Abstract In this work, a series of polybutylmethacrylate/kapok fiber (PBMA/KF) composites were synthesized by suspended emulsion polymerization and well characterized by means of Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The effects of reaction parameters, such as amount of initiator, crosslinker, emulsifier, KF content on oil absorbency, were investigated in detail. The optimum polymerization conditions were obtained as initiator of 0.4 wt %, crosslinker of 1.0 wt %, emulsifier of 2.0 wt %, and KF content of 8.0 wt %. Compared with PBMA, the as-prepared PBMA/KF (8 wt % KF) showed better oil sorption capacity, with the increase percentage of 58.7% in toluene and 66.7% in chloroform. Swelling behavior indicated that the sorption equilibrium was e...

...Zone 148--Knoxville, TN; Application for Subzone; Toho Tenax America, Inc. (Carbon Fiber and Oxidized Polyacrylonitrile...fiber (OPF) manufacturing and warehousing facilities of Toho Tenax America, Inc. (Toho), located in Rockwood,...

The report concerns the use of unconventional natural fibers for the manufacture of textiles in India. It covers: (1) fiber extraction and processing: raw material, decortication, retting, and chemical extraction; (2) spinning of cotton, jute and coconut ...

Fiber-Reinforced-Foam (FRF) Core Composite Sandwich Panel Concept for Advanced Composites Technologies Project - Preliminary Manufacturing Demonstration Articles for Ares V Payload Shroud Barrel Acreage Structure

Carbon fibers were obtained from several manufacturers. Surface treatments were performed on these fibers by anodization. The surfaces of these fibers were analyzed by X-ray photoelectron spectroscopy and wetting force measurement. The breaking strength of these fibers was measured at 2.5 cm length. It was seen that the surface treatments reduces the strength of the fibers. It was also seen that the Hercules fibers had a higher breaking strength than the Union Carbide fibers. Fiber critical length measurements showed no difference in critical lengths between AS-4 and AU-4 fibers embedded in polysulfone. However, the fiber lengths were much shorter for the surface treated fibers. This effect could be related to increased adhesion between fiber and matrix, or it could be due to the lower breaking strength of the surface treated fiber.

The goal of this project is to develop an innovative manufacturing process for Type IV high-pressure hydrogen storage vessels, with the intent to significantly lower manufacturing costs. Part of the development is to integrate the features of high precision AFP and commercial FW. Evaluation of an alternative fiber to replace a portion of the baseline fiber will help to reduce costs further.

Development, testing and optimization of advanced metal and ceramic, barrier and fiber safeguard devices (SGDs) is described. Metal barrier devices are found prone to manufacturing defects and premature blinding. Fiber devices are found to be satisfactory if fine fibers are used. Durable alloys are identified for both oxidation and gasification conditions. Ceramic honeycomb SGDs were found to perform as excellent barrier devices. Optimization has shown such devices to be durable. Field testing of ceramic honeycomb SGDs from two different manufacturers is being pursued.

Carbon fibers are selected for ceramic matrix composites (CMC) are based on their as-fabricated properties or on "that is what we have always done" technical culture while citing cost and availability when there are others with similar cost and availability. However, the information is not available for proper selection of carbon fibers since heat-treated properties are not known for the fibers on the market currently. Heat-treating changes the fiber's properties. Therefore, an effort was undertaken to establish fiber properties on 19 different types of fibers from six different manufactures for both PAN and pitch fibers. Heat-treating has been done at three different temperatures.

Photonic crystal fibers are novel optical waveguides containing a periodic array of air holes running along the fiber around a solid or hollow core. These fibers have recently attracted great interest in many research areas such as in nonlinear optics and measurement science as their manufacturing p...

Fused fiber components are the key building blocks that enable reliable and efficient operation of high power fiber lasers. In this paper, we review fabrication techniques for the manufacture of such devices, including mode-field adaptors, fiber tapers, fused couplers, and fused combiners. We present the basic equations governing both the optical performance and fabrication requirements for these devices, and demonstrate how these apply to some common fiber laser applications. We then describe and discuss component fabrication techniques and available hardware.

The interface of short alumina fiber-reinforced aluminum alloy composite manufactured by the infiltration method was studied. The results indicate that there are obvious interface layers between the fiber and the matrix in the composites, and the alloy elements may improve the interface wettability by suitable chemical reaction between the fiber and the matrix. The analysis of the specimen fracture also indicates that the bonding between fiber and matrix is strong enough to transmit loading from matrix to fiber so as to play a reinforcing role of the fibers. 11 refs.

A ceramic fiber composite structure particularly suitable for use as a hot gas cleanup ceramic fiber composite filter and method of making same from ceramic composite material has a structure which provides for increased strength and toughness in high temperature environments. The ceramic fiber composite structure or filter is made by a process in which a continuous ceramic fiber is intimately surrounded by discontinuous chopped ceramic fibers during manufacture to produce a ceramic fiber composite preform which is then bonded using various ceramic binders. The ceramic fiber composite preform is then fired to create a bond phase at the fiber contact points. Parameters such as fiber tension, spacing, and the relative proportions of the continuous ceramic fiber and chopped ceramic fibers can be varied as the continuous ceramic fiber and chopped ceramic fiber are simultaneously formed on the porous vacuum mandrel to obtain a desired distribution of the continuous ceramic fiber and the chopped ceramic fiber in the ceramic fiber composite structure or filter.

Little data are available on ambient concentrations of glass fibers which along with other manmade vitreous fibers are receiving increased regulatory attention. The purpose of this study was to measure glass and total respirable fibers around a large fiberglass wool manufacturing plant and a rural area. Samples were collected on mixed esters of cellulose filters using high-volume air samplers at flow rates of 1.2 m3/min. Fibers were counted using a modified NIOSH 7400B procedure. Glass fibers were found in very low concentrations for both areas sampled; 90% of the samples were below the detectable limit of 0.00001 fibers/cc. Average glass fiber concentrations accounted for less than 1% of the total fibers measured. Dispersion modeling was used to estimate ambient glass fiber concentrations around the plant. Predicted and measured results showed relatively good agreement. PMID:7724859

Carbon fibers are highly conductive, lightweight and of small dimensions. When released as emissions from production, manufacturing, processing and disposal sources they may become airborne and disperse over wide areas. If they settle onto electronic or electrical components they...

...310. transportation in commerce of Boron Trifluoride in electron tubes that are...fully wrapped carbon-fiber reinforced aluminum lined cylinders. (modes 1, 2, 3...Specification 3AL cylinders manufactured from aluminum alloy 6061-T6 that are requalified...

...existing plywood and composite wood products (PCWP) facilities. Plywood and/or composite products are manufactured by bonding wood material (fibers...panel or engineered wood product. Plywood and composite products...

This citation summarizes a one-page announcement of technology available for utilization. Progress in the development of processes to manufacture rugged optical-fiber cables is outlined in a report by the U.S. Army Communications Research and Development ...

... Acrylamide is a chemical widely used during the manufacturing of papers, dyes, and other industrial products. It ... balanced eating plan that includes fruits and vegetables, lean meats, fish, high-fiber grains, and beans. The ...

2) Optical fiber termini manufactured by Amphenol/Bendix and used in MIL-C- 38999 Series III ... contact with the adhesive is critical to a reliable bond and end product. .... because of the high magnification, the microscope lens and terminus ...

This paper investigated the damage transition mechanism between the fiber-breakage mode and the fiber-avoiding crack mode when the fiber-length is reduced in the unidirectional discontinuous carbon-fiber-reinforced-plastics (CFRP) composites. The critical fiber-length for the transition is a key parameter for the manufacturing of flexible and high-strength CFRP composites with thermoset resin, because below this limit, we cannot take full advantage of the superior strength properties of fibers. For this discussion, we presented a numerical model for the microscopic damage and fracture of unidirectional discontinuous fiber-reinforced plastics. The model addressed the microscopic damage generated in these composites; the matrix cracking with continuum damage mechanics model and the fiber breakage with the Weibull model for fiber strengths. With this numerical model, the damage transition behavior was discussed when the fiber length was varied. The comparison revealed that the length of discontinuous fibers in composites influences the formation and growth of the cluster of fiber-end damage, which causes the damage mode transition. Since the composite strength is significantly reduced below the critical fiber-length for the transition to fiber-avoiding crack mode, we should understand the damage mode transition appropriately with the analysis on the mechanism of the cluster growth of fiber-end damage.   

The present conference on embedded fiber-optics incorporating 'smart' structural systems and structural surfaces discusses topics in the nature and current status of university- and government-sponsored smart-structure development programs, manufacturing and cure-monitoring for composite smart structures, smart-structure damage assessment, smart-structure actuators, and smart-structure sensors and components. Attention is given to fiber-optic sensor selection, the optical properties of curing epoxies, the automated production of smart structures, damage-detection in composites with embedded fiber-optic interferometers, fiber-optic strain and impact sensors, dynamically-tunable smart composites, smart structures incorporating artificial neural networks, active structural acoustic control with smart structures, and fiber-optic shape sensing for flexible structures.

Optical glass fiber is a better choice than copper media for supporting both today/tomorrow`s communication network requirements. The optical fiber cable as its final product will play an important role in the high bandwidth superhighway traffic that networks will soon carry. The basic manufacturing technology of fiber optic cables, including its processes and materials, entails the same as that of the conventional copper wire cable, but the performance of the final products is strongly dependent on the details of the cabling designs, materials and processes because the optical fiber is extremely sensitive to environmental conditions. This paper will discuss the technological development of optical fiber cables used in various communication applications.

Applications of optical fibers in telecommunication and sensing are rapidly emerging where the fiber properties are related to the controlled addition of dopants such as germanium, phosphorous, fluorine and erbium. The modern ToF-SIMS instrument, with its high sensitivity and high lateral resolution, has shown to be an excellent tool to directly analyze cross-sections of as-manufactured fibers. The present work describes ToF-SIMS imaging of the dopant distribution in fluorine, germanium and rare-earth doped fibers where dopants are confined to a few {mu}m in the core. The increased fluorine diffusion in the fluorine doped fibers due to chemical reactions with hydroxyl groups was examined. This process is utilized in the manufacture of thermally stable chemical composition fiber Bragg gratings. We were able to produce ToF-SIMS elemental images with a lateral resolution around 0.5 {mu}m showing the detailed distribution of the dopants.

A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described.

The objective of this paper is to confirm the slow-axis loss of less than 0.1 dB/m for the PZ fiber manufactured for LLNL by 3M and to provide samples of the fiber to CEA/Thomson that will permit them to readily verify this result.

We investigated the influence of core material, cladding thickness, drawing speed, and coating material on the radiation sensitivity of pure silica core step-index fibers with high OH-content. The gamma radiation-induced attenuation at 660 nm and 850 nm of fibers by different manufacturers are compa...

An activated carbon fiber nonwoven (ACF) was manufactured from cotton nonowoven fabric. For the ACF acoustical application, a nonwoven composite of ACF with cotton nonwoven as a base layer was developed. Also produced were the composites of the cotton nonwoven base layer with a layer of glass fiber ...

Fiber glass has been used widely in manufacturing industries, especially marine industries, because of low cost and high strength. However, glass fiber can cause acute irritation to the skin, eyes, and upper respiratory tract. This study looked at the possibility of substituting glass fiber with natural fiber in composite materials. The surface properties of sugar palm fiber (Arenga pinnata) were modified using seawater and freshwater as treatment substances. This led to biological, chemical, and water degradation of the sugar palm fiber. Morphological and structural changes in the fibers were investigated using a scanning electron microscope (SEM). A series of tensile tests based on ASTM D638-99 was carried out on epoxy composites with 15% sugar palm fiber by volume. It was found that sea...

This article gives a survey of the history, properties and applications of 'Kevlar' aramide fibers. For example, the 'Kevlar' para-aramide fiber is used in compound materials in ship-, aircraft- and vehicle construction. 'Kevlar' is used as a replacement for asbestos, for example in brakes, clutches and seals or as rubber reinforcement (tyres, conveyor belts, hoses). The aramide fibers also offer manufacturers of ropes, hawsers and cables a near ideal range of properties. (MM).

An advanced design method has been developed for manufacturing large fiber-reinforced-plastic (FRP) structures to be used in next-generation satellites such as the quasi-zenith satellite (QZS). The design method enables highly accurate shape and strength predictions, including of the thermal residual stresses, without trial manufacture. The design, manufacture and tests of the satellite’s main structure (verification model) are also reported. The verification model is used to make the main structure of the successfully launched QZS.   

The decline in price of carbon fibers gives an economic incentive to reconsider the use of these reinforcements in markets previously deemed too expensive, such as the automotive industry. Additionally, it would be advantageous if carbon fibers could be immediately used with polymers and manufacturing methods currently used for the production of fiberglass composites, and thus minimize development and startup costs. Of particular interest is the use of carbon fibers in vinyl esters manufactured by resin transfer molding, a leading manufacturing technology for the production of large and complex shaped composite parts. However, carbon fiber-vinyl ester composites have inferior mechanical properties as a result of poor bonding between fiber and matrix. The objective of this program was to evaluate the physical and chemical mechanisms currently thought responsible for adhesion in order to improve the performance of carbon fiber-vinyl ester composites. The effect of carbon fiber surface treatment on fiber chemistry and topography was evaluated to uncover the fundamental mechanisms governing carbon fiber to vinyl ester adhesion.

Abstract The melt-electrospinning system with a spot-like carbon dioxide laser melting device was used to form fibers directly from solid-like polymer rods. Fiber bundles were made from pie wedge fibers comprised of poly(lactide) (PLA) and poly(ethylene-co-vinyl alcohol) (EVOH) by gathering the fibers and twisting them together, and then melt electrospinning was performed for the bundles using the spinning system. Nanofibers with an average fiber diameter of ca. 400 nm were successfully obtained from the bundle by the optimization of manufacturing parameters such as laser output power, voltage, and collector distance. To investigate the morphological structure of the electrospun fibers, each structural component was extracted from the fibers with its solvent. It was found that three types ...

Fiber-optic based smart structures have recently become the subject of intense study in university and industrial research laboratories. A smart structure can monitor itself throughout its lifetime and provide an accurate estimate of its integrity. The sensors in smart structures must therefore be able to detect even small changes in the operating environment (like stress, temperature, chemical reaction, etc.). This paper pertains to the sensing of strain using embedded twisted and braided fibers which have a much greater sensitivity to changes in applied stress than normal fibers as a result of enhanced microbending. In addition, step-index multimode fibers were used in this research program because the ease of manufacture and lower cost of these fibers (compared to the more commonly used graded index fibers) can be significant and deciding factors in many applications. Results obtained from the experimental program confirm the concept and potential of the fibers used in this study for use in smart structures.

A method for manufacturing sheath-core structured fibers was developed using wet spinning techniques. The core portion of a fiber was prepared using a carbon nanotube (CNT) solution while the sheath used a fiber-forming polymer such as polyvinyl alcohol (PVA). Preparation methods of CNT solutions were investigated and it was found that dispersivity and concentration played an important role in the formation and spinning of fiber?s core. CNT solution prepared using a surfactant with high molecular weight such as sodium lignosulfonate (SLS) was most effective and the CNT concentration was as high as 30 g/l. Fiber processing conditions were optimized and it was determined that stretching fibers in the coagulation bath was a significant step in the formation of a solid and well structured core...

Long fiber reinforced thermoplastics (LFRTP) are a class of injection molding materials that extend the physical property envelope of thermoplastics polymers. These materials are manufactured by pulling continuous fiber tows through a thermoplastic polymer melt in a specialized processing die. The strands are subsequently cooled and chopped into pellets of equal length. LFRTP materials are available in virtually every common thermoplastic resin with glass, aramid, stainless steel, or carbon fiber reinforcement at levels up to 60% by weight. Unlike short fiber reinforced thermoplastics manufactured by conventional screw compounding processes, LFRTP exhibit simultaneous improvements in both flexural modulus and impact resistance. Improvements in load transfer, creep resistance at elevated temperatures, and dimensional stability can also be attributed to the long fiber network formed in the molded part. This unique combination of properties makes LFRTP the material of choice for replacement of metal structural assemblies in many automotive, industrial, consumer and recreational applications.

