Academic literature on the topic 'Indented Head'
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Journal articles on the topic "Indented Head"
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Ebsary, B. A. "Ceramotylenchus tesselatus n. gen., n. sp. and Pleurotylenchus minor n. sp. (Nematoda: Tylenchida) from Alabama." Canadian Journal of Zoology 64, no. 1 (January 1, 1986): 238–42. http://dx.doi.org/10.1139/z86-037.
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A new genus and species of Duosulciinae and a new species of Pleurotylenchus are described and illustrated. Ceramotylenchus tesselatus n. gen., n. sp. is distinguished by having a cuplike oral disc, two crenate lateral incisures, absence of lateral vulval flaps, and alternating rows of blocks on the head and body that gives a tilelike appearance. Pleurotylenchus minor n. sp. is distinguished from P. sachsi by a smaller body size, more posterior vulva, shorter stylet, laterally indented head annules, and by the lateral field that begins on the first body annule.
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Charchar, João, Maria Jose Charchar, Jonathan Eisenback, and Maria Esther Boiteux. "Meloidogyne pisi n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitising pea in Brazil." Nematology 10, no. 4 (2008): 479–93. http://dx.doi.org/10.1163/156854108784513905.
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AbstractMeloidogyne pisi n. sp. is described and illustrated from specimens obtained from roots of pea cv. Mikado in Brasilia, Brazil. The female perineal pattern is variable in shape, most are rounded to ovoid, whereas others have a moderately high, squarish dorsal arch, and can be marked with several striae parallel to the vulva or may be nearly free of striae. Lateral fields may contain a few irregular, wavy, transverse striae or be difficult to discern. Female medial lips are wide and long, sometimes with distinctly indented outer margins; the lateral lips are large and triangular, head annule is wide and marked by incomplete annulations and transverse folds. Stylet is 13-17 μm long with large, elongated knobs and a shaft that is cylindrical, straight and thick. Lumen lining of pharynx containing numerous rounded cuticular thickenings throughout its length; excretory pore located between base of stylet and median bulb. Males are 893-2510 μm long with a 19-26 μm long stylet bearing large elongated knobs, shaft marked with small, rounded projections. Second-stage juveniles are 374-463 μm long with medial lips often indented medially and 10-11 μm long stylet. Tail slender, 42-66 μm long with large irregular annules in posterior region, a slightly pointed tip and hyaline region 9-17 μm long. Many galls and egg masses are produced on tomato, tobacco and varieties of pea and bean. Few galls occur on watermelon and corn and reproduction is poor on pepper. No reproduction occurs on peanut, cotton or soybean.
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Folęga, Piotr. "Impact of Structural Characteristics of Flexspline on the Stresses Occurring at the Tooth Space Bottom." Advanced Materials Research 1036 (October 2014): 631–36. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.631.
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The author of the article applied the boundary element method (BEM) to determine stresses occurring in a toothed rim of a flexspline. The relevant numerical calculations were conducted using software developed at the Faculty of Transport of the Silesian University of Technology. The numerical analysis conducted for flexsplines entailed the impact exerted by parameters of an indented toothed flexspline rim (number of teeth, addendum modification coefficient) and of a gear tool (gear tool head curve radius, pressure angle) on values of the stresses occurring at the tooth space bottom. Results of the said calculations have been depicted as curves of dependences between stresses at the tooth space bottom in the function of the number of flexspline rim teeth on constant values of the addendum modification coefficient. The cumulative diagrams developed based on the results of the calculations conducted may provide guidelines as to the manner of designing flexsplines for harmonic drives.
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BRUCE, NIEL L. "A new deep-water species of Natatolana (Crustacea: Isopoda: Cirolanidae) from the Chatham Rise, eastern New Zealand." Zootaxa 265, no. 1 (August 11, 2003): 1. http://dx.doi.org/10.11646/zootaxa.265.1.1.
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Natatolana rekohu sp. nov. from the Chatham Rise, off southeastern New Zealand is described and figured. Natatolana rekohu was collected at a depth of 2799 metres, close to the greatest recorded depth for this genus. The species is a scavenger, and was feeding on dead fish in a sediment trap. Natatolana rekohu is characterised by: reduced eyes; strongly indented anterior margin of the head; pentagonal frontal lamina, with weakly convex lateral margins; pleonites 1 and 2 not produced, 3 weakly and pleonite 4 rounded; pereopods 1 and 2 usually with 5 or 6 setae on the propodal palm. In males the large flat and widely separated penes and the strongly curved, wide and terminally toothed appendix masculina are additional diagnostic characters. As in most Natatolana the numbers of robust setae on the margins of the uropodal rami and pleotelson are also important in making a correct identification.
