Journal articles: '3DPD'

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Bertholdt, Charline, Gabriela Hossu, Claire Banasiak, Marine Beaumont, and Olivier Morel. "First trimester screening for pre-eclampsia and intrauterine growth restriction using three-dimensional Doppler angiography (SPIRIT): protocol for a multicentre prospective study in nulliparous pregnant women." BMJ Open 10, no. 10 (October 2020): e037751. http://dx.doi.org/10.1136/bmjopen-2020-037751.

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IntroductionPre-eclampsia (PE) and intrauterine growth restriction (IUGR) are two major pregnancy complications, related to chronic uteroplacental hypoperfusion. Nowadays, there is no screening or diagnostic test for uteroplacental vascularisation deficiency in pregnant women. Since 2004, 3 three-imensional power Doppler (3DPD) angiography has been used for the evaluation of uteroplacental vascularisation and three vascular indices are usually calculated: Vascularisation Index (VI), Flow Index (FI) and vascularisation-FI (VFI). A high intraobserver and interobserver reproducibility and a potential interest for placental function study were reported by our team and others.The main objective of our study is to determine differences in 3DPD indices at first trimester between pregnancies defined at their outcome as uncomplicated pregnancy, PE (mild and severe) and IUGR in nulliparous women.Methods and analysisThis is a national multicentre prospective cohort study conducted in four French maternity units. We expect to include 2200 women in a period of 36 months. The nulliparous pregnant women will be recruited during their first trimester consultation (11–13+6 gestation week (GW)).The 3DPD and uterine artery Doppler acquisition will be included in the current routine 11–13+6 GW ultrasound. Also, additional blood samples will be taken for biomarker analysis (PAPP-A and P1GF) and biological collection. Uteroplacental VIs (FI and VFI) will be measured. For each subgroup (uncomplicated pregnancy, PE and IUGR), mean values in 3DPD indices will be computed and compared using a pairwise t test with a Bonferroni correction p value adjustment.Ethics and disseminationThe study was approved by the French Ethics Committee, the Comité de Protection des Personnes SUD MEDITERRANEE IV on 13 February 2018 with reference number 17 12 03. The results of this study will be published in a peer-reviewed journal and will be presented at relevant conferences.Trial registration numberNCT03342014; Pre-results. PHRCN-16-0567.

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Bertholdt, Charline, Marie-Laure Eszto, Mathilde Tournier, Gabriela Hossu, Naoual Mellouki, Aboubaker Cherifi, and Olivier Morel. "Assessment of uteroplacental vascularisation in early first-trimester pregnancy with contrast-enhanced ultrasound and 3D power Doppler angiography: protocol for a prospective, cross-sectional, multicentre and non-randomised open study (“HOPE Study”)." BMJ Open 9, no. 9 (September 2019): e030353. http://dx.doi.org/10.1136/bmjopen-2019-030353.

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IntroductionKnowledge about the mechanisms leading to the establishment of uteroplacental vascularisation is inadequate, and some of what has been thought to be known for decades has recently been challenged by showing that the intervillous space, the major area of maternal-fetal exchange, appears to be perfused by maternal blood at as early as 6 weeks of gestation. The vascular flow then seems relatively constant until 13 weeks when it appears to increase suddenly.ObjectivesThe principal objective is to quantify the perfusion of the intervillous space by contrast-enhanced ultrasonography (CEUS) during the first-trimester at three different gestational ages (8, 11 and 13 weeks). The secondary objectives are to: (1) describe the indicators of vascularisation of the placenta (intervillous space) and the myometrium at the three gestational ages, measured by CEUS and three-dimensional power Doppler (3DPD) angiography; (2) compare the diagnostic performance of CEUS and 3DPD for the demonstration and quantification of uteroplacental vascularisation and (3) establish a biological collection of placentas to increase knowledge about placental development and functions during pregnancy.Methods and analysisThis is a prospective, cross-sectional, multicentre and non-randomised open study. We will include 42 women with ongoing pregnancy and divided into three groups of gestational ages (ie, 14 women by per group): 8, 11 and 13 weeks of gestation. 3DPD and then CEUS will be performed and the data about the perfusion kinetics and the 3DPD indices will be calculated and then compared with each other and for each gestational age.Ethics and disseminationThe appropriate French Ethics Committee Est III approved this study and the related consent forms on 5 April 2016, and the competent authority (Agence Nationale de Sécurité du Médicament et des Produits de Santé) authorised the study on 21 June 2016. The results of this study will be published in a peer-reviewed journal and will be presented at relevant conferences.Trial registration numbersClinicalTrials.gov registry (NCT02884297); EudraCT registry (2015-005655-27).

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Simioni, E., C. Re, T. Mudric, G. Cremonese, S. Tulyakov, A. Petrella, A. Pommerol, and N. Thomas. "3DPD: A photogrammetric pipeline for a PUSH frame stereo cameras." Planetary and Space Science 198 (April 2021): 105165. http://dx.doi.org/10.1016/j.pss.2021.105165.

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Re, C., S. Tulyakov, E. Simioni, T. Mudric, G. Cremonese, and N. Thomas. "PERFORMANCE EVALUATION OF 3DPD, THE PHOTOGRAMMETRIC PIPELINE FOR THE CASSIS STEREO IMAGES." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W13 (June 5, 2019): 1443–49. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w13-1443-2019.

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<p><strong>Abstract.</strong> A novel photogrammetric pipeline has been designed by INAF-Padova for the processing of the recent stereo images of CaSSIS and it will be a starting point for the future procedures that will be applied to Stereo Camera (STC) (Cremonese, 2009; Da Deppo, 2010) images for the BepiColombo mission to Mercury. The large number of stereo pairs being generated has made it necessary that several teams attempt to generate products. The presented procedures are the two strategies (proposed by INAF-PADOVA and by EPFLLausanne) available nowadays in an international attempt to generate 3D products from the CaSSIS images. The comparisons here presented will be the first of several such efforts and are important to make the planetary community aware of the accuracy of the 3D data available. Furthermore, the possibility to consider higher accuracy DTMs as the ones of HiRISE makes the quality assessment of stereo products of CaSSIS robust and important for the assessment of data to be provided to the scientific community. The performance evaluation of the INAF-Padova pipeline (3DPD software) is the main objectives of this work. Additionally, the comparison between the correlation phase of 3DPD and of ASP (Moratto, 2010) that is integrated in the EPFL pipeline has been considered.</p>

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Zhang, De Ke, Ying Bin Cao, Rong Jun Liu, and Ya Nan Jiao. "Effect of Braided Structure on Mechanical Properties of C_f/SiC Composites." Advanced Materials Research 538-541 (June 2012): 423–26. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.423.

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Using polycarbosilane(PCS) as precursor materials, 2.5D、3D3d、3D4d、3D5d braided structure Cf/SiC composites were prepared by Precursor Infiltration and Pyrolysis (PIP). The result showed that different braided structure Cf/SiC composites had dissimilar change tendency of density and porosity. The braided structure and pore position influenced mechanical properties of Cf/SiC composites obviously. 2.5D Cf/SiC composites had the lowest mechanical properties compared others braided structure via PIP process, 3D5d Cf/SiC composites had the highest mechanical properties for the bending strength reached 334MPa, modulus 99.5GPa. Furthermore, the microstructure and properties of different braided structure Cf/SiC composites has been investigated by means of SEM.

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Molnár, András, Andrea Surányi, Mária Jakó, Tibor Nyári, and Gábor Németh. "A háromdimenziós power Doppler-indexek és a perinatalis kimenetel vizsgálata méhen belüli növekedési restrikcióval szövődött terhességekben." Orvosi Hetilap 158, no. 26 (July 2017): 1008–13. http://dx.doi.org/10.1556/650.2017.30784.

