Development of an AMR-ACB Array for Gastrointestinal Motility Studies

The association between anisotropic magnetoresistive (AMR) sensor and AC biosusceptometry (ACB) to evaluate gastrointestinal motility is presented. The AMR-ACB system was successfully characterized in a bench-top study, and in vivo results were compared with those obtained by means of simultaneous manometry. Both AMR-ACB and manometry techniques presented high temporal cross correlation between the two periodicals signals (R = 0.9 +/- 0.1; P < 0.05). The contraction frequencies using AMR-ACB were 73.9 +/- 7.6 mHz and using manometry were 73.8 +/- 7.9 mHz during the baseline (r = 98, p < 0.05). The amplitude of contraction using AMR-ACB was 396 +/- 108 mu T.s and using manometry were 540 +/- 198 mmHg.s during the baseline. The amplitudes of signals for AMR-ACB and manometric recordings were similarly increased to 86.4% and 89.3% by neostigmine, and also decreased to 27.2% and 21.4% by hyoscine butylbromide in all animals, respectively. The AMR-ACB array is nonexpensive, portable, and has high-spatiotemporal resolution to provide helpful information about gastrointestinal tract.

Hardware and software development of a multichannel readout board named CARLOSrx for the ALICE experiment

ALICE, that is an experiment held at CERN using the LHC, is specialized in analyzing lead-ion collisions. ALICE will study the properties of quarkgluon plasma, a state of matter where quarks and gluons, under conditions of very high temperatures and densities, are no longer confined inside hadrons. Such a state of matter probably existed just after the Big Bang, before particles such as protons and neutrons were formed. The SDD detector, one of the ALICE subdetectors, is part of the ITS that is composed by 6 cylindrical layers with the innermost one attached to the beam pipe. The ITS tracks and identifies particles near the interaction point, it also aligns the tracks of the articles detected by more external detectors. The two ITS middle layers contain the whole 260 SDD detectors. A multichannel readout board, called CARLOSrx, receives at the same time the data coming from 12 SDD detectors. In total there are 24 CARLOSrx boards needed to read data coming from all the SDD modules (detector plus front end electronics). CARLOSrx packs data coming from the front end electronics through optical link connections, it stores them in a large data FIFO and then it sends them to the DAQ system. Each CARLOSrx is composed by two boards. One is called CARLOSrx data, that reads data coming from the SDD detectors and configures the FEE; the other one is called CARLOSrx clock, that sends the clock signal to all the FEE. This thesis contains a description of the hardware design and firmware features of both CARLOSrx data and CARLOSrx clock boards, which deal with all the SDD readout chain. A description of the software tools necessary to test and configure the front end electronics will be presented at the end of the thesis.

