Physics

Permanent URI for this collection

https://hdl.handle.net/20.500.11888/3207

Browse

Browsing Physics by Title

Now showing 1 - 20 of 98
  • Thumbnail Image
    Item
    Adiabatic Coupling Constant g of the Binary Liquid Mixture Methanol – Cyclohexane
    (2014) Saja Ghazi Omar; Prof. Issam Rashid Abdelraziq
    The dynamic shear viscosity of the binary liquid mixture methanol - cyclohexane for different temperatures and concentrations is measured using digital viscometer with UL adapter. Shear viscosity anomaly is clearly observed near the critical temperature Tc = 45.2 ℃ and the critical concentration Xc = 30% by weight of methanol. The specific heat at constant pressure of the critical mixture methanol – cyclohexane was calculated using two scale factor universality. The dynamic scaling theory of Ferrell and Bhattacharjee is applied to the data of the ultrasonic absorption coefficients αc at different frequencies. The linear relation of α_c/ƒ^2 versus ƒ^(-1.06) was obtained. The adiabatic coupling constant g, isobaric thermal expansion coefficient αp and diffusion coefficient D were calculated. The experimental values of (α(X_(c ,) T))/(α(X_c,T_c)) were plotted as a function of the reduced frequency ω* and it showed a good agreement with the theoretical scaling function F(ω*) presented by Ferrell and Bhattacharjee.
  • Thumbnail Image
    Item
    Analysis of Palestinian Olive Oil of Different Storage Ages by Fluorescence Spectroscopy Technique
    (2016) Jihan Marouf Turkey Abu Snouber; Prof. Issam Rashid Abdelraziq; Dr. Mohammed Abu-Jafar
    This work focuses on the effect of storage age of Palestinian olive oil on the emission and absorption wavelengths using the fluorescence spectroscopy technique. In addition, the effect of storage age of olive oil on the physical properties: viscosity, refractive index, acidity, and mass density are studied. The results of the emission and absorption spectra of olive oil samples at different storage ages give indication about how the amounts of the fluorescent components of olive oil affected by storage age. It was noticed that all vitamin E components, chlorophylls and phenolic compounds decrease as the storage age increases. The viscosity, refractive index, acidity (FFA%) and mass density for the sample collected from Saida (S2) of 5 years storage age at 25oC are found to be 58.9 cP, 1.4672, 2.98% and 0.90922 g/cm3, respectively. The viscosity, refractive index and mass density of olive oil samples at different storage ages decrease as the storage age increases, whereas the acidity increases as the storage age increases. The measured viscosity, refractive index, acidity and mass density of olive oil samples at 5 years storage ages agree with the standard values. The olive oil of storage age less than 5 years is considered as an edible olive oil. The Palestinian standard values of olive oil for viscosity, refractive index, acidity and mass density are regarded as; 84.0 cP – 63.6 cP, 1.4677 – 1.4705, 0.8 % - 3.3 % and 0.910 g/cm3 – 0.916 g/cm3, respectively (PS188, 1997).
  • Thumbnail Image
    Item
    Biodiesel Viscosity and Flash Point Determination
    (2015) Eman Ateeq; Prof. Issam Rashid Abdelraziq; Prof. Sharif M. Musameh
    In this research, biodiesel samples of different percentages of blend biodiesel (Palestinian biodiesel prepared from waste oil) and petro-diesel were studied. The density, refractive index, flash point and viscosity of the samples were measured. The flash points were measured as a function of percentage of biodiesel, the results emphasized that the flash points increase as the percentage of biodiesel increases in the sample. Two equations were proposed to obtain more suitable prediction of the flash point. The values of flash points of biodiesel were compared with the standard value of flash point of biodiesel. The comparison shows that samples contain more than 40% biodiesel coincide with standard values. The values of kinematic viscosity of biodiesel were compared with the Palestinian standard value of biodiesel. The comparison shows that samples contain less than 72% biodiesel coincide with standard value. Taking into consideration results of kinematic viscosity and flash point one can suggest percentage 71% of biodiesel and 29% petro-diesel as the best percentage that the two materials can be mixed and the flash point 115.3 ºC according the Palestinian standards.
