scholarly journals Energies and Structure of Additive Sets

10.37236/4369 ◽  
2014 ◽  
Vol 21 (3) ◽  
Author(s):  
Shkredov Ilya
Keyword(s):  
Disjoint Union ◽  
Difference Set ◽  
Full Description ◽  
Random Structure ◽  
Large Subset ◽  
Gowers Norms

In this paper we prove that any sumset or difference set has large $\textsf{E}_3$ energy. Also, we give a full description of families of sets having critical relations between some kind of energies such as $\textsf{E}_k$, $\textsf{T}_k$ and Gowers norms. In particular, we give criteria for a set to be a set of the form $H\dotplus \Lambda$, where $H+H$ is small and $\Lambda$ has "random structure",set equal to a disjoint union of sets $H_j$ each with small doubling,set having a large subset $A'$ with $2A'$ equal to a set with small doubling and $|A'+A'| \approx |A|^4 / \textsf{E}(A)$.

X-ray mapping without STEM

1994 ◽  
Vol 52 ◽  
pp. 508-509
Author(s):  
Judith M. Brock ◽  
Max T. Otten
Keyword(s):  
Life Science ◽  
Materials Science ◽  
Chemical Elements ◽  
Full Description ◽  
Scanning System ◽  
Elemental Distribution ◽  
X Ray ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
Made In

A knowledge of the distribution of chemical elements in a specimen is often highly useful. In materials science specimens features such as grain boundaries and precipitates generally force a certain order on mental distribution, so that a single profile away from the boundary or precipitate gives a full description of all relevant data. No such simplicity can be assumed in life science specimens, where elements can occur various combinations and in different concentrations in tissue. In the latter case a two-dimensional elemental-distribution image is required to describe the material adequately. X-ray mapping provides such of the distribution of elements.The big disadvantage of x-ray mapping hitherto has been one requirement: the transmission electron microscope must have the scanning function. In cases where the STEM functionality – to record scanning images using a variety of STEM detectors – is not used, but only x-ray mapping is intended, a significant investment must still be made in the scanning system: electronics that drive the beam, detectors for generating the scanning images, and monitors for displaying and recording the images.

General Cluster Sorption Isotherm

2020 ◽  
Author(s):  
Christoph Buttersack
Keyword(s):  
Density Functional ◽  
Capillary Condensation ◽  
Cluster Formation ◽  
Full Range ◽  
Full Description ◽  
Cross Sectional ◽  
Macroporous Silica ◽  
Isotherm Equation ◽  
Type Iv ◽  
Classical Thermodynamics

<p>Adsorption isotherms are an essential tool in chemical physics of surfaces. However, several approaches based on a different theoretical basis exist and for isotherms including capillary condensation existing approaches can fail. Here, a general isotherm equation is derived and applied to literature data both concerning type IV isotherms of argon and nitrogen in ordered mesoporous silica, and type II isotherms of disordered macroporous silica. The new isotherm covers the full range of partial pressure (10<sup>-6</sup> - 0.7). It relies firstly on the classical thermodynamics of cluster formation, secondly on a relationship defining the free energy during the increase of the cluster size. That equation replaces the Lennard-Jones potentials used in the classical density functional theory. The determination of surface areas is not possible by this isotherm because the cross-sectional area of a cluster is unknown. Based on the full description of type IV isotherms, most known isotherms are accessible by respective simplifications. </p>

An Overview of Second Generation Nanoparticles− Nanostructure Lipid Carrier Drug Delivery System

2020 ◽  
Vol 13 (6) ◽  
pp. 5181-5189
Author(s):  
Prabhat Kumar Sahoo ◽  
Neha S.L ◽  
Arzoo Pannu
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Second Generation ◽  
Drug Loading ◽  
Scale Up ◽  
Delivery Systems ◽  
Route Of Administration ◽  
Random Structure ◽  
Stability Parameters

