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The thesis deals with the proposal, implementation and evaluation of test for fault condition indicators. Thesis focusing on earth fault indicators based on admittance principles. These indicators must be able to evaluate earth faults in compensated, compensated with auxiliary resistor, unearthed and high-resistance earthed networks. The proposed tests verify the current and voltage measurement errors in inputs including monitored characteristic variables such as conductance and susceptance. The proposed test are applied to a selected ample of the fault indicator. As part of the tests, the indicator is subjected to secondary test using the Omicron CMC256plus tester as well as test on fault records that have been converted to COMTRADE for this purpose. The last series of tests carried out uses the physical model of the medium voltage system, where the tested equipment is subjected to fault states in the compensated whit auxiliary resistor system and isolated system. Furthermore, part of the thesis is research of new methods of earth fault detection, including their principles and function description. Also included in the thesis is an overview of manufacturers of indicators, or protection, who are involved in the production of earth fault protection.

No description available.

Neste trabalho, foram caracterizados eletricamente capacitores MOS com alumina (Al2O3) e aluminato de háfnio (AlxHf1-xOy) como dielétricos de porta, além disso, estes filmes dielétricos foram caracterizados fisicamente. A alumina foi obtida da oxidação anódica de filmes de alumínio evaporados sobre p-Si (100) através de imersão em ácido nítrico por 4 ou 6 min, para diferentes etapas de limpeza finais do substrato: solução diluída de ácido fluorídrico (DHF) ou solução de peróxido sulfúrico (SPM). Análises de retroespalhamento de Rutherford (RBS), espectroscopia por dispersão em energia (EDS) e espectroscopia por dispersão de comprimento de onda (WDS) indicam a formação da alumina estequiométrica, sendo que a difração de raios-X (XRD), mostrou o caráter amorfo do dielétrico. Por intermédio de curvas capacitância x tensão (CV) foram obtidas a espessura equivalente ao óxido de silício (EOT2,8nm), a densidade de estados de interface (Dit1,4x1011ev-1cm-2) e a permissividade elétrica da alumina (high-k10,6). A admitância associada à corrente de fuga em capacitores MOS foi modelada através de emissão por Frenkel-Poole, tunelamento por Fowler-Nordheim e/ou corrente de fuga constante. Os aluminatos de háfnio (AlxHf1-xOy) foram obtidos sobre p-Si (100), através de deposição atômica por camadas (ALD) para diferentes proporções molares de háfnio (25, 50 ou 75%) e para diferentes tratamentos posteriores (1000ºC, 60s em N2 ou N2+O2 ou laser). A espessura e a rugosidade foram obtidas com a ajuda da técnica de reflectometria de raios-X (XRR). A proporção molar de háfnio adotada no processo de obtenção dos filmes foi confirmada através de análises RBS e WDS. Por XRD, foi verificado o caráter amorfo e a separação de fases nos aluminatos e, por espalhamento de raios-X em ângulo-rasante e pequena abertura (GISAXS), foram analisadas as novas fases formadas. Por fim, da análise CV, foram obtidos EOT9,54nm, resistência série (Rs68,3) e a permissividade elétrica para o aluminato de háfnio (high-k15,2). Finalmente, uma modelagem da admitância associada à corrente de fuga em função da frequência foi proposta para as estruturas MOS. / In this work, MOS capacitors were electrically characterized using alumina (Al2O3) and hafnium aluminate (AlxHf1-xOy) as gate dielectrics; also, the same dielectrics films were physically characterized. Anodic alumina was obtained from oxidation of evaporated aluminum films immersed in nitric acid for 4 or 6 min for different last step cleanings of the p-Si (100) substrates: diluted hydrofluoric acid (DHF) or sulfur peroxide mixture (SPM). Rutherford Backscattering (RBS), Energy Dispersive Spectroscopy (EDS) and Wavelength Dispersive Spectroscopy (WDS) have shown the formation of stoichiometric alumina and the dielectric amorphous structure was revealed by X-Ray Diffraction (XRD). From Capacitance x Voltage curves (CV), it was obtained the equivalent oxide thickness (EOT2.8nm), interface trap density (Dit1.4x1011ev-1cm-2) and Al2O3 dielectric constant (high-k10.6). The admittance that represents the leakage process was modeled according to Frenkel-Poole emission, Fowler-Nordheim tunneling and/or constant leakage admittance. Hafnium aluminates (AlxHf1-xOy) were obtained on (100) silicon wafer surfaces by Atomic Layer Deposition (ALD) for different hafnium molar ratios (25, 50 or 75%) and for different treatments (1000ºC, 60s in N2 or N2+O2 or laser). Thickness and roughness were extracted from X-Ray Reflectometry (XRR) spectra. The hafnium molar ratios used in ALD process were confirmed by RBS and WDS. XRD analysis was used to establish the amorphous structure and phase separation in the aluminates after thermal treatments and Grazing-Incidence Small-Angle X-Ray Scattering (GISAXS) was used to analyze the new phases formed. From CV analysis, it was extracted EOT9.54nm, series resistance (Rs68.3) and dielectric constant from hafnium aluminate (high-k15.2). Finally, the admittance that represents the leakage was modeled in function of the frequency for the MOS structures.

