Quantum Sensing Technologies and Smart Cities:Opportunities and Challenges

Quantum technologies are likely to raise significant benefits but also challenges to the continued development of smart cities. This paper looks at one of the more operationally ready of the quantum technologies, namely quantum sensing, and considers some of the opportunities and challenges facing city planners if they wish to introduce the capabilities of quantum sensing. The paper briefly outlines the evolution of quantum technologies and where quantum sensing fits in the quantum portfolio. It then considers two quantum sensing capabilities in more detail, namely the use of quantum sensing in navigation and in detection. The paper then describes the attributes of smart cities and discusses the opportunities and challenges of the introduction of these two quantum sensing capabilities, and outlines potential mitigation strategies to optimize the benefits while addressing the challenges

zkMixer:A Configurable Zero-Knowledge Mixer with Anti-Money Laundering Consensus Protocols

We introduce a zero-knowledge cryptocurrency mixer framework that allows groups of users to set up a mixing pool with configurable governance conditions, configurable deposit delays, and the ability to refund or confiscate deposits if it is suspected that funds originate from crime. Using a consensus process, group participants can monitor inputs to the mixer and determine whether the inputs satisfy the mixer conditions. If a deposit is accepted by the group, it will enter the mixer and become untraceable. If it is not accepted, the verifiers can freeze the deposit and collectively vote to either refund the deposit back to the user, or confiscate the deposit and send it to a different user. This behaviour can be used to examine deposits, determine if they originate from a legitimate source, and if not, return deposits to victims of crime

Generating auxeticity in graphene Kirigami with rectangular and rhomboidal perforations

Graphene Kirigami presents a transformative approach to achieving tunable auxeticity in two-dimensional materials. This study employs molecular dynamics simulations to explore the mechanical behavior of graphene with rectangular and rhomboidal perforations. The findings reveal that auxeticity, characterized by a negative Poisson's ratio (NPR), can be precisely controlled by manipulating geometric parameters such as aspect ratio (AR) and intercell spacing (IS). Structures with larger AR and smaller IS exhibit enhanced auxetic behavior, with rectangular perforations outperforming rhomboidal ones. Mechanistically, the interplay between in-plane rotation and out-of-plane deformation of Kirigami units drives the NPR, bridging macroscopic design concepts with nanoscale material phenomena. These results provide critical insights for designing graphene-based nanoscale devices with tunable mechanical properties, enabling advancements in flexible electronics, sensors, and actuators

Truly Supercritical Trade-Offs for Resolution, Cutting Planes, Monotone Circuits, and Weisfeiler–Leman

We exhibit supercritical trade-off for monotone circuits, showing that there are functions computable by small circuits for which any circuit must have depth super-linear or even super-polynomial in the number of variables, far exceeding the linear worst-case upper bound. We obtain similar trade-offs in proof complexity, where we establish the first size-depth trade-offs for cutting planes and resolution that are truly supercritical, i.e., in terms of formula size rather than number of variables, and we also show supercritical trade-offs between width and size for treelike resolution. Our results build on a new supercritical width-depth trade-off for resolution, obtained by refining and strengthening the compression scheme for the Cop-Robber game in [Grohe, Lichter, Neuen & Schweitzer 2023]. This yields robust supercritical trade-offs for dimension versus iteration number in the Weisfeiler-Leman algorithm, which also translate into trade-offs between number of variables and quantifier depth in first-order logic. Our other results follow from improved lifting theorems that might be of independent interest

Rapid Experimental Characterisation of A.C. Losses in Printed Litz Hairpins

In electric machines, higher operating fundamental frequencies result in more significant AC winding losses, further increased by inverter-induced loss at high switching frequencies. Winding AC loss characteristics may be improved with novel geometries made possible by advancements in additive manufacturing techniques, such as including targeted Litz stranding within the active length of hairpin bars. A challenge with additive manufacture is the variability in surface finish, strand separation tolerances, and electrical conductivity which impact the subsequent performance of the hairpins. This paper introduces a rapid characterisation test bench and analysis tool for validating the success of manufacturing and post-processing of additive manufactured hairpin samples. A motorette fixture is made to replicate the application slot geometry using a ferrite core to minimise parasitic iron loss. Two approaches are adopted for rapid measurement of the AC loss in the winding sample: 1. Measurement of air gap flux using a search coil in the slot with the test sample (Poynting Vector); 2. Impedance measurement of the change in primary coil resistance. The results, analysis, and accuracy of these methods are compared. Results are presented for additively manufactured Litz hairpin samples of different geometries at varying fundamental frequency

