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1. Formation of twin compact stars in low-mass X-ray binaries: Implications on eccentric and isolated millisecond pulsar populations

Author

Chanlaridis, S., Ohse, D., Antoniadis, J., Blaschke, D., Alvarez-Castillo, D. E., Danchev, V., Misra, D., and Langer, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, Nuclear Theory
Abstract

Millisecond pulsars (MSPs) are laboratories for stellar evolution, strong gravity, and ultra-dense matter. Although MSPs are thought to originate in low-mass X-ray binaries (LMXBs), approximately 27% lack a binary companion, while others are found in systems with large orbital eccentricities. Understanding how these systems form may provide insight into the internal properties of neutron stars (NSs). We study the formation of a twin compact star through rapid first-order phase transitions in NS cores due to mass accretion in LMXBs. We investigate whether this mechanism, possibly coupled with secondary kick effects such as neutrino or electromagnetic rocket effects, may leave an observable long-lasting imprint on the orbit. We simulate mass accretion in LMXBs consisting of a NS and a low-mass main sequence companion, following the evolution of the NS mass, radius, and spin until a strong phase transition is triggered. For the NS structure, we assume a multipolytrope equation-of-state that allows for a sharp phase transition from hadronic to quark matter and satisfies observational constraints. We find that in compact binaries with relatively short pre-Roche lobe overflow orbital periods, an accretion-induced phase transition may occur during the LMXB phase. In contrast, in systems with wider orbits, this transition may take place during the spin-down phase, forming an eccentric binary MSP. If the transition is accompanied by a secondary kick (w > 20 km/s), the binary is likely to be disrupted, forming an isolated MSP or reconfigured to an ultra-wide orbit. Our results suggest that accretion in LMXBs provides a viable path for forming twin compact stars, potentially leaving an observable imprint on the orbit. The eccentricity distribution of binary MSPs with long (> 50 d) orbital periods could provide constraints on first-order phase transitions in dense nuclear matter., Comment: 12 pages, 6 figures. To be submitted to Astronomy & Astrophysics (A&A)

Published
2024

4. Alkylresorcinol, a biomarker for whole grain intake, and its association with osteoarthritis: the MOST study.

Author

Zertuche, J-P, Rabasa, G, Lichtenstein, A, Matthan, N, Torner, J, Lewis, C, Dai, Z, Misra, D, Felson, D, and Nevitt, Michael

Subjects
Alkylresorcinol, Biomarker, Diet, Dietary, OA, fiber, Biomarkers, Female, Humans, Imidazoles, Knee Joint, Male, Osteoarthritis, Osteoarthritis, Knee, Sulfonamides, Thiophenes, Whole Grains
Abstract

INTRODUCTION: Higher intake of fiber has been associated with lower risk of incident symptomatic osteoarthritis (OA). We examined whether levels of alkylresorcinol (AR), a marker of whole grain intake, were associated with OA in subjects in The Multicenter Osteoarthritis (MOST) Study. METHOD: Knee x-rays and knee pain were assessed at baseline and through 60-months. Stored baseline fasting plasma samples were analyzed for AR homologues (C17:0, C19:0, C21:0, C23:0, C25:0) and total AR levels (AR sum). Two nested case-control studies, one for incident radiographic OA and one for incident symptomatic OA were performed with participants re-assessed at 15, 30 and 60 months. Multivariable conditional logistic regression with baseline covariates including age, sex, BMI, physical activity, quadriceps strength, race, smoking, depressive symptoms, diabetes and knee injury tested the association of log transformed AR levels with OA outcomes. RESULTS: Seven hundred seventy-seven subjects were, on average, in their 60s, and most were women. For 60-month cumulative incidence, there was no significant association between quartiles of AR concentration and incident radiographic (e.g., for incident radiographic OA, highest vs lowest quartile of AR sum showed RR = 0.93 (95% CI 0.59, 1.47), and for symptomatic OA RR was 1.22 (95% CI 0.76, 1.94). In secondary analyses examining 30-month incidence, high AR levels were associated with a reduced risk of X-ray OA (RR = 0.31 (95% CI 0.15, 0.64). CONCLUSION: In primary analyses, AR levels were not associated with risk of OA, but secondary analyses left open the possibility that high AR levels may protect against OA.

