties of the irradiated tissues as a function of frequency and time, frequency dependence of conductivity and relative permittivity are measured. The rats were, whole body, exposed to (400 rads) X-rays from a clinical therapeutic 6 MV linear accelerator. At time intervals, the excised samples were obtained by sacrificing rats according to experimental (1, 2, 4, 9, 16, 23, 30 day post-irradiated). Electrical impedance of each excised sample is measured between 100 Hz to 5 MHz for (93) frequency points. Changes in electrical properties and readings at low, intermediate and high frequency as function of time for all samples reveal that there exist significant differences between both conductivity and permittivity of non-irradiated and irradiated muscle tissues (p < 0.05). At high frequency (1 MHz), the conductivity values (0.67 4 to 0.767 S/m) of longitudinal muscle and (0.582 to 0.731 S/m) of transverse muscle of irradiated tissues for all times, are higher than non-irradiated values (0.573 and 0.546 S/m) respectively. The differences in conductivity values between non-irradiated and 30 days post-irradiated, for longitudinal and transverse muscles are (34.103% and 33.922 %) respectively. The normalized values of relative permittivity at both low (5KHz) and high (1 MHz) frequencies are (26.38% and 36.641%) and (44.901% and 18.202%) for longitudinal and transverse muscles respectively. No significant differences in the conductivity and permittivity for liver and kidney were observed. Statistically significant differences observed only in muscle tissues therefore the effect due to whole body exposure are appeared more rapidly at 30 days in the muscle tissue than other organs (liver and kidney).
Ahmed M. elhaj, Ahmed M. El Khateeb , Nabil Kassam Madi, Moustafa M. Mohamed, Samia A M. Rezk(4-2010)
Publisher's website


EFFECTS OF X-RAY IRRADIATION ON BODY WATER, AND ELECTRICAL PROPERTIES OF RAT TISSUES

In vivo measurements for whole body exposed to doses 50–600 rads and ex vivo measurements of dielectric properties of excised tissues are carried out at 10 days post-irradiation using multiple frequency bioelectrical impedance analysis (MFBIA). Changes in the extracellular water (ECW) and total body water (TBW) of rats are estimated. The results show significant increases above non-irradiated rats in intracellular water (ICW) by 11.61% (P = 0.0001) and ECW by 9.95% (P = 0.0216) of rats exposed to 600 rads. These significant changes indicate a reduced activity of the ion pumps, which leads to changes in ion distribution between inter- and extra-cellular spaces. Dielectric properties (permittivity and conductivity) of freshly excised samples are measured at frequencies between 100 Hz and 5 MHz using two-electrode technique. The results for liver and muscle tissues reveal differences between non-irradiated and irradiated tissues (600 rads). The irradiation of rats with 600 rads causes 17% (P = 0.1139) non-significant decrease in the conductivity and 26% (P = 0.0091) significant decrease in the permittivity of liver below that of non-irradiated. While irradiation of rats causes significant increases by 19% (P = 0.005) and 25% (P = 0.0217)) in conductivity and permittivity of rat muscle tissues, respectively. Also the increase of irradiation doses (50 to 600 rads) causes a decrease on the characteristic frequency (the point of the maximum value for the reactive component of impedance). This indicates that there is a variability of the electrical properties which could be used as indicator to determine the degree of damage of tissue due to irradiation.
A.M. ELHAJ, M. MOUSTAFA, A.M. EL-KHATIB, N.K. MADI, SAMIA REZK(4-2012)
Publisher's website


EFFECTS OF X-RAY IRRADIATION ON BLOOD VISCOSITY AND BLOOD COMPONENTS

In this work, we accurately modelled the influence of shear rate and radiation on the blood viscosity. Blood samples of 50 albino rats were examined under different doses (0.50–6 Gy) at constant temperature 37 °C. The mechanism of interaction between radiation and blood are not very clear. The influence of X-rays on blood viscosity at different shear rates (52.8–264 s–1) is noticed for all doses. The viscosity reduction is observed for radiation doses greater than 3.50 Gy. This could be explained by the fact that the irradiated red blood cells form chains (i.e., rouleaux) which enable the cells to move through the blood in a more streamlined fashion, thus reducing the blood viscosity. Also, the radiation may increase plasma protein concentration, which reduces the viscosity of the blood. In conclusion, the changes in blood viscosity are altered by radiation and this effect can be used as an indicator in understanding the effects of radiation during the whole-body exposure
A.M. ELHAJ, A.M. EL KHATIB, K.A. MARGHANI, A.M. GSIEA, M. MOUSTAFA(1-2019)
Publisher's website


التردد المميز لأنسجة الكلى المشععة باستخدام نموذج كول ودافيدسون

Tissue response to radiation is important, and can be used as indicator to determine the damage degree due to radiation, and therefore can help in medical diagnosis that leads to affective therapy. In this paper, the electro-biological impedance, and radiation effects on rates kidney tissues is studied over a frequency range (300 Hz- 5 MHz), with x-ray exposure doses (0.5 – 6 Gy), and in different time periods (1, 2, 4, 16, 23, 30 days). The data were computationally fitted to the selected models, and the necessary parameters were calculated for the Cole-Davidson model. The characteristic frequency is obtained for all samples, and finally, its trend with dose and time is explained. Further investigations are required to help radiation therapy management and limit the excessive dose exposure, and time in medical trial
أحمد محمد الحاج, عالية محمد الشريف, خالد عبد الحفيظ المرغني, أحمد عمر الحماصي(6-2018)
موقع المنشور