Analysis on Development of Transverse - Sectioned Weld Zone using FEM Verified with Multipulsed Resistance Seam Welding

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N Muhammad

2013-12-01

Full Text Available This paper details an investigation, through an experimental study, of the development of weld nuggets and a heat-affected zone (HAZ in resistance seam welding(RSEW using a numerical simulation approach. SYSWELD software for the simulation of heat treatment, welding, and welding assembly was utilized for the simulation process. The integrated Spot Weld Advisor (SWA in SYSWELD was applied to simulate the RSEW model using a two-dimensional axis-symmetric FE model with customized electrode meshing. The thermal-mechanical-electrical characteristic and contact condition were taken into account throughout this study. The developed model comprised a transverse cross section for welding two layers of low carbon steel with a thickness of 1 mm. For the experimental verification, three-pulsed RSEW with two different current stages was carried out. It was discovered that this program code, Spotweld Advisor, when used with the meshing method, was capable of offering results that were in agreement with physical experiments.

Nuevas expresiones para el cálculo a torsión de costuras soldadas de filete de configuración compleja. // New expressions for torsion shear stress calculation in welding fillets.

Directory of Open Access Journals (Sweden)

H. Hernández Herrera

2004-09-01

Full Text Available En el presente trabajo se aplica la Teoría de la Torsión de Perfiles de Paredes Delgadas para el cálculo de las tensiones enlas uniones soldadas con costuras de filete en perfiles de configuración geométrica compleja sometidas a torsión. Seobtienen nuevas expresiones para el cálculo de las tensiones cuyos resultados se aproximan mejor que las expresionesclásicas con relación a los resultados obtenidos por el Método de los Elementos Finitos.Palabras claves: Torsión, uniones soldadas, soldadura de filete._______________________________________________________________________________Abstract.In this paper, the Thin Walled profiles Torsion Theory is applied to calculation of torsional shear stresses of complex geometryprofiles welded joints fillets. New calculation expressions are obtained that allowed to obtain a better aproach than the classicexpressions in relation to the values obtained by the Finite Elements Method.Key words: Torsion, welded joints, welding fillets.

Analysis and Prediction of the Billet Butt and Transverse Weld in the Continuous Extrusion Process of a Hollow Aluminum Profile

Science.gov (United States)

Lou, Shumei; Wang, Yongxiao; Liu, Chuanxi; Lu, Shuai; Liu, Sujun; Su, Chunjian

2017-08-01

In continuous extrusions of aluminum profiles, the thickness of the billet butt and the length of the discarded extrudate containing the transverse weld play key roles in reducing material loss and improving product quality. The formation and final distribution of the billet butt and transverse weld depend entirely on the flow behavior of the billet skin material. This study examined the flow behavior of the billet skin material as well as the formation and evolution of the billet butt and the transverse weld in detail through numerical simulation and a series of experiments. In practical extrusions, even if the billet skin is removed by lathe turning shortly before extrusion, billet skin impurities are still distributed around the transverse weld and in the billet butt. The thickness of the scrap billet butt and the length of the discarded extrudate containing the transverse weld can be exactly predicted via simulation.

Numerical simulation of the laser welding process for the prediction of temperature distribution on welded aluminium aircraft components

Science.gov (United States)

Tsirkas, S. A.

2018-03-01

The present investigation is focused to the modelling of the temperature field in aluminium aircraft components welded by a CO2 laser. A three-dimensional finite element model has been developed to simulate the laser welding process and predict the temperature distribution in T-joint laser welded plates with fillet material. The simulation of the laser beam welding process was performed using a nonlinear heat transfer analysis, based on a keyhole formation model analysis. The model employs the technique of element ;birth and death; in order to simulate the weld fillet. Various phenomena associated with welding like temperature dependent material properties and heat losses through convection and radiation were accounted for in the model. The materials considered were 6056-T78 and 6013-T4 aluminium alloys, commonly used for aircraft components. The temperature distribution during laser welding process has been calculated numerically and validated by experimental measurements on different locations of the welded structure. The numerical results are in good agreement with the experimental measurements.

Welding deformation analysis based on improved equivalent strain method to cover external constraint during cooling stage

Directory of Open Access Journals (Sweden)

Tae-Jun Kim

2015-09-01

Full Text Available In the present study, external restraints imposed normal to the plate during the cooling stage were determined to be effective for reduction of the angular distortion of butt-welded or fillet-welded plate. A welding analysis model under external force during the cooling stage was idealized as a prismatic member subjected to pure bending. The external restraint was represented by vertical force on both sides of the work piece and bending stress forms in the transverse direction. The additional bending stress distribution across the plate thickness was reflected in the improved inherent strain model, and a set of inherent strain charts with different levels of bending stress were newly calculated. From an elastic linear FE analysis using the inherent strain values taken from the chart and comparing them with those from a 3D thermal elasto-plastic FE analysis, welding deformation can be calculated.

Study on unified fatigue strength assessment method for welded structure. Hot spot stress evaluating method for various combinations of plate thickness and weld leg length; Yosetsu kozo no toitsutekina hiro kyodo hyokaho ni kansuru kenkyu. Itaatsu to yosetsu ashinaga no kumiawase ni taisuru hot spot oryoku sanshutsu ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Nihei, K.; Inamura, F.; Koe, S. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

1996-12-31

There has been tried to apply unified assessment method using hot spot stress, which is effective to evaluate fatigue strength of fillet welded structures for ships and marine structures. This method can be applied to complicated structures and is independent of welding processes. In this study, first, stress analysis has been conducted for two-dimensional fillet welded joint models with various combinations of plate thickness and weld leg length of general fillet structures by means of boundary element method. Then, critical position, which is not affected by local stress concentration due to bead, was determined from the detailed stress distribution in the vicinity of weld toe. As a result, a general equation has been proposed to estimate the hot spot stress by one-point representative method. Second, the fatigue tests of typical fillet welded joints have been conducted by applying this method. Consequently, it was demonstrated that the unified fatigue strength can be evaluated by the S-N data based on hot spot stress range determined from the proposed equation, independent of structural stress concentration. 22 refs., 14 figs.

Study on unified fatigue strength assessment method for welded structure. Hot spot stress evaluating method for various combinations of plate thickness and weld leg length; Yosetsu kozo no toitsutekina hiro kyodo hyokaho ni kansuru kenkyu. Itaatsu to yosetsu ashinaga no kumiawase ni taisuru hot spot oryoku sanshutsu ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Nihei, K; Inamura, F; Koe, S [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

1997-12-31

There has been tried to apply unified assessment method using hot spot stress, which is effective to evaluate fatigue strength of fillet welded structures for ships and marine structures. This method can be applied to complicated structures and is independent of welding processes. In this study, first, stress analysis has been conducted for two-dimensional fillet welded joint models with various combinations of plate thickness and weld leg length of general fillet structures by means of boundary element method. Then, critical position, which is not affected by local stress concentration due to bead, was determined from the detailed stress distribution in the vicinity of weld toe. As a result, a general equation has been proposed to estimate the hot spot stress by one-point representative method. Second, the fatigue tests of typical fillet welded joints have been conducted by applying this method. Consequently, it was demonstrated that the unified fatigue strength can be evaluated by the S-N data based on hot spot stress range determined from the proposed equation, independent of structural stress concentration. 22 refs., 14 figs.

Tubes of stainless steel - Welding of fuel elements for nuclear industry

International Nuclear Information System (INIS)

Bittencourt, M.S.Q.; Carvalho Perdigao, S. de

1984-01-01

Aiming at welding fuel elements of 316 AISI alloy steel by the TIG self generating process, the welding parameters which could provide. The major total penetration / width of welded fillet relation, were selected. Tensile tests at room temperature and at 650 0 C were done in the obtained welds. (M.C.K.) [pt

Reasonable designing method for fillet welding leg length

Energy Technology Data Exchange (ETDEWEB)

Kiso, T; Michiyuki, T; Nagao, S; Yoshikawa, M; Miyazaki, S

1976-12-01

In VLCC and ULCC vessels, the scantling of structural members, especially the thickness of web plate, increases naturally. The present rule of each classification society generally prescribes that welding leg length should be based on the thickness of the web plate. Welding leg length between this web plate and skin plate such as shell plate, deck plate, etc., or face plate, increases according to increase of the thickness of the web plate. We investigated the method to decide reasonable welding leg length and its programming by using the results of finite element method structural analysis, without adhering to the above rule about welding leg length. As a result of applying this method to actual ships under classification societies' approval, the amount of welding decreased by from about 10 percent to 15 percent compared with that required by the above rule. The rationality of the method has been already confirmed by successful results of the application to several vessels in service.

Effect of fin-endwall fillet on thermal hydraulic performance of airfoil printed circuit heat exchanger

International Nuclear Information System (INIS)

Ma, Ting; Xin, Fei; Li, Lei; Xu, Xiang-yang; Chen, Yi-tung; Wang, Qiu-wang

2015-01-01

Printed circuit heat exchanger (PCHE) is recommended to be used for intermediate heat exchanger in Very High Temperature Reactor (VHTR). One of the key features is that it is manufactured by the photochemical etching in order to maintain the internal structure and metal properties. In this paper, a photochemical etching experiment is conducted to manufacture the airfoil PCHE plate. The result indicates that the airfoil fin is not an ideal airfoil profile, but has a fin-endwall fillet. For the purpose of simplifying the numerical model and saving computational time, a validated model with a single fluid is used to further study the effect of fin-endwall fillet on the thermal hydraulic performance of airfoil PCHE. It is found that the fin-endwall fillet can increase the heat transfer and pressure drop in the cases with the non-dimensional longitudinal pitch being 1.63. The effect of fin-endwall fillet on thermal hydraulic performance decreases with the increase of transverse pitch, but the longitudinal pitch has little effect when the non-dimensional longitudinal pitch is greater than 1.88. In the studied cases, the maximum difference of Nusselt number and friction factor between the two models with and without fin-endwall fillet is up to 6.7% and 6.4%. - Highlights: • Fillets are formed in the endwall of airfoil fins during the photochemical etching. • Two-fluid model can be replaced by single-fluid model to perform simulation. • Fin-endwall fillet can increase heat transfer and pressure drop at ζ_l = 1.63. • Effect of fin-endwall fillet decreases as transverse pitch increases at ζ_l = 1.63. • Longitudinal pitch has little effect at ζ_l ≥ 1.88.

Stress indices for girth welded joints, including radial weld shrinkage, mismatch and tapered-wall transitions

International Nuclear Information System (INIS)

Rodabaugh, E.C.; Moore, S.E.

1978-09-01

A review is presented of B, C and K stress indices used in the ASME Nuclear Power Plant Code for girth butt welds and girth fillet welds. Theoretical stresses are presented to aid in evaluating C-indices. Fatigue test data are presented to aid in evaluating K-indices and CK-products. A limit load theory is presented to aid in evaluating B-indices. As a result of this review, recommendations are made for changes in the ASME Code. A major part of this consists of presenting definitions for girth welded joints and transitions and appropriate stress indices for those joints

Effects of residual stress on fatigue strength of small diameter welded pipe joint

International Nuclear Information System (INIS)

Yamashita, Tetsuo; Hattori, Takahiro; Nomoto, Toshiharu; Iida, Kunihiro; Sato, Masanobu

1996-01-01

A power plant consists of many welded components, therefore, it is essential in establishing the reliability of the power plant to maintain the reliability of all welded components. The fatigue failure caused by mechanical vibrations of small diameter welded joints, which is represented by socket welded joints, is one of the major causes of trouble for the welded parts of the power plant. Here, bending fatigue tests were conducted to investigate the fatigue strength of small diameter socket welded pipe joints. In the most cases of large diameter socket joints, a fatigue crack started from the root of the fillet weld though the stress amplitude at the root was smaller than that at the toe of fillet weld. Additionally, the fatigue strength was affected by the weld bead sequence. The residual stress was considered to be one of the important parameters governing fatigue strength, therefore, its effects were investigated. In several types of pipe joints, the local stress and residual stress distributions were calculated by finite element analysis. The residual stresses were compressive at the toe and tensile at the root of the socket welded joints. Based on these results, the effects of residual stresses on the fatigue strength are discussed for small diameter welded pipe joints in the present work

Ultrasonic inspection of austenitic welds

Energy Technology Data Exchange (ETDEWEB)

Tomlinson, J R; Wagg, A R; Whittle, M J [N.D.T. Applications Centre, CEGB, Manchester (United Kingdom)

1980-11-01

The metallurgical structure of austenitic welds is described and contrasted with that found in ferritic welds. It is shown that this structure imparts a marked elastic anisotropy in the ultrasonic propagation parameters. Measurements of variations in the apparent attenuation of sound and deviations in the beam direction are described. The measurements are interpreted in terms of the measured velocity anisotropy. Two applications of the fundamental work are described. In the first it is shown how, by using short pulse compression wave probes, and with major modification of the welding procedure, a stainless steel fillet weld in an AGR boiler can be inspected. In the second application, alternative designs of a transition butt weld have been compared for ease of ultrasonic inspection. The effects of two different welding processes on such an inspection are described. Finally, the paper examines the prospects for future development of inspection and defect-sizing techniques for austenitic welds. (author)

The mechanical properties of high speed GTAW weld and factors of nonlinear multiple regression model under external transverse magnetic field

Science.gov (United States)

Lu, Lin; Chang, Yunlong; Li, Yingmin; He, Youyou

2013-05-01

A transverse magnetic field was introduced to the arc plasma in the process of welding stainless steel tubes by high-speed Tungsten Inert Gas Arc Welding (TIG for short) without filler wire. The influence of external magnetic field on welding quality was investigated. 9 sets of parameters were designed by the means of orthogonal experiment. The welding joint tensile strength and form factor of weld were regarded as the main standards of welding quality. A binary quadratic nonlinear regression equation was established with the conditions of magnetic induction and flow rate of Ar gas. The residual standard deviation was calculated to adjust the accuracy of regression model. The results showed that, the regression model was correct and effective in calculating the tensile strength and aspect ratio of weld. Two 3D regression models were designed respectively, and then the impact law of magnetic induction on welding quality was researched.

Simulation of Welding Distortions in Theory and Practice

DEFF Research Database (Denmark)

Birk-Sørensen, Martin; Kierkegaard, Henning

1997-01-01

by an optimised welding order. Welding test samples prove that the constraint of the sample and the time between each pass in a multipass weld affect the magnitude of distortion. Experiments with welding specimens in the form of butt-and fillet welds have been carried out. They show angular deflections as well......In the last few years the use of robot welding processes has increased significatnly. The programming of the robots has until now mainly focused on high efficiency, i.e.high torch rate time, and hence, minimising the inefficient "travelling" time. Together with developing high-performance welding...... due to cutting and welding and parlty in the form of dimensional variation due to human factors. Measurements have been made of the production line for assemblies. The measurements show that distortions related to the multirobot welding are a factor which can rather easily be controlled...

Influence of Welding Strength Matching Coefficient and Cold Stretching on Welding Residual Stress in Austenitic Stainless Steel

Science.gov (United States)

Lu, Yaqing; Hui, Hu; Gong, Jianguo

2018-05-01

Austenitic stainless steel is widely used in pressure vessels for the storage and transportation of liquid gases such as liquid nitrogen, liquid oxygen, and liquid hydrogen. Cryogenic pressure vessel manufacturing uses cold stretching technology, which relies heavily on welding joint performance, to construct lightweight and thin-walled vessels. Residual stress from welding is a primary factor in cases of austenitic stainless steel pressure vessel failure. In this paper, on the basis of Visual Environment 10.0 finite element simulation technology, the residual stress resulting from different welding strength matching coefficients (0.8, 1, 1.2, 1.4) for two S30408 plates welded with three-pass butt welds is calculated according to thermal elastoplastic theory. In addition, the stress field was calculated under a loading as high as 410 MPa and after the load was released. Path 1 was set to analyze stress along the welding line, and path 2 was set to analyze stress normal to the welding line. The welding strength matching coefficient strongly affected both the longitudinal residual stress (center of path 1) and the transverse residual stress (both ends of path 1) after the welding was completed. However, the coefficient had little effect on the longitudinal and transverse residual stress of path 2. Under the loading of 410 MPa, the longitudinal and transverse stress decreased and the stress distribution, with different welding strength matching coefficients, was less diverse. After the load was released, longitudinal and transverse stress distribution for both path 1 and path 2 decreased to a low level. Cold stretching could reduce the effect of residual stress to various degrees. Transverse strain along the stretching direction was also taken into consideration. The experimental results validated the reliability of the partial simulation.

Methods for Solving a Stress Behaviour of Welded Joints under Repeated Loads

Directory of Open Access Journals (Sweden)

Semrád K.

2016-05-01

Full Text Available The article processes issue of strength of cyclically loaded welded joints with a focus on fillet welds. The data for used steels and basic information were obtained at U.S. Steel Research Laboratory and from articles by Lehigh University and the University of Illinois in USA. The practical application of the solution is presented for crane car body to crawler connection.

A study on the fatigue strength characteristics of ship structural steel with gusset welds

Directory of Open Access Journals (Sweden)

Sung-Jo Park

2012-06-01

Full Text Available This study aims to assess fatigue property by the static overload and average load in the fillet welded joints which is on the ship structural steel having gusset welds. To this end, a small specimen was made, to which the same welding condition for the actual ship structure was applied, to perform fatigue tests. In this study, a method to simply assess changes in welding residual stress according to different static overload was suggested. By measuring actual strain at the weld toe, the weld stress concentration factor and property which is determined by recrystallization in the process of welding were estimated to investigate the relation between overload and fatigue strength.

A Probabilistic Damage Tolerance Concept for Welded Joints

DEFF Research Database (Denmark)

Lassen, T.; Sørensen, John Dalsgaard

2002-01-01

The present paper presents the necessary crack growth statistics and suggests stochastic models for a reliability analysis of the fatigue fracture of welded steel plate joints. The reliability levels are derived from extensive testing with fillet-welded joints for which the entire crack growth...... history has been measured, not only the final fatigue life. The statistics for the time to reach given crack depths are determined. Fracture-mechanics-derived crack growth curves are fitted to the measured experimental curves and the best fit defines the growth parameters involved for each test specimen...

Real weld geometry determining mechanical properties of high power laser welded medium plates

Science.gov (United States)

Liu, Sang; Mi, Gaoyang; Yan, Fei; Wang, Chunming; Li, Peigen

2018-06-01

Weld width is commonly used as one of main factors to assess joint performances in laser welding. However, it changes significantly through the thickness direction in conditions of medium or thick plates. In this study, high-power autogenous laser welding was conducted on 7 mm thickness 201 stainless steel to elucidate the factor of whole weld transverse shape critically affecting the mechanical properties with the aim of predicting the performance visually through the weld appearance. The results show that single variation of welding parameters could result in great changes of weld pool figures and subsequently weld transverse shapes. All the obtained welds are composed of austenite containing small amount of cellular dendritic δ-Ferrite. The 0.2% proof stresses of Nail- and Peanut-shaped joint reach 458 MPa and 454 MPa, 88.2% and 87.5% of the base material respectively, while that of Wedge-shaped joint only comes to 371 MPa, 71.5% of the base material. The deterioration effect is believed to be caused by the axial grain zone in the weld center. The fatigue strength of joint P is a bit lower than N, but much better than W. Significant deformation incompatibility through the whole thickness and microstructure resistance to crack initiation should be responsible for the poor performance of W-shaped joints.

Metallurgical and fatigue assessments of welds in cast welded hydraulic turbine runners

International Nuclear Information System (INIS)

Trudel, A; Sabourin, M

2014-01-01

Decades of hydraulic turbine operation around the world have shown one undeniable fact; welded turbine runners can be prone to fatigue cracking, especially in the vicinity of welds. In this regard, three factors are essential to consider in runner fatigue assessments: (1) the runner's design, which can induce stress concentrations in the fillets, (2) the casting process, which inherently creates defects such as shrinkage cavities and (3) the welding process, which induces significant residual stresses as well as a heat affected zone in the cast pieces near the interface with the filler metal. This study focuses on the latter, the welding process, with emphasis on the influence of the heat affected zone on the runner's fatigue behavior. In a recently concluded study by a large research consortium in Montreal, the microstructure and fatigue crack propagation properties of a CA6NM runner weld heat affected zone were thoroughly investigated to find if this zone deteriorates the runner's resistance to fatigue cracking. The main results showed that this zone's intrinsic fatigue crack propagation resistance is only slightly lower than the unaffected base metal because of its somewhat finer martensitic microstructure leading to a less tortuous crack path. However, it was also confirmed that weld-induced residual stresses represent the dominant influencing factor regarding fatigue crack propagation, though post-weld heat treatments are usually very effective in reducing such residual stresses. This paper aims to further confirm, through a case study, that the weld-induced heat affected zone does not compromise the reliability of welded turbine runners when its fatigue crack propagation properties are considered in fatigue damage models

Probing heat transfer, fluid flow and microstructural evolution during fusion welding of alloys

Science.gov (United States)

Zhang, Wei

The composition, geometry, structure and properties of the welded joints are affected by the various physical processes that take place during fusion welding. Understanding these processes has been an important goal in the contemporary welding research to achieve structurally sound and reliable welds. In the present thesis research, several important physical processes including the heat transfer, fluid flow and microstructural evolution in fusion welding were modeled based on the fundamentals of transport phenomena and phase transformation theory. The heat transfer and fluid flow calculation is focused on the predictions of the liquid metal convection in the weld pool, the temperature distribution in the entire weldment, and the shape and size of the fusion zone (FZ) and heat affected zone (HAZ). The modeling of microstructural evolution is focused on the quantitative understanding of phase transformation kinetics during welding of several important alloys under both low and high heating and cooling conditions. Three numerical models were developed in the present thesis work: (1) a three-dimensional heat transfer and free surface flow model for the gas metal arc (GMA) fillet welding considering the complex weld joint geometry, (2) a phase transformation model based on the Johnson-Mehl-Avrami (JMA) theory, and (3) a one-dimensional numerical diffusion model considering multiple moving interfaces. To check the capabilities of the developed models, several cases were investigated, in which the predictions from the models were compared with the experimental results. The cases studied are the follows. For the modeling of heat transfer and fluid flow, the welding processes studied included gas tungsten arc (GTA) linear welding, GTA transient spot welding, and GMA fillet welding. The calculated weldment geometry and thermal cycles was validated against the experimental data under various welding conditions. For the modeling of microstructural evolution, the welded

Detection and measurement of fatigue cracks in welded joints

International Nuclear Information System (INIS)

Smith, F.C.

1985-01-01

A direct current potential drop system was developed for the detection and measurement of very small fatigue cracks that grow from the toes of welds. Measurement of crack growth less than 0.01 mm and of crack growth rates less than 10 -10 m/cycle, even for cracks less than 1.0 mm deep, is made possible by using a high stability measurement apparatus and an adjustment based on initial conditions. Thus far, the measurement system has successfully examined several aspects of fatigue in welded elements. Crack growth results justified the use of a linear elastic expression for the stress intensity factor and provided an evaluation of a growth law which includes the threshold stress intensity factor. Needle peening fillet welded joints did not change the small proportion of crack initiation life to total fatigue life observed for untreated (not improved) welded joints. However, the measurement system demonstrated that needle peening retarded crack growth rates up to 1 mm depth below the weld toe

Thermographic Analysis of Stress Distribution in Welded Joints

Directory of Open Access Journals (Sweden)

Domazet Ž.

2010-06-01

Full Text Available The fatigue life prediction of welded joints based on S-N curves in conjunction with nominal stresses generally is not reliable. Stress distribution in welded area affected by geometrical inhomogeneity, irregular welded surface and weld toe radius is quite complex, so the local (structural stress concept is accepted in recent papers. The aim of this paper is to determine the stress distribution in plate type aluminum welded joints, to analyze the reliability of TSA (Thermal Stress Analysis in this kind of investigations, and to obtain numerical values for stress concentration factors for practical use. Stress distribution in aluminum butt and fillet welded joints is determined by using the three different methods: strain gauges measurement, thermal stress analysis and FEM. Obtained results show good agreement - the TSA mutually confirmed the FEM model and stresses measured by strain gauges. According to obtained results, it may be stated that TSA, as a relatively new measurement technique may in the future become a standard tool for the experimental investigation of stress concentration and fatigue in welded joints that can help to develop more accurate numerical tools for fatigue life prediction.

Thermographic Analysis of Stress Distribution in Welded Joints

Science.gov (United States)

Piršić, T.; Krstulović Opara, L.; Domazet, Ž.

2010-06-01

The fatigue life prediction of welded joints based on S-N curves in conjunction with nominal stresses generally is not reliable. Stress distribution in welded area affected by geometrical inhomogeneity, irregular welded surface and weld toe radius is quite complex, so the local (structural) stress concept is accepted in recent papers. The aim of this paper is to determine the stress distribution in plate type aluminum welded joints, to analyze the reliability of TSA (Thermal Stress Analysis) in this kind of investigations, and to obtain numerical values for stress concentration factors for practical use. Stress distribution in aluminum butt and fillet welded joints is determined by using the three different methods: strain gauges measurement, thermal stress analysis and FEM. Obtained results show good agreement - the TSA mutually confirmed the FEM model and stresses measured by strain gauges. According to obtained results, it may be stated that TSA, as a relatively new measurement technique may in the future become a standard tool for the experimental investigation of stress concentration and fatigue in welded joints that can help to develop more accurate numerical tools for fatigue life prediction.

Fatigue evaluation of socket welded piping in nuclear power plant

International Nuclear Information System (INIS)

Vecchio, R.S.

1996-01-01

Fatigue failures in piping systems occur, almost without exception, at the welded connections. In nuclear power plant systems, such failures occur predominantly at the socket welds of small diameter piping ad fillet attachment welds under high-cycle vibratory conditions. Nearly all socket weld fatigue failures are identified by leaks which, though not high in volume, generally are costly due to attendant radiological contamination. Such fatigue cracking was recently identified in the 3/4 in. diameter recirculation and relief piping socket welds from the reactor coolant system (RCS) charging pumps at a nuclear power plant. Consequently, a fatigue evaluation was performed to determine the cause of cracking and provide an acceptable repair. Socket weld fatigue life was evaluated using S-N type fatigue life curves for welded structures developed by AASHTO and the assessment of an effective cyclic stress range adjacent to each socket weld. Based on the calculated effective tress ranges and assignment of the socket weld details to the appropriate AASHTO S-N curves, the socket weld fatigue lives were calculated and found to be in excellent agreement with the accumulated cyclic life to-date

Influence of weld structure on cross-weld creep behavior in P23 steel

Energy Technology Data Exchange (ETDEWEB)

Allen, D.J.; Degnan, C.C. [E.ON Engineering (United Kingdom); Brett, S.J. [RWE npower (United Kingdom); Buchanan, L.W. [Doosan Babcock (United Kingdom)

2010-07-01

A thick section pipe weld in low alloy steel P23 has been characterised by cross-weld creep rupture testing at a range of stresses, together with all-weld-metal and parent material testing, under the auspices of the UK High Temperature Power Plant Forum. The results generally show that the weld metal can be weak when tested in the transverse (cross-weld) orientation, and can fail with limited overall ductility by cracking in the zone of refined weld metal beneath the fusion boundary of the superposed weld bead. However, one specimen showed a much superior performance, which could be understood in terms of its locally more creep resistant weld macrostructure. The implications for P23 performance and weld manufacture are discussed. (orig.)

Thawed cod fillets spoil less rapidly than unfrozen fillets when stored under modified atmosphere at 2 C

DEFF Research Database (Denmark)

Guldager, H.S.; Bøknæs, Niels; Østerberg, Carsten

1998-01-01

The effect of two months of frozen storage at -20 degrees C on the spoilage characteristics and shelf life of thawed and modified atmosphere packed (MAP) cod fillets stored at 2 degrees C was studied. Thawed MAP cod fillets were compared with fresh cod fillets stored in CO2-containing modified at...

Closing the weld gap with laser/mig hybrid welding process

DEFF Research Database (Denmark)

Bagger, Claus; Olsen, Flemming Ove; Wiwe, Bjarne David

2003-01-01

In this article, laboratory tests are demonstrated that systematically accesses the critical gap distance when welding CMn 2.13 mm steel with a 2.6 kW CO2 laser, combined with a MIG energy source. In the work, the welding speed is varied at gap distances from 0 to 0.8 mm such that the limits...... for obtaining sound welds are identified. The welds are quality assessed according to ISO 13.919-1 and EN25817, transversal hardness measurements are made and the heat input to the workpiece is calculated. The results show that the critical gap is 0.1 mm for a laser weld alone. With hybrid welding, this can...... be increased to 0.6 mm, even at a welding speed of 3.5 m/min. The maximum welding speed with the hybrid process is comparable to laser welding alone, 4.5 m/min. The measured hardness is comparable to MIG welding, and this corresponds to a 33 percent reduction compared to laser welding alone. The heat input...

COMPETITIVEVENESS STRATEGIES OF INDONESIA PANGASIUS FILLET

Directory of Open Access Journals (Sweden)

Arfin Ramadhan

2016-05-01

Full Text Available Pangasius fillet industry in Indonesia that has grown in recent years will face the ASEAN regional competitiveness that began in late 2015. To face competitiveness from other countries, especially Vietnam as the largest Pangasius fillet producer, this study was carried out with regard to internal and external factors as a consideration in determining future strategies. This study aims to generate alternative competitiveness strategies of Pangasius fillet through descriptive analysis, SWOT, and AHP. The analysis result of internal forces obtains the total scores of 2.645 and external forces with the score of 2.505; this means that suggested strategy belongs to hold and maintain category. AHP analysis shows that alternative strategy with the highest score consecutively is the development of aquaculture technology for quality and efficient raw material, institutional strengthening of fish farmers and suppliers, diversification and product innovation, encouragement in investment on an integrated Pangasius fillet industry, branding of the Indonesian yellow fillet. The main objective of the strategy is focusing on the continuity of production and fulfillment of consumer preferences in order to create stability of supply and demand.Keywords: AHP, competitiveness, Pangasius fillet, SWOT

Thawed cod fillets spoil less rapidly than unfrozen fillets when stored under modified atmosphere at 2 degrees C.

Science.gov (United States)

Guldager, H S; Bøknaes, N; Osterberg, C; Nielsen, J; Dalgaard, P

1998-09-01

The effect of two months of frozen storage at -20 degrees C on the spoilage characteristics and shelf life of thawed and modified atmosphere packed (MAP) cod fillets stored at 2 degrees C was studied. Thawed MAP cod fillets were compared with fresh cod fillets stored in CO2-containing modified atmospheres with and without added oxygen. The shelf life of 11 to 12 days in the fresh MAP cod was extended to more than 20 days in the thawed MAP cod at 2 degrees C. This shelf life extension was most likely due to the inactivation of the spoilage bacterium Photobacterium phosphoreum during frozen storage as reflected both in chemical analyses and sensory evaluation. In contrast to fresh MAP cod fillets no significant production of trimethylamine occurred and almost no amine odor and taste were detected during 20 days of chill storage of thawed MAP cod fillets. The use of frozen fillets as raw material not only provides a more stable product in MAP but also allows much greater flexibility for production and distribution. However, a slightly increased concentration of dimethylamine, a larger drip loss, and detection of weak frozen storage flavor were observed in the thawed MAP cod fillets.

COMPETITIVEVENESS STRATEGIES OF INDONESIA PANGASIUS FILLET

OpenAIRE

Arfin Ramadhan; Ruddy Suwandi; Wini Trilaksani

2016-01-01

Pangasius fillet industry in Indonesia that has grown in recent years will face the ASEAN regional competitiveness that began in late 2015. To face competitiveness from other countries, especially Vietnam as the largest Pangasius fillet producer, this study was carried out with regard to internal and external factors as a consideration in determining future strategies. This study aims to generate alternative competitiveness strategies of Pangasius fillet through descriptive analysis, SWOT, an...

The influence of the weld toe grinding and wig remelting weld toe rehabilitation techniques, on variable stresses, in case of cross fillet welds, reinforced with additional welding rows

Directory of Open Access Journals (Sweden)

Babis Claudiu

2017-01-01

Full Text Available Variable stresses where the load value varies between a maximum and a minimum value, or varies the position in time, cause after accumulating a large number of load cycles in those structures, the emergence of drug fatigue. Fatigue is characterized by failure on values of the applied stress from the load cycles, below the material flow, values which in case of static stress would not have caused problems. Knowing that the variable stressed structures are sensitive to stress concentrators, the paper aims to highlight the influence of two techniques to reduce stress concentrator weld toe grinding and WIG remelting weld toe, on the behavior of variable tensile test of cross corner welded specimens, reinforced with additional welding rows.

Machine for welding solar cell connections

Energy Technology Data Exchange (ETDEWEB)

Lorans, D.Y.

1977-08-09

A machine for welding a connection wire over a solar cell electrode is described which comprises a base, a welding mount for the solar cell which is supported on the base, means for holding the solar cell on the welding mount, welding electrodes, means to lower the welding electrodes over the solar cell and the connection wire superimposed thereon, means for applying electric current pulses to said welding electrodes. It is characterized by the fact that it further comprises means for imparting to said mount an alternating transverse movement in relation to said base before and during the welding operation.

Mechanized and robotized welding in shipbuilding; Zosen ni okeru yosetsu no jidoka robot ka

Energy Technology Data Exchange (ETDEWEB)

Kanda, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

1997-12-01

Large-scale ships such as VLCC are built at the Kure No.1 Works of IHI (Ishikawajima-Harima Heavy Industry). This paper introduces current status of mechanized and robotized welding at the works. For the sub-assembly with short weld length and horizontal fillet, simplified automatic welders are used in which mag-welding method using CO2 is adopted. The frequent wound welding of member ends can be automatically conducted using welders developed by IHI. In the large-scale assembly processes, remarkable rationalization and highly accurate assembly of flat plate welding have been promoted. Tankers, container ships, and bulk carriers can be treated at the same time. Teaching times of welding robots can be greatly reduced by a technique called parametric treatment. In the future, it is essential to enhance the accuracy of members by introducing the laser cutting during machining processes. Completely self-type mechanization is required as well as large-output laser welding and sensor technology. 3 refs., 12 figs., 2 tabs.

Weld defect identification in friction stir welding using power spectral density

Science.gov (United States)

Das, Bipul; Pal, Sukhomay; Bag, Swarup

2018-04-01

Power spectral density estimates are powerful in extraction of useful information retained in signal. In the current research work classical periodogram and Welch periodogram algorithms are used for the estimation of power spectral density for vertical force signal and transverse force signal acquired during friction stir welding process. The estimated spectral densities reveal notable insight in identification of defects in friction stir welded samples. It was observed that higher spectral density against each process signals is a key indication in identifying the presence of possible internal defects in the welded samples. The developed methodology can offer preliminary information regarding presence of internal defects in friction stir welded samples can be best accepted as first level of safeguard in monitoring the friction stir welding process.

Soldagem de um aço inoxidável ferrítico com o processo A-TIG Ferritic stainless steel welding with the A-TIG process

Directory of Open Access Journals (Sweden)

Alessandra Gois Luciano de Azevedo

2009-03-01

Full Text Available O processo de soldagem TIG com fluxo (processo A-TIG apresenta como principal vantagem a possibilidade de se obter uma maior penetração do cordão de solda empregando os mesmos parâmetros de soldagem do processo TIG convencional. Diversos estudos mostram a influência dos fluxos ativos sobre as características geométricas das soldas em aços inoxidáveis austeníticos, porém pouco se sabe sobre a influência deste processo nas características geométricas e metalúrgicas de cordões de solda em aços inoxidáveis ferríticos. Neste trabalho são aplicados diferentes tipos de fluxo na soldagem de aço inoxidável ferrítico com o objetivo de verificar possíveis influências no perfil do cordão de solda, no seu aspecto visual, na microestrutura, na dureza da zona fundida e na resistência ao impacto (ensaio Charpy. As soldagens "bead-on-plate" foram realizadas sem metal de adição. Foram utilizados seis tipos de fluxo, sendo um óxido elaborado em laboratório (TiO2 e cinco fluxos comerciais. Os resultados mostraram que a utilização do fluxo permite um aumento na penetração com mudanças significativas no aspecto do cordão de solda. Verificou-se ainda que a microestrutura e a dureza do cordão de solda do aço estudado não foram afetadas pelo tipo de fluxo utilizado, com a microestrutura analisada em microscópio óptico. O aço em estudo mostrou um alto grau de fragilidade à temperatura ambiente.The A-TIG welding process presents as main advantage the possibility of increase in the penetration depth using the same parameters as conventional TIG welding. Many researchers show the influence of the active flux on the weld geometry in austenitic stainless steel, however little it is known of the influence of this process in the weld fillet shape and metallurgic characteristics of the weld fillet in ferritic stainless steel. In this work different types of flux are applied with the objective to verify possible influences on the weld

Stress Analysis of Non-Ferrous Metals Welds by Numerical Simulation

Directory of Open Access Journals (Sweden)

Kravarikova Helena

2017-01-01

Full Text Available Thermal energy welded material unevenly heated and thus supports the creation of tension. During the fusing process welding transient tensions generated in the welded material. Generation of the transient tensions depends on the thermal expansion and fixed permanently welded parts. Tensions are the result of the interaction of material particles. For welded parts and constructions it is necessary to know the size and direction of application of tensions. The emerging tensions can cause local change or a total deformation of welded materials. Deformations and residual stresses impair the performance of a welded construction, reduces the stability of the parts. To reduce or eliminate of action or a screening direction stresses and strains it is necessary to know the mechanism of their emergence. It is now possible to examine the emergence of tensions numerical experiments on any model using numerical simulation using FEM. Results of numerical experiment is the analysis of stress and deformation course. In the plane the tension it divided into normal σ and τ tangential folders. Decomposition stress on components simplifies the stress analysis. The results obtained from numerical analysis are correct to predict the stress distribution and size. The paper presents the results of numerical experiments stress analysis solutions fillet welds using FEM numerical simulation of welding of non-ferrous metals.

Local strain energy density for the fatigue assessment of hot dip galvanized welded joints: some recent outcomes

Directory of Open Access Journals (Sweden)

M. Peron

2017-10-01

Full Text Available Since in literature only data about the effect of the hot-dip galvanizing coating on fatigue behavior of unnotched specimens are available, whereas very few for notched components and none for welded joints, the aim of this paper is to partially fill this lack of knowledge comparing fatigue strength of uncoated and hot-dip galvanized fillet welded cruciform joints made of structural steel S355 welded joints, subjected to a load cycle R = 0. 34. The results are shown in terms of stress range ?s and of the averaged strain energy density range DW in a control volume of radius R0 = 0.28 mm

Effect of weld morphology on mechanical response and failure of friction stir welds in a naturally aged aluminium alloy

International Nuclear Information System (INIS)

Imam, Murshid; Biswas, Kajal; Racherla, Vikranth

2013-01-01

Highlights: ► Friction stir welds of AA 6063-T4 are obtained using three tool pin profiles. ► Signature of weld defects in mechanical response of welds is investigated. ► Correlation between peak temperatures in HAZs and their hardness is studied. ► Reasons for strengthening of WNZ and softening of HAZs are found using TEM and XRD. ► A FEM model for the weld zone is developed and validated. -- Abstract: Friction stir butt welds in 6063-T4 aluminium alloy were obtained using square and two tapered tool pin profiles. Tensile tests at 0°, 45°, and 90° to the weld line, hardness contours in the weld cross-section, temperatures in the heat affected zones, cross-sectional macrographs, transmission electron micrographs, and X-ray diffraction studies were used to characterize the welds. In transverse weld specimen, tunnel defects appearing at higher weld speeds for tapered pin profiles, were found to result in mechanical instabilities, i.e. sharp drops in load–displacement curves, much before macroscopic necking occured. Further, in comparison to the base metal, a marked reduction in ductility was observed even in transverse specimen with defect free welds. Hardness contours in the weld cross-section suggest that loss in ductility is due to significant softening in heat affected zone on the retreating side. Transmission electron microscopy images demonstrate that while recovery and overaging are responsible for softening in the heat affected zone, grain size refinement from dynamic recrystallization is responsible for strengthening of the weld nugget zone. X-ray diffraction studies in the three weld zones: weld nugget zone, heat affected zone, and the base metal corroborate these findings. A weld zone model, for use in forming simulations on friction stir welded plates of naturally aged aluminium alloys, was proposed based on mechanical characterization tests. The model was validated using finite element analysis.

3D finite element modeling of in-service sleeve repair welding of gas pipelines

International Nuclear Information System (INIS)

Alian, Ahmed R.; Shazly, Mostafa; Megahed, Mohammad M.

2016-01-01

The present work investigates the influence of welding sequence and scheme on residual stresses induced during in-service sleeve repair welding of gas pipelines. For this purpose, a 3D thermo-mechanical FE analysis is conducted on an 8″-Schedule-20, API 5L-X65 steel pipe. Two welding sequences for the sleeve-pipe circumferential fillet welds are compared in the present study: sequential welding in which one side of the sleeve is welded first and then the other side is welded by the same welder, and simultaneous welding in which both sides of the sleeve are welded concurrently by two welders. Within the simultaneous welding sequence, four different welding schemes, designed to investigate the influence of the number of welders and welding directions on residual stresses, are investigated. The results show that the sequential welding sequence induces less residual stresses and distortions. Within the simultaneous welding sequence, the back-step welding scheme is found to induce the least average residual stresses as compared to other welding schemes. - Highlights: • We model in-service sleeve repair welding using 3D FE. • Model was validated through comparison with existing experimental results. • The study presents results on the effect of both welding sequence and welding scheme on the resulting residual stresses. • Sequential welding sequence generates lower residual stresses than simultaneous welding sequence. • Back-step welding scheme generates the lowest average residual stresses along the pipe circumference.

Tensile properties of four types of austenitic stainless steel welded joints

International Nuclear Information System (INIS)

Balladon, P.

1990-01-01

In the field of an LMFBR research programme on austenitic stainless steel welds in a Shared Cost Action Safety, Research Area 8, coordinated by JRC-Ispra, four cooperating laboratories (ECN, IKE/MPA, the Welding Institute and UNIREC) have been involved in the fabrication and extensive characterization of welded joints made from one plate of ICL 167 stainless steel. The materials included parent metal, four vacuum electron beam welds, one non vacuum electron beam weld, one submerged arc weld, one gas metal arc weld and one manual metal arc weld. This report summarizes the 106 tensile tests performed at room temperature and 550 0 C, including the influence of strain rate, specimen orientation and welding procedure. Main results are that electron beam welds have tensile properties close to those of parent metal with higher values of yield strength in longitudinal orientation and lower values of total elongation in transverse orientation but with a similar reduction of area, that filler metal welds own the highest values of yield strength and lowest values of ductility. Most of the welds properties are higher than the minimum specified for parent metal, except for some values of total elongation, mainly in transverse orientation. In view of using electron beam welding for production of components used in LMFBR, results obtained show that tensile properties of electron beam welds compare well to those of classical welds. (author)

Welding Residual Stress Analysis and Fatigue Strength Assessment at Elevated Temperature for Multi-pass Dissimilar Material Weld Between Alloy 617 and P92 Steel

Science.gov (United States)

Lee, Juhwa; Hwang, Jeongho; Bae, Dongho

2018-03-01

In this paper, welding residual stress analysis and fatigue strength assessment were performed at elevated temperature for multi-pass dissimilar material weld between Alloy 617 and P92 steel, which are used in thermal power plant. Multi-pass welding between Alloy 617 and P92 steel was performed under optimized welding condition determined from repeated pre-test welding. In particular, for improving dissimilar material weld-ability, the buttering welding technique was applied on the P92 steel side before multi-pass welding. Welding residual stress distribution at the dissimilar material weld joint was numerically analyzed by using the finite element method, and compared with experimental results which were obtained by the hole-drilling method. Additionally, fatigue strength of dissimilar material weld joint was assessed at the room temperature (R.T), 300, 500, and 700 °C. In finite element analysis results, numerical peak values; longitudinal (410 MPa), transverse (345 MPa) were higher than those of experiments; longitudinal (298 MPa), transverse (245 MPa). There are quantitatively big differences between numerical and experimental results, due to some assumption about the thermal conductivity, specific heat, effects of enforced convection of the molten pool, dilution, and volume change during phase transformation caused by actual shield gas. The low fatigue limit at R.T, 300 °C, 500 °C and 700 °C was assessed to be 368, 276, 173 and 137 MPa respectively.

Welding Residual Stress Analysis and Fatigue Strength Assessment at Elevated Temperature for Multi-pass Dissimilar Material Weld Between Alloy 617 and P92 Steel

Science.gov (United States)

Lee, Juhwa; Hwang, Jeongho; Bae, Dongho

2018-07-01

In this paper, welding residual stress analysis and fatigue strength assessment were performed at elevated temperature for multi-pass dissimilar material weld between Alloy 617 and P92 steel, which are used in thermal power plant. Multi-pass welding between Alloy 617 and P92 steel was performed under optimized welding condition determined from repeated pre-test welding. In particular, for improving dissimilar material weld-ability, the buttering welding technique was applied on the P92 steel side before multi-pass welding. Welding residual stress distribution at the dissimilar material weld joint was numerically analyzed by using the finite element method, and compared with experimental results which were obtained by the hole-drilling method. Additionally, fatigue strength of dissimilar material weld joint was assessed at the room temperature (R.T), 300, 500, and 700 °C. In finite element analysis results, numerical peak values; longitudinal (410 MPa), transverse (345 MPa) were higher than those of experiments; longitudinal (298 MPa), transverse (245 MPa). There are quantitatively big differences between numerical and experimental results, due to some assumption about the thermal conductivity, specific heat, effects of enforced convection of the molten pool, dilution, and volume change during phase transformation caused by actual shield gas. The low fatigue limit at R.T, 300 °C, 500 °C and 700 °C was assessed to be 368, 276, 173 and 137 MPa respectively.

Optimization of bridge cables with concave fillets

DEFF Research Database (Denmark)

Burlina, Celeste; Georgakis, Christos T.; Larsen, Søren V.

In this paper the aerodynamic performance of new cable surfaces with concave fillet are examined and compared to plain, dimpled and helically filleted surfaces. To this end, an extensive wind-tunnel campaign was undertaken. Preliminary flow visualizations tests and static tests were performed to ...

Development of maintenance technology with underwater TIG welding for spent fuel storage pool

International Nuclear Information System (INIS)

Obana, Takeshi; Hamada, Yasumitsu; Ooeda, Kaoru; Katou, Masahide; Ootsuka, Toshihiro; Toyoda, Seiichi; Hosogane, Atsushi

2007-01-01

The core technology of underwater TIG welding process has been developed and welding equipment system has been manufactured, for application to the maintenance of the spent fuel storage pool of Rokkasho reprocessing plant. Basic experiments for understanding the conditions of dry area and the range of welding conditions was performed, and mock examination for simulation of real environment by using the developed welding equipment was also carried out to judge the applicability of the system. For the purpose that can be selected water removing method for different spatial conditions of the parts to be maintained in underwater, two kinds of welding equipment systems of Chamber type and Partition type were developed and manufactured. On the basis of fundamental experiments, the conditions of dry area formation and welding parameters range for high-reliability weld were discussed. Thus the proper condition in this process was able to be established. With the welding equipment systems of the Chamber type and Partition type, the practical use examination of underwater TIG welding process was executed by mock examination for simulating the real environment. As a result, it was confirmed that the underwater TIG welding could obtain the same reliability as a usual in-air TIG welding, and the operation and the control at remote distance were also possible. And the reliability of the patch-plate fillet weld could be evaluated by remote inspection with the expansion visual test. (author)

Influence of repair length on residual stress in the repair weld of a clad plate

International Nuclear Information System (INIS)

Jiang Wenchun; Xu, X.P.; Gong, J.M.; Tu, S.T.

2012-01-01

Highlights: ► Residual stress in the repair weld of a stainless steel clad plate is investigated. ► The effect of repair length on residual stress has been studied. ► Large tensile residual stress is generated in the repair weld and heat affected zone. ► With the increase of repair length, transverse stress is decreased. ► Repair length has little effect on longitudinal stress. - Abstract: A 3-D sequential coupling finite element simulation is performed to investigate the temperature field and residual stress in the repair weld of a stainless steel clad plate. The effect of repair length on residual stress has been studied, aiming to provide a reference for repairing the cracked clad plate. The results show that large tensile residual stresses are generated in the repair weld and heat affected zone (HAZ), and then decrease gradually away from the weld and HAZ. The residual stresses through thickness in the clad layer are relative uniform, while they are non-uniform in the base metal. A discontinuous stress distribution is generated across the interface between weld metal and base metal. The repair length has a great effect on transverse stress. With the increase of repair length, the transverse stress is decreased. When the repair length is increased to 14 cm, the peak of transverse stress has been decreased below yield strength, and the transverse stress in the weld and HAZ has also been greatly decreased. But the repair length has little effect on longitudinal stress.

Characterization and Strain-Hardening Behavior of Friction Stir-Welded Ferritic Stainless Steel

Science.gov (United States)

Sharma, Gaurav; Dwivedi, Dheerendra Kumar; Jain, Pramod Kumar

2017-12-01

In this study, friction stir-welded joint of 3-mm-thick plates of 409 ferritic stainless steel (FSS) was characterized in light of microstructure, x-ray diffraction analysis, hardness, tensile strength, ductility, corrosion and work hardening properties. The FSW joint made of ferritic stainless steel comprises of three distinct regions including the base metal. In stir zone highly refined ferrite grains with martensite and some carbide precipitates at the grain boundaries were observed. X-ray diffraction analysis also revealed precipitation of Cr23C6 and martensite formation in heat-affected zone and stir zone. In tensile testing of the transverse weld samples, the failure eventuated within the gauge length of the specimen from the base metal region having tensile properties overmatched to the as-received base metal. The tensile strength and elongation of the longitudinal (all weld) sample were found to be 1014 MPa and 9.47%, respectively. However, in potentiodynamic polarization test, the corrosion current density of the stir zone was highest among all the three zones. The strain-hardening exponent for base metal, transverse and longitudinal (all weld) weld samples was calculated using various equations. Both the transverse and longitudinal weld samples exhibited higher strain-hardening exponents as compared to the as-received base metal. In Kocks-Mecking plots for the base metal and weld samples at least two stages of strain hardening were observed.

Weakening Pin Bone Attachment in Fish Fillets Using High-Intensity Focused Ultrasound.

