scholarly journals Amphiphilic Porphyrin Aggregates: A DFT Investigation

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 133
Author(s):  
Federica Sabuzi ◽  
Manuela Stefanelli ◽  
Donato Monti ◽  
Valeria Conte ◽  
Pierluca Galloni
Keyword(s):  
Material Science ◽  
Science Studies ◽  
Hydrophobic Effect ◽  
Geometry Optimization ◽  
Attractive Potential ◽  
Theoretical Studies ◽  
Frontier Orbital ◽  
Long Range Interactions ◽  
Potential Applications ◽  
Porphyrin Aggregation

Owing to the attractive potential applications of porphyrin assemblies in photocatalysis, sensors, and material science, studies presently concerning porphyrin aggregation are widely diffused. π–π stacking, H-bonding, metal coordination, hydrophobic effect, and electrostatic forces usually drive porphyrin interaction in solution. However, theoretical studies of such phenomena are still limited. Therefore, a computational examination of the different porphyrin aggregation approaches is proposed here, taking into account amphiphilic [5-{4-(3-trimethylammonium)propyloxyphenyl}-10,15,20-triphenylporphyrin] chloride, whose aggregation behavior has been previously experimentally investigated. Different functionals have been adopted to investigate the porphyrin dimeric species, considering long-range interactions. Geometry optimization has been performed, showing that for the compound under analysis, H-type and cation–π dimers are the most favored structures that likely co-exist in aqueous solution. Of note, frontier orbital delocalization showed an interesting interaction between the porphyrin units in the dimer at the supramolecular level.

Application of electron holography to material science studies on magnetic domain states of small particles

1993 ◽  
Vol 51 ◽  
pp. 1028-1029
Author(s):  
T. Hirayama ◽  
Q. Ru ◽  
T. Tanji ◽  
A. Tonomura
Keyword(s):  
Magnetic Field ◽  
Material Science ◽  
Science Studies ◽  
Phase Distribution ◽  
Carbon Film ◽  
Objective Lens ◽  
Electron Holography ◽  
Transform Method ◽  
Transmission Electron ◽  
Thin Carbon

The observation of small magnetic materials is one of the most important applications of electron holography to material science, because interferometry by means of electron holography can directly visualize magnetic flux lines in a very small area. To observe magnetic structures by transmission electron microscopy it is important to control the magnetic field applied to the specimen in order to prevent it from changing its magnetic state. The easiest method is tuming off the objective lens current and focusing with the first intermediate lens. The other method is using a low magnetic-field lens, where the specimen is set above the lens gap.Figure 1 shows an interference micrograph of an isolated particle of barium ferrite on a thin carbon film observed from approximately [111]. A hologram of this particle was recorded by the transmission electron microscope, Hitachi HF-2000, equipped with an electron biprism. The phase distribution of the object electron wave was reconstructed digitally by the Fourier transform method and converted to the interference micrograph Fig 1.

Morphology of Voltage-Triggered Ordered Wrinkles of a Dielectric Elastomer Sheet

2017 ◽  
Vol 84 (11) ◽  
Author(s):  
Guoyong Mao ◽  
Lei Wu ◽  
Xueya Liang ◽  
Shaoxing Qu
Keyword(s):  
High Voltage ◽  
Optical Sensor ◽  
Material Science ◽  
Dielectric Elastomer ◽  
Theoretical Studies ◽  
Science And Engineering ◽  
Future Design ◽  
Experimental And Theoretical Studies ◽  
Theory And Experiment ◽  
Good Agreement

Wrinkles widely existing in sheets and membranes have attracted a lot of attention in the fields of material science and engineering applications. In this paper, we present a new method to generate ordered (striplike) and steady wrinkles of a constrained dielectric elastomer (DE) sheet coated with soft electrodes on both sides subjected to high voltage. When the voltage reaches a certain value, wrinkles will nucleate and grow. We conduct both experimental and theoretical studies to investigate the wavelength and amplitude of the wrinkle. The results show a good agreement between theory and experiment. Moreover, the amplitude and wavelength of ordered wrinkles can be tuned by varying the prestretch and geometry of the DE sheet, as well as the applying voltage. This study can help future design of DE transducers such as diffraction grating and optical sensor.

New cyclometalated Ir(iii) complexes with bulky ligands with potential applications in LEC devices: experimental and theoretical studies of their photophysical properties

2016 ◽  
Vol 40 (7) ◽  
pp. 6253-6263 ◽  
Author(s):  
Paulina Dreyse ◽  
Iván González ◽  
Diego Cortés-Arriagada ◽  
Oscar Ramírez ◽  
Ignacio Salas ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Theoretical Studies ◽  
Bulky Ligands ◽  
Potential Applications ◽  
Cyclometalated Complexes ◽  
Experimental And Theoretical Studies

The synthesis and the electrochemical, photoluminescent and electroluminescent properties is reported for two new Ir(iii) cyclometalated complexes described as [Ir(F2ppy)2L1](PF6) and [Ir(F2ppy)2L2](PF6).

