Optical spectroscopy studies of ion bombarded gallium arsenide and vanadium carbide thin films

Abstract This thesis gives a report on two projects involving the use of the optical techniques of surface Brillouin scattering and Raman spectroscopy to study thin layered materials. In the first case, the thin layered material is formed from ion bombardment of a semiconductor which results in an amorphous layer on a single crystal substrate. The second case involved the study of the elastic properties of vanadium carbide deposited by RF magnetron sputtering on silicon carbide and silicon substrates. There have been a number of reports on the recrystallization of ion implanted GaAs in which it has been noted that it is not a single step process as observed in Ge and Si. These studies have used ion channelling and Raman spectroscopy techniques to establish that the nature of the damaged gallium arsenide layer depends on the implantation conditions such as substrate temperature, implantation ion energy, and fluence. In the present work, the investigation of the recrystallization of ion implanted GaAs using the two optical spectroscopic techniques of surface Brillouin scattering (SBS) and Raman spectroscopy has been carried out for the first time. Single crystals of (100) gallium arsenide were implanted with 100 keV argon ions at liquid nitrogen temperature using ion fluences of 2 × 1014 ions/cm2 and 1 × 1015 ions/cm2 on samples denoted A and B respectively. Additionally, sample C was also implanted with 100 keV argon ions but at an elevated temperature of 50 oC. Raman spectroscopy and SBS measurements are in good agreement for samples A and B showing recrystallization below 300 oC in both cases. Raman measurements on sample A, implanted at the lowest fluence, showed that before annealing was carried out a completely amorphous layer was not achieved. In the early stages of isochronal annealing on both samples A and B, the transverse optical peak is observed to have higher intensity compared to the longitudinal optical peak. At higher annealing temperatures, the longitudinal peak attains higher intensity. Changes in the Rayleigh surface acoustic wave frequency from SBS measurements on Sample C during isochronal annealing are observed from 100 oC and saturation is obtained at about 450 oC. The Raman results show that recrystallization commences above 450 oC and saturates at about 600 oC implying complete recrystallization of the overlayer. Vanadium carbide is a refractory material known for its high hardness, corrosion resistance, high melting point, and high electrical conductivity. There have been a number of studies on the properties of vanadium carbides of different compositions and structures but to the best of the author’s knowledge, there has never been a study on the elastic properties of the thin deposited films. Thin films of vanadium carbide have been grown using RF magnetron sputtering with varying thicknesses on SiC and Si substrates. Different deposition times were used in order to have films with varying thicknesses. X-ray reflectometry, X-ray diffraction, Rutherford backscattering, and atomic force microscopy, have been used to determine the film characteristics such as thickness, roughness, density, and stoichiometry. Surface Brillouin scattering was then carried out. The SBS results were used together with a least squares fitting approach to determine the elastic constants of the VC films computationally. A Green’s function approach was used to verify the results of the fitting procedure.EM201

HUBUNGAN ANTARA HARGA DENGAN KEPUTUSAN PEMBELIAN AIR MINERAL AQUA PADA MAHASISWA PROGRAM STUDI PENDIDIKAN TATA NIAGA DI UNIVERSITAS NEGERI JAKARTA

TENGKU TIARA MUSTIQA. The Correlation Between price With Purchase Decision Mineral Water Aqua In The Commerce Education Student At Universitas Negeri Jakata. Commerce Education Studies Program, Department of Economics and Administration, Faculty of Economics, Universitas Negeri Jakarta. This research was conducted The Commerce Education Student At Universitas Negeri Jakata, for seven months, starting from October 2015 to May 2016. The purpose of this study is to determine correlation between Price With Purchase Decision Mineral Water Aqua In The Commerce Education Student At Universitas Negeri Jakata. The research method used is survey method with the correlational approach, population used are all The Commerce Education Student At Universitas Negeri Jakata which bought Mineral Water Aqua on three month ago. Sample data for this research.is 90 students and then according to the sampling table from Isaac and Michael, sample total from population with sampling error 5% is 72 students. The sampling technique used technique of purposive sampling. The resulting regression equation is Ŷ = 47.76 + 0.58X. Test requirements analysis that estimates the error normality test regression of Y on X with test Liliefors produce Lcount = 0.1044, while Ltable for n = 72 at 0.05 significant level is 0.1012. Because Lcount Ftable which, 92.10 ttable , tcount = 9.597 and ttable = 1.67 .It can conclude that the correlation coefficient (rxy) = 0.754 is significant. The coefficient of determination obtain for is 56.82% which show that 56.82% of the variant of Purchase Decision is determined by price

Evaluation of The Training Team Development Program DKI Jakarta Men's Rugby at Pon XX Papua 2021

