Academic literature on the topic 'Insert shape'
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Journal articles on the topic "Insert shape"
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Morovič, Ladislav, Juraj Vagovský, and Ivan Buranský. "Shape Investigation of Worn Cutting Inserts with Utilization of Active Triangulation." Key Engineering Materials 581 (October 2013): 22–25. http://dx.doi.org/10.4028/www.scientific.net/kem.581.22.
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The paper deals with utilization of active triangulation method for shape investigation of cutting inserts after wear. For measuring of cutting insert shape a method using the structured light (fringe projection) was used. As a measuring device the optical 3D scanner GOM ATOS II TripleScan SO was used. Cutting inserts with different shapes was measured. With the measurement method mentioned in the paper the accurate shape of the cutting insert can be captured. From the 3D model moreover it is possible to measure the geometrical properties as well as tool wear, plastical deformation, build-up-edge, corner damage and chipping of cutting insert.
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Shrirao, Pankaj, Hanumant Jagtap, Pramod Magade, Pitambar Gadhave, and Dnyaneshwar Kamble. "Thermo-hydraulic Analysis of Fluid Flowing Through Circular Pipe with Wire Mesh Inserts having Varying Mesh Porosity." IOP Conference Series: Earth and Environmental Science 1285, no. 1 (January 1, 2024): 012028. http://dx.doi.org/10.1088/1755-1315/1285/1/012028.
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Abstract The experimental investigation was made to analysis the rate of heat transfer of fluid flowing through a heat exchanger with varying wire-mesh porosity inserts. The Nusselt number (Nu), friction factor (f), and overall heat transfer rate (Q) were evaluated using experiments. Three different wire mesh inserts of square, hexagonal and diamond porosity were examined. The SS 316 stainless wire mesh with a porosity of 9 pores per inch (PPI) were inserted normal to the flow field with a pitch distance of 5 cm for each shape of wire mesh. The experiments were conducted on test rig with air as a working fluid for turbulent flow regime having Reynolds number ranging from 6,000 to 16,000. Experiments were performed on computerized test rig with heated air flowed in one direction through inner pipe and counter flow cold water flowing through the outer concentric pipe. The circular inner pipe of 40 cm long having 4 cm inner diameter (Di), and 3 mm thick was used for experimentation. The experimental results showed that Nusselt number (Nu) increases with decrease in friction factor (f) with increase in Reynolds number (Re). Also, it is observed that the hexagonal porosity shape of wire mesh insert provides higher material contact and gain more energy absorption from hot air resulted in improvement in heat transfer coefficient as compared to diagonal and square porosity shapes of wire mesh inserts, under similar operating conditions. The friction factor and pressure drop for square porosity shape of wire mesh insert is higher as compared to hexagonal and diagonal porosity shapes of wire mesh inserts respectively. This is due to the fact that square porosity wire mesh provides more obstruction in the flow field compared with hexagonal and diagonal porosity shapes of wire mesh inserts. The hexagonal porosity shape of wire mesh insert provides better option for heat exchange applications.
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Ahmed, Md Shamim, and Mohammad Zoynal Abedin. "Review on Heat Transfer Enhancement by Insert Devices." International Journal of Engineering Materials and Manufacture 5, no. 4 (October 20, 2020): 130–47. http://dx.doi.org/10.26776/ijemm.05.04.2020.03.
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The scientists revise the heat transfer enhancement techniques time to time to achieve better performance and to obtain optimized designs of heat exchangers. The present study reviews the performance and techniques of heat transfer enhancement using various insert devices such as twisted tape and wire coil insert as well as completely different forms of other inserts like air-foil shape inserts, X-shaped twisted tape inserts, baffles and V-winglets inserts with various types of medium and nanofluids. According to the summary of recent significant researches on the heat transfer enhancement by using different types of inserts and combinations of these inserts with various nanofluids showed that insert can indicatively enhance the heat transfer rate by modifying its geometry or configurations like twist ratio, length ratio, pitch ratio, segmented tape, perforated tape, angle of arrangements and insert quantities and so on which caused a considerable impact on performance characteristics of heat transfer enhancement along with the pressure drop and friction factor. It is revealed through reviewing the related literature that the highest value of equivalence heat transfer enhancement is as maximum as 400%, 300% and 9% for the twisted tape insert with helical tube, the air foil shaped inserts and for the wire coil inserts, respectively when compared with the smooth tube. In the case of baffles in nanofluids, as maximum as 255% equivalence heat transfer enhancement could be achieved when compared with that of baffles without nanofluids.
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Stafford, Myra, Robert L. Geneve, and Jack W. Buxton. "Marigold Root Growth in 12-cm Containers Modified with Two or Four Copper-treated Inserts." HortScience 31, no. 4 (August 1996): 679f—680. http://dx.doi.org/10.21273/hortsci.31.4.679f.
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This study evaluated the effect of container shape and copper hydroxide on root and shoot development of marigold (Tagetes patula `Little Devil Flame') seedlings. Containers were modified in shape and volume by gluing triangular polycarbonate inserts vertically onto sides of the container. The inserts were either painted with copper or not painted. Inserts decreased container volumes (no insert = 480 cm3, two inserts = 340 cm3, and four inserts = 200 cm3). After 38 days the seedling roots were scanned for computer analysis, and leaf area and dry weights were determined. Copper effectively prevented roots from growing in contact with copper treated surfaces. Shoot dry weight and leaf area were greater with no inserts, but if inserts were treated with copper the shoot dry weight and leaf area were greater. Root dry weight was reduced 7%–10 % with two inserts and 20% with four inserts compared to no inserts. Copper treated inserts reduced the dry weight further. However, at the insert interface, root length was increased between 15%–20% by all copper treatments, with the greatest increase in the four-insert treatment.
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Yang, Jin, Can Weng, Jun Lai, Tao Ding, and Hao Wang. "Molecular Dynamics Simulation on the Influences of Nanostructure Shape, Interfacial Adhesion Energy, and Mold Insert Material on the Demolding Process of Micro-Injection Molding." Polymers 11, no. 10 (September 27, 2019): 1573. http://dx.doi.org/10.3390/polym11101573.
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In micro-injection molding, the interaction between the polymer and the mold insert has an important effect on demolding quality of nanostructure. An all-atom molecular dynamics simulation method was performed to study the effect of nanostructure shape, interfacial adhesion energy, and mold insert material on demolding quality of nanostructures. The deformation behaviors of nanostructures were analyzed by calculating the non-bonded interaction energies, the density distributions, the radii of gyration, the potential energies, and the snapshots of the demolding stage. The nanostructure shape had a direct impact on demolding quality. When the contact areas were the same, the nanostructure shape did not affect the non-bonded interaction energy at PP-Ni interface. During the demolding process, the radii of gyration of molecular chains were greatly increased, and the overall density was decreased significantly. After assuming that the mold insert surface was coated with an anti-stick coating, the surface burrs, the necking, and the stretching of nanostructures were significantly reduced after demolding. The deformation of nanostructures in the Ni and Cu mold inserts were more serious than that of the Al2O3 and Si mold inserts. In general, this study would provide theoretical guidance for the design of nanostructure shape and the selection of mold insert material.
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Vignesh, Ganesan, Debabrata Barik, Samraj Aravind, Ponnusamy Ragupathi, and Munusamy Arun. "Numerical investigation of dimple-texturing on the turning performance of hardened AISI H-13 steel." International Journal for Simulation and Multidisciplinary Design Optimization 13 (2022): 10. http://dx.doi.org/10.1051/smdo/2021043.
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Forming micro-dimples nearer to the cutting edge on the rack face of the tungsten carbide cutting inserts will positively influence the machinability. However, it is challenging to machine the perfect micro-dimple dimensions by utilizing the available machining techniques. Finite element analysis can be an efficient way to observe the influence of dimple-texture area density, micro-dimple size, and various micro-dimple shapes on cutting inserts' machinability. This paper numerically analyses the impact of micro-dimple-textured cutting inserts in dry machining of AISI H-13 steel using AdvantEdge (virtual machining and finite element analysis software). Micro-dimples are formed on the rack face of tungsten carbide cutting inserts to observe the effect of dimple-textured cutting inserts on machinability compared to non-textured cutting inserts in terms of micro-dimple shape, micro-dimple size, and micro-dimple area density ratio. Their outcomes are analysed in terms of chip-insert contact length, main cutting force, and thrust force. It is observed that micro-dimple textured cutting inserts exhibit minimal main cutting force and thrust force in line with increasing the cutting insert life span. The abrasive wear was reduced in dimple-textured cutting inserts due to minimal contact between the cutting insert and chip developed compared to non-textured cutting inserts.
