Hard Clad Research Articles

Designing Cladded Components for High Temperature Nuclear Service: Part II—Design Rules

AbstractThe challenge of using existing ASME Section III, Division 5, class A metallic materials for the construction of structural components of advanced reactors with corrosive coolants could be mitigated by allowing designers to use cladding to protect the base material from corrosion. However, the existing Section III, Division 5 rules provide no guidance on the evaluation of strain accumulation and creep-fatigue damage in cladded components. The availability of design rules for cladded components that do not require long-term clad material testing could promote the application of the cladding approach to accelerate the deployment schedule of these advanced reactor systems. To avoid long-term properties for the clad materials Part I of this work proposes two approximate design analysis methods for two types of clad materials—soft clads that creep much faster and have lower yield stress than the class A base material, and hard clads that creep much slower and have higher yield stress than the class A base material. The proposed analysis methods approximate the response of a soft clad by treating it as perfectly compliant and of a hard clad by treating it as linear elastic. Based on these approximate design analysis strategies this Part II develops a complete set of design rules for class A components cladded with either soft or hard clad materials. Part II discusses the reasoning behind the proposed design rules and uses example finite element analyses of representative reactor components to illustrate the use of these design methods.

Designing Cladded Components for High Temperature Nuclear Service: Part I—Analysis Methods

AbstractUse of corrosion-resistant cladding can greatly extend the design life of structural components in many advanced reactor systems. However, there are currently no ASME design rules for cladded components to guard against creep-fatigue failure and ratcheting strain accumulation in elevated temperature nuclear service. This paper, presented in two parts, addresses this gap by proposing a design strategy for cladded components that do not require long-term testing of clad materials. The proposed approach relies on approximate design analysis methods for two types of clad materials—a soft clad that creeps much faster than and has lower yield stress than the class A base material and a hard clad that creeps much slower than and has higher yield stress than the class A base material. Part I discusses the approximate analysis strategies for the clad materials—treat a soft clad as perfectly compliant and a hard clad as linear elastic—and Part II develops a complete set of design rules for each of the two types of cladded components. Finite element analyses of representative high temperature reactor components show that the proposed design analysis methods can bound the design quantities in soft cladded components and approximate the design quantities in hard cladded components.

PENGGUNAAN KAOLIN SEBAGAI BAHAN PENGISI KOMPON LATEKS UNTUK PELAPIS KAIN INTERLINING

A study of the manufacture of natural latex liquid compound as a coating material on the manufacture of hard interlining fabric by varying the fineness of kaolin 100 mesh, 250 mesh and 400 mesh as a filler material plus other chemicals. The purpose of this research is to get the right natural liquid latex compound formula as a coating material in the manufacture of interlining fabrics that have specifications in accordance with the SNI 0894-2008 Standard of Hard Cloth (Interlining). Interlining fabrics are fabrics used to coat certain parts of clothing such as collars, waist, buttons, sleeves, shoulders and other parts that require high stiffness and a stable shape to enhance the appearance of clothing. The study was conducted by varying the fineness of the kaolin filler in 3 treatments each 100 mesh, 250 mesh and 400 mesh and varying the amount of kaolin filler in 4 treatments each 90 g, 180 g, 270 g and 360 g. The parameters tested were fabric rigidity, adhesive power, tensile strength, elongation and tear strength of fabric. Increased fineness of a kaolin filler from 100 mesh to 400 mesh in latex compound as a coating material, the fabric rigidity, adhesion, tensile strength, elongation and tear strength of the fabric tend to increase. Whereas the increasing amount of kaolin filler usage from 90 g to 270 g as a coating material can increase the fabric rag, but the subsequent addition decreases fabric rigidity. Conversely, the weight gain of fillers from 90 g to 360 g decreases the adhesiveness, tensile strength, elongation and tear strength of the fabric. The best results and fulfill the requirements of SNI 0894-2008 were obtained on formula IX using a 90 g kaolin filler and kaolin 400 mesh fineness with fabric stiffness value of 86.2 mg.cm, adhesion 1,8 kg / cm, tensile strength 40,59 kg for direction of warp and 31,43 kg for feed direction, 41.64% for luran direction and 36,63% for feed direction, tear strength 7,12 kg for warp and 6,53 kg for feed direction.

Study on alignment technique of ferroelectric liquid crystals for display application

ABSTRACTThe rubbing conditions are researched in terms of the rubbing cloth materials for ferroelectric liquid crystal (FLC) display application. Although cotton is generally used as the rubbing cloth, a good FLC molecular alignment can be obtained even in (semi) synthetic fiber clothes such as acetate, cellulose, and polyester. In order to obtain the good alignment without rubbing scratches, it is important to use a soft cloth. On the other hand, for a hard cloth, there is a possibility to obtain the good alignment by increasing the rubbing number and thus, polishing the alignment film surface.