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Taylor, Blake E. S., Irene Say, Pratit Patel, and Luke D. Tomycz. "Microsurgical Clip Ligation of an Unruptured Azygos Bifurcation Aneurysm Indented by the Falx Cerebri: 3-Dimensional Operative Video." Operative Neurosurgery 19, no. 3 (January 13, 2020): E294. http://dx.doi.org/10.1093/ons/opz393.
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Abstract Dissecting pericallosal aneurysms from the falx cerebri is technically challenging, as one must release the adherent dome but minimize shearing injury, which could result in intraoperative rupture. We discuss a 51-yr-old woman with a history of hypertension and smoking who presented with severe headaches and was found to have a 6-mm unruptured, multilobulated pericallosal aneurysm abutting the falx, with anterior and superior projecting domes on either side. She also had an azygos anterior cerebral artery (ACA), a rare anatomic variant associated with pericallosal aneurysms, where both A1 segments form a single A2. After considering endovascular and open surgical techniques, we proceeded with clip ligation given her younger age, smoking history, daughter aneurysms seen on angiography, and azygos ACA. We positioned her supine with her head turned lateral, left side down to maximize gravitational retraction, mapped a bicoronal incision, and performed a small craniotomy, followed by an interhemispheric approach. Rather than cutting the falx around the dome, a described technique that risks blind vessel injury, we temporarily clipped inflow vessels to reduce the dome's turgor and sharply and bluntly dissected apart its attachments, which freed the aneurysm from beneath the falx and allowed visualization of associated vessels. Using suction to manipulate the dome, we then placed stacked, angled clips, and used a micro-Doppler to confirm brisk inflow and outflow. Postoperatively, she was neurologically intact, and her angiogram showed no residual aneurysm. Our 3-dimensional video demonstrates a safer, alternative approach to treating this rare aneurysm with its associated anatomical variant. Patient consented to her clinical presentation and microscope media being used for academic purposes.
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Wang, Bo, Kathleen M. C. Sullivan, and Kathy Beckingham. "Drosophila Calmodulin Mutants With Specific Defects in the Musculature or in the Nervous System." Genetics 165, no. 3 (November 1, 2003): 1255–68. http://dx.doi.org/10.1093/genetics/165.3.1255.
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Abstract We have studied lethal mutations in the single calmodulin gene (Cam) of Drosophila to gain insight into the in vivo functions of this important calcium sensor. As a result of maternal calmodulin (CaM) in the mature egg, lethality is delayed until the postembryonic stages. Prior to death in the first larval instar, Cam nulls show a striking behavioral abnormality (spontaneous backward movement) whereas a mutation, Cam7, that results in a single amino acid change (V91G) produces a very different phenotype: short indented pupal cases and pupal death with head eversion defects. We show here that the null behavioral phenotype originates in the nervous system and involves a CaM function that requires calcium binding to all four sites of the protein. Further, backward movement can be induced in hypomorphic mutants by exposure to high light levels. In contrast, the V91G mutation specifically affects the musculature and causes abnormal calcium release in response to depolarization of the muscles. Genetic interaction studies suggest that failed regulation of the muscle calcium release channel, the ryanodine receptor, is the major defect underlying the Cam7 phenotype.
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Castillo, Pablo, Alberto Troccoli, and Nicola Vovlas. "Hemicriconemoides macrodorus n. sp. with observations on two other species of the genus (Nematoda: Criconematidae)." Nematology 2, no. 4 (2000): 395–405. http://dx.doi.org/10.1163/156854100509259.
