EB Processing Research Articles

Influence of 24-Epibrassinolide on Water Exchange of Wheat Varieties Various in Dry Resistance under Osmotic Stress

We studied the effect of presowing treatment with 0.4 μM concentration of 24-epibrassinolide (EB) on water metabolism and leaf growth under osmotic stress simulated by 5% mannitol in two contrasting soft wheat (Triticum aestivum L.) varieties—Omskaya 35 (Om-35, drought-tolerant) and Salavat Yulaev (SYu, less drought-tolerant)—on the fifth and seventh days of germination. It was found that EB processing reduced the water deficit against the background of mannitol, which was more pronounced in the Om-35 variety than in the less tolerant variety SYu. The compensation by the seventh day of the influence of osmotic stress in the Om-35 cultivar was due to a lesser degree of increase in the leaf area, which led to a lower water loss as a result of transpiration, a decrease in the osmotic potential due to a higher accumulation of the osmoprotectant proline, and a decrease in the negative effect on the exosmosis of electrolytes.

Multi-layer Laser Mirrors for Optical Sensors Deposited by Electron Beam Deposition and Ion Assisted Electron Beam Deposition

High reflectivity and low loss mirrors are very much essential for state-of art sensors like Ring Laser Gyroscopes widely used for navigation of moving platforms. Surface scattering is the main source of loss for the Laser mirrors of high reflectivity. Surface scattering also lead to coupling of back reflected light leading to dead band of optical sensors at low input rotation. Super polished glass substrates have been prepared from low expansion glass ceramic material. Surface roughness is achieved about 3-5Å (RMS value) for the ceramic glass substrates prior to thin film coating. The substrates are deposited with 41 alternative layers of SiO2 and Ta2O5 of Quarter-Wave optical thickness with Electron Beam Deposition (EBD) technique. Ion beam Assisted Electron Beam Deposition (IAEBD) is used for another batch of substrates to coat identical stack of layers on glass substrates of the same surface quality. The key process parameters of both the coating processes are presented. The optical constants of the films are evaluated with spectroscopic Ellipsometer from 400nm to 1600nm. Total Integrated Scattering is estimated from the achieved surface finishing of mirrors deposited. The multi-layer coatings are characterized with UV-Vis-IR Spectrophotometer and Cavity Ring Down(CRD) loss meter. The quantitative optical loss of the mirrors is measured at 45o angle of incidence with CRD loss meter. The merits of ion assisted EB process over simple EB coating processes are evaluated against optical constants of thin films and performances of mirrors. Fitness of the processes for realizing Laser mirrors for optical sensors at 632.8nm is evaluated.

Influence of cooling rate on the microstructural features of a remelted white-solidified cast iron surface and its effects on nitriding behaviour

Electron beam remelting (EBR) of cast irons is an established procedure for generating hard and wear-resistant functional surfaces. Due to process-specific rapid cooling after the surface melting of cast iron, solidification occurs according to the metastable system, and a ledeburitic surface-layer microstructure is generated (eutectic carbide + austenite + pearlite). When a subsequent nitriding process is added, carbide morphology and distribution have a decisive influence on the formation of nitride layers.In this analysis, investigations on the influence of different EB process parameters are presented and discussed, such as beam current and acceleration voltage, as well as the effect of focus position on the ledeburite morphology, the layer thickness and surface deformation after the EBR process. Cast iron with globular graphite was used as the base material for the present investigations.The classification of the ledeburite was carried out by examining polished metallographic cross-sections for the determination of the EBR layer thickness, the layer hardness and the secondary dendrite arm spacing. The latter factor also allowed conclusions to be reached regarding the rates of cooling. Furthermore, the local distribution of C and Si in the microstructural constituents of the ledeburitic surface layer was essential in understanding the diffusion processes and phase transformations during the subsequent nitriding process. For this reason, EBR layers with defined coarse and fine ledeburitic carbides were generated and characterized in detail using EDX surface scans.The influence of the local microstructure, the carbide morphology and the element distributions in the EBR layer on the formation and properties of the nitride layers are discussed in light of initial nitriding experiments. Based on these findings, further optimization of the surface layer is possible with respect to the selection of parameters for both the EBR and nitriding processes.

