The Processing and Characterization of DCCA Modified Gel-Derived Silica

1984 ◽  
Vol 32 ◽  
Author(s):  
S. Wallace ◽  
L. L. Hench
Keyword(s):  
Large Scale ◽  
Sol Gel ◽  
Scale Space ◽  
Gel Strength ◽  
Common Procedure ◽  
Drying Time ◽  
Densification Temperature ◽  
Large Structures ◽  
Wide Range ◽  
Silica Gel Monoliths

The production of small silica gel monoliths by the hydrolysis and polycondensation of tetramethyl orthosilicate (TMS) in a methanol solution is now a common procedure. Drying is generally done slowly in a methanolic atmosphere [1] or under hypercritical conditions [2]. The potential application of sol-gel technology in the production of materials for large structures requires a rapid processing time, which causes a problem due to cracking. For large scale space structures the materials produced also require a low molecular weight, a low densification temperature, control of devitrification and a wide range of physical properties and gel densities. These requirements are potentially met by multicomponent silica based gels [3]. To decrease the drying time, which is the longest part of gel processing, the gel strength needs to be increased to resist cracking and the drying stress reduced. The gel strength can be improved by optimizing the variables in the gel manufacturing process.

Continuous-Flow Direct Writing of Hybrid TiO2 Flexible Photo-Electrodes: Processing, Microstructure and Functionality Interrelations

MRS Advances ◽  
2017 ◽  
Vol 2 (18) ◽  
pp. 1021-1028 ◽  
Author(s):  
Maria A. Torres Arango ◽  
Domenic T. Cipollone ◽  
Lynnora O. Grant ◽  
Dimitris Korakakis ◽  
Konstantinos A. Sierros
Keyword(s):  
Flexible Electronics ◽  
Continuous Flow ◽  
Large Scale ◽  
Sol Gel ◽  
Direct Writing ◽  
Typical Application ◽  
Organic Precursor ◽  
Wide Range ◽  
Compositional Variations ◽  
Functional Components

ABSTRACTFlexible electronics manufacturing from functional inks is a versatile approach gaining interest from both industry and academia at an accelerated pace; towards its full development, research studies establishing connections between the inks processing conditions and final materials functionalities become necessary. In this work, we report on the relations between synthesis, continuous - flow direct writing parameters, and low energy intensity post-processing of functional TiO2 hybrid ink patterns. Such inks are printed on heat sensitive polymer substrates with typical application in dye solar cell photoelectrodes; nevertheless, their versatility spans a wide range of other applications from sensors to photocatalysts. For the ink formulation, we use an initial crystalline nanoparticle TiO2 phase that provides the main functionality of the printed films. We also add a Ti-precursor that, when post-treated, provides connecting paths for the initial phase thus forming continuous porous structures. We find that the ink’s formulation plays a pivotal role by providing the means for tuning its rheological properties (necessary for successful direct writing), the ink-substrate interactions, and the printed microstructures. We further discuss the implications of such compositional variations, introduced when adding polymeric agents, such as polyacrylic acid, on the crystallization of the Ti-organic precursor into TiO2 bridges between the nanoparticles. We finally report on the electrical properties of the printed TiO2 photoelectrodes as compared to conventionally fabricated counterparts. The design, continuous – flow direct writing, and the subsequent mild thermal-energy treatments of hybrid sol-gel based TiO2 inks may hold the key for large-scale and sustainable additive manufacturing of flexible functional components for a range of applications.

Preparation of Silicon Oxide Nanostructures Using Anodic Alumina as Templates

1999 ◽  
Vol 5 (S2) ◽  
pp. 814-815
Author(s):  
Ming Zhang ◽  
Y. Bando ◽  
K. Wada ◽  
K. Kurashima
Keyword(s):  
Large Scale ◽  
Silicon Oxide ◽  
Sol Gel ◽  
Film Surface ◽  
Anodic Alumina ◽  
Semiconductor Nanowire ◽  
Oxide Nanostructures ◽  
Wide Range ◽  
Uniform Diameter ◽  
Nanochannel Array

