Simulation of Tunneling Conductivity and Controlled Percolation In 3D Nanotube-Insulator Composite System

2019 ◽  
pp. 307-322
Author(s):  
I. Karbovnyk ◽  
Yu. Olenych ◽  
D. Chalyy ◽  
D. Lukashevych ◽  
H. Klym ◽  
...  
Keyword(s):  
Composite System ◽  
Tunneling Conductivity

Processing and characterization of YBa2Cu3O7−x/Ag composites

1990 ◽  
Vol 48 (4) ◽  
pp. 46-47
Author(s):  
Jafar Javadpour ◽  
Bradley L. Thiel ◽  
Sarikaya Mehmet ◽  
Ilhan A. Aksay
Keyword(s):  
Composite System ◽  
Precursor Solution ◽  
Microstructural Development ◽  
Superconducting Properties ◽  
Practical Applications ◽  
Nitrate Precursor ◽  
Cold Pressed ◽  
Tape Cast ◽  
Composite Samples

Practical applications of bulk YBa2Cu3O7−x materials have been limited because of their inadequate critical current density (jc) and poor mechanical properties. Several recent reports have indicated that the addition of Ag to the YBa2Cu3O7−x system is beneficial in improving both mechanical and superconducting properties. However, detailed studies concerning the effect of Ag on the microstructural development of the cermet system have been lacking. Here, we present some observations on the microstructural evolution in the YBa2Cu3O7−x/Ag composite system.The composite samples were prepared by mixing various amounts (2.5 - 50 wt%) AgNO3 in the YBa2Cu3O7−x nitrate precursor solution. These solutions were then spray dried and the resulting powders were either cold pressed or tape cast. The microstructures of the sintered samples were analyzed using SEM (Philips 515) and an analytical TEM (Philips 430T).The SEM micrographs of the compacts with 2.5 and 50 wt% Ag addition sintered at 915°C (below the melting point of Ag) for 1 h in air are displayed in Figs. 1 and 2, respectively.

Islamic Law and Society

1990 ◽  
Vol 7 (2) ◽  
pp. 177-191
Author(s):  
Louay M. Safi
Keyword(s):  
Composite System ◽  
Islamic Law ◽  
Legal Theory ◽  
Fifth Century ◽  
Muslim Community ◽  
Social Growth ◽  
The Social ◽  
Collective Experience ◽  
Law And Morality ◽  
The Impact

Shari'ah (Islamic law) has been the dominant moral and legal code ofMuslim societies for the gnxter part of their history. During the early centuriesof Islam, Shari'ah hcilitated the social growth and develojment of the Muslims,growth that culminaa in the establishment of a vast emph and an outstandmgcivilization. By the close of the fifth century of Islam, however, Shari'ahbegan to lose its role as the guiding force that inspired Muslim creativityand ingenuity and that nurtured the growing spirit of the Muslim community(Ummah). Consequently, the Ummah entered a period of stagnation thatgradually gave way to intellectual decline and social decadence. Regrettably,this painful trend continues to be more or less 'part of the individualconsciousness and collective experience of Muslims.This paper attempts to trace the development of the principles of Islamicjurisprudence, and to assess the impact of Shari'ah on society. It argues thatthe law ceased to grow by the sixth century of Islam as a result of thedevelopment of classical legal theory; more specifically, law was put on hold,as it were, after the doctrine of the infallibility of ijma' (juristic consensus)was articulated. The rigid principles of classical theory, it is contended, havebeen primarily induced by the hulty epistemology employed.by sixth-centuryjurists.Shari'ah, or Islamic law, is a comprehensive system encompassing thewhole field of human experience. It is not simply a legal system, but rathera composite system of law and morality. That is, Islamic law aspires to regulateall aspects of human activities, not only those that may entail legalconsequences. Hence, all actions and relationships are evaluated in accordancewith a scale of five moral standards.According to Shari'ah, an act may be classified as obligatory (wajib),recommended (mandub), permissible (mubah), reprehensible (makruh), orprohibited (haram). These five categories reflect the varying levels of moral ...

scholarly journals Mechanochemical synthesis of NaBH4 starting from NaH–MgB2 reactive hydride composite system

2013 ◽  
Vol 38 (5) ◽  
pp. 2363-2369 ◽  
Author(s):  
S. Garroni ◽  
C. Bonatto Minella ◽  
D. Pottmaier ◽  
C. Pistidda ◽  
C. Milanese ◽  
...  
Keyword(s):  
Mechanochemical Synthesis ◽  
Composite System

scholarly journals Chitosan/Silver Nanoparticle/Graphene Oxide Nanocomposites with Multi-Drug Release, Antimicrobial, and Photothermal Conversion Functions

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2351
Author(s):  
Zheng Su ◽  
Daye Sun ◽  
Li Zhang ◽  
Miaomiao He ◽  
Yulin Jiang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Drug Release ◽  
Release Rate ◽  
Composite System ◽  
Methyl Blue ◽  
Burst Release ◽  
Fluorescein Sodium ◽  
Photothermal Conversion ◽  
Dual Drug