  • Thumbnail Image
    Item
    Carbon Nanofibers/ Graphene Nanoplateletes Composite as Supercapacitor Electrode Using KOH Aqueous Electrolyte
    (An-Najah National University, 2020-09-28) جرار, صابرين صبري
    In this thesis, supercapacitor composite pallet electrodes had been prepared using different concentrations of carbon nanofibers and graphene nanoplateletes. The percentage weight of carbon nanofibers/ graphene nanoplateletes were changed from 90%/ 10% to 10%/ 90%, in steps of 20%. Electrochemical characterization had been characterized by cyclic voltammetry, galvanostatic charge/ discharge and electrochemical impedance spectroscopy methods in 1M KOH aqueous electrolyte. The specific capacitance was found to increase with increasing graphene nanoplateletes, which was increased from 47.0 to 119.7 F/g as graphene nanoplateletes increased from 10 to 90% weight at scan rate 5 mV/s by cyclic voltammetry method. The power and energy densities were evaluated from galvanostatic charge/ discharge method. Power and energy densities were increased with increasing graphene nanoplateletes concentration up to 70% then decreased when weight of graphene nanoplateletes increased to 90 % weight; the power density increased from 528.33 to 1095.43 W/kg, then decreased to 956.97 W/kg. The energy density increased from 2.32 to 5.26 Wh/kg, then decreased to 5.05 Wh/kg. Finally, equivalent series resistance was calculated from electrochemical impedance spectroscopy, which was found to increase with increasing graphene nanoplateletes concentrations up to 70%, then increases when graphene nanoplateletes increased to 90% weight. The equivalent series resistance was found to decrease from 1.48 to 0.632 Ω, then increases to 1.26 Ω as graphene nanoplateletes weight increases to 90%. The optimized composition in terms of best specific capacitance, power density, energy density and equivalent series resistance was 30%/ 70% of carbon nanofibers/ graphene nanoplateletes, which corresponds to 102.2 F/g, 1095.43 W/kg, 5.26 Wh/kg and 0.632 Ω, respectively. The specific surface area, pore size distribution and morphology structure of the prepared composites had been investigated by Brunauer- Emmett- Teller, Barrett- Joyner- Halenda, Harkins- Jura methods and scanning electron microscope. It is found that the specific surface area increases with increasing graphene nanoplateletes concentrations. It was increased from 271.27 to 665.93 m^2/g as graphene nanoplateletes changed from 10% to 90% weight. Total pore volume increases with increasing graphene nanoplateletes weight up to 70%, then it decreases as the concentration of graphene nanoplateletes increases to 90%. The total pore volume increased from 1.22 to 1.72 cm^3/g, then it decreased to 1.33 cm^3/g. Furthermore, micro, ultra- micro and mesopore volumes were found to increase by increasing graphene nanoplateletes concentrations from 10 to 90%. Micropore volume increases from 0.023 to 0.08 cm^3/g, ultra- micropore volume increases from 0.023 to 0.28 cm^3/g and mesopore volume increases from 0.55 to 0.88 cm^3/g when graphene nanoplateletes increase from 10% to 90% weight, respectively. Finally, Macropore volume increases with increasing graphene nanoplateletes from 10% to 30%, which decreases from 0.64 to 0.29 cm^3/g, and then increases up to 70% weight of graphene nanoplateletes, which increases from 0.29 to 0.88 cm^3/g, then it decreases for graphene nanoplateletes 90% weight; 0.33 cm^3/g. The best structural characterization was found for 70% weight of graphene nanoplateletes, which has the highest total pore volume (1.72 cm^3/g) and the highest macropore volume (0.88 cm^3/g). Also, it has optimized higher specific surface area, micropore, ultra- micropore and mesopore volumes which was 528.52 m^2/g, 0.0614 cm^3/g, 0.234 cm^3/g and 0.78 cm^3/g, respectively.