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Abstract: Introduction: Development of intrauterine growth restriction (IUGR) can be traced back to maternal or fetal factors, but in many cases we find placental factors (reduced placental circulation) in the background. Aim: Our aim was to examine whether the reduced placental bloodperfusion and vascularity show any correlation with cesarean section frequency and the clinical outcome in IUGR pregnancies. The aim of the present study was also to use a properly calibrated and reproducible method for evaluating placental blood flow, that can later be incorporated into the routine examination. Method: 254 women were recruited in our prospective case-control study. The 3 dimensional power Doppler (3DPD) ultrasound indices; vascularisation index (VI), flow index (FI) and vascularization flow index (VFI) were measured on each participant. Results: Median VI was 3.7% (interquartile range [IQR] 3.2%–4.2%) in the IUGR group and 10.1% (IQR 8.6%–10.9%) in the control group (p = 0.001). Median FI value was 40.0 (IQR 39.7–42.5) in the IUGR group and 45.1 (IQR 44.1–53.1) in the control group (p = 0.012). Median VFI was 2.2 (IQR 2.1–2.4) in the IUGR group and 4.8 (IQR 4.4–5.3) in the control. Conclusions: The 3DPD indices may be useful for examining changes in circulation in IUGR pregnancies to characterize the underlying pathology. Orv Hetil. 2017; 158(26): 1008–1013.

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Chen, Sue-Jar, Chie-Pein Chen, Fang-Ju Sun, and Chen-Yu Chen. "Comparison of Placental Three-Dimensional Power Doppler Vascular Indices and Placental Volume in Pregnancies with Small for Gestational Age Neonates." Journal of Clinical Medicine 8, no. 10 (October 11, 2019): 1651. http://dx.doi.org/10.3390/jcm8101651.

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This prospective observational study aimed to compare the changes in placental vascular indices and placental volume using three-dimensional power Doppler (3DPD) ultrasound in pregnancies with small for gestational age (SGA) neonates. We enrolled 396 women with singleton pregnancies from September 2013 to June 2016. Placental vascular indices, including the vascularization index (VI), flow index (FI), and vascularization flow index (VFI), and placental volume were obtained using 3DPD ultrasound in the first and second trimesters. Of the enrolled women, 21 delivered SGA neonates and 375 did not. In the first trimester, the SGA group had a significantly lower mean FI (25.10 ± 7.51 versus 33.10 ± 10.97, p < 0.001) and VFI (4.59 ± 1.95 versus 6.28 ± 2.35, p = 0.001) than the non-SGA group. However, there was no significant difference in the placental volume between the two groups during the first trimester. In the second trimester, the SGA group also had a significantly lower mean FI (27.08 ± 7.97 versus 31.54 ± 11.01, p = 0.022) and VFI (6.68 ± 1.71 versus 8.68 ± 3.09, p < 0.001) than the non-SGA group. In addition, a significantly smaller placental volume was noted in the SGA group (104.80 ± 24.23 cm3 versus 122.67 ± 26.35 cm3, p = 0.003) than in the non-SGA group during the second trimester. The results showed that a decreased placental VFI occurred earlier than a decreased placental volume in SGA pregnancies.

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Nagori, C., and S. Panchal. "OP19.01: Comparison of CD & 3DPD for prehCG follicular & endometrial assessment in IUI cycles." Ultrasound in Obstetrics & Gynecology 38, S1 (September 14, 2011): 110. http://dx.doi.org/10.1002/uog.9435.

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Sciaky-Tamir, Yael, Sarah M. Cohen, Drorith Hochner-Celnikier, Dan V. Valsky, Baruch Messing, and Simcha Yagel. "Three-dimensional power Doppler (3DPD) ultrasound in the diagnosis and follow-up of fetal vascular anomalies." American Journal of Obstetrics and Gynecology 194, no. 1 (January 2006): 274–81. http://dx.doi.org/10.1016/j.ajog.2005.08.045.

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Alcazar, J., S. Guerriero, B. Olartecoechea, S. Ajossa, M. Jurado, and G. B. Melis. "P28.05: Three-dimensional power Doppler angiography (3DPD) in adnexal masses: re-analysis of prospective collected data." Ultrasound in Obstetrics & Gynecology 38, S1 (September 14, 2011): 263. http://dx.doi.org/10.1002/uog.9953.

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Ito, M., J. Noguchi, C. Tenkumo, M. Sato, N. Mori, U. Hanaoka, K. Kanenishi, H. Tanaka, A. Shiota, and T. Hata. "P13.17: Transvaginal 3D power Doppler (3DPD) sonographic evaluation of the fetal brain at 10-13 weeks' gestation." Ultrasound in Obstetrics & Gynecology 40, S1 (September 2012): 222. http://dx.doi.org/10.1002/uog.11942.

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Choudhary, Sumesh, Vineet Mishra, Rohina Aggarwal, and Kavita Mistry. "Evaluation and correlation of placental vasculature by three-dimensional power Doppler ultrasonography with umbilical Doppler in normal and IUGR pregnancies." International Journal of Reproduction, Contraception, Obstetrics and Gynecology 7, no. 9 (August 27, 2018): 3818. http://dx.doi.org/10.18203/2320-1770.ijrcog20183801.

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Background: In recent years there have been significant developments in the use of 3D Power Doppler (3DPD) imaging and quantitative 3DPD histogram analysis to estimate both placental volume and intraplacental vasculature. This study is to evaluate the distribution and variation of placental vascular indices according to gestational age and placental volume and position. Co relate the umbilical Doppler indices with placental vascular indices.Methods: From September 2016 to October 2017, three-dimensional (3D)-power Doppler ultrasound was performed in 200 singalton pregnancies from 20 to 40 weeks of gestation. Using the same pre-established settings for all patients, power Doppler was applied to the placenta and placental volume was obtained by the rotational technique (VOCAL). The 3D-power histogram was used to determine the placental vascular indices: vascularization index (VI), flow index (FI) and vascularization-flow index (VFI). Umbilical Doppler was measured on the free loop of umbilical cord. The placental vascular indices were then plotted against gestational age placental volume, position and umbilical Doppler SD ratio, PI and RI. These values were evaluated in IUGR fetus.Results: Analysis of the results showed that the placental vascular indices estimated by 3D-power Doppler ultrasonography presented constant distribution throughout gestation despite the significant increase in placental volume. Placental position at fundal region shows higher value of VI, FI, and VFI. Placental position with relation to VI, FI, and VFI shows statistically significant with p value <0.01. Placental vascular indices VI, FI and VFI when corelated with systolic/ diastolic ratio, pulsatility index and resistive resistance index of umbilical artery shows poor negative correlation, only VI and FI shows statistically significant with SD ratio as p value is <0.01and <0.04. VFI did not show statistically significant as p value is 0.10(NS). With pulsatility index p value is statistically significant is less than<0.01 with vascular indices. Resistive index p value is statistically significant is less than <0.01 for VI and VFI but not significant with FI as p value is 0.06.Conclusions: Doppler ultrasound assists in the evaluation of placental vascularization in normal and IUGR pregnancies, may play an important role in future research on fetoplacental insufficiency.

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Gebb, J., M. Rosner, T. C. McAndrew, F. H. Einstein, and P. Dar. "P16.03: 3-dimensional power Doppler (3DPD) “biopsy” of the Utero-Placental Circulation Space (UPCS): inter/intraobserver variability and reproducibility." Ultrasound in Obstetrics & Gynecology 40, S1 (September 2012): 230. http://dx.doi.org/10.1002/uog.11972.