A strain gauge is made of an optical fiber into which quasi-sinusoidal microbends have been permanently introduced. The permanent microbends cause a reduction in the fiber's optical transmission, but, when the gauge is attached to a substrate that is subsequently strained, the amplitude of the deformations will diminish and the optical transmission through the fiber will increase. An apparatus and process for manufacturing these microbends into the optical fiber through a heat-set process is employed; this apparatus and process includes a testing and calibration system. 5 figs.

Entangled materials can be manufactured using fibers made from various materials, such as carbon, glass or steel. The mechanical properties of these low-density materials are linked to their architecture (fiber orientation, number of contacts, etc.). Specimens can be produced with and without cross-links between fibers by sintering for steel wool or by using epoxy spraying for carbon or glass fibers. Experimental mechanical compression tests were performed on these materials. The results were analyzed taking into account the architecture thanks to the relationships existing between morphological data and macroscopic mechanical behavior.

The US Department of Energy has established the Continuous Fiber Ceramic Composites (CFCC) program to develop technology for the manufacture of CFCC`s for use in industrial applications where a reduction in energy usage or emissions could be realized. As part of this program, the Dow Chemical Company explored the manufacture of a fiber reinforced/self reinforced silicon nitride for use in industrial chemical processing. In Dow`s program, CFCC manufacturing technology was developed around traditional, cost effective, tape casting routes. Formulations were developed and coupled with unique processing procedures which enabled the manufacture of tubular green laminates of the dimension needed for the application. An evaluation of the effect of various fibers and fiber coatings on the properties of a fiber reinforced composites was also conducted. Results indicated that fiber coatings could provide composites exhibiting non-catastrophic failure and substantially improved toughness. However, an evaluation of these materials in industrial process environments showed that the material system chosen by Dow did not provide the required performance improvements to make replacement of current metallic components with CFCC components economically viable.

Background and Purpose: Numerous holmium:YAG laser fibers are available for flexible ureteroscopy. Fibers performance and durability can vary widely amongst different manufacturers and their product lines with differences within a single product line have been reported. We sought to evaluate a newly developed non-tapered, single-use 240 µm fiber, Flexiva™ 200 (Boston Scientific, Natick, MA), during clinical use and in bench-testing model. Materials and Methods: A total of 100 new fibers were tested after their use in 100 consecutive flexible ureteroscopic lithotripsy procedures by single surgeon (BK). Prospectively recorded clinical parameters were laser pulse energy and frequency settings, total energy delivered and fibers failure. Subsequently, each fiber was bench-tested using an established protocol. Parameters evaluated for were fibers true diameter, flexibility, tip degradation, energy transmission in straight and 180° bent configuration and fibers failure threshold with stress testing. Results: The mean total energy delivered was 2.20 kJ (Range 0-18.24 kJ) and most common laser settings used were 0.8 J at 8 Hz, 0.2 J at 50 Hz and 1.0 J at 10 Hz respectively. No fiber fractured during clinical procedures. The true fiber diameter was 450 µm. Fiber tips burnt back an average of 1.664 mm but were highly variable. With laser setting of 400 mJ at 5Hz, the mean energy transmitted was 451 mJ and 441 mJ in straight and 180° bend configuration respectively. 13% of fibers fractured at bend radius of 0.5 cm with a positive correlation to the total energy transmitted during clinical use identified. Conclusion: Fiber performance was consistent in terms of energy transmission and resistance to fracture when activated in bent configuration. Fiber failure during stress testing showed significant correlation with the total energy delivered during clinical procedure. The lack of fiber fracture during clinical use may reduce the risk of flexible endoscopes damage due to fiber failure. PMID:23030764

The U.S. fiber glass industry disposes of more than 260,000 tons of industrial fiber glass waste in landfills annually. New technology is needed to reprocess this industrial waste into useful products. A low-cost energy-saving method of manufacturing ceramic tile from fiber glass waste was developed. The technology is based on sintering fiber glass waste at 700-900 degrees C to produce products which traditionally require firing temperatures of >1200 degrees C, or glass-melting temperatures >1500 degrees C. The process also eliminates other energy intensive processing steps, including mining and transportation of raw materials, spray-drying to produce granulated powder, drying pressed tile, and glazing. The technology completely transforms fiber glass waste into a dense ceramic product, so that all future environmental problems in the handling and disposal of the fibers is eliminated. The processing steps were developed and optimized to produce glossy and matte surface finishes for wall and floor tile applications. High-quality prototype tile samples were processed for demonstration and tile standards testing. A Market Assessment confirmed the market potential for tile products produced by the technology. Manufacturing equipment trials were successfully conducted for each step of the process. An industrial demonstration plant was designed, including equipment and operating cost analysis. A fiber glass manufacturer was selected as an industrial partner to commercialize the technology. A technology development and licensing agreement was completed with the industrial partner. Haun labs will continue working to transfer the technology and assist the industrial partner with commercialization beyond the DOE project.

With the rising cost of petroleum-based fibers, the utilization of plant fibers in the manufacture of polymer-matrix composites is gaining importance worldwide. The scope of this study was to examine the perspective of the use of pineapple leaf fibers (PALFs) as reinforcements for polypropylene (PP). These fibers are environmentally friendly, low-cost byproducts of pineapple cultivation and are readily available in the northeastern region of India. Here, both untreated and treated pineapple fibers were used. Maleic anhydride grafted polypropylene (MA-g-PP) was used as a compatibilizing agent. The polymer matrix of PP was used to prepare composite specimens with different volume fractions (5-20%) of fibers by the addition of 5% of MA-g-PP. These specimens were tested for their mechanical pr...

Abstract in english The development of an eco-friendly material that could reduce CO² emission and that could aggregate value to a natural fiber, setting man at the countryside and raising the income of populations from poor regions is a challenge. Lignocellulosic fibers are cheap and are a readily available reinforcement, requiring only a low degree of industrialization for their processing. The main drawback of using cement composites reinforced with lignocellulosic fibers is that the fib (more) ers can be mineralized inside the alkaline environment. In this work, Portland cement was partially replaced by metakaolinite in order to produce a matrix free from calcium hydroxide, avoiding thus the problem of fiber mineralization. Cement composites reinforced with 2, 4 and 6% of short curaua fibers, were manufactured. The composites were submitted to four pointing bending tests in order to determine their mechanical behavior. The results obtained were compared with those found for cement composites reinforced with sisal fibers.

In the present work, carbon nanotube (CNT) fibers had been embedded to glass fiber reinforced polymers (GFRP) for the structural health monitoring of the composite material. The addition of the conductive CNT fiber to the non-conductive GFRP material aims to enhance its multi-function ability; the test specimen's response to mechanical load and the in situ CNT fiber's electrical resistance measurements were correlated for sensing and damage monitoring purposes. It is the first time this fiber is used in composite materials for sensing purposes; CNT fiber is easy to be embedded and does not downgrade the material's mechanical properties. Various incremental loading-unloading steps had been applied to the manufactured specimens in tension as well as in three-point bending tests. The CNT fibe...

In an alternative approach to increasing the degrees of wetting and adhesion between the fiber and matrix components of organic-fiber/polymer matrix composite materials, the matrix resins are modified. Heretofore, it has been common practice to modify the fibers rather than the matrices: The fibers are modified by chemical and/or physical surface treatments prior to combining the fibers with matrix resins - an approach that entails considerable expense and usually results in degradation (typically, weakening) of fibers. The alternative approach of modifying the matrix resins does not entail degradation of fibers, and affords opportunities for improving the mechanical properties of the fiber composites. The alternative approach is more cost-effective, not only because it eliminates expensive fiber-surface treatments but also because it does not entail changes in procedures for manufacturing conventional composite-material structures. The alternative approach is best described by citing an example of its application to a composite of ultra-high-molecular- weight polyethylene (UHMWPE) fibers in an epoxy matrix. The epoxy matrix was modified to a chemically reactive, polarized epoxy nano-matrix to increase the degrees of wetting and adhesion between the fibers and the matrix. The modification was effected by incorporating a small proportion (0.3 weight percent) of reactive graphitic nanofibers produced from functionalized nanofibers into the epoxy matrix resin prior to combining the resin with the UHMWPE fibers. The resulting increase in fiber/matrix adhesion manifested itself in several test results, notably including an increase of 25 percent in the maximum fiber pullout force and an increase of 60-65 percent in fiber pullout energy. In addition, it was conjectured that the functionalized nanofibers became involved in the cross linking reaction of the epoxy resin, with resultant enhancement of the mechanical properties and lower viscosity of the matrix.

After a first R&D and testing activity to develop and characterize by tensile and creep tests a high strength glass fiber-epoxy composite as reference material for the manufacture of ITER pre-compression rings, ENEA designed and manufactured a dedicated testing facility and different sub-scale composite ring mock-ups in order to characterize their mechanical properties. The paper reports the results of the overall testing activities performed during the last years on a total number of eleven sub-scale pre-compression ring mock-ups manufactured by winding S2 glass fibers on a diameter of 1m (1/5 of the full scale) both by vacuum pressure epoxy impregnation (VPI) and filament wet winding techniques (WW). The first three rings were manufactured by ENEA Frascati thanks to a particular VPI tech...

TPI Composites, Inc. (TPI), Global Energy Concepts, LLC (GEC), and MDZ Consulting (MDZ) have collaborated on a project to design, manufacture, and test prototype carbon-fiberglass hybrid wind turbine blades of 9-m length. The project, funded by Sandia National Laboratories, involves prototype blades in both conventional (unidirectional spar fibers running along the blade span) and ''adaptive'' (carbon fibers in off-axis orientation to achieve bend-twist-coupling) configurations. After manufacture, laboratory testing is being conducted to determine the static and fatigue strength of the prototypes, in conjunction with field testing to evaluate the performance under operational conditions.

We demonstrate a multicore multidopant fiber which, when pumped with a single pump source around approximately 800 nm, emits a more than one octave-spanning fluorescence spectrum ranging from 925 to 2300 nm. The fiber preform is manufactured from granulated oxides and the individual cores are doped with five different rare earths, i.e., Nd3+, Yb3+, Er3+, Ho3+, and Tm3+. PMID:18382589

Recent advances and future trends in aerospace materials technology are reviewed with reference to metal alloys, high-temperature composites and adhesives, tungsten fiber-reinforced superalloys, hybrid materials, ceramics, new ablative materials, such as carbon-carbon composite and silica tiles used in the Shuttle Orbiter. The technologies of powder metallurgy coupled with hot isostatic pressing, near net forging, complex large shape casting, chopped fiber molding, superplastic forming, and computer-aided design and manufacture are emphasized.

The integration of optical components with polysilicon surface micromechanical actuation mechanisms show significant promise for signal switching, fiber alignment, and optical sensing applications. Monolithically integrating the manufacturing process for waveguide structures with the processing of polysilicon actuators allows actuated waveguides to take advantage of the economy of silicon manufacturing. The optical and stress properties of the oxides and nitrides considered for the waveguide design along with design, fabrication, and testing details for the polysilicon actuators are presented.

Strip force is the key to identifying the quality of product during manufacturing tight sets of fiber. This study used Integrated computer-aided manufacturing DEFinition 0 (IDEF0) modeling to discuss detailed cladding processes of tight sets of fiber in transnational optical connector manufacturing. The results showed that, the key factor causing an instable interface connection is the extruder adjustment process. The factors causing improper strip force were analyzed through literature, practice, and gray relational analysis. The parameters design method of Taguchi's Quality Engineering was used to determine the optimal experimental combinations for processes of tight sets of fiber. This study employed case empirical analysis to obtain a model for improving the process of strip force of tight sets of fiber, and determines the correlation factors that affect the processes of quality for tight sets of fiber. The findings indicated that, process capability index (CPK) increased significantly, which can facilitate improvement of the product process capability and quality. The empirical results can serve as a reference for improving the product quality of the optical fiber industry.

Sufficient flexural strength is required for long-term clinical use of fixed partial dentures made with fiber-reinforced composite. The flexural strengths of indirect composite materials reinforced with a monomer-preimpregnated glass fiber material were determined to evaluate the compatibility of the composites to glass fiber material. Four types (microhybrid, nanohybrid, microfilled, and minifilled) of indirect composites and a unidirectional long glass fiber material were selected for investigation. The composites were placed on a fiber plate and polymerized in accordance with the respective manufacturer's instructions. Rectangular bar fiber-composite specimens were machined and the flexural strength was calculated. The flexural strength of each indirect composite was also measured. The microfilled composite with the lowest filler content (70 wt%) exhibited the highest increase ratio using the fiber, although its strength without fiber reinforcement was the lowest (62.1 MPa). The fiber-microhybrid specimen demonstrated the highest mean strength (355.9 MPa), although the filler content of the microhybrid composite was comparatively low (73 wt%). The type of composite material should be considered for the selection of an optimal fiber-composite combination. PMID:21932008

In industrial applications using high-brilliance lasers at power levels up to and exceeding 20 kW and similarly direct diode lasers of 10 kW, there is an increasing demand to continuously monitor component status even in passive components such as fiber-optic cables. With fiber-optic cables designed according to the European Automotive Industry fiber standard interface there is room for integrating active sensors inside the connectors. In this paper we present the integrated active sensors in the new Optoskand QD fiber-optic cable designed to handle extreme levels of power losses, and how these sensors can be employed in industrial manufacturing. The sensors include photo diodes for detection of scattered light inside the fiber connector, absolute temperature of the fiber connector, difference in temperature of incoming and outgoing cooling water, and humidity measurement inside the fiber connector. All these sensors are connected to the fiber interlock system, where interlock break enable functions can be activated when measured signals are higher than threshold levels. It is a very fast interlock break system as the control of the signals is integrated in the electronics inside the fiber connector. Also, since all signals can be logged it is possible to evaluate what happened inside the connector before the interlock break instance. The communication to the fiber-optic connectors is via a CAN interface. Thus it is straightforward to develop the existing laser host control to also control the CAN-messages from the QD sensors.

Smart structures research and development, with the ultimate aim of rapid commercial and military production of these structures, are at the forefront of the Synthesis and Processing of Intelligent Cost-Effective Structures (SPICES) program. As part of this ARPA-sponsored program, MDA-E is using fiber placement processes to manufacture integrated smart structure systems. These systems comprise advanced composite structures with embedded fiber optic sensors, shape memory alloys, piezoelectric actuators, and miniature accelerometers. Cost-effective approaches and solutions to smart material synthesis in the fiber-placement process, based upon integrated product development, are discussed herein.

In the paper a new broadband photonic crystal fiber coupler is presented. The proper application of the biconical taper technology has been used for manufacturing the coupler without air holes collapse in LMA10 fiber (NKT Photonics Crystal). This coupler, operates in the weakly coupling condition, protects coupling operation in range from 900 nm to 1700 nm. The coupling ratio between output arms is depending on wavelength and can be tuning by selection the proper input state of polarization. It gives opportunity to use the broadband crystal fiber coupler in many applications in which it is necessary to tune a coupling between output arms during the measurement.

A state-of-the art study of thermoplastic polymer matrix materials for fiber composites has identified polyamide 6 (PA6) as a potential candidate thermoplastic polymer relevant for manufacturing large composite structures like wind turbine blades. The mechanical properties of PA6 are highly sensitive to moisture, and if PA6 is used as matrix material in a fiber composite, the properties of the fiber composite will depend on the moisture content of the material. At standard condition (23 °C and 50% RH) polyamide6 absorbs about 3 weight-% of water, whereas the PA6 material is dry right after manufacturing of components. In the current article, lamina properties of dry glass fiber/PA6 and conditioned (23 °C, 50% RH) glass fiber/PA6 are calculated for lamina with two different fiber content (45 and 50 vol.-%) by the use of classical micro mechanics. The matrix dominated properties like the shear stiffness, the shear strength and the stiffness and strength across the fiber direction are the ones which are mostly affected by the moisture content in the material.