Extended donor and acceptor molecules for organic electronics

Die Untersuchung von halbleitenden Materialien auf der Basis von organischen Molekülen stellt ein Gebiet der angewandten Forschung an der Schwelle zur industriellen Nutzung dar. Geringes Gewicht und hohe mechanische Flexibilität ermöglichen völlig neue Produkte, die mit anorganischen Halbleitern nicht zu realisieren sind. Die Herstellung von Bauteilen wie Transistoren, Solarzellen oder Leuchtdioden aus organischen Materialien ist ein komplexes Gebiet, das einer Vielzahl von unterschiedlichen Optimierungen bedarf, um eine konkurrenzfähige Leistung zu erreichen. Die synthetische organische Chemie bietet vielfältige Möglichkeiten, mit maßgeschneiderten Lösungen zum Optimierungsprozess beizutragen. Zum einen können neue aktive Materialien hergestellt werden mit besserer Leistung und leichterer Verarbeitbarkeit. Zum anderen sind Substanzen zugänglich, die z.B. bei der Ladungsträgerinjektion hilfreich sein können.rnIn dieser Arbeit wurde an beiden dieser Fronten gearbeitet. Dabei lag die Entwicklungsstrategie darin, ausgedehnte π-konjugierte Moleküle herzustellen, die entweder besonders elektronenarme Akzeptoren oder elektronenreiche Donoren darstellen. Die genaue Kontrolle der elektronischen Niveaus stellt einen wichtigen Bestandteil dar, um niedrige elektrische Kontaktbarrieren zu Metallen zu erreichen und ausreichend stabile Materialien zu erreichen.rnDer erste Fokus der Arbeiten lag in der Funktionalisierung von Coronen. Dieser PAH stellt einen guten Kompromiss bezüglich seiner Größe dar: Er ist groß genug, um Diffusion in andere Schichten von Bauteilen zu vermeiden, aber nicht zu groß, um Verarbeitung durch Vakuumsublimation zu ermöglichen. Bislang sind praktisch keine Coronen-Derivate in der Literatur beschrieben, weshalb eine neue Synthese entwickelt werden musste, die die Einführung starker Donor- und Akzeptorfunktionalitäten erlaubt. Die photochemische Cyclodehydrierung von substituierten [2.2.2]paracyclophan-trienen stellte sich als hervorragende Möglichkeit heraus, dies zu bewerkstelligen. Es wurde eine Reihe von methoxy-substitutierten Coronenen mit unterschiedlicher Symmetrie hergestellt. Mittels optischer Spektroskopie konnte gezeigt werden, dass Methoxygruppen wenig Einfluss auf die elektronischen Eigenschaften von Coronen haben. Unter Spaltung der Methylether und anschließender Oxidation allerdings sind Coronenketone zugänglich, welche bis zu drei α-Diketongruppen besitzen. Diese Moleküle sind enorm starke Akzeptoren, was durch Cyclovoltammetrie und Vergleich zu anderen Akzeptoren eindrucksvoll gezeigt werden konnte. Die Sublimation dieses Akzeptors auf die Oberfläche von Metallen zeigt einen dramatischen Einfluss auf die Austrittsarbeit dieses Metalls, was zur Herstellung eines ohmschen Kontakts zu organischen Halbleitern von außerordentlichem Nutzen ist. rnDen zweiten Teil der Arbeit bilden Benzodithiophen enthaltende Polymere, die für den Einsatz als aktive Komponente in elektronischen Bauteilen entwickelt wurden. Nach systematischer Strukturoptimierung wurde ein Polymer enthalten, welches in einem Feldeffekt-Transistor auf Standard-Silizium-Substraten Ladungsträger-Mobilitäten über 0,1 cm2/Vs erreicht mit großer Reproduzierbarkeit und ausgezeichneter Transistor-Charakteristik. Es konnte gezeigt werden, dass die durch die Monomergeometrie erzeugte Kurvung des Polymers zu einem optimalen Kompromiss aus Löslichkeit und effektiver Packung darstellt. Auf für industrielle Anwendungen besonders interessanten polymer-basierten Substraten wurde eine noch erheblich bessere Leistung gezeigt. Auf einem PET-Substrat wurden Feldeffekt-Mobilitäten von 0,5 cm2/Vs gemessen mit überzeugenden Reproduzierbarkeit und Stabilität.rnDamit konnte in der Arbeit ein bedeutender Beitrag zur Weiterentwicklung von Materialien für den Einsatz in elektronischen Bauteilen geleistet werden. Die Substanzen versprechen noch erhebliches Potenzial nach intensiver Optimierung und wurden deshalb zum Patent angemeldet.rn

Development and testing of the atlas ibl rod pre production boards

Il lavoro di questa tesi riguarda principalmente la progettazione, simulazione e test di laboratorio di tre versioni successive di schede VME, chiamate Read Out Driver (ROD), che sono state fabbricate per l'upgrade del 2014 dell'esperimento ATLAS Insertable B-Layer (IBL) al CERN. IBL è un nuovo layer che diverrà parte del Pixel Detector di ATLAS. Questa tesi si compone di una panoramica descrittiva dell'esperimento ATLAS in generale per poi concentrarsi sulla descrizione del layer specifico IBL. Inoltre tratta in dettaglio aspetti fisici e tecnici: specifiche di progetto, percorso realizzativo delle schede e test conseguenti. Le schede sono state dapprima prodotte in due prototipi per testare le prestazioni del sistema. Queste sono state fabbricate al fine di valutare le caratteristiche e prestazioni complessive del sistema di readout. Un secondo lotto di produzione, composto di cinque schede, è stato orientato alla correzione fine delle criticità emerse dai test del primo lotto. Un'indagine fine e approfondita del sistema ha messo a punto le schede per la fabbricazione di un terzo lotto di altre cinque schede. Attualmente la produzione è finita e complessivamente sono state realizzate 20 schede definitive che sono in fase di test. La produzione sarà validata prossimamente e le 20 schede verranno consegnate al CERN per essere inserite nel sistema di acquisizione dati del rivelatore. Al momento, il Dipartimento di Fisica ed Astronomia dell'Università di Bologna è coinvolto in un esperimento a pixel solamente attravers IBL descritto in questa tesi. In conclusione, il lavoro di tesi è stato prevalentemente focalizzato sui test delle schede e sul progetto del firmware necessario per la calibrazione e per la presa dati del rivelatore.