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AbstractHemicriconemoides macrodorus n. sp. is described and illustrated from a bisexual population collected in a natural habitat at Santa Elena, Jaén, southern Spain. The new species falls into the 'group 2', based on lip patterns (Decraemer & Geraert, 1992), which contains 13 other species characterised by a cephalic region with an offset, raised, narrower oral disc, followed by broader head annuli. The main distinctive characters of the new species are: lip region truncate, very long stylet (90-100 μ m), long body 548-750 μ m, R = 127-148, conical tail, VL/VB = 1.0-1.5, spined juvenile cuticular ornamentation (multispined scales, indented at their edges) arranged in ten alternate rows, and male lateral field with four incisures. Morphometric data, illustrations and brief descriptions are presented for an Italian population of H. ortonwilliamsi Ye & Siddiqi, 1994, while, for the first time, morphometric data and illustrations are given for the male and the juvenile of H. alexis Vovlas, 1980. Hemicriconemoides macrodorus n. sp. et observations sur deux autres espèces du genre (Nematoda: Criconematidae) - Hemicriconemoides macrodorus n. sp. est décrit et figuré d'une population bisexuelle collectée dans un habitat naturel à Santa Elena, Jaén, le Sud d'Espagne. La nouvelle espèce appartient au ''groupe 2'' sur la base de la morphologie labiale (Decraemer & Geraert, 1992), groupe comptant 13 autres espèces caractérisées par une région céphalique avec un disque labial séparé du reste du corps, proéminent et rétréci, suivi des anneaux céphaliques plus larges. Les principaux caractères distinctifs de la nouvelle espèce sont: région labiale tronquée, très long stylet (90-100 μ m), corps long 548-750 μ m, R = 127-148, queue conique, VL/VB = 1.0- 1.5, ornementations cuticulaires des juvéniles avec épines (écailles avec plusieurs épines, indentées sur les côtés) arrangées en dix rangées alternées, et champ latéral du mâle comportant quatre incisures. Des données morphométriques, des illustrations et de brèves descriptions sont présentées pour une population italienne de H. ortonwilliamsi Ye & Siddiqi, 1994, alors que, pour la première fois, des données morphométriques et des illustrations sont produites pour le mâle et les juvéniles de H. alexis Vovlas, 1980.
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Putra, I. B. Werdi, Yohanes Setiyo, and I. Gusti Ngurah Apriadi Aviantara. "Kajian Kualitas Beras Sosoh Dari Berbagai Macam Ukuran Daya Mesin Penggiling." Jurnal BETA (Biosistem dan Teknik Pertanian) 8, no. 1 (September 3, 2019): 130. http://dx.doi.org/10.24843/jbeta.2020.v08.i01.p16.
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Rice is a staple food for the people of Indonesia. Even though Indonesia is an agrarian country, Indonesia currently imports rice. In producing rice from rice there are obstacles. One of the main obstacles is post-harvest handling of rice with high yield loss during post-harvest. The amount of post-harvest loss occurs because most farmers still use traditional methods or the handling is not good and right. The purpose of this study was to determine the relationship between the capacity of the grinding machine and the quality of sosoh rice produced by the mill and to know the quality comparison of various types of grinding machine capacity. The research was carried out in the area of ??Wanasari Village, Tabanan-Bali to find out the quality of sosoh rice in the region. Head Rice is broken rice grains, both healthy and defective, which have a size greater than or equal to 6/10 part of the average length size of whole rice grains that can pass through the surface of the indented plate basin with a requirement of 4.2 mm hole size. Rice husk is a protective cover from rice grains which is separated from seeds during the grinding process. In the grinding process, there is rice which remains the husk which is caused by the power / rpm of the grinding machine which is too low because the friction force produced by the engine is not sufficient for the overall release of rice husk
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Gao, Jinling, Nesredin Kedir, Boon Him Lim, Yizhou Nie, Xuedong Zhai, and Weinong Chen. "Transverse Loading on Single High-Performance Fibers by Round-Head Indenters and the Fibers’ Failure Visualization." Fibers 10, no. 6 (May 30, 2022): 48. http://dx.doi.org/10.3390/fib10060048.
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High-performance fibers are well-known for their high stiffness and strength under axial tension. However, in their many applications as critical components of textiles and composites, transverse loads widely exist in their normal service life. In this study, we modified a micro material testing system to transverse load single fibers using round-head indenters. By integrating the loading platform with the Scanning Electron Microscopy (SEM) operating at a low-vacuum mode, we visualized the failure processes of fibers without conductive coatings. Post-fracture analysis was conducted to provide complementary information about the fibers’ failure. The energy dissipation was compared with the axial tensile experiments. Three inorganic and two organic fibers were investigated, namely carbon nanotube, ceramic, glass, aramid, and ultrahigh molecule weight polyethylene fibers. Different failure characteristics were reported. It is revealed that the organic fibers had higher energy dissipation than the inorganic fibers under the transverse loading by the round-head indenters. The fiber’s energy dissipation under transverse loading was no more than 17.9% of that subjected to axial tension. Such a reduced energy dissipation is believed to be due to the stress concentration under the indenter. It is suggested that the fiber’s material constituent, structural characteristics, and stress concentration under the indenter should be considered in the fiber model for textiles and composites.