The disclosed invention introduces a novel method of manufacturing carbon and/or graphite fibers that avoids the high costs associated with conventional carbonization processes. The method of the present invention avoids these costs by utilizing plasma technology in connection with electromagnetic radiation to produce carbon and/or graphite fibers from fully or partially stabilized carbon fiber precursors. In general, the stabilized or partially stabilized carbon fiber precursors are placed under slight tension, in an oxygen-free atmosphere, and carbonized using a plasma and electromagnetic radiation having a power input which is increased as the fibers become more carbonized and progress towards a final carbon or graphite product. In an additional step, the final carbon or graphite product may be surface treated with an oxygen-plasma treatment to enhance adhesion to matrix materials.

This paper reports on different parameters that influence the closed mould resin transfer moulding (CM-RTM) process for fiber-reinforced plastics. A sensitivity study of selective parameters is performed. This includes material parameters (i.e., viscosity, permeability), process parameters (i.e., temperature) and geometrical parameters (i.e., position of preform in the tool). Furthermore, fiber type and targeted fiber volume content are considered to validate the full range of fiber-reinforced plastics. As an example for the sensitivity study, the aeronautical carbon fabric G0926 and epoxy resin system RTM6 (both manufactured by Hexcel) are analyzed for targeted fiber volume contents in a range of ~60%. The infiltration of a rectangular panel was simulated with the flow simulation software...

Bending strength and elasticity modulus of composite, with and without embedded optical fibers, were experimentally studied. Two kinds of laminates, which were denoted as group 1 and group 2, were fabricated from an orthogonal woven glass/epoxy prepreg. Since the normal stress value becomes the biggest at the surface of a beam, the optical fibers were embedded at the outmost layer and were all along the loading direction. Four types of materials, using each kind of laminated prepreg respectively, were manufactured. The embedded optical fibers for the 4 material types were 0, 10, 30 and 50 respectively. Three-point bending tests were carried out on the produced specimens to study the influence of embedded optical fiber on host composite. The experimental results indicated that the materials in group 2 were more sensitive to the embedded optical fibers.

This thesis presents a design for a 10,000 ton liquid scintillator neutrino detector being considered for the MINOS project at Fermilab. Details of designing, manufacturing, and assembling the active detector components are presented. The detector consists of 1080 magnetized steel absorber planes alternating with 1080 active detector planes. Each active plane is made up of plastic extrusions divided into nearly 400 cells for positional resolution. Life tests on the plastic extrusions determine their feasibility for containing the scintillator. The extrusions are sealed at the bottom, filled with liquid scintillator, and have an optical fiber running the entire length of each cell. The fibers terminate at the top of each extrusion in a manifold. An optical-fiber-light-guide connects the fibers in each manifold to a photo-detector. The photo-detector converts the light signals from the scintillator and optical fibers into electrical impulses for computer analysis.

Activated carbon fiber composites show great promise as fixed-bed catalytic reactors for use in environmental applications such as flue gas clean-up and ground water decontamination. A novel manufacturing process produces low density composites from chopped carbon fibers and binders. These composites have high permeability, can be activated to have high surface area, and have many potential environmental applications. This paper reports the mechanical and flow properties of these low density composites. Three point flexural strength tests were used to measure composite yield strength and flexural moduli. Composites containing over 10 pph binder had an adequate yield strength of about 200 psi at activations up to 40% weight loss. The composites were anisotropic, having along-fiber to cross-fiber yield strength ratios between 1.2 and 2.0. The friction factor for flow through the composites can be correlated using the fiber Reynolds number, and is affected by the composite bulk density.

A colonoscopy's near-blind navigation process frequently causes disorientation for the scope operator, leading to harm for the patient. Navigation can be improved if real-time colonoscope shape, location, and orientation information is provided by a shape-tracking aid, such as a fiber optic bend sensor. Fiber optic bend sensors provide advantages over conventional electromechanical shape-trackers, including low cost and ease of integration. However, current fiber optic bend sensors lack either the ability to detect both bending direction and curvature, or the ability to detect multiple localized bends. An inexpensive multifiber bend sensor was developed to aid users in navigation during colonoscopy. The bend sensor employs active-cladding optical fibers modified with fluorescent quantum dots, bandpass filters, and a complementary metal-oxide-semiconductor imager as key components. Results from three-fiber sensors demonstrate the bend sensor's ability to measure curvature (error of 0.01 mm), direction (100% accuracy), and location (predetermined distance) of a bend in the fiber bundle. Comparison with spectroscopy data further confirmed the accuracy of the bending direction measurement for a three-fiber sensor. Future work includes improvements in fiber manufacturing to increase sensor sensitivity and consistency. An expanded 31 fiber bundle would be needed to track the full length of a colonoscope.

The aim of this work was to develop chemically a compound glass body reinforced with endless fibers for appplication above 800deg C. First, the endless fibers considered for this temperature range were subjected to varied high temperature annealing and were examined for their recrystallisation behaviour. The high modulus (of elasticity) carbon fibers is the only one of the fibers examined which shows no crystalline modification at 1400deg C. However, like very strong carbon fibers and coated very strong carbon fibers, it is physically incompatible with a glass matrix due to its high thermal expansion transversely to the direction of the fiber. In spite of crystalline modifications which appear as spontaneous crystallisation at temperatures above 800deg C, the isotrope NICALON-SiC fiber is qualified to be a reinforcement component, as it retains its strength up to 1200deg C after this spontaneous crystallization. It will stand the temperature of 1400deg C necessary in manufacture for a short time, which should be used for compression of a glass which is to be used above 800deg C. In the second part of the work, a glass matrix compatible, both chemically and physically with the NICALON fiber was chemically developed, which was built up by the sol/gel technique. (orig./RHM).

combination of a wire mesh screen and fiberglass cloth, a bulk material such as a .... suppressor at Site 3, Plant 42, of the Rockwell International manufacturing facility at ... layer of PF 3530 glass fiber material (0.84 lb/cu.ft.) backed by a ... conditions a coherent, but out of phase, floor reflection occurs to cause destructive ...

In a microwave tube, an improved collector surface coating comprises a porous carbon composite material, preferably a carbon-bonded carbon fiber composite having a bulk density less than about 2 g/cc. Installation of the coating is readily adaptable as part of the tube manufacturing process. 4 figs.

This invention relates to an improved method of manufacturing carbon fibers from a coal derived pitch. The improvement resides in the use of a solvent refined coal which has been hydrotreated and subjected to solvent extraction whereby the hetero atom content in the resulting product is less than 4.0% by weight and the softening point is between about 100.degree.-250.degree. F.

The low-velocity impact behavior was studied in hybrid laminates manufactured by RTM with woven carbon and glass (S2) fabrics. Specimens with different thicknesses and glass fiber content (from 0 to 21 vol.%) were tested with impact energies in the range 30–245 J and the resulting deformation and fr...

Freudenberg Household Products AB in Norrköping are manufacturer of sponge cloths with the well-known brand names of Wettex® and Vileda®. The production is based on the viscose fiber process and involves a high chemical demand. Recent customer complaints involve a diffuse smell from the cloths that ...

The report describes work done toward providing a totally recycled water system for Owens-Corning's textile fiber manufacturing plant at Anderson, SC. (The work was based on pre-1968 pilot plant work by Owens-Corning that resulted in development of totally recycled industrial was...

We describe simple methods of manufacturing in a laboratory gaseous detectors of visible photons with GaAs(Cs) and SbCs photocathodes and Ti getters. Covered by CsI protective layers they are robust enough to be stable under ordinary experimental conditions. First attempts to use these detectors for crystal scintillator and fiber readout are presented.

Composite rotor blades have demonstrated improvements over .... arid rotor aerodynamics as well as the rotor system mass nioinent of ... two cases of shaft torque transmission from the power plant. .... T300 graphite fibers are manufactured by Union Carbide. Corp. ..... Holmes, R. Doug: S-Glass-Reinforced Plastic Adopted ...

1. Temporal dispersion at 351-nm was measured in the following: a 35-m bundle of 19 each 50-µm-core fibers, a companion 35-m single fiber, a 100-µm-core single fiber (at 4 lengths), and a 50-µm-core single fiber (two samples, 7 lengths). The 50-µm-core fiber was from preform #24; the 100-µm-core fiber was a prototype version having a thick cladding. All of the fibers were developed and manufactured at the Vavilov State Optical Institute, St. Petersburg, Russia. 2. Dispersion measurements were made by propagating a 20-ps 351-nm pulse through the fiber under test and recording the output on an S20 streak camera. The width of the pulse transmitted by the fiber was compared to that of a fraction of the pulse that had propagated over an air path. Values of dispersion were calculated as, D = {radical}(F² - A²) , where F and A are the full widths at half maximum (FWHM) for, respectively, the fiber-path and the air-path streaks. 3. In each of the experiments, the measured dispersion increased with counts in the streak record, which in principle, are proportional to intensity in the fiber. Measured values of dispersion ranged from about 0.6 to 1.0 ps/m for the single fibers. 4. The measured FWHMs of both the fiber-path pulse and the air-path pulse increased with increase in counts in the streak record. The rate of broadening was greatest for the fiber-path pulse, and the broadening of that pulse was the primary cause for the dependence of dispersion on counts in the streak record. Pulse broadening with increase in counts is symptomatic of camera saturation, but it is difficult to understand why saturation should have effected the fiber-path pulses more strongly. 5. There were spatial anomalies in the streak records of the output pulses from some of the fibers. Emission by the bundle of a "doubled" pulse is a primary example. In streaks recorded at about 800 counts, the total duration for the pair of pulses was about 100 ps. The maxima of the pulses occurred in different columns of the streak, so there was a relative spatial or angular offset between the two pulses. Pulses with extended tails were observed in each streak that was recorded at about 400 counts. 6. We frequently had difficulty obtaining adequate transmittance through 50-mm single fibers. Some of our problems probably were related to inexperience in cleaving this particular fiber.

Cosmic radiation shielding properties are important for spacecraft. Hydrogenous materials such as polyethylene have been shown effective against galactic cosmic rays (GCR) and solar energetic particles. Ultrahigh molecular weight polyethylene (UHMWPE) fibers have advanced mechanical and physical properties, which are very valuable for NASA missions. Unfortunately, poor interface in the UHMWPE fiber/polymer matrix hinders the structural integrity of the composites, and restricts the effectiveness of radiation shielding for practical applications. Fiber treatment methods can not only incur an extra cost for manufacturing the composite structures, but also may sacrifice intrinsic properties of the fibers. In our study, we fabricated a reactive nano-epoxy matrix with reactive graphitic nanofibers, which showed enhanced mechanical (including strength, modulus and toughness) and thermal properties (higher Tg, stable CTE, and higher ageing resistant), as well as wetting and adhesion ability to UHMWPE fibers. 1 GeV/nucleon 35Cl ions, high energy ions for the complex GCR heavy ion radiation field, was used for the radiation tests. The results showed that the radiation shielding property was not reduced by the addition of graphitic nanofibers. The studies indicated that the UHMWPE fiber/nano-epoxy will have potential in manufacturing more durable space composites and structures.

Researches were conducted with a view to organizing projects for developing intelligent fibers, equipped with environmental friendliness and amenity without being deprived of their original properties as structural and clothing materials, the ultimate goal of the effort being the creation of harbingers of next-generation fibers which would contribute to the advance of industries related to environments, medicine and welfare, and information. What were learned from fiscal 1998 researches are mentioned below. The strength that the general-purpose fibers currently in use exhibit is so small as to be but several percent of what is theoretically predicted for them. Demand will increase a great deal if the actual strength is doubled, for which new technologies have to be developed including those involving super-fiber texture control. For providing the fiber with such functions as environment-friendliness, amenity, etc., it is necessary to develop phasal structure control technologies with regard to fiber morphology, surface texture, etc. For success in practical application in the future of such super-fiber materials, each specimen needs to be manufactured in the order of kilogram by way of trial. Moreover, fiber evaluation techniques have to be developed in the three domains of software, hardware, and interface. (NEDO)

Coefficients of thermal expansion (CTE) of carbon fibers create residual stresses in aggressive manufacturing and service environments. In this effort, environmental scanning electron microscope (ESEM) is used for in situ observations of a carbon fiber cross-section up to 1000 C in order to evaluate the much neglected transverse CTE. The perimeter of fiber cross-section is calculated with the Scion image processing program from images that were taken at every 100 C increments. CTE values are calculated by linear regression of the strain data based on the perimeter changes. Furthermore, through SEM, WDS and TEM observations, we are in the process of bringing an interactive rationale between CTE, crystallinity and surface roughness of carbon fibers.

This publication is comprised of fourteen papers on the utilization of residues such as bark, small branches and secondary fibers (prepared by the Forest Products Division of AIChE for the 77th National Meeting, Pittsburgh, June 1974). The future role of wood as a material, the availability of residuals in the US pulp and paper industry, biomass of forest residuals, impact of forest management practices, harvesting of forest residues, economics of utilizing residuals from logging - problems and opportunities, the effect of energy costs on the competitive position of secondary fiber, secondary fibers for the manufacture of containerboard - current cost factors and future demand effects, new handling concepts for an oil commodity, gasification of tall oil pitch for low-Btu gas and power production, chemical utilization of Douglas Fir bark, secondary fiber utilization with the Riverside recovery process, pyrolytic oil from tree bark - its production and combustion properties, and utilization of whole tree hardwood chips are the topics discussed.

This special issue includes papers on cement, aggregate, admixture, additive, fiber, polymer for cement mixing, reinforcement, and concrete refuse. For the cement, low heat property, high fluidity, and high strength property of cement for highly workable concrete are summarized. For the aggregate, development of a new type crushed stone and sand manufacturing plant, namely, a traveling crusher, is described. For the admixture, research trend of admixtures is introduced, as to fly ash, blast furnace slag, and silica fume. For the additive, technology trend of additives is presented, as to AE (air entraining) agent, AE water reducing agent, and high performance AE water reducing agent. For the fiber, application examples of new material fibers and continuous fiber reinforcers used for reinforcement of cement and concrete are illustrated. In addition, properties of concrete containing polymer for mixing of concrete are provided. Furthermore, new products of reinforcement and utilization technology of concrete refuse are also provided. 101 refs., 30 figs., 23 tabs.

A large tracking detector consisting of scintillating plastic optical fibers has been chosen by the DO collaboration as a part of a planned upgrade at the Fermilab Tevatron. The tracker will utilize a state of the art photodetector known as the Visible Light Photon Counter. The benefits of fiber tracking in high energy physics will be presented along with recent progress in several key areas, including: optimization of scintillating dyes and light yields, fiber construction, fiber ribbon manufacture and placement, optical transmission and photodetection. The current status of the D0 development effort will be outlined, including results from the characterization of 5,000 channels of VLPC. Finally, results from simulations of expected detector performance will be shown and discussed.

Concrete material expected in the near future is described in consideration of various conditions required in concrete structures to be used for a very long time. For example, self-diagnosis concrete is desirable as a new material capable of improving durability and safety. New materials will be utilized for sensors as well as reinforcing material, for example, by using glass fiber in the form of optical fiber which can detect, e.g., the cross-sectional reduction of fiber due to deterioration or temperature distribution. Besides, the change of electrical resistance in carbon fiber can be used to detect its stress conditions or stress history. The change of the conventional cement in composition may develop self-restoring concrete making an ultra delayed hydration reaction, concrete for road safety not depending on surface coating but emitting light without being irradiated with street lamps, recycling aggregate, self-reproducing concrete capable of easy re-sintering (re-manufacturing), etc. 3 refs., 2 figs.

Activated carbon fiber composites show great promise as fixed-bed catalytic reactors for use in environmental applications such as flue gas clean-up and ground water decontamination. A novel manufacturing process produces low density composites from chopped carbon fibers and binders. These composites have high permeability, can be activated to have high surface area, and have many potential environmental applications. This paper reports the mechanical and flow properties of these low density composites. Three point flexural strength tests were used to measure composite yield strength and flexural moduli. Composites containing over 10 pph binder had an adequate yield strength of about 200 psi at activations up to 40% weight loss. The composites were anisotropic, having along-fiber to cross-fiber yield strength ratios between 1.2 and 2.0. The pressure drop of air through the composites correlated with the gas velocity, and showed a dependence on sample density.

