Academic literature on the topic 'Multi probe cut'
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Journal articles on the topic "Multi probe cut"
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Rodríguez Varela, Fernando, Manuel José López Morales, Rubén Tena Sánchez, Alfonso Tomás Muriel Barrado, Elena de la Fuente González, Guillermo Posada Quijano, Carlos Zarzuelo Torres, Manuel Sierra Pérez, and Manuel Sierra Castañer. "Multi-Probe Measurement System Based on Single-Cut Transformation for Fast Testing of Linear Arrays." Sensors 21, no. 5 (March 3, 2021): 1744. http://dx.doi.org/10.3390/s21051744.
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This paper introduces a near-field measurement system concept for the fast testing of linear arrays suited for mass production scenarios where a high number of nominally identical antennas needs to be measured. The proposed system can compute the radiation pattern, directivity and gain on the array plane, as well as the array complex feeding coefficients in a matter of seconds. The concept is based on a multi-probe antenna array arranged in a line which measures the near field of the antenna under test in its array plane. This linear measurement is postprocessed with state-of-the-art single-cut transformation techniques. To compensate the lack of full 3D information, a previous complete characterization of a “Gold Antenna” is performed. This antenna is nominally identical to the many ones that will be measured with the proposed system. Therefore, the data extracted from this full characterization can be used to complement the postprocessing steps of the single-cut measurements. An X-band 16-probe demonstrator of the proposed system is implemented and introduced in this paper, explaining all the details of its architecture and operation steps. Finally, some measurement results are given to compare the developed demonstrator with traditional anechoic measurements, and show the potential capabilities of the proposed concept to perform fast and reliable measurements.
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Nhean, Sophea, Supat Isarangkool Na Ayutthaya, Alain Rocheteau, and Frederic C. Do. "Multi-species test and calibration of an improved transient thermal dissipation system of sap flow measurement with a single probe." Tree Physiology 39, no. 6 (March 22, 2019): 1061–70. http://dx.doi.org/10.1093/treephys/tpz017.
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Abstract Transient thermal dissipation (TTD) systems provide a simple way to measure xylem sap flow with dual or single Granier-type probe, which gives lower energy consumption and higher accuracy due to its lessor sensitivity to thermal interferences. A new system, TTD heat within 5 min (TTD5), proposed on the reduction of the heating duration. This evolution captured interest through decreased energy consumption and increased temporal resolution. Within our study, the first objective was to test and calibrate this new system with a single probe for young rubber tree – Hevea brasiliensis. The second objective was to explore the sources of variability in calibration such as species, individual cut-stems and probe–wood contact. The complementary species consisted of two diffuse-porous species (mango tree – Mangifera indica, eucalyptus tree – Eucalyptus camaldulensis) and one ring-porous species (teak tree – Tectonia grandis). Twenty-eight response curves were assessed over a large range of flux densities from 0.5 to 10 l dm−2 h−1. The incremental rise of temperature from 30 to 300 s (T300–30) after commencement of heating was sensitive to flux density over the complete range. Compared with the full signal at 300 s, the incremental signal markedly reduced the variability between response curves within species and between species. Moreover, a new index K2, defined as (T0 – Tu)/T0, normalized the responses between 0 and 1. However, the responses had a non-linear trend above 5 l dm−2 h−1. Within diffuse-porous wood type, the species did not differ in calibration, whereas the ring-porous species was markedly different. A sigmoid function provided the best fit for the diffuse-porous species. Individual stems were identified as the main source of within-species variability in calibration. The normalizing K2 index removed the influence of probe–wood contacts, controlled through drilling difference; however, there was still an effect of individual stems interacting with flux density (P = 0.019). Replications of cut-stems and response curves are necessary to assess a reliable averaged calibration. In conclusion, the applicability of the TTD5 system with a single probe has been confirmed and several sources of variability in calibration have been evaluated.
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Jarallah, Ishaq, and Vasudevan P. Kanjirakkad. "Improving the fidelity of aerodynamic probes using additive manufacturing." Rapid Prototyping Journal 22, no. 1 (January 18, 2016): 200–206. http://dx.doi.org/10.1108/rpj-08-2014-0091.
