Broad-beam three-dimensional irradiation system for heavy-ion radiotherapy at HIMAC
Futami, Y; Fujita, M; Tomura, H; Higashi, A; Matsufuji, N; Miyahara, N; Endo, M; Kawachi, K
1999-01-01
A three-dimensional irradiation system using a broad beam has been installed for heavy-ion cancer therapy at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility. Only the target region is irradiated at the 100% dose level; the dose level at other parts of irradiated tissues is less, using a range shifter, a multileaf collimator and a compensator. The devices are the same as those used in two-dimensional irradiation, except that the setting values of the devices can be dynamically changed during the treatment. The thickness of the absorber and the aperture of the multileaf collimator are dynamically controlled during irradiation, so that the Bragg peak is swept in the depth direction and the Bragg peak outside of the target volume is blocked by the multileaf collimator. The performance of this system was checked by irradiation of a phantom using a 290 MeV/nucleon carbon beam. The dose distribution realized by this three-dimensional irradiation agreed satisfactorily with the planned one.
Irradiation Response of Adipose-derived Stem Cells under Three-dimensional Culture Condition
Institute of Scientific and Technical Information of China (English)
DU Ya Rong; PAN Dong; CHEN Ya Xiong; XUE Gang; REN Zhen Xin; LI Xiao Man; ZHANG Shi Chuan; HU Bu Rong
2015-01-01
Objective Adipose tissue distributes widely in human body. The irradiation response of the adipose cells in vivo remains to be investigated. In this study we investigated irradiation response of adipose-derived stem cells (ASCs) under three-dimensional culture condition. Methods ASCs were isolated and cultured in low attachment dishes to form three-dimensional (3D) spheres in vitro. The neuronal differentiation potential and stem-liked characteristics was monitored by using immunofluoresence staining and flow cytometry in monolayer and 3D culture. To investigate the irradiation sensitivity of 3D sphere culture, the fraction of colony survival and micronucleus were detected in monolayer and 3D culture. Soft agar assays were performed for measuring malignant transformation for the irradiated monolayer and 3D culture. Results The 3D cultured ASCs had higher differentiation potential and an higher stem-like cell percentage. The 3D cultures were more radioresistant after either high linear energy transfer (LET) carbon ion beam or low LET X-ray irradiation compared with the monolayer cell. The ASCs’ potential of cellular transformation was lower after irradiation by soft agar assay. Conclusion These findings suggest that adipose tissue cell are relatively genomic stable and resistant to genotoxic stress.
Energy Technology Data Exchange (ETDEWEB)
Gatti, M.; Bresciani, S.; Ponzone, R.; Panaia, R.; Salatino, A.; Stasi, M.; Gabriele, P. [IRCC, Candiolo (Italy)
2011-10-15
Full text of publication follows: Purpose.- To analyse the incidence and severity of acute and late normal tissue toxicity and cosmetic outcome using three - dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Patients and Methods.- 70 patients with stage I disease were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation, in an approved protocol. The prescribed dose was 34 Gy in all patients delivered in 10 fractions over 5 consecutive days. On all CT scans gross tumor volume (GTV ) was defined around surgical clips. A 1.5 cm margin was added in order to account for clinical target volume (CTV) . A margin of 1 cm was added to CTI to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the specifications as dictated in the NSABP/RTOG protocol. After treatment, patients underwent a clinical and cosmetic evaluation every 3 months. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed by the physicians using the controlateral untreated breast as the reference (Harvard scale). Results.- Median patient age was 66 years (range 51-80). Median follow-up was 15 months (range 6-46). Tumor size was < 10 mm in 33 patients (53%) and > 2 cm in 4(6%). The mean value of the ratio between the PTV and the whole ipsilateral breast volume was 38 % and the median percentage whole breast volume that received 95 % of prescribed dose was 34% (range 16%-55%). The rate of G1 and G2 acute skin toxicity was 28% and 2% respectively and the late toxicity was 17% (G1). G2 or greater toxicities were not observed. The most pronounced G1 late toxicity was subcutaneous fibrosis, developed in 3 patients. The cosmetic outcome was excellent in 83% and good in 17%. Conclusion.- Accelerated partial breast irradiation using three-dimensional conformal radiotherapy is technically feasible with very low acute and late toxicity. Long
Ikeda, Hiroko; Souda, Hikaru; Puspitasari, Anggraeini; Held, Kathryn D.; Hidema, Jun; Nikawa, Takeshi; Yoshida, Yukari; Kanai, Tatsuaki; Takahashi, Akihisa
2017-02-01
Outer space is an environment characterized by microgravity and space radiation, including high-energy charged particles. Astronauts are constantly exposed to both microgravity and radiation during long-term stays in space. However, many aspects of the biological effects of combined microgravity and space radiation remain unclear. We developed a new three-dimensional (3D) clinostat synchronized heavy-ion irradiation system for use in ground-based studies of the combined exposures. Our new system uses a particle accelerator and a respiratory gating system from heavy-ion radiotherapy to irradiate samples being rotated in the 3D clinostat with carbon-ion beams only when the samples are in the horizontal position. A Peltier module and special sample holder were loaded on a static stage (standing condition) and the 3D clinostat (rotation condition) to maintain a suitable temperature under atmospheric conditions. The performance of the new device was investigated with normal human fibroblasts 1BR-hTERT in a disposable closed cell culture chamber. Live imaging revealed that cellular adhesion and growth were almost the same for the standing control sample and rotation sample over 48 h. Dose flatness and symmetry were judged according to the relative density of Gafchromic films along the X-axis and Y-axis of the positions of the irradiated sample to confirm irradiation accuracy. Doses calculated using the carbon-ion calibration curve were almost the same for standing and rotation conditions, with the difference being less than 5% at 1 Gy carbon-ion irradiation. Our new device can accurately synchronize carbon-ion irradiation and simulated microgravity while maintaining the temperature under atmospheric conditions at ground level.
Coexistence of Two- and Three-dimensional Shubnikov-de Haas Oscillations in Ar^+ -irradiated KTaO_3
Energy Technology Data Exchange (ETDEWEB)
Harashima, S.; Bell, C.; Kim, M.; Yajima, T.; Hikita, Y.; Hwang, H.Y.
2012-05-16
We report the electron doping in the surface vicinity of KTaO{sub 3} by inducing oxygen-vacancies via Ar{sup +}-irradiation. The doped electrons have high mobility (> 10{sup 4} cm{sup 2}/Vs) at low temperatures, and exhibit Shubnikov-de Haas oscillations with both two- and three-dimensional components. A disparity of the extracted in-plane effective mass, compared to the bulk values, suggests mixing of the orbital characters. Our observations demonstrate that Ar{sup +}-irradiation serves as a flexible tool to study low dimensional quantum transport in 5d semiconducting oxides.
Energy Technology Data Exchange (ETDEWEB)
Sun, Xue-Zhi; Takahashi, Sentaro; Kubota, Yoshihisa; Sato, Hiroshi [National Inst. of Radiological Sciences, Chiba (Japan); Cui, Chun; Fukui, Yoshihiro [Tokushima Univ. (Japan). School of Medicine; Inouye, Minoru [Shin Nippon Biomedical Lab., Ltd., Miyanoura, Kagoshima (Japan)
2002-03-01
The types and three-dimensional distribution of neocortical ectopias following prenatal exposure to X-irradiation were studied by a histological examination and computer reconstruction techniques. Pregnant ICR mice were subjected to X-irradiation at a dose of 1.5 Gy on embryonic day 13. The brains from 30-day-old mice were serially sectioned on the frontal plane at 15 {mu}m, stained with HE and observed with a microscope. The image data for the sections were input to a computer, and then reconstructed to three-dimensional brain structures using the Magellan 3.6 program. Sectional images were then drawn on a computer display at 240 {mu}m intervals, and the positions of the different types of neocortical ectopias were marked using color coding. Three types of neocortical ectopias were recognized in the irradiated brains. Neocortical Lay I ectopias were identified as small patches in the caudal occipital cortex, and were located more laterally in the neocortex in caudal sections than in the rostral sections. Periventricular ectopias were located more rostrally than Lay I ectopias, and were found from the most caudal extent of the presumed motor cortex to the most caudal extent of the lateral ventricle. Hippocampal ectopias appeared as continuous linear bands, and were frequently associated with the anterior parts of the periventricular ectopias. (author)
K. Kozuma (Ken); M.A. Costa (Marco); M. Sabaté (Manel); I.P. Kay (Ian Patrick); J.P. Marijnissen (Johannes); V.L.M.A. Coen (Veronique); P. Serrano (Pedro); J.M.R. Ligthart (Jürgen); P.W.J.C. Serruys (Patrick); P.C. Levendag (Peter)
2000-01-01
textabstractBACKGROUND: The "edge effect," late lumen loss at the margins of the treated segment, has become an important issue in the field of coronary brachytherapy. The aim of the present study was to assess the edge effect in noninjured margins adjacent to the irradiated segmen
Directory of Open Access Journals (Sweden)
Ji Kai
2012-11-01
Full Text Available Abstract Background To quantify the incidental irradiation dose to esophageal lymph node stations when irradiating T1-4N0M0 thoracic esophageal squamous cell carcinoma (ESCC patients with a dose of 60 Gy/30f. Methods Thirty-nine patients with medically inoperable T1–4N0M0 thoracic ESCC were treated with three-dimensional conformal radiation (3DCRT with involved-field radiation (IFI. The conformal clinical target volume (CTV was re-created using a 3-cm margin in the proximal and distal direction beyond the barium esophagogram, endoscopic examination and CT scan defined the gross tumor volume (GTV and a 0.5-cm margin in the lateral and anteroposterior directions of the CT scan-defined GTV. The PTV encompassed 1-cm proximal and distal margins and 0.5-cm radial margin based on the CTV. Nodal regions were delineated using the Japanese Society for Esophageal Diseases (JSED guidelines and an EORTC-ROG expert opinion. The equivalent uniform dose (EUD and other dosimetric parameters were calculated for each nodal station. Nodal regions with a metastasis rate greater than 5% were considered a high-risk lymph node subgroup. Results Under a 60 Gy dosage, the median Dmean and EUD was greater than 40 Gy in most high-risk nodal regions except for regions of 104, 106tb-R in upper-thoracic ESCC and 101, 104-R, 105, 106rec-L, 2, 3&7 in middle-thoracic ESCC and 107, 3&7 in lower-thoracic ESCC. In the regions with an EUD less than 40Gy, most incidental irradiation doses were significantly associated with esophageal tumor length and location. Conclusions Lymph node stations near ESCC receive considerable incidental irradiation doses with involved-field irradiation that may contribute to the elimination of subclinical lesions.
Yamada, Magda K; Uo, Motohiro; Ohkawa, Shoji; Akasaka, Tsukasa; Watari, Fumio
2004-10-15
A three-dimensional analyzer installed in a scanning electron microscope was used to evaluate the morphology and surface roughness using noncontact profilometry. Observations were carried out on the enamel and dentin surface irradiated by three different lasers: Nd:YAG (wavelength 1.06 microm), Er:YAG (2.94 microm), and CO(2) (10.6 microm). Spectroscopic analysis was done by Raman spectroscopy for nonirradiated and laser-irradiated surfaces. The lasers were applied perpendicularly to vertically sectioned and polished human extracted caries-free molars. The tooth was sectioned at each cavity for cross-section analysis after laser irradiation. Irradiation by Nd:YAG and CO(2) lasers of the enamel surface showed an opaque white color, different from dentin where the surface turned black. The Er:YAG laser induced no changes in color of the dentin. Numerous cracks associated with thermal stress were observed in the CO(2) laser-irradiated dentin. Noncontact surface profile analysis of Er:YAG laser-irradiated enamel and dentin showed the deepest cavities, and direct cross-sectional observations of them showed similar cavity outlines. The CO(2) laser-irradiated dentin had the least surface roughness. Raman spectroscopic analysis showed that fluorescence from the laser-irradiated tooth was generally greater than from nonirradiated teeth. Bands in dentin attributed to organic collagen matrix were lost after Nd:YAG and CO(2) laser irradiation, and a broad peak due to amorphous carbon appeared. The Er:YAG laser-irradiated dentin showed no sign of a carbon band and had more suitable results for dental ablation. Noncontact surface profile analysis was effective to evaluate the structural change in the tooth in the microarea of study after laser irradiation.
Energy Technology Data Exchange (ETDEWEB)
Eke, Iris; Storch, Katja; Kaestner, Ina; Vehlow, Anne [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Faethe, Christina; Mueller-Klieser, Wolfgang [Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz (Germany); Taucher-Scholz, Gisela [Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt (Germany); Temme, Achim; Schackert, Gabriele [Section of Experimental Neurosurgery/Tumor Immunology, Department of Neurosurgery, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Cordes, Nils, E-mail: Nils.Cordes@Oncoray.de [OncoRay-National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany); Department of Radiation Oncology, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden (Germany)
2012-11-15
Purpose: Cell invasion represents one of the major determinants that treatment has failed for patients suffering from glioblastoma. Contrary findings have been reported for cell migration upon exposure to ionizing radiation. Here, the migration and invasion capability of glioblastoma cells on and in collagen type I were evaluated upon irradiation with X-rays or carbon ions. Methods and Materials: Migration on and invasion in collagen type I were evaluated in four established human glioblastoma cell lines exposed to either X-rays or carbon ions. Furthermore, clonogenic radiation survival, proliferation (5-bromo-2-deoxyuridine positivity), DNA double-strand breaks ({gamma}H2AX/53BP1-positive foci), and expression of invasion-relevant proteins (eg, {beta}1 integrin, FAK, MMP2, and MMP9) were explored. Migration and invasion assays for primary glioblastoma cells also were carried out with X-ray irradiation. Results: Neither X-ray nor carbon ion irradiation affected glioblastoma cell migration and invasion, a finding similarly observed in primary glioblastoma cells. Intriguingly, irradiated cells migrated unhampered, despite DNA double-strand breaks and reduced proliferation. Clonogenic radiation survival was increased when cells had contact with extracellular matrix. Specific inhibition of the {beta}1 integrin or proliferation-associated signaling molecules revealed a critical function of JNK, PI3K, and p38 MAPK in glioblastoma cell invasion. Conclusions: These findings indicate that X-rays and carbon ion irradiation effectively reduce proliferation and clonogenic survival without modifying the migration and invasion ability of glioblastoma cells in a collagen type I environment. Addition of targeted agents against members of the MAPK and PI3K signaling axis to conventional chemoradiation therapy seems potentially useful to optimize glioblastoma therapy.
Institute of Scientific and Technical Information of China (English)
Xia Yong; Liu Jian-Sheng; Ni Guo-Quan; Xu Zhi-Zhan
2004-01-01
Using classic particle dynamics simulations, the interaction process between an intense femtosecond laser pulse and icosahedral hydrogen atomic clusters H13, H55 and H147 has been studied. It is revealed that with increasing number of atoms in the cluster, the kinetic energy of ions generated in the Coulomb explosion of the ionized hydrogen clusters increases. The expansion process of the clusters after laser irradiation has also been examined, showing that the expansion scale decreases with increasing cluster size.
Directory of Open Access Journals (Sweden)
Tanaka Y
2016-08-01
Full Text Available Yohei Tanaka,1,2 Jun Nakayama2 1Department of Plastic Surgery, Clinica Tanaka Plastic, Reconstructive Surgery and Anti-aging Center, 2Department of Molecular Pathology, Shinshu University Graduate School of Medicine, Matsumoto, Nagano, Japan Background and objective: Humans are increasingly exposed to near-infrared (NIR radiation from both natural (eg, solar and artificial (eg, electrical appliances sources. Although the biological effects of sun and ultraviolet (UV exposure have been extensively investigated, the biological effect of NIR radiation is still unclear. We previously reported that NIR as well as UV induces photoaging and standard UV-blocking materials, such as sunglasses, do not sufficiently block NIR. The objective of this study was to investigate changes in gene expression in three-dimensional reconstructed corneal epithelial tissue culture exposed to broad-spectrum NIR irradiation to simulate solar NIR radiation that reaches human tissues.Materials and methods: DNA microarray and quantitative real-time polymerase chain reaction analysis were used to assess gene expression levels in a three-dimensional reconstructed corneal epithelial model composed of normal human corneal epithelial cells exposed to water-filtered broad-spectrum NIR irradiation with a contact cooling (20°C. The water-filter allowed 1,000–1,800 nm wavelengths and excluded 1,400–1,500 nm wavelengths.Results: A DNA microarray with >62,000 different probes showed 25 and 150 genes that were up- or downregulated by at least fourfold and twofold, respectively, after NIR irradiation. In particular, epidermal growth factor receptor (EGFR was upregulated by 19.4-fold relative to control cells. Quantitative real-time polymerase chain reaction analysis revealed that two variants of EGFR in human corneal epithelial tissue were also significantly upregulated after five rounds of 10 J/cm2 irradiation (P<0.05.Conclusion: We found that NIR irradiation induced the
Li, Guoqiang; Li, Jiawen; Zhang, Chenchu; Hu, Yanlei; Li, Xiaohong; Chu, Jiaru; Huang, Wenhao; Wu, Dong
2015-01-14
The capability to realize 2D-3D controllable metallic micro/nanostructures is of key importance for various fields such as plasmonics, electronics, bioscience, and chemistry due to unique properties such as electromagnetic field enhancement, catalysis, photoemission, and conductivity. However, most of the present techniques are limited to low-dimension (1D-2D), small area, or single function. Here we report the assembly of self-organized three-dimensional (3D) porous metal micro/nanocages arrays on nickel surface by ethanol-assisted femtosecond laser irradiation. The underlying formation mechanism was investigated by a series of femtosecond laser irradiation under exposure time from 5 to 30 ms. We also demonstrate the ability to control the size of micro/nanocage arrays from 0.8 to 2 μm by different laser pulse energy. This method features rapidness (∼10 min), simplicity (one-step process), and ease of large-area (4 cm(2) or more) fabrication. The 3D cagelike micro/nanostructures exhibit not only improved antireflection from 80% to 7% but also enhanced hydrophobicity from 98.5° to 142° without surface modification. This simple technique for 3D large-area controllable metal microstructures will find great potential applications in optoelectronics, physics, and chemistry.
Three dimensional strained semiconductors
Energy Technology Data Exchange (ETDEWEB)
Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui
2016-11-08
In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.