Clinical and cost-effectiveness of lithium versus quetiapine augmentation for treatment-resistant depression in adults:LQD a pragmatic randomised controlled trial

BACKGROUND: Lithium and several atypical antipsychotics are the recommended first-line augmentation options for treatment-resistant depression; however, few studies have compared them directly, and none for longer than 8 weeks. Consequently, there is little evidence-based guidance for clinicians when choosing an augmentation option for patients with treatment-resistant depression.OBJECTIVES: This trial examined whether it is more clinically and cost-effective to prescribe lithium or quetiapine augmentation therapy for patients with treatment-resistant depression over 12 months.DESIGN: This was a parallel group, multicentre, pragmatic, open-label superiority trial comparing the clinical and cost-effectiveness of lithium versus quetiapine augmentation of antidepressant medication in treatment-resistant depression. Participants were randomised 1 : 1 at baseline to the decision to prescribe either lithium or quetiapine.SETTING: Six National Health Service trusts in England.PARTICIPANTS: Eligible participants were aged ≥ 18 years, met Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria for major depressive disorder, scored ≥ 14 on the 17-item Hamilton Depression Rating Scale and whose depression had had an inadequate response to at least two therapeutic antidepressant treatment trials in the current episode, with a current antidepressant treatment at or above the therapeutic dose for ≥ 6 weeks. Patients with a history of psychosis or bipolar disorder were excluded. Patients were judged suitable for either treatment. INTERVENTIONS: After randomisation, pre-prescribing safety checks were undertaken as per standard care and trial clinicians decided whether to proceed with prescribing the allocated medication. Trial clinicians received recommendations for titration and dosing in line with current clinical guidelines; however, dosing regimens could be altered according to tolerability and response. Participants were followed up using weekly self-report questionnaires and 8-, 26- and 52-week research visits.MAIN OUTCOME MEASURES: The co-primary outcome measures were depressive symptom severity over 52 weeks, measured weekly using the self-rated Quick Inventory of Depressive Symptomatology, and time to all-cause treatment discontinuation of the trial medication. Economic analyses compared costs between the two treatment arms over 52 weeks, from a National Health Service and Personal Social Services perspective, and a societal perspective.RESULTS: Two hundred and twelve participants were randomised, 107 to quetiapine and 105 to lithium. The quetiapine arm showed a significantly greater reduction in depressive symptoms than the lithium arm over 52 weeks (quetiapine vs. lithium area under the differences curve = -68.36, 95% confidence interval: -129.95 to -6.76, p  = 0.0296). Median days to discontinuation did not significantly differ between the two arms (quetiapine = 365.0, interquartile range = 57.0-365.0, lithium = 212.0, interquartile range = 21.0-365.0), p  = 0.1196. Quetiapine was more cost effective than lithium. Thirty-two serious adverse events were recorded, only one of which was deemed possibly related to the intervention (lithium). LIMITATIONS: The trial was unblinded, therefore expectancies regarding the trial medications may have influenced the results. Further, there was substantial missing data for some of the secondary outcome measures.CONCLUSIONS: As well as being more cost-effective, quetiapine may be a more clinically effective augmentation option for treatment-resistant depression.FUTURE WORK: Examining predictors of treatment response, including clinical, sociodemographic and biological factors, will help establish whether there are additional factors to consider when choosing an augmentation treatment for treatment-resistant depression.TRIAL REGISTRATION: This trial is registered as ISRCTN16387615.FUNDING: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 14/222/02) and is published in full in Health Technology Assessment; Vol. 29, No. 12. See the NIHR Funding and Awards website for further award information. </p