This study aims to evaluate the context, input, process and product components in  the DKI Jakarta men's Rugby Training Team coaching program in 2021. Evaluation research with the CIPP model uses qualitative methods. The subjects of this study are the coaching components of Achievements, Athletes, and Coaches. The results show that the context evaluation in the DKI Jakarta Rugby Training Program is included in the very good category (100%).  In the input component, it is stated that it is very good 100% visible from, All athletes' conditions have been met, namely, Meeting the age criteria of 18+, Physical and spiritual health meeting body posture qualifications (anthropometric), Meeting the criteria for Rugby cabor skills, Meeting physical capacity standards, Meeting psychological criteria, Meeting health criteria. Have dormitory / TC equipment, Training equipment, Sparring equipment. In the Process component, decision making is very good (100%), the supervision process is also very good (100%), but the monintoring process is included in the less category (50%). In the Product component, the results of the men's team coaching program for the Dki Jakata Men's Rugby Rugby Team at PON XX Papua 2021 won a silver medal but did not match the targets and expectations that had been made for the Dki Jakata Men's Rugby Team coaching program at PON XX Papua 2021. Based on the things mentioned above, the results of the men's team coaching program of the Dki Jakata Men's Rugby Team coaching at PON XX Papua 2021 are included in the category of very less (0%). Based on the results of the evaluation component research above, the coaching program of the Dki Jakata Men's Rugby Team at PON XX Papua 2021 as a whole obtained a value of 70.83%. So it can be concluded that the coaching program of the Dki Jakata Men's Rugby Team at PON XX Papua 2021 is considered good.&nbsp

Fitting Statistical Parent Distributions to Quantify Financial Risk in the South African Financial Index (J580)

The purpose of this study is to investigate and describe the riskiness of an investment in the South African Financial Index (J580) using four relatively heavy tailed statistical parent distributions, viz: the Exponential, Weibull, Gamma and Burr distributions. The statistical distributions describe the Index returns, and quantify the riskiness of the monthly South African Financial Index (J580) for the period 1995-2018. The Maximum Likelihood Estimation (MLE) method is used to estimate the distribution parameters. The heavier-tailed Burr distribution in the heavy tailed Frétchet domain distribution is the best fitting statistical parent distribution for losses as evidenced by the AIC, BIC and other graphical measures of goodness of fit. The lighter tailed Exponential distribution is the best fitting statistical parent distribution for the positive returns (gains). The Exponential distribution is in the light tailed Gumbel domain distribution. Summary measures of financial risk, such as the Value at Risk (VaR) and Expected Shortfall (ES) are calculated using the two best fitting distributions. Financial risk (VaR and ES) quantification and risk mitigation is topical in light of the failure of the Normal distribution-based risk models, which under estimated risk in leading up to the Global Financial Crisis (GFC) of 2008-2009. The practical implications are that the Normal distribution-based risk measures ought to be replaced with other statistical parent distributions and even extreme value distributions (EVD) in order to accurately estimate financial risk. Given the limited empirical investigations on the South Africa Financial Index (J580), the results from this research provide additional and valuable information for both investors and practitioners on how to accurately estimate and assess financial risk. The study extends the empirical literature on more accurate financial risk assessment, more specifically in the context of the Financial Index in South Africa

Quantifying Diversification Effects of A Portfolio Using the Generalised Extreme Value Distribution- Archimedean Gumbel Copula Model

This paper uses the Generalized Extreme Value Distribution - Archimedean Gumbel copula modelling approach to quantify diversification effects in a bivariate portfolio of financial asset returns. This paper estimates Value at Risk (VaR) and Expected Shortfall (ES) of a portfolio consisting of the South African Industrial and Financial Indices using Monte-Carlo simulation. Results show that the portfolio risks are smaller than the sum of the individual component risks, indicating diversification benefits for investors. This approach is valuable for assessing, preparing, and mitigating risks in investment decisions, particularly for international investors considering cross-market diversification

Spatial dispersion in phonon focusing

The ballistic phonon flux emanating from a point–like heat source in a crystal shows strong directional dependence. This effect is called phonon focusing and is measured using a technique called phonon imaging. In situations where long wavelength phonons are involved, the observations can be explained on the basis of classical continuum elasticity theory. Dispersion i.e. the variation of velocity with wavelength, sets in when the phonon wavelengths become comparable to the natural scale of length of the material, the lattice constant. This has a significant effect in the phonon focusing pattern and causes shorter wavelength phonons to lag behind longer wavelength ones and the dispersion relation i.e. the relation between angular frequency ω and wave number k becomes non-linear. A number of studies have used lattice dynamics models to explain the observed dispersive phonon images. Measured phonon images are not entirely satisfactorily reproduced by any of these lattice dynamics models and the different models tend to predict somewhat different focusing patterns. In this thesis, we set out to explain the observed dispersive phonon focusing patterns of cubic crystals by using a modification of continuum elasticity theory. This is done by including third and fourth order spatial derivatives of the displacement field in the wave equation. The coefficients of these higher order terms are the dispersive elastic constants. They are determined through optimized fitting to frequency versus wave vector data extracted from neutron scattering experiments for the acoustic modes in symmetry directions of a number of cubic crystals. Our approach is limited to the first onset of spatial dispersion and does not apply to near Brillouin zone boundary phonons. It is also applicable to crystals of any symmetry but in this thesis we focus on crystals of cubic symmetry. We report results on two crystals with a centre of inversion, Ge and Si, and two crystals without a centre of inversion, InSb and GaAs