  • Thumbnail Image
    Item
    Carbon Nanotube-Composite Material for Dipole Antenna at Terahertz Range, Analysis, Properties, Efficiency and Performance
    (An-Najah National University, 2021-06-23) السيد, جيلان طارق
    Carbon nanotubes (CNTs) are very interesting material for nano devices for their uncommon mechanical and electrical properties. They may be metallic or semiconducting, depending on their geometry. It has been examined for a wide range of applications including the possibility of building antennas in the nanometer scale. Many studies have been carried out to solve the problems associated with the CNTs antennas. The limitations on the adopted numerical analysis methods such as method of moments (MoM) and the inefficient assumption concerning the conductivity of CNTs materials don’t give an adequate solution. In this thesis, complex permittivity approach have been considered to define the characteristics of various terahertz antenna configurations formed by metallic CNTs materials after modeling its conductivity accurately. Complex conductivity that depends on frequency is taken into account of the CNTs material in the investigation of these advanced antennas. CNTs-composite materials have been proposed that consist of CNTs coated by a thin layer of aluminum, or copper, for THz frequency band, where the single wall carbon nanotubes (SWCNTs) is a specific structure of CNTs utilized in this work. The CNTs-composite material is a promising nano material for different applications, where CNTs are coated by other materials to modify its structure to be more effective for various applications that have been explored in recent years. The idea of using copper or aluminum in coating dipole antennas have been applied in this thesis to exhibit the enhancement of performance for the proposed dipole antennas. The radiation characteristics of various configurations of coating and non-coating CNTs dipole antenna is investigated using the concept of the effective conductivity of carbon nanotube (CNTs) material. It takes into account the frequency dependent complex permittivity of the CNTs material and gives way to a virtual CNTs dipole suitable for adaptation in conventional antenna theory and in commercial electromagnetic software solvers. Simulation results related to SWCNTs dipole antennas are presented using CST software package or HFSS to show the effect of parameters on antenna performance. HFSS (high frequency structure simulator) and CST (computer simulation technology) both simulation program have been used to simulate the same prototype. Firstly, complex permittivity as a function of frequency have been calculated by using a matlab code, then the complex conductivity of CNTs have been obtained, after that the modeling have been done to get the efficiency measurement of CNTs.
  • Thumbnail Image
    Item
    Characterization of Dissolved Organic Matter in Wadi Al-Badan using Fourier Transform Infrared Microspectroscopy at SESAME
    (جامعة النجاح الوطنية, 2019-05-15) عطاري, امل
    وادي البادان هو أحد روافد حوض الفارعة الذي يبدا جريانه من الأجزاء الشرقية لمدينة نابلس. تدهورت جودة المياه في الوادي بسبب التلوث الناتج عن التدفق المستمر للمياه العادمة الغير المعالجة من شرق مدينة نابلس. المياه العادمة تحتوي على المواد العضوية الذائبة (DOM) والتي بدورها يمكن ان تنشط نمو الكائنات الحية الدقيقة في مياه الوادي. وجود الملوثات الميكروبيولوجية يمكن أن تلوث موارد المياه السطحية والجوفية في حوض الفارعة وهذا سوف يعرض المستهلكين المحلين للخطر وبشكل رئيسي أولئك الذين يستخدمون المياه لأغراض الشرب. لذلك، من المهم دراسة وتوصيف DOM في وادي البادان. تم جمع عينات ممثلة لمياه الوادي وتحليلها باستخدام طريقتين: أولاً ، باستخدام التحليل التقليدي الذي أجري في مختبرات معهد الدراسات المائية والبيئية (WESI) في جامعة النجاح الوطنية وثانياً باستخدام تحليلFTIR في ضوء السنكروترون للعلوم والتطبيقات التجريبية (SESAME) في الأردن. لتحليل FTIR، بعد الحصول على أطياف DOM، تم تحليلها باستخدام برنامج Essential FTIR، الذي يسمح بتحديد قمم مختلفة لمكونات DOM. أظهرت نتائج FTIR أن التواجد الكبير للمركبات المختلفة لـ DOM هي: أميد، مركبات عطرية، أليفاتية، وكربوهيدرات. بالإضافة إلى ذلك، تتأثر المركبات الكيميائية لـ DOM بمدخلات من البيئة المحيطة والتنقية الطبيعية التي تحدث على طول الوادي الرئيسي. أوضحت الدراسة أنه يمكن استخدام طريقة FTIR لتوصيف DOM في النظام المائي وكذلك لتتبع المصادر المحتملة لـ DOM في مياه الوادي.
