scholarly journals Structure retrieval in liquid-phase electron scattering

2021 ◽  
Author(s):  
Jie Yang ◽  
J. Pedro F. Nunes ◽  
Kathryn Ledbetter ◽  
Elisa Biasin ◽  
Martin Centurion ◽  
...  
Keyword(s):  
Charged Particle ◽  
Liquid Phase ◽  
Electron Scattering ◽  
Real Space ◽  
Space Distribution ◽  
Analysis Method ◽  
The Real ◽  
Particle Pairs

A novel analysis method for the direct retrieval of the real-space distribution of charged particle pairs from liquid-phase electron scattering.

Atomic resolution imaging using the real-space distribution of electrons scattered by a crystalline material

2011 ◽  
Vol 67 (5) ◽  
pp. 487-490 ◽  
Author(s):  
Sorin Lazar ◽  
Joanne Etheridge ◽  
Christian Dwyer ◽  
Bert Freitag ◽  
Gianluigi A. Botton
Keyword(s):  
Real Space ◽  
Crystalline Material ◽  
Atomic Resolution ◽  
Space Distribution ◽  
The Real ◽  
Resolution Imaging

Atomic Imaging of Crystals using Large-Angle Electron Scattering in STEM

1990 ◽  
Vol 48 (1) ◽  
pp. 74-75
Author(s):  
D.E. Jesson ◽  
S. J. Pennycook
Keyword(s):  
Wave Function ◽  
Electron Scattering ◽  
Numerical Solutions ◽  
Large Angle ◽  
Real Space ◽  
High Angle ◽  
Analytical Treatment ◽  
Order Zero ◽  
Experimental Conditions ◽  
Ewald Sphere

It is well known that conventional atomic resolution electron microscopy is a coherent imaging process best interpreted in reciprocal space using contrast transfer function theory. This is because the equivalent real space interpretation involving a convolution between the exit face wave function and the instrumental response is difficult to visualize. Furthermore, the crystal wave function is not simply related to the projected crystal potential, except under a very restrictive set of experimental conditions, making image simulation an essential part of image interpretation. In this paper we present a different conceptual approach to the atomic imaging of crystals based on incoherent imaging theory. Using a real-space analysis of electron scattering to a high-angle annular detector, it is shown how the STEM imaging process can be partitioned into components parallel and perpendicular to the relevant low index zone-axis.It has become customary to describe STEM imaging using the analytical treatment developed by Cowley. However, the convenient assumption of a phase object (which neglects the curvature of the Ewald sphere) fails rapidly for large scattering angles, even in very thin crystals. Thus, to avoid unpredictive numerical solutions, it would seem more appropriate to apply pseudo-kinematic theory to the treatment of the weak high angle signal. Diffraction to medium order zero-layer reflections is most important compared with thermal diffuse scattering in very thin crystals (<5nm). The electron wave function ψ(R,z) at a depth z and transverse coordinate R due to a phase aberrated surface probe function P(R-RO) located at RO is then well described by the channeling approximation;

scholarly journals Current Trends in Random Walks on Random Lattices

Mathematics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1148
Author(s):  
Jewgeni H. Dshalalow ◽  
Ryan T. White
Keyword(s):  
Random Walk ◽  
Random Walks ◽  
Real Time ◽  
Real Space ◽  
Historical Background ◽  
Escape Time ◽  
The Real ◽  
Current Trends ◽  
One Step ◽  
Time Position

In a classical random walk model, a walker moves through a deterministic d-dimensional integer lattice in one step at a time, without drifting in any direction. In a more advanced setting, a walker randomly moves over a randomly configured (non equidistant) lattice jumping a random number of steps. In some further variants, there is a limited access walker’s moves. That is, the walker’s movements are not available in real time. Instead, the observations are limited to some random epochs resulting in a delayed information about the real-time position of the walker, its escape time, and location outside a bounded subset of the real space. In this case we target the virtual first passage (or escape) time. Thus, unlike standard random walk problems, rather than crossing the boundary, we deal with the walker’s escape location arbitrarily distant from the boundary. In this paper, we give a short historical background on random walk, discuss various directions in the development of random walk theory, and survey most of our results obtained in the last 25–30 years, including the very recent ones dated 2020–21. Among different applications of such random walks, we discuss stock markets, stochastic networks, games, and queueing.

Eulerian partial-differential-equation methods for complex-valued eikonals in attenuating media

Geophysics ◽  
2021 ◽  
pp. 1-53
Author(s):  
Jiangtao Hu ◽  
Jianliang Qian ◽  
Jian Song ◽  
Min Ouyang ◽  
Junxing Cao ◽  
...  
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Ray Tracing ◽  
Seismic Waves ◽  
Real Space ◽  
Advection Equation ◽  
Partial Differential ◽  
The Real ◽  
Eikonal Function ◽  
Complex Valued

