Applications of Chemiluminescence in Rubber Research

1992 ◽  
Vol 65 (4) ◽  
pp. 736-743 ◽  
Author(s):  
Dan Forsström ◽  
Anna Kron ◽  
Bengt Mattson ◽  
Torbjörn Reitberger ◽  
Bengt Stenberg ◽  
...  
Keyword(s):  
Service Life ◽  
Natural Rubber ◽  
Organic Materials ◽  
Photon Counting ◽  
Cellulose Fiber ◽  
Polymeric Materials ◽  
Sensitive Technique ◽  
Weak Light ◽  
Counting Equipment

Abstract The oxidation of most organic materials is accompanied by the emission of weak light, so called chemiluminescence (CL). This emission has previously often been designated oxyluminescence. CL has been known for several years, but it is not until recently that the development of photon counting equipment has allowed detection of levels down to a few photons per second. This development makes CL a promising nondestructive and extremely sensitive technique to provide data which may be useful to estimate the service life of polymeric materials. Various applications of the CL-method for the detection of oxidation of elastomers are reported: such as, stabilization of hydroxyl-terminated polybutadiene; degradation of latex coating of paper; long-term thermo-oxidation of natural rubber; indication of ultrathin coating of cellulose fiber with polybutadiene.

Prospects of Time-Resolved Photon Emission as a Debug Tool

2002 ◽  
Author(s):  
Jim Vickers ◽  
Nader Pakdaman ◽  
Steven Kasapi
Keyword(s):  
Photon Emission ◽  
Photon Counting ◽  
Signal Propagation ◽  
General Function ◽  
Hot Electron ◽  
Detector Performance ◽  
Time Resolved ◽  
Switching Event ◽  
Emission System

Abstract Dynamic hot-electron emission using time-resolved photon counting can address the long-term failure analysis and debug requirements of the semiconductor industry's advanced devices. This article identifies the detector performance parameters and components that are required to scale and keep pace with the industry's requirements. It addresses the scalability of dynamic emission with the semiconductor advanced device roadmap. It is important to understand the limitations to determining that a switching event has occurred. The article explains the criteria for event detection, which is suitable for tracking signal propagation and looking for logic or other faults in which timing is not critical. It discusses conditions for event timing, whose goal is to determine accurately when a switching event has occurred, usually for speed path analysis. One of the uses of a dynamic emission system is to identify faults by studying the emission as a general function of time.

scholarly journals A Novel Highly Durable Carbon/Silver/Silver Chloride Composite Electrode for High-Definition Transcranial Direct Current Stimulation

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1962
Author(s):  
Lingjun Li ◽  
Guangli Li ◽  
Yuliang Cao ◽  
Yvonne Yanwen Duan
Keyword(s):  
Service Life ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Silver Chloride ◽  
Cycling Performance ◽  
High Definition ◽  
Silver Silver ◽  
Sintered Ag ◽  
Silver Silver Chloride

High-definition transcranial direct current stimulation (HD-tDCS) is a promising non-invasive neuromodulation technique, which has been widely used in the clinical intervention and treatment of neurological or psychiatric disorders. Sintered Ag/AgCl electrode has become a preferred candidate for HD-tDCS, but its service life is very short, especially for long-term anodal stimulation. To address this issue, a novel highly durable conductive carbon/silver/silver chloride composite (C/Ag/AgCl) electrode was fabricated by a facile cold rolling method. The important parameters were systematically optimized, including the conductive enhancer, the particle size of Ag powder, the C:Ag:PTFE ratio, the saline concentration, and the active substance loading. The CNT/Ag/AgCl-721 electrode demonstrated excellent specific capacity and cycling performance. Both constant current anodal polarization and simulated tDCS measurement demonstrated that the service life of the CNT/Ag/AgCl-721 electrodes was 15-16 times of that of sintered Ag/AgCl electrodes. The much longer service life can be attributed to the formation of the three-dimensional interpenetrating conductive network with CNT doping, which can maintain a good conductivity and cycling performance even if excessive non-conductive AgCl is accumulated on the surface during long-term anodal stimulation. Considering their low cost, long service life, and good skin tolerance, the proposed CNT/Ag/AgCl electrodes have shown promising application prospects in HD-tDCS, especially for daily life scenarios.

scholarly journals Study of the Ultraviolet Effect and Thermal Analysis on Polypropylene Nonwoven Geotextile

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  
Keyword(s):  
Uv Light ◽  
Polymeric Materials ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Material Stiffness ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Physical Tests ◽  
Nonwoven Geotextile

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.