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Rodriguez Morante, D., M. Gómez Roig, and J. Alcazar. "OP23.07: Impact of ultrasound system settings on three-dimensional power Doppler ultrasound (3dpd) vascular indexes measurements in secretory endometrium." Ultrasound in Obstetrics & Gynecology 44, S1 (September 2014): 167. http://dx.doi.org/10.1002/uog.13863.

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Morel, O., J. Duan, E. Perdriolle-Galet, V. Tsatsaris, and P. Chavatte-Palmer. "P14.20: Impact of machine settings on 3DPD utero-placental indices in a pregnant sheep model with controlled uterine blood flow." Ultrasound in Obstetrics & Gynecology 44, S1 (September 2014): 266. http://dx.doi.org/10.1002/uog.14274.

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Panchal, S. Y., and C. B. Nagori. "OP18.09: 3D and 3DPD assessment of polycystic ovaries and correlation of these parameters to 2D, CD parameters (study of 125 patients)." Ultrasound in Obstetrics and Gynecology 32, no. 3 (August 2008): 374. http://dx.doi.org/10.1002/uog.5818.

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Gabriel, P., J. Duan, G. Hossu, A. Cherifi, M. Dap, M. Beaumont, G. Ambroise‐Grandjean, C. Bertholdt, E. Perdriolle‐Galet, and O. Morel. "VP37.15: Third trimester placental 3DPD quantification is feasible only for non‐posterior placentas: first results from the prospective EVUPA study 1." Ultrasound in Obstetrics & Gynecology 56, S1 (October 2020): 220. http://dx.doi.org/10.1002/uog.22912.

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Muñante-Cardenas, JoseLuis, and LuisAugusto Passeri. "Biomechanical Comparison of Four Mandibular Angle Fracture Fixation Techniques." Craniomaxillofacial Trauma & Reconstruction 8, no. 2 (June 2015): 123–28. http://dx.doi.org/10.1055/s-0034-1393737.

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The aim of this study was to make a comparison of the biomechanical behavior of four different internal fixation systems for mandibular angle fractures. A total of 40 polyurethane mandible replicas were employed with different fixation methods: group 1SP, one 2.0-mm four-hole miniplate; group 2PPL, two 2.0-mm four-hole parallel miniplates; group 3DP, one 3D 2.0-mm four-hole miniplate; and group 3DPP, one 3D 2.0-mm eight-hole miniplate. Each group was subjected to incisal or homolateral molar region loading. The load resistance values were measured at load application causing tip displacement of 1, 3, and 5 mm, and at the time at which the system achieves its maximum strength (MS). Means and standard deviations were compared among groups using analysis of variance and the Tukey test. Group 2PPL showed higher strength for all the displacements. For incisal loading, no statistically significant differences were found between groups 1SP, 3DP, and 3DPP. For molar loading, group 1SP and 3DPP showed statistically significant differences. For MS testing, group 1SP and 2PPL showed statistically significant differences in incisal loading; group 1SP and 3DP showed no statistically significant differences; and group 3DPP showed lower values of strength. Two parallel miniplates provide the most favorable mechanical behavior under the conditions tested.

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Abdel-Hamid, Ahmed Sherif, Mohamed Sayed Aly, Shahira Zakaria Mohamed Ali Ghaly, and Maged Mahmoud Elshourbagy. "Detecting Accuracy of Three Dimensional Power Doppler (3DPD) Vascular Indices for Prenatal Diagnosis of Morbidly Adherent Placenta in Patients with Placenta Previa." Open Journal of Obstetrics and Gynecology 10, no. 01 (2020): 49–64. http://dx.doi.org/10.4236/ojog.2020.101005.

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Kuo, Cheng-Hsiang, Yi-Hsun Huang, Po-Ku Chen, Gang-Hui Lee, Ming-Jer Tang, Edward M. Conway, Guey-Yueh Shi, and Hua-Lin Wu. "VEGF-Induced Endothelial Podosomes via ROCK2-Dependent Thrombomodulin Expression Initiate Sprouting Angiogenesis." Arteriosclerosis, Thrombosis, and Vascular Biology 41, no. 5 (May 5, 2021): 1657–71. http://dx.doi.org/10.1161/atvbaha.121.315931.

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Objective: VEGF (vascular endothelial growth factor) plays a critical role in physiological and pathological angiogenesis. Endothelial 3D podosomes (3DPs) are a type of F-actin-rich membrane microdomain, predominantly found in endothelial tip cells controlled by VEGF signaling during sprouting angiogenesis, such as occurs in retinal vasculature development. The molecular mechanisms governing 3DP formation have not been completely elucidated. Approach and Results: By using in vitro cell models and in vivo mouse models, we study the role of TM (thrombomodulin) in VEGF-induced endothelial 3DPs. Here, we report that VEGF can induce the expression of TM via ROCK2 (Rho-associated coiled-coil kinase 2). Furthermore, ROCK2 can catalyze the phosphorylated activation of ezrin to promote the association of the cytoplasmic domain of TM with F-actin in 3DPs and thereby promote the formation of 3DPs. We used endothelial cells transfected with different TM mutants as models to verify the role of TM domains in 3DPs and angiogenic activity. TM expression in endothelial cells augments angiogenic activity, a response that is dependent on the interaction of the cytoplasmic tail of TM with ezrin, and the integrity of the lectin-like domain of TM. Thus, as compared with wild-type counterparts, mice lacking the lectin-like domain of TM exhibit reduced neovascularization of granulation tissues during cutaneous wound healing and less retinal neovascularization in a model of oxygen-induced retinopathy. Conclusions: VEGF-ROCK2-ezrin-TM-F-actin axis promotes the formation of the lipid raft membrane-associated complex configuration, 3DP, which plays a critical role in mediating tube formation and cell migration of endothelial cells in sprouting angiogenesis.

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Suntharalingam, Thadshajini, Irindu Upasiri, Perampalam Gatheeshgar, Keerthan Poologanathan, Brabha Nagaratnam, Heshachanaa Rajanayagam, and Satheeskumar Navaratnam. "Fire resistance of 3D printed concrete composite wall panels exposed to various fire scenarios." Journal of Structural Fire Engineering 12, no. 3 (July 15, 2021): 377–409. http://dx.doi.org/10.1108/jsfe-10-2020-0029.

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Purpose Fire safety of a building is becoming a prominent consideration due to the recent fire accidents and the consequences in terms of loss of life and property damage. ISO 834 standard fire test regulation and simulation cannot be applied to assess the fire performance of 3D printed concrete (3DPC) walls as the real fire time-temperature curves could be more severe, compared to standard fire curve, in terms of the maximum temperature and the time to reach that maximum temperature. Therefore, this paper aims to describe an investigation on the fire performance of 3DPC composite wall panels subjected to different fire scenarios. Design/methodology/approach The fire performance of 3DPC wall was traced through developing an appropriate heat transfer numerical model. The validity of the developed numerical model was confirmed by comparing the time-temperature profiles with available fire test results of 3DPC walls. A detailed parametric study of 140 numerical models were, subsequently, conducted covering different 3DPC wall configurations (i.e. solid, cavity and rockwool infilled cavity), five varying densities and consideration of four fire curves (i.e. standard, hydrocarbon fire, rapid and prolong). Findings 3DPC walls and Rockwool infilled cavity walls showed superior fire performance. Furthermore, the study indicates that the thermal responses of 3DPC walls exposed to rapid-fire is crucial compared to other fire scenarios. Research limitations/implications To investigate the thermal behaviour, ABAQUS allows performing uncoupled and coupled thermal analysis. Coupled analysis is typically used to investigate combined mechanical-thermal behaviour. Since, considered 3DPC wall configurations are non-load bearing, uncouple heat transfer analysis was performed. Time-temperature variations can be obtained to study the thermal response of 3DPC walls. Originality/value At present, there is limited study to analyse the behaviour of 3DPC composite wall panels in real fire scenarios. Hence, this paper presents an investigation on the fire performance of 3DPC composite wall panels subjected to different fire scenarios. This research is the first attempt to extensively study the fire performance of non-load bearing 3DPC walls.

