Academic literature on the topic 'Z-pin'

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Journal articles on the topic "Z-pin"

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Ji, Guobiao, Liang Cheng, Shaohua Fei, Jiangxiong Li, and Yinglin Ke. "A novel model of Z-pin insertion in prepreg based on fracture mechanics." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 235, no. 12 (June 12, 2021): 1971–82. http://dx.doi.org/10.1177/09544054211014442.

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Through-thickness reinforcement is a promising solution to the problem of delamination susceptibility in laminated composites. Modeling Z-pin–prepreg interaction is essential for accurate robotics-assisted Z-pin insertion. In this paper, a novel Z-pin insertion force model combining the classical cohesive finite element (FE) method with a dynamic analytical fracture mechanics model is proposed. The velocity-dependent cohesive elements, in which the fracture toughness is provided by the analytical model, are implemented in Z-pin insertion FE model to predict the crack initiation and propagation. Then Z-pin insertion experiments are performed on prepreg sample with metallic Z-pins at different velocities to identify the analytical model parameters and validate the simulation predictions offered by the model. Dynamics of Z-pin interaction with inhomogeneous prepreg is described and the effects of insertion velocity on prepreg contact force are studied. Results show that the force model agrees well with experiments and the fracture toughness rises with the increasing Z-pin insertion velocity.
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Kaya, Gaye, and Erdem Selver. "Impact resistance of Z-pin-reinforced sandwich composites." Journal of Composite Materials 53, no. 26-27 (April 23, 2019): 3681–99. http://dx.doi.org/10.1177/0021998319845428.

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This study investigates the effect of face materials, Z-pin types and distribution densities on drop-weight impact properties of foam core sandwich composites. The novelty of this study is to eliminate damage of face part by only reinforcing the core part of sandwich structures. Impact test was performed at different energy levels (20–50 J). The addition of Z-pins into the sandwich composites decreased the elasticity and ductility while it increased the stiffness of sandwich composites. The Z-pin reinforcement increased the peak forces, but decreased the peak deformations of the sandwich composites. However, higher energy absorption was only observed at the higher Z-pin distribution density. The results showed that Z-pin distribution density, bonding between the face sheets/pins, and the face sheet material have a great influence on the impact behaviour of the Z-pin-reinforced sandwich composites besides the Z-pin types.
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Wang, Sian, Yunhe Zhang, Pibo Sun, Yanhong Cui, and Gaohui Wu. "Microstructure and Flexural Properties of Z-Pinned Carbon Fiber-Reinforced Aluminum Matrix Composites." Materials 12, no. 1 (January 7, 2019): 174. http://dx.doi.org/10.3390/ma12010174.

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Z-pinning can significantly improve the interlaminar shear properties of carbon fiber-reinforced aluminum matrix composites (Cf/Al). However, the effect of the metal z-pin on the in-plane properties of Cf/Al is unclear. This study examines the effect of the z-pin on the flexural strength and failure mechanism of Cf/Al composites with different volume contents and diameters of the z-pins. The introduction of a z-pin leads to the formation of a brittle phase at the z-pin/matrix interface and microstructural damage such as aluminum-rich pockets and carbon fiber waviness, thereby resulting in a reduction of the flexural strength. The three-point flexural test results show that the adding of a metal z-pin results in reducing the Cf/Al composites’ flexural strength by 2–25%. SEM imaging of the fracture surfaces revealed that a higher degree of interfacial reaction led to more cracks on the surface of the z-pin. This crack-susceptible interface layer between the z-pin and the matrix is likely the primary cause of the reduction of the flexural strength.
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Zhang, Yunhe, Sian Wang, Xiwang Zhao, Fanming Wang, and Gaohui Wu. "In Situ Study on Fracture Behavior of Z-Pinned Carbon Fiber-Reinforced Aluminum Matrix Composite via Scanning Electron Microscope (SEM)." Materials 12, no. 12 (June 17, 2019): 1941. http://dx.doi.org/10.3390/ma12121941.

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Inside a scanning electron microscope (SEM) chamber, we performed an in situ interlaminar shear test on a z-pinned carbon fiber-reinforced aluminum matrix composite (Cf/Al) fabricated by the pressure the infiltration method to understand its failure mechanism. Experiments show that introducing a stainless-steel z-pin increases the interlaminar shear strength of Cf/Al composite by 148%. The increase in interlaminar shear strength is attributed to the high strength of the stainless-steel z-pin and the strong bonding between the z-pin and the matrix. When the z-pin/matrix interface failed, the z-pin can still experience large shear deformation, thereby enhancing delamination resistance. The failure mechanism of composite includes interfacial debonding, aluminum plough, z-pin shear deformation, frictional sliding, and fracture. These results in this study will help us understand the interlaminar strengthening mechanism of z-pins in the delamination of metal matrix composites.
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Wang, Xu Xu, and Li Chen. "Manufacture and Characteristics of Fibrous Composite Z-Pins." Applied Mechanics and Materials 33 (October 2010): 110–13. http://dx.doi.org/10.4028/www.scientific.net/amm.33.110.

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Z-pins are thin fibrous composite or metallic rods that could increase the strength of laminated composites in the thickness direction. In this paper, three kinds of composite z-pins were made by improved pultrusion method. The length of pultrusion die is shortened to 30mm with no function of curing. The curing equipment is individual control drying ovens. And then, tensile properties of z-pins were reported as well as the appearance and fiber content. Results show that three kinds of z-pins have good flexural resilience. The fiber volume fraction is around 60%. Carbon fiber z-pin has smoother surface than aramid fiber z-pin. And, The thinner z-pin corresponds to the higher tensile strength and tensile modulus. The elongation rate of aramid fiber z-pin is greater than that of carbon fiber one.
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Vaidya, U. K., A. N. Palazotto, and L. N. B. Gummadi. "Low Velocity Impact and Compression-After-Impact Response of Z-Pin Reinforced Core Sandwich Composites." Journal of Engineering Materials and Technology 122, no. 4 (April 21, 2000): 434–42. http://dx.doi.org/10.1115/1.1289141.

