Design and Applications of a Decade-Spanning Terahertz Frequency Comb Spectrometer: Doppler-limited Rotational Spectroscopy of Methanol and Methanol-OD

This thesis details the design and applications of a terahertz (THz) frequency comb spectrometer. The spectrometer employs two offset locked Ti:Sapphire femtosecond oscillators with repetition rates of approximately 80 MHz, offset locked at 100 Hz to continuously sample a time delay of 12.5 ns at a maximum time delay resolution of 15.6 fs. These oscillators emit continuous pulse trains, allowing the generation of a THz pulse train by the master, or pump, oscillator and the sampling of this THz pulse train by the slave, or probe, oscillator via the electro-optic effect. Collecting a train of 16 consecutive THz pulses and taking the Fourier transform of this pulse train produces a decade-spanning frequency comb, from 0.25 to 2.5 THz, with a comb tooth width of 5 MHz and a comb tooth spacing of ~80 MHz. This frequency comb is suitable for Doppler-limited rotational spectroscopy of small molecules. Here, the data from 68 individual scans at slightly different pump oscillator repetition rates were combined, producing an interleaved THz frequency comb spectrum, with a maximum interval between comb teeth of 1.4 MHz, enabling THz frequency comb spectroscopy.

The accuracy of the THz frequency comb spectrometer was tested, achieving a root mean square error of 92 kHz measuring selected absorption center frequencies of water vapor at 10 mTorr, and a root mean square error of 150 kHz in measurements of a K-stack of acetonitrile. This accuracy is sufficient for fitting of measured transitions to a model Hamiltonian to generate a predicted spectrum for molecules of interest in the fields of astronomy and physical chemistry. As such, the rotational spectra of methanol and methanol-OD were acquired by the spectrometer. Absorptions from 1.3 THz to 2.0 THz were compared to JPL catalog data for methanol and the spectrometer achieved an RMS error of 402 kHz, improving to 303 kHz when excluding low signal-to-noise absorptions. This level of accuracy compares favorably with the ~100 kHz accuracy achieved by JPL frequency multiplier submillimeter spectrometers. Additionally, the relative intensity performance of the THz frequency comb spectrometer is linear across the entire decade-spanning bandwidth, making it the preferred instrument for recovering lineshapes and taking absolute intensity measurements in the THz region. The data acquired by the Terahertz Frequency Comb Spectrometer for methanol-OD is of comparable accuracy to the methanol data and may be used to refine the fit parameters for the predicted spectrum of methanol-OD.

Feasibility study and flow scheduling optimization of a multi-product pipeline system

The first goal of this study is to analyse a real-world multiproduct onshore pipeline system in order to verify its hydraulic configuration and operational feasibility by constructing a simulation model step by step from its elementary building blocks that permits to copy the operation of the real system as precisely as possible. The second goal is to develop this simulation model into a user-friendly tool that one could use to find an “optimal” or “best” product batch schedule for a one year time period. Such a batch schedule could change dynamically as perturbations occur during operation that influence the behaviour of the entire system. The result of the simulation, the ‘best’ batch schedule is the one that minimizes the operational costs in the system. The costs involved in the simulation are inventory costs, interface costs, pumping costs, and penalty costs assigned to any unforeseen situations. The key factor to determine the performance of the simulation model is the way time is represented. In our model an event based discrete time representation is selected as most appropriate for our purposes. This means that the time horizon is divided into intervals of unequal lengths based on events that change the state of the system. These events are the arrival/departure of the tanker ships, the openings and closures of loading/unloading valves of storage tanks at both terminals, and the arrivals/departures of trains/trucks at the Delivery Terminal. In the feasibility study we analyse the system’s operational performance with different Head Terminal storage capacity configurations. For these alternative configurations we evaluated the effect of different tanker ship delay magnitudes on the number of critical events and product interfaces generated, on the duration of pipeline stoppages, the satisfaction of the product demand and on the operative costs. Based on the results and the bottlenecks identified, we propose modifications in the original setup.