Published
2022

5. Revisiting the explodability of single massive star progenitors of stripped-envelope supernovae

Author

Zapartas, E., Renzo, M., Fragos, T., Dotter, A., Andrews, J. J., Bavera, S. S., Coughlin, S., Misra, D., Kovlakas, K., Román-Garza, J., Serra, J. G., Qin, Y., Rocha, K. A., Tran, N. H., and Xing, Z. P.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract

Stripped-envelope supernovae (Types IIb, Ib, and Ic) that show little or no hydrogen comprise roughly one-third of the observed explosions of massive stars. Their origin and the evolution of their progenitors are not yet fully understood. Very massive single stars stripped by their own winds ($\gtrsim 25-30 M_{\odot}$ at solar metallicity) are considered viable progenitors of these events. However, recent 1D core-collapse simulations show that some massive stars may collapse directly into black holes after a failed explosion, with a weak or no visible transient. In this letter, we estimate the effect of direct collapse into a black hole on the rates of stripped-envelope supernovae that arise from single stars. For this, we compute single-star MESA models at solar metallicity and map their final state to their core-collapse outcome following prescriptions commonly used in population synthesis. According to our models, no single stars that have lost their entire hydrogen-rich envelope are able to explode, and only a fraction of progenitors left with a thin hydrogen envelope do (IIb progenitor candidates), unless we use a prescription that takes the effect of turbulence into account or invoke increased wind mass-loss rates. This result increases the existing tension between the single-star paradigm to explain most stripped-envelope supernovae and their observed rates and properties. At face value, our results point toward an even higher contribution of binary progenitors to stripped-envelope supernovae. Alternatively, they may suggest inconsistencies in the common practice of mapping different stellar models to core-collapse outcomes and/or higher overall mass loss in massive stars., Comment: Published in Astronomy & Astrophysics Letters; One main enhancement: added Couch et al. (2020) in the list of supernova engines

Published
2021
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6. A Brief Discussion on GMR and TMR Effect and Importance of Metrology for Accurate Measurements of Its Parameters

Author

Bhatt, Komal, Misra, D. K., Govind, Bal, Bano, Sahiba, Kumar, Ashish, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Yadav, Sanjay, editor, Chaudhary, K.P., editor, Gahlot, Ajay, editor, Arya, Yogendra, editor, Dahiya, Aman, editor, and Garg, Naveen, editor

Published
2023
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7. Errors in Measurement of Magnetic Field and Magnetic Moment with its Associated Uncertainty

Author

Govind, Bal, Misra, D. K., Khanna, S. P., Kumar, Ashish, Bano, Sahiba, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Yadav, Sanjay, editor, Chaudhary, K.P., editor, Gahlot, Ajay, editor, Arya, Yogendra, editor, Dahiya, Aman, editor, and Garg, Naveen, editor

Published
2023
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8. Error Analysis in Measurement of Electrical Conductivity

Author

Bano, Sahiba, Kumar, Ashish, Govind, Bal, Komal, Misra, D. K., Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Yadav, Sanjay, editor, Chaudhary, K.P., editor, Gahlot, Ajay, editor, Arya, Yogendra, editor, Dahiya, Aman, editor, and Garg, Naveen, editor

Published
2023
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9. A Review on Sources of Uncertainty in Thermal Conductivity Measurement for Thermal Transport Metrology

Author

Kumar, Ashish, Misra, D. K., Bano, Sahiba, Govind, Bal, Bhatt, Komal, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Yadav, Sanjay, editor, Chaudhary, K.P., editor, Gahlot, Ajay, editor, Arya, Yogendra, editor, Dahiya, Aman, editor, and Garg, Naveen, editor

Published
2023
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10. Fatty acids and osteoarthritis: the MOST study

Author

Felson, DT, Misra, D, LaValley, M, Clancy, M, Chen, X, Lichtenstein, A, Matthan, N, Torner, J, Lewis, CE, and Nevitt, MC