The surface characteristics of carbon fibers were studied by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and wetting measurements. The surface of carbon fiber was modified by means of plasma graft silsesquioxane. The oxygen/carbon and silicon/carbon ratio increased rapidly after treatments. Fitting the C 1s, O 1s, and Si 2p spectra demonstrated that new photopeaks were emerged, which were indicated C-Si, Si-O groups, respectively. The degree of surface roughness and the wettability of carbon fiber surface were both increased by plasma graft silsesquioxane. The results may shed some light on the design of the appropriate surface structure, which could react with resin, and the manufacture of the carbon fiber reinforced composites.

In the view of micromechanics, bamboo can be idealized as a 2-phase composite consisting of vascular bundles (fibers which serves as reinforcement) and ground tissues (serves as matrixes). To determine mechanical parameters of fibers and matrixes is essential to quantitatively evaluate the mechanical properties of bamboo. This is significant to control the mechanical properties of engineered bamboo materials as expected in manufacture. However, it is impossible to measure the mechanical parameters of the fibers and the matrixes of bamboo at first hand because they cannot be separated from bamboo without damage. This paper presents a hybrid approach to determine the mechanical parameters of fibers and matrixes of natural bamboo. By micromechanical analysis, macro tensile experiments, and mi...

Iran imports nearly 55,000 metric tons of asbestos per year, and asbestos cement (AC) plants contribute nearly 94% of the total national usage. In the present study, asbestos fiber concentrations during AC sheet and pipe manufacturing were measured by phase-contrast microscopy (PCM) and polarized light microscopy (PLM) in 98 personal air samples. The fiber type and its chemical composition were also evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). Personal monitoring of fiber levels indicated a range from 0.02 to 0.55PCM f/ml (0.02-0.69PLM f/ml). The AC workers' geometric mean asbestos exposure was 0.09 PCM f/ml (0.11 PLM f/ml), with arithmetic mean of 0.13 PCM f/ml (0.16 PLM f/ml). The observed fiber concentrations in many processes were higher t...

At present, the high cost of optoelectronic (OE) devices is caused in part by the labor-intensive processes involved with packaging. Automating the packaging processes should result in a significant cost reduction. One of the most labor-intensive steps is aligning and attaching the fiber to the OE device, the so-called pigtailing process. Therefore, the goal of this 2-year ARPA-funded project is to design and build 3 low-cost machines to perform sub-micron alignments and attachments of single-mode fibers to different OE devices. These Automated Fiber Pigtailing Machines (AFPMS) are intended to be compatible with a manufacturing environment and have a modular design for standardization of parts and machine vision for maximum flexibility. This work is a collaboration among Uniphase Telecommunications Products (formerly United Technologies Photonics, UTP), Ortel, Newport/Klinger, the Massachusetts Institute of Technology Manufacturing Institute (MIT), and Lawrence Livermore National Laboratory (LLNL). UTP and Ortel are the industrial partners for whom two of the AFPMs are being built. MIT and LLNL make up the design and assembly team of the project, while Newport/Klinger is a potential manufacturer of the AFPM and provides guidance to ensure that the design of the AFPM is marketable and compatible with a manufacturing environment. The AFPM for UTP will pigtail LiNbO{sub 3} waveguide devices and the AFPM for Ortel will pigtail photodiodes. Both of these machines will contain proprietary information, so the third AFPM, to reside at LLNL, will pigtail a non-proprietary waveguide device for demonstrations to US industry.

This paper reveals information on the mechanical properties of the agricultural composites and their commercial potential as a substitute for plastics and woods leading to a lower cost for these products. Chopped and particulate agricultural co-products (hereafter referred to agro-fibers) such as wheat, brome hay, switchgrass, and corn were mixed at a ratio of 66:34 fiber/epoxy by volume to manufacture agricultural composites (hereafter referred to agrocomposites) using the hand lay-up molding technique. The manufactured composite samples were tested for their mechanical properties such as tensile stress, compressive stress, moisture absorption, and thermal expansion. According to results, chopped switchgrass agro-composite samples showed the highest tensile strength, yet less than that of soft woods and slightly higher than that of plastics (high density polyethylene known as HDPE). As a result, a second set of agro-composite samples using only chopped switchgrass was manufactured at 10%, 20%, 30%, 40%, and 50% agro-fiber content to obtain the optimal fiber/epoxy ratio for which agro-composite samples show the maximum tensile stress. The same procedure was followed for comprehensive strength, thermal expansion, and moisture absorption measurements. According to the obtained results, at 50:50, agro-composite samples showed the highest tensile stress at 2,925 psi compared to that of plastic at 2,000 psi and of soft wood at 6,600 psi. At 10:90 agro-fiber/epoxy, compressive strength of the agro-composite samples were 60% higher than that of plastic and 80% higher than that of soft woods. Thermal expansion and moisture absorption of the manufactured agro-composite samples showed better performances than both woods and plastics. Optimized agro-composite samples, due to their cost competitiveness and low weight, could replace woods and plastics in some applications. A small fraction of plastic and wood market wood lead to new source of revenues for farmers.

In the past 2 years, we investigated up to 10 different types of silica optical fibers (optical fibers with an enhanced UV response, solarization resistant optical fibers, H{sub 2} loaded optical fibers), with a large core diameter (in this case 400 {mu}m), and having various cladding materials. The research was carried out under gamma-ray, neutron and proton irradiation, both off-line and on-line. For the off-line measurements optical fibers were subjected to temperature stress between the irradiation steps (up to 250 deg. C, according to their cladding material). Depending on the optical fiber type, the manufacturing technology or the cladding material we noticed different aspects of the irradiation-induced optical attenuation, as different color centers are generated. Some of these color centers are partially reverted under high temperature exposure. For a better understanding of the irradiation-induced phenomena we decomposed the automatically acquired optical transmission spectra using a Gaussian deconvolution, for the color centers reported in the literature in the UV spectral range. The paper is a comparative study of these color centers dynamics in various optical fibers, for different irradiation conditions and, in same cases, under temperature stress.

A two and a half year ONR/ARPA funded program to develop a low cost process for manufacture of a high strength/high modulus sigma/E boron nitride (BN) fiber was initiated on 7/1/90 and ended on 12/31/92. The preparation of high sigma/E BN fibers had been demonstrated in the late 1960's by the PI using a batch nitriding of B2O3 fiber with NH3 followed by stress graphitization at approx. 2000 deg C. Such fibers displayed values comparable to PAN based carbon fibers but the mechanicals were variable most likely because of redeposition of volatiles at 2000 deg C. In addition, the cost of the fibers was very high due to the need for many hours of nitriding necessary to convert the B2O3 fibers. The use of batch nitriding negated two possible cost advantages of this concept, namely, the ease of drawing very fine, multi-filament yarn of B2O3 and more importantly the very low cost of the starting materials.

This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240 C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.

A scintillating tile/fiber design had been selected for the SDC calorimeter. It consisted of scintillator plates embedded with a wavelength shifting (WLS) fiber which was spliced to a clear fiber. Based on the results from previous radiation damage studies on different scintillating materials, SCSN38 had been chosen for the scintillating tile and BCF91 or Y7 for the WLS fiber. SCSN38 is a blue-emitting scintillator and both WLS fibers use K-27, a green-emitting compound, as dopant. K-27 has a decay time of approximately 12 ns which is long in comparison to that of most blue-emitting materials. Of all the factors that affect the speed of the scintillator tile/fiber calorimeter, the lifetime of the green-emitting dopant is the dominant component. To increase the speed of the calorimeter, it would be desirable that the green WLS fibers utilized had lifetimes between 3 and 5 ns. However, currently available green WLS fibers exhibit decay times between 7 and 12 ns. Development of new green-emitting WLS fibers with short decay times must be investigated. The goal of this project was to search for commercially available fluorescent compounds with {lambda}{sub abs} = 400--450 nm, {lambda}{sub em} = 450--550 nm, {tau} = 3--7 ns, and quantum efficiency of minimum 0.7 (current K-27 baseline). Large Stokes shift and low self-absorption were not important requirements since the optical pathlength for the shifted light was small. Characterization of the spectroscopic properties of these compounds after styrene polymerization is important since this is an essential part of the manufacturing of WLS fibers. This summary presents the transmittance and fluorescence data for each dopant tested. However, many fluorescence measurements using different excitation wavelengths and orientations were recorded. Volume 1 presents a plot for each dopant combining transmittance and the most representative fluorescence measurement.

In this study, we focused on optimizing a part of the furnace and operating conditions of the fiber yielding system from fused coal ash to expand ash utilization for building materials; promotion of ash use is desirable because slag inhibits the elution of toxic heavy metals, such as Hg, Pb and As, to undetectable levels, making the fibers safe to use. In particular, the fiber materials from coal ash slag are expected to be used as thermal insulators and acoustic materials. We designed a coal ash fusing furnace which is suitable for the fiber manufacturing and recovery process. To manufacture fiber materials which are both safe and homogeneous, the slag viscosity had to be stabilized to approximately 1 Pa·s at the slag-tapping hole of the furnace. However, the slag temperature at 1 Pa·s was too high to measure. Thus, we estimated the slag temperature at 1 Pa·s using Riboud’s and Urbain’s expressions. To control the slag viscosity and temperature, CaCO3 addition to coal ash was effective. When the basicity (CaO/SiO2(wt%/wt%)) of the coal ash sample was 0.98, the fused slag temperature at 1 Pa·s was estimated as 1563 °C. Then, we verified that to yield 1 Pa·s fusing slag from 120 kg/h coal ash, the necessary fuel quantity of the coal ash fusing furnace was 40 kg/h coal and 4 m3N/h LPG.   

Applied NanoStructured Solutions, LLC (ANS) has developed a unique Chemical Vapor Deposition (CVD) process for the growth of Carbon Nanotubes (CNT) onto various fiber substrates including carbon, glass, ceramics and aramids. This process is continuous and operates at atmospheric pressures enabling high volume/low cost manufacturing. This process infuses conductive CNTs in a highly entangled form referred to as Carbon Nanostructures (CNS) onto the surface of the normally insulative fiber making it highly conductive overall. Composites made from this CNS-infused filler then have unique Electromagnetic Interference (EMI) shielding and Lightening Strike Protection (LSP) properties.

We manufactured pulsed illuminators emitting in the far infrared for the Planck-HFI bolometric instrument ground calibrations. Specific measurements have been conducted on these light sources, based on Carbon fibers, to understand and predict their properties. We present a modelisation of the temperature dependence of the thermal conductivity and the calorific capacitance of the fibers. A comparison between simulations and bolometer data is given, that shows the coherence of our model. Their small time constants, their stability and their emission spectrum pointing in the submm range make these illuminators a very usefull tool for calibrating FIR instruments.

In this paper, methods of welding and sealing optically transparent materials using an ultrashort pulsed (USP) fiber laser are demonstrated which overcome the limit of small area welding of optical materials. First, the interaction of USP fiber laser radiation inside glass was studied and single line welding results with different laser parameters were investigated. Then multiline scanning was used to obtain successful area bonding. Finally, complete four-edge sealing of fused silica substrates with a USP laser was demonstrated and the hermetic seal was confirmed by water immersion test. This laser microwelding technique can be extended to various applications in the semiconductor industry and precision optic manufacturing. PMID:22614601

A preliminary investigation of shape memory (SM) effects of SMPU (shape memory polyurethane) knitting fabric is presented in this paper. Three SMPU knitted fabrics series with different content of SMPU fibers: 100% SMPU, 50% SMPU and 50% cotton, 16% SMPU and 84% cotton are designed and manufactured in our lab. Their shape memory behaviors at different temperatures are characterized in terms of bagging. Our experimental results showed that shape memory effect can be improved with increasing content of SMPU fibers. A comparison between Lycra and SMPU knitted fabrics was also made to validate the shape memory effects of SMPU knitted fabrics.

The Fiber and Electro-Optics Research Center (FEORC) has developed a sensing technique for the intelligent processing of a multilayer ceramic actuator (MCA) elements manufactured by the AVX Corporation in Conway, SC. Presented are the results of the fiber optic strain sensor used to monitor the burnout of organic binders from a green actuator sample. The results establish the operation of the short gage length, low finesse Fabry-Perot interferometric strain sensor as a tool for intelligent processing of such ceramic actuator elements. Also presented is the method of sensor operation, and post processing results using the same sensor for tracking actuator performance and hysteresis.

Molecular simulations are carried out to elucidate the differences in the properties of the commercial fibers Kevlar 29, Kevlar 49 and Kevlar 149, which are manufactured under different processing conditions, and are composed of poly(p-phenylene teraphthalamide) (PPTA). In going from Kevlar 29 to Kevlar 49 to Kevlar 149, the axial Young`s modulus increases significantly and the torsion modulus decreases significantly, while the compressive strength stays roughly the same. Previous investigators have shown that the increase in the Young`s modulus arises from increased axial orientation. The present paper addresses the torsion modulus and compressive strength of the fibers.

For a long time, the building industry has been an important outlet for materials containing asbestos. The use and manufacturing of these potentially dangerous products and materials is forbidden by the French law since January 1, 1997. This short paper summarizes the physical properties (thermal and acoustic insulation, fire and corrosion resistance) of the available substitution materials (rock and glass wool, vermiculite plaster, intumescent paint, silicone and resin based materials for thermal insulation and fire protection of structures; cements with glass fiber and organic fiber matrices for roofing; steel, PVC and glass reinforced polyester materials for piping etc..) and the consequences of their use on human health. (J.S.)

The paper analyses the electromagnetic shielding measurements of carbon fiber composite structure. In particular the shielding effectiveness is measured applying the nested reverberation chamber method in the frequency range of 3.5 GHz - 8.5 GHz. This method ensure a realistic electromagnetic excitation of the sample under test characterized by a random polarization and incoming direction. The paper also describes the material manufacturing procedure and gives important details about the sample mounting technique. Three material samples are considered which differ in carbon fiber orientation and stratification. Obtained results highlight the capability of such materials to behave as high-performance shields in the microwave region.

The aim of this study is to characterize the microstructure and high temperature induced structural changes within fiber reinforced silicon carbide (SiCf/SiC) composites by means of non-destructive techniques. In order to understand their properties, the characterization of the microstructure of SiCf/SiC composites is the crucial issue. Porosity within composites is unavoidable with currently available manufacturing processes, and reduces significantly the life time and performance of the composites under harsh environments. Moreover, the internal pores, created in the manufacturing process cause the degradation most of the outstanding properties such as thermal conductivity, mechanical properties at high temperature, and radiation stability. Cold neutron tomography and diffusion structura...

Long fibers are generally preferred for reinforcing foams for performance reasons. However, uniform dispersion is difficult to achieve because they must be mixed with liquid resin prior to foam expansion. New approaches aiming to overcome such problem have been developed at USC's Composites Center. Fiber-reinforced syntactic foams with long fibers (over 6 mm in length) manufactured at USC's Composites Center have achieved promising mechanical properties and demonstrated lower density relative to conventional composite foams. Fiber-reinforced syntactic foams were synthesized from thermosetting polymeric microspheres (amino and phenolic microspheres), as well as thermoplastic PVC heat expandable microspheres (HEMs). Carbon and/or aramid fibers were used to reinforce the syntactic foams. Basic mechanical properties, including shear, tensile, and compression, were measured in syntactic foams and fiber-reinforced syntactic foams. Microstructure and crack propagation behavior were investigated by scanning electron microscope and light microscopy. Failure mechanisms and reinforcing mechanisms of fiber-reinforced syntactic foams were also analyzed. As expected, additions of fiber reinforcements to foams enhanced both tensile and shear properties. However, only limited enhancement in compression properties was observed, and fiber reinforcement was of limited benefit in this regard. Therefore, a hybrid foam design was explored and evaluated in an attempt to enhance compression properties. HEMs were blended with glass microspheres to produce hybrid foams, and hybrid foams were subsequently reinforced with continuous aramid fibers to produce fiber-reinforced hybrid foams. Mechanical properties of these foams were evaluated. Findings indicated that the production of hybrid foams was an effective way to enhance the compressive properties of syntactic foams, while the addition of fiber reinforcements enhanced the shear and tensile performance of syntactic foams. Another approach to produce ultralight sandwich core materials was explored in which towpreg (fiber bundles impregnated with resin) were configured to produce 3D pyramidal truss structures. The composite truss structures were subsequently filled with foam to improve resistance to buckling. Mechanical properties of the foam-filled truss structures were measured and contrasted with analytical predictions based on simple truss theory. Results indicated that combination of foams and carbon fiber truss structures had synergistic effects that enhanced the capacity to carry compressive and shear loads.