Soft assurance: Coping with uncertainty through haptic sensations

Uncertainty is an inescapable element of human life. But how do people deal with it? To date, most research has focused on the cognitive strategies people adopt to do so. In four experiments we examine, whether people may also use an alternative experiential route to cope with uncertainty. We demonstrate that (1) when faced with uncertainty, people seek soft haptic sensations (Experiments 1 and 2) and (2) that doing so is functional (Experiments 3 and 4). More specifically, we show that people shift their preference to objects with soft (i.e., soft-grip pen, soft candy) rather than hard properties (i.e., hard-grip pen, hard candy) when feeling uncertain. Furthermore, we show that holding something soft (i.e., a soft-grip pen, a soft cloth) as compared to something hard (i.e., a hard-grip pen, a hard cloth) reduces uncertainty on a subsequent ambiguous task and helps to shield against uncertainty in daily life by increasing tolerance toward uncertainty. Overall, this research reveals that humans may use their oldest and most fundamental sense – touch – as a basic experiential device to cope with uncertainty.

Micro Fresnel Zone Plate Lens Inscribed on a Hard Polymer Clad Fiber Using Femtosecond Pulsed Laser

We report a novel process to directly inscribe a Fresnel zone plate (FZP) lens on the cleaved facet of a hard clad polymer fiber using a femtosecond pulsed laser. The FZPs are designed by adopting modal analysis and free-space diffraction, which are experimentally implemented by locally ablating silica glass using femtosecond laser pulses. A good agreement between the design and fabricated FZP lens is obtained with an exceptionally long focal length over 600 m, which can have a strong potential in all-fiber beam shaping technology and optical interconnections.

Development of Hard Plastic Clad Fiber (HPCF)-Compatible Devices and Demonstration of HPCF-PON

We report implementation and packaging of a whole line-up of hard plastic clad fiber (HPCF)-compatible devices: HPCF pigtailed 850-nm vertical-cavity surface-emitting lasers, HPCF pigtailed GaAs PIN photodiode, and 4times4 HPCF power splitter. Using these devices, an all-HPCF 4times4 passive optical network (PON) link suitable for short reach optical networks was successfully constructed. The PON link was operating well at a data rate of 1.25 Gb/s. The structures of the devices and their fabrication processes are discussed in detail along with characterizations of transmission performance by measuring the eye diagrams

Infection Control Risk Assessment Activities for Floods, Sewage Spills, and Malfunctions

ISSUE: During the 2004 hurricane season, our facility was undergoing major renovation. Infection Control Risk Assessments had been completed for all projects. However, through a malfunction of a contractor's sump pump, rain water and construction debris were pumped into radiology and central supply areas causing major flood damage. Prompt remediation of this crisis was impaired through stress on systems, poor communication and documentation of appropriate steps. PROJECT: A performance improvement team was formed to address communication and remediation steps which included infection control, facilities operation and development, environmental services, and safety. A checklist was developed to address all components of an infection control assessment. This checklist included a place to indicate which activity was appropriate for the situation and the responsible party to carry it out as well as a place for signoff when the task was completed. The form listed the key components identified from the Guideline for Environmental Infection Control, 2003 which are: patient and supply management, furniture removal, traffic control, access restriction, removal of sewage and other solid wastes, and removal of water. Elements listed in structure remediation included cleaning and disinfection of hard surfaces, management of carpeting, assessment and replacement of tiles and flooring, evaluation of wallboard and other porous structural material. Furniture assessment and recommendations for management of furniture and cubicle panels (i.e. hard surface, cloth and wood) as well as electrical equipment assessment were included. The checklist was posted on the infection control website making it available to all employees. All areas were inserviced on the tool to facilitate teamwork, communications, and quick and appropriate remediation of affected areas. RESULTS: The tool was developed and approved by the Infection Prevention and Control Committee. The tool provided an efficient and effective way to assess the impacted area after flooding, sewage spills or malfunctions. The team found that all parties understood their roles and responsibilities better and the process was documented. Improved communication facilitated by the tool streamlined the response effort and improved turn around time. LESSONS LEARNED: Infection control risk assessment for remediation after a flood, sewage spills or other malfunctions can be streamlined via the use of checklist form that includes key elements, assigns responsibility and documents when tasks are completed. This tool facilitates communications during a time of crisis and assures that all key factors are addressed. Placing the tool on a hospital website makes it available for use to all areas. Checklist was used as an example in the APIC/JCAHO workbook in 2005 but not discussed in depth that this presentation will cover.