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Purpose – This paper aims to offer the aerodynamic testing community a new procedure for manufacturing high-quality aerodynamic probes suitable for 3D flow measurements with consistent geometry and calibration by taking advantage of the additive manufacturing technology. Design/methodology/approach – The design methodology combines the advantages and flexibilities of computer aided design (CAD)/computer aided manufacturing (CAM) along with the use of computational fluid dynamics to design and analyse suitable probe shapes prior to manufacturing via rapid prototyping. Findings – A viable procedure to design and possibly batch manufacture geometrically accurate pneumatic probes with consistent calibration is shown to be possible through this work. Multi-jet modelling prototyping methods with wax-based support materials are found to be a cost-effective method when clean and long sub-millimetre pressure channels are to be cut. Originality/value – Utilisation of the geometry consistency that is made possible by 3D printing technology for the design and development of pneumatic probes is described. It is suggested that the technique could lead to batch production of identical probes, thus avoiding precious time of a skilled labourer and elaborate individual calibration requirement.
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RIBEIRO, Rosângela Almeida, Silvio Issáo MYAKI, Marco Antônio GIOSO, and Ney Soares de ARAÚJO. "Pulpal response of dogs primary teeth to an adhesive system or to a calcium hydroxide cement." Pesquisa Odontológica Brasileira 14, no. 1 (March 2000): 47–52. http://dx.doi.org/10.1590/s1517-74912000000100009.
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The aim of this study was to evaluate the pulpal response of dogs primary teeth to an adhesive system or to a calcium hidroxide cement after mechanic exposure of the pulp. Three mongrel dogs were used and ten class V cavities were prepared on their teeth. A mechanic pulp exposure was produced with a sterile exploratory probe in the central portion of each cavity and bleeding was controlled with dry sterile cotton pellets. Enamel, dentin and the site of the pulp exposure of five teeth were etched with 35% phosphoric acid followed by the application of an adhesive system (Scotchbond Multi-Purpose - 3M). In the other five teeth, calcium hydroxide cement (Hydro C - Dentsply) was applied on the site of the pulp exposition before application of the adhesive system (Scotchbond Multi-Purpose - 3M). All teeth were restored with a resin composite (Z-100 - 3M). After 7, 30 or 45 days the dogs were anesthetized and perfused with saline followed by a solution of neutral buffered formalin. Maxilla and mandible were sectioned into three parts and placed in a solution for demineralization. Following bone demineralization, all teeth were cut, trimmed, embedded in paraffin and longitudinally cut. Then, the teeth were stained with hematoxilin and eosin and observed under a light microscope. The results obtained with the treatments proposed in this study showed the presence and persistence of an inflammatory response of different intensities at the three experimental periods. There was no variation in the inflammatory response regarding the different treatments performed.
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Šlaus, B., V. Smolčić, M. Novak, S. Fotopoulou, P. Ciliegi, N. Jurlin, L. Ceraj, et al. "The XXL Survey." Astronomy & Astrophysics 638 (June 2020): A46. http://dx.doi.org/10.1051/0004-6361/201937258.
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We study the space density evolution of active galactic nuclei (AGN) using the 610 MHz radio survey of the XXL-North field, performed with the Giant Metrewave Radio Telescope. The survey covers an area of 30.4 deg2, with a beamsize of 6.5 arcsec. The survey is divided into two parts, one covering an area of 11.9 deg2 with 1σ rms noise of 200 μJy beam−1 and the other spanning 18.5 deg2 with rms noise of 45 μJy beam−1. We extracted the catalog of radio components above 7σ. The catalog was cross-matched with a multi-wavelength catalog of the XXL-North field (covering about 80% of the radio XXL-North field) using a likelihood ratio method, which determines the counterparts based on their positions and their optical properties. The multi-component sources were matched visually with the aid of a computer code: Multi-Catalog Visual Cross-Matching. A flux density cut above 1 mJy selects AGN hosts with a high purity in terms of star formation contamination based on the available source counts. After cross-matching and elimination of observational biases arising from survey incompletenesses, the number of remaining sources was 1150. We constructed the rest-frame 1.4 GHz radio luminosity functions of these sources using the maximum volume method. This survey allows us to probe luminosities of 23 ≲ log(L1.4 GHz[W Hz−1]) ≲ 28 up to redshifts of z ≈ 2.1. Our results are consistent with the results from the literature in which AGN are comprised of two differently evolving populations, where the high luminosity end of the luminosity functions evolves more strongly than the low-luminosity end.
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Hathi, Nimish P., and Olivier Le Fèvre. "The VIMOS Ultra Deep Survey: Lyα Emission and Stellar Populations of Star-Forming Galaxies at 2 < z < 6." Proceedings of the International Astronomical Union 11, S319 (August 2015): 22–25. http://dx.doi.org/10.1017/s174392131501039x.