Weight savings in vehicles enhances fuel efficiency and decreases maintenance costs, especially in mass transit systems. Lightweight composite materials, such as glass fiber reinforced polymers, have been used to replace traditional steel and aluminum components. In this paper, a mass transit bus side body panel was designed, analyzed, and manufactured using thermoplastic composite materials. The design featured a sandwich composite with E-glass fiber/polypropylene (glass/PP) face sheets and PP honeycomb core as constituents that provide low weight, high strength and energy absorption benefits. The panel was designed and analyzed using Pro/Engineer 2001 (Pro/E), Altair Hypermesh 6.0 (Hypermesh) and ANSYS 7.0 (ANSYS). A single diaphragm forming process was used to manufacture the glass/PP f...

In Liquid Composite Molding (LCM) processes, a fibrous reinforcement preform is placed or draped over a mold surface, the mold is closed and a resin is either injected under pressure or infused under vacuum to cover all the spaces in between the fibers of the preform to create a composite part. LCM is used in a variety of manufacturing applications, from the aerospace to the medical industries. In this manufacturing process, the properties of the fibrous reinforcement inside the closed mold is of great concern. Preform structure, volume fraction, and permeability all influence the processing characteristics and final part integrity. When preform fabrics are draped over a mold surface, the geometry and characteristics of both the bulk fabric and fiber tow bundles change as the fabric shears...

The manufacturing of sandwich structures using the automated polyurethane (PU) fiber spraying process combines economical and light weight requirements in a most efficient way. The focus of the presented work was put on the influence of different materials as well as various process- and manufacturing parameters and their impact on the sandwich properties. Different core materials, as well as sandwich covers with various glass fiber contents were evaluated. For characterization purposes the produced sandwich structures were tested statically with regards to their mechanical properties. Furthermore, important requirements for the layout of polyurethane composite sandwich structures and their dimensioning were determined. Finally, the importance of specific sandwich properties, their characterization and evaluation as well as the influence on different standardized testing methods were shown. (orig.)

Use of the fertilizer industry waste product SiF4 for the manufacturing of optical fibers for telecommunication is discussed. The SiF4 can be obtained from H2SiF6, a by-product of the manufacturing process. A relatively simple distillation procedure can be used to remove impurities such as HF and the (salts of the) transition metals. After purification, SiF4 might be a proper raw material for production of solar grade silicon (photovoltaic cells) or pure quartz (optical fibers). However, application of SiF4 in a flame burner of chemical vapor deposition process is not feasible on thermodynamic grounds. In plasma processes, a sooty deposit is formed, and efficiency is a factor of 20 less compared with SiCl4. The reaction mechanisms in SiF4-O2 and SiCl4-O2 discharges were studied to explain this difference.

The low loss and large bandwidth-length product of optical fibers, together with recent advances in the manufacturing of fiber-optic components provide an attractive technology for the processing of broadband signals. This report involves the use of fiber-optic technology for signal processing applications. Previous work on fiber-optic signal processors has concentrated on feed-forward tapped delay lines, but in this research attention is on a more general fiber-optic structural form, namely the lattice structure, which has both feed-forward and feed-backward implementations. These two configurations are simple and regular, yet at the same time permit the operation of complex broadband optical signal processing functions. We examine the implementation of fiber-optic lattice structures incorporating single-mode fibers and directional couplers. Applications of these structures to high-speed matrix-vector multiplication and wide-band frequency filtering are also described with a presentation of both experimental and theoretical results. In this report we mainly consider systems in which the signals (optical intensities) and coupling coefficients are non-negative quantities; these systems fit well in the theory of positive systems. We use this theory to conclude, for example, that for such systems the pole of the system transfer function with the largest magnitude is simple and positive-valued (in the Z-plane), and that the magnitude of the frequency response can nowhere exceed its value at the origin. We also discuss the effects of various noise phenomena on the performance of fiber-optic signal processors, particularly considering the effects of laser source phase fluctuations. Experimental results are presented showing that the dynamic range of fiber-optic systems, discussed in this report, is limited by the laser phase-induced intensity noise. Mathematical analyses of lattice structures as well as additional applications are also presented.

Flame retardant elastomeric compositions were developed, comprised of: (1) spandex type polyurethane having incorporated into the polymer chain, halogen containing polyols; (2) conventional spandex type polyurethanes in physical admixture flame retardant additives; and (3) fluoroelastomeric resins in physical admixture with flame retardant additives. Methods of preparing fibers of the flame retardant elastomeric materials are presented and articles of manufacture comprised of the elastomeric materials are mentioned.

A new imaging atmospheric Cherenkov telescope (CANGAROO-II) with a light-weight reflector has been constructed. Light, robust, and durable mirror facets of containing CFRP (Carbon Fiber Reinforced Plastic) laminates were developed for the telescope. The attitude of each facet can be adjusted by stepping motors. In this paper, we describe the design, manufacturing, alignment procedure, and the performance of the CANGAROO-II optical reflector system.

The carbon fiber reinforced silicon carbide matrix composites were developed by the combined process of chemical vapor infiltration (CVI) and precursor impregnation and pyrolysis (PIP). The properties of the composites were characterized also. The combined process demonstrated short manufacturing period and capability of achieving high-performance composites, with high flexural strength (643 MPa) and high fracture toughness (17.91 MPa.m{sup 1/2}). (orig.) 3 refs.

The production of plastics is discussed. An overview of the South African plastics industry is given. The development of fiber reinforced plastic composites and their applications are discussed. The use of plastics in automobile manufacturing is discussed, as well as the industrial radiation processing of plastics and the use of plastics in the construction industry. Designing in plastics, with particular reference to the role of the mold designer is discussed. For individual titles, see N83-22426 through N83-22428.

Bending is the most common form of loading for many construction elements. The bending strength or Modulus of Rupture (MOR) and flexural ductility are therefore critical properties particularly for those elements which are not reinforced by rebars. Such elements include highway barriers, certain wall panels, thin sheet elements and small diameter pipes. The tensile and bending strengths of concrete are very low. In addition, as a brittle material, concrete also demonstrates a large variability in bending strength. A large variability in MOR leads to inefficient use of the material since the design strength has to be close to the lower bound of the material's strength distribution. The potential of fiber in improving MOR is well recognized in fiber reinforced concrete. The use of fiber to enhance material reliability is much less studied. This thesis addresses both aspects employing a combination of theoretical and experimental treatments. Research findings are reported as Part I and Part II of this thesis. Carbon fibers are increasingly attractive for reinforcing cementitious composites. They can be manufactured to yield a wide range in modulus and strength. Carbon fibers are non-corrosive, and fire and alkali. In addition, the price of pitch based carbon fibers are dropping rapidly to make them economically viable for the building and construction industries. In Part I of the thesis, a study on the optimization of the bending strength of carbon FRCC using a fracture based flexural model that links the fiber, interface, and matrix micro-parameters to composite bending strength is presented. Carbon fiber, interface and matrix parameters were tailored to yield optimal properties such as high MOR and ductility. Four point bend tests were conducted on CFRCCs to confirm the findings. Some problems specially affecting carbon FRCCs such as fiber breakage during mixing were also studied and its effects on composite uniaxial tensile properties analyzed by developing new models. In Part II of the thesis an investigation on the use of fibers for reduction of MOR variability of cementitious materials is reported. Specifically, the concept of lowering the sensitivity of MOR to flaw size based on fiber bridging is confirmed with experimental studies of flexural strength of mesh reinforced mortar beams. Variability of composite properties due to variability introduced by fiber itself was identified, and techniques in controlling such variability were introduced. In this connection, the influence of viscosity of the fresh mix on fiber dispersion uniformity was investigated.

Optical tools offer a route to increasing throughput and efficiency in industrial inspection operations, one of the most time-consuming and labour-intensive aspects of modern manufacturing. One prominent example in the medical device industry is inspection of drilled holes, particularly in narrow-bore tubes (precision-flow devices, such as catheters for drug delivery, radio-opaque contrast agents, etc). The products in which these holes feature are increasing in complexity (reduced dimensions, increasing number of drilled features- in some products now reaching into the hundreds). These trends present a number of technical challenges, not least to ensure that holes are completed and that no damage to the part occurs as a result of over-drilling, for example. This paper will present a novel sensor based on back-side illumination of the drilled hole using side-glowing optical fibers to detect, qualify and quantify drilled holes. The concept is based on inserting a laser-coupled side-glowing optical fiber into the lumen of the tube to be drilled, and imaging the light emitted from this fiber through a drilled hole using a vision system mounted external to the tube. The light from the fiber allows rapid determination of hole completion, shape and size, as well as quantity in the case of products with multiple holes. If the fiber is mounted in the tube prior to drilling, the light emitted from the fiber can be used as a real-time hole breakthrough sensor, preventing under or overdrilling of the tube.

This article examines the effect of the chemical composition of glass fibers on the physicomechanical properties of the fiberglass-reinforced plastics based on these fibers at temperatures of 293 and 77/sup 0/K. The strength of the fiberglass-reinforced plastic in tensile loading is determined mainly by the strength of the glass fibers. The results indicate that the strength of the fiberglass reinforced plastic based on the fibers of nonalkaline composition at 77/sup 0/K and the strength of the fiberglass-reinforced plastic based on fibers of high-modulus glass at 293/sup 0/K are almost identical and equal. The increase of the strength of the fiberglass-reinforced plastic in bending with the reduction of temperature from 293 to 77/sup 0/K for all the fiberglass-reinforced plastics examined equals on average 88%. It is concluded that the fibers based on the alumoborosilicate nonalkaline glass are most suitable for the manufacture of the fiberglass-reinforced plastics working at cryogenic temperatures.

This research uses three kinds of recycled synthetic fibers that all possess excellent thermal plasticity property as raw material to develop a new firm cultivation media: polyethylene terephthalate, polyamide and polypropylene. One can not only freely control plants cultivation growing condition by changing bulk density of the media, but also solve disposal problem after usage by applying thermal oxidative treatment during manufacturing processes. The water content, air permeability and formation conditions of these fiber growing media that are required in plants growing habitat were discussed, and compared the fallout with rockwool (RW) growing media that is commonly used at present days. The results indicated that the polyethylene terephthalate fiber media could attain best formation characteristics among these fibers at the same bulk density range. Furthermore, the fiber media that were thermo-oxidative treated at 240-260 deg. C could obtained above 90% total porosity, 23-49% air capacity and 48-68% water availability, water contents raised from 1735-1094 to 2145-1156% under bulk densities of 0.03-0.09 g/cm{sup 3}, which conforms to the common plant growing habitat conditions. Its performance well surpasses the rockwool growing media. We also discovered that the thermo-oxidative treated polyethylene terephthalate (PET) fiber media could be easily broken down and become powdery by exerting pressure, thus greatly reduce its volume and effectively improve disposal processes that are difficult presently for the huge refuse create by rockwool.

The objective of this study is to develop the radiation sensor, which is composed of a scintillator, an optical fiber bundle and a light measuring device to detect the tritium in real-time. In this study, we have fabricated fiber-optic radiation sensors using inorganic scintillators and plastic optical fiber bundles. Each scintillator interacts with electron or beta ray and generates 455-550 nm wavelength of scintillation photons. An optical fiber bundle is usually made of plastic or glass, which is used to guide the light signal from a scintillating probe to light measuring device. For the purpose of selecting the best scintillator with a high efficiency, fiber-optic sensors manufactured using three kinds of inorganic scintillator such as Gd2O2S:Tb, Y3Al5O12:Ce and CsI:Tl, and they are tested with a metal hydride type of tritium source. In addition, the scintillation photons are measured as a function of distance between a fiber-optic sensor and source. Finally, we have measured the amounts of scintillation photon with different activities of tritium source and compared the measured results with those obtained using a surface activity monitor.

This paper describes the development of a measuring equipment capable of analysing the beam profile at high optical powers emitted by delivery fibers used in manufacturing processes. Together with the optical delivery system, the output beam quality from the delivery fiber and the shape of the focused spot can be determined. The analyser is based on the principle of a rotating wire being swept though the laser beam, while the reflected signal is recorded [1]. By changing the incident angle of the rotating rod from 0° to 360° in relation to the fiber, the full profile of the laser beam is obtained. Choosing a highly reflective rod material and a sufficiently high rotation speed, these measurements can be done with high laser powers, without any additional optical elements between the fiber and analyzer. The performance of the analyzer was evaluated by coupling laser light into different fibers, and measuring the output beam profiles. Fibers with different core diameters and different surface qualities were tested.

The results are summarized of several interlaboratory 'round robin' test programs for measuring the mode 1 interlaminar fracture toughness of advanced fiber reinforced composite materials. Double Cantilever Beam (DCB) tests were conducted by participants in ASTM committee D30 on High Modulus Fibers and their Composites and by representatives of the European Group on Fracture (EGF) and the Japanese Industrial Standards Group (JIS). DCB tests were performed on three AS4 carbon fiber reinforced composite materials: AS4/3501-6 with a brittle epoxy matrix; AS4/BP907 with a tough epoxy matrix; and AS4/PEEK with a tough thermoplastic matrix. Difficulties encountered in manufacturing panels, as well as conducting the tests are discussed. Critical issues that developed during the course of the testing are highlighted. Results of the round robin testing used to determine the precision of the ASTM DCB test standard are summarized.

Flexural fatigue tests have been conducted on unidirectional glass fiber/epoxy, [U]"5 and random glass fiber/epoxy, [R]"5 composite laminates with a constant fiber volume fraction (V"f)=37% and average thickness=5.5+/-0.2mm. The laminates were manufactured using hand lay-up technique. Flexural fatigue tests were performed on standard specimens at zero mean stress, i.e. a cyclic stress ratio=S"m"i"n/S"m"a"x=-1. A 20% reduction of the initial flexural stiffness was taken as a failure criterion. The specimens' surface temperature increase was investigated. To construct the S-N curve for each composite type, four stress levels have been considered using five specimens for each one. The failure modes of the test specimens were investigated. Two-parameter Weibull distribution function was used t...

Perfos and the laboratory Glasses and Ceramics Group of University of Rennes 1 have worked together to develop a new fabrication technique for chalcogenide preforms based on the glass-casting process. Various fiber profiles have been designed by the Fresnel Institute and fiber losses have been significantly improved, approaching those of the material losses. Using this technology, we have manufactured an AsSe CPCF exhibiting a nonlinear coefficient ? of 46 000 W-1km-1. Self-phase modulation, Raman effect, Brillouin effect, Four-Wave Mixing have been observed leading to the demonstration of various optical functions such four-wave mixing based wavelength conversion at 1.55 ?m by FOTON, the demonstration of Raman Shifts and the generation of a mid-IR supercontinuum source by ONERA and the demonstration of a Brillouin fiber laser by FOTON.