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Struzikiewicz, Grzegorz. "Application of 3D Imaging for Analyzing the Chip Groove Shapes of Cutting Inserts." Applied Sciences 14, no. 7 (April 8, 2024): 3134. http://dx.doi.org/10.3390/app14073134.
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An effective chip formation process is significant for an efficient metal-cutting process. Long continuous chips can lead to scratches on the machined surface, increasing the risk to operator safety and stability of the machining process. The use of chip grooves on cutting inserts allows for control of the chip formation and breaking process during machining. The shape of the rake surface and the design of the chip groove also affect the efficiency of the machining process. The article presents the use of 3D imaging to analyze changes in the selected chip groove shapes depending on the cutting depth ap = 0.10, 0.25, and 0.50 mm and the angular location of the cutting insert relative to the machined surface of the workpiece (i.e., major cutting-edge angle K = 60° and K = 90°). The analysis methodology was based on the use of 3D image registration and surface shape modeling. In the analysis based on the 3D imaging presented, the novelty was the adaptation of methods typically used to map and model the terrain surface, which have not been used previously in cutting processes. The evaluation of the shape of the chip groove surface was carried out using, e.g., watershed maps and 3D surface maps. The obtained results indicated a significant influence of the cutting depth and major cutting-edge angle on the surface shape, profile, and length of the chip former; chip groove volume; and the theoretical contact area of the formed chip with the cutting insert. It was observed that for small depths of cut, i.e., ap < 0.25 mm, the chip-curling process may be difficult due to the flattened shape of the rake surface. In addition, the influence of the convexity of the rake surface of the cutting insert on the chip formation process was demonstrated. The results of the experimental research that verified the conclusions are presented. The developed results may be useful in the process of selecting the parameters and conditions of the metal finishing through use of tools with a shaped rake surface.
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Sun, Bao Jun, and Xi Wu Fang. "The Optimization of Edge-Shape Parameter for Curve-Edge Milling Insert Based on Thermal-Mechanic Coupling Physical Field." Advanced Materials Research 308-310 (August 2011): 1665–68. http://dx.doi.org/10.4028/www.scientific.net/amr.308-310.1665.
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The edge shape of milling insert has important influence on the heat loading and mechanical loading during metal cutting. The optimization of edge-shape parameter for curve-edge milling insert based on evaluation criteria of thermal-mechanic coupling field was carried out in order to improve the thermal-mechanic coupling field and to raise lifetime and production rate of milling insert. A new edge shape function was obtained. The curve-edge milling insert was designed driven by the edge function. The coupling field of milling insert has obvious improvement by finite element analysis (FEM). The maximal equivalent stress and displacement in cutting deformation area decreased by 17.2% and 15.7% respectively.
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Papadakis, Loucas, Stelios Avraam, Demetris Photiou, Simona Masurtschak, and Juan Carlos Pereira Falcón. "Use of a Holistic Design and Manufacturing Approach to Implement Optimized Additively Manufactured Mould Inserts for the Production of Injection-Moulded Thermoplastics." Journal of Manufacturing and Materials Processing 4, no. 4 (October 24, 2020): 100. http://dx.doi.org/10.3390/jmmp4040100.
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Injection moulding is one the most familiar processes for manufacturing of plastic parts by injecting molten thermoplastic polymers into a metallic mould. The cycle time of this process consists of the phases of injection, packing, cooling, and ejection of the final product. Shortening of cycle time is a key consideration to increase productivity. Therefore, in this manuscript the adoption of additively manufactured mould inserts with conformal cooling channels by means of selective laser melting (SLM) with the aim to reduce process cycles is presented. The design and manufacture of a mould insert with conformal cooling channels for producing pressure fitting thermoplastic parts is described. Numerical analysis of the injection process and simulation of shape distortions after SLM were conducted providing useful results for the design and manufacture of the mould insert. The results of the numerical analyses are compared with experimental 3D geometrical data of the additively manufactured mould insert. Temperature measurements during the real injection moulding process demonstrating promising findings. The adoption of the introduced method for the series production of injection moulded thermoplastics proves a shortening of cycle times of up to 32% and a final product shape quality improvement of up to 77% when using mould inserts with conformal cooling channels over the conventional mould inserts.
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Valdez, Dustin, Jami Fukui, Thomas Wolfgruber, Lambert Leong, Gertraud Maskarinec, and John Shepherd. "Abstract P3-01-13: Comparing portable and clinical ultrasound systems using 3D printed breast phantom inserts." Cancer Research 82, no. 4_Supplement (February 15, 2022): P3–01–13—P3–01–13. http://dx.doi.org/10.1158/1538-7445.sabcs21-p3-01-13.
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Abstract Background: Late-stage breast cancer rates in the Pacific where mammography services are limited are exceedingly high. Therefore, alternative accessible breast cancer screening technologies such as portable ultrasound is needed. However, little is known about the performance of portable ultrasound when compared to clinical ultrasound for use in breast cancer screening. By utilizing 3D printing technology, it is possible to design breast phantom inserts to replicate various types of lesions. In this study, we utilized 3D printed breast phantom inserts to compare portable and clinical ultrasound lesion detection performance. Methods: Four different breast inserts were designed using FreeCAD (version 0.19) to replicate different lesion detection properties. The first insert compares lesion shape, the second insert investigates depth and size, the third insert looks at fiber diameter, and the fourth insert looks at clusters. The four inserts were printed using a photopolymer resign (Formlabs Inc Rigid resign, Somerville, MA, USA) and then placed in a gelatin-based breast phantom designed for ultrasound use. Using the portable ultrasound (GE Vscan Extend) and clinical ultrasound (Philips EPIQ 5G), various images were captured of identical angle and orientation for both devices. The number of lesions visualized were counted and presented as a percentage of lesions detected. Results: The portable ultrasound had a 100% lesion detection rate for breast insert 1, 90.3% for breast insert 2, 70% for breast insert 3 and 55.8% for breast insert 4. Clinical ultrasound had 100% lesion detection rate for breast insert 1, 93.1% for breast insert 2, 76.6% for breast insert 3, and 99% for breast insert 4. Conclusion: Portable ultrasound shows comparable lesion detection capabilities to clinical ultrasound in 3 of the 4 breast phantom insert tests. Portable ultrasound may have potential as a capable accessible breast cancer screening device in areas without mammography. Citation Format: Dustin Valdez, Jami Fukui, Thomas Wolfgruber, Lambert Leong, Gertraud Maskarinec, John Shepherd. Comparing portable and clinical ultrasound systems using 3D printed breast phantom inserts [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-01-13.
Dissertations / Theses on the topic "Insert shape"
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Chu, C. C., E. T. Natwick, T. J. Henneberry, D. R. Nelson, J. S. Buckner, and T. P. Freeman. "Silverleaf Whitefly Studies: Effects of Trichome Density and Leaf Shape." College of Agriculture, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/211329.
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We examined nine upland cotton cultivars in 2000 to determine silverleaf whitefly (SLW)-cotton leaf trichome relationships. The hairy leaf cultivar Stoneville 474 had significantly higher numbers of SLW eggs, nymphs and adults compared to eight other smooth leaf cotton cultivars. The top young leaves on main stem terminals had fewer SLW eggs, nymphs and adults, but higher numbers of trichomes compared with older leaves. Among the eight smooth leaf cultivars, the four okra leaf cultivars as a group had fewer SLW eggs, nymphs and adults compared with the four normal leaf cultivars.
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Maartens, Aidan Patrick. "Intercellular signalling, cell fate and cell shape in the Drosophila pupal wing." Thesis, University of Sussex, 2012. http://sro.sussex.ac.uk/id/eprint/38663/.