Subjects
Biomedical and Clinical Sciences, Clinical Sciences, Clinical Research, Osteoarthritis, Nutrition, Chronic Pain, Prevention, Pain Research, Aging, Arthritis, 2.1 Biological and endogenous factors, Aetiology, Musculoskeletal, Aged, Fatty Acids, Female, Humans, Longitudinal Studies, Magnetic Resonance Imaging, Male, Middle Aged, Osteoarthritis, Knee, X-Rays, Knee osteoarthritis, n-3 fatty acids, Saturated fatty acids, Pain, Cartilage, Biomedical Engineering, Human Movement and Sports Sciences, Arthritis & Rheumatology, Clinical sciences, Sports science and exercise
Abstract

ObjectiveInflammation worsens joint destruction in osteoarthritis (OA) and aggravates pain. Saturated and n-6 fatty acids (FAs) increase, whereas n-3 FAs reduce inflammation. We examined whether FA levels affected the development of OA.DesignWe studied participants from the Multicenter Osteoarthritis study (MOST) at risk of developing knee OA. After baseline, repeated knee x-rays and MRIs were obtained and knee symptoms queried through 60 month follow-up. Using baseline fasting samples, serum FAs were analyzed with standard assays. After excluding participants with baseline OA, we defined two sets of cases: those developing radiographic OA and those developing symptomatic OA (knee pain and radiographic OA). Controls did not develop these outcomes. Additionally, we examined worsening of MRI cartilage loss and synovitis and of knee pain using WOMAC and evaluated the number of hand joints affected by nodules. In regression models, we tested the association of each OA outcome with levels of saturated, n-3 and n-6 FAs adjusting for age, sex, BMI, education, race, baseline pain and depressive symptoms.ResultsWe studied 260 cases with incident symptomatic and 259 with incident radiographic OA. Mean age was 61 years (61% women). We found no signficant nor suggestive associations of FA levels with incident OA (e.g., for incident symptomatic OA, OR per s.d. increase in n-3 FA 1.00 (0.85, 1.18) nor with any OA outcome in knee or hand.ConclusionDespite previously described effects on systemic inflammation, blood levels of FAs were not associated with risk of later knee OA or other OA outcomes.

Published
2021

12. CO2 electroreduction on single atom catalysts: the role of the DFT functional

Author

Misra, D, Di Liberto, G, Pacchioni, G, Misra D., Di Liberto G., Pacchioni G., Misra, D, Di Liberto, G, Pacchioni, G, Misra D., Di Liberto G., and Pacchioni G.

Abstract

One key process involving single atom catalysts (SACs) is the electroreduction of CO2 to fuels. The chemistry of SACs differs largely from that of extended catalytic surfaces, presenting an opportunity to improve the ability to activate very stable molecules, such as CO2. In this work, we performed a density functional theory (DFT) study of CO2 activation on a series of SACs, focusing on the role played by the adopted functional in activity predictions. The role of the exchange-correlation functional has been widely investigated in heterogenous catalysts, but it is less explored in SACs. We tested the widely used PBE and the PBE+U corrected functionals against the more robust hybrid PBE0 functional. The results show that PBE is reliable if one is interested in qualitative predictions, but it leads to some inaccuracies in other cases. A possible way to attenuate this effect is by adopting the PBE+U framework, as it gives results that are very similar to PBE0 at an acceptable computational cost. The results of this study further underline the importance of the computational framework adopted in predicting the activity of SACs. The work suggests that one needs to go beyond PBE for quantitative estimates, an important consideration when performing screening and high-throughput calculations.

Published
2024

19. POS1047 STATIN USE ATTENUATES THE IMPACT OF SYSTEMIC INFLAMMATION ON ISCHEMIC CARDIOVASCULAR RISK IN PATIENTS WITH RHEUMATOID ARTHRITIS

Author

Karpouzas, G., primary, Ormseth, S., additional, Van Riel, P., additional, Myasoedova, E., additional, González-Gay, M. Á., additional, Corrales Martinez, A., additional, Rantapää Dahlqvist, S., additional, Sfikakis, P. P., additional, Dessein, P., additional, Tsang, L., additional, Hitchon, C., additional, El-Gabalawy, H., additional, Pascual, V., additional, Contreras-Yáñez, I., additional, Colunga-Pedraza, I. J., additional, Galarza-Delgado, D. A., additional, Azpiri-Lopez, J. R., additional, Semb, A. G., additional, Rollefstad, S., additional, Misra, D. P., additional, Kitas, G., additional, and Hauge, E. M., additional

Published
2024
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24. Weld Pool Dimensions and Mechanical Properties of Laser Welded 2205 Duplex Stainless Steel.