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AbstractThe extensive ground-based spectroscopy campaign from the VIMOS Ultra-Deep Survey (VUDS), and the deep multi-wavelength photometry in three very well observed extragalactic fields (ECDFS, COSMOS, VVDS), allow us to investigate physical properties of a large sample (~4000 galaxies) of spectroscopically confirmed faint (iAB ≲ 25 mag) SFGs, with and without Lyα in emission, at z ~ 2–6. The fraction of Lyα emitters (LAEs; equivalent width (EW) ≥ 20Å) increases from ~10% at z ~ 2 to ~40% at z ~ 5–6, which is consistent with previous studies that employ higher Lyα EW cut. This increase in the LAE fraction could be, in part, due to a decrease in the dust content of galaxies as redshift increases. When we compare best-fit SED estimated stellar parameters for LAEs and non-LAEs, we find that Es(B-V) is smaller for LAEs at all redshifts and the difference in the median Es(B-V) between LAEs and non-LAEs increases as redshift increases, from 0.05 at z ~ 2 to 0.1 at z ~ 3.5 to 0.2 at z ~ 5. For the luminosities probed here (~L*), we find that star formation rates (SFRs) and stellar masses of galaxies, with and without Lyα in emission, show small differences such that, LAEs have lower SFRs and stellar masses compared to non-LAEs. This result could be a direct consequence of the sample selection. Our sample of LAEs are selected based on their continuum magnitudes and they probe higher continuum luminosities compared to narrow-band/emission line selected LAEs. Based on our results, it is important to note that all LAEs are not universally similar and their properties are strongly dependent on the sample selection, and/or continuum luminosities.
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Jamil, Jeffry, Syed Yusainee Syed Yahya, and Rosnah Zakaria. "Multi Display Scan in Detecting Weld Discontinuity of Thick Carbon Steel Plate using Ultrasonic Testing Phased Array (UTPA) with Comparison to Conventional Ultrasonic Testing (UT)." Scientific Research Journal 17, no. 2 (August 28, 2020): 209. http://dx.doi.org/10.24191/srj.v17i2.8345.
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Non-destructive testing (NDT) is a method of testing and analysis that relies on the application of physical principles to determine the integrity of materials without causing damage. The existence of weld discontinuity can affect the service ability of the structures. Ultrasonic testing Phases Array (UTPA) is advanced ultrasonic testing technology widely practiced in many industries. The multiple ultrasonic elements and electronic time delay will create constructive and destructive interference and steering capability, which could improve detectability compared to a single element of conventional UT. The multi displays presented in A-Scan, S-scan, B-Scan, and C-Scan of UTPA equipment capable of locating, inspecting, and characterise defects within the welded component. Two carbon steel plates with thickness 18 mm and 24 mm were prepared and cut to V-shape configuration and welded using shielded metal arc welding (SMAW) process, labelled as NDE-8826 and NDE-8827 respectively. Both samples were induced with artificial defects of the weld. 16 elements of phased array probe with 0.5 mm pitch and 4 MHz were carried out for this study with encoded scanning to identify weld discontinuity plotted in different types of UT displays. Additional testing was performed using conventional ultrasonic testing (UT) using a 4 MHz probe to compare with the UTPA results and the acceptability of each defect detections. The length and datum of toe crack, slag, and lack of inter run fusion detected by UTPA in NDE-8826 give the same value as the actual value. However, the localisation of the defect is slightly different at 1.0 mm for UT detection. While the detection value for slag gives the same values for UT and UTPA, which also the same as the actual values. The detection of lack of penetration and lack of fusion in sample NDE-8827 was precisely can be detected by UT and UTPA; hence their datum value has slightly different in the centerline crack and porosity at 2.0 mm for UT measurement, and as for UTPA, it was found that the porosity at 3.0 mm which higher value compared to the actual value, 250 mm. From the result, a relevant indication from the UTPA and conventional UT collected it was found that the UTPA technique is capable of improving the Probability of Detection (POD) of defects compared to the conventional UT.
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Lin, Ah-Der, Wen-Kai Yu, Sian Zheng Poon, Cheng-Yi Chen, and Chao-Ming Hsu. "Study on Nitrogen-Doped Graphene Ink and Its Effects on the Heat Dissipation for the LED Lamps." Applied Sciences 10, no. 8 (April 15, 2020): 2738. http://dx.doi.org/10.3390/app10082738.
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This study explored the application of nitrogen-doped graphene (NDG) ink to the coating of light-emitting diode (LED) lamps for the thermal management. Unlike the general solutions of graphene, the NDG ink used in this study was tuned with high electrical resistance and quietly suitable for the application of the LED lamp coating, which prevented the short circuit problem; besides, the NDG ink also provided a high heat dissipation effect to improve the performance of the LED lamp. The investigation of adhesion and resistance for the NDG ink were conducted by the cross-cut test and the four-point probe resistance measurement, respectively. Three types of LED lamps including the original lamp, fin-removed lamp, and NDG-ink coated (NGC) lamp were tested for the actual operating temperature distribution by K-type thermal couples and for the lumens by the integrating sphere. The results showed that the heat dissipation of the NGC lamp was better than that of the original lamp. In addition, the inspections for the properties of NDG powder were also performed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and Raman spectroscopy. According to the inspectional results, the NDG powder had a percentage of nitrogen of about 3.8% by XPS, a surface roughness Rq of 0.9 nm by AFM, and over ten layers by Raman analysis. It showed that the NDG powder in this study belonged to the type of multi-layer graphene.