A técnica de Microbalança de Cristal de Quartzo (QCM) tem sido utilizada para a aplicação em biossensores. Esta técnica consiste no monitoramento da freqüência de oscilação do cristal de quartzo e a variação de freqüência está relacionada com a variação de massa na superfície do cristal por meio da equação de Sauerbrey. Porém, sabe-se que há discrepância entre a massa calculada pela equação de Sauerbrey e a massa real aderida na superfície do cristal de quartzo, sendo tal discrepância causada por fatores tais como a viscoelasticidade, o que é especialmente observado para macromoléculas e sistemas biológicos. Com a técnica de Admitância Eletroacústica (AE) é possível analisar a massa real devido à análise em separado dos parâmetros que compõem o circuito equivalente do cristal de quartzo e também inferir informações sobre a estrutura das monocamadas montadas sobre a superfície do cristal de quartzo. Neste trabalho foi utilizada técnica de AE para se potencializar e detalhar o estudo da formação de monocamadas automontadas e interações entre diferentes proteínas e carboidratos. Em muitos casos verificou-se que durante a formação de determinadas monocamadas, grande parte da variação de massa estava relacionada a interações fracas e não-específicas. Também durante a formação das monocamadas de tióis de cistamina, verificou-se que a estrutura da monocamada é extremamente dependente das concentrações iniciais de cistamina utilizadas para formar a monocamada. As interações entre proteínas e carboidratos foram realizadas após formação de multicamadas nas quais as proteínas eram imobilizadas para depois estudar-se, então, sua interação com carboidratos específicos. No caso da Jacalina, um tipo de lectina, observou-se interações bastante específicas com a fetuína e interações fracas com a alfa-lactose. A atividade da enzima GumH também foi testada com sucesso utilizando a técnica de AE. / The Quartz Crystal Microbalance (QCM) has been largely used for biosensor applications. This technique consists on monitoring quartz crystal oscillation frequency. The relationship of quartz crystal frequency variation with mass deposited on the crystal surface is described by Sauerbrey´s equation. However, the relationship is not directly inferred and discrepancy exists caused mainly by viscoelasticity features of mass adsorbed on the quartz crystal surface. The viscoelastic influence is very common to be observed especially for macro-molecules and biological systems. By using Electroacoustic Admittance (EA) technique it is possible to calculate and separate the real mass deposited over the quartz crystal from other contributions. Therefore, the EA was used to infer about self-assembly monolayer structure being deposited over the quartz crystal. In this work EA technique was used to study details of self-assembled monolayer formation and specific interactions between different proteins and carbohydrate molecules. It was observed that during monolayer formation the majority of mass variation was related to non-specific interactions. For instance, regarding cystamine monolayer formation it was observed that the monolayer structure is dependent on the cystamine concentrations in the liquid medium. The study of interactions between proteins and carbohydrates was conducted by means of multilayers approach in which the proteins are immobilized previously to study the interaction between its active sites and carbohydrates. In the specific case of Jacalin, a type of lectin, it was observed a large formation of specific bonding between this protein and alpha-lactose or fetuin. The GumH enzyme activity was also tested successfully by using of EA technique.

