Product assurance technology for procuring reliable, radiation-hard, custom LSI/VLSI electronics

Advanced measurement methods using microelectronic test chips are described. These chips are intended to be used in acquiring the data needed to qualify Application Specific Integrated Circuits (ASIC's) for space use. Efforts were focused on developing the technology for obtaining custom IC's from CMOS/bulk silicon foundries. A series of test chips were developed: a parametric test strip, a fault chip, a set of reliability chips, and the CRRES (Combined Release and Radiation Effects Satellite) chip, a test circuit for monitoring space radiation effects. The technical accomplishments of the effort include: (1) development of a fault chip that contains a set of test structures used to evaluate the density of various process-induced defects; (2) development of new test structures and testing techniques for measuring gate-oxide capacitance, gate-overlap capacitance, and propagation delay; (3) development of a set of reliability chips that are used to evaluate failure mechanisms in CMOS/bulk: interconnect and contact electromigration and time-dependent dielectric breakdown; (4) development of MOSFET parameter extraction procedures for evaluating subthreshold characteristics; (5) evaluation of test chips and test strips on the second CRRES wafer run; (6) two dedicated fabrication runs for the CRRES chip flight parts; and (7) publication of two papers: one on the split-cross bridge resistor and another on asymmetrical SRAM (static random access memory) cells for single-event upset analysis

The ampere and the electrical units in the quantum era

By fixing two fundamental constants from quantum mechanics, the Planck constant $h$ and the elementary charge $e$, the revised Syst\`eme International (SI) of units endorses explicitly quantum mechanics. This evolution also highlights the importance of this theory which underpins the most accurate realization of the units. From 20 May 2019, the new definitions of the kilogram and of the ampere, based on fixed values of $h$ and $e$ respectively, will particularly impact the electrical metrology. The Josephson effect (JE) and the quantum Hall effect (QHE), used to maintain voltage and resistance standards with unprecedented reproducibility since 1990, will henceforth provide realizations of the volt and the ohm without the uncertainties inherited from the older electromechanical definitions. More broadly, the revised SI will sustain the exploitation of quantum effects to realize electrical units, to the benefit of end-users. Here, we review the state-of-the-art of these standards and discuss further applications and perspectives.Comment: 78 pages, 35 figure

Security Analysis of Phasor Measurement Units in Smart Grid Communication Infrastructures

Phasor Measurement Units (PMUs), or synchrophasors, are rapidly being deployed in the smart grid with the goal of measuring phasor quantities concurrently from wide area distribution substations. By utilizing GPS receivers, PMUs can take a wide area snapshot of power systems. Thus, the possibility of blackouts in the smart grid, the next generation power grid, will be reduced. As the main enabler of Wide Area Measurement Systems (WAMS), PMUs transmit measured values to Phasor Data Concentrators (PDCs) by the synchrophasor standard IEEE C37.118. IEC 61850 and IEC 62351 are the communication protocols for the substation automation system and the security standard for the communication protocol of IEC 61850, respectively. According to the aforementioned communication and security protocols, as well as the implementation constraints of different platforms, HMAC-SHA1 was suggested by the TC 57 WG group in October 2009. The hash-based Message Authentication Code (MAC) is an algorithm for verifying both message integrity and authentication by using an iterative hash function and a supplied secret key. There are a variety of security attacks on the PMU communications infrastructure. Timing Side Channel Attack (SCA) is one of these possible attacks. In this thesis, timing side channel vulnerability against execution time of the HMAC-SHA1 authentication algorithm is studied. Both linear and negative binomial regression are used to model some security features of the stored key, e.g., its length and Hamming weight. The goal is to reveal secret-related information based on leakage models. The results would mitigate the cryptanalysis process of an attacker. Adviser: Yi Qia