Changes in urethral sphincter size following rehabilitation in older women with stress urinary incontinence

Introduction and hypothesis The purpose of this study was to evaluate the effects of a pelvic floor muscle (PFM) rehabilitation program on the striated urethral sphincter in women over 60 years with stress urinary incontinence (SUI). We hypothesized that the PFM rehabilitation program would also exercise the striated urethral sphincter and that this would be demonstrated by hypertrophy of the sphincter on magnetic resonance imaging (MRI). Methods Women with at least weekly episodes of SUI were recruited. Participants were evaluated before and after a 12-week group PFM rehabilitation intervention with T2-weighted fast-spin-echo MRI sequences recorded in the axial plane at rest to assess urethral sphincter size. Data on SUI symptoms and their bother were also collected. No control group was included. Results Seventeen women participated in the study. The striated urethral sphincter increased significantly in thickness (21 %, p < 0.001), cross-sectional area (20 %, p = 0.003), and volume (12 %, p = 0.003) following the intervention. The reported number of incontinence episodes and their bother also decreased significantly. Conclusions This study appears to demonstrate that PFM training for SUI also trains the striated urethral sphincter and that improvement in incontinence signs and symptoms is associated with sphincter hypertrophy in older women with SUI. These findings support previous ultrasound (US) data showing an increase in urethral cross-sectional area following PFM training and extend the previous findings by more specifically assessing the area of hypertrophy and by demonstrating that older women present the same changes as younger women when assessed using MRI data.

Initiation and early crack growth in VHCF of stainless steels : Experimental and theoretical analysis

Mechanical fatigue is a failure phenomenon that occurs due to repeated application of mechanical loads. Very High Cycle Fatigue (VHCF) is considered as the domain of fatigue life greater than 10 million load cycles. Increasing numbers of structural components have service life in the VHCF regime, for instance in automotive and high speed train transportation, gas turbine disks, and components of paper production machinery. Safe and reliable operation of these components depends on the knowledge of their VHCF properties. In this thesis both experimental tools and theoretical modelling were utilized to develop better understanding of the VHCF phenomena. In the experimental part, ultrasonic fatigue testing at 20 kHz of cold rolled and hot rolled stainless steel grades was conducted and fatigue strengths in the VHCF regime were obtained. The mechanisms for fatigue crack initiation and short crack growth were investigated using electron microscopes. For the cold rolled stainless steels crack initiation and early growth occurred through the formation of the Fine Granular Area (FGA) observed on the fracture surface and in TEM observations of cross-sections. The crack growth in the FGA seems to control more than 90% of the total fatigue life. For the hot rolled duplex stainless steels fatigue crack initiation occurred due to accumulation of plastic fatigue damage at the external surface, and early crack growth proceeded through a crystallographic growth mechanism. Theoretical modelling of complex cracks involving kinks and branches in an elastic half-plane under static loading was carried out by using the Distributed Dislocation Dipole Technique (DDDT). The technique was implemented for 2D crack problems. Both fully open and partially closed crack cases were analyzed. The main aim of the development of the DDDT was to compute the stress intensity factors. Accuracy of 2% in the computations was attainable compared to the solutions obtained by the Finite Element Method.

Changes in urethral sphincter size following rehabilitation in older women with stress urinary incontinence

Introduction and hypothesis The purpose of this study was to evaluate the effects of a pelvic floor muscle (PFM) rehabilitation program on the striated urethral sphincter in women over 60 years with stress urinary incontinence (SUI). We hypothesized that the PFM rehabilitation program would also exercise the striated urethral sphincter and that this would be demonstrated by hypertrophy of the sphincter on magnetic resonance imaging (MRI). Methods Women with at least weekly episodes of SUI were recruited. Participants were evaluated before and after a 12-week group PFM rehabilitation intervention with T2-weighted fast-spin-echo MRI sequences recorded in the axial plane at rest to assess urethral sphincter size. Data on SUI symptoms and their bother were also collected. No control group was included. Results Seventeen women participated in the study. The striated urethral sphincter increased significantly in thickness (21 %, p < 0.001), cross-sectional area (20 %, p = 0.003), and volume (12 %, p = 0.003) following the intervention. The reported number of incontinence episodes and their bother also decreased significantly. Conclusions This study appears to demonstrate that PFM training for SUI also trains the striated urethral sphincter and that improvement in incontinence signs and symptoms is associated with sphincter hypertrophy in older women with SUI. These findings support previous ultrasound (US) data showing an increase in urethral cross-sectional area following PFM training and extend the previous findings by more specifically assessing the area of hypertrophy and by demonstrating that older women present the same changes as younger women when assessed using MRI data.