Chemical exfoliation of graphene and its application in organic electronics and energy storage devices

Graphene, the thinnest two-dimensional material possible, is considered as a realistic candidate for the numerous applications in electronic, energy storage and conversion devices due to its unique properties, such as high optical transmittance, high conductivity, excellent chemical and thermal stability. However, the electronic and chemical properties of graphene are highly dependent on their preparation methods. Therefore, the development of novel chemical exfoliation process which aims at high yield synthesis of high quality graphene while maintaining good solution processability is of great concern. This thesis focuses on the solution production of high-quality graphene by wet-chemical exfoliation methods and addresses the applications of the chemically exfoliated graphene in organic electronics and energy storage devices.rnPlatinum is the most commonly used catalysts for fuel cells but they suffered from sluggish electron transfer kinetics. On the other hand, heteroatom doped graphene is known to enhance not only electrical conductivity but also long term operation stability. In this regard, a simple synthetic method is developed for the nitrogen doped graphene (NG) preparation. Moreover, iron (Fe) can be incorporated into the synthetic process. As-prepared NG with and without Fe shows excellent catalytic activity and stability compared to that of Pt based catalysts.rnHigh electrical conductivity is one of the most important requirements for the application of graphene in electronic devices. Therefore, for the fabrication of electrically conductive graphene films, a novel methane plasma assisted reduction of GO is developed. The high electrical conductivity of plasma reduced GO films revealed an excellent electrochemical performance in terms of high power and energy densities when used as an electrode in the micro-supercapacitors.rnAlthough, GO can be prepared in bulk scale, large amount of defect density and low electrical conductivity are major drawbacks. To overcome the intrinsic limitation of poor quality of GO and/or reduced GO, a novel protocol is extablished for mass production of high-quality graphene by means of electrochemical exfoliation of graphite. The prepared graphene shows high electrical conductivity, low defect density and good solution processability. Furthermore, when used as electrodes in organic field-effect transistors and/or in supercapacitors, the electrochemically exfoliated graphene shows excellent device performances. The low cost and environment friendly production of such high-quality graphene is of great importance for future generation electronics and energy storage devices. rn

Titanate-based paraelectric glass-ceramics for applications in GHz electronics

Das Gebiet der drahtlosen Kommunikationsanwendungen befindet sich in einem permanenten Entwicklungsprozess (Mobilfunkstandards: GSM/UMTS/LTE/5G, glo-bale Navigationssatellitensysteme (GNSS): GPS, GLONASS, Galileo, Beidou) zu immer höheren Datenraten und zunehmender Miniaturisierung, woraus ein hoher Bedarf für neue, optimierte Hochfrequenzmaterialien resultiert. Diese Entwicklung zeigt sich besonders in den letzten Jahren in der zunehmenden Entwicklung und Anzahl von Smartphones, welche verschiedene Technologien mit unterschiedlichen Arbeitsfrequenzen innerhalb eines Geräts kombinieren (data: 1G-4G, GPS, WLAN, Bluetooth). Die für zukünftige Technologien (z.B. 5G) benötigte Performance-steigerung kann durch die Verwendung von auf MIMO basierenden Antennensystemen realisiert werden (multiple-input & multiple-output, gesteuerte Kombination von mehreren Antennen) für welche auf dielectric Loading basierende Technologien als eine der vielversprechendsten Implementierungslösungen angesehen werden. rnDas Ziel dieser Arbeit war die Entwicklung einer geeigneten paraelektrischen Glaskeramik ($varepsilon_{r}$ > 20, $Qf$ > 5000 GHz, |$tau_f$| < 20 ppm/K; im GHz Frequenzbe-reich) im $mathrm{La_{2}O_{3}}$-$mathrm{TiO_{2}}$-$mathrm{SiO_{2}}$-$mathrm{B_{2}O_{3}}$-System für auf dielectric Loading basierende Mobilfunkkommunikationstechnologien als Alternative zu existierenden kommerziell genutzten Sinterkeramiken. Der Fokus lag hierbei auf der Frage, wie die makroskopi-schen dielektrischen Eigenschaften der Glaskeramik mit ihrer Mikrostruktur korreliert bzw. modifiziert werden können. Es konnte gezeigt werden, dass die dielektrischen Materialanforderungen durch das untersuchte System erfüllt werden und dass auf Glaskeramik basierende Dielektrika weitere vorteilhafte nichtelektro-nische Eigenschaften gegenüber gesinterten Keramiken besitzen, womit dielektrische Glaskeramiken durchaus als geeignete Alternative angesehen werden können. rnEin stabiles Grünglas mit minimalen Glasbildneranteil wurde entwickelt und die chemische Zusammensetzung bezüglich Entglasung und Redoxinstabilitäten optimiert. Geeignete Dotierungen für dielektrisch verlustarme $mathrm{TiO_{2}}$-haltige Glaskeramiken wurden identifiziert.rnDer Einfluss der Schmelzbedingungen auf die Keimbildung wurde untersucht und der Keramisierungsprozess auf einen maximalen Anteil der gewünschten Kristallphasen optimiert um optimale dielektrische Eigenschaften zu erhalten. Die mikroskopische Struktur der Glaskeramiken wurde analysiert und ihr Einfluss auf die makroskopischen dielektrischen Eigenschaften bestimmt. Die Hochfrequenzverlustmechanismen wurden untersucht und Antennen-Prototypenserien wurden analysiert um die Eignung von auf Glaskeramik basierenden Dielektrika für die Verwendung in dielectric Loading Anwendungen zu zeigen.

