O desvio de segregação, processo biológico definido pela formação de progênie cujas proporções genotípicas diferem das predições mendelianas, pode apresentar diferentes causas: a segregação não aleatória dos cromossomos durante a meiose, a seleção gamética e a viabilidade pós-zigótica diferencial. A fim de investigar a distorção de segregação em humanos, estudamos uma família com transmissão preferencial paterna de uma alteração patogênica no gene CAPN3(CAPN3 c.759_761del), previamente associada à distrofia muscular de cinturas do tipo 2A (LGMD2A). Inicialmente, definimos uma região com 2,1 Mb de extensão, presente na maior parte dos indivíduos da família. O sequenciamento direto de 14 genes contidos nesse intervalo não revelou variantes raras que pudessem estar diretamente associadas à vantagem da subpopulação de gametas portadores da alteração em CAPN3. Entretanto, a presença de variantes comuns distribuídas em cinco genes da região pode indicar que a distorção de segregação observada é consequência da interação, em nível proteico, de pequenas alterações genômicas, resultando no desempenho diferencial de tais células gaméticas. Além disso, utilizamos outra abordagem: espermatozoides de indivíduos saudáveis foram selecionados segundo sua motilidade e as frequências alélicas de cada loco em heterozigose foram comparadas entre células lentas e rápidas, a fim de identificarmos regiões suscetíveis ao desvio de segregação. Alguns resultados estatisticamente significantes foram obtidos para regiões que contêm genes envolvidos na reação acrossômica e na motilidade espermática, como PDE1C e PDE4D. Isso nos sugere que tais processos constituem alvos da seleção, o que pode culminar em formação de progênie com proporções que fogem às predições mendelianas. Esses achados são importantes porque possibilitam a ampliação de nossos conhecimentos acerca do desvio de segregação e seu impacto na espécie humana, considerando ainda possíveis efeitos na fertilidade masculina / The transmission ratio distortion (TRD), a biological process defined as a deviation from Mendelian predictions, is caused by different mechanisms: nonrandom segregation of chromosomes during meiosis or gametic and postzygotic viability selection. In order to investigate TRD in humans, we have studied a family with an overtransmitted pathogenic deletion in the CAPN3 gene (CAPN3 c.759_761del), previously associated to limb-girdle muscular dystrophy type 2A (LGMD2A). Initially, it was possible to define a 2.1 Mb region which was present in most of the individuals. The direct sequencing of 14 genes contained in this interval did not reveal rare variants that could be responsible for the advantage of gametes carrying the CAPN3 mutation. Nevertheless, common variants identified in five genes could indicate that the observed transmission distortion is caused by the interaction among proteins with small dissimilarities, resulting in differential performance of these gametic cells. Subsequently we developed another approach: spermatozoa from healthy individuals were sorted according to their motility and allelic frequencies at each locus in heterozygous state were compared in order to identify genomic regions susceptible to TRD. Surprisingly, some statistically significant results were achieved for regions containing genes involved with acrosome reaction and sperm motility, as PDE1 and PDE4, suggesting these processes are targets of the selection that ends in offspring with proportions skewed away from the Mendelian predictions. These results are important for enlarge our knowledge about TRD and its impact in humans, considering possible effects in male fertility

M.Ing. / This study covers the problem of a periodic distortion and it's electronic compensation. The description and definition of power transfer in a single-phase electrical network is investigated. The various techniques for achieving optimal power transfer are then derived. From this the principle of the compensation of reactive power in an electrical power network is derived using the definition of power transfer. In order to evaluate and illustrate this principle a system configuration, consisting of a controlled source of reactive power is used. Due to the complexity of the system it was initially decided that a computer simulation would serve as an analytical aid. This provides the opportunity to conduct a thorough investigation into the functioning of the proposed compensator. Using the knowledge thus gained. an experimental system was developed. The simulated system is compared to practically obtained results in an experimentally developed compensator in order to evaluate the accuracy and reliability of the simulation. The study then concentrates on the characterization of the two systems as applied in the compensation of reactive power. This analysis also contributes to the identification of deficiencies in the system. The study then concludes with a critical evaluation of the work and suggestions for improvement. This includes the optimization of the total system and the application in industrial power networks.