Neste trabalho, foram caracterizados eletricamente capacitores MOS com alumina (Al2O3) e aluminato de háfnio (AlxHf1-xOy) como dielétricos de porta, além disso, estes filmes dielétricos foram caracterizados fisicamente. A alumina foi obtida da oxidação anódica de filmes de alumínio evaporados sobre p-Si (100) através de imersão em ácido nítrico por 4 ou 6 min, para diferentes etapas de limpeza finais do substrato: solução diluída de ácido fluorídrico (DHF) ou solução de peróxido sulfúrico (SPM). Análises de retroespalhamento de Rutherford (RBS), espectroscopia por dispersão em energia (EDS) e espectroscopia por dispersão de comprimento de onda (WDS) indicam a formação da alumina estequiométrica, sendo que a difração de raios-X (XRD), mostrou o caráter amorfo do dielétrico. Por intermédio de curvas capacitância x tensão (CV) foram obtidas a espessura equivalente ao óxido de silício (EOT2,8nm), a densidade de estados de interface (Dit1,4x1011ev-1cm-2) e a permissividade elétrica da alumina (high-k10,6). A admitância associada à corrente de fuga em capacitores MOS foi modelada através de emissão por Frenkel-Poole, tunelamento por Fowler-Nordheim e/ou corrente de fuga constante. Os aluminatos de háfnio (AlxHf1-xOy) foram obtidos sobre p-Si (100), através de deposição atômica por camadas (ALD) para diferentes proporções molares de háfnio (25, 50 ou 75%) e para diferentes tratamentos posteriores (1000ºC, 60s em N2 ou N2+O2 ou laser). A espessura e a rugosidade foram obtidas com a ajuda da técnica de reflectometria de raios-X (XRR). A proporção molar de háfnio adotada no processo de obtenção dos filmes foi confirmada através de análises RBS e WDS. Por XRD, foi verificado o caráter amorfo e a separação de fases nos aluminatos e, por espalhamento de raios-X em ângulo-rasante e pequena abertura (GISAXS), foram analisadas as novas fases formadas. Por fim, da análise CV, foram obtidos EOT9,54nm, resistência série (Rs68,3) e a permissividade elétrica para o aluminato de háfnio (high-k15,2). Finalmente, uma modelagem da admitância associada à corrente de fuga em função da frequência foi proposta para as estruturas MOS. / In this work, MOS capacitors were electrically characterized using alumina (Al2O3) and hafnium aluminate (AlxHf1-xOy) as gate dielectrics; also, the same dielectrics films were physically characterized. Anodic alumina was obtained from oxidation of evaporated aluminum films immersed in nitric acid for 4 or 6 min for different last step cleanings of the p-Si (100) substrates: diluted hydrofluoric acid (DHF) or sulfur peroxide mixture (SPM). Rutherford Backscattering (RBS), Energy Dispersive Spectroscopy (EDS) and Wavelength Dispersive Spectroscopy (WDS) have shown the formation of stoichiometric alumina and the dielectric amorphous structure was revealed by X-Ray Diffraction (XRD). From Capacitance x Voltage curves (CV), it was obtained the equivalent oxide thickness (EOT2.8nm), interface trap density (Dit1.4x1011ev-1cm-2) and Al2O3 dielectric constant (high-k10.6). The admittance that represents the leakage process was modeled according to Frenkel-Poole emission, Fowler-Nordheim tunneling and/or constant leakage admittance. Hafnium aluminates (AlxHf1-xOy) were obtained on (100) silicon wafer surfaces by Atomic Layer Deposition (ALD) for different hafnium molar ratios (25, 50 or 75%) and for different treatments (1000ºC, 60s in N2 or N2+O2 or laser). Thickness and roughness were extracted from X-Ray Reflectometry (XRR) spectra. The hafnium molar ratios used in ALD process were confirmed by RBS and WDS. XRD analysis was used to establish the amorphous structure and phase separation in the aluminates after thermal treatments and Grazing-Incidence Small-Angle X-Ray Scattering (GISAXS) was used to analyze the new phases formed. From CV analysis, it was extracted EOT9.54nm, series resistance (Rs68.3) and dielectric constant from hafnium aluminate (high-k15.2). Finally, the admittance that represents the leakage was modeled in function of the frequency for the MOS structures.