DETERMINATION OF ADDITIVES IN FUELS USING AUTOMATED FLOW INJECTION ANALYSIS WITH CHEMILUMINESCENCE DETECTION

The overall objective of this thesis was to develop field deployable instrumentation for the selective, sensitive determination of additives in diesel fuels using flow injection with chemiluminescence detection. The target analytes were the detergent dodecylamine and the lubricity additive P655. Chapter One describes the types of additives that are used in fully formulated diesel fuels in order to improve performance and outlines the need for robust analytical methods to be able to detect their presence / absences in fuels at the point of distribution, i.e. at the petrol pump. Flow injection (FI), and chemiluminescence (CL) are described as suitable techniques for sample preparation and detection respectively. The application of FI-CL for the quantitative determination of various analytes is reviewed, with the focus on real sample matrices. Finally the technique of solid phase extraction is discussed as a means of selective analyte preconcentration / matrix removal prior to FI-CL detection Chapter Two describes the development and optimisation (both univariate and simplex) of an FI-CL method for the determination of dodecylamine in acetonitrile / water mixtures using the catalytic effect of amines on the peroxyoxalate / sulphorhodamine 101 CL reaction. The linear range for dodecylamine was 0 - 50 mg Lˉ¹ with a detection limit of 190 µg Lˉ¹ and RSDs typically < 4 %. The effect of indigenous diesel compounds on the CL response is also investigated. Chapter Three investigates the applicability of the method developed in Chapter Two to determine dodecylamine in diesel fuels. Solid phase extraction was needed prior to analysis by FI-CL. The development of a solid phase extraction that is compatible with the FI-CL system is detailed. GC-NPD and GC-MS analysis are used in order to validate the solid phase extraction procedure. A range of diesel fuels have been spiked with an additive package containing dodecylamine and have been analysed off-line using FI-CL. Recoveries for all diesel fuels analysed were < 72 % and all fuels could by identified from the corresponding base fuel. Chapter Four describes the design and construction of a fully automated on-line solid phase extraction flow injection chemiluminescence analyser for the determination of dodecylamine in diesel fuel. Details of the automation and programming using LabVIEW are described. Results obtained using the automated on-line system are compared with results obtained using off-line SPE with FI-CL detection from Chapter Three. Recoveries for all fuels except SNV were < 71 %, and all fuels except SNV could be positively identified from the corresponding base fuels. No significant differences were found between the on-line and off-line results (within 95 % confidence limits). Chapter Five investigates the feasibility of determining the lubricity additive P655 in diesel fuel using FI-CL. The optimisation and development of a method using the competing reactions of periodate with alcohols and periodate with the CL oxidation reaction with pyrogallol is discussed, and the development of a solid phase extraction procedure for the extraction of P655 from an organic matrix is described. The limit of detection for P655 using SPE without preconcentration was 860 mg Lˉ¹ and was linear in the range 0 - 10000 mg Lˉ¹ (R² = 0.9965).Shell Global Solutions, Cheshire Innovation Park, Cheste

Development and application of autonomous nutrient analysers for natural waters

The warming of the oceans and consequent enhanced stratification will have significant consequences for ecosystem functioning and carbon sequestration. Nutrient supply will reduce as a result of a strengthening in the stratification, with consequences for microbial ecosystems. Oligotrophic ocean regions are therefore predicted to increase in size as a consequence of global warming. This strengthens the requirement for analytical techniques with low limits of detection for nitrate and phosphate as conventional methods are unable to detect the nanomolar nutrient concentrations in surface waters in these regions. In recent years, sensitive techniques have been developed for shipboard nutrient analysis at nanomolar level with a high sample throughput. An analyser coupled with liquid waveguide capillary cells was deployed in the Atlantic. These techniques are however not suitable for autonomous deployment in oceans for long-term observations. Therefore, I have been working on the miniaturisation of nanomolar nutrient techniques using novel Lab-on-a-chip devices. The aim is to develop systems that are small, low-cost and low-power, and can be used autonomously and remotely to provide in situ real-time data on processes with high temporal and spatial resolution. Microfluidic technology is being used as it enables minimization of reagent and power consumption for in situ deployment of wet-chemical methods which provide accurate results with low limits of detection and high spatial and temporal resolution. In the 3rd chapter, we describe the development of an autonomous analyser for the determination of dissolved reactive phosphorus based on the vanadomolybdate method which allows long-term deployments thanks to the stability of the reagents. It has been deployed off the coast in Plymouth and during D361 (Atlantic). Then in the 4th chapter, a microfluidic platform to measure phosphate with the molybdenum blue method is characterised with optimised parameters and applied to marine waters

