scholarly journals Degradation induced lattice anchoring self-passivation in CsPbI3−xBrx

2020 ◽  
Vol 8 (19) ◽  
pp. 9963-9969
Author(s):  
Jingwei Xiu ◽  
Bo Dong ◽  
Elizabeth Driscoll ◽  
Xiyuan Feng ◽  
Abubakar Muhammad ◽  
...  
Keyword(s):  
Solution Approach ◽  
Ambient Environment ◽  
Improved Stability ◽  
First Time

A facile ambient environment solution approach to prepare γ-CsPbI3−xBrx is reported for the first time, leading to samples that exhibit vastly improved stability towards both moisture and heating in air.

scholarly journals Construction of a cross-layer linked G-octamer via conformational control: a stable G-quadruplex in H-bond competitive solvents

2019 ◽  
Vol 10 (15) ◽  
pp. 4192-4199 ◽  
Author(s):  
Ying He ◽  
Yanbin Zhang ◽  
Lukasz Wojtas ◽  
Novruz G. Akhmedov ◽  
David Thai ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Cross Layer ◽  
Conformational Control ◽  
G Quadruplex ◽  
Improved Stability ◽  
First Time

A discrete and well-defined G-octamer system has been established through conformational design of monomers. The crystal structures of G-octamers were obtained for the first time. The covalent linked G-quadruplex exhibited significantly improved stability in both methanol and DMSO.

Novel Perturbation Analysis for a Widely Applicable Curvature Law of the Wall

1999 ◽  
Author(s):  
Namhyo Kim ◽  
David L. Rhode
Keyword(s):  
Perturbation Analysis ◽  
Richardson Number ◽  
Perturbation Technique ◽  
Solution Approach ◽  
Law Of The Wall ◽  
Streamline Curvature ◽  
Curvature Effects ◽  
Gradient Richardson Number ◽  
Closed Form Analytical Solution ◽  
First Time

Abstract A streamline curvature law of the wall is analytically derived to include very strong curved-channel wall curvature effects through a novel perturbation analysis. The new law allows improved analysis of such flows, and it provides the basis for improved wall function boundary conditions for their computation (CFD) over a wider range of y+, even for very strong curvature cases. The unique derivation is based on the Boussinesq eddy viscosity and curvature-corrected mixing length concepts, which is a linear function of the gradient Richardson number. For the first time, to include more complete curved flow physics, local streamline curvature effects in the gradient Richardson number are kept. To overcome the mathematical difficulty of keeping all of these local streamline curvature terms, a novel perturbation solution approach is successfully developed. This novel perturbation technique allows a closed-form analytical solution to many similar non-linear problems which previously required more complicated techniques. Qualitative and quantitative comparisons with measurements and previous curvature laws of the wall obtained by different approaches reveal that the new law shows improved representation of the wall curvature effects for all of the four test cases.

Multiobjective Collaborative Robust Optimization With Interval Uncertainty and Interdisciplinary Uncertainty Propagation

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
M. Li ◽  
S. Azarm
Keyword(s):  
Robust Optimization ◽  
Probability Distributions ◽  
Uncertainty Propagation ◽  
Multiple Objectives ◽  
Interval Uncertainty ◽  
Optimization Approach ◽  
Solution Approach ◽  
Time In Literature ◽  
Collaborative Robust Optimization ◽  
First Time

We present a new solution approach for multidisciplinary design optimization (MDO) problems that, for the first time in literature, has all of the following characteristics: Each discipline has multiple objectives and constraints with mixed continuous-discrete variables; uncertainty exists in parameters and as a result, uncertainty propagation exists within and across disciplines; probability distributions of uncertain parameters are not available but their interval of uncertainty is known; and disciplines can be fully (two-way) coupled. The proposed multiobjective collaborative robust optimization (McRO) approach uses a multiobjective genetic algorithm as an optimizer. McRO obtains solutions that are as best as possible in a multiobjective and multidisciplinary sense. Moreover, for McRO solutions, the variation of objective and/or constraint functions can be kept within an acceptable range. McRO includes a technique for interdisciplinary uncertainty propagation. The approach can be used for robust optimization of MDO problems with multiple objectives, or constraints, or both together at system and subsystem levels. Results from an application of McRO to a numerical and an engineering example are presented. It is concluded that McRO can solve fully coupled MDO problems with interval uncertainty and obtain solutions that are comparable to a single-disciplinary robust optimization approach.