Science.gov (United States)

Skjelvareid, Martin H; Stormo, Svein Kristian; Þórarinsdóttir, Kristín Anna; Heia, Karsten

2017-09-18

High Intensity Focused Ultrasound (HIFU) can be used for the localized heating of biological tissue through the conversion of sound waves into heat. Although originally developed for human medicine, HIFU may also be used to weaken the attachment of pin bones in fish fillets to enable easier removal of such bones. This was shown in the present study, where a series of experiments were performed on HIFU phantoms and fillets of cod and salmon. In thin objects such as fish fillets, the heat is mainly dissipated at the surfaces. However, bones inside the fillet absorb ultrasound energy more efficiently than the surrounding tissue, resulting in a "self-focusing" heating of the bones. Salmon skin was found to effectively block the ultrasound, resulting in a significantly lower heating effect in fillets with skin. Cod skin partly blocked the ultrasound, but only to a small degree, enabling HIFU treatment through the skin. The treatment of fillets to reduce the pin bone attachment yielded an average reduction in the required pulling force by 50% in cod fillets with skin, with little muscle denaturation, and 72% in skinned fillets, with significant muscle denaturation. Salmon fillets were treated from the muscle side of the fillet to circumvent the need for penetration through skin. The treatment resulted in a 30% reduction in the peak pulling force and 10% reduction in the total pulling work, with a slight denaturation of the fillet surface.

Assuring reliability of unconventional weld joint configurations in austenitic stainless steel pressure vessels through non-destructive examination

International Nuclear Information System (INIS)

Jayakumar, I.; Manimohan, M.; Chandrasekaran, G.V.; Abdul Majeeth, S.; Subrahmanyam, P.S.

1996-01-01

Design of weld configurations in engineering structures is based on NDE inspectability apart from other considerations. They are mostly standardised. This paper deals with the development of an effective NDE methodology for an unconventional weld joint configuration occurring in a critical pressure vessel with edge preparation orientations different from that normally encountered in fabrication of such vessels. It is K-type butt joint between a heavy load bearing member and a curved vessel wall resulting in an oblique fillet weld. The heavy load bearing functional requirement needs a high integrity fail safe joint during its operating life and the stringent quality level specified by customer was ensured at every stage of its workmanship through effective NDE relying on conventional methods as explained. (author)

Advanced examination techniques applied to the qualification of critical welds for the ITER correction coils

CERN Document Server

Sgobba, Stefano; Libeyre, Paul; Marcinek, Dawid Jaroslaw; Piguiet, Aline; Cécillon, Alexandre

2015-01-01

The ITER correction coils (CCs) consist of three sets of six coils located in between the toroidal (TF) and poloidal field (PF) magnets. The CCs rely on a Cable-in-Conduit Conductor (CICC), whose supercritical cooling at 4.5 K is provided by helium inlets and outlets. The assembly of the nozzles to the stainless steel conductor conduit includes fillet welds requiring full penetration through the thickness of the nozzle. Static and cyclic stresses have to be sustained by the inlet welds during operation. The entire volume of helium inlet and outlet welds, that are submitted to the most stringent quality levels of imperfections according to standards in force, is virtually uninspectable with sufficient resolution by conventional or computed radiography or by Ultrasonic Testing. On the other hand, X-ray computed tomography (CT) was successfully applied to inspect the full weld volume of several dozens of helium inlet qualification samples. The extensive use of CT techniques allowed a significant progress in the ...

A Parametric Study on Welding Process Simulation for Multi-pass welds in a Plate

Energy Technology Data Exchange (ETDEWEB)

Park, Won Dong; Bahn, Chi Bum; Kim, Ji Hun [Pusan National University, Busan (Korea, Republic of)

2016-05-15

EPRI (MRP-316, 317) (1,2) and USNRC (NUREG-2162)(3) have performed related studies for FEA models to predict the weld residual stress distribution. In this work, a systematic parametric study was performed to find out how major assumptions and conditions used in the simulation could affect the weld residual stress distribution. 2- dimensional simulation was conducted by using commercial FEA software, ABAQUS(4) , for multi-pass Alloy 82 welds performed in a stainless steel plate (EPRI MRP-316, P-4, phase 1). From the previous results, we could make the following conclusions. 1. The method of applying power density is more realistic than predefined temperature. 2. It seems that annealing effect reduces the transverse direction weld residual stress (S33). However more detailed analyses for annealing effect are needed.

Plasma Arc Augmented CO2 laser welding

DEFF Research Database (Denmark)

Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels

2001-01-01

In order to reduce the hardness of laser beam welded 2.13 mm medium strength steel CMn 250, a plasma arc has been used simultaneously with a 2.6 kW CO2 laser source. In a number of systematic laboratory tests, the plasma arc current, plasma gas flow and distance to the laser source were varied...... with all laser parameters fixed. The welds were quality assessed and hardness measured transversely to the welding direction in the top, middle and root of the seam. In the seams welded by laser alone, hardness values between 275 and 304 HV1 were measured, about the double of the base material, 150 HV1...

Analysis of the production of salmon fillet - Prediction of production yield

DEFF Research Database (Denmark)

Johansson, Gine Ørnholt; Guðjónsdóttir, María; Nielsen, Michael Engelbrecht

2017-01-01

The aim was to investigate the influence of raw material variation in Atlantic salmon from aquaculture on filleting yield, and to develop a decision tool for choosing the appropriate raw material for optimized yield. This was achieved by tracking salmon on an individual level (n = 60) through...... a primary production site. The majority of the salmon exhibited a heavier right fillet compared to the left fillet after filleting. No explicit explanation was found for this observation although the heading procedure was shown to have a large impact. A Partial Least Square model was built to predict....... This may facilitate optimal planning of the production of salmon fillets by ordering and assigning the right batch to the right product category to obtain an optimal yield and quality....

Fatigue strength reduction factors for welds based on nondestructive examination

International Nuclear Information System (INIS)

Hechmer, J.L.; Kuhn, E.J. III

1999-01-01

Based on the author's hypothesis that nondestructive examination (NDE) has a major role in predicting the fatigue life of pressure vessels, a project was initiated to develop a defined relationship between NDE and fatigue strength reduction factors (FSRF). Even though a relationship should apply to both base metal and weld metal, the project was limited to weld metal because NDE for base metal is reasonably well established, whereas NDE for weld metal is more variable, depending on application. A matrix of FSRF was developed based on weld type (full penetration, partial penetration, and fillet weld) versus the NDE that is applied. The NDE methods that are included are radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), dye penetrant testing (PT), and visual testing (VT). The first two methods (RT and UT) are volumetric examinations, and the remaining three are surface examinations. Seven combinations of volumetric and surface examinations were defined; thus, seven levels of FSRF are defined. Following the initial development of the project, a PVRC (Pressure Vessel Research Council) grant was obtained for the purpose of having a broad review. The report (Hechmer, 1998) has been accepted by PVRC. This paper presents the final matrix, the basis for the FSRF, and key definitions for accurate application of the FSRF matrix. A substantial amount of additional information is presented in the PVRC report (Hechmer, 1998)

Radiopasteurization of Merluccius, merluccius hubbsi fillet. Pt. 3

International Nuclear Information System (INIS)

Kaupert, Norma.

1977-11-01

The actomyosin system of the ''Merluccius merluccius hubbsi'' fillet exposed to a dose of 0,50 Mrad gamma radiation was studied. The experiment was performed in order to evaluate the physical properties of these proteins from fillet that has been irradiated to extend its storage time at 4 deg C. The proteins extraction was made immediately after irradiation; at the same time, control samples were processed. A Spinco L2-65 Ultracentrifuge with a Schlieren Optics Accessory was used for velocity sedimentation measurements on the protein solutions. The results show that there are no changes in the sedimentation diagram of actomyosin system from irradiated fillet. (author) [es

Qualitative assessment of imported frozen fish fillets in Sulaimani markets

Directory of Open Access Journals (Sweden)

Z.K. Khidhir

2013-06-01

Full Text Available This study aims to determine the quality of frozen fish fillets sold in Sulaimani city markets a total number of (64 sample of frozen fish fillets belonged to 4 foreign trademarks were collected from different parts of Sulaimani markets. The samples were subjected to physical and chemical tests to determine their quality and suitability for human consumption. The proximate chemical analysis referred to presence of significant differences in moisture, fat and protein content among the four trademarks except for ash content. While the physical indices showed that White fish fillets recorded the lowest thawing and cooking loss which in return recorded the highest WHC. Chemical indices showed that the pH mean values of Myanmar and Flander mark were significantly differed (P<0.05 than Hasson and White fish fillet, Although, the results of FFA recorded no significant differences among the trademarks, and Flander mark recorded the highest PV and TBA among the other which made it significantly differed than them and White fish fillet recorded the lowest, still, they were within the international standard limits. Where, the results of TVN values recorded no significant differences ( among the inspected marks. All obtained results referred to the validity of these fish fillets for human consumption.

Non destructive evaluation of residual stresses in welding and hard-surfacing processes

International Nuclear Information System (INIS)

Suarez, J.C.; Fernandez, L.M.; Cruz, C.; Aragon, B.; Merino, F.

1995-01-01

In this paper transversal and longitudinal stress profiles in welding and hard-surfacing by welding processes are presented. The stresses were measured by RMS of Barkhausen signal. In this work it is shown that in each case the level of stresses is strongly dependent on the number of weld beads of surfacing layers deposited. The subsequent deposition of new weld beads or surfacing layers produces a stress-relieving effect

Numerical investigation on the variation of welding stresses after material removal from a thick titanium alloy plate joined by electron beam welding

International Nuclear Information System (INIS)

Liu, Chuan; Zhang, Jianxun; Wu, Bing; Gong, Shuili

2012-01-01

Highlights: → After less materials removal from the top, stresses on the bottom remain unchanged. → The transverse stress within the weld decreases significantly with material removal. → Local material removal does not influence the longitudinal stress significantly. -- Abstract: The stress modification after material removal from a 50 mm thick titanium alloy plate jointed by electron beam welding (EBW) was investigated through the finite element method (FEM). The welding experiment and milling process were carried out to experimentally determine the stresses induced by EBW and their modification after local material removal. The modification of as-welded stresses due to the local material removal method and the whole layer removal method was discussed with the finite element analysis. Investigated results showed that with less materials removal from the top, the stresses on the bottom surface remain almost unchanged; after material removal from the top and bottom part, the transverse stress on the newly-formed surface decreases significantly as compared to the as-welded stresses at the same locations; however, the stress modification only occurs at the material removal region in the case of local region removal method; the longitudinal stress decreases with the whole layer removal method while remains almost unchanged with the local region removal method.

Vibration stress relief treatment in welded samples of ST-3 steel

International Nuclear Information System (INIS)

Suarez, J.C.; Fernandez, L.M.; Echevarria, J.F.; Estevez, A.; Perez, A.; Aragon, B.

1996-01-01

The presented work is aimed to find the optimal vibration frequency and treatment duration for ST-3 steel welded test pieces. In the experiment transversal stresses were not virtually relieved by the application of vibrations at the three natural frecuencies. With regard to the optimal frequency for our system, the firths natural frequency appears to be most effective one, wherewith a maximum 35-70 % longitudinal stress relief was obtained. The influence of the propagation direction (transversal or longitudinal) of vibrations on stress relief in a welded joint was confirmed

PENGARUH PERBEDAAN POSISI PENGELASAN TERHADAP KEKUATAN SAMBUNGAN T-Joint PENGELASAN FILLET DENGAN LAS FCAW PADA PLAT MILD STEEL

Directory of Open Access Journals (Sweden)

Sarjito Jokosisworo

2012-07-01

Full Text Available To get quality of good weld joint that in scheme of construction welder of hull must be planned about way of welder, way of inspection, welding flux and weld type which would in utilizing. By karna to get quality of good weld of welder engineering at ship must be followed by will have an effect on to end result from welder process and mechanical properties yielded at construction welder process of ship steel which in the end will influence strength of construction weld joint of ship steel. How big the influence can be done with assaying of mechanical properties at steel plate weld joint. Data analysis result of the assaying can be taken a a real conclusion assists in increasing grade and security and safety of weld joint. This research aim to know strength of joint T-join at weld material to influence position of welder at buckling strength, and visually with EDSA. By using low alloy steel containing grade C=0,15%, Si=0,24%, Mn=0,88%, P=0,018%, S=0,034%. Material is given [by] treatment of welder with various position of welder Horizontal ( 2F , Vertical ( 3F , Overhead ( 4F by using weld FCAW ( Flux cord Arc Welding with electrode E71T-1, Ø cord 1,2 mm, applies gas CO2, Pada joint type Tjoin welder fillet. Method used in this research is experiment method, that is experimental method directly to object. In this case steel ST42 joint Tjoin with Thick plate 8 mm Marine Plate 18 piece weld by using gas CO2.To get research data is applied [by] observation method by using testing machine bending and test EDSA. Data which collected then is analysed difference of result from visual and mechanic assaying. Result of research shows existence of difference from strength of bending and its(the visulisation is especially to level of weave bead formed between differences of position of Horizontal ( 2F , Vertical ( 3F , Overhead ( 4F. And level of influence position of welder to strain bending 72,65 %.. At execution of workmanship of construction of welder

Microstructure and Mechanical Properties of an Ultrasonic Spot Welded Aluminum Alloy: The Effect of Welding Energy

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He Peng

2017-04-01

Full Text Available The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique–ultrasonic spot welding (USW–at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain sizes at lower levels of welding energy. The tensile lap shear strength, failure energy, and critical stress intensity of the welded joints first increase, reach their maximum values, and then decrease with increasing welding energy. The tensile lap shear failure mode changes from interfacial fracture at lower energy levels, to nugget pull-out at intermediate optimal energy levels, and to transverse through-thickness (TTT crack growth at higher energy levels. The fatigue life is longer for the joints welded at an energy of 1400 J than 2000 J at higher cyclic loading levels. The fatigue failure mode changes from nugget pull-out to TTT crack growth with decreasing cyclic loading for the joints welded at 1400 J, while TTT crack growth mode remains at all cyclic loading levels for the joints welded at 2000 J. Fatigue crack basically initiates from the nugget edge, and propagates with “river-flow” patterns and characteristic fatigue striations.

Radiopasteurization of Merlucius-merlucius hubsi fillet

International Nuclear Information System (INIS)

Kaupert, Norma; Ferreiro, Nora.

1974-11-01

The composition in amino acids of the ''Merlucius-merlucius hubsi'' fillet exposed to a dose of 0,50 Mrad gamma radiation was studied. The experiment was performed in order to evaluate the feeding value of protein component from fillet that has been irradiated to extend its storage time at 4 0 C. The extraction and subsequent hydrolysis of fish proteins, was made immediately after irradiation, at the same time control samples were processed. The results, obtained for each one of the analized amino acids, show that there are no important changes of values in their concentration due to irradiation effects. (author)

Extension of E7024 Electrode Applications in Shipbuilding

National Research Council Canada - National Science Library

1980-01-01

The primary objective of the project is to determine the extent to which use of AWS type E7O24 electrodes can be broadened in regard to fillet welding applications with particular emphasis on single pass fillet welding...

Mechanical Properties of Welded Deformed Reinforcing Steel Bars

Directory of Open Access Journals (Sweden)

Ghafur H. Ahmed

2015-05-01

Full Text Available Reinforcement strength, ductility and bendability properties are important components in design of reinforced concrete members, as the strength of any member comes mainly from reinforcement. Strain compatibility and plastic behaviors are mainly depending on reinforcement ductility. In construction practice, often welding of the bars is required. Welding of reinforcement is an instant solution in many cases, whereas welding is not a routine connection process. Welding will cause deficiencies in reinforcement bars, metallurgical changes and re-crystallization of microstructure of particles. Weld metal toughness is extremely sensitive to the welding heat input that decreases both of its strength and ductility. For determining the effects of welding in reinforcement properties, 48 specimens were tested with 5 different bar diameters, divided into six groups. Investigated parameters were: properties of un-welded bars; strength, ductility and density of weld metal; strength and ductility reduction due to heat input for bundled bars and transverse bars; welding effect on bars’ bending properties; behavior of different joint types; properties of three weld groove shapes also the locations and types of failures sections. Results show that, strength and elongation of the welded bars decreased by (10-40% and (30-60% respectively. Cold bending of welded bars and groove welds shall be prevented.

An Analysis of Laser-Welded Nicr-Ir and Nicr-Pt Micro Joints on Spark Plug Electrodes in Biogas-Fuelled Engines

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Grabas B.

2016-06-01

Full Text Available The paper deals with the laser beam welding of tips to central and side spark plug electrodes made of a nickel-chromium alloy. The tips attached to the central electrodes were made from a solid iridium wire 0.8 mm in diameter and 2 mm in length, while the tips connected to the side electrodes were made from a platinum wire 1.5 mm in diameter and 0.25 mm in thickness. In both cases, accurate positioning of the tips was required before they were resistance welded to the electrodes. Then, a fillet weld was produced with an Nd:YAG laser using single, partly overlapping conductive pulses. The laser welding was performed at different laser power levels and pulse durations. Metallographic sections of the joints were prepared to observe changes in the microstructure and determine their correlation with the changes in the process parameters. The results were used to select appropriate welding parameters for the materials joined. The microscopic analysis indicated welding imperfections such as micro cracks at the interface between the elements joined. The tips welded to the spark plug electrodes can help extend the service life of spark plugs in highly corrosive environments.

Numerical analysis of weld pool for galvanized steel with lap joint in GTAW

Energy Technology Data Exchange (ETDEWEB)

Jeong, Hunchul; Park, Kyungbae; Kim, Yougjun; Cho, Jungho [Chungbuk National University, Cheongju (Korea, Republic of); Kim, Dong-Yoon; Kang, Moon-Jin [Korea Institute of Industrial Technology, Incheon (Korea, Republic of)

2017-06-15

Galvanized steel is widely used and its demand is growing in automotive industry due to high quality requirement for corrosion resistance. Although there are a lot of demands on using galvanized steel as automotive parts especially for outer body, it has a grave flaw in its welding process. The difficulty is low weldability due to various defects such as porosities and blow holes in weldment, which occurred during welding. A solution to prevent these defects is using hybrid welding process, with two more welding processes. One of the hybrid solutions is using Gas tungsten arc welding (GTAW) as leading position in order to remove the zinc (Zn) coating on the surface before the followed practical fusion welding process. In this research, a numerical analysis model which can predict the eliminated Zn coated layers and the area of Fusion zone (FZ). Developed numerical analysis model was validated through comparing experiment to simulation. Basically, arc heat flux, arc pressure, electromagnetic force and Marangoni flow were employed as the boundary conditions and body force terms. Governing equations such as the continuity, momentum, Volume of fluid (VOF) and energy equations were adopted as usual. In addition to previous model, concentrated arc heat flux and contact thermal conductance models are newly suggested and showed successful result. They are adopted to realize edge concentrated arc and interfacial thermal conductance in lap joint fillet arc welding. Developed numerical analysis model successfully simulated the weld pool and temperature profile therefore the predicted Zn removed area considerably coincided with experimental result.

Numerical analysis of weld pool for galvanized steel with lap joint in GTAW

International Nuclear Information System (INIS)

Jeong, Hunchul; Park, Kyungbae; Kim, Yougjun; Cho, Jungho; Kim, Dong-Yoon; Kang, Moon-Jin

2017-01-01

Galvanized steel is widely used and its demand is growing in automotive industry due to high quality requirement for corrosion resistance. Although there are a lot of demands on using galvanized steel as automotive parts especially for outer body, it has a grave flaw in its welding process. The difficulty is low weldability due to various defects such as porosities and blow holes in weldment, which occurred during welding. A solution to prevent these defects is using hybrid welding process, with two more welding processes. One of the hybrid solutions is using Gas tungsten arc welding (GTAW) as leading position in order to remove the zinc (Zn) coating on the surface before the followed practical fusion welding process. In this research, a numerical analysis model which can predict the eliminated Zn coated layers and the area of Fusion zone (FZ). Developed numerical analysis model was validated through comparing experiment to simulation. Basically, arc heat flux, arc pressure, electromagnetic force and Marangoni flow were employed as the boundary conditions and body force terms. Governing equations such as the continuity, momentum, Volume of fluid (VOF) and energy equations were adopted as usual. In addition to previous model, concentrated arc heat flux and contact thermal conductance models are newly suggested and showed successful result. They are adopted to realize edge concentrated arc and interfacial thermal conductance in lap joint fillet arc welding. Developed numerical analysis model successfully simulated the weld pool and temperature profile therefore the predicted Zn removed area considerably coincided with experimental result.

Estimation of bacterial quality of cod fillets with the disc flotation method

International Nuclear Information System (INIS)

Boismenu, D.; Lepine, F.; Thibault, C.; Gagnon, M.; Charbonneau, R.; Dugas, H.

1991-01-01

Spoilage bacteria of cod fillets were desorbed off the fillet surface by ultrasonication. Catalase activity of these bacteria was determined using the disc flotation method after selective heat inactivation of the endogenous cod catalase and then correlated with the colony forming units. The method was applied to cod fillets from ten retail sources with satisfactory results

Apparatus for assembling and welding end plugs to nuclear fuel cladding tubes and inspecting the end plug welds on an automated basis

International Nuclear Information System (INIS)

Schoenig, F.C. Jr.; Walker, E.S.; Cueman, M.K.; Haughton, R.A.; Zuloaga, J.A. Jr.

1989-01-01

This patent describes an automated apparatus for welding a separate end plug to one open end of each of a succession of nuclear fuel cladding tubes and for inspecting each end plug weld. The apparatus comprising, in combination: a welding station; a cooldown station for cooling each end plug weld in an inert gas atmosphere; a serial number reader station for reading a serial number on each end plug; a first weld inspection station; a second weld inspection station for generating second weld inspection data; a computer system linked with the serial number reader and the first and second weld inspection stations; an input queue for holding a plurality of tubes; a tube transporter for periodically picking individual tubes from the input queque and conveying the tubes in a direction transverse to their tube axis in indexing steps to index positions respectively axially aligned with the welding, serial number reader, and first and second weld inspection stations; and a sorter positioned at an output end of the tube transporter

Nondestructive control of residual stresses during welding and recharge processes

International Nuclear Information System (INIS)

Suarez, J.C.; Fernandez, L.M.; Cruz, C.; Merino, F.; Aragon, B.

1993-01-01

In this work, the stress state of material during welding and recharge processes is controlled with the help of Barkhausen effect. The changes, occurred in the longitudinal and transversal stress profile are show during deposition of welding rings. It is proved that the stress state of the base-material depends on the amount of recharge layers, deposited on it

Metallurgical and mechanical characterization of a submerged arc welded joint in a 316 type stainless steel

International Nuclear Information System (INIS)

Piatti, G.; Vedani, M.

1990-01-01

The tensile (deformation and fracture) behaviour of a multipass submerged arc welded joint Type 316 stainless steel is investigated by tests at room temperature and at 400 0 C on all-weld metal and transverse to weld (composite) specimens as well as by microstructural and compositional analyses (optical, scanning electron and transmission electron microscopy). The as-deposited metal is characterised by a systematic variation in the tensile properties across the thickness with the higher strength and the lower ductility in the weld centre. These variations are related to material variability (mainly in dislocation density) because of local dissimilarities in thermal and mechanical histories occurring during the welding process. However, the material variability in the fusion zone, although important is not so large in the present weld and it does not influence the tensile properties of the weld as a whole. Moreover, the tensile behaviour concerning the transverse to weld specimens is characterized by a supporting effect from the higher yield strength material zone (fusion zone) to the lower yield strength material zone (parent metal) justified by the different contribution of the parent metal and of the weld-deposit metal to the integral plastic strain of the specimens. (author)

STUDI KELAYAKAN AGROINDUSTRI FILLET IKAN NILA (Oreochromis niloticus DI KABUPATEN MESUJI

Directory of Open Access Journals (Sweden)

Masithoh Priyantini

2014-07-01

Full Text Available This study was carried out to examine the feasibility of tilapia’s fillet agroindustry in Mesuji District. A series of analysis including the determination of agroindustry location, feasibility analysis in terms of market, technique and technology, management aspects, as well as the financial aspects, and added value analysis has been done. The results showed that this agroindustry was feasible to be developed in Mesuji District based on significant increasing demand for export every year and great potential of tilapia production as raw material of fillet in Mesuji District. Financially, This fillet industry met all the criteria of feasibility such as NPV value was Rp. 1.601.906.357, break even point was reached on the sale of 34.785 kg, with  2,68 year payback period, IRR was greater than the discount factor of 12.75%, that was 39,85%, and the B/C ratio was 1,12. Based on Hayami Methods, processing of tilapia into fillet gave Rp.10.264 of added value. Keywords : agroindustry, tilapia, fillet, feasibility.

78 FR 18957 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Initiation of Antidumping...

Science.gov (United States)

2013-03-28

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... frozen fish fillets (``fish fillets'') from the Socialist Republic of Vietnam (``Vietnam''). The..., DC 20230; telephone: 202-482-0238. SUPPLEMENTARY INFORMATION: Background The AD order on fish fillets...

Effect of A-TIG Welding Process on the Weld Attributes of Type 304LN and 316LN Stainless Steels

Science.gov (United States)

Vasudevan, M.

2017-03-01

The specific activated flux has been developed for enhancing the penetration performance of TIG welding process for autogenous welding of type 304LN and 316LN stainless steels through systematic study. Initially single-component fluxes were used to study their effect on depth of penetration and tensile properties. Then multi-component activated flux was developed which was found to produce a significant increase in penetration of 10-12 mm in single-pass TIG welding of type 304LN and 316LN stainless steels. The significant improvement in penetration achieved using the activated flux developed in the present work has been attributed to the constriction of the arc and as well as reversal of Marangoni flow in the molten weld pool. The use of activated flux has been found to overcome the variable weld penetration observed in 316LN stainless steel with TIG welds compared to that of the welds produced by conventional TIG welding on the contrary the transverse strength properties of the 304LN and 316LN stainless steel welds produced by A-TIG welding exceeded the minimum specified strength values of the base metals. Improvement in toughness values were observed in 316LN stainless steel produced by A-TIG welding due to refinement in the weld microstructure in the region close to the weld center. Thus, activated flux developed in the present work has greater potential for use during the TIG welding of structural components made of type 304LN and 316LN stainless steels.

77 FR 73424 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Partial Rescission of...

Science.gov (United States)

2012-12-10

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... order on certain frozen fish fillets (``fish fillets'') from the Socialist Republic of Vietnam..., 2011. \\1\\ See Notice of Antidumping Duty Order: Certain Frozen Fish Fillets from the Socialist Republic...

77 FR 20356 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Preliminary...

Science.gov (United States)

2012-04-04

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... frozen fish fillets (``fish fillets'') from the Socialist Republic of Vietnam (``Vietnam''). These... on fish fillets from Vietnam.\\1\\ On October 3, 2011 the Department published a notice of initiation...

78 FR 59915 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Initiation of Antidumping...

Science.gov (United States)

2013-09-30

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... fillets (``fish fillets'') from the Socialist Republic of Vietnam (``Vietnam'') that meets the statutory... INFORMATION: Background The AD order on fish fillets from Vietnam was published on August 12, 2003.\\1\\ On...

Chitosan extends the shelf-life of filleted tilapia ( Oreochromis niloticus) during refrigerated storage

Science.gov (United States)

Cao, Rong; Liu, Qi; Yin, Bangzhong; Wu, Biao

2012-09-01

Shelf-life extension of aquatic products is of significant economical importance. To determine the potential effect of chitosan on the shelf-life of filleted tilapia, this study analyzed the bacterial community diversity in fresh and spoiled tilapia fillets stored at (4 ± 1)°C and examined the antimicrobial activity of chitosan against relevant bacteria isolates. Results showed that Pseudomonas (20%) and Aeromonas (16%) were abundant in fresh tilapia fillets, whereas Pseudomonas (52%), Aeromonas (32%) and Staphylococcus (12%) were dominant in the spoiled samples. Chitosan showed wide-spectrum antibacterial activity against bacteria isolated from tilapia and 5.0 g L-1 chitosan was selected for application in preservation. We further determined the shelf-life of chitosan-treated, filleted tilapia stored at (4 ± 1)°C based on microbiological, biochemical and sensory analyses. Results showed that the shelf-life of chitosan-treated, filleted tilapia was extended to 12 d, whereas that of untreated, control samples was 6 d. These indicate that chitosan, as a natural preservative, has great application potential in the shelf-life extension of tilapia fillets.

Analysis of Residual Stress and Deformation of Rolling Strengthen Crankshaft Fillet

Directory of Open Access Journals (Sweden)

Han Shaojun

2016-01-01

Full Text Available Based on the analysis of crankshaft fillet rolling process, used ANSYS finite element analysis software to conduct the elastic-plastic mechanical simulation of crankshaft rolling process, and gained the variation law of the residual stress and plastic deformation in the radial path of the fillet under different rolling laps and rolling pressure. Established the relationship between the rolling pressure and the plastic deformation and residual stress of the fillet, and provided theoretical support for the evaluation and detection of the crankshaft rolling quality.

A thermal study of pipes with outer transverse fins

Directory of Open Access Journals (Sweden)

S. Gil

2016-10-01

Full Text Available This paper provides results of thermal investigations on pipes with outer transverse fins produced by placing a strip, being a form of helical spring which functions as a radiator, on the basis pipe. The investigations were carried out at the facility that enables measurements with respect to both natural and forced convection. Performance of the investigated pipes was assessed in relation to a non-finned pipe and a pipe welded with the use of Metal Active Gas (MAG technology. The experiments have shown that the finned pipe welding technology does not markedly affect their thermal efficiency, which has been confirmed by performed model calculations, while the welding technology has a crucial impact on their operating performance.

Microbial ecology of Vietnamese Tra fish (Pangasius hypophthalmus) fillets during processing.

Science.gov (United States)

Tong Thi, Anh Ngoc; Noseda, Bert; Samapundo, Simbarashe; Nguyen, Binh Ly; Broekaert, Katrien; Rasschaert, Geertrui; Heyndrickx, Marc; Devlieghere, Frank

2013-10-15

There are numerous factors that can have an impact on the microbial ecology and quality of frozen Pangasius hypophthalmus fillets during processing in Vietnam. The presence of spoilage bacteria along the processing line can shorten the shelf-life of thawed frozen fish products. Therefore, the spoilage microbiota throughout the processing chain of two companies (BC: large scale factory, chlorine-based process, BW: large scale factory, water-based process and SC: small scale factory, chlorine-based process) was identified by culture-dependent techniques and 16S rRNA gene sequencing. The microbiological counts were observed to be insignificantly different (p>0.05) between BC and BW. Surprisingly, chlorine treated fillets from the SC line were revealed to have significantly higher microbial counts than potable water treated fillets at BW line. This was determined to be a result of temperature abuse during processing at SC, with temperatures even greater than 10 °C being recorded from skinning onwards. On the contrary, the microbiota related to spoilage for BC and BW lines was determined by 16S rRNA gene sequencing to be more diverse than that on the SC line. A total of 174 isolates, 20 genera and 38 species were identified along the processing chains. The genera Aeromonas, Acinetobacter, Lactococcus and Enterococcus were prevalent at various processing steps on all the processing lines evaluated. A diverse range of isolates belonging to the Enterobacteriaceae such as Providencia, Shigella, Klebsiella, Enterobacter and Wautersiella were isolated from fillets sampled on the SC line whereas Serratia was only observed on fillets sampled on the BC and BW lines. The results can be used to improve Good Manufacturing Practices for processed Pangasius fillets and to select effective measures to prolong the shelf-life of thawed Vietnamese Pangasius fillets products. © 2013.

Evaluation of Distortion in Welding Unions of 304 Stainless Steel with Elliptic Trajectory Using a Welding Robot

Science.gov (United States)

Carrasco-González, L. A.; Hurtado-Delgado, E.; Reyes-Valdés, F. A.

The aim of this investigation is to evaluate the distortions generated in welding unions of stainless steel 304 by effect of the welding temperature and the microestructural changes. The joint design is a 100 × 100 mm steel plate of 3 mm thickness. The plate was joined to a tube of 50 mm diameter and 2 mm thickness, which has a defined angular cut; therefore, the trajectory followed by the seam has an elliptic form. Temperature data acquisition was developed by type K thermocouples, placed in pairs at 0°, 90°, 180° and 270° along the welding trajectory and connected to a data acquisition device yo obtain the measures to generate time-temperature plots. The welding process was executed by a KUKA ®; KR16 welding robot with an integrated GMAW (Gas metal arc welding) process where the input parameters of voltage, wire feed and travel speed are set to constant. The distortion of the work piece was measured using a laser scanning technique that generates a point cloud with the VXelements TM software for comparison between the pre and post-weld condition. Microstructural evaluation was performed on transversal sections of the seam, at the mentioned angles for correlation.

Determination of perfluorinated compounds in fish fillet homogenates: Method validation and application to fillet homogenates from the Mississippi River

International Nuclear Information System (INIS)

Malinsky, Michelle Duval; Jacoby, Cliffton B.; Reagen, William K.

2011-01-01

We report herein a simple protein precipitation extraction-liquid chromatography tandem mass spectrometry (LC/MS/MS) method, validation, and application for the analysis of perfluorinated carboxylic acids (C7-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA) in fish fillet tissue. The method combines a rapid homogenization and protein precipitation tissue extraction procedure using stable-isotope internal standard (IS) calibration. Method validation in bluegill (Lepomis macrochirus) fillet tissue evaluated the following: (1) method accuracy and precision in both extracted matrix-matched calibration and solvent (unextracted) calibration, (2) quantitation of mixed branched and linear isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) with linear isomer calibration, (3) quantitation of low level (ppb) perfluorinated compounds (PFCs) in the presence of high level (ppm) PFOS, and (4) specificity from matrix interferences. Both calibration techniques produced method accuracy of at least 100 ± 13% with a precision (%RSD) ≤18% for all target analytes. Method accuracy and precision results for fillet samples from nine different fish species taken from the Mississippi River in 2008 and 2009 are also presented.

Determination of perfluorinated compounds in fish fillet homogenates: Method validation and application to fillet homogenates from the Mississippi River

Energy Technology Data Exchange (ETDEWEB)

Malinsky, Michelle Duval, E-mail: mmalinsky@mmm.com [3M Environmental Laboratory, 3M Center, Building 0260-05-N-17, St. Paul, MN 55144-1000 (United States); Jacoby, Cliffton B.; Reagen, William K. [3M Environmental Laboratory, 3M Center, Building 0260-05-N-17, St. Paul, MN 55144-1000 (United States)

2011-01-10

We report herein a simple protein precipitation extraction-liquid chromatography tandem mass spectrometry (LC/MS/MS) method, validation, and application for the analysis of perfluorinated carboxylic acids (C7-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA) in fish fillet tissue. The method combines a rapid homogenization and protein precipitation tissue extraction procedure using stable-isotope internal standard (IS) calibration. Method validation in bluegill (Lepomis macrochirus) fillet tissue evaluated the following: (1) method accuracy and precision in both extracted matrix-matched calibration and solvent (unextracted) calibration, (2) quantitation of mixed branched and linear isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) with linear isomer calibration, (3) quantitation of low level (ppb) perfluorinated compounds (PFCs) in the presence of high level (ppm) PFOS, and (4) specificity from matrix interferences. Both calibration techniques produced method accuracy of at least 100 {+-} 13% with a precision (%RSD) {<=}18% for all target analytes. Method accuracy and precision results for fillet samples from nine different fish species taken from the Mississippi River in 2008 and 2009 are also presented.

Metallurgical and mechanical examinations of steel–copper joints arc welded using bronze and nickel-base superalloy filler materials

International Nuclear Information System (INIS)

Velu, M.; Bhat, Sunil

2013-01-01

Highlights: ► Optical and scanning electron microscopy show defect free weld interfaces. ► Energy dispersive spectroscopy shows low dilution level of the weld by Fe. ► XRD studies show no brittle intermetallic phases in the weld interfaces. ► Weld interfaces did not fail during tensile, transverse bending and impact tests. ► The joint exhibits superior strength properties than that of bronze filler. - Abstract: The paper presents metallurgical and mechanical examinations of joints between dissimilar metals viz. copper (UNSC11000) and alloy steel (En31) obtained by Shielded Metal Arc Welding (SMAW) using two different filler materials, bronze and nickel-base super alloy. The weld bead of the joint with bronze-filler displayed porosity, while that with nickel-filler did not. In tension tests, the weldments with bronze-filler fractured in the centre of the weld, while those with nickel-filler fractured in the heat affected zone (HAZ) of copper. Since the latter exhibited higher strength than the former, all the major tests were undertaken over the joints with nickel-filler alone. Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) indicated corrugated weld interfaces and favorable elemental diffusions across them. X-ray diffraction (XRD) studies around the weld interfaces did not reveal any detrimental intermetallic compounds. Transverse bending tests showed that flexural strengths of the weldments were higher than the tensile strengths. Transverse side bend tests confirmed good ductility of the joints. Shear strength of the weld-interface (Cu–Ni or Ni–steel) was higher than the yield strength of weaker metal. Microhardness and Charpy impact values were measured at all the important zones across the weldment

Vibration stress relief of DH 36 rectangle welded plates

Science.gov (United States)

Li, Shuqi; Fang, Hongyuan

2018-03-01

Vibration stress relief (VSR) is widely used in reducing residual stress in welded structures. However, the effectiveness of this method is still instable in some circumstance. In this study, a covert negative treatment phenomenon was investigated, i.e. natural frequency of welded structures decreased after VSR but residual stress in one direction increased. When the alteration of natural frequency after VSR is significant, the residual stresses in both the longitudinal and transversal directions shall decrease. Otherwise, residual stresses may increase on one direction. Thus, sufficient power shall be applied to the welded structures to avoid negative results.

Analysis of fatigue resistance of continuous and non-continuous welded rectangular frame intersections by finite element method

International Nuclear Information System (INIS)

McCoy, M. L.; Moradi, R.; Lankarani, H. M.

2011-01-01

Agricultural and construction equipment are commonly implemented with rectangular tubing in their structural frame designs. A typical joining method to fabricate these frames is by welding and the use of ancillary structural plating at the connections. This aids two continuous members to pass through an intersection point of the frame with some degree of connectivity, but the connections are highly unbalanced as the tubing centroids exhibit asymmetry. Due to the practice of welded continuous member frame intersections in current agricultural equipment designs, a conviction may exist that welded continuous member frames are superior in structural strength over that of structural frame intersections implementing welded non-continuous members where the tubing centroids lie within two planes of symmetry, a connection design that would likely fabricating a more fatigue resistant structural frame. Three types of welded continuous tubing frame intersections currently observed in the designs of agricultural equipment were compared to two non-continuous frame intersection designs. Each design was subjected to the same loading condition and then examined for stress levels using the Finite Element Method to predict fatigue life. Results demonstrated that a lighter weight, non-continuous member frame intersection design was two magnitudes superior in fatigue resistance than some current implemented frame designs when using Stress-Life fatigue prediction methods and empirical fatigue strengths for fillet welds. Stress-Life predictions were also made using theoretical fatigue strength calculations for the fatigue strength at the welds for comparison to the empirical derived weld fatigue strength

78 FR 55676 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Preliminary Results of the...

Science.gov (United States)

2013-09-11

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... order on certain frozen fish fillets (``fish fillets'') from the Socialist Republic of Vietnam... preliminary results. \\1\\ See Notice of Antidumping Duty Order: Certain Frozen Fish Fillets From the Socialist...

PREDICTION OF FATIGUE LIFE FOR A TRANSVERSE FILLET WELDED JOINT AND ANALYSIS OF THE INFLUENCE OF CRACK ECCENTRICITY ON THE FAILURE

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NELSON ARZOLA

2013-01-01

Full Text Available En este artículo se presenta un procedimiento basado en el Método de los Elementos Finitos y en la Mecánica de la Fractura Elástica Lineal para obtener un modelo matemático de propagación de grietas en uniones soldadas de filete transversal. Se empleó como material para las placas acero estructural ASTM-A36 y como material de aporte fueron utilizados electrodos E6013, usando un procedimiento de soldadura SMAW. Las grietas modeladas fueron de tipo superficial ubicadas en el pie de la soldadura. Se encontraron razones de propagación que difieren hasta en un 41% entre grietas centradas y con excentricidad de un 90%. Se emplearon cordones con perfil recto y convexo encontrándose una diferencia pequeña en la vida de fatiga entre ambos tipos. Los resultados de los modelos obtenidos fueron contrastados con el método convencional de cálculo y validados por medio de ensayos experimentales. Los valores de vida de fatiga se encontraron dentro del intervalo de confianza para p=95%.

Incorporation and profile of fatty acids in tilapia fillets (Oreochromis niloticus fed with tung oil

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Elton Guntendorfer Bonafé

2013-02-01

Full Text Available The acceptance of tung oil enriched diet and the incorporation of conjugated linolenic acid - CLnA into fillets of Genetically Improved Farmed Tilapia (GIFT were investigated. The diet was well accepted, and after 10 days CLnA was incorporated into the fillets with a 1.02% content of total fatty acids (FA. In addition, biosynthesis of the conjugated linoleic acid isomers - CLA (0.31% of fillet total FA content from CLnA, and the presence of alpha-linolenic acid - LNA (1.08% of fillet total FA content, eicosapentaenoic acid - EPA (2.85% of fillet total FA content and docosahexaenoic acid - DHA (3.08% of fillet total FA content were observed. Therefore, the consumption of this fish can increase the intake of different FA (CLnA, CLA, LNA, EPA and DHA, which play an important role in human metabolism.

78 FR 48415 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Amended Final Results of...

Science.gov (United States)

2013-08-08

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... review of the antidumping duty order on certain frozen fish fillets (``fish fillets'') from the Socialist... August 1, 2011, through January 31, 2012. \\1\\ See Certain Frozen Fish Fillets from the Socialist Republic...

78 FR 29323 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Amended Final Results of...

Science.gov (United States)

2013-05-20

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... administrative review and aligned new shipper reviews on certain frozen fish fillets (``fish fillets'') from the... (``POR'') is August 1, 2010, through July 31, 2011. \\1\\ See Certain Frozen Fish Fillets from the...

Modeling the pullout characteristics of welded wire mats embedded in silty sand

International Nuclear Information System (INIS)

Sampaco, C.L.; Anderson, L.R.; Nielson, M.R.

1994-01-01

This paper is an outgrowth of the on-going research on discrete finite element modeling of welded wire mesh reinforced soil structures such as the welded wire and RSE walls. The stiffness characteristics of the wire mesh-soil interfaces are modeled by a nonlinear hyperbolic relationship between the applied pullout stress and the associated mat placement. The relevant parameters are estimated from laboratory pullout tests that were conducted for welded wire mats embedded on silty sand. Since the bulk of the pullout resistance of welded wire mesh reinforcements is derived from the bearing resistance of the transverse wires that constitute the test mats. This feature permits proper evaluation of actual interface parameters for the actual reinforced soil structures in which the actual lengths of the mats are longer (i.e. more transverse members) than the specimen used in the laboratory pullout tests. The resulting pullout stress-displacement formulations are then verified by comparing the predicted pullout resistance to the existing specifications and design methods for estimated the pullout capacities of grid reinforcements. 22 refs., 13 figs

Residual stresses determination in an 8 mm Incoloy 800H weld via neutron diffraction

International Nuclear Information System (INIS)

Chen, Xizhang; Zhang, Shu Yan; Wang, Jingjun; Kelleher, Joe F.

2015-01-01

Highlights: • Stress through thickness at 5 mm from weld centerline indicates a “U” distribution. • Declining of tensile stress through thickness occurred at weld centerline. • Residual stress between layers is the lowest. - Abstract: To investigate the distribution of residual stresses, the 8 mm 800H alloy was joined by multi-layer butt TIG process. Residual stresses in the longitudinal, transverse and normal directions were measured via neutron diffraction. These residual stress measurements were taken at a series of points 2 mm below the top surface, covering the fusion zone, heat affected zone (HAZ) and base metal. In addition, two lines of longitudinal residual stress values at the weld centerline and 5 mm from weld centerline through thickness were measured. Results show that both the longitudinal and transverse stresses from the weld centerline to base metal are mainly tensile stresses. The longitudinal residual stress is the largest, with a maximum value of 330 MPa. As for the normal residual stress, the weld zone shows tensile stress, while the HAZ shows compressive stress. The middle of the thickness shows compressive residual stress along the thickness direction. The longitudinal stress at weld centerline through thickness reveals the interlayer heat treat effects leads to a declining of tensile stress. While the stress at 5 mm from weld centerline indicates a “U” distribution due to the mixed microstructure close to fusion line. With the increasing distance from weld seam, the residual stress decreases gradually

Experimental Study of Fillets to Reduce Corner Effects in an Oblique Shock-Wave/Boundary Layer Interaction

Science.gov (United States)

Hirt, Stefanie M.

2015-01-01

A test was conducted in the 15 cm x 15 cm supersonic wind tunnel at NASA Glenn Research Center that focused on corner effects of an oblique shock-wave/boundary-layer interaction. In an attempt to control the interaction in the corner region, eight corner fillet configurations were tested. Three parameters were considered for the fillet configurations: the radius, the fillet length, and the taper length from the square corner to the fillet radius. Fillets effectively reduced the boundary-layer thickness in the corner; however, there was an associated penalty in the form of increased boundary-layer thickness at the tunnel centerline. Larger fillet radii caused greater reductions in boundary-layer thickness along the corner bisector. To a lesser, but measureable, extent, shorter fillet lengths resulted in thinner corner boundary layers. Overall, of the configurations tested, the largest radius resulted in the best combination of control in the corner, evidenced by a reduction in boundary-layer thickness, coupled with minimal impacts at the tunnel centerline.

Static behavior of the weld in the joint of the steel support element using experiment and numerical modeling

Science.gov (United States)

Krejsa, M.; Brozovsky, J.; Mikolasek, D.; Parenica, P.; Koubova, L.

2018-04-01

The paper is focused on the numerical modeling of welded steel bearing elements using commercial software system ANSYS, which is based on the finite element method - FEM. It is important to check and compare the results of FEM analysis with the results of physical verification test, in which the real behavior of the bearing element can be observed. The results of the comparison can be used for calibration of the computational model. The article deals with the physical test of steel supporting elements, whose main purpose is obtaining of material, geometry and strength characteristics of the fillet and butt welds including heat affected zone in the basic material of welded steel bearing element. The pressure test was performed during the experiment, wherein the total load value and the corresponding deformation of the specimens under the load was monitored. Obtained data were used for the calibration of numerical models of test samples and they are necessary for further stress and strain analysis of steel supporting elements.

Effect of natural antioxidants on the quality of frozen sardine fillets (Sardina pilchardus

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Rui Manuel Maneta Ganhão

2014-06-01

Full Text Available The use of new technologies / processes provides different benefits on seafood sector, namely by enhanced the shelf-life of fish products with high polyunsaturated fatty acid composition. This is particularly critical during some months of the year when fish (e.g. sardines are larger supply than demand by consumers. The aim of this study was to performed the optimization process of adding natural antioxidants on frozen sardine fillets and evaluated the effect of addition of two natural antioxidants on the lipid oxidation process during storage at -200C. To evaluate the effect of the addition of antioxidants in sardine fillets, the product matrix was chemical characterized, including by the evaluation of the fatty acid profile. The lipid oxidation process was followed by the primary products (peroxide value and secondary products (TBARS quantification, and also by the analysis of the sensory changes (instrumental assessment of color. Finally, it was done a hedonic preference test to know the opinion of consumers about the frozen fillets with and without antioxidant. The natural antioxidants used, tocopherol (54 mg/fillet and tocopherols (15 mg/fillet with rosemary extract (6.5 mg/fillet inhibited or retarded the oxidation over time of storage when compared with the control samples, that had advanced oxidation process. There was not statistically differences among the fillets treated with tocopherol in the presence and absence of rosemary extract. However, our laboratorial results shown slight tendency for the view that the antioxidant tocopherols and rosemary extract had a greater effect on the oxidative stability of fillets. This observation is in line with results of the hedonic test consumer preference. The use of natural antioxidants is an inexpensive solution which allows the complete use of products with less waste of fish products and with a great need for disposal. At the same time meets the consumer´s requirements.

Finite element analysis for the initiation of lamellar tearing in welded joints

International Nuclear Information System (INIS)

Krieg, R.D.; Thomas, R.K.

1980-01-01

A numerical procedure using the finite element method is presented for predicting the initiation of lamellar tearing in fillet welded T-joints commonly employed in large structures. Starting with a prescribed geometry, the welding process is approximated by a known time-dependent volumetric heat source which simulates the arc heating and deposition of liquid metal. The transient nonlinear thermal and stress problems are then solved using finite element computer codes. Results of the elastic-plastic stress analysis are presented showing a predicted region of incipient lamellar tearing based on a ductile fracture theory which qualitatively agrees with the size and location of tears typically observed in photomicrographs. Additional insight into post failure crack length and stability is presented based on a simplified linear elastic fracture mechanics approach. Although the analysis procedure shows signs of promise, several weak points in the model are pointed out which must be improved before lamellar tearing can be quantified in an approach of this general type

Determination of perfluorinated compounds in fish fillet homogenates: method validation and application to fillet homogenates from the Mississippi River.

Science.gov (United States)

Malinsky, Michelle Duval; Jacoby, Cliffton B; Reagen, William K

2011-01-10

We report herein a simple protein precipitation extraction-liquid chromatography tandem mass spectrometry (LC/MS/MS) method, validation, and application for the analysis of perfluorinated carboxylic acids (C7-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA) in fish fillet tissue. The method combines a rapid homogenization and protein precipitation tissue extraction procedure using stable-isotope internal standard (IS) calibration. Method validation in bluegill (Lepomis macrochirus) fillet tissue evaluated the following: (1) method accuracy and precision in both extracted matrix-matched calibration and solvent (unextracted) calibration, (2) quantitation of mixed branched and linear isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) with linear isomer calibration, (3) quantitation of low level (ppb) perfluorinated compounds (PFCs) in the presence of high level (ppm) PFOS, and (4) specificity from matrix interferences. Both calibration techniques produced method accuracy of at least 100±13% with a precision (%RSD) ≤18% for all target analytes. Method accuracy and precision results for fillet samples from nine different fish species taken from the Mississippi River in 2008 and 2009 are also presented. Copyright © 2010 Elsevier B.V. All rights reserved.

Incorporation of conjugated linoleic acid (CLA and α-linolenic acid (LNA in pacu fillets

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Deoclécio José Barilli

2014-03-01

Full Text Available The objective of this study was to evaluate the incorporation of conjugated linoleic acid and α-linolenic acid in fillets of pacu fish raised in net cages and fed diets enriched with these acids. The fish were fed for 49 days, and at the end of this period the fatty acid content in the fillets was determined by gas chromatography. Concentrations of α-linolenic acid, eicosapentaenoic acid, and the total omega-3 (n-3 fatty acid in the fillets increased, improving the n-6/n-3 ratio. In addition, the incorporation of conjugated linoleic acid in the fish fillets proved well established. This study showed that the use of diets enriched with conjugated linoleic acid and α-linolenic acid results in the incorporation of these acids in the of pacu fish fillets, improving their nutritional quality.

Material Characterization of Dissimilar Friction Stir Spot Welded Aluminium and Copper Alloy

Science.gov (United States)

Sanusi, K. O.; Akinlabi, E. T.

2017-08-01

In this research study, material characterization of dissimilar friction stir spot welded Aluminium and Copper was evaluated. Rotational speeds of 800 rpm and transverse speeds of 50 mm/min, 150 mm/min and 250 mm/min were used. The total numbers of samples evaluated were nine altogether. The spot welds were characterised by microstructure characterization using optical microscope (OEM) and scanning electron microscopy technique (SEM) by observing the evolution of the microstructure across the weld’s cross-section. lap-shear test of the of the spot weld specimens were also done. From the results, it shows that welding of metals and alloys using Friction stir spot welding is appropriate and can be use in industrial applications.