Abstract Eddy currents and susceptibility differences are the most important sources that interfere with the quality of MR images in the presence of an artificial macroscopic object in the volume to be imaged. In this study, both of these factors have been examined. The findings show that the RF field is the most important cause of induced eddy currents when gradients with relatively slow slew rates are used. The induced eddy currents amplify or dampen the RF field with the result that the flip angle changes. At the proximal end in the vicinity of the hip prosthesis surface, there have been areas where the flip angle is nearly threefold compared to the reference flip angle. Areas with decreased flip angles have also been found near the surface of the prosthesis top. The incompleteness of the image due to eddy currents manifests as signal loss areas. Two different methods based on MRI were developed to estimate the susceptibility of a cylindrical object. One of them is based on geometrical distortions in SE magnitude images, while the other takes advantage of phase differences in GRE phase images. The estimate value of the Profile™ test hip prosthesis is χ = (170 ± 13) 10-6. A remapping method was selected to correct susceptibility image distortions. Correction was accomplished with pixel shifts in the frequency domain. The magnetic field distortions were measured using GRE phase images. The method was tested by simulations and by imaging a hip prosthesis in a water tank and in a human pelvis. The main limitations of the method described here are the loss of a single-valued correction map with higher susceptibility differences and the problems with phase unwrapping in phase images. Modulation transfer functions (MTF) were exploited to assess the effect of correction procedure. The corrected image of a prosthesis in a human hip after total hip arthroplasty appears to be equally sharp or slightly sharper than the corresponding original images. The computer programs written for this study are presented in an appendix.

Renewed interest in open rotor aeroengines, due to their fuel efficiency, has driven renewed interest in all aspects of the noise they generate. Noise due to the ingestion of distorted atmospheric turbulence, known as Unsteady Distortion Noise (UDN), is likely to be higher for open rotors than for conventional turbofan engines since the rotors are fully exposed to oncoming turbulence and lack ducting to attenuate the radiated sound. However, UDN has received less attention to date, particularly in wind-tunnel and flight testing programmes. In this thesis a new prediction scheme for UDN is described, which allows inclusion of many key features of real open rotors which have not previously been investigated theoretically. Detailed features of the mean flow induced by the rotor, the form of atmospheric turbulence, asymmetries due to installation features, and the effect of rotor incidence are all considered. Parameter studies are conducted in each of these cases to investigate their effect upon UDN in typical static testing and flight conditions. A thorough review of the technological issues of most relevance and previous theoretical work on all types of turbulence-blade interaction noise is first undertaken. The prediction scheme is then developed for the case in which the mean flow into the rotor is axisymmetric. This shows excellent qualitative agreement with previous findings, with increased streamtube contraction resulting in a more tonal noise spectrum. The theoretical framework involves using Rapid Distortion Theory to calculate the distortion of an isotropic turbulence field (such as given by the von Karman spectrum) by the mean flow induced by the rotor (such as given by actuator disk theory), leading to an expression for the velocity incident upon the leading edge of the rotor blades. Strip theory is then used to calculate the pressure jumps across the blades, input as the forcing term in the far-field wave equation. Models are derived for open rotor-induced flow which account for the variation of blade circulation with radius, and the presence of the rotor hub and rear blade row. An investigation of appropriate turbulence models and realistic turbulence parameters is also undertaken. A key finding is that the heights of the tonal peaks are determined by the overall magnitude of the induced streamtube contraction (dependent on the total thrust generated) whereas the precise form of distortion (affected by the detailed components of the mean flow and the form of atmospheric turbulence present) alters the resulting broadband level. The prediction scheme is formulated in such a way as to facilitate extension to the asymmetric case, which is also fully derived. The model is applied in the first instance to the case of two adjacent rotors and then to the case of a single rotor at incidence. Under flight conditions, when distortion is reduced but UDN can still contribute a significant broadband component to overall noise levels, asymmetry is found to increase broadband levels around 1 Blade Passing Frequency but reduce levels elsewhere.