  • Thumbnail Image
    Item
    Characterization of Dissolved Organic Matter in Wadi Al-Badan using Fourier Transform Infrared Microspectroscopy at SESAME
    (An Najah National University, 2019-05-15) Atari, Amal
    Wadi Al-Badan is one the Faria catchment tributaries that drains from the eastern parts of Nablus city. Water quality in the Wadi is being deteriorated due to the continuous effluent of untreated wastewater from the city of Nablus. Contamination by Dissolved Organic Matter (DOM) is a predominant problem in the Wadi which in turn can activate microorganisms growth in the Wadi flow. The presences of microbiological contaminants will potentially contaminate the surface water and groundwater resources in the catchment. The contaminated water will endanger the local consumers mainly those use water for drinking purposes. Therefore, it is important to study and characterize the DOM in Wadi Al-Badan. Selected water samples were collected along the main Wadi (stream flow) and analyzed using two methods: firstly, traditional analysis that was conducted at the labs of the Water and Environmental Studies Institute (WESI) of An-Najah National University and secondly, using FTIR analysis at Synchrotron light for Experimental Science and Applications (SESAME) in Jordan. For FTIR analysis, after survey spectra were obtained, they were analyzed using Essential FTIR software, which allows for identifying various peaks of DOM components. FTIR results showed that the considerable presences of different compounds of DOM are: Amide, aromatic, aliphatic, and carbohydrate compounds. In addition, DOM chemical compositions are affected by DOM inputs from the surrounding environment and natural purification that take place along the main Wadi. The study demonstrated that FTIR method could be used to characterize DOM in aquatic system, as well as to track the potential sources of DOM in Wadi flow.
  • Thumbnail Image
    Item
    Combined effects of pressure, temperature, and magnetic field on energy states of donor impurities in a GaAs/AlGaAs quantum heterostructure
    (An-Najah National University, 2017-10-19) أبوزيد, سماح فايز نمر; السعيد, محمد
    The ground state energy of shallow donor impurity in GaAs/AlGaAs heterostructure with an applied magnetic field along z direction, using exact diagonalization method, had been calculated. The effects of the impurity distance on the ground state energy versus the confining frequency and magnetic field strength had been investigated. The impurity binding energy of the ground state had been calculated as a function of impurity position, confining frequency and magnetic field strength. In addition, the combined effects of pressure and temperature, on the binding energy as a function of magnetic field strength had been studied using the effective-mass approximation. The result is that, the donor impurity binding energy enhances with increasing the pressure while it decreases as the temperature decreases.
  • Thumbnail Image
    Item
    Concentration and Temperature Dependence of Viscosity in Mode-Coupling Theory of Binary Mixture of Water and Phenol
    (2015) Shadia "Mohammed Said" Saleh Elayyat; Prof. Issam Rashid Abdelraziq; Dr. Mohammad Abu-Jafar
    The dynamic shear viscosity of a binary liquid mixture of water and phenol has been measured at different temperatures (32.0 ℃≤T≤75.0 ℃) and different concentrations (0.00% up to 100.00% by weight of phenol) by using glass capillary viscometer and Brookfield viscometer model DV-I+. The critical temperature and critical concentration have been determined to be 67.0 ℃ and 33.90% by weight of phenol respectively. The mode coupling theory (MCT) has been used to calculate the value of background viscosity (noncritical part of shear viscosity) η_0=0.684 cP, the Debye momentum cutoff q_D=0.786 Å^(-1) and the MCT constant A = 0.050. The intermolecular force range L of water and phenol molecules in a binary mixture has been calculated to be 11.17 Å, this large value indicates that the mutual force between binary mixture molecules considered as a week attractive force. The critical amplitude of specific heat at constant pressure at critical concentration and above critical temperature C_pc has been found to be 259.16 J/(kg.K) by using the two scale factor university.
  • Thumbnail Image
    Item
    The Conductance Calculation of Silicene Field Effect Transistor
    (An-Najah National University, 2018-11-07) معالي, فاطمه هلال هليل; السعيد, محمد
    In this thesis, we have produced the number of carriers concentration expression of Silicene channel in Field Effect Transistor (FET) against gate voltage at various temperatures. Furthermore, we have also presented explicit analytical calculations for the conductance of Silicene 2D sheet, using Landauer's Formula, in the presence of an applied perpendicular electric field and the spin-orbital-interaction effect. The calculations show that the electric field and the SOI significantly affect the conductance, band structure and the density of state for the silicene used as a channel in the field effect transistor.