The evolution of and challenges for industrial radiation processing—2012

The evolution of industrial radiation processing is traced from Roentgen's discovery of X-radiation in 1895 by following the development of high current, electron beam accelerators (EB) throughout the twentieth century. Although Becquerel soon followed Roentgen with his discovery of what became to be known as radioactivity, electrical sources for ionizing radiation dominate industrial processing with there being more than ten times as many industrial installations using high current EB equipment than the facilities relying upon large concentrations of radioactive isotopes. In the 1950s, the discovery that ionizing radiation would enhance the value of what has become the world's largest volume commodity plastic, polyethylene (PE), opened the way for full scale commercial use of high current EB equipment. While the crosslinking of the PE insulation on wire became one of the first major industrial applications, other uses of EB processing soon followed. In the 1970s, low-energy, self-shielded EB equipment made the surface curing of inks, coatings and adhesives more industrially viable. In the early part of the twenty-first century, new market applications involving the low-energy EB surface decontamination of packaging materials emerged. This new area poses challenges for the metrology needed to control industrial processes, in that there is limited EB penetration into what have been used as dosimeters by industry. Major industrial use of radiation process is now over 50 years old. Because of the diversity of end-uses and the fact that the use of ionizing radiation in industry is a process technique, it is hard to quantify the value-added to numerous commercial products that benefit from this energy efficient process. It may be in excess of a trillion Euros in value-added to articles of commerce. In this milieu, there are some broad-based opportunities for research which are noted.

Radiation technologies: past, present and future

The radiation technologies applying gamma sources and electron accelerators for material processing are well-established processes. New fields concerning radiation sources are development of compact size gamma irradiators, high-power accelerators with direct e −/X conversion and low-energy EB processing systems. The technologies to be developed besides environmental applications, could be nanomaterials, structure engineered materials (sorbents, the composites, ordered polymers, etc.) and natural polymers processing. The International Atomic Energy Agency (the Agency) has been involved in the support of projects related to the application of radiation technology for many years. Due to its assistance, advanced radiation processing centers were established in many countries. New materials and processes were developed as well: wound hydrogel dressing, radiation vulcanized latex, industrial plant for electron beam flue gas treatment, pilot plant for electron beam wastewater treatment and others.

EB processing of braided carbon fibre composite profiles

A new type of carbon fibre reinforced composite profile has been developed by applying braiding, a well-known process of textile technology. Pipe and hollow profile composite products can be manufactured this way by using electron beam cross-linking. The fabric-like braided reinforcing structure was manufactured out of carbon fibre roving. A vinylester type epoxy derivative has been used as matrix material for the composite. The EB irradiation of the impregnated system resulted in better mechanical properties than conventional chemical curing. Besides the static mechanical testing, an advanced dynamical testing method, the falling weight crash test has been successfully tried out on those braided composite systems, to be applied later in the transport industry.

Recent developments in EB processing equipment

Conventional applications of electron beam processing such as, crosslinking of polyethylene foam, of rubber tire components, electrical wire and cable insulations have been a main part of the EB business for many years. New applications are continuing to appear, however, the growth of the new applications has been relatively slow. Nissin High-Voltage, as one of the worlds leading manufacturers of electron beam equipment, continues to develop and improve its equipment to meet the requirements of these new applications. In this paper recent improvements are described, we will also report briefly on the activities of Nissin High-Voltage and NHV-America.

Mits of energy utilization in EB radiation processing

Utilization of energy in EB processing is determined primarily by the yield of electrical energy transformation, resulting from the particular construction of the machine. The basic ratio of power in the beam to the input power cannot be changed. However, on the users side, the use of energy may be improved by pushing the ratio of maximum dose to minimum in the object, to the highest acceptable value and limiting the idle work of the accelerator (tuning, dosimetry, development of irradiation technology) to the bare necessity.

ALA/DRS as the alternative to ALA/EPR dosimetry

L-α alanine dosimeter with diffuse reflectance spectrophotometric (DRS) determination of the free radical CH3-CH-COO− is described. With many features similar to the ALA/EPR dosimetry (the same free radical is measured) it shows also some advantages, like independence of the orientation of crystals of alarune. It is working well in thin layers. Dosimeter is showing precise responses to congested isodose curves, as in EB processing.

A total-absorption calorimeter for medium-energy electron beam calibration

A total-absorption calorimeter was studied from the point of the materials, the size, and the structure for calibration of the medium-energy electron beams in radiation processing. The calorimeter with graphite core with 40 mm in diameter and 12 mm in thickness is useful for 3 MeV class electrons. A surrounding ring for the calorimeter core is found to be effective for accurate measurements. The total absorption calorimeter is a useful tool for periodical calibration of irradiation parameters in industrial EB processing.