A Simplified Model for the Effect of Weld-Induced Residual Stresses on the Axial Ultimate Strength of Stiffened Plates

Science.gov (United States)

Chen, Bai-Qiao; Guedes Soares, C.

2018-03-01

The present work investigates the compressive axial ultimate strength of fillet-welded steel-plated ship structures subjected to uniaxial compression, in which the residual stresses in the welded plates are calculated by a thermo-elasto-plastic finite element analysis that is used to fit an idealized model of residual stress distribution. The numerical results of ultimate strength based on the simplified model of residual stress show good agreement with those of various methods including the International Association of Classification Societies (IACS) Common Structural Rules (CSR), leading to the conclusion that the simplified model can be effectively used to represent the distribution of residual stresses in steel-plated structures in a wide range of engineering applications. It is concluded that the widths of the tension zones in the welded plates have a quasi-linear behavior with respect to the plate slenderness. The effect of residual stress on the axial strength of the stiffened plate is analyzed and discussed.

Development of Inspection Technique for Socket Weld of Small Bore Piping in Nuclear Power Plant

International Nuclear Information System (INIS)

Yoon, Byungsik; Kim, Yongsik; Lee, Jeongseok

2013-01-01

The losses incurred by unplanned shutdowns are significant; consequently, early crack initiation and crack detection, including the detection of fillet weld manufacturing defects, is of the utmost importance. Current inspection techniques are not capable of reliably inspecting socket welds; therefore, new approaches are needed. The new technique must be sensitive to socket weld cracking, which usually initiates from the root, in order to detect the cracking during the early failure phase. In 2008, Kori unit 3 experienced leakage from the drain line socket weld of a steam generator. From this experience, KHNP enforced a management program to focus on enhancing the reliability of small bore socket weld piping inspections. Currently, conventional manual ultrasonic inspection techniques are used to detect service induced fatigue cracks. But there was uncertainty on manual ultrasonic inspection because of limited access to the welds and difficulties with contact between the ultrasonic probe and the OD surface of small bore piping. In this study, phased array ultrasonic inspection techniques are applied to increase inspection speed and reliability. Additionally a manually encoded scanner has been developed to enhance contact conditions and maintain constant signal quality. A phased array UT technique and system was developed to inspect small bore socket welds. The experimental results show all artificial flaws in the specimen were detected and measured. These experimental results show, that the newly developed inspection system, has improved the reliability and speed of small bore socket weld inspection. Based on these results, future works shall focus on additional experiments, with more realistic flaw responses. By applying this technique to the field, we expect that it can improve the integrity of small bore piping in nuclear power plants

Tailored Welding Technique for High Strength Al-Cu Alloy for Higher Mechanical Properties

Science.gov (United States)

Biradar, N. S.; Raman, R.

AA2014 aluminum alloy, with 4.5% Cu as major alloying element, offers highest strength and hardness values in T6 temper and finds extensive use in aircraft primary structures. However, this alloy is difficult to weld by fusion welding because the dendritic structure formed can affect weld properties seriously. Among the welding processes, AC-TIG technique is largely used for welding. As welded yield strength was in the range of 190-195 MPa, using conventional TIG technique. Welding metallurgy of AA2014 was critically reviewed and factors responsible for lower properties were identified. Square-wave AC TIG with Transverse mechanical arc oscillation (TMAO) was postulated to improve the weld strength. A systematic experimentation using 4 mm thick plates produced YS in the range of 230-240 MPa, has been achieved. Through characterization including optical and SEM/EDX was conducted to validate the metallurgical phenomena attributable to improvement in weld properties.

77 FR 60675 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Initiation of Antidumping...

Science.gov (United States)

2012-10-04

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... fillets (``fish'') from the Socialist Republic of Vietnam (``Vietnam''). The Department has determined... Notice of Antidumping Duty Order: Certain Frozen Fish Fillets From the Socialist Republic of Vietnam, 68...

76 FR 17837 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Initiation of Antidumping...

Science.gov (United States)

2011-03-31

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... new shipper review (``NSR'') of the antidumping duty order on certain frozen fish fillets (``fish... INFORMATION: Background The notice announcing the antidumping duty order on fish fillets from Vietnam was...

78 FR 40100 - Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Rescission of Antidumping...

Science.gov (United States)

2013-07-03

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... frozen fish fillets from the Socialist Republic of Vietnam (``Vietnam'') covering the period August 1... Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Initiation of Antidumping Duty New...

PENGARUH MINYAK ATSIRI JAHE MERAH DAN LENGKUAS MERAH PADA EDIBLE COATING TERHADAP KUALITAS FILLET IKAN PATIN (Effect of Edible Coating Enriched with Red Ginger and Red Galangal Essential Oil on the Quality of Patin Fillet

Directory of Open Access Journals (Sweden)

Rohula Utami

2014-02-01

edible coating will retain the patin fillets quality. In terms of microbial quality and TVB value, 1% essential oil of red ginger and red galangal enrichment in edible coating could extend shelf life of patin fillets for 2-4 days. Keywords: Edible coating, essential oil, patin, red ginger, red galangal   ABSTRAK Penentuan pengaruh penambahan minyak atsiri jahe merah dan lengkuas merah dalam edible coating terhadap kualitas fillet ikan patin selama penyimpanan dingin dilakukan pada periode waktu 8 hari. Parameter kualitas ikan yang dianalisis adalah kualitas mikrobiologis (Total Plate Count/TPc, dan kualitas fisikokimia (Total Volatile Bases/TVB, Thiobarbituricacid/TBa, pH, dan warna. Variasi perlakuan fillet ikan patin yaitu konsentrasi minyak atsiri (0 %; 0,1%; 1% yang ditambahkan dalam edible coating. Hasil penelitian ini mengindikasikan bahwa penambahan minyak atsiri baik jahe merah maupun lengkuas merah berpengaruh terhadap kualitas fillet ikan patin selama penyimpanan dingin. Penambahan minyak atsiri dalam edible coating mampu mempertahankan kualitas fillet ikan patin lebih baik dibandingkan perlakuan edible coating tanpa minyak atsiri. Berdasarkan kualitas mikrobiologis dan nilai TVB, perlakuan minyak atsiri jahe merah 1% dan minyak atsiri lengkuas merah 1% mampu meningkatkan umur simpan fillet ikan patin selama 2-4 hari. Kata kunci: Edible coating, jahe merah, lengkuas merah, minyak atsiri, patin

Tensometry technique for X-ray diffraction in applied analysis of welding

International Nuclear Information System (INIS)

Turibus, S.N.; Caldas, F.C.M.; Miranda, D.M.; Monine, V.I.; Assis, J.T.

2010-01-01

This paper presents the analysis of residual stress introduced in welding process. As the stress in a material can induce damages, it is necessary to have a method to identify this residual stress state. For this it was used the non-destructive X-ray diffraction technique to analyze two plates from A36 steel jointed by metal inert gas (MIG) welding. The stress measurements were made by the sin 2 ψ method in weld region of steel plates including analysis of longitudinal and transverse residual stresses in fusion zone, heat affected zone (HAZ) and base metal. To determine the stress distribution along the depth of the welded material it was used removing of superficial layers made by electropolishing. (author)

Persistent Organohalogens in Paired Fish Fillet and Eggs: Implications for Fish Consumption Advisories.

Science.gov (United States)

Zhang, Xianming; Gandhi, Nilima; Bhavsar, Satyendra P

2016-04-13

Fish consumption is associated with both health benefits from high-quality proteins, minerals, vitamins, and fatty acids and risks from contaminants in fish. Fish consumption advisories are issued by many government agencies to keep exposure to contaminants at a safe level. Such advisories are typically based on fillets and neglect consumption of other fish parts such as eggs by certain subpopulations. To evaluate potential for dietary exposure to toxic organic chemicals via fish eggs, we analyzed polybrominated diphenyl ethers (PBDEs), polychlorinated naphthalenes (PCNs), dioxin-like polychlorinated biphenyls (dlPCBs), and polychlorinated dibenzodioxins/furans (PCDD/Fs) in paired fillet and eggs of fish from a tributary to Lake Ontario, one of the North American Great Lakes. All wet weight based concentrations in fish eggs were statistically higher than in the paired fillet samples. In fish eggs, concentrations of Σ14PBDEs, Σ14PCNs, and Σ12dlPCBs were 41-118, 0.3-1.7, and 30-128 ng/g wet weight (ww), respectively; Σ3PCDD/Fs and total (dlPCB+ PCDD/Fs) toxic equivalents (TEQs) were 4-22 and 9-54 pg/g ww, respectively. In fillet samples, Σ14PBDEs, Σ14PCNs, and Σ12dlPCBs were 4-116, 0.05-0.66, and 6-85 ng/g, respectively; Σ3PCDD/Fs and TEQs were 2-10 and 3.4-31 pg/g ww, respectively. In contrast, the fillets had higher lipid normalized concentrations than the paired egg samples, suggesting that these chemicals did not reach equilibrium between the fillets and eggs. Accordingly, measured concentrations in eggs or empirical relationship with fillet rather than prediction from equilibrium partitioning model should be used to evaluate contaminant exposure via consumption of fish eggs. For fatty fish from the lower Great Lakes area, we suggest one fillet meal be reduced from the advised fish consumption frequency for consumptions of 207 ± 37, 39 ± 2, 105 ± 51, and 119 ± 9 g fish eggs of brown trout, Chinook salmon, Coho salmon, and rainbow trout, respectively.

77 FR 20008 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Initiation of Antidumping...

Science.gov (United States)

2012-04-03

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... four new shipper reviews (``NSRs'') of the antidumping duty order on certain frozen fish fillets... Antidumping Duty Order: Certain Frozen Fish Fillets From the Socialist Republic of Vietnam, 68 FR 47909...

Dietary α-tocopheryl acetate on fillet quality of tilapia - DOI: 10.4025/actascianimsci.v31i4.6929

Directory of Open Access Journals (Sweden)

Léa Silvia Sant'Ana

2009-10-01

Full Text Available This work compared the effects of dietary α-tocopheryl acetate on storage life of tilapia fillets. Three experimental diets containing increasing α-tocopherol levels (zero, 100, and 200 mg kg-1 were used. The fish, with a mean initial weight of 184.23 ± 1.68 g, were fed diets for 63 days. After that period, they were slaughtered, filleted, and the fillets were grounded to accelerate lipid oxidation. Fish growth, survival, fillet yield, chemical composition and lipid oxidation of tilapia ground fillets were evaluated 0, 30 and 60 days after frozen storage. The results demonstrated that there was no significant difference between treatments for performance, and also, tocopherol did not influence the chemical composition values of fillets. Increased tocopherol levels in the feeds promoted a reduction in ground fillets lipid oxidation values.

Prevalence and contamination patterns of Listeria monocytogenes in catfish processing environment and fresh fillets.

Science.gov (United States)

Chen, Bang-Yuan; Pyla, Rajkumar; Kim, Tae-Jo; Silva, Juan L; Jung, Yean-Sung

2010-08-01

Catfish skins, intestines, fresh fillets, processing surfaces at different production stages, chiller water and non-food contact surfaces were sampled for Listeria monocytogenes and other Listeria species. Among 315 samples, prevalence of L. monocytogenes, Listeria innocua and a group of Listeria seeligeri-Listeria welshimeri-Listeria ivanovii was 21.6, 13.0 and 29.5%, respectively. No Listeria grayi was detected in this survey. While no L. monocytogenes strains were isolated from catfish skins and intestines, the strains were found with a frequency of 76.7% in chilled fresh catfish fillets and 43.3% in unchilled fillets. L. monocytogenes and Listeria spp. were also detected in fish contact surfaces such as deheading machine, trimming board, chiller water, conveyor belts at different stages, and fillet weighing table. Among L. monocytogenes, 1/2b (47.0%), 3b (16.0%) and 4c (14%) were the predominant serotypes isolated, whereas 4b, 4e, 1/2c and 1/2a were detected at much lower frequencies. Genotype analyses of L. monocytogenes isolates using serotyping, pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-PCR revealed that chiller water represented an important contamination source of L. monocytogenes in the chilled catfish fillets of two processing facilities, whereas fillet weighing table significantly contributed to the catfish fillet contamination of the third facility. This study suggests that L. monocytogenes contamination in the processed catfish fillets originates from the processing environment, rather than directly from catfish. Results from this study can aid the catfish industry to develop a plant-specific proper cleaning and sanitation procedure for equipment and the processing environment designed to specifically target L. monocytogenes contamination. Copyright 2010 Elsevier Ltd. All rights reserved.

Experimental study on variations in Charpy impact energies of low carbon steel, depending on welding and specimen cutting method

Energy Technology Data Exchange (ETDEWEB)

Yang, Zhaorui; Kang, Hansaem; Lee, Young Seog [Chung-Ang University, Seoul (Korea, Republic of)

2016-05-15

This paper presents an experimental study that examines variations of Charpy impact energy of a welded steel plate, depending upon the welding method and the method for obtaining the Charpy specimens. Flux cored arc welding (FCAW) and Gas tungsten arc welding (GTAW) were employed to weld an SA516 Gr. 70 steel plate. The methods of wire cutting and water-jet cutting were adopted to take samples from the welded plate. The samples were machined according to the recommendations of ASTM SEC. II SA370, in order to fit the specimen dimension that the Charpy impact test requires. An X-ray diffraction (XRD) method was used to measure the as-weld residual stress and its redistribution after the samples were cut. The Charpy impact energy of specimens was considerably dependent on the cutting methods and locations in the welded plate where the specimens were taken. The specimens that were cut by water jet followed by FCAW have the greatest resistance-to-fracture (Charpy impact energy). Regardless of which welding method was used, redistributed transverse residual stress becomes compressive when the specimens are prepared using water-jet cutting. Meanwhile, redistributed transverse residual stress becomes tensile when the specimens are prepared using wire cutting.

75 FR 15416 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Initiation of Antidumping...

Science.gov (United States)

2010-03-29

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... new shipper review (``NSR'') of the antidumping duty order on certain frozen fish fillets (``fish... order on fish fillets from Vietnam was published in the Federal Register on August 12, 2003. See Notice...

Modelling of fillet traits based on body measurements in three Nile tilapia strains (Oreochromis niloticus L.)

NARCIS (Netherlands)

Rutten, M.J.M.; Bovenhuis, H.; Komen, J.

2004-01-01

In Nile tilapia, breeding programs focus mainly on growth, and information on genetic improvement of fillet yield is scarce. In this study, slaughter data were collected on 1215 tilapia and used to analyze the relationship between body measurements and fillet weight and fillet yield. Fish were

MICROBIOLOGICAL QUALITY AND SHELF LIFE OF FRESH PACKAGED TILAPIA FILLETS STORED UNDER DIFFERENT CHILL TEMPERATURES

Directory of Open Access Journals (Sweden)

Odoli Cyprian

2013-02-01

Full Text Available Nile tilapia (Oreochromis niloticus farmed in recirculation aquaculture system (RAS was filleted and packaged in 100% air and 50% CO2: 50% N2 modified atmosphere (MA prior to storage at 1˚C and -1˚C for up to 27 days. Fillets were sampled regularly and analysed for headspace gas composition, sensory and microbial changes. Shelf life varied with apparent relation to storage temperature, package atmosphere and microflora. Pseudomonads were reported as the main spoilage organisms in tilapia fillets during chilled storage conditions. Sensory analysis of cooked samples as well as microbial growth indicated fillets packaged in 100% air had a shelf life of 13-15 days during storage at 1˚C and 20 days at -1˚C. At the end of shelf life in 100% air packaged groups, TVC and pseudomonads counts reached log 7 colony-forming units g-1 in flesh. Whereas in 50% CO2: 50% N2 packaged fillets, the lag phase and generation time of bacteria was extended and recorded counts of < log 4 colony-forming units g-1 up to 27 days of storage at both 1˚C and -1˚C. However, 50% CO2 : 50% N2 conditions restricted fillets shelf life to 23 days based on sensorial changes mainly fillets colour characteristics.

Grain refinement and hardness distribution in cryogenically cooled ferritic stainless steel welds

International Nuclear Information System (INIS)

Amuda, M.O.H.; Mridha, S.

2013-01-01

Highlights: ► Grain refinement was undertaken in AISI 430 FSS welds using cryogenic cooling. ► Flow rates of the cryogenic liquid influenced weld grain structure. ► Cryogenic cooling of welds generates about 45% grain refinement in welds. ► Phase structure of welds is not affected by flow rates of cryogenic liquid. ► Hardness profile in cryogenically cooled and conventional welds is similar. - Abstract: The energy input and heat dissipation dynamics during fusion welding generates coarse grain in the welds resulting in poor mechanical properties. While grain refinement in welds via the control of the energy input is quite common, the influence of heat dissipation on grain morphology and properties is not fully established. This paper characterized cryogenically cooled ferritic stainless steel (FSS) welds in terms of grain structure and hardness distribution along transverse and thickness directions. Cryogenic cooling reduces the weld dimension by more than 30% and provides grain refinement of almost 45% compared to conventional weld. The hardness distribution in the thickness direction gives slightly higher profile because of decreased grain growth caused by faster cooling effects of cryogenic liquid

Ultrasonic inspection for testing the PWR fuel rod endplug welds

International Nuclear Information System (INIS)

Pillet, C.; Destribats, M.T.; Papezyk, F.

1976-01-01

A method of ultrasonic testing with local immersion and transversal waves was developed. It is possible to detect defects as the lacks of fusion and penetration and porosity in the PWR fuel rod endplug welds [fr

Alternate design of ITER cryostat skirt support system

International Nuclear Information System (INIS)

Pandey, Manish Kumar; Gupta, Girish Kumar; Bhardwaj, Anil Kumar; Jha, Saroj Kumar

2015-01-01

The skirt support of ITER cryostat is a support system which takes all the load of cryostat cylinder and dome during normal and operational condition. The present design of skirt support has full penetration weld joints at the bottom (shell to horizontal plate joint). To fulfill the requirements of tolerances and control the welding distortions, we have proposed to change the full penetration weld into fillet weld. A detail calculation is done to check the feasibility and structural impact due to proposed design. The calculations provide the size requirements of fillet weld. To verify the structural integrity during most severe load case, finite element analysis (FEA) has been done in line with ASME section VIII division 2. By FEA 'Plastic Collapse' and 'Local Failure' modes has been assessed. 5° sector of skirt clamp has been modeled in CATIA V5 R21 and used in FEA. Fillet weld at shell to horizontal plate joint has been modeled and symmetry boundary condition at ± 2.5° applied. 'Elastic Plastic Analysis' has been performed for the most severe loading case i.e. Category IV loading. The alternate design of Cryostat Skirt support system has been found safe by analysis against Plastic collapse and Local Failure Modes with load proportionality factor 2.3. Alternate design of Cryostat skirt support system has been done and validated by FEA. As per alternate design, the proposal of fillet weld has been implemented in manufacturing. (author)

Fish quality – linking previous infections to the quality of consumers’ fillet

DEFF Research Database (Denmark)

The quality of the fish meat is dependent upon a wide range of biological and non-biological factors. In the present study it has been established that previous infections by Vibrio anguillarum in rainbow trout (Oncorhynchus mykiss) influence the quality of the fish meat (fillet) at slaughter more...... than after the fish have recovered from the infection. The texture of the fillet analysed by sensory analysis showed changes, which could be explained by previous tissue damage caused by the infection. These changes indicated formation of scars in affected tissue during the processes of tissue repair......, which gave rise to a more fibrous, tougher and flaky texture of the fillets....

Effect of Gamma Radiation and Microwave Cooking on Aeromonas Hydrophila in Bolti Fish Fillet

International Nuclear Information System (INIS)

Mohamad, W.S.; Megahed, A.A.; El-Ghaiaty, H.A.; Hafez, T.A.

2016-01-01

The objective of this study is to determine the bactericidal effect of gamma and microwave radiation on Aeromonas hydrophila inoculated in fish fillets. The study revealed that treatment of fish fillets with a dose of 1 kGy gamma radiation reduced the population of A.hydrophila by 104 cfu/g, while the dose of 2 and 3 kGy completely eliminated the microorganism. Treatment of fish fillets with microwave cooking for 1 and 2 minutes completely eliminated the microorganism. The physical examination of fish after gamma radiation treatment revealed that the used doses had no significant changes on fish fillets. The changes in protein profile (amino acids %) depended on radiation dose and period of cooking in microwave alongside controls while the total protein content was not affected.

75 FR 29726 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Notice of Partial Rescission...

Science.gov (United States)

2010-05-27

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... antidumping duty order on certain frozen fish fillets from the Socialist Republic of Vietnam (``Vietnam''). See Notice of Antidumping Duty Order: Certain Frozen Fish Fillets From the Socialist Republic of...

76 FR 47149 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Notice of Partial Rescission...

Science.gov (United States)

2011-08-04

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... antidumping duty order on certain frozen fish fillets from the Socialist Republic of Vietnam (``Vietnam''). See Notice of Antidumping Duty Order: Certain Frozen Fish Fillets From the Socialist Republic of...

High-energy-beam welding of type 316LN stainless steel for cryogenic applications

International Nuclear Information System (INIS)

Siewert, T.A.; Gorni, D.; Kohn, G.

1988-01-01

Laser and electron beam welds in 25-mm-thick AISI 316LN specimens containing 0.16 wt.$% N were evaluated for fusion reactor applications and their mechanical properties were compared with those of welds generated by lower productivity processes such as shielded-metal-arc and gas-metal-arc welding. Tensile tests were performed on transverse tensile specimens at 4 K. For both welding processes the fractures occurred in the base metal at a strength level near 950 MPa. This indicated that the weld and heat affected zone had a strength similar to that of the base metal. The 4 K weld fracture toughness was only slightly less than that for the base metal and comparable to the best values achieved with conventional welding processes in 316Ln weld metal. The Charpy V-notch absorbed energies averaged near 70 J at 76 K. Metallographic analysis revealed cellular and fully austenitic solidification with little porosity and no evidence of hot cracking

Research of Technological Properties of Steel X6CRNITI18-10 Welded Joints Exploited in Nitric Acid Medium

Directory of Open Access Journals (Sweden)

Gediminas Mikalauskas

2016-04-01

Full Text Available The repair of chemical industry equipments often requires to replace long time operated pipes or welded inserts with the simi-lar chemical composition. During the study the joints from corro-sion resistant steel X6CrNiTi18-10 were welded by manual metal arc welding with covered electrodes (MMA process 111 and tungsten inert gas welding (TIG process 141 at different welding parameters. The visual, radiographic, penetrant control and ferrite content analysis were carried out. The transverse tensile and bending samples were produced from welded samples; also the macroscopic and microscopic analyse were carried out.

75 FR 12726 - Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Final Results of the...

Science.gov (United States)

2010-03-17

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... two new shipper reviews of the antidumping duty order on certain frozen fish fillets from the... of price or production. See Certain Frozen Fish Fillets From the Socialist Republic of Vietnam...

76 FR 61088 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Initiation of New Shipper...

Science.gov (United States)

2011-10-03

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... antidumping duty order on certain frozen fish fillets from the Socialist Republic of Vietnam, received between... on certain frozen fish fillets from the Socialist Republic of Vietnam was published in the Federal...

Improvement of the quality of nile bolti fish fillets by combination treatments with gamma irradiation

International Nuclear Information System (INIS)

El-Fouly, M.Z.; Hammad, A.A.I.; Yousef, B.M.

1986-01-01

Immersing bolti fish fillets in saturated solution of sodium chloride alone or plus 10 ppm of chlorotetracycline (CTC) resulted in remarkable reduction of total bacterial counts, psychrophilic, proteolytic and H 2 S producing bacteria. The treatments also decreased the growth rate of these groups of microorganisms during storage at 5 0 C and hence increased the shelf-life of fillets to 24 days storage. Treating the bolti fillets by 3 KGy gamma rays combined with salt and CTC caused highly depression in the mentioned groups but spots of fungi started to appear at the twenty first day of storage on the surface of irradiated fillets. Application of potassium sorbate as anti fungus instead of sodium chloride and CTC kept the bolti fillet in good quality as indicated by microbial, chemical and sensory determinations for more than four weeks at 5 0 C with decreasing the irradiation dose to only 1.5 kGy

Electron beam welding of dissimilar metals

International Nuclear Information System (INIS)

Metzger, G.; Lison, R.

1976-01-01

Thirty-three two-memeber combinations of dissimilar metals were electron beam welded as square-groove butt joints in 0.08 and 0.12 in. sheet material. Many joints were ''braze welded'' by offsetting the electron beam about 0.02 in. from the butt joint to achieve fusion of the lower melting point metal, but no significant fusion of the other member of the pair. The welds were evaluated by visual and metallographic examination, transverse tensile tests, and bend tests. The welds Ag/Al, Ag/Ni15Cr7Fe, Cu/Ni15Cr7Fe, Cu/V, Cu20Ni/Ni15Cr7Fe, Fe18Cr8Ni/Ni, Fe18Cr8Ni/Ni15Cr7Fe, Nb/Ti, Nb/V, Ni/Ni15Cr7Fe, and Cb/V10Ti were readily welded and weld properties were excellent. Others which had only minor defects included the Ag/Cu20Ni, Ag/Ti, Ag/V, Cu/Fe18Cr8Ni, Cu/V10Ti, Cu20Ni/Fe18Cr8Ni, and Ti/Zr2Sn welds. The Cu/Ni weld had deep undercut, but was in other respects excellent. The mechanical properties of the Ag/Fe18Cr8Ni weld were poor, but the defect could probably be corrected. Difficulty with cracking was experienced with the Al/Ni and Fe18Cr8Ni/V welds, but sound welds had excellent mechanical properties. The remaining welds Al-Cu, Al/Cu20Ni, Al/Fe18Cr8Ni, Al/Ni15Cr7Fe, Cu20Ni/V, Cu20Ni/V10Ti, Cb/Zr2Sn, Ni/Ti, Ni15Cr7Fe/V, Ni15Cr7Fe/V10Ti, and Ti/V were unsuccessful, due to brittle phases, primarily at the weld metal-base metal interface. In addition to the two-member specimens, several joints were made by buttering. Longitudinal weld specimens of the three-member combination Al/Ni/Fe18Cr8Ni and the five member combination Fe18Cr8Ni/V/Cb/Ti/Zr2Sn showed good tensile strength and satisfactory elongation. 6 tables, 16 figures

Technology of Welding Joints Mixed with Duplex Steel

Directory of Open Access Journals (Sweden)

Słania J.

2016-03-01

Full Text Available Results of the examinations of sample plates of mixed joints with the duplex steel were discussed. Examinations were taken on the sample plates of mixed joints of sheet plates type P355NL1 and X2CrNiMoN22-5-3 welded by the flux-cored wire DW-329A by the Kobelco company of the following category T 22 9 3 NL RC/M3 in the gas shroud M21 (Ar+18%CO2 (plate no.1, and nickel covered electrodes E Ni 6082 by the Böhler company (plate no. 2. Results of the side bend test of welded joint, transverse tensile test, stretching of the weld metal, impact strength, micro and macroscopic metallographic examinations, and measurements of the delta ferrite content were presented.

76 FR 70111 - Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Extension of Deadline for...

Science.gov (United States)

2011-11-10

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... antidumping duty order on certain frozen fish fillets from the Socialist Republic of Vietnam (``Vietnam'').\\1... 4, 2011.\\3\\ \\1\\ See Notice of Antidumping Duty Order: Certain Frozen Fish Fillets from the Socialist...

Effects of low dose irradiation on the K-value and hypoxanthine concentration of fish fillets

International Nuclear Information System (INIS)

Williams, D.J.; Mitchell, G.E.; Nottingham, S.M.; Jarrett, S.J.; Petroff, M.

1993-01-01

Fillets of five fish species were irradiated at 0, 1 and 3kGy to investigate whether the K-value test of freshness can be applied to irradiated fish. Following irradiation, the fillets were stored on ice and sampled regularly for K-value analysis. Hypoxanthine (Hx) and total nucleotide content were also determined on fillets of two species. K-values of irradiated fillets were generally lower than those of unirradiated controls. Hypoxanthine levels paralleled the K-value changes. These results indicated that quality standards based on K-values or Hx levels that have been set for unirradiated species cannot be directly applied to fish that has been irradiated. Total nucleotide content did not appear to be affected by irradiation

Effects of coating chitosan inhibition to quality of fish fillet Oreochromis niloticus at room temperature storage

Science.gov (United States)

Saputra, Eka; Tjahjaningsih, Wahju; Patmawati

2017-02-01

Fresh fish shelf life can be extended by adding antibacterial compounds such as synthetic chemicals or natural materials. One of the natural ingredients that are safe to use to prolong the freshness of the fish is chitosan. Chitosan is able to provide quality deterioration inhibitory effect of fillet of tilapia. The rate of decline in the value of organoleptic fillet of tilapia treated chitosan solution is slower when compared to no treatment tilapia fillet chitosan solution. In the organoleptic test until the 18 hours of storage, 2% chitosan solution capable of maintaining the highest organoleptic value for the parameter sightings meat, texture, and smell fillet. The use of 2% chitosan solution provided the best results based on the parameters of the appearance of meat, the texture, the smell, the pH value and the value of TVB fillet.

Elimination of the risk of brittle fracture in thick welded pressure vessels

International Nuclear Information System (INIS)

Leymonie, C.; Genevray, R.

1975-01-01

The builder of welded pressure vessels faces the risk of brittle fracture throughout fabrication. He is forced to observe many precautions, in selecting the following: materials possessing good impact strength in the service conditions of the vessels; filler materials preventing transverse cracking of the welds: welding parameters preventing cold cracking. Fracture mechanics establish the relationships between material characteristics and critical defect size for a given set of service conditions. These principles must be expanded to increase the safety of thick pressure vessels. However, in order to derive maximum benefit, a major effort must be applied to increasing the effectiveness of nondestructive testing [fr

Microstructure-based modeling of tensile deformation of a friction stir welded AZ31 Mg alloy

Energy Technology Data Exchange (ETDEWEB)

He, Weijun, E-mail: weijun.he@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Zheng, Li [College of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110870 (China); Xin, Renlong, E-mail: rlxin@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Liu, Qing [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China)

2017-02-27

The deformation and fracture behaviors of friction stir welded (FSWed) Mg alloys are topics under investigation. The microstructure and texture of a FSWed Mg alloy were characterized by electron back scattered diffraction. Four characteristic sub-zones with different orientations in the FSWed Mg alloy joint were identified. The texture distribution across the stir zones and transition zone were obviously inhomogeneous. For comparison, four sub-regions in the base material were also characterized. Based on the experimental microstructure and texture, a crystal plasticity finite element model was developed to represent the friction stir welded Mg alloy. Simulations were carried out to study the effect of texture variation on the deformation behaviors during transverse tension. Compared with the base material case, strong macroscopic strain localization was observed for the FSWed joint case after transverse tension. Strain localization may have contributed to the decayed elongation of the FSWed joint in the transverse tension. Texture variation in the thermal-mechanical affected zone did not change the deformation mechanism in the stir zones, while it did decrease the strain localization, thus assuming to improve the elongation of the friction stir welded Mg alloy.

Microstructure-based modeling of tensile deformation of a friction stir welded AZ31 Mg alloy

International Nuclear Information System (INIS)

He, Weijun; Zheng, Li; Xin, Renlong; Liu, Qing

2017-01-01

The deformation and fracture behaviors of friction stir welded (FSWed) Mg alloys are topics under investigation. The microstructure and texture of a FSWed Mg alloy were characterized by electron back scattered diffraction. Four characteristic sub-zones with different orientations in the FSWed Mg alloy joint were identified. The texture distribution across the stir zones and transition zone were obviously inhomogeneous. For comparison, four sub-regions in the base material were also characterized. Based on the experimental microstructure and texture, a crystal plasticity finite element model was developed to represent the friction stir welded Mg alloy. Simulations were carried out to study the effect of texture variation on the deformation behaviors during transverse tension. Compared with the base material case, strong macroscopic strain localization was observed for the FSWed joint case after transverse tension. Strain localization may have contributed to the decayed elongation of the FSWed joint in the transverse tension. Texture variation in the thermal-mechanical affected zone did not change the deformation mechanism in the stir zones, while it did decrease the strain localization, thus assuming to improve the elongation of the friction stir welded Mg alloy.

Physicochemical Characteristics and Lipid Oxidation of Chicken Inner Fillets Subjected to Different Thermal Processing Types

Directory of Open Access Journals (Sweden)

NN Arguelo

Full Text Available ABSTRACT The objective of this study was to evaluate the effects of different types of thermal processing on the physiochemical characteristics and lipid oxidation of chicken inner fillets. The study was divided into three assays. In the first assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Treatments consisted in cooking in water bath, electric oven, microwave oven, deep frying, or grilling. The analyzed variables were: cooking weight loss (CWL and lipid oxidation determined by thiobarbituric acid reactive substances (TBARS. In the second assay, 50 chicken inner fillets were divided into five treatments, totaling 10 samples per treatment. Each treatment consisted of the same cooking methods applied in the first assay, and storage for 48 hours under refrigeration and reheating in a microwave oven. The variable analyzed in the second assay was lipid oxidation (TBARS. In the third assay, 30 samples of chicken inner fillets were subjected to one, four and eight freeze-thaw cycles, after which meat pH, myofibrillar fragmentation index (MFI, water retention capacity (WRC, and lipid oxidation (TBARS were determined. Chicken inner fillets submitted to deep frying and cooked in a microwave oven presented greater lipid oxidation than the other cooking methods, and deep frying resulted in the highest cooking weight loss. Reheating chicken inner fillets in a microwave oven caused the highest meat lipid oxidation. Increasing the number of freeze-thaw cycles increases the pH, MFI, WRC and TBARS values of chicken inner fillets.

Prediction of pH of fresh chicken breast fillets by VNIR hyperspectral imaging

Science.gov (United States)

Visible and near-infrared (VNIR) hyperspectral imaging (400–900 nm) was used to evaluate pH of fresh chicken breast fillets (pectoralis major muscle) from the bone (dorsal) side of individual fillets. After the principal component analysis (PCA), a band threshold method was applied to the first prin...

75 FR 30374 - Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2010-06-01

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets.... See Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Preliminary Results of New.... See Memorandum to the File, from Javier Barrientos, Senior Case Analyst, Certain Frozen Fish Fillets...

75 FR 26199 - Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2010-05-11

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... 31, 2009. See Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Preliminary Results... Barrientos, Senior Case Analyst, Certain Frozen Fish Fillets from the Socialist Republic of Vietnam, dated...

Gas tungsten arc welding assisted hybrid friction stir welding of dissimilar materials Al6061-T6 aluminum alloy and STS304 stainless steel

International Nuclear Information System (INIS)

Bang, HanSur; Bang, HeeSeon; Jeon, GeunHong; Oh, IkHyun; Ro, ChanSeung

2012-01-01

Highlights: ► GTAW assisted hybrid friction stir welding (HFSW) has been carried out for dissimilar butt joint. ► Mechanical strength of dissimilar butt joint by HFSW and FSW has been investigated and compared. ► Microstructure of dissimilar butt joint by HFSW and FSW has been investigated and compared. -- Abstract: The aim of this research is to evaluate the potential for using the gas tungsten arc welding (GTAW) assisted hybrid friction stir welding (HFSW) process to join a stainless steel alloy (STS304) to an aluminum alloy (Al6061) in order to improve the weld strength. The difference in mechanical and microstructural characteristics of dissimilar joint by friction stir welding (FSW) and HFSW has been investigated and compared. Transverse tensile strength of approximately 93% of the aluminum alloy (Al6061) base metal tensile strength is obtained with HFSW, which is higher than the tensile strength of FSW welds. This may be due to the enhanced material plastic flow and partial annealing effect in dissimilar materials due to preheating of stainless steel surface by GTAW, resulting in significantly increased elongation of welds. The results indicate that HFSW that integrates GTAW preheating to FSW is advantageous in joining dissimilar combinations compared to conventional FSW.

76 FR 81913 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2011-12-29

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... antidumping duty order on certain frozen fish fillets from the Socialist Republic of Vietnam.\\1\\ Subsequent to..., 2012. \\1\\ See Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Preliminary Results...

76 FR 20626 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2011-04-13

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... and requests for revocation in part for certain frozen fish fillets from the Socialist Republic of... administrative reviews and requests for revocation in part for certain frozen fish fillets from the Socialist...

75 FR 44938 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2010-07-30

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... the period August 1, 2008, through July 31, 2009. See Certain Frozen Fish Fillets from the Socialist...: Antidumping Duty Administrative Review of Certain Frozen Fish Fillets from the Socialist Republic of Vietnam...

75 FR 57261 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Correction of Date for the...

Science.gov (United States)

2010-09-20

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... reviews for certain frozen fish fillets from the Socialist Republic of Vietnam covering the period August 1, 2009, through February 15, 2010. See Certain Frozen Fish Fillets From the Socialist Republic of...

Effects of cooking on levels of PCBs in the fillets of winter flounder (Pseudopleuronectes americanus)

Energy Technology Data Exchange (ETDEWEB)

Poston, T.M. [Pacific Northwest Lab., Richland, WA (United States); Durell, G.S.; Koczwara, G.; Spellacy, A.M. [Battelle Ocean Sciences, Duxbury, MA (United States)

1995-08-01

The Pacific Northwest Laboratory and Battelle Ocean Sciences performed a study to determine the effect of cooking on polychlorinated biphenyl (PCB) levels in the fillets of winter flounder (Pseudopleuronectes americanus). Broiling, pan frying, and deep frying in oil were tested on fillets from 21 fish collected from New Bedford Harbor, Massachusetts, on February 21, 1991. The evaluation involved estimating the change in PCB concentrations using a mass-balance approach that factored the change in fillet weight resulting from cooking with the changes in PCB concentration expressed on a precooked wet-weight basis. Deep frying in oil resulted in a 47% reduction in total PCB levels in fillet tissue. Additionally, deep frying caused a 40% reduction in fillet mass. Pan frying and broiling resulted in statistically in insignificant increases in total PCB levels of 15% and 17%, respectively. Fillet mass reductions resulting from pan frying and broiling were 7% and 15%, respectively. The effects of cooking on 18 individual congeners generally paralleled the results observed for total PCB. All 18 congeners were significantly reduced by deep frying. Congener Cl{sub 2}(08) also was significantly reduced by either pan frying. Congeners Cl{sub 5}(105) and Cl{sub 5}(118) showed apparent significant increases in concentrations following pan frying. Congeners Cl{sub 5}(105), Cl{sub 5}(118), and C1{sub 6}(138) showed significant increases in concentration following broiling.

76 FR 12939 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2011-03-09

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... the Preliminary Results of the seventh new shipper reviews of certain frozen fish fillets from the... later than April 14, 2011. \\1\\ See Certain Frozen Fish Fillets From the Socialist Republic of Vietnam...

75 FR 20983 - Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2010-04-22

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... frozen fish fillets from the Socialist Republic of Vietnam covering the period August 1, 2008, through...''), covering the period August 1, 2008, through July 31, 2009. See Certain Frozen Fish Fillets from the...

75 FR 80795 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2010-12-23

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... of the sixth administrative and new shipper reviews of certain frozen fish fillets from the Socialist... January 13, 2011. \\1\\ See Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Notice of...

Microstructure and mechanical properties of friction stir welded SAF 2507 super duplex stainless steel

International Nuclear Information System (INIS)

Sato, Y.S.; Nelson, T.W.; Sterling, C.J.; Steel, R.J.; Pettersson, C.-O.

2005-01-01

The microstructure and mechanical properties of friction stir (FS) welded SAF 2507 super duplex stainless steel were examined. High-quality, full-penetration welds were successfully produced in the super duplex stainless steel by friction stir welding (FSW) using polycrystalline cubic boron nitride (PCBN) tool. The base material had a microstructure consisting of the ferrite matrix with austenite islands, but FSW refined grains of the ferrite and austenite phases in the stir zone through dynamic recrystallisation. Ferrite content was held between 50 and 60% throughout the weld. The smaller grain sizes of the ferrite and austenite phases caused increase in hardness and strength within the stir zone. Welded transverse tensile specimen failed near the border between the stir zone and TMAZ at the retreating side as the weld had roughly the same strengths as the base material

Characteristics of Laser Beam and Friction Stir Welded AISI 409M Ferritic Stainless Steel Joints

Science.gov (United States)

Lakshminarayanan, A. K.; Balasubramanian, V.

2012-04-01

This article presents the comparative evaluation of microstructural features and mechanical properties of friction stir welded (solid-state) and laser beam welded (high energy density fusion welding) AISI 409M grade ferritic stainless steel joints. Optical microscopy, microhardness testing, transverse tensile, and impact tests were performed. The coarse ferrite grains in the base material were changed to fine grains consisting duplex structure of ferrite and martensite due to the rapid cooling rate and high strain induced by severe plastic deformation caused by frictional stirring. On the other hand, columnar dendritic grain structure was observed in fusion zone of laser beam welded joints. Tensile testing indicates overmatching of the weld metal relative to the base metal irrespective of the welding processes used. The LBW joint exhibited superior impact toughness compared to the FSW joint.

77 FR 1470 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Time for Final...

Science.gov (United States)

2012-01-10

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... preliminary results of the new shipper review of certain frozen fish fillets from the Socialist Republic of... due no later than March 4, 2012. \\1\\ See Certain Frozen Fish Fillets From the Socialist Republic of...

Perspektif Six Sigma dalam Analisis Manajemen Kualitas Kasus Produksi Fish Fillet di PT Dharma Samudra Fishing Industry, Jakarta

OpenAIRE

Farmayanti, Narni; ., Dinarwan; S, I I Fithri Yunindari

2006-01-01

Fish fillet is a superior commodity for the company of PT Dharma Samudra Fishing Industry (DSFI), and having the highest production and demand. The product of fish fillet giving a big opportunity for defect level of fish fillet and it´s caused from some mistakes that happen in process production. Hence, the optimalization of input process of fish fillet production is related with six sigma methods application which try to eliminate or minimize mistakes and wastes of time and money. It is hope...

Predicting water-holding capacity of intact chicken broiler breast fillets with Vis/NIR spectroscopy

Science.gov (United States)

The ability of using visible and near-infrared (Vis/NIR) spectroscopy to predict water-holding capacity (WHC) of intact chicken broiler breast fillets (pectoralis major) was assessed in this study. Boneless and skinless chicken fillets (214 in total) were procured from a commercial processing plant ...

Fatigue behaviour of T welded joints rehabilitated by tungsten inert gas and plasma dressing

International Nuclear Information System (INIS)

Ramalho, Armando L.; Ferreira, Jose A.M.; Branco, Carlos A.G.M.

2011-01-01

Highlights: → This study addresses the use of improvement techniques for repair T welded joints. → TIG and plasma arc re-melting are applied in joints with fatigue cracks at weld toes. → Plasma dressing provides reasonable repair in joints with cracks greater than 4 mm. → TIG dressing produces a deficient repair in joints with cracks greater than 4 mm. → TIG dressing provides good repair in joints with fatigue cracks lesser than 2.5 mm. -- Abstract: This paper concerns a fatigue study on the effect of tungsten inert gas (TIG) and plasma dressing in non-load-carrying fillet welds of structural steel with medium strength. The fatigue tests were performed in three point bending at the main plate under constant amplitude loading, with a stress ratio of R = 0.05 and a frequency of 7 Hz. Fatigue results are presented in the form of nominal stress range versus fatigue life (S-N) curves obtained from the as welded joints and the TIG dressing joints at the welded toe. These results were compared with the ones obtained in repaired joints, where TIG and plasma dressing were applied at the welded toes, containing fatigue cracks with a depth of 3-5 mm in the main plate and through the plate thickness. A deficient repair was obtained by TIG dressing, caused by the excessive depth of the crack. A reasonable fatigue life benefits were obtained with plasma dressing. Good results were obtained with the TIG dressing technique for specimens with shallower initial defects (depth lesser than 2.5 mm). The fatigue life benefits were presented in terms of a gain parameter assessed using both experimental data and life predictions based on the fatigue crack propagation law.

Impact of friction stir welding on the microstructure of ODS steel

Energy Technology Data Exchange (ETDEWEB)

Dawson, H., E-mail: huwdawson@gmail.com [School of Materials, The University of Manchester, Manchester M13 9PL (United Kingdom); Serrano, M. [Structural Materials Division, Technology Department, CIEMAT, Avda de la Complutense 40, 28040 Madrid (Spain); Cater, S.; Iqbal, N. [Friction and Forge Processes Department, Joining Technologies Group, TWI Technology Centre, Advanced Manufacturing Park, Wallis Way, Catcliffe, Rotherham S60 5TZ (United Kingdom); Almásy, L. [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, P.O. Box 49, H-1525 Budapest (Hungary); Tian, Q. [Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, P.O. Box 49, H-1525 Budapest (Hungary); Jimenez-Melero, E. [School of Materials, The University of Manchester, Manchester M13 9PL (United Kingdom); Dalton Cumbrian Facility, The University of Manchester, Moor Row CA24 3HA (United Kingdom)

2017-04-01

We have assessed the impact of the welding parameters on the nano-sized oxide dispersion and the grain size in the matrix of an ODS steel after friction stir welding. Our results, based on combined small angle neutron scattering and electron microscopy, reveal a decrease in the volume fraction of the particles smaller than 80 nm in the welds, mainly due to particle agglomeration. The increase in tool rotation speed or decrease in transverse speed leads to a higher reduction in nano-sized particle fraction, and additionally to the occurrence of particle melting. The dependence of the average grain size in the matrix on the particle volume fraction follows a Zener pinning-type relationship. This result points to the principal role that the particles have in pinning grain boundary movement, and consequently in controlling the grain size during welding.

Impact of friction stir welding on the microstructure of ODS steel

Science.gov (United States)

Dawson, H.; Serrano, M.; Cater, S.; Iqbal, N.; Almásy, L.; Tian, Q.; Jimenez-Melero, E.

2017-04-01

We have assessed the impact of the welding parameters on the nano-sized oxide dispersion and the grain size in the matrix of an ODS steel after friction stir welding. Our results, based on combined small angle neutron scattering and electron microscopy, reveal a decrease in the volume fraction of the particles smaller than 80 nm in the welds, mainly due to particle agglomeration. The increase in tool rotation speed or decrease in transverse speed leads to a higher reduction in nano-sized particle fraction, and additionally to the occurrence of particle melting. The dependence of the average grain size in the matrix on the particle volume fraction follows a Zener pinning-type relationship. This result points to the principal role that the particles have in pinning grain boundary movement, and consequently in controlling the grain size during welding.

Slaughter yield and fatty acid profiles of fillets of pike (Esox lucius L. caught before and after spawning

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Zakęś Zdzisław

2015-12-01

Full Text Available The aim of the study was to determine the impact pike fishing season (before spawning in fall (group A and after spawning in spring (group B had on the slaughter yield and fillet fatty acid profile. The slaughter yield of fillets with skin and skinned fillets from the group B fish was significantly lower (by approximately 7.5% of body weight. The fatty acid profile of the fish meat from the groups examined differed significantly. The fillets of pike caught before spawning were dominated by unsaturated fatty acids (UFA, while those from fish caught after spawning had mainly saturated fatty acids (SFA. The share of polyunsaturated fatty acids (PUFA in the fillets of fish that had spawned was sixfold lower, and the n-3 PUFA differences were nearly ninefold. The content of eicosapentaenoic (EPA and docosahexaenoic (DHA fatty acids in fillets of fish that had spawned was ninefold lower than in those that had not yet done so. Consequently, the ratio of n-3 PUFA/n-6 PUFA in pike from group A was over three times higher than that in the fish that had spawned (2.61 vs 0.82. Fillets from pike that have spawned are a significantly poorer source of valuable fatty acids for consumers.

Atlantic salmon skin and fillet color changes effected by perimortem handling stress, rigor mortis, and ice storage.

Science.gov (United States)

Erikson, U; Misimi, E

2008-03-01

The changes in skin and fillet color of anesthetized and exhausted Atlantic salmon were determined immediately after killing, during rigor mortis, and after ice storage for 7 d. Skin color (CIE L*, a*, b*, and related values) was determined by a Minolta Chroma Meter. Roche SalmoFan Lineal and Roche Color Card values were determined by a computer vision method and a sensory panel. Before color assessment, the stress levels of the 2 fish groups were characterized in terms of white muscle parameters (pH, rigor mortis, and core temperature). The results showed that perimortem handling stress initially significantly affected several color parameters of skin and fillets. Significant transient fillet color changes also occurred in the prerigor phase and during the development of rigor mortis. Our results suggested that fillet color was affected by postmortem glycolysis (pH drop, particularly in anesthetized fillets), then by onset and development of rigor mortis. The color change patterns during storage were different for the 2 groups of fish. The computer vision method was considered suitable for automated (online) quality control and grading of salmonid fillets according to color.

The effect of nisin from Lactococcus lactis subsp. lactis on refrigerated patin fillet quality

Science.gov (United States)

Adilla, S. N.; Utami, R.; Nursiwi, A.; Nurhartadi, E.

2017-04-01

The effect of nisin from Lactococcus lactis subsp. lactis with spraying method application on quality of patin fillet during refrigerated storage (4±1°C) was investigated. The quality of patin fillet based on total plate count (TPC), pH, TVB-N, and TBA values during 16 days at 4±1°C. Completely Randomized Design (CDR) was used in one factor (nisin activity) at 0 IU/ml, 500 IU/ml, 1000 IU/ml, and 2000 IU/ml. The observation was done at 0, 4th, 8th, 12th, and 16th days of storage. The result showed that variation of nisin activity significantly affected the quality of fillet according to TPC, pH, and TVB-N values, however no significant difference on the obtained of TBA value. Nisin in 500 IU/ml, 1000 IU/ml, and 2000 IU/ml could extend the shelf-life of fillet until 4th, 8th, and 12th days respectively based on standard in all parameters.

Friction weld ductility and toughness as influenced by inclusion morphology

International Nuclear Information System (INIS)

Eberhard, B.J.; Schaaf, B.W. Jr.; Wilson, A.D.