The development of a point of care device for measuring blood ammonia

Ammonia is produced in the body during the metabolism of amino acids. In the liver, it is converted to urea via the urea cycle and excreted by the kidneys as urine. Normal levels are between 11 to 50 µM, whereas a blood ammonia level of approximately 100 µM indicates pathology. Elevated blood ammonia is associated with a number of pathological conditions including liver and kidney dysfunction. Conditions such as these can affect brain function and can be fatal. Current blood ammonia analysis requires a laboratory blood test. Few, if any of the techniques used are suitable for point of care (POC) testing. The development of a reliable and simple method for blood ammonia determination is essential for clinical diagnosis and management of patient progress in order to prevent further debilitating illnesses developing, and extending life. This is particularly critical in many disorders such as hyperammonaemia of the newborn, inborn errors of metabolism including urea cycle defects, organic acidaemias, hyperinsulinism/hyperammonaemia, liver disease and other cause of hyperammonaemic encephalopathy. This thesis investigates the development of an electrochemical sensor for the measurement of ammonia in blood. Polyaniline has a known affinity for ammonia which operates on the deprotonation of the polyaniline backbone forming an ammonium ion. In this work, polyaniline nanoparticles were fabricated and inkjet-printed onto silver screen printed electrodes. The sensors were then incorporated into devices containing a gas-permeable membrane, which facilitated the measurement of gaseous ammonia from a liquid sample (blood) using electrochemical impedance spectroscopy. The combination of impedance spectroscopy with a gas-permeable membrane allowed the measurement of gaseous ammonia from solution. The ammonia device developed possessed refinements to enhance its sensitivity and included careful optimisation of other aspects of the measurement. For example, an air purge through the device gas chamber was employed to remove matrix interferences from the sensor and improve the specificity to ammonia. The pH of the sample to be analysed was modified in order to increase the mass of ammonia in solution, thus lowering the limit of detection (LOD) of the device. Finally, assay timings were optimised in order to increase the impedimetric response of ammonia. These optimisations resulted in the effective detection of ammonia in a liquid sample down to the lowest clinically relevant levels found in blood. The devices displayed an impedimetric baseline intra- and inter-variability of 25 and 6.9%, respectively for n = 15 over a period of 160 s. A calculated limit of LOD of 12 µM was achieved for human serum measurements. A coefficient of determination of 0.9984, slope of 0.0046 and an intercept of 1.1534 was obtained in human serum across the linear range of 25 to 200 μM ammonia (n = 3). The device was validated against a commercial spectrophotometric assay which resulted in excellent correlation (0.9699, p < 0.0001) with a slope of 1.4472 and an intercept of 0.5631 between both methods (n = 3). The devices could be stored in desiccant for up to five months and displayed minimal variation (0.64%) over time (n = 12)

United Technologies Robotic Tool for Aircraft Rim Cleaning

Conventional systems for cleaning aircraft split rims waste millions of dollars in water and electrical resources annually. Team B.E.E.M. was tasked by the United Technologies Research Center (UTRC) in East Hartford, CT, with developing an alternative method for cleaning aircraft rims. To suit the needs of operation facilities under United Technologies Aerospace Systems, the product must reduce annual waste, maintain the current cleaning cycle time, and avoid damaging the anodized coating on the wheel rim’s surface. These design requirements are to be met with a fully automated system that implements laser ablation. Laser ablation is a no-contact process that vaporizes targeted materials, eliminates the use of water, and significantly reduces electrical wattage. The system design consists of a 1.0 KW Yttrium-fiber laser coupled with a collimator and galvanometer on the head of a robotic arm. The galvanometer aims at a rotating wheel to ablate the entire surface. Scaled testing with a 20-watt laser and five varying mixtures of dirt, grease, and carbon dust proved that an ablation system can clean up to 95% of the targeted dirt surface. A half-scale model of the loading system was developed to simulate the laser trajectory across the surface of the wheel rim and proved to be capable of reaching all surfaces, including the bolt and spoke holes. This report presents design specifications for the project, as well as research on optic technology and contamination found on an aircraft wheel rim. The team proposed 120 concepts as alternative methods for cleaning aircraft split rims, which were judged by the ability to satisfy parameters in a Quality Function Deployment analysis set by the United Technologies Research Center. Engineering analysis is provided for theoretical energy requirements for vaporizing contamination, the dynamics and structural integrity of the turntable, and the trajectory algorithm for the robotic manipulator. The design and production of the half-scale model are documented, along with additional redesign features. The laser parameters were verified through scaled tests at IPG Photonics in Oxford, Massachusetts, and the half-scale model was tested for covering the entire surface of the wheel rim. A financial analysis of the project proved to significantly reduce operation costs after a high initial cost. The Laser Ablation Robotic Rim Intensive Cleaner (LARRIC) has exceeded all design specifications outlined throughout this report. The LARRIC successfully met design considerations throughout the prototyping phase of product development. Further design considerations are provided in this report to optimize the system design and laser trajectory

Quantifying, Understanding and Predicting Differences Between Planned and Delivered Dose to Organs at Risk in Head & Neck Cancer Patients Undergoing Radical Radiotherapy to Promote Intelligently Targeted Adaptive Radiotherapy