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Yun, Hae Yong, and Ho Chan Kim. "Basic Research For The 3DCD (3D Circuit Devices)." Journal of the Korean Society for Precision Engineering 31, no. 12 (December 1, 2014): 1061–66. http://dx.doi.org/10.7736/kspe.2014.31.12.1061.

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Yin, Hao, and Guang Xue Chen. "3D Printing Job Editor for Workflow Visualization Design and Implementation." Applied Mechanics and Materials 644-650 (September 2014): 2661–65. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.2661.

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This paper presents design and development of a viewing and editing tool, namely 3DPJ Editor, for Workflow visualization of 3D Print Job files. 3D Print Job (3DPJ) is an XML based format for 3D Printing job purposed to enable automation and integration of multiple vendor systems in a 3D Printing manufacture environment. The paper also shows preliminary 3DPJ format for further development of 3D Printing manufacture community with multiple vendors. The 3DPJ Format tries to separate content information and meta-data of 3D Print Jobs, in order to integrate different processes into one standard 3D Printing Workflow. The complete specification of 3DPJ should be further complex and comprehensive, and it should be gradually adopted by major 3D Printer vendors.

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Paul, Suvash Chandra, Gideon P. A. G. van Zijl, Ming Jen Tan, and Ian Gibson. "A review of 3D concrete printing systems and materials properties: current status and future research prospects." Rapid Prototyping Journal 24, no. 4 (May 14, 2018): 784–98. http://dx.doi.org/10.1108/rpj-09-2016-0154.

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Purpose Three-dimensional printing of concrete (3DPC) has a potential for the rapid industrialization of the housing sector, with benefits of reduced construction time due to no formwork requirement, ease of construction of complex geometries, potential high construction quality and reduced waste. Required materials adaption for 3DPC is within reach, as concrete materials technology has reached the point where performance-based specification is possible by specialists. This paper aims to present an overview of the current status of 3DPC for construction, including existing printing methods and material properties required for robustness of 3DPC structures or structural elements. Design/methodology/approach This paper has presented an overview of three categories of 3DPC systems, namely, gantry, robotic and crane systems. Material compositions as well as fresh and hardened properties of mixes currently used for 3DPC have been elaborated. Findings This paper presents an overview of the state of the art of 3DPC systems and materials. Research needs, including reinforcement in the form of bars or fibres in the 3D printable cement-based materials, are also addressed. Originality/value The critical analysis of the 3D concrete printing system and materials described in this review paper is original.

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Song, Xuejing, Lingqian Kong, Hongmei Du, Xiangyu Li, Hanlin Feng, Jinsheng Zhao, and Yu Xie. "Effects of Pyrazine Derivatives and Substituted Positions on the Photoelectric Properties and Electromemory Performance of D–A–D Series Compounds." Materials 11, no. 10 (October 22, 2018): 2063. http://dx.doi.org/10.3390/ma11102063.

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Pyrazine derivatives quinoxaline and pyridopyrazine were selected as the acceptors, and benzocarbazole was used as the donor to synthesize four different D–A–D compounds. The results showed that 2,3-bis(decyloxy)pyridine[3,4-b]pyrazine (DPP) exhibited stronger electron-withdrawing ability than that of 2,3-bis(decyloxy)quinoxaline (DPx), because DPP possesses one more nitrogen (N) atom, resulting in a red-shift of the intramolecular charge transfer (ICT) absorption bands and fluorescent emission spectra for compounds with DPP as the acceptor compared with those that use DPx as the acceptor. The band-gap energy (Eg) of the four D–A–D compounds were 2.82 eV, 2.70 eV, 2.48 eV, and 2.62 eV, respectively, for BPC-2DPx, BPC-3DPx, BPC-2DPP, and BPC-3DPP. The solvatochromic effect was insignificant when the four compounds were in the ground state, which became significant in an excited state. With increasing solvent polarity, a 30–43 nm red shift was observed in the emissive spectra of the compounds. The thermal decomposition temperatures of the four compounds between 436 and 453 °C had very high thermal stability. Resistor-type memory devices based on BPC-2DPx and BPC-2DPP were fabricated in a simple sandwich configuration, Al/BPC-2DPx/ITO or Al/BPC-2DPP/ITO. The two devices showed a binary non-volatile flash memory, with lower threshold voltages and better repeatability.

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Che, Yujun, Shengwen Tang, Huashan Yang, Weiwei Li, and Mengyuan Shi. "Influences of Air-Voids on the Performance of 3D Printing Cementitious Materials." Materials 14, no. 16 (August 8, 2021): 4438. http://dx.doi.org/10.3390/ma14164438.

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This paper focuses on inspecting the influences of anti-foaming agent (AFA) on the performance of 3D printing cementitious materials (3DPC). The mini-slump, spreading diameter, yield stress, and strength of 3DPC were evaluated. Additionally, the air-void content, air-void morphology, and air-void size distribution of mortar with and without 0.05% AFA were assessed through image analysis. The mechanical performance and air-void structure of 3D printed samples were also investigated and compared to that of conventionally mould cast samples. Test results show that an optimal AFA content enables 3DPC to achieve favorable workability and mechanical performance. The addition of AFA exhibits lower air-void content in 3DPC than that of the sample without the AFA addition. This reduction in air-void content is further strengthened by the results of strength analysis. Electron microscope analysis shows that the use of AFA results in the suppressed formation of large air-voids during the process of fresh 3DPC. Moreover, the air-void morphology substantially influenced the mechanical performance of hardened 3DPC.

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Stoebe, Stephan, Dietrich Pfeiffer, and Andreas Hagendorff. "Feasibility of 3D4D echocardiography for the detection of colour-coded flow in the left anterior descending artery." Echo Research and Practice 1, no. 1 (August 2014): 23–30. http://dx.doi.org/10.1530/erp-14-0024.

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The aim of this study was to test the feasibility of the visualisation of 3D4D coronary flow in detectable segments of coronary arteries. Regarding the feasibility of this new approach, the hypothesis was proposed that the flow signals of the course of detectable coronary arteries can be better visualised by 3D4D echocardiography than by the conventional 2D approach. A total of 30 consecutive patients with sinus rhythm, in whom the distal left anterior descending artery (LAD) was visualised by 2D colour-coded Doppler echocardiography, were selected for 3D4D scanning procedures. All measurements were performed using a Vivid 7 or E9. All segments visualised by 2D colour-coded Doppler echocardiography were also examined by 3D4D echocardiography. Using defined settings, the width of the colour-coded flow signal differs significantly between 2D- and 3D4D echocardiography. The length of larger segments of the visualised colour-coded flow signal of the coronary flow could be better detected with 2D imaging. Small segments of coronary artery flow (<11 mm), however, could be significantly better visualised by 3D4D echocardiography. The main advantage of 3D4D echocardiography of the coronary artery flow is the visualisation of the proportions of vessels with complex morphology. 3D4D echocardiography of LAD flow by colour-coded Doppler echocardiography raises new possibilities for the direct flow visualisation of the detectable segments of coronaries. With its sufficiently high spatial and temporal resolution, this new method has the potential to be implemented in clinical scenarios. The possible application to the quantification of stenoses by the flow visualisation has to be evaluated in further studies.

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Ge, Meng, Xiaodong Zou, and Zhehao Huang. "Three-Dimensional Electron Diffraction for Structural Analysis of Beam-Sensitive Metal-Organic Frameworks." Crystals 11, no. 3 (March 8, 2021): 263. http://dx.doi.org/10.3390/cryst11030263.