Energy Technology Data Exchange (ETDEWEB)
Leite, Elton Trigo Teixeira; Ugino, Rafael Tsuneki; Lopes, Mauricio Russo; Pelosi, Edilson Lopes; Silva, Joao Luis Fernandes da, E-mail: eltontt@gmail.com [Hospital Sirio-Libanes, Sao paulo, SP (Brazil). Departamento de Radiologia e Oncologia; Santana, Marco Antonio; Ferreira, Denis Vasconcelos; Carvalho, Heloisa de Andrade [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Departamento de Radiologia e Oncologia
2016-05-15
Objective: to evaluate incidental irradiation of the internal mammary lymph nodes (IMLNs) through opposed tangential fields with conventional two-dimensional (2D) or three-dimensional (3D) radiotherapy techniques and to compare the results between the two techniques. Materials and Methods: This was a retrospective study of 80 breast cancer patients in whom radiotherapy of the IMLNs was not indicated: 40 underwent 2D radiotherapy with computed tomography for dosimetric control, and 40 underwent 3D radiotherapy. The total prescribed dose was 50.0 Gy or 50.4 Gy (2.0 or 1.8 Gy/day, respectively). We reviewed all plans and defined the IMLNs following the Radiation Therapy Oncology Group recommendations. For the IMLNs, we analyzed the proportion of the volume that received 45 Gy, the proportion of the volume that received 25 Gy, the dose to 95% of the volume, the dose to 50% of the volume, the mean dose, the minimum dose (Dmin), and the maximum dose (Dmax). Results: Left-sided treatments predominated in the 3D cohort. There were no differences between the 2D and 3D cohorts regarding tumor stage, type of surgery (mastectomy, breast-conserving surgery, or mastectomy with immediate reconstruction), or mean delineated IMLN volume (6.8 vs. 5.9 mL; p = 0.411). Except for the Dmin, all dosimetric parameters presented higher mean values in the 3D cohort (p < 0.05). The median Dmax in the 3D cohort was 50.34 Gy. However, the mean dose to the IMLNs was 7.93 Gy in the 2D cohort, compared with 20.64 Gy in the 3D cohort. Conclusion: Neither technique delivered enough doses to the IMLNs to achieve subclinical disease control. However, all of the dosimetric parameters were significantly higher for the 3D technique. (author)
Leite, Elton Trigo Teixeira; Ugino, Rafael Tsuneki; Santana, Marco Antônio; Ferreira, Denis Vasconcelos; Lopes, Maurício Russo; Pelosi, Edilson Lopes; da Silva, João Luis Fernandes; Carvalho, Heloisa de Andrade
2016-01-01
Objective To evaluate incidental irradiation of the internal mammary lymph nodes (IMLNs) through opposed tangential fields with conventional two-dimensional (2D) or three-dimensional (3D) radiotherapy techniques and to compare the results between the two techniques. Materials and Methods This was a retrospective study of 80 breast cancer patients in whom radiotherapy of the IMLNs was not indicated: 40 underwent 2D radiotherapy with computed tomography for dosimetric control, and 40 underwent 3D radiotherapy. The total prescribed dose was 50.0 Gy or 50.4 Gy (2.0 or 1.8 Gy/day, respectively). We reviewed all plans and defined the IMLNs following the Radiation Therapy Oncology Group recommendations. For the IMLNs, we analyzed the proportion of the volume that received 45 Gy, the proportion of the volume that received 25 Gy, the dose to 95% of the volume, the dose to 50% of the volume, the mean dose, the minimum dose (Dmin), and the maximum dose (Dmax). Results Left-sided treatments predominated in the 3D cohort. There were no differences between the 2D and 3D cohorts regarding tumor stage, type of surgery (mastectomy, breast-conserving surgery, or mastectomy with immediate reconstruction), or mean delineated IMLN volume (6.8 vs. 5.9 mL; p = 0.411). Except for the Dmin, all dosimetric parameters presented higher mean values in the 3D cohort (p < 0.05). The median Dmax in the 3D cohort was 50.34 Gy. However, the mean dose to the IMLNs was 7.93 Gy in the 2D cohort, compared with 20.64 Gy in the 3D cohort. Conclusion Neither technique delivered enough doses to the IMLNs to achieve subclinical disease control. However, all of the dosimetric parameters were significantly higher for the 3D technique. PMID:27403017
Three-dimensional photovoltaics
Myers, Bryan; Bernardi, Marco; Grossman, Jeffrey C.
2010-03-01
The concept of three-dimensional (3D) photovoltaics is explored computationally using a genetic algorithm to optimize the energy production in a day for arbitrarily shaped 3D solar cells confined to a given area footprint and total volume. Our simulations demonstrate that the performance of 3D photovoltaic structures scales linearly with height, leading to volumetric energy conversion, and provides power fairly evenly throughout the day. Furthermore, we show that optimal 3D shapes are not simple box-like shapes, and that design attributes such as reflectivity can be optimized in new ways using three-dimensionality.
Institute of Scientific and Technical Information of China (English)
Jin Hu; Yeqing Zhou; Mi Liu
2009-01-01
Objective: To observe the recently therapeutic effects and toxicity of three-dimensional conformal radiotherapy combined with whole brain irradiation for patients with brain metastasis. Methods: 33 cases were treated by whole brain irradiation at first, the dose of which was 36-40 Gy (18-20 f). Then three-dimensional conformal radiotherapy was added to the focus with a total dose of 20-25 Gy, whose fractionated dose was 2-5 Gy/time, 5 times/week or 3 times/week. Results: Within 1 month after radiotherapy, according to imaging of the brain, the CR of all patients was 45.5%, PR 36.4%, NC 15.1%, and PD 3%. For the 32 cases with neural symptoms before radiation, the CR of the symptoms was 40.6% and PR 59.4%. All patients gained different increases in KPS grade. By the end of the follow-up period, there were 22 deaths with the mean survival time up to 9.3 months. Conclusion: Three-dimensional conformal radiotherapy combined with whole brain irradiation can not only effectively control brain metastases and improve life quality, but also tends to prolong survival time.
T.A. Knoch (Tobias)
2000-01-01
textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal stru
T.A. Knoch (Tobias)
2000-01-01
textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal struc
Energy Technology Data Exchange (ETDEWEB)
Mozsa, Emoeke [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Landesklinikum Wiener Neustadt, Department of Radiooncology and Radiotherapy, Wiener Neustadt (Austria); Meszaros, Norbert; Major, Tibor; Froehlich, Georgina; Stelczer, Gabor; Fodor, Janos; Polgar, Csaba [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Sulyok, Zoltan [National Institute of Oncology, Centre of Surgery, Budapest (Hungary)
2014-05-15
The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.) [German] Evaluation der 5-Jahres-Ergebnisse bezueglich Ueberleben, Tumorkontrolle, Nebenwirkungen und Kosmetik nach Teilbrustbestrahlung (APBI) mittels 3-D-konformaler, akzelerierter Radiotherapie (3D-CRT). Zwischen 2006 und 2011 wurden 44 Patienten mit Brustkrebs im Stadium I-II und niedrigem Risikoprofil brusterhaltend operiert. Die adjuvante, 3-D-konformale APBI wurde mittels 3-5 nonkoplanarer Feldern durchgefuehrt. Die Gesamtdosis betrug 36,9 Gy bei 9 -mal 4,1 Gy b.i.d.. Nach
Three dimensional system integration
Papanikolaou, Antonis; Radojcic, Riko
2010-01-01
Three-dimensional (3D) integrated circuit (IC) stacking is the next big step in electronic system integration. It enables packing more functionality, as well as integration of heterogeneous materials, devices, and signals, in the same space (volume). This results in consumer electronics (e.g., mobile, handheld devices) which can run more powerful applications, such as full-length movies and 3D games, with longer battery life. This technology is so promising that it is expected to be a mainstream technology a few years from now, less than 10-15 years from its original conception. To achieve thi
Three-dimensional metamaterials
Burckel, David Bruce
2012-06-12
A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.
Three-Dimensional Complex Variables
Martin, E. Dale
1988-01-01
Report presents new theory of analytic functions of three-dimensional complex variables. While three-dimensional system subject to more limitations and more difficult to use than the two-dimensional system, useful in analysis of three-dimensional fluid flows, electrostatic potentials, and other phenomena involving harmonic functions.
Three-dimensional echocardiography
Energy Technology Data Exchange (ETDEWEB)
Buck, Thomas [University Hospital Essen (Germany). West German Heart Center; Franke, Andreas [Klinikum Region Hannover - Klinikum Siloah, Hannover (Germany). Dept. of Cardiology, Angiology and Intensive Care Medicine; Monaghan, Mark J. (eds.) [King' s College Hospital, London (United Kingdom)
2011-07-01
Presents tips and tricks for beginners and experts Provides educational material for 3D training courses Features comprehensively illustrated cases Includes an accompanying DVD with video clips of all sample cases Three-dimensional echocardiography is the most recent fundamental advancement in echocardiography. Since real-time 3D echocardiography became commercially available in 2002, it has rapidly been accepted in echo labs worldwide. This book covers all clinically relevant aspects of this fascinating new technology, including a comprehensive explanation of its basic principles, practical aspects of clinical application, and detailed descriptions of specific uses in the broad spectrum of clinically important heart disease. The book was written by a group of well-recognized international experts in the field, who have not only been involved in the scientific and clinical evolution of 3D echocardiography since its inception but are also intensively involved in expert training courses. As a result, the clear focus of this book is on the practical application of 3D echocardiography in daily clinical routine with tips and tricks for both beginners and experts, accompanied by more than 150 case examples comprehensively illustrated in more than 800 images and more than 500 videos provided on a DVD. In addition to an in-depth review of the most recent literature on real-time 3D echocardiography, this book represents an invaluable reference work for beginners and expert users of 3D echocardiography. - Tips and tricks for beginners and experts - Educational material for 3D training courses - Comprehensively illustrated cases - DVD with video clips of all sample cases.
Three dimensional Dirac semimetals
Zaheer, Saad
We extend the physics of graphene to three dimensional systems by showing that Dirac points can exist on the Fermi surface of realistic materials in three dimensions. Many of the exotic electronic properties of graphene can be ascribed to the pseudorelativistic behavior of its charge carriers due to two dimensional Dirac points on the Fermi surface. We show that certain nonsymmorphic spacegroups exhibit Dirac points among the irreducible representations of the appropriate little group at high symmetry points on the surface of the Brillouin zone. We provide a list of all Brillouin zone momenta in the 230 spacegroups that can host Dirac points. We describe microscopic considerations necessary to design materials in one of the candidate spacegroups such that the Dirac point appears at the Fermi energy without any additional non-Dirac-like Fermi pockets. We use density functional theory based methods to propose six new Dirac semimetals: BiO 2 and SbO2 in the beta-cristobalite lattice (spacegroup 227), and BiCaSiO4, BiMgSiO4, BiAlInO 4, and BiZnSiO4 in the distorted spinels lattice (spacegroup 74). Additionally we derive effective Dirac Hamiltonians given group representative operators as well as tight binding models incorporating spin-orbit coupling. Finally we study the Fermi surface of zincblende (spacegroup 216) HgTe which is effectively point-like at Gamma in the Brillouin zone and exhibits accidental degeneracies along a threefold rotation axis. Whereas compressive strain gaps the band structure into a topological insulator, tensile strain shifts the accidental degeneracies away from Gamma and enlarges the Fermi surface. States on the Fermi surface exhibit nontrivial spin texture marked by winding of spins around the threefold rotation axis and by spin vortices indicating a change in the winding number. This is confirmed by microscopic calculations performed in tensile strained HgTe and Hg0.5Zn 0.5 Te as well as k.p theory. We conclude with a summary of recent
Energy Technology Data Exchange (ETDEWEB)
Liu, Shuaishuai; Wang, Na; Zhang, Yuchang; Li, Yaru [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Han, Zhuo [CECEP Environmental Protection Investment Development Co., Ltd., Jiangxi 3300969 (China); Na, Ping, E-mail: naping@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tianjin Co-Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China)
2015-03-02
Highlights: • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites have been synthesized through a facile method. • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites exhibit large photocatalytic adsorption capacity, high selectivity, and excellent trace removal performance of I{sup −} under visible light. • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites could be easily separated and regenerated. • The adsorption capacity of Ag{sub 2}O for I{sup −} is enlarged 4.4 times by the photooxidation of Ag/TiO{sub 2}. • The cooperative effects mechanism between Ag{sub 2}O and Ag/TiO{sub 2} is proposed and verified. - Abstract: Three-dimensional Ag{sub 2}O and Ag co-loaded TiO{sub 2} (3D Ag{sub 2}O–Ag/TiO{sub 2}) composites have been synthesized through a facile method, characterized using SEM, EDX, TEM, XRD, XPS, UV–vis DRS, BET techniques, and applied to remove radioactive iodide ions (I{sup −}). The photocatalytic adsorption capacity (207.6 mg/g) of the 3D Ag{sub 2}O–Ag/TiO{sub 2} spheres under visible light is four times higher than that in the dark, which is barely affected by other ions, even in simulated salt lake water where the concentration of Cl{sup −} is up to 590 times that of I{sup −}. The capability of the composites to remove even trace amounts of I{sup −} from different types of water, e.g., deionized or salt lake water, is demonstrated. The composites also feature good reusability, as they were separated after photocatalytic adsorption and still performed well after a simple regeneration. Furthermore, a mechanism explaining the highly efficient removal of radioactive I{sup −} has been proposed according to characterization analyses of the composites after adsorption and subsequently been verified by adsorption and desorption experiments. The proposed cooperative effects mechanism considers the interplay of three different phenomena, namely, the adsorption performance of Ag{sub 2}O for I{sup −}, the photocatalytic ability of Ag/TiO{sub 2} for oxidation
Jung, Woo-Young; Seol, Jae-Bok; Kwak, Chan-Min; Park, Chan-Gyung
2016-03-01
The compositional distribution of In atoms in InGaN/GaN multiple quantum wells is considered as one of the candidates for carrier localization center, which enhances the efficiency of the light-emitting diodes. However, two challenging issues exist in this research area. First, an inhomogeneous In distribution is initially formed by spinodal decomposition during device fabrication as revealed by transmission electron microscopy. Second, electron-beam irradiation during microscopy causes the compositional inhomogeneity of In to appear as a damage contrast. Here, a systematic approach was proposed in this study: Electron-beam with current density ranging from 0 to 20.9 A/cm2 was initially exposed to the surface regions during microscopy. Then, the electron-beam irradiated regions at the tip surface were further removed, and finally, atom probe tomography was performed to run the samples without beam-induced damage and to evaluate the existence of local inhomegenity of In atoms. We proved that after eliminating the electron-beam induced damage regions, no evidence of In clustering was observed in the blue-emitting InGaN/GaN devices. In addition, it is concluded that the electron-beam induced localization of In atoms is a surface-related phenomenon, and hence spinodal decomposition, which is typically responsible for such In clustering, is negligible for biaxially strained blue-emitting InGaN/GaN devices.
Energy Technology Data Exchange (ETDEWEB)
Caudrelier, J.M.; Auliard, A.; Sarrazin, T.; Gibon, D.; Coche-Dequeant, B.; Castelain, B. [Centre de Lutte Contre le Cancer Oscar-Lambret, 59 - Lille (France)
2001-06-01
Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors. Purpose. - We prospectively compared a conventional treatment planning (PT2D) and 3-dimensional conformal treatment planning (PT3D) for radiotherapy of cerebral tumours. Patients and methods.- Patients treated between 1/10/98 and 1/4/99 by irradiation for cerebral tumours were analysed. For each case, we planned PT2D using conventional orthogonal x-ray films, and afterward, PT3D using CT scan. Gross tumor volume, planning target volume and normal tissue volumes were defined. Dose was prescribed according to report 50 of the International Commission on Radiation Units and Measurements (ICRU). We compared surfaces of sagittal view targets defined on PT2D and PT3D and called them S2D and S3D, respectively. Irradiated volumes by 90% isodoses (VE-90%) and normal tissue volumes irradiated by 20, 50, 90% isodoses were calculated and compared using Student's paired t-test. Results. -There was a concordance of 84% of target surfaces defined on PT2D and PT3D. Percentages of target surface under- or-over defined by PT2D were 16 and 13% respectively. VE-90% was decreased by 15% (p = 0.07) with PT3D. Normal brain volume irradiated by 90% isodose was decreased by 27% with PT3D (p = 0.04). Conclusion.- For radiotherapy of cerebral tumors using only coplanar beams, PT3D leads to a reduction of normal brain tissue irradiated. We recommend PT3D for radiotherapy of cerebral tumors, particularly for low-grade or benign tumors (meningiomas, neuromas, etc.). (authors)
Energy Technology Data Exchange (ETDEWEB)
Kurobori, T., E-mail: kurobori@staff.kanazawa-u.ac.jp [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192 (Japan); Itoi, H. [Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192 (Japan); Yanagida, Y. [Oarai Research Center, Chiyoda Technol Corporation, Oarai 311-1313 (Japan); Chen, Y.Q. [China Techwin Co., Ltd, Dongguan, Guangdong 523467 (China)
2015-09-01
Ag-activated phosphate glass based on the radiophotoluminescence (RPL) phenomenon has been used as the most commonly known RPL material and as an accumulated-type passive detector. In this work, the transient-state evaluation of the dose distributions achieved by X- and gamma-ray irradiations within the Ag-activated phosphate glass was performed using a time-resolved technique for the first time. Specifically, the blue RPL intensity ascribed to the electron-trapped Ag{sup 0} centres as a function of the depth at the vicinity of the surface was investigated for different types of radiation and a wide range of energies. In addition, the dose distributions at each layer within the glass confirmed by the time-resolved measurement were compared with those reconstructed by a disk-type transparent glass detector based on the blue RPL with a diameter of 100 mm. - Highlights: • The time-resolved dose evaluation of Ag-activated glass was performed. • The RPL intensity as a function of the depth was investigated for X- and gamma-rays. • The origin and mechanisms for the RPL enhancement in the near-surface layers were discussed.
Creating Three-Dimensional Scenes
Krumpe, Norm
2005-01-01
Persistence of Vision Raytracer (POV-Ray), a free computer program for creating photo-realistic, three-dimensional scenes and a link for Mathematica users interested in generating POV-Ray files from within Mathematica, is discussed. POV-Ray has great potential in secondary mathematics classrooms and helps in strengthening students' visualization…
Quasicrystalline three-dimensional foams
Cox, S. J.; Graner, F.; Mosseri, R.; Sadoc, J.-F.
2017-03-01
We present a numerical study of quasiperiodic foams, in which the bubbles are generated as duals of quasiperiodic Frank–Kasper phases. These foams are investigated as potential candidates to the celebrated Kelvin problem for the partition of three-dimensional space with equal volume bubbles and minimal surface area. Interestingly, one of the computed structures falls close to (but still slightly above) the best known Weaire–Phelan periodic candidate. In addition we find a correlation between the normalized bubble surface area and the root mean squared deviation of the number of faces, giving an additional clue to understanding the main geometrical ingredients driving the Kelvin problem.
Energy Technology Data Exchange (ETDEWEB)
Bergom, Carmen; Kelly, Tracy; Morrow, Natalya; Wilson, J. Frank [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Walker, Alonzo [Department of Surgery, Medical College of Wisconsin, Milwaukee, WI (United States); Xiang Qun; Ahn, Kwang Woo [Division of Biostatistics, Medical College of Wisconsin, Milwaukee, WI (United States); White, Julia, E-mail: jwhite@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)
2012-07-01
Purpose: To report our institution's experience using prone positioning for three-dimensional conformal radiotherapy (3D-CRT) to deliver post-lumpectomy whole breast irradiation (WBI) in a cohort of women with large and/or pendulous breasts, to determine the rate of acute and late toxicities and, more specifically, cosmetic outcomes. We hypothesized that using 3D-CRT for WBI in the prone position would reduce or eliminate patient and breast size as negative prognostic indicators for toxicities associated with WBI. Methods and Materials: From 1998 to 2006, 110 cases were treated with prone WBI using 3D-CRT. The lumpectomy, breast target volumes, heart, and lung were contoured on all computed tomography scans. A dose of 45-50 Gy was prescribed to the breast volume using standard fractionation schemes. The planning goals were {>=}95% of prescription to 95% of the breast volume, and 100% of boost dose to 95% of lumpectomy planning target volume. Toxicities and cosmesis were prospectively scored using the Common Terminology Criteria for Adverse Effects Version 3.0 and the Harvard Scale. The median follow-up was 40 months. Results: The median body mass index (BMI) was 33.6 kg/m{sup 2}, and median breast volume was 1396 cm{sup 3}. The worst toxicity encountered during radiation was Grade 3 dermatitis in 5% of our patient population. Moist desquamation occurred in 16% of patients, with only 2% of patients with moist desquamation outside the inframammary/axillary folds. Eleven percent of patients had Grade {>=}2 late toxicities, including Grade 3 induration/fibrosis in 2%. Excellent to good cosmesis was achieved in 89%. Higher BMI was associated with moist desquamation and breast pain, but BMI and breast volume did not impact fibrosis or excellent to good cosmesis. Conclusion: In patients with higher BMI and/or large-pendulous breasts, delivering prone WBI using 3D-CRT results in favorable toxicity profiles and high excellent to good cosmesis rates. Higher BMI was
Three-dimensional display technologies.