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Javaheri, Ehsan, Verdiana Kumala, Alireza Javaheri, Reza Rawassizadeh, Janot Lubritz, Benjamin Graf, and Michael Rethmeier. "Quantifying Mechanical Properties of Automotive Steels with Deep Learning Based Computer Vision Algorithms." Metals 10, no. 2 (January 22, 2020): 163. http://dx.doi.org/10.3390/met10020163.
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This paper demonstrates that the instrumented indentation test (IIT), together with a trained artificial neural network (ANN), has the capability to characterize the mechanical properties of the local parts of a welded steel structure such as a weld nugget or heat affected zone. Aside from force-indentation depth curves generated from the IIT, the profile of the indented surface deformed after the indentation test also has a strong correlation with the materials’ plastic behavior. The profile of the indented surface was used as the training dataset to design an ANN to determine the material parameters of the welded zones. The deformation of the indented surface in three dimensions shown in images were analyzed with the computer vision algorithms and the obtained data were employed to train the ANN for the characterization of the mechanical properties. Moreover, this method was applied to the images taken with a simple light microscope from the surface of a specimen. Therefore, it is possible to quantify the mechanical properties of the automotive steels with the four independent methods: (1) force-indentation depth curve; (2) profile of the indented surface; (3) analyzing of the 3D-measurement image; and (4) evaluation of the images taken by a simple light microscope. The results show that there is a very good agreement between the material parameters obtained from the trained ANN and the experimental uniaxial tensile test. The results present that the mechanical properties of an unknown steel can be determined by only analyzing the images taken from its surface after pushing a simple indenter into its surface.
Dissertations / Theses on the topic "Indented Head"
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Булик, Михайло Олегович. "Контрольно-вимірювальна система для випробувань твердості компонентів медичних приладів." Master's thesis, КПІ ім. Ігоря Сікорського, 2019. https://ela.kpi.ua/handle/123456789/30656.
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Магістерська дисертація має аналітичну та дослідну частини. В даній роботі було розглянуто і розроблено технічну документацію та створено дослідну модель автоматизованого приладу вимірювання твердості деталей, який має назву “Мікротвердомір М20-2”. Призначення автоматизованого приладу є вимірювання твердості деталей медичних приладів та систем із різних матеріалів. Та проведено лабораторні дослідження.The master's dissertation has analytical and research parts. In this work, the technical documentation was considered and developed and a pilot model of an automated instrument for measuring the hardness of parts, called "Microhardness meter M20-2", was created. The purpose of an automated device is to measure the hardness of parts of medical devices and systems made of different materials. Yes, laboratory tests were carried out.
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Amerena, Massimo. "Something before, that still remains: experiential treaty-making on Kulin Country." Thesis, 2020. https://vuir.vu.edu.au/42145/.
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Narrm, later named Port Phillip Bay by colonisers, shapes Aboriginal politics. This thesis is a place-based
examination of the forms of treaty-making practised around Narrm. It aims to deepen the understandings of
settler-Australians and historians of the political sophistication of the Kulin federation, a group of allied
Aboriginal nations whose Country covers what is now central Victoria, Australia. Drawing on Aboriginal oral
histories and colonial primary sources, as well as anthropological and archaeological scholarship, I use
knowledge of Kulin culture and philosophy to explore, imagine, and decolonise the history of their politics from
14,000 years ago to the end of 1835. The forms of treaty explored in this thesis have been continuously practised
for thousands of generations and exist within, and as an expression of, Kulin law. This thesis is divided into two
parts, each consisting of two chapters. Part I examines the Kulin’s pre-colonial traditions of treaty-making,
showing political relations were performed with Country, the non-human world and humans. Part II builds on
this and shows that when encountering settlers in 1835 the bayside Kulin continued, and evolved, their treatymaking traditions.
To describe these forms of Kulin political agreement-making, highlight Kulin agency and the political role of
women, I introduce the term experiential treaties. An experiential treaty exists within the Indigenous oral
tradition and is a political accord between a sovereign Aboriginal group and another party, be they a
neighbouring Aboriginal clan, a refugee, a group of settlers as guests, or the non-human world of Country and
animals. Exploring the Kulin world through experiential treaties centres Aboriginal political agency and selfdetermination. It is important to highlight that the practice of treaty-making does not have to include the modern
or colonial settler-state. Experiential treaties are characterised by reciprocity and repetition, as they require
iterative renewal through personal interactions between host and guest.