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Electrons interact strongly with matter, which makes it possible to obtain high-resolution electron diffraction data from nano- and submicron-sized crystals. Using electron beam as a radiation source in a transmission electron microscope (TEM), ab initio structure determination can be conducted from crystals that are 6–7 orders of magnitude smaller than using X-rays. The rapid development of three-dimensional electron diffraction (3DED) techniques has attracted increasing interests in the field of metal-organic frameworks (MOFs), where it is often difficult to obtain large and high-quality crystals for single-crystal X-ray diffraction. Nowadays, a 3DED dataset can be acquired in 15–250 s by applying continuous crystal rotation, and the required electron dose rate can be very low (<0.1 e s−1 Å−2). In this review, we describe the evolution of 3DED data collection techniques and how the recent development of continuous rotation electron diffraction techniques improves data quality. We further describe the structure elucidation of MOFs using 3DED techniques, showing examples of using both low- and high-resolution 3DED data. With an improved data quality, 3DED can achieve a high accuracy, and reveal more structural details of MOFs. Because the physical and chemical properties of MOFs are closely associated with their crystal structures, we believe 3DED will only increase its importance in developing MOF materials.

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Lipson, Hod. "Welcome to 3DP." 3D Printing and Additive Manufacturing 1, no. 1 (March 2014): 1. http://dx.doi.org/10.1089/3dp.2013.1501.

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Suntharalingam, Thadshajini, Perampalam Gatheeshgar, Irindu Upasiri, Keerthan Poologanathan, Brabha Nagaratnam, Heshachanaa Rajanayagam, and Satheeskumar Navaratnam. "Numerical Study of Fire and Energy Performance of Innovative Light-Weight 3D Printed Concrete Wall Configurations in Modular Building System." Sustainability 13, no. 4 (February 20, 2021): 2314. http://dx.doi.org/10.3390/su13042314.

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3D Printed Concrete (3DPC) technology is currently evolving with high demand amongst researches and the integration of modular building system (MBS) with this technology would provide a sustainable solution to modern construction challenges. The use of lightweight concrete in such innovative construction methods offers lightweight structures with better heat and sound insulation compared to normal weight concrete. It is worth noting that fire and energy performance has become central to building design. However, there are limited research studies on the combined thermal energy and fire performance of 3DPC walls. Therefore, this study investigates fire performance of 20 numbers of varying 3DPC wall configurations using validated finite element models under standard fire conditions. The fire performance analysis demonstrated that 3DPC non-load bearing cavity walls have substantial resistance under standard fire load and its performance can be further improved with Rockwool insulation. There is significant improvement in terms of fire performance when the thickness of the walls increases in a parallel row manner. Previous thermal energy investigation also showed a lower U-value for increased thickness of similar 3DPC walls. This research concludes with a proposal of using 3DPC wall with Rockwool insulation for amplified combined thermal energy and fire performance to be used in MBS.

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Ohmori, Shunichi. "The impact of location of 3D printers and robots on the supply chain." Uncertain Supply Chain Management 9, no. 2 (2021): 489–500. http://dx.doi.org/10.5267/j.uscm.2021.1.002.

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3D printers and robots (3DPR) are new technologies that may disrupt traditional supply chains.The location of the manufacturing place can be moved toward more customer side in the supply chain, which brings both agility and the ability of customization.The impact is yet to be examined quantitatively. In this paper we study the location of 3DPR in the supply chain. We present and compare three models of supply chains: Traditional supply chain; 3DPR at warehouse; 3DPR at shop. The semodels are compared by the equipment installation cost, the production cost,and inventory cost for safety-stock. The study presents a practical case study motivated from a real-world apparel company, discusses the three models under various parameter settings, comparing the obtained total cost and discovers the advantages and disadvantages.

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Hoefer, Kevin, Alexander Nitsche, André Haelsig, and Peter Mayr. "Manufacturing of Titanium Components with 3DPMD." Metals 9, no. 5 (May 14, 2019): 562. http://dx.doi.org/10.3390/met9050562.

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Within this work, the 3D plasma metal deposition (3DPMD) process is introduced as an additive manufacturing process for titanium components. For this purpose, demonstrators were designed, manufactured and subsequently analyzed. Process-structure-property relationships are discussed. By analyzing the microstructure, the chemical composition and the mechanical-technological properties, it is shown that the production of titanium parts with 3DPMD is possible. The micro tensile tests showed that a load parallel to the build direction is the most critical case for the component. Furthermore, a brittle material behavior could be determined due to enhanced oxygen content in the component. By subsequent heat treatment, the brittle failure behavior could be increased to a fracture elongation of 4.6%. In sum, the 3DPMD process has the potential to manufacture near-net-shape titanium parts out of metal powders. Critical issues are the protection of the weldment and the lack of ductility of the titanium component.

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Chaudhuri, Atanu, Helen Rogers, Peder Soberg, and Kulwant S. Pawar. "The role of service providers in 3D printing adoption." Industrial Management & Data Systems 119, no. 6 (July 8, 2019): 1189–205. http://dx.doi.org/10.1108/imds-08-2018-0339.

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Purpose The purpose of this paper is to identify challenges faced by industrial firms at different phases of adoption of 3D printing (3DP), and outline how 3DP service providers can help address these challenges. Design/methodology/approach Separate interview questionnaires for 3DP users and 3DP service providers were used to conduct semi-structured interviews. Findings The key 3DP adoption challenges are as follows: creating a business case; difficulty in using different materials; optimising the process for specific parts; lack of “plug and play” solutions offered by equipment manufacturers; limited availability of training and educational support; poor end product quality; machine breakdowns; and high cost of maintenance and spare components. Using the theoretical lens of the technology acceptance model, results show a lack of ease of use and technological turbulence impact companies’ decisions to adopt 3DP. 3DP service providers can indeed attempt to alleviate the above challenges faced by customers through providing multiple 3DP services across different stages of adoption. Research limitations/implications Future research should examine the role of 3DP equipment manufacturers and design and modeling software solutions providers in improving adoption and how 3DP equipment manufacturers could develop into more integrated service providers as the technology advances. Practical implications Service providers can help customers transition to 3DP and should develop a portfolio of services that fits different phases of adoption. Originality/value The paper outlines how 3DP service providers can help address customer challenges in adoption of 3DP across different stages of adoption.

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Alaluss, Khaled, and Peter Mayr. "Additive Manufacturing of Complex Components through 3D Plasma Metal Deposition—A Simulative Approach." Metals 9, no. 5 (May 17, 2019): 574. http://dx.doi.org/10.3390/met9050574.

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This study examines simulative experimental investigations on the additive manufacturing of complex component geometries using 3D plasma metal deposition (3DPMD). Here, complex contour surfaces for a cross-rolling tool were produced from weld metals in multilayer technology through 3DPMD. As a consequence of the special features of 3DPMD with large-weld metal volumes, greatly differing properties between base material/deposited material and asymmetrical heat input, the resulting shrinkage, deformation and residual stresses are particularly critical. These lead to dimensional and form deviations as well as the formation of cracks, which has a negative influence on the quality of the plasma deposition-welded component structures. By means of the thermo-elastic-plastic simulation model, the temperature field distribution, deformation, and residual stresses occurring during additive 3DPMD of tool contours were predicted and analyzed. The temperature field distribution and its gradients were determined using the ellipsoid heat-source model for the 3DPMD process. On this basis, a coupled thermo-elastic-plastic structural–mechanical analysis was performed. Accordingly, the results achieved were used for the production of almost-net-shaped tool contour surfaces with predefined layer properties. The acquired simulation results of the temperature fields, deformation, and residual stress condition show good alignment with the experimental results.