1983-01-01

Friction welding consistently provides high strength, freedom from fusion defects, and high productivity. However, friction welds in carbon steel exhibit impact toughness and bend ductility that are significantly lower than that of the base metal. The inclusion content and morphology were suspected to be major contributors to the reduction in weld ductility. For this reason, four electric furnace steels - three types of ASTM A516 Grade 70, and an ASTM A737 Grade B steel - were investigated. Friction welds were made by both the inertia and direct drive process variations and the welds evaluated. It was shown that friction welds of inclusion-controlled steels exhibited much improved toughness and bend ductility were demonstrated. Upper shelf impact energy was equivalent to or greater than that of the base metal in the short transverse direction. The transition temperature range for all four materials was shifted to higher temperatures for both types of friction welds. Under the conditions of this test, the direct drive friction welds showed a greater shift than the inertia friction welds. The ductility and toughness of welds in A737 Grade B steel were superior to welds in A516 Grade 70 steels, reflecting the superior properties of the base metal. Welds of the A737 material had usable Charpy V-notch impact toughness of 20 to 30 ft-lb (27 to 41 J) at temperatures as low as -40 0 F (-40 0 C). All the welds had an acicular structure. The differences in properties between the inertia and direct drive friction welds appear associated with microstructural variations. These variations resulted from the different heat inputs and cooling rates of the two process variations were demonstrated. The beneficial effects of inclusion control on toughness and ductility. In addition, it also indicates that additional improvements may be attainable through control of the as-welded microstructure by process manipulation

A study on laser welding deformation of 304 stainless steel

International Nuclear Information System (INIS)

Kitagawa, Akikazu; Maehara, Kenji; Takeda, Shinnosuke; Matsunawa, Akira

2002-01-01

In heavy industries, 304 austenitic stainless steel is the most popular material which is used for nuclear equipment, chemical vessels, vacuum vessels and so on. On the fabrication, not only a joint quality but also severe dimensional accuracy is required. To keep dimensional accuracy, considerable cost and efforts are requested, because the welding deformation of austenitic stainless steel is deeply depended on the physical properties of material itself. To decrease welding deformation, big jigs or water cooling method are commonly used which lead to the high cost. In general, the fusion welding by high energy density heat source results in less distortion. Today, laser welding technology has grown up to the stage that enables to weld thick plate with small deformation. The researches of welding deformation have been conducted intensively, but they are mainly concerned for arc welding, and studies for laser welding are very few. In this report, the authors will show the test results of deformation behavior in laser welding of 304 stainless steel. Also, they will discuss the deformation behavior comparing to that in arc welding. The main results of this study are as follows. 1. The angular distortion of laser welding can be unified by heat input parameter (Hp) which is used for arc welding deformation. 2. The angular distortion are same under the condition of Hp 3 in spite of different welding method, however under the condition of Hp>6-9 J/mm 3 the angular distortion is quite different depending on the power density of welding method. 3. Pure angular distortion seemed to complete just after welding, but following longitudinal distortion took place for long period. 4. The critical value of longitudinal distortion can be estimated from heat input parameter. The transverse deformation can be also estimated by heat input parameter. (author)

Meat quality of broiler breast fillets with white striping and woody breast muscle myopathies.

Science.gov (United States)

Tijare, V V; Yang, F L; Kuttappan, V A; Alvarado, C Z; Coon, C N; Owens, C M

2016-09-01

The global poultry industry has been faced with emerging broiler breast meat quality issues including conditions known as white striping (WS, white striations parallel to muscle fibers) and woody breast (WB, hardness of raw fillet). Experiments were conducted to evaluate effects of WS and WB hardness on meat quality traits in broiler breast fillets. In Exp. 1, birds were processed at approximately 9 wk of age and deboned at 4 h postmortem (PM); in Exp. 2, birds were processed at approximately 6 and 9 wk of age and deboned at 2 h PM. Fillets were categorized as: normal for both white striping and woody breast (NORM); moderate for white striping and mild for woody breast (MILD); severe for white striping and mild for woody breast (WS); severe for woody breast and moderate for white striping (WB); or severe for both white striping and woody breast (BOTH). Sarcomere length, gravimetric fragmentation index, marination uptake, cook loss, and Meullenet-Owens razor shear energy (MORSE) values on non-marinated and marinated fillets were assessed. Sarcomeres tended to be longer (P = 0.07) with increasing severity of WS and WB in both experiments and gravimetric fragmentation index did not differ (P > 0.05) among categories. Marinade uptake decreased (P  0.05) in non-marinated fillets, the marinated BOTH fillets had greater MORSE values (P  0.05) among categories of marinated breasts. At 9 wk, WS and BOTH were higher (P white striping and woody breast, individually or in combination, negatively impact meat quality, especially water holding capacity attributes such as marinade uptake and cook loss. © 2016 Poultry Science Association Inc.

Application of Highly Purified Electrolyzed Chlorine Dioxide for Tilapia Fillet Disinfection

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Chen-Hsing Yu

2014-01-01

Full Text Available This research aimed to develop an electrolysis method to generate high-concentration chlorine dioxide (ClO2 for tilapia fillet disinfection. The designed generator produced up to 3500 ppm of ClO2 at up to 99% purity. Tilapia fillets were soaked in a 400 ppm ClO2 solution for 5, 10, and 25 min. Results show that total plate counts of tilapia, respectively, decreased by 5.72 to 3.23, 2.10, and 1.09 log CFU/g. In addition, a 200 ppm ClO2 solution eliminated coliform bacteria and Escherichia coli in 5 min with shaking treatment. Furthermore, ClO2 and trihalomethanes (THMs residuals on tilapia fillets were analyzed by GC/MS and were nondetectable (GC-MS detection limit was 0.12 ppb. The results conform to Taiwan’s environmental protection regulations and act governing food sanitation.

Evaluation of a Method for Quantifying Eugenol Concentrations in the Fillet Tissue from Freshwater Fish Species.

Science.gov (United States)

Meinertz, Jeffery R; Schreier, Theresa M; Porcher, Scott T; Smerud, Justin R

2016-01-01

AQUI-S 20E(®) (active ingredient, eugenol; AQUI-S New Zealand Ltd, Lower Hutt, New Zealand) is being pursued for approval as an immediate-release sedative in the United States. A validated method to quantify the primary residue (the marker residue) in fillet tissue from AQUI-S 20E-exposed fish was needed. A method was evaluated for determining concentrations of the AQUI-S 20E marker residue, eugenol, in freshwater fish fillet tissue. Method accuracies from fillet tissue fortified at nominal concentrations of 0.15, 1, and 60 μg/g from six fish species ranged from 88-102%. Within-day and between-day method precisions (% CV) from the fortified tissue were ≤8.4% CV. There were no coextracted compounds from the control fillet tissue of seven fish species that interfered with eugenol analyses. Six compounds used as aquaculture drugs did not interfere with eugenol analyses. The lower limit of quantitation (LLOQ) was 0.012 μg/g. The method was robust, i.e., in most cases, minor changes to the method did not impact method performance. Eugenol was stable in acetonitrile-water (3 + 7, v/v) for at least 14 days, in fillet tissue extracts for 4 days, and in fillet tissue stored at ~ -80°C for at least 84 days.

Study of MA Effect on Yield Strength and Ductility of X80 Linepipe Steels Weld

Science.gov (United States)

Huda, Nazmul; Lazor, Robert; Gerlich, Adrian P.

2017-09-01

Multipass GMAW (Gas Metal Arc Welding) welding was used to join X80 linepipe materials using two weld metals of slightly different compositions. Welding wires with diameters of 0.984 and 0.909 mm were used while applying the same heat input in each pass. The slight difference in the wire diameters resulted in different HAZ microstructures. The microstructures in the doubly reheated HAZ of both welds were found to contain bainite-ferrite. However, etching also revealed a difference in martensite-austenite (MA) fraction in these reheated zones. The MA exhibited twice the hardness of ferrite when measured by nanoindentation. Tensile testing from the reheated zone of both welds revealed a difference in yield strength, tensile strength and elongation of the transverse weld specimens. In the reheated zone of weld A, (produced with a 0.984 mm wire) a higher fraction of MA was observed, which resulted in higher strength but lower elongation compared to weld B. The ductility of weld A was found severely impaired (to nearly half of weld B) due to formation of closely spaced voids around the MA, along with debonding of MA from the matrix, which occurs just above the yield stress.

Microstructural Evolution in Friction Stir Welding of Ti-6Al-4V

Science.gov (United States)

Rubisoff, H.; Querin, J.; Magee, D.; Schneider, J.

2008-01-01

Friction stir welding (FSW) is a thermo-mechanical process that utilizes a nonconsumable rotating pin tool to consolidate a weld joint. In the conventional FSW process, the pin tool is responsible for generating both the heat required to soften the material and the forces necessary to deform and combine the weld seam. As such, the geometry of the pin tool is important to the quality of the weld and the process parameters required to produce the weld. Because the geometry of the pin tool is limitless, a reduced set of pin tools was formed to systematically study their effect on the weldment with respect to mechanical properties and resultant microstructure. In this study 0deg, 15deg, 30deg, 45deg, and 60deg tapered, microwave sintered, tungsten carbide (WC) pin tools were used to FSW Ti-6Al-4V. Transverse sections of the weld were used to test for mechanical properties and to document the microstructure using optical microscopy. X-ray diffraction (XRD) was also used to characterize the microstructure in the welds. FSW results for the 45deg and 60deg pin tools are reported in this paper.

Effects of tartary buckwheat polysaccharide combined with nisin edible coating on the storage quality of tilapia (Oreochromis niloticus) fillets.

Science.gov (United States)

Wang, Fengping; Zhang, Huijun; Jin, Wengang; Li, Lirong

2018-06-01

To investigate the effect of tartary buckwheat polysaccharide (TBP) combined with nisin edible coatings on the preservation of tilapia (Oreochromis niloticus) fillets, fillets were dip treated with different concentrations of TBP (5, 10 and 15 g kg -1 ) combined with nisin and stored at 4 °C for 12 days. The pH values, thiobarbituric acid contents, total volatile base nitrogen (TVB-N) content, total viable count (TVC), surface colors, textures and sensory properties of the tilapia fillets at storage were all periodically investigated. TBP combined with nisin-treated groups significantly improved the bacteriological, physicochemical, and sensory characteristics of the tilapia fillets to a greater extent compared to the control group and presented better quality preservation effects than nisin coating alone. Based on the limits of the TVB-N, TVC and sensory scores, the shelf life of the control tilapia fillets was 4 days, whereas that for nisin with TBP-coated fillets was 8-10 days. Edible coatings made from TBP combined with nisin are suitable for maintaining qualities and enhancing the shelf lives of tilapia fillets stored at 4 °C. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Molecular authentication of Pargo fillets Lutjanus purpureus (Perciformes: Lutjanidae by DNA barcoding reveals commercial fraud

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Ivana Veneza

2018-03-01

Full Text Available ABSTRACT The Caribbean Red Snapper (Pargo Lutjanus purpureus is the most economically important snapper in Brazil, which is sold, among other forms, as frozen fillets. During the process of transformation into fillets there is the removal of the distinctive morphological traits, being able to favor the substitution by less valued species. In addition, there is no national legislation requiring the insertion of the specific name on the product label. However, according to a Normative Instruction (IN N ° 29/2015 MAPA that correlates the common and specific names of the products destined to the national trade, in Brazil only L. purpureus and L. campechanus can be denominated “Pargo”. Thus, the DNA barcode tool was used to identify the fillets sold in north of Brazil, labeled “Pargo”, with the aid of sequences from the public and control databases. The results showed that among 142 fillets examined, 78% was identified as L. purpureus and 22% as Rhomboplites aurorubens, a snapper with low commercial value in the country, revealing commercial fraud. The molecular identification method successfully used in this study to authenticate fillets snappers may also be used by surveillance authorities in the quality control of processed fish products, towards ensuring consumer rights.

Longitudinal analyses of correlated response efficiencies of fillet traits in Nile tilapia.

Science.gov (United States)

Turra, E M; Fernandes, A F A; de Alvarenga, E R; Teixeira, E A; Alves, G F O; Manduca, L G; Murphy, T W; Silva, M A

2018-03-01

Recent studies with Nile tilapia have shown divergent results regarding the possibility of selecting on morphometric measurements to promote indirect genetic gains in fillet yield (FY). The use of indirect selection for fillet traits is important as these traits are only measurable after harvesting. Random regression models are a powerful tool in association studies to identify the best time point to measure and select animals. Random regression models can also be applied in a multiple trait approach to analyze indirect response to selection, which would avoid the need to sacrifice candidate fish. Therefore, the aim of this study was to investigate the genetic relationships between several body measurements, weight and fillet traits throughout the growth period and to evaluate the possibility of indirect selection for fillet traits in Nile tilapia. Data were collected from 2042 fish and was divided into two subsets. The first subset was used to estimate genetic parameters, including the permanent environmental effect for BW and body measurements (8758 records for each body measurement, as each fish was individually weighed and measured a maximum of six times). The second subset (2042 records for each trait) was used to estimate genetic correlations and heritabilities, which enabled the calculation of correlated response efficiencies between body measurements and the fillet traits. Heritability estimates across ages ranged from 0.05 to 0.5 for height, 0.02 to 0.48 for corrected length (CL), 0.05 to 0.68 for width, 0.08 to 0.57 for fillet weight (FW) and 0.12 to 0.42 for FY. All genetic correlation estimates between body measurements and FW were positive and strong (0.64 to 0.98). The estimates of genetic correlation between body measurements and FY were positive (except for CL at some ages), but weak to moderate (-0.08 to 0.68). These estimates resulted in strong and favorable correlated response efficiencies for FW and positive, but moderate for FY. These results

Effect of fiber laser parameters on laser welded AZ31B Magnesium alloys

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Mat Salleh Naqiuddin

2017-01-01

Full Text Available Recently, the usage of Magnesium (Mg alloys has been hugely applied in the industrial application such as in automotive, marine, and electronic due to its advantages of recyclability and lightweight. This alloys required low heat input to be weld since it is easily evaporated due to the Magnesium Oxide (MgO at the surface and it also possesses lower melting point compared to steel. Laser welding is more convenient to weld Mg alloys due to its high power and lower heat input. AZ31B was selected since it has strong mechanical properties among others Mg alloys due to the major alloying elements; Aluminium (Al and Zinc (Zn. Low power fiber laser machine with wavelength of 900 nm was used in this experiment. The intention of this work was to investigate the effect of low power fiber laser parameters and effect of shielding gas on weld penetration and microstructure. Another aim in this work was to produce the joint for this thin sheets metal. Penetration depth and microstructure evaluation were emphasized in the analysis section. Bead-on-Plate (BOP and laser lap welding was conducted on AZ31B with thicknesses of 1.0 mm and 0.6 mm for feasibility study using pulsed wave (PW mode. Defocusing features was used in order to find better focal position, which has less occurrence of evaporation (underfill. The effect of different angle of irradiation was also investigated. Two types of shielding gases, Argon (Ar and Nitrogen (N2 were used in order to study the effect of shielding gas. Lastly, the effect of pulsed energy on penetration types and depth of BOP welded samples was investigated. Focus point was found at focal length of 156 mm with 393.75 μm. For BOP experiment, higher pulsed energy used contributes to melt through defect. Meanwhile, Ns shielding gas proved to be better shielding gas in laser welding the AZ31B. Higher angle of irradiation could reduce the underfill defect. Fillet Lap joint of similar metal was successfully done where 2.0 J of

Numerical Simulation on the Origin of Solidification Cracking in Laser Welded Thick-Walled Structures

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Nasim Bakir

2018-06-01

Full Text Available One of the main factors affecting the use of lasers in the industry for welding thick structures is the process accompanying solidification cracks. These cracks mostly occurring along the welding direction in the welding center, and strongly affect the safety of the welded components. In the present study, to obtain a better understanding of the relation between the weld pool geometry, the stress distribution and the solidification cracking, a three-dimensional computational fluid dynamic (CFD model was combined with a thermo-mechanical model. The CFD model was employed to analyze the flow of the molten metal in the weld pool during the laser beam welding process. The weld pool geometry estimated from the CFD model was used as a heat source in the thermal model to calculate the temperature field and the stress development and distributions. The CFD results showed a bulging region in the middle depth of the weld and two narrowing areas separating the bulging region from the top and bottom surface. The thermo-mechanical simulations showed a concentration of tension stresses, transversally and vertically, directly after the solidification during cooling in the region of the solidification cracking.

Determination of total mercury in fillets of sport fishes collected from Folsom and New Melones Reservoirs, California, 2004

Science.gov (United States)

May, Thomas W.; Brumbaugh, William G.

2007-01-01

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom and New Melones Reservoirs in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fish fillets from Folsom Reservoir ranged from 0.09 to 1.16 micrograms per gram wet weight, and from New Melones Reservoir ranged from 0.03 to 0.94 microgram per gram wet weight. Most of the fish fillets from Folsom Reservoir (87 percent) and 27 percent of the fillets from New Melones Reservoir exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Basic numerical study on gap influence of residual stress and distortion during high-brightness laser butt welding

International Nuclear Information System (INIS)

Serizawa, Hisashi; Mori, Daiki; Murakawa, Hidekazu

2013-01-01

High-brightness laser such as fiber laser or disk laser is expected to minimize the total heat input energy in welding due to its high beam quality, and the welding residual stress and distortion also seem to be reduced as a result. However, the diameter of high-brightness laser beam is less than 0.6 mm and it is difficult to set the beam position to contact face between two parts because in general there would be a gap due to quality of parts. In this study, in order to reveal the effect of gap on the residual stress and the welding distortion during fiber laser welding, the butt welding of two plates were examined through the thermal elastic-plastic analysis with a new gap element. From the result of thermal analyses, it was found that the homogeneous ellipsoid body could be applicable to model the shape of heat source for the fiber laser and the gap width would not influence the penetration shape when the gap width was changed from 0.1 to 0.25 mm. In addition, the elastic-plastic analyses indicated that the transverse shrinkage slightly increased with increasing the gap width, while this shrinkage without gap was much smaller than that with gap. Also, it was revealed that the welding speed largely affects both the welding residual stress and distortion. Moreover, it was found that the residual stress was almost independent of the jig position, while the position of fixtures slightly affected the transverse shrinkage. (author)

High-power laser and arc welding of thorium-doped iridium alloys

International Nuclear Information System (INIS)

David, S.A.; Liu, C.T.

1980-05-01

The arc and laser weldabilities of two Ir-0.3% W alloys containing 60 and 200 wt ppM Th have been investigated. The Ir-.03% W alloy containing 200 wt ppM Th is severely prone to hot cracking during gas tungsten-arc welding. Weld metal cracking results from the combined effects of heat-affected zone liquation cracking and solidification cracking. Scanning electron microscopic analysis of the fractured surface revealed patches of low-melting eutectic. The cracking is influenced to a great extent by the fusion zone microstructure and thorium content. The alloy has been welded with a continuous-wave high-power CO 2 laser system with beam power ranging from 5 to 10 kW and welding speeds of 8 to 25 mm/s. Successful laser welds without hot cracking have been obtained in this particular alloy. This is attributable to the highly concentrated heat source available in the laser beam and the refinement in fusion zone microstructure obtained during laser welding. Efforts to refine the fusion zone structure during gas tungsten-arc welding of Ir-0.3 % W alloy containing 60 wt ppM Th were partially successful. Here transverse arc oscillation during gas tungsten-arc welding refines the fusion zone structure to a certain extent. However, microstructural analysis of this alloy's laser welds indicates further refinement in the fusion zone microstructure than in that from the gas tungsten-arc process using arc oscillations. The fusion zone structure of the laser weld is a strong function of welding speed

Fish gelatin combined with chitosan coating inhibits myofibril degradation of golden pomfret (Trachinotus blochii) fillet during cold storage.

Science.gov (United States)

Feng, Xiao; Bansal, Nidhi; Yang, Hongshun

2016-06-01

Coating of gelatin and chitosan can improve fish fillet's quality, but the mechanism is not clear. Chitosan/gelatin coatings significantly prevented deterioration of golden pomfret fillet at 4 °C. Chitosan with 7.2% gelatin group showed the best effect on preserving the length of myofibril, which remained greater than 15 μm at day 17 of storage, while for control, chitosan and chitosan combined with 3.6% gelatin group, it was 5.03, 10.04 and 9.02 μm, respectively. The MALDI-TOF MS result revealed that the coatings slowed down the protein deterioration of fillet. On days 13 and 17, the myosin light chain and myoglobin in control group degraded, while the two proteins still existed in chitosan/gelatin coated groups. Overall, the chitosan with 7.2% gelatin coating had the best effect on preserving fillet's quality during storage. The coating may exert its protective effect via inhibiting myofibril degradation within fillet. Copyright © 2016 Elsevier Ltd. All rights reserved.

X-Ray diffraction technique applied to study of residual stresses after welding of duplex stainless steel plates

International Nuclear Information System (INIS)

Monin, Vladimir Ivanovitch; Assis, Joaquim Teixeira de; Lopes, Ricardo Tadeu; Turibus, Sergio Noleto; Payao Filho, Joao C.

2014-01-01

Duplex stainless steel is an example of composite material with approximately equal amounts of austenite and ferrite phases. Difference of physical and mechanical properties of component is additional factor that contributes appearance of residual stresses after welding of duplex steel plates. Measurements of stress distributions in weld region were made by X-ray diffraction method both in ferrite and austenite phases. Duplex Steel plates were joined by GTAW (Gas Tungsten Arc Welding) technology. There were studied longitudinal and transverse stress components in welded butt joint, in heat affected zone (HAZ) and in points of base metal 10 mm from the weld. Residual stresses measured in duplex steel plates jointed by welding are caused by temperature gradients between weld zone and base metal and by difference of thermal expansion coefficients of ferrite and austenite phases. Proposed analytical model allows evaluating of residual stress distribution over the cross section in the weld region. (author)

Teknik Pengawetan Fillet Ikan Nila Merah dengan Senyawa Anti Bakteri asal Lactobacillus Acidophilus dan Bifido Bacteria Biffidum

Directory of Open Access Journals (Sweden)

Dede Saputra

2014-12-01

Full Text Available Red tilapia is a good commodity to be developed because it has a high nutritional value composition, with a protein content 17.8%, fat 2.8%, and others composition. The fillet of red tilapia fish is easy to spoil, because of S. aureus, Salmonella sp., and other microbes. Many methods are used to save and preserve the quality of fillet, such fillet preparation through good sanitation practices, cooling process, but the effort were not optimal. The objectives of this study were to 1 evaluate the potency of antibacterial produced by Lactobacillus acidophilus and Bifidobacteria biffidum to inhibit the growth of spoilage bacteria that contaminated the red tilapia fillet; 2 evaluate the effect of antibacterial compounds produced by Lactobacillus acidophilus and Bifidobacteria biffidum of inhibiting the setback fillet quality, 3 determine the shelf life of red tilapia fillet at room temperature. Antibacterial activity test is done by using the well diffusion method; the rate of deterioration of quality of fish tests done by observing the organoleptic parameters, pH measurement test, total volatile base method. Total number of bacteria were performed by Standard Plate Count (SPC test. The LAB’s are able to inhibit the growth of spoilage bacteria Pseudomonas aeruginosa about 8.67-9.00 mm and Listeria monocytogenes about 8.33-9.00 mm through the well diffusion method. pH values about 5.71-5.74, TVB values about 1,26-21.43 with SPC test about 1.39-4.83 CFU/mL. The antibacterial compounds could inhibit  the rate of deterioration of quality red tilapia fillets until 14 hours.

Characterization of Mechanical Properties and Residual Stress in API 5L X80 Steel Welded Joints

Science.gov (United States)

de Sousa Lins, Amilton; de Souza, Luís Felipe Guimarães; Fonseca, Maria Cindra

2018-01-01

The use of high-strength and low-alloy steels, high design factors and increasingly stringent safety requirements have increased the operating pressure levels and, consequently, the need for further studies to avoid and prevent premature pipe failure. To evaluate the possibility of improving productivity in manual arc welding of this type of steel, this work characterizes the mechanical properties and residual stresses in API 5L X80 steel welded joints using the SMAW and FCAW processes. The residual stresses were analyzed using x-ray diffraction with the sin2 ψ method at the top and root of the welded joints in the longitudinal and transverse directions of the weld bead. The mechanical properties of the welded joints by both processes were characterized in terms of tensile strength, impact toughness and Vickers microhardness in the welded and shot peening conditions. A predominantly compressive residual stress was found, and shot peening increased the tensile strength and impact toughness in both welded joints.

The influence of low dose irradiation on the creep properties of type 316 welds

International Nuclear Information System (INIS)

Marshall, P.; Steeds, J.W.; Lin, Y.P.; Finlan, G.T.

1987-01-01

Fully instrumented creep and stress rupture tests have been performed at 873K for times up to 20,000h on a series of type 316 steel/17Cr 8Ni 2Mo weld metal specimens in the unirradiated and thermal neutron irradiated conditions. The specimens tested included all weld metal longitudinal and transverse composites in the as-welded condition and following a stress relief heat treatment of 10h at 1075K. Simulated heat affected zone (HAZ) specimens were also tested. Analysis of the creep results combined with metallography, autoradiography and TEM established that the decrease in properties of irradiated samples is caused by an increasing secondary strain rate due to enhanced helium induced grain boundary fracture of the simulated HAZ and enhanced interdendritic fracture in the weld metal. Implications of strength reductions on the design of welded structures subjected to thermal irradiation are briefly assessed. (author)

Shelf Life of Tilapia Fillets Treated with low dose Gamma Irradiation

International Nuclear Information System (INIS)

Mohamed, W.S.; El-Mossalami, I.I.

2009-01-01

The bacterial load (total bacterial count), Psychrophilic count, chemical and sensory examinations in Tilapia fish fillets were determined to evaluate its sanitary status and to increase its storage period during storage at -18 degree C for one year. The experiment was carried out at the time of receiving the samples and after gamma radiation treatment with dose levels of 1, 2 and 3 kGy. The initial total bacterial count was 5.4x10 0 cfu/gm and the psychrophilic count was 4x10 5 cfu/gm; it was slightly increased during freezing storage. The chemical parameters were more indicative in evaluating the shelf life of frozen fish; as they exceeded the permissible limits, so that the frozen non-irradiated samples were rejected after 6 months. The exposure to gamma irradiation at a dose of 1 kGy extended the storage time of the samples to 9 months while irradiation with 3 kGy extended the storage time of the samples to 12 months without changing its quality attributes. The quality during storage at -18 degree C of non irradiated and irradiated fish fillets was investigated every 3 months for one year by measuring the bacterial counts, chemical parameters and sensorial evaluation of the samples to study the effect of irradiation on increasing the storage time of fish fillets. So, it is recommended that fish fillets should be properly cleaned, packaged and exposed to gamma irradiation at a dose of 3 kGy to extend its freezing storage period

Yield and composition of pirarucu fillet in different weight classes - doi: 10.4025/actascianimsci.v33i1.10843 Yield and composition of pirarucu fillet in different weight classes - doi: 10.4025/actascianimsci.v33i1.10843

Directory of Open Access Journals (Sweden)

Samanta Eulles Quixaba Carvalho

2011-02-01

Full Text Available The fillet yield and quantity of waste generated after processing are important for planning and evaluating the growth performance of species and systems of aquaculture production in Brazil. The pirarucu (Arapaima gigas is among the species with desirable characteristics for intensive fish with high market value. The objective was to evaluate the performance of pirarucu fillet in different weight classes: 7.0 to 9.0 kg (group I, 11.0 to 13.0 kg (group II and 14.0 to 17.0 kg (group III. The fillet yield presented no significant difference between groups. The composition showed significant differences (p The fillet yield and quantity of waste generated after processing are important for planning and evaluating the growth performance of species and systems of aquaculture production in Brazil. The pirarucu (Arapaima gigas is among the species with desirable characteristics for intensive fish with high market value. The objective was to evaluate the performance of pirarucu fillet in different weight classes: 7.0 to 9.0 kg (group I, 11.0 to 13.0 kg (group II and 14.0 to 17.0 kg (group III. The fillet yield presented no significant difference between groups. The composition showed significant differences (p < 0.05 for moisture (77.96 to 75.04% and ash (2.21 to 2.46%, while values of lipid and protein were similar between classes evaluated. In assessing the fat percentage per serving (loin, belly and tail there was higher fat deposition in the ventral part and in group III. Thus, it can be lessen the pirarucu with weight ranging from 7.0 to 9.0 kg, using shorter production cycles and obtaining better quality fillets by having a lower muscle percentage of lipids.

Effects of Chilling and Partial Freezing on Rigor Mortis Changes of Bighead Carp (Aristichthys nobilis) Fillets: Cathepsin Activity, Protein Degradation and Microstructure of Myofibrils.

Science.gov (United States)

Lu, Han; Liu, Xiaochang; Zhang, Yuemei; Wang, Hang; Luo, Yongkang

2015-12-01

To investigate the effects of chilling and partial freezing on rigor mortis changes in bighead carp (Aristichthys nobilis), pH, cathepsin B, cathepsin B+L activities, SDS-PAGE of sarcoplasmic and myofibrillar proteins, texture, and changes in microstructure of fillets at 4 °C and -3 °C were determined at 0, 2, 4, 8, 12, 24, 48, and 72 h after slaughter. The results indicated that pH of fillets (6.50 to 6.80) was appropriate for cathepsin function during the rigor mortis. For fillets that were chilled and partially frozen, the cathepsin activity in lysosome increased consistently during the first 12 h, followed by a decrease from the 12 to 24 h, which paralleled an increase in activity in heavy mitochondria, myofibrils and sarcoplasm. There was no significant difference in cathepsin activity in lysosomes between fillets at 4 °C and -3 °C (P > 0.05). Partially frozen fillets had greater cathepsin activity in heavy mitochondria than chilled samples from the 48 to 72 h. In addition, partially frozen fillets showed higher cathepsin activity in sarcoplasm and lower cathepsin activity in myofibrils compared with chilled fillets. Correspondingly, we observed degradation of α-actinin (105 kDa) by cathepsin L in chilled fillets and degradation of creatine kinase (41 kDa) by cathepsin B in partially frozen fillets during the rigor mortis. The decline of hardness for both fillets might be attributed to the accumulation of cathepsin in myofibrils from the 8 to 24 h. The lower cathepsin activity in myofibrils for fillets that were partially frozen might induce a more intact cytoskeletal structure than fillets that were chilled. © 2015 Institute of Food Technologists®

A comparison of residual stresses in built-up steel beams using hole-drilling method

International Nuclear Information System (INIS)

Nawafleh, M. A.; Hunaiti, Y. M.; Younes, R. M.

2009-01-01

Residual stresses have a significant effect on the stability resistance of metal building systems. An experimental program was conducted to measure these stresses in built-up steel beams using incremental hole-drilling method. The experimental results reveal that the predicted residual stress type of pattern for built-up I-sections with fillet welds on one side of the web is not the same as the pattern of residual stresses in built-up I-sections with fillet welds on both sides of the web

Fatty Acid Profile of Sunshine Bass: II. Profile Change Differs Among Fillet Lipid Classes.

Science.gov (United States)

Trushenski, Jesse T; Lewis, Heidi A; Kohler, Christopher C

2008-07-01

Fatty acid (FA) profile of fish tissue mirrors dietary FA profile and changes in a time-dependent manner following a change in dietary FA composition. To determine whether FA profile change varies among lipid classes, we evaluated the FA composition of fillet cholesteryl esters (CE), phospholipids (PL), and triacylglycerols (TAG) of sunshine bass (SB, Morone chrysops x M. saxatilis) raised on feeds containing fish oil or 50:50 blend of fish oil and coconut, grapeseed, linseed, or poultry oil, with or without implementation of a finishing period (100% FO feed) prior to harvest. Each lipid class was associated with a generalized FA signature, irrespective of nutritional history: fillet PL was comprised largely of saturated FA (SFA), long-chain polyunsaturated FA (LC-PUFA), and total n-3 FA; fillet TAG was higher in MC-PUFA and total n-6 FA; and fillet CE was highest in monounsaturated FA (MUFA). Neutral lipids reflected dietary composition in a near-direct fashion; conversely, PL showed evidence of selectivity for MC- and LC-PUFA. Shorter-chain SFA were not strongly reflected within any lipid fraction, even when dietary availability was high, suggesting catabolism of these FA. FA metabolism in SB is apparently characterized by a division between saturated and unsaturated FA, whereby LC-PUFA are preferentially incorporated into tissues and SFA are preferentially oxidized for energy production. We demonstrated provision of SFA in grow-out feeds for SB, instead MC-PUFA which compete for tissue deposition, meets energy demands and allows for maximum inclusion of LC-PUFA within fillet lipids.

Detection of Fish Bones in Cod Fillets by UV Illumination.

Science.gov (United States)

Wang, Sheng; Nian, Rui; Cao, Limin; Sui, Jianxin; Lin, Hong

2015-07-01

The presence of fish bones is now regarded as an important hazard in fishery products, and there is increasing demand for new analytical techniques to control it more effectively. Here, the fluorescent properties of cod bones under UV illumination were investigated, and the maximal wavelengths for excitation and emission were determined to be 320 nm and 515 nm, respectively, demonstrating significantly different fluorescence characteristics and much higher fluorescence intensity compared to those of fillet muscles. Based on the results, UV fluorescence-assisted candling for the detection of bones in fishery products was developed for the first time. Using cod fillets as samples, the detection ratio of this technique was calculated as 90.86%, significantly higher than that of traditional candling under daylight (76.78%). Moreover, the working efficiency of the new technique was about 26% higher than that of the traditional method. A UV fluorescence imaging framework was also developed, and a method for automatic identification of the fish bones in the cod fillets based on the linear discriminant analysis proposed by Fisher was preliminarily realized, but the detection ratio was demonstrated to be relatively poor compared to those of candling techniques. These results allow us to suggest UV-based methods as new and promising approaches for routine monitoring of bones in fishery products.

Identification of tetrodotoxin and fish species in a dried dressed fish fillet implicated in food poisoning.

Science.gov (United States)

Hwang, Deng-Fwu; Hsieh, Yu-Wen; Shiu, Yu-Cheng; Chen, Shu-Kong; Cheng, Chao-An

2002-02-01

There were five victims of neurotoxic food poisoning from a dried dressed fish fillet in Changhua County, Taiwan, in February 2000. The toxicity of the dried dressed fish fillets was 243 mouse units per g according to a tetrodotoxin bioassay. The partially purified toxin was identified as tetrodotoxin and anhydrotetrodotoxin. The sequence of the 376-nucleotide region in the cytochrome b gene of the mitochondrial DNA exhibited the same genotype as that of the toxic puffer fish Lagocephalus lunaris. The same single restriction site for Hinfl was found in the polymerase chain reaction (PCR) products from the dried dressed fish fillet and the muscle of L. lunaris, yielding two DNA fragments of 170 and 206 bp. However, no restriction site for Hinfl was found in the PCR products from other toxic puffer fishes, including Takifugu niphobles, Takifugu oblongus, and Takifugu rubripes. Therefore, the species of the dried dressed fish fillet was identified as L. lunaris and its causative agent was identified as tetrodotoxin.

Determination of methylmercury and inorganic mercury in shark fillets

NARCIS (Netherlands)

Krystek, Petra; Ritsema, Rob

2004-01-01

Three samples of deep-frozen shark fillets were analysed according to the following procedure: dissolution in tetramethylammonium hydroxide, derivatization/ethylation with sodium tetraethylborate, extraction into iso-octane and measurement with gas chromatography hyphenated to inductively coupled

Effect of pre- and post-marination aging on meat quality attributes of early deboned (2 h postmortem) broiler breast fillets.

Science.gov (United States)

Kuttappan, V A; Gunsaulis, V B; Mauromoustakos, A; Meullenet, J F; Owens, C M

2016-11-01

Marination is an effective method that can be used to improve the tenderness of early deboned breast fillets. The present study was designed to evaluate the effect of pre- and post-marination aging of 2 h postmortem (PM) deboned chicken fillets to get optimum meat quality. In this study, a total of 300 broilers (43 to 46 d of age) were processed using an in-line system and deboned at 2 h PM. Fillets were marinated, at either 2.5, 4, 6, 8 or 24 h PM, using vacuum tumbling (20 min) with a 15% marinade (final concentration of 0.5% salt and 0.45% phosphate). A non-marinated control (CON) was included. The left (HOLD) fillets were aged (held at 4°C for 24 h) prior to freezing post-marination while the right (NO HOLD) fillets were frozen immediately after marination to simulate various commercial practices. Marination pickup (MPU), total marinade retained after thawing (TMR), total purge loss after thawing (TPL), cook loss (CL), and Meullenet-Owens Razor Shear energy (MORSE) values were measured. Both in HOLD and NO HOLD fillets, there was an increase (P water holding capacity. However, both in HOLD and NO HOLD groups, the MORSE values for the marinated fillets decreased (P retention as well as tenderness (or lower shear values). © 2016 Poultry Science Association Inc.

Soldadura (Welding). Spanish Translations for Welding.

Science.gov (United States)

Hohhertz, Durwin

Thirty transparency masters with Spanish subtitles for key words are provided for a welding/general mechanical repair course. The transparency masters are on such topics as oxyacetylene welding; oxyacetylene welding equipment; welding safety; different types of welds; braze welding; cutting torches; cutting with a torch; protective equipment; arc…

Upgrading weld quality of a friction stir welded aluminum alloys AMG6

Science.gov (United States)

Chernykh, I. K.; Vasil'ev, E. V.; Matuzko, E. N.; Krivonos, E. V.

2018-01-01

In the course of introduction of FSW technology into the industry there is a keen interest in this process; there are issues such as how does joining take place, what is the structure of the joint, and where there are dangerous zones. The objective of this research is to obtain information about the structure of the joint, what are the temperatures that arise during the joining, what strength is apply to the tool when joining the material, what tensile strength of joint, and where fracture tended to occur. Specimens were produced at different modes of welding at a tool rotation speed of 315 to 625 rpm and tool travel speed of 40 to 125 mm/min. During the experiment, the strength applied to the tool was measured, which reached 800016000 N (Fz) and 400-1400 N (Fx) and the temperature on the surface of the tool, which is in the range 250-400°C. Before the welding process the tool was heated to a temperature in the range of 100-250 degrees, but the tensile strength is not had a tangible impact. The tensile strength is about 80 % of that of the aluminum alloy base metal tensile strength, and fracture tended is occur not at the line of joint but follow the shape of the tool. In the transverse cross section of a FSW material there is a microstructural regions such as weld nugget, thermomechanically affected zone and heat-affected zone with parent material.

Sloped Connections and Connections with Fillet Welded Continuity Plates for Seismic Design of Special Moment Frames

OpenAIRE

Mashayekh, Adel

2017-01-01

Steel Special Moment Frames (SMF) are one of the most popular lateral force-resisting systems for multistory building construction in high seismic regions due to their architectural versatility. With a significant amount of research that was conducted after the 1994 Northridge, California earthquake, AISC has published design guidelines (AISC 341 and AISC 358) to avoid brittle fracture of beam-to-column welded moment connections that occurred in more than 100 steel buildings. This dissertat...

Optimized design on condensing tubes high-speed TIG welding technology magnetic control based on genetic algorithm

Science.gov (United States)

Lu, Lin; Chang, Yunlong; Li, Yingmin; Lu, Ming

2013-05-01

An orthogonal experiment was conducted by the means of multivariate nonlinear regression equation to adjust the influence of external transverse magnetic field and Ar flow rate on welding quality in the process of welding condenser pipe by high-speed argon tungsten-arc welding (TIG for short). The magnetic induction and flow rate of Ar gas were used as optimum variables, and tensile strength of weld was set to objective function on the base of genetic algorithm theory, and then an optimal design was conducted. According to the request of physical production, the optimum variables were restrained. The genetic algorithm in the MATLAB was used for computing. A comparison between optimum results and experiment parameters was made. The results showed that the optimum technologic parameters could be chosen by the means of genetic algorithm with the conditions of excessive optimum variables in the process of high-speed welding. And optimum technologic parameters of welding coincided with experiment results.

Effect of sex on the fillet quality of Nile tilapia fed varying lipid sources

Directory of Open Access Journals (Sweden)

Tamás Molnár

2010-01-01

Full Text Available Effect of sex and three different oil supplementations on main production traits, and fatty acid composition of the fillet and gonads was investigated in Nile tilapia. Males and females had significantly different final weights owing to the occasional reproduction of fish. Diets had no significant effects on the main production traits. The percentage of ALA in the fillet was significantly higher in the males in all diets. Significant differences were found between the two sexes in the n-3 PUFA, resulting in a higher n-3/ n-6 ratio in the males. MUFA and n-6 PUFA percentages and EPA/DHA ratio in the fillet were affected by the fat sources in the diet. The proportion of the main fatty acids showed significant changes in the gonads. Both sex and the diet had a significant effect on LA, AA, and DHA percentages. In case of EPA the males had significantly higher values than the females. ALA was affected by the different diets, the fillets of the LO group containing the highest percentage Regarding the main FA groups, n-3 PUFA, n-6 PUFA, n-3/n-6 ratio and the DHA/EPA ratio were affected by sex and diets.

Formation of trans fatty acids during the frying of chicken fillet in corn oil.

Science.gov (United States)

Yang, Meiyan; Yang, Ying; Nie, Shaoping; Xie, Mingyong; Chen, Feng; Luo, Pengju George

2014-05-01

To assess effects of heated edible oils on intake of trans fatty acids (TFAs); the formation of TFAs in cooking conditions was investigated by a frying system model, in which chicken fillet was fried in a commercial corn oil at 170 °C, for 12 frying cycles. The main TFAs detected in chicken fillet were trans C18:2 fatty acids (FAs) and trans C18:3 FAs, which exhibited no significant differences among the frying cycles. Besides, the content of trans C18:1 FAs were very low in all samples on different frying cycles. The intake of TFAs was estimated to be 0.06 g/100 g when chicken fillet fried in this process was consumed. These results suggest that an ordinary frying process upon a commercial corn oil has little impact on the daily TFAs intake.

A non-conventional technique for evaluating welded joints based on the electrical conductivity

Energy Technology Data Exchange (ETDEWEB)

Santos, T.G.; Sorger, G., E-mail: telmo.santos@fct.unl.pt, E-mail: lgs18243@campus.fct.unl.pt [Universidade Nova de Lisboa, UNIDEMI, Departamento de Engenharia Mecanica e Industrial, Faculdade de Ciencias e Tecnologia, Caparica (Portugal); Vilaca, P., E-mail: pedro.vilaca@aalto.fi [Aalto Univ., Dept. of Engineering Design and Production, School of Engineering, Aalto (Finland); Miranda, R., E-mail: rmiranda@fct.unl.pt [Universidade Nova de Lisboa, UNIDEMI, Departamento de Engenharia Mecanica e Industrial, Faculdade de Ciencias e Tecnologia, Caparica (Portugal)

2015-01-15

Recent studies showed that electrical conductivity is a valuable technique to identify the different zones of solid-state welded joints with a good correlation with the microstructure and hardness. This is a relevant result since this technique is fast and, in some cases, non destructive, The concept was applied to other welding processes such as the ones involving fusion to a wide range of materials, For this, a comprehensive study was performed using friction stir welding, tungsten inert gas (TlG) and gas metal arc (MAG) welding processes in either bead on plate or butt joints in: carbon steel, magnesium and titanium, Eddy current nondestructive testing (NDT) was used to measure the electrical conductivity at different depths in transverse sections of the processed materials. The profiles were compared to the hardness profiles in the same sections. As a result, a correlation was observed in most materials welded by solid state and by fusion processes. The variation of the electrical conductivity closely follows that measured in the hardness. Another interesting conclusion is that, even for fusion welding of carbon steels, the technique has potential to complement the hardness measurements and microstructural observations, allowing the identification of the distinct zones of welds in materials commonly used in industry. (author)

Study on microstructure and tensile properties of fly ash AMCs welded by FSW

Science.gov (United States)

Sachinkumar, Narendranath, S.; Chakradhar, D.

2018-04-01

Aluminum matrix composite (AMCs) constitute a new class of light weight and high strength materials which have widespread applications in almost all engineering sectors. But the cost of AMCs is the only barrier to increase their applications still. Hence there is a huge demand for the composites containing low cost reinforcement with less weight, keeping this in mind, in the present work, Friction stir welding (FSW) of AA6061/SiC/fly ash was carried out successfully. Microstructural study on the welded specimens was performed using optical microscopy (OM) and scanning electron microscopy (SEM). Results indicate that fly ash particles were uniformly distributed in the weld nugget area because of the stirring action of the FSW tool also promoted the grain refinement of the matrix material with complete elimination of clusters present in matrix material which resulting in sound welds without any defects for AA6061/SiC/fly ash composites. 82% of joint efficiency is obtained for selected AMCs. Transverse tensile test results showed that all welds fractured in HAZ.

Gamma-radiography techniques applied to quality control of welds in water pipe lines

International Nuclear Information System (INIS)

Sanchez, W.; Oki, H.

1974-01-01

Non-destructive testing of welds may be done by the gamma-radiography technique, in order to detect the presence or absence of discontinuities and defects in the bulk of deposited metal and near the base metal. Gamma-radiography allows the documentation of the test with a complete inspection record, which is a fact not common in other non-destructive testing methods. In the quality control of longitudinal or transversal welds in water pipe lines, two exposition techniques are used: double wall and panoramic exposition. Three different water pipe lines systems have analysed for weld defects, giving a total of 16,000 gamma-radiographies. The tests were made according to the criteria established by the ASME standard. The principal metallic discontinuites found in the weld were: porosity (32%), lack of penetration (29%), lack of fusion (20%), and slag inclusion (19%). The percentage of gamma-radiographies showing welds without defects was 39% (6168 gamma-radiographies). On the other hand, 53% (8502 gamma-radiographies) showed the presence of acceptable discontinuities and 8% (1330 gamma-radiographies) were rejected according to the ASME standards [pt

76 FR 59658 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2011-09-27

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets..., the antidumping duty order on certain frozen fish fillets from the Socialist Republic of Vietnam... of initiation for the new shipper review of [[Page 59659

Irradiation of fish fillets: Relation of vapor phase reactions to storage quality

Science.gov (United States)

Spinelli, J.; Dollar, A.M.; Wedemeyer, G.A.; Gallagher, E.C.

1969-01-01

Fish fillets irradiated under air, nitrogen, oxygen, or carbon dioxide atmospheres developed rancidlike flavors when they were stored at refrigerated temperatures. Packing and irradiating under vacuum or helium prevented development of off-flavors during storage.Significant quantities of nitrate and oxidizing substances were formed when oxygen, nitrogen, or air were present in the vapor or liquid phases contained in a Pyrex glass model system exposed to ionizing radiation supplied by a 60Co source. It was demonstrated that the delayed flavor changes that occur in stored fish fillets result from the reaction of vapor phase radiolysis products and the fish tissue substrates.

Microstructure and Mechanical Properties of Ultrasonic Spot Welded Mg/Al Alloy Dissimilar Joints

Directory of Open Access Journals (Sweden)

He Peng

2018-04-01

Full Text Available Lightweight structural applications of magnesium and aluminum alloys inevitably necessitate welding and joining, especially dissimilar welding between these alloys. The objective of this study was to examine the feasibility of joining ZEK100 Mg alloy to Al6022 alloy via ultrasonic spot welding, focusing on effects of welding energy. An interface diffusion layer consisting of α-Mg and Al12Mg17 eutectic structure was observed to form, with its thickness increased from ~0.5 µm to ~30 µm with increasing welding energy from 500 J to 2000 J. The tensile lap shear peak load or strength and critical stress intensity of the welded joints first increased and then decreased with increasing welding energy, with their peak values achieved at 750 J. Fatigue life of the joints made at 750 J and 2000 J was equivalent at the lower cyclic loading levels, while it was longer for the joints made at 750 J at the higher cyclic loading levels. Fatigue fracture mode changed from interfacial failure to mainly transverse-through-thickness crack growth with decreasing cyclic loading level, which corresponded well to the bi-linear characteristic of S-N curves. Crack initiation basically occurred at the weld nugget border and at the interface between the two sheets, which can be understood via a theoretical stress analysis.

PROCESSING YELD AND PROXIMATE COMPOSITION OF Rhamdia voulezi FILLETS

Directory of Open Access Journals (Sweden)

Elenice Souza dos Reis Goes

2015-10-01

Full Text Available The aim of this study was evaluate the effect of slaughter weight and sex on processing yield and on the proximate composition of Rhamdia voulezi. We calculated the percentage yield of the whole fish (carcass, clean trunk, abdominal muscle, fillet, edible parts, head, skin, gonads and visceral fat yield. There was no statistical difference in yields among weight classes (P>0.05. However, when assessing the income between sexes we observed significant difference (P0.05 among the classes, however, moisture, lipids and calories had significant difference (P<0.05 among the classes, and humidity decreased with increasing size of the fish, and lipid content and calorific value were higher for fish weighing 301-400 g. We oncluded R. voulezi with mass between 100 and 400 g presents equal yield processing, and fish weighing 301-400 g have higher lipid content in the fillet.

Evolution of microstructure and mechanical properties in naturally aged 7050 and 7075 Al friction stir welds

Energy Technology Data Exchange (ETDEWEB)

Fuller, Christian B., E-mail: christian.fuller@yahoo.com [Rockwell Scientific, 1049 Camino Dos Rios, Thousand Oaks, CA 93021 (United States); Mahoney, Murray W., E-mail: murraymahoney@comcast.net [Rockwell Scientific, 1049 Camino Dos Rios, Thousand Oaks, CA 93021 (United States); Calabrese, Mike [Rockwell Scientific, 1049 Camino Dos Rios, Thousand Oaks, CA 93021 (United States); Micona, Leanna [The Boeing Company, P.O. Box 3707 MC 19-HP, Seattle, WA 98124 (United States)

2010-04-15

The microstructural and mechanical property evolution of friction stir welded 7050-T7651 and 7075-T651 Al alloys were examined as a function of room temperature (natural) aging for up to 67,920 h. During the range of aging times studied, transverse tensile strengths continuously increased, and are still increasing, with improvements of 24% and 29% measured for the 7050-T7651 and 7075-T651 Al alloy friction stir welds, respectively. Microstructural evolution within the weld nugget and heat-affected zone was evaluated with both transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). Formation of a high volume fraction of GP(II) zones produced a majority of the strength improvement within the weld nugget and HAZ regions. The rational for the microstructural changes are discussed in light of the mechanical properties.

Development of a process envelope for friction stir welding of DH36 steel – A step change

International Nuclear Information System (INIS)

Toumpis, Athanasios; Galloway, Alexander; Cater, Stephen; McPherson, Norman

2014-01-01

Highlights: • The friction stir welding speed on DH36 steel has been substantially increased. • Excellent quality welds offering potential economic advantages are obtained. • Friction stir welding of steel generates a very complex metallurgical system. • Slow and intermediate welding speed tensile samples fractured in the parent material. • Increasing traverse speed is seen to improve the impact toughness of the weld. - Abstract: Friction stir welding of steel presents an array of advantages across many industrial sectors compared to conventional fusion welding techniques. However, the fundamental knowledge of the friction stir welding process in relation to steel remains relatively limited. A microstructure and property evaluation of friction stir welded low alloy steel grade DH36 plate, commonly used in ship and marine applications has been undertaken. In this comprehensive study, plates of 2000 × 200 × 6 mm were butt welded together at varying rotational and traverse speeds. Samples were examined microscopically and by transverse tensile tests. In addition, the work was complemented by Charpy impact testing and micro-hardness testing in various regions of the weld. The study examined a wide range of process parameters; from this, a preliminary process parameter envelope has been developed and initial process parameter sets established that produce commercially attractive excellent quality welds through a substantial increase in the conventionally recognised weld traverse speed

Ultrasonic inspection of the strength member weld of transit and pioneer heat sources

International Nuclear Information System (INIS)

Dudley, W.A.