scholarly journals Photoinduced Porcine Gelatin Cross-Linking by Homobi- and Homotrifunctional Tetrazoles

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 124
Author(s):  
Luca Vaghi ◽  
Mauro Monti ◽  
Marcello Marelli ◽  
Elisa Motto ◽  
Antonio Papagni ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Amino Acid ◽  
Cross Linking ◽  
Natural Origin ◽  
Physiological Conditions ◽  
Biomaterial Scaffold ◽  
Amino Acid Side Chains ◽  
Improved Stability ◽  
First Time

Gelatin is a costless polypeptide material of natural origin, able to form hydrogels that are potentially useful in biomaterial scaffold design for drug delivery, cell cultures, and tissue engineering. However, gelatin hydrogels are unstable at physiological conditions, losing their features only after a few minutes at 37 °C. Accordingly, treatments to address this issue are of great interest. In the present work, we propose for the first time the use of bi- and trifunctional tetrazoles, most of them unknown to date, for photoinduced gelatin cross-linking towards the production of physiologically stable hydrogels. Indeed, after UV-B irradiation, aryl tetrazoles generate a nitrilimine intermediate that is reactive towards different functionalities, some of them constitutively present in the amino acid side chains of gelatin. The efficacy of the treatment strictly depends on the structure of the cross-linking agent used, and substantial improved stability was observed by switching from bifunctional to trifunctional cross-linkers.

scholarly journals A New Solution Approach for Maritime Surveillance Operation: The Case of Aegean Sea

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Selçuk K. İşleyen ◽  
Ukbe Uçar ◽  
Figen Balo
Keyword(s):  
Time Window ◽  
Operation Time ◽  
Aegean Sea ◽  
Internal Conflict ◽  
Target Number ◽  
Acceptable Solution ◽  
Solution Approach ◽  
Maritime Surveillance ◽  
Illegal Activities ◽  
First Time

Nowadays, many people illegally migrate to other countries by sea because of warfare or internal conflict in their countries, and thousands of people lose their lives for this reason. Besides, illegal trafficking of drugs or historical artifacts, illegal fishing, and various terrorist activities are conducted through the seas. Maritime surveillance operations are of great importance to prevent all these threats and maintain national security. In this study, the problem of surveillance and exploration which is performed by helicopters on the seas is discussed. A solution approach based on simulated annealing is proposed for the solution of the problem and the proposed algorithm has been tested on various scenarios. This methodology, at least to our knowledge, is used for the first time in the Moving Target Traveling Salesman Problem-Time Window. The proposed solution approach was tested on 50 different scenarios where the target number ranged from 20 to 100. As a result, in all of these scenarios, it has been determined that all of the targets have been destroyed with minimum operation time within the acceptable solution period. Thanks to this method, it is aimed at intervening quickly to illegal activities on the seas and contributing to the prevention of deaths due to refugee boats.

Mn-Doped CsPbCl3 perovskite nanocrystals: solvothermal synthesis, dual-color luminescence and improved stability

2018 ◽  
Vol 6 (33) ◽  
pp. 8990-8998 ◽  
Author(s):  
Daqin Chen ◽  
Gaoliang Fang ◽  
Xiao Chen ◽  
Lei Lei ◽  
Jiasong Zhong ◽  
...  
Keyword(s):  
Solvothermal Synthesis ◽  
Perovskite Nanocrystals ◽  
Dual Color ◽  
Improved Stability ◽  
First Time ◽  
Mn Doped

Solvothermal synthesis of Mn-doped CsPbCl3 nanocrystals with dual-color luminescence and superior stability was reported for the first time.

An analytical solution for the HJB equation arising from the Merton problem

2018 ◽  
Vol 05 (01) ◽  
pp. 1850008 ◽  
Author(s):  
Song-Ping Zhu ◽  
Guiyuan Ma
Keyword(s):  
Analytical Solution ◽  
Hjb Equation ◽  
Analysis Method ◽  
Solution Approach ◽  
General Utility ◽  
Merton Problem ◽  
Homotopy Analysis ◽  
Hamilton Jacobi Bellman ◽  
First Time ◽  
Taylor’S Series

In this paper, an analytical solution for the well-known Hamilton–Jacobi–Bellman (HJB) equation that arises from the Merton problem subject to general utility functions is presented for the first time. The solution presented in this paper is written in the form of a Taylor’s series expansion and constructed through the homotopy analysis method (HAM). The fully nonlinear HJB equation is decomposed into an infinite series of linear PDEs which can be solved analytically. Four examples are presented with the first two cases showing the accuracy of our solution approach; while the last two demonstrating its versatility.