Introduction: Radical radiotherapy (RT) is an effective but toxic treatment for head and neck cancer (HNC). Contemporary radiotherapy techniques sculpt dose to target disease and avoid organs at risk (OARs), but anatomical change during treatment mean that the radiation dose delivered to the patient – delivered dose (DA), is different to that anticipated at planning – planned dose (DP). Modifying the RT plan during treatment – Adaptive Radiotherapy (ART) – could mitigate these risks by reducing dose to OARs. However, clinical data to guide patient selection for, and timing of ART, are for lacking. Methods: 337 patients with HNC were recruited to the Cancer Research UK VoxTox study. Demographic, disease and treatment data were collated, and both DP and DA to organs at risk (OARs) were computed from daily megavoltage CT image guidance scans, using an open-source deformable image registration package (Elastix). Toxicity data were prospectively collected. Relationships between DP, DA and late toxicities were investigated with univariate, and logistic regression normal tissue complication probability (NTCP) modelling approaches. A sub-study of VoxTox recruited 18 patients who had MRI scans before RT fractions 1, 6, 16, and 26. Changes in salivary gland volumes and relative apparent diffusion coefficient (ADC) values were measured and related to toxicity events. Results: Spinal cord dose differences were small, and not predicted by weight loss or shape change. Mean DA to all other OARs was higher than DP; factors predicting higher DA included primary disease site, concomitant therapy, shape change and advanced neck disease. Nine patients (3.7%) saw DA>DP by 2Gy to more than half of the OARs assessed. These patients all had received bilateral neck RT for N-stage 2b oropharyngeal cancer. Strong uni- and multivariate relationships between OAR dose and toxicity were seen. Differences between DA and DP-based dose-toxicity models were minimal, and not statistically significant. On MRI, both parotid and submandibular glands shrank during treatment, whilst relative ADC rose. Relationships with toxicity were inconclusive. Conclusions: Small differences between OAR DP and DA mean that DA-based toxicity prediction models confer negligible additional benefit at the population level. Factors such as primary disease sub-site, concomitant systemic therapy, staging and shape change may help to select the patients that do develop clinically significant dose differences, and would benefit most from ART for toxicity reduction

Development and Applications of the Rapid Analysis of Post-Irradiation Debris (RAPID) Method to Nuclear Materials

Chemical analysis of nuclear materials is a well-developed area of research, through use of mass spectrometers and other destructive analysis techniques. These analyses are applicable to several nuclear fields, such as nuclear forensics, fuel characterization and modeling, and environmental monitoring. For nuclear forensics particularly, a rapid analytical chemistry technique can be useful, given the need for a quick turn-around of data in certain attribution cases for nuclear forensics. An analytical technique for low-level nuclear material analyses has been developed and applied to various samples at Oak Ridge National Laboratory (ORNL), named Rapid Analysis of Post-Irradiation Debris (RAPID). This technique combines a high-pressure ion chromatography unit and an inductively-coupled plasma mass spectrometer for a rapid, direct separation-detection method, with a turn-around of less than four hours per sample, including dissolution, analysis, and data processing. Analyzed samples include irradiated highly-enriched uranium, ORNL-developed, and UTK-developed surrogate nuclear “debris”. This dissertation will present the development of RAPID and its subsequent evolution and application to nuclear forensics, obtaining the sensitivity and accuracy for operational usage at ORNL. Additionally, a novel inline gamma detection technique was developed as an extension of RAPID and will be presented, demonstrating the feasibility of elementally-isolated gamma spectrometry and the benefit of having two complementary analytical techniques to fully characterize fission products in a short timeframe

The design and evaluation of discrete wearable medical devices for vital signs monitoring

The observation, recording and appraisal of an individual’s vital signs, namely temperature, heart rate, blood pressure, respiratory rate and blood oxygen saturation (SpO2), are key components in the assessment of their health and wellbeing. Measurements provide valuable diagnostic data, facilitating clinical diagnosis, management and monitoring. Respiratory rate sensing is perhaps the most under-utilised of all the vital signs, being routinely assessed by observation or estimated algorithmically from respiratory-induced beat-to-beat variation in heart rate. Moreover there is an unmet need for wearable devices that can measure all or most of the vital signs. This project therefore aims to a) develop a device that can measure respiratory rate and b) develop a wearable device that can measure all or most of the vital signs. An accelerometer-based clavicular respiratory motion sensor was developed and compared with a similar thoracic motion sensor and reference using exhalatory flow. Pilot study results established that the clavicle sensor accurately tracked the reference in monitoring respiratory rate and outperformed the thoracic device. An Ear-worn Patient Monitoring System (EPMS) was also developed, providing a discrete telemonitoring device capable of rapidly measuring tympanic temperature, heart rate, SpO2 and activity level. The results of a comparative pilot study against reference instruments revealed that heart rate matched the reference for accuracy, while temperature under read (< 1°C) and SpO2 was inconsistent with poor correlation. In conclusion, both of the prototype devices require further development. The respiratory sensor would benefit from product engineering and larger scale testing to fully exploit the technology, but could find use in both hospital and community-based The design and evaluation of discrete wearable medical devices for vital signs monitoring DG Pitts ii Cranfield University monitoring. The EPMS has potential for clinical and community use, having demonstrated its capability of rapidly capturing and wirelessly transmitting vital signs readings. Further development is nevertheless required to improve the thermometer probe and resolve outstanding issues with SpO2 readings