Geng, Jason
2013-01-01
The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain's power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies.
Three dimensional magnetic abacus memory
Zhang, Shilei; Zhang, Jingyan; Baker, Alexander; Wang, Shouguo; Yu, Guanghua; Hesjedal, Thorsten
2015-03-01
Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the individual data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme which envisages a classical abacus with the beads operated by electron spins. It is inspired by the idea of second quantization, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered `quantized' Hall voltage, representing a count of the spin-up and spin-down layers in the stack. This concept of `second quantization of memory' realizes the 3D memory architecture with superior reading and operation efficiency, thus is a promising approach for future nonvolatile magnetic random access memory.
Three-dimensional colloidal lithography
Nagai, Hironori; Poteet, Austen; Zhang, Xu A.; Chang, Chih-Hao
2017-03-01
Light interactions with colloidal particles can generate a variety of complex three-dimensional (3D) intensity patterns, which can be utilized for nanolithography. The study of particle–light interactions can add more types of intensity patterns by manipulating key factors. Here we investigate a novel 3D nanolithography technique using colloidal particles under two-beam coherent illuminations. The fabricated 3D nanostructures are hollow, nested within periodic structures, and possess multiple chamber geometry. The effects of incident angles and particle size on the fabricated nanostructures were examined. The relative phase shift between particle position and interference pattern is identified as another significant parameter influencing the resultant nanostructures. A numerical model has been developed to show the evolution of nanostructure geometry with phase shifts, and experimental studies confirm the simulation results. Through the introduction of single colloidal particles, the fabrication capability of Lloyd’s mirror interference can now be extended to fabrication of 3D nanostructure with complex shell geometry. The fabricated hollow nanostructures with grating background could find potential applications in the area of photonics, drug delivery, and nanofluidics.
Energy Technology Data Exchange (ETDEWEB)
Akasaka, Y.
1986-12-01
VLSI will be reaching to the limit of minimization in the 1990s, and after that, further increase of packing density or functions might depend on the vertical integration technology. Three-dimensional (3-D) integration is expected to provide several advantages, such as 1) parallel processing, 2) high-speed operation, 3) high packing density, and 4) multifunctional operation. Basic technologies of 3-D IC are to fabricate SOI layers and to stack them monolithically. Crystallinity of the recrystallized layer in SOI has increasingly become better, and very recently crystal-axis controlled, defect-free single-crystal areas has been obtained in chip size level by laser recystallization technology. Some basic functional models showing the concept or image of a future 3-D IC were fabricated in two or three stacked active layers. Some other proposals of subsystems in the application of 3-D structure, and the technical issues for realizing practical 3-D IC, i.e., the technology for fabricating high-quality SOI crystal on complicated surface topology, crosstalk of the signals between the stacked layers, total power consumption and cooling of the chip, are also discussed in this paper.
Three-dimensional colloidal lithography.
Nagai, Hironori; Poteet, Austen; Zhang, Xu A; Chang, Chih-Hao
2017-03-24
Light interactions with colloidal particles can generate a variety of complex three-dimensional (3D) intensity patterns, which can be utilized for nanolithography. The study of particle-light interactions can add more types of intensity patterns by manipulating key factors. Here we investigate a novel 3D nanolithography technique using colloidal particles under two-beam coherent illuminations. The fabricated 3D nanostructures are hollow, nested within periodic structures, and possess multiple chamber geometry. The effects of incident angles and particle size on the fabricated nanostructures were examined. The relative phase shift between particle position and interference pattern is identified as another significant parameter influencing the resultant nanostructures. A numerical model has been developed to show the evolution of nanostructure geometry with phase shifts, and experimental studies confirm the simulation results. Through the introduction of single colloidal particles, the fabrication capability of Lloyd's mirror interference can now be extended to fabrication of 3D nanostructure with complex shell geometry. The fabricated hollow nanostructures with grating background could find potential applications in the area of photonics, drug delivery, and nanofluidics.
Kornreich, Philipp; Farell, Bart
2013-01-01
An imager that can measure the distance from each pixel to the point on the object that is in focus at the pixel is described. This is accomplished by short photo-conducting lightguides at each pixel. In the eye the rods and cones are the fiber-like lightguides. The device uses ambient light that is only coherent in spherical shell-shaped light packets of thickness of one coherence length. Modern semiconductor technology permits the construction of lightguides shorter than a coherence length of ambient light. Each of the frequency components of the broad band light arriving at a pixel has a phase proportional to the distance from an object point to its image pixel. Light frequency components in the packet arriving at a pixel through a convex lens add constructively only if the light comes from the object point in focus at this pixel. The light in packets from all other object points cancels. Thus the pixel receives light from one object point only. The lightguide has contacts along its length. The lightguide charge carriers are generated by the light patterns. These light patterns, and thus the photocurrent, shift in response to the phase of the input signal. Thus, the photocurrent is a function of the distance from the pixel to its object point. Applications include autonomous vehicle navigation and robotic vision. Another application is a crude teleportation system consisting of a camera and a three-dimensional printer at a remote location.
Elastocapillary fabrication of three-dimensional microstructures
Honschoten, van J.W.; Berenschot, J.W.; Ondarcuhu, T.; Sanders, R.G.P.; Sundaram, J.; Elwenspoek, M.; Tas, N.R.
2010-01-01
We describe the fabrication of three-dimensional microstructures by means of capillary forces. Using an origami-like technique, planar silicon nitride structures of various geometries are folded to produce three-dimensional objects of 50–100 m. Capillarity is a particularly effective mechanism since
Three-Dimensional Gravity and String Ghosts
Carlip, S.; Kogan, I. I.
1991-01-01
It is known that much of the structure of string theory can be derived from three-dimensional topological field theory and gravity. We show here that, at least for simple topologies, the string diffeomorphism ghosts can also be explained in terms of three-dimensional physics.
Application of ESPRIT in Broad Beam HF Ground Wave Radar Sea Surface Current Mapping
Institute of Scientific and Technical Information of China (English)
Liu Dan-hong; Wu Xiong-bin; Wen Bi-yang; Cheng Feng
2004-01-01
HF surface wave radar system OSMAR2000 is a broad-beam sea-state detecting radar. ESPRIT (Estimation of Signal Parameters via Rotational Invariance Technique) algorithm is proposed to apply in DOA (direction of arrival) determination of sea echoes. The algorithm of ESPRIT is briefly introduced first. Then discussions are made on the technique for application in the OSMAR2000 framework. Numerical simulation results are presented to demonstrate the feasibility of radial current mapping based on this method. The algorithm manifests significant performance and computational advantages compared with that of MUSIC. Data acquired by OSMAR2000 are processed to give radial current map and the synthesized vector currents are compared with the in-situ measurement with traditional means. The results show the validity of ESPRIT application in DOA determination for broad-beam radar.
Three Dimensional Illustrating--Three-Dimensional Vision and Deception of Sensibility
Szállassy, Noémi; Gánóczy, Anita; Kriska, György
2009-01-01
The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena…
Polycrystalline diamond detectors with three-dimensional electrodes
Energy Technology Data Exchange (ETDEWEB)
Lagomarsino, S., E-mail: lagomarsino@fi.infn.it [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Bellini, M. [INO-CNR Firenze, Largo E. Fermi 6, 50125 Firenze (Italy); Brianzi, M. [INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Carzino, R. [Smart Materials-Nanophysics, Istituto Italiano di Tecnologia, Genova, Via Morego 30, 16163 Genova (Italy); Cindro, V. [Joseph Stefan Institute, Jamova Cesta 39, 1000 Ljubljana (Slovenia); Corsi, C. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); LENS Firenze, Via N. Carrara 1, 50019 Sesto Fiorentino (Italy); Morozzi, A.; Passeri, D. [INFN Perugia, Perugia (Italy); Università degli Studi di Perugia, Dipartimento di Ingegneria, via G. Duranti 93, 06125 Perugia (Italy); Sciortino, S. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Servoli, L. [INFN Perugia, Perugia (Italy)
2015-10-01
The three-dimensional concept in diamond detectors has been applied, so far, to high quality single-crystal material, in order to test this technology in the best available conditions. However, its application to polycrystalline chemical vapor deposited diamond could be desirable for two reasons: first, the short inter-electrode distance of three-dimensional detectors should improve the intrinsically lower collection efficiency of polycrystalline diamond, and second, at high levels of radiation damage the performances of the poly-crystal material are not expected to be much lower than those of the single crystal one. We report on the fabrication and test of three-dimensional polycrystalline diamond detectors with several inter-electrode distances, and we demonstrate that their collection efficiency is equal or higher than that obtained with conventional planar detectors fabricated with the same material. - Highlights: • Pulsed laser fabrication of polycristalline diamond detectors with 3D electrodes. • Measurement of the charge collection efficiency (CCE) under beta irradiation. • Comparation between the CCE of 3D and conventional planar diamond sensors. • A rationale for the behavior of three-dimensional and planar sensors is given.
Schmitz, Christoph; Grolms, Norman; Hof, Patrick R; Boehringer, Robert; Glaser, Jacob; Korr, Hubert
2002-09-01
Prenatal X-irradiation, even at doses <1 Gy, can induce spatial disarray of neurons in the brains of offspring, possibly due to disturbed neuronal migration. Here we analyze the effects of prenatal low-dose X-irradiation using a novel stereological method designed to investigate the three-dimensional (3D) spatial arrangement of neurons in thick sections. Pregnant mice were X-irradiated with 50 cGy on embryonic day 13 or were sham-irradiated. The right brain halves of their 180-day-old offspring were dissected into entire series of 150 microm thick frontal cryostat sections and stained with gallocyanin. Approximately 700 layer V pyramidal cells per animal were sampled in a systematic-random manner in the middle of the section's thickness. The x-y-z coordinates of these 'parent neurons' were recorded, as well as of all neighboring (up to 10) 'offspring neurons' close to each 'parent neuron'. From these data, the nearest neighbor distance (NND) distributions for layer V pyramidal cells were calculated. Using this novel 3D analysis method, we found that, in comparison to controls, prenatal X-irradiation had no effect on the total neuron number, but did cause a reduction in the mean volume of layer V by 26.5% and a more dispersed spatial arrangement of these neurons. Considering the recent literature, it seems reasonable to consider abnormal neuronal migration as the potential basic cause of this finding.
Three-dimensional imaging modalities in endodontics
Mao, Teresa; Neelakantan, Prasanna
2014-01-01
Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualize...
Three-Dimensional Icosahedral Phase Field Quasicrystal
Subramanian, P.; Archer, A. J.; Knobloch, E.; Rucklidge, A. M.
2016-08-01
We investigate the formation and stability of icosahedral quasicrystalline structures using a dynamic phase field crystal model. Nonlinear interactions between density waves at two length scales stabilize three-dimensional quasicrystals. We determine the phase diagram and parameter values required for the quasicrystal to be the global minimum free energy state. We demonstrate that traits that promote the formation of two-dimensional quasicrystals are extant in three dimensions, and highlight the characteristics required for three-dimensional soft matter quasicrystal formation.
Modeling and experimental verification for a broad beam light transport in optical tomography.
Janunts, Edgar; Pöschinger, Thomas; Eisa, Fabian; Langenbucher, Achim
2010-01-01
This paper describes a general theoretical model for computing a broad beam excitation light transport in a 3D diffusion medium. The model is based on the diffusion approximation of the radiative transport equation. An analytical approach for the light propagation is presented by deriving a corresponding Green's function. A finite cylindrical domain with a rectangular cross section was considered as a 3D homogeneous phantom model. The results of the model are compared with corresponding experimental data. The measurements are done on solid and liquid phantoms replicating tissue-like optical properties.
Mixed diffusive-convective relaxation of a broad beam of energetic particles in cold plasma
Carlevaro, Nakia; Falessi, Matteo V; Montani, Giovanni; Terzani, Davide; Zonca, Fulvio
2015-01-01
We revisit the applications of quasi-linear theory as a paradigmatic model for weak plasma turbulence and the associated bump-on-tail problem. The work, presented here, is built around the idea that large-amplitude or strongly shaped beams do not relax through diffusion only and that there exists an intermediate time scale where the relaxations are {\\it convective} (ballistic-like). We cast this novel idea in the rigorous form of a self-consistent nonlinear dynamical model, which generalizes the classic equations of the quasi-linear theory to "broad" beams with internal structure. We also present numerical simulation results of the relaxation of a broad beam of energetic particles in cold plasma. These generally demonstrate the mixed diffusive-convective features of supra-thermal particle transport; and essentially depend on nonlinear wave-particle interactions and phase-space structures. Taking into account modes of the stable linear spectrum is crucial for the self-consistent evolution of the distribution f...
Lo Giudice, Alessandro; Re, Alessandro; Angelici, Debora; Calusi, Silvia; Gelli, Nicla; Giuntini, Lorenzo; Massi, Mirko; Pratesi, Giovanni
2012-07-01
Broad beam ionoluminescence (IL) microscopy is a promising technique for the non-destructive characterisation of rocks and stone objects. Luminescence imaging by means of broad ion beams has been sporadically used by other authors but, to our knowledge, its potential has not yet been fully investigated, neither in geological science nor in other fields. The in-air broad beam IL microscope was developed and installed at the INFN-LABEC external microbeam in Florence. Similar to the cathodoluminescence (CL) microscope, the apparatus exploits a CCD colour camera collecting images (few square millimetres wide, with ~10-μm spatial resolution) of the luminescence emitted by the sample hit by a defocused megaelectron volt (MeV) proton beam. The main differences with the well-established and widespread CL are the possibility of working in air (no sampling or conductive coatings required) and the possibility of combining the analysis with microbeam analysis, such as, for example, μ-IL and μ-PIXE (particle-induced X-ray emission). To show the potential of the technique, IL images of thin sections of lapis lazuli are compared with those obtained by means of an in-vacuum cold CL. An application to the study of stone artworks is also reported. This technique and apparatus will provide a valuable help for interdisciplinary applications, e.g. in geological sciences and in the cultural heritage field.
Three dimensional dynamics of ferromagnetic swimmer
Energy Technology Data Exchange (ETDEWEB)
Erglis, K.; Livanovics, R. [Department of Physics, University of Latvia, Zellu 8, Ri-bar ga LV-1002 (Latvia); Cebers, A., E-mail: aceb@tesla.sal.l [Department of Physics, University of Latvia, Zellu 8, Ri-bar ga LV-1002 (Latvia)
2011-05-15
It is shown that a flexible ferromagnetic filament self-propels perpendicularly to the AC magnetic field during a limited period of time due to the instability of the planar motion with respect to three dimensional perturbations. The transition from the oscillating U-like shapes to the oscillating S-like shapes is characterized by the calculated Wr number. - Research Highlights: A ferromagnetic filament self-propels perpendicularly to the AC field. During the self-propulsion cycle the filament moves both forward and backward. The self-propulsion stops due to the three dimensional instability. The mechanism of the self-propulsion is similar to that used by some microorganisms.
Transferring color between three-dimensional objects
Shen, Hui-Liang; Xin, John H.
2005-04-01
A framework for transferring image-based color between three-dimensional objects by the use of a dichromatic reflection model is proposed. The framework addresses the following issues: (1) accurate recovery of an implicit geometric coefficient, (2) calculation of body color, (3) color transfer between different illuminants, and (4) segmentation of multicolored regions. The experimental results show that high color accuracy and photorealistic effects of the synthesized images can be achieved. The proposed technique has wide applications in image-based design and visualization of three-dimensional objects.
Three-Dimensional Robotic Vision System
Nguyen, Thinh V.
1989-01-01
Stereoscopy and motion provide clues to outlines of objects. Digital image-processing system acts as "intelligent" automatic machine-vision system by processing views from stereoscopic television cameras into three-dimensional coordinates of moving object in view. Epipolar-line technique used to find corresponding points in stereoscopic views. Robotic vision system analyzes views from two television cameras to detect rigid three-dimensional objects and reconstruct numerically in terms of coordinates of corner points. Stereoscopy and effects of motion on two images complement each other in providing image-analyzing subsystem with clues to natures and locations of principal features.
Three-dimensional patterning methods and related devices
Energy Technology Data Exchange (ETDEWEB)
Putnam, Morgan C.; Kelzenberg, Michael D.; Atwater, Harry A.; Boettcher, Shannon W.; Lewis, Nathan S.; Spurgeon, Joshua M.; Turner-Evans, Daniel B.; Warren, Emily L.
2016-12-27
Three-dimensional patterning methods of a three-dimensional microstructure, such as a semiconductor wire array, are described, in conjunction with etching and/or deposition steps to pattern the three-dimensional microstructure.
Three dimensional electrochemical system for neurobiological studies
DEFF Research Database (Denmark)
Vazquez, Patricia; Dimaki, Maria; Svendsen, Winnie Edith
2009-01-01
In this work we report a novel three dimensional electrode array for electrochemical measurements in neuronal studies. The main advantage of working with these out-of-plane structures is the enhanced sensitivity of the system in terms of measuring electrochemical changes in the environment...
Three-dimensional broadband tunable terahertz metamaterials
DEFF Research Database (Denmark)
Fan, Kebin; Strikwerda, Andrew; Zhang, Xin;
2013-01-01
We present optically tunable magnetic three-dimensional (3D) metamaterials at terahertz (THz) frequencies which exhibit a tuning range of ~30% of the resonance frequency. This is accomplished by fabricating 3D array structures consisting of double-split-ring resonators (DSRRs) on silicon on sapph...
Electron crystallography of three dimensional protein crystals
Georgieva, Dilyana
2008-01-01
This thesis describes an investigation of the potential of electron diffraction for studying three dimensional sub-micro-crystals of proteins and pharmaceuticals. A prerequisite for using electron diffraction for structural studies is the predictable availability of tiny crystals. A method for grow
Broad beam and narrow beam attenuation in Lipowitz's metal
Energy Technology Data Exchange (ETDEWEB)
el-Khatib, E.E.; Podgorsak, E.B.; Pla, C.
1987-01-01
Attenuation properties of Lipowitz's metal have been studied for narrow and broad beams of cobalt-60 gamma rays and 4-10 MV x-rays. The measured transmitted fraction for geometries used in radiotherapy depends on the field size and depth of measurement. Therefore a calculation of dose for partially attenuated beams based on narrow beam attenuation coefficients can cause large errors in dosimetry. Our simple calculation of transmitted fractions based on primary attenuation and scattered radiation agrees quite well with the measured data for therapeutic geometries. Also given is a table for linear, mass attenuation, and mass energy absorption coefficients of Lipowitz's metal in the photon energy range from 10 keV to 10 MeV.
Three-dimensional imaging modalities in endodontics
Energy Technology Data Exchange (ETDEWEB)
Mao, Teresa; Neelakantan, Prasanna [Dept. of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha University, Chennai (India)
2014-09-15
Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.
Three-dimensional imaging modalities in endodontics.
Mao, Teresa; Neelakantan, Prasanna
2014-09-01
Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.
THREE DIMENSIONAL GRAPHICAL REPRESENTATION OF QUALITY
Directory of Open Access Journals (Sweden)
Vineet V. Kumar
2014-03-01
Full Text Available Quality is an important aspect for every firm in modern era of competition. Every product has tough competition in terms of market reach. The factor, which actually makes any product long run in market, is quality and hence quality is the stepping-stone for success of any firm. For everyone meaning of quality is different. We have seen several economists who have defined quality by considering different factors, but what all of them have common in them is Customer satisfaction. Customer satisfaction is the ultimate result of quality. In three-dimensional graphical representation of quality, optimum quality is obtained by using three-dimensional graph by considering some important factors governing quality of any product, limiting factor, and customer satisfaction.