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Lam, Hugo K. S., Li Ding, T. C. E. Cheng, and Honggeng Zhou. "The impact of 3D printing implementation on stock returns." International Journal of Operations & Production Management 39, no. 6/7/8 (December 2, 2019): 935–61. http://dx.doi.org/10.1108/ijopm-01-2019-0075.

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Purpose The purpose of this paper is to theoretically hypothesize and empirically test the impact of 3D printing (3DP) implementation on stock returns. It further explores how the stock returns due to 3DP implementation vary across different industry environments. Design/methodology/approach This paper integrates the dynamic capabilities view with contingency theory to provide a contingent dynamic capabilities (CDC) perspective on 3DP implementation. It argues that implementing 3DP enables firms to enhance their manufacturing capabilities and gain a competitive advantage, but the extent to which the competitive advantage can be realized is contingent on the fit between 3DP-enhanced manufacturing capabilities and firms’ operating environments. Those arguments are tested based on an event study of 232 announcements of 3DP implementation made by US publicly listed firms between 2010 and 2017. Findings The event study results show that firms implementing 3DP gain higher stock returns compared with their non-implementation industry peers over two years after the implementation. Such stock returns due to 3DP implementation are more pronounced for firms operating in more munificent, more dynamic and less competitive industry environments. Those findings are consistent with the CDC perspective. Originality/value This is the first research empirically examining the impact of 3DP implementation on stock returns. It provides important implications for managers to implement 3DP to enhance firms’ manufacturing capabilities and for researchers to study 3DP implementation from the CDC perspective.

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Li, Jie, Jincheng Zhang, Heqi Gong, Li Tao, Yanqing Wang, and Qiang Guo. "Efficient Deep-Blue Electroluminescence Employing Heptazine-Based Thermally Activated Delayed Fluorescence." Photonics 8, no. 8 (July 22, 2021): 293. http://dx.doi.org/10.3390/photonics8080293.

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We report an efficient deep-blue organic light-emitting diode (OLED) based on a heptazine-based thermally activated delayed fluorescent (TADF) emitter, 2,5,8-tris(diphenylamine)-tri-s-triazine (HAP-3DPA). The deep-blue-emitting compound, HAP-3DPA, was designed and synthesized by combining the relatively rigid electron-accepting heptazine core with three electron-donating diphenylamine units. Due to the rigid molecular structure and intramolecular charge transfer characteristics, HAP-3DPA in solid state presented a high photoluminescence quantum yield of 67.0% and obvious TADF nature with a short delayed fluorescent lifetime of 1.1 μs. Most importantly, an OLED incorporating HAP-3DPA exhibited deep-blue emission with Commission Internationale de l’Eclairage (CIE) coordinates of (0.16, 0.13), a peak luminance of 10,523 cd/m−2, and a rather high external quantum efficiency of 12.5% without any light out-coupling enhancement. This finding not only reports an efficient deep-blue TADF molecule, but also presents a feasible pathway to construct high-performance deep-blue emitters and devices based on the heptazine skeleton.

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Li, Zuhao, Chenyu Wang, Chen Li, Zhonghan Wang, Fan Yang, He Liu, Yanguo Qin, and Jincheng Wang. "What we have achieved in the design of 3D printed metal implants for application in orthopedics? Personal experience and review." Rapid Prototyping Journal 24, no. 8 (November 12, 2018): 1365–79. http://dx.doi.org/10.1108/rpj-10-2017-0205.

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PurposeThis paper aims to review the latest applications in terms of three-dimensional printed (3DP) metal implants in orthopedics, and, importantly, the design of 3DP metal implants through a series of cases operated at The Second Hospital of Jilin University were presented.Design/methodology/approachThis paper is available to practitioners who are use 3DP implants in orthopedics. This review began with the deficiency of traditional prostheses and basic concepts of 3DP implants. Then, representative 3DP clinical cases were summarized and compared, and the experiences using customized prostheses and directions for future potential development are also shown.FindingsThe results obtained from the follow-up of clinical applications of 3DP implants show that the 3D designed and printed metal implants could exhibit good bone defect matching, quick and safe joint functional rehabilitation as well as saving time in surgery, which achieved high patient satisfaction collectively.Originality/valueSingle center experiences of 3DP metal implants design were shared and the detailed technical points between various regions were compared and analyzed. In conclusion, the 3DP technology is infusive and will present huge potential to reform future orthopedic practice.

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Lee, Won Hee, Dong Soo Kim, Jung Su Kim, and Min Cheol Lee. "A Study on Reduction of Processing Time and Improvement of Strength by Using Photopolymer Resin in the 3DP Process." Key Engineering Materials 326-328 (December 2006): 151–54. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.151.

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3DP(three dimensional printing) technology is one of SFF(solid freeform fabrication) technologies which have recently come into a spotlight due to its adaptability to various applications. This technology has a great advantage in terms of short fabrication time for a prototype at a low cost, especially when it comes with multi-nozzle inkjet printing technology. However, it has also a disadvantage since it requires additional curing time, after jetting a binder material, and post-processing time in order to increase the mechanical strength of a product. In this study, a novel 3DP process is proposed to overcome slow solidification and elaborate post-process by adopting photo curing method into the conventional 3DP process. Mechanical properties, such as tensile and bending strengths, of specimens fabricated with the proposed 3DP process were measured and compared with those fabricated with the conventional 3DP process. As a result, it is found that mechanical strengths of specimens from the proposed novel 3DP process show three times higher than those from the conventional 3DP process. Besides, the overall fabrication time with the proposed novel 3DP process is about two times faster than that with the conventional 3DP process, because it does not need additional curing and post-processing time.

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Bolles, Robert C., and Patrice Horaud. "3DPO: A Three- Dimensional Part Orientation System." International Journal of Robotics Research 5, no. 3 (September 1986): 3–26. http://dx.doi.org/10.1177/027836498600500301.

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Braziotis, Christos, Helen Rogers, and Ajeseun Jimo. "3D printing strategic deployment: the supply chain perspective." Supply Chain Management: An International Journal 24, no. 3 (May 7, 2019): 397–404. http://dx.doi.org/10.1108/scm-09-2017-0305.

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Purpose The emergence and application of 3D Printing (3DP) is changing the way products are developed and reach the customer, allowing for unprecedented customisation options. Past research has focussed on the modus operandi of the technology, providing indications for wider future adoption. 3DP is predicted to complement current production processes and is anticipated to have a profound effect on the value chain and, therefore, on supply chain (SC) management. Management-related 3DP research has, however, been largely fragmented in terms of analysing the strategic deployment of 3DP and the corresponding effects on performance objectives. The aim of this paper is to identify, define and exemplify typical 3DP deployment strategies pursued. Design/methodology/approach The approach taken is a critical literature review, synthesising and interpreting past research on cross-industry deployment of 3DP, including illustrative examples. This enabled the development of a framework of current stage knowledge. Findings Building on past research, the authors propose a conceptual framework to be used as a classification system for 3DP operations, based on process and SC level configurations across different industries. They discuss the potential impact on operations performance objectives and then highlight research gaps, proposing specific research avenues to enhance understanding of the effects of 3DP adoption on SCs. Practical implications The proposed framework outlines strategic guidelines for 3DP and provides practitioners with the range of strategic options available for 3DP deployment and anticipated impacts on performance. Originality/value The framework can be used to map 3DP deployment at an operational level and identify the likely impact on performance objectives. Relevant implications and a future research agenda are explored.