With an imaginative approach based on Greg Dening’s historical methodology, I explore experiential treatymaking on Kulin country to decolonise Victorian history and highlight the silences and absences within current
revisionist historiography of 1835. Rather than analyse the founding of Melbourne, I turn to the underresearched and unacknowledged political agency of the Waddawurrung living around present-day Geelong.
Through exploring interactions with John Batman and his crew, I examine the exclusion of women from the
narrative of 1835. Re-interpreting the political relations between the Waddawurrung and settlers camped at
Indented Head shows that Kulin political traditions were continued, not disrupted, through what I term the
Geelong Treaty based on the principle of iterative renewal and reciprocity.
This thesis has significance in expanding the narrative of 1835 to include Kulin women and the Waddawurrung,
but it also gives new depth to understandings of modern treaty-making and Indigenous activism in Victoria. As
Wiradjuri legal scholar Mark McMillan states on the history and custom of Indigenous treaty-making: “There
was something before, that still remains”.
Key Words: treaty-making, Geelong Treaty, Kulin Treaty, Batman Treaty, Aboriginal treaties, decolonisation,
Victorian colonisation, experiential treaties, Indigenous sovereignty, settler-colonialism, Kulin agency,
Waddawurrung (Waddawurrung, Wathawurrung), Narrm (Port Phillip Bay), Beangala, Indented Head, William
Buckley, cross-cultural lawful relations, environmental history, the Yarra camp.
Books on the topic "Indented Head"
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Waters, Kristin. Maria W. Stewart and the Roots of Black Political Thought. University Press of Mississippi, 2021. http://dx.doi.org/10.14325/mississippi/9781496836748.001.0001.
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In 1833 Maria W. Stewart told a gathering at the African Masonic Hall on Boston’s Beacon Hill, “African rights and liberty is a subject that ought to fire the breast of every free man of color in these United States.” She held that the founding principles of the United States must extend to all people, otherwise they are merely the hypocritical expression of an ungodly white power. This first-ever biography of a profoundly significant writer explores her early life as an indentured servant in Hartford, Connecticut. Later, she defied adversity, journeying to Boston where she met and married a wealthy commercial agent and former seaman and became a powerful force within the lively black community on Beacon Hill’s North Slope. Between 1831-1833 Stewart’s “intellectual productions” ranged across topics including true emancipation for African Americans, abolition, the hypocrisy of white Christianity, black liberation theology, and gender inequity. Along with David Walker’s Appeal to the Coloured Citizens of the World, (1829), her body of work constitutes a significant foundation for black radical politics.
Book chapters on the topic "Indented Head"
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"Comparison of Hardness Tests." In Principles of the Heat Treatment of Plain Carbon and Low Alloy Steels, 432. ASM International, 1996. http://dx.doi.org/10.31399/asm.tb.phtpclas.t64560432.
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Bunonyo, K. W., C. Israel-Cookey, and E. Amos. "MHD Oscillatory Flow of Jeffrey Fluid in an Indented Artery with Heat Source." In Theory and Practice of Mathematics and Computer Science Vol. 8, 133–45. Book Publisher International (a part of SCIENCEDOMAIN International), 2021. http://dx.doi.org/10.9734/bpi/tpmcs/v6/2382e.
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Lagrandeur, Kevin. "Artificial Slaves in the Renaissance and the Dangers of Independent Innovation." In AI Narratives, 95–118. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780198846666.003.0005.
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This chapter discusses how Renaissance stories of the golem of Prague, of Paracelsus’s homunculus, and of a talking brass head built by a natural philosopher in Robert Greene’s play Friar Bacon and Friar Bungay show the fears and hopes embedded in that culture’s reactions to human invention—as well as an ambivalence to the idea of slavery, for intelligent objects are almost uniformly proxies for indentured servants. Moreover, the tales examined in this chapter about artificial servants foreshadow our modern ambivalence about our innate technological abilities. The power of their technological promise is countervailed by fears that these products of our own ingenuity will overwhelm us.
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Kallel, Mouna, Amir Bahri, and Khaled Elleuch. "Investigation on the Wear Resistance of Ni-B-TiO2 Composite Coatings for Dry Crushing Application." In Handbook of Research on Tribology in Coatings and Surface Treatment, 218–44. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-9683-8.ch010.