Deformations of three-dimensional metrics
Pugliese, Daniela; Stornaiolo, Cosimo
2015-03-01
We examine three-dimensional metric deformations based on a tetrad transformation through the action the matrices of scalar field. We describe by this approach to deformation the results obtained by Coll et al. (Gen. Relativ. Gravit. 34:269, 2002), where it is stated that any three-dimensional metric was locally obtained as a deformation of a constant curvature metric parameterized by a 2-form. To this aim, we construct the corresponding deforming matrices and provide their classification according to the properties of the scalar and of the vector used in Coll et al. (Gen Relativ Gravit 34:269, 2002) to deform the initial metric. The resulting causal structure of the deformed geometries is examined, too. Finally we apply our results to a spherically symmetric three geometry and to a space sector of Kerr metric.
Artifacts in three-dimensional transesophageal echocardiography.
Faletra, Francesco Fulvio; Ramamurthi, Alamelu; Dequarti, Maria Cristina; Leo, Laura Anna; Moccetti, Tiziano; Pandian, Natesa
2014-05-01
Three-dimensional (3D) transesophageal echocardiography (TEE) is subject to the same types of artifacts encountered on two-dimensional TEE. However, when displayed in a 3D format, some of the artifacts appear more "realistic," whereas others are unique to image acquisition and postprocessing. Three-dimensional TEE is increasingly used in the setting of percutaneous catheter-based interventions and ablation procedures, and 3D artifacts caused by the metallic components of catheters and devices are particularly frequent. Knowledge of these artifacts is of paramount relevance to avoid misinterpretation of 3D images. Although artifacts and pitfalls on two-dimensional echocardiography are well described and classified, a systematic description of artifacts in 3D transesophageal echocardiographic images and how they affect 3D imaging is still absent. The aim of this review is to describe the most relevant artifacts on 3D TEE, with particular emphasis on those occurring during percutaneous interventions for structural heart disease and ablation procedures.
Three-dimensional Imaging, Visualization, and Display
Javidi, Bahram; Son, Jung-Young
2009-01-01
Three-Dimensional Imaging, Visualization, and Display describes recent developments, as well as the prospects and challenges facing 3D imaging, visualization, and display systems and devices. With the rapid advances in electronics, hardware, and software, 3D imaging techniques can now be implemented with commercially available components and can be used for many applications. This volume discusses the state-of-the-art in 3D display and visualization technologies, including binocular, multi-view, holographic, and image reproduction and capture techniques. It also covers 3D optical systems, 3D display instruments, 3D imaging applications, and details several attractive methods for producing 3D moving pictures. This book integrates the background material with new advances and applications in the field, and the available online supplement will include full color videos of 3D display systems. Three-Dimensional Imaging, Visualization, and Display is suitable for electrical engineers, computer scientists, optical e...
Three-Dimensional Ocean Noise Modeling
2015-03-01
particular attention paid to the case of Gaussian canyon . The solution to the three-dimensional wave equation in Cartesian co-ordinates can be written...in terms of a modal decomposition, carried out in the vertical and across- canyon horizontal directions. Work Completed 1. Nx2D and 3D Noise PE...azimuth in the Hudson Canyon [Figure 2). Additionally, the PE-reciprocity noise model was used to estimate the size, speed and distance from the
Lossless compression for three-dimensional images
Tang, Xiaoli; Pearlman, William A.
2004-01-01
We investigate and compare the performance of several three-dimensional (3D) embedded wavelet algorithms on lossless 3D image compression. The algorithms are Asymmetric Tree Three-Dimensional Set Partitioning In Hierarchical Trees (AT-3DSPIHT), Three-Dimensional Set Partitioned Embedded bloCK (3D-SPECK), Three-Dimensional Context-Based Embedded Zerotrees of Wavelet coefficients (3D-CB-EZW), and JPEG2000 Part II for multi-component images. Two kinds of images are investigated in our study -- 8-bit CT and MR medical images and 16-bit AVIRIS hyperspectral images. First, the performances by using different size of coding units are compared. It shows that increasing the size of coding unit improves the performance somewhat. Second, the performances by using different integer wavelet transforms are compared for AT-3DSPIHT, 3D-SPECK and 3D-CB-EZW. None of the considered filters always performs the best for all data sets and algorithms. At last, we compare the different lossless compression algorithms by applying integer wavelet transform on the entire image volumes. For 8-bit medical image volumes, AT-3DSPIHT performs the best almost all the time, achieving average of 12% decreases in file size compared with JPEG2000 multi-component, the second performer. For 16-bit hyperspectral images, AT-3DSPIHT always performs the best, yielding average 5.8% and 8.9% decreases in file size compared with 3D-SPECK and JPEG2000 multi-component, respectively. Two 2D compression algorithms, JPEG2000 and UNIX zip, are also included for reference, and all 3D algorithms perform much better than 2D algorithms.
Three-Dimensional Printing in Orthopedic Surgery.
Eltorai, Adam E M; Nguyen, Eric; Daniels, Alan H
2015-11-01
Three-dimensional (3D) printing is emerging as a clinically promising technology for rapid prototyping of surgically implantable products. With this commercially available technology, computed tomography or magnetic resonance images can be used to create graspable objects from 3D reconstructed images. Models can enhance patients' understanding of their pathology and surgeon preoperative planning. Customized implants and casts can be made to match an individual's anatomy. This review outlines 3D printing, its current applications in orthopedics, and promising future directions.
Volumetric Three-Dimensional Display Systems
Blundell, Barry G.; Schwarz, Adam J.
2000-03-01
A comprehensive study of approaches to three-dimensional visualization by volumetric display systems This groundbreaking volume provides an unbiased and in-depth discussion on a broad range of volumetric three-dimensional display systems. It examines the history, development, design, and future of these displays, and considers their potential for application to key areas in which visualization plays a major role. Drawing substantially on material that was previously unpublished or available only in patent form, the authors establish the first comprehensive technical and mathematical formalization of the field, and examine a number of different volumetric architectures. System level design strategies are presented, from which proposals for the next generation of high-definition predictable volumetric systems are developed. To ensure that researchers will benefit from work already completed, they provide: * Descriptions of several recent volumetric display systems prepared from material supplied by the teams that created them * An abstract volumetric display system design paradigm * An historical summary of 90 years of development in volumetric display system technology * An assessment of the strengths and weaknesses of many of the systems proposed to date * A unified presentation of the underlying principles of volumetric display systems * A comprehensive bibliography Beautifully supplemented with 17 color plates that illustrate volumetric images and prototype displays, Volumetric Three-Dimensional Display Systems is an indispensable resource for professionals in imaging systems development, scientific visualization, medical imaging, computer graphics, aerospace, military planning, and CAD/CAE.
Multiparallel Three-Dimensional Optical Microscopy
Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel
2010-01-01
Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.
Imaging unsteady three-dimensional transport phenomena
Indian Academy of Sciences (India)
K Muralidhar
2014-01-01
Careful and continuous measurements of flow, heat and mass transfer are required in quite a few contexts. Using appropriate light sources, it is possible to map velocity, temperature, and species concentration over a cross-section and as a function of time. Image formation in optical measurements may rely on scattering of radiation from particles. Alternatively, if the region of interest is transparent, refractive index would be a field variable and beam bending effects can be used to extract information about temperature and concentration of solutes dissolved in liquids. Time-lapsed images of light intensity can be used to determine fluid velocity. Though used originally for flow visualization, optical imaging has now emerged as a powerful tool for quantitative measurements. Optical methods that utilize the dependence of refractive index on concentration and temperature can be configured in many different ways. Three available routes considered are interferometry, schlieren imaging, and shadowgraph. Images recorded in these configurations can be analysed to yield time sequences of three-dimensional distributions of the transported variables. Optical methods are non-intrusive, inertia-free and can image cross-sections of the experimental apparatus. The image data can be jointly analysed with the physical laws governing transport and principles of image formation. Hence, with the experiment suitably carried out, three-dimensional physical domains with unsteady processes can be accommodated. Optical methods promise to breach the holy grail of measurements by extracting unsteady three-dimensional data in applications related to transport phenomena.
Three dimensional illustrating - three-dimensional vision and deception of sensibility
Directory of Open Access Journals (Sweden)
Anita Gánóczy
2009-03-01
Full Text Available The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena of movement parallax, which can be used efficiently in making three-dimensional graphics, the Zöllner- and Corridor-illusion. There are present in this paper the visual elements, which contribute to define a plane two-dimensional image in three-dimension: coherent lines, the covering, the measurement changes, the relative altitude state, the abatement of detail profusion, the shadings and the perspective effects of colors.
Three-dimensional analysis of craniofacial bones using three-dimensional computer tomography
Energy Technology Data Exchange (ETDEWEB)
Ono, Ichiro; Ohura, Takehiko; Kimura, Chu (Hokkaido Univ., Sapporo (Japan). School of Medicine) (and others)
1989-08-01
Three-dimensional computer tomography (3DCT) was performed in patients with various diseases to visualize stereoscopically the deformity of the craniofacial bones. The data obtained were analyzed by the 3DCT analyzing system. A new coordinate system was established using the median sagittal plane of the face (a plane passing through sella, nasion and basion) on the three-dimensional image. Three-dimensional profilograms were prepared for detailed analysis of the deformation of craniofacial bones for cleft lip and palate, mandibular prognathia and hemifacial microsomia. For patients, asymmetry in the frontal view and twist-formed complicated deformities were observed, as well as deformity of profiles in the anteroposterior and up-and-down directions. A newly developed technique allows three-dimensional visualization of changes in craniofacial deformity. It would aid in determining surgical strategy, including crani-facial surgery and maxillo-facial surgery, and in evaluating surgical outcome. (N.K.).
Stability of three-dimensional boundary layers
Nayfeh, A. H.
1979-01-01
A theory is presented for the three-dimensional stability of boundary layers. Equations are derived for the evolution of a disturbance having a given frequency and originating at a given curve. These equations are used to determine the rays along which the disturbance energy propagates. It is shown that the results can be obtained by using the saddle-point method, or kinematic wave theory, or the method of multiple scales. Extension of the theory to the case of a wave packet is also presented.
Nonparallel stability of three-dimensional flows
Padhye, A. R.; Nayfeh, A. H.
1981-01-01
The linear stability of three-dimensional incompressible, isothermal, nonparallel boundary-layer flows has been investigated. The method of multiple scales is used to derive the partial-differential equations that describe the spatial modulations of the amplitude, phase and wavenumber of a disturbance. Group velocities are used to determine the disturbance growth direction. The envelope method is used to calculate the logarithmic amplitude growth rate N. The theory is applied to the flows over a swept-back tapered wing with boundary-layer suction. Results of such analysis for the X-21 wing are discussed. It is found that the nonparallel effects for this wing is substantial.
Three-dimensional cooling of muons
Vsevolozhskaya, T A
2000-01-01
The simultaneous ionization cooling of muon beams in all three - the longitudinal and two transverse - directions is considered in a scheme, based on bent lithium lenses with dipole constituent of magnetic field in them, created by a special configuration of current-carrying rod. An analysis of three-dimensional cooling is performed with the use of kinetic equation method. Results of numerical calculation for a specific beam line configuration are presented together with results of computer simulation using the Moliere distribution to describe the Coulomb scattering and the Vavilov distribution used to describe the ionization loss of energy.
Stabilization of Three-Dimensional Collective Motion
Scardovi, Luca; Sepulchre, Rodolphe
2008-01-01
This paper proposes a methodology to stabilize relative equilibria in a model of identical, steered particles moving in three-dimensional Euclidean space. Exploiting the Lie group structure of the resulting dynamical system, the stabilization problem is reduced to a consensus problem on the Lie algebra. The resulting equilibria correspond to parallel, circular and helical formations. We first derive the stabilizing control laws in the presence of all-to-all communication. Providing each agent with a consensus estimator, we then extend the results to a general setting that allows for unidirectional and time-varying communication topologies.
Three dimensional dilatonic gravity's rainbow: exact solutions
Hendi, Seyed Hossein; Panahiyan, Shahram
2016-01-01
Deep relations of dark energy scenario and string theory results with dilaton gravity, on one hand, and the connection between quantum gravity with gravity's rainbow, on the other hand, motivate us to consider three dimensional dilatonic black hole solutions in gravity's rainbow. We obtain two classes of the solutions which are polynomial and logarithmic forms. We also calculate conserved and thermodynamic quantities, and examine the first law of thermodynamics for both classes. In addition, we study thermal stability and show that one of the classes is thermally stable while the other one is unstable.
Three-dimensional echocardiography in valve disease.
Colombo, Chiara; Tamborini, Gloria; Pepi, Mauro; Alimento, Marina; Fiorentini, Cesare
2007-01-01
This review covers the role of three-dimensional (3D) echocardiography in the diagnosis of heart valve disease. Several factors have contributed to the evolution of this technique, which is currently a simple and routine method: rapid evolution in probe and computer technologies, demonstration that 3D data sets allowed more complete and accurate evaluation of cardiac structures, emerging clinical experience indicating the strong potential particularly in valve diseases, volume and function of the two ventricle measurements and several other fields. This report will review current and future applications of 3D echocardiography in mitral, aortic and tricuspid valve diseases underlying both qualitative (morphologic) and quantitative advantages of this technique.
Pober, Jonathan C; DeBoer, David R; McDonald, Patrick; McQuinn, Matthew; Aguirre, James E; Ali, Zaki; Bradley, Richard F; Chang, Tzu-Ching; Morales, Miguel F
2012-01-01
This work describes a new instrument optimized for a detection of the neutral hydrogen 21cm power spectrum between redshifts of 0.5-1.5: the Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) Array. BAOBAB will build on the efforts of a first generation of 21cm experiments which are targeting a detection of the signal from the Epoch of Reionization at z ~ 10. At z ~ 1, the emission from neutral hydrogen in self-shielded overdense halos also presents an accessible signal, since the dominant, synchrotron foreground emission is considerably fainter than at redshift 10. The principle science driver for these observations are Baryon Acoustic Oscillations in the matter power spectrum which have the potential to act as a standard ruler and constrain the nature of dark energy. BAOBAB will fully correlate dual-polarization antenna tiles over the 600-900MHz band with a frequency resolution of 300 kHz and a system temperature of 50K. The number of antennas will grow in staged deployments, and reconfigurations...
Three dimensional quantum geometry and deformed symmetry
Joung, E.; Mourad, J.; Noui, K.
2009-05-01
We study a three dimensional noncommutative space emerging in the context of three dimensional Euclidean quantum gravity. Our starting point is the assumption that the isometry group is deformed to the Drinfeld double D(SU(2)). We generalize to the deformed case the construction of E3 as the quotient of its isometry group ISU(2) by SU(2). We show that the algebra of functions on E3 becomes the noncommutative algebra of SU(2) distributions, C(SU(2))∗, endowed with the convolution product. This construction gives the action of ISU(2) on the algebra and allows the determination of plane waves and coordinate functions. In particular, we show the following: (i) plane waves have bounded momenta; (ii) to a given momentum are associated several SU(2) elements leading to an effective description of ϕ ɛC(SU(2))∗ in terms of several physical scalar fields on E3; (iii) their product leads to a deformed addition rule of momenta consistent with the bound on the spectrum. We generalize to the noncommutative setting the "local" action for a scalar field. Finally, we obtain, using harmonic analysis, another useful description of the algebra as the direct sum of the algebra of matrices. The algebra of matrices inherits the action of ISU(2): rotations leave the order of the matrices invariant, whereas translations change the order in a way we explicitly determine.
Three-dimensional flow in Kupffer's Vesicle
Montenegro-Johnson, Thomas D; Smith, David J; Lopes, Susana S
2016-01-01
Whilst many vertebrates appear externally left-right symmetric, the arrangement of internal organs is asymmetric. In zebrafish, the breaking of left-right symmetry is organised by Kupffer's Vesicle (KV): an approximately spherical, fluid-filled structure that begins to form in the embryo 10 hours post fertilisation. A crucial component of zebrafish symmetry breaking is the establishment of a cilia-driven fluid flow within KV. However, it is still unclear (a) how dorsal, ventral and equatorial cilia contribute to the global vortical flow, and (b) if this flow breaks left-right symmetry through mechanical transduction or morphogen transport. Fully answering these questions requires knowledge of the three-dimensional flow patterns within KV, which have not been quantified in previous work. In this study, we calculate and analyse the three-dimensional flow in KV. We consider flow from both individual and groups of cilia, and (a) find anticlockwise flow can arise purely from excess of cilia on the dorsal roof over...
Three dimensional force balance of asymmetric droplets
Kim, Yeseul; Lim, Su Jin; Cho, Kun; Weon, Byung Mook
2016-11-01
An equilibrium contact angle of a droplet is determined by a horizontal force balance among vapor, liquid, and solid, which is known as Young's law. Conventional wetting law is valid only for axis-symmetric droplets, whereas real droplets are often asymmetric. Here we show that three-dimensional geometry must be considered for a force balance for asymmetric droplets. By visualizing asymmetric droplets placed on a free-standing membrane in air with X-ray microscopy, we are able to identify that force balances in one side and in other side control pinning behaviors during evaporation of droplets. We find that X-ray microscopy is powerful for realizing the three-dimensional force balance, which would be essential in interpretation and manipulation of wetting, spreading, and drying dynamics for asymmetric droplets. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2016R1D1A1B01007133).
Two component-three dimensional catalysis
Schwartz, Michael; White, James H.; Sammells, Anthony F.
2002-01-01
This invention relates to catalytic reactor membranes having a gas-impermeable membrane for transport of oxygen anions. The membrane has an oxidation surface and a reduction surface. The membrane is coated on its oxidation surface with an adherent catalyst layer and is optionally coated on its reduction surface with a catalyst that promotes reduction of an oxygen-containing species (e.g., O.sub.2, NO.sub.2, SO.sub.2, etc.) to generate oxygen anions on the membrane. The reactor has an oxidation zone and a reduction zone separated by the membrane. A component of an oxygen containing gas in the reduction zone is reduced at the membrane and a reduced species in a reactant gas in the oxidation zone of the reactor is oxidized. The reactor optionally contains a three-dimensional catalyst in the oxidation zone. The adherent catalyst layer and the three-dimensional catalyst are selected to promote a desired oxidation reaction, particularly a partial oxidation of a hydrocarbon.
Three-dimensional computed tomography of the acetabulum
Energy Technology Data Exchange (ETDEWEB)
Pozzi Mucelli, R.S.; Muner, G.; Pozzi Mucelli, F.; Pozzi Mucelli, M.; Marotti, F.; Dalla Palma, L.
1986-08-01
Acetabular fractures represent a complex variety that are classified in different types. Conventional radiology is often inadequate to demonstrate and classify the fractures. Computed tomography (CT) has already been shown to be superior in this field. A further advantage of CT is represented by the recent availability of three-dimensional (3D) images that are realized from axial CT scans by means of a new software. The Authors report the applications of this new software to the study of the normal acetabulum and in patients with fractures. 3D images allows an effective demonstration of the fracture, its irradiation and the dislocation of bone fragments. The information is contained in one or few images rather than many axial images. Therefore the role of 3D images may be considered complementary to axial CT scans.