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Ji, Yuwei, Hugues Plourde, Valerie Bouzo, Robert D. Kilgour, and Tamara R. Cohen. "Validity and Usability of a Smartphone Image-Based Dietary Assessment App Compared to 3-Day Food Diaries in Assessing Dietary Intake Among Canadian Adults: Randomized Controlled Trial." JMIR mHealth and uHealth 8, no. 9 (September 9, 2020): e16953. http://dx.doi.org/10.2196/16953.

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Background Accurate dietary assessment is needed in studies that include analysis of nutritional intake. Image-based dietary assessment apps have gained in popularity for assessing diet, which may ease researcher and participant burden compared to traditional pen-to-paper methods. However, few studies report the validity of these apps for use in research. Keenoa is a smartphone image-based dietary assessment app that recognizes and identifies food items using artificial intelligence and permits real-time editing of food journals. Objective This study aimed to assess the relative validity of an image-based dietary assessment app — Keenoa — against a 3-day food diary (3DFD) and to test its usability in a sample of healthy Canadian adults. Methods We recruited 102 participants to complete two 3-day food records. For 2 weeks, on 2 non-consecutive days and 1 weekend day, in random order, participants completed a traditional pen-to-paper 3DFD and the Keenoa app. At the end of the study, participants completed the System Usability Scale. The nutrient analyses of the 3DFD and Keenoa data before (Keenoa-participant) and after they were reviewed by dietitians (Keenoa-dietitian) were analyzed using analysis of variance. Multiple tests, including the Pearson coefficient, cross-classification, kappa score, % difference, paired t test, and Bland-Altman test, were performed to analyze the validity of Keenoa (Keenoa-dietitian). Results The study was completed by 72 subjects. Most variables were significantly different between Keenoa-participant and Keenoa-dietitian (P<.05) except for energy, protein, carbohydrates, fiber, vitamin B1, vitamin B12, vitamin C, vitamin D, and potassium. Significant differences in total energy, protein, carbohydrates, % fat, saturated fatty acids, iron, and potassium were found between the 3DFD and Keenoa-dietitian data (P<.05). The Pearson correlation coefficients between the Keenoa-dietitian and 3DFD ranged from .04 to .51. Differences between the mean intakes assessed by the 3DFD and Keenoa-dietitian were within 10% except for vitamin D (misclassification rate=33.8%). The majority of nutrients were within an acceptable range of agreement in the Bland-Altman analysis; no agreements were seen for total energy, protein, carbohydrates, fat (%), saturated fatty acids, iron, potassium, and sodium (P<.05). According to the System Usability Scale, 34.2% of the participants preferred using Keenoa, while 9.6% preferred the 3DFD. Conclusions The Keenoa app provides acceptable relative validity for some nutrients compared to the 3DFD. However, the average intake of some nutrients, including energy, protein, carbohydrates, % fat, saturated fatty acids, and iron, differed from the average obtained using the 3DFD. These findings highlight the importance of verifying data entries of participants before proceeding with nutrient analysis. Overall, Keenoa showed better validity at the group level than the individual level, suggesting it can be used when focusing on the dietary intake of the general population. Further research is recommended with larger sample sizes and objective dietary assessment approaches.

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Ganesan, K., and S. Parthasarathy. "PSS-3D1D: an improved 3D1D profile method of protein fold recognition for the annotation of twilight zone sequences." Journal of Structural and Functional Genomics 12, no. 4 (December 2011): 181–89. http://dx.doi.org/10.1007/s10969-011-9119-x.

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Lin, Yi-Chen, Li-Ying Huang, and Chen-Sheng Chen. "Strength Evaluation and Modification of a 3D Printed Anterior Ankle Foot Orthoses." Applied Sciences 10, no. 20 (October 18, 2020): 7289. http://dx.doi.org/10.3390/app10207289.

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Ankle foot orthosis (AFO) is widely used to prevent foot drop and improve walking ability for individuals with cerebral palsy and stroke. However, traditional anterior AFO (TAAFO) could only last within months because the bilateral neck of TAAFO was easy to break. Currently, a 3D-printing technique is used to develop assistive devices for rehabilitation. The study aimed to implement the finite element (FE) method to revise the 3D printed AAFO (3DP-AAFO) and evaluate its strength. A 3.2 mm-thickness for the TAAFOs and 3DP-AAFOs were fabricated, respectively. The stiffness of TAAFO and 3DP-AAFO were tested by a material machine and compared to the FE model. In the FE analysis, the thickness of AAFO model was increased at the neck to enhance its strength. A plantarflexion and dorsiflexion moment were respectively subjected to 3DP-AAFO models to undergo stress analysis. Under the mechanical test, the 3DP-AAFO (K = 1.09 Nm/degree) was 7.8 times stiffer than the traditional AAFO (K = 0.14 Nm/degree). The FE results showed that thickening the 3DP-AAFO on the neck up to 4.7 mm could moderate stress concentration and increase the stiffness of the 3DP-AAFO. Therefore, the study concluded that the 3DP-AAFO was stiffer than the traditional AAFO. Increasing the appropriate thickness around neck of 3DP-AAFO could avoid neck fracture as much as possible.

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Chaudhuri, Atanu, Hussein Naseraldin, Peder Veng Søberg, Ehud Kroll, and Michael Librus. "Should hospitals invest in customised on-demand 3D printing for surgeries?" International Journal of Operations & Production Management 41, no. 1 (November 16, 2020): 55–62. http://dx.doi.org/10.1108/ijopm-05-2020-0277.

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PurposeThe purpose of this research is to (1) analyse the effect of customised on-demand 3DP on surgical flow time, its variability and clinical outcomes (2) provide a framework for hospitals to decide whether to invest in 3DP or to outsource.Design/methodology/approachThe research design included interviews, workshops and field visits. Design science approach was used to analyse the impact of the 3D printing (3DP) interventions on specific outcomes and to develop frameworks for hospitals to invest in 3DP, which were validated through further interviews with stakeholders.FindingsEvidence from this research shows that deploying customised on-demand 3DP can reduce surgical flow time and its variability while improving clinical outcomes. Such outcomes are obtained due to rapid development of the anatomical model and surgical guides along with precise cutting during surgery.Research limitations/implicationsWe outline multiple opportunities for research on supply chain design and performance assessment for surgical 3DP. Further empirical research is needed to validate the results.Practical implicationsThe decision to implement 3DP in hospitals or to engage service providers will require careful analysis of complexity, demand, lead-time criticality and a hospital's own objectives. Hospitals can follow different paths in adopting 3DP for surgeries depending on their context.Originality/valueThe operations and supply chain management community has researched on-demand distributed manufacturing for multiple industries. To the best of our knowledge, this is the first paper on customised on-demand 3DP for surgeries.

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Son, Seunghyun, Dongjoo Lee, Jinhyuk Oh, and Sunkuk Kim. "Embodied CO2 Reduction Effects of Free-Form Concrete Panel Production Using Rod-Type Molds with 3D Plastering Technique." Sustainability 13, no. 18 (September 14, 2021): 10280. http://dx.doi.org/10.3390/su131810280.

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When using concrete to produce exterior finishing panels of free-form building structures, different panel shapes make it difficult to reuse the forms. This results in increased formwork cost as well as a significant amount of embodied CO2 (ECO2) generation. Through years of research, we have developed a free-form panel (FCP) production technique engaging the 3D plastering technique (3DPT) without using conventional plywood forms. When 3DPT becomes available for free-form building projects, a great deal of ECO2 reduction effects is expected in addition to reduced time and cost in FCP production. The purpose of this study is to prove this by analyzing ECO2 reduction effects achieved through sustainable FCP production using 3DPT. The study involved project case selection, calculation of resources consumed for conventional plywood forms, and analysis of the reduction effects. As a result, it was demonstrated from the case project that 1196 tons of CO2 were reduced using 3DPT, accounting for approximately 99% of the amount produced from conventional plywood forms (CPF). The study findings will be used as a basic reference for sustainable production of FCPs ensuring speed and precision in production as well as innovative ECO2 reduction effects.