1975-01-01

A nondestructive technique was developed which allows ultrasonic inspection of the closure weld for the strength member component in plutonium-238 radioisotopic heat sources. The advantage of the ultrasonic approach, over that of the more commonly used radiographic one, is the recognized superiority of ultrasonic testing for identifying lack-of-weld penetration (LOP) when accompanied by incomplete diffusion bonding. The ultrasonic technique, a transverse mode scan of the weld for detection of LOP, is primarily accomplished by use of a holding fixture which permits the vented heat source to be immersed into an inspection tank. The mechanical portion of the scanning system is a lathe modified with an inspection tank and a manipulator. This scanning system has been used in the past to inspect SNAP-27 heat sources. The analyzer-transducer combination used in the inspection is capable of detecting a channel type flaw with a side wall depth of 0.076 mm (0.003 in.) in a weld standard. (U.S.)

The effect of various concentration of tilapia (Oreochromis sp.) surimi for edible coating on the shelf-life of Pangasius sp. fillets

Science.gov (United States)

Purnama, M. A. P.; Agustono; Sahidu, A. M.

2018-04-01

Pangasius sp. fillets prone to deterioration the quality that will affect the appearance and the shelf life of fillets. The effort to extend the shelf life of fish fillet that is by using an edible coating. Surimi can be used as a protein-based edible coating because they have superior inhibitory and mechanical properties compared to the polysaccharides based material. Surimi can be made from freshwater tilapia (Oreochromis sp.) fish. The experimental design used was Completely Randomized Design (CRD) with five treatments of surimi (0 gr, 2 gr, 4 gr, 6 gr, 8 gr) with four replications. The results showed that Pangasius sp. fillets with an edible coating 8 gr surimi have the highest value in the organoleptic test. The pH testing on Pangasius sp. fillets with edible coating 2 gr, 4 gr, 6 gr, and 8 gr surimi from the 0th hour to 18th hour have increased but slower than Pangasius sp. fillets without edible coating surimi. The best value of Total Plate Count (TPC) test is in edible coating 6 gr and 8 gr surimi as it is in accordance with SNI 2696:2013 at room temperature storage until the 18th hours.

Liquid chromatographic determination of oxytetracycline in edible fish fillets from six species of fish

Science.gov (United States)

Meinertz, J.R.; Stehly, G.R.; Gingerich, W.H.

1998-01-01

The approved use of oxytetracycline (OTC) in U.S. Aquaculture is limited to specific diseases in salmonids and channel catfish. OTC may also be effective in controlling diseases in other fish species important to public aquaculture, but before approved use of OTC can be augmented, an analytical method for determining OTC in fillet tissue from multiple species of fish will be required to support residue depletion studies. The objective of this study was to develop and validate a liquid chromatographic (LC) method that is accurate, precise, and sensitive for OTC in edible fillets from multiple species of fish. Homogenized fillet tissues from walleye, Atlantic salmon, striped bass, white sturgeon, rainbow trout, and channel catfish were fortified with OTC at nominal concentrations of 10, 20, 100, 1000, and 5000 ng/g. In tissues fortified with OTC at 100, 1000, and 5000 ng/g, mean recoveries ranged from 83 to 90%, and relative standard deviations (RSDs) ranged from 0.9 to 5.8%. In all other tissues, mean recoveries ranged from 59 to 98%, and RSDs ranged from 3.3 to 20%. Method quantitation limits ranged from 6 to 22 ng/g for the 6 species. The LC parameters produced easily integratable OTC peaks without coelution of endogenous compounds. The method is accurate, precise, and sensitive for OTC in fillet tissue from 6 species of fish from 5 phylogenetically diverse groups.

Multi-objective Optimization of Pulsed Gas Metal Arc Welding Process Using Neuro NSGA-II

Science.gov (United States)

Pal, Kamal; Pal, Surjya K.

2018-05-01

Weld quality is a critical issue in fabrication industries where products are custom-designed. Multi-objective optimization results number of solutions in the pareto-optimal front. Mathematical regression model based optimization methods are often found to be inadequate for highly non-linear arc welding processes. Thus, various global evolutionary approaches like artificial neural network, genetic algorithm (GA) have been developed. The present work attempts with elitist non-dominated sorting GA (NSGA-II) for optimization of pulsed gas metal arc welding process using back propagation neural network (BPNN) based weld quality feature models. The primary objective to maintain butt joint weld quality is the maximization of tensile strength with minimum plate distortion. BPNN has been used to compute the fitness of each solution after adequate training, whereas NSGA-II algorithm generates the optimum solutions for two conflicting objectives. Welding experiments have been conducted on low carbon steel using response surface methodology. The pareto-optimal front with three ranked solutions after 20th generations was considered as the best without further improvement. The joint strength as well as transverse shrinkage was found to be drastically improved over the design of experimental results as per validated pareto-optimal solutions obtained.

COMPARISON OF POND AND RACEWAY PRODUCTION METHODS ON TEXTURE OF CHANNEL CATFISH (Ictalurus punctatus) FILLETS, SHOWING A DEPENDENCY ON SIZE AND FILLET POSITION

Science.gov (United States)

The objective of this study was to compare the effect of the production environment (pond vs in-pond raceway) on the chemical composition, color, and textural properties of channel catfish fillets. Compositional analysis consisted of percent moisture, lipid, protein, and ash content. Additional sa...

Application of Chitosan as Antibacterial for Pangasius Fillet at Low Temperature Storage

Directory of Open Access Journals (Sweden)

Windi Damayanti

2017-02-01

Full Text Available AbstractThis research were to obtain the optimal concentration of chitosan as an antibacterial material wich had the longest of storage period of pangasius fillet at low temperature storage (5-10oC. The method used is an experimental method with a completely randomized design, four treatments and three replications. Pangasius fillet was soaked with chitosan 0%, 1%, 2% and 3% for 3 minutes, then packed with styrofoam and plastic wrap and stored at low teperature. The observation were made on day 1st, 3rd, 5th, 6th ,7th, 9th,10th, 11th and 12th. The parameters observed total bacterial colonies, the degree of acidity (pH, weight loss, and antibacterial activity of chitosan using disc diffusion methods. The conclusion of research was that the 2% chitosan is optimal concentration for pangasius fillet storage at a low temperature until day 11th, with a total 6.7 X105 cfu/g of bacterial colonies, pH 6.67 and total 6,78 % of weight loss.Chitosan also has a higher antibacterial capability against Escherichia coli (Gram negative bacteria than Staphylococcus aureus and Bacillus subtilis (Gram positive bacteria.

Influence of ionizing radiation on the fatty acid composition of herring fillets

International Nuclear Information System (INIS)

Adam, S.; Paul, G.; Ehlermann, D.

1982-01-01

The effect of γ-irradiation (absorbed dose: 50 kGy, dose-rate: 2.9 kGy/h) on the distribution of fatty acid components in herring fillets has been examined using high-resolution gas chromatographic methods. Radiolytic treatment at 0 0 C and exclusion of atmospheric oxygen caused no significant decrease in the relative amounts of the constituent saturated, monounsaturated and polyunsaturated fatty acid components. Specifically, eicosapentaenoic acid (20:5) and docosahexaenoic acid (22:6), which are of particular physiological interest were not affected by γ-rays, even after additional storage of the irradiated material at 0 0 C for 4 weeks. Irradiation of oil extracted from herring fillets or of herring oil/water emulsions under aerobic conditions, however, destroyed eicosapentaenoic acid and docosahexaenoic acid significantly. The loss of radio-resistance - as compared to the radiation-induced processes in the fillets - is explained by the absence of proteins, which effectively protect the lipid components from radiolytic decomposition. It is concluded that the commercial radiation processing of herring at the recommended dose levels (1 to 2 kGy) should not reduce the content of unsaturated fatty acid components. (author)

75 FR 47771 - Certain Frozen Fish Fillets from the Socialist Republic of Vietnam: Extension of Time Limit for...

Science.gov (United States)

2010-08-09

... DEPARTMENT OF COMMERCE International Trade Administration [A-552-801] Certain Frozen Fish Fillets... initiation of antidumping duty new shipper reviews for certain frozen fish fillets from the Socialist Republic of Vietnam covering the period August 1, 2009, through February 15, 2010. See Certain Frozen Fish...

Effect of electron irradiation and bayberry polyphenols on the quality change of yellowfin tuna fillets during refrigerated storage

International Nuclear Information System (INIS)

Bu, Tingting; Jin, Yang; Li, Xiaohui; Zhang, Jinjie; Xu, Dalun; Yang, Wenge; Lou, Qiaoming

2017-01-01

This study evaluated the synergistic effect of bayberry polyphenols and electron irradiation in controlling the chemical, microbiological and sensory changes of raw yellowfin tuna fillets at 4 °C for 7 days. The results indicated that the initial values of each index were dose-dependent. The dose of 5 kGy notably accelerated adenosine triphosphate degradation and lipid oxidation, while the doses of 1 and 3 kGy had acceptable sensory quality and yielded a shelf-life of 5 days. The addition of bayberry polyphenols had evident effect in inhibiting freshness breakdown, bacteria growth, histamine formation, and discoloration of tuna fillets. Bayberry polyphenols, as an antioxidant, could inhibit lipid oxidation and sensory side-effects made by irradiation up to 3 kGy. The dose of 1–3 kGy coupled with bayberry polyphenols was optimum to preserve tuna fillets which prolonged the shelf-life to 7 days. - Highlights: • Electron irradiation inhibited bacteria growth and histamine formation. • Electron irradiation increased the red color of tuna fillets. • 5 kGy irradiation decreased the sensory quality of raw tuna fillets. • Bayberry polyphenols combined with irradiation could retard the quality change. • Bayberry polyphenols could be used as natural antioxidant and color fixative.

Elimination of vibrio cholerae El Tor, in jurel fillets (trachurus picturatus murphyi) by gamma radiation and product organoleptic evaluation

International Nuclear Information System (INIS)

Torres, Z.; Kahn, G.; Bernuy, B.; Vivanco, M.

1999-03-01

This study was carried out in order to establish D 10 value for vibrio cholerae 'El Tor' in fresh jurel fillets. D value was estimated in 122 Gy, suggesting an elimination dose of 0,96 kGy (8D), and evaluating a life span extension for the 1 kGy dose, also suggested as optimal dose. Based on the method of least squares, life span extension for appearance, smell and texture of radiated raw fillets was estimated in 20, 15 and 32 days, respectively, compared with 13, 8 and 16 days estimated for non-radiated samples. Acceptance time for flavor and texture of radiated cooked fillets was estimated in 27 and 22 days, respectively, compared with 10 and 13 days estimated for non-radiated fillets, under the same conditions. Based on a partially unsteady statistical design, reliability limits during storage at 0-1 o C for a period of 15 days were determined, considering smell evaluation of raw products as the most reliable one. Pretreatment with sodium tripoli phosphate, lead to a 2% reduction in the exudation of radiated fillets with respect to the non-radiated ones the fifteenth day of storage. (authors)

Residual strains and microstructure development in single and sequential double sided friction stir welds in RQT-701 steel

Energy Technology Data Exchange (ETDEWEB)

Barnes, S.J. [School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom)], E-mail: simon.barnes-2@manchester.ac.uk; Steuwer, A. [FaME38, ILL ESRF, 6 rue J.Horowitz, 38042 Grenoble, Cedex (France); University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Mahawish, S. [School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom); Johnson, R. [TWI Yorkshire, Wallis Way, Catcliffe, Rotherham S60 5TZ (United Kingdom); Withers, P.J. [School of Materials, University of Manchester, Grosvenor Street, Manchester M1 7HS (United Kingdom)

2008-09-25

Single and double sided partial penetration friction stir butt welds, in a rolled, quenched and tempered steel (RQT-701), were produced at The Welding Institute (TWI) under controlled process conditions. The residual strain distributions in the longitudinal and transverse directions have been measured using energy dispersive synchrotron X-ray diffraction. The measured strains were indicative of longitudinal tensile residual stresses at levels greater than the 0.2% yield stress of the parent metal in both the single and double pass welds. In both cases, the maximum tensile strain was found in the parent metal at the boundary of the heat affected zone (HAZ). Microstructural analysis of the welds was carried out using optical microscopy and hardness variations were also mapped across the weld-plate cross-section. The maximum hardness was observed in the mixed bainite/martensite structure of the weld nugget on the advancing side of the stir zone. The minimum hardness was observed in the HAZ.

Residual strains and microstructure development in single and sequential double sided friction stir welds in RQT-701 steel

International Nuclear Information System (INIS)

Barnes, S.J.; Steuwer, A.; Mahawish, S.; Johnson, R.; Withers, P.J.

2008-01-01

Single and double sided partial penetration friction stir butt welds, in a rolled, quenched and tempered steel (RQT-701), were produced at The Welding Institute (TWI) under controlled process conditions. The residual strain distributions in the longitudinal and transverse directions have been measured using energy dispersive synchrotron X-ray diffraction. The measured strains were indicative of longitudinal tensile residual stresses at levels greater than the 0.2% yield stress of the parent metal in both the single and double pass welds. In both cases, the maximum tensile strain was found in the parent metal at the boundary of the heat affected zone (HAZ). Microstructural analysis of the welds was carried out using optical microscopy and hardness variations were also mapped across the weld-plate cross-section. The maximum hardness was observed in the mixed bainite/martensite structure of the weld nugget on the advancing side of the stir zone. The minimum hardness was observed in the HAZ

Effect of a traditional marinating on properties of rainbow trout fillet during chilled storage.

Science.gov (United States)

Maktabi, Siavash; Zarei, Mehdi; Chadorbaf, Milad

2016-01-01

In recent years, there has been an increasing interest in using food additives from natural sources to improve taste and also extend the shelf-life of semi-preserved foodstuffs. The aim of this study was to examine the chemical and microbiological changes promoted by a local marinating process in rainbow trout fillets during chilled storage. Fish fillets were immersed in marinades and stored at 4 ˚C for 10 days and were analyzed for total volatile basic nitrogen (TVN), thiobarbitoric acid (TBA), water holding capacity (WHC), pH, mesophilic and psychrophilic bacterial count every two days. Variations in TBA and WHC were not statistically significant between marinated and control groups. The values of TVN, pH, total psychrophilic bacteria count (TPC) and total mesophilic bacteria count (TMC) in marinated samples were significantly lower than controls. The most obvious finding of this study was that traditional marinated rainbow trout fillet stored in 4 ˚C had no undesirable changes at least for eight days.

Relating instrumental texture, determined relating instrumental texture, determined attachments, to sensory analysis of rainbow trout, Oncorhynchus mykiss, fillets

Science.gov (United States)

Texture is one of the most important quality attributes of fish fillets, and accurate assessment of variation in this attribute, as affected by storage and handling, is critical in providing consistent quality product. Trout fillets received 4 treatments: 3-d refrigeration (R3), 7-d refrigeration (R...

Modeling and application of plasma charge current in deep penetration laser welding

International Nuclear Information System (INIS)

Zhang, Xudong; Chen, Wuzhu; Jiang, Ping; Guo, Jing; Tian, Zhiling

2003-01-01

Plasma charge current distribution during deep penetration CO 2 laser welding was analyzed theoretically and experimentally. The laser-induced plasma above the workpiece surface expands up to the nozzle, driven by the particle concentration gradient, forming an electric potential between the workpiece and the nozzle due to the large difference between the diffusion velocities of the ions and the electrons. The plasma-induced current obtained by electrically connecting the nozzle and the workpiece can be increased by adding a negative external voltage. For a fixed set of welding conditions, the plasma charge current increases with the external voltage to a saturation value. The plasma charge current decreases as the nozzle-to-workpiece distance increases. Therefore, closed-loop control of the nozzle-to-workpiece distance for laser welding can be based on the linear relationship between the plasma charge current and the distance. In addition, the amount of plasma above the keyhole can be reduced by a transverse magnetic field, which reduces the attenuation of the incident laser power by the plasma so as to increase the laser welding thermal efficiency

Impact of carbon dioxide level, water velocity, and feeding regimen on growth and fillet attributes of cultured rainbow trout (Oncorhynchus mykiss)

Science.gov (United States)

Mazik, Patricia M.; Mazik, P.M.; Kenney, P.B.; Silverstein, J.T

2016-01-01

Production and management variables such as carbon dioxide (CO2) level, water velocity, and feeding frequency influence the growth and fillet attributes of rainbow trout (Oncorhynchus mykiss), as well as cost of production. More information is needed to determine the contributions of these variables to growth and fillet attributes to find the right balance between input costs and fish performance. Two studies, of 84 and 90 days duration, were conducted to determine the effects of CO2 level, water velocity, and feed frequency on rainbow trout growth, fillet yield, and fillet quality. In the first study, two CO2levels (30 and 49 mg/L) and two velocity levels (0.5 and 2.0 body lengths/s) were tested. In the second study two CO2 levels (30 and 49 mg/L) and two feeding regimens (fed once daily to satiation or three times daily to satiation) were tested. In the first study, after 84 days, fillet weight from high CO2 tanks was 13.5% lower than the fillet weights of fish from low CO2 tanks. Percent fat of fillets was higher in low CO2 fish (P = 0.05) after 84 days and, fish from the low CO2 treatment were larger (P < 0.01). Both studies had similar results in regards to fat content and weight of fillets in response to elevated CO2levels. Velocity had little affect on either whole wet weight or fillet attributes of rainbow trout in this study. Muscle tissue contained more (P < 0.01) fat when fish were fed three times daily (7.3%; day 90) compared to once daily (5.4%; day 90). Also, fish were larger (P < 0.05) when fed 3 times per day (1079 g; day 90) in comparison to only one daily feeding (792 g; day 90). Fish in high feed/high CO2 tanks were larger and had more fillet fat than fish from low feed/low CO2 tanks. To maximize rainbow trout growth at aquaculture facilities, management strategies should attempt to keep CO2 levels below 30 mg/L when cost efficient. However, feeding 2–3 times daily should reduce production losses if CO2 cannot be minimized. The

Weldability of Advanced High Strength Steels using Ytterbium:Yttrium Aluminium Garnet high power laser for Tailor-Welded Blank applications

Science.gov (United States)

Sharma, Rajashekhar Shivaram

transverse direction were evaluated. Metallographic examinations determined that most of the fusion zone is martensitic with small regions of bainite and ferrite. High microhardness values of the order of 550--600 Hv were noted in most joints, which are attributed to high alloy content of the fusion zone as well as high rates of cooling typical of laser welds. During tensile, fatigue and formability tests, no fractures in the fusion or heat affected zones were observed. Geometric variability evaluations indicated that coatings such as aluminum (in the case of USIBOR) and galvanized zinc (TRIP780) can affect the variability of the weld zone and the surface roughness on the top of the weld. Excessive variability in the form of weld concavity in the weld zones can lead to fractures in the weld region, even though higher hardness can, to some extent, compensate for these surface irregularities. The 2-factor design of experiments further confirmed that coatings adversely affect the surface roughness on the top of the welds. Although thickness differentials alone do not make a significant impact on surface roughness, together with coatings, they can have an adverse effect on roughness. Tensile tests in the direction of rolling as well as in the transverse direction indicate that TRIP780 seems weaker in the direction of rolling when compared to transverse direction while mild steel is stronger in the direction of rolling. Weldability analyses revealed that the typical melting efficiency is on the order of 50--70% for full penetration welding. Formability tests showed that TR/MS joints fractured in a direction parallel to the weld line when tested with the loads perpendicular to the weld line. Tests have also confirmed that weld speed and power have no impact on the outcome of formability results. Overall, this work conclusively proves that high power Yb:YAG lasers can effectively join high strength materials such as DP980, TRIP780, USIBOR, as well as mild steel, for use in tailor-welded

Effects of Technological Parameters and Fishing Ground on Quality Attributes of Thawed, Chilled Cod Fillets Stored in Modified Atmosphere Packaging

DEFF Research Database (Denmark)

Bøknæs, Niels; Østerberg, Carsten; Sørensen, Rie

2001-01-01

. The parameters investigated were: (1) packaging in modified atmosphere during frozen storage, (2)frozen storage period and temperature, (3),fishing ground and chill storage temperature, together with (4) the addition of trimethylamine oxide (TMAO) and sodium chloride (NaCl) to cod fillets before freezing......Effects were studied of various technological parameters and fishing ground on quality attributes of thawed, chilled cod fillets stored in modified atmosphere packaging Frozen fillets of Baltic Sea and Barents Sea cod, representing two commercial fishing grounds, were used as raw material...... of Baltic Sea cod. Therefore, addition of trimethylamine oxide and NaCl to Baltic Sea cod fillets was evaluated and shown to protect P, phosphoreum against fro::en storage inactivation and this explained the observed differences in growth of the spoilage bacteria and trimethylamine production between thawed...

Pengaruh Perbedaan Konsentrasi Ekstrak Sargassum sp. dan Lama Penyimpanan terhadap Oksidasi Lemak pada Fillet Ikan Patin (Pangasius sp.

Directory of Open Access Journals (Sweden)

Fatin Hidayati

2017-05-01

Full Text Available ABSTRAK Ikan patin merupakan ikan air tawar yang mengandung lemak dan protein tinggi sehingga apabila dilakukan penyimpanan rentan terjadi oksidasi yang mengakibatkan ketengikan. Sargassum sp. dengan kandungan fenol dan flavonoid mampu menghambat terjadinya oksidasi pada fillet ikan patin. Penelitian ini bertujuan untuk mengetahui pengaruh perbedaan ekstrak Sargassum sp. dan lama penyimpanan dalam menghambat terjadinya oksidasi pada fillet ikan patin. Materi yang digunakan dalam penelitian ini adalah ekstrak Sargassum sp. dan fillet ikan patin. Metode penelitian yang digunakan adalah experimental laboratories dengan menggunakan Rancangan Acak Lengkap (RAL faktorial dengan 2 faktor yaitu konsentrasi ekstrak Sargassum sp. (0%, 1%, 1,5% dan 2% dan lama penyimpanan (hari ke-0, hari ke-2, hari ke-4, dan hari ke-6. Hasil penelitian menunjukkan bahwa perbedaan penambahan konsentrasi ekstrak Sargassum sp. dan lama penyimpanan memberikan pengaruh nyata terhadap nilai PV, nilai TBA, kadar lemak, kadar protein, kadar air serta organoleptik (P < 0,05. Hasil penelitian tahap I didapatkan rendemen Sargassum sp. dengan pelarut etanol 96% sebesar 1,39%, kandungan fenol 1,813%, flavonoid 0,278% dan aktivitas antioksidan 99,1659 ppm (kuat. Hasil penelitian tahap II didapatkan nilai PV berkisar antara 2,03 - 19,82 meq/kg, nilai TBA 0,63 - 6,72 mg.mal/kg. Konsentrasi 1,5% merupakan konsentrasi terbaik ekstrak Sargassum sp. dalam menghambat oksidasi lemak pada fillet ikan patin selama penyimpanan. Kata kunci: Antioksidan, Ekstrak Sargassum sp., Lama Penyimpanan, Oksidasi lemak, Fillet Ikan patin ABSTRACT Catfish is a freshwater fish that contain high fat and protein so that if its stored it will susceptible to oxidation process which leads to rancidity. Sargassum sp. with its phenolic and flavonoid content are able to inhibit the oxidation process in catfish fillet. This research was aimed to know the effects of different concentrations of Sargassum sp. extracts and

Material flow in butt friction stir welds in AA2024-T3

International Nuclear Information System (INIS)

Schmidt, H.N.B.; Dickerson, T.L.; Hattel, J.H.

2006-01-01

The properties of a workpiece joined by friction stir welding (FSW) are directly related to the material flow around the tool. In the present work, the material flow is investigated by traditional metallography as well as X-ray and computer tomography (CT). By introducing a thin copper strip in the workpiece and welding through it, thus, acting as a marker material, detailed information about the flow field is gathered. The two- and three-dimensional CT images are used in parallel with micrographs for visualization of the flow field. Two procedures for estimating the average velocities for material flowing through the shear layer are presented. The procedures depend on the configuration of marker material relative to the welding direction, i.e. longitudinal and transverse. As such, the present work constitutes the first attempt in the literature to estimate flow velocities in FSW based on thorough experimental investigations

Efficiency of ascorbic acid and γ-rays to ameliorate the quality of ready-to-eat baked bolti fish fillets

International Nuclear Information System (INIS)

Tawfik, S.S.; El-Kabani, H.E.; SalIam, M.H.; Ragab, E.A.

2007-01-01

Ascorbic acid (vitamin C) is a reducing agent, inhibits oxidative reactions developed in cold-storage Bolti (Tilapia nilotica) fish. It is the most popular fish repasts in Egypt. To determine the influence of ascorbic acid on cooking (roasting) and irradiated fish fillets to extend their storage-time in refrigerators, 3 patches of fish fillets were prepared; control (0 kGy), ascorbic acid plus 2.5 kGy and ascorbic acid plus 4 kGy and were tested for bacteriological examination, chemical analysis and sensory evaluation at 0, 1, 2 and 3 weeks of cold storage at 5±1 degree C. The bacteriological examinations were total aerobic plate counts, psychotropic bacterial counts, Enterobacteriaceae counts, total mould and yeast counts and microbial pathogens counts (Salmonella and Vibrio species). The chemical analyses were thiobarbituric acid reactive substances (TBARS), inosine 5-monophosphate (IMP) concentration, hypoxanthine (HX) concentration, ph figure, total volatile nitrogen (TVN) and total trimethylamine nitrogen (TMA-N). The sensory evaluation was (texture and odour factors) of the cold-storage Bolti fish fillets samples. The results revealed that aerobically packed fish fillets samples treated with ascorbic acid plus 4 kGy after cooking had satisfied bacteriological, chemical and organoleptical trails. Conclusion: using of baking, irradiation combined with natural antioxidant nd refrigeration could reduce the energy requirements for freezing and costs for the marketing of ready- to-eat fish repasts. Recommendation: combination effects of γ-irradiation plus ascorbic acid in processing fish fillets help to preserve its quality. The possible strategies for improving fish fillets quality and acceptability are discussed

The effect of melanin-free extract from Sepia esculenta ink on lipid peroxidation, protein oxidation and water-holding capacity of tilapia fillet during cold storage.

Science.gov (United States)

Duan, Zhen-Hua; Liu, Hua-Zhong; Luo, Ping; Gu, Yi-Peng; Li, Yan-Qun

2018-03-14

Preservative effect of melanin-free extract of Sepia esculenta ink (MFESI) on Sparus latus fillet has been verified in our previous work. This study aims to further approach the mechanism of MFESI for extending the shelf-life of fish fillet during cold storage. Tilapia fillets were treated with different dosage of MFESI (0, 15, 25 and 35 mg/ml) and packed with preservative film for succedent cold-storage at 4 °C for scheduled time. Contents of total volatile basic nitrogen and sulfydryl and carbanyl groups were measured for evaluating protein oxidation. Malondialdehyde contents were measured for estimating lipid peroxidation and loss of water was used to determine water-holding capacity of fillet. The data indicated that MFESI not only possessed certain degree of antioxidant capacity in vitro, also lengthened shelf-life of tilapia fillet in cold-storage condition. Apart from 15 mg/ml, both 25 and 35 mg/ml of MFESI obviously prevented lipid and protein from oxidation and reduced loss of water from tilapia fillets, and the latter was more effective than the former. MFESI can repress lipid peroxidation and protein oxidation and reduce water loss, maintain the tilapia fillets quality and, thus, it could be an effective and natural preservative for extending the shelf-life of tilapia fillets during cold storage.

Use of the gapped bead-on-plate test to investigate hydrogen induced cracking of flux cored arc welds of a quenched and tempered steel

International Nuclear Information System (INIS)

Chen, Liang; Dunne, Druce; Davidson, Len

2014-01-01

Gapped bead-on-plate (G-BOP) testing of flux cored arc welds was conducted to assess the susceptibility to hydrogen induced cold cracking (HICC) of weld metal deposited on a high strength quenched and tempered steel. For preheat temperatures higher than 40°C, no weld metal cracking was observed using a shielding gas consisting of argon with 20% carbon dioxide. In contrast, the no-crack condition was not achieved for a shielding gas consisting of argon-5% carbon dioxide for preheat temperatures lower than 100°C. This extraordinary difference in weld metal HICC resistance indicates that, in general, the shielding gas mixture can exert a major influence on weld metal transverse cold cracking behaviour

Prediction of Weld Residual Stress of Narrow Gap Welds

International Nuclear Information System (INIS)

Yang, Jun Seog; Huh, Nam Su

2010-01-01

The conventional welding technique such as shield metal arc welding has been mostly applied to the piping system of the nuclear power plants. It is well known that this welding technique causes the overheating and welding defects due to the large groove angle of weld. On the other hand, the narrow gap welding(NGW) technique has many merits, for instance, the reduction of welding time, the shrinkage of weld and the small deformation of the weld due to the small groove angle and welding bead width comparing with the conventional welds. These characteristics of NGW affect the deformation behavior and the distribution of welding residual stress of NGW, thus it is believed that the residual stress results obtained from conventional welding procedure may not be applied to structural integrity evaluation of NGW. In this paper, the welding residual stress of NGW was predicted using the nonlinear finite element analysis to simulate the thermal and mechanical effects of the NGW. The present results can be used as the important information to perform the flaw evaluation and to improve the weld procedure of NGW

Evaluation of a method for determining concentrations of isoeugenol, an AQUI-S residue, in fillet tissue from freshwater fish species.

Science.gov (United States)

Meinertz, Jeffery R; Schreier, Theresa M; Bernardy, Jeffry A

2008-01-01

AQUI-S is a fish anesthetic/sedative that is approved for use in a number of countries throughout the world and has the potential for use in the United States. The active ingredient in AQUI-S is isoeugenol. A method for determining isoeugenol concentrations in edible fillet tissue is needed for regulatory purposes, including surveillance and potential use in studies fulfilling human food safety data requirements if U.S. Food and Drug Administration approval is pursued. A method was developed and evaluated for determining isoeugenol concentrations in fillet tissue using relatively common procedures and equipment. The method produced accurate and precise results with fillet tissue from 10 freshwater fish species. The percentage of isoeugenol recovered from samples fortified with isoeugenol at nominal concentrations of 1, 50, and 100 microg/g for all species was always >80 and fillet tissue containing biologically incurred isoeugenol was fillet tissue extracts from 9 of the 10 species. The method detection limits for all but one species ranged from 0.004 to 0.014 microg/g, and the quantitation limits ranged from 0.012 to 0.048 microg/g.

Quantification of fatty acids in salmon fillets conserved by different methods

Directory of Open Access Journals (Sweden)

Renata Menoci Gonçalves

2017-09-01

Full Text Available Lipid contents and the composition of fatty acids of fillets from Chilean salmon (Salmo salar were determined under different conservation methods: fresh salmon, frozen salmon, water-conserved canned salmon and frozen salmon in long-term storage. Fatty acid contents were determined by gas chromatography. The fillets had high lipid levels, ranging between 9.71 and 12.86%. All samples presented high levels of monounsaturated fatty acids, between 363.69 and 425.30 mg g-1 of total lipids, followed by polyunsaturated fatty acids (294.46 - 342.45 mg g-1 of total lipids and saturated fatty acids (203.32 - 223.17 mg g-1 of total lipids. Although samples revealed different lipid contents, all proved to be great sources of omega-3 fatty acids, regardless of the manner of conservation.

Cast-to-cast variation in end-plug welds for TRIGA fuel elements

International Nuclear Information System (INIS)

Gondac, C.; Truta, C.

2013-01-01

In the Institute for Nuclear Research (INR) Pitesti - TRIGA Reactor Department there are under development activities for assembling TRIGA-LEU fuel elements locally manufactured, through autogenous Tungsten-Inert-Gas (TIG) welding. Due to specific problems occurring in welding Ni alloys, namely the dissimilar joint between Inconel 600 and Inconel 800 at the end-plug weld, weldability tests on Inconel 600 under various conditions were performed. The tests had been carried out in two stages: basic tests, on simple turned rods of Inconel 600; confirmation tests, on real (actual) end plug –to – clad welding. The basic tests had been done on simple rods machined (turned) at 13.8 mm (main diameter of the plugs) on which there have been made simple semicircular weldings ( no joint involved). Confirmation tests were done on the plug-clad assembly (dissimilar welding Incoloy-Inconel), with the welding parameters resulted from the preliminary conclusions of the basic tests. After welding, the samples were transversally sectioned, prepared for metallographic examination according to the specific procedure. The samples were examined at the metallographic microscope, and photo records for each sectioned welding bead have been taken . Measurements have been made on the recorded photos resulting the essential characteristics of the penetration: width W, depth d and ratio W/d. From the obtained results the following conclusions can be formulated: the penetration depth of the end-plug weld at the TRIGA fuel element varies substantially depending on the material cast of which the plug is produced; the optimization tests had covered the whole range of parameters in which do not appear systematic defects in welds that are specific to the alloys of Nickel ( porosity, hot cracking); for 2011-2012 casts higher energy (640 As) is required compared to the welding energy used for the 2009 batch, but to be sure that the manufacturing requirements are fulfilled, it is necessary to carry

Influence of use of ultrasound on the mechanical properties of plated pieces by welding in ultrasonic field

Directory of Open Access Journals (Sweden)

Gh. Amza

2015-07-01

Full Text Available Plating by welding in an ultrasonic field represents a technological solution to increase resistance to corrosion and / or wear of pieces of the machinery industry. Research has been carried out for two types of parts, namely a piece of flange end type and bonnet type made of AISI 4130 steel, and as filler material for plating was used Inconel 625 Fe developed as electrode wire with a diameter of ø 1.2 / mm. The plating was done by depositing a single layer by welding in ultrasonic field, welding process in Ar 100/ % environment non-consumable tungsten electrode, WIG process, and when using ultrasonic activation it was used a longitudinal and a transverse wave with a frequency of 15 / kHz. For pieces plated by welding there have been made attempts of the hardness and tensile and bend shock.

Determination of total mercury in fillets of sport fishes collected from Folsom Reservoir, California, 2006

Science.gov (United States)

May, Thomas W.; Brumbaugh, William G.

2007-01-01

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom Reservoir in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fillets ranged from 0.031 to 0.20 micrograms per gram wet weight in rainbow trout (Oncorhynchus mykiss) samples and 0.071 to 0.16 micrograms per gram wet weight in bluegill (Lepomis macrochirus) samples. Mercury concentration was 0.98 microgram per gram wet weight in a single spotted bass (Micropterus punctulatus) sample, which was the only one in the sample set which exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Depletion of eugenol residues from the skin-on fillet tissue of rainbow trout exposed to 14C-labeled eugenol

Science.gov (United States)

Meinertz, Jeffery R.; Schreier, Theresa M.; Porcher, Scott T.; Smerud, Justin R.; Gaikowski, Mark P.

2014-01-01

The U.S. is lagging in access to an approved immediate-release sedative, i.e. a compound that can be safely and effectively used to sedate fish and has no withdrawal period. AQUI-S® 20E (10% active ingredient, eugenol) is under investigation as an immediate-release sedative for freshwater finfish. Because of its investigational status, data are needed to characterize the depletion, distribution, and identity of AQUI-S® 20E residues in fillet tissue. Rainbow trout (Oncorhynchus mykiss) were exposed to uniformly ring labeled 14C-eugenol at a nominal concentration of 10 mg/L for 60 min in 18 °C water. Fish (n = 6) were sampled immediately after the exposure (0 min) then at 30, 60, 120, and 240 min. Eugenol concentrations and characterization of 14C residues in the fillet tissue were determined by high pressure liquid chromatography and flow-through liquid scintillation counting techniques. Total 14C-residue burdens in fillet tissue were determined by tissue oxidation and static liquid scintillation counting techniques. Maximum eugenol and 14C-eugenol equivalent residue concentrations in the fillet tissue were measured immediately after the exposure (44.5 and 38.8 μg/g, respectively). Eugenol was the primary 14C-residue (> 90% of all 14C-residues) in extracts from fillet tissue taken from fish sampled immediately after the exposure (0 min) and from fish sampled at 30 and 60 min after the exposure. The depletion of 14C-eugenol residues from the fillet tissue was rapid (t1/2 = 26.25 min) after transferring the exposed fish to fresh flowing water.

Investigation on mechanical properties of welded material under different types of welding filler (shielded metal arc welding)

Science.gov (United States)

Tahir, Abdullah Mohd; Lair, Noor Ajian Mohd; Wei, Foo Jun

2018-05-01

The Shielded Metal Arc Welding (SMAW) is (or the Stick welding) defined as a welding process, which melts and joins metals with an arc between a welding filler (electrode rod) and the workpieces. The main objective was to study the mechanical properties of welded metal under different types of welding fillers and current for SMAW. This project utilized the Design of Experiment (DOE) by adopting the Full Factorial Design. The independent variables were the types of welding filler and welding current, whereas the other welding parameters were fixed at the optimum value. The levels for types of welding filler were by the models of welding filler (E6013, E7016 and E7018) used and the levels for welding current were 80A and 90A. The responses were the mechanical properties of welded material, which include tensile strength and hardness. The experiment was analyzed using the two way ANOVA. The results prove that there are significant effects of welding filler types and current levels on the tensile strength and hardness of the welded metal. At the same time, the ANOVA results and interaction plot indicate that there are significant interactions between the welding filler types and the welding current on both the hardness and tensile strength of the welded metals, which has never been reported before. This project found that when the amount of heat input with increase, the mechanical properties such as tensile strength and hardness decrease. The optimum tensile strength for welded metal is produced by the welding filler E7016 and the optimum of hardness of welded metal is produced by the welding filler E7018 at welding current of 80A.

Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella Typhimurium on Chicken Breast Fillet during Cooking

NARCIS (Netherlands)

Jong, de A.E.I.; Asselt, van E.D.; Zwietering, M.H.; Nauta, M.J.; Jonge, de R.

2012-01-01

The aim of this research was to determine the decimal reduction times of bacteria present on chicken fillet in boiling water. The experiments were conducted with Campylobacter jejuni, Salmonella, and Escherichia coli. Whole chicken breast fillets were inoculated with the pathogens, stored overnight

Preliminary Investigation on the Use of Allyi Isothiocyanate to Increase the Shelf-Life of Gilthead Sea Bream (Sparus Aurata) Fillets.

Science.gov (United States)

Giarratana, Filippo; Crinò, Chiara; Muscolino, Daniele; Beninati, Chiara; Ziino, Graziella; Giuffrida, Alessandro; Panebianco, Antonio

2015-06-30

The aim of this work is to evaluate the activity of allyl isothiocyanate (AITC) against fish spoilage bacteria (specific spoilage organisms; SSOs) as well as its possible use in gilthead sea bream ( Sparus aurata ) fillets to extend their shelf-life. In this regard, in vitro tests are carried out in order to evaluate the inhibitory activity of AITC and its vapours on several strains of SSOs. The AITC effect on the shelf-life of sea bream fillets was made by putting them in plastic trays hermetically closed with the addition AITC. Microbiological and sensorial evaluations were made on fish fillets during storage. Treated fillets maintained microbial populations at a significantly lower level compared with the control samples during storage, showing better sensorial characteristics. Therefore, the use of AITC's vapours seems to be a new and interesting alternative way to increase fish product shelf-life.

Pengaruh Kecepatan Putar Indentor Las Gesek Puntir (Friction Stir Welding Terhadap Kualitas Hasil Pengelasan Alumunium 1100-H18

Directory of Open Access Journals (Sweden)

Irza Sukmana

2016-03-01

Full Text Available Aluminum and their alloys have been applied in many industrial sectors. Although it shows a good corrosion properties, however welding process of aluminum still a challenge as it covered by oxide layer on the surface. Friction Stir Welding (FSW technology gives a potential chance to be used for joining process of aluminum. In this study, we use a vertical milling machine Milko-12 that has been utilized with indentor of FSW process for Aluminum 1100-H18 at 4 (four different rotation speed (Rt, i.e.: 352, 490, 653, and 910 rpm and constant transversal speed (V 20mm/minutes. Based on mechanical properties and metallography data of welded materials, the higher the Rt the higher the tensile strength. Rt of 653 rpm results the highest tensile strength of 107 MPa. The crack areas of all welded metals are at base metal (BM concluded that our vertical milling machine Milko-12 can be utilized for friction stir welding (FSW process for Aluminum.

Efficacy of sanitized ice in reducing bacterial load on fish fillet and in the water collected from the melted ice.

Science.gov (United States)

Feliciano, Lizanel; Lee, Jaesung; Lopes, John A; Pascall, Melvin A

2010-05-01

This study investigated the efficacy of sanitized ice for the reduction of bacteria in the water collected from the ice that melted during storage of whole and filleted Tilapia fish. Also, bacterial reductions on the fish fillets were investigated. The sanitized ice was prepared by freezing solutions of PRO-SAN (an organic acid formulation) and neutral electrolyzed water (NEW). For the whole fish study, the survival of the natural microflora was determined from the water of the melted ice prepared with PRO-SAN and tap water. These water samples were collected during an 8 h storage period. For the fish fillet study, samples were inoculated with Escherichia coli K12, Listeria innocua, and Pseudomonas putida then stored on crushed sanitized ice. The efficacies of these were tested by enumerating each bacterial species on the fish fillet and in the water samples at 12 and 24 h intervals for 72 h, respectively. Results showed that each bacterial population was reduced during the test. However, a bacterial reduction of fillet samples. A maximum of approximately 2 log CFU and > 3 log CFU reductions were obtained in the waters sampled after the storage of whole fish and the fillets, respectively. These reductions were significantly (P < 0.05) higher in the water from sanitized ice when compared with the water from the unsanitized melted ice. These results showed that the organic acid formulation and NEW considerably reduced the bacterial numbers in the melted ice and thus reduced the potential for cross-contamination.

Rigor index, fillet yield and proximate composition of cultured striped catfish (Pangasianodon hypophthalmus for its suitability in processing industries in Bangladesh

Directory of Open Access Journals (Sweden)

Salma Noor-E Islami

2014-12-01

Full Text Available Rigor-index in market-size striped catfish (Pangasianodon hypophthalmus, locally called Thai-Pangas was determined to assess fillet yield for production of value-added products. In whole fish, rigor started within 1 hr after death under both iced and room temperature conditions while rigor-index reached a maximum of 72.23% within 8 hr and 85.5% within 5 hr at room temperature and iced condition, respectively, which was fully relaxed after 22 hr under both storage conditions. Post-mortem muscle pH decreased to 6.8 after 2 hr, 6.2 after 8 hr and sharp increase to 6.9 after 9 hr. There was a positive correlation between rigor progress and pH shift in fish fillets. Hand filleting was done post-rigor and fillet yield experiment showed 50.4±2.1% fillet, 8.0±0.2% viscera, 8.0±1.3% skin and 32.0±3.2% carcass could be obtained from Thai-Pangas. Proximate composition analysis of four regions of Thai-Pangas viz., head region, middle region, tail region and viscera revealed moisture 78.36%, 81.14%, 81.45% and 57.33%; protein 15.83%, 15.97%, 16.14% and 17.20%; lipid 4.61%, 1.82%, 1.32% and 24.31% and ash 1.09%, 0.96%, 0.95% and 0.86%, respectively indicating suitability of Thai-Pangas for production of value-added products such as fish fillets.

Microbiology, sensory evaluation and shelf life of irradiated chicken breast fillets stored in air or vacuum

Directory of Open Access Journals (Sweden)

Samira Pirola Santos Mantilla

2011-06-01

Full Text Available This work investigated the effects of different packaging methods (air and vacuum combined with irradiation (0.0, 2.0 and 3.0 kGy on the preservation of chicken breast fillets stored at 1ºC for up to 18 days by sensorial test, determination of pH and bacterial growth. The findings indicated that the post-irradiation lag phase increased with the dose, leading to an extension in shelf-life. Vacuum-packed samples irradiated at 3.0 kGy exhibited the longest shelf life. Among the analyzed bacteria, coliforms and Listeria spp. were most sensitive to gamma radiation. All the fillets acquired more attractive coloration and better overall impression with irradiation. The combined use of vacuum packaging and irradiation (3.0 kGy reduced the microbial populations without causing change in pH and yielded a significant shelf-life extension of refrigerated fillets, besides improving its appearance.

The shelf life extension of refrigerated grass carp (Ctenopharyngodon idellus) fillets by chitosan coating combined with glycerol monolaurate.

Science.gov (United States)

Yu, Dawei; Jiang, Qixing; Xu, Yanshun; Xia, Wenshui

2017-08-01

A novel chitosan-based coating solution was prepared by combining glycerol monolaurate (GML) for shelf life extension of refrigerated grass carp fillets. The control and coated fillets were analyzed periodically for physicochemical (pH, thiobarbituric acid (TBA) value, total volatile basic nitrogen (TVB-N) value, K value, and shear force), microbiological (total viable counts (TVC), psychrophilic bacteria counts (PTC), Pseudomonads and H 2 S-producing bacteria) and sensorial characteristics. The results showed that chitosan-GML coated samples presented better quality preservation effects than chitosan coating alone. In addition, 2% chitosan enriched with 0.3% GML showed the significant (Pchitosan coating enriched with GML was a promising method to extend the shelf life of refrigerated fillets. Copyright © 2017. Published by Elsevier B.V.

The effect of single and double doses of gamma radiation on pre-rigor mortis filleted saithe

International Nuclear Information System (INIS)

Underdahl, B.; Lunde, G.

1973-01-01

Saithe, caught off the western coast of Norway, were filleted immediately after killing, packed in plastic bags and irradiated using a cobalt-60 source at the Institutt for Atomenergi, Kjeller. The doses were 50, 100, 150, 50+50 and 50+100 krad. All samples were analysed for their total bacterial count, proteolytic activity, ammonia, total volatile acids, trimethylamine oxide, tri- and dimethylamine and formaldehyde. The organoleptic quality was evaluated by a panel of tasters. Double doses were more effective in reducing the total bacterial count than an equivalent single dose. A close relation was found between the bacterial count and the proteolytic activity. The trimethylamine oxide concentration was found to vary between 33 and 44 mg/100 g muscle, decreasing rapidly in non-irradiated fillets to 3 mg/100 g. In non-irradiated fillets trimethylamine oxide was mainly reduced to trimethylamine and in irradiated fillets to dimethylamine and formaldehyde. A split dose of 50+50 krad may have a favourable effect on the total bacterial number, but the analyses of proteolytic activity, the volatile acids and the trimethylamine indicate that a higher proportion of spoilage bacteria survive. The low proteolytic activity and the high content of DMA/FA prove that the split doses of 50+100 krad as compared with a single dose of 150 krad are particularly favourable in the case of saithe. (Auth.)

Activity of R(+) limonene on the maximum growth rate of fish spoilage organisms and related effects on shelf-life prolongation of fresh gilthead sea bream fillets.

Science.gov (United States)

Giarratana, Filippo; Muscolino, Daniele; Beninati, Chiara; Ziino, Graziella; Giuffrida, Alessandro; Panebianco, Antonio

2016-11-21

R(+)limonene (LMN) is the major aromatic compound in essential oils obtained from oranges, grapefruits, and lemons. The improvement of preservation techniques to reduce the growth and activity of spoilage microorganisms in foods is crucial to increase their shelf life and to reduce the losses due to spoilage. The aim of this work is to evaluate the effect of LMN on the shelf life of fish fillets. Its effectiveness was preliminarily investigated in vitro against 60 strains of Specific Spoilage Organisms (SSOs) and then on gilt-head sea bream fillets stored at 2±0.5°C for 15days under vacuum. LMN showed a good inhibitory effect against tested SSOs strains. On gilt-head sea bream fillets, LMN inhibited the growth SSOs effectively, and its use resulted in a shelf-life extension of ca. 6-9days of treated fillets, compared to the control samples. The LMN addition in Sparus aurata fillets giving a distinctive smell and like-lemon taste to fish fillets that resulted pleasant to panellists. Its use contributed to a considerable reduction of fish spoilage given that the fillets treated with LMN were still sensory acceptable after 15days of storage. LMN may be used as an effective antimicrobial system to reduce the microbial growth and to improve the shelf life of fresh gilt-head sea bream fillets. Copyright © 2016 Elsevier B.V. All rights reserved.

SAFT and TOFD evaluation for ultrasonic testing of longitudinal welds in large-diameter pipes; SAFT- und TOFD-Auswertung fuer die Ultraschall-Schweissnahtpruefung von laengsnahtgeschweissten Grossrohren

Energy Technology Data Exchange (ETDEWEB)

Rieder, Hans; Dillhoefer, Alexander; Spies, Martin [Fraunhofer-Institut fuer Techno- und Wirtschaftsmathematik ITWM, Kaiserslautern (Germany); Graff, Alfred; Orth, Thomas [Salzgitter Mannesmann Forschung GmbH, Duisburg (Germany); Kersting, Thomas [Europipe GmbH, Muelheim an der Ruhr (Germany). Werk Muelheim

2010-07-01

The authors present a mobile multichannel system for testing of longitudinal welds in large-diameter tubes. The prototype was designed for in situ inspection of longitudinal welds using transversal and longitudinal waves impacting at an angle from both sides in combined SE and IE operation. The reconstruction and imaging software enables SAFT calculations for all surface curves and superposition of the SAFT reconstructions from both sides into a general image of the weld. This includes superposition of the TOFD test data with a suitable evaluation and assessment concept. Details are presented, as are test results on test pieces for validation and on longitudinal welds in large-diameter tubes. (orig.)

Kaftas prepared with V-shaped filleting chips of the Nile tilapia (Oreochromis niloticus exposed to smoking techniques

Directory of Open Access Journals (Sweden)

Maria Luiza Rodrigues de Souza

2015-05-01

Full Text Available Kaftas with V-shaped filleting chips of the Nile tilapia (Oreochromis niloticus were developed and the effects of the smoking technique on the characteristics of chemical composition, microbiological, sensory and benzo(apyrene were investigated. The filleting chips were ground and filleting included condiments and bacon. Kaftas were molded, frozen and distributed in a completely randomized design with three treatments (T 1 = baked in a grid; T 2 = smoked by friction and T 3 = smoked by liquid smoke with 10 replications. The kaftas subjected to hot smoke had lower moisture content (13.97%, whereas the no-smoking kaftas had the highest content (20.49%. Kaftas with liquid smoke had high crude protein content (48.06% and ash (9.49%, whereas the ash content was different only from no-smoking kaftas (8.79%. There was no significant difference in sensory parameters, except for flavor; smoked kaftas with liquid smoke were more accepted by the judges and the worst kaftas were no-smoked kaftas. Microbiological analysis showed that kaftas developed were appropriate to feed human beings within the required standards. Chips filleting is an alternative for the development of kaftas and those subjected to liquid smoke were considered the best.

Rancidity development of refrigerated rainbow trout (Oncorhynchus mykiss) fillets: comparative effects of in vivo and in vitro lycopene.