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In the current work, sandwich composite structures with innovative constructions referred to as Z-pins, or truss core pins, are investigated. The Z-pin core sandwich construction offers enhanced transverse stiffness, high damage resistance, and multi-functional benefits. The present study deals with analysis of low-velocity impact (LVI) of Z-pin sandwich plate, and experimental studies of compression-after-impact characterization. Experimental studies on LVI of Z-pin sandwich plate considered in the analysis have been reported in Vaidya, et al., 1999, “Low Velocity Impact Response of Laminated Sandwich Composites with Hollow and Foam-Filled Z-Pin Reinforced Core,” Journal of Composites Technology and Research, JCTRER, 21, No. 2, Apr., pp. 84–97, where the samples were subjected to 11, 20, 28, 33, and 40 J of impact energy. The LVI analysis is developed with regards to Z-pin buckling as a primary failure mode (and based on experimental observations). A finite element model accounting for buckling of the pins has been developed and analyzed using ABAQUS. This paper also presents experimental results on compression-after-impact (CAI) studies which were performed on the sandwich composites with Z-pin reinforced core “with” and “without” foam. The experimental LVI tests were performed in Vaidya, et al., 1999, “Low Velocity Impact Response of Laminated Sandwich Composites with Hollow and Foam-Filled Z-Pin Reinforced Core,” Journal of Composites Technology and Research, JCTRER, 21, No. 2, Apr., pp. 84–97. The results indicate that selective use of Z-pin core is a viable idea in utilizing space within the core for sandwich composites in structural applications. [S0094-4289(00)02904-2]
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Zheng, Xi Tao, Lin Hu Gou, Shu Yun Han, and Fan Yang. "Experimental and Numerical Study on the Mode I Delamination Toughness of Z-Pinned Composite Laminates." Key Engineering Materials 417-418 (October 2009): 185–88. http://dx.doi.org/10.4028/www.scientific.net/kem.417-418.185.

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An experimental investigation was performed on mode I delamination of z-pinned double-cantilever-beams (DCB) and associate z-pin bridging mechanisms. Tests were performed with ten types of samples: (1) big-pin reinforced DCB (double-cantilever-beams) with three areal densities D=2.01%, 5.15%, 8.04%, respectively; (2) median-pin reinforced DCB with three areal densities D=0.85%, 2.17%, 3.40%; (3) small-pin reinforced DCB with three areal densities D=0.25%, 0.63%, 0.90% and (4) without pin reinforced DCB specimens. Delamination tests samples were prepared from unidirectional continuous carbon fibre/epoxy prepreg (T300/TDE86), made into 3 mm thick unidirectional laminates with and without a block of Z-pins in the crack path. Fracture testing was carried out under Mode I (standard DCB test). Experiments have shown that increases in debond resistance and ultimate strength depend on the material, size, density, location of the pins and the mechanisms of pin deformation. A finite element (FE) model is developed to investigate mode I delamination toughness of z-pin reinforced composite laminates. The z-pin pullout process is simulated by the deformation of a set of non-linear springs. A critical crack opening displacement (COD) criterion is used to simulate crack growth in a DCB made of z-pinned laminates. The toughness of the structure is quantified by the energy release rate, which is calculated using the contour integral method. The FE model is verified for both unpinned and z-pinned laminates. Predicted loading forces from FE analysis are compared to available test data. Good agreement is achieved. The numerical results indicate that z-pins can greatly increase the mode I delamination toughness of the composite laminates.
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Mouritz, A. P., P. Chang, and M. D. Isa. "Z -Pin Composites: Aerospace Structural Design Considerations." Journal of Aerospace Engineering 24, no. 4 (October 2011): 425–32. http://dx.doi.org/10.1061/(asce)as.1943-5525.0000078.

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Li, Chenghu, Zhe Wu, Zhijun Meng, and Muchen Li. "Influential Factors of Z-pin Bridging Force." Applied Composite Materials 21, no. 4 (November 27, 2013): 615–31. http://dx.doi.org/10.1007/s10443-013-9358-z.

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Hoffmann, Julian, Alexander Brast, and Gerhard Scharr. "Z-pin insertion process for through-thickness reinforced thermoplastic composites." Journal of Composite Materials 53, no. 2 (June 4, 2018): 173–81. http://dx.doi.org/10.1177/0021998318781233.

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This paper presents a novel method for the ultrasonically assisted insertion of metallic z-pins into thermoplastic composites. Mechanical and microstructural investigations were carried out on glass fiber-reinforced polyamide and polypropylene specimens. The insertion of steel pins into thermoplastic composites led to microstructural changes that differ significantly from the known microstructure of z-pinned thermoset fiber-reinforced plastics. Optical microscopy showed an absence of notable fiber waviness and resin-rich zones around each pin. Instead, the fibers were predominantly deflected in the through-thickness direction by the high insertion forces arising during pin penetration. To gain an initial insight on the resulting properties of the z-pin/thermoplastic interface, the mechanical properties of z-pinned thermoplastic composites under mode I loading were investigated using pullout tests. For reference, the pullout behavior of thermoset carbon fiber-reinforced plastic specimens, reinforced with steel pins was determined too. Due to the poor bonding and lack of friction between the pin and laminate, the determined traction loads of the thermoplastic specimens are well below typical values achieved from pin pullout in thermoset laminates.
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Dissertations / Theses on the topic "Z-pin"

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Fert, Marcin Maciej. "An investigation of the mechanical performance of Z-pin reinforced composites." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/33729.