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The morphogenesis of tissues in animal development is orchestrated by intercellular signalling and executed by cell behaviours such as changes to shape. Understanding the link between signalling and cell shape changes is a key task of developmental biology. This work addresses this problem using the development of the pupal wing of Drosophila melanogaster. The pupal wing is a bilayered epithelium which is patterned into vein and intervein domains, and which secretes the cuticle of the adult wing. I first address the cellular basis of pupal wing development, and show that the process comprises a series of dynamic cell shape changes involving alterations to the apical and basolateral surfaces of the cells. Using temporally controlled mis-expression, I then investigate the role of intercellular signalling in these shape changes, and define the competence of cells in the wing to respond to ectopic signals. The dimensions of signalling in the pupal wing are then investigated, and I show that while BMP ligands can travel between the layers to promote vein development, such signalling is not a prerequisite for cellular differentiation. Within the plane of the epithelium, the BMP ligand Dpp can only induce signalling at a short range, potentially due to the upregulation of receptor levels in receiving cells. Finally, attention is turned to the means by which cell signalling controls cell shape changes, specifically in the crossveins. I identify the RhoGAP Cv-c as a downstream target of BMP signalling which acts to inhibit a novel RhoGTPase function in intervein development. This provides an example of how signalling pathways can enact cell shape changes, via the transcriptional regulation of RhoGAPs.
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Milani, Mauro. "Optimization of the pressing process of triangular shaped cutting tool inserts." Thesis, Linnéuniversitetet, Institutionen för maskinteknik (MT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-58282.
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Pressing of metallic powders is a manufacturing process widely investigated in the research field and in the industry. This thesis project is focused on optimizing the pressing process of cemented carbide powder utilized for the production of triangular shaped cutting tool inserts. In particular, the filling of powder into the die cavity was investigated with respect to different pressing parameters. The aim of the project was to obtain a uniform density distribution of the powder into the die cavity, and hence to reduce the variation of the height of the insert obtaining more precise dimension of the latter. The tests were carried out at the Sandvik Coromant production department which is the creator of the project. The optimization of the pressing process was performed according to the Design of experiments theory. The dynamic of the sintering process was also investigated. The results showed a significant improvement in the filling of the die cavity and a significant decrease of the variation of the height of the inserts. The new insert obtained has more precise dimensions and is able to meet the more demanding requirements of the customers. The results achieved are directly applicable to a larger number of products, and indicate the direction to follow for further development of the manufacturing process.
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Aldannawy, Houssam Aldine. "Le forage percussif en conditions extrêmes : expérimentations et modélisations numériques." Electronic Thesis or Diss., Université Paris sciences et lettres, 2022. http://www.theses.fr/2022UPSLM043.
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Le forage percussif est une technologie qui consiste à appliquer une série d’impacts dynamiques conduisant à la fragmentation de la roche par deux mécanismes principaux : l’écrasement et l’écaillage. Ces mécanismes sont fortement influencés par de nombreux facteurs qui ont fait l’objet d’investigations expérimentales et numériques pendant cette thèse. Un dispositif expérimental a été développé pour réaliser des essais d’impacts dynamiques. Un système de mesure précis a été également mis au point afin d’avoir les résultats des nombreuses séries d’essais qui ont été menées dans le cadre de cette thèse. Quant au volet numérique, un laboratoire virtuel a été construit en se basant sur un modèle rhéologique élasto-viscoplatique validé sur des essais de laboratoire pour décrire le comportement du granite et un mécanisme de contact pour simuler l’interaction insert-roche pendant un impact dynamique. Dans un premier temps, plusieurs études paramétriques ont été réalisées sur un matériau homogène. Dans un deuxième temps, une nouvelle approche de modélisation de l’hétérogénéité a été développée pour décrire la distribution des minéraux dans le granite.Ces études ont fournis des éléments primordiaux pour la compréhension des mécanisme physiques de destruction des roches dures en percussion, pour l’évaluation des effets des principaux paramètres et facteurs de forage et pour l’optimisation de l’outil de foragePercussive drilling is a technology that consists in applying a series of dynamic impacts leading to the rock fragmentation by two main mechanisms: crushing and chipping. These mechanisms are highly influenced by many factors on which experimental and numerical investigations were carried out in this thesis. An experimental set up was developed to carry out dynamic impact tests. Several series of tests were realized and their results were measured using a precise measurement system which was also developed during the thesis. As for the numerical work, a virtual laboratory was built based on an elasto-viscoplastic constitutive model validated on laboratory tests to describe the granite behavior and a contact mechanism to simulate the insert-rock interaction during a dynamic impact. First, several parametric studies were carried out on a homogeneous material. Secondly, a new heterogeneity modeling approach was developed to describe the distribution of minerals in the granite. These studies have provided essential elements for understanding the physical mechanisms of hard rocks destruction in percussion, for evaluating the effects of the main drilling parameters and factors and for optimizing the drilling tool
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Georgitis, Kathryn M. "Evaluating Shade Bias in Insect Trap Catch and Assessing the Short- and Long-term Impacts of Herbicide Application in Regenerating Clearcuts on Flowering Plant Communities." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/GeorgitisKM2001.pdf.
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Srivastava, Nittie. "Studies on seasonal occurance of insects associated with the major shade tree, Alnus nepalensis D.Don, of learge cardamon agro forestry, with bio-ecology of some common folivores at different attitudes of Sikkim." Thesis, University of North Bengal, 2003. http://hdl.handle.net/123456789/1009.
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Humphrey, Parris Taylor. "The Ecology Of Co-Infection In The Phyllosphere: Unraveling The Interactions Between Microbes, Insect Herbivores, And The Host Plants They Share." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/565900.
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Infection by multiple parasites is a part of everyday life for many organisms. The host immune system may be a central mediator of the many ways parasites might influence one another (and their hosts). Immunity provides a means for the colonized to reduce the success of current and future colonizers and has evolved across the tree of life several times independently. Along the way, the immune systems of plants as well as many groups of animals has evolved perhaps an accidental vulnerability wherein defense against one parasite can increase susceptibility to others. This so-called immune 'cross-talk' is a conundrum worth investigating not only to understand the impact of parasites on focal organisms, but also to better predict how immunity itself influences the evolution and epidemiology of parasites whose spread we might like to curtail. For plants, co-infection often comes from insect herbivores and various bacteria that colonize the leaf interior. Both colonizers can reduce plant fitness directly or indirectly by potentiating future enemies via cross-talk in plant immunity. This phenomenon has largely been studied in laboratory model plants, leaving a substantial gap in our knowledge from native species that interact in the wild. This dissertation helps close this gap by investigating the ecology of co-infection of a native plant by its major insect herbivore and diverse leaf-colonizing bacteria. I revealed that leaf co-infection in the field by leaf-mining herbivores and leaf-colonizing ("phyllosphere") bacteria is substantially more common than single infection by either group and that bacterial infection can cause increased feeding by herbivores in the laboratory. Immune cross-talk can also shape the field-scale patterns of herbivory across a native plant population. Studying the main herbivore of this native plant in detail revealed that, in contrast to many specialist herbivores, our focal species avoids plant defenses likely because it does not possess a specialized means of avoiding their toxicity. Nonetheless, this species may depend on the very same defenses it avoids by being initially attracted to plants that produce them. This foraging strategy is unique among known specialists. Lastly, I moved beyond immune cross-talk to explore how co-occurring phyllosphere bacteria might directly impact one another through competition. In the lab, I found that different growth strategies underlie competitive ability for two major clades of bacteria within the genus Pseudomonas, and that toxin production and resistance may be important mediators of competition within the phyllosphere. However, competitively superior bacteria that produce toxins may indirectly facilitate the survival of inferior competitors through their being toxin resistant, which likely enhances co-existence of diverse bacteria in the phyllosphere. Together, this dissertation has revealed a variety of means by which co-infecting bacteria and insects might influence one another through plant defense cross-talk, as well as how the complex interplay of colonization and competition might affect the structure of leaf microbial communities in nature.
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Pretorius, Rudolph Johannes. "A plant health management system for aphididae on lettuce under variable shadehouse conditions in the central Free State, South Africa." Thesis, Bloemfontein : Central University of Technology, Free State, 2008. http://hdl.handle.net/11462/114.