A new objective measurement system to predict speech intelligibility in binaural listening conditions is proposed for use with nonlinear hearing devices. Digital processing inside such devices often involves nonlinear operations such as clipping, compression, and noise reduction algorithms. Standard objective measures such as the Articulation Indeix (AI), the Speech Intelligibility Index (SII) and the Speech Transmission Index (STI) have been developed for monaural listening. Binaural extensions of these measures have been proposed in the literature, essentially consisting of a binaural pre-processing stage followed by monaural intelligibility prediction using the better ear or the binaurally enhanced signal. In this work, a three-stage extension of the binaural SII approach is proposed that deals with nonlinear acoustic input signals. The reference-based model operates as follows: (1) a stage to deal with nonlinear processing based on a signal-separation model to recover estimates of speech, noise and distortion signals at the output of hearing devices; (2) a binaural processing stage using the Equalization-Cancellation (EC) model; and (3) a stage for intelligibility prediction using the SII or the short-time Extended SII (ESII). Multiple versions of the model have been developed and tested for use with hearing devices. A software simulator is used to perform hearing-device processing under various binaural listening conditions. Details of the modeling procedure are discussed along with an experimental framework for collecting subjective intelligibility data. In the absence of hearing-device processing, the model successfully predicts speech intelligibility in all spatial configurations considered. Varying levels of success were obtained using two simple distortion modeling approaches with different distortion mechanisms. Future refinements to the model are proposed based on the results discussed in this work.

Channel diversity techniques are effective ways to combat channel fading and noise in communication systems. In this thesis, I compare the performance of source and channel diversity techniques on fading and symmetric continuous channels. My experiments suggest that when SNR is low, channel diversity performs better, and when SNR is high, source diversity shows better performance than channel diversity.

Heat treatment processes are used to develop the desired mechanical properties for steels. Unfortunately, heat treatment, especially quenching, can cause distortion. Failure to meet geometry specifications can result in extensive rework or rejection of the parts. A series of quenching simulations, using DANTE, have been conducted on an AISI 4140 steel Navy C-ring distortion coupon and a WPI designed plate with a hole to determine the effects of quenching process parameters including part geometry, agitation during quenching, and quench start temperatures on distortion. The heat transfer coefficients (HTC) of the quenchant with selected pump speeds were measured by CHTE quench probe system, which is the key input for heat treatment simulation. The maximum HTC of the quenching oil was increased from 2350 W/m2K to 2666 W/m2K with higher pump speed. Quenching experiments were also conducted. It was found that the experimental measured gap opening of the standard Navy C-rings increased from 0.307mm without agitation to 0.536mm at a high agitation. Quench start temperature does not have a significant effect on the gap opening. The experimental results showed good agreement with simulation results. The important processing parameter identification was conducted using design of experiments (DoE) coupled with analysis of variance (ANOVA). The effect of processing parameters in decreasing order of importance were determined to be: quenchant type, part geometry, agitation speed, quenching orientation, quenchant temperature, immersion rates, and quench starts temperature. Based on the simulation and experimental results, it was found that the two most import parameters are: 1. The part geometry and size (product design) 2. The temperature dependent heat transfer coefficients between the part and the quenchant (process design) The coupling of these product and process parameters is necessary to apply the systems analysis that must be accomplished to understand the interaction between the part design and process design parameters. This coupling can be accomplished by locally applying the well-known Biot number. Bi (T) = h(T) * L / k(T) Where h(T) = film coefficient or convective heat transfer coefficient [W/m2*K]. LC = characteristic length, which is generally described as the volume of the body divided by the surface area of the body [m]. k(T) = thermal conductivity of the body [W/m*k] The concept of a local Biot number is introduced to quantify the local variations of part size, geometry and heat transfer coefficient. First, a large Bi indicates large temperature gradients within the part. Second, large local (geometry dependent) variations in Bi number will lead to large lateral temperature gradients. Therefore, variations in local Bi can lead to large temperature gradients and therefore high stress during quenching and finally distortion. This local Bi concept can be used in a systems approach to designing a part and the quenching system. This systems approach can be designated as design for heat treating.

The purpose of this diploma thesis is to research and compare available wireless communication technologies (frequency, modulation type, transmission speed and consumption). Describe transmission electron microscopes theory and deduce the most sensitive microscope parts to high frequency distortion. Investigate effect of wireless technology on CE standards and come up with, perform and evaluate the influence measurement of chosen technologies on base parameters of transmission electron microscope.