Tympanometry and acoustic stapedial reflex (ASR) are routinely used in audiology clinics to assess the functional integrity of the eardrum and middle ear system in humans. Conventional tympanometry (which delivers a probe tone of 226 Hz into the ear canal and measures the mobility of the eardrum as the air pressure in the ear canal is varied) and acoustic reflex testing are effective in detecting middle ear pathologies in children and adults. However, the clinical application of these two tests to infants younger than 7 months has major limitations. In recent years, high frequency tympanometry (HFT) with a probe tone of 1000 Hz has been trialled successfully in young infants (< 7 months) and research on ASRs as they apply to this age group is continuing. Although preliminary HFT data for this population are emerging, there has been no detailed study that describes the effect of age on HFT and ASR results, no clear guideline on ways to interpret the HFT results, and no investigation to measure the feasibility and reliability of the ASR findings. For these reasons, systematic investigation into the use of HFT and ASR measures for evaluating the middle ear function of young infants is warranted. This thesis aimed to: (i) investigate the feasibility of obtaining HFT and ASR findings from newborn and 6-week-old infants, and study the characteristics of the immittance findings in these two age groups; (ii) investigate methods within HFT to measure the middle ear admittance of newborn babies; (iii) establish normative HFT data from healthy newborn babies using the new component compensation method; (iv) examine the test-retest reliability of the ASR test in healthy neonates; and (v) investigate the test-retest reliability of the ASR test in 6-week-old infants. The aims of the thesis were met through five studies. In study one (Chapter 2), a pilot study was conducted to examine the feasibility of performing HFT and ASR in 42 healthy infants and study the characteristics of the immittance findings obtained from these infants using a longitudinal study design. In this pilot study, all infants were tested at birth and then re-tested approximately 6 weeks after the first test. This study confirmed the feasibility of obtaining valid immittance findings from healthy young infants. Most importantly, the findings of this pilot study revealed that the mean values of the majority of HFT parameters and acoustic stapedial reflex threshold (ASRT) obtained at 6 weeks were significantly greater than those obtained at birth, indicating the need to have separate sets of normative data for both tests for newborn and 6-week-old infants. In study 2 (Chapter 3), three different methods to measure middle ear admittance (often described as peak compensated static admittance) in 36 healthy neonates were compared. The three methods were the traditional baseline compensation method (compensated for the susceptance component at 200 daPa pressure) and two new component compensated methods (compensated for both the susceptance and conductance components at 200 daPa and -400 daPa). The results showed that the mean middle ear admittances obtained by compensating for the two components of admittance at a pressure of 200 daPa (YCC200) and -400 daPa (YCC-400) were significantly greater than that using the traditional baseline compensation method (YBC). The higher mean admittance results obtained using the new component compensated methods suggests that the two new methods have the potential to better separate normal from abnormal admittance results. The test-retest reliability of YBC, YCC200 and YCC-400 was investigated, with the result that a lower test-retest reliability was obtained for YCC-400 than for the other two measures. It was, therefore, concluded that the component compensation method compensated at 200 daPa may serve as an alternative method for estimating middle ear admittance, especially in the context of assessing neonates using HFT. In study 3 (Chapter 4), normative data were gathered using the new component compensation method (compensated at 200 daPa) on a group of 157 healthy newborn babies. In addition to the component compensated static admittance (YCC), normative data showing the 90 % ranges for tympanometric peak pressure, admittance at 200 daPa, uncompensated peak admittance, and traditional baseline compensated static admittance (YBC) were established in this study. No gender effect was found on any of the tympanometric measures. In study 4 (Chapter 5), the use of ASR to evaluate middle ear function in neonates was studied. The feasibility of obtaining ipsilateral ASR from neonates by stimulating their ears with a 2 kHz tone and broadband noise (BBN) was demonstrated. ASRs were elicited from 91.3% of 219 full-term normal neonates, while the remaining 8.7% of neonates who had flat tympanograms and no transient evoked otoacoustic emissions did not exhibit ASRs. Good test-retest reliability was demonstrated in the ASRT obtained using both the 2 kHz and BBN stimulus; there was no significant difference between test and retest conditions and intra-correlation coefficients of 0.83 for the 2 kHz tone and 0.76 for the BBN stimulus. In the last study (Chapter 6), the test-retest reliability of ASRT obtained from 70 6-week-old infants was investigated. The methodology described in Chapter 5 was followed. No significant difference in ASRT between test and retest conditions was found for the 2 kHz tone (mean ASRT = 67.3 dB HL versus 67.1 dB HL) and BBN stimulus (mean ASRT = 80.9 dB HL versus 81.6 dB HL). Good test-retest reliability of ASRT with intra-correlation coefficients of 0.78 was found for both the 2 kHz tone and the BBN stimulus. In essence, through achieving the aforementioned aims, the current research program was able to enhance the minimal literature available concerning the use of HFT and ASR testing in young infants. Ultimately, the findings presented in this thesis will inform clinicians of the recent developments in HFT and ASR testing, and assist them in evaluating the middle ear function of young infants with accuracy and confidence.