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Thesis (M. Tech) --Central University of Technology, Free State, 2008Aphids (Hemiptera: Aphididae) are amongst the most destructive insects in agricultural crop production systems. This reputation stems from their complex life cycles which are mostly linked to a parthenogenetic mode of reproduction, allowing them to reach immense population sizes within a short period of time. They are also notorious as important and efficient vectors of several plant viral diseases. Their short fecund life cycles allow them to be pests on crops with a short growth period, e.g. lettuce (Lactuca sativa L.). It is common practice to provide this crop with some degree of protection from environmental extremes on the South African Highveld. Shadehouses are popular in this regard, but aphids are small enough to find their way into these structures, and their presence on lettuce is discouraged due to phytosanitary issues. In addition, the excessive use of insecticides is criticized due to the negative influence on human health, and because aphids can rapidly develop resistance. This necessitates the use of alternative control options in order to suppress aphid numbers. Biological control is popular in this regard and the use of predatory ladybirds (Coleoptera: Coccinellidae) is a popular choice. This study investigated the aphid and coccinellid species complex encountered under varying shadehouse conditions on cultivated head lettuce in the central Free State Province (South Africa). Their seasonality was also examined, along with variations in their population size throughout a one-year period. Finally, the impact of varying aphid populations on some physical characteristics of head lettuce was examined, and recommendations for aphid control (using naturally occurring coccinellid predators) were made. Two shadehouse structures were evaluated during this study. One was fully covered with shade netting and designed to exclude the pugnacious ant, Anoplolepis custodiens (Hymenoptera: Formicidae), while the other was partially covered with shade netting (on the roof area) allowing access to the ants. Six cycles of head lettuce were planted and sampled four times during each cycle. These were scheduled to monitor the seedling, vegetative and heading stage of lettuce. Four important aphid species were recorded on the lettuce, namely Acyrthosiphon lactucae, Nasonovia ribisnigri, Myzus persicae and Macrosiphum euphorbiae. Both structures harboured similar aphid and coccinellid species, but their population dynamics differed. A. lactucae dominated in the absence of A. custodiens in the fully covered structure (whole study), while N. ribisnigri dominated in the partially covered structure in the presence of these ants during the warmer months (December – January). M. euphorbiae replaced this species as the dominant species in the absence of A. custodiens (April – September). M. persicae occured during the winter (May – August) in the fully covered structure. Promising coccinellid predators were Hippodamia variegata and Scymnus sp. 1, and to a lesser extent, Exochomus flavipes and Cheilomenes lunata. However, the fully covered structure hampered the entrance of the larger adult coccinellid species, resulting in their lower occurrence. Aphid and coccinellid activity peaked during the summer months (October – January), and the fully covered structure attained the highest aphid infestation levels and coccinellid larval numbers during this time. On the other hand, aphid numbers were higher in the partially covered structure during the cooler months of the year (April – July) and this structure also harboured more adult coccinellids. In most cases, aphid infestation levels did not affect the amount of leaves formed. However, symptomatic damage in terms of head weight reduction did occur under severe infestation levels. Specific environmental conditions within a shadehouse structure concurrently contributed to this reduction, with less favourable conditions accelerating this condition. Results from this study have shown that even though the type of shadehouse structure does not influence the insect species complex found on lettuce, it does have an influence on detrimental and beneficial insect population dynamics. Aphid species infesting lettuce have been identified, along with coccinellid predators that could potentially be used in their control. Both types of structures had advantages and disadvantages, and therefore, decisions concerning shadehouses should not be focused on which type of structure to use, but rather which type of structure to use during different seasons of the year.
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蘇森傑. "The Study of Machinability of End Milling MAR-M247 under different shapes of insert." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/09536226181604740152.
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碩士國立中正大學
機械系
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Due to the fast engineering advancement in the aerospace industry . Nickel-based superalloy MAR-M247 using in aircraft turbine engine widely becomes more important gradually . However ,the nickel-based alloys possess a very low machinability because of its high strength , poor thermal diffusion and work hardening during machining. In order to achieve a highest quality of machining for this kind of materials , we decided to use different shapes of tool insert such as round , square carbide inserts with various cutting speeds , feed rates , and depths of cut to observe the tool wear and the surface roughness .We hope that this research will produce a great contributions for today''''s concerned industries.
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(10757814), Angel David Lozano Galarza. "EXPERIMENTAL STUDIES ON FREE JET OF MATCH ROCKETS AND UNSTEADY FLOW OF HOUSEFLIES." Thesis, 2021.
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The aerodynamics of insect flight is not well understood despite it has been extensively investigated with various techniques and methods. Its complexities mainly have two folds: complex flow behavior and intricate wing morphology. The complex flow behavior in insect flight are resulted from flow unsteadiness and three-dimensional effects. However, most of the experimental studies on insect flight were performed with 2D flow measurement techniques whereas the 3D flow measurement techniques are still under developing. Even with the most advanced 3D flow measurement techniques, it is still impossible to measure the flow field closed to the wings and body. On the other hand, the intricate wing morphology complicates the experimental studies with mechanical flapping wings and make mechanical models difficult to mimic the flapping wing motion of insects. Therefore, to understand the authentic flow phenomena and associated aerodynamics of insect flight, it is inevitable to study the actual flying insects.
In this thesis, a recently introduced technique of schlieren photography is first tested on free jet of match rockets with a physics based optical flow method to explore its potential of flow quantification of unsteady flow. Then the schlieren photography and optical flow method are adapted to tethered and feely flying houseflies to investigate the complex wake flow and structures. In the end, a particle tracking velocimetry system: Shake the Box system, is utilized to resolve the complex wake flow on a tethered house fly and to acquire some preliminary 3D flow field data
Books on the topic "Insert shape"
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R, Wagner Michael, ed. Introduction to forest and shade tree insects. San Diego: Academic Press, 1989.
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Fetting, Christopher J. Sampling methods for forest and shade tree insects of North America. Morgantown, W. Va: U.S. Dept. of Agriculture, Forest Service, Forest Health Technology Enterprise Team, 2010.
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Mogensen, Jan. The Land of the Big. New York: Crocodile Books, USA, 1992.
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Schmidt, Troy. To share or nut to share. Nashville: Tommy Nelson, 2006.
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Schmidt, Troy. To share or nut to share. Nashville: Tommy Nelson, 2006.
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Cosgrove, Stephen. Shrugg LaBugg: Learning to share. San Antonio, Tex: PCI Educational Pub., 2004.
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Tie pi ren mei shu, ed. Tang lang tai tai de xin jia. Xianggang: Xin ya wen hua shi ye you xian gong si, 2008.
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Biggest vs. smallest incredible insects. Berkeley Heights, NJ: Enslow Elementary, 2010.
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ill, Ricks Sam, ed. Invasion of the insects. New York: Little Simon, 2017.
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Locust: The Devastating Rise and Mysterious Disappearance of the Insect That Shaped the American Frontier. New York: Basic Books, a member of the Perseus Books Group, 2004.
Find full textBook chapters on the topic "Insert shape"
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John, Leonard, Dina Becker, Steffen Reuter, Hans-Christian Möhring, Martin Doppelbauer, and Lars F. Berg. "Resource Efficient Manufacturing of Complex Cooling Structures." In Advances in Automotive Production Technology – Towards Software-Defined Manufacturing and Resilient Supply Chains, 307–13. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27933-1_28.
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AbstractThe combination of additive manufacturing (LPBF) and plastic injection molding offers great benefits for functional integration and thereby the functionality of parts, components and systems. By manufacturing cooling channels as very thin-walled structures, short laser processing time is needed to produce these parts. The combination with plastic overmolding allows the mechanical loads to be absorbed, while at the same time utilizing the freedom of shape of the LPBF process. In order to prevent the structures from collapsing during overmolding or to ensure that they do not have to be very thick-walled in order to withstand the high injection pressures, the structures are closed, so that the base-powder is still contained in the structure during the overmolding. After opening the overmolded components, the powder can be extracted and reused. This technique offers great potential for high functional integration and new possibilities in terms of realizing internal cooling structures of electric traction machines. Other advantages that can be exploited are the thermally good connection due to the material bond and the possibility of local reinforcement due to the design freedom of the insert. Thanks to the injection-molded component, complex geometries can also be produced without additional unit costs.
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Smith, Cole. "Technical Concept Development, Testing, and Modeling: Development of a Shape-Memory Alloy (SMA) Tire Insert for Flat Tire Prevention and Airless Conversions." In The Proceedings of the 2023 Conference on Systems Engineering Research, 279–93. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-49179-5_19.
