scholarly journals A modified pseudo 2D physically-based model for double-gate TFETs: Role of precise calculations of drain and source depletion regions

2021 ◽  
Author(s):  
Yasmin Yahia ◽  
Marwa. S. Salem ◽  
A. Shaker ◽  
H. Kamel ◽  
M. Abouelatta ◽  
...  
Keyword(s):  
Double Gate ◽  
Physically Based Model ◽  
Physically Based ◽  
Source Depletion

scholarly journals Analysis of landslide triggering conditions in the Sarno area using a physically based model

2014 ◽  
Vol 18 (8) ◽  
pp. 3225-3237 ◽  
Author(s):  
G. Capparelli ◽  
P. Versace
Keyword(s):  
Dominant Role ◽  
Technical Literature ◽  
Subsurface Hydrology ◽  
Physically Based Model ◽  
Physically Based ◽  
Prone Area ◽  
Triggering Conditions ◽  
Slope Instabilities ◽  
Analytical Approaches

Abstract. Rainfall is recognized as a major precursor of many types of slope movements. The technical literature reports both study cases and models of landslides induced by rainfall. Subsurface hydrology has a dominant role since changes in the soil water content significantly affect the soil shear strength. The analytical approaches used are very different, ranging from statistical models to distributed and complete models. The latter take several components into account, including specific site conditions, mechanical, hydraulic and physical soil properties, local seepage conditions, and the contribution of these to soil strength. This paper reports a study using a complete model, named SUSHI (Saturated Unsaturated Simulation for Hillslope Instability), to simulate the role of subsurface hydrology in rain-induced landslides, on a case of great interest both in terms of its complexity and its severity. The landslide-prone area in question is located in Campania (southern Italy), where disastrous mudflows occurred in May 1998. The region has long been affected by rainfall-induced slope instabilities, which often involve large areas and affect many people. The application allows a better understanding of the role of rainfall infiltration and suction changes in the triggering mechanism of the phenomena. These changes must be carefully considered when assessing hazard levels and planning mitigation interventions regarding slope stability.

A Physically Based Model to Study the Role of Soils in the Generation of Urban Flow Rates

2002 ◽  
Author(s):  
Emmanuel Berthier ◽  
Hervé Andrieu ◽  
Jean-Dominique Creutin ◽  
Georges Raimbault
Keyword(s):  
Flow Rates ◽  
Physically Based Model ◽  
Physically Based ◽  
Urban Flow

Modelling the Crystallization Reactions of Amorphous Precursors in Fe3B/Nd2Fe14B Nanocomposite Magnets

2010 ◽  
Vol 654-656 ◽  
pp. 1166-1169
Author(s):  
Vanalysa Ly ◽  
Stéphane Gorsse ◽  
Kiyonori Suzuki ◽  
Christopher R. Hutchinson
Keyword(s):  
Homogeneous Nucleation ◽  
Thermodynamic Assessment ◽  
Nucleation And Growth ◽  
Rate Model ◽  
Model Calculations ◽  
Physically Based Model ◽  
Thermodynamics And Kinetics ◽  
Physically Based ◽  
Hard Magnets

A physically-based model is proposed for the competitive precipitation of multiple phases (bcc-Fe, Fe3B, Nd2Fe14B, Nd2Fe23B3, NdFe4B4 and Fe2B) from an amorphous Fe-B-Nd matrix. These materials form the basis of a class of nanocomposite hard magnets. The nucleation and growth of the different phases are calculated using computational thermodynamics and kinetics tools with input from a thermodynamic assessment of this system. In some alloy compositions, the phase formation sequence during crystallization shows significant sensitivity to the heating-rate. Model calculations illustrate that this effect cannot be explained by homogeneous nucleation and growth of the phases. The possible role of heterogeneous nucleation is briefly discussed.

scholarly journals A physically based model to predict hydraulic erosion of fine-grained riverbanks: The role of form roughness in limiting erosion

2010 ◽  
Vol 115 (F4) ◽  
Author(s):  
Stephen E. Darby ◽  
Hai Q. Trieu ◽  
Paul A. Carling ◽  
Juha Sarkkula ◽  
Jorma Koponen ◽  
...  
Keyword(s):  
Physically Based Model ◽  
Fine Grained ◽  
Physically Based

scholarly journals A new approach to mapping landslide hazards: a probabilistic integration of empirical and physically based models in the North Cascades of Washington, USA

2019 ◽  
Vol 19 (11) ◽  
pp. 2477-2495
Author(s):  
Ronda Strauch ◽  
Erkan Istanbulluoglu ◽  
Jon Riedel
Keyword(s):  
Statistical Approach ◽  
Joint Probability ◽  
North Cascades ◽  
Physically Based Model ◽  
New Approach ◽  
The North ◽  
Debris Avalanches ◽  
Landslide Hazards ◽  
Infinite Slope Stability Model ◽  
Physically Based