Seismic waves in earth media usually undergo attenuation, causing energy losses and phase distortions. In the regime of high-frequency asymptotics, a complex-valued eikonal is an essential ingredient for describing wave propagation in attenuating media, where the real and imaginary parts of the eikonal function capture dispersion effects and amplitude attenuation of seismic waves, respectively. Conventionally, such a complex-valued eikonal is mainly computed either by tracing rays exactly in complex space or by tracing rays approximately in real space so that the resulting eikonal is distributed irregularly in real space. However, seismic data processing methods, such as prestack depth migration and tomography, usually require uniformly distributed complex-valued eikonals. Therefore, we propose a unified framework to Eulerianize several popular approximate real-space ray-tracing methods for complex-valued eikonals so that the real and imaginary parts of the eikonal function satisfy the classical real-space eikonal equation and a novel real-space advection equation, respectively, and we dub the resulting method the Eulerian partial-differential-equation method. We further develop highly efficient high-order methods to solve these two equations by using the factorization idea and the Lax-Friedrichs weighted essentially non-oscillatory (WENO) schemes. Numerical examples demonstrate that the proposed method yields highly accurate complex-valued eikonals, analogous to those from ray-tracing methods. The proposed methods can be useful for migration and tomography in attenuating media.

Challenging structure determination from powder diffraction data: two pharmaceutical salts and one cocrystal with Z′ = 2

2019 ◽  
Vol 234 (4) ◽  
pp. 257-268 ◽  
Author(s):  
Carina Schlesinger ◽  
Michael Bolte ◽  
Martin U. Schmidt
Keyword(s):  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Real Space ◽  
Powder Diffraction Data ◽  
The Real ◽  
Pharmaceutical Salts ◽  
Structure Solution ◽  
Space Method

Abstract Structure solution of molecular crystals from powder diffraction data by real-space methods becomes challenging when the total number of degrees of freedom (DoF) for molecular position, orientation and intramolecular torsions exceeds a value of 20. Here we describe the structure determination from powder diffraction data of three pharmaceutical salts or cocrystals, each with four molecules per asymmetric unit on general position: Lamivudine camphorsulfonate (1, P 21, Z=4, Z′=2; 31 DoF), Theophylline benzamide (2, P 41, Z=8, Z′=2; 23 DoF) and Aminoglutethimide camphorsulfonate hemihydrate [3, P 21, Z=4, Z′=2; 31 DoF (if the H2O molecule is ignored)]. In the salts 1 and 3 the cations and anions have two intramolecular DoF each. The molecules in the cocrystal 2 are rigid. The structures of 1 and 2 could be solved without major problems by DASH using simulated annealing. For compound 3, indexing, space group determination and Pawley fit proceeded without problems, but the structure could not be solved by the real-space method, despite extensive trials. By chance, a single crystal of 3 was obtained and the structure was determined by single-crystal X-ray diffraction. A post-analysis revealed that the failure of the real-space method could neither be explained by common sources of error such as incorrect indexing, wrong space group, phase impurities, preferred orientation, spottiness or wrong assumptions on the molecular geometry or other user errors, nor by the real-space method itself. Finally, is turned out that the structure solution failed because of problems in the extraction of the integrated reflection intensities in the Pawley fit. With suitable extracted reflection intensities the structure of 3 could be determined in a routine way.

scholarly journals Strategi Kampanye Gubernur Basuki Tjahaja Purnama-Djarot Saiful Hidayat Dalam Menghadapi Pilkada Dki Jakarta 2017

2018 ◽  
Vol 10 (2) ◽  
pp. 142
Author(s):  
Rahmadya Putra Nugraha ◽  
Anastasya Christy Puspitasari
Keyword(s):  
Social Construction ◽  
Descriptive Analysis ◽  
Social Reality ◽  
Social Situation ◽  
Analysis Method ◽  
Campaign Strategy ◽  
The Real ◽  
Qualitative Descriptive ◽  
Gubernatorial Election ◽  
Selection Of

The selection of the 2017 DKI Jakarta governor was attended by 3 candidates, including the pair Agus Harimurti - Sylviana Murni, the pair Basuki Tjahaja Purnama - Djarot Saiful Hidayat and the couple Anies Baswedan - Sandiaga Uno. Basuki Tjahaj Purnama - Djarot Saiful Hidayat is a pair of incumbent governors who again competed in this gubernatorial election. The researcher focused on research to find out how the strategy used by the incumbent governor pair in facing the 2017 DKI Jakarta gubernatorial election. In this case, the author uses the Constructivist paradigm, namely, the truth of a social reality seen as a result of social construction, and the truth of a social reality is relative. The type of research used is descriptive, which describes a social situation as it is by using a qualitative descriptive analysis method. Based on this research regarding the campaign strategy of Basuki Tjahaja Purnama - Djarot Saiful Hidayat in facing the gubernatorial election, the researchers concluded that the pair Basuki Tjahaja Purnama - Djarot Saiful Hidayat possessed and re-demonstrated the real program that was directly felt by the community and also maximized the entire media to socialize their upcoming programs. Pemilihan gubernur DKI Jakarta 2017 diikuti oleh 3 pasangan calon antara lain pasangan Agus Harimurti – Sylviana Murni, Basuki Tjahaja Purnama – Djarot Saiful Hidayat dan Anies Baswedan – Sandiaga Uno. Pasangan Basuki Tjahaj Purnama – Djarot Saiful Hidayat adalah pasangan gubernur petahana yang kembali bersaing dalam pemilihan gubernur ini. Peneliti memfokuskan penelitian untuk mengetahui bagaimana strategi yang digunakan oleh pasangan gubernur petahana dalam menghadapi pemilihan gubernur DKI Jakarta 2017 ini. Dalam hal ini, penulis menggunakan paradigma Konstruktivis yaitu,  kebenaran suatu realitas sosial dilihat sebagai hasil konstruksi sosial, dan kebenaran suatu realitas sosial bersifat relatif.  Tipe penelitian yang digunakan dalam penelitian yaitu deskriptif, yang menggambarkan suatu keadaan sosial secara apa adanya dengan menggunakan metode analisis deskriptif kualitatif. Berdasarkan penelitian ini mengenai strategi kampanye Basuki Tjahaja Purnama – Djarot Saiful Hidayat dalam menghadapi pemilihan gubernur, maka peneliti membuat kesimpulan bahwa pasangan Basuki Tjahaja Purnama - Djarot Saiful Hidayat memiliki dan menunjukkan kembali program nyata yang sudah dirasakan langsung oleh masyarakat dan juga pasangan ini memaksimalkan seluruh media untuk mensosialisasikan program mereka yang akan datang.