Lipids are used as vehicles for the preparation of various formulations prescribed for administrations, including emulsions, ointments, suspension, tablets, and suppositories. The first parental nano-emulsion was discovered from the 1950s when it was added to the intravenous administration of lipid and lipid-soluble substances. Lipid-based drug delivery systems are important nowadays. Solid nanoparticles (SLN) and Nanostructured lipid carriers (NLC) are very proficient due to the ease of production process, scale-up capability, bio-compatibility, the biodegradability of formulation components and other specific features of the proposed route. The administration or nature of the materials must be loaded into these delivery systems. The main objectives of this review are to discuss an overview of second-generation nanoparticles, their limitations, structures, and route of administration, with emphasis on the effectiveness of such formulations. NLC is the second generation of lipid nanoparticles having a structure like nanoemulsion. The first generation of nanoparticles was SLN. The difference between both of them is at its core. Both of them are a colloidal carrier in submicron size in the range of 40-1000 nm. NLC is the most promising novel drug delivery system over the SLN due to solving the problem of drug loading and drug crystallinity. Solid and liquid lipids combination in NLC formation, improve its quality as compare to SLN. NLC has three types of structures: random, amorphous, and multiple. The random structure containing solid-liquid lipids and consisting crystal and the liquid lipid irregular in shape; thereby enhance the ability of the lipid layer to pass through the membrane. The second is the amorphous structure. It is less crystalline in nature and can prevent the leakage of the loaded drug. The third type is multiple structures, which have higher liquid lipid concentrations than other types. The excipients used to form the NLC are bio-compatible, biodegradable and non-irritating, most of which can be detected using GRAS. NLC is a promising delivery system to deliver the drug through pulmonary, ocular, CNS, and oral route of administration. Various methods of preparation and composition of NLC influence its stability Parameters. In recent years at the educational level, the potential of NLC as a delivery mechanism targeting various organs has been investigated in detail.

scholarly journals Systematics of type IIA moduli stabilisation

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Fernando Marchesano ◽  
David Prieto ◽  
Joan Quirant ◽  
Pramod Shukla
Keyword(s):  
Scalar Potential ◽  
Systematic Search ◽  
Stability Criteria ◽  
De Sitter ◽  
Large Subset

Abstract We analyse the flux-induced scalar potential for type IIA orientifolds in the presence of p-form, geometric and non-geometric fluxes. Just like in the Calabi-Yau case, the potential presents a bilinear structure, with a factorised dependence on axions and saxions. This feature allows one to perform a systematic search for vacua, which we implement for the case of geometric backgrounds. Guided by stability criteria, we consider configurations with a particular on-shell F-term pattern, and show that no de Sitter extrema are allowed for them. We classify branches of supersymmetric and non-supersymmetric vacua, and argue that the latter are perturbatively stable for a large subset of them. Our solutions reproduce and generalise previous results in the literature, obtained either from the 4d or 10d viewpoint.

scholarly journals Random pore structure and REV scale flow analysis of engine particulate filter based on LBM

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 881-896
Author(s):  
Chunrui Wu ◽  
Tiechen Zhang ◽  
Jiale Fu ◽  
Xiaori Liu ◽  
Boxiong Shen
Keyword(s):  
Single Channel ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Axial Direction ◽  
Particulate Filter ◽  
Random Structure ◽  
Structure Generation ◽  
Inlet Flow ◽  
Random Structures ◽  
Boltzmann Method

Abstract In this article, lattice Boltzmann method (LBM) is used to simulate the multi-scale flow characteristics of the engine particulate filter at the pore scale and the representative elementary volume (REV) scale, respectively. Four kinds of random wall-pore structures are considered, which are circular random structure, square random structure, isotropic quartet structure generation set (QSGS), and anisotropic QSGS, with difference analysis done. In terms of the REV scale, the influence of different inlet flow velocities and wall permeabilities on the flow in single channel is analyzed. The result indicates that the internal seepage laws of random structures constructed in this article and single channel are in accordance with Darcy’s law. Circular random structure has better permeability than square random structure. Isotropic QSGS has better fluidity than anisotropic one. The flow in single channel is similar to Poiseuille flow. The flow lines in the channel are complicated and a large number of vortices appear at the ends of channel with high inlet flow rate. With the increase of inlet velocity, the static pressure in channel gradually increases along the axial direction as well as the seepage velocity. The temperature field in the channel becomes more uniform as the flow velocity increases, and the higher temperature distribution appears on the wall of the porous media.

scholarly journals A Full Description of ω-Limit Sets of Cournot Maps Having Non-Empty Interior and Some Economic Applications

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 452
Author(s):  
Antonio Linero-Bas ◽  
María Muñoz-Guillermo
Keyword(s):  
Economic Models ◽  
Full Description ◽  
Cournot Model ◽  
Empty Interior ◽  
Limit Sets ◽  
Economic Applications

Given a continuous Cournot map F(x,y)=(f2(y),f1(x)) defined from I2=[0,1]×[0,1] into itself, we give a full description of its ω-limit sets with non-empty interior. Additionally, we present some partial results for the empty interior case. The distribution of the ω-limits with non-empty interior gives information about the dynamics and the possible outputs of each firm in a Cournot model. We present some economic models to illustrate, with examples, the type of ω-limits that appear.