Different cellulose pulps were produced from sulfur-free chemical treatments of Empty Palm Fruit Bunch Fibers (EPFBF), a by-product from palm oil processing. The pulps were microfluidized for deconstruction into nanofibrillated cellulose (NFC) and nanopaper was manufactured by using an overpressure device. The morphological and structural features of the obtained NFCs were characterized via atomic force and scanning electron microscopies. The physical properties as well as the interactions with water of sheets from three different pulps were compared with those of nanopaper obtained from the corresponding NFC. Distinctive chemical and morphological characteristics and ensuing nanopaper properties were generated by the EPFBF fibers. The NFC grades obtained compared favorably with associated materials typically produced from bleached wood fibers. Lower water absorption, higher tensile strengths (107-137MPa) and elastic modulus (12-18GPa) were measured, which opens the possibility for valorization of such widely available bioresource. PMID:23026341

Herein we report a 52-year-old man with subacute right-sided proptosis and diffuse intraconal enhancing abnormality on MRI. Orbital biopsy revealed granulomatous inflammation consistent with idiopathic orbital inflammatory syndrome (IOIS), or orbital pseudotumor. However, further examination under polarizing light microscopy also revealed acetate fiber fragments within the orbit. Prominent speckles within the acetate fibers were identified as titanium by Energy Dispersive X-ray Analysis (EDXA). Acetate impregnated with titanium (as a delustrant) is a common synthetic fiber used in textile and clothing manufacture. The mechanism for entrance into the orbit in this case is not known. Granulomatous idiopathic orbital inflammatory syndrome without local or systemic cause is an uncommon clinical entity, with less than 50 cases reported in the literature. Predominance of lacrimal gland (and thus superficial) involvement in granulomatous IOIS suggests the possibility of occult foreign body in such cases. PMID:20497088

Potato pulp is a high-volume, low-value byproduct stream resulting from the industrial manufacture of potato starch. The pulp is a rich source of biologically functional dietary fibers, but the targeted valorisation of the fibers requires removal of the residual starch from the pulp. The objective of this study was to release the residual starch, making up 21-22% by weight of the dry matter, from the potato pulp in a rational way employing as few steps, as few enzyme activities, as low enzyme dosages, as low energy input (temperature and time), and as high pulp dry matter as possible. Starch removal to obtain dietary fibers is usually accomplished via a three step, sequential enzymatic treatment procedure using a heat stable a-amylase, protease, and amyloglucosidase. Statistically designed...

Measurements of the internal geometry of a carbon fiber non-crimp 3D orthogonal woven composite are presented, including: waviness of the yarns, cross sections of the yarns, dimensions of the yarn cross sections, and local fiber volume fraction. The measured waviness of warp and fill yarns are well below 0.1%, which shows that the fabric termed here "non-crimp" has nearly straight in-plane fibers as-produced, and this feature is maintained after going through all steps of fabric handling and composite manufacturing. The variability of dimensions of the yarns is in the range of 4-8% for warp and fill directions, while the variability of the yarn spacing is in the range of 3-4%. These variability parameters are lower than respective ranges of variability of the yarn waviness and the cross-se...

PESf hollow fiber membrane was used to recover sulfur hexafluoride (SF6) from N2/SF6 binary mixture gas. To fabricate a hollow fiber membrane, a dry-wet phase inversion method was used. Fiber was post-treated by methanol to increase permeance. Fabricated membrane was characterized by scanning electron microscopy (SEM) and N2, SF6 single gas permeation according to temperature and pressure difference. Using N2/SF6 binary mixture gas (10 vol% of SF6), we checked the separation of mixture gas in a manufactured single module according to temperature, pressure difference, and retentate flow rate. The highest SF6 purity in recovered gas was 50.4 vol% when the pressure difference, temperature, and stage cut was highest in experimental conditions, but the recovery ratio marked the lowest value.

In this work, E-glass fibers (GF) with different fiber forms, loadings and orientation angles were introduced into wood/poly(vinyl chloride) (WPVC) composites. The GF reinforced WPVC composites were manufactured either by compression molding or by twin-screw extrusion process, and the mechanical properties of the composites from these two processes were then compared. The experimental results suggested that the compression process was more effective for the production of GF reinforced WPVC composites than the twin-screw extrusion process. The specific density of the GF/WPVC composite by the compression technique was greater. The orientation angle of glass fiber was found to have a more pronounced effect on the impact properties of the GF/WPVC composites. The maximum mechanical properties o...

In vacuum infusion molding process (VIMP), it is difficult to manufacture a composite part with small dimensional tolerance, since the upper mold for the process is flexible. In this study, the static and cyclic compaction responses of five kinds of fabrics were experimentally studied under real VIMP conditions, with the effects of compaction pressure, compaction time, compaction cycle and number of the fabric layers. The static and cyclic compaction responses of the all fabrics follow different power law models and the resulting fiber volume fraction and relaxation factor increase with the number of layers. Although the resulting fiber volume fraction increases with the layer numbers, change of the fiber volume fraction of the composite parts with 10 layers to 100 layers of the all fabric...

In this paper, a new type of smart basalt fiber-reinforced polymer (BFRP) bar is developed and their sensing performance is investigated by using the Brillouin scattering-based distributed fiber optic sensing technique. The industrial manufacturing process is first addressed, followed by an experimental study on the strain, temperature and fundamental mechanical properties of the BFRP bars. The results confirm the superior sensing properties, in particular the measuring accuracy, repeatability and linearity through comparing with bare optical fibers. Results on the mechanical properties show stable elastic modulus and high ultimate strength. Therefore, the smart BFRP bar has potential applications for long-term structural health monitoring (SHM) as embedded sensors as well as strengthening and upgrading structures. Moreover the coefficient of thermal expansion for smart BFRP bars is similar to the value for concrete.

The aim of this work was to determine the content of selected heavy metals in flax materials depending on the stage of fiber manufacturing. Non-treated natural fiber composition was compared with that of fibers processed. Changes in the composition of yarn before and after the following scutching, hackling, washing, and bleaching were also investigated. Analysis of heavy metals was performed applying inductively coupled plasma mass spectrometry. Flax material was mineralized in closed Teflon vials with a mixture of concentrated nitric acid which were then placed in a microwave oven system. Analytical quality of the obtained results was checked by the determination of elements in the Certificate Reference Materials of IAEA-V-10. The acquired results proved that the content of metals in flax...

This article addresses the processing and ageing properties of jute fiber reinforced polypropylene (PP) composites. The composite has been manufactured by a continuous extrusion process and results in free flowing composite granules, comprising up to 50 weight percent (wt %) jute fiber in PP. These granules have similar shape and diameter as commercially available PP granules. Rheological analysis shows that viscosity of the compounds follows the same shear rate dependency as PP and is on the same level as glass-PP compounds. The mechanical properties show very little variation and exhibit strength and stiffness values at the upper range of competing natural fiber reinforced compounds for injection molding. The mechanical performance reduces gradually upon prolonged thermal loading and imm...

As part of our involvement in the EU MICROTRAP project, we have designed, manufactured and assembled a micro-scale ion trap with integrated optical fibers. These prealigned fibers will allow delivering cooling laser light to single ions. Therefore, such a trap will not require any direct optical access for laser cooling. All the parts for the trap have been made in our institute [1]. The electrodes and the spacers were laser cut in the collaboration with the group of P.  Balling. In our group we have developed a technique to manufacture lensed optical fibers. The trap is now assembled and installed in an ultra high vacuum chamber, which includes an ablation oven for all-optical loading of the trap [2]. The next steps on the project are to demonstrate the operation of the micro-trap and the cooling of ions using fiber delivered light. [1] D. Grant, Development of Micro-Scale Ion traps, Master Thesis (2008). [2] R.J. Hendricks, D.M. Grant, P.F. Herskind, A. Dantan and M. Drewsen, An all-optical ion-loading technique for scalable microtrap architectures, Applied Physics B, 88, 507 (2007).

Rice husk is a by-product of rice milling process, and a great resource as a raw biomass material for manufacturing value-added composite products. One of the potential applications is to use rice husk as filler for manufacturing lignocellulosic fiber-thermoplastic composites. This study was conducted to examine the silica distribution in rice husk in preparation to use it as reinforcing filler for thermoplastic polymers. Microscopic techniques, such as light microscopy, scanning electron microscopy and field-emission SEM (FE-SEM) were used to observe the surface and internal structure of rice husk. Microscopic examination showed that two main components of husk, lemma and palea consisted of outer epidermis, layers of fibers, vascular bundles, parenchyma cells, and inner epidermis, in sequence from the outer to the inner surface. Histochemical staining showed that epidermal and fiber cell walls were lignified, and the walls of parenchyma and lower epidermal cells were not lignified. The outer epidermal walls were extremely thick, highly convoluted and lignified. The outer surface of both lemma and palea were conspicuously ridged. The energy dispersive X-ray micro-analysis attached to the FE-SEM provided information on the distribution of silica in the husk. Most of the silica was present in the outer epidermal cells, being particularly concentrated in the dome-shaped protrusions. These observations provided valuable background information on the organization of husk tissues and the distribution of silica, which will help optimize processes related to the use of rice husk for making lignocellulosic fiber-thermoplastic composites in our future work.

The impact of five different water/powder (w/p) ratios in the characterization of high strength dental stone was evaluated, since the recommendations of the gypsum’ manufacturers are not always correctly followed by the dental prosthesis technicians. Fiber Bragg grating (FBG) sensors were used to measure the setting expansion and temperature variation which occurred during the setting reaction for each w/p ratio, as well as the thermal expansion coefficient. Thick mixtures with low w/p ratios had more crystals impinging upon each other during crystal growth, resulting in more expansion and more heat released. This thermal behavior was only achieved to w/p ratios within the manufacturer-recommended mixing ratio range. The results also revealed the existence of boundary condition; this corresponding to the limit of the mixing ratio recommended by the gypsum’ manufacturer. Data provided in this study are particularly important for dental technicians with a view to attaining the best results in accuracy of fit for their prosthetic works.   

The field of 'Adaptronics' combines sensor and actuator effects with electronics. The components furnished with adaptronics shall sense relevant properties and shall adapt in an intelligent way - they shall 'feel, thick and act'. For instance, one application is the active vibration compensation of dynamically stressed structures. So far, adaptronics utilizes actuators - and partly also sensors - in the mm size range which posses a substantial stiffness. If such actuators/sensors were to be integrated into light weight structures - e.g. an carbon fiber reinforced aeroplane part or a glass fiber reinforced robot arm - the light weight structures would be severely affected in their advantageous properties. If however, these specific properties are to be maintained, the actuators/sensors have to feature a small volume and stiffness. The micro manufacturing of such systems is an activity of the Fraunhofer Institute IFAM. The approach chosen includes the utilization of piezo electric fibers in the diameter range from 20 micrometers - 200 micrometers . The micro systems consist of many fibers being contacted by interdigitized electrodes made of electrically conductive adhesives. In addition, structural adhesives and casting polymers are used. These actuator/sensor modules can be both applied onto structures, or integrated into structures. The performance of the different modules will be compared. An interesting approach for the use of sensor/actuator modules especially in prepreg fiber reinforced plastics is to also make the PZT fiber modules in a prepreg state. The presentation will feature the latest result of the developments regarding both, the manufacture and the performance of cured as well as prepreg modules.

In this paper, we reviewed our previous work concerning the responses of rare-earth (RE) doped fibers (Yb, Er and Er/Yb) to various types of radiations like gamma-rays, X-rays and protons. For all these harsh environments, the main measured macroscopic radiation-induced effect is an increase of the linear attenuation of these waveguides due to the generation of point defects in the RE-doped core and silica-based cladding. To evaluate the vulnerability of this class of optical fibers for space missions, we characterize the growth and decay kinetics of their radiation-induced attenuation (RIA) during and after irradiation for various compositions. Laboratory testing reveals that this class of optical fibers is very sensitive to radiations compared to passive (RE-free) samples. As a consequence, despite the small length used for space applications, the understanding of the radiation-induced effects in this class of optical fibers becomes necessary before their integration as part of fiber-based systems like gyroscopes or communication systems. In this paper, we more particularly discussed about the relative influence of the rare-earth ions (Er{sup 3+} and/or Yb{sup 3+}) and of the glass matrix dopants (Al, P, ... ) on the optical degradation due to radiations. This has been done by using a set of five prototype optical fibers designed by the fiber manufacturer iXFiber SAS to enlighten the role of these parameters. Additional spectroscopic tools like con-focal microscopy of luminescence are also used to detect possible changes in the spectroscopy of the rare-earth ions and their consequences on the functionality of the active optical fibers. (authors)

Occupational exposure to asbestos fiber and total dust of workers of a major brake lining manufacture plant in a developing country were examined and compared with those in developed countries. Time weighted average of total dust and asbestos fiber concentration in the potential sources of exposure were monitored. All personal air sampling were collected on membrane filters and analyzed by phase contrast optical microscopy (PCM) for comparison with the occupational safety and health administration (OSHA) permissible exposure limit (PEL) of 0.1 f/cc, 8-h time ? weighted average. This study demonstrates that routine mixing, polishing and beveling process in the brake lining production can result in elevated levels of airborne asbestos. Greater releases of airborne asbestos were observed during mixing process and mixer machine. The results also showed that the employees working in the process had the exposure to total dust concentrations ranging from 2.08 to 16.32 mg/m³ that is higher than OSHA, recommendation. According to OSHA definition of fibers, it has been indicated that from 3,000 counted particles, 90% of particles are in the form of non-fiber and reaming have fiber-shaped. The particle analyze gives the geometric mean diameter as 6.02 ?m, and also indicated that the arithmetic mean of the number distribution for the particle population was 8.4 ?m. Approximately 60.4% of the counted fibers were lower than 10 ?m in length, from which only 8% consists of fibers (>5 ?m in length). In conclusion, the analysis showed a presence in the air of only chrysotile asbestos and an absence of other types of asbestos. During an 8-h shift, the average asbestos fiber exposure (0.78 f/cc) were 7.8 time in excess of OSHA PEL. Additional studies in occupational exposure to asbestos are needed.   

Some of the critical properties of high performance organic fibers and fiber assemblies have been addressed vis-a-vis their applications in flexible structural composites. These include: tensile properties; mechanical properties under complex modes of deformation; creep at high tensile loads; changes in physical properties due to thermo-mechanical/chemical treatments used in manufacturing of reinforced rubber goods. The axial elastic modulus of fibers and tautly twisted filament assemblies of high performance organic polymers have been measured along with their crystalline orientation distributions. Based on well established procedures in continuum mechanics of axially symmetric structures, a quantitative relationship has been derived to relate the axial elastic modulus to the second and fourth moment of average crystalline orientation distribution. The latter was determined by X-ray diffraction measurements with yarns. This model, valid for single-phase materials, has been found to provide an excellent fit of data from twisted yams of aromatic polyamide and highly ordered polyethylene fibers, with a wide range of overall crystalline orientation distributions. An important property of concern in engineering applications of polymeric filament assemblies of high performance organic fibers is creep. In this study, creep deformation data of gel-spun Ultra High Molecular Weight Polyethylne (UHMWPE) SpectraRTM 1000 yams have been fitted to a model obtained through an empirical mechanical analog of the viscoelastic process. The non-linear viscoelastic model composed of stress-dependent non-linear mechanical analogs qualitatively predicted the creep response to a series of step-loads applied on the UHMWPE yarns. To understand the mechanical properties of high performance organic fibers under combined bending and extension, a simple pin-test procedure has been employed to characterize fibers and twisted yarns. The results obtained from the test have been interpreted with regard to the mechanisms through which fibers can exhibit superior performance characteristics under such deformation conditions. An exploratory study of the changes in the mechanical properties of poly(p-phenylene terephthalamide) (PPTA) fibers due to the thermo-mechanical/chemical treatments used in commercial manufacturing of reinforced rubber goods has been conducted. The changes in tensile properties of PPTA yams have been inferred to be due to the process-induced changes in the overall crystalline orientation distribution.

