Three-dimensional charge transport mapping by two-photon absorption edge transient-current technique in synthetic single-crystalline diamond

We demonstrate the application of two-photon absorption transient current technique to wide bandgap semiconductors. We utilize it to probe charge transport properties of single-crystal Chemical Vapor Deposition (scCVD) diamond. The charge carriers, inside the scCVD diamond sample, are excited by a femtosecond laser through simultaneous absorption of two photons. Due to the nature of two-photon absorption, the generation of charge carriers is confined in space (3-D) around the focal point of the laser. Such localized charge injection allows to probe the charge transport properties of the semiconductor bulk with a fine-grained 3-D resolution. Exploiting spatial confinement of the generated charge, the electrical field of the diamond bulk was mapped at different depths and compared to an X-ray diffraction topograph of the sample. Measurements utilizing this method provide a unique way of exploring spatial variations of charge transport properties in transparent wide-bandgap semiconductors.Comment: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Applied Physics Letters and may be found at https://doi.org/10.1063/1.509085

Perancangan Aplikasi E-Commerce Berbasis Android pada Kelompok Swadaya Masyarakat Desa Margakaya Pringsewu

E-commerce adalah kegiatan jual beli barang dan jasa melalui penggunaan smartphone dan internet yang biasanya sering di sebut Business to Consumer. Perancangan Aplikasi Berbasis Android untuk Kelompok Swadaya Masyarakat di Desa Margakaya nantinya akan digunakan dalam pemesanan produk kerajinan masyarkat Margakaya Pringsewu. Pengembangan sistem informasi yang di gunakan menggunakan siklus Systems Development Life Cycle dengan tahapan-tahapan yang telah di tentukan. Dari hasil uji sistem didaptakan hasil bahwa sistem ini sangat memantu pemasaran produk uasaha kecil menenga

Attosecond screening dynamics mediated by electron-localization

Transition metals with their densely confined and strongly coupled valence electrons are key constituents of many materials with unconventional properties, such as high-Tc superconductors, Mott insulators and transition-metal dichalcogenides. Strong electron interaction offers a fast and efficient lever to manipulate their properties with light, creating promising potential for next-generation electronics. However, the underlying dynamics is a fast and intricate interplay of polarization and screening effects, which is poorly understood. It is hidden below the femtosecond timescale of electronic thermalization, which follows the light-induced excitation. Here, we investigate the many-body electron dynamics in transition metals before thermalization sets in. We combine the sensitivity of intra-shell transitions to screening effects with attosecond time resolution to uncover the interplay of photo-absorption and screening. First-principles time-dependent calculations allow us to assign our experimental observations to ultrafast electronic localization on d-orbitals. The latter modifies the whole electronic structure as well as the collective dynamic response of the system on a timescale much faster than the light-field cycle. Our results demonstrate a possibility for steering the electronic properties of solids prior to electron thermalization, suggesting that the ultimate speed of electronic phase transitions is limited only by the duration of the controlling laser pulse. Furthermore, external control of the local electronic density serves as a fine tool for testing state-of-the art models of electron-electron interactions. We anticipate our study to facilitate further investigations of electronic phase transitions, laser-metal interactions and photo-absorption in correlated electron systems on its natural timescale

A Framework for Evaluating Security in the Presence of Signal Injection Attacks

Sensors are embedded in security-critical applications from medical devices to nuclear power plants, but their outputs can be spoofed through electromagnetic and other types of signals transmitted by attackers at a distance. To address the lack of a unifying framework for evaluating the effects of such transmissions, we introduce a system and threat model for signal injection attacks. We further define the concepts of existential, selective, and universal security, which address attacker goals from mere disruptions of the sensor readings to precise waveform injections. Moreover, we introduce an algorithm which allows circuit designers to concretely calculate the security level of real systems. Finally, we apply our definitions and algorithm in practice using measurements of injections against a smartphone microphone, and analyze the demodulation characteristics of commercial Analog-to-Digital Converters (ADCs). Overall, our work highlights the importance of evaluating the susceptibility of systems against signal injection attacks, and introduces both the terminology and the methodology to do so.Comment: This article is the extended technical report version of the paper presented at ESORICS 2019, 24th European Symposium on Research in Computer Security (ESORICS), Luxembourg, Luxembourg, September 201

Impact of Variations in the Nursing Care Supply-Demand Ratio on Postoperative Outcomes and Costs.