Processing of Composite Rod with Embedded Optical Fiber

Polymer composite rods have promising uses in telecommunications as cable strength members, in maritime structures because of their resistance to various environmental in uences, and as railway insulating rods. The use of optical ®bers as sensors for this structure enables the chance of real-time damage and strain assessment in structural applications. The investigations performed by past researchers differ in the variety of the laminate composite structure, optical ®ber coating, and type of testing (three-point bending, fatigue and, impact). One of the ®rst applications of optical ®ber sensors was that of the impact damage detection via ®ber breakage sensors [1, 2]. Waite and Sage [3] described the failure of silane solution-treated and acrylate buffered optical ®bers, which were either embedded in polymer composites or loaded individually. In another study by the same author [4], conclusive results were obtained by using hard clad silica and strippable co-polymer coated optical ®bers for the detection of fatigue damage. To the authors' best knowledge, no results have thus far been presented for embedding an optical ®ber in composite rod structures. It is dif®cult to integrate optical ®bers precisely into composites that do not have a ply structure. In our previous study [5], we detailed the development of an experimental facility for manufacturing composite rods with embedded optical ®bers by vacuum molding. Vacuum in®ltration involves placing the reinforcing ®bers and the optical ®ber in a die, applying a vacuum at one end of the die and a source of epoxy matrix at the other, and then using the vacuum to draw the resin through the die to impregnate the ®bers. The ®berous reinforcement used in the composite was E-glass ®ber Etex R2105 roving. An acrylatecoated multimode optical ®ber (with core=cladding= coating equal to 62.5=125=250 im) was chosen due to its relatively easy handling, simplicity of mounting, low cost of fabrication, and simple electronic detection. The matrix material was based on a diglycidyl ether or bisphenol A, together with an aromatic amine hardener (Araldite CY 223=HT972, Ciba-Geigy). The epoxy-amine mixtures were prepared by heating the resin in an oil bath to 70 8C, and adding the curing agent with continuous stirring until a clear homogeneous solution was obtained. The exural, impact, and fatigue resistance of a composite rod structure is related to the strength of the material at the surface. The specimen initially has a tensile force acting on the top surface, while the bottom surface is compressed. The fatigueor impact-induced rod bending causes tension on the rear surface, inducing strain in the matrix and the optical ®ber embedded at that location. When the strain in the exed rod exceeds the ultimate strain of the optical ®ber, it will fracture. Therefore, embedding optical ®bers near the die=composite interface is considered to be essential from the standpoint of strain sensing. The degree of cure of a composite is important in many aspects because the amount of cure can in uence the mechanical properties of the product and probably melt the buffer on the optical ®ber. In order to achieve a uniform degree of cure in the cross-section of a composite rod, the die temperature is the most important processing variable. Control of the die temperature requires information about the curing reactions taking place inside the die. A mathematical model has been developed to simulate the vacuum molding process, namely, the pro®les of temperature and the degree of cure in the radial direction in a die of cylindrical shape. A similar approach was taken by several authors [6±8], who were interested in modeling the pultrusion process. The kinetic parameters of the epoxy resin were obtained from the differential scanning calorimeter (DSC) scans. From the data shown in Fig. 1 and the peak obtained by scanning a standard Indium sample (Perkin Elmer DSC-2), the calculated reaction heats (yAH) at 423.15 K and 443.15 K were 579.3 J=g resin and 535.7 J/g resin, respectively. Other kinetic parameters were calculated by a nonlinear curve®tting method. The reaction rate equation used in this study was:

Use of a fibre optic immunosensor for the detection of pesticides

The principle of a competitive immunoassay was employed for the development of an optical immunosensor for pesticide analysis. Triazines were assayed using fluorescence labelled antibodies. On one end of a hard clad silica fibre, which was stripped of cladding, a derivative of the s-triazines, aminohexylatrazine, was immobilized. The fibre was inserted in a flow through cuvette. Triazine antibodies conjugated with fluoresceine isothiocyanate (FITC) were detected after binding to the fibre surface by the fluorescence coupled into the fibre via the evanescent field. In the presence of triazines the fluorescence signal decreases due to the inhibition of antibody binding to the fibre. The detection limit of the sensor for terbutryn was 0.1 ng/ml (obtained using a monoclonal antibody). This is the maximum concentration of a single pesticide which may be present in drinking water, according to European Community regulations.

Slip-Line Solutions for Plain-Strain Indentation of Sandwich Metal Strips Between Flat Dies

The method of slip-lines has been used historically to solve two-dimensional problems of plane-strain plasticity in homogeneous metals. The application of the theory to obtain solutions for sandwich metals consisting of a hard core and softer clad is described here. The behavior of stress components, strain rate components, and velocity discontinuities at the interface between the two metals is examined. Some slip-line solutions for incipient plastic flow due to indentation of a sandwich strip with flat dies are presented. Three modes of deformation are considered: full penetration of the plastic zone with lateral motion of the rigid overhangs, bulging with clad flow only, and bulging with flow of clad and core. The numerical construction of the slip-line fields and hodagraphs is described and some results given. The differences between these results and the results of using homogeneous theory with an average yield strength are shown to be significant for strips of intermediate clad fraction. In addition, the results show that bulging, rather than full penetration of the plastic zone, is the expected mode of deformtion for a wide range of the strip parameters.

Medical Milestones

Journal Article Medical Milestones Get access Medical Milestones. By Henry J. L. Marriott, M.D. Foreword by Sir Alexander Fleming. Hard cloth; price $3.50; pp. 293. Published by the Williams and Wilkins Co., Baltimore, 1952. Physical Therapy, Volume 32, Issue 10, October 1952, Page 539, https://doi.org/10.1093/ptj/32.10.539 Published: 01 October 1952