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Meineke, Emily K., Elsa Youngsteadt, Mia K. Lippey, and Katherine C. R. Baldock. "Urbanization Shapes Insect Diversity." In Routledge Handbook of Urban Biodiversity, 219–46. London: Routledge, 2023. http://dx.doi.org/10.4324/9781003016120-19.
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Hjältén, Joakim, Jari Kouki, Anne Tolvanen, Jörgen Sjögren, and Martijn Versluijs. "Ecological Restoration of the Boreal Forest in Fennoscandia." In Advances in Global Change Research, 467–89. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-15988-6_18.
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AbstractMixed-severity disturbances have historically shaped boreal forests, creating a dynamic mosaic landscape. In Fennoscandia, however, intensive even-aged forest management has simplified the forest landscape, threatening biodiversity. To safeguard this biodiversity, we therefore need to restore structural complexity in hitherto managed forests. Knowledge generated from relevant case studies on natural disturbance emulation–based ecological restoration suggests that prescribed burning positively affects many early-successional organisms. Gap cutting benefits some insects and wood fungi but has a limited effect on birds, bryophytes, and vascular plants. Restoration of deciduous forests appears to benefit light- and deciduous tree–associated insect species and some forest birds.
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Hattori, Momoko, Naoki Kobayashi, and Ryosuke Sato. "Gradual Tensor Shape Checking." In Programming Languages and Systems, 197–224. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-30044-8_8.
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AbstractTensor shape mismatch is a common source of bugs in deep learning programs. We propose a new type-based approach to detect tensor shape mismatches. One of the main features of our approach is the best-effort shape inference. As the tensor shape inference problem is undecidable in general, we allow static type/shape inference to be performed only in a best-effort manner. If the static inference cannot guarantee the absence of the shape inconsistencies, dynamic checks are inserted into the program. Another main feature is gradual typing, where users can improve the precision of the inference by adding appropriate type annotations to the program. We formalize our approach and prove that it satisfies the criteria of gradual typing proposed by Siek et al. in 2015. We have implemented a prototype shape checking tool based on our approach and evaluated its effectiveness by applying it to some deep neural network programs.
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Mayoral-Peña, Zyanya, Roberto Álvarez-Martínez, Juan Fornoni, and Etzel Garrido. "The Extended Microbiota: How Microbes Shape Plant-Insect Interactions." In Evolutionary Ecology of Plant-Herbivore Interaction, 135–46. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-46012-9_7.
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Asitoakor, Bismark Kwesi, Anders Ræbild, Philippe Vaast, Hans Peter Ravn, Kwadwo Owusu, Eric Opoku Mensah, and Richard Asare. "Shade Tree Species Matter: Sustainable Cocoa-Agroforestry Management." In Agroforestry as Climate Change Adaptation, 59–92. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-45635-0_3.
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AbstractShade trees are important components of cocoa-agroforestry systems because they influence yields, soil fertility and the occurrence of pests and diseases and may support adaptation to climate change. Based on a review of the existing literature and on primary data from field experiments, this chapter reports on the species-specific effects of shade trees in relation to the management of insect pests, black pod diseases and their impacts on cocoa yield. Shade tree species in cocoa systems impact soil available phosphorus differently and shade tree species such as Spanish cedar (Cedrela odorata), limba (Terminalia superba) and mahogany (Khaya ivorensis) increase cocoa yield compared with cocoa systems without shade trees. The architecture of shade tree species may influence below-canopy temperatures and relative humidity, which potentially affect pests such as mirids and black pod disease infections and ultimately cocoa yield. As farmers have local knowledge of and preferences for certain shade tree species, strengthening the combination of scientific and local knowledge can prove a powerful tool for the improved management of shade tree species, as well as cocoa pests and diseases.
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Dwivedi, Smrity. "Partial Ground-Inserted H-shaped Antenna for Beyond 5G Applications." In ICT Analysis and Applications, 313–21. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-6568-7_28.
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Shorohova, Ekaterina, Tuomas Aakala, Sylvie Gauthier, Daniel Kneeshaw, Matti Koivula, Jean-Claude Ruel, and Nina Ulanova. "Natural Disturbances from the Perspective of Forest Ecosystem-Based Management." In Advances in Global Change Research, 89–121. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-15988-6_3.
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AbstractNatural disturbances drive forest dynamics and biodiversity at different spatial and temporal scales. Forests in the boreal biome are shaped by several types of disturbance, including fire, windthrow, and insect outbreaks, that vary in frequency, extent, severity, and specificity. In managed forests, disturbances also affect the amount and quality of available timber. Ecosystem management uses information on disturbance regimes as a guide to finding a balance between ecological, economic, and social viewpoints. In this chapter, we review current knowledge on disturbance regimes in boreal forests and discuss some implications for managing the impact and risk of disturbances in the context of forest ecosystem management and restoration.
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Degen, Thomas, and Erich Städler. "Influence of natural leaf shapes on oviposition in three phytophagous flies: a comparative study." In Proceedings of the 9th International Symposium on Insect-Plant Relationships, 97–100. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-1720-0_23.
Full textConference papers on the topic "Insert shape"
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Grabovskii, V. I. "Optimum Design of Porous Gas Bearings With Maximum Load Carrying Capacity and Static Stiffness." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63153.
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The problem of optimum porous infinite sliding bearings design with isothermal compressed lubricant is solved. The sliders and journal bearings with maximum load carrying capacity or maximum a lubricant film static stiffness in conditions of restriction on the lubricant flow rate through a pored insert are examined. The found optimum shapes of bearings depend on problem parameters, determining property of lubricant and insert, conditions of feed and lubricant flow rate through an insert. Besides the bearings shape a size and position of insert are determined. The optimum shape features are the discontinuity of their gap height function and insert arrangement in the vicinity of this function breaking. In the case of journal bearing at fixed gap height only the best sizes of bushing and their positions from a point of view of maximum load capacity are founded. The method of calculus of variations is used.
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Tanbour, Emad Y., and Ramin K. Rahmani. "A Numerical Study of the Thermal Performance of Two Stationary Insert Designs in Internal Compressible Flows." In ASME 2009 Heat Transfer Summer Conference collocated with the InterPACK09 and 3rd Energy Sustainability Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/ht2009-88102.
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Enhancement of the natural and forced convection heat transfer has been the subject of numerous academic and industrial studies. Air blenders, mechanical agitators, and static mixers have been developed to increase the forced convection heat transfer rate in compressible and incompressible flows. Stationary inserts can be efficiently employed as heat transfer enhancement devices in the natural convection systems. Generally, a stationary heat transfer enhancement insert consists of a number of equal motionless segments, placed inside of a pipe in order to control flowing fluid streams. These devices have low maintenance and operating costs, low space requirements and no moving parts. A range of designs exists for a wide range of specific applications. The shape of the elements determines the character of the fluid motion and thus determines thermal effectiveness of the insert. There are several key parameters that may be considered in the design procedure of a heat transfer enhancement insert, which lead to significant differences in the performance of various designs. An ideal insert, for natural conventional heat transfer in compressible flow applications, provides a higher rate of heat transfer and a thermally homogenous fluid with minimized pressure drop and required space. To choose an insert for a given application or in order to design a new insert, besides experimentation, it is possible to use Computational Fluid Dynamics to study the insert performance. This paper presents the outcomes of the numerical studies on industrial stationary heat transfer enhancement inserts and illustrates how a heat transfer enhancement insert can improve the heat transfer in buoyancy driven compressible flows. Using different measuring tools, thermal performance of two different inserts (twisted and helix) are studied. It is shown that the helix design leads to a higher rate of heat transfer, while causes a lower pressure drop in the flowfield, suggesting the insert effectiveness is higher for the helix design, compared to a twisted plate.
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Doerffer, S. S., D. C. Groeneveld, K. F. Rudzinski, I. L. Pioro, and J. W. Martin. "Some Aspects of Critical-Heat-Flux Enhancement in Tubes." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1518.