Energy Technology Data Exchange (ETDEWEB)
Pober, Jonathan C.; Parsons, Aaron R.; McQuinn, Matthew; Ali, Zaki [Astronomy Department, University of California, Berkeley, CA (United States); DeBoer, David R. [Radio Astronomy Laboratory, University of California, Berkeley, CA (United States); McDonald, Patrick [Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Aguirre, James E. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA (United States); Bradley, Richard F. [Astronomy Department and Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA (United States); Chang, Tzu-Ching [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan (China); Morales, Miguel F. [Department of Physics, University of Washington, Seattle, WA (United States)
2013-03-15
This work describes a new instrument optimized for a detection of the neutral hydrogen 21 cm power spectrum between redshifts of 0.5 and 1.5: the Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) array. BAOBAB will build on the efforts of a first generation of 21 cm experiments that are targeting a detection of the signal from the Epoch of Reionization at z {approx} 10. At z {approx} 1, the emission from neutral hydrogen in self-shielded overdense halos also presents an accessible signal, since the dominant, synchrotron foreground emission is considerably fainter than at redshift 10. The principle science driver for these observations are baryon acoustic oscillations in the matter power spectrum which have the potential to act as a standard ruler and constrain the nature of dark energy. BAOBAB will fully correlate dual-polarization antenna tiles over the 600-900 MHz band with a frequency resolution of 300 kHz and a system temperature of 50 K. The number of antennas will grow in staged deployments, and reconfigurations of the array will allow for both traditional imaging and high power spectrum sensitivity operations. We present calculations of the power spectrum sensitivity for various array sizes, with a 35 element array measuring the cosmic neutral hydrogen fraction as a function of redshift, and a 132 element system detecting the BAO features in the power spectrum, yielding a 1.8% error on the z {approx} 1 distance scale, and, in turn, significant improvements to constraints on the dark energy equation of state over an unprecedented range of redshifts from {approx}0.5 to 1.5.
Low-energy broad-beam photon shielding data for constituents of concrete.
Ogundare, Folorunso O; Ogundele, Samuel A; Akerele, Olumide O; Balogun, Fatai A
2012-03-08
The ability of concrete to attenuate ionizing radiation intensity is assessed using its linear or mass attenuation coefficient. In this work, the broad-beam linear and mass attenuation coefficients of different types of soils and cements used for making concrete were measured at different photon energies (60-1333 keV), nearly spanning the diagnostic photon energy range, using a NaI detector. The mass attenuation coefficients of cement decreased from 0.133 ± 0.002 at 60 keV to 0.047 ± 0.003 at 1332.5 keV. For soils, the mass attenuation coefficient of those collected from the beach was the highest, decreasing from 0.176 ± 0.003 cm²/g at 60 keV to 0.054 ± 0.001 cm²/g at 1332.5 keV. Land soils had the least value, decreasing from 0.124 ± 0.002 cm²/g at 60 keV to 0.044 ± 0.003 cm²/g at 1332.5 keV. Limestone had smaller mass attenuation coefficients than the cement produced using it. The implication of the above is that for making concrete, beach sand should be preferred as the sand component of the concrete. Models of the form μ(L) = A(E) exp[B(E)ρ] and μ(m) = αln(E)+β are proposed for fitting the linear attenuation coefficient and mass attenuation coefficient data, respectively.
Three-Dimensional Reflectance Traction Microscopy.
Directory of Open Access Journals (Sweden)
Jihan Kim
Full Text Available Cells in three-dimensional (3D environments exhibit very different biochemical and biophysical phenotypes compared to the behavior of cells in two-dimensional (2D environments. As an important biomechanical measurement, 2D traction force microscopy can not be directly extended into 3D cases. In order to quantitatively characterize the contraction field, we have developed 3D reflectance traction microscopy which combines confocal reflection imaging and partial volume correlation postprocessing. We have measured the deformation field of collagen gel under controlled mechanical stress. We have also characterized the deformation field generated by invasive breast cancer cells of different morphologies in 3D collagen matrix. In contrast to employ dispersed tracing particles or fluorescently-tagged matrix proteins, our methods provide a label-free, computationally effective strategy to study the cell mechanics in native 3D extracellular matrix.
Three-dimensional tori and Arnold tongues
Energy Technology Data Exchange (ETDEWEB)
Sekikawa, Munehisa, E-mail: sekikawa@cc.utsunomiya-u.ac.jp [Department of Mechanical and Intelligent Engineering, Utsunomiya University, Utsunomiya-shi 321-8585 (Japan); Inaba, Naohiko [Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kawasaki-shi 214-8571 (Japan); Kamiyama, Kyohei [Department of Electronics and Bioinformatics, Meiji University, Kawasaki-shi 214-8571 (Japan); Aihara, Kazuyuki [Institute of Industrial Science, the University of Tokyo, Meguro-ku 153-8505 (Japan)
2014-03-15
This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.
Steady inviscid three-dimensional flows
Adamczyk, J. J.; Chang, S.-C.
1985-01-01
The present analysis combines some of the theoretical concepts suggested by Hawthorne (1955) with a numerical integration procedure suggested by Martin (1978). The resulting algorithm is for inviscid subsonic flows. Thus, it is restricted to high Reynolds number flows. Chang and Adamczyk (1983) have provided a detailed derivation of the present algorithm along with a discussion of its stability bounds. The present paper represents a summary of this work. The integration of the continuity equation is considered along with an evaluation of the entropy, total temperature, and vorticity field. Attention is given to the shear-flow algorithm construction, and an application to a shear flow in a turning channel. A description of numerical results is also provided. The discussed algorithm represents a new procedure for solving inviscid subsonic three-dimensional rotational flows.
Scaffolding for Three-Dimensional Embryonic Vasculogenesis
Kraehenbuehl, Thomas P.; Aday, Sezin; Ferreira, Lino S.
Biomaterial scaffolds have great potential to support efficient vascular differentiation of embryonic stem cells. Vascular cell fate-specific biochemical and biophysical cues have been identified and incorporated into three-dimensional (3D) biomaterials to efficiently direct embryonic vasculogenesis. The resulting vascular-like tissue can be used for regenerative medicine applications, further elucidation of biophysical and biochemical cues governing vasculogenesis, and drug discovery. In this chapter, we give an overview on the following: (1) developmental cues for directed differentiation of human embryonic stem cells (hESCs) into vascular cells, (2) 3D vascular differentiation in embryoid bodies (EBs), (3) preparation of 3D scaffolds for the vascular differentiation of hESCs, and (4) the most significant studies combining scaffolding and hESCs for development of vascular-like tissue.
AAOGlimpse: Three-dimensional Data Viewer
Shortridge, Keith
2011-10-01
AAOGlimpse is an experimental display program that uses OpenGL to display FITS data (and even JPEG images) as 3D surfaces that can be rotated and viewed from different angles, all in real-time. It is WCS-compliant and designed to handle three-dimensional data. Each plane in a data cube is surfaced in the same way, and the program allows the user to travel through a cube by 'peeling off' successive planes, or to look into a cube by suppressing the display of data below a given cutoff value. It can blink images and can superimpose images and contour maps from different sources using their world coordinate data. A limited socket interface allows communication with other programs.
Three-Dimensional Pneumatic Molding of Veneers
Directory of Open Access Journals (Sweden)
Milan Gaff
2014-07-01
Full Text Available The goal of this paper is to introduce a new testing method suitable for the evaluation of the three-dimensional (3-D moldability of veneers and to use this method to test the impact of specific factors on the 3-D pneumatic molding process. The tested factors included veneer moisture content, wood species, shape of test piece, and fixing method on the maximum wood deflection. Veneers were molded using compressed air on equipment designed by our group for the sole purpose of this experiment. The results indicated that the monitored factors had an effect on deflection during the 3-D molding process. The results of this investigation extend the state-of-the-art knowledge regarding this technology and indicate the possibility of utilizing this innovative testing method for 3-D molded veneers.
Entanglement entropy in three dimensional gravity
Maxfield, Henry
2014-01-01
The Ryu-Takayanagi and covariant Hubeny-Rangamani-Takayanagi proposals relate entanglement entropy in CFTs with holographic duals to the areas of minimal or extremal surfaces in the bulk geometry. We show how, in three dimensional pure gravity, the relevant regulated geodesic lengths can be obtained by writing a spacetime as a quotients of AdS3, with the problem reduced to a simple purely algebraic calculation. We explain how this works in both Lorentzian and Euclidean formalisms, before illustrating its use to obtain novel results in a number of examples, including rotating BTZ, the RP2 geon, and several wormhole geometries. This includes spatial and temporal dependence of single-interval entanglement entropy, despite these symmetries being broken only behind an event horizon. We also discuss considerations allowing HRT to be derived from analytic continuation of Euclidean computations in certain contexts, and a related class of complexified extremal surfaces.
Dual solutions for three-dimensional
Directory of Open Access Journals (Sweden)
C.S.K. Raju
2016-03-01
Full Text Available In this study we investigated the effect of space and temperature dependent heat generation/absorption on three-dimensional magnetohydrodynamic nanofluid flow over a nonlinearly permeable stretching sheet. After using appropriate self-similarity transformation the governing equations are solved numerically using bvp4c Matlab package. The effects of the non-dimensional governing parameters on velocity, temperature and concentration profiles are discussed with the help of graphs. Also, coefficient of skin friction and Nusselt number is analyzed and presented through tables. It is found that present results have an excellent agreement with the existed studies under some special cases. Results indicate that an increase in space and temperature dependent heat source or sink increases the temperature and concentration profiles of the flow. Dual solutions exist only for certain range of power-law index.
Three-dimensional context regulation of metastasis.
Erler, Janine T; Weaver, Valerie M
2009-01-01
Tumor progression ensues within a three-dimensional microenvironment that consists of cellular and non-cellular components. The extracellular matrix (ECM) and hypoxia are two non-cellular components that potently influence metastasis. ECM remodeling and collagen cross-linking stiffen the tissue stroma to promote transformation, tumor growth, motility and invasion, enhance cancer cell survival, enable metastatic dissemination, and facilitate the establishment of tumor cells at distant sites. Matrix degradation can additionally promote malignant progression and metastasis. Tumor hypoxia is functionally linked to altered stromal-epithelial interactions. Hypoxia additionally induces the expression of pro-migratory, survival and invasion genes, and up-regulates expression of ECM components and modifying enzymes, to enhance tumor progression and metastasis. Synergistic interactions between matrix remodeling and tumor hypoxia influence common mechanisms that maximize tumor progression and cooperate to drive metastasis. Thus, clarifying the molecular pathways by which ECM remodeling and tumor hypoxia intersect to promote tumor progression should identify novel therapeutic targets.
Lattice Three-Dimensional Skyrmions Revisited
Charalampidis, E G; Kevrekidis, P G
2014-01-01
In the continuum a skyrmion is a topological nontrivial map between Riemannian manifolds, and a stationary point of a particular energy functional. This paper describes lattice analogues of the aforementioned skyrmions, namely a natural way of using the topological properties of the three-dimensional continuum Skyrme model to achieve topological stability on the lattice. In particular, using fixed point iterations, numerically exact lattice skyrmions are constructed; and their stability under small perturbations is verified by means of linear stability analysis. While stable branches of such solutions are identified, it is also shown that they possess a particularly delicate bifurcation structure, especially so in the vicinity of the continuum limit. The corresponding bifurcation diagram is elucidated and a prescription for selecting the branch asymptoting to the well-known continuum limit is given. Finally, the robustness of the solutions by virtue of direct numerical simulations is corroborated.
Three-dimensional hologram display system
Mintz, Frederick (Inventor); Chao, Tien-Hsin (Inventor); Bryant, Nevin (Inventor); Tsou, Peter (Inventor)
2009-01-01
The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.
Three-dimensional printing physiology laboratory technology.
Sulkin, Matthew S; Widder, Emily; Shao, Connie; Holzem, Katherine M; Gloschat, Christopher; Gutbrod, Sarah R; Efimov, Igor R
2013-12-01
Since its inception in 19th-century Germany, the physiology laboratory has been a complex and expensive research enterprise involving experts in various fields of science and engineering. Physiology research has been critically dependent on cutting-edge technological support of mechanical, electrical, optical, and more recently computer engineers. Evolution of modern experimental equipment is constrained by lack of direct communication between the physiological community and industry producing this equipment. Fortunately, recent advances in open source technologies, including three-dimensional printing, open source hardware and software, present an exciting opportunity to bring the design and development of research instrumentation to the end user, i.e., life scientists. Here we provide an overview on how to develop customized, cost-effective experimental equipment for physiology laboratories.
Primary and Secondary Three Dimensional Microbatteries
Cirigliano, Nicolas
Today's MEMS devices are limited more so by the batteries that supply their power than the fabrication methods used to build them. Thick battery electrodes are capable of providing adequate energy, but long and tortuous diffusion pathways lead to low power capabilities. On the other hand, thin film batteries can operate at significant current densities but require large surface areas to supply practical energy. This dilemma can be solved by either developing new high capacity materials or by engineering new battery designs that decouple power and energy. Three dimensional batteries redesign traditional configurations to create nonplanar interfaces between battery components. This can be done by introducing hierarchical structures into the electrode shape. Designs such as these provide a maximum surface area over which chemical reactions can occur. Furthermore, by maintaining small feature sizes, ion diffusion and electronic transport distances can remain minimal. Manipulating these properties ensures fast kinetics that are required for high power situations. Energy density is maximized by layering material in the vertical direction, thus ensuring a minimal footprint area. Three dimensional carbon electrodes are fabricated using basic MEMS techniques. A silicon mold is anisotropically etched to produce channels of a predetermined diameter. The channels are then filled using an infiltration technique with electrode slurry. Once dried, the mold is attached to a current collector and etched using a XeF2 process. Electrodes of varying feature sizes have been fabricated using this method with aspect ratios ranging from 3.5:1 to 7:1. 3D carbon electrodes are shown to obtain capacities over 8 mAh/cm2 at 0.1 mA/cm2, or nearly 700% higher than planar carbon electrodes. When assembled with a planar cathode, the battery cell produced an average discharge capacity of 40 J/cm 2 at a current density of 0.2 mA/cm2. This places the energy density values slightly less than thick
THEORETICAL STUDY OF THREE-DIMENSIONAL NUMERICAL MANIFOLD METHOD
Institute of Scientific and Technical Information of China (English)
LUO Shao-ming; ZHANG Xiang-wei; L(U) Wen-ge; JIANG Dong-ru
2005-01-01
The three-dimensional numerical manifold method(NMM) is studied on the basis of two-dimensional numerical manifold method. The three-dimensional cover displacement function is studied. The mechanical analysis and Hammer integral method of three-dimensional numerical manifold method are put forward. The stiffness matrix of three-dimensional manifold element is derived and the dissection rules are given. The theoretical system and the numerical realizing method of three-dimensional numerical manifold method are systematically studied. As an example, the cantilever with load on the end is calculated, and the results show that the precision and efficiency are agreeable.
Three Dimensional CAPP Technology of Projectile Based on MBD
Directory of Open Access Journals (Sweden)
Hongzhi Zhao
2013-07-01
Full Text Available This study aims at the research goal of three-dimensional digital process design of projectile, which adopts three-dimensional computer-aided process design technology based on MBD and uses MBD to conduct parametric modeling of projectile that can reduce the input of projectile’s process information and data conversion and produce reasonable, feasible and three-dimensional projectile manufacturing process to realize paperless three-dimensional process design of projectile. The application of three-dimensional computer-assisted process design technology of projectile based on model definition can shorten the design cycle of projectile, thus improving rapid manufacturing capacity of product and reducing cost.
Chaotic Mixing in Three Dimensional Porous Media
Lester, Daniel R; Borgne, Tanguy Le
2016-01-01
Under steady flow conditions, the topological complexity inherent to all random 3D porous media imparts complicated flow and transport dynamics. It has been established that this complexity generates persistent chaotic advection via a three-dimensional (3D) fluid mechanical analogue of the baker's map which rapidly accelerates scalar mixing in the presence of molecular di?usion. Hence pore-scale fluid mixing is governed by the interplay between chaotic advection, molecular di?usion and the broad (power-law) distribution of fluid particle travel times which arise from the non-slip condition at pore walls. To understand and quantify mixing in 3D porous media, we consider these processes in a model 3D open porous network and develop a novel stretching continuous time random walk (CTRW) which provides analytic estimates of pore-scale mixing which compare well with direct numerical simulations. We ?nd that chaotic advection inherent to 3D porous media imparts scalar mixing which scales exponentially with longitudi...
Three dimensional characterization and archiving system
Energy Technology Data Exchange (ETDEWEB)
Sebastian, R.L.; Clark, R.; Gallman, P. [and others
1996-04-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D and D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D and D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. The 3D-ICAS system robotically conveys a multisensor probe near the surfaces to be inspected. The sensor position and orientation are monitored and controlled using coherent laser radar (CLR) tracking. The CLR also provides 3D facility maps which establish a 3D world view within which the robotic sensor system can operate.
Three dimensional characterization and archiving system
Energy Technology Data Exchange (ETDEWEB)
Sebastian, R.L.; Clark, R.; Gallman, P. [and others
1995-12-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. Chemical analysis plays a vital role throughout the process of decontamination. Before clean-up operations can begin the site must be characterized with respect to the type and concentration of contaminants, and detailed site mapping must clarify areas of both high and low risk. During remediation activities chemical analysis provides a means to measure progress and to adjust clean-up strategy. Once the clean-up process has been completed the results of chemical analysis will verify that the site is in compliance with federal and local regulations.
Why Observable Space Is Solely Three Dimensional
Rabinowitz, Mario
2015-01-01
Quantum (and classical) binding energy considerations in n-dimensional space indicate that atoms (and planets) can only exist in three-dimensional space. This is why observable space is solely 3-dimensional. Both a novel Virial theorem analysis, and detailed classical and quantum energy calculations for 3-space circular and elliptical orbits indicate that they have no orbital binding energy in greater than 3-space. The same energy equation also excludes the possibility of atom-like bodies in strictly 1 and 2-dimensions. A prediction is made that in the search for deviations from r^-2 of the gravitational force at sub-millimeter distances such a deviation must occur at < ~ 10^-10 m (or < ~10^-12 m considering muoniom), since atoms would disintegrate if the curled up dimensions of string theory were larger than this. Callender asserts that the often-repeated claim in previous work that stable orbits are possible in only three dimensions is not even remotely established. The binding energy analysis herein ...
Clinical significance of three-dimensional sonohysterography
Energy Technology Data Exchange (ETDEWEB)
Lee, Eun Hye; Lee, Mi Hwa; Lee, Chan; Kim, Jong Wook; Shin, Myung Choel [Pochon Cha University College of Medicine, Pochon (Korea, Republic of)
1999-12-15
To evaluate the usefulness of three dimensional sonohysterography (3D SHG) in the evaluation of uterine endometrial and submucosal lesions in comparison with conventional two-dimensional sonohysterography (2D SHG). Our series consisted of 26 patients (mean aged 41 years) who complained of uterine bleeding, menorrhagia, or dysmenorrhea. 2D SHG was performed, and then 3D SHG was done after the volume mode was switched on. Simultaneous display of three perpendicular two-dimensional planes and surface rendering of findings on particular section were obtained. We analyzed whether the endometrium was thickened or not, and the location, size, shape, echogenicity, posterior shadowing, and echogenic rim of the focal lesion. The results were compared with the pathologic findings or MRI. There were submucosal myomas (n=12), intramural myomas (n=2), endometrial polyps (n=7), placental polyp (n=1), and normal endometrial cavities (n=4) on SHG. Nineteen cases were confirmed by pathologic findings or MRI. The results were correlated in 89% (17/19) of the cases. We misdiagnosed 2 cases: focal endometrial hyperplasia and choriocarcinoma were misdiagnosed as endometrial polyp and placental polyp, respectively. Imaging diagnoses were same in the techniques. Comparing with 2D SHG, 3D SHG provided a subjective display of pathologic findings and an additional information about spatial relationship between focal lesion and surroundings.
Three-dimensionally Perforated Calcium Phosphate Ceramics
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
Porous calcium phosphate ceramics were produced by compression molding using a special mold followed by sintering. The porous calcium phosphate ceramics have three-dimensional and penetrated open pores380-400μm in diameter spaced at intervals of 200μm. The layers of the linear penetration pores alternately lay perpendicular to pore direction. The porosity was 59%-65% . The Ca/P molar ratios of the porous calcium phosphate ceramics range from 1.5 to 1.85. A binder containing methyl cellulose was most effective for preparing the powder compact among vinyl acetate, polyvinyl alcohol, starch, stearic acid, methyl cellulose and their mixtures. Stainless steel, polystyrene, nylon and bamboo were used as the long columnar male dies for the penetrated open pores. When polystyrene, nylon and bamboo were used as the long columnar male dies, the dies were burned out during the sintering process. Using stainless steel as the male dies with the removal of the dies before heat treatment resulted in a higher level of densification of the calcium phosphate ceramic.