Author

Ghosh, A., Kalvettukaran, P., Misra, D., and Acharyya, S. K.

Subjects
LASER welding, DUPLEX stainless steel, BUTT welding, WELDED joints, WELDING, TENSILE strength
Abstract

The effects of laser beam welding (LBW) process parameters on the characteristics of Nd:YAG laser butt welding 1.5 mm thick 2205 duplex stainless steel. Specifically, the study focuses on the depth of penetration, bead width, ultimate tensile strength (UTS) and elongation. To achieve this, a parametric study is conducted using a central composite design (CCD) with response surface methodology (RSM) to establish mathematical regression equations that identify the key process parameters and their effects on the responses. The investigations showed that the size of the meltpool at the fusion zone (FZ) increases as the laser power increases. This leads to the formation of wider and deeper weld beads, ultimately leading to stronger and more flexible joints. Similarly, pulse width and scanning speed have a significant impact on the weld bead geometry, UTS, and elongation. It is observed that the FZ is free of any visible cracks, voids, or porosity. The LBW process parameters have been optimized to reduce operating costs by lowering the line energy, without compromising the welding quality. The optimal UTS value for the welded joint is around 865 MPa, which is almost equivalent to 99% of the UTS of the 2205 duplex stainless steel base material (BM). To obtain high-quality welded joints, it is recommended to use a laser power ranging from 423 to 425 W, scanning speed of 5.3 mm/s and pulse width of 5.4 ms. [ABSTRACT FROM AUTHOR]

Published
2024

29. Multi-objective Optimization of Laser Cutting Parameters Using Particle Swarm Optimization (PSO).

Author

KALVETTUKARAN, P., CHAKRAVARTY, A. D., and MISRA, D.

Subjects
MULTI-objective optimization, PARTICLE swarm optimization, LASER beam cutting, CERAMIC tiles, SURFACE finishing, FLOOR tiles, ENERGY industries, TILE flooring
Abstract

Studies have shown that unconventional machining offers advantages when it comes to machining ceramics in the form of higher material removal rate (MRR) and better surface finish. This present study focuses on the experimental investigations using a fibre laser to cut 7 mm thick ceramic plates used as glazed floor tiles. It involved a systematic experimental study to determine the relationships between process parameters and machining characteristics. Based on the experimental results, regression equations are developed to estimate the responses as functions of the laser process parameters and gas pressure. The developed regression equations are then used in a particle swarm optimization (PSO) technique with a MATLAB algorithm to minimize glass formation and taper angle in the cutting region which, in turn, improves productivity and surface finish. The optimal parameters of the process are found based on the minimization of the taper angle with relatively low operating energy cost. [ABSTRACT FROM AUTHOR]

Published
2024

33. CO2 electroreduction on single atom catalysts: Is water just a solvent?

Author

Misra, D, Di Liberto, G, Pacchioni, G, Misra D., Di Liberto G., Pacchioni G., Misra, D, Di Liberto, G, Pacchioni, G, Misra D., Di Liberto G., and Pacchioni G.

Abstract

The electrochemical reduction of CO2 on single atom catalysts (SAC) has emerged as a highly promising yet intricate process, requiring an in-depth understanding of each elementary step of the reaction. Most of the theoretical studies pertaining the screening of new efficient catalysts neglect important effects such as the capability of the catalytic site to bind and activate CO2, the occurrence of competing reaction paths via formation of different isomers in the intermediate steps, and the role of water. In this work we will show that these are key aspects of the CO2 reduction reaction (CO2RR). Employing density functional theory, we investigated a series of Transition Metal atoms (Sc-Cu, Mo-Ag, W-Au) embedded in nitrogen doped graphene (TM@4N-Gr) and their activity in the CO2 reduction. Our results show that water is not only solvating the reaction intermediates, but it acts as a ligand itself, competing with CO2 when binding to the catalytic site. This coordination chemistry effect largely affects the stability of the chemical intermediates. Furthermore, only a small fraction of the investigated SACs can bind and activate CO2, and that in most cases the reaction proceeds via formation of the OCHO intermediate and not of the COOH one, as often assumed.

