Universal Distribution of Kondo Temperatures in Dirty Metals

Kondo screening of diluted magnetic impurities in a disordered host is studied analytically and numerically in one, two and three dimensions. It is shown that in the T_K \to 0 limit the distribution of Kondo temperatures has a universal form, P(T_K) \sim T_K^{-\alpha} that holds in the insulating phase and persists in the metallic phase close to the metal insulator transition. Moreover, the exponent \alpha depends only on the dimensionality. The most important consequence of this result is that the T-dependence of thermodynamic properties is smooth across the metal-insulator transition in three dimensional systems.Comment: 4 pages, 3 figures; added referenc

Lattice specific heat for the RMIn5_5 (R = Gd, La, Y, M = Co, Rh) compounds: non-magnetic contribution subtraction

We analyze theoretically a common experimental process used to obtain the magnetic contribution to the specific heat of a given magnetic material. In the procedure, the specific heat of a non-magnetic analog is measured and used to subtract the non-magnetic contributions, which are generally dominated by the lattice degrees of freedom in a wide range of temperatures. We calculate the lattice contribution to the specific heat for the magnetic compounds GdMIn$_5$ (M = Co, Rh) and for the non-magnetic YMIn$_5$ and LaMIn$_5$ (M = Co, Rh), using density functional theory based methods. We find that the best non-magnetic analog for the subtraction depends on the magnetic material and on the range of temperatures. While the phonon specific heat contribution of YRhIn$_5$ is an excellent approximation to the one of GdCoIn$_5$ in the full temperature range, for GdRhIn$_5$ we find a better agreement with LaCoIn$_5$, in both cases, as a result of an optimum compensation effect between masses and volumes. We present measurements of the specific heat of the compounds GdMIn$_5$ (M = Co, Rh) up to room temperature where it surpasses the value expected from the Dulong-Petit law. We obtain a good agreement between theory and experiment when we include anharmonic effects in the calculations

Finger Number and Device Performance: A Case Study of Reduced Graphene Oxide Microsupercapacitors

Microsupercapacitors (MSCs) are recognized as suitable energy storage devices for the internet of things (IoTs) applications. Herein is described the work conducted to assess the areal energy and power densities of MSCs with 2, 10, 20, and 40 interdigital finger electrodes on a fixed device footprint area (the finger interspacing is fixed at 40 μm, and the finger width and length are allowed to vary to fit the footprint area). The MSCs are based on reduced graphene oxide (rGO) materials and fabricated with a spin-coating and etch method. The performance evaluation indicates a strong dependency of areal capacitance and energy density on the number of fingers, and the maximum (impedance match) power density is also influenced to a relatively large extent, whereas the average power density is not sensitive to the configuration parameters in the present evaluation settings (scan rate 20–200 mV s−1 and current density of 100 μA cm−2). For the rGO-based devices, the equivalent distributed resistance may play an important role in determining the device resistance and power-related performance

Admissions to paediatric medical wards with a primary mental health diagnosis: a systematic review of the literature.

OBJECTIVE: To systematically review the literature describing children and young people (CYP) admissions to paediatric general wards because of primary mental health (MH) reasons, particularly in MH crisis. DESIGN: PubMed, Embase, PsycINFO, Web of Science and Google Scholar were searched, with no restriction on country or language. We addressed five search questions to inform: trends and/or the number of admissions, the risk factors for adverse care, the experiences of CYP, families/carers and healthcare professionals (HCPs) and the evidence of interventions aimed at improving the care during admissions.Two reviewers independently assessed the relevance of abstracts identified, extracted data and undertook quality assessment. This review was registered with PROSPERO (CRD42022350655). RESULTS: Thirty-two studies met the inclusion criteria. Eighteen addressed trends and/or numbers/proportions of admissions, 12 provided data about the views/experiences of HCPs, two provided data about CYP's experiences and four explored improving care. We were unable to identify studies examining risk factors for harm during admissions, but studies did report the length of stay in general paediatric/adult settings while waiting for specialised care, which could be considered a risk factor while caring for this group. CONCLUSIONS: MH admissions to children's wards are a long-standing issue and are increasing. CYP will continue to need to be admitted in crisis, with paediatric wards a common location while waiting for assessment. For services to be delivered effectively and for CYP and their families/carers to feel supported and HCPs to feel confident, we need to facilitate more integrated physical and MH pathways of care. PROSPERO REGISTRATION NUMBER: CRD42022350655