Characterization of aluminum nitride thin films by ion beam analysis techniques.

AlN thin films have been deposited on silicon substrate by vacuum arc discharge technique at different substrate temperatures. The information regarding depth profiling of AlN thin films has been determined by applying both elastic backscattering (EBS) and nuclear reaction analysis (NRA) techniques simultaneously at optimized experimental conditions. Additionally, combined SEM/EDX techniques have been employed to gain further information regarding thickness and composition of the AlN thin films. The Al/N ratio has been determined, while the oxygen content was found to be negligible. The substrate temperature influence on depth profile of AlN thin films as well as densities has been discussed. The advantages of using ion beam analysis techniques have been reviewed.

Elemental characterization of freeze dried domestic animals' milk using ion beam analysis techniques.

Particle induced X-ray emission (PIXE) and particle induced γ-ray emission (PIGE) techniques were employed to perform elemental analysis in four milk samples of local domestic animals, namely sheep, caw, camel and goat. Additionally, Rutherford backscattering (RBS) spectra were acquired simultaneously with PIXE and PIGE to determine matrix elements. Milk samples were prepared in a simple dried base following freeze drying process. Optimization of PIXE/PIGE/RBS experimental conditions as well as data acquisition and analysis procedures were carefully addressed. Verification study was performed relying on the analysis of both IAEA-11 and IAEA-153 reference materials. Accuracies of ±5-10% together with relative standard deviations of less than 15% were mostly reported. Chemical element concentrations of 11 elements were determined, namely Na, Mg, P, S, Cl, K, Ca, Zn, Br, Rb and Sr. Obtained element concentration values were mostly in the range 1000-10000 µg/g for major elements and 5-100 µg/g for trace elements. No significant changes in elemental concentration differences for both trace and major elements were noticed in the four different milk samples. The contribution of the elements in these milk samples to the dietary recommended intakes (DRI) has been evaluated. Advantages of applying multiple ion beam analysis techniques have been discussed.

Software for standard-based analysis of thick target PIGE data.

Software, "SyrPIGE", has been developed to perform particle induced γ-ray emission (PIGE) data analysis of thick targets relying on a standard-based method. It allows self-consistent and direct analysis of PIGE data considering easy calibration of PIGE spectra, on-screen identification of every γ-ray line, manual input or evaluation of E12 values for every element at established γ-ray energies, direct generation of stopping power data based on built-in electronic stopping power calculations for protons, ability to compare results with standards and batch mode analysis capability. The software was tested on standards and showed reliable and consistent results, with PIGE data analysis performed in a very short time compared with time-consuming traditional analysis.

Utilization of Si wafers as a supporting material for in-vacuum PIXE analysis of aqueous solutions.

The use of high pure industrial crystalline Si wafers as backing materials for PIXE elemental analysis of aqueous liquid samples has been investigated. It can potentially be applied as supporting material of liquid samples owing to its advantages being available at high purity, resistant to ion beam heating effects, unaffected by chemicals, surface easily cleanable, semi-conductor that inhibits local ion beam charging effects, durable, relatively cheap and easily prepared for liquid sample deposition. Sample preparation procedure, deposition homogeneity aspects, experimental conditions and ion beam parameters optimization have been discussed. Comprehensive verification study to perform direct PIXE measurements on reference aqueous liquid sample containing 27 elements, micropipetted on Si wafers has been implemented. A combination of minimum sample preparation procedures and specific experimental conditions applied enables simple and accurate elemental analysis. Elemental concentrations, at about 5-15% absolute accuracy and uncertainties less than 15% for most elements detected, sensitivity curves and detection limits have been determined. Advantages and limitations of using Si wafers in this investigation have been discussed. Comprehensive literature comparison with other backing materials has been reviewed.

Investigation of chloramphenicol release from PVA/CMC/HEA hydrogel using ion beam analysis, UV and FTIR techniques.

PVA/CMC/HEA based cross-linked hydrogels were synthesized. These were utilized as matrix chloramphenicol drug releasing systems. Combination of different analytical techniques was applied to understand drug releasing process. Ion beam analysis (IBA) measurements, namely micro-PIXE analysis, were applied to gain information regarding spatial distribution of chloramphenicol within the system. Independent complement measurements utilizing UV and pore volume measurements were also employed to additionally characterize and verify the experimental findings obtained by IBA techniques. FTIR was utilized to both characterize and justify the releasing behavior of the crosslinked systems. Comprehensive literature comparison between different analytical methods has been reviewed.

Characterization and application of in-vacuum PIXE/EBS system for the direct elemental analysis of thick solid biological samples.

Utilization of combined particle-induced X-ray emission (PIXE) and elastic backscattering (EBS) spectrometry for the direct elemental analysis of thick solid biological samples was thoroughly discussed. Powdered samples pressed as pellets were directly analyzed. Combination of applying low ion beam currents, random scanning of the sample across the beam during data acquisition, and using special sample holder enabled effective minimization of local ion beam heating. This subsequently inhibited potential element loss during ion beam irradiation. Matrix elements were determined from multiple EBS spectra, which were acquired using three different ion beam energies. Subsequently, averaging of the elemental concentrations obtained was achieved using novel MultiSIMNRA software. Moreover, combined EBS spectrometry, nuclear reaction analysis (NRA), and elastic recoil detection analysis (ERDA) measurements were used to overcome the limitations of using EBS separately and subsequently obtain accurate matrix element concentrations. The validity of the PIXE/EBS system for the direct elemental analysis of thick biological samples was comprehensively evaluated. The obtained concentration values demonstrated reliable results for most investigated elements (5-15%), starting from sodium onwards. The non-satisfying results were evaluated and justified.

Setting up of in-vacuum PIXE system for direct elemental analysis of thick solid environmental samples.

Experimental set-up, development, characterization, and calibration of an in-vacuum PIXE system at the tandem accelerator facility of the Atomic Energy Commission of Syria (AECS) is described. The PIXE system calibration involved experimental characterization of the X-ray detector parameters and careful determination of the H-values that control dependence of the detector solid angle with the X-ray energies and correct imperfect values of the detector efficiency. Setting up of an electron flood gun to compensate charge built up and utilization of a beam profile monitor to perform indirect measurement of the beam charge, provide a direct PIXE measurement of thick insulating samples in-vacuum. The PIXE system has been subsequently examined to verify its ability to perform direct PIXE measurements on geological materials. A combination of minimum sample preparation procedures and specific experimental conditions applied enables simple and accurate elemental analysis. Elemental concentrations of several elements heavier than sodium in different reference geological samples, at about 5-10% absolute accuracy for most elements, have been determined. Comprehensive discussion of the obtained elemental concentration values, for most elements of visible X-ray peaks in the PIXE spectra, has been considered.

PIXE and GC-MS investigation for the determination of the chemical composition of Syrian Cuminum cyminum L.

The chemical composition and concentration of Syrian cumin (Cuminum cyminum L.) were investigated. The particle-induced X-ray emission (PIXE) analytical technique was used to analyze a wide range of elements from Mg to Sr. The advantages and disadvantages of the PIXE technique in plant material elemental analysis are discussed. A high level of iron was detected in the cumin samples, clarifying the possible contribution of cumin to maintaining the immune system. The contribution of the elements in cumin seeds to the dietary recommended intakes (DRI) of elements was evaluated. Additionally, GC-MS measurements were performed to determine the chemical composition of cumin essential oil. Twenty-one components were identified, and cuminaldehyde, γ-terpinene, o-cymene, limonene and ß-pinene were determined to be the major constituents. A correlation between the chemical composition of cumin seeds and their use as a traditional remedy is proposed.