  • Thumbnail Image
    Item
    A Confined Hydrogen Atom in A Spherical Cavity in N Dimensions “excited states”
    (An-Najah National University, 2017-04-06) مصلح, منار عبدالرحيم صالح; الجبر , سامي
    The energy eigenvalues for the excited states of a confined Hydrogen atom in an impenetrable spherical cavity in N-dimensional space had been calculated by applying the boundary conditions to the radial wave function of this quantum problem which had been investigated by Shaqqur and AL-Jaber [1]. The energy eigenvalues for the excited states depend on both the space dimension and the cavity size. So, we had investigated the dependence of these energies on the dimension N and on the radius of the cavity S. Also, we deduced the limits of the cavity size at which the H-atom still has bound states. For certain N, when the cavity radius increases enough the H-atom become free atom while when it decreases enough there will be no bound states beyond; these critical values of the cavity radius had been obtained for different dimensions N. Moreover, we had derived a simple equation which shows the relation between higher excited states with respect to higher dimensions started from N=3. Finally, we had examined the behavior of the pressure exerted by the confined H-atom on the cavity as the radius S is varied in different space dimensions. We found that: for a fixed N, the pressure gradually increases as the cavity radius decreases up to a maximum value, suddenly after it, the value of pressure diminishes to zero.
  • Thumbnail Image
    Item
    Confined Hydrogen Atom In Spherical Cavity In N - Dimensions
    (2009) Muzayan Abed Al Hameed Ali Shaqour; Prof.Sami Al-Jaber
    In this research the Schrödinger equation for a confined hydrogen atom in a spherical cavity in N dimensional spatial space has been solved for N ≥3. The eigen functions as well as the eigen values have been determined. We show that the Schrodinger equation here doesn’t differ from that of the free hydrogen atom in N dimensions; therefore they have similar wave functions namely: (see The Equation in The PDF File) while they differ in energy. A series solution of the Schrödinger equation is adopted here, and then, by applying the boundary conditions to the wave functions we found the energy eigen-values.The dependence of the ground state energy eigen-values of a confined hydrogen atom for l = 0 for certain values of N, on the radius of the cavity S, has been examined. We found that they depend on the radius of the cavity S, we show that for a given N, if S increases the ground state energies decreases until they approach a limiting value which approaches the energy eigen value of that N of the free hydrogen atom. While as S decreases, the ground state energy eigen values increases up until it approaches zero at a minimum value of S that is called the critical cage radius (Sc ) at which the total energy of the confined hydrogen atom equals zero. The critical values Sc are calculated for dimensions from (2-10), whose values are 0.722890, 1.835247, 3.296830, 5.088308, 7.200250, 9.617367, 12.35000, 15.36350, 18.68200 respectively, (all the values here are multiples of Bohr radius (α0)=0.529x10-10 meters It is shown here that Sc increases as N increases. It is also shown that for a given S, the energy eigen-values for l=0 depend on the dimensionality of space N, that is, as N increases, the ground state energy eigen-values increase. The dependence of bound states of a confined H-atom, for a given S, as a function of N is investigated, and it is found that it decreases as N increases, while if we choose a larger value of S, the number of the bound states increases for each value of N. We found it interesting to compare the energy eigen-values of a confined hydrogen atom in a spherical cavity of a certain radius, with those energies of the corresponding energy eigen-states of a free hydrogen atom in the same dimension N. We found that the effect of confinement becomes more profound for larger N. Finally, I considered the behavior of pressure on the cavity as the radius S is varied. It has been shown that the pressure exerted on the atom increases as S decreases up to a certain maximum value which occurs at a radius value called Sp max max, but then it decreases within a small range of S.
  • Thumbnail Image
    Item
    Critical Behavior of Refractive Index of Binary Mixture Cyclohexane - Phenol
    (2015) Heba Yousef Bsharat; Prof. Issam Rashid Abdelraziq; Dr. Mohammed Abu-Jafar
    The dynamic shear viscosity of binary mixture of cyclohexane - phenol was measured over the temperatures range (14.0 °C – 21.0 °C) and at concentration range (0.00% – 39.70%) by weight of phenol. The results above the critical temperature and critical concentration were analyzed by the mode coupling theory of one phase. The anomaly of the dynamic shear viscosity was detected as a function of temperature and concentration. Dynamic shear viscosity anomaly was clearly observed near the critical temperature Tc = 17.0 ℃ and the critical concentration χc = 2.70% by weight of phenol. The behavior of refractive index of cyclohexane - phenol obeys power law universality above the phase transition. The value of noncritical part of refractive index was found to be n_0D = 1.4276. The universal critical exponent for refractive index χ_n is also calculated to be 0.00156. The critical isobaric specific heat for the critical binary mixture c_pc was found to be 106.6 J/Kg.K using two scale factor universality. Joule`s constant for cyclohexane - phenol binary mixture was found to be 4.15 Calorie/J.