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To achieve a more important service life of hammers, used in crushing process, a Ni-B-TiO2 composite coating was electrodeposited on heat treated AISI P20 using conventional and novel methods. The prepared coatings underwent different tribological tests to quantify the coating that offers the best resistance against wear. For this reason, abrasive wear tests such as pin-on-disk test and multi-pass scratch test were performed to evaluate the abrasive wear resistance of the coatings under a round counterbody (alumina ball) and a sharper contrerbody (sphero-conical indenter), respectively. In addition, the impact-sliding test was also performed to assess the impact resistance of the composite coatings. The obtained results showed that the novel method promotes the best mechanical and tribological properties of the elaborated Ni-B-TiO2 composite coating. This is attributed to the fact of adding TiO2 sol into Ni-B electrolyte which enhances the dispersive strength of the formed TiO2 nanoparticles, contrary to adding solid TiO2 nanoparticles into the electroplating bath.
Conference papers on the topic "Indented Head"
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Wang, Yun-Che, Jun-Liang Chen, Ming-Liang Liao, Chuan Chen, Yan-Chi Chen, and Chi-Chuan Hwang. "Stress and Temperature Analysis of the Copper Substrate Indented With Nanotubes and Nanocones." In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18379.
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It has been shown that nanotubes and nanocones are most effective to make indents with large aspect ratios. Detailed studies in the heat transfer processes under the nano-scale indentation, and the accompanying stress distributions are required much attention. In this study, the copper substrate was indented with a nanotube or nano-cone. It is found that nano-cones may make indents with larger aspect ratios than the nanotubes due to the local shell buckling. Time-domain heat transfer and stress analysis was carried out by using a control-volume technique with an atomic spatial resolution, except near the boundaries. The effect of temperatures and stresses on the changes of the microstructures of the substrate will be discussed.
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YAMAMOTO, Y. "Numerical simulation of three-dimensional hypersonic viscous flow over an indented nosetip." In 4th Thermophysics and Heat Transfer Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1986. http://dx.doi.org/10.2514/6.1986-1287.
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Liu, Jie, Walfre Franco, J. Stuart Nelson, and Guillermo Aguilar. "Cryogen Droplet Impingement Onto Indented Surfaces Relevant to Dermatologic Laser Surgery Therapies." In ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56223.
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To protect the epidermis during selected dermatological laser surgeries, Cryogen Spray Cooling (CSC) is used as an auxiliary procedure to remove the heat generated in the epidermis by laser irradiation. The impingement of cryogen droplets onto the skin determines not only the effective amount of cryogen deposited on the surface, but also the dynamic behavior of the cryogen layer that forms on the skin surface and thus, it strongly affects the heat extraction process. Recently, it has been shown that the force of the spray alters the skin surface producing an indentation that in turn affects CSC efficiency. To achieve a better understanding of cryogen spray deposition, the impingement of a single cryogen (R-134a) droplet onto indented skin phantoms was experimentally studied. We first built an experimental pressure chamber where the pressure may be raised slightly above the saturation pressure of R-134a (600 kPa), with the objective to suppress and control the rapid evaporation that cryogen droplets undergo as they are released from the nozzles into ambient pressure. This allows us to focus on individual droplet impingement. Two nozzles of different outer diameters were used to generate droplets of different outer diameters were used to generate droplets of different sizes, which fall by gravity onto various indented skin phantoms. To maintain similarity, the range of Weber (We) and Reynolds (Re) numbers measured at the point of impact for typical cryogen spurts were matched with the We and Re of the individual droplets under study. A high-speed digital camera (500 fps) recorded the droplet impingement on indented surfaces resembling in vivo skin indentation measurements. Different indentation geometries were used since studies have shown that skin deformation depends on factors such as nozzle-to-skin distance, skin type and anatomical location. Experimental results showed different droplet impingement dynamics for droplets of two different sizes but same velocity. For We = 130 and Re = 25000 the amount of cryogen left at the bottom of the indentation after two droplets impinged consecutively was equivalent to the total mass of one droplet, whereas for We = 96 and Re = 18500, the amount of cryogen left at the bottom of indentation was twice as much as that after first droplet impingement. The effect of the depth and radius of curvature of the indentations appeared to have small effect on the droplet impingement behavior, compared to that associated with the droplet size (We and Re), as confirmed by the high speed videos.
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Liu, Jie, Walfre Franco, and Guillermo Aguilar. "The Effect of Roughness on the Impact Dynamics and Heat Transfer of Cryogen Droplets Impinging Onto Indented Skin Phantoms." In ASME 2005 Summer Heat Transfer Conference collocated with the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems. ASMEDC, 2005. http://dx.doi.org/10.1115/ht2005-72584.