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Fibrous composites, having excellent mechanical properties in the direction of the fibres, have lower mechanical properties in the through thickness direction, controlled by resin. Z-pinning improves the delamination toughness (up to 500%) with a relatively modest reduction to the in-plane mechanical properties (typically 5-15%). This experimental study investigates the mechanical performance of Z-Pins bridging an existing delamination in fibre reinforced resin composites under pull-out (Mode I), shear-out (Mode II) and mixed mode loading conditions using a specially designed testing rig. In Mode II the opening displacement was restricted and measured by springs of three different stiffnesses. A new technique of needle assisted Z-Pin insertion was developed, in which prepreg panels were perforated with a steel needle in order to insert Z-Pins. This technique ensured the desired orientation of Z-Pins, improved pinning quality and removed the necessity of costly preforms used in the traditional UAZ method. Test specimens were blocks (15 mm x 15 mm x 6mm thick) of carbon-epoxy IM7/8552 composite in unidirectional (UD) and quasi-isotropic (QI) stacking sequences, with PTFE delamination film in the mid-plane recreating an existing crack, bridged with a single T300/9310 Z-Pin or a group of four pins of either 0.28 mm or 0.51 mm diameter. Three phases of pull-out were identified: Linear Phase (linear force-displacement curve), Crack Formation (unstable crack propagation phase) and Frictional Sliding (friction-controlled pull-out). Two phases of shear-out were identified: Linear Phase (with no energy loss) and Breaking Phase (where the fibrous structure of the Z-Pins is fractured, ending with Z-Pin breakage). In mixed mode specimens behaved similarly to pull-out for the pin angles up to 45°. For higher angles the behaviour was more similar to pure shear-out. The influence of the Z-Pin diameter, z-pinning depth, distance between adjacent Z-Pins, composite stacking sequence and pull-out speed on the Z-Pins behaviour were investigated. The results will be useful in the formulation of improved Z-Pin bridging laws for use in finite element models.
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Knopp, André [Verfasser]. "Beitrag zur Verbesserung der mechanischen Eigenschaften z-Pin-verstärkter Faser-Kunststoff-Verbundlaminate / André Knopp." Aachen : Shaker, 2015. http://d-nb.info/1075436931/34.

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Chang, Paul, and mrpc@tpg com au. "The Mechanical Properties and Failure Mechanisms of Z-Pinned Composites." RMIT University. Aerospace, Mechanical and Manufacturing Engineering, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070111.145714.

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Z-pinning is a through-thickness reinforcement technology for polymer composite materials that has been developed and commercialised over the past fifteen years. The through-thickness reinforcement of composites with thin metallic or fibrous pins aids in suppressing delamination, improving impact damage tolerance and increasing joint strength. Z-pins are applied to the composite part during its manufacture. Pins are embedded within sheets of foam and placed over the unconsolidated part. Subsequently, the foam is compacted and the pins transferred into the part, which is usually an uncured prepreg. In this manner, large numbers of pins can be inserted quickly and easily. The pinned composite is then cured using conventional processes. The use of z-pins is currently limited to several high performance composite structures, most notably Formula One racing cars and F/A-18 E/F (Superhornet) fighter aircraft, although the technology has potential applications in a d iverse variety of aerospace and non-aerospace composite structures. A limited understanding of the mechanical performance of z-pinned parts under high load and fatigue loading conditions currently hinders the application of z-pinned composites. The aim of this PhD project is to investigate the mechanical properties, strengthening mechanics and failure mechanisms of z-pinned carbon/epoxy laminates and joints. The effect of z-pin reinforcement on the tensile and flexural properties of laminates under monotonic and fatigue loading is studied. The sensitivity of these properties to the volume content and diameter of the z-pins is systematically studied by experimentation and analytical modelling. This PhD also evaluates the efficacy of z-pins in improving the load-bearing properties of carbon/epoxy lap joints. Improvements to the room temperature and elevated temperature properties of z-pinned lap joints under monotonic and fatigue tensile loading were determined. The effect of strain rate on the load-bearing properties of z-pinned lap joints was also evaluated. A further aim of the PhD project was to assess the z-pin manufacturing process and the microstructural damage caused by that process. The outcome of this study augments the analysis of the me chanical properties of z-pinned laminates and joints.
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Berry, Seth David. "Experimental Characterization of Mode I Fracture Toughness of Reinforced Carbon Fiber Laminate with Nano-Cellulose and CNT Additives." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/72132.

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Effective treatment of carbon fiber components to improve delamination resistance is vital to the application of such materials since delamination is one of the biggest concerns regarding the use of composites in the aerospace sector. Due to the significant application benefit gained from increased stiffness to density ratio with composite materials, innovative developments resulting in improved through-thickness strength have been on the rise. The inherent anisotropy of composite materials results in an added difficulty in designing structural elements that make use of such materials. Proposed techniques to improve the through-thickness strength of laminar composites are many and varied; however all share the common goal of improving inter-laminar bond strength. This research makes use of novel materials in the field of wet flocking and Z-pinning. Cellulose nanofibers (CNFs) have already demonstrated excellent mechanical properties in terms of stiffness and strength, originating at the nano-scale. These materials were introduced into the laminate while in a sol-gel suspension in an effort to improve load transfer between laminate layers. The effect of CNFs as lightweight renewable reinforcement for CFRPs will be investigated. Carbon nanotube (CNT) additives were also considered for their beneficial structural properties.
Master of Science
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Lander, James K. "Designing with z-pins : locally reinforced composite structures." Thesis, Cranfield University, 2008. http://dspace.lib.cranfield.ac.uk/handle/1826/4072.

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This thesis describes specific new applications of Z-Fibre ® pinning and focuses the attention onto the failure modes of locally reinforced (z-pinned) structures. Design implications of the use of localised reinforcement on structures, rather than laboratory coupons, are considered. Z-pinning reinforcement is applied to cylindrical crash tubes and I-section patch joints manufactured from woven carbon / epoxy pre-pregs. Z-pinning is shown to improve the Specific Energy Absorption (SEA) of the crash tubes by up to 76 %, the exact amount depending on the tube geometry. For the I-section patch joints, an initial increase in ultimate load carrying capability due to z-pin use is observed and, as the quantity of z- pins increases, a change in failure mode is induced. Z-pinning is also shown to enhance the damage tolerance of these. The ability to predict major changes to the structural response due to use of z-pins, and design for them accordingly, is the next step in the understanding of the technology. The design element of this study is contained in the development of a new Finite Element model using cohesive interface elements. The provision of mode II input data for this model comes from End Loaded Split (ELS) testing of the woven laminates and continued development of the Z-shear test. A new analysis for quantifying the crack sliding displacement, based on the ELS test, is developed. Z-shear testing has shown that the z-pin ‘mode II’ fracture energy is strongly affected by the amount of mode I opening of the shear surfaces. Here, new data are obtained for a fully constrained, pure mode II case. Using this modelling tool, changes in failure mode due to z-pin use can be predicted. Verification is provided by a new simulation of the I-section patch joint geometry.
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Odier, Philippe. "Mesure de la production inclusive de pio dans les desintegrations hadroniques du z#o avec le detecteur aleph au lep." Chambéry, 1995. http://www.theses.fr/1995CHAMS018.