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Sharma, Shweta, Richa Bansal, and Shubham Jain. "Comparative evaluation of strain ratio on sonographic elastography and T2* values on 3 Tesla magnetic resonance imaging in differentiating malignant from benign axillary lymph nodes in breast cancer." International Journal of Research in Medical Sciences 9, no. 4 (March 26, 2021): 1156. http://dx.doi.org/10.18203/2320-6012.ijrms20211368.
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Background: The study aimed to assess whether strain ratio and T2* values can improve the sensitivity and specificity of differentiating metastatic from benign axillary lymph nodes in breast cancer patients taking histopathology as reference standard.Methods: The study was done on 43 patients. A multi-echo transverse T2*W MR sequence was obtained with TE = 0.9- 1.5 ms, TR=37.2 ms and flip angle = 25°. Sonographic elastography was done using high frequency linear probe (L3-16 MHz). Manual selection of the region of interest was done on suspicious lymph nodes for calculation of T2* values and strain ratio. ROC curves were obtained for various T2* and strain ratio values in comparison to histopathological findings as gold standard.Results: Correlation with histopathology was better with T2* values than strain ratio. The sensitivity and specificity were calculated using cut off values obtained from ROC curve (31.225 ms for T2* value and 1.85 for SR) and were 70.37%, 68.75% for strain ratio and 96.29%, 93.75% for T2* value respectively. The positive predictive value and negative predictive value were also assessed, values being higher for T2* than strain ratio. Comparison of areas under ROC curve was statistically significant with p=0.018.Conclusions: T2* can be used as a potential biomarker for differentiating metastatic from benign axillary lymph nodes owing to its high sensitivity, specificity and relative ease of performance. Quantitative assessment of changes in T2* values may allow more objective analysis of signal changes with significant differences between benign and malignant lymph nodes, even in case of partial infiltration.
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Oshima, K., K. Yoshihara, T. Kojima, M. Komatsu, and N. Yamamoto. "274 LOCALIZATION OF MACROPHAGE COLONY STIMULATING FACTOR (M-CSF) GENE IN THE ENDOMETRIUM OF JAPANESE BLACK COW." Reproduction, Fertility and Development 19, no. 1 (2007): 253. http://dx.doi.org/10.1071/rdv19n1ab274.
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Macrophage colony stimulating factor (M-CSF), a member of the group of hemopoietic cytokines, plays an important role in placental physiology of humans and mice. The objective of this study was to investigate the localization of M-CSF gene in bovine endometrial tissues during pregnancy using in situ hybridization (ISH). Twelve Japanese Black cows aged between 1.4 and 14.5 years, with normal estrous cycles, were used in this study. They were observed daily for estrous behavior, and the day of estrus was considered as Day 0. Cows were artificially inseminated, and pregnancy was confirmed by presence of conceptus and/or corpus luteum using ultrasonography. They were euthanized and their uteri were collected on Days 20 to 21 (n = 2), 36 to 42 (n = 3), 59 to 64 (n = 3), 127 to 137 (n = 2), and 225 to 226 (n = 2) of pregnancy. Pregnancy was confirmed finally by the presence of a conceptus in the uterus, and the uterus was isolated by dissection, avoiding damage of the uterine artery. The uterus was perfused with 4% paraformaldehyde (PFA) solution using catheters inserted into the uterine artery, and placental tissues were isolated by dissection. Each tissue was cut into small pieces (5 mm thick) and fixed in 4% PFA solution. After being fixed in 4% PFA solution for 20 to 24 h, tissue pieces were embedded in paraffin using routine procedures. Several tissue pieces were collected from each individual cow. Sections (6 mm thick) were cut and placed on MAS-coated glass slides (Matsunami Glass, Kishiwada, Japan). The sections were dried in an oven for 3 days at 40�C. Antisense and sense biotin-labeled oligonucleotide probes for bovine M-CSF were designed from the sequence information (GenBank accession number D87917). Sense probe was used as the negative control. ISH was carried out using the GenPoint System (DakoCytomation, Glostrup, Denmark) according to the manufacturer's instructions. The sections were observed under an Eclipse 800 microscope (Nikon, Tokyo, Japan), and the positive signal for M-CSF gene was detected. Density analysis was performed by using Scion Image (Scion Corporation, Frederick, MD, USA). Data were analyzed by one-way ANOVA and Tukey-Kramer's HSD, using 0.05 as a significant level. The M-CSF gene was expressed in the stromal and luminal epithelial cells of endometrium, stromal cells of the fetal cotyledonary villus and caruncular crypt, and mono- and multi-nuclear epithelium cells of the fetal cotyledonary villus and caruncular crypt. Intensities of M-CSF gene-positive signals in all positive cells at Days 225 to 226 of pregnancy were stronger than those at other periods (P < 0.05). These results suggest that M-CSF is produced in several cell types in the endometrium and placental tissues and may play important roles in bovine pregnancy.