Three dimensional modeling of CR propagation
Gaggero, Daniele; Di Bernardo, Giuseppe; Evoli, Carmelo; Grasso, Dario
2013-01-01
We present here a major upgrade of DRAGON, a numerical package that computes the propagation of a wide set of CR species from both astrophysical and exotic origin in the Galaxy in a wide energy range from tens of MeV to tens of TeV. DRAGON takes into account all relevant processes in particular diffusion, convection, reacceleration, fragmentation and energy losses. For the first time, we present a full 3D version of DRAGON with anisotropic position-dependent diffusion. In this version, the propagation is calculated within a 3D cartesian grid and the user is able to implement realistic and structured three dimensional source, gas and regular magnetic field distributions. Moreover, it is possible to specify an arbitrary function of position and rigidity for the diffusion coefficients in the parallel and perpendicular direction to the regular magnetic field of the Galaxy. The code opens many new possibilities in the study of CR physics. In particular, we can study for the first time the impact of the spiral arm ...
Three Dimensional Hydrodynamic Model With Multiquadtree Meshes
Directory of Open Access Journals (Sweden)
G. P. Vanegas
2008-01-01
Full Text Available This study presents a three dimensional model for the transport of conservative contaminants, which can be used for bodies of water which are affected by winds and/or tides. The model solves the equation of mass transport, based on results obtained using a hydrodynamic model for shallow waters that works in a finite volume scheme and a type of hierarchical grid, called multi-quadtree, which is adaptable to the bathymetry. To solve the vertical coordinates, the coordinate z is transformed into a sigma (σ coordinate, thus allowing the same number of layers in the vertical, regardless of depth. This hydrodynamic model is validated using two cases: a long wave propagated in a channel of variable width and bottom and wind action in a rectangular basin. Finally, the results obtained are presented for a hypothetical single port outfall in the bay of Campeche, México. The model developed here is both quick and easy to use and is efficient when compared with models presented by other authors since it uses adaptable grids which allow detailed solutions to be obtained for areas of interest such as coastlines and the area around an outfall.
Globographic visualisation of three dimensional joint angles.
Baker, Richard
2011-07-07
Three different methods for describing three dimensional joint angles are commonly used in biomechanics. The joint coordinate system and Cardan/Euler angles are conceptually quite different but are known to represent the same underlying mathematics. More recently the globographic method has been suggested as an alternative and this has proved particularly attractive for the shoulder joint. All three methods can be implemented in a number of ways leading to a choice of angle definitions. Very recently Rab has demonstrated that the globographic method is equivalent to one implementation of the joint coordinate system. This paper presents a rigorous analysis of the three different methods and proves their mathematical equivalence. The well known sequence dependence of Cardan/Euler is presented as equivalent to configuration dependence of the joint coordinate system and orientation dependence of globographic angles. The precise definition of different angle sets can be easily visualised using the globographic method using analogues of longitude, latitude and surface bearings with which most users will already be familiar. The method implicitly requires one axis of the moving segment to be identified as its principal axis and this can be extremely useful in helping define the most appropriate angle set to describe the orientation of any particular joint. Using this technique different angle sets are considered to be most appropriate for different joints and examples of this for the hip, knee, ankle, pelvis and axial skeleton are outlined.
Three dimensional characterization and archiving system
Energy Technology Data Exchange (ETDEWEB)
Sebastian, R.L.; Clark, R.; Gallman, P. [Coleman Research Corp., Springfield, VA (United States)] [and others
1995-10-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. The 3D-ICAS system robotically conveys a multisensor probe near the surface to be inspected. The sensor position and orientation are monitored and controlled by Coherent laser radar (CLR) tracking. The ICAS fills the need for high speed automated organic analysis by means of gas chromatography-mass spectrometry sensors, and also by radionuclide sensors which combines alpha, beta, and gamma counting.
Three-dimensional Printing in the Intestine.
Wengerter, Brian C; Emre, Gulus; Park, Jea Young; Geibel, John
2016-08-01
Intestinal transplantation remains a life-saving option for patients with severe intestinal failure. With the advent of advanced tissue engineering techniques, great strides have been made toward manufacturing replacement tissues and organs, including the intestine, which aim to avoid transplant-related complications. The current paradigm is to seed a biocompatible support material (scaffold) with a desired cell population to generate viable replacement tissue. Although this technique has now been extended by the three-dimensional (3D) printing of geometrically complex scaffolds, the overall approach is hindered by relatively slow turnover and negative effects of residual scaffold material, which affects final clinical outcome. Methods recently developed for scaffold-free 3D bioprinting may overcome such obstacles and should allow for rapid manufacture and deployment of "bioprinted organs." Much work remains before 3D bioprinted tissues can enter clinical use. In this brief review we examine the present state and future perspectives of this nascent technology before full clinical implementation.
Isotropic three-dimensional MRI-Fricke-infused gel dosimetry
Energy Technology Data Exchange (ETDEWEB)
Cho, Nai-Yu; Chu, Woei-Chyn [Institute of Biomedical Engineering, National Yang-Ming University, Taipei 11221, Taiwan (China); Huang, Sung-Cheng [Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, California 90095 (United States); Chung, Wen-Yuh [Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan (China); Guo, Wan-Yuo [Department of Radiology, Taipei Veterans General Hospital, Taipei 11217, Taiwan (China)
2013-05-15
Purpose: Fricke-infused gel has been shown to be a simple and attainable method for the conformal measurement of absorbed radiation dose. Nevertheless, its accuracy is seriously hindered by the irreversible ferric ion diffusion during magnetic resonance imaging, particularly when three-dimensional (3D) dose measurement in radiosurgery is considered. In this study, the authors developed a fast three-dimensional spin-echo based Fricke gel dosimetry technique to reduce the adverse effects of ferric ion diffusion and to obtain an accurate isotropic 3D dose measurement. Methods: A skull shaped phantom containing Fricke-infused gel was irradiated using Leksell Gamma Knife. The rapid image-based dosimetry technique was applied with the use of a 3D fast spin-echo magnetic resonance imaging sequence. The authors mathematically derived and experimentally validated the correlations between dose-response characteristics and parameters of the 3D fast spin-echo MR imaging sequence. Absorbed dose profiles were assessed and compared to the calculated profiles given by the Gamma Knife treatment planning system. Coefficient of variance (CV%) and coefficient of determination (R{sup 2}) were used to evaluate the precision of dose-response curve estimation. The agreement between the measured and the planned 3D dose distributions was quantified by gamma-index analysis of two acceptance criteria. Results: Proper magnetic resonance imaging parameters were explored to render an accurate three-dimensional absorbed dose mapping with a 1 mm{sup 3} isotropic image resolution. The efficacy of the dose-response estimation was approved by an R{sup 2} > 0.99 and an average CV% of 1.6%. Average gamma pass-rate between the experimentally measured and GammaPlan calculated dose distributions were 83.8% and 99.7% for 2%/2 and 3%/3 mm criteria, respectively. Conclusions: With the designed MR imaging sequence and parameters, total 3D MR acquisition time was confined to within 20 min postirradiation
Application of Simulated Three Dimensional CT Image in Orthognathic Surgery
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyun Don; Park, Chang Seo [Dept. of Dental Radiology, College of Dentistry, Yensei University, Seoul (Korea, Republic of); Yoo, Sun Kook; Lee, Kyoung Sang [Dept. of Medical Engineering, College of Medicine, Yensei University, Seoul (Korea, Republic of)
1998-08-15
In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of
Reinhart, Anna Merle; Jakubek, Jan; Martisikova, Maria
2016-01-01
Carbon ion beam radiotherapy enables a very localised dose deposition. However, already small changes in the patient geometry or positioning errors can significantly distort the dose distribution. A live monitoring system of the beam delivery within the patient is therefore highly desirable and could improve patient treatment. We present a novel three-dimensional imaging method of the beam in the irradiated object, exploiting the measured tracks of single secondary ions emerging under irradiation. The secondary particle tracks are detected with a TimePix stack, a set of parallel pixelated semiconductor detectors. We developed a three-dimensional reconstruction algorithm based on maximum likelihood expectation maximisation. We demonstrate the applicability of the new method in an irradiation of a cylindrical PMMA phantom of human head size with a carbon ion pencil beam of 226MeV/u. The beam image in the phantom is reconstructed from a set of 9 discrete detector positions between -80 and 50 degrees from the bea...
Measurements using three-dimensional product imaging
Directory of Open Access Journals (Sweden)
A. Sioma
2010-07-01
Full Text Available This article discusses a method of creating a three-dimensional cast model using vision systems and how that model can be used in thequality assessment process carried out directly on the assembly line. The technology of active vision, consisting in illumination of theobject with a laser beam, was used to create the model. Appropriate configuration of camera position geometry and laser light allows thecollection of height profiles and construction of a 3D model of the product on their basis. The article discusses problems connected with the resolution of the vision system, resolution of the laser beam analysis, and resolution connected with the application of the successive height profiles on sample cast planes. On the basis of the model, measurements allowing assessment of dimension parameters and surface defects of a given cast are presented. On the basis of tests and analyses of such a threedimensional cast model, a range of checks which are possible to conduct using 3D vision systems is indicated.Testing casts using that technology allows rapid assessment of selected parameters. Construction of the product’s model and dimensional assessment take a few seconds, which significantly reduces the duration of checks in the technological process. Depending on the product, a few checks may be carried out simultaneously on the product’s model.The possibility of controlling all outgoing products, and creating and modifying the product parameter control program, makes the solutionhighly flexible, which is confirmed by pilot industrial implementations. The technology will be developed in terms of detection andidentification of surface defects. It is important due to the possibility of using such information for the purposes of selecting technologicalprocess parameters and observing the effect of changes in selected parameters on the cast parameter controlled in a vision system.
[Three-dimensional reconstruction of heart valves].
Flachskampf, F A; Kühl, H; Franke, A; Frielingsdorf, J; Klues, H; Krebs, W; Hanrath, P
1995-08-01
The reconstruction of three-dimensional data sets from two-dimensional echocardiographic images offers several fundamental advantages: 1. more complete data than present in the few standard 2D-view; 2. off-line generation of any desired plane, cut, or perspective after the data set has been acquired; 3. access to quantitative parameters like surface areas (e.g., of valve leaflets or portions of leaflets), volumes, and others, without geometric assumptions. The mitral valve has been the focus of several studies using various techniques of reconstruction of transthoracic or transesophageal images. These studies have shown the mitral annulus to be a non-planar, "saddle-shaped" structure, with an average distance of highest to lowest points of 14 mm in normals. This recognition of mitral annular non-planarity has led to a more stringent echocardiographic definition of mitral valve prolapse. Further studies have shown systolic shrinkage of mitral annular area by about 30% and systolic apico-basal translation of the annulus by approximately 1 cm in normals. In patients with dilated cardiomyopathy, the annulus is flattened, and both cyclic change in annular area and apico-basal translation are significantly reduced. 3D-studies of the left ventricular outflow tract in hypertrophic obstructive cardiomyopathy allow measurement of outflow tract and leaflet surface areas and dynamic spatial visualization of systolic anterior motion of the anterior mitral leaflet. Automated techniques to reconstruct the full grey value data set from a high number of parallel or rotational transesophageal planes allow impressive visualization of normal and diseased mitral and aortic valves or valve prostheses, with special emphasis on generating "surgical" views and perspectives, which cannot be obtained by conventional tomographic imaging.(ABSTRACT TRUNCATED AT 250 WORDS)
Three-dimensional kinematics of hummingbird flight.
Tobalske, Bret W; Warrick, Douglas R; Clark, Christopher J; Powers, Donald R; Hedrick, Tyson L; Hyder, Gabriel A; Biewener, Andrew A
2007-07-01
Hummingbirds are specialized for hovering flight, and substantial research has explored this behavior. Forward flight is also important to hummingbirds, but the manner in which they perform forward flight is not well documented. Previous research suggests that hummingbirds increase flight velocity by simultaneously tilting their body angle and stroke-plane angle of the wings, without varying wingbeat frequency and upstroke: downstroke span ratio. We hypothesized that other wing kinematics besides stroke-plane angle would vary in hummingbirds. To test this, we used synchronized high-speed (500 Hz) video cameras and measured the three-dimensional wing and body kinematics of rufous hummingbirds (Selasphorus rufus, 3 g, N=5) as they flew at velocities of 0-12 m s(-1) in a wind tunnel. Consistent with earlier research, the angles of the body and the stroke plane changed with velocity, and the effect of velocity on wingbeat frequency was not significant. However, hummingbirds significantly altered other wing kinematics including chord angle, angle of attack, anatomical stroke-plane angle relative to their body, percent of wingbeat in downstroke, wingbeat amplitude, angular velocity of the wing, wingspan at mid-downstroke, and span ratio of the wingtips and wrists. This variation in bird-centered kinematics led to significant effects of flight velocity on the angle of attack of the wing and the area and angles of the global stroke planes during downstroke and upstroke. We provide new evidence that the paths of the wingtips and wrists change gradually but consistently with velocity, as in other bird species that possess pointed wings. Although hummingbirds flex their wings slightly at the wrist during upstroke, their average wingtip-span ratio of 93% revealed that they have kinematically ;rigid' wings compared with other avian species.
Three-dimensional Spontaneous Magnetic Reconnection
Beresnyak, Andrey
2017-01-01
Magnetic reconnection is best known from observations of the Sun where it causes solar flares. Observations estimate the reconnection rate as a small, but non-negligible fraction of the Alfvén speed, so-called fast reconnection. Until recently, the prevailing pictures of reconnection were either of resistivity or plasma microscopic effects, which was contradictory to the observed rates. Alternative pictures were either of reconnection due to the stochasticity of magnetic field lines in turbulence or the tearing instability of the thin current sheet. In this paper we simulate long-term three-dimensional nonlinear evolution of a thin, planar current sheet subject to a fast oblique tearing instability using direct numerical simulations of resistive-viscous magnetohydrodynamics. The late-time evolution resembles generic turbulence with a ‑5/3 power spectrum and scale-dependent anisotropy, so we conclude that the tearing-driven reconnection becomes turbulent reconnection. The turbulence is local in scale, so microscopic diffusivity should not affect large-scale quantities. This is confirmed by convergence of the reconnection rate toward ∼ 0.015{v}{{A}} with increasing Lundquist number. In this spontaneous reconnection, with mean field and without driving, the dissipation rate per unit area also converges to ∼ 0.006ρ {v}{{A}}3, and the dimensionless constants 0.015 and 0.006 are governed only by self-driven nonlinear dynamics of the sheared magnetic field. Remarkably, this also means that a thin current sheet has a universal fluid resistance depending only on its length to width ratio and to {v}{{A}}/c.
Three-dimensional nonlinear acoustical holography
Niu, Yaying
Nearfield Acoustical Holography (NAH) is an acoustic field visualization technique that can be used to reconstruct three-dimensional (3-D) acoustic fields by projecting two-dimensional (2-D) data measured on a hologram surface. However, linear NAH algorithms developed and improved by many researchers can result in significant reconstruction errors when they are applied to reconstruct 3-D acoustic fields that are radiated from a high-level noise source and include significant nonlinear components. Here, planar, nonlinear acoustical holography procedures are developed that can be used to reconstruct 3-D, nonlinear acoustic fields radiated from a high-level noise source based on 2-D acoustic pressure data measured on a hologram surface. The first nonlinear acoustic holography procedure is derived for reconstructing steady-state acoustic pressure fields by applying perturbation and renormalization methods to nonlinear, dissipative, pressure-based Westervelt Wave Equation (WWE). The nonlinear acoustic pressure fields radiated from a high-level pulsating sphere and an infinite-size, vibrating panel are used to validate this procedure. Although the WWE-based algorithm is successfully validated by those two numerical simulations, it still has several limitations: (1) Only the fundamental frequency and its second harmonic nonlinear components can be reconstructed; (2) the application of this algorithm is limited to mono-frequency source cases; (3) the effects of bent wave rays caused by transverse particle velocities are not included; (4) only acoustic pressure fields can be reconstructed. In order to address the limitations of the steady-state, WWE-based procedure, a transient, planar, nonlinear acoustic holography algorithm is developed that can be used to reconstruct 3-D nonlinear acoustic pressure and particle velocity fields. This procedure is based on Kuznetsov Wave Equation (KWE) that is directly solved by using temporal and spatial Fourier Transforms. When compared
Airway branching morphogenesis in three dimensional culture
Directory of Open Access Journals (Sweden)
Gudjonsson Thorarinn
2010-11-01
Full Text Available Abstract Background Lungs develop from the fetal digestive tract where epithelium invades the vascular rich stroma in a process called branching morphogenesis. In organogenesis, endothelial cells have been shown to be important for morphogenesis and the maintenance of organ structure. The aim of this study was to recapitulate human lung morphogenesis in vitro by establishing a three dimensional (3D co-culture model where lung epithelial cells were cultured in endothelial-rich stroma. Methods We used a human bronchial epithelial cell line (VA10 recently developed in our laboratory. This cell line cell line maintains a predominant basal cell phenotype, expressing p63 and other basal markers such as cytokeratin-5 and -14. Here, we cultured VA10 with human umbilical vein endothelial cells (HUVECs, to mimic the close interaction between these cell types during lung development. Morphogenesis and differentiation was monitored by phase contrast microscopy, immunostainings and confocal imaging. Results We found that in co-culture with endothelial cells, the VA10 cells generated bronchioalveolar like structures, suggesting that lung epithelial branching is facilitated by the presence of endothelial cells. The VA10 derived epithelial structures display various complex patterns of branching and show partial alveolar type-II differentiation with pro-Surfactant-C expression. The epithelial origin of the branching VA10 colonies was confirmed by immunostaining. These bronchioalveolar-like structures were polarized with respect to integrin expression at the cell-matrix interface. The endothelial-induced branching was mediated by soluble factors. Furthermore, fibroblast growth factor receptor-2 (FGFR-2 and sprouty-2 were expressed at the growing tips of the branching structures and the branching was inhibited by the FGFR-small molecule inhibitor SU5402. Discussion In this study we show that a human lung epithelial cell line can be induced by endothelial cells to
Three-dimensional decomposition method of global atmospheric circulation
Institute of Scientific and Technical Information of China (English)
LIU HaiTao; HU ShuJuan; XU Ming; CHOU JiFan
2008-01-01
By adopting the idea of three-dimensional Walker, Hadley and Rossby stream functions, the global atmospheric circulation can be considered as the sum of three stream functions from a global perspective. Therefore, a mathematical model of three-dimensional decomposition of global atmospheric circulation is proposed and the existence and uniqueness of the model are proved. Besides, the model includes a numerical method leading to no truncation error in the discrete three-dimensional grid points. Results also show that the three-dimensional stream functions exist and are unique for a given velocity field. The mathematical model shows the generalized form of three-dimensional stream functions equal to the velocity field in representing the features of atmospheric motion. Besides, the vertical velocity calculated through the model can represent the main characteristics of the vertical motion. In sum, the three-dimensional decomposition of atmospheric circulation is convenient for the further investigation of the features of global atmospheric motions.
The Three-dimensional Digital Factory for Shipbuilding Technology Research
Directory of Open Access Journals (Sweden)
Xu Wei
2016-01-01
Full Text Available The three-dimensional digital factory technology research is the hotspot in shipbuilding recently. The three-dimensional digital factory technology not only focus on design the components of the product, but also discuss on the simulation and analyses of the production process.Based on the three-dimensional model, the basic data layer, application control layer and the presentation layer of hierarchical structure are established in the three-dimensional digital factory of shipbuilding in this paper. And the key technologies of three-dimensional digital factory of shipbuilding are analysed. Finally, a case study is applied and the results show that the three-dimensional digital factory will play an important role in the future.