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Ce memoire presente une mesure de la production inclusive de pio dans les desintegrations hadroniques du z#o avec l'experience aleph au lep. Cette mesure s'inscrit dans le cadre de l'etude de la production des hadrons issus de la fragmentation des quarks et des gluons, decrite pour la partie perturbative par la chromodynamique quantique et pour la partie non perturbative par des modeles phenomenologiques. Nous commencons par une breve revue de l'etat actuel des connaissances sur ces deux aspects de la fragmentation. L'analyse presentee ensuite utilise deux millions d'evenements, selectionnes parmi les donnees prises par aleph pendant les annees 1992, 93 et 94. Les pio sont reconstruits a partir de leur desintegration en deux photons. Ces photons sont identifies soit par leur depot d'energie dans le calorimetre electromagnetique, soit a partir de leur conversion en une paire electron-positron, detectee dans les chambres a traces. Au cours des differentes etapes de la selection des photons, les efficacites calculees avec le monte-carlo sont controlees a l'aide des donnees elles-memes. Le signal des pio est alors extrait par un ajustement des distributions de masse invariante photon/photon. Les trois combinaisons de photons (converti/calorimetrique, calorimetrique/calorimetrique et converti/converti) sont utilisees. Les sections efficaces differentielles en energie, impulsion transverse et rapidite sont mesurees. Le nombre de pio mesures par evenement pour e#p#i#o superieure a 1. 14 gev est: n(pio) = 5. 24 0. 02 (stat. ) 0. 29 (syst. ) ces resultats sont compares a ceux obtenus par d'autres experiences lep, aux resultats obtenus par aleph sur les pions charges, ainsi qu'aux predictions de differents generateurs d'evenements. Un accord raisonnable est observe, meme si nous mesurons une section efficace legerement superieure, l'ecart atteignant deux deviations standard a basse energie. Pour terminer, une breve etude topologique est presentee, utilisant les variables globales d'evenement
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Nascimento, Liane Caroline Sousa. "Caracteriza??o centesimal, composi??o qu?mica e atividade antioxidante do noni (Morinda Citrifolia L.) cultivado no Munic?pio de Z? Doca-MA." Universidade Federal Rural do Rio de Janeiro, 2012. https://tede.ufrrj.br/jspui/handle/jspui/1549.