Dissertations / Theses on the topic "Multi probe cut"
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Ekbom, Andreas. "Studium av Othellospelande program : Design, algoritmer och implementation." Thesis, Linköping University, Department of Computer and Information Science, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2381.
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Att "smarta" brädspelande datorprogram har blivit mycket bättre under de senaste årtiondena har väl knappast kunnat undgå någon. Med brädspel menar jag spel såsom Go, Othello, Backgammon och Schack. Idag spelar program, som körs på en reguljär PC, bättre än de flesta människor. Vad är det som gör dessa program så bra? Hur kan man lära en dator att spela ett så pass komplext spel som Othello på en sådan nivå att ingen människa har en chans att vinna? I detta examensarbete kommer jag att försöka förklara mekanismerna bakom ett toppspelande Othelloprogram. Jag har dessutom implementerat ett eget Othellospelande program som jag använt som testapplikation för att prova olika sökmetoder, metoder för att öka exekveringshastigheten och tekniker för att öka spelskickligheten. Jag kommer att presentera empiriska data där jag utvärderar och jämför flera andra program med mitt eget.
Book chapters on the topic "Multi probe cut"
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Siddiqui, Tauseef Uddin, and Mukul Shukla. "Modeling and Optimization of Abrasive Water Jet Cutting of Kevlar Fiber-Reinforced Polymer Composites." In Computational Methods for Optimizing Manufacturing Technology, 262–86. IGI Global, 2012. http://dx.doi.org/10.4018/978-1-4666-0128-4.ch011.
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This chapter presents a detailed study of abrasive water jet (AWJ) cutting of thin and thick Kevlar fiber-reinforced polymer (FRP) composites used in transport aircraft and anti-ballistic applications. Kevlar composites are considered to be very challenging to machine using traditional techniques. Most of the research conducted in the area of AWJ cutting has been limited to single response optimization. However, in real life machining, the performance of a process/product demands multi-objective optimization (MOO). No work has been reported till now using different MOO techniques for AWJ cutting of Kevlar FRP composites. Experimental modeling of depth of cut and various design of experiments based single and multi-objective optimization studies are presented here. Statistical analysis of variance has been performed to rank the different process parameters and estimate their effects on various AWJ cut kerf quality characteristics. The studies conducted in this chapter are likely to prove beneficial to the AWJ community in performing modeling and simultaneous optimization of multiple quality characteristics.
Conference papers on the topic "Multi probe cut"
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Kumar, Apoorva, Gaurav Agrawal, Kamaljeet Singh, Nitesh Kumar, and Shaktim Dutta. "Demystifying Openhole and Outer Casing Geometry and Annulus Material Characterization with Third Interface Echo TIE Response." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206323-ms.
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Abstract Ultrasonic imaging based tools have been used for long for delivering high-resolution, comprehensive real-time confirmation of the pipe-to-cement bond quality and downhole pipe condition. However, for comprehensive analysis of cement barriers in challenging scenarios like lightweight cement and for better distinction between different annular materials downhole, a multi-physics evaluation has been developed which combines the measurements taken in thickness-mode with measurements taken in flexural-mode of the casing. Signals from these independent measurements are then processed to provide robust interpretation of solid-liquid-gas behind casing using acquired flexural attenuation and acoustic impedance data. The information provided by the flexural attenuation is related to the state of the material in contact with the casing and does not probe deeper into the cement sheath. However, the pulse radiated by the flexural wave packet into the annulus may be reflected by the third interface, the interface with the formation or outer casing. The inner casing is fairly transparent to this reflected pulse so that it can also be picked by the receivers with significant amplitude. Since this reflected pulse propagate through the thickness of the annulus layer it may bring valuable information about the annulus geometry and material, and about the formation or outer casing geometry. This paper demonstrates third interface echo principles and showcases several case studies for evaluating the outer casing geometry, annular material characterization, casing cut and pull depth suggestion and determining open hole size.