There is currently an intensive effort to develop large-scale semiconductor nanowire or nanotube materials, such as Si and silicon oxide SiOx (l<x<2), with the uniform wide range of sizes up to 30nm, which would open us new opportunities in semiconductor and catalysis industries but is difficult to achieve at present. Up to our knowledge, the detailed study on macroscopic synthesis of aligned silicon oxide nanostructures with about 30nm diameter has not been carried on yet.The ordered nanochannel-array anodic alumina were prepared via the anodization of aluminum textured pattern on the surface in a 3% oxalic acidic solution under the constant-voltage condition. It is about 6 μm and contains ordered cylindrical pores with the uniform diameter of 20-30nm and almost perpendicular to the film surface. The aligned silicon oxide nanostructures were prepared on this anodic alumina using a sol-gel method.For sol aged at room temperature and dipped for lmin., nanowires are formed in a shorter period of aging time; while nanotubes are synthesized in a longer time (above 23 days).

Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1362-1363
Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Hexagonal Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Tin Films ◽  
Wide Range ◽  
Fcc Phase ◽  
Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

Influencia de las condiciones de secado solar en la coloración de plantas medicinales

2019 ◽  
pp. 28-34
Author(s):  
Margarita Castillo-Téllez ◽  
Beatriz Castillo-Téllez ◽  
Juan Carlos Ovando-Sierra ◽  
Luz María Hernández-Cruz
Keyword(s):  
Medicinal Plants ◽  
Forced Convection ◽  
Rural Areas ◽  
Color Change ◽  
Drying Process ◽  
Scientific Medicine ◽  
Drying Time ◽  
Bacterial Proliferation ◽  
Wide Range ◽  
Very High

For millennia, humans have used hundreds of medicinal plants to treat diseases. Currently, many species with important characteristics are known to alleviate a wide range of health problems, mainly in rural areas, where the use of these resources is very high, even replacing scientific medicine almost completely. This paper presents the dehydration of medicinal plants that are grown in the State of Campeche through direct and indirect solar technologies in order to evaluate the influence of air flow and temperature on the color of the final product through the L* a* scale. b*, analyzing the activity of water and humidity during the drying process. The experimental results showed that the direct solar dryer with forced convection presents a little significant color change in a drying time of 400 min on average, guaranteeing the null bacterial proliferation and reaching a final humidity between 9 % and 11 %.

THE SOME QUESTIONS OF AUTONOMOUS MOTION AND MANAGEMENT OF LAND-MOBILE ROBOTIC COMPLEXES FOR UKRAINIAN GROUND FORCESE

2019 ◽  
pp. 53-58
Author(s):  
О. Кravchuk ◽  
V. Symonenkov ◽  
I. Symonenkova ◽  
O. Hryhorev
Keyword(s):  
Large Scale ◽  
Armed Forces ◽  
Distributed Information ◽  
Wide Range ◽  
Highly Effective ◽  
Information Management Systems ◽  
Robotic Devices ◽  
Principles And Standards ◽  
And Control ◽  
The Eu

Today, more than forty countries of the world are engaged in the development of military-purpose robots. A number of unique mobile robots with a wide range of capabilities are already being used by combat and intelligence units of the Armed forces of the developed world countries to conduct battlefield intelligence and support tactical groups. At present, the issue of using the latest information technology in the field of military robotics is thoroughly investigated, and the creation of highly effective information management systems in the land-mobile robotic complexes has acquired a new phase associated with the use of distributed information and sensory systems and consists in the transition from application of separate sensors and devices to the construction of modular information subsystems, which provide the availability of various data sources and complex methods of information processing. The purpose of the article is to investigate the ways to increase the autonomy of the land-mobile robotic complexes using in a non-deterministic conditions of modern combat. Relevance of researches is connected with the necessity of creation of highly effective information and control systems in the perspective robotic means for the needs of Land Forces of Ukraine. The development of the Armed Forces of Ukraine management system based on the criteria adopted by the EU and NATO member states is one of the main directions of increasing the effectiveness of the use of forces (forces), which involves achieving the principles and standards necessary for Ukraine to become a member of the EU and NATO. The inherent features of achieving these criteria will be the transition to a reduction of tasks of the combined-arms units and the large-scale use of high-precision weapons and land remote-controlled robotic devices. According to the views of the leading specialists in the field of robotics, the automation of information subsystems and components of the land-mobile robotic complexes can increase safety, reliability, error-tolerance and the effectiveness of the use of robotic means by standardizing the necessary actions with minimal human intervention, that is, a significant increase in the autonomy of the land-mobile robotic complexes for the needs of Land Forces of Ukraine.