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This paper describes the investigation of the centesimal composition, chemical and antioxidant activity of Morinda citrifolia L. (Rubiaceae), native of Southeast Asia, popularly known as noni, which has emerged in Brazil as a plant with great healing potential. The empirical knowledge of the population has meant that the fruit is constantly present in the diet of Maranh?o. Early in the second half of 2010 seedlings of the species were planted in two experimental areas of the Federal Institute of Maranh?o (IFMA), Campus of Z? Doca-MA, broken down by planting time. After three months of the planting in the first area the fruiting process was initiated, and it was possible to perform bromatologic analyzes. For the centesimal composition was found in pulp, seed and mixtures of both, respectively: the ash content (0,82%?0,01; 0,60%?0,01 e 0,79%?0,03), moisture (90%?0,01; 28,34%?0,01; 80,64%?0,05), proteins (4,2%?0,01; 7,47%?0,06; 4,70%?0,02), total lipids (0,34%?0,04; 0,79%?0,03; 0,63%?0,07), carbohydrates (2,68%?0,01; 25,83%?0,02; 13,24%?0,01) and calorific value (30,58kcal/100g?0,02; 140,31 kcal/100g?0,03; 77,43 kcal/100g?0,03). It was found in the pulp and seed values soluble dietary fiber (0,51?0,04; 0,93%?0,03) and insoluble (1,44?0,05; 36,04%?0,38). For the chemical characterization it was found in the pulp, seed and mixtures of both: ? Brix (8,17?0,05;-), the total acidity (0,54?0,02; 0,28?0,01; 0,62?0,02%) and pH (3,95?0,07; 4,5?0,04; 4,1?0,05), the relationship TA / SS pulp was 14.97?0,07. The content of ascorbic acid was calculated by the method Tilmans, pulp and seed fractions (117,33?0,01; 24,33?0,03), expressed in mg/100 g sample. The antioxidant capacity analyzes were performed in three different parts: the pulp, peel and seed using alcoholic extracts (11,63?0,07; 10,03?0,04; 11,19?0,01) and aqueous extract (7,20?0,07; 6,98?0,07; 7,60?0,01) through the sequestration of free radical DPPH, expressed in mM of Trolox / g sample. It was further evaluated the antioxidant capacity of different extracts of the three parts of the fruit and alcoholic extract (98.78% in pulp, 84.76% in peel and 94.96% in the seed) showed much higher antioxidant capacity than the aqueous extract ( 8.08% in the pulp, 5.22% in peel and 22.66% in the seed) and the prominence given to the pulp, followed by seed and peel, respectively. It was demonstrated that the noni fruit grown in the municipality of Z? Doca presented a rich source of nutrition important fact that justifies its inclusion in the diet. It should be noted that the pulp showed a high content of vitamin C and antioxidant activity, and seed a significant amount of insoluble fiber, suggesting that this product can be inserted in the consumer market for being a nutritious food with great herbal medicine potential
Este trabalho descreve a investiga??o da composi??o centesimal, qu?mica e atividade antioxidante de Morinda citrifolia L. (Rubiaceae), origin?rio do sudoeste da ?sia, popularmente conhecida como noni, que vem se configurando no territ?rio brasileiro como um vegetal com grande potencial fitoter?pico. O conhecimento popular tem feito com que o fruto esteja presente constantemente na dieta alimentar maranhense. No in?cio do segundo semestre de 2010 foram plantadas mudas da esp?cie em duas ?reas experimentais do Instituto Federal do Maranh?o (IFMA), Campus Z? Doca-MA, divididas por ?poca de plantio. Ap?s tr?s meses do plantio na primeira ?rea o processo de frutifica??o foi iniciado, sendo poss?vel realizar as an?lises bromatol?gicas. Para composi??o centesimal verificou-se na polpa, semente e mistura de ambos, respectivamente: o teor de cinzas (0,82%?0,01; 0,60%?0,01 e 0,79%?0,03); a umidade (90%?0,01; 28,34%?0,01; 80,64%?0,05); prote?nas (4,2%?0,01; 7,47%?0,06; 4,70%?0,02); lip?deos totais (0,34%?0,04; 0,79%?0,03; 0,63%?0,07); carboidratos (2,68%?0,01; 25,83%?0,02; 13,24%?0,01) e valor cal?rico (30,58 kcal/100g?0,02; 140,31 kcal/100g?0,03; 77,43 kcal/100g?0,03). Verificou-se na polpa e semente os valores de fibras alimentares sol?veis (0,51?0,04; 0,93%?0,03) e insol?veis (1,44?0,05; 36,04%?0,38). Para caracteriza??o qu?mica verificou-se na polpa, semente e mistura de ambos: o ?Brix (8,17?0,05;-), a acidez total (0,54?0,02; 0,28?0,01; 0,62?0,02%) e o pH (3,95?0,07; 4,5?0,04; 4,1?0,05), a rela??o ATT/SS na polpa foi de 14,97?0,07. O Teor de ?cido asc?rbico foi calculado pelo m?todo Tilmans, nas fra??es polpa e semente (117,33?0,01; 24,33?0,03), expressos em mg/100g amostra. As an?lises da capacidade antioxidante foram realizadas em tr?s partes diferentes: polpa, casca e semente utilizando extrato alco?lico (11,63?0,07; 10,03?0,04; 11,19?0,01) e extrato aquoso (7,20?0,07; 6,98?0,07; 7,60?0,01), atrav?s do sequestro do radical livre DPPH, expressos em ?M de Trolox/g amostra. Foi ainda avaliada a capacidade antioxidante dos diferentes extratos, das tr?s partes do fruto e o extrato alco?lico (98,78% na polpa; 84,76% na casca e 94,96% na semente) apresentou capacidade antioxidante bem maior que o extrato aquoso (8,08% na polpa, 5,22% na casca e 22,66% na semente) sendo o destaque dado ? polpa, seguido da semente e da casca, respectivamente. Demonstrou-se que os frutos do noni cultivados no munic?pio de Z? Doca apresentaram uma rica fonte nutricional importante fato que justifica sua inser??o na dieta alimentar. Cabe destacar que a polpa apresentou um elevado teor de vitamina C, e atividade antioxidante, e a semente um relevante teor de fibras insol?veis, sugerindo que esse produto pode ser inserido no mercado consumidor por ser um alimento nutritivo e com grande potencial fitoter?pico.
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Boschi, Filippo. "Imaging quantitativo cerebrale in pazienti affetti da patologie neurodegenerative con traccianti PiB e FDG marcati con 18-F." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13506/.

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Il numero di casi riguardanti patologie neurodegenerative che colpiscono il sistema nervoso centrale sotto forma di demenza aumenta di anno in anno. Si ha quindi la necessità di individuare la presenza della malattia non solo a livello qualitativo, ovvero tramite la sola diagnosi del medico, ma anche a livello quantitativo, cercando di elaborare un metodo di analisi che tenga conto della variabilità tra individuo e individuo, ma che rimanga applicabile per la maggior parte della popolazione. In questo lavoro di tesi sono stati utilizzati due metodi di analisi statistica di immagini PET cerebrali, denominati SPM e SSP Z-score, al fine di individuare mappe statistiche 3D che evidenzino, con probabilità fissata, le aree del cervello colpite. Entrambe le analisi statistiche si basano su un confronto del paziente con un gruppo di soggetti sani. Le immagini elaborate in questo lavoro di tesi provengono dal database dell'Ospedale di Parma, registrate dallo stesso scanner PET-CT, con l'utilizzo di traccianti diversi, denominati FDG e PiB marcato Fluoro. I due traccianti rilevano uno stato cerebrale anomalo, ma attraverso due indicatori diversi: FDG rende visibile l'afflusso sanguigno all'interno del cervello, legato al metabolismo; il PiB invece è in grado di rilevare i depositi di beta-amiloide, una proteina che, legandosi ai tessuti cerebrali, forma delle placche in grado di bloccare la connessioni tra neuroni. I traccianti sono legati al radionuclide 18F. Le analisi sono state effettuate principalmente su pazienti con morbo di Alzheimer utilizzando i due metodi di analisi precedentemente introdotti. Sono anche stati confrontati attraverso SPM due gruppi di pazienti con iniziale demenza lieve, che nel tempo si è evoluta in morbo di Alzheimer in alcuni casi, mentre in altri non sono state riscontrate variazioni. Infine, tramite un approccio SPM, sono stati valutati due template diversi per determinare quale potesse essere considerato migliore per l'analisi quantitativa.
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GUIRLET, REMY. "Utilisation des premieres donnees du detecteur aleph au lep pour la mesure de la polarisation des tau dans l'annihilation electron-positron au pic du z." Paris 11, 1990. http://www.theses.fr/1990PA112092.