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Laser dermatological surgery (LDS) is the preferred therapeutic modality for various dermatoses, including port wine stain (PWS) birthmarks. LDS is commonly used in conjunction with cryogen spray cooling, which is an auxiliary procedure that pre-cools the superficial skin layer (epidermis) prior to laser irradiation to avoid non-specific and excessive epidermal heating. Clinical observations show that skin indents markedly during spray deposition due to the large momentum of cryogen droplets. Furthermore, the human skin surface is far from smooth. Therefore, with the objective to provide some insight into the interaction between cryogen sprays and the rough and deformable human skin surface, the impingement dynamics and heat transfer induced by single cryogen droplets falling on rough and indented skin phantoms are present in this paper. Epoxy skin phantoms with a constant semispherical indentation of depth and radius of 2.44 mm and 6.34 mm, respectively, were used to simulate indented skin. Each phantom had a different surface roughnesses varying from 0.5 μm to 50μm. The experiments were carried out within a pressurized chamber to control or eliminate droplet evaporation. A high-speed camera and the temperature sensors placed on the upper surface of the skin phantoms were synchronized to record the impact dynamics and temperature changes as cryogen droplets fell on them. The results show that the surface roughness affects the impact dynamics and heat transfer during single droplet impingement. As the surface roughness (Ra) increasing, the heat flux decrease.
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Sui, Yang, Hengyun Zhang, Peichao Li, and Tingyu Lin. "Design analysis of minichannel heat sink with indented fins under impingement flow condition." In 2017 18th International Conference on Electronic Packaging Technology (ICEPT). IEEE, 2017. http://dx.doi.org/10.1109/icept.2017.8046467.
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Nikbakht, Ali, Alireza Fallahi Arezoodar, Mojtaba Sadighi, and Ali Tale Zadeh Lari. "Indentation of a Functionally Graded Plate by a Rigid Spherical Indenter in the Presence of a Semi-Elliptic Surface Crack." In ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/esda2012-82714.
Full textAbstract:
Graded materials, also known as functionally graded materials (FGMs), are multiphase composites mainly composed of a ceramic and a metal; thus, they exploit the heat, oxidation and corrosion resistance typical of ceramics, and the strength, ductility and toughness typical of metals. These materials are mainly used as heat barriers. In addition, many of the present and potential applications of FGMs involve contact problems. On the other hand, the production process of FGMs is somewhat complex and leaves some defects in the produced structure. One of the most important defects in such structures is surface cracks. Here, the combination of the contact and crack problems is investigated in a functionally graded rectangular plate containing a semi–elliptic surface crack indented by a frictionless rigid spherical indenter. The plate is simply supported and the crack is located in the middle of the plate surface in the tension part. The crack surface is parallel to one of the plate edges. The gradient of mechanical properties variation is considered through the thickness of the plate and the volume fraction distribution of the constituting phases is modeled by a polynomial function and the Poisson’s ratio is kept constant. The analyzing of the problem is divided into two steps. At the first step, for an uncracked plate the equations of equilibrium are derived in terms of the displacement field and are solved numerically to find the contact rule. As the second step in studying the problem, the contact problem of a cracked plate is modeled by using ABAQUS finite element package. The aim of this step is to find the effect of the presence of the crack on the contact rule. The optimum mesh for the ABAQUS model is found by using the results of the first step. In order to do so, an ABAQUS model is created for the uncracked plate. The analytical results and the obtained results from ABAQUS for specified plate and indenter dimensions and material properties are compared. After finding the optimum mesh, a crack is added to the ABAQUS model of the plate under contact loading. The effects of gradient changes and indenter dimensions on the contact rule and stress distribution at the crack tip are then investigated by using the obtained ABAQUS model. The acquired results show that the influence of the material nonhomogeneity on the stress distribution around the crack tip and in the plate (uncracked and cracked) and contact rule can be quite significant. In general, increasing the overall volume fraction of the metal phase increases the load carrying capacity in an uncracked plate. In a cracked plate, the changes in material distribution as well as the changes of the indenter diameter does not affect the results that much.
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Lin, Yuan, and Timothy C. Ovaert. "Thermal Distortion of an Anisotropic Elastic Half-Plane and Its Application in Contact Problems Including Frictional Heating." In ASME/STLE 2004 International Joint Tribology Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/trib2004-64040.