Aplicación del modelo Discovering Hands en Argentina

Discovering Hands (DH) es un proyecto que nace en Alemania en el 2006, liderado por el doctor Frank Hoffmann. El programa se desarrolla pensando en el importante problema de salud pública en el cual se ha convertido en el cáncer de mama, pues según la Organización Mundial de la Salud es el mayor causal de muerte en mujeres, tanto en países desarrollados como en vía de desarrollo, y en Alemania esta enfermedad acaba con la vida de aproximadamente 18.000 mujeres cada año. (The Global Journal, 2014) DH entrena y capacita mujeres visualmente impedidas para detectar de manera temprana los signos de cáncer de mama, dado que estas poseen un sentido del tacto más desarrollado que el de una persona que no se encuentre limitada visualmente. Esto les permite localizar el cáncer de forma más rápida que un médico general ya que son capaces de identificar los tumores más pequeños, logrando así reducir notablemente los costos totales del tratamiento de esta enfermedad. Adicional a esto, el capacitar y preparar a mujeres con discapacidad visual para la detección temprana de cáncer de mama, incrementa la fuerza laboral del país, pues estas mujeres pasarían a ser parte de la población económicamente activa del mismo (PEA) y lograrían que las personas dejen de percibir esta condición como una discapacidad y por el contrario la vean como una ventaja. Después de unos años de prueba, el programa ha sido mejorado y extendido tanto en Alemania como en otros países (Austria), razón por la cual se realizó el estudio de factibilidad del proyecto en países como Colombia - donde se quiere llevar a cabo un proyecto piloto en la ciudad de Cali - México y Argentina. El presente trabajo se enfoca en Argentina, por medio del cual se busca proponer aportes para disminuir las causas de muertes originadas por esta enfermedad y los altos costos que estas le generan al sector de la salud de este país. Con el estudio se logró identificar la factibilidad de la implementación del modelo de negocio, evidenciando que Argentina cuenta con unas particularidades en su sistema de gobierno que pueden hacer que la puesta en práctica del proyecto sea más compleja que en otros países.

The Support Educational Commitee Participation in the Pedagogical Approach of an Educational Integration

Educational services are essential to social and economical development of people, mainly to the progress of all sectors of society. Establishing actions that can promote the participation of various social groups is essential to improve their quality of life and building more respectful and fair human rights without any discrimination or exclusion. In recent years, the Costa Rican education system has undergone significant changes due to the pedagogical approach of inclusive education in which students with educational needs may require different support and specialized resources for training and development. For this, the Basic Educational Division of the Center for Teaching and Research in Education, generated a concern of investigating the participation of the Committee of Educational Support in the process of educational integration, thus, determine the functions performed in the educational context, under the rules of the 7600 Equal Opportunity Act for people with disabilities, which is the entity that corresponds to regulate access to education by identifying the support required for students with educational needs and, advice and trains, administrative staff in schools both public and private in the country. In addition, there is also a concern for exploring the role of the Special Education teacher for this Committee, as well as learning the perceptions of teachers and parents about the functions performed by the committee.

Transition Matters. Il ruolo del designer nella transizione sostenibile e circolare dei materiali polimerici