Published
2023

36. Ion-lithium collision dynamics studied with an in-ring MOTReMi

Author

Fischer, D., Globig, D., Goullon, J., Grieser, M., Hubele, R., de Jesus, V. L. B., Kelkar, A., LaForge, A., Lindenblatt, H., Misra, D., Najjari, B., Schneider, K., Schulz, M., Sell, M., and Wang, X.

Subjects
Physics - Atomic Physics
Abstract

We present a novel experimental tool allowing for kinematically complete studies of break-up processes of laser-cooled atoms. This apparatus, the 'MOTReMi', is a combination of a magneto-optical trap (MOT) and a Reaction Microscope (ReMi). Operated in an ion-storage ring, the new setup enables to study the dynamics in swift ion-atom collisions on an unprecedented level of precision and detail. In first experiments on collisions with 1.5 MeV/amu O$^{8+}$-Li the pure ionization of the valence electron as well as ionization-excitation of the lithium target has been investigated.

Published
2012
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39. Assessment of Open Government Data Initiative - A Perception Driven Approach

Author

Mishra, Alka, Misra, D. P., Kar, Arpan Kumar, Babbar, Sunil, Biswas, Shubhadip, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Pandu Rangan, C., Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Kar, Arpan Kumar, editor, Ilavarasan, P. Vigneswara, editor, Gupta, M.P., editor, Dwivedi, Yogesh K., editor, Mäntymäki, Matti, editor, Janssen, Marijn, editor, Simintiras, Antonis, editor, and Al-Sharhan, Salah, editor

Published
2017
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45. Effects of Laser Operating Parameters on Hole Characteristics When Fibre Laser Trepanning Drilling of Glazed Ceramic Tiles.

Author

KALVETTUKARAN, P., REAZ, S., and MISRA, D.

Subjects
CERAMIC tiles, LASER drilling, SURFACE plates, LASERS, FIBER lasers
Abstract

The circularity of the drilled hole at the top and bottom surfaces of the plate, as well as the taper angle of the drilled hole, are important characteristics in drilling that have a significant impact on the quality of a drilled hole. In this present study the laser trepanning drilling process is carried out on 7 mm thick glazed ceramic tiles using a fibre laser. The study investigates the effects of laser process parameters; namely, laser power, scanning speed, frequency and number of trepanning passes on the hole diameter at the top and bottom surfaces of the ceramic tile, the circularity of the hole at the top and bottom surface and the taper angle of the drilled hole. The effects of gas pressure and hole diameter on the hole characteristics are also investigated. It is observed that the circularity of the hole at the top surface increases with an increase in laser power, gas pressure, and hole diameter, whereas the circularity of the hole at the bottom surface decreases with an increase in laser power and scanning speed. It is also observed that the taper angle of the drilled hole increases with an increase in laser power, gas pressure and hole diameter. It is seen that the hole diameters on the top surface of the plate do not get much affected when the trepanning passes are increased. [ABSTRACT FROM AUTHOR]

Published
2024

48. POS0030 METHOTREXATE USE ASSOCIATES WITH ISCHEMIC CARDIOVASCULAR RISK REDUCTION IN MALES BUT NOT FEMALES WITH RHEUMATOID ARTHRITIS

Author

Karpouzas, G., primary, Ormseth, S., additional, Van Riel, P., additional, Crowson, C. S., additional, Myasoedova, E., additional, Gabriel, S., additional, González-Gay, M. A., additional, Corrales, A., additional, Rantapää Dahlqvist, S., additional, Sfikakis, P., additional, Dessein, P., additional, Tsang, L., additional, Hitchon, C., additional, El-Gabalawy, H., additional, Pascual, V., additional, Colunga-Pedraza, I. J., additional, Galarza-Delgado, D. Á., additional, Azpiri-López, J. R., additional, Rollefstad, S., additional, Semb, A. G., additional, Misra, D. P., additional, Kitas, G., additional, and Hauge, E. M., additional

Published
2023
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