The motivation of this thesis is to investigate the role of multi-walled carbon nanotube (MWCNT) in enhancing the interlaminar shear strength (ILSS) of hybrid composites. The objective of this thesis is to understand the relationships between processing history, material variability, matrix properties, glass fiber/matrix interface properties and their correlations with interlaminar shear strength of hybrid composites. The interlaminar shear strength (ILSS) of hybrid composites made from glass fiber and multi-walled carbon nanotube (MWCNT) modified epoxy is compared with that for unmodified epoxy/glass fiber composites (control). By combining the techniques of high speed mechanical stirring and ultrasonic agitation, 0.5% MWCNT by weight were dispersed in epoxy to prepare a suspension. Composites were manufactured by both injection double vacuum-assisted resin transfer molding (IDVARTM) and the flow flooding chamber (FFC) methods. Compression shear tests (CST) were conducted on the manufactured samples to determine the ILSS. The effect of processing history and batch-to-batch variability of materials---glass fiber preform, resin and carbon nanotubes---on the ILSS of samples made by both techniques was investigated. Statistical comparison of the measured ILSS values for hybrid composites with the control specimens clearly show that hybrid composites made by the FFC process resulted in significant ILSS enhancement relative to the control and the IDVARTM specimens. After it was established that the FFC process improved the ILSS, the effect of functionalizing the nanotubes was explored. Multi walled carbon nanotubes (MWCNT) were oxidized by acid treatment and heated with triethylene tetra amine (TETA) to obtain amino functionalized MWCNTs (f-MWCNT). Hybrid composites with f-MWCNTs were manufactured using FFC technique and control samples were fabricated using the same E-Glass fiber mat and unmodified epoxy resin subjected to the same processing history. CST results show 41% increase in ILSS for hybrid composites containing p-MWCNTs and a 61% increase for samples containing f-MWCNTs relative to the control samples without MWCNT. Tests of the epoxy preparations were conducted to investigate if the increase in ILSS is due to an increase in the shear strength of epoxy containing nanotubes or to strengthening of the interface between the glass fiber and the epoxy containing nanotubes. Small punch test and miniature shear punch tests were conducted to characterize the young's modulus, yield shear strength and ultimate shear strength of the neat epoxy and MWCNT epoxy composites and micro droplet tests were conducted to characterize the interfacial shear strength, the strength of the fiber-matrix interface for both modified and unmodified matrix. The results indicate that the ILSS increase was due to the stronger interface bond due to the addition of nanotubes rather than any enhancement in the epoxy shear properties.

A project to redesign a wind turbine blade for manufacturing out of engineered wood was presented. The aim of the Aeolus Blades design project was to reduce typical manufacturing costs of $3000 for wind turbine blades to $1000 per blade using cheaper materials and less intensive manufacturing processes. The wooden blades were designed to meet the same design standards as typical wind turbine blades. The project also aimed to reduce startup costs for wind turbine applications in remote locations as well as for the residential sector. Baseline stiffness data were obtained through a series of benchmark tests on existing fiberglass and carbon fiber blades. Wooden billets were used to re-orient veneer planes and avoid interlaminar shear stress. The blades were produced from 2 machined billets. The wood blade was tested experimentally, and compared to the benchmark data and a series of finite element analyses (FEA). Results indicated that the laminated veneer lumber (LVL) was not stiff enough to support design wind pressure loads of up to 5000 Pa. Carbon fiber strips were inserted onto the outer surfaces of the blade. Results of further tests showed that overall stiffness compared to carbon fiber and fiberglass blades. Total tip deflection predicted by the FEA was within 1.5 per cent of the measured tests. The results of an economic analysis showed that the wood blades could be produced for approximately $1000 each in a 50-blade batch manufacturing run. It was concluded that engineered wood is a suitable material for wind turbine blades. 20 refs., 8 tabs., 75 figs.

The relative in vitro and in vivo toxicity of several types of manufactured fibrous glass insulation and crocidolite asbestos was investigated to aid in selection of a suitable glass fiber for subsequent use in inhalation exposures. The in vitro cytotoxicity to pulmonary alveolar macrophages of small glass fibers from microfiber insulation (count median diameter (CMD) approx. 0.1-0.2 ..mu..m) was greater than that of the larger fibers from household insulation (CMD approx. 2.4 ..mu..m). To screen for in vivo pulmonary toxicity, 2-21 mg of glass or asbestos fibers were administered in divided doses to male Syrian hamsters by intratracheal instillation. Animals were sacrificed at 1, 3.5 and 11 months following initial administration of material. One type of glass microfiber count median diameter (CMD) approx. 0.1 ..mu..m caused deaths from pulmonary edema at early times after instillation. High levels of asbestos, a second glass microfiber (CMD approx. 0.2 ..mu..m) and one type of household insulation fiber (CMD 2.3 ..mu..m) all resulted in increases in total collagen and mild pulmonary fibrosis at later times after instillation, although microfiber insulation produced a greater response than household insulation. Asbestos insulation produced the greatest response. A five-day inhalation exposure to a high level of glass microfibers deposited in lung <10 percent of the lowest instilled amount which elicited indications of lung injury. This amount did not produce significant biological changes at 1 to 12 months after exposure. 20 references, 4 figures, 2 tables.

Due to a series of continuous improvements in the manufacturing know-how of ceramic fiber, effective composition compounds, use of protective and high emissivity coatings, and innovative anchoring methods for lining, utilization of ceramic fiber products is nowadays extremely diversified. The advantages of all-fiber linings for industrial furnaces can be briefly summarized as: short heating-up and cooling-down periods, low energy consumption, high production capacity, optimum temperature balance, and more uniform quality of finished products. The major disadvantage is that the use of fiber is questionable with the production of aggressive fuel gases and/or glaze vapors. This is because the fibrous materials are less resistant to the attack of aggressive environment than the other insulating products, and thus quickly lose their properties. The application of high emissivity ceramic coatings on the working surface of fibrous insulating lining can improve the resistance of these materials against the aggressive environment. And as a result of increasing the radiating efficiency of the refractory lining, more energy is directed to the work load, thus requiring less fuel to be fired. Ceramic fiber products is a perfect example of what composite materials are.

The emergence of nanotechnology represents an important milestone, as it opens the way to a broad spectrum of applications for nanomaterials in the fields of engineering, industry and medicine. One example of nanomaterials that have the potential for widespread use is carbon nanotubes, which have a tubular structure made of graphene sheets. However, there have been concerns that they may pose a potential health risk due to their similarities to asbestos, namely their high biopersistence and needle-like structure. We recently found that despite these similarities, carbon nanotubes and asbestos differ in certain aspects, such as their mechanism of entry into mesothelial cells. In the study, we showed that non-functionalized, multi-walled carbon nanotubes enter mesothelial cells by directly piercing through the cell membrane in a diameter- and rigidity-dependent manner, whereas asbestos mainly enters these cells through the process of endocytosis, which is independent of fiber diameter. In this review, we discuss the key differences, as well as similarities, between asbestos fibers and carbon nanotubes. We also summarize previous reports regarding the mechanism of carbon nanotube entry into non-phagocytic cells. As the entry of fibers into mesothelial cells is a crucial step in mesothelial carcinogenesis, we believe that a comprehensive study on the differences by which carbon nanotubes and asbestos fibers enter into non-phagocytic cells will provide important clues for the safer manufacture of carbon nanotubes through strict regulation on fiber characteristics, such as diameter, surface properties, length and rigidity. PMID:22568550

The successful application of ceramic matrix composites as hot-section components in advanced gas turbine engines will require the development of constituent materials and processes that can provide the material systems with the key thermostructural properties required for long-term component service. Much initial progress in identifying these materials and processes was made under the former NASA Enabling Propulsion Materials Program using stoichiometric Sylramic (trademark) silicon-carbide (SiC) fibers, 2D (two dimensional)-woven fiber architectures, chemically vapor-infiltrated (CVI) BN fiber coatings (interphases), and SiC-based matrices containing CVI SiC interphase over-coatings, slurry-infiltrated SiC particulate, and melt-infiltrated (MI) silicon. The objective of this paper is to discuss the property benefits of this SiC/SiC composite system for high-temperature engine components and to elaborate on further progress in SiC/SiC development made under the new NASA Ultra Efficient Engine Technology Program. This progress stems from the recent development of advanced constituent materials and manufacturing processes, including specific treatments at NASA that improve the creep, rupture, and environmental resistance of the Sylramic fiber as well as the thermal conductivity and creep resistance of the CVI SiC over-coatings. Also discussed are recent observations concerning the detrimental effects of inadvertent carbon in the fiber-BN interfacial region and the beneficial effects of certain 2D-architectures for thin-walled SiC/SiC panels.

The sensitivity of fiber-optic surface plasmon resonance (SPR) sensors was improved by a factor of at least thirteen for aqueous solutions by modifying the tip geometry to allow interrogation of the surface plasmon (SP) band in the near-infrared (NIR) region. This was achieved by tuning the angle at the distal end of the SPR sensor to a dual taper of 71 degrees and 19 degrees . Using a low numerical aperture (NA) fiber-optic sensor, NA = 0.12, is necessary to obtain a functional SPR sensor working in the NIR region. Theoretical simulations using the Maxwell equations demonstrated that even higher enhancement is theoretically possible while maintaining a narrow spectral feature upon the excitation of the SP bands on gold surfaces. The manufacture of the SPR sensors yields good agreement between theoretical simulations and experimental observations. To investigate the properties of these fiber-optic SPR-NIR sensors, sucrose solutions ranging from 0 to 15 x 10(-3) in mole fraction were utilized. The increased sensitivity of the fiber-optic SPR sensors, when used to monitor biomarkers, would yield lower detection limits. The smaller sensing area, compared to planar or other fiber-optic SPR sensors, combined with an improvement of the sensitivity, would yield a dramatic reduction of the absolute amount detected by biosensors. PMID:17132440

The coupling efficiency of a pigtailed optical fiber lens is often a critical parameter in the manufacture of optical devices. For example, efficient coupling from high power semiconductor lasers to optical fiber pigtails with fiber lenses is of great importance as the uncoupled power can affect the lifetime of the device through thermal degradation of the pigtail or its welding point; for optical amplifiers, the coupling efficiency determines the overall gain. Generally, mass-produced optical fiber lenses do not have a consistent enough quality and it is often necessary to discard lenses that exhibit poor coupling. We previously demonstrated a method for digitally modifying optical fiber lenses. We have now developed a scheme whereby we are able to produce high quality optical fibre lenses with a given lens radius and then to iteratively alter it to achieve the required divergence and spot size in a repeatable fashion for efficient coupling to a variety of devices such as semiconductor optical amplifiers, lasers and wave-guides. We have consistently demonstrated 75% coupling efficiency to angled facet semiconductor optical amplifiers at 1550nm with only three-axis adjustment, and believe the true coupling efficiency to be close to 90%. Our powerful scheme allows the use of nearly all of the lenses for a given application.

A combined experimental and computational methodology was used to determine the relevant strength and residual-stress parameters in a manufactured, high-fiber-volume-fraction multiply metal matrix composite (MMC). The method was similar to that previously demonstrated on single-fiber composites, which had an extremely low fiber volume fraction. Variabilities in residual stresses and debond strengths in high-fiber-volume-fraction multiply composites, as well as current demands on the micromechanics-based computational prediction and validation of complex composite systems, necessitated the establishment of the test methodology described here. The model material chosen for this investigation was a plasma-processed six-ply, unidirectional Sigma-1240/Ti-6Al-2Sn-4Zr-2Mo (wt pct) MMC containing 32 vol pct continuous fibers. Room-temperature transverse tensile experiments were conducted on cruciform specimens. In addition, rectangular specimens were also evaluated in order to verify their applicability in obtaining valid interfacial property data. Debonding events, evaluated at different positions within a given specimen geometry, were captured by stress-strain curves and metallographic examination. Analytical and finite-element stress analyses were conducted to estimate the geometrical stress-concentration factors associated with the cruciform geometry. Residual stresses were estimated using etching and computational procedures. For the cruciform specimens, the experimental fiber-matrix debond strength was determined to be 22 MPa. Separation occurred within the carbon-rich interfacial layer, consistent with some previous observations on similar systems. Thus, the cruciform test methodology described here can be successfully used for transverse interfacial-property evaluation of high-fiber-volume-fraction composites. For the rectangular specimens, the strain gages at different positions along the specimen width confirmed that the interface crack had initiated from the free edge and propagated inward. Hence, rectangular specimens cannot be used for valid interface strength measurements in multiply composites.

The ever increasing need for lower density and higher temperature-capable materials for aircraft engines has led to the development of Ceramic Matrix Composites (CMCs). Today's aircraft engines operate with >3000"F gas temperatures at the entrance to the turbine section, but unless heavily cooled, metallic components cannot operate above approx.2000 F. CMCs attempt to push component capability to nearly 2700 F with much less cooling, which can help improve engine efficiency and performance in terms of better fuel efficiency, higher thrust, and reduced emissions. The NASA Glenn Research Center has been researching the benefits of the SiC/SiC CMC for engine applications. A CMC is made up of a matrix material, fibers, and an interphase, which is a protective coating over the fibers. There are several methods or architectures in which the orientation of the fibers can be manipulated to achieve a particular material property objective as well as a particular component geometric shape and size. The required shape manipulation can be a limiting factor in the design and performance of the component if there is a lack of bending capability of the fiber as making the fiber more flexible typically sacrifices strength and other fiber properties. Various analysis codes are available (pcGINA, CEMCAN) that can predict the effective Young's Moduli, thermal conductivities, coefficients of thermal expansion (CTE), and various other properties of a CMC. There are also various analysis codes (NASAlife) that can be used to predict the life of CMCs under expected engine service conditions. The objective of this summer study is to utilize and optimize these codes for examining the tradeoffs between CMC properties and the complex fiber architectures that will be needed for several different component designs. For example, for the pcGINA code, there are six variations of architecture available. Depending on which architecture is analyzed, the user is able to specify the fiber tow size, tow spacing, weave parameter, and angle of orientation of fibers. By holding the volume fraction of the fibers constant, variations in tow spacing can be explored for different architectures. The CMC material properties are usually calculated assuming the component is manufactured perfectly. However, this is typically not the case so that a quantification of the material property variability is needed to account for processing and/or manufacturing imperfections. The overall inputs and outputs are presented using a regression software to rapidly investigate the tradeoffs associated with fiber architecture, material properties, and ultimately cost. This information is then propagated through lifing models and Larson-Miller data to assess timehemperature-dependent CMC strength. In addition, a first order cost estimation will be quantified from a current qualitative perspective. This cost estimation includes the manufacturing challenges, such as tooling, as well as the component cost for a particular application. Ultimately, a cost to performance ratio should be established that compares the effectiveness of CMCs to their current rival, nickel superalloys.

Facilities have been completed to manufacture a long glass reinforced thermoplastic composite. This sheet is obtained based on a special paper making technique using a foam solution. The starting materials are polypropylene (1) powder and glass fibers chopped to about 13 mm. The manufacturing method consists of opening chopped glass fibers composed of bound single fibers and (1) in a foam solution containing a surfactant, and feeding the material into a paper making machine to make it into a non-woven fabric. The method is characterized by using the foam solution to suppress a secondary material coagulation when the materials are opened. The non-woven fabric, which contains clearances, is heated and then pressed while being cooled to make it into a dense sheet. The sheet has such features that it can be formed using a press; formed products with excellent mechanical properties can be obtained; and it can be made in short forming cycles. Weights required to form products with certain rigidity were compared on different materials. The result showed that this sheet used as a flat plate enables reducing weight as much as 50% of steels. Its main application would be automotive use. 3 figs., 1 tab.

Polymer-matrix composites offer greater stiffness and strength per unit weight than conventional materials resulting in new opportunities for lightweighting of automotive and heavy vehicles. Other benefits include design flexibility, less corrosion susceptibility, and the ability to tailor properties to specific load requirements. However, widespread implementation of structural composites requires lower-cost manufacturing processes than those that are currently available. Advanced, directed-fiber preforming processes have demonstrated exceptional value for rapid preforming of large, glass-reinforced, automotive composite structures. This is due to process flexibility and inherently low material scrap rate. Hence directed fiber performing processes offer a low cost manufacturing methodology for producing preforms for a variety of structural automotive components. This paper describes work conducted at the Oak Ridge National Laboratory (ORNL), focused on the development and demonstration of a high speed chopper gun to enhance throughput capabilities. ORNL and the Automotive Composites Consortium (ACC) revised the design of a standard chopper gun to expand the operational envelope, enabling delivery of up to 20kg/min. A prototype unit was fabricated and used to demonstrate continuous chopping of multiple roving at high output over extended periods. In addition fiber handling system modifications were completed to sustain the high output the modified chopper affords. These hardware upgrades are documented along with results of process characterization and capabilities assessment.