La ricerca indaga il ruolo del designer nella transizione sostenibile e circolare all’uso di materiali polimerici. Nel contesto contemporaneo la plastica è utilizzata in quasi ogni settore merceologico ma la sua futura applicazione è messa in forte discussione a causa dei visibili impatti ambientali del suo uso irresponsabile. Un passaggio netto dalla totale dipendenza alla liberazione dei polimeri è difficile; è necessario un periodo di transizione che permetta di coesistere responsabilmente con i polimeri in attesa di trovare dei validi sostituti. L’obiettivo della ricerca è lavorare su questo periodo ponendo il designer e le sue competenze come soggetti chiave del movimento. La tesi di ricerca propone un approccio per calare le pratiche del Transition Design nella progettazione di sistemi-prodotto, nutrendosi degli attributi anticipatori dell’Advanced Design e puntando agli obiettivi del Circular Design, lavorando a partire dalle merci più critiche nel contesto contemporaneo: quelle in polimero fossile non riciclabile. Contributo della tesi è la figura del Transition Matter Designer, un progettista di transizioni dei materiali che prevede metamorfosi di sistemi-prodotto nel tempo grazie alle sue competenze a diverse scale del progetto: forma l’utente agli atteggiamenti circolari e sostenibili, caratterizza i materiali per individuarne nuovi usi, seleziona i processi produttivi adatti a prevenire scarti e ne anticipa i cicli di vita nei prodotti. I Knitted Fasteners sono il risultato della simulazione del lavoro del Transition Matter Designer nel tessile: un sistema di elementi di fissaggio, personalizzabili dallo stilista e integrati negli abiti a maglia, che permettono di eliminare l’uso di fashion fasteners in plastica e metallo, elementi che rendono difficile il riciclo dei capi. Dalla sperimentazione è emerso il modello concettuale della Transindustrial Production: un lavoro di collaborazione fra Transition Matter Designer e creativo per dare identità ai materiali polimerici circolari attraverso l’ibridazione fra artigianato e industria, tipico del Made in Italy.

Mitigation of Train-Induced waves by resonant filled-trench (RFT)

The increase of railways near the urban areas is a significant cause of discomfort for inhabitants due to train-induced vibration and noise. Vibration characteristics can vary widely according to the train type: for high-speed trains, if train speed becomes comparable to the ground wave speed, the vibration level becomes significant; for freight trains, due to their heavier weight and lower speed, the vibration amplitudes are greater and propagate at a more considerable distance from the track; for urban tramways, although the vibration amplitude is relatively low, they can have a negative structural effect on the closest buildings [51]. Therefore, to dampen the vibration level, it is possible to carry out some interventions both on the track and the transmission path. This thesis aims to propose and numerically investigate a novel method to dampen the train-induced vibrations along the transmission path. The method is called "resonant filled-trench (RFT)" and consists of a combination of expanded polystyrene (EPS) geofoam to stabilize the trench wall against the collapse and drowned cylindrical embedded inclusions inside the geofoam, which act as a resonator, reflector, and attenuator. By means of finite element simulations, we show that up to 50% higher attenuation than the open trench is achievable after overcoming the resonance frequency of the inclusion, i.e., 35Hz, which covers the frequency contents of the train-induced vibration. Moreover, depending on the filling material used for the inclusions, trench depth can be reduced up to 17% compared to the open trench showing the same screening performance as the open trench. Also, an RFT with DS inclusion installed in dense sand soil shows a high hindrance performance (i.e., IL≥6dB) when the trench depth is larger than 0.5λ_R while it is 0.6λ_R for the open trench.

Performance Analysis of 5G based Positioning in Railway Applications

Rail transportation has significant importance in the future world. This importance is tightly bounded to accessible, sustainable, efficient and safe railway systems. Precise positioning in railway applications is essential for increasing railway traffic, train-track control, collision avoidance, train management and autonomous train driving. Hence, precise train positioning is a safety-critical application. Nowadays, positioning in railway applications highly depends on a cellular-based system called GSM-R, a railway-specific version of Global System for Mobile Communications (GSM). However, GSM-R is a relatively outdated technology and does not provide enough capacity and precision demanded by future railway networks. One option for positioning is mounting Global Navigation Satellite System (GNSS) receivers on trains as a low-cost solution. Nevertheless, GNSS can not provide continuous service due to signal interruption by harsh environments, tunnels etc. Another option is exploiting cellular-based positioning methods. The most recent cellular technology, 5G, provides high network capacity, low latency, high accuracy and high availability suitable for train positioning. In this thesis, an approach to 5G-based positioning for railway systems is discussed and simulated. Observed Time Difference of Arrival (OTDOA) method and 5G Positioning Reference Signal (PRS) are used. Simulations run using MATLAB, based on existing code developed for 5G positioning by extending it for Non Line of Sight (NLOS) link detection and base station exclusion algorithms. Performance analysis for different configurations is completed. Results show that efficient NLOS detection improves positioning accuracy and implementing a base station exclusion algorithm helps for further increase.