Koroseal, a New Plastic. Some Properties and Uses

1935 ◽  
Vol 8 (4) ◽  
pp. 641-654
Author(s):  
S. L. Brous ◽  
W. L. Semon
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Natural Product ◽  
Organic Materials ◽  
Linear Polymers ◽  
Independent Source ◽  
Historical Treatise ◽  
The Many ◽  
Marked Resistance ◽  
Modern Industry

Abstract Rubber has found its widest use in industry because its properties can be altered and improved by compounding and cure to give strong, flexible, resilient products which are resistant to abrasion, impervious to fluids, electrically insulating, and relatively inert chemically. For such other desirable characteristics as resistance to oils and solvents, and freedom from attack by air, sunlight, and oxidizing materials, skillful compounding has brought marked improvements, but even better properties are needed to meet the demands of modern industry. The search for synthetic rubbers has been stimulated not merely by the desire for an economically independent source of supply, but also with the hope that there might be obtained materials having properties superior to the natural product. Whitby and Katz (4) have published a comprehensive historical treatise dealing with the development of numerous synthetic rubbers which have appeared in the last few years. It has been believed that linear polymers obtained from dienes hold most promise for the preparation of rubber-like materials. Carothers (1) has studied the relation between the structure of dienes and the types of polymerization products which may be obtained therefrom. On the basis of these data he inferred that, from the standpoint of their polymerization products, the best dienes will be of the type CH2:CXCH:CH2, in which X is an activating group other than alkyl or aryl. In general it has been found that there may be obtained polymerization products with physical properties equal to, or often superior to those of natural rubber, and with marked resistance to the action of solvents and chemicals. Among the many types of organic materials which will polymerize, the vinyl compounds only recently have been modified suitably to yield commercial rubber-like materials.

Molecular materials for micro-electronics

2000 ◽  
Vol 78 (3) ◽  
pp. 231-241 ◽  
Author(s):  
M D'Iorio
Keyword(s):  
High Performance ◽  
Organic Materials ◽  
Coming Of Age ◽  
Polymeric Materials ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Plastic Electronics ◽  
Organic Light ◽  
Recent Developments

Molecular organic materials have had an illustrious past but the ability to deposit these as homogeneous thin films has rejuvenated the field and led to organic light-emitting diodes (OLEDs) and the development of an increasing number of high-performance polymers for nonlinear and electronic applications. Whereas the use of organic materials in micro-electronics was restricted to photoresists for patterning purposes, polymeric materials are coming of age as metallic interconnects, flexible substrates, insulators, and semiconductors in all-plastic electronics. The focus of this topical review will be on organic light-emitting devices with a discussion of the most recent developments in electronic devices.PACS Nos.: 85.60Jb, 78.60Fi, 78.55Kz, 78.66Qn, 73.61Ph, 72.80Le

scholarly journals Replacing Synthetic Nitrogen Fertilizer with Different Types of Organic Materials Improves Grain Yield in China: A Meta-Analysis

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2429
Author(s):  
Xiaoru Fan ◽  
Zekai Chen ◽  
Zihan Niu ◽  
Ruiyao Zeng ◽  
Jingmin Ou ◽  
...  
Keyword(s):  
Grain Yield ◽  
Nitrogen Fertilizer ◽  
Organic Materials ◽  
Crop Yields ◽  
Meta Analysis ◽  
Chicken Manure ◽  
Agricultural Practice ◽  
Different Types ◽  
Synthetic Nitrogen Fertilizer

Synthetic nitrogen fertilizer substitution (NSS) with different types of organic material is a cleaner agricultural practice for reducing the application of synthetic N input in farmlands while also relieving the environmental issues caused by the discharge of organic wastes. However, the effects of the NSS practice on crop yields, being the primary objective of agricultural activity, is still uncertain in China. This study conducted a meta-analysis to assess the impacts of the NSS practices with different types of organic materials on crop yields. Results showed that the average crop yield was increased by 3.4%, with significant differences under NSS, thereby demonstrating that this practice contributed to improving crop yields, especially of rice and maize. According to published reports, the NSS practices involving chicken manure, pig manure, and crop straw increased crop yields by 4.79, 7.68, and 3.28%, respectively, with significant differences, thus demonstrating the superior effects needed for replacing synthetic N fertilizer. Moreover, substitution ratios (SR) between 0% and 60% could be suggested when using the NSS practice, with the high SR recommended when the original soil fertility was adequate for crops. Considering the long-term effects of applied organic materials, improving the grain yield with the NSS practice should be expected in the long-term. By effectively applying the NSS, this study attempted to scientifically decide on the type of organic materials and the appropriate SR based on the conditions of the soil and the crop. The results provide research information for the development of clean agricultural production and food security in China.

Sign in / Sign up

Export Citation Format

Share Document