Y-Logic: A Framework for Reasoning About Chameleonic Programs with Inconsistent Completions

1990 ◽  
Vol 13 (4) ◽  
pp. 465-483
Author(s):  
V.S. Subrahmanian
Keyword(s):  
Classical Logic ◽  
Logic Program ◽  
Logic Programs ◽  
Large Subset ◽  
General Logic ◽  
Traditional Sense

Large logic programs are normally designed by teams of individuals, each of whom designs a subprogram. While each of these subprograms may have consistent completions, the logic program obtained by taking the union of these subprograms may not. However, the resulting program still serves a useful purpose, for a (possibly) very large subset of it still has a consistent completion. We argue that “small” inconsistencies may cause a logic program to have no models (in the traditional sense), even though it still serves some useful purpose. A semantics is developed in this paper for general logic programs which ascribes a very reasonable meaning to general logic programs irrespective of whether they have consistent (in the classical logic sense) completions.

scholarly journals From Slater to Mott physics by epitaxially engineering electronic correlations in oxide interfaces

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Carla Lupo ◽  
Evan Sheridan ◽  
Edoardo Fertitta ◽  
David Dubbink ◽  
Chris J. Pickard ◽  
...  
Keyword(s):  
Phase Diagram ◽  
High Pressure ◽  
Charge Transfer ◽  
Lower Mantle ◽  
Random Structure ◽  
Titanium Oxides ◽  
Oxide Interfaces ◽  
Electronic Correlations ◽  
Epitaxial Strain ◽  
Magnetic Switching

AbstractUsing spin-assisted ab initio random structure searches, we explore an exhaustive quantum phase diagram of archetypal interfaced Mott insulators, i.e. lanthanum-iron and lanthanum-titanium oxides. In particular, we report that the charge transfer induced by the interfacial electronic reconstruction stabilises a high-spin ferrous Fe2+ state. We provide a pathway to control the strength of correlation in this electronic state by tuning the epitaxial strain, yielding a manifold of quantum electronic phases, i.e. Mott-Hubbard, charge transfer and Slater insulating states. Furthermore, we report that the electronic correlations are closely related to the structural oxygen octahedral rotations, whose control is able to stabilise the low-spin state of Fe2+ at low pressure previously observed only under the extreme high pressure conditions in the Earth’s lower mantle. Thus, we provide avenues for magnetic switching via THz radiations which have crucial implications for next generation of spintronics technologies.

DENSE STABLE RANK AND RUNGE-TYPE APPROXIMATION THEOREMS FOR MAPS

2021 ◽  
pp. 1-29
Author(s):  
ALEXANDER BRUDNYI
Keyword(s):  
Disjoint Union ◽  
A Priori ◽  
Holomorphic Functions ◽  
Stable Rank ◽  
Open Unit ◽  
Uniform Estimates ◽  
Approximation Theorems ◽  
Type Approximation ◽  
Similar Approximation ◽  
Bounded Holomorphic

Abstract Let $H^\infty ({\mathbb {D}}\times {\mathbb {N}})$ be the Banach algebra of bounded holomorphic functions defined on the disjoint union of countably many copies of the open unit disk ${\mathbb {D}}\subset {{\mathbb C}}$ . We show that the dense stable rank of $H^\infty ({\mathbb {D}}\times {\mathbb {N}})$ is $1$ and, using this fact, prove some nonlinear Runge-type approximation theorems for $H^\infty ({\mathbb {D}}\times {\mathbb {N}})$ maps. Then we apply these results to obtain a priori uniform estimates of norms of approximating maps in similar approximation problems for the algebra $H^\infty ({\mathbb {D}})$ .

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