Sorafenib in malignant mesothelioma (MM): A phase II trial of the Cancer and Leukemia Group B (CALGB 30307)

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 7707-7707 ◽  
Author(s):  
P. A. Janne ◽  
X. F. Wang ◽  
L. M. Krug ◽  
L. Hodgson ◽  
E. E. Vokes ◽  
...  
Keyword(s):  
Phase Ii ◽  
Science Studies ◽  
Phase Ii Trial ◽  
Single Agent ◽  
Angiogenesis Inhibitors ◽  
Attractive Potential ◽  
Type I ◽  
Open Label ◽  
Previously Treated Patients ◽  
Previously Treated

7707 Background: Systemic chemotherapy with cisplatin/pemetrexed is the approved first line treatment regimen for patients with MM. There is no approved second line therapy. In addition, many patients, especially those >70, cannot tolerate combination chemotherapy. Angiogenesis inhibitors have emerged as attractive potential therapies for MM and SU5416 and PTK787 have previously demonstrated single agent activity. We examined the efficacy of sorafenib, an inhibitor of VEGFR2 and PDGFR-b, in chemotherapy naïve and previously treated patients with MM. Methods: This was an open label single arm phase II study of sorafenib in chemotherapy naïve and previously pemetrexed treated patients with MM. Primary end point was response rate (RR). Secondary objectives were 3-month failure free and overall survival (FFS and OS). Forty-four (44) eligible patients were expected to enroll to differentiate a RR of <5% versus >20%, with a Type I error of 0.0675 and a power of 0.955 Results: Between 10/04 and 8/05, 51 patients were enrolled and treated with sorafenib 400 mg bid. One cycle was defined as 28 days; restaging occurred every 2 cycles. Baseline demographics: M/F (36/15); Median age (69; range 36–88; 45% >70); Histology (epithelial/sarcomatoid/mixed/unknown: 37/4/8/2); pleural/peritoneal MM (46/5); ECOG PS 0/1 (11/40); chemo-naive/prior chemo (20/31). Grade 3/4 toxicities occurring in >10% of patients: Fatigue (12 (25%); 11/1) and hand-foot reaction (6 (13%); 6/0). No study related deaths occurred. Estimates of RR and FFS are based on 47 patients with available follow-up data. Response: CR: 0; PR 2: 4% (95% CI; 1- 14%); SD 28 (60%); PD 11 (23%); unevaluable 6 (14%). Three month FFS was 78%; median FFS was 3.7 months and median OS was 10.7 months. The median FFS were 3.6 and 3.6 months and the median OS were 4.9 and 14.6 months in chemo naïve and previously treated patients, respectively. Conclusions: Sorafenib demonstrated modest activity in this phase II trial but did not meet its primary endpoint. The improved outcome in previously treated patients likely reflects patient selection. Ongoing correlative science studies including expression of p-ERK 1/2, baseline VEGF and PDGF levels, are being performed to help identify patient subsets who may benefit (PR or SD) from sorafenib. No significant financial relationships to disclose.

INTRODUCTION

2012 ◽  
Vol 22 (04) ◽  
pp. 1202002 ◽  
Author(s):  
CHANGPIN LI ◽  
YANG QUAN CHEN ◽  
BLAS M. VINAGRE ◽  
IGOR PODLUBNY
Keyword(s):  
Fractional Calculus ◽  
Scaling Laws ◽  
Power Laws ◽  
Fractional Dynamics ◽  
Long Range Interactions ◽  
Potential Applications ◽  
Dynamics And Control ◽  
Long Memory Processes ◽  
Fractional Differential ◽  
And Control

Fractional Dynamics and Control is emerging as a new hot topic of research which draws tremendous attention and great interest. Although the fractional calculus appeared almost in the same era when the classical (or integer-order) calculus was born, it has recently been found that it can better characterize long-memory processes and materials, anomalous diffusion, long-range interactions, long-term behaviors, power laws, allometric scaling laws, and so on. Complex dynamical evolutions of these fractional differential equation models, as well as their controls, are becoming more and more important due to their potential applications in the real world. This special issue includes one review article and twenty-three regular papers, covering fundamental theories of fractional calculus, dynamics and control of fractional differential systems, and numerical calculation of fractional differential equations.

D2AM: A CRG Beamline at ESRF for Material Science Studies

1996 ◽  
Vol 228-231 ◽  
pp. 223-226 ◽  
Author(s):  
J.F. Bérar ◽  
J.P. Simon ◽  
J.-L. Ferrer ◽  
D. Dallé
Keyword(s):  
Material Science ◽  
Science Studies

scholarly journals Complete Face Recovering: An Approach towards Recognizing a Person by a Single Partial Face Image without the Target Photo in Gallery

2020 ◽  
Author(s):  
Yiu-ming Cheung ◽  
Mengke Li
Keyword(s):  
Promising Result ◽  
Face Image ◽  
Attractive Potential ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Discriminative Feature ◽  
New Variant ◽  
Potential Applications ◽  
Benchmark Datasets