Fast frontend electronics for high rate particle detectors

Future experiments in nuclear and particle physics are moving towards the high luminosity regime in order to access rare processes. In this framework, particle detectors require high rate capability together with excellent timing resolution for precise event reconstruction. In order to achieve this, the development of dedicated FrontEnd Electronics (FEE) for detectors has become increasingly challenging and expensive. Thus, a current trend in R&D is towards flexible FEE that can be easily adapted to a great variety of detectors, without impairing the required high performance. This thesis reports on a novel FEE for two different detector types: imaging Cherenkov counters and plastic scintillator arrays. The former requires high sensitivity and precision for detection of single photon signals, while the latter is characterized by slower and larger signals typical of scintillation processes. The FEE design was developed using high-bandwidth preamplifiers and fast discriminators which provide Time-over-Threshold (ToT). The use of discriminators allowed for low power consumption, minimal dead-times and self-triggering capabilities, all fundamental aspects for high rate applications. The output signals of the FEE are readout by a high precision TDC system based on FPGA. The performed full characterization of the analogue signals under realistic conditions proved that the ToT information can be used in a novel way for charge measurements or walk corrections, thus improving the obtainable timing resolution. Detailed laboratory investigations proved the feasibility of the ToT method. The full readout chain was investigated in test experiments at the Mainz Microtron: high counting rates per channel of several MHz were achieved, and a timing resolution of better than 100 ps after walk correction based on ToT was obtained. Ongoing applications to fast Time-of-Flight counters and future developments of FEE have been also recently investigated.

Development of a computer-assisted high-pressure Injection device for vertebroplasty

A novel computer-assisted injection device for the delivery of highly viscous bone cements in vertebroplasty is presented. It addresses the shortcomings of manual injection systems ranging from low-pressure and poor level of control to device failure. The presented instrument is capable of generating a maximum pressure of 5000 kPa in traditional 6-ml syringes and provides an advanced control interface for precise cement delivery from outside radiation fields emitted by intraoperative imaging systems. The integrated real-time monitoring of injection parameters, such as flow-rate, volume, pressure, and viscosity, simplifies consistent documentation of interventions and establishes a basis for the identification of safe injection protocols on the longer term. Control algorithms prevent device failure due to overloading and provide means to immediately stop cement flow to avoid leakage into adjacent tissues.

Texas electronics waste management: A policy analysis for the 21st century

Electronic waste is a fairly new and largely unknown phenomenon. Accordingly, governments have only recently acknowledged electronic waste as a threat to the environment and public health. In attempting to mitigate the hazards associated with this rapidly growing toxic waste stream, governments at all levels have started to implement e-waste management programs. The legislation enacted to create these programs is based on extended producer responsibility or EPR policy. ^ EPR shifts the burden of final disposal of e-waste from the consumer or municipal solid waste system to the manufacturer of electronic equipment. Applying an EPR policy is intended to send signals up the production chain to the manufacturer. The desired outcome is to change the methods of production in order to reduce production outputs/inputs with the ultimate goal of changing product design. This thesis performs a policy analysis of the current e-waste policies at the federal and state level of government, focusing specifically on Texas e-waste policies. ^ The Texas e-waste law known, as HB 2714 or the Texas Computer TakeBack Law, requires manufacturers to provide individual consumers with a free and convenient method for returning their used computers to manufacturers. The law is based on individual producer responsibility and shared responsibility among consumer, retailers, recyclers, and the TCEQ. ^ Using a set of evaluation criteria created by the Organization for Economic Co-operation and Development, the Texas e-waste law was examined to determine its effectiveness at reducing the threat of e-waste in Texas. Based on the outcomes of the analysis certain recommendations were made for the legislature to incorporate into HB 2714. ^ The results of the policy analysis show that HB 2714 is a poorly constructed law and does not provide the desired results seen in other states with EPR policies. The TakeBack Law does little to change the collection methods of manufacturers and even less to change their production habits. If the e-waste problem is to be taken seriously, HB 2714 must be amended to reflect the proposed changes in this thesis.^