Capture Strategy Based on a Distributed Control System for a Large-scale Space End-Effector

ROBOT ◽  
2011 ◽  
Vol 33 (4) ◽  
pp. 434-439 ◽  
Author(s):  
Dangyang JIE ◽  
Fenglei NI ◽  
Yisong TAN ◽  
Hong LIU ◽  
Hegao CAI
Keyword(s):  
Control System ◽  
Distributed Control ◽  
Large Scale ◽  
Scale Space ◽  
Distributed Control System ◽  
End Effector

Stirring and aeration system for the upgrading of small waste water treatment plants

1994 ◽  
Vol 29 (12) ◽  
pp. 149-156 ◽  
Author(s):  
Marcus Höfken ◽  
Katharina Zähringer ◽  
Franz Bischof
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Large Scale ◽  
Waste Water Treatment ◽  
Water Treatment Plants ◽  
Waste Water Treatment Plants ◽  
Basic Fluid ◽  
Aeration System ◽  
Technical Realization ◽  
Wide Range

A novel agitating system has been developed which allows for individual or combined operation of stirring and aeration processes. Basic fluid mechanical considerations led to the innovative hyperboloid design of the stirrer body, which ensures high efficiencies in the stirring and the aeration mode, gentle circulation with low shear forces, excellent controllability, and a wide range of applications. This paper presents the basic considerations which led to the operating principle, the technical realization of the system and experimental results in a large-scale plant. The characteristics of the system and the differences to other stirring and aeration systems are illustrated. Details of the technical realization are shown, which conform to the specific demands of applications in the biological treatment of waste water. Special regard is given to applications in the upgrading of small compact waste water treatment plants.

Thin structure of heterogeneous and multiphase fluid flows

2012 ◽  
Vol 9 (1) ◽  
pp. 175-180
Author(s):  
Yu.D. Chashechkin
Keyword(s):  
Large Scale ◽  
Fundamental System ◽  
Fluid Flows ◽  
Regular Solutions ◽  
Flow Models ◽  
Group Methods ◽  
Wide Range ◽  
Thin Structure ◽  
Multiphase Fluid ◽  
Complete Solutions

According to the results of visualization of streams, the existence of structures in a wide range of scales is noted: from galactic to micron. The use of a fundamental system of equations is substantiated based on the results of comparing symmetries of various flow models with the usage of theoretical group methods. Complete solutions of the system are found by the methods of the singular perturbations theory with a condition of compatibility, which determines the characteristic equation. A comparison of complete solutions with experimental data shows that regular solutions characterize large-scale components of the flow, a rich family of singular solutions describes formation of the thin media structure. Examples of calculations and observations of stratified, rotating and multiphase media are given. The requirements for the technique of an adequate experiment are discussed.

Integrative Data Analysis from a Unifying Research Synthesis Perspective

2018 ◽  
Author(s):  
Eun-Young Mun ◽  
Anne E. Ray
Keyword(s):  
Data Analysis ◽  
Large Scale ◽  
Research Synthesis ◽  
Alcohol Intervention ◽  
Data Set ◽  
Integrative Data Analysis ◽  
Level Data ◽  
Model Complex ◽  
Wide Range ◽  
Individual Participant

Integrative data analysis (IDA) is a promising new approach in psychological research and has been well received in the field of alcohol research. This chapter provides a larger unifying research synthesis framework for IDA. Major advantages of IDA of individual participant-level data include better and more flexible ways to examine subgroups, model complex relationships, deal with methodological and clinical heterogeneity, and examine infrequently occurring behaviors. However, between-study heterogeneity in measures, designs, and samples and systematic study-level missing data are significant barriers to IDA and, more broadly, to large-scale research synthesis. Based on the authors’ experience working on the Project INTEGRATE data set, which combined individual participant-level data from 24 independent college brief alcohol intervention studies, it is also recognized that IDA investigations require a wide range of expertise and considerable resources and that some minimum standards for reporting IDA studies may be needed to improve transparency and quality of evidence.

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