  • Thumbnail Image
    Item
    Critical Behavior of the Density of Binary Liquid Mixture Cyclohexane – Phenol
    (2015) Ghadeer Nafez Hussien; Prof. Issam Rashid Abdelraziq; Dr. Iyad Saadeddin
    The dynamic shear viscosity coefficients of the binary liquid mixture cyclohexane-phenol for different phenol concentrations and temperatures are measured using glass capillary viscometer. Dynamic shear viscosity anomaly is observed near the critical temperature T_c =17.0℃ and the critical concentration of phenol x_c=2.70% by weight. Mode Coupling Theory is used to fit our experimental data above the critical temperature. It is found that the value of noncritical part of the dynamic shear viscosity η_0 = 0.8174 cP. The power law is expected for the mass density above critical temperature. The value of noncritical part of the mass density is found to be ρ_0= 0.7357 gm/cm^3 . The critical isobaric thermal expansion coefficient α_pc was calculated to be 1.66×〖10〗^(-6) ℃^(-1). The critical isobaric specific heat 〖 c〗_pc was found to be 106.6 Joule/(kg .K). Joule`s constant J was found to be 4.1180 Calorie/Joule and pressure derivation of the critical temperature 〖T_c〗^' was also calculated to be 1.22×〖10〗^(-4) ( K)/ Pa.
  • Thumbnail Image
    Item
    Critical Behavior of the Electrical Conductivity for the Binary Mixture of Water and Phenol
    (2015) Hiba Zahra; Prof. Issam Rashid Abdelraziq; Dr. Iyad Saadeddin
    The dynamic viscosity was measured for water-phenol binary mixture at several concentrations and temperatures to determine the critical concentration and critical temperature. The critical concentration was determined at XC = 33.90% by weight of phenol, the critical temperature was TC = 67.0oC determined from the viscosity measurements. The electrical conductivity measurements showed that TC = 67.8oC at XC = 33.90% by weight of phenol. The electrical conductivity measurements for various concentrations (0.00%, 10.17%, 20.80% and 50.00%) by weight of phenol were fitted by using Arhenius equation. The activation energy and the electrical conductivity at infinite temperature were calculated for several concentrations. The electrical conductivity as a function of temperature was fitted by using power law above the critical temperature and critical concentration. The noncritical part of the measured electrical was found to be 30.26µS/cm and the critical exponent value was 0.032. The molar electrical conductivity was calculated and plotted by using Walden rule. The slope of Walden plot was found to be 0.9439. The water – phenol mixture is classified as a poor ionic mixture.
  • Thumbnail Image
    Item
    Critical Behavior of the Ultrasonic Attenuation for the Binary Mixture of Water and Phenol
    (2015) Maryam Reehan; Prof. Issam Rashid Abdelraziq; Dr. Mohammad Abu-Jafar
    The dynamic shear viscosity of the binary liquid mixture water – phenol was measured for different temperatures and concentrations using the glass capillary and digital viscometers. Dynamic shear viscosity anomaly was detected near the critical temperature T_(c )= 67 °C and the critical concentration x_c= 33.9% by weight of phenol. The specific heat at constant pressure was calculated using the two scale factor universality and found to be 241.9 J/(kg K) . The critical and the background isobaric thermal expansion coefficients were determined and found to be 2.729 x10-3 °Cˉ¹ and 22.59 x10-3 °Cˉ¹ respectively. Ultrasonic attenuation data at 9, 15, 30 and 35 MHz were analyzed using the dynamic scaling theory of Ferrell and Bhattacharjee. The values of α_c/f^2 versus f^(ˉ¹˙⁰⁶) yields a straight line as predicted by the theory. The experimental values of α(x_c,T)/(α_c (x_c,T_c)) for water – phenol were compared to the scaling function F(ω*') and showed good agreement with the theory.
  • Thumbnail Image
    Item
    Debye Momentum Cutoff of the Critical Binary Mixture of Carbon Tetrachloride and Coconut Oil
    (2014) Yusur Hisham Kittany; Prof. Issam Rashid Abdelraziq
    The dynamic shear viscosity coefficients of the binary liquid mixture carbon tetrachloride and coconut oil for different temperatures and concentrations are measured using digital viscometer with UL adapter. Shear viscosity anomaly is clearly observed near the critical temperature Tc = 22.2 ℃ and the critical concentration xc = 0.732 by weight of carbon tetrachloride. Debye parameter L (the intermolecular force range) was calculated using a Light scattering formula to be L = 5.5 Å. Mode Coupling Theory (MCT) of the dynamic shear viscosity is used to fit our experimental data above the critical temperature in the range 0.05 ≤ T-Tc ≤ 8 ℃. It is found that the noncritical part of the dynamic shear viscosity (background viscosity) η0 = 2.59 cP and the Debye momentum cutoff (the upper cutoff wave number) qD = 0.126 Å-1. The MCT universal constant A is measured to be A = 0.054 which is consistent with the theoretical value. The correlation coefficient (R2) value is 0.85, which shows that there is a good fitting.