On the Evolution of the Spatial Economy with Multi-unit/Multi-plant Firms: The Impact of IT Development

This paper examines how the decline of communication costs between management and production facilities within firms and the decrease in trade costs of manufactured goods affect the spatial organization of a two-region economy with multi-unit/multi-plant firms. The development of information technology decreases the costs of communication and trade costs. Thus, the fragmentation of firms is promoted. Our result indicates that, with decreasing communication costs, firms producing low trade-cost products (such as consumer electronics) tend to concentrate their manufacturing plants in low wage countries. In contrast, firms producing high trade-cost products (such as automobiles) tend to have multiple plants serving to segmented markets, even in the absence of wage differentials.

Development of a grid connected micro wind generator. A practical activity for the course on electric generation with wind energy

This paper describes a practical activity, part of the renewable energy course where the students have to build their own complete wind generation system, including blades, PM-generator, power electronics and control. After connecting the system to the electric grid the system has been tested during real wind scenarios. The paper will describe the electric part of the work surface-mounted permanent magnet machine design criteria as well as the power electronics part for the power control and the grid connection. A Kalman filter is used for the voltage phase estimation and current commands obtained in order to control active and reactive power. The connection to the grid has been done and active and reactive power has been measured in the system.

Development of a human movement monitoring system based on wearable devices

It is essential to remotely and continuously monitor the movements of individuals in many social areas, for example, taking care of aging people, physical therapy, athletic training etc. Many methods have been used, such as video record, motion analysis or sensor-based methods. Due to the limitations in remote communication, power consumption, portability and so on, most of them are not able to fulfill the requirements. The development of wearable technology and cloud computing provides a new efficient way to achieve this goal. This paper presents an intelligent human movement monitoring system based on a smartwatch, an Android smartphone and a distributed data management engine. This system includes advantages of wide adaptability, remote and long-term monitoring capacity, high portability and flexibility. The structure of the system and its principle are introduced. Four experiments are designed to prove the feasibility of the system. The results of the experiments demonstrate the system is able to detect different actions of individuals with adequate accuracy.

Rapid Scan Electron Paramagnetic Resonance (EPR) and Digital EPR Development

Rapid scan electron paramagnetic resonance (EPR) was developed in the Eaton laboratory at the University of Denver. Applications of rapid scan to wider spectra, such as for immobilized nitroxides, spin-labeled proteins, irradiated tooth and fingernail samples were demonstrated in this dissertation. The scan width has been increased from 55 G to 160 G. The signal to noise (S/N) improvement for slowly tumbling spin-labeled protein samples that is provided by rapid scan EPR will be highly advantageous for biophysical studies. With substantial improvement in S/N by rapid scan, the dose estimation for irradiated tooth enamels became more reliable than the traditional continuous wave (CW) EPR. An alternate approach of rapid scan, called field-stepped direct detection EPR, was developed to reconstruct wider EPR signals. A Mn2+ containing crystal was measured by field-stepped direct detection EPR, which had a spectrum more than 6000 G wide. Since the field-stepped direct detection extends the advantages of rapid scan to much wider scan ranges, this methodology has a great potential to replace the traditional CW EPR. With recent advances in digital electronics, a digital rapid scan spectrometer was built based on an arbitrary waveform generator (AWG), which can excite spins and detect EPR signals with a fully digital system. A near-baseband detection method was used to acquire the in-phase and quadrature signals in one physical channel. The signal was analyzed digitally to generate ideally orthogonal quadrature signals. A multiharmonic algorithm was developed that employed harmonics of the modulation frequencies acquired in the spectrometer transient mode. It was applied for signals with complicated lineshapes, and can simplify the selection of modulation amplitude. A digital saturation recovery system based on an AWG was built at X-band (9.6 GHz). To demonstrate performance of the system, the spin-lattice relaxation time of a fused quartz rod was measured at room temperature with fully digital excitation and detection.

Molecular bandpass amplifiers. Contract AF33(616)-7252. Interim scientific report no. 1- [of the] Development Laboratory, Semiconductor Division, Hughes Aircraft Co.

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