Radiation curing progress in Hungary

Radiation chemistry and radiation processing is an actively cultivated field of chemical technology and of applied research in several Central/Eastern European countries. Hungary, with his synthetic polymer production over 50 kg/capita/year, with his strong commitment in nuclear power production /almost 40 % of total electric power/, with his pioneering activity in food irradiation, radiation sterilization as well as EB processing of polymer — performs an iniciating role in this region. Actually four industrial EB machines are working in Hungary on plastics converting. Two of these accelerators, manufactured in SU are producing heat-shrinkable products. Two other, low-energy EB machines from FRG are working on industrial-scale surface-coating. An ELECTROCURTAIN /USA/ is serving R/D. Some actual problems of the applied radiation chemistry of EB-curing will be discussed.

The recent status of EB processing accelerators in Asia

New applications of the electron processing system in Asia and recent development of the equipment are descrived in this report.

The role of multifunctional acrylates in radiation grafting and curing reactions

Multifunctional acrylates (MFAs) are used extensively in radiation rapid cure (RRC) formulations involving u.v. and EB processing to achieve fast rates of polymerization and cross-linking if required. For certain RRC applications, the ability to achieve concurrent grafting with cure can lead to improved properties of the finished product. In the current work the effect of MFAs on concurrent grafting during the curing process is evaluated from a basic study of the role of these MFAs on a typical grafting reaction initiated by u.v. or ionizing radiation. The model used for the grafting work was the copolymerization of styren to the polyolefins and cellulose. It is found that the presence of the MFA and related polyfunctional monomers (PFMs) in additive amounts in the styrene grafting solution enhances the copolymerization yield under certain radiation conditions. Synergistic effects of the MFAs and PFMs with other additives such as mineral acids, inorganic salts (e.g. lithium perchlorate) and specific organic compounds (e.g. urea) were observed in the model grafting reactions. When additives such as silanes and fluorinated alkyl esters, which are important in RRC formulations to achieve slip and flow in the cured film, are incorporated into the model grafting monomer solution, the former additive retards copolymerization whereas the latter enhances it. The inclusion of MFAs in these monomer solutions leads to large increases in graft with both silanes and fluorinated alkyl esters. The result implies that MFAs, in addition to speeding cure and cross-linking in RRC processes, may also enhance adhesion to certain substrates because of an increase in concurent grafting during cure. A mechanism for these additive effects in concurrent grafting and curing is proposed.

Advanced composite materials made by radiation processing

An industrial EB processing line is started to produce cement-bound /CB/ chipboard with radiation cured acrylic coating. The basic features of this line are presented here. The main technological parameters of coating such as: effect of oligomer- and monomer reactivity, monomer functionality, dose-rate and inerting atmosphere on the progress of curing have been discussed. The EB processed CB board is an advanced composite material for the modern lightweight architecture.

The production of high-voltage cathode rays outside of the generating tube

The evolution of industrial radiation processing is traced from Roentgen's discovery of X-radiation in 1895 by following the development of high current, electron beam accelerators (EB) throughout the twentieth century. Although Becquerel soon followed Roentgen with his discovery of what became to be known as radioactivity, electrical sources for ionizing radiation dominate industrial processing with there being more than ten times as many industrial installations using high current EB equipment than the facilities relying upon large concentrations of radioactive isotopes. In the 1950s, the discovery that ionizing radiation would enhance the value of what has become the world's largest volume commodity plastic, polyethylene (PE), opened the way for full scale commercial use of high current EB equipment. While the crosslinking of the PE insulation on wire became one of the first major industrial applications, other uses of EB processing soon followed. In the 1970s, low-energy, self-shielded EB equipment made the surface curing of inks, coatings and adhesives more industrially viable. In the early part of the twenty-first century, new market applications involving the low-energy EB surface decontamination of packaging materials emerged. This new area poses challenges for the metrology needed to control industrial processes, in that there is limited EB penetration into what have been used as dosimeters by industry. Major industrial use of radiation process is now over 50 years old. Because of the diversity of end-uses and the fact that the use of ionizing radiation in industry is a process technique, it is hard to quantify the value-added to numerous commercial products that benefit from this energy efficient process. It may be in excess of a trillion Euros in value-added to articles of commerce. In this milieu, there are some broad-based opportunities for research which are noted.