Detection Optimization of Disbond in Layered Composites with Varying Thicknesses using an Open-Ended Rectangular Waveguide

The detection of air disbond in layered dielectric composite, which is an important practical issue in many industries, is studied both theoretically and experimentally. Sensitivity of disbond detection depends on certain parameters, like the frequency of operation, the distance between the sensor and the first dielectric layer, and the layered composite geometry (conductor backed or terminated by an infinite half-space of air). The impact of all these parameters is investigated theoretically and then verified experimentally

Paracetamol Detoxification Using ODTMA Micelles-Activated Charcoal Complex

Paracetamol poisoning is among the most common causes of medication related poisoning and death. The evidence for all interventions for paracetamol overdose is weak. Activated charcoal, gastric lavage, and ipecacuanha are able to reduce absorption of paracetamol if started within one to two hours of paracetamol ingestion, but the clinical benefit is unclear. Therefore, there is a pressing need to invent modified forms of activated carbon and other adsorbents to treat paracetamol toxification. In this study we have investigated the efficiency of octadecyltrimethylammonium (ODTMA) micelles-activated charcoal (OMAC) complex that possesses a positive charge, a high surface area and a high affinity to capture paracetamol molecules. Various pHs were studied to evaluate the effect of pH on the removal of paracetamol by this adsorbent. The adsorption isotherm results demonstrate a fit to Freundlich adsorption isotherm and adsorption kinetics follow a pseudo second order kinetics model. The results revealed that OMAC complex can enhance the detoxification of paracetamol at high doses in the stomach even at low pH compared to activated charcoal. Furthermore, the results indicate that OMAC complex can adsorb paracetamol in different forms at different pHs relative to charcoal, which renders the complex a better detoxification agent than activated charcoal

Reconstruction probing

https://doi.org/10.18653/v1/2023.findings-acl.523Published versio

A semantically-enriched quality governance framework in the system of systems context applied to cancer care

Organisations are becoming more complex with diverse businesses, and therefore accomplishing their business objectives entails the need to develop System of Systems (SoS) with new capabilities based on existing monolithic systems of different domains. Regardless of the business objectives of these organisations, they can only be achieved if the right level of quality is ensured across the SoS arrangement. In order to deliver new SoS capabilities, interoperability between the SoS’s Constituent Systems (CSs) is required. Semantic inconsistencies at different levels of SoS’s constituent systems causes various challenges which can degrade the level of quality governance among the SoS arrangement. These inconsistencies mainly are due to the domain process’ heterogeneities, multiple standards followed, policies and varying levels of quality requirements of the CSs, and hence the level of interoperability affecting the anticipated quality.To respond to the above challenges, this research is aimed at investigating the effectiveness of semantically-enriched quality governance in relation to policies, processes, standards and quality requirements of the constituent systems in a SoS arrangement. For this purpose, a semantically enriched framework for the quality governance of SoS, i.e. OntoSoS.QM.Gov (Ontology-based System of Systems Quality Management Governance) has been developed and evaluated incrementally using an adaptation of the Design Science Research Methodology (DSRM). A sufficient and representative case study has been utilised in the DSRM process increments from the SoS cancer care domain, in particular, the Cell Therapy and Applied Genomics (CTAG) at the King Hussein Cancer Centre (KHCC), Jordan. The OntoSoS.QM.Gov framework consists of four ontological models: (i) the SoS standards ontology model (OntoSoS.Stand), (ii) the SoS quality requirements ontology model (OntoSoS.QR), (iii) the SoS process ontology model (OntoSoS.Process), and (iv) the SoS policies ontology model (OntoSoS.Policy). They are linked together using a fit-for-purpose governance process in managing the semantics of the relevant quality governance areas.The outcomes of demonstrating the OntoSoS.QM.Gov framework using the CTAG case study and evaluating it with the cancer care domain experts revealed the following. First, semantic heterogeneities between CSs and SoS in relation to their policies, processes, quality requirements and standards have been resolved. Second, the fit- for- purpose quality governance process was observed to mostly determining and resolving conflicts with minimum human intervention. Third, the adequacy of the four ontological governance models in capturing the semantics of governance in relation to policies, processes, quality requirements and standards not only for CSs but also as stand-alone models that may further be utilised in different contexts or domains.Finally, this research has to identify further research areas to explore in relation to the governance of change management of constituent systems’ processes, policies, standards where their business processes change