Complete face recovering (CFR) is to recover the complete face image of a given partial face image of a target person whose photo may not be included in the gallery set. The CFR has several attractive potential applications but is challenging. As far as we know, the CFR problem has yet to be explored in the literature. This paper therefore proposes an identity-preserved CFR approach (IP-CFR) to addressing the CFR. First, a denoising auto-encoder based network is applied to acquire the discriminative feature. Then, we propose an identity-preserved loss function to keep the personal identity information. Furthermore, the acquired features are fed into a new variant of the generative adversarial network (GAN) to restore the complete face image. In addition, a two-pathway discriminator is leveraged to enhance the quality of the recovered image. Experimental results on the benchmark datasets show the promising result of the proposed approach.

scholarly journals Complete Face Recovering: An Approach towards Recognizing a Person by a Single Partial Face Image without the Target Photo in Gallery

2020 ◽  
Author(s):  
Yiu-ming Cheung ◽  
Mengke Li
Keyword(s):  
Promising Result ◽  
Face Image ◽  
Attractive Potential ◽  
Generative Adversarial Network ◽  
Adversarial Network ◽  
Discriminative Feature ◽  
New Variant ◽  
Potential Applications ◽  
Benchmark Datasets

Complete face recovering (CFR) is to recover the complete face image of a given partial face image of a target person whose photo may not be included in the gallery set. The CFR has several attractive potential applications but is challenging. As far as we know, the CFR problem has yet to be explored in the literature. This paper therefore proposes an identity-preserved CFR approach (IP-CFR) to addressing the CFR. First, a denoising auto-encoder based network is applied to acquire the discriminative feature. Then, we propose an identity-preserved loss function to keep the personal identity information. Furthermore, the acquired features are fed into a new variant of the generative adversarial network (GAN) to restore the complete face image. In addition, a two-pathway discriminator is leveraged to enhance the quality of the recovered image. Experimental results on the benchmark datasets show the promising result of the proposed approach.

Effects of element doping on electronic structures and optical properties in cubic boron nitride from first-principles

2017 ◽  
Vol 31 (16) ◽  
pp. 1750166 ◽  
Author(s):  
Yin Wei ◽  
Hongjie Wang ◽  
Xuefeng Lu ◽  
Xingyu Fan ◽  
Heng Wei
Keyword(s):  
Optical Properties ◽  
Boron Nitride ◽  
Electronic Structures ◽  
Cubic Boron Nitride ◽  
Attractive Potential ◽  
Covalent Bonds ◽  
Density Maps ◽  
Element Doping ◽  
Potential Applications ◽  
Lower Energy Region

Attractive potential applications of cubic boron nitride (c-BN) derive from the properties of semiconductors, widely used in optoelectronic and microelectronic devices. In this paper, the effects of element doping on the electronic structures and optical properties in cubic boron nitride are investigated. The Al- and Ga-doped systems have the lower bonding energies of −11.544 eV and −5.302 eV, respectively, indicating better stability. Difference charge density maps demonstrate that the electron loss increases after P doping and decreases after Al, Ga and As dopings, indicating that the covalent character of polar covalent bonds decreases by doping in the range of P, Al, Ga and As, which is in accordance with the calculated atom population values. The Al- and Ga-doped systems show lower dielectric loss, absorption and reflectivity in the lower energy region, displaying the “transparent-type” characteristic and their potential applications in electron devices.

Nozzle Diaphragms of Liquid Rocket Engines. Residual Life Estimation of the Blade with a Crack

NDT World ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 54-58
Author(s):  
Полянский ◽  
Aleksandr Polyansky ◽  
Полянский ◽  
Vladislav Polyansky
Keyword(s):  
Fracture Mechanics ◽  
Material Science ◽  
Science Studies ◽  
Residual Life ◽  
Rocket Engines ◽  
Pressure Side ◽  
Surface Cracks ◽  
Life Estimation ◽  
Liquid Rocket Engines ◽  
Liquid Rocket

Introduction. The results of multiple tests of liquid rocket engines indicate that the engine with cracks in blades can &#34;safely&#34; work within a few launchings. Therefore, the resource estimation of the nozzle blade with a crack becomes highly relevant, especially for reusable rocket engines. The objective of this work was to determine the residual life of nozzle diapgragm blades with cracks. Method. For reliable residual life estimation of the blade with a crack the comprehensive approach was used: fractographic and material science studies on the one hand and fracture mechanics propositions on the other hand. Results. Fractographic and material science studies have shown that blade destruction occurs through the countergrowth of fatigue surface cracks from the blade pressure side and the blade suction face, which interconnects to form a &#34;main&#34; crack, whose growth is controlled by growth of surface cracks from the blade pressure side. Using the fracture mechanics propositions and the results of finite element calculations of the stress-strain state of nozzle diaphragm blades under gas and thermal loads in elasto-plastic formulation, equations of crack growth in nozzle blades were obtained. Finally the scheme of blade unstable fracture is proposed; the blade guaranteed residual life under certain conditions is evaluated and the maximum tolerable crack length in the blade suction face is determined. Conclusion. The method offered in this work makes it possible to evaluate the blade residual life as the number of loading cycles while fatigue crack propagation and as the tolerable number of firing tests. The method also enables the maximum permissible crack lenth to be determined.

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