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Lee, Soo Il, Arvind Raman, Stephen W. Howell, Ron Reifenberger, Cattien V. Nguyen, and Meyya Meyyappan. "Complex Dynamics of Carbon Nanotube Probe Tips." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42643.
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Carbon nanotube (CNT) tips in tapping mode atomic force microscopy (AFM) enable very high-resolution imaging, measurements, and manipulation at the nanoscale. We present recent results based on experimental analysis that yield new insights into the dynamics of CNT probe tips in tapping mode AFM. Experimental measurements are presented of the static response, the frequency response and dynamic amplitude-distance data of a high-aspect-ratio multi-walled (MW) CNT tip to demonstrate the nonlinear features including tip amplitude saturation preceding the dynamic buckling of the MWCNT. The differences between the nonlinear tapping mode response of CNT tips are compared with previously known results on the nonlinear response of conventional tips. Surface scanning is performed using a MWCNT tip on a SiO2 grating to verify the imaging instabilities associated with MWCNT buckling when used with normal control schemes in the tapping mode. Lastly, the choice of optimal setpoints for tapping mode control using CNT tip are discussed using the experimental results.
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Takahashi, Koji, Jun Hirotani, Satoshi Kai, and Tatsuya Ikuta. "Carbon Nanotube Thermal Probe Using Platinum Nano Hot-Film." In ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer. ASMEDC, 2009. http://dx.doi.org/10.1115/mnhmt2009-18356.
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This paper reports on a thermal probe using a carbon nanotube (CNT) on a platinum hot-film. CNT probe is expected to breakthrough the limitations of the existing ones owing to its unique characteristics but no practical thermal device has been fabricated yet. In order to explore the mechanisms of heating and measuring the smaller region than 10nm, we applied our recently developed sensor coupled with CNT, which consists of a suspended platinum film of 40nm × 500nm × 10micrometer. The principle of this probe as heater and sensor is explained, based on one dimensional heat conduction. Fabrication process using MEMS technique is also introduced, especially for a couple of critical techniques. One is to fabricate the nano sensor on an edge of the sensor substrate. The other is to bond a CNT on the suspended hot-film sensor. A CNT thermal probe using a multi-walled CNT of 70nm diameter and ca. 10 micrometers length is successfully fabricated. Its performances are tested in vacuum environment as to eliminate the presence of in-air conduction effect and water absorption effect around the contact point, which work for heat transport dominantly in atmospheric condition and degrade the spatial resolution. Our CNT probe showed a clear and reliable signal in vacuum and its sensitivity available for nanoscale thermal sensing and heating is confirmed.
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Hosseini, Mahmoud Reza, and Nader Jalili. "A New Nanomechanical Cantilever Sensing Paradigm Using Piezoelectric Boron Nitride Nanotube-Based Actuation." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35425.
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Nanomechanical Cantilever Sensors (NMCS) have recently attracted a widespread attention for use in different nano- and micro-size applications such as studying the nanoscale surface topography by scanning probe microscopy and atomic force microscopy (AFM). In newer AFM systems, a sharp probe is placed at the tip of the microcantilever and a piezoelectric patch actuator deposited on the cantilever surface produces the movements of the probe above the examined surface. Similar system can be also utilized for mass sensing purposes by adding an unknown mass to the tip and measuring the beam deflection and the amount of shift in the resonance frequency that is caused by the addition of the tip mass. This sensing paradigm finds many applications in medical and biological fields such as DNA strand and bacteria weight measurement. However, one of the major issues in all piezoelectrically-actuated microcantilevers is the low actuation energy of the piezoelectric patch. Most of the current and widely used piezoelectric materials possess low mechanical characteristics such as low Young’s modulus of elasticity, low yield strength and most importantly incompatibility with most biological species and environment. It has been shown that both carbon and boron nitride nanotubes (CNT and BNNT) possess outstanding mechanical, chemical and electrical properties with acceptable piezoelectricity which make them suitable for microcantilever actuation applications. In this paper, a multi-physics multi-scale model is proposed in which the actuation of microcantilevers is produced by two sets of nanotube layers. Through extensive simulations, BNNTs were chosen to be used as the actuators because of their enhanced piezoelectric characteristics compared to CNTs. The modeling framework proposed here is used to investigate the effects of deposited tip mass with different weights on frequency response and resonance frequency of the microcantilever beam. These microbeams are made of aluminum or titanium materials and the results are compared with each other.
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Ngabonziza, Yves, and Jackie Li. "Electrical Conductivity and Elastic Properties of Carbon Nanotube Reinforced Polycarbonate Nanocomposites." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62685.