Calibration and Measurement of Dielectric Properties of Finite Thickness Composite Sheets with Open-Ended Coaxial Sensors

The application of open-ended coaxial sensors for dielectric measurement of finite thickness composite sheets is studied. Expressions for calculation of the complex aperture admittance for two geometries are presented. These expressions are used to calculate the dielectric constant of infinite half-space as well as finite thickness slabs. A more efficient method of such calculations, using a personal computer, for low to medium loss dielectrics is demonstrated. The question of when a dielectric layer may be considered as infinitely thick is also addressed, and examples are presented. A different calibration technique (compared to the conventional ones) is described and successfully implemented. This calibration technique utilizes a dielectric sheet with known dielectric properties and thickness. Measurements for different airgaps between the open-ended coaxial line and the dielectric sheet are used to perform and enhance the calibration. The results of this calibration technique and several subsequent measurements are presented and discussed

Microwave Detection Optimization of Disbond in Layered Dielectrics with Varying Thickness

The detection sensitivity optimization of air disbond in layered dielectric composites, using an open-ended rectangular waveguide, is studied both theoretically and experimentally. The sensitivity of the disbond detection is strongly influenced by the proper choice of parameters such as the operating frequency and the layered composite geometry (conductor backed or terminated by an infinite half-space of air). The capability of optimizing the measurement system parameters to detect and estimate the thickness of a disbonded layer independent of some changes in the thickness of the dielectric coating is also demonstrated. The impact of the parameters influencing detection optimization is theoretically investigated and then experimentally verified

Microwave Noncontact Examination of Disbond and Thickness Variation in Stratified Composite Media

Numerical and experimental results of a microwave noncontact, nondestructive detection and evaluation of disbonds and thickness variations in stratified composite media are presented. The aperture admittance characteristics of a flange mounted rectangular waveguide radiating into a layered, generally lossy dielectric media backed or unbacked by a conducting sheet is modeled. The theoretical implementation is based on a Fourier transform boundary matching technique to construct the field components in each medium, coupled with a stationary form of the terminating aperture admittance of the waveguide. The model can serve as a reliable test bed for real-time examination of layered composite media. Experimental results for several cases are presented which show good agreement with the theoretical findings. This is a versatile technique for near-field in situ interrogation of stratified composite media which provides for high resolution measurements

What's my role? Modelling responsibility for AI-based safety-critical systems

AI-Based Safety-Critical Systems (AI-SCS) are being increasingly deployed in the real world. These can pose a risk of harm to people and the environment. Reducing that risk is an overarching priority during development and operation. As more AI-SCS become autonomous, a layer of risk management via human intervention has been removed. Following an accident it will be important to identify causal contributions and the different responsible actors behind those to learn from mistakes and prevent similar future events. Many authors have commented on the "responsibility gap" where it is difficult for developers and manufacturers to be held responsible for harmful behaviour of an AI-SCS. This is due to the complex development cycle for AI, uncertainty in AI performance, and dynamic operating environment. A human operator can become a "liability sink" absorbing blame for the consequences of AI-SCS outputs they weren't responsible for creating, and may not have understanding of. This cross-disciplinary paper considers different senses of responsibility (role, moral, legal and causal), and how they apply in the context of AI-SCS safety. We use a core concept (Actor(A) is responsible for Occurrence(O)) to create role responsibility models, producing a practical method to capture responsibility relationships and provide clarity on the previously identified responsibility issues. Our paper demonstrates the approach with two examples: a retrospective analysis of the Tempe Arizona fatal collision involving an autonomous vehicle, and a safety focused predictive role-responsibility analysis for an AI-based diabetes co-morbidity predictor. In both examples our primary focus is on safety, aiming to reduce unfair or disproportionate blame being placed on operators or developers. We present a discussion and avenues for future research.Comment: 22 pages, 7 figures, 2 table

Microwave Diagnosis of Rubber Compounds

The results of a study investigating the dielectric properties of rubber compounds and their constituents in the frequency range of 5 to 24 GHz are presented. A completely filled short circuited waveguide technique was used to conduct these dielectric measurements. The influence of carbon black content in rubber was investigated for carefully prepared rubber samples. The results showed that for all frequencies, the dielectric constant increases as a function of increasing carbon black content. The variation of dielectric constant values decreases as frequency increases. The presence of curatives in uncured rubber samples was also detected, which indicates the sensitivity of microwaves to the chemical reaction triggered by curatives