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Hsu, Megan R., Meraaj S. Haleem, and Wellington Hsu. "3D Printing Applications in Minimally Invasive Spine Surgery." Minimally Invasive Surgery 2018 (April 1, 2018): 1–8. http://dx.doi.org/10.1155/2018/4760769.

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3D printing (3DP) technology continues to gain popularity among medical specialties as a useful tool to improve patient care. The field of spine surgery is one discipline that has utilized this; however, information regarding the use of 3DP in minimally invasive spine surgery (MISS) is limited. 3D printing is currently being utilized in spine surgery to create biomodels, hardware templates and guides, and implants. Minimally invasive spine surgeons have begun to adopt 3DP technology, specifically with the use of biomodeling to optimize preoperative planning. Factors limiting widespread adoption of 3DP include increased time, cost, and the limited range of diagnoses in which 3DP has thus far been utilized. 3DP technology has become a valuable tool utilized by spine surgeons, and there are limitless directions in which this technology can be applied to minimally invasive spine surgery.

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Sandhu, Simrenjeet, Chris Rudnisky, Sourabh Arora, Faazil Kassam, Gordon Douglas, Marianne C. Edwards, Karin Verstraten, Beatrice Wong, and Karim F. Damji. "Compressed 3D and 2D digital images versus standard 3D slide film for the evaluation of glaucomatous optic nerve features." British Journal of Ophthalmology 102, no. 3 (August 23, 2017): 364–68. http://dx.doi.org/10.1136/bjophthalmol-2017-310447.

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SynopsisClinicians can feel confident compressed three-dimensional digital (3DD) and two-dimensional digital (2DD) imaging evaluating important features of glaucomatous disc damage is comparable to the previous gold standard of stereoscopic slide film photography, supporting the use of digital imaging for teleglaucoma applications.Background/aimsTo compare the sensitivity and specificity of 3DD and 2DD photography with stereo slide film in detecting glaucomatous optic nerve head features.MethodsThis prospective, multireader validation study imaged and compressed glaucomatous, suspicious or normal optic nerves using a ratio of 16:1 into 3DD and 2DD (1024×1280 pixels) and compared both to stereo slide film. The primary outcome was vertical cup-to-disc ratio (VCDR) and secondary outcomes, including disc haemorrhage and notching, were also evaluated. Each format was graded randomly by four glaucoma specialists. A protocol was implemented for harmonising data including consensus-based interpretation as needed.ResultsThere were 192 eyes imaged with each format. The mean VCDR for slide, 3DD and 2DD was 0.59±0.20, 0.60±0.18 and 0.62±0.17, respectively. The agreement of VCDR for 3DD versus film was κ=0.781 and for 2DD versus film was κ=0.69. Sensitivity (95.2%), specificity (95.2%) and area under the curve (AUC; 0.953) of 3DD imaging to detect notching were better (p=0.03) than for 2DD (90.5%; 88.6%; AUC=0.895). Similarly, sensitivity (77.8%), specificity (98.9%) and AUC (0.883) of 3DD to detect disc haemorrhage were better (p=0.049) than for 2DD (44.4%; 99.5%; AUC=0.72). There was no difference between 3DD and 2DD imaging in detecting disc tilt (p=0.7), peripapillary atrophy (p=0.16), grey crescent (p=0.1) or pallor (p=0.43), although 3D detected sloping better (p=0.013).ConclusionsBoth 3DD and 2DD imaging demonstrates excellent reproducibility in comparison to stereo slide film with experts evaluating VCDR, notching and disc haemorrhage. 3DD in this study was slightly more accurate than 2DD for evaluating disc haemorrhage, notching and sloping.

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Faulkner, Ronan, Mingqi Wang, Padraig Dunne, Arne Arnesen, Filip Heijkenskjöld, Reinhold Hallin, and Gerard O'Sullivan. "Observation of (3d4p→3d4d) and (3d4d→3d4f) transitions in the vacuum ultraviolet spectra of calcium-like MnVI, FeVIIand CoVIII." Journal of Physics B: Atomic, Molecular and Optical Physics 34, no. 4 (February 12, 2001): 593–603. http://dx.doi.org/10.1088/0953-4075/34/4/307.

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Zhang, Di, Xi Tao Zheng, and Tian Chi Wu. "Prediction of Elastic Properties of 3D4d Braided Composite Based on Hybrid Model." Key Engineering Materials 754 (September 2017): 222–25. http://dx.doi.org/10.4028/www.scientific.net/kem.754.222.

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This paper presents a meso-scale hybrid model which is used to predict the elastic properties of three-dimensional (3D) four-directional (4d) braided composites. At first, based on meso-structural model of 3D4d braided composite and the assumptions of iso-strain and iso-stress, two analytical models are established. Secondly, a hybrid model used to predict the elastic modulus of the 3D4d braided composite is established which introduces a new factor called hybrid-coefficient Ψ, which incorporates the iso-strain and iso-stress models at the same time, the value of Ψ is dependant on the braiding angle. Comparison between theoretical and experimental results shows that the hybrid model is more accurate than the iso-strain and iso-stress models, and can be used to predict the elastic properties of 3D4d braided composites, with the relative errors around 10%.

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Cabitza, Federico, Angela Locoro, and Aurelio Ravarini. "3D printing objects as knowledge artifacts for a do-it-yourself approach in clinical practice." Data Technologies and Applications 52, no. 1 (February 5, 2018): 163–86. http://dx.doi.org/10.1108/dta-03-2017-0019.

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Abstract:

Purpose The purpose of this paper is to investigate the phenomenon of the digital do-it-yourself (DiDIY) in the medical domain. In particular, the main contribution of the paper is the analysis and discussion of a questionnaire-based user study focused on 3D printing (3DP) technology, which was conducted among clinicians of one of the most important research hospital group in Lombardy, Italy. Design/methodology/approach A general reflection on the notion of knowledge artifacts (KAs) and on the use of 3DP in medicine is followed by the research questions and by a more detailed analysis of the specialist literature on the usage of 3DP technology for diagnostic, training and surgical planning activities for clinicians and patients. The questionnaire-based user study design is then emerging from the conceptual framework for DiDIY in healthcare. To help focus on the main actors and assets composing the 3DP innovation roles in healthcare, the authors model: the DiDIY-er as the main initiator of the practice innovation; the available technology allowing the envisioning of new practices; the specific activities gaining benefits from the innovative techniques introduced; and the knowledge community continuously supporting and evolving knowledge practices. Findings The authors discuss the results of the user study in the light of the four main components of our DiDIY framework and on the notion of KA. There are differences between high expertise, or senior, medical doctors (MDs) and relatively lower expertise MDs, or younger MDs, regarding the willing to acquire 3DP competences; those who have seen other colleagues using 3DP are significantly more in favor of 3DP adoption in medical practices, and those who wish to acquire 3DP competence and do-by-themselves are significantly more interested in the making of custom-made patient-specific tools, such as cutting guides and templates; there are many recurrent themes regarding how 3DP usage and application may improve medical practice. In each of the free-text questions, there were comments regarding the impact of 3DP on medical knowledge practices, such as surgical rehearsal, surgery, pathology comprehension, patient-physician communication and teaching. Originality/value The 3DP adoption in healthcare is seen favorably and advocated by most of the respondents. In this domain, 3DP objects can be considered KAs legitimately. They can support knowledgeable practices, promote knowledge sharing and circulation in the healthcare community, as well as contribute to their improvement by the introduction of a new DiDIY mindset in the everyday work of MDs.

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