In this work, we designed and fabricated a multifunctional nanocomposite system that consists of chitosan, raspberry-like silver nanoparticles, and graphene oxide. The room temperature atmospheric pressure microplasma (RT-APM) process provides a rapid, facile, and environmentally-friendly method for introducing silver nanoparticles into the composite system. Our composite can achieve a pH controlled single and/or dual drug release. Under pH 7.4 for methyl blue loaded on chitosan, the drug release profile features a burst release during the first 10 h, followed by a more stabilized release of 70–80% after 40–50 h. For fluorescein sodium loaded on graphene oxide, the drug release only reached 45% towards the end of 240 h. When the composite acted as a dual drug release system, the interaction of fluorescein sodium and methyl blue slowed down the methyl blue release rate. Under pH 4, both single and dual drug systems showed a much higher release rate. In addition, our composite system demonstrated strong antibacterial abilities against E. coli and S. aureus, as well as an excellent photothermal conversion effect under irradiation of near infrared lasers. The photothermal conversion efficiency can be controlled by the laser power. These unique functionalities of our nanocomposite point to its potential application in multiple areas, such as multimodal therapeutics in healthcare, water treatment, and anti-microbials, among others.

scholarly journals Clinoptilolite Microparticles as Carriers of Catechin-Rich Acacia Catechu Extracts: Microencapsulation and In Vitro Release Study

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1655
Author(s):  
Zvezdelina Yaneva ◽  
Donika Ivanova ◽  
Nikolay Popov
Keyword(s):  
Composite System ◽  
Release Kinetics ◽  
Spectral Characteristics ◽  
In Vitro Release ◽  
Medium Ph ◽  
Release Capacity ◽  
Bioactive Substance ◽  
Acacia Catechu ◽  
Vitro Release

The main goal of the present study was to investigate the microencapsulation, in vitro release capacity and efficiency of catechin-rich Acacia catechu extract by Clinosorbent-5 (CLS-5) microparticles by in-depth detailed analyses and mathematical modelling of the encapsulation and in vitro release kinetics behaviour of the polyphenol-mineral composite system. The bioflavanol encapsulation and release efficiency on/from the mineral matrix were assessed by sorption experiments and interpretative modelling of the experimental data. The surface and spectral characteristics of the natural bioactive substance and the inorganic microcarrier were determined by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet/Visible (UV/Vis) spectrophotometric analyses. The maximum extent of catechin microencapsulation in acidic medium was 32%. The in vitro release kinetics study in simulated enzyme-free gastric medium (pH = 1.2) approved 88% maximum release efficiency achieved after 24 h. The in vitro release profile displayed that the developed bioflavanol/clinoptilolite microcarrier system provided sustained catechin in vitro release behaviour without an initial burst effect. Thus, the results from the present study are essential for the design and development of innovative catechin-CLS-5 microcarrier systems for application in human and veterinary medicine.

scholarly journals Insight into the Mechanical Performance of the UHPC Repaired Cementitious Composite System after Exposure to High Temperatures

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4095
Author(s):  
Qing Chen ◽  
Zhiyuan Zhu ◽  
Rui Ma ◽  
Zhengwu Jiang ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
High Temperatures ◽  
Bonding Strength ◽  
Composite System ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Interfacial Structure ◽  
Cementitious Composite ◽  
Average Percentage

In this paper, the mechanical performance of an ultra-high-performance concrete (UHPC) repaired cementitious composite system, including the old matrix and the new reinforcement (UHPC), under various high temperature levels (20 °C, 100 °C, 300 °C, and 500 °C) was studied. In this system, UHPC reinforced with different contents of steel fibers and polypropylene (PP) fibers was utilized. Moreover, the physical, compressive, bonding, and flexural behaviors of the UHPC repaired system after being exposed to different high temperatures were investigated. Meanwhile, X-ray diffraction (XRD), baseline evaluation test (BET), and scanning electron microscope (SEM) tests were conducted to analyze the effect of high temperature on the microstructural changes in a UHPC repaired cementitious composite system. Results indicate that the appearance of the bonded system changed, and its mass decreased slightly. The average percentage of residual mass of the system was 99.5%, 96%, and 94–95% at 100 °C, 300 °C, and 500 °C, respectively. The residual compressive strength, bonding strength, and flexural performance improved first and then deteriorated with the increase of temperature. When the temperature reached 500 °C, the compressive strength, bonding strength, and flexural strength decreased by about 20%, 30%, and 15% for the UHPC bonded system, respectively. Under high temperature, the original components of UHPC decreased and the pore structure deteriorated. The cumulative pore volume at 500 °C could reach more than three times that at room temperature (about 20 °C). The bonding showed obvious deterioration, and the interfacial structure became looser after exposure to high temperature.

Sign in / Sign up

Export Citation Format

Share Document