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In the past years, carbon nanotubes and their composites have been intensively studied due to their extremely high strength and high electrical and thermal conductivities. However, to be able to use CNT-reinforced composites as structural materials in real applications, more cost-efficient processing methods should be adopted and the properties of such nanocomposites need to be further analyzed. Here we investigate the electrical and elastic properties of multi-walled carbon nanotubes (MWCNT) reinforced polycarbonate (PC) nanocomposites produced by injection molding which has been widely used in industrial plastic production. Nanocomposite samples with MWCNT ranging from 0 to 7wt% were tested for both electrical conductivity using a 2-probe measurement and mechanical properties under tensile loading. It has been found that the electrical conductivity depends on both injection velocity and the CNT content while the elastic properties of the nanocomposites only depend on the CNT content. Besides the experimental testing, a percolation theory and micromechanics models have been applied to determine the electrical conductivity percolation threshold and the effective elastic modulus of the nanocomposites in terms of CNT contents. The results are compared with our experimental data. It shows that a percolation threshold is around 1.8wt% of MWCNT. The evaluation of elastic properties using micromechanics models not only indicates the influence of MWCNT on elastic properties but also the presence of an interphase between the CNT and PC matrix.
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Osaki, Katsuya, Hideki Fuji, Masato Onishi, Ken Suzuki, and Hideo Miura. "Remote Strain Measurement by Multi-Walled Carbon Nanotube-Dispersed Resin." In ASME 2009 InterPACK Conference collocated with the ASME 2009 Summer Heat Transfer Conference and the ASME 2009 3rd International Conference on Energy Sustainability. ASMEDC, 2009. http://dx.doi.org/10.1115/interpack2009-89146.
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A new remote strain measurement method has been developed by applying the highly sensitive change of electronic conductivity of CNTs. Multi-walled CNTs were dispersed in various kinds of resins to form a thin film which can be attached rounded surfaces. The length of the CNTs was about a few μm. One of the base materials of resin employed was polycarbonate and the volumetric concentration of CNT dispersed was about 11.5%. The thickness of the film was about 500 μm. An uni-axial strain was applied to the CNT-dispersed resin by applying a 4 point bending method, and the change of the electric resistance was measured. The range of the applied strain was from −0.025% to 0.025%. The electric resistance changed almost linearly with the applied strain. The ratio of the resistance change under the tensile strain was about 40%/1000-μstrain and that under the compressive strain was about 15%/1000-μstrain. The micro wave of 99.5 GHz was irradiated to the CNT-dispersed polycarbonate film through the metallic prove 1 mm in diameter. The change of the intensity of the beam reflected from the film was measured by changing the amplitude of the uni-axial in-plane strain applied to the film. The intensity of the reflected beam increased almost linearly with the increase of the applied tensile strain and the change rate of the intensity was about 0.5%/1000-μstrain. This result clearly indicated that the surface dynamic strain can be detected by micro wave nondestructively and remotely.
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Yamamoto, Namiko, Hai M. Duong, Aaron J. Schmidt, Brian L. Wardle, Dimitrios V. Papavassiliou, and Shigeo Maruyama. "Simulation of Thermal Conductivity in Fabricated Variable Volume Fraction Aligned Carbon Nanotube Polymer Composites." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-66557.
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Thermal conductivities of aligned carbon nanotube (CNT)–polymer nano-composites were estimated using the off-lattice Monte Carlo simulation. High thermal conductivity to density ratio is theoretically and experimentally recognized as one of the exceptional properties of CNTs. Aligned CNTs combined with existing advanced composites are being explored for macro-scale aerospace structures that benefit from thermal tailoring and light weight. Accurate thermal transport models within different polymer nanocomposites, and larger-scale and complexity composites, remain to be developed. The model previously developed for single-walled nanotube (SWNT)-polymer composites was modified to simulate the thermal property of aligned multi-walled nanotube (MWNT)-polymer nanocomposites of different volume fraction. Random walk simulations of thermal walkers are used to determine the interfacial resistance to heat flow inside the nano-composites in the directions parallel and perpendicular to the CNT alignment axis. The thermal equilibrium factor between the MWNTs and the composite matrix material is also determined numerically in this study. The CNT-polymer samples were fabricated for thermal conductivity measurements using two methods: the pump-and-probe method and the infrared microscopy. Aligned SWNT and MWNT forests were grown using chemical vapor deposition (CVD). The MWNTs were mechanically densified up to ∼20% aligned-CNT volume fraction. The MWNT forests were immersed in an aerospace-grade thermoset resin, and cured. Near future work is to compare the simulated effective thermal conductivities of the CNT-epoxy composites with the measured data of the fabricated specimens to determine thermal boundary resistance between CNTs and the polymer.