In this report, the properties of two carbon-epoxy prepreg materials are presented. The epoxy resin used in these two materials can yield lower manufacturing costs due to its low initial cure temperature, and the capability of being cured using vacuum pressure only. The two materials selected for this study are MR50/LTM25, and CFS003/LTM25 with Amoco T300 fiber; both prepregs are manufactured by The Advanced Composites Group. MR50/LTM25 is a unidirectional prepreg tape using Mitsubishi MR50 carbon fiber impregnated with LTM25 epoxy resin. CRS003/LTM25 is a 2 by 2 twill fabric using Amoco T300 fiber and impregnated with LTM25 epoxy resin. Among the properties presented in this report are strength, stiffness, bolt bearing, and damage tolerance. Many of these properties were obtained at three environmental conditions: cold temperature/dry (CTD), room temperature/dry (RTD), and elevated temperature/wet (ETW). A few properties were obtained at room temperature/wet (RTW), and elevated temperature/dry (ETD). The cold and elevated temperatures used for testing were -125 F and 180 F, respectively. In addition, several properties related to processing are presented.

The structural performance of several pultruded fiberglass utility poles is investigated and compared with wood pole standards. The fiberglass poles are thin-walled tubes with an approximately hexagonal configuration. The outside of the poles have longitudinal grooves which create a dovetail configuration. The dovetails provide a convenient mechanism for attaching crossarms and other hardware to the tubular structure and contribute additional stiffness and strength at these attachment points. Manually operated clamping devices which can run up and down the grooves provide a safe environment for utility linemen. Structural evaluation includes a comparison of axial stiffness, flexural stiffness, maximum load, maximum bending moment, and load-deflection curves for several different pole cross-sectional geometry`s. Material elastic properties and fiber orientations are varied to determine the effect on structural performance. Several different fiber preforms, including unidirectional rovings and multidirectional fabrics, are evaluated. Results of the analyses are compared with the manufacturer`s (Composite Power Corporation) preference in terms of manufacturability. The effect of fiberglass sleeve inserts and solid foam cores is also investigated. Some of the analyses are compared with full scale test data and both the experimental and theoretical results are compared with utility standards for pole design. Failure mechanisms for different loading conditions and future analysis is discussed. Preliminary results show that the composite poles can achieve the standards required for the highest quality wood poles.

The objective of the microwave filament processing project is to develop microwave techniques to manufacture continuous ceramic oxide filaments. Microwave processing uses the volumetric absorption of microwave power in oxide filament tows to drive off process solvents, to burn out organic binders, and to sinter the dried fibers to produce flexible, high-strength ceramic filaments. The technical goal is to advance filament processing technology by microwave heating more rapidly with less energy and at a lower cost than conventional processing, but with the same quality as conventional processing. The manufacturing goal is to collaborate with the 3M Company, a US manufacturer of ceramic oxide filaments, to evaluate the technology using a prototype filament system and to transfer the microwave technology to the 3M Company. Continuous ceramic filaments are a principal component in many advanced high temperature materials like continuous fiber ceramic composites (CFCC) and woven ceramic textiles. The use of continuous ceramic filaments in CFCC radiant burners, gas turbines, waste incineration, and hot gas filters in U.S. industry and power generation is estimated to save at least 2.16 quad/yr by year 2010 with energy cost savings of at least $8.1 billion. By year 2010, continuous ceramic filaments and CFCC`s have the potential to abate pollution emissions by 917,000 tons annually of nitrous oxide and 118 million tons annually of carbon dioxide (DOE Report OR-2002, February, 1994).

This project addresses the problem of lower solar conversion efficiency and waste in the typical solar cell manufacturing process. The work from the proposed development will lead toward developing a system which should be able to increase solar panel conversion efficiency by an additional 12-15% resulting in lower cost panels, increased solar technology adoption, reduced carbon emissions and reduced dependency on foreign oil. All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is needed, able to acquire local information about the panel under deposition and measure its local characteristics, including the light scattering in very close proximity to the surface of the film. This information cannot be obtained by monitoring from outside the deposition chamber (as traditional monitoring systems do) due to the significant signal attenuation and loss of its scattering component before the reflected beam reaches the detector. In addition, it would be too costly to install traditional external in-situ monitoring systems to perform any real-time monitoring over large solar panels, since it would require significant equipment refurbishing needed for installation of multiple separate ellipsometric systems, and development of customized software to control all of them simultaneously. The proposed optical monitoring system comprises AccuStrata’s fiber optics sensors installed inside the thin film deposition equipment, a hardware module of different components (beyond the scope of this project) and our software program with iterative predicting capability able to control material bandgap and surface roughness as films are deposited. Our miniature fiber optics monitoring sensors are installed inside the vacuum chamber compartments in very close proximity where the independent layers are deposited (an option patented by us in 2003). The optical monitoring system measures two of the most important parameters of the photovoltaic thin films during deposition on a moving solar panel - material bandgap and surface roughness. In this program each sensor array consists of two fiber optics sensors monitoring two independent areas of the panel under deposition. Based on the monitored parameters and their change in time and from position to position on the panel, the system is able to provide to the equipment operator immediate information about the thin films as they are deposited. This DoE Supply Chain program is considered the first step towards the development of intelligent optical control system capable of dynamically adjusting the manufacturing process “on-the-fly” in order to achieve better performance. The proposed system will improve the thin film solar cell manufacturing by improving the quality of the individual solar cells and will allow for the manufacturing of more consistent and uniform products resulting in higher solar conversion efficiency and manufacturing yield. It will have a significant impact on the multibillion-dollar thin film solar market. We estimate that the financial impact of these improvements if adopted by only 10% of the industry ($7.7 Billion) would result in about $1.5 Billion in savings by 2015 (at the assumed 20% improvement). This can b

Intravehicle communications has been increasing at a rapid pace in recent years. The advent of multimedia applications, global positioning systems and increased use of safety devices and sensors has fueled network traffic within vehicular networks. Military vehicles have had similar advances as well. The bandwidth necessary to provide adequate communication between systems is slowly approaching the limit of traditional copper based networks. Optical fiber is finding its way into these networks for a variety of reasons including large bandwidth, low weight and small volume. Along with these advantages optical fiber allows the possibility to directly integrate fiber into the structure of a vehicle, thus offering an automated process for running network cabling. Automating this process eliminates a large manufacturing cost associated with running cable manually throughout the vehicle. Also, for military applications it can add an extra layer of protection to the network for increased reliability. Along with communications applications, the integration of optical fiber into structural components allows for the possibility of embedding sensor networks within structures. The major hurdle in achieving integration is the communication from outside to inside the panel. To overcome this, various methods of optical data porting to embedded optical fibers were designed, fabricated and tested. Active methods, both electrical and photonic in nature, were explored as well as using external and self-powering techniques. In the end a passive method of integrating a mirror into the fibers themselves was determined to provide the most advantageous approach. The application of this approach towards off chip optical interconnects was also explored as it was noticed that the mirror integration technique provided for a low-cost process for parallel optical interconnects between chips on a PCB.

In this paper I examine how knowledge claims operating through two types of governance techniques can guide product innovations in the agri-food sector. The notion that knowledge claims have strong social and material components informs the analysis undertaken, developed through a discussion of social science approaches to the role of human groups and biophysical properties in social change. I apply this socio-technical perspective to two case studies: defining dietary fiber and reducing saturated fat. The first involves attempts to produce an international definition of dietary fiber standards in the Codex Alimentarius Commission. The second involves efforts by food manufacturers to reduce the saturated fat content of food products in line with UK government guidelines. The case studies d...

Abstract:- Tiger nut (Cyperus esculentus) is a weed plant (yellow nut sedge) of tropical and Mediterranean regions. Its sweet almond-like tubers are highly appreciated for their health benefits and nutritive value: high content of fiber, proteins, and sugars. They are rich in oleic acid and glucose, as well as in phosphorus, potassium, and vitamins C and E. In Spain, these tuberous -nuts- are mainly used to manufacture a milky beverage called -horchata de chufa.- Tiger nut has attracted very little scientific and technological interest, except for the production of -horchata de chufa- and some studies on its oil. Development of new products from the tubers could enhance more interest in this crop. In this respect, various opportunities are offered: source of dietary fiber, use of its oil i...

Metal-matrix-composites may offer better damping properties than unreinforced alloys. Because damping properties (and metal-matrix composites) are becoming important in airframe design, the damping capabilities of a number of aluminum-matrix composites were measured over a wide range of frequencies at low strain amplitudes, using a new laser vibrometer technique. Silicon carbide and alumina reinforcements resulted in a material with damping properties similar to that of unreinforced aluminum 6061-T6, but unidirectional and planar-random graphite continuous-fiber reinforcements increased the damping by 5 and 14 times, respectively. The increased damping of the continuous fiber composites is attributed to the absence of interfacial reaction resulting from the high-pressure infiltration method used for their manufacture. 25 refs.

Abstract Purpose: During dowel space preparation, the instrumentation forms a thick smear layer along with sealer-occluded dentinal tubules. The purpose of this study was to evaluate the effect of different obturating materials on push-out bond strength of a fiber dowel. Materials and Methods: Fifty human uniradicular teeth were decoronated and prepared using the step-back technique. The specimens were divided into five groups on the basis of obturating materials: group I received no obturation; group II (ZOE) gutta-percha and zinc oxide eugenol sealer; group III (ZOAH) gutta-percha and AH plus sealer; group IV (GF) GuttaFlow; and group V (RE) with Resilon Epiphany system. Dowel spaces were made with manufacturer's provided drills, and a fiber dowel was luted. Horizontal slices were obtain...

As part of the French Program of Research and Technology for Advanced Hypersonic Propulsion (PREPHA) which was launched in 1992 between Aerospatiale, Dassault Aviation, ONERA, SNECMA and SEP, an important work is specially devoted to the development of titanium and intermetallic composite materials for large airframe structures. At Dassault Aviation, starting from a long experience in Superplastic Forming - Diffusion Bonding (SPF-DB) of titanium parts, the effort is brought on the manufacturing and characterization of composites made from Timet beta 21S or IMI 834 foils and Textron SCS6 fiber fabrics. At `Aersopatiale Espace & Defence`, associated since a long time about intermetallic composite materials with university research laboratories, the principal effort is brought on plasma technology to develop the gamma titanium aluminide TiAl matrix composite reinforced by protected silicon carbide fibers (BP SM 1240 or TEXTRON SCS6). The objective, is to achieve, after 3 years of time, to elaborate a medium size integrally stiffened panel (300 x 600 sq mm).

In recent years Silicon Photomultipliers (SiPMs) have been proposed as a new type of readout system for scintillating detectors in many experiments. SiPMs consist of a matrix of parallel-connected silicon micro-pixels, which are independent photon counters working in limited Geiger mode with very high gain (~106). This contribution presents the use of an array of SiPMs (manufactured by FBK-irst) for the readout of a shashlik calorimeter composed by lead and scintillator tiles for a total of ~23 X0; the scintillator light is carried out by 64 WLS fibers (4 fibers per SiPM). The performances of the calorimeter in terms of linearity and energy resolution have been tested in a beam test with charged particles (e±, muons and pions) with a momentum up to 6 GeV/c at the CERN PS T10 line.

This paper reports on a magnet system comprising a pair of self-supporting disk-shaped coils designed for the ASTROMAG facility on the space station Freedom. The coils are connected in a quadrupole configuration in order to eliminate their dipole moment. One of the primary requirements of this design is that the magnet coils must have near-perfect structural integrity. To this end, each coil would be manufactured as a monolithic composite, in which the superconducting wire is incorporated as one of the components. By utilizing a precision X-Y numerically controlled wiring machine, the coil can be built up in pancake layers, alternating prepreg sheets of fiber/epoxy (e.g., carbon or kevlar fiber) with a layer of NbTi wire that spirals form OD to ID in one layer, from ID to OD in the next, and so on.

For the long-distance communication and manufacturing problems in optical fibers, the propagation of subpicosecond or femtosecond optical pulses can be governed by the variable-coefficient nonlinear Schroedinger equation with higher order effects, such as the third-order dispersion, self-steepening and self-frequency shift. In this paper, we firstly determine the general conditions for this equation to be integrable by employing the Painleve analysis. Based on the obtained 3 x 3 Lax pair, we construct the Darboux transformation for such a model under the corresponding constraints, and then derive the nth-iterated potential transformation formula by the iterative process of Darboux transformation. Through the one- and two-soliton-like solutions, we graphically discuss the features of femtosecond solitons in inhomogeneous optical fibers.

Glass/epoxy composites were manufactured using RIFT (Resin Infusion under Flexible Tool), a closed mould process capable of obtaining large and complex forms, by impregnating, under a vacuum, a dry preform placed on a flat rigid mould. At certain points of these composite laminates, molded-in holes were made in the dry perform before the resin infusion phase, using two different methods: displacing or cutting the yarn of the fibers. After the resin treatment, other holes were made in the same laminates by drilling. Single-point pin-loaded specimens, cut from laminates, were tested for different values of specimen width-to-hole diameter ratio (W/D) and edge distance-to-hole diameter ratio. In the results of the experiment, the specimens with molded in holes made by displacing the fiber yarn showed higher bearing strength values.

During manufacture of dimethyl terephthalate, which is used as a monomer in production of polyester fibers, by joint oxidation of p-xylene and methyl p-toluate waste products are obtained at various stages of its purification; these have usually been burnt. One type of waste product (residue III), separated from the mother liquor during recrystallization of dimethyl terephthalate from methanol, contains in addition to dimethyl phthalates and resinous products a considerable amount of trimethyl trimellitate (TMT), the content of which in the wastes varies in the range 12-40% and depends mainly on the performance of the distillation and recrystallization stages. It was of interest to isolate pure TMT from the wastes so that, on the one hand, it could be used for improving fiber quality, and on the other hand the amount of wastes would be reduced. Our method for isolating TMT from the wastes includes vacuum fractionation with subsequent removal of impurities from TMT by treatment with reagents of basic character.

Fiber-reinforced polymer (FRP) bars can be used as internal reinforcement for new reinforced concrete (RC) structures and as near-surface mounted (NSM) reinforcement for the strengthening of RC structures. The NSM method is an emerging strengthening technique for RC structures, where FRP bars are embedded into grooves cut in the cover of RC members. In both cases, strain monitoring of the FRP bars is desirable either for the investigation of the structural behavior or for the long-term health monitoring of the structure. This paper presents a study in which fiber-optic sensors were embedded into glass FRP (GFRP) bars to produce smart GFRP bars for NSM applications. The manufacturing process of the smart FRP bars is illustrated and their performance in tensile, bond and beam flexural tests ...

Carbon fiber reinforced plastics have gained large interest among the community of composites manufactures and consumers due to their excellent adaptability to various industrial applications. In particular, there exists a demand for optimizing machining conditions of mechanical parts made from poly ether ether ketone reinforced with 30% of carbon fiber when using TiN coated cutting tools. In this work, predictive models that describe the relationship between the independent machining variables: cutting speed, feed rate and depth of cut, and the criteria of machinability: cutting force, cutting power and specific cutting pressure were derived. This was achieved by using either classical response surface regression technique or by implementing fuzzy logic models which are based on the compo...

Since World War II, textile composites have been used as ballistic armor. Ultra-high molecular weight polyethylene (UHMWPE) fibers are used in the production of armor materials. As they have been developed and commercialized only recently, there is not enough information about the effect of environmental agents in the ballistic performance of UHMWPE composites. In the present work, was evaluated the ballistic behavior of composite plates manufactured with UHMWPE fibers after exposure to gamma radiation. The ballistic tests results were related to the macromolecular alterations induced by the radiation through mechanical (hardness, impact and flexure) and physicochemical (Ftir/Mir. DSC and TGA) testing. It was observed that irradiation induces changes in the UHMWPE, degrading the ballistic performance of the composite. These results are presented and discussed. (author)