2D-TCAD Simulation on Retention Time of Z2FET for DRAM Application

Traditional memory devices are facing more challenges due to continuous down-scaling. 6T-SRAM suffers from variability [1-2] and reliability [3-4] issues, which introduce cell stability problems. DRAM cells with one transistor, one capacitor (1T1C) struggle to maintain refresh time [5-6]. Efforts have been made to find new memory solutions, such as one transistor (1T) solutions [7-9]. Floating body based memory structures are among the potential candidates, but impact ionization or band-to-band tunnelling (B2BT) limits their refresh time [10]. A recently proposed zero impact ionization and zero subthreshold swing device named Z2FET [9, 11-12] has been demonstrated and is a promising candidate for 1T DRAM memory cell due to technology advantages such as CMOS technology compatibility, novel capacitor-less structure and sharp switching characteristics. In the Z2FET memory operation, refresh frequency is determined by data retention time. Previous research [11-12] is lacking systematic simulation analysis and understanding on the underlying mechanisms. In this paper, we propose a new simulation methodology to accurately extract retention time in Z2FET devices and understand its dependency on applied biases, temperatures and relevant physical mechanisms. Since the stored ‘1’ state in Z2FET is an equilibrium state [9, 11-12] and there is no need to refresh, we will concentrate on state ‘0’ retention. Two types of ‘0’ retention time: HOLD ‘0’ and READ ‘0’ retention time will be discussed separately

Parameter inference in mechanistic models of cellular regulation and signalling pathways using gradient matching

A challenging problem in systems biology is parameter inference in mechanistic models of signalling pathways. In the present article, we investigate an approach based on gradient matching and nonparametric Bayesian modelling with Gaussian processes. We evaluate the method on two biological systems, related to the regulation of PIF4/5 in Arabidopsis thaliana, and the JAK/STAT signal transduction pathway

Primary accumulation in the Soviet transition

The Soviet background to the idea of primary socialist accumulation is presented. The mobilisation of labour power and of products into public sector investment from outside are shown to have been the two original forms of the concept. In Soviet primary accumulation the mobilisation of labour power was apparently more decisive than the mobilisation of products. The primary accumulation process had both intended and unintended results. Intended results included bringing most of the economy into the public sector, and industrialisation of the economy as a whole. Unintended results included substantial economic losses, and the proliferation of coercive institutions damaging to attainment of the ultimate goal - the building of a communist society

Beam interactions in one-dimensional saturable waveguide arrays

The interaction between two parallel beams in one-dimensional discrete saturable systems has been investigated using lithium niobate nonlinear waveguide arrays. When the beams are separated by one channel and in-phase it is possible to observe soliton fusion at low power levels. This new result is confirmed numerically. By increasing the power, soliton-like propagation of weakly-coupled beams occurs. When the beams are out-of-phase the most interesting result is the existence of oscillations which resemble the recently discovered Tamm oscillations.Comment: 5 pages, 6 figures, submitted to Phys. Rev.

Optical properties of highly n-doped germanium obtained by in situ doping and laser annealing

High n-type doping in germanium is essential for many electronic and optoelectronic applications especially for high performance Ohmic contacts, lasing and mid-infrared plasmonics. We report on the combination of in situ doping and excimer laser annealing to improve the activation of phosphorous in germanium. An activated n-doping concentration of 8.8  ×  1019 cm−3 has been achieved starting from an incorporated phosphorous concentration of 1.1  ×  1020 cm−3. Infrared reflectivity data fitted with a multi-layer Drude model indicate good uniformity over a 350 nm thick layer. Photoluminescence demonstrates clear bandgap narrowing and an increased ratio of direct to indirect bandgap emission confirming the high doping densities achieved

Dielectric Haloscopes: A New Way to Detect Axion Dark Matter

We propose a new strategy to search for dark matter axions in the mass range of 40-400 µeV by introducing dielectric haloscopes, which consist of dielectric disks placed in a magnetic field. The changing dielectric media cause discontinuities in the axion-induced electric field, leading to the generation of propagating electromagnetic waves to satisfy the continuity requirements at the interfaces. Large-area disks with adjustable distances boost the microwave signal (10-100 GHz) to an observable level and allow one to scan over a broad axion mass range. A sensitivity to QCD axion models is conceivable with 80 disks of 1 m2 area contained in a 10 T field

Problematica da caracterizacao de solos aluviais para fins de drenagem subterranea.