A técnica de Microbalança de Cristal de Quartzo (QCM) tem sido utilizada para a aplicação em biossensores. Esta técnica consiste no monitoramento da freqüência de oscilação do cristal de quartzo e a variação de freqüência está relacionada com a variação de massa na superfície do cristal por meio da equação de Sauerbrey. Porém, sabe-se que há discrepância entre a massa calculada pela equação de Sauerbrey e a massa real aderida na superfície do cristal de quartzo, sendo tal discrepância causada por fatores tais como a viscoelasticidade, o que é especialmente observado para macromoléculas e sistemas biológicos. Com a técnica de Admitância Eletroacústica (AE) é possível analisar a massa real devido à análise em separado dos parâmetros que compõem o circuito equivalente do cristal de quartzo e também inferir informações sobre a estrutura das monocamadas montadas sobre a superfície do cristal de quartzo. Neste trabalho foi utilizada técnica de AE para se potencializar e detalhar o estudo da formação de monocamadas automontadas e interações entre diferentes proteínas e carboidratos. Em muitos casos verificou-se que durante a formação de determinadas monocamadas, grande parte da variação de massa estava relacionada a interações fracas e não-específicas. Também durante a formação das monocamadas de tióis de cistamina, verificou-se que a estrutura da monocamada é extremamente dependente das concentrações iniciais de cistamina utilizadas para formar a monocamada. As interações entre proteínas e carboidratos foram realizadas após formação de multicamadas nas quais as proteínas eram imobilizadas para depois estudar-se, então, sua interação com carboidratos específicos. No caso da Jacalina, um tipo de lectina, observou-se interações bastante específicas com a fetuína e interações fracas com a alfa-lactose. A atividade da enzima GumH também foi testada com sucesso utilizando a técnica de AE. / The Quartz Crystal Microbalance (QCM) has been largely used for biosensor applications. This technique consists on monitoring quartz crystal oscillation frequency. The relationship of quartz crystal frequency variation with mass deposited on the crystal surface is described by Sauerbrey´s equation. However, the relationship is not directly inferred and discrepancy exists caused mainly by viscoelasticity features of mass adsorbed on the quartz crystal surface. The viscoelastic influence is very common to be observed especially for macro-molecules and biological systems. By using Electroacoustic Admittance (EA) technique it is possible to calculate and separate the real mass deposited over the quartz crystal from other contributions. Therefore, the EA was used to infer about self-assembly monolayer structure being deposited over the quartz crystal. In this work EA technique was used to study details of self-assembled monolayer formation and specific interactions between different proteins and carbohydrate molecules. It was observed that during monolayer formation the majority of mass variation was related to non-specific interactions. For instance, regarding cystamine monolayer formation it was observed that the monolayer structure is dependent on the cystamine concentrations in the liquid medium. The study of interactions between proteins and carbohydrates was conducted by means of multilayers approach in which the proteins are immobilized previously to study the interaction between its active sites and carbohydrates. In the specific case of Jacalin, a type of lectin, it was observed a large formation of specific bonding between this protein and alpha-lactose or fetuin. The GumH enzyme activity was also tested successfully by using of EA technique.

Dalarna University aspires to improve the student admittance process as it strives to ensure efficient use of public funds. The aim of Dalarna University in the student admittance process is to admit candidates that are likely to be successful in their studies. There have been two selection procedures for the Business Intelligence and Data Science programmes: the default procedure, which selects from all eligible candidates randomly, and the motivation letter procedure in which the university bases their selection on a motivation letter that each eligible candidate must provide. it is of interest whether the motivation letter procedure outperforms the default procedure as a selection instrument. For that, it is needed to analyse student data. Student data is stored in foremost two national databases: NyaWebben and Ladok. These databases are not conducive for analysis. The main objective of this researchis to create a data template that can store data from these systems and can also be used to analyse student data in order to evaluate the performances of the selection instruments. To demonstrate the usability of the data template, we formulated two demonstration questions that relate to the performance of the selection instruments that we tentatively tried to answer: 1) Do the motivation letter intakes show a higher degree completion rate and strength of degree completion than the default intakes? 2) How do the assigned motivation letter scores relate to degree completion rate and strength of degree completion? Firstly, we identified which variables were to be extracted from NyaWebben and Ladok and established what KPIs would serve as the working indicators used to analyse the performances of the selection instruments. From a literature review, we deduced that degree completion and strength of degree completion were the KPIs that considered the overarching perspectives of universities, students, the labourmarket, and the government on what constitutes a favourable educational outcome. After that, we employed a manual extraction method to store the data in a spreadsheet; our data template of choice. We then build multiple interfaces and automation procedures for increased efficiency and ease of use. The data template was made analysis-ready through data cleaning, categorisation, and formatting of the data. We furthermore conducted a usability test to assess the ease of use of our data template and the results were positive. We learned that there are still too few data points because of an insufficiently long follow-up time, even when considering only first semester completion, to conclusively answer the demonstration questions and that our results were not statistically significant. The demonstration questions can therefore only be answered in time once more student intakes are added to the data template. However, we found that the implications of the data template are manyfold, since we considered a wide range of variables, including those outside the scope of the demonstration questions, that are ready to be analysed via our data template.