Improving surgical outcomes is a priority during the last decades because of the rising economic health care burden. The adoption of enhanced recovery programs has been proven to be part of the solution. In this context, the impact of variations in the nursing care supply-demand ratio on postoperative complications and its economic consequences is still not well elucidated. Because patients require different amounts of care, the present study focused on the more accurate relationship between demand and supply of nursing care rather than the nurse-to-patient ratio. Through a 3-year period, 838 patients undergoing elective and emergent colorectal and pancreatic surgery within the institutional enhanced recovery after surgery (ERAS) protocol were retrospectively investigated. Nursing demand and supply estimations were calculated using a validated program called the Projet de Recherche en Nursing (PRN), which assigns points to each patient according to the nursing care they need (estimated PRN) and the actual care they received (real PRN), respectively. The real/estimated PRN ratio was used to create 2 patient groups: one with a PRN ratio higher than the mean (PRN+) and a second with a PRN ratio below the mean (PRN-). These 2 groups were compared regarding their postoperative complication rates and cost-revenue characteristics. The mean PRN ratio was 0.81. A total of 710 patients (84.7%) had a PRN+ ratio, and 128 (15.3%) had a PRN- ratio. Multivariable analysis focusing on overall complications, severe complications, and prolonged length of stay revealed no significant impact of the PRN ratio for all outcomes (P > 0.2). The group PRN- had a mean margin per patient of U.S. dollars 1426 (95% confidence interval, 3 to 2903) compared with a margin of U.S. dollars 676 (95% confidence interval, -2213 to 3550) in the PRN+ group (P = 0.633). A PRN ratio of 0.8 may be sufficient for patients treated following enhanced recovery after surgery guidelines, pending the adoption of an accurate nursing planning system. This may contribute to better allocation of nursing resources and optimization of expenses on the long run

Design of Experiments for Factor Hierarchization in Complex Structure Modelling

Modelling the power-grid network is of fundamental interest to analyse the conducted propagation of unintentional and intentional electromagnetic interferences. The propagation is indeed highly influenced by the channel behaviour. In this paper, we investigate the effects of appliances and the position of cables in a low voltage network. First, the power-grid architecture is described. Then, the principle of Experimental Design is recalled. Next, the methodology is applied to power-grid modelling. Finally, we propose an analysis of the statistical moments of the experimental design results. Several outcomes are provided to describe the effects induced by parameter variability on the conducted propagation of spurious compromising emanations

Increasing prevalence of obesity and diabetes among patients evaluated for liver transplantation in a Swiss tertiary referral center: a 10-year retrospective analysis.

Non-alcoholic fatty liver disease (NAFLD) is now the first cause of chronic liver disease in developed countries. We aimed to assess trends in the prevalence of obesity, type 2 diabetes mellitus (T2DM) and NAFLD in patients undergoing liver transplantation evaluation and to assess whether obese patients were less likely to be listed or had an increased drop-out rate after listing. We conducted a retrospective study of all consecutive patients who underwent liver transplantation evaluation at a Swiss tertiary referral centre between January 2009 and March 2020. A total of 242 patients were included, 83% were male. The median age was 59 years (IQR, 51-64 years). The most common causes of end-stage liver disease were viral hepatitis (28%), alcoholic liver disease (21%) and NAFLD (12%). Obesity was present in 28% of our cohort, with a significant increase over time. Prevalence of type 2 diabetes mellitus followed the same trend (p = 0.02). The proportions of non-listed and listed obese patients did not differ (21% vs. 30% respectively; p = 0.3). The prevalence of obesity and type 2 diabetes mellitus significantly increased over our study period. Obese patients had similar chances of being listed. The landscape of liver transplantation indications is shifting towards NAFLD, highlighting the urgent need to prevent NAFLD progression