Objetivou-se estudar os problemas de interpretacao e representatividade de resultados de campo e de condutividade hidraulica de solos aluviais, definir o melhor metodo para sua caracterizacao e verificar o procedimento mais adequado para a analise desses resultados, com fins de drenagem subterranea. O trabalho foi conduzido no Projeto de Irrigacao de Sao Goncalo, PB, onde se estabeleceu um Campo Piloto de testes de drenagem subterranea de 1,3 ha. Estudou-se tambem a variabilidade espacial, horizontal e vertical das propriedades fisico-hidricas: textura, densidade global e infiltracao basica. Para o estudo da condutividade hidraulica (K) usaram-se tres metodos de campo (poco, piezometro e infiltracao basica) e um metodo indireto baseado na granulometria. Observou-se grande variacao horizontal das propriedades fisicas, principalmente devido a mistura de camadas de solo com texturas areia barrenta e barro arenoso, com outras mais adensadas pela alta concentracao de sodio. Constatou-se que os dados de densidade global e infiltracao basica tendem a ter uma distribuicao normal. A variacao da densidade aparente foi de 1,45 a 1,77 g/cm3 e a de infiltracao basica de 0,06 a 1,28 m/dia. Quanto a condutividade hidraulica, encontrou-se baixa correlacao entre valores obtidos pelos diferentes metodos, num mesmo lugar. Atraves do calculo da probabilidade de ocorrencia, definiu-se que os valores de K seguem a tendencia de uma distribuicao logaritmica. Com essa metodologia, valores representativos (...)

Cognitive Behavioral Therapy for Foreign Accent Syndrome: A single-case experimental design

Foreign accent syndrome (FAS) has historically been attributed to a neurological etiology. However, recent research has identified psychogenic causes of FAS, where patients present to health care services with medically unexplained FAS symptomology. Due to the rare nature of psychogenic FAS, there is currently no evidence-based psychological treatment for this syndrome. Although patients with psychogenic FAS do not meet the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) or the International Classification of Diseases (ICD)-10 diagnostic criteria for a diagnosis of somatization disorder, there are some similarities in presentation between psychogenic FAS and the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) criteria for somatic symptom disorder (SSD). These include the presence of distressing and disruptive symptoms that result in increased health care utilization. Given the emerging evidence for cognitive behavioral therapy (CBT) for SSDs, it is arguable that CBT could help patients with psychogenic FAS to manage the psychological distress they experience. This paper aims to explore the use of CBT in reducing the psychological distress of a patient with no organic explanation for FAS using a single-case (A-B) experimental design. The results suggest that CBT was effective in reducing distress, as measured using the Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE-OM). This paper highlights the value in using an individualized formulation-driven CBT approach for presentations that do not yet have evidence-based guidelines. In this case, cognitive restructuring, activity scheduling, and stress management appear to be key mechanisms of change in reducing psychological distress associated with FAS

D3 Brane Action and Fermion Zero Modes in Presence of Background Flux

We derive the fermion bilinear terms in the world volume action for a D3 brane in the presence of background flux. In six-dimensional compactifications non-perturbative corrections to the superpotential can arise from an Euclidean D3-brane instanton wrapping a divisor in the internal space. The bilinear terms give rise to fermion masses and are important in determining these corrections. We find that the three-form flux generically breaks a U(1) subgroup of the structure group of the normal bundle of the divisor. In an example of compactification on T^6/Z_2, six of the sixteen zero modes originally present are lifted by the flux.Comment: Important factor of ``i'' was overlooked in Euclidean continuation of WZ term. This changes the count of zero-modes in the T^6/Z_2 example. Main result stays unchanged. We thank Bergshoeff, Kallosh, Kashani-Poor, Sorokin and Tomasiello for pointing this ou