Three-dimensional carbon nanotube based photovoltaics
Flicker, Jack
2011-12-01
Photovoltaic (PV) cells with a three dimensional (3D) morphology are an exciting new research thrust with promise to create cheaper, more efficient solar cells. This work introduces a new type of 3D PV device based on carbon nanotube (CNT) arrays. These arrays are paired with the thin film heterojunction, CdTe/CdS, to form a complete 3D carbon nanotube PV device (3DCNTPV). Marriage of a complicated 3D structure with production methods traditionally used for planar CdTe solar cell is challenging. This work examines the problems associated with processing these types of cells and systematically alters production methods of the semiconductor layers and electrodes to increase the short circuit current (Isc), eliminate parasitic shunts, and increase the open circuit voltage (Voc). The main benefit of 3D solar cell is the ability to utilize multiple photon interactions with the solar cell surface. The three dimensionality allows photons to interact multiple times with the photoactive material, which increases the absorption and the overall power output over what is possible with a two dimensional (2D) morphology. To quantify the increased power output arising from these multiple photon interactions, a new absorption efficiency term, eta3D, is introduced. The theoretical basis behind this new term and how it relates to the absorption efficiency of a planar cell, eta 2D, is derived. A unique model for the average number of multiple photon impingements, Gamma, is proposed based on three categories of 3D morphology: an infinite trench, an enclosed box, and an array of towers. The derivation of eta3D and Gamma for these 3D PV devices gives a complete picture of the enhanced power output over 2D cells based on CNT array height, pitch, radius, and shape. This theory is validated by monte carlo simulations and experiment. This new type of 3D PV devices has been shown to work experimentally. The first 3DCNTPV cells created posses Isc values of 0.085 to 17.872mA/cm2 and Voc values
Three-Dimensional Gear Crack Propagation Studied
Lewicki, David G.
1999-01-01
Gears used in current helicopters and turboprops are designed for light weight, high margins of safety, and high reliability. However, unexpected gear failures may occur even with adequate tooth design. To design an extremely safe system, the designer must ask and address the question, "What happens when a failure occurs?" With gear-tooth bending fatigue, tooth or rim fractures may occur. A crack that propagates through a rim will be catastrophic, leading to disengagement of the rotor or propeller, loss of an aircraft, and possible fatalities. This failure mode should be avoided. A crack that propagates through a tooth may or may not be catastrophic, depending on the design and operating conditions. Also, early warning of this failure mode may be possible because of advances in modern diagnostic systems. One concept proposed to address bending fatigue fracture from a safety aspect is a splittooth gear design. The prime objective of this design would be to control crack propagation in a desired direction such that at least half of the tooth would remain operational should a bending failure occur. A study at the NASA Lewis Research Center analytically validated the crack-propagation failsafe characteristics of a split-tooth gear. It used a specially developed three-dimensional crack analysis program that was based on boundary element modeling and principles of linear elastic fracture mechanics. Crack shapes as well as the crack-propagation life were predicted on the basis of the calculated stress intensity factors, mixed-mode crack-propagation trajectory theories, and fatigue crack-growth theories. The preceding figures show the effect of the location of initial cracks on crack propagation. Initial cracks in the fillet of the teeth produced stress intensity factors of greater magnitude (and thus, greater crack growth rates) than those in the root or groove areas of the teeth. Crack growth was simulated in a case study to evaluate crack-propagation paths. Tooth
Femtosecond laser three-dimensional micro- and nanofabrication
Sugioka, Koji; Cheng, Ya
2014-12-01
The rapid development of the femtosecond laser has revolutionized materials processing due to its unique characteristics of ultrashort pulse width and extremely high peak intensity. The short pulse width suppresses the formation of a heat-affected zone, which is vital for ultrahigh precision fabrication, whereas the high peak intensity allows nonlinear interactions such as multiphoton absorption and tunneling ionization to be induced in transparent materials, which provides versatility in terms of the materials that can be processed. More interestingly, irradiation with tightly focused femtosecond laser pulses inside transparent materials makes three-dimensional (3D) micro- and nanofabrication available due to efficient confinement of the nonlinear interactions within the focal volume. Additive manufacturing (stereolithography) based on multiphoton absorption (two-photon polymerization) enables the fabrication of 3D polymer micro- and nanostructures for photonic devices, micro- and nanomachines, and microfluidic devices, and has applications for biomedical and tissue engineering. Subtractive manufacturing based on internal modification and fabrication can realize the direct fabrication of 3D microfluidics, micromechanics, microelectronics, and photonic microcomponents in glass. These microcomponents can be easily integrated in a single glass microchip by a simple procedure using a femtosecond laser to realize more functional microdevices, such as optofluidics and integrated photonic microdevices. The highly localized multiphoton absorption of a tightly focused femtosecond laser in glass can also induce strong absorption only at the interface of two closely stacked glass substrates. Consequently, glass bonding can be performed based on fusion welding with femtosecond laser irradiation, which provides the potential for applications in electronics, optics, microelectromechanical systems, medical devices, microfluidic devices, and small satellites. This review paper
Femtosecond laser three-dimensional micro- and nanofabrication
Energy Technology Data Exchange (ETDEWEB)
Sugioka, Koji, E-mail: ksugioka@riken.jp [RIKEN Center for Advanced Photonics, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Cheng, Ya, E-mail: ya.cheng@siom.ac.cn [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)
2014-12-15
The rapid development of the femtosecond laser has revolutionized materials processing due to its unique characteristics of ultrashort pulse width and extremely high peak intensity. The short pulse width suppresses the formation of a heat-affected zone, which is vital for ultrahigh precision fabrication, whereas the high peak intensity allows nonlinear interactions such as multiphoton absorption and tunneling ionization to be induced in transparent materials, which provides versatility in terms of the materials that can be processed. More interestingly, irradiation with tightly focused femtosecond laser pulses inside transparent materials makes three-dimensional (3D) micro- and nanofabrication available due to efficient confinement of the nonlinear interactions within the focal volume. Additive manufacturing (stereolithography) based on multiphoton absorption (two-photon polymerization) enables the fabrication of 3D polymer micro- and nanostructures for photonic devices, micro- and nanomachines, and microfluidic devices, and has applications for biomedical and tissue engineering. Subtractive manufacturing based on internal modification and fabrication can realize the direct fabrication of 3D microfluidics, micromechanics, microelectronics, and photonic microcomponents in glass. These microcomponents can be easily integrated in a single glass microchip by a simple procedure using a femtosecond laser to realize more functional microdevices, such as optofluidics and integrated photonic microdevices. The highly localized multiphoton absorption of a tightly focused femtosecond laser in glass can also induce strong absorption only at the interface of two closely stacked glass substrates. Consequently, glass bonding can be performed based on fusion welding with femtosecond laser irradiation, which provides the potential for applications in electronics, optics, microelectromechanical systems, medical devices, microfluidic devices, and small satellites. This review paper
DEFF Research Database (Denmark)
Kyrsting, Anders; Bendix, Pól Martin; Stamou, Dimitrios
2011-01-01
Irradiated metallic nanoparticles hold great promise as heat transducers in photothermal applications such as drug delivery assays or photothermal therapy. We quantify the temperature increase of individual gold nanoparticles trapped in three dimensions near lipid vesicles exhibiting temperature ...... sensitive permeability. The surface temperature can increase by hundreds of degrees Celsius even at moderate laser powers. Also, there are significant differences of the heat profiles in two-dimensional and three-dimensional trapping assays....
Semifolded Localized Structures in Three-Dimensional Soliton Systems
Institute of Scientific and Technical Information of China (English)
FANG Jian-Ping; ZHENG Chun-Long; CHEN Li-Qun
2004-01-01
By means ora Painlevé-Backlund transformation and a multi-linear variable separation approach, abundant localized coherent excitations of the three-dimensional Broer-Kaup-Kupershmidt system with variable coefficients are derived. There are possible phase shifts for the interactions of the three-dimensional novel localized structures discussed in this paper.
Semifolded Localized Structures in Three-Dimensional Soliton Systems
Institute of Scientific and Technical Information of China (English)
FANGJian-Ping; ZHENGChun-Long; CHENLi-Qun
2004-01-01
By means ofa Painlev6 Backlund transformation and a multi-linear variable separation approach, abundant localized coherent excitations of the three-dimensional Broer Kaup Kupershmidt system with variable coeft~cients are derived. There are possible phase shifts for the interactions of the three-dimensional novel localized structures discussed in this paper.
Synthetic Spectrum Methods for Three-Dimensional Supernova Models
Thomas, R C
2003-01-01
Current observations stimulate the production of fully three-dimensional explosion models, which in turn motivates three-dimensional spectrum synthesis for supernova atmospheres. We briefly discuss techniques adapted to address the latter problem, and consider some fundamentals of line formation in supernovae without recourse to spherical symmetry. Direct and detailed extensions of the technique are discussed, and future work is outlined.
Three-dimensional simulations of resistance spot welding
DEFF Research Database (Denmark)
Nielsen, Chris Valentin; Zhang, Wenqi; Perret, William
2014-01-01
This paper draws from the fundamentals of electro-thermo-mechanical coupling to the main aspects of finite element implementation and three-dimensional modelling of resistance welding. A new simulation environment is proposed in order to perform three-dimensional simulations and optimization of r...
Computer-Generated, Three-Dimensional Character Animation.
Van Baerle, Susan Lynn
This master's thesis begins by discussing the differences between 3-D computer animation of solid three-dimensional, or monolithic, objects, and the animation of characters, i.e., collections of movable parts with soft pliable surfaces. Principles from two-dimensional character animation that can be transferred to three-dimensional character…
Three-dimensional Reciprocal Structures: Morphology, Concepts, Generative Rules
DEFF Research Database (Denmark)
Parigi, Dario; Pugnale, Alberto
2012-01-01
This paper present seven different three dimensional structures based on the principle of structural reciprocity with superimposition joint and standardized un-notched elements. Such typology could be regarded as being intrinsically three-dimensional because elements sit one of the top of the oth...
Collapse in a forced three-dimensional nonlinear Schrodinger equation
DEFF Research Database (Denmark)
Lushnikov, P.M.; Saffman, M.
2000-01-01
We derive sufficient conditions for the occurrence of collapse in a forced three-dimensional nonlinear Schrodinger equation without dissipation. Numerical studies continue the results to the case of finite dissipation.......We derive sufficient conditions for the occurrence of collapse in a forced three-dimensional nonlinear Schrodinger equation without dissipation. Numerical studies continue the results to the case of finite dissipation....
Three dimensional periodic foundations for base seismic isolation
Yan, Y.; Cheng, Z.; Menq, F.; Mo, Y. L.; Tang, Y.; Shi, Z.
2015-07-01
Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations.
Robust three dimensional surface contouring method with digital holography
Institute of Scientific and Technical Information of China (English)
YUAN Cao-jin; ZHAI Hong-chen; WANG Xiao-lei; WU Lan
2006-01-01
In this paper,a digital holography system with short-coherence light source is used to record a series of holograms of a micro-object. The three dimensional reconstruction is completed by the least-square-polynomial-fitting with a series of two dimensional intensity images which are obtained through holographic reconstruction. This three dimensional reconstruction method can be used to carry out three-dimensional reconstruction of a micro-object with strong laser speckle noise,which can not be obtained from the conventional method.
DEVELOPMENT OF A HYBRID MODEL FOR THREE-DIMENSIONAL GIS
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
This paper presents a hybrid model for three-dimensional Geographical Information Systems which is an integration of surface- and volume-based models. The Triangulat ed Irregular Network (TIN) and octree models are integrated in this hybrid model. The TIN model works as a surface-based model which mainly serves for surface presentation and visualization. On the other hand, the octree encoding supports volumetric analysis. The designed data structure brings a major advantage in the three-dimensional selective retrieval. This technique increases the efficiency of three-dimensional data operation.
Protein conformation in solution by three-dimensional fluorescence spectrometry
Institute of Scientific and Technical Information of China (English)
鄢远; 许金钩; 陈国珍
1996-01-01
The conformations of bovine serum albumin (USA) and egg albumin (EA) in solution and their conformation changes under different conditions were studied by using three-dimensional fluorescence spectrometry (TDFS) such as three-dimensional fluorescence (TDF) spectra and three-dimensional fluorescence polarization (TDFP) spectra with tryptophan residues in protein molecules as an intrinsic fluorescent probe. The results show that the microenvironment of tryptophan residues of protein molecules in various solutions can be directly indicated and TDFS is an effective tool for studying protein conformation in solution. Meantime, some valuable results were obtained.
Cylindrical Three-Dimensional Porous Anodic Alumina Networks
Directory of Open Access Journals (Sweden)
Pedro M. Resende
2016-11-01
Full Text Available The synthesis of a conformal three-dimensional nanostructure based on porous anodic alumina with transversal nanopores on wires is herein presented. The resulting three-dimensional network exhibits the same nanostructure as that obtained on planar geometries, but with a macroscopic cylindrical geometry. The morphological analysis of the nanostructure revealed the effects of the initial defects on the aluminum surface and the mechanical strains on the integrity of the three-dimensional network. The results evidence the feasibility of obtaining 3D porous anodic alumina on non-planar aluminum substrates.
Interactive dynamic three-dimensional scene for the ground-based three-dimensional display
Hou, Peining; Sang, Xinzhu; Guo, Nan; Chen, Duo; Yan, Binbin; Wang, Kuiru; Dou, Wenhua; Xiao, Liquan
2016-10-01
Three-dimensional (3D) displays provides valuable tools for many fields, such as scientific experiment, education, information transmission, medical imaging and physical simulation. Ground based 360° 3D display with dynamic and controllable scene can find some special applications, such as design and construction of buildings, aeronautics, military sand table and so on. It can be utilized to evaluate and visualize the dynamic scene of the battlefield, surgical operation and the 3D canvas of art. In order to achieve the ground based 3D display, the public focus plane should be parallel to the camera's imaging planes, and optical axes should be offset to the center of public focus plane in both vertical and horizontal directions. Virtual cameras are used to display 3D dynamic scene with Unity 3D engine. Parameters of virtual cameras for capturing scene are designed and analyzed, and locations of virtual cameras are determined by the observer's eye positions in the observing space world. An interactive dynamic 3D scene for ground based 360° 3D display is demonstrated, which provides high-immersion 3D visualization.
Three-Dimensional Measurement and Reconstruction of Fabric Drape Shape
Institute of Scientific and Technical Information of China (English)
SHEN Yi; YIN Hong-yuan; LIU Xuan-mu
2007-01-01
This paper introduces a new method of measuring the three-dimensional drape shape of fabrics with structural light. First, we apply parallel annular structural light to form light and shade alternating contour stripes on the surface of fabrics. We then collect the images of contour stripes using Charge Coupled Device (CCD). Subsequently, we process the images to identify the contour stripes and edges of fabrics, and obtain the fabric contour lines of curved surfaces. Finally, we apply three-dimensional curved surface modeling method based on a network of polar coordinates, and reconstruct the three-dimensional drape shape of fabrics. Experiments show that our method is effective in testing and reconstructing three-dimensional drape shape of fabrics.
Study on three-dimensional freehand stroke creation
Directory of Open Access Journals (Sweden)
Cuixian Xuan
2015-05-01
Full Text Available The automotive frames that can be created consciously with three-dimensional freehand strokes are quite important and useful in the early stage of automotive styling. However, all the strokes are drawn on the screen in two-dimensional. This study focuses on the creation of three-dimensional freehand strokes by applying the interpolation algorithm in two orthogonal planes, the projection algorithm and the resultant matrix algorithm. The fitting algorithms of strokes have been developed as the bridges between the traditional two-dimensional sketching and three-dimensional digital modeling. The stylists could use the digital tablet and pen to sketch the frames or outlines of a vehicle in three-dimensional space and then those could be used for establishing the automotive surfaces in any engineering software.
Direct Linear Transformation Method for Three-Dimensional Cinematography
Shapiro, Robert
1978-01-01
The ability of Direct Linear Transformation Method for three-dimensional cinematography to locate points in space was shown to meet the accuracy requirements associated with research on human movement. (JD)
Magnetic structure of two- and three-dimensional supramolecular compounds
Energy Technology Data Exchange (ETDEWEB)
Decurtins, S.; Schmalle, H.W.; Pellaux, R. [Zurich Univ. (Switzerland); Fischer, P.; Fauth, F. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ouladdiaf, B. [Institut Max von Laue - Paul Langevin, 75 - Paris (France)
1997-09-01
Supramolecular chiral networks of oxalato-bridged transition metals show either two- or three-dimensional structural features. The magnetic structures of such compounds have been investigated by means of elastic neutron powder diffraction. (author) 2 figs., 2 refs.
Stability of compressible three-dimensional boundary-layer flows
Reed, H. L.; Nayfeh, A. H.
1982-01-01
For compressible three-dimensional flow, the method of multiple scales to formulate the three-dimensional stability problem and determine the partial-differential equations governing variations of the amplitude and complex wavenumbers is used. A method for following one specific wave along its trajectory to ascertain the characteristics of the most unstable disturbance is proposed. Numerical results using the flow over the X-21 wing as calculated from the Kaups-Cebeci code will be presented.
Three-dimensional network of Drosophila brain hemisphere
Mizutani, Ryuta; Saiga, Rino; Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio
2016-01-01
The first step to understanding brain function is to determine the brain's network structure. We report a three-dimensional analysis of the brain network of the fruit fly Drosophila melanogaster by synchrotron-radiation tomographic microscopy. A skeletonized wire model of the left half of the brain network was built by tracing the three-dimensional distribution of X-ray absorption coefficients. The obtained models of neuronal processes were classified into groups on the basis of their three-d...
Three-dimensional reconstruction of functional brain images
Energy Technology Data Exchange (ETDEWEB)
Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao [Kyoto Univ. (Japan)
1999-08-01
We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface
Alignment-free three-dimensional optical metamaterials.
Zhao, Yang; Shi, Jinwei; Sun, Liuyang; Li, Xiaoqin; Alù, Andrea
2014-03-01
Three-dimensional optical metamaterials based on multilayers typically rely on critical vertical alignment to achieve the desired functionality. Here the conditions under which three-dimensional metamaterials with different functionalities may be realized without constraints on alignment are analyzed and demonstrated experimentally. This study demonstrates that the release of alignment constraints for multilayered metamaterials is allowed, while their anomalous interaction with light is preserved.
Uniform Deterministic Discrete Method for Three Dimensional Systems
Institute of Scientific and Technical Information of China (English)
无
1997-01-01
For radiative direct exchange areas in three dimensional system,the Uniform Deterministic Discrete Method(UDDM) was adopted.The spherical surface dividing method for sending area element and the regular icosahedron for sending volume element can meet with the direct exchange area computation of any kind of zone pairs.The numerical examples of direct exchange area in three dimensional system with nonhomogeneous attenuation coefficients indicated that the UDDM can give very high numercal accuracy.