scholarly journals EXPLORATION OF E-LEARNING VS TRADITIONAL LEARNING IN INDIA

2020 ◽  
Vol 8 (2) ◽  
pp. 69-76 ◽  
Author(s):  
Gulbir Singh ◽  
Vivek Bhatnagar ◽  
Rajeev Gupta ◽  
Gautam Kumar
Keyword(s):  
Comparative Analysis ◽  
Real Time ◽  
Real Life ◽  
Research Data ◽  
University Education ◽  
Traditional Learning ◽  
Analysis Method ◽  
The Real ◽  
Huge Impact ◽  
E Learning

Purpose of Study: The purpose of the study is to carry out the comparison of traditional learning and e-learning with reference to university education. Methodology: A comparative analysis method that has been selected to fulfill the purpose of the study. The research data has been collected by various sources internet, previous research studies published in the Journal, universities which offer different technical and nontechnical programs .and further analyzed by in-depth understanding approach. Result: The outcome of this study will show the effect of e-learning in the current era. As we have compared e-learning with traditional learning and the result shows us that e-learning has filled the gap between the universities and the real-life industries' demands. Main finding: The result of this study showed that e-learning is the need of the present era in order to fulfill the gap between the universities and the real-life industries' demands. Additionally, e-learning based courses will have more impact and provide more skill and exposure to students as compared to traditional learning mode. Implications/Applications: This article can help the different universities and students to introduce more e-learning courses in their curriculum and they can fill the real-time industries' demands. Novelty/originality of the study: Our research can ensure that e-learning has a huge impact on our students and can help to increase the skills and exposure of them according to the current demands.

scholarly journals Technological displacement: The Coat Check interactive augmented reality installation in perspective

2021 ◽  
Author(s):  
Aysegul Koc
Keyword(s):  
Augmented Reality ◽  
Data Storage ◽  
Motion Tracking ◽  
Physical Space ◽  
Digital Technologies ◽  
Real Space ◽  
Embodied Experience ◽  
Global Networks ◽  
The Real ◽  
Technological Displacement

Technological Displacement: The Coat Check Interactive AR Installation in Perspective is a two-part dissertation that involves the research/creation of an augmented reality installation and a textual critique of displacement both as a socio-cultural phenomenon and a technology-driven status quo. Digital technologies involve a series of displacements from data storage and transfer to creating global networks. Going hand in hand with human mobilities technological displacement affects our lives and interactions deeply. Multimedia and digital overlaying of information and interconnectedness (mobile devices, tracking technologies, the internet...) make up our quotidian in various degrees, impelling us to be 'present' in time and places we actually are not. Technological displacement may be viewed as an extension of physical displacement of individuals and communities in that the need to reconcile, re-invent and innovatively market proximity becomes more and more an underlying theme of contemporary lives. Nowhere the reorientations of presence is more accentuated than 'augmented space', as described by Lev Manovich, "a physical space overlaid with dynamically changing information, multimedia in form and localized for each user." (219) It may be argued that our sense of reality is already 'augmented' by digital stimuli in many ways. Here I make the case that in an augmented or digitally enhanced environment we are displaced multiple times, or "multiplaced". Augmentation is superimposing multimedia to real space, blurring the boundary between the real and the virtual, creating a heterogeneous space defined neither by the standards of the virtual nor the real but the coexistence and cooperation of both. Augmented reality functions on the principle of multiple displacements in that real space is not a backdrop to multimedia: it is indispensable to the overall embodied experience. I created the Coat Check in 2011 using motion tracking technologies (Intersense IS900), specialized cameras (Point Grey 360 degree Spherical Vision Camera), screens (Fog Screen), software (Max/MSP), tools and applications (Snapdragon AR). The conceptualization of The Coat Check is based on an analogy between digital technologies and coat checks that are both storage, retrieval and displacement systems. The Coat Check also raises questions on identity and history as it refers to belonging, temporality, and mobility.

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