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Abstract This paper summarizes the effects of various types or numbers of critical-heat-flux (CHF)-enhancing inserts in tubular geometries. The impact of inserts on CHF is frequently expressed by an enhancement ratio K: the ratio of CHF with an insert to the CHF in a bare tube for the same local flow conditions. The impact on K of the following parameters was investigated: (i) fluid type (Freon-134a, water), (ii) axial spacing between inserts, (iii) shape of the insert, (iv) flow blockage of the insert, (v) number of similar/dissimilar insert planes upstream, and (vi) impact of flow conditions. The spacing and flow-obstruction area were found to be the major geometric factors that affected K: by decreasing the relative spacing, L/D, to 16, K can reach a value of from 2 to 3, depending on the flow-obstruction area. Among flow parameters, the critical quality, xc, usually has a strong effect on K: K can increase from a value of 1 to 3, when xc increases from 0 to 0.4 for a mass flux G ≥ 2 Mg/m2s. For G < 2 Mg/m2s, CHF enhancement can disappear or become negative (K < 1). No cumulative effect was found on K for a series of upstream insert planes. CHF enhancement does not depend on fluid type, provided that the conditions in the fluids meet the CHF fluid-to-fluid modelling requirements.
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Tanbour, Emad Y., and Ramin K. Rahmani. "Experimental Study of Natural Convection Heat Transfer in a Vertical Pipe With Stationary Inserts." In ASME 2008 Heat Transfer Summer Conference collocated with the Fluids Engineering, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/ht2008-56079.
Full textAbstract:
Enhancement of natural and forced convectional heat transfer rate has been the subject of several academic and industrial studies. Air blenders, mechanical agitators, and static mixers have been developed to increase the forced convectional heat transfer rate in compressible and incompressible flows. Stationary devices can be efficiently employed as heat transfer enhancement tool in the natural convection systems with compressible flow. Generally, a stationary heat transfer enhancement insert consists of a number of equal motionless units, placed on the inside of a pipe or channel in order to control flowing fluid streams. These devices have low maintenance and operating costs, low space requirements and no moving parts. A range of designs exist for a wide range of specific applications. The shape of the elements determines the character of the fluid motion and thus determines thermal effectiveness of the heat transfer enhancement insert. There are several key parameters that may be considered in the design procedure of a heat transfer enhancement insert, which lead to significant differences in the performance of various designs. An ideal heat transfer enhancement insert for natural conventional heat transfer of compressible flow applications provides a higher rate of heat transfer and a thermally homogenous fluid with minimized pressure drop and required space. This paper presents the outcomes of the experimental studies by the authors on two industrial stationary inserts and illustrates how a heat transfer enhancement insert can improve the heat transfer in a buoyancy driven compressible flow. Using different measuring tools, the global performance of the inserts are studied in order to choose the most effective design.
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Tanbour, Emad Y., and Ramin K. Rahmani. "Enhancement of Natural Convection Heat Transfer Rate in Internal Compressible Flows by Inserting Stationary Inserts." In ASME 2008 Heat Transfer Summer Conference collocated with the Fluids Engineering, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/ht2008-56078.
Full textAbstract:
Enhancement of the natural and forced convection heat transfer has been the subject of numerous academic and industrial studies. Air blenders, mechanical agitators, and static mixers have been developed to increase the forced convection heat transfer rate in compressible and incompressible flows. Stationary inserts can be efficiently employed as heat transfer enhancement device in the natural convection systems with compressible flow. Generally, a stationary heat transfer enhancement insert consists of a number of equal motionless units, placed on the inside of a pipe or channel in order to control flowing fluid streams. These devices have low maintenance and operating costs, low space requirements and no moving parts. A range of designs exists for a wide range of specific applications. The shape of the elements determines the character of the fluid motion and thus determines thermal effectiveness of the insert. There are several key parameters that may be considered in the design procedure of a heat transfer enhancement insert, which lead to significant differences in the performance of various designs. An ideal insert for natural conventional heat transfer of compressible flow applications provides a higher rate of heat transfer and a thermally homogenous fluid with minimized pressure drop and required space. To choose an insert for a given application or in order to design a new insert, besides experimentation, it is possible to use computational fluid dynamics (CFD) tools to study insert performance. This paper presents the outcomes of the numerical studies by the authors on an industrial stationary heat transfer enhancement insert and illustrates how a heat transfer enhancement insert can improve the heat transfer in a buoyancy driven compressible flow. The numerical predictions were validated using experimental data. Using different measuring tools, the global performance of the insert and the impact of the geometrical parameters are studied in order to choose the most effective design for a given application.
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Osaki, Toru, and Hiroshi Matsuzawa. "Reconstitution of V-Notched Charpy Impact Specimen Made of Short Insert." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93031.
Full textAbstract:
Reconstitution in this paper means to constitute the original size V-notched Charpy impact specimen, which is made of the irradiated insert cut out from broken piece and un-irradiated tabs welded to the insert. It is a promising technique to secure an adequate number of surveillance specimens for long-term operation of nuclear power plants. Every Japanese nuclear power plant has its own surveillance test program, and is operated considering its unique surveillance test results along with the general reduction tendency of fracture toughness. This practice should be continued and enhanced if possible, after the full use of originally installed specimens, because its fracture toughness is lower than before. Reconstitution of V-notched Charpy impact specimens to the original shape by using a short insert was studied. Charpy absorption energy is generally shifted by reconstitution, if the insert length is as short as 10 mm. Reconstitution with a short insert is necessary when the transverse property of the original specimen is required although only the longitudinal surveillance specimen is installed as in some early constructed reactor pressure vessels in Japan. This case is important when the reactor pressure vessel is suspected to be a so-called low upper shelf toughness reactor pressure vessel. The minimum required insert length to avoid affect on the specimen properties depends on the Charpy absorption energy of the insert and reconstitution weld condition. Correlation between Charpy absorption energy and plastic deformation size, and short time annealing properties of irradiated pressure vessel steels were investigated. A method to evaluate the minimum required insert length was proposed, which depends on the expected Charpy absorption energy and thermal transient during reconstitution. It was demonstrated that the reconstituted specimens of 10 mm-long irradiated inserts, whose upper shelf absorption energy was 69J and required insert length was 9.5mm, showed little shift of upper shelf absorption energy.
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Nandikolla, Vidya K., Marco P. Schoen, and Ajay Mahajan. "Active Foot Pressure Control for Diabetic Patients." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-59549.
Full textAbstract:
Foot Ulcer in diabetic patients is a serious medical problem. A major contributor for the development of diabetic foot ulcers is a high, localized plantar foot pressure. It is believed that in diabetes the nerves in the extreme parts of the human body are damaged and cause deregulated blood flow, which may cause an insufficient blood supply. This can lead to a loss of feeling, change in shape of the feet, necrosis and ulcerations, and ultimately to partial or total amputation of the body part. The loss of feeling in the feet results in a loss of feedback to control the foot pressure distribution. It is proposed that high foot pressure concentration can be avoided by using an active, intelligent shoe insert, which is based on the mechanics of smart materials. This paper investigates the controls schemes necessary to accomplish an external foot pressure distribution scheme for preventing ulcerations or the progression of existing ulcers. A simple mathematical model of the shoe insert is developed. Foot pressure distributions for healthy subjects are used as a basis to control elevated foot pressures by changing the shape of the shoe insert. The optimal shape of the shoe insert with regard to the existing pressure distribution is computed. The optimal shape is implemented using different control schemes. The performance and the efficiency of the proposed control schemes are compared and analyzed. The main advantage of the proposed active shoe insert is its capability to sense the pressure peaks, change the pressure distribution, and provide stimuli for increased blood flow in the diabetic feet. [1,2,3]
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Tabesh, Maiid, and Mohammad Elahinia. "Primary Design of a Shape Memory Alloy Expandable Insert to Enhance Pedicle Screw Performance." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-206357.
Full textAbstract:
Shape Memory Alloys, such as Nickel Titanium, undergo a phase transformation in their crystalline structure when transformed from Austenite into Martensite. This inherent phase transformation is the basis for the unique properties of shape memory and superelasticity. Shape memory is attributed to the recovery of large mechanically induced deformations upon raising the temperature upto a specific level (Af). The superelasticity is the ability of the material, at a temperature above Austenite start Af, to recover mechanical deformations upon unloading. Thanks to superelasticity, shape memory effect, high damping capacity, corrosion resistance and biocompatibility, NiTi SMA alloys gain researchers attention for implementation in biomedical fields for the past 40 years [1].
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Shull, Gabriella, Jay Jia Hu, Justin Buschnyj, Henry Koon, Julianna Abel, and Suhasa B. Kodandaramaiah. "Shape Memory Alloy Actuatable Woven Neural Probes." In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-8169.