PENGARUH KUALITAS PELAYANAN TERHADAP KEPUASAN NASABAH PADA PT. BANK MANDIRI (PERSERO) CABANG RSCM JAKARTA

Hasil penelitian menunjukkan terdapat pengaruh yang positif dan signifikan kualitas pelayanan terhadap kepuasan nasabah pada PT. Bank Mandiri Tbk (Persero) Cabang RSCM Jakarta. Hal ini dapat dibuktikan dari persamaan regresi linier sederhana yang didapat Y = 20,375+0,442X, Artinya nilai (a) atau konstanta sebesar 20,375 nilai ini menunjukan bahwa pada saat kualitas pelayanan (X) bernilai nol atau tidak meningkat, maka kepuasan nasabah (Y) akan tetap bernilai 20,375 koefisien regresi nilai (b) sebesar 0,442 (positif) yaitu menunjukkan pengaruh yang searah artinya setiap kenaikan kualitas pelayanan sebesar satu satuan maka akan meningkatkan kepuasan nasabah sebesar 0,442 satuan. Nilai koefisien korelasi sebesar 0,502 artinya hubungan kualitas pelayanan terhadap kepuasan nasabah pada PT. Bank Mandiri cabang RSCM Jakarta memiliki tingkat hubungan yang sedang atau cukup kuat, nilai koefisien determiasi sebesar 0,252 yang artinya bahwa kualitas pelayanan (X) memberikan kontribusi terhadap variabel kepuasan nasabah (Y) sebesar 25,2%, sedangkan sisanya sebesar 74,8% di pengaruhi oleh variabel lain yang tidak diteliti dalam penelitian ini. Nilai thitung sebesar 5,743 > ttabel 1,984 dengan Sig 0,00 ttabel, maka H0 ditolak dan Ha diterima, artinya terdapat pengaruh yang positif dan signifikan kualitas pelayanan terhadap kepuasan nasabah pada PT Bank Mandiri Cabang RSCM Jakata

PENGARUH KECERDASAN ADVERSITAS DAN EFEKTIVITAS PEMANFAATAN PERPUSTAKAAN SEKOLAH TERHADAP HASIL BELAJAR EKONOMI PADA SISWA SMA N 4 JAKARTA

ABSTRACT ELLIA HUMAIROH. The Influence of Adversity Quotient and Effectivity Utilization Of School Library to Learning Outcome of Economics on Students of 4 Senior High School Jakarta. Concentration of Cooperative Economics Education, Study Program of Economics Education, Department of Economics and Administration, Faculty of Economics, State University of Jakarta, 2016. This research aims to determine influence adversity quotient and effectivity utilization of school library on learning outcome to learning outcome of economics on students on 4 Senior High School Jakata.The research used ex post facto method with correlational approach.The observation in students of 4 Senior High School use census technique. Data recoding, interview and questionaire are data collection technique. This research used the classic assumption, multiple regression, and hypothesis test. Based on the results showed positive effect of adversity quotient on learning outcome of economic, positive effect of effectivity utilization of school libray on learning outcome of economics, and positive effect of adversity quotient and effectivity utilization of school library to learning outcome of economics. Simultaneously, the strength of the relation between the variable of adversity quotient, effectivity utilization of school library and learning outcome of economics was strong. Keywords: adversity quotient, effectivity utilization of school library, learning outcom

Economic sanctions as a means to enforce human rights in Burma (Myanmar) : a thesis presented in partial fulfillment of the requirement for the degree of Master of Philosophy in Development Studies

Since the end of the Cold War, human rights has become a central focus of international relationships, especially the relationship between developed countries (the West) and developing countries (the Rest). Burma is one of the developing countries whose relationship with Western governments is premised on the issue of human rights. In the pursuit of human rights enforcement, the United States and the European Union employ economic sanctions against Burma. While economic sanctions are designed to encourage a transition to democratic rule and a greater respect for human rights, studies show that little attention has been paid to the effectiveness of such measurements. In this study, a literature review and field research are carried out as an effort to assess the effectiveness of economic sanctions in Burma