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L'etude de la desintegration du z en une paire de leptons tau est faite au lep, grand collisionneur electron-positron du cern, avec le detecteur aleph. L'amplitude du processus etudie (l'annihilation d'une paire electron-positron en un z qui se desintegre en une paire de leptons tau) est fonction des constantes des couplages vectoriel et vectoriel-axial, dont le rapport depend quadratiquement de la masse du top. La polarisation des leptons produits est l'observable la plus sensible a ce rapport, et n'est mesurable que dans le cas des tau, a l'aide de l'analyse des spectres en impulsion des pions d'une part et des muons d'autre part produits dans la desintegration des tau. Apres une description des methodes employees pour la selection de ces pions et ces muons, fondees essentiellement sur la chambre a projection temporelle et les calorimetres electromagnetique et hadronique d'aleph, on donne une estimation de la polarisation et on en deduit une valeur de l'angle de weinberg avec les statistiques actuelles; les methodes exposees ici permettront par la suite une estimation de la masse du top
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Valiev, Abduvali. "Enzymology." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608217/index.pdf.

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In this study, two symbiotic fungi of Southern Pine Beetle (SPB), Entomocorticium peryii and Entomocorticium sp.A were evaluated in terms of polyphenol oxidase (PPO) production. The effect of different inhibitors, inducers and assay parameters such as temperature and pH on enzyme activity were investigated and maximum PPO activity was observed at 30°
C, pH 8.0 and when tannic acid was used as an inducer. Copper-chelator salicyl hydroxamic acid (SHAM) and pcoumaric acid, both indicated as inhibitors of tyrosinase and catechol oxidase significantly reduced the activity. For biochemical characterization studies, the enzyme was concentrated by ultrafiltration. To determine type of the enzyme, activity staining after Native-PAGE was carried out. Type of polyphenol oxidase produced by E. peryii and E. sp.A was determined as catechol oxidase by activity staining. However higher activity was observed on hydroquinone (p-diphenol) rather than catechol (o-diphenol). The enzyme obeys Michealis-Menten kinetics with Km and Vmaxvalues being 10.72 mM hydroquinone and 59.44 U/ml for E. peryii and 8.55 mM hydroquinone and 73.72 U/ml for E. sp.A respectively..
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Books on the topic "Z-pin"

1

Ferguson, Sheila (Sheila S.) and Cai Yiling, eds. Oxford Niujin Ying wen pin zi shou ce: Oxford A-Z of spelling. Taibei Xian Xindian Shi: Bo shi tu shu chu ban you xian gong si, 2008.

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1974-, Z͡H︡adan Serhiĭ, ed. Lysty z-pid kovdry: [zbirka poeziĭ]. Kyïv: Vyd-vo "Fakt", 2002.

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Cohen, Rachel. Mr Pin's, ou--, Les pin's de A-- à Z. Argenteuil: Société d'études personnalisées appliquées, 1991.

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Lyzanchuk, Vasylʹ. Z-pid iha idoliv: Rozdumy pro perez͡h︡yte. Lʹviv: Fakulʹtet z͡h︡urnalistyky Lʹvivsʹkoho derz͡h︡. universytetu im. I. Franka, 1997.

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Atlanty i kariatydy: Z-pid "dakhu" Prezydenta. Lʹviv: Kalʹvarii͡a︡, 2000.

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Lepkyĭ, Bohdan. Z-pid Poltavy do Bender: Istorychna povistʹ. Kyïv: Vyd-vo khudoz͡h︡. lit-ry "Dnipro", 1992.

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Horbati︠u︡k, Vasylʹ. Z-pid travy zabutti︠a︡: Podilʹsʹki shli︠a︡khy ukraïnsʹkykh pysʹmennykiv. Khmelʹnyt︠s︡ʹkyĭ: TOV "Polihrafist-2", 2011.

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Sylka, Pavlo. Z-pid kaminni͡a︡ b'i͡e︡ voda: Khudoz͡h︡nʹo-dokumentalʹna povistʹ : opovidanni͡a︡. Kharkiv: "Prapor", 1992.

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Khambata, Adi J. Introduction to the Z80 microcomputer. 2nd ed. New York: J. Wiley, 1987.

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Pid zakhystom muriv: Z istoriï ukraïnsʹkoï fortyfikat︠s︡iï X-XVII st. Kyïv: Nash chas, 2007.

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Book chapters on the topic "Z-pin"

1

Francesconi, L., and F. Aymerich. "Impact and Post-impact Behavior of Composite Laminates Reinforced by Z-Pins." In Mechanics of Composite, Hybrid and Multifunctional Materials, Volume 5, 159–67. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95510-0_18.

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Gupta, Akhilesh K., Paulson Samuel, and Deepak Kumar. "Jaya Optimization-Based PID Controller for Z-Source Inverter Using Model Reduction." In Intelligent Computing Techniques for Smart Energy Systems, 257–67. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-15-0214-9_30.

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Jasanoff, Jay H. "11. *gṷes-, *(z)g ṷes-, *(s)g ṷesh2-? The PIE root for 'extinguish/go out'." In Morphology and Language History, 155–66. Amsterdam: John Benjamins Publishing Company, 2008. http://dx.doi.org/10.1075/cilt.298.15jas.

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Pattnaik, Ashribad, Bidyadhar Rout, and Akshaya Kumar Patra. "Comparative Study of System Performances Using Integral Type LQR with DE and Z-N Optimized PID Controller in AVR System." In Advances in Electrical Control and Signal Systems, 349–59. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5262-5_25.

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Yan, W., and H.-Y. Liu. "Z-pin bridging in composite delamination." In Delamination Behaviour of Composites. CRC Press, 2008. http://dx.doi.org/10.1201/9781439832677.ch23.

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LIU, H.-Y., and W. YAN. "Z-pin bridging in composite delamination." In Delamination Behaviour of Composites, 674–705. Elsevier, 2008. http://dx.doi.org/10.1533/9781845694821.5.674.

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Liu, Hong-Yuan, Wenyi Yan, and Yiu-Wing Mai. "Z-Pin Bridging Force in Composite Delamination." In European Structural Integrity Society, 491–502. Elsevier, 2003. http://dx.doi.org/10.1016/s1566-1369(03)80119-x.

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Prasad, Sumer Chand. "Design of Fuzzy Logic Controller for Up to 25MW Hydropower Plant." In Applications of Artificial Intelligence in Electrical Engineering, 95–106. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-2718-4.ch005.