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Ardebili, Mahmoud K., Kerim T. Ikikardaslar, Shivron Sugrim, and Feridun Delale. "Damage Quantification and Location Detection in Carbon Nanotube Enhanced Composite Panels." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-66483.
Full textAbstract:
Epoxy resin based composite panels enhanced with carbon nanotube were subjected to damage while their electrical resistivity was monitored. The objective of the study was to utilize the composite piezoresistivity as means of damage quantification and location detection. Two different multi walled CNT-epoxy composites were manufactured for this study: one was CNT enhanced epoxy resin and the second was glass fabric reinforced CNT epoxy resin. Rectangular panels of various proportions were studied. Disks made out of copper foil were affixed to surfaces of CNT epoxy specimen, while in glass fabric CNT epoxy specimen the disks were embedded inside the samples. The disks acted as electrodes, enabling resistivity measurements using Kelvin in-line four-probe technique. The technique minimizes contact resistance between electrodes and the composite. Two different configurations of electrode network were employed to scan resistivity of entire samples. The networks included evenly spaced electrodes that spanned the entire surface of the panel, and one that covered the panel’s diagonals and its edges. To further investigate influence of electrodes distribution, finite element methods were employed to solve for the electrical potential distribution in the panel simulating various damage location and extent. Pre and post damage resistivity change was used as gauge in determining the damage location and its extent quantification. The finite element method simulation results matched experimental data closely allowing further studies with electrodes distribution, damage geometry and location. The results indicated that a relatively small spaced electrode network is capable of determining location and quantification of visible and hardly visible damages. As spacing between electrodes is increased they become less responsive to smaller damages.
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Yekani Fard, Masoud, Jack Mester, and Alek Pensky. "Nanoscale Interphase Characterization of Porous CNT Buckypaper Composites in Correlation to Interlaminar Mode I Fracture." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23618.
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Abstract In this conference paper, nanoscale material property data and ASTM mode I interlaminar fracture results for three-phase buckypaper samples are presented and analyzed. Vacuum filtration and surfactant-free methods were used to manufacture buckypaper membranes. Epoxy infused buckypaper membranes were placed in front of the crack tip in a stitch bonded carbon fiber polymer matrix composite. Peak Force Quantitative Nanomechanical Mapping (PFQNM), using probes with nominal tip radius in the range of 5–8 nm were used. PFQNM characterized the interphase region between a three-phase sample of carbon monofilament, epoxy resin, and multi-walled carbon nanotube (MWCNT) buckypaper. This experiment captured reproducible nanoscale morphological, viscoelastic, elastic and energy properties of porous MWCNT buckypaper samples. An enlarged interphase region surrounding the CNT buckypaper was found. The buckypaper and epoxy interphase thickness was found to be 50nm, higher than the 10–40nm reported for epoxy and carbon monofilaments. The observed MWCNT structure provides explanation of the increased surface roughness compared to the smooth carbon monofilaments. The increased surface roughness likely improves mechanical interlocking with the epoxy of adjacent lamina. The nanoscale interphase and subsurface characterization data provide explanation for a change in crack propagation toughness. Buckypaper exhibited inhomogeneous properties at micrometer length scales.
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Takehara, Isashi, Tetsuo Tatsumi, and Yoshihiro Ichikawa. "Summary of CGT302 Ceramic Gas Turbine Research and Development Program." In ASME Turbo Expo 2000: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/2000-gt-0644.
Full textAbstract:
The Japanese Ceramic Gas Turbine (CGT) research and development program (FY1988–1998) as a part of the New Sunshine Project funded by the Ministry of International Trade and Industry (MITI) was completed in March 1999. Kawasaki Heavy Industries, Ltd. (KM) participated in this research program from the beginning and developed a twin-shaft CGT with a recuperator, designated as the “CGT302”. The purposes of this program were: 1) to achieve both a high efficiency and low pollutant emissions level using ceramic components, 2) to prove a multi-fuel capability to be used in co-generation systems, and 3) to demonstrate long-term operation. The targets of this program were: i) to achieve a thermal efficiency of over 42% at a turbine inlet temperature (TIT) of 1350°C, ii) to keep its emissions within the regulated value by the law, and iii) to demonstrate continuous operation for more than a thousand hours at 1200°C TIT. The CGT302 has successfully attained its targets. In March 1999 the CGT302 recorded 42.1% thermal efficiency, and 31.7 ppm NOx emissions (O2 = 16%) at 1350°C TIT. At this time it had also accumulated over two thousand hours operation at 1200°C. In this paper, we summarize the development of the CGT302.