Full textAbstract:
The thermal surface distortion of an anisotropic elastic half-plane is studied using the extended version of Stroh’s formalism. In general, the curvature of the surface depends both on the local heat flux into the half-plane and the local temperature variation along the surface. However, if the material is orthotropic, the curvature of the surface depends only on the local heat flux into the half-plane. As a direct application, the two-dimensional thermoelastic contact problem of an indenter sliding against an orthotropic half-plane is considered. Two cases, where the indenter has either a flat or a parabolic profile, are studied in detail. Comparisons with other available results in the literature show that the present method is correct and accurate.
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Jeong, D. Y. "Probabilistic Approach to Conditional Probability of Release of Hazardous Materials From Railroad Tank Cars During Accidents." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10872.
Full textAbstract:
This paper describes a probabilistic approach to estimate the conditional probability of release of hazardous materials from railroad tank cars during train accidents. Monte Carlo methods are used in developing a probabilistic model to simulate head impacts. The model is based on the physics of impact in conjunction with assumptions regarding the probability distribution functions of the various factors that affect the loss of lading. These factors include impact velocity, indenter size, tank material, tank diameter, effective collision mass, and tank thickness. Moreover, each factor is treated as a random variable characterized by its assumed distribution function, mean value, and standard deviation (or variance). Reverse engineering is performed to back-calculate the mean values and standard deviations of these random variables that reproduce trends observed in available accident data. The calibrated model is then used to conduct a probabilistic sensitivity analysis to examine the relative effect of these factors on the conditional probability of release. Results from the probabilistic sensitivity analysis indicate that the most significant factors that affect conditional probability of release are impact velocity, effective collision mass, and indenter size.
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Raju, Hermise, and Assimina A. Pelegri. "Experimental Investigation of Transverse Mechanical Properties of High-Performance Kevlar KM2 Single Fiber." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71724.
Full textAbstract:
Transverse nanoindentation modulus of high performance Kevlar KM2 single fibers are experimentally studied using a nanoindenter. Researchers have investigated the transverse compression behavior of these fibers using flat punch indentation heads, in which the curved circular transverse shape of the fiber is not included, and consecutively fit the data into the analytical models to calculate their mechanical properties. During this process, the force is normalized to a point on the transverse fiber surface and the analytical model assumes a flat semi-infinite plate for substrate. Other studies consider embedding the fibers on a substrate and indenting on the transverse surface. This method bounds the fibers resulting in inaccurate measurements of their mechanical responses. There has not been an appropriate study on the transverse material properties of the Kevlar fibers determined via nanoindentation without embedding them because it is challenging to rigidly secure the fibers. Here, we have developed a methodology to secure the Kevlar fiber on an SEM puck under pretension. The tension at the fiber is calculated and accounted for in the final determination of the mechanical properties. Fibers are glued at the ends and are not embedded. The employed Vantage nanoimpactor indents the fiber radially at three different loads, namely, 2, 3, and 5 mN and calculates the mechanical properties. A Berkovich indenter is used for indentation. The Kevlar fibers are assumed transversely isotropic and have 12μm diameter measured via the Vantage optical microscope. For Kevlar KM2 fiber the experimental transverse modulus using impact nanoindenter instrument is ∼3.46 GPa. The presented experiments aim to improve our understanding of the mechanical properties of these high performance fibers on the transverse direction.
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Sun, Bin, Zhiqiang Hu, and Jin Wang. "On Prediction for Structural Performance of Ship Side Structures in Head-On Collision Scenario." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41358.
Full textAbstract:
The crashworthiness of ship side structures should be taken into consideration during the structural design phase. When a ship is struck by a head-on collision, the main participants of the side structures include outer plating, longitudinal girders, transverse frames and the stiffeners attached on them. This paper is centered on establishing an integrated deformation mechanism program by identifying the theoretical deformation modes of the side structures, including the plating and stiffeners. The primary failure models of plating structures are the crushing, stretching and tearing modes, and a new crushing model of side plating structures subject to an ellipsoid-shaped indenter is proposed. As for the stiffeners on outer plating, the smeared thickness method is often used, but the role of the stiffeners cannot be traced clearly during the deformation process and the structural performance predictive accuracy may not be guaranteed. Therefore, a theoretical model of stiffeners is established in this paper, on purpose of providing deep insight of the deformation mechanism with reasonable accuracy. The expressions of resistance force of the side structures are also derived based on a study of the progressive deformation process of numerical simulation results and the plastic analytical methods. The accuracy of the analytical method is verified by numerical simulations using code LS_DYNA. The proposed analytical method can be used for quick assessment of the performances of ship side structures during ship collision.