Indoor Radon Concentration Measurements At Hebron University Campus :A Case Study

Indoor Radon Concentration Measurements At Hebron University Campus :A Case Study

Fakhri I. Hasan

Associate Professor, Physics Department, Hebron University, Hebron

Received : 00-00-0000 , Accepted : 00-00-0000

Language: English

Abstract

TASTRAK, a solid state nuclear track detector has been used to measure indoor radon concentrations at Hebron University. Fifty- four radon pot detectors were mounted in the four university buildings. It was found that the radon concentrations vary considerably from about 1 Bq/m 3 to 250 Bq/m3 The average radon concentrations vary from 20.5 Bq/m3 in the Main Building to 41.3 Bq/m3 in the Agriculture Building. The average radon concentration in the four buildings is found to be 29.8 Bq/m 3. This leads to an average effective dose equivalent of 1.49 mSvly. This dose is slightly higher than the global value of 1.3 mSv/y. Elevated radon concentrations have been found in few rooms. However, these concentrations are well below the action level of 150 Bq/m3.

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Evaluation of the Stiffness Matrix of an Indeterminate Truss Using Minimization Techniques

Evaluation of the Stiffness Matrix of an Indeterminate Truss Using Minimization Techniques

Samir H. Helou

Assistant Professor, Civil Engineering, An-Najah National University, Nablus.

Received : 00-00-0000 , Accepted : 00-00-0000

Language: English

Abstract

For an existing reinforced concrete or steel structure the evaluation of the stiffness matrix may be hampered by certain physical limitations such as material deterioration resulting from prolonged use an adverse or in a corrosive environment. The following is a method that allows the determination of the member stiffness of an indeterminate truss through a minimization technique of a properly constructed Error Function. Thus exact sectional and material properties do not have to be known a priori.

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Cluster Catalysis of Olefin Hydrosilylation and Isomerization Thermal Reaction Using Co4(Co)10(PPh)2

Cluster Catalysis of Olefin Hydrosilylation and Isomerization Thermal Reaction Using Co4(Co)10(PPh)2

Waheed J. Jondi

Assistant Professor Dept. of Chem., An-Najah N. University, Nablus.

Received : 00-00-0000 , Accepted : 00-00-0000

Language: English

Abstract

The cobalt cluster [Co4(C0)10(PPh)2], 1/~, has been evaluated as a catalyst for 1-octene thermal hydrosilylation and isomerization reactions. The kinetics indicates that the hydrosilylation reaction occurs via cluster catalysis at temperatures ranging from 50-70°c. The 1 - octene isomerization was selective to trans-2-octene only. The kinetics indicates that at 50°c or lower isomerization reaction occurs via cluster catalysis whereas at 70°c or higher catalysis by lower nuclearity species is involved. The effects of solvent silane temperature and catalyst and reactant concentrations on the rates of hydrosilylation and isomerization reactions have been investigated. Plausible mechanisms based on experimental data have been proposed.

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Stoichiometry, Kinetics and Mechanism of Oxidation of L-Cysteine by Hexacyanoferrate (III) in Acidic Media

Stoichiometry, Kinetics and Mechanism of Oxidation of L-Cysteine by Hexacyanoferrate (III) in Acidic Media

Rajab Abu El-Hallow, Mohammad M. Al-Subu, Hani M. Abed, Waheed J. Jondi

1 Associate Prof. Dept. of Chemistry An Najah N. University, Nablus, 2 Associate Prof. Dept. of Chemistry An Najah N. University, Nablus, 3 Martyr 1992, 4 Assist. Prof. Dept. of Chemistry, An-Najah N. University. Nablus.

Received : 00-00-0000 , Accepted : 00-00-0000

Language: English

Abstract

The Stoichiometry, kinetics, and mechanism of oxidation of L-cysteine by hexacyanoferrate (III) in acidic media at constant ionic strength have been studied spectrophotometrically. A1:1 L-cysteine:hexacyanoferrate (III) has been established with 1..-cysteine as the only product. The reaction is zero order in hexacyanoferrate (III), first order in L-cysteine and inverse first in hydrogen ion concentration. The activation parameters were evaluated in the temperature range 15-40°C (Ea.# = 28.2 kJ/mol. ?S# = -192.4 J/mol. deg). The oxidation was inhibited in the presence of added hexacyanoferrate (II). The effects of other added salts and composition of the solvent have been rationalized. Two mechanisms are offered to explain the kinetic data.

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The Effects of Substrate Material, Quenching and Annealing on the Properties of High Temperature Superconductor BSCCO (Bi-2212) Thick Tapes

The Effects of Substrate Material, Quenching and Annealing on the Properties of High Temperature Superconductor BSCCO (Bi-2212) Thick Tapes

Abed Al-Kariem Saleh, Dived Haase

1 Associate professor, Al-Quds University, College of Science & Technology, Jerusalem, Abu Deis; 2 Physics Dept., North Carolina State Univ., Raleigh, NC, USA.

Received : 00-00-0000 , Accepted : 00-00-0000

Language: English

Abstract

The effects of substrate material and heat treatment conditions on the electrical and thermal properties for partially melt-solidified superconducting tapes BSCOO (2212), grown on single crystal MgO and Ag MgO substrates m were investigated. Results show that the resistivity of the normal state varies with the size and orientation of the grains. It is found that larger grains lower both the concentration of second phases and the grain boundaries, hence decreasing the resistivity of the normal state and enhancing the critical current density of the superconducting state. Also, the material of the substrate has no effect on either the resistivity or the critical current density of the Bi-2212 phase. Heat treatment conditions and the annealing atmosphere play an important role in determining the critical current density and the transition temperature. Slow cooling from 840°C lowers both the critical current and the transition temperature; while quenching the sample from 840°C to room temperature and annealing it in a nitrogen atmosphere increase both the critical current density and the transition temperature.

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On Composition Operators on A2

On Composition Operators on A2

Mahmud Ilayyan Masri

Department of Mathematics, An-Najah National University

Received : 00-00-0000 , Accepted : 00-00-0000

Language: English

Abstract

If (?) is an analytic function mapping the open unit disk D into itself and A2 is the Bergman space of analytic functions on D, the compositon operator C?, on A2 is defined by C?f=fo?feA2. In this paper we consider the spectral radius, unitary equivalence, sub-normality of C? and study the case ?(z) = zm, m = 2, 3,….. in detail.

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A Historical Review of the Land Tenure and Registration System in Palestine

A Historical Review of the Land Tenure and Registration System in Palestine

Najeh S. Tamim

Faculty of Engineering, An-Najah National University

Received : 00-00-0000 , Accepted : 00-00-0000

Language: English

Abstract

Due to its strategic location, Palestine has played a significant role in world politics. These politics, in turn, have been major influencing factors in the culture and history of Palestine. The land in Palestine has been, and still is, the central issue in the Palestinian - Israeli conflict; each claiming sovereignty over it. This paper will briefly outline the evolution of the land tenure and registration system in Palestine from the early days of Islam up to the present. A future methodology that may improve the current system will be proposed at the end of the paper.

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