Abstract. We developed a new approach for mapping landslide hazards by combining probabilities of landslide impacts derived from a data-driven statistical approach and a physically based model of shallow landsliding. Our statistical approach integrates the influence of seven site attributes (SAs) on observed landslides using a frequency ratio (FR) method. Influential attributes and resulting susceptibility maps depend on the observations of landslides considered: all types of landslides, debris avalanches only, or source areas of debris avalanches. These observational datasets reflect the detection of different landslide processes or components, which relate to different landslide-inducing factors. For each landslide dataset, a stability index (SI) is calculated as a multiplicative result of the frequency ratios for all attributes and is mapped across our study domain in the North Cascades National Park Complex (NOCA), Washington, USA. A continuous function is developed to relate local SI values to landslide probability based on a ratio of landslide and non-landslide grid cells. The empirical model probability derived from the debris avalanche source area dataset is combined probabilistically with a previously developed physically based probabilistic model. A two-dimensional binning method employs empirical and physically based probabilities as indices and calculates a joint probability of landsliding at the intersections of probability bins. A ratio of the joint probability and the physically based model bin probability is used as a weight to adjust the original physically based probability at each grid cell given empirical evidence. The resulting integrated probability of landslide initiation hazard includes mechanisms not captured by the infinite-slope stability model alone. Improvements in distinguishing potentially unstable areas with the proposed integrated model are statistically quantified. We provide multiple landslide hazard maps that land managers can use for planning and decision-making, as well as for educating the public about hazards from landslides in this remote high-relief terrain.

New physically based model for thermal induced initial stress in 3D for silicon germanium films after deposition

2014 ◽  
Vol 33 (6) ◽  
pp. 2121-2138 ◽  
Author(s):  
Abderrazzak El Boukili
Keyword(s):  
Thermal Expansion ◽  
Initial Stress ◽  
Silicon Germanium ◽  
Rate Of Change ◽  
Thermal Mismatch ◽  
Electronic Band ◽  
Physically Based Model ◽  
Content Type ◽  
Physically Based ◽  
Pmos Transistor

Purpose – The purpose of this paper is to provide a new three dimension physically based model to calculate the initial stress in silicon germanium (SiGe) film due to thermal mismatch after deposition. We should note that there are many other sources of initial stress in SiGe films or in the substrate. Here, the author is focussing only on how to model the initial stress arising from thermal mismatch in SiGe film. The author uses this initial stress to calculate numerically the resulting extrinsic stress distribution in a nanoscale PMOS transistor. This extrinsic stress is used by industrials and manufacturers as Intel or IBM to boost the performances of the nanoscale PMOS and NMOS transistors. It is now admitted that compressive stress enhances the mobility of holes and tensile stress enhances the mobility of electrons in the channel. Design/methodology/approach – During thermal processing, thin film materials like polysilicon, silicon nitride, silicon dioxide, or SiGe expand or contract at different rates compared to the silicon substrate according to their thermal expansion coefficients. The author defines the thermal expansion coefficient as the rate of change of strain with respect to temperature. Findings – Several numerical experiments have been used for different temperatures ranging from 30 to 1,000°C. These experiments did show that the temperature affects strongly the extrinsic stress in the channel of a 45 nm PMOS transistor. On the other hand, the author has compared the extrinsic stress due to lattice mismatch with the extrinsic stress due to thermal mismatch. The author found that these two types of stress have the same order (see the numerical results on Figures 4 and 12). And, these are great findings for semiconductor industry. Practical implications – Front-end process induced extrinsic stress is used by manufacturers of nanoscale transistors as the new scaling vector for the 90 nm node technology and below. The extrinsic stress has the advantage of improving the performances of PMOSFETs and NMOSFETs transistors by enhancing mobility. This mobility enhancement fundamentally results from alteration of electronic band structure of silicon due to extrinsic stress. Then, the results are of great importance to manufacturers and industrials. The evidence is that these results show that the extrinsic stress in the channel depends also on the thermal mismatch between materials and not only on the material mismatch. Originality/value – The model the author is proposing to calculate the initial stress due to thermal mismatch is novel and original. The author validated the values of the initial stress with those obtained by experiments in Al-Bayati et al. (2005). Using the uniaxial stress generation technique of Intel (see Figure 2). Al-Bayati et al. (2005) found experimentally that for 17 percent germanium concentration, a compressive initial stress of 1.4 GPa is generated inside the SiGe layer.

A physically based model to simulate maxillo-facial surgery from 3D CT images

1999 ◽  
Vol 15 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Alessandro Sarti ◽  
Roberto Gori ◽  
Claudio Lamberti
Keyword(s):  
Ct Images ◽  
3D Ct ◽  
Physically Based Model ◽  
Facial Surgery ◽  
Physically Based
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