Science.gov (United States)

Ehsani, Ali; Jasour, Mohammad Sedigh; Agh, Naser; Hashemi, Mohammad; Khodadadi, Mahdi

2018-01-01

The problem of lipid oxidation in fish during storage is well known and is related to both temperature and storage time. Antioxidants could have a main role in limiting the deteriorative effects of lipid oxidation in fish. The present study aimed to investigate the effect of dietary supplement against postmortem addition of lycopene on the deterioration of trout fillets during storage at 4 ± 1 °C for 12 days. At the end of the feeding trial, no significant differences were observed with respect to the fatty acid composition of different dietary groups. However, a strong positive correlation (r = 0.96) was observed between fillet and diet lycopene levels. Lower indices of lipid oxidation (peroxide value and thiobarbituric acid) and lipid hydrolysis (free fatty acids) were observed in fillets that received lycopene (P lycopene was more effective (P lycopene in delaying lipid oxidation, the fatty acid composition of fillets that received dietary lycopene supplement showed a higher stability (P lycopene, especially at higher levels, was more effective in terms of quality parameters. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Weld Nugget Temperature Control in Thermal Stir Welding

Science.gov (United States)

Ding, R. Jeffrey (Inventor)

2014-01-01

A control system for a thermal stir welding system is provided. The control system includes a sensor and a controller. The sensor is coupled to the welding system's containment plate assembly and generates signals indicative of temperature of a region adjacent and parallel to the welding system's stir rod. The controller is coupled to the sensor and generates at least one control signal using the sensor signals indicative of temperature. The controller is also coupled to the welding system such that at least one of rotational speed of the stir rod, heat supplied by the welding system's induction heater, and feed speed of the welding system's weld material feeder are controlled based on the control signal(s).

A New Approach to Predict the Fish Fillet Shelf-Life in Presence of Natural Preservative Agents.

Science.gov (United States)

Giuffrida, Alessandro; Giarratana, Filippo; Valenti, Davide; Muscolino, Daniele; Parisi, Roberta; Parco, Alessio; Marotta, Stefania; Ziino, Graziella; Panebianco, Antonio

2017-04-13

Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS) were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets.

Dissimilar friction stir welds in AA5083-AA6082: The effect of process parameters on residual stress

International Nuclear Information System (INIS)

Steuwer, A.; Peel, M.J.; Withers, P.J.

2006-01-01

The effect of tool traverse and rotation speeds on the residual stresses are quantified for welds between non-age-hardening AA5083 and age-hardening AA6082 and compared to single alloy joints made from each of the two constituents. The residual stresses have been characterised non-destructively by neutron diffraction and synchrotron X-ray diffraction. The region around the weld line was characterised by significant tensile residual stress fields which are balanced by compressive stresses in the parent material. The rotation speed of the tool has been found to have a substantially greater influence than the transverse speed on the properties and residual stresses in the welds, particularly on the AA5083 side where the location of the peak stress moves from the stir zone to beyond the edge of the tool shoulder. The changes in residual stress are related to microstructural and hardness changes as determined in a previous study . In particular the larger stresses under the weld tool on the AA5083 side compared to the AA6082 side are related to a transient reduction in yield stress due to dissolution of the hardening precipitates during welding prior to natural aging after welding

Transition welds in welding of two-ply steels

International Nuclear Information System (INIS)

Fartushnyj, V.G.; Evsyukov, Yu.G.

1977-01-01

Studied were physico-mechanical properties of welds made by various welding wires of chromium-nickel and nickel-chromium steels in submerged arc welding of double-layer steels with main layer of the VSt.3sp. carbon steel. It is shown that service-reliable structures welded of two-layer steels are obtained by providing the content from 11 to 20 % Ni in the automatically welded transition layer

Head waves in ultrasonic testing. Physical principle and application to welded joint testing

International Nuclear Information System (INIS)

Wustenberg, H.; Erhard, A.

1984-01-01

A head wave sensor is developed from distinct emitter and receiver sensors using longitudinal waves under a 70 0 incidence. These heat wave sensors present a high sensitivity for underlying cracks and are not influenced by surface accidents like liquid drops or welding projection. They are multi mode sensors emitting simultaneously longitudinal head waves, a main longitudinal lobe and a transverse wave with a maximum at about 38 0 . This wave combination can be used for automatic testing of welded joints even with austenitic materials for defect detection near internal or external surfaces. This process can substitute or complete liquid penetrant inspection or magnetic inspection for testing pipes (13 references are given) [fr

Inclusion of Palmaria palmata (red seaweed) in Atlantic salmon diets: effects on the quality, shelf-life parameters and sensory properties of fresh and cooked salmon fillets.

Science.gov (United States)

Moroney, Natasha C; Wan, Alex H L; Soler-Vila, Anna; FitzGerald, Richard D; Johnson, Mark P; Kerry, Joe P

2015-03-30

The use of Palmaria palmata (PP) as a natural ingredient in farmed Atlantic salmon diets was investigated. The effect of salmon diet supplementation with P. palmata (0, 5, 10 and 15%) or synthetic astaxanthin (positive control, PC) for 16 weeks pre-slaughter on quality indices of fresh salmon fillets was examined. The susceptibility of salmon fillets/homogenates to oxidative stress conditions was also measured. In salmon fillets stored in modified atmosphere packs (60% N2 /40% CO2 ) for up to 15 days at 4 °C, P. palmata increased surface -a* (greenness) and b* (yellowness) values in a dose-dependent manner, resulting in a final yellow/orange flesh colour. In general, the dietary addition of P. palmata had no effect on pH, lipid oxidation (fresh, cooked and fillet homogenates) and microbiological status. 'Eating quality' sensory descriptors (texture, odour and oxidation flavour) in cooked salmon fillets were not influenced by dietary P. palmata. Salmon fed 5% PP showed increased overall acceptability compared with those fed PC and 0% PP. Dietary P. palmata was ineffective at providing red coloration in salmon fillets, but pigment deposition enhanced fillets with a yellow/orange colour. Carotenoids from P. palmata may prove to be a natural pigment alternative to canthaxanthin in salmon feeds. © 2014 Society of Chemical Industry.

Effects of transportation stress on quality and sensory profiles of Nile tilapia fillets

Directory of Open Access Journals (Sweden)

Elenice Souza dos Reis Goes

Full Text Available ABSTRACT: This study evaluated pre-slaughter stress and its influence on the stress indicators, quality characteristics and sensory characteristics of Nile tilapia fillets. To this end, two experiments were conducted: (1 two transportation times (60 and 240 min, with a density of 200 kg m−3, were compared to control treatment fish (in which the fish were removed from the net cage and immediately euthanized; and (2 two transportation densities (100 and 400 kg m−3, transported for 180 min, compared with control treatment fish. In experiment 1, the transportation time of 60 min resulted in higher levels of serum cortisol and plasma glucose compared to the transportation time of 240 min and the control. Fish fillets transported for 240 min had higher water-holding capacity, less water loss by pressure and higher levels of juiciness compared to fish transported for 60 min. Color, pH and water loss during cooking were not affected by transportation time. In experiment 2, transportation densities of 100 and 400 kg m−3 did not significantly affect the stress indicators nor the instrumental quality parameters of the fillets, but fish transported at 400 kg m−3 showed better visual acceptance by panellists.

Fatty acids and amino acids contents in Scomber scombrus fillets ...

African Journals Online (AJOL)

Proximate composition, fats and amino acids of Atlantic Mackerel fillets (Scomber scombrus) from the South East of Tunisia in different seasons, were analyzed in order to assess nutritive characteristics of this species. Samples were collected monthly from Zarzis fishing port located in the South-East of Tunisia. Total fats and ...

Weld controller for automated nuclear service welding

International Nuclear Information System (INIS)

Barfield, K.L.; Strubhar, P.M.; Green, D.I.

1995-01-01

B and W Nuclear Technologies (BWNT) uses many different types of weld heads for automated welding in the commercial nuclear service industry. Some weld heads are purchased as standard items, while others are custom designed and fabricated by BWNT requiring synchronized multiaxis motion control. BWNT recently completed a development program to build a common weld controller that interfaces to all types of weld heads used by BWNT. Their goal was to construct a system that had the flexibility to add different modules to increase the capability of the controller as different application needs become necessary. The benefits from having a common controller are listed. This presentation explains the weld controller system and the types of applications to which it has been applied

Effects of baked and raw salmon fillet on lipids and n-3 PUFAs in serum and tissues in Zucker fa/fa rats

OpenAIRE

Vikøren, Linn Anja Slåke; Drotningsvik, Aslaug; Bergseth, Marthe Tønder; Mjøs, Svein Are; Mola, Nazanin; Leh, Sabine Maria; Mellgren, Gunnar; Gudbrandsen, Oddrun Anita

2017-01-01

ABSTRACT Knowledge of the health impact of consuming heat-treated versus raw fish fillet is limited. To investigate effects of baked or raw salmon fillet intake on lipids and n-3 PUFAs in serum and tissues, obese Zucker fa/fa rats were fed diets containing 25% of protein from baked or raw salmon fillet and 75% of protein from casein, or casein as the sole protein source (control group) for four weeks. Salmon diets had similar composition of amino and fatty acids. Growth and energy intake were...

Effect of using the double layer technique on the microstructure, microhardness and residual stress of welded ASTM A516 GR70 structural steel

International Nuclear Information System (INIS)

Oliveira, George Luiz Gomes de; Miranda, Helio Cordeiro de

2010-01-01

The aim of this work is to evaluate the effect of using the double layer technique on the microstructure, microhardness and residual stresses of welded ASTM A516 Gr70 structural steel. Samples were welded with the same welding parameters and two types of chamfers, while the samples welded using the double layer technique underwent a buttering process on their chamfer face. Residual stress measurement was accomplished through x-ray diffraction, using a mini diffractometer for measurement in field. Metallographic analysis was accomplished in the transverse section of the welded joint, using optic microscopy and scanning electron microscopy. The double layer technique showed that can be used in the welding of ASTM A516 Gr70 steel, because, besides promote a refinement and a drawing back of the CG-HAZ, it increased compressive residual stress in the whole surface of the analyzed samples.(author)

Use of servo controlled weld head for end closure welding

Energy Technology Data Exchange (ETDEWEB)

Pathak, S.K.; Setty, D.S.; Rameswara Rao, A.; Hemantha Rao, G.V.S.; Jayaraj, R.N. [Nuclear Fuel Complex, Dept. of Atomic Energy, Hyderabad (India)

2010-07-01

In the PHWR fuel fabrication line resistance welding processes are used for joining various zirconium based alloy components to fuel tube of similar material. The quality requirement of these welding processes is very stringent and has to meet all the product requirements. At present these welding processes are being carried out by using standard resistance welding machines. In the resistance welding process in addition to current and time, force is one of the critical and important parameter, which influences the weld quality. At present advanced feed back type fast response medium frequency weld controllers are being used. This has upslope/down slope, constant and repetitive weld pattern selection features makes this critical welding process more reliable. Compared to weld controllers, squeeze force application devices are limited and normally standard high response pneumatic cylinders are used in the welding process. With this type of devices the force is constant during welding process and cannot be varied during welding process as per the material deformation characteristics. Similarly due to non-availability of feed back systems in the squeeze force application systems restricts the accuracy and quality of the welding process. In the present paper the influence of squeeze force pattern on the weld quality using advanced feed back type servo based force control system was studied. Different squeeze forces were used during pre and post weld heat periods along with constant force and compared with the weld quality. (author)

Influence of in-package cold plasma treatment on microbiological shelf life and appearance of fresh chicken breast fillets.

Science.gov (United States)

Wang, Jiamei; Zhuang, Hong; Hinton, Arthur; Zhang, Jianhao

2016-12-01

The effect of in-package cold plasmas (CP) was studied on microbiological shelf life and surface lightness of fresh chicken fillets (pectoralis major). Chicken fillets were packaged in food trays in air or modified atmosphere (MA) gas (O2:CO2:N2 = 65:30:5) and stored at 4 °C after exposed to an in-package cold plasma (80 kV for 180 s) treatment. Populations of mesophiles, psychrophiles, and pseudomonas spp. were measured as indicators for microbiological shelf life and CIELAB L(∗) values as an indicator for raw meat appearance. Results show that regardless of microbial type, there were no significant differences in microbial counts between the control and CP treated chicken fillets packed in air. However, in the MA packages, microbial counts were consistently lower than the non-treated control during refrigerated storage. Regardless of CP treatment, the microbial counts on the samples packed in air were much higher than in MA. They were more than 6 logs cfu/g in air compared to fewer than 4 logs cfu/g in MA after 7 d storage and fewer than 6 logs cfu/g after 14 d storage. Regardless of CP treatment and gas composition in package, there were no significant differences in the surface L(∗) value between the fillets pre-treatment and those after storage at 4 °C. These results demonstrate that the effects of in-package CP treatments on microbiological shelf life of fresh chicken fillets depend upon headspace composition in packages. When fresh chicken fillets are packed in air, CP treatment has no effect on microbiological shelf life. MA packages with high O2 and CO2 significantly extend shelf life and CP treatment with MA can at least double shelf life of fresh chicken meat (more than 14 days). Regardless of headspace composition, in-package CP does not have negative effects on chicken meat appearance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Welding hazards

International Nuclear Information System (INIS)

Khan, M.A.

1992-01-01

Welding technology is advancing rapidly in the developed countries and has converted into a science. Welding involving the use of electricity include resistance welding. Welding shops are opened in residential area, which was causing safety hazards, particularly the teenagers and children who eagerly see the welding arc with their naked eyes. There are radiation hazards from ultra violet rays which irritate the skin, eye irritation. Welding arc light of such intensity could damage the eyes. (Orig./A.B.)

Efficacy evaluation of a new water sanitizer for increasing the shelf life of Southern Australian King George Whiting and Tasmanian Atlantic Salmon fillets.

Science.gov (United States)

Khazandi, Manouchehr; Deo, Permal; Ferro, Sergio; Venter, Henrietta; Pi, Hongfei; Crabb, Simon; Amorico, Tony; Ogunniyi, Abiodun D; Trott, Darren J

2017-12-01

The bacterial species and specific spoilage organisms associated with the Southern Australian King George Whiting (KGW) and Tasmanian Atlantic Salmon (TAS), and the efficacy of a HOCl-containing water-based sanitization product (Electro-Chemically Activated Solution, by ECAS4) in extending the shelf life of KGW and TAS fillets were evaluated. Fillets were washed with an ECAS4 solution containing either 45 ppm or 150 ppm of free chlorine and bacterial species enumerated on selective and non-selective media, followed by identification of pure isolates by 16 S rRNA gene sequencing. The dominant spoilage microbiota in KGW and TAS fillets stored at 4 ± 1 °C were Pseudomonas spp. and Shewanella spp. At either concentration, ECAS4 significantly reduced total bacterial load and specific spoilage organisms on KGW and TAS fillets (approx. 1-2 log colony-forming units) during storage and significantly extended the shelf life of the fillets by 2 and 4 days, respectively. The significant increase in shelf life and quality of fillets was corroborated by raw and cooked sensory evaluation. ECAS4 sanitization could have a significant impact on the overall food industry, translating into health and economic benefits through reduction of food spoilage bacteria and potentially, foodborne pathogens without many of the disadvantages of currently approved biocides. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Comparison of the Effects of Packaging Containing Nano ZnO or Polylysine on the Microbial Purity and Texture of Cod (Gadus morhua) Fillets

Science.gov (United States)

Mizielińska, Małgorzata; Kowalska, Urszula; Jarosz, Michał; Sumińska, Patrycja

2018-01-01

Portions of fresh Baltic cod fillets were packed into cellulose boxes (control samples), which were covered with Methyl Hydroxypropyl Celluloses (MHPC) coating with 2% polylysine. The cellulose boxes had square PE films and were enclosed in MHPC coating containing ZnO nanoparticles. The cod fillets were stored at 5 °C and examined after 72 h and 144 h storage times. Results obtained in this study showed that the textural parameters of the cod fillets increased, with both Springiness and Cohesiveness found greater after 144 h of storage for all analysed packaging materials. The Gumminess of fillets increased after storage, but the lowest increase was noted in cod samples that were stored in boxes containing PE films with ZnO nanoparticles. It was found that water loss from the cod fillets in these boxes was also lowest. The Adhesiveness of the fish samples stored in boxes devoid of active coatings also increased. In contrast to the packaging material devoid of active coatings, the storage of fillets in active coating boxes resulted in a decrease of adhesiveness. Microbial analysis showed that packaging material containing nano-ZnO was found to be more active against mesophilic and psychotropic bacterial cells than the coatings with polylysine after 72 h and 144 h of storage. PMID:29534544

A Comparison of the Effects of Packaging Containing Nano ZnO or Polylysine on the Microbial Purity and Texture of Cod (Gadus morhua Fillets

Directory of Open Access Journals (Sweden)

Małgorzata Mizielińska

2018-03-01

Full Text Available Portions of fresh Baltic cod fillets were packed into cellulose boxes (control samples, which were covered with Methyl Hydroxypropyl Celluloses (MHPC coating with 2% polylysine. The cellulose boxes had square PE films and were enclosed in MHPC coating containing ZnO nanoparticles. The cod fillets were stored at 5 °C and examined after 72 h and 144 h storage times. Results obtained in this study showed that the textural parameters of the cod fillets increased, with both Springiness and Cohesiveness found greater after 144 h of storage for all analysed packaging materials. The Gumminess of fillets increased after storage, but the lowest increase was noted in cod samples that were stored in boxes containing PE films with ZnO nanoparticles. It was found that water loss from the cod fillets in these boxes was also lowest. The Adhesiveness of the fish samples stored in boxes devoid of active coatings also increased. In contrast to the packaging material devoid of active coatings, the storage of fillets in active coating boxes resulted in a decrease of adhesiveness. Microbial analysis showed that packaging material containing nano-ZnO was found to be more active against mesophilic and psychotropic bacterial cells than the coatings with polylysine after 72 h and 144 h of storage.

A new approach to predict the fish fillet shelf-life in presence of natural preservative agents

Directory of Open Access Journals (Sweden)

Alessandro Giufffrida

2017-06-01

Full Text Available Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets.

ULiAS 4 - Experimental validation of a software that models ultrasonic wave propagation through an anisotropic weld

International Nuclear Information System (INIS)

Wirdelius, Haakan; Persson, Gert; Hamberg, Kenneth; Hoegberg, Kjell

2008-01-01

New and stronger demands on reliability of used NDE/NDT procedures and methods have evolved in Europe during the last decade. In order to elaborate these procedures, efforts have to be taken towards the development of mathematical models of applied NDT methods. Modelling of ultrasonic non-destructive testing is useful for a number of reasons, e.g. physical understanding, parametric studies, and the qualification of procedures and personnel. An important issue regarding all models is the validation, i.e. securing that the results of the model and the corresponding computer programs are correct. This can be accomplished by comparisons with other models, but ultimately by comparisons with experiments. In this study a numerical model and experimental results are compared and the work has been performed in collaboration with SQC Kvalificeringscentrum AB. Four different welds have been investigated to give basic data to a mathematical model that describes the ultra sonic wave paths through the welds in these materials. The welds are made in austenitic stainless steel (type 18-8) and in Inconel 182. Two cuts outs are made in each weld, one longitudinal and one transversal cut across the welds, in order to determine the material orientation. In the numerical model the incident field, described by rays, is given by a P wave probe model. The ray tracing technique is based on geometrical optics and a 2D algorithm has been developed. The model of the weld is based on a relatively primitive assumption of the grain structure for a V-butt weld. The columnar structure of austenitic welds is here modelled as a weld where each sub region corresponds to a grain group. The response of the receiver is calculated according to Auld's reciprocity principle. UT data collection was performed by SQC according to guidelines given from Chalmers. The purpose to collect data from real inspection objects with known material structure is to compare experimental data with theoretically calculated

ULiAS 4 - Experimental validation of a software that models ultrasonic wave propagation through an anisotropic weld

Energy Technology Data Exchange (ETDEWEB)

Wirdelius, Haakan; Persson, Gert; Hamberg, Kenneth (SCeNDT, Chalmers Univ. Of Tech., SE-412 96 Goeteborg (SE)); Hoegberg, Kjell (SQC Kvalificeringscentrum AB, SE-183 25 Taeby (SE))

2008-07-01

New and stronger demands on reliability of used NDE/NDT procedures and methods have evolved in Europe during the last decade. In order to elaborate these procedures, efforts have to be taken towards the development of mathematical models of applied NDT methods. Modelling of ultrasonic non-destructive testing is useful for a number of reasons, e.g. physical understanding, parametric studies, and the qualification of procedures and personnel. An important issue regarding all models is the validation, i.e. securing that the results of the model and the corresponding computer programs are correct. This can be accomplished by comparisons with other models, but ultimately by comparisons with experiments. In this study a numerical model and experimental results are compared and the work has been performed in collaboration with SQC Kvalificeringscentrum AB. Four different welds have been investigated to give basic data to a mathematical model that describes the ultra sonic wave paths through the welds in these materials. The welds are made in austenitic stainless steel (type 18-8) and in Inconel 182. Two cuts outs are made in each weld, one longitudinal and one transversal cut across the welds, in order to determine the material orientation. In the numerical model the incident field, described by rays, is given by a P wave probe model. The ray tracing technique is based on geometrical optics and a 2D algorithm has been developed. The model of the weld is based on a relatively primitive assumption of the grain structure for a V-butt weld. The columnar structure of austenitic welds is here modelled as a weld where each sub region corresponds to a grain group. The response of the receiver is calculated according to Auld's reciprocity principle. UT data collection was performed by SQC according to guidelines given from Chalmers. The purpose to collect data from real inspection objects with known material structure is to compare experimental data with theoretically

Radiation decontamination of Bolti Nile fish (Tilapia nilotica) and its fillets from some pathogenic and market bacteria

International Nuclear Information System (INIS)

Elfouly, M.Z.; Abdelbaki, M.M.; Roushdy, M.M.; Taha, R.A.; Yousef, B.M.

1984-01-01

Application of different dose levels of gamma radiation (0.25-3.0 KGy) on bolti fish resulted in remarkable suppression of the pathogenic organisms contaminating the samples. The D 10 values were found to be 0.31, 0.55 and 0.63 KGy for the Escherichia coli, Staphylococcus aureus and Streptococcus faecalis respectively. It has been found that the dose of 3.0 KGy is almost sufficient for 5 log cycles reduction of strept. faecalis being the most radio-resistant species of these organisms. Irradiation considerably decreased the numbers of salmonella typhimurium artificially contaminated the whole bolti fish and bolti fillets. The D 10 value of S.thyphimurium for whole bolti fillets. For the reduction of 5 log cycles of S.typhimurium, radiation dose levels of at least 4.50 KGy for the whole fish and 2.0 KGy for fish fillets were required

Advanced Welding Concepts

Science.gov (United States)

Ding, Robert J.

2010-01-01

Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.

Resistance seam welding

International Nuclear Information System (INIS)

Schueler, A.W.

1977-01-01

The advantages and disadvantages of the resistance seam welding process are presented. Types of seam welds, types of seam welding machines, seam welding power supplies, resistance seam welding parameters and seam welding characteristics of various metals

Residual stress measurement of electron beam welded copper plates using prism hole drilling method

International Nuclear Information System (INIS)

Laakkonen, M.

2013-12-01

Eleven electron beam (EB) welded copper plates were measured in this investigation with Prism hole drilling equipment made by Stresstech Oy. All samples contained a linear weld in their center. Two different sets of plates were measured in this investigation. The first set included five samples (X436, X437, X438, X439 and X440) which were welded using four different welding speeds. Samples X439 and X440 were welded with the same speed but X440 is the only sample of the set that received a cosmetic pass. The second set received heat treatments at four different temperatures. Samples X456 and X458 were annealed at the same temperature but sample X456 received a cosmetic pass while X458 did not. Samples X455 and X457 were both annealed at a different temperature, with (X455) or without (X457) the cosmetic pass. Two areas were machined from the samples. About five millimeters was machined from the surfaces on the both of areas. Machined surfaces located on the top surfaces. The measurement points on the top surface are located on the weld and 20 mm and 120 mm from the weld on machined areas. Lower surface measurements are located -20 mm, 20 mm and 120 mm from the weld. All measurements were about 122 mm from the edges perpendicular to the weld. The top surfaces of all samples were machined in two areas across the weld. About 5 mm were removed. Stress measurements on the top surfaces were performed in these two areas, on the weld and 20 mm and 120 mm away from the weld. Stresses were also measured on the back sides, at -20 mm, 20 mm and 120 mm distance from the weld. All measurement locations were about 122mm from the sample edges. Most of the measurements give tensile strengths from 0 MPa to 30 MPa. Stresses parallel to the weld were slightly higher than weld stresses in transverse direction. The machined surfaces have residual stress values above 30 MPa near the surface. (orig.)

Residual stress measurement of electron beam welded copper plates using prism hole drilling method

Energy Technology Data Exchange (ETDEWEB)

Laakkonen, M. [Stresstech Oy, Jyvaeskylae (Finland)

2013-12-15

Eleven electron beam (EB) welded copper plates were measured in this investigation with Prism hole drilling equipment made by Stresstech Oy. All samples contained a linear weld in their center. Two different sets of plates were measured in this investigation. The first set included five samples (X436, X437, X438, X439 and X440) which were welded using four different welding speeds. Samples X439 and X440 were welded with the same speed but X440 is the only sample of the set that received a cosmetic pass. The second set received heat treatments at four different temperatures. Samples X456 and X458 were annealed at the same temperature but sample X456 received a cosmetic pass while X458 did not. Samples X455 and X457 were both annealed at a different temperature, with (X455) or without (X457) the cosmetic pass. Two areas were machined from the samples. About five millimeters was machined from the surfaces on the both of areas. Machined surfaces located on the top surfaces. The measurement points on the top surface are located on the weld and 20 mm and 120 mm from the weld on machined areas. Lower surface measurements are located -20 mm, 20 mm and 120 mm from the weld. All measurements were about 122 mm from the edges perpendicular to the weld. The top surfaces of all samples were machined in two areas across the weld. About 5 mm were removed. Stress measurements on the top surfaces were performed in these two areas, on the weld and 20 mm and 120 mm away from the weld. Stresses were also measured on the back sides, at -20 mm, 20 mm and 120 mm distance from the weld. All measurement locations were about 122mm from the sample edges. Most of the measurements give tensile strengths from 0 MPa to 30 MPa. Stresses parallel to the weld were slightly higher than weld stresses in transverse direction. The machined surfaces have residual stress values above 30 MPa near the surface. (orig.)

Welding method, and welding device for use therein, and method of analysis for evaluating welds

NARCIS (Netherlands)

Aendenroomer, A.J.; Den Ouden, G.; Xiao, Y.H.; Brabander, W.A.J.

1995-01-01

Described is a method of automatically welding pipes, comprising welding with a pulsation welding current and monitoring, by means of a sensor, the variations occurring in the arc voltage caused by weld pool oscillations. The occurrence of voltage variations with only frequency components below 100

Comparison of Welding Residual Stresses of Hybrid Laser-Arc Welding and Submerged Arc Welding in Offshore Steel Structures

DEFF Research Database (Denmark)

Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen

2016-01-01

In the offshore industry, welding-induced distortion and tensile residual stresses have become a major concern in relation to the structural integrity of a welded structure. Particularly, the continuous increase in size of welded plates and joints needs special attention concerning welding induced...... residual stresses. These stresses have a negative impact on the integrity of the welded joint as they promote distortion, reduce fatigue life, and contribute to corrosion cracking and premature failure in the weld components. This paper deals with the influence and impact of welding method on the welding...... induced residual stresses. It is also investigated whether the assumption of residual stresses up to yield strength magnitude are present in welded structures as stated in the design guidelines. The fatigue strength for welded joints is based on this assumption. The two welding methods investigated...

[Study on tetrodotoxin detection and toxic puffer fish identification of roasted fish fillet at the retail in Beijing and Qingdao].

Science.gov (United States)

Shen, Qing; Jiang, Tao; Li, Nan; Wang, Jiahui; Han, Chunhui; Zhang, Jing; Xu, Jin; Zhang, Dongfeng; Li, Fengqin

2014-11-01

The roasted fish fillet sample at the retail collected in Beijing and Qingdao were detected for TTX, and the TTX positive samples was analyzed for fish species identification. TTX was tested by EUSA method and the cytochrome c oxidase I (COI) genome of TTX-positive samples was extracted and identified by DNA barcode. Totally, 90 samples were tested by EUSA and 58 (64.4%) samples were positive for TTX with the levels ranging from 0.10 mg/kg to 63.81 mg/kg. Among the TTX positive samples, 24 (41.3%) were identified containing toxic puffer fish and 21 (87.5%) were Lagocephalus lunaris, the highly toxic puffer fish. Some roasted fish fillet samples obtained from the retail in two cities were positive for TTX and contained toxic puffer fish. Based on these results, we suggest that roasted fish fillet producers should prevent toxic puffer fish from mixing in the raw material and the I regulators should strengthen the TTX surveillance and product labeling supervision of roasted fish fillet.

Effect of Activated Flux on the Microstructure, Mechanical Properties, and Residual Stresses of Modified 9Cr-1Mo Steel Weld Joints

Science.gov (United States)

Maduraimuthu, V.; Vasudevan, M.; Muthupandi, V.; Bhaduri, A. K.; Jayakumar, T.

2012-02-01

A novel variant of tungsten inert gas (TIG) welding called activated-TIG (A-TIG) welding, which uses a thin layer of activated flux coating applied on the joint area prior to welding, is known to enhance the depth of penetration during autogenous TIG welding and overcomes the limitation associated with TIG welding of modified 9Cr-1Mo steels. Therefore, it is necessary to develop a specific activated flux for enhancing the depth of penetration during autogeneous TIG welding of modified 9Cr-1Mo steel. In the current work, activated flux composition is optimized to achieve 6 mm depth of penetration in single-pass TIG welding at minimum heat input possible. Then square butt weld joints are made for 6-mm-thick and 10-mm-thick plates using the optimized flux. The effect of flux on the microstructure, mechanical properties, and residual stresses of the A-TIG weld joint is studied by comparing it with that of the weld joints made by conventional multipass TIG welding process using matching filler wire. Welded microstructure in the A-TIG weld joint is coarser because of the higher peak temperature in A-TIG welding process compared with that of multipass TIG weld joint made by a conventional TIG welding process. Transverse strength properties of the modified 9Cr-1Mo steel weld produced by A-TIG welding exceeded the minimum specified strength values of the base materials. The average toughness values of A-TIG weld joints are lower compared with that of the base metal and multipass weld joints due to the presence of δ-ferrite and inclusions in the weld metal caused by the flux. Compressive residual stresses are observed in the fusion zone of A-TIG weld joint, whereas tensile residual stresses are observed in the multipass TIG weld joint.

Welding technology transfer task/laser based weld joint tracking system for compressor girth welds

Science.gov (United States)

Looney, Alan

1991-01-01

Sensors to control and monitor welding operations are currently being developed at Marshall Space Flight Center. The laser based weld bead profiler/torch rotation sensor was modified to provide a weld joint tracking system for compressor girth welds. The tracking system features a precision laser based vision sensor, automated two-axis machine motion, and an industrial PC controller. The system benefits are elimination of weld repairs caused by joint tracking errors which reduces manufacturing costs and increases production output, simplification of tooling, and free costly manufacturing floor space.

Friction Stir Welding

Science.gov (United States)

Nunes, Arthur C., Jr.

2008-01-01

Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and promises to be an important welding process for any industries where welds of optimal quality are demanded. This article provides an introduction to the FSW process. The chief concern is the physical effect of the tool on the weld metal: how weld seam bonding takes place, what kind of weld structure is generated, potential problems, possible defects for example, and implications for process parameters and tool design. Weld properties are determined by structure, and the structure of friction stir welds is determined by the weld metal flow field in the vicinity of the weld tool. Metal flow in the vicinity of the weld tool is explained through a simple kinematic flow model that decomposes the flow field into three basic component flows: a uniform translation, a rotating solid cylinder, and a ring vortex encircling the tool. The flow components, superposed to construct the flow model, can be related to particular aspects of weld process parameters and tool design; they provide a bridge to an understanding of a complex-at-first-glance weld structure. Torques and forces are also discussed. Some simple mathematical models of structural aspects, torques, and forces are included.

Numerical analysis of weld pool oscillation in laser welding

Energy Technology Data Exchange (ETDEWEB)

Cho, Jung Ho [Chungbuk National University, Cheongju (Korea, Republic of); Farson, Dave F [The Ohio State University, Columbus (United States); Hollis, Kendall; Milewski, John O. [Los Alamos National Laboratory, Los Alamos (United States)

2015-04-15

Volume of fluid (VOF) numerical simulation was used to investigate melt flow and volumetric oscillation of conduction-mode pulsed laser weld pools. The result is compared to high speed video stream of titanium laser spot welding experiment. The total simulation time is 10ms with the first 5 ms being heating and melting under constant laser irradiation and the remaining 5 ms corresponding to resolidification of the weld pool. During the melting process, the liquid pool did not exhibit periodic oscillation but was continually depressed by the evaporation recoil pressure. After the laser pulse, the weld pool was excited into volumetric oscillation by the release of pressure on its surface and oscillation of the weld pool surface was analyzed. The simulation model suggested adjusting thermal diffusivity to match cooling rate and puddle diameter during solidification which is distinguishable from previous weld pool simulation. The frequency continuously increased from several thousand cycles per second to tens of thousands of cycles per second as the weld pool solidified and its diameter decreased. The result is the first trial of investigation of small weld pool oscillation in laser welding although there have been several reports about arc welding.

Alternate Welding Processes for In-Service Welding

Science.gov (United States)

2009-04-24

Conducting weld repairs and attaching hot tap tees onto pressurized pipes has the advantage of avoiding loss of service and revenue. However, the risks involved with in-service welding need to be managed by ensuring that welding is performed in a rep...

Hybrid laser-TIG welding, laser beam welding and gas tungsten arc welding of AZ31B magnesium alloy

International Nuclear Information System (INIS)

Liu Liming; Wang Jifeng; Song Gang

2004-01-01

Welding of AZ31B magnesium alloy was carried out using hybrid laser-TIG (LATIG) welding, laser beam welding (LBW) and gas tungsten arc (TIG) welding. The weldability and microstructure of magnesium AZ31B alloy welded using LATIG, LBW and TIG were investigated by OM and EMPA. The experimental results showed that the welding speed of LATIG was higher than that of TIG, which was caught up with LBW. Besides, the penetration of LATIG doubles that of TIG, and was four times that of LBW. In addition, arc stability was improved in hybrid of laser-TIG welding compared with using the TIG welding alone, especially at high welding speed and under low TIG current. It was found that the heat affect zone of joint was only observed in TIG welding, and the size of grains in it was evidently coarse. In fusion zone, the equiaxed grains exist, whose size was the smallest welded by LBW, and was the largest by TIG welding. It was also found that Mg concentration of the fusion zone was lower than that of the base one by EPMA in three welding processes

Fundamental Study of Electron Beam Welding of AA6061-T6 Aluminum Alloy for Nuclear Fuel Plate Assembly (II)

International Nuclear Information System (INIS)

Kim, Soosung; Lee, Haein; Lee, Donbae; Park, Jongman; Lee, Yoonsang

2013-01-01

Certain characteristics, such as solidification cracking, porosity, HAZ (Heat-affected Zone) degradation must be considered during welding. Because of high energy density and low heat input, especially LBW and EBW processes posses the advantage of minimizing the fusing zone and HAZ and producing deeper penetration than arc welding processes. In present study, to apply for the nuclear fuel plate fabrication and assembly, a fundamental EBW experiment using AA6061-T6 aluminum alloy specimens was conducted. Furthermore, to establish the welding process, and satisfy the requirements of the weld quality, EBW apparatus using a electron welding gun and vacuum chamber was developed, and preliminary investigations for optimizing the welding parameters of the specimens using AA6061-T6 aluminum plates were also performed. In this experiment, a feasibility test was carried out by tensile tester, bead-on-plate welding and metallographic examination to comply with the aluminum welding procedure. The EB weld quality of AA6061-T6 aluminum alloy for the fuel plate assembly has been also studied by the mechanical testing and microstructure examinations. This study was carried out to determine the suitable welding process and to investigate tensile strength of AA6061-T6 aluminum alloy. In the present experiment, satisfactory EBW of the square butt weld specimens was developed. In comparison with the rolling directions of test specimens, the tensile strengths were no difference between the longitudinal and transverse welds. Based on this fundamental study, fabrication and assembly of the nuclear fuel plates will be provided for the future Kijang research reactor project

Mehanical Properties of Electron Beam Welded Joints in Thick Gage CA6NM Stainless Steel

Science.gov (United States)

Sarafan, Sheida; Wanjara, Priti; Gholipour, Javad; Champliaud, Henri; Mathieu, Louis

2017-10-01

Design of hydroelectric turbine components requires high integrity welds (without detectable volumetric defects) in heavy gage sections of stainless steel materials, such as ASTM A743 grade CA6NM—a low carbon 13% Cr-4% Ni martensitic stainless steel that is manufactured in cast form. In this work, 90-mm-thick plates of CA6NM were joined using a single-pass autogenous electron beam (EB) welding process and the mechanical properties were evaluated in the as-welded condition to characterize the performance of the joints. The static tensile properties that were evaluated in two directions—transverse and longitudinal to the EB weld seam—demonstrated conformance of the joints with the requirements of the ASME Section IX standard. The Charpy impact energies of the EB welds—measured at -18 °C on samples with V-notch roots located in the fusion and heat-affected zones—met the minimum requirements of 27 J specified in ASME Section VIII standard. In addition, bend tests that were conducted on the entire weld cross section displayed no discontinuities on the tension side of the bent joints. Hence, the developed EB welding process was demonstrated to render high-performance joints and promises key advantages for industrialization, such as cost savings through reductions in consumable material, production time and labor intensity.

Effect of friction stir welding on microstructure and corrosion behavior of LF6 aluminum alloy

Science.gov (United States)

Ghauri, Faizan Ali; Farooq, A.; Ahmad, A.; Deen, K. M.

2017-03-01

The LF6 aluminum alloy plates were joined by friction stir welding method. The tool rotational (1180 rpm) and transverse speed (0.56 mm s-1) were kept constant during welding of 4 mm thick plates. The microstructural features, hardness and tensile properties of the welded samples were determined to evaluate the structural integrity in comparison with the base metal. The electrochemical behavior of base metal (BM), thermo-mechanically affected zone (TMAZ) and weld nugget zone (WNZ) was also investigated by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5% NaCl solution. The microstructural study revealed significant grain refinement and agglomeration of β (Mg2Al3) intermetallic precipitates in the WNZ. The relatively higher hardness and a decrease in the ductility (3%) also assured the formation of precipitates β precipitates in the WNZ welded samples. The fracture surface of welded sample also revealed the existence of β precipitates within the elongated dimples which may be considered as the crack initiation sites. The relatively lower corrosion rate (23.68 mpy) and higher charge transfer resistance (403 Ω cm2) of BM compared to WNZ could be associated with the galvanic dissolution of Al-matrix through competitive charge transfer and relaxation (adsorption/desorption of intermediate species) processes specifically at the vicinity of the β precipitates.

Comparison of hematologic and serologic profiles of broiler birds with normal and severe degrees of white striping in breast fillets.

Science.gov (United States)

Kuttappan, V A; Huff, G R; Huff, W E; Hargis, B M; Apple, J K; Coon, C; Owens, C M

2013-02-01

White striping is the white striation occasionally observed parallel to the direction of muscle fibers in broiler breast fillets and thighs at the processing plant. Broiler breast fillets can be categorized as normal (NORM), moderate (MOD), or severe (SEV) based on the degree of white striping. Histologically, SEV fillets are characterized by the highest degree of degeneration of muscle fibers along with fibrosis and lipidosis when compared with NORM. The present study was undertaken to compare the hematologic and serologic profiles of broilers with NORM and SEV degrees of white striping to get more information on the systemic changes associated with the condition. Day-old male broiler chicks of a commercial strain were grown on the same diet in 6 replicate pens (n = 32 birds/pen). Blood samples (5 mL) were collected from the wing vein of each bird on the day before processing for analyzing hematologic and serologic profiles. At 63 d, the birds were weighed and processed in a commercial inline processing system. Weight of the butterfly fillets, liver, and abdominal fat pad were recorded. Left-side fillets were scored to obtain the degree of white striping for each bird. Representative samples for NORM (n = 24) and SEV (n = 17) categories were selected to compare the hematologic and serologic profiles. The SEV birds had greater (P white striping. The elevated serum enzyme levels confirm the muscle damage associated with the degenerative myopathy in SEV birds.

Concentrations of cadmium, Cobalt, Lead, Nickel, and Zinc in Blood and Fillets of Northern Hog Sucker (Hypentelium nigricans) from streams contaminated by lead-Zinc mining: Implications for monitoring

Science.gov (United States)

Schmitt, C.J.; Brumbaugh, W.G.; May, T.W.

2009-01-01

Lead (Pb) and other metals can accumulate in northern hog sucker (Hypentelium nigricans) and other suckers (Catostomidae), which are harvested in large numbers from Ozark streams by recreational fishers. Suckers are also important in the diets of piscivorous wildlife and fishes. Suckers from streams contaminated by historic Pb-zinc (Zn) mining in southeastern Missouri are presently identified in a consumption advisory because of Pb concentrations. We evaluated blood sampling as a potentially nonlethal alternative to fillet sampling for Pb and other metals in northern hog sucker. Scaled, skin-on, bone-in "fillet" and blood samples were obtained from northern hog suckers (n = 75) collected at nine sites representing a wide range of conditions relative to Pb-Zn mining in southeastern Missouri. All samples were analyzed for cadmium (Cd), cobalt (Co), Pb, nickel (Ni), and Zn. Fillets were also analyzed for calcium as an indicator of the amount of bone, skin, and mucus included in the samples. Pb, Cd, Co, and Ni concentrations were typically higher in blood than in fillets, but Zn concentrations were similar in both sample types. Concentrations of all metals except Zn were typically higher at sites located downstream from active and historic Pb-Zn mines and related facilities than at nonmining sites. Blood concentrations of Pb, Cd, and Co were highly correlated with corresponding fillet concentrations; log-log linear regressions between concentrations in the two sample types explained 94% of the variation for Pb, 73-83% of the variation for Co, and 61% of the variation for Cd. In contrast, relations for Ni and Zn explained Fillet Pb and calcium concentrations were correlated (r = 0.83), but only in the 12 fish from the most contaminated site; concentrations were not significantly correlated across all sites. Conversely, fillet Cd and calcium were correlated across the range of sites (r = 0.78), and the inclusion of calcium in the fillet-to-blood relation explained an

Mechanical behavior of multipass welded joint during stress relief annealing

International Nuclear Information System (INIS)

Ueda, Yukio; Fukuda, Keiji; Nakacho, Keiji; Takahashi, Eiji; Sakamoto, Koichi.

1978-01-01

An investigation into mechanical behavior of a multipass welded joint of a pressure vessel during stress relief annealing was conducted. The study was performed theoretically and experimentally on idealized research models. In the theoretical analysis, the thermal elastic-plastic creep theory developed by the authors was applied. The behavior of multipass welded joints during the entire thermal cycle, from welding to stress relief annealing, was consistently analyzed by this theory. The results of the analysis show a good, fundamentally coincidence with the experimental findings. The outline of the results and conclusions is as follows. (1) In the case of the material (2 1/4Cr-1Mo steel) furnished in this study, the creep strain rate during stress relief annealing below 575 0 C obeys the strain-hardening creep law using the transient creep and the one above 575 0 C obeys the power creep law using the stational creep. (2) In the transverse residual stress (σsub(x)) distribution after annealing, the location of the largest tensile stress on the top surface is about 15 mm away from the toe of weld, and the largest at the cross section is just below the finishing bead. These features are similar to those of welding residual stresses. But the stress distribution after annealing is smoother than one from welding. (3) The effectiveness of stress relief annealing depends greatly on the annealing temperature. For example, most of residual stresses are relieved at the heating stage with a heating rate of 30 0 C/hr. to 100 0 C/hr. if the annealing temperature is 650 0 C, but if the annealing temperature is 550 0 C, the annealing is not effective even with a longer holding time. (4) In the case of multipass welding residual stresses studied in this paper, the behaviors of high stresses during annealing are approximated by ones during anisothermal relaxation. (auth.)

Effects of irradiation, antimicrobial agents and modified packaging on histamine production by Morganella morganii in mackerel fillets

International Nuclear Information System (INIS)

Aytac, S.A.; Ozbas, Z.Y.; Vural, H.

2000-01-01

The effects of gamma irradiation (0.5 and 2.0 kGy), antimicrobial agents (5% sodium chloride and 1% potassium sorbate) and modified atmosphere (100% CO2) packaging (MAP) on histamine production by Morganella morganii were examined in mackerel fillets during 8 days of cold storage. MAP combined with antimicrobial agents was also applied to the fillets. The changes in histamine levels, M. morganii and total aerobic bacterial counts were determined during the storage. All methods used in this study showed beneficial effect in controlling bacterial growth and histamine production on mackerel fillets during 2-3 days of storage. MAP combined with 5% sodium chloride has more retarding effect on production of histamine than the other methods. For M. morganii, maximum inhibition effect was found at the dose of 2.0 kGy. Irradiation with a dose of 2.0 kGy, MAP combined with sodium chloride and MAP were also found to have the most inhibiting effects on total aerobic bacterial count during the storage

LASER WELDING WITH MICRO-JET COOLING FOR TRUCK FRAME WELDING

Directory of Open Access Journals (Sweden)

Jan PIWNIK

2017-12-01

Full Text Available The aim of this paper is to analyse the mechanical properties of the weld steel structure of car body truck frames after laser welding. The best welding conditions involve the use of proper materials and alloy elements in steel and filer materials, in addition to welding technology, state of stress and temperature of exploitation. We present for the first time the properties of steel track structures after laser welding with micro-jet cooling. Therefore, good selection of both welding parameters and micro-jet cooling parameters is very important to achieve a proper steel structure. In this study, the metallographic structure, tensile results and impact toughness of welded joints have been analysed in terms of welding parameters.

Forming Completely Penetrated Welded T-joints when Pulsed Arc Welding

Science.gov (United States)

Krampit, N. Yu; Krampit, M. A.; Sapozhkov, A. S.

2016-04-01

The paper is focused on revealing the influence of welding parameters on weld formation when pulsed arc welding. As an experimental sample a T-joint over 10 mm was selected. Welding was carried out in flat position, which required no edge preparation but provided mono-directional guaranteed root penetration. The following parameters of welding were subjected to investigation: gap in the joint, wire feed rate and incline angles of the torch along and across the weld axis. Technological recommendations have been made with respect to pulsed arc welding; the cost price of product manufacturing can be reduced on their basis due to reduction of labor input required by machining, lowering consumption of welding materials and electric power.

Quantity and functionality of protein fractions in chicken breast fillets affected by white striping.

Science.gov (United States)

Mudalal, S; Babini, E; Cavani, C; Petracci, M

2014-08-01

Recently, white striations parallel to muscle fibers direction have been observed on the surface of chicken breast, which could be ascribed to intensive growth selection. The aim of this study was to evaluate the effect of white striping on chemical composition with special emphasis on myofibrillar and sarcoplasmic protein fractions that are relevant to the processing features of chicken breast meat. During this study, a total of 12 pectoralis major muscles from both normal and white striped fillets were used to evaluate chemical composition, protein solubility (sarcoplasmic, myofibrillar, and total protein solubility), protein quantity (sarcoplasmic, myofibrillar, and stromal proteins), water holding capacity, and protein profile by SDS-PAGE analysis. White-striped fillets exhibited a higher percentage of moisture (75.4 vs. 73.8%; P cooking loss (33.7 vs. 27.4%; P chicken breast meat with white striping defect had different chemical composition (more fat and less protein) and protein quality and quantity (low content of myofibrillar proteins and high content of stromal proteins) with respect to normal meat. Furthermore, white striped fillets had lower protein functionality (higher cooking loss). All the former changes indicate that white striping has great impact on quality characteristics of chicken breast meat. © Poultry Science Association Inc.

Application of Lactic Acid Bacteria (LAB) in freshness keeping of tilapia fillets as sashimi

Science.gov (United States)

Cao, Rong; Liu, Qi; Chen, Shengjun; Yang, Xianqing; Li, Laihao

2015-08-01

Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria (LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19 (obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.

Resistance welding

DEFF Research Database (Denmark)

Bay, Niels; Zhang, Wenqi; Rasmussen, Mogens H.

2003-01-01

Resistance welding comprises not only the well known spot welding process but also more complex projection welding operations, where excessive plastic deformation of the weld point may occur. This enables the production of complex geometries and material combinations, which are often not possible...... to weld by traditional spot welding operations. Such joining processes are, however, not simple to develop due to the large number of parameters involved. Development has traditionally been carried out by large experimental investigations, but the development of a numerical programme system has changed...... this enabling prediction of the welding performance in details. The paper describes the programme in short and gives examples on industrial applications. Finally investigations of causes for failure in a complex industrial joint of two dissimilar metals are carried out combining numerical modelling...

Cu-Fe welding techniques by electromagnetic and electron beam welding processes

International Nuclear Information System (INIS)

Kumar, Satendra; Saroj, P.C.; Kulkarni, M.R.; Sharma, A.; Rajawat, R.K.; Saha, T.K.

2015-01-01

Electromagnetic welding being a solid state welding process has been found suitable for welding Copper and Iron which are conventionally very tricky. Owing to good electrical conductivity of both copper and iron, they are best suited combination for EM welding. For the experimental conditions presented above, 1.0 mm wall thickness of Cu tube was lap welded to Fe disc. A heavy duty four disc stainless steel coil was used for electromagnetic welding of samples. MSLD of the welded samples indicated leak proof joints. Metallographic examination of the welds also revealed defect free interfaces. Electron beam welding is also a non-conventional welding process used for joining dissimilar materials. Autogenous welding of the above specimen was carried out by EBW method for the sake of comparison. A characterization analysis of the above mentioned joining processes will be discussed in the paper. (author)

Effects of chitosan on the shelf life of marinated sardine (Sardina pilchardus fillets during refrigerated storage

Directory of Open Access Journals (Sweden)

Aygül Küçükgülmez

2012-07-01

Full Text Available This study was carried out to evaluate the effect of chitosan on chemical, colour, sensory and microbial changes of marinated sardine (Sardina pilchardus fillets. Marination solution consisted of 10% sodium chloride + 1% chitosan (dissolved in 3% acetic acid for the chitosan group, and 10% sodium chloride + 3% acetic acid solution for the control group. After the marination process, sardine fillets were packed and stored at 4ºC for 60 days. Thiobarbituric acid (TBA values were found to be lower in the chitosan group than the control group (PL*, a*, or b* values of marinated sardine fillets. According to sensory analysis, shelf life of the chitosan group was found to be ten days longer than that of the control group. Total bacteria count of two marinated groups was found to be less than 1 log CFU/g. This study concluded that sardine marination with the addition of chitosan can delay undesirable chemical changes, retard lipid oxidation, improve sensory attributes and extend the shelf life of the product during refrigerated storage.