Full textAbstract:
The ability to sense neural activity using electrodes has allowed scientists to use this information to temporarily restore movement in paralyzed individuals using brain-computer interfaces (BCI). However, current electrodes do not provide chronic recording of the brain due to the inflammatory response of the immune system caused by the large (∼ 20–80 μm) size of the shanks, and the mechanical mismatch of the shanks relative to the brain. Electrode designs are evolving to use small (< 15 μm) flexible neural probes to minimize inflammatory responses and enable chronic use. However, their flexibility limits the scalability — it is challenging to assemble 3D arrays of such electrodes, to insert the arrays of flexible neural probes into the brain without buckling, and to uniformly distribute them into large areas of the brain. Thus, we created Shape Memory Alloy (SMA) actuated Woven Neural Probes (WNPs). A linear array of 32 flexible insulated microwires were interwoven with SMA wires resulting in an ordered array of parallel electrodes. SMA WNPs were shaped to an initial constricted profile for reliable insertion into a tissue phantom. Following insertion, the SMA wires were used as actuators to unravel the constricted WNP to distribute electrodes across large volumes. We demonstrated that the WNPs could be inserted into the brain without buckling and record neural activity. In separate experiments, we showed that the SMA could mechanically distribute the WNPs via thermally induced actuation. This work thus highlights the potential of actuatable WNPs to be used as a platform for neural recording.
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Kazakov, Kirill. "ON THE INTERACTION OF A VISCOELASTIC CYLINDRICAL PIPE WITH INNER UNIFORM COATING AND INSERTS WITH A COMPLEX PROFILE." In PROBLEMS OF APPLIED MECHANICS. Bryansk State Technical University, 2020. http://dx.doi.org/10.30987/conferencearticle_5fd1ed03c43727.62383321.
Full textAbstract:
This work is devoted to the formulation and construction of an analytical solution to the problem of contact between a cylindrical viscoelastic aging pipe with an internal thin coating and an insert having a complex shape placed inside the pipe with an interference fit. In practice, the presence of such coatings is required, for example, to protect the main structure from aggressive external or internal environments, for its electrical insulation, etc. The manufacturing process of the inner coating determines its possible heterogeneity (dependence of properties on coordinates). An insert placed inside a pipe can have a complex profile that has a rapidly changing function. Taking these features into account is important when analyzing the stress-strain state of pipes with an internal coating. Using an approach based on the use of special basis functions and the type of solution, a representation for the contact stresses in the pipe in the region of the rigid insert is obtained. This approach makes it possible to distinguish functions that describe the properties of the inner coating and the shape of the outer profile of the insert in the form of separate terms and factors in the expression for the contact stresses in the insert region. Therefore, in order to achieve high accuracy when carrying out calculations, it is sufficient to restrict ourselves to a relatively small number of terms
Reports on the topic "Insert shape"
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Hartman-Glaser, Barney, Hanno Lustig, and Mindy Xiaolan. Capital Share Dynamics When Firms Insure Workers. Cambridge, MA: National Bureau of Economic Research, September 2016. http://dx.doi.org/10.3386/w22651.
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Williams, D., and W. Maxey. NR198506 Evaluation of an X70 Low-Carbon Bainitic-Steel Pipe. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), October 1985. http://dx.doi.org/10.55274/r0011411.
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A 24-inch-diameter x 0.75-inch-wall X70 low-carbon bainitic-steel pipe was evaluated to obtain an independent measurement of pipe properties and to examine metallurgical characteristics that may affect behavior in gas-transmission service. The steel from which the pipe was produced was processed using advanced steelmaking methods to insure cleanliness but apparently was not treated for sulfide shape control since no sour gas exposure in service was anticipated. Primary microalloying additions in this high manganese steel, other than columbium, were titanium and boron. Titanium was added to form a TiN dispersion during continuous casting to aid in the control of austenite grain size during slab rolling. Boron was added to suppress the transformation of austenite to ferrite or pearlite during and following controlled rolling, so as to promote formation of bainite. Heavy controlled rolling at temperatures below the austenite recrystallization temperature, and finish rolling at temperatures perhaps as low as 1290 F were used to develop a very fine grain size in the bainite.
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Brice, Jeremy. Investment, power and protein in sub-Saharan Africa. Edited by Tara Garnett. TABLE, October 2022. http://dx.doi.org/10.56661/d8817170.
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The place of protein in sub-Saharan Africa’s food system is changing rapidly, raising complex international development, global health and environmental sustainability issues. Despite substantial growth in the region’s livestock agriculture sector, protein consumption per capita remains low, and high levels of undernourishment persist. Meanwhile sub-Saharan Africa’s population is growing and urbanising rapidly, creating expectations that demand for protein will increase rapidly over the coming decades and triggering calls for further investment in the expansion and intensification of the region’s meat and dairy sector. However, growing disquiet over the environmental impacts of further expansion in livestock numbers, and growing sales of alternative protein products in the Global North, has raised questions about the future place of plant-based, insect and lab-grown proteins in African diets and food systems. This report examines financial investment in protein production in sub-Saharan Africa. It begins from the position that investors play an important role in shaping the development of diets and food systems because they are able to mobilise the financial resources required to develop new protein products, infrastructures and value chains, or to prevent their development by withholding investment. It therefore investigates which actors are financing the production in sub-Saharan Africa of: a) animal proteins such as meat, fish, eggs and dairy products; b) ‘protein crops’ such as beans, pulses and legumes; and c) processed ‘alternative proteins’ derived from plants, insects, microbes or animal cells grown in a tissue culture. Through analysing investment by state, philanthropic and private sector organisations – as well as multilateral financial institutions such as development banks – it aims to establish which protein sources and stages of the value chain are financed by different groups of investors and to explore the values and goals which shape their investment decisions. To this end, the report examines four questions: 1. Who is currently investing in protein production in sub-Saharan Africa? 2. What goals do these investors aim to achieve (or what sort of future do they seek to bring about) through making these investments? 3. Which protein sources and protein production systems do they finance? 4. What theory of change links their investment strategy to these goals? In addressing these questions, this report explores what sorts of protein production and provisioning systems different investor groups might be helping to bring into being in sub-Saharan Africa. It also considers what alternative possibilities might be marginalised due to a lack of investment. It thus seeks to understand whose priorities, preferences and visions for the future of food might be informing the changing place of protein in the region’s diets, economies and food systems.
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Zhao, George, Grang Mei, Bulent Ayhan, Chiman Kwan, and Venu Varma. DTRS57-04-C-10053 Wave Electromagnetic Acoustic Transducer for ILI of Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2005. http://dx.doi.org/10.55274/r0012049.
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In this project, Intelligent Automation, Incorporated (IAI) and Oak Ridge National Lab (ORNL) propose a novel and integrated approach to inspect the mechanical dents and metal loss in pipelines. It combines the state-of-the-art SH wave Electromagnetic Acoustic Transducer (EMAT) technique, through detailed numerical modeling, data collection instrumentation, and advanced signal processing and pattern classifications, to detect and characterize mechanical defects in the underground pipeline transportation infrastructures. The technique has four components: (1) thorough guided wave modal analysis, (2) recently developed three-dimensional (3-D) Boundary Element Method (BEM) for best operational condition selection and defect feature extraction, (3) ultrasonic Shear Horizontal (SH) waves EMAT sensor design and data collection, and (4) advanced signal processing algorithm like a nonlinear split-spectrum filter, Principal Component Analysis (PCA) and Discriminant Analysis (DA) for signal-to-noise-ratio enhancement, crack signature extraction, and pattern classification. This technology not only can effectively address the problems with the existing methods, i.e., to detect the mechanical dents and metal loss in the pipelines consistently and reliably but also it is able to determine the defect shape and size to a certain extent.
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Asenath-Smith, Emily, Emily Jeng, Emma Ambrogi, Garrett Hoch, and Jason Olivier. Investigations into the ice crystallization and freezing properties of the antifreeze protein ApAFP752. Engineer Research and Development Center (U.S.), September 2022. http://dx.doi.org/10.21079/11681/45620.