  • Thumbnail Image
    Item
    Determination of Some Metallic Elements and their Effect on Physical Properties of Edible Olive Oil in Palestine
    (2015) Estiklal Basem Fuqha; Prof. Issam Rashid Abdelraziq; Dr. Mohammed Abu- Jafar
    The physical properties such as: density, refractive index, viscosity, and acidity of samples of olive oil from different geographical locations and heights in Palestine were measured. The measured physical properties are in agreement with the international and local assigned value. The concentration of Al, Cd, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn elements in olive oil samples are measured by inductively coupled plasma mass spectrometry ICP-MS. It was found that Magnesium (Mg) is the most concentrated metal detected (294.7-783.0μg/g), followed by concentration of sodium (Na) (73.4-390.7μg/g) and potassium (K) (23.1 -168.9μg/g). Concentrations of iron, copper and lead in Palestinian olive oil don’t agree with concentration of International Olive Council (IOC). The differences in concentration in metals of olive oil depend on several factors among the type of olive tree, storage age, height and geographical location. There is a positive relation between the concentration of metals in olive oil and physical properties as density, refractive index, viscosity, and acidity. The daily intake rate of these metals shows no risk to human health according to US Environmental Protection Agency (EPA) report.
  • Thumbnail Image
    Item
    Development of Efficient Photovoltaic Solar Cells’ Various Models
    (Aya Mahmoud Abu Baker, 2019-03-21) Abu Baker, Aya
    This thesis deals with three different types of photovoltaic (PV) cells namely monocrystalline silicon and polycrystalline silicon and organic PV cells. We studied four models of PV cells equivalent circuits for each of mono- and polycrystalline silicon cells by QUCS software. The input parameters were extracted from the datasheet of the cells. The main goal of this research is to conclude the most efficient model of DC PV cells that gives the highest maximum power point. This work also deals with the main factors affecting the behavior of the PV cell: the cell temperature and solar irradiance. I-V characteristic curves will be drawn properly under the variation of temperature and irradiance. Depending on varying the models of PV cells, cell temperature and irradiance we saw how efficiency and different parameters of the cell will be varied. This thesis opens up a new field which is the organic solar cells devices or third generation of PV cells devices. The electrical simulation of an organic bulk heterojunction (BHJ) PV cell based on P3HT:PCBM as an active layer was done using GPVDM software under STC. The conversion efficiency of organic BHJ cells is studied under changing the thickness of the active layer. Furthermore, the current density-voltage characteristics were obtained under changing series resistance value. The simulation results confirmed, as expected, that monocrystalline silicon solar cells are more efficient than polycrystalline silicon solar cells but polycrystalline solar cells have higher quality than monocrystalline solar cells. It was concluded also that the non-crystalline solar cells are not as efficient as the crystalline ones but they are cheaper.
  • Thumbnail Image
    Item
    An Educational Biogas Project in Tulkarem
    (2003) Ayoub Mohamed Eshraideh; Dr. Muneer Abdoh; Dr. Abdellatif Mohamed
    The construction and production of biomass digesters has become very important in recent years due to their wide advantages. A systematic study of different properties of the biogas and its amount provides us with a great deal of information about digesters. Thus the appropriate nature and type of digesters are suitable for different areas in Palestine. The experiment described in this work was carried out in Tulkami city in the northern part of Palestine. The floating drum type of digesters was used in this work. When the addition rate of slurry added on daily basis was 50 liters/day, the amount of biogas produced is 0.685 m³, the average pH is 7.91 and the average ambient air temperature is 34.055°C while for the 100 liters/day rate, the amount of biogas produced was 1.610 m m³ the average pH is 7.96, and the average ambient air temperature is 34.29°C. In both cases the slurry temperature was 27°C. Therefore, the possibility of making use of biogas as a source of energy in Palestine is promising and building more biogas digesters in Palestine is recommended.