Heat treatment processes are used to develop the desired mechanical properties for steels. Unfortunately, heat treatment, especially quenching, can cause distortion. Failure to meet geometry specifications can result in extensive rework or rejection of the parts. A series of quenching simulations, using DANTE, have been conducted on an AISI 4140 steel Navy C-ring distortion coupon and a WPI designed plate with a hole to determine the effects of quenching process parameters including part geometry, agitation during quenching, and quench start temperatures on distortion. The heat transfer coefficients (HTC) of the quenchant with selected pump speeds were measured by CHTE quench probe system, which is the key input for heat treatment simulation. The maximum HTC of the quenching oil was increased from 2350 W/m2K to 2666 W/m2K with higher pump speed. Quenching experiments were also conducted. It was found that the experimental measured gap opening of the standard Navy C-rings increased from 0.307mm without agitation to 0.536mm at a high agitation. Quench start temperature does not have a significant effect on the gap opening. The experimental results showed good agreement with simulation results. The important processing parameter identification was conducted using design of experiments (DoE) coupled with analysis of variance (ANOVA). The effect of processing parameters in decreasing order of importance were determined to be: quenchant type, part geometry, agitation speed, quenching orientation, quenchant temperature, immersion rates, and quench starts temperature. Based on the simulation and experimental results, it was found that the two most import parameters are: 1. The part geometry and size (product design) 2. The temperature dependent heat transfer coefficients between the part and the quenchant (process design) The coupling of these product and process parameters is necessary to apply the systems analysis that must be accomplished to understand the interaction between the part design and process design parameters. This coupling can be accomplished by locally applying the well-known Biot number. Bi (T) = h(T) * L / k(T) Where h(T) = film coefficient or convective heat transfer coefficient [W/m2*K]. LC = characteristic length, which is generally described as the volume of the body divided by the surface area of the body [m]. k(T) = thermal conductivity of the body [W/m*k] The concept of a local Biot number is introduced to quantify the local variations of part size, geometry and heat transfer coefficient. First, a large Bi indicates large temperature gradients within the part. Second, large local (geometry dependent) variations in Bi number will lead to large lateral temperature gradients. Therefore, variations in local Bi can lead to large temperature gradients and therefore high stress during quenching and finally distortion. This local Bi concept can be used in a systems approach to designing a part and the quenching system. This systems approach can be designated as design for heat treating.

Characterization of distortion transfer and generation through fans with distorted inlet conditions enables progress towards designs with improved distortion tolerance. The abruptness of transition from undistorted to distorted total pressure regions at the inlet impacts the induced swirl profile and therefore the distortion transfer and generation. These impacts are characterized using URANS simulations of PBS Rotor 4 geometry under a variety of inlet distortion profiles. A 90° and a 135° sector, both of 15% total pressure distortion, are considered. Variants of each sector size, with decreasing levels of distortion transition abruptness, are each applied to the fan. Fourier-based distortion descriptors are used to quantify levels of distortion transfer and generation at axial locations through the fan, principally at the stator inlet. It is shown that a gradual transition in distortion at the inlet results in decreased levels of distortion transfer and generation. The flow physics resulting in this reduction are explored. URANS simulations involving turbomachinery are complex and often require simplifying assumptions to balance computational costs with accuracy. One assumption removes the need for a nozzle to control nozzle operation condition and replaces it with a static pressure boundary condition located at the stator exit. This assumption is challenged by conducting a series of distorted inlet simulations with a nozzle, which are then compared to a corresponding set of simulations conducted using the exit boundary assumption. Performance parameters for each set of simulations are compared. Performance was observed to be within 1% difference between the two methods, supporting the assumption that a static pressure boundary is adequate for controlling inlet distortion simulations. Finally, full annulus URANS simulations are presented to investigate distortion phase shift in a single stage transonic fan. The fan is subject to a 90° sector inlet total pressure distortion. Simulation results are presented for choke, design, and near-stall operating conditions. Circumferential profiles of swirl, total pressure, total temperature, power, and phase shift are analyzed at 10%, 30%, 50%, 70%, and 90% span. Several metrics for phase shift, which is a measure of the rotational translation of a distortion profile, are presented and compared. Each aims to assist understanding the translational motion of distortion as it passes through the fan. The different metrics used for phase shift are used to analyze distortion phase. Insights from each are presented alongside limitations for each method. A combination of methods is proposed to address their respective limitations.