Tensometry technique for X-ray diffraction in applied analysis of welding; Tensometria por tecnica de difracao de raios X aplicada na analise de soldagens

Energy Technology Data Exchange (ETDEWEB)

Turibus, S.N.; Caldas, F.C.M.; Miranda, D.M.; Monine, V.I.; Assis, J.T., E-mail: snturibus@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico

2010-07-01

This paper presents the analysis of residual stress introduced in welding process. As the stress in a material can induce damages, it is necessary to have a method to identify this residual stress state. For this it was used the non-destructive X-ray diffraction technique to analyze two plates from A36 steel jointed by metal inert gas (MIG) welding. The stress measurements were made by the sin{sup 2{psi}} method in weld region of steel plates including analysis of longitudinal and transverse residual stresses in fusion zone, heat affected zone (HAZ) and base metal. To determine the stress distribution along the depth of the welded material it was used removing of superficial layers made by electropolishing. (author)

Deconvoluting the Friction Stir Weld Process for Optimizing Welds

Science.gov (United States)

Schneider, Judy; Nunes, Arthur C.

2008-01-01

In the friction stir welding process, the rotating surfaces of the pin and shoulder contact the weld metal and force a rotational flow within the weld metal. Heat, generated by the metal deformation as well as frictional slippage with the contact surface, softens the metal and makes it easier to deform. As in any thermo-mechanical processing of metal, the flow conditions are critical to the quality of the weld. For example, extrusion of metal from under the shoulder of an excessively hot weld may relax local pressure and result in wormhole defects. The trace of the weld joint in the wake of the weld may vary geometrically depending upon the flow streamlines around the tool with some geometry more vulnerable to loss of strength from joint contamination than others. The material flow path around the tool cannot be seen in real time during the weld. By using analytical "tools" based upon the principles of mathematics and physics, a weld model can be created to compute features that can be observed. By comparing the computed observations with actual data, the weld model can be validated or adjusted to get better agreement. Inputs to the model to predict weld structures and properties include: hot working properties ofthe metal, pin tool geometry, travel rate, rotation and plunge force. Since metals record their prior hot working history, the hot working conditions imparted during FSW can be quantified by interpreting the final microstructure. Variations in texture and grain size result from variations in the strain accommodated at a given strain rate and temperature. Microstructural data from a variety of FSWs has been correlated with prior marker studies to contribute to our understanding of the FSW process. Once this stage is reached, the weld modeling process can save significant development costs by reducing costly trial-and-error approaches to obtaining quality welds.

Effects of Fusion Tack Welds on Self-Reacting Friction Stir Welds

Science.gov (United States)

Nunes, A. C., Jr.; Pendleton, M. L.; Brooke, S. A.; Russell, C. K.

2012-01-01

In order to know whether fusion tack welds would affect the strength of self-reacting friction stir seam welds in 2195-T87 aluminum alloy, the fracture stresses of 144 tensile test coupons cut from 24 welded panels containing segments of friction stir welds were measured. Each of the panels was welded under unique processing conditions. A measure of the effect of the tack welds for each panel was devised. An analysis of the measures of the tack weld effect supported the hypothesis that fusion tack welds do not affect the strength of self-reacting friction stir welds to a 5% level of confidence.

Residual stress reduction in the penetration nozzle weld joint by overlay welding

International Nuclear Information System (INIS)

Jiang, Wenchun; Luo, Yun; Wang, B.Y.; Tu, S.T.; Gong, J.M.

2014-01-01

Highlights: • Residual stress reduction in penetration weld nozzle by overlay welding was studied. • The overlay weld can decrease the residual stress in the weld root. • Long overlay welding is proposed in the actual welding. • Overlay weld to decrease residual stress is more suitable for thin nozzle. - Abstract: Stress corrosion cracking (SCC) in the penetration nozzle weld joint endangers the structural reliability of pressure vessels in nuclear and chemical industries. How to decrease the residual stress is very critical to ensure the structure integrity. In this paper, a new method, which uses overlay welding on the inner surface of nozzle, is proposed to decrease the residual stresses in the penetration joint. Finite element simulation is used to study the change of weld residual stresses before and after overlay welding. It reveals that this method can mainly decrease the residual stress in the weld root. Before overlay welding, large tensile residual stresses are generated in the weld root. After overlay weld, the tensile hoop stress in weld root has been decreased about 45%, and the radial stress has been decreased to compressive stress, which is helpful to decrease the susceptibility to SCC. With the increase of overlay welding length, the residual stress in weld root has been greatly decreased, and thus the long overlay welding is proposed in the actual welding. It also finds that this method is more suitable for thin nozzle rather than thick nozzle

Welding processes handbook

CERN Document Server

Weman, Klas

2011-01-01

Offers an introduction to the range of available welding technologies. This title includes chapters on individual techniques that cover principles, equipment, consumables and key quality issues. It includes material on such topics as the basics of electricity in welding, arc physics, and distortion, and the weldability of particular metals.$bThe first edition of Welding processes handbook established itself as a standard introduction and guide to the main welding technologies and their applications. This new edition has been substantially revised and extended to reflect the latest developments. After an initial introduction, the book first reviews gas welding before discussing the fundamentals of arc welding, including arc physics and power sources. It then discusses the range of arc welding techniques including TIG, plasma, MIG/MAG, MMA and submerged arc welding. Further chapters cover a range of other important welding technologies such as resistance and laser welding, as well as the use of welding techniqu...

Specific inhibition of Photobacterium phosphoreum extends the shelf life of modified-atmosphere-packed cod fillets

DEFF Research Database (Denmark)

Dalgaard, Paw; Munoz, L.G.; Mejlholm, Ole

1998-01-01

rather than the development of a new product. In naturally contaminated modified-atmosphere-packed cod fillets, 500 ppm Na(2)CaEDTA reduced the growth rate of P. phosphoreum by 40% and shelf life was increased proportionally by 40%, from 15 to 17 days to 21 to 23 days at 0 degrees C. In aerobically...... stored cod fillets other microorganisms were responsible for spoilage and Na2CaEDTA had no effect on shelf Life. The extension of the shelf life of modified-atmosphere-packed cod therefore was a result of the reduced growth of P. phosphoreum and no other microbial or nonmicrobial spoilage reactions...

Welding Curriculum.

Science.gov (United States)

Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

This competency-based curriculum guide is a handbook for the development of welding trade programs. Based on a survey of Alaskan welding employers, it includes all competencies a student should acquire in such a welding program. The handbook stresses the importance of understanding the principles associated with the various elements of welding.…

Amount and qualities of carotenoids in fillets of fish species fed with ...

African Journals Online (AJOL)

Using column (CC), thin- layer (TLC) and high- performance liquid chromatography (HPLC), carotenoid content was examined in the fillets (muscles with skin) of 16 fish species from the fisheries of West African Coast. 15 carotenoids, including 6 ketocarotenoids (4'- hydroxyechinenone, canthaxanthin, phoenicopterone, ...

Updating of actual technique for ultrasonic testing of austenitic stainless materials and welds

International Nuclear Information System (INIS)

Lindholm, P.O.; Pers-Anderson, E.B.

1982-01-01

The technique for ultrasonic testing of stainless austenitic steels and weldings has been studied and it has been brought to the latest standard. Many problems exist when testing, the most serious being the occurence of false indications and the damping of energy. Laboratory tests show that the detectors with transversal sound waves should be used for plane defects. Best results were achieved with a 45 degrees detector. (GB)

Effect of electron irradiation and bayberry polyphenols on the quality change of yellowfin tuna fillets during refrigerated storage

Science.gov (United States)

Bu, Tingting; Jin, Yang; Li, Xiaohui; Zhang, Jinjie; Xu, Dalun; Yang, Wenge; Lou, Qiaoming

2017-09-01

This study evaluated the synergistic effect of bayberry polyphenols and electron irradiation in controlling the chemical, microbiological and sensory changes of raw yellowfin tuna fillets at 4 °C for 7 days. The results indicated that the initial values of each index were dose-dependent. The dose of 5 kGy notably accelerated adenosine triphosphate degradation and lipid oxidation, while the doses of 1 and 3 kGy had acceptable sensory quality and yielded a shelf-life of 5 days. The addition of bayberry polyphenols had evident effect in inhibiting freshness breakdown, bacteria growth, histamine formation, and discoloration of tuna fillets. Bayberry polyphenols, as an antioxidant, could inhibit lipid oxidation and sensory side-effects made by irradiation up to 3 kGy. The dose of 1-3 kGy coupled with bayberry polyphenols was optimum to preserve tuna fillets which prolonged the shelf-life to 7 days.

High Strain Rate Testing of Welded DOP-26 Iridium

Energy Technology Data Exchange (ETDEWEB)

Schneibel, J. H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, R. G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carmichael, C. A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fox, E. E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ulrich, G. B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); George, E. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-08-01

The iridium alloy DOP-26 is used to produce Clad Vent Set cups that protect the radioactive fuel in radioisotope thermoelectric generators (RTGs) which provide electric power for spacecraft and rovers. In a previous study, the tensile properties of DOP-26 were measured over a wide range of strain rates and temperatures and reported in ORNL/TM-2007/81. While that study established the properties of the base material, the fabrication of the heat sources requires welding, and the mechanical properties of welded DOP-26 have not been extensively characterized in the past. Therefore, this study was undertaken to determine the mechanical properties of DOP-26 specimens containing a transverse weld in the center of their gage sections. Tensile tests were performed at room temperature, 750, 900, and 1090°C and engineering strain rates of 1×10^-3 and 10 s^-1. Room temperature testing was performed in air, while testing at elevated temperatures was performed in a vacuum better than 1×10^-4 Torr. The welded specimens had a significantly higher yield stress, by up to a factor of ~2, than the non-welded base material. The yield stress did not depend on the strain rate except at 1090°C, where it was slightly higher for the faster strain rate. The ultimate tensile stress, on the other hand, was significantly higher for the faster strain rate at temperatures of 750°C and above. At 750°C and above, the specimens deformed at 1×10^-3 s^-1 showed pronounced necking resulting sometimes in perfect chisel-edge fracture. The specimens deformed at 10 s^-1 exhibited this fracture behavior only at the highest test temperature, 1090°C. Fracture occurred usually in the fusion zone of the weld and was, in most cases, primarily intergranular.

LASER WELDING WITH MICRO-JET COOLING FOR TRUCK FRAME WELDING

OpenAIRE

Jan PIWNIK; Bożena SZCZUCKA-LASOTA; Tomasz WĘGRZYN; Wojciech MAJEWSKI

2017-01-01

The aim of this paper is to analyse the mechanical properties of the weld steel structure of car body truck frames after laser welding. The best welding conditions involve the use of proper materials and alloy elements in steel and filer materials, in addition to welding technology, state of stress and temperature of exploitation. We present for the first time the properties of steel track structures after laser welding with micro-jet cooling. Therefore, good selection of both welding paramet...

Ship construction and welding

CERN Document Server

Mandal, Nisith R

2017-01-01

This book addresses various aspects of ship construction, from ship types and construction materials, to welding technologies and accuracy control. The contents of the book are logically organized and divided into twenty-one chapters. The book covers structural arrangement with longitudinal and transverse framing systems based on the service load, and explains basic structural elements like hatch side girders, hatch end beams, stringers, etc. along with structural subassemblies like floors, bulkheads, inner bottom, decks and shells. It presents in detail double bottom construction, wing tanks & duct keels, fore & aft end structures, etc., together with necessary illustrations. The midship sections of various ship types are introduced, together with structural continuity and alignment in ship structures. With regard to construction materials, the book discusses steel, aluminum alloys and fiber reinforced composites. Various methods of steel material preparation are discussed, and plate cutting and form...

Effect of inoculum size, bacterial species, type of surfaces and contact time to the transfer of foodborne pathogens from inoculated to non-inoculated beef fillets via food processing surfaces.

Science.gov (United States)

Gkana, E; Chorianopoulos, N; Grounta, A; Koutsoumanis, K; Nychas, G-J E

2017-04-01

The objective of the present study was to determine the factors affecting the transfer of foodborne pathogens from inoculated beef fillets to non-inoculated ones, through food processing surfaces. Three different levels of inoculation of beef fillets surface were prepared: a high one of approximately 10 7  CFU/cm 2 , a medium one of 10 5  CFU/cm 2 and a low one of 10 3  CFU/cm 2 , using mixed-strains of Listeria monocytogenes, or Salmonella enterica Typhimurium, or Escherichia coli O157:H7. The inoculated fillets were then placed on 3 different types of surfaces (stainless steel-SS, polyethylene-PE and wood-WD), for 1 or 15 min. Subsequently, these fillets were removed from the cutting boards and six sequential non-inoculated fillets were placed on the same surfaces for the same period of time. All non-inoculated fillets were contaminated with a progressive reduction trend of each pathogen's population level from the inoculated fillets to the sixth non-inoculated ones that got in contact with the surfaces, and regardless the initial inoculum, a reduction of approximately 2 log CFU/g between inoculated and 1st non-inoculated fillet was observed. S. Typhimurium was transferred at lower mean population (2.39 log CFU/g) to contaminated fillets than E. coli O157:H7 (2.93 log CFU/g), followed by L. monocytogenes (3.12 log CFU/g; P < 0.05). Wooden surfaces (2.77 log CFU/g) enhanced the transfer of bacteria to subsequent fillets compared to other materials (2.66 log CFU/g for SS and PE; P < 0.05). Cross-contamination between meat and surfaces is a multifactorial process strongly depended on the species, initial contamination level, kind of surface, contact time and the number of subsequent fillet, according to analysis of variance. Thus, quantifying the cross-contamination risk associated with various steps of meat processing and food establishments or households can provide a scientific basis for risk management of such products. Copyright © 2016 Elsevier Ltd

Depletion of isoeugenol residues from the fillet tissue of AQUI-S™ exposed rainbow trout (Oncorhynchus mykiss)

Science.gov (United States)

Meinertz, Jeffery R.; Schreier, Theresa M.

2009-01-01

There is a critical need in U.S. public aquaculture and fishery management for an approved sedative that allows for the immediate release of fish after sedation. AQUI-STM is a fish anesthetic/sedative approved for use in several countries and until recently was being developed in the U.S. as a sedative for immediate release of fish after sedation. The U.S. National Toxicology Program reported that isoeugenol (the active ingredient in AQUI-STM) exposed male mice showed clear evidence of carcinogenicity, therefore efforts within the U.S. Department of Interior to develop AQUI-STM as a sedative that allows for immediate release ceased. Despite the ruling, AQUI-STM still has the potential to be approved as an anesthetic with a short withdrawal time. Among the data required to gain approval for use in the U.S. are data describing the composition and depletion of all AQUI-STM residues from fish fillet tissue. A total residue depletion study for AQUI-STM was conducted by exposing market-sized rainbow trout, Oncorhynchus mykiss (mean weight, 502.7 ± 54 g; s.d.) to 8.9 mg/L of 14C-[URL]-isoeugenol for 60 min in 17 °C water. The 14C-[URL]-isoeugenol was mixed with a surfactant resulting in a mixture that mimicked AQUI-STM. Groups of fish (n = 6) were sampled immediately after the exposure (0-h sample group) and at 0.5, 1, 2, and 4 h thereafter. Total isoeugenol-equivalent residue concentrations in the fillet tissue were determined by oxidizing triplicate subsamples of homogenized skin-on fillet tissue from each fish to 14CO2 and enumerating the radioactivity by static liquid scintillation counting. Isoeugenol concentrations in fillet tissue were determined by extracting homogenized fillet tissue with solvents and determining the isoeugenol concentrations in the extracts with high performance liquid chromatography techniques. The mean total isoeugenol-equivalent residue concentrations in the 0, 0.5, 1, 2, and 4-h sample groups were 55.4, 32.0, 19.8, 11

Thermal Stir Welding: A New Solid State Welding Process

Science.gov (United States)

Ding, R. Jeffrey

2003-01-01

Thermal stir welding is a new welding process developed at NASA's Marshall Space Flight Center in Huntsville, AL. Thermal stir welding is similar to friction stir welding in that it joins similar or dissimilar materials without melting the parent material. However, unlike friction stir welding, the heating, stirring and forging elements of the process are all independent of each other and are separately controlled. Furthermore, the heating element of the process can be either a solid-state process (such as a thermal blanket, induction type process, etc), or, a fusion process (YG laser, plasma torch, etc.) The separation of the heating, stirring, forging elements of the process allows more degrees of freedom for greater process control. This paper introduces the mechanics of the thermal stir welding process. In addition, weld mechanical property data is presented for selected alloys as well as metallurgical analysis.

POSSIBLE RAMIFICATIONS OF HIGHER MERCURY CONCENTRATIONS IN FILLET TISSUE OF SKINNIER FISH

Science.gov (United States)

Mercury concentrations were found to be statistically higher in the fillet tissue of the skinnier individuals of a fish species (striped bass) that was experiencing starvation when collected from Lake Mead, which is located on the Arizona-Nevada border. This is considered a conse...

Sustainability of Welding Process through Bobbin Friction Stir Welding

Science.gov (United States)

Sued, M. K.; Samsuri, S. S. M.; Kassim, M. K. A. M.; Nasir, S. N. N. M.

2018-03-01

Welding process is in high demand, which required a competitive technology to be adopted. This is important for sustaining the needs of the joining industries without ignoring the impact of the process to the environment. Friction stir welding (FSW) is stated to be benefitting the environment through low energy consumption, which cannot be achieved through traditional arc welding. However, this is not well documented, especially for bobbin friction stir welding (BFSW). Therefore, an investigation is conducted by measuring current consumption of the machine during the BFSW process. From the measurement, different phases of BFSW welding process and its electrical demand are presented. It is found that in general total energy in BFSW is about 130kW inclusive of all identified process phases. The phase that utilise for joint formation is in weld phase that used the highest total energy of 120kWs. The recorded total energy is still far below the traditional welding technology and the conventional friction stir welding (CFSW) energy demand. This indicates that BFSW technology with its vast benefit able to sustain the joining technology in near future.

Enabling high speed friction stir welding of aluminum tailor welded blanks

Science.gov (United States)

Hovanski, Yuri

Current welding technologies for production of aluminum tailor-welded blanks (TWBs) are utilized in low-volume and niche applications, and have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high-volumes. While friction stir welding (FSW) has traditionally been applied at linear velocities less than one meter per minute, high volume production applications demand the process be extended to higher velocities more amenable to cost sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low to moderate welding velocities do not directly translate to high speed linear friction stir welding. Therefore, in order to facilitate production of high volume aluminum FSW components, parameters were developed with a minimum welding velocity of three meters per minute. With an emphasis on weld quality, welded blanks were evaluated for post-weld formability using a combination of numerical and experimental methods. Evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum tailor-welded blanks, which provided validation of the numerical and experimental analysis of laboratory scale tests.

Microstructural transformations and mechanical properties of cast NiAl bronze: Effects of fusion welding and friction stir processing

International Nuclear Information System (INIS)

Fuller, M.D.; Swaminathan, S.; Zhilyaev, A.P.; McNelley, T.R.

2007-01-01

A plate of as-cast NiAl bronze (NAB) material was sectioned from a large casting. A six-pass fusion weld overlay was placed in a machined groove; a portion of the weld reinforcement was removed by milling and a single friction stir processing (FSP) pass was conducted in a direction transverse to the axis of and over the weld overlay. A procedure was developed for machining of miniature tensile samples and the distributions of strength and ductility were evaluated for the fusion weld metal; for the stir zone (SZ) produced by the friction stir processing; and for a region wherein friction stir processing had taken place over the fusion weld. A region of low ductility in the heat affected zone (HAZ) of the fusion weld and in the thermomechanically affected zone (TMAZ) of friction stir processed material was attributed to partial reversion of an equilibrium lamellar eutectoid constituent upon local heating above ∼800 deg. C and formation of non-equilibrium transformation products upon subsequent cooling. The adverse effect on ductility is worse in the heat affected zone of the fusion weld than in the thermomechanically affected zone of friction stir processing due to the lower heat input of the latter process. The implications of this work to engineering applications of friction stir processing are discussed

The Influence of Friction Stir Weld Tool Form and Welding Parameters on Weld Structure and Properties: Nugget Bulge in Self-Reacting Friction Stir Welds

Science.gov (United States)

Schneider, Judy; Nunes, Arthur C., Jr.; Brendel, Michael S.

2010-01-01

Although friction stir welding (FSW) was patented in 1991, process development has been based upon trial and error and the literature still exhibits little understanding of the mechanisms determining weld structure and properties. New concepts emerging from a better understanding of these mechanisms enhance the ability of FSW engineers to think about the FSW process in new ways, inevitably leading to advances in the technology. A kinematic approach in which the FSW flow process is decomposed into several simple flow components has been found to explain the basic structural features of FSW welds and to relate them to tool geometry and process parameters. Using this modelling approach, this study reports on a correlation between the features of the weld nugget, process parameters, weld tool geometry, and weld strength. This correlation presents a way to select process parameters for a given tool geometry so as to optimize weld strength. It also provides clues that may ultimately explain why the weld strength varies within the sample population.

Modeling and monitoring of tooth fillet crack growth in dynamic simulation of spur gear set

Science.gov (United States)

Guilbault, Raynald; Lalonde, Sébastien; Thomas, Marc

2015-05-01

This study integrates a linear elastic fracture mechanics analysis of the tooth fillet crack propagation into a nonlinear dynamic model of spur gear sets. An original formulation establishes the rigidity of sound and damaged teeth. The formula incorporates the contribution of the flexible gear body and real crack trajectories in the fillet zone. The work also develops a KI prediction formula. A validation of the equation estimates shows that the predicted KI are in close agreement with published numerical and experimental values. The representation also relies on the Paris-Erdogan equation completed with crack closure effects. The analysis considers that during dN fatigue cycles, a harmonic mean of ΔK assures optimal evaluations. The paper evaluates the influence of the mesh frequency distance from the resonances of the system. The obtained results indicate that while the dependence may demonstrate obvious nonlinearities, the crack progression rate increases with a mesh frequency augmentation. The study develops a tooth fillet crack propagation detection procedure based on residual signals (RS) prepared in the frequency domain. The proposed approach accepts any gear conditions as reference signature. The standard deviation and mean values of the RS are evaluated as gear condition descriptors. A trend tracking of their responses obtained from a moving linear regression completes the analysis. Globally, the results show that, regardless of the reference signal, both descriptors are sensitive to the tooth fillet crack and sharply react to tooth breakage. On average, the mean value detected the crack propagation after a size increase of 3.69 percent as compared to the reference condition, whereas the standard deviation required crack progressions of 12.24 percent. Moreover, the mean descriptor shows evolutions closer to the crack size progression.

Visible and Near-Infrared Hyperspectral Imaging for Cooking Loss Classification of Fresh Broiler Breast Fillets

Directory of Open Access Journals (Sweden)

Hongzhe Jiang

2018-02-01

Full Text Available Cooking loss (CL is a critical quality attribute directly relating to meat juiciness. The potential of the hyperspectral imaging (HSI technique was investigated for non-invasively classifying and visualizing the CL of fresh broiler breast meat. Hyperspectral images of total 75 fresh broiler breast fillets were acquired by the system operating in the visible and near-infrared (VNIR, 400–1000 nm range. Mean spectra were extracted from regions of interest (ROIs determined by pure muscle tissue pixels. CL was firstly measured by calculating the weight loss in cooking, and then fillets were grouped into high-CL and low-CL according to the threshold of 20%. The classification methods partial least square-discriminant analysis (PLS-DA and radial basis function-support vector machine (RBF-SVM were applied, respectively, to determine the optimal spectral calibration strategy. Results showed that the PLS-DA model developed using the data, that is, first-order derivative (Der1 of VNIR full spectra, performed best with correct classification rates (CCRs of 0.90 and 0.79 for the calibration and prediction sets, respectively. Furthermore, to simplify the optimal PLS-DA model and make it practical, effective wavelengths were individually selected using uninformative variable elimination (UVE and competitive adaptive reweighted sampling (CARS. Through performance comparison, the CARS-PLS-DA combination was identified as the optimal method and the PLS-DA model built with 18 informative wavelengths selected by CARS resulted in good CCRs of 0.86 and 0.79. Finally, classification maps were created by predicting CL categories of each pixel in the VNIR hyperspectral images using the CARS-PLS-DA model, and the general CL categories of fillets were readily discernible. The overall results were encouraging and showed the promising potential of the VNIR HSI technique for classifying fresh broiler breast fillets into different CL categories.

Automatic orbital GTAW welding: Highest quality welds for tomorrow's high-performance systems

Science.gov (United States)

Henon, B. K.

1985-01-01

Automatic orbital gas tungsten arc welding (GTAW) or TIG welding is certain to play an increasingly prominent role in tomorrow's technology. The welds are of the highest quality and the repeatability of automatic weldings is vastly superior to that of manual welding. Since less heat is applied to the weld during automatic welding than manual welding, there is less change in the metallurgical properties of the parent material. The possibility of accurate control and the cleanliness of the automatic GTAW welding process make it highly suitable to the welding of the more exotic and expensive materials which are now widely used in the aerospace and hydrospace industries. Titanium, stainless steel, Inconel, and Incoloy, as well as, aluminum can all be welded to the highest quality specifications automatically. Automatic orbital GTAW equipment is available for the fusion butt welding of tube-to-tube, as well as, tube to autobuttweld fittings. The same equipment can also be used for the fusion butt welding of up to 6 inch pipe with a wall thickness of up to 0.154 inches.

Microbiological changes occurring in trout fillets (Oncorhynchus mykiss W. 1792) salted and treated with potassium sorbate during production and storage.

Science.gov (United States)

Oksüztepe, Gülsüm; Gürel Inanli, Ayşe

2007-08-15

In this study, microbiological changes during processing and storage of salted-cured trout fillets treated with potassium sorbate were investigated. For this purpose, 10 and 15% (w/w) NaCl and 1, 5 and 10% (w/v) potassium sorbate were applied to the fillets. The processed fillets were vacuum-packed and storage at 4 degrees C. The samples were analyzed in some periods of production and in the storage days of 7, 14, 28, 42, 56, 70 and 84 for numbers of total mesophilic aerob, psycrophylic, yeast and mould. In conclusion, the microbiological quality of all samples treated with 15% NaCl and potassium sorbate were found better. Consequently, it can be concluded that the usage of potassium sorbate may be useful and a synergistic effect between salt and potassium sorbate determined.

Determination of ten perfluorinated compounds in bluegill sunfish (Lepomis macrochirus) fillets

International Nuclear Information System (INIS)

Delinsky, Amy D.; Strynar, Mark J.; Nakayama, Shoji F.; Varns, Jerry L.; Ye, XiBiao; McCann, Patricia J.; Lindstrom, Andrew B.

2009-01-01

A rigorous solid phase extraction/liquid chromatography/tandem mass spectrometry method for the measurement of 10 perfluorinated compounds (PFCs) in fish fillets is described and applied to fillets of bluegill sunfish (Lepomis macrochirus) collected from selected areas of Minnesota and North Carolina. The 4 PFC analytes routinely detected in bluegill fillets were perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (C10), perfluoroundecanoic acid (C11), and perflurododecanoic acid (C12). Measures of method accuracy and precision for these compounds showed that calculated concentrations of PFCs in spiked samples differed by less than 20% from their theoretical values and that the %RSD for repeated measurements was less than 20%. Minnesota samples were collected from areas of the Mississippi River near historical PFC sources, from the St. Croix River as a background site, and from Lake Calhoun, which has no documented PFC sources. PFOS was the most prevalent PFC found in the Minnesota samples, with median concentrations of 47.0-102 ng/g at locations along the Mississippi River, 2.08 ng/g in the St. Croix River, and 275 ng/g in Lake Calhoun. North Carolina samples were collected from two rivers with no known historical PFC sources. PFOS was the predominant analyte in fish taken from the Haw and Deep Rivers, with median concentrations of 30.3 and 62.2 ng/g, respectively. Concentrations of C10, C11, and C12 in NC samples were among the highest reported in the literature, with respective median values of 9.08, 23.9, and 6.60 ng/g in fish from the Haw River and 2.90, 9.15, and 3.46 ng/g in fish from the Deep River. These results suggest that PFC contamination in freshwater fish may not be limited to areas with known historical PFC inputs.

Moderate exercise of rainbow trout induces only minor differences in fatty acid profile, texture, white muscle fibres and proximate chemical composition of fillets

DEFF Research Database (Denmark)

Rasmussen, Richard Skøtt; Heinrich, Maike Timm; Hyldig, Grethe

2011-01-01

when the lipid content in the fillet increased (R2≥0.85, Pb1·10−6). Fillet texture measured instrumentally as shear force (g) after 72 h of ice storage did not differ between the two experimental groups, and neither did the content of lipid, protein or dry matter in the fillet. Muscle fibre sizes have...... a possible role in textural characteristics and were determined by histological analyses of white, glycolytic muscle tissue. These data showed that although differences in average fibre diameters were small (excF: 75.04 (s.d.=48.96)μm; ctrlF: 74.50 (46.21)μm) the general fibre size distribution differed...... significantly among the two groups (Pb0.01). Moreover, moderate exercise induced small but significant changes in fibre circularity (excF: circ.=0.724; ctrlF:=0.720, Pb0.05) but neither muscle fibre diameter nor circularity was significantly related to fillet texture. Altogether, the results suggest...

Influence of Welding Process and Post Weld Heat Treatment on Microstructure and Pitting Corrosion Behavior of Dissimilar Aluminium Alloy Welds

Science.gov (United States)

Venkata Ramana, V. S. N.; Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

2018-03-01

Welding of dissimilar Aluminum alloy welds is becoming important in aerospace, shipbuilding and defence applications. In the present work, an attempt has been made to weld dissimilar aluminium alloys using conventional gas tungsten arc welding (GTAW) and friction stir welding (FSW) processes. An attempt was also made to study the effect of post weld heat treatment (T4 condition) on microstructure and pitting corrosion behaviour of these welds. Results of the present investigation established the differences in microstructures of the base metals in T4 condition and in annealed conditions. It is evident that the thickness of the PMZ is relatively more on AA2014 side than that of AA6061 side. In FS welds, lamellar like shear bands are well noticed on the top of the stir zone. The concentration profile of dissimilar friction stir weld in T4 condition revealed that no diffusion has taken place at the interface. Poor Hardness is observed in all regions of FS welds compared to that of GTA welds. Pitting corrosion resistance of the dissimilar FS welds in all regions was improved by post weld heat treatment.

Torque Measurement of Welding of Endplug-Endplate using Multi-pin Remote Welding System

Energy Technology Data Exchange (ETDEWEB)

Koo, Dae-Seo; Kim, Soo-Sung; Park, Geun-Il; Lee, Jung-Won; Song, Kee-Chan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2006-07-01

As fuel bundles in PHWR irradiates, inner pressure in claddings of fuel rods increases owing to outer pressure and fission products of nuclear fissions. Because of leak possibility of welding between cladding and end plug, this welding part connects with safety of nuclear fuel rods. Because of importance of this welding part, weldability of end plug-cladding of nuclear fuel rods is continually researched. Welding method for research and commercialization is classified as melting, solid type welding or resistance welding. End plug cladding welding of nuclear fuel rods in PHWR takes advantage of resistance upset butt welding using multicycle mode. This method makes weld flash and shapes re-entrant corner owing to welding heat due to resistivity, contact resistance of cladding-end plug, and inelasticity deformation due to pressure. Welding part between cladding and end plug receives stresses and makes small cracks. In this study, remote welding system for multi-pin assembly was designed, fabricated and welding specimens of end plug-endplate were made using electrical resistance method. The torques of welding between end plug and endplate were measured. These results on welding current, pressure of main electrode and pressure of branch electrode were analyzed. Weldability between end plug and endplate was confirmed through metallographic examinations. In the future, optimal welding examinations due to welding current, welding pressure and welding time will be performed to improve weldability of end plug-endplate.

Reduction of mercury from mackerel fillet using combined solution of cysteine, EDTA, and sodium chloride.

Science.gov (United States)

Hajeb, P; Jinap, S

2012-06-13

An acidic solution containing mercury chelating agents to eliminate mercury in raw fish (mackerel) fillet was developed. The solution contained hydrochloric acid, sodium hydroxide, cysteine, EDTA, and NaCl. The optimum conditions for mercury reduction were achieved using response surface methodology (RSM) at cysteine concentration of 1.25%, EDTA of 275 mg/L, NaCl of 0.5%, pH of 3.75, and exposure time of 18 min. The optimized conditions produced a solution which can remove up to 91% mercury from raw fish fillet. Cysteine and EDTA were identified as potential chelating agents with the greatest potential for use. The solution can be employed in fish industries to reduce mercury in highly contaminated fish.

Advantages of new micro-jet welding technology on weld microstructure control

Directory of Open Access Journals (Sweden)

Jan PIWNIK

2013-01-01

Full Text Available An innovative apparatus to welding process with micro-jet cooling of the weld made it possible to carry out technological tests, which have proved theoretical considerations about this problem. This project gives real opportunities for professional development in the field of welding with controlling the parameters of weld structure. These tests have proved that the new micro-jet technology has the potential for growth. It may be great achievement of welding technology in order to increase weld metal strength. The new technology with micro-jet cooling may have many practical applications in many fields, for example such as in the transport industry or to repair damaged metal elements. The advantages of the new device over the traditional system are the ability to control the structure of the weld, the weld mechanical performance increases and improve the quality of welded joints.

Diphyllobothrium latum in Italy: plerocercoids larvae distribution in perch (Perca fluviatilis fillets

Directory of Open Access Journals (Sweden)

MariaLetizia Fioravanti

2013-04-01

Full Text Available Following the diffusion of new eating habits (consumption of uncooked, undercooked, marinated or cold-smoked fish, some cases of parasitic zoonosis from freshwater fish are recently reappeared in Italy. One of these is tapeworm Diphyllobothrium latum, whose final host could be human. This study aimed to individuate the position of plerocercoid larvae inside perch fillets (Perca fluviatilis caught in 4 different sites on Como lake in 2011. The fish analyzed were 390. The larvae totally isolated from 112 positive fishes were 164: 85 found in the right fillets and 79 in left ones. According to dorso-ventral disposition in fish, 144 larvae were individuated in dorsal muscles and 20 in ventral ones. Data collected confirm that plerocercoid larvae prefer the upper mass of perch muscle. Dietary education and sanitary care on fish supply are necessary to prevent the diffusion of tapeworm zoonosis in high-risk zones. European legislation establishes freezing to sanitize fish to be eaten raw, marinated or cold-smoked.

Macronutrient and fatty acid profiles of meagre (Argyrosomus regius fillets as influenced by harvesting time and boiling

Directory of Open Access Journals (Sweden)

Roberta Martelli

2013-12-01

Full Text Available The effect of harvesting time and cooking on water, protein, lipid, ash and fatty acid content of farmed meagre was assessed. Significant differences in nutrient content of raw fillets were detected in relation to harvesting time. Cooking by boiling induced loss of some macronutrients, mainly lipids and some fatty acids. Retention of total lipids, C18:2n-6 and C18:3n-3 decreased significantly with harvesting time, while C20:5n-3 (EPA and C22:6n-3 (DHA were retained in the same quantity. DHA retention was higher than that of the other FAs considered, at all harvesting times. The changes detected did not diminish the nutritional value of the fish. Despite losses induced by cooking and the low fat content, typical of this species, 100 g of fillet ensured an intake of EPA plus DHA more than double the recommended daily intake (250 mg day–1, at all harvesting times. The ability to preserve nutrients is an essential requirement for quality maintenance and suggests the possibility of heat-processing fillets. 

TECHNOLOGICAL ISSUES IN MECHANISED FEED WIG/TIG WELDING SURFACING OF WELDING

Directory of Open Access Journals (Sweden)

BURCA Mircea

2016-09-01

manual welding tests in the light of using the process for welding surfacing being known that in such applications mechanised operations are recommended whenever possible given the latter strengths i.e. increased productivity and quality deposits. The research also aims at achieving a comparative a study between wire mechanised feed based WIG manual welding and the manual rod entry based manual welding in terms of geometry deposits, deposits aesthetics, operating technique, productivity, etc . In this regard deposits were made by means of two welding procedures, and subsequently welding surfacing was made with the optimum values of the welding parameters in this case.

Welding Penetration Control of Fixed Pipe in TIG Welding Using Fuzzy Inference System

Science.gov (United States)

Baskoro, Ario Sunar; Kabutomori, Masashi; Suga, Yasuo

This paper presents a study on welding penetration control of fixed pipe in Tungsten Inert Gas (TIG) welding using fuzzy inference system. The welding penetration control is essential to the production quality welds with a specified geometry. For pipe welding using constant arc current and welding speed, the bead width becomes wider as the circumferential welding of small diameter pipes progresses. Having welded pipe in fixed position, obviously, the excessive arc current yields burn through of metals; in contrary, insufficient arc current produces imperfect welding. In order to avoid these errors and to obtain the uniform weld bead over the entire circumference of the pipe, the welding conditions should be controlled as the welding proceeds. This research studies the intelligent welding process of aluminum alloy pipe 6063S-T5 in fixed position using the AC welding machine. The monitoring system used a charge-coupled device (CCD) camera to monitor backside image of molten pool. The captured image was processed to recognize the edge of molten pool by image processing algorithm. Simulation of welding control using fuzzy inference system was constructed to simulate the welding control process. The simulation result shows that fuzzy controller was suitable for controlling the welding speed and appropriate to be implemented into the welding system. A series of experiments was conducted to evaluate the performance of the fuzzy controller. The experimental results show the effectiveness of the control system that is confirmed by sound welds.

Versatile Friction Stir Welding/Friction Plug Welding System

Science.gov (United States)

Carter, Robert

2006-01-01

A proposed system of tooling, machinery, and control equipment would be capable of performing any of several friction stir welding (FSW) and friction plug welding (FPW) operations. These operations would include the following: Basic FSW; FSW with automated manipulation of the length of the pin tool in real time [the so-called auto-adjustable pin-tool (APT) capability]; Self-reacting FSW (SRFSW); SR-FSW with APT capability and/or real-time adjustment of the distance between the front and back shoulders; and Friction plug welding (FPW) [more specifically, friction push plug welding] or friction pull plug welding (FPPW) to close out the keyhole of, or to repair, an FSW or SR-FSW weld. Prior FSW and FPW systems have been capable of performing one or two of these operations, but none has thus far been capable of performing all of them. The proposed system would include a common tool that would have APT capability for both basic FSW and SR-FSW. Such a tool was described in Tool for Two Types of Friction Stir Welding (MFS- 31647-1), NASA Tech Briefs, Vol. 30, No. 10 (October 2006), page 70. Going beyond what was reported in the cited previous article, the common tool could be used in conjunction with a plug welding head to perform FPW or FPPW. Alternatively, the plug welding head could be integrated, along with the common tool, into a FSW head that would be capable of all of the aforementioned FSW and FPW operations. Any FSW or FPW operation could be performed under any combination of position and/or force control.

Effect of Welding Parameters on Dilution and Weld Bead Geometry in Cladding

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

The effect of pulsed gas metal arc welding (GMAW) variables on the dilution and weld bead geometry in cladding X65 pipeline steel with 316L stainless steel was studied. Using a full factorial method, a series of experiments were carried out to know the effect of wire feed rate, welding speed, distance between gas nozzle and plate, and the vertical angle of welding on dilution and weld bead geometry. The findings indicate that the dilution of weld metal and its dimension i.e. width, height and depth increase with the feed rate, but the contact angle of the bead decreases first and then increases. Meantime, welding speed has an opposite effect except for dilution. There is an interaction effect between welding parameters at the contact angle. The results also show forehand welding or decreasing electrode extension decrease the angle of contact. Finally,a mathematical model is contrived to highlight the relationship between welding variables with dilution and weld bead geometry.

Modeling of welded bead profile for rapid prototyping by robotic MAG welding

Institute of Scientific and Technical Information of China (English)

CAO Yong; ZHU Sheng; WANG Tao; WANG Wanglong

2009-01-01

As a deposition technology, robotic metal active gas(MAG) welding has shown new promise for rapid prototyping (RP) of metallic parts. During the process of metal forming using robotic MAG welding, sectional profile of single-pass welded bead is critical to formed accuracy and quality of metal pans. In this paper, the experiments of single-pass welded bead for rapid prototyping using robotic MAG welding were carried out. The effect of some edge detectors on the cross-sectional edge of welded bead was discussed and curve fitting was applied using leat square fitting. Consequently, the mathematical model of welded bead profile was developed. The experimental results show that good shape could be obtained under suitable welding parameters. Canny operawr is suitable to edge detection of welded bead profile, and the mathematical model of welded bead profile developed is approximately parabola.

Descriptive sensory analysis of marinated and non-marinated wooden breast fillet portions.

Science.gov (United States)

Maxwell, A D; Bowker, B C; Zhuang, H; Chatterjee, D; Adhikari, K

2018-05-14

The wooden breast (WB) myopathy influences muscle composition and texture characteristics in broiler breast meat. It is unknown if marination reduces the negative influence of WB on meat sensory quality or if WB effects are uniform throughout the Pectoralis major. The objective of this study was to determine the effects of marination on the sensory attributes and instrumental shear force measurements of the ventral (skin-side) and dorsal (bone-side) portions of normal and severe WB meat. Sixty butterfly fillets (30 normal and 30 severe WB) were selected from the deboning line of a commercial processing plant. Individual fillets were portioned into ventral and dorsal halves. Portions from one side of each butterfly were used as non-marinated controls, and portions from the other side were vacuum-tumble marinated (16 rpm, -0.6 atm, 4°C, 20 min) with 20% (wt/wt) marinade to meat ratio. Marinade was formulated to target a concentration of 0.75% (w/v) salt and 0.45% (w/v) sodium tripolyphosphate in the final product. Descriptive sensory analysis (9 trained panelists) was conducted to evaluate visual, texture, and flavor attributes (0-15 point scale) of breast portions along with Warner-Bratzler shear force. Significant interaction effects between WB and marination were not observed for the sensory attributes. Greater springiness, cohesiveness, hardness, fibrousness, and chewiness scores were observed in WB samples (P sensory texture attributes were more apparent in the ventral portions of the breast fillets. Flavor attributes (salty and brothy) increased (P sensory quality is not uniform throughout the Pectoralis major and that WB-related differences in cooked meat sensory texture attributes are lessened but not eliminated by vacuum-tumbling marination.

Elimination of vibrio cholerae in lisa fillets (Mugil cephalus) by gamma radiation

International Nuclear Information System (INIS)

Torres, Z.

1999-03-01

The elimination of Vibrio cholerae 01 biotype El Tor (1,87 8 cuf/g) in fresh lisa fillets (Mugil cephalus) with radiation doses of 0 and 0,5 kGy was investigated. Furthermore, in order to evaluate physical, chemical and sensory changes, doses of 1,2,3 and 4 kGy were applied to non inoculated fillets of lisa. Finally, D 10 for Vibrio cholerae was determined in a saline suspension (5,2x10 8 cfu/ml) based on the Most Probable Number (MPN) method and radiation doses of 0,5, 0,75, 1,0, 1,25 and 1,5 kGy. D value found in a 1,87 8 cfu/g concentration of fillet was 0,13 kGy. Humidity, protein, fat and ash contents were not affected significantly and remained around 73 to 75,5, 3,8 to 4,2 and 1% respectively. Control samples showed a 'drip' variation ranging between 0,82 and 0,88% and a N-BVT variation between 1,77 and 1,56, 0,89 and 1,99, 2,13 and 2,47, 1,86 and 2,10%, and a N-BVT variation between 17,79 and 30,16, 16,37 and 26,88 16,33 and 25,12, 15,31 and 33,54 mg N/100 g, respectively. The highest life span for the appearance characteristic was obtained by control samples (23 days) and the lowest by samples radiated at 3 and 4 kGy (28 days). 4 kGy dose resulted in organoleptic changes perceived by panelists during tasting of cooked fish. D 10 found in a saline suspension was 0,13 kGy

Fusion welding process

Science.gov (United States)

Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

1983-01-01

A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

Resistance to wear and microstructure of martensitic welds deposits for recharge

International Nuclear Information System (INIS)

Gualco, Agustin; Svoboda, Hernan G; Surian, Estela S; Vedia, Luis A

2006-01-01

This work studied the welding metal for a martensitic steel (alloyed to Cr, Mn, Mo, V and W), deposited with a tubular metal-cored wire with gaseous protection of 82%Ar-18%Co 2 on a low carbon steel using the semi-automatic welding process. Transverse pieces were cut from the welded coupon for microstructural characterization, measurement of hardness profiles, determination of the chemical composition and wear trials. The microstructural characterization was done using optic and scanning electronic microscopes, X-rays diffraction and energy-dispersive X-ray spectroscopy and Vicker microhardness (1 kg.) was measured. The wear trials (metal-metal) were performed in an Amsler machine under pure flow conditions. Different loads were used and the reference material was a SAE 1020 steel. The temperatures for each case were measured and the weight loss curves were defined as a function of the distance run and of the load. After testing the wear surfaces and the debris were measured. The microstructure of the welded deposit mostly consists of martensite and some retained austenite, with a pattern of dendritic segregation, and a hardness on the surface of 612 HVI. A lineal variation between the weight loss and the load applied was obtained as a response to the wear. The following phenomena were observed: abrasion, plastic deformation, oxidation and adhesion to the wear surfaces, as well as a tempering effect in the condition of the biggest load. The wear mechanisms acting on both surfaces were identified (CW)

The Plunge Phase of Friction Stir Welding

Science.gov (United States)

McClure, John C.

2005-01-01

The many advantages of Friction Stir Welding have led to a relatively rapid acceptance in the often conservative welding community. Because the process is so different from traditional fusion welding, with which most investigators are most familiar, there remain many aspects of FSW for which there is no clear consensus. For example, the well known onion rings seen in transverse sections have been variously interpreted as grain size variations, variation in density of second phase particles and parts of the carousel of material rotating with the pin that have been shed from the carousel. Using Orientation Imaging Microscopy, Schneider has recently noted that the onion rings have a different orientation (and hence etch differently) than the surrounding material, and this orientation is consistent with slip plane orientations at the edge of the carousel. Likewise, the forces and torque exerted by the FSW tool on the work piece largely remain unaccounted for. Although these forces are routinely measured by investigators with commercial instrumented welders, they are rarely reported or even qualitatively analyzed. This paper will introduce a model based on a carousel or disk of material that rotates with the tool to estimate the torque and plunge force required to plunge a tool into the work piece. A stationary tool is modeled rather than the moving tool because effects such as thermal transients and metallurgical changes in the sample (primarily aging in aluminum) can be more easily accounted for. It is believed, however, that with some modifications the model should be applicable to a moving tool also.

MAG narrow gap welding - an economic way to minimize welding expenses

International Nuclear Information System (INIS)

Kast, W.; Scholz, E.; Weyland, F.

1982-01-01

The thicker structural components are, the more important it is to take measures to reduce the volume of the weld. The welding process requiring the smallest possible weld section is the so-called narrow gap process. In submerged arc narrow gap welding as well as in MAG narrow gap welding different variants are imaginable, some of them already in practical use. With regard to efficiency and weld quality an optimum variant of the MAG narrow gap welding process is described. It constitutes a two wire system in which two wire electrodes of 1.2 mm diameter are arranged one behind the other. In order to avoid lack of fusion, the wire guides are slightly pointed towards each groove face. Thus, by inclining the two arcs burning one behind the other in the direction of weld progress, it is achieved that two separately solidifying weld pools and two beads per layer are simultaneously formed. Welding parameters are selected in such a way that a heat input of 16-20 kJ/cm and a deposition rate of 11-16 kgs/h are obtained. In spite of this comparatively high deposition rate, good impact values are found both in the weld and HAZ (largely reduced coarse-grain zone) which is due to an optimum weld build-up. With the available welding equipment the process can be applied to structural members having a thickness of 40-400 mm. The width of gap is 13 mm (root section) with a bevel angle of 1 0 . As filler metal, basic flux-cored wires are used which, depending on the base metal to be welded and the required tensile properties, can be of the Mn-, MnMo-, MnCrMo-, MnNi-, or MnNiMo-alloyed types. (orig.)

Comparison of the aerodynamics of bridge cables with helical fillets and a pattern-indented surface in normal flow

DEFF Research Database (Denmark)

Kleissl, Kenneth; Georgakis, Christos

2011-01-01

Over the last two decades, several bridge cable manufacturers have introduced surface modi-fications on the high-density polyethylene (HDPE) sheathing that is often installed for the protection of inner strands. The main goal of this is rain rivulet impedance, leading to the suppression of rain......-wind induced vibrations (RWIVs). The modifications are based on re-search undertaken predominantly in Europe and Japan, with two different systems prevailing; HDPE tubing fitted with helical surface fillets and HDPE tubing with pattern-indented sur-faces. In the US and Europe, helical fillets dominate, whilst...

Seasonal and sexual variations of fatty acid composition in fillet of Capoeta erhani

Directory of Open Access Journals (Sweden)

Yılmaz Emre

2014-11-01

Full Text Available The lowest lipid levels of Capoeta erhani observed in winter and vice versa in summer. The fatty acid composition of the fillets was significantly different among seasons (P0.05. The ratios of the unsaturated fatty acids (UFAs were higher than half of the total fatty acids among all seasons. The level of PUFA was highest in autumn (25.91%, and lowest in summer (22.11%. Among seasons and sexes, the levels of total n3 PUFAs in total fatty acids changed from 15.43% to 21.89% and n6 PUFAs from 3.8% to 7.97%, respectively. The level of n3 PUFAs was present in excess that of the n6 PUFAs. The ratios of the n3 PUFAs to n6 PUFAs in the fillets of C. erhani were highest in autumn for both sexes and remarkably influenced by seasons.

Advanced Welding Applications

Science.gov (United States)

Ding, Robert J.

2010-01-01

Some of the applications of advanced welding techniques are shown in this poster presentation. Included are brief explanations of the use on the Ares I and Ares V launch vehicle and on the Space Shuttle Launch vehicle. Also included are microstructural views from four advanced welding techniques: Variable Polarity Plasma Arc (VPPA) weld (fusion), self-reacting friction stir welding (SR-FSW), conventional FSW, and Tube Socket Weld (TSW) on aluminum.

WELDING METHOD

Science.gov (United States)

Cornell, A.A.; Dunbar, J.V.; Ruffner, J.H.

1959-09-29

A semi-automatic method is described for the weld joining of pipes and fittings which utilizes the inert gasshielded consumable electrode electric arc welding technique, comprising laying down the root pass at a first peripheral velocity and thereafter laying down the filler passes over the root pass necessary to complete the weld by revolving the pipes and fittings at a second peripheral velocity different from the first peripheral velocity, maintaining the welding head in a fixed position as to the specific direction of revolution, while the longitudinal axis of the welding head is disposed angularly in the direction of revolution at amounts between twenty minutas and about four degrees from the first position.