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In this chapter the emerging control techniques for 25 MW small hydropower (SHP) plants which utilize fuzzy logic are compared with conventional PID control for the speed control of hydraulic turbine in terms of rise time, smoothness of response, settling time, and overshoot in wicket gate opening with the response to change in turbine speed. In the case of the PID controller, gain adjustment (tuning) is required. The fuzzy controller algorithm is based on intuition, experience, and it incorporates a simple, rule-based IF X AND Y THEN Z approach. These controllers obtained don't require gain adjustment. The work done is a small step towards the automation of the hydropower plants.
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Chen, Honghua, and Fen Xu. "Barriers and Facilitators of Front Identification in China’s Pork Traceability System." In Frontiers in Artificial Intelligence and Applications. IOS Press, 2020. http://dx.doi.org/10.3233/faia200639.

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The identification is the sole carrier of the whole-process information of the pig traceability system. The front identification is the first component, an indispensible part of the proper traceability of the product. This paper conducts in-depth study on company B, company S and company Z from Beijing, Shandong and Zhejiang to understand their specific management process, cooperation model and interest allocation, identification method, willingness to implement, the cost and benefit before and after the implementation as well as the effect of the implementation. The Cannikin Law is also employed to conduct the comparison analysis on the implementation of the system, so as to set an example for the pig traceability system in other relevant companies of the sort. The results show that, the organization model plays the most important part in the front identification management, with “company + bases + farmers” as the most conducive mode for the implementation of front identification yet not prone to be promoted; “company + cooperative + farmers” is more apt to promotion. Other important impact factors of the implementation level of front identification in pig traceability system include the education level of the implementation subject, the scale and the location of the company.
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Koh, T., S. Feih, and A. Mouritz. "Structural properties of composite T-joints reinforced with z-pins." In Incorporating Sustainable Practice in Mechanics and Structures of Materials, 415–20. CRC Press, 2010. http://dx.doi.org/10.1201/b10571-74.

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Conference papers on the topic "Z-pin"

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Lu, Xunfeng, Weihong Li, Xueying Li, Jing Ren, and Hongde Jiang. "Influences of Micro Pin-Fin on Jet Array Impingement Heat Transfer: Effects of Jet to Target Distance, Micro Pin-Fin Shapes, Height, and Reynolds Number." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-76942.

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In the current research of impingement on pin-fin wall, researchers mainly pay attention to macro pin-fin due to the limitation of manufacture. With the development of additive manufacturing, it is possible to manufacture the micro pin-fin. Hence, impingement on micro pin-fin wall becomes a new cooling technique that has attracted the researchers’ attention. With experimental methodology, the investigation utilizes different jet to target distance, micro pin-fin shapes, height and Reynolds number for impingement cooling augmentation to illustrate the effects on jet array impingement heat transfer. The area-averaged target surface heat transfer coefficient distributions are measured with lumped capacitance method. The impingement hole diameter (D) is 4 millimeter, with streamwise and spanwise jet-to-jet spacing 4D. Considered are effects of jet to target plate distance (Z/D:0.75,3), micro pin-fin shapes (rectangle, pentahedron), and pin-fin height (h/D:0.05,0.2,0.4). In total, ten different test surfaces are considered (smooth surface included). Tests are performed at impingement jet Reynolds numbers from 2000 to 10000 for configuration of Z/D = 0.75, from 5000–20000 for configuration of Z/D = 3. The experimental results illustrate that there are significant heat transfer augmentation (30%–120% more than baseline flow condition) with micro pin-fin on impingement target surface, and discharge coefficient is almost the same.
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Yan, Wenyi. "Experimental Study on Z-pin Bridging Law by Pull-out Tests." In 44th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2003. http://dx.doi.org/10.2514/6.2003-1478.

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JOGLEKAR, SHREYAS, MARK PANKOW, and VIPUL RANATUNGA. "An Efficient Material Model to Simulate the Effects of z-pin Reinforcement." In American Society for Composites 2017. Lancaster, PA: DEStech Publications, Inc., 2017. http://dx.doi.org/10.12783/asc2017/15264.

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Clarke, Andrew, Emile Greenhalgh, and Charlotte Meeks. "Enhanced Structural Damage Tolerance of CFRP Primary Structures by Z-Pin Reinforcement." In 44th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 2003. http://dx.doi.org/10.2514/6.2003-1679.

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Swenson, Eric D., Som R. Soni, and Hitesh Kapoor. "Lamb wave propagation in Z-pin reinforced co-cured composite pi-joints." In SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, edited by Peter J. Shull, Aaron A. Diaz, and H. Felix Wu. SPIE, 2010. http://dx.doi.org/10.1117/12.848787.

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Ranatunga, Vipul, Savannah M. Crampton, and Stephen B. Clay. "Assessment of Damage Tolerance and Static Residual Strength of Z-Pin Reinforced Composites." In AIAA Scitech 2019 Forum. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2019. http://dx.doi.org/10.2514/6.2019-1044.

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Kan, Rui, and Shuqing Tian. "Numerical Investigation of Heat Transfer in a High Aspect Ratio Double Wall Channel With Pin Fin and Jet Array Impingement." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56642.

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A combined impingement-pedestal geometry for turbomachinery double wall cooling application is studied numerically with the shear stress transport turbulence model. Conjugated CFD simulation is performed to investigate the cooling effectiveness distribution. The configuration consists of a high aspect ratio cooling duct, with jet array impinging onto the pin fin-roughed wall. The jet Reynolds number varies from 8,000 to 80,000, jet-to-target wall spacing is kept constant at Z/Dj=0.8. Three main parameters are investigated, including the jet Reynolds number, pin fin shapes (circular and elongated) and the relative location between jets and pin fins (the jet placed uniformly inside the duct or more densely at the front of the duct). For more detailed investigations, the pin fin diameter and impingement hole diameter are varied independently, and a total of 26 configurations are studied. The results show that the double wall configuration with pin fins significantly increases the heat transfer coefficients, compared to that with only impingement. Non-uniform jet arrangement results in a stronger crossflow and enhances heat transfer on the pins, which brings an increase of cooling effectiveness and more uniform temperature distribution.
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Alzahrani, Yasser S., Lesley M. Wright, Andrew Chen, and Je-Chin Han. "Jet Impingement Heat Transfer in a Rectangular Channel With Smooth and Pinned Target Walls." In ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-59343.