Annulate lamellae in the Sertoli cells of guinea pig testis after unilateral torsion of the spermatic cord

1984 ◽  
Vol 42 ◽  
pp. 196-197
Author(s):  
J. Chakraborty ◽  
A. P. Sinha Hikim ◽  
J. S. Jhunjhunwala
Keyword(s):  
Sertoli Cells ◽  
Guinea Pigs ◽  
Spermatic Cord ◽  
Present Report ◽  
Cell Types ◽  
Annulate Lamellae ◽  
Spermatogenic Cells ◽  
Electron Microscopic ◽  
Structural Details ◽  
First Time

Although the presence of annulate lamellae was noted in many cell types, including the rat spermatogenic cells, this structure was never reported in the Sertoli cells of any rodent species. The present report is based on a part of our project on the effect of torsion of the spermatic cord to the contralateral testis. This paper describes for the first time, the fine structural details of the annulate lamellae in the Sertoli cells of damaged testis from guinea pigs.One side of the spermatic cord of each of six Hartly strain adult guinea pigs was surgically twisted (540°) under pentobarbital anesthesia (1). Four months after induction of torsion, animals were sacrificed, testes were excised and processed for the light and electron microscopic investigations. In the damaged testis, the majority of seminiferous tubule contained a layer of Sertoli cells with occasional spermatogonia (Fig. 1). Nuclei of these Sertoli cells were highly pleomorphic and contained small chromatinic clumps adjacent to the inner aspect of the nuclear envelope (Fig. 2).

Electron spectroscopic imaging and diffraction

1991 ◽  
Vol 49 ◽  
pp. 706-707
Author(s):  
M. Rühle ◽  
J. Mayer ◽  
J.C.H. Spence ◽  
J. Bihr ◽  
W. Probst ◽  
...  
Keyword(s):  
Materials Science ◽  
Electron Spectroscopic Imaging ◽  
Magnetic Filter ◽  
Magnetic Imaging ◽  
Illumination System ◽  
Probe Size ◽  
Diffraction Patterns ◽  
Fritz Haber ◽  
Koehler Illumination ◽  
First Time

A new Zeiss TEM with an imaging Omega filter is a fully digitized, side-entry, 120 kV TEM/STEM instrument for materials science. The machine possesses an Omega magnetic imaging energy filter (see Fig. 1) placed between the third and fourth projector lens. Lanio designed the filter and a prototype was built at the Fritz-Haber-Institut in Berlin, Germany. The imaging magnetic filter allows energy-filtered images or diffraction patterns to be recorded without scanning using efficient area detection. The energy dispersion at the exit slit (Fig. 1) results in ∼ 1.5 μm/eV which allows imaging with energy windows of ≤ 10 eV. The smallest probe size of the microscope is 1.6 nm and the Koehler illumination system is used for the first time in a TEM. Serial recording of EELS spectra with a resolution < 1 eV is possible. The digital control allows X,Y,Z coordinates and tilt settings to be stored and later recalled.

A Novel TEM Technique for Characterizing As-Grown CVD Diamond Films

1991 ◽  
Vol 49 ◽  
pp. 956-957 ◽  
Author(s):  
Z.L. Wang ◽  
J. Bentley ◽  
R.E. Clausing ◽  
L. Heatherly ◽  
L.L. Horton
Keyword(s):  
Diamond Films ◽  
Chemical Vapor ◽  
Growth Direction ◽  
Dark Field ◽  
Growth Surface ◽  
Specimen Preparation ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
First Time ◽  
Microstructural Studies

Microstructural studies by transmission electron microscopy (TEM) of diamond films grown by chemical vapor deposition (CVD) usually involve tedious specimen preparation. This process has been avoided with a technique that is described in this paper. For the first time, thick as-grown diamond films have been examined directly in a conventional TEM without thinning. With this technique, the important microstructures near the growth surface have been characterized. An as-grown diamond film was fractured on a plane containing the growth direction. It took about 5 min to prepare a sample. For TEM examination, the film was tilted about 30-45° (see Fig. 1). Microstructures of the diamond grains on the top edge of the growth face can be characterized directly by transmitted electron bright-field (BF) and dark-field (DF) images and diffraction patterns.

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