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Antifreeze proteins (AFPs) allow biological organisms, including insects, fish, and plants, to survive in freezing temperatures. While in solution, AFPs impart cryoprotection by creating a thermal hysteresis (TH), imparting ice recrystallization inhibition (IRI), and providing dynamic ice shaping (DIS). To leverage these ice-modulating effects of AFPs in other scenarios, a range of icing assays were performed with AFPs to investigate how AFPs interact with ice formation when tethered to a surface. In this work, we studied ApAFP752, an AFP from the beetle Anatolica polita, and first investigated whether removing the fusion protein attached during protein expression would result in a difference in freezing behavior. We performed optical microscopy to examine ice-crystal shape, micro-structure, and the recrystallization behavior of frozen droplets of AFP solutions. We developed a surface chemistry approach to tether these proteins to glass surfaces and conducted droplet-freezing experiments to probe the interactions of these proteins with ice formed on those surfaces. In solution, ApAFP752 did not show any DIS or TH, but it did show IRI capabilities. In surface studies, the freezing of AFP droplets on clean glass surfaces showed no dependence on concentration, and the results from freezing water droplets on AFP-decorated surfaces were inconclusive.
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Quarry, Mike. PR-462-143703-R01 Development and Evaluation of Guided Wave Structural Health Monitoring for Buried Pipe. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), May 2019. http://dx.doi.org/10.55274/r0011594.
Full textAbstract:
Excavations to inspect buried piping are often costly and risk damaging other plant assets during the digging. Some utilities have used permanently installed guided wave sensors to monitor piping condition and reduce the excavations. The project that is the subject of this report has two objectives-to evaluate the current state-of-the-art and to create a test bed for vendors to improve their technology and data analysis algorithms. Understanding the state-of-the-art will enable utilities to effectively use guided wave structural health monitoring in support of their underground piping aging management plans and their license renewal activities. Guided wave effectiveness in buried pipe applications depends on many variables, including coating, backfill, temperature, soil moisture, and environmental noise. An important aspect of monitoring is the effectiveness of data analysis algorithms in distinguishing changes in data due to damage to the pipe wall from those resulting from the environment. A buried mockup was constructed with common coatings and backfills, and two vendors installed commercially available guided wave systems. An initial flaw set was initiated in the mockup. Then, about every three months, holes were dug to modify some existing flaws, initiate new flaws, and leave some unchanged. Data were collected over a timeframe that included all four seasons. Damage was generally initiated with grinding tools to produce irregular shapes and sizes and to simulate corrosion. Flaws were characterized with a structured white light camera technology. Flaw information was kept confidential from the vendors until all data were complete and vendors had provided their assessment of the mockup at each stage. After the results were reviewed with the vendors, the flaw information at each stage was provided to the vendors for continued development of their technology. This enables the vendors to conduct lessons learned and improve their procedures, data analysis algorithms, and hardware designs. Utility operators can use the results of this report to better apply guided wave structural health monitoring technology. Benefits will also result from lessons learned and improvements by vendors. It is better for vendors to learn about needed improvements and data analysis through a test bed than to find them out in the field. The buried pipe mockup also provides a potential test bed for future studies and evaluations of structural health monitoring technologies or in-line pipe devices.
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Jones, David, Roy Cook, John Sovell, Matt Ley, Hannah Shepler, David Weinzimmer, and Carlos Linares. Natural resource condition assessment: Lincoln Boyhood National Memorial. National Park Service, 2024. http://dx.doi.org/10.36967/2301822.
Full textAbstract:
The National Park Service (NPS) Natural Resource Condition Assessment (NRCA) Program administered by the NPS Water Resources Division evaluates current conditions for important natural resources and resource indicators using primarily existing information and data. NRCAs also report on trends in resource condition, when possible, identify critical data gaps, and characterize a general level of confidence for study findings. This NRCA complements previous scientific endeavors, is multi-disciplinary in scope, employs a hierarchical indicator framework, identifies and develops reference conditions/values for comparison against current conditions, and emphasizes spatial evaluation of conditions where possible. Lincoln Boyhood National Memorial (LIBO) was authorized by an act of Congress on February 19, 1962, (Public Law 87-407) to preserve the site associated with the boyhood and family of President Abraham Lincoln, including a portion of the original Tom Lincoln farm and the nearby gravesite of Nancy Hanks Lincoln. The 200-acre memorial commemorates the pioneer farm where Abraham Lincoln lived from the age of 7 to 21. The NRCA for LIBO employed a scoping process involving Colorado State University, LIBO and other NPS staffs to establish the NRCA framework, identify important park resources, and gather existing information and data. Indicators and measures for each resource were then identified and evaluated. Data and information were analyzed and synthesized to provide summaries and address condition, trend and confidence using a standardized but flexible framework. A total of nine focal resources were examined: four addressing system and human dimensions, one addressing chemical and physical attributes, and four addressing biological attributes. The quality and currentness of data used for the evaluation varied by resource. Landscape context ? system and human dimensions included land cover and land use, natural night skies, soundscape, and climate change. Climate change and land cover/land use were not assigned a condition or trend?they provide important context to the memorial and many natural resources and can be stressors. Some of the land cover and land use-related stressors at LIBO and in the larger region are related to the development of rural land and increases in population/housing over time. The trend in land development, coupled with the lack of significantly sized and linked protected areas, presents significant challenges to the conservation of natural resources of LIBO to also include natural night skies, natural sounds and scenery. Climate change is happening and is affecting resources, but is not considered good or bad per se. The information synthesized in that section is useful in examining potential trends in the vulnerability of sensitive resources and broad habitat types such as forests. Night skies and soundscapes, significantly altered by disturbance due to traffic, development and urbanization, warrant significant and moderate concern, respectively, and appear to be in decline. Air quality was the sole resource supporting chemical and physical environment at the memorial. The condition of air quality can affect human dimensions of the park such as visibility and scenery as well as biological components such as the effect of ozone levels on vegetation health. Air quality warrants significant concern and is largely impacted by historical and current land uses outside the memorial boundary. The floral biological component was examined by assessing native species composition, Mean Coefficient of Conservation, Floristic Quality Assessment Index, invasive exotic plants, forest pests and disease, and forest vulnerability to climate change. Vegetation resources at LIBO have been influenced by historical land uses that have changed the species composition and age structure of these communities. Although large tracts of forests can be found surrounding the park, the majority of forested areas are fragmented, and few areas within and around LIBO exhibit late-successional or old-growth characteristics. Vegetation communities at LIBO have a long history of being impacted by a variety of stressors and threats including noxious and invasive weeds, diseases and insect pests; compounding effects of climate change, air pollution, acid rain/atmospheric chemistry, and past land uses; and impacts associated with overabundant white-tail deer populations. These stressors and threats have collectively shaped and continue to impact plant community condition and ecological succession. The sole metric in good condition was native species composition, while all other indicators and metrics warranted either moderate or significant concern. The faunal biological components examined included birds, herptiles, and mammals. Birds (unchanging trend) and herptiles (no trend determined) warrant moderate concern, while mammal populations warrant significant concern (no trend determined). The confidence of both herptiles and mammals was low due to length of time since data were last collected. Current forest structure within and surrounding LIBO generally reflects the historical overstory composition but changes in the hardwood forest at LIBO and the surrounding area have resulted in declines in the avian fauna of the region since the 1970s. The decline in woodland bird populations has been caused by multiple factors including the conversion of hardwood forest to other land cover types, habitat fragmentation, and increasing human population growth. The identification of data gaps during the course of the assessment is an important NRCA outcome. Resource-specific details are presented in each resource section. In some cases, significant data gaps contributed to the resource not being evaluated or low confidence in the condition or trend being assigned to a resource. Primary data gaps and uncertainties encountered were lack of recent survey data, uncertainties regarding reference conditions, availability of consistent long-term data, and the need for more robust or sensitive sampling designs. Impacts associated with development outside the park will continue to stress some resources. Regionally, the direct and indirect effects of climate change are likely but specific outcomes are uncertain. Nonetheless, within the past several decades, some progress has been made toward restoring the quality of natural resources within the park, most notably the forested environments. Regional and park-specific mitigation and adaptation strategies are needed to maintain or improve the condition of some resources over time. Success will require acknowledging a ?dynamic change context? that manages widespread and volatile problems while confronting uncertainties, managing natural and cultural resources simultaneously and interdependently, developing disciplinary and interdisciplinary knowledge, and establishing connectivity across broad landscapes beyond park borders.