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Abstract An experimental study was completed to quantify heat transfer enhancement, pressure loss, and crossflow effect within a channel of inline impinging jets. The jet diameter is 5.08 mm and the jet-to-jet spacing in the streamwise and spanwise directions is fixed at x/d = 11.1 and y/d = 5.9, respectively. The effect of jet-to-target surface spacing was considered with z/d = 3 and 6. For both of the jet-to-target surface spacings, a smooth surface, the reference case, and a surface roughened with partial height pins were investigated. The roughened surface has a staggered array of 120 partial height copper pin fins. The pin to jet diameter and the pin height to diameter ratios are D/d = 0.94 and H/D = 1.6, respectively. Regionally averaged heat transfer coefficient distributions were measured on the target surface, and these distributions were coupled with pressure measurements through the array. The heat transfer augmentation and pressure penalty were investigated over a range of jet Reynolds numbers (10K–70K). The results show high discharge coefficients for all the cases. The channels with the tight jet-to-target surface spacing experience double the cross-flow effect of its increased spacing counterpart. The addition of surface roughness showed a negligible effect on the crossflow. The best heat transfer performance was observed in the impingement channel with the pinned target surface at z/d = 3.
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Chougule, Nagesh K., Gajanan V. Parishwad, Sachin Pagnis, and Prashant R. Gore. "Multijet Impingement on Pin Fin Heat Sink With Different Crossflow Schemes." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-64764.

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The fluid flow and heat transfer characteristics of multi air jet array impinging on a 4×4 pin fin heat sink with 3×3 nozzle arrays are investigated both numerically and experimentally. The results for multi jet impingement with wide range of parameters are not readily available in the literature. Different exit flow conditions such as minimum, semi and maximum cross flow conditions are simulated using shear stress transport (SST) k-ω turbulence model to study the combined effects of Reynolds number (Re) and spacing between nozzle exit and target surface (Z/d) on heat transfer coefficient (havg). The jet Reynolds number is varied from 7000 to 50000 and Z/d is varied from 6 to 10. For Re ≤ 18000, it is noticed that the minimum cross flow scheme gives maximum heat transfer, than semi cross flow and the maximum cross flow schemes at all Z/d considered here. Semi cross flow scheme works better for Re ≥ 18000. At Re = 11000 the minimum cross flow scheme indicates that Nua decreases from 50.1 to 36.41 with increase in Z/d from 6 to 10. It is also observed that the symmetry of the heat transfer patterns occur in the minimum and semi cross flow schemes as the sidewalls restrict the flow in opposite direction. However, in the maximum cross flow scheme, the stagnation peaks shifted and reduced in the stream wise direction by the strong cross flow degradation.
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El-Jummah, Abubakar M., Gordon E. Andrews, and John E. J. Staggs. "Impingement Jet Cooling With Ribs and Pin Fin Obstacles in Co-Flow Configurations: Conjugate Heat Transfer Computational Fluid Dynamic Predictions." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57021.

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Conjugate heat transfer (CHT) computational fluid dynamics (CFD) predictions were carried out for impingement heat transfer with obstacle (fins) walls on the target surface midway between the impingement jets and aligned in the direction of the crossflow (direction of outflow of the impingement cooling air) to minimise the pressure loss increase due to the fins. A single sided flow exit was used in a geometry that was applicable to reverse flow cooling of low NOx combustors, but was also relevant to turbine blade and nozzle cooling. A 10 × 10 row of impingement jet holes (hole density n of 4306 m−2) was used, which had ten rows of holes in the cross-flow direction. One heat transfer enhancement obstacle per impingement jet was investigated and compared with previously published experimental results, for Nimonic 75 metal walls, for flow pressure loss and surface averaged heat transfer coefficients. Two different shaped obstacles were investigated with an impingement gap, Z, of 10mm: a continuous rectangular rib 4.5mm high (H) and 3.0 mm thick and a rectangular pin-fin rib with ten 8mm high (H) pins that were 8.6mm wide and 3.0 mm thick. The obstacles were equally spaced on the centreline between each row of impingement jets aligned with the crossflow. The impingement jet pitch to diameter X/D and gap to diameter Z/D ratios were kept constant at 4.66 and 3.06 for X, Z and D of 15.24, 10.00 and 3.27 mm, respectively. The two obstacles investigated had obstacle height to diameter ratio H/D of 1.38 and 2.45. The computations were carried out for three different air coolant mass fluxes G of 1.08, 1.48 and 1.94 kg/sm2bar. The pressure loss ΔP/P and surface average heat transfer coefficient (HTC) h predictions for all three G showed good agreement with the experimental results. The predicted results were also compared with the impingement jet single exit flow, for a smooth target wall of the same impingement hole configuration. A significant increase in the overall surface averaged heat transfer was predicted and measured for the co-flow configuration with rectangular pin-fins. This was a 20% improvement at low coolant flow rates for the rectangular pin fin obstacles and 15% for the ribs. At high coolant flow rates the improvement was smaller at 5% for the rectangular pin fins and 1% for the rectangular ribs.
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Reports on the topic "Z-pin"

1

Clay, Stephen B., and Amanda K. Pommer. Z-Pin Stubble Technology Advanced Research (ZSTAR). Fort Belvoir, VA: Defense Technical Information Center, April 2008. http://dx.doi.org/10.21236/ada482759.

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Muller, David. Production of Charged {pi}{sup {+-}}, {Kappa}{sup {+-}} and p/p in Hadronic Z{sup 0} Decays. Office of Scientific and Technical Information (OSTI), July 1999. http://dx.doi.org/10.2172/10088.

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Rubbo, Francesco. Search for a $Z(4430)^{\pm} \to \psi(2S)\pi^{\pm}$ resonance in hadron collisions at CDF II. Office of Scientific and Technical Information (OSTI), January 2010. http://dx.doi.org/10.2172/1329231.

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