Friction stir welding tool and process for welding dissimilar materials

Science.gov (United States)

Hovanski, Yuri; Grant, Glenn J; Jana, Saumyadeep; Mattlin, Karl F

2013-05-07

A friction stir welding tool and process for lap welding dissimilar materials are detailed. The invention includes a cutter scribe that penetrates and extrudes a first material of a lap weld stack to a preselected depth and further cuts a second material to provide a beneficial geometry defined by a plurality of mechanically interlocking features. The tool backfills the interlocking features generating a lap weld across the length of the interface between the dissimilar materials that enhances the shear strength of the lap weld.

Feature Extraction of Weld Defectology in Digital Image of Radiographic Film Using Geometric Invariant Moment and Statistical Texture

International Nuclear Information System (INIS)

Muhtadan

2009-01-01

The purpose of this research is to perform feature extraction in weld defect of digital image of radiographic film using geometric invariant moment and statistical texture method. Feature extraction values can be use as values that used to classify and pattern recognition on interpretation of weld defect in digital image of radiographic film by computer automatically. Weld defectology type that used in this research are longitudinal crack, transversal crack, distributed porosity, clustered porosity, wormhole, and no defect. Research methodology on this research are program development to read digital image, then performing image cropping to localize weld position, and then applying geometric invariant moment and statistical texture formulas to find feature values. The result of this research are feature extraction values that have tested with RST (rotation, scale, transformation) treatment and yield moment values that more invariant there are ϕ 3 , ϕ 4 , ϕ 5 from geometric invariant moment method. Feature values from statistical texture that are average intensity, average contrast, smoothness, 3 rd moment, uniformity, and entropy, they used as feature extraction values. (author)

Syllabus in Trade Welding.

Science.gov (United States)

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

The syllabus outlines material for a course two academic years in length (minimum two and one-half hours daily experience) leading to entry-level occupational ability in several welding trade areas. Fourteen units covering are welding, gas welding, oxyacetylene welding, cutting, nonfusion processes, inert gas shielded-arc welding, welding cast…

Latest MIG, TIG arc-YAG laser hybrid welding systems for various welding products

Science.gov (United States)

Ishide, Takashi; Tsubota, Shuho; Watanabe, Masao

2003-03-01

Laser welding is capable of high-efficiency low-strain welding, and so its applications are started to various products. We have also put the high-power YAG laser of up to 10 kW to practical welding use for various products. On the other hand the weakest point of this laser welding is considered to be strict in the welding gap aiming allowance. In order to solve this problem, we have developed hybrid welding of TIG, MIG arc and YAG laser, taking the most advantages of both the laser and arc welding. Since the electrode is coaxial to the optical axis of the YAG laser in this process, it can be applied to welding of various objects. In the coaxial MIG, TIG-YAG welding, in order to make irradiation positions of the YAG laser beams having been guided in a wire or an electrode focused to the same position, the beam transmitted in fibers is separated to form a space between the separated beams, in which the laser is guided. With this method the beam-irradiating area can be brought near or to the arc-generating point. This enables welding of all directions even for the member of a three-dimensional shape. This time we carried out welding for various materials and have made their welding of up to 1 mm or more in welding groove gap possible. We have realized high-speed 1-pass butt welding of 4m/min in welding speed with the laser power of 3 kW for an aluminum alloy plate of approximately 4 mm thick. For a mild steel plate also we have realized butt welding of 1m/min with 5 kW for 6 mm thick. Further, in welding of stainless steel we have shown its welding possibility, by stabilizing the arc with the YAG laser in the welding atmosphere of pure argon, and shown that this welding is effective in high-efficiency welding of various materials. Here we will report the fundamental welding performances and applications to various objects for the coaxial MIG, TIG-YAG welding we have developed.

Effect of the clove (Eugenia caryophyllus L. ethanol extract and essential oil on the quality of pre-cooked rainbow trout fillet during storage at -18°C

Directory of Open Access Journals (Sweden)

H. Shabani

2017-07-01

Full Text Available This study aimed to investigate the effects of clove (Eugenia caryophyllus L. extract and essential oil (EO on oxidative stability and sensory properties of pre-cooked trout fillet during frozen storage period. Trout fillets (treated with clove EO (0.1%, extract (2%, BHT (0.02% and the control were fried, oven baked and steamed and stored at -18 ºC for 4 months. By the end of storage period, the highest value peroxide value was obtained from fried fillets contained EO and extract (4.48 and 5.45 meq/kg, respectively and the lowest was observed in oven-baked samples contained EO and extract (2.63 and 3.47 meq/kg, respectively. TBA values did not increase in pre-cooked fillets with EO and extract except control steamed samples (0.58 mg MA/kg. Samples treated with clove EO showed slower PV and TBA increse than those of extract-treated samples or control. However, the additions of clove EO and extract have positive effect on sensory quality of baked fillets.

Shelf-life extension of gilthead seabream fillets by osmotic treatment and antimicrobial agents.

Science.gov (United States)

Tsironi, T N; Taoukis, P S

2012-02-01

The objectives of the study were to evaluate the effect of selected antimicrobial agents on the shelf life of osmotically pretreated gilthead seabream and to establish reliable kinetic equations for shelf-life determination validated in dynamic conditions. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (HDM, DE 47) plus 5% NaCl and 0·5% carvacrol, 0·5% glucono-δ-lactone or 1% Citrox (commercial antimicrobial mix). Untreated and treated slices were aerobically packed and stored isothermally (0-15°C). Microbial growth and quality-related chemical indices were modelled as functions of temperature. Models were validated at dynamic storage conditions. Osmotic pretreatment with the use of antimicrobials led to significant shelf-life extension of fillets, in terms of microbial growth and organoleptic deterioration. The shelf life was 7 days for control samples at 5°C. The osmotic pretreatment with carvacrol, glucono-δ-lactone and Citrox allowed for shelf-life extension by 8, 10 and 5 days at 5°C, respectively. The results of the study show the potential of adding carvacrol, glucono-δ-lactone or Citrox in the osmotic solution to extend the shelf life and improve commercial value of chilled osmotically pretreated fish products. The developed models can be a reliable tool for predicting the shelf life of fresh or minimally processed gilthead seabream fillets in the real chill chain. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Ultrasonic testing of austenitic welds and its dependency on the welding process

International Nuclear Information System (INIS)

Tabatabaeipour, S.M.; Honarvar, F.

2009-01-01

This paper describes the ultrasonic testing of austenitic welds prepared by two different welding processes. The tests were carried out by the ultrasonic Time-of-Flight Diffraction (ToFD) technique. Shielded Metal Arc Welding (SMAW) and Gas Tungsten Arc Welding (GTAW) are the welding processes used for preparing the specimens. Identical artificial defects were implanted in both welds during the welding process. Both specimens were examined by the ToFD technique under similar conditions. Metallographic images were also obtained from the cross sectional plane of both the SMA and GTA welds. These images show that the grain orientation in the two welded specimens are different. D-scan images obtained by the ToFD technique from these welds indicates that inspecting the specimens prepared by the SMAW process is easier than the one made by the GTAW process. The results also show that the D-scan images cannot reveal the small vertical drilled holes implanted in the specimens. (author)

Friction Stir Welding of Tapered Thickness Welds Using an Adjustable Pin Tool

Science.gov (United States)

Adams, Glynn; Venable, Richard; Lawless, Kirby

2003-01-01

Friction stir welding (FSW) can be used for joining weld lands that vary in thickness along the length of the weld. An adjustable pin tool mechanism can be used to accomplish this in a single-pass, full-penetration weld by providing for precise changes in the pin length relative to the shoulder face during the weld process. The difficulty with this approach is in accurately adjusting the pin length to provide a consistent penetration ligament throughout the weld. The weld technique, control system, and instrumentation must account for mechanical and thermal compliances of the tooling system to conduct tapered welds successfully. In this study, a combination of static and in-situ measurements, as well as active control, is used to locate the pin accurately and maintain the desired penetration ligament. Frictional forces at the pin/shoulder interface were a source of error that affected accurate pin position. A traditional FSW pin tool design that requires a lead angle was used to join butt weld configurations that included both constant thickness and tapered sections. The pitch axis of the tooling was fixed throughout the weld; therefore, the effective lead angle in the tapered sections was restricted to within the tolerances allowed by the pin tool design. The sensitivity of the FSW process to factors such as thickness offset, joint gap, centerline offset, and taper transition offset were also studied. The joint gap and the thickness offset demonstrated the most adverse affects on the weld quality. Two separate tooling configurations were used to conduct tapered thickness welds successfully. The weld configurations included sections in which the thickness decreased along the weld, as well as sections in which the thickness increased along the weld. The data presented here include weld metallography, strength data, and process load data.

Inspection of austenitic welds with ultrasonic phased array technology

Energy Technology Data Exchange (ETDEWEB)

Garcia, A.; Fernandez, F. [Tecnatom (Spain); Dutruc, R.; Ferriere, R. [Metalscan (France)

2011-07-01

This series of slides presents the use of ultrasonic phased array technology in the inspection of austenitic welds. The inspection from outside surface (the inspection is performed in contact using wedges to couple the probe to the outer surface of the component) shows that longitudinal wave is the most adequate for perpendicular scans and transversal ultrasonic wave is the most adequate for parallel scans. Detection and length sizing are performed optimally in perpendicular scans. The inspection from inside surface shows: -) Good results in the detection of defects (Sizing has met the requirements imposed by the Authority of the Russian Federation); -) The new design of the mechanical equipment and of the numerous ultrasonic beams refracted by the array probes has increased the volume inspected. The design of the mechanical equipment has also allowed new areas to be inspected (example a piping weld that was not accessible from the outer surface; -) The ultrasonic procedure and Inspection System developed have been validated by the Authority of the Russian Federation. Phase array technique supplies solutions to solve accessibility concerns and improve the ultrasonic inspections of nuclear components

The technology and welding joint properties of hybrid laser-tig welding on thick plate

Science.gov (United States)

Shenghai, Zhang; Yifu, Shen; Huijuan, Qiu

2013-06-01

The technologies of autogenous laser welding and hybrid laser-TIG welding are used on thick plate of high strength lower alloy structural steel 10CrNiMnMoV in this article. The unique advantages of hybrid laser-TIG welding is summarized by comparing and analyzing the process parameters and welding joints of autogenous laser welding laser welding and hybrid laser-TIG welding. With the optimal process parameters of hybrid welding, the good welding joint without visible flaws can be obtained and its mechanical properties are tested according to industry standards. The results show that the hybrid welding technology has certain advantages and possibility in welding thick plates. It can reduce the demands of laser power, and it is significant for lowering the aspect ratio of weld during hybrid welding, so the gas in the molten pool can rise and escape easily while welding thick plates. Therefore, the pores forming tendency decreases. At the same time, hybrid welding enhances welding speed, and optimizes the energy input. The transition and grain size of the microstructure of hybrid welding joint is better and its hardness is higher than base material. Furthermore, its tensile strength and impact toughness is as good as base material. Consequently, the hybrid welding joint can meet the industry needs completely.

Effects of post weld heat treatment and weld overlay on the residual stress and mechanical properties in dissimilar metal weld

International Nuclear Information System (INIS)

Campos, Wagner R.C.; Ribeiro, Vladimir S.; Vilela, Alisson H.F.; Almeida, Camila R.O.; Rabello, Emerson G.

2017-01-01

The object of this work is a dissimilar metal weld (DMW) pipe joint between carbon steel (A-106 Gr B) and stainless steel (A-312 TP316L) pipes and filler metals of Nickel alloy (82/182), which find wide application in the field of chemical, oil, petroleum industries, fossil fuel and nuclear power plant. A lot of the failures that have occurred in dissimilar metal welded are affected greatly by residual stresses. Residual stress is often a cause of premature failure of critical components under normal operation of welded components. Several methods have been tested and developed for removing the tensile residual stresses. The aim of the methods is to reduce the tensile stress state or to create compressive stresses at a predefined area, such as the inner surface of a welded pipe joint. Post weld heat treatment (PWHT) and weld overlay (WOL) are two of the residual stress mitigation methods which reduce the tensile residual stress, create compressive stresses and arrest crack initiation and crack growth. The technique used to substantially minimized or eliminated this failure development in the root weld is the post weld heat treatments (stress relief heat treatment) or the weld overlay. In this work was studied the effectiveness in reducing internal residual stress in dissimilar metal welded pipe joints subjected to post weld heat treatment and weld overlay, measurement by hole-drilling strain-gage method of stress relaxation. Also held was mechanical characterization of the welded pipe joint itself. (author)

Effects of post weld heat treatment and weld overlay on the residual stress and mechanical properties in dissimilar metal weld

Energy Technology Data Exchange (ETDEWEB)

Campos, Wagner R.C.; Ribeiro, Vladimir S.; Vilela, Alisson H.F.; Almeida, Camila R.O.; Rabello, Emerson G., E-mail: wrcc@cdtn.br, E-mail: camilarezende.cr@gmail.com, E-mail: egr@cdtn.br, E-mail: vladimirsoler@hotmail.com, E-mail: ahfv02@outlook.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

The object of this work is a dissimilar metal weld (DMW) pipe joint between carbon steel (A-106 Gr B) and stainless steel (A-312 TP316L) pipes and filler metals of Nickel alloy (82/182), which find wide application in the field of chemical, oil, petroleum industries, fossil fuel and nuclear power plant. A lot of the failures that have occurred in dissimilar metal welded are affected greatly by residual stresses. Residual stress is often a cause of premature failure of critical components under normal operation of welded components. Several methods have been tested and developed for removing the tensile residual stresses. The aim of the methods is to reduce the tensile stress state or to create compressive stresses at a predefined area, such as the inner surface of a welded pipe joint. Post weld heat treatment (PWHT) and weld overlay (WOL) are two of the residual stress mitigation methods which reduce the tensile residual stress, create compressive stresses and arrest crack initiation and crack growth. The technique used to substantially minimized or eliminated this failure development in the root weld is the post weld heat treatments (stress relief heat treatment) or the weld overlay. In this work was studied the effectiveness in reducing internal residual stress in dissimilar metal welded pipe joints subjected to post weld heat treatment and weld overlay, measurement by hole-drilling strain-gage method of stress relaxation. Also held was mechanical characterization of the welded pipe joint itself. (author)

On use of weld zone temperatures for online monitoring of weld quality in friction stir welding of naturally aged aluminium alloys

International Nuclear Information System (INIS)

Imam, Murshid; Biswas, Kajal; Racherla, Vikranth

2013-01-01

Highlights: • FSWs for 6063-T4 AA are done at different process parameters and sheet thicknesses. • Weld nugget zone and heat affected zone temperatures are monitored for each case. • Microstructural and mechanical characterisation of welds is done in all cases. • Weld ductility is found to be particularly sensitive to weld zone temperatures. • Strong correlation is found between WNZ and HAZ temperatures and weld properties. - Abstract: 6063-T4 aluminium alloy sheets of 3 and 6 mm thicknesses were friction stir butt welded using a square tool pin at a wide range of tool rotational speeds. Properties of obtained welds were characterised using tensile tests, optical micrographs, X-ray diffraction, and transmission electron microscopy. Shape, size, and distribution of precipitates in weld zones, and strength and ductility of welds were seen to directly correlate with peak temperatures in weld nugget and heat affected zones, independent of sheet thickness. In addition, fluctuations in measured temperature profiles, for 3 mm sheets, were seen to correlate with an increase in scatter of weld nugget zone properties for 3 mm sheets. Optimal weld strength and ductility were obtained for peak weld nugget zone temperatures of around 450 °C and corresponding peak heat affected zone temperatures of around 360–380 °C. Results obtained suggest that, at least for naturally aged aluminium alloys, nature of temperature evolution and magnitudes of peak temperatures in weld nugget and heat affected zones provide information on uniformity of properties in weld zones, overaging of heat affected zones, and formation of tunnel defects from improper material mixing at low weld zone temperatures

Measuring weld heat to evaluate weld integrity

Energy Technology Data Exchange (ETDEWEB)

Schauder, V., E-mail: schauder@hks-prozesstechnik.de [HKS-Prozesstechnik GmbH, Halle (Germany)

2015-11-15

Eddy current and ultrasonic testing are suitable for tube and pipe mills and have been used for weld seam flaw detection for decades, but a new process, thermography, is an alternative. By measuring the heat signature of the weld seam as it cools, it provides information about weld integrity at and below the surface. The thermal processes used to join metals, such as plasma, induction, laser, and gas tungsten arc welding (GTAW), have improved since they were developed, and they get better with each passing year. However, no industrial process is perfect, so companies that conduct research in flaw detection likewise continue to develop and improve the technologies used to verify weld integrity: ultrasonic testing (UT), eddy current testing (ET), hydrostatic, X-ray, magnetic particle, and liquid penetrant are among the most common. Two of these are used for verifying the integrity of the continuous welds such as those used on pipe and tube mills: UT and ET. Each uses a transmitter to send waves of ultrasonic energy or electrical current through the material and a receiver (probe) to detect disturbances in the flow. The two processes often are combined to capitalize on the strengths of each. While ET is good at detecting flaws at or near the surface, UT penetrates the material, detecting subsurface flaws. One drawback is that sound waves and electrical current waves have a specific direction of travel, or an alignment. A linear defect that runs parallel to the direction of travel of the ultrasonic sound wave or a flaw that is parallel to the coil winding direction of the ET probe can go undetected. A second drawback is that they don't detect cold welds. An alternative process, thermography, works in a different fashion: It monitors the heat of the material as the weld cools. Although it measures the heat at the surface, the heat signature provides clues about cooling activity deep in the material, resulting in a thorough assessment of the weld's integrity It

The effect of post-welding conditions in friction stir welds: From weld simulation to Ductile Failure

DEFF Research Database (Denmark)

Hattel, Jesper Henri; Nielsen, Kim Lau; Tutum, Cem Celal

2012-01-01

software ANSYS, a thermo-mechanical model is employed to predict the thermally induced stresses and strains during welding, while an in-house finite element code is used to study the plastic flow localization and failure in a subsequent structural analysis. The coupling between the two models is made......The post-welding stress state, strain history and material conditions of friction stir welded joints are often strongly idealized when used in subsequent modeling analyses, typically by neglecting one or more of the features above. But, it is obvious that the conditions after welding do influence......, showed the largest influence of the post-welding conditions, even though significant relaxation of the residual stress state was predicted....

Nitrogen And Oxygen Amount In Weld After Welding With Micro-Jet Cooling

Directory of Open Access Journals (Sweden)

Węgrzyn T.

2015-06-01

Full Text Available Micro-jet cooling after welding was tested only for MIG welding process with argon, helium and nitrogen as a shielded gases. A paper presents a piece of information about nitrogen and oxygen in weld after micro-jet cooling. There are put down information about gases that could be chosen both for MIG/MAG welding and for micro-jet process. There were given main information about influence of various micro-jet gases on metallographic structure of steel welds. Mechanical properties of weld was presented in terms of nitrogen and oxygen amount in WMD (weld metal deposit.

A study of weld quality in ultrasonic spot welding of similar and dissimilar metals

International Nuclear Information System (INIS)

Al-Sarraf, Z; Lucas, M

2012-01-01

Several difficulties are faced in joining thinner sheets of similar and dissimilar materials from fusion welding processes such as resistance welding and laser welding. Ultrasonic metal welding overcomes many of these difficulties by using high frequency vibration and applied pressure to create a solid-state weld. Ultrasonic metal welding is an effective technique in joining small components, such as in wire bonding, but is also capable of joining thicker sheet, depending on the control of welding conditions. This study presents the design, characterisation and test of a lateral-drive ultrasonic metal welding device. The ultrasonic welding horn is modelled using finite element analysis and its vibration behaviour is characterised experimentally to ensure ultrasonic energy is delivered to the weld coupon. The welding stack and fixtures are then designed and mounted on a test machine to allow a series of experiments to be conducted for various welding and ultrasonic parameters. Weld strength is subsequently analysed using tensile-shear tests. Control of the vibration amplitude profile through the weld cycle is used to enhance weld strength and quality, providing an opportunity to reduce part marking. Optical microscopic examination and scanning electron microscopy (SEM) were employed to investigate the weld quality. The results show how the weld quality is particularly sensitive to the combination of clamping force and vibration amplitude of the welding tip.

Welding and cutting

International Nuclear Information System (INIS)

Drews, P.; Schulze Frielinghaus, W.

1978-01-01

This is a survey, with 198 literature references, of the papers published in the fields of welding and cutting within the last three years. The subjects dealt with are: weldability of the materials - Welding methods - Thermal cutting - Shaping and calculation of welded joints - Environmental protection in welding and cutting. (orig.) [de

Welding Technician

Science.gov (United States)

Smith, Ken

2009-01-01

About 95% of all manufactured goods in this country are welded or joined in some way. These welded products range in nature from bicycle handlebars and skyscrapers to bridges and race cars. The author discusses what students need to know about careers for welding technicians--wages, responsibilities, skills needed, career advancement…

Chemometrics applied to the incorporation of omega-3 in tilapia fillet feed flaxseed flour

Directory of Open Access Journals (Sweden)

Márcia Fernandes Nishiyama

2014-09-01

Full Text Available This study evaluated the effect of adding flaxseed flour to the diet of Nile tilapia on the fatty acid composition of fillets using chemometrics. A traditional and an experimental diet containing flaxseed flour were used to feed the fish for 60 days. An increase of 18:3 n-3 and 22:6 n-3 and a decrease of 18:2 n-6 were observed in the tilapia fillets fed the experimental diet. There was a reduction in the n-6:n-3 ratio. A period of 45 days of incorporation caused a significant change in tilapia chemical composition. Principal Component Analysis showed that the time periods of 45 and 60 days positively contributed to the total content of n-3, LNA, and DHA, highlighting the effect of omega-3 incorporation in the treatment containing flaxseed flour.

Role of biogenic amines in the post-mortem migration of Anisakis pegreffii (Nematoda: Anisakidae Dujardin, 1845) larvae into fish fillets.

Science.gov (United States)

Šimat, Vida; Miletić, Jelena; Bogdanović, Tanja; Poljak, Vedran; Mladineo, Ivona

2015-12-02

Infective third-stage larvae (L3) of nematode Anisakis spp. have been recognized as one of the major food-borne threats in lightly processed fish products in Europe, particularly in the Mediterranean region. Therefore, the effect of different storage temperatures of fish on larval post-mortem migration from visceral cavity into fillets is an important parameter to take into account when evaluating the risk for consumer safety. The European anchovy (Engraulis encrasicolus) were caught during fishing season, a subsample of fillets was checked for the presence of Anisakis larvae at capture (mean abundance=0.07), and the rest was stored at four different temperatures (-18, 0, 4 and 22°C) in order to count migrating larvae and measure the production of biogenic amines over a period of time. Larvae were identified by morphological features and molecular tools. Post-mortem migration was observed in fillets stored at 0 and 4°C after three and five days, respectively, but not at 22 and -18°C. In case of storage at 22°C for two days, at the onset of putrefaction of the visceral organs, larvae migrated out of the visceral cavity towards the fish surface. Measured pH and biogenic amine profile during storage indicated that certain biochemical conditions trigger larval migration into fillets. Likewise, migration was observed at pH ~6.4 when sensory degradation of the fish was markedly visible. Although larval migration was delayed for approximately four days at a temperature of fillet was high and statistically significant at both 0 (r=0.998, p<0.01) and 4°C (r=0.946, p<0.05). Out of eight biogenic amines measured, cadaverine and putrescine levels correlated the most with the post-mortem migration at 4°C, while tyramine levels were significant at both temperatures. Copyright © 2015 Elsevier B.V. All rights reserved.

Introduction to Welding.

Science.gov (United States)

Fortney, Clarence; Gregory, Mike

This curriculum guide provides six units of instruction on basic welding. Addressed in the individual units of instruction are the following topics: employment opportunities for welders, welding safety and first aid, welding tools and equipment, basic metals and metallurgy, basic math and measuring, and procedures for applying for a welding job.…

Orbital welding technique

International Nuclear Information System (INIS)

Hoeschen, W.

2003-01-01

The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.) [de

Welding stresses

International Nuclear Information System (INIS)

Poirier, J.; Barbe, B.; Jolly, N.

1976-01-01

The aim is to show how internal stresses are generated and to fix the orders of magnitude. A realistic case, the vertical welding of thick plates free to move one against the other, is described and the deformations and stresses are analyzed. The mathematical model UEDA, which accounts for the elastic modulus, the yield strength and the expansion coefficient of the metal with temperature, is presented. The hypotheses and results given apply only to the instantaneous welding of a welded plate and to a plate welded by a moving electrode [fr

Reduction of Biomechanical and Welding Fume Exposures in Stud Welding.

Science.gov (United States)

Fethke, Nathan B; Peters, Thomas M; Leonard, Stephanie; Metwali, Mahmoud; Mudunkotuwa, Imali A

2016-04-01

The welding of shear stud connectors to structural steel in construction requires a prolonged stooped posture that exposes ironworkers to biomechanical and welding fume hazards. In this study, biomechanical and welding fume exposures during stud welding using conventional methods were compared to exposures associated with use of a prototype system that allowed participants to weld from an upright position. The effect of base material (i.e. bare structural beam versus galvanized decking) on welding fume concentration (particle number and mass), particle size distribution, and particle composition was also explored. Thirty participants completed a series of stud welding simulations in a local apprenticeship training facility. Use of the upright system was associated with substantial reductions in trunk inclination and the activity levels of several muscle groups. Inhalable mass concentrations of welding fume (averaged over ~18 min) when using conventional methods were high (18.2 mg m(-3) for bare beam; 65.7 mg m(-3) for through deck), with estimated mass concentrations of iron (7.8 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), zinc (0.2 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), and manganese (0.9 mg m(-3) for bare beam; 1.5 mg m(-3) for through deck) often exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs). Number and mass concentrations were substantially reduced when using the upright system, although the total inhalable mass concentration remained above the TLV when welding through decking. The average diameters of the welding fume particles for both bare beam (31±17 nm) through deck conditions (34±34 nm) and the chemical composition of the particles indicated the presence of metallic nanoparticles. Stud welding exposes ironworkers to potentially high levels of biomechanical loading (primarily to the low back) and welding fume. The upright system used in this study improved exposure

High-Speed Friction-Stir Welding to Enable Aluminum Tailor-Welded Blanks

Science.gov (United States)

Hovanski, Yuri; Upadhyay, Piyush; Carsley, John; Luzanski, Tom; Carlson, Blair; Eisenmenger, Mark; Soulami, Ayoub; Marshall, Dustin; Landino, Brandon; Hartfield-Wunsch, Susan

2015-05-01

Current welding technologies for production of aluminum tailor-welded blanks (TWBs) are utilized in low-volume and niche applications, and they have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high volumes. While friction-stir welding (FSW) has been traditionally applied at linear velocities less than 1 m/min, high-volume production applications demand the process be extended to higher velocities more amenable to cost-sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low-to-moderate welding velocities do not directly translate to high-speed linear FSW. Therefore, to facilitate production of high-volume aluminum FSW components, parameters were developed with a minimum welding velocity of 3 m/min. With an emphasis on weld quality, welded blanks were evaluated for postweld formability using a combination of numerical and experimental methods. An evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum TWBs, which provided validation of the numerical and experimental analysis of laboratory-scale tests.

Estimation of weld nugget temperature by thermography method in resistance projection welding process

International Nuclear Information System (INIS)

Setty, D.S.; Rameswara Roa, A.; Hemantha Rao, G.V.S.; Jaya Raj, R.N.

2008-01-01

In the Pressurized Heavy Water Reactor (PHWR) fuel manufacturing, zirconium alloy appendages like spacer and bearing pads are welded to the thin wall zirconium alloy fuel tubes by using resistance projection welding process. Out of many joining processes available, resistance-welding process is reliable, environment friendly and best suitable for mass production applications. In the fuel assembly, spacer pads are used to get the required inter-element spacing and Bearing pads are used to get the required load-bearing surface for the fuel assembly. Performance of the fuel assembly in the reactor is greatly influenced by these weld joint's quality. Phase transformation from α to β phase is not acceptable while welding these tiny appendages. At present only destructive metallography test is available for this purpose. This can also be achieved by measuring weld nugget temperature where in the phase transformation temperature for zirconium alloy material is 853 o C. The temperature distribution during resistance welding of tiny parts cannot be measured by conventional methods due to very small space and short weld times involved in the process. Shear strength, dimensional accuracy and weld microstructures are some of the key parameters used to measure the quality of appendage weld joints. Weld parameters were optimized with the help of industrial experimentation methodology. Individual projection welding by split electrode concept, and during welding on empty tube firm support is achieved on inner side of the tube by using expandable pneumatic mandrel. In the present paper, an attempt was made to measure the weld nugget temperature by thermography technique and is correlated with standard microstructures of zirconium alloy material. The temperature profiles in the welding process are presented for different welding conditions. This technique has helped in measuring the weld nugget temperature more accurately. It was observed that in the present appendage welding

Influence of Loading Direction and Weld Reinforcement on Fatigue Performance of TIG Weld Seam

Directory of Open Access Journals (Sweden)

HUI Li

2018-02-01

Full Text Available The influence of loading direction and weld reinforcement on fatigue performance of TC2 titanium alloy TIG weld seam was investigated via fatigue experiments and SEM fracture observation. The results show that the fatigue life of retaining weld reinforcement specimens is lower than that of removing one in the same weld direction. The fatigue life of oblique weld specimens is higher than that of straight one with the same weld reinforcement treatment. The initiation of removing weld reinforcement specimens' fatigue crack sources is in the hole defect, but the weld reinforcement specimen initiate at the weld toes. During the early stage of fatigue crack propagation, the cracks all grow inside the weld seam metal with obvious fatigue striation. And the fatigue cracks of oblique weld specimens pass through the weld seam into the base with a typical toughness fatigue striation during the last stage of fatigue crack propagation. The dimple of straight weld specimens is little and shallow in the final fracture zone. The oblique weld specimens broke in the base metal area, and the dimple is dense.

Nitrogen And Oxygen Amount In Weld After Welding With Micro-Jet Cooling

OpenAIRE

Węgrzyn T.; Piwnik J.

2015-01-01

Micro-jet cooling after welding was tested only for MIG welding process with argon, helium and nitrogen as a shielded gases. A paper presents a piece of information about nitrogen and oxygen in weld after micro-jet cooling. There are put down information about gases that could be chosen both for MIG/MAG welding and for micro-jet process. There were given main information about influence of various micro-jet gases on metallographic structure of steel welds. Mechanical properties of weld was pr...

Fillet proximate composition, lipid quality, yields, and organoleptic quality of Mediterranean-farmed marine fish: A review with emphasis on new species.

Science.gov (United States)

Grigorakis, Kriton

2017-09-22

Species diversification in Mediterranean mariculture involves various important fish that contribute to the diet of many human populations. These include meagres (Sciaenidae), flatfishes, mullets, and various sparids. Their quality aspects (yields, fillet proximate composition, and lipid quality) are discussed in this review. Their filleting yield is mostly 40-45%. The viscerosomatic index ranges from 1.5% to 14%, depending on species. Low muscle fat contents of flatfishes and meagres differentiate them from the rest of the farmed species. Farmed fish contain high n-3 polyunsaturates fatty acids (PUFA; 12.3-36.3% vs. 5.48-37.2% in the wild) and have higher muscle fat and n-6 PUFA contents (mainly 18:2 n-6) than their wild counterparts. The aquaculture management, diet, and season can affect fillet composition and fatty acids, while season (i.e. food availability and maturation) largely affects lipid quality in wild fish. Data on the sensory quality of Mediterranean-farmed species are mainly limited to whether specific management differentiates the sensory quality; thus, further development of tools for sensory analysis is required. Observations on the quality features in farmed Mediterranean fish indicate that species diversification can also provide product diversification based on different commercial weights and fillet quality specifications.

Advanced ultrasonic techniques for nondestructive testing of austenitic and dissimilar welds in nuclear facilities

Science.gov (United States)

Juengert, Anne; Dugan, Sandra; Homann, Tobias; Mitzscherling, Steffen; Prager, Jens; Pudovikov, Sergey; Schwender, Thomas

2018-04-01

Austenitic stainless steel welds as well as dissimilar metal welds with nickel alloy filler material, used in safety relevant parts of nuclear power plants, still challenge the ultrasonic inspection. The weld material forms large oriented grains that lead, on the one hand, to high sound scattering and, on the other hand, to inhomogeneity and to the acoustic anisotropy of the weld structure. The ultrasonic wave fronts do not propagate linearly, as in ferritic weld joints, but along the curves, which depend on the specific grain structure of the weld. Due to the influence of these phenomena, it is difficult to analyze the inspection results and to classify the ultrasonic indications, which could be both from the weld geometry and from the material defects. A correct flaw sizing is not possible. In an ongoing research project, different techniques to improve the reliability of ultrasonic testing at these kinds of welds are investigated. In a first step (in the previous research project) two ultrasonic inspection techniques were developed and validated on plane test specimens with artificial and realistic flaws. In the ongoing project, these techniques are applied to circumferential pipe welds with longitudinal and transverse flaws. The technique developed at the Federal Institute for Materials Research and Testing (BAM) in Germany uses a combination of ray tracing and synthetic aperture focusing technique (SAFT). To investigate the unknown grain structure, the velocity distribution of weld-transmitting ultrasound waves is measured and used to model the weld by ray tracing. The second technique, developed at the Fraunhofer Institute for Nondestructive Testing (IZFP) in Germany, uses Sampling Phased Array (Full Matrix Capture) combined with the reverse phase matching (RPM) and the gradient elastic constant descent algorithm (GECDM). This inspection method is able to estimate the elastic constants of the columnar grains in the weld and offers an improvement of the

Texture, color, lipid oxidation and sensory acceptability of gamma-irradiated marinated anchovy fillets

Science.gov (United States)

Tomac, Alejandra; Cova, María C.; Narvaiz, Patricia; Yeannes, María I.

2015-01-01

The effect of gamma irradiation (0, 2, 3 and 4 kGy) on vacuum-packed marinated anchovy fillets was analyzed for their texture, color, lipid oxidation and sensory acceptability after 10 months under refrigeration. Marinated (3% acetic acid, 10% sodium chloride and 0.2% citric acid) Engraulis anchoita fillets were vacuum-packed and irradiated with a cobalt-60 source at a semi-industrial irradiation facility. The irradiation caused a slight increase in hardness values regardless of the applied dose but maintained a consistent texture over the 10 months, even though the control samples softened, most likely due to degradation. This hardness increase did not affect the textural sensory acceptability. Irradiation did not modify the color but still reduced color changes during storage, benefitting the product's quality. TBARS was increased in every sample throughout storage, but irradiation decreased these values. Sensory acceptability was not affected by gamma irradiation. Therefore, gamma irradiation could be successfully applied to this type of product for the purpose of shelf-life extension.

Welded joints integrity analysis and optimization for fiber laser welding of dissimilar materials

Science.gov (United States)

Ai, Yuewei; Shao, Xinyu; Jiang, Ping; Li, Peigen; Liu, Yang; Liu, Wei

2016-11-01

Dissimilar materials welded joints provide many advantages in power, automotive, chemical, and spacecraft industries. The weld bead integrity which is determined by process parameters plays a significant role in the welding quality during the fiber laser welding (FLW) of dissimilar materials. In this paper, an optimization method by taking the integrity of the weld bead and weld area into consideration is proposed for FLW of dissimilar materials, the low carbon steel and stainless steel. The relationships between the weld bead integrity and process parameters are developed by the genetic algorithm optimized back propagation neural network (GA-BPNN). The particle swarm optimization (PSO) algorithm is taken for optimizing the predicted outputs from GA-BPNN for the objective. Through the optimization process, the desired weld bead with good integrity and minimum weld area are obtained and the corresponding microstructure and microhardness are excellent. The mechanical properties of the optimized joints are greatly improved compared with that of the un-optimized welded joints. Moreover, the effects of significant factors are analyzed based on the statistical approach and the laser power (LP) is identified as the most significant factor on the weld bead integrity and weld area. The results indicate that the proposed method is effective for improving the reliability and stability of welded joints in the practical production.

Residual stress reduction in beam welded joints by means of stress redistribution using defocused electron or laser beams; Eigenspannungsreduktion in strahlgeschweissten Naehten mittels Spannungsumlagerung durch den Einsatz defokussierter Elektronen- bzw. Laserstrahlen

Energy Technology Data Exchange (ETDEWEB)

Toelle, Florian

2013-08-01

Among the multiple advantages of beam welding processes the high longitudinal residual stresses in beam welds ranging till the local yield stress are one disadvantage. These high stresses can influence the service life of the welded components. The residual stresses in other welding processes exist in an equal high level but primarily in the transverse direction to the weld. To mitigate the high residual stresses a couple of methods were developed for these welding processes in the last decades. However these methods need large contact surfaces next to the welds for the installation of matched heating and cooling elements and other additional equipment. Furthermore, the previous developed stress mitigating processes offer a low efficiency for the small beam welds. The stress reduction by using the welding source after the welding process for a remote heat treatment of the welded components afford a flexible tool for the stress mitigation in beam welds. This method does not need any additional equipment and it is applicable for complex welding and component geometries. During this post welding heat treatment the material next to the weld is heated by the defocused electron or by the defocused laser beam, respectively, to temperatures of some hundreds degree Celsius. Hereby low plastic deformations in these regions are generated. While cooling down due to the thermal shrinkage the material between the weld and the heat treated region is compressed in longitudinal direction to the weld. This intermediate material zone constrained the shrinkage of the weld while cooling down from the melting temperature and leads to the high longitudinal residual stresses in the weld. In consequence of the compression of this intermediate zones by the heat treated zones the resistance to the shrinkage of the weld is lowered and the longitudinal stresses in the weld are reduced. In the process the quantity of the stress reduction is controlled by the selection of the process parameters

Laser Welding Test Results with Gas Atmospheres in Welding Chamber

Energy Technology Data Exchange (ETDEWEB)

Joung, Chang-Young; Hong, Jin-Tae; Ahn, Sung-Ho; Heo, Sung-Ho; Jang, Seo-Yun; Yang, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

The weld beads of specimens welded under identical conditions in the helium and argon gas were cleaner, more regular, and steadier than those in a vacuum. The penetration depth of the FZ in the vacuum was much deeper than those in the helium and argon gas. To measure the irradiation properties of nuclear fuel in a test reactor, a nuclear fuel test rod instrumented with various sensors must be fabricated with assembly processes. A laser welding system to assemble the nuclear fuel test rod was designed and fabricated to develop various welding technologies of the fuel test rods to joint between a cladding tube and end-caps. It is an air-cooling optical fiber type and its emission modes are a continuous (CW) mode of which the laser generates continuous emission, and pulse (QCW) mode in which the laser internally generates sequences of pulses. We considered the system welding a sample in a chamber that can weld a specimen in a vacuum and inert gas atmosphere, and the chamber was installed on the working plate of the laser welding system. In the chamber, the laser welding process should be conducted to have no defects on the sealing area between a cladding tube and an end-cap.

Development of a multiresidue method for the determination of endocrine disrupters in fish fillet using gas chromatography-triple quadrupole tandem mass spectrometry.

Science.gov (United States)

Munaretto, Juliana S; Ferronato, Giovana; Ribeiro, Lucila C; Martins, Manoel L; Adaime, Martha B; Zanella, Renato

2013-11-15

Endocrine Disrupter Compounds (EDCs) are responsible for alterations in the endocrine system functions. Aquatic organisms are able to accumulate EDCs residues, being the major source of contamination for top predators and human consumers. This study aimed to develop and validate a method for the determination of 40 EDCs in fish fillet using modified QuEChERS and Gas Chromatography coupled with Mass Spectrometry in tandem (GC-MS/MS). A factorial design was used to optimize the extraction procedure. Method validation presented recoveries from 70.1% to 120.0% with RSDfish fillet from different species and residues of bisphenol A, chlorpyrifos and bifenthrin were detected. The proposed method proved to be effective for the determination of EDCs in fish fillet at very low concentration levels. © 2013 Elsevier B.V. All rights reserved.

Welding of Thin Steel Plates by Hybrid Welding Process Combined TIG Arc with YAG Laser

Science.gov (United States)

Kim, Taewon; Suga, Yasuo; Koike, Takashi

TIG arc welding and laser welding are used widely in the world. However, these welding processes have some advantages and problems respectively. In order to improve problems and make use of advantages of the arc welding and the laser welding processes, hybrid welding process combined the TIG arc with the YAG laser was studied. Especially, the suitable welding conditions for thin steel plate welding were investigated to obtain sound weld with beautiful surface and back beads but without weld defects. As a result, it was confirmed that the shot position of the laser beam is very important to obtain sound welds in hybrid welding. Therefore, a new intelligent system to monitor the welding area using vision sensor is constructed. Furthermore, control system to shot the laser beam to a selected position in molten pool, which is formed by TIG arc, is constructed. As a result of welding experiments using these systems, it is confirmed that the hybrid welding process and the control system are effective on the stable welding of thin stainless steel plates.

Hybrid laser-arc welding

DEFF Research Database (Denmark)

Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

[New welding processes and health effects of welding].

Science.gov (United States)

La Vecchia, G Marina; Maestrelli, Piero

2011-01-01

This paper describes some of the recent developments in the control technology to enhance capability of Pulse Gas Metal Arc Welding. Friction Stir Welding (FSW) processing has been also considered. FSW is a new solid-state joining technique. Heat generated by friction at the rotating tool softens the material being welded. FSW can be considered a green and energy-efficient technique without deleterious fumes, gas, radiation, and noise. Application of new welding processes is limited and studies on health effects in exposed workers are lacking. Acute and chronic health effects of conventional welding have been described. Metal fume fever and cross-shift decline of lung function are the main acute respiratory effects. Skin and eyes may be affected by heat, electricity and UV radiations. Chronic effects on respiratory system include chronic bronchitis, a benign pneumoconiosis (siderosis), asthma, and a possible increase in the incidence of lung cancer. Pulmonary infections are increased in terms of severity, duration, and frequency among welders.

Plug-welding of ODS cladding tube for BOR-60 irradiation. Welding condition setting. Device remodeling and welding

International Nuclear Information System (INIS)

Seki, Masayuki; Ishibashi, Fujio; Kono, Syusaku; Hirako, Kazuhito; Tsukada, Tatsuya

2003-04-01

Irradiation test in BOR-60 at RIAR to judge practical use prospect of ODS cladding tube at early stage is planned as Japan-Russia a joint research. RIAR does fuel design of fuel pin used for this joint research. JNC manufactures ODS cladding tube and bar materials (two steel kind of martensite and ferrite), upper endplug production. They are welded by pressurized resistance welding, and are inspected in JNC Tokai, transported to RIAR. And RIAR manufactures vibration packing fuel pin. On the upper endplug welding by pressurized resistance welding method, we worded on the problems such as decision of welding condition by changing the size and crystallization of cladding tube and the design of endplug, and the chucking device remodeling to correspond to the long scale cladding tube welding system (included handling) and of quality assurance method. Especially, use of long scale cladding tube caused problem that bending transformation occurred in cladding tube by welding pressure. However, we solved this problem by shortening the distance of cladding tube colette chuck and pressure receiving, and by putting the sleeve in an internal space of welding machine, losing the bending of cladding tube. Moreover, welding defects were occurred by the difference of an inside state, an inside defect and recrystallization of cladding tube. We solved the problem by inside grinding for the edge of tube, angle beam method by ultrasonic wave, and ultrasonic wave form confirmation. Manufacturing process with long scale cladding tube including heat-treatment to remove combustion return and remaining stress was established besides, Afterwards, welding of ODS cladding tube and upper endplug. As the quality assurance system, we constructed [Documented procedure (referred to JOYO)] based on [Document of the QA plan] by OEC. Welding and inspection were executed by the document procedure. It is thought that the quality assurance method become references for the irradiation test in JOYO in the

Weld analysis and control system

Science.gov (United States)

Kennedy, Larry Z. (Inventor); Rodgers, Michael H. (Inventor); Powell, Bradley W. (Inventor); Burroughs, Ivan A. (Inventor); Goode, K. Wayne (Inventor)

1994-01-01

The invention is a Weld Analysis and Control System developed for active weld system control through real time weld data acquisition. Closed-loop control is based on analysis of weld system parameters and weld geometry. The system is adapted for use with automated welding apparatus having a weld controller which is capable of active electronic control of all aspects of a welding operation. Enhanced graphics and data displays are provided for post-weld analysis. The system provides parameter acquisition, including seam location which is acquired for active torch cross-seam positioning. Torch stand-off is also monitored for control. Weld bead and parent surface geometrical parameters are acquired as an indication of weld quality. These parameters include mismatch, peaking, undercut, underfill, crown height, weld width, puddle diameter, and other measurable information about the weld puddle regions, such as puddle symmetry, etc. These parameters provide a basis for active control as well as post-weld quality analysis and verification. Weld system parameters, such as voltage, current and wire feed rate, are also monitored and archived for correlation with quality parameters.

Fine tuning of dwelling time in friction stir welding for preventing material overheating, weld tensile strength increase and weld nugget size decrease

Directory of Open Access Journals (Sweden)

Mijajlović Miroslav M.

2016-01-01

Full Text Available After successful welding, destructive testing into test samples from Al 2024-T351 friction stir butt welds showed that tensile strength of the weld improve along the joint line, while dimensions of the weld nugget decrease. For those welds, both the base material and the welding tool constantly cool down during the welding phase. Obviously, the base material became overheated during the long dwelling phase what made conditions for creation of joints with the reduced mechanical properties. Preserving all process parameters but varying the dwelling time from 5-27 seconds a new set of welding is done to reach maximal achievable tensile strength. An analytical-numerical-experimental model is used for optimising the duration of the dwelling time while searching for the maximal tensile strength of the welds

Optimum welding condition of 2017 aluminum similar alloy friction welded joints

Energy Technology Data Exchange (ETDEWEB)

Tsujino R.; Ochi, H. [Osaka Inst. of Tech., Osaka (Japan); Morikawa, K. [Osaka Sangyo Univ., Osaka (Japan); Yamaguchi, H.; Ogawa, K. [Osaka Prefecture Univ., Osaka (Japan); Fujishiro, Y.; Yoshida, M. [Sumitomo Metal Technology Ltd., Hyogo (Japan)

2002-07-01

Usefulness of the statistical analysis for judging optimization of the friction welding conditions was investigated by using 2017 aluminum similar alloy, where many samples under fixed welding conditions were friction welded and analyzed statistically. In general, selection of the optimum friction welding conditions for similar materials is easy. However, it was not always the case for 2017 aluminum alloy. For optimum friction welding conditions of this material, it is necessary to apply relatively larger upset pressure to obtain high friction heating. Joint efficiencies obtained under the optimum friction welding conditions showed large shape parameter (m value) of Weibull distribution as well as in the dissimilar materials previously reported. The m value calculated on the small number of data can be substituted for m value on the 30 data. Therefore, m value is useful for practical use in the factory for assuming the propriety of the friction welding conditions. (orig.)

Dual wire welding torch and method

Science.gov (United States)

Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

2009-04-28

A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

TIG welding method and TIG welding device

International Nuclear Information System (INIS)

Yoneda, Eishi

1998-01-01

The present invention provides a method of TIG welding for members having different heat capacities including a cladding tube and an end plug of a fuel rod to be used, for example, in a reactor, and a device therefor. Namely, in the TIG welding method, the flow rate of a sealed gas to the side of a member having smaller heat capacity is made greater than that on the side of the member having greater heat capacity bordered on the top end of a welding electrode. Since the sealed gas is jetted being localized relative to the welding electrode, arc is restricted in a region of the member having smaller heat capacity and is increased at a region having a larger heat capacity. As a result, the arc is localized, so that the heat input amount to the region having a large heat capacity is increased, and then a plurality of members at the abutting portion are melted uniformly thereby capable of obtaining a uniform molten pool. A bead is formed at the abutting portion thereby capable of obtaining a welded portion with less unevenness and having large strength. (I.S.)

Experimental investigation on the weld pool formation process in plasma keyhole arc welding

Science.gov (United States)

Van Anh, Nguyen; Tashiro, Shinichi; Van Hanh, Bui; Tanaka, Manabu

2018-01-01

This paper seeks to clarify the weld pool formation process in plasma keyhole arc welding (PKAW). We adopted, for the first time, the measurement of the 3D convection inside the weld pool in PKAW by stereo synchronous imaging of tungsten tracer particles using two sets of x-ray transmission systems. The 2D convection on the weld pool surface was also measured using zirconia tracer particles. Through these measurements, the convection in a wide range of weld pools from the vicinity of the keyhole to the rear region was successfully visualized. In order to discuss the heat transport process in a weld pool, the 2D temperature distribution on the weld pool surface was also measured by two-color pyrometry. The results of the comprehensive experimental measurement indicate that the shear force due to plasma flow is found to be the dominant driving force in the weld pool formation process in PKAW. Thus, heat transport in a weld pool is considered to be governed by two large convective patterns near the keyhole: (1) eddy pairs on the surface (perpendicular to the torch axis), and (2) eddy pairs on the bulk of the weld pool (on the plane of the torch). They are formed with an equal velocity of approximately 0.35 m s-1 and are mainly driven by shear force. Furthermore, the flow velocity of the weld pool convection becomes considerably higher than that of other welding processes, such as TIG welding and GMA welding, due to larger plasma flow velocity.

Preliminary studies on nutritive and organoleptic properties in processed fish fillets obtained from Iran

Directory of Open Access Journals (Sweden)

Ali Aberoumand

2014-06-01

Full Text Available The effects of boiling, frying, and roasting methods on nutrients and properties some of marine fishes were studies. AOAC official methods were used for the analyses of the samples. Frying reduced the protein content of Nemipterus japonicas, while roasting reduced the protein content of Carangoides malabaricus and Saurida undosquamis. Fresh and fried C. malabaricus had 71.2% and 57.05% protein content, respectively, while N. japonicas had 57.39% and 47.51%, respectively. The highest oil content in C.malabaricus was 16.80%, followed by N.japonicus 12.80%; while the lowest oil content in S.undosquamis was 5.88%. N.japonicusis protein content reduced with frying. Some cooking methods used in the processing can have an effect on of fish nutrient composition. The texture of fried and boiled fish fillets significantly differ from that of the roasted fillets (p<0.05.

Automatization of welding

International Nuclear Information System (INIS)

Iwabuchi, Masashi; Tomita, Jinji; Nishihara, Katsunori.

1978-01-01

Automatization of welding is one of the effective measures for securing high degree of quality of nuclear power equipment, as well as for correspondence to the environment at the site of plant. As the latest ones of the automatic welders practically used for welding of nuclear power apparatuses in factories of Toshiba and IHI, those for pipes and lining tanks are described here. The pipe welder performs the battering welding on the inside of pipe end as the so-called IGSCC countermeasure and the succeeding butt welding through the same controller. The lining tank welder is able to perform simultaneous welding of two parallel weld lines on a large thin plate lining tank. Both types of the welders are demonstrating excellent performance at the shops as well as at the plant site. (author)

Electric arc welding gun

Science.gov (United States)

Luttrell, Edward; Turner, Paul W.

1978-01-01

This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.