Ordered three-dimensional interconnected nanoarchitectures in anodic porous alumina
Martín, Jaime; Martín-González, Marisol; Fernández, Jose Francisco; Caballero-Calero, Olga
2014-01-01
Three-dimensional nanostructures combine properties of nanoscale materials with the advantages of being macro-sized pieces when the time comes to manipulate, measure their properties, or make a device. However, the amount of compounds with the ability to self-organize in ordered three-dimensional nanostructures is limited. Therefore, template-based fabrication strategies become the key approach towards three-dimensional nanostructures. Here we report the simple fabrication of a template based on anodic aluminum oxide, having a well-defined, ordered, tunable, homogeneous 3D nanotubular network in the sub 100 nm range. The three-dimensional templates are then employed to achieve three-dimensional, ordered nanowire-networks in Bi2Te3 and polystyrene. Lastly, we demonstrate the photonic crystal behavior of both the template and the polystyrene three-dimensional nanostructure. Our approach may establish the foundations for future high-throughput, cheap, photonic materials and devices made of simple commodity plastics, metals, and semiconductors. PMID:25342247
Three-dimensional decomposition method of global atmospheric circulation
Institute of Scientific and Technical Information of China (English)
2008-01-01
By adopting the idea of three-dimensional Walker, Hadley and Rossby stream functions, the global atmospheric circulation can be considered as the sum of three stream functions from a global per- spective. Therefore, a mathematical model of three-dimensional decomposition of global atmospheric circulation is proposed and the existence and uniqueness of the model are proved. Besides, the model includes a numerical method leading to no truncation error in the discrete three-dimensional grid points. Results also show that the three-dimensional stream functions exist and are unique for a given velocity field. The mathematical model shows the generalized form of three-dimensional stream func- tions equal to the velocity field in representing the features of atmospheric motion. Besides, the vertical velocity calculated through the model can represent the main characteristics of the vertical motion. In sum, the three-dimensional decomposition of atmospheric circulation is convenient for the further in- vestigation of the features of global atmospheric motions.
Bantema-Joppe, Enja J.; van der Laan, Hans Paul; de Bock, Geertruida H.; Wijsman, Robin; Dolsma, Wil V.; Busz, Dianne M.; Langendijk, Johannes A.; Maduro, John H.
2011-01-01
PURPOSE: To report on local control and survival after breast conserving therapy (BCT) including three-dimensional conformal simultaneous integrated boost irradiation (3D-CRT-SIB) and on the influence of age on outcome. PATIENT AND METHODS: For this study, 752 consecutive female breast cancer patien
Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)
Energy Technology Data Exchange (ETDEWEB)
De Deene, Y.; De Wagter, C.; Van Duyse, B.; Achten, E.; De Neve, W. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; De Poorter, J. [Ghent Univ. (Belgium). Dept. of Magnetic Resonance
1995-12-01
As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes.
Three-dimensional magnetospheric equilibrium with isotropic pressure
Energy Technology Data Exchange (ETDEWEB)
Cheng, C.Z.
1995-05-01
In the absence of the toroidal flux, two coupled quasi two-dimensional elliptic equilibrium equations have been derived to describe self-consistent three-dimensional static magnetospheric equilibria with isotropic pressure in an optimal ({Psi},{alpha},{chi}) flux coordinate system, where {Psi} is the magnetic flux function, {chi} is a generalized poloidal angle, {alpha} is the toroidal angle, {alpha} = {phi} {minus} {delta}({Psi},{phi},{chi}) is the toroidal angle, {delta}({Psi},{phi},{chi}) is periodic in {phi}, and the magnetic field is represented as {rvec B} = {del}{Psi} {times} {del}{alpha}. A three-dimensional magnetospheric equilibrium code, the MAG-3D code, has been developed by employing an iterative metric method. The main difference between the three-dimensional and the two-dimensional axisymmetric solutions is that the field-aligned current and the toroidal magnetic field are finite for the three-dimensional case, but vanish for the two-dimensional axisymmetric case. With the same boundary flux surface shape, the two-dimensional axisymmetric results are similar to the three-dimensional magnetosphere at each local time cross section.
Biodynamic profiling of three-dimensional tissue growth techniques
Sun, Hao; Merrill, Dan; Turek, John; Nolte, David
2016-03-01
Three-dimensional tissue culture presents a more biologically relevant environment in which to perform drug development than conventional two-dimensional cell culture. However, obtaining high-content information from inside three dimensional tissue has presented an obstacle to rapid adoption of 3D tissue culture for pharmaceutical applications. Biodynamic imaging is a high-content three-dimensional optical imaging technology based on low-coherence interferometry and digital holography that uses intracellular dynamics as high-content image contrast. In this paper, we use biodynamic imaging to compare pharmaceutical responses to Taxol of three-dimensional multicellular spheroids grown by three different growth techniques: rotating bioreactor, hanging-drop and plate-grown spheroids. The three growth techniques have systematic variations among tissue cohesiveness and intracellular activity and consequently display different pharmacodynamics under identical drug dose conditions. The in vitro tissue cultures are also compared to ex vivo living biopsies. These results demonstrate that three-dimensional tissue cultures are not equivalent, and that drug-response studies must take into account the growth method.
Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels
Energy Technology Data Exchange (ETDEWEB)
Lu, Hongbing [Univ. of Texas, Austin, TX (United States); Bukkapatnam, Satish; Harimkar, Sandip; Singh, Raman; Bardenhagen, Scott
2014-01-09
Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding and validate against simulation results; and 7. Expand the adaptive mesh refinement infrastructure parallel processing environment to allow adaptive mesh refinement at the 3D crack fronts and adaptive mesh merging in the wake of cracks. Fuel cladding is made of materials such as stainless steels and ferritic steels with added alloying elements, which increase stability and durability under irradiation. As fuel cladding is subjected to water, chemicals, fission gas, pressure, high temperatures, and irradiation while in service, understanding performance is essential. In the fast fuel used in advanced burner reactors, simulations of the nuclear
Radiation hardness of three-dimensional polycrystalline diamond detectors
Energy Technology Data Exchange (ETDEWEB)
Lagomarsino, Stefano, E-mail: lagomarsino@fi.infn.it; Sciortino, Silvio [National Institute of Nuclear Physics (INFN), Via B. Rossi, 1-3, 50019 Sesto Fiorentino (Italy); Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Bellini, Marco [European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Istituto Nazionale di Ottica (INO-CNR), Largo Enrico Fermi 6, 50125 Firenze (Italy); Corsi, Chiara [Department of Physics and Astronomy, University of Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); European Laboratory for Non-Linear Spectroscopy, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Cindro, Vladimir [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Kanxheri, Keida; Servoli, Leonello [National Institute of Nuclear Physics (INFN), Via A. Pascoli, 06123 Perugia (Italy); Department of Physics, University of Perugia, Via A. Pascoli, 06123 Perugia (Italy); Morozzi, Arianna [Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Passeri, Daniele [National Institute of Nuclear Physics (INFN), Via A. Pascoli, 06123 Perugia (Italy); Department of Engineering, University of Perugia, Via G. Duranti 93, 06125 Perugia (Italy); Schmidt, Christian J. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt (Germany)
2015-05-11
The three-dimensional concept in particle detection is based on the fabrication of columnar electrodes perpendicular to the surface of a solid state radiation sensor. It permits to improve the radiation resistance characteristics of a material by lowering the necessary bias voltage and shortening the charge carrier path inside the material. If applied to a long-recognized exceptionally radiation-hard material like diamond, this concept promises to pave the way to the realization of detectors of unprecedented performances. We fabricated conventional and three-dimensional polycrystalline diamond detectors, and tested them before and after neutron damage up to 1.2 ×10{sup 16 }cm{sup −2}, 1 MeV-equivalent neutron fluence. We found that the signal collected by the three-dimensional detectors is up to three times higher than that of the conventional planar ones, at the highest neutron damage ever experimented.
Coupled particle dispersion by three-dimensional vortex structures
Energy Technology Data Exchange (ETDEWEB)
Troutt, T.R.; Chung, J.N.; Crowe, C.T.
1996-12-31
The primary objective of this research program is to obtain understanding concerning the role of three-dimensional vortex structures in the dispersion of particles and droplets in free shear flows. This research program builds on previous studies which focused on the nature of particle dispersion in large scale quasi two-dimensional vortex structures. This investigation employs time dependent experimental and numerical techniques to provide information concerning the particulate dispersion produced by three dimensional vortex structures in free shear layers. The free shear flows investigated include modified plane mixing layers, and modified plane wakes. The modifications to these flows involve slight perturbations to the initiation boundary conditions such that three-dimensional vortex structures are rapidly generated by the experimental and numerical flow fields. Recent results support the importance of these vortex structures in the particle dispersion process.
Time of Closest Approach in Three-Dimensional Airspace
Munoz, Cesar A.; Narkawicz, Anthony J.
2010-01-01
In air traffic management, the aircraft separation requirement is defined by a minimum horizontal distance and a minimum vertical distance that the aircraft have to maintain. Since this requirement defines a cylinder around each aircraft rather than a sphere, the three-dimensional Euclidean distance does not provide an appropriate basis for the definition of time of closest approach. For instance, conflicting aircraft are not necessarily in loss of separation at the time of closest three-dimensional Euclidean distance. This paper proposes a definition of time of closest approach that characterizes conflicts in a three-dimensional airspace. The proposed time is defined as the time that minimizes a distance metric called cylindrical norm. An algorithm that computes the time of closest approach between two aircraft is provided and the formal verification of its main properties is reported.
Three-dimensional network of Drosophila brain hemisphere
Mizutani, Ryuta; Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio
2016-01-01
The first step to understanding brain function is to determine the brain's network structure. We report a three-dimensional analysis of the brain network of the fruit fly Drosophila melanogaster by synchrotron-radiation tomographic microscopy. A skeletonized wire model of the left half of the brain network was built by tracing the three-dimensional distribution of X-ray absorption coefficients. The obtained models of neuronal processes were classified into groups on the basis of their three-dimensional structures. These classified groups correspond to neuronal tracts that send long-range projections or repeated structures of the optic lobe. The skeletonized model is also composed of neuronal processes that could not be classified into the groups. The distribution of these unclassified structures correlates with the distribution of contacts between neuronal processes. This suggests that neurons that cannot be classified into typical structures should play important roles in brain functions. The quantitative de...
Hydrofocusing Bioreactor for Three-Dimensional Cell Culture
Gonda, Steve R.; Spaulding, Glenn F.; Tsao, Yow-Min D.; Flechsig, Scott; Jones, Leslie; Soehnge, Holly
2003-01-01
The hydrodynamic focusing bioreactor (HFB) is a bioreactor system designed for three-dimensional cell culture and tissue-engineering investigations on orbiting spacecraft and in laboratories on Earth. The HFB offers a unique hydrofocusing capability that enables the creation of a low-shear culture environment simultaneously with the "herding" of suspended cells, tissue assemblies, and air bubbles. Under development for use in the Biotechnology Facility on the International Space Station, the HFB has successfully grown large three-dimensional, tissuelike assemblies from anchorage-dependent cells and grown suspension hybridoma cells to high densities. The HFB, based on the principle of hydrodynamic focusing, provides the capability to control the movement of air bubbles and removes them from the bioreactor without degrading the low-shear culture environment or the suspended three-dimensional tissue assemblies. The HFB also provides unparalleled control over the locations of cells and tissues within its bioreactor vessel during operation and sampling.
Computational methods for three-dimensional microscopy reconstruction
Frank, Joachim
2014-01-01
Approaches to the recovery of three-dimensional information on a biological object, which are often formulated or implemented initially in an intuitive way, are concisely described here based on physical models of the object and the image-formation process. Both three-dimensional electron microscopy and X-ray tomography can be captured in the same mathematical framework, leading to closely-related computational approaches, but the methodologies differ in detail and hence pose different challenges. The editors of this volume, Gabor T. Herman and Joachim Frank, are experts in the respective methodologies and present research at the forefront of biological imaging and structural biology. Computational Methods for Three-Dimensional Microscopy Reconstruction will serve as a useful resource for scholars interested in the development of computational methods for structural biology and cell biology, particularly in the area of 3D imaging and modeling.
A class of auxetic three-dimensional lattices
Cabras, Luigi
2015-01-01
We propose a class of auxetic three-dimensional lattice structures. The elastic microstructure can be designed in order to have omni-directional Poisson's ratio arbitrarily close to the stability limit -1. The cubic behavior of the periodic system has been fully characterized; the minumum and maximum Poisson's ratio and the associated principal directions are given as a function of the microstructural parameters. The initial microstructure is then modified into a body centered-cubic system that can achieve a Poisson's ratio lower than -1 and that can also behave as an isotropic three-dimensional auxetic structure.
Three Dimensional Imaging with Multiple Wavelength Speckle Interferometry
Energy Technology Data Exchange (ETDEWEB)
Bernacki, Bruce E.; Cannon, Bret D.; Schiffern, John T.; Mendoza, Albert
2014-05-28
We present the design, modeling, construction, and results of a three-dimensional imager based upon multiple-wavelength speckle interferometry. A surface under test is illuminated with tunable laser light in a Michelson interferometer configuration while a speckled image is acquired at each laser frequency step. The resulting hypercube is Fourier transformed in the frequency dimension and the beat frequencies that result map the relative offsets of surface features. Synthetic wavelengths resulting from the laser tuning can probe features ranging from 18 microns to hundreds of millimeters. Three dimensional images will be presented along with modeling results.
Three dimensional super-resolution in metamaterial slab lenses
Mesa, F; Freire, M; Baena, J D
2005-01-01
This letter presents a theoretical and experimental study on the viability of obtaining three dimensional super-resolution (i.e. resolution overcoming the diffraction limit for all directions in space) by means of metamaterial slab lenses. Although the source field cannot be actually reproduced at the back side of the lens with super-resolution in all space directions, the matching capabilities of metamaterial slabs does make it possible the detection of images with three-dimensional super-resolution. This imaging takes place because of the coupling between the evanescent space harmonic components of the field generated at both the source and the detector.
Urologic applications of multiplanar and three-dimensional computed tomography.
Olson, M C; Posniak, H V
1995-01-01
The introduction of helical computed tomography (CT) has resulted in improved quality of multiplanar reformations and three-dimensional reconstructions in the chest and abdomen and has made CT angiography a clinical reality. These imaging techniques are useful for evaluating the urinary tract, adding a new dimension to its display, resulting in improved diagnosis of renal and perirenal disease. This article reviews the indications and techniques utilized for multiplanar and three-dimensional CT for urology. The advantages and limitations are discussed, and normal and pathologic findings in the urinary tract illustrated.
Gas-Kinetic BGK Scheme for Three Dimensional Magnetohydrodynamics
Institute of Scientific and Technical Information of China (English)
Huazhong
2010-01-01
The gas-kinetic theory based flux splitting method has been successfully proposed for solving one- and two-dimensional ideal magnetohydrodynamics by Xu et al.[J. Comput. Phys., 1999; 2000], respectively. This paper extends the kinetic method to solve three-dimensional ideal magnetohydrodynamics equations, where an adaptive parameter η is used to control the numerical dissipation in the flux splitting method.Several numerical examples are given to demonstrate that the proposed method can achieve high numerical accuracy and resolve strong discontinuous waves in three dimensional ideal MHD problems.
Three-dimensional microtomographic imaging of human brain cortex
Mizutania, Ryuta; Uesugi, Kentaro; Ohyama, Masami; Takekoshi, Susumu; Osamura, R Yoshiyuki; Suzuki, Yoshio
2016-01-01
This paper describes an x-ray microtomographic technique for imaging the three-dimensional structure of the human cerebral cortex. Neurons in the brain constitute a neural circuit as a three-dimensional network. The brain tissue is composed of light elements that give little contrast in a hard x-ray transmission image. The contrast was enhanced by staining neural cells with metal compounds. The obtained structure revealed the microarchitecture of the gray and white matter regions of the frontal cortex, which is responsible for the higher brain functions.
A system of three-dimensional complex variables
Martin, E. Dale
1986-01-01
Some results of a new theory of multidimensional complex variables are reported, including analytic functions of a three-dimensional (3-D) complex variable. Three-dimensional complex numbers are defined, including vector properties and rules of multiplication. The necessary conditions for a function of a 3-D variable to be analytic are given and shown to be analogous to the 2-D Cauchy-Riemann equations. A simple example also demonstrates the analogy between the newly defined 3-D complex velocity and 3-D complex potential and the corresponding ordinary complex velocity and complex potential in two dimensions.
Fabrication and characterization of three-dimensional biomimetic chiral composites.
Turner, Mark D; Schröder-Turk, Gerd E; Gu, Min
2011-05-09
Here we show the fabrication and characterization of a novel class of biomimetic photonic chiral composites inspired by a recent finding in butterfly wing-scales. These three-dimensional networks have cubic symmetry, are fully interconnected, have robust mechanical strength and possess chirality which can be controlled through the composition of multiple chiral networks, providing an excellent platform for developing novel chiral materials. Using direct laser writing we have fabricated different types of chiral composites that can be engineered to form novel photonic devices. We experimentally show strong circular dichroism and compare with numerical simulations to illustrate the high quality of these three-dimensional photonic structures.
Symmetries and defects in three-dimensional topological field theory
Fuchs, Jurgen
2015-01-01
Boundary conditions and defects of any codimension are natural parts of any quantum field theory. Surface defects in three-dimensional topological field theories of Turaev-Reshetikhin type have applications to two-dimensional conformal field theories, in solid state physics and in quantum computing. We explain an obstruction to the existence of surface defects that takes values in a Witt group. We then turn to surface defects in Dijkgraaf-Witten theories and their construction in terms of relative bundles; this allows one to exhibit Brauer-Picard groups as symmetry groups of three-dimensional topological field theories.
Fenton, Flavio H.; Evans, Steven J.; Hastings, Harold M.; Cherry, Elizabeth M.
2006-03-01
Presentation and analysis of large three-dimensional data sets is in general hard to do using only two-dimensional figures and plots. In this talk, we will demonstrate techniques for illustrating static and dynamic three-dimensional objects and data using Virtual Reality Modeling Language (VRML) as well as Java. The advantage of these two languages is that they are platform-independent, which allows for easy sharing of data and visualizations. In addition, manipulation of data is relatively easy as rotation, translation and zooming can be done in real- time for static objects as well as for data and objects that vary and deform in time. Examples of fully three-dimensional movies will be shown, including dendritic growth and propagation of electrical waves in cardiac tissue. In addition, we will show how to include VRML and Java viewers in PowerPoint for easy presentation of results in classes and seminars.
Thermodynamics of a Simple Three-Dimensional DNA Hairpin Model
Kremer, Kellan; Boggess, Erin; Mask, Walker; Saucedo, Tony; Hansen, JJ; Appelgate, Ian; Jurgensen, Taylor; Santos, Aaron
2016-01-01
We characterize the equation of state for a simple three-dimensional DNA hairpin model using a Metropolis Monte Carlo algorithm. This algorithm was run at constant temperature and fixed separation between the terminal ends of the strand. From the equation of state, we compute the compressibility, thermal expansion coefficient, and specific heat along with adiabatic path.
Three-dimensional reconstruction of the pigeon inner ear
Hofman, R.; Segenhout, J. M.; Wit, H. P.
2009-01-01
Three-dimensional reconstructions of the inner ear of the pigeon (Columba livia domestica), from two-dimensional images, obtained with (conventional) light microscopy or orthogonal-plane fluorescence optical sectioning (OPFOS), are presented. The results are compared with available information on th
A Three-Dimensional Haptic Matrix Test of Nonverbal Reasoning
Miller, Joseph C.; Skillman, Gemma D.; Benedetto, Joanne M.; Holtz, Ann M.; Nassif, Carrie L.; Weber, Anh D.
2007-01-01
Three-dimensional haptic matrices were pilot-tested as a nonvisual measure of cognitive ability. The results indicated that they correlated with convergent measures, with emphasis on spatial processing and that the participants who described items "visually" completed them more quickly and accurately and tended to have become visually impaired…
Two-Dimensional Chirality in Three-Dimensional Chemistry.
Wintner, Claude E.
1983-01-01
The concept of two-dimensional chirality is used to enhance students' understanding of three-dimensional stereochemistry. This chirality is used as a key to teaching/understanding such concepts as enaniotropism, diastereotopism, pseudoasymmetry, retention/inversion of configuration, and stereochemical results of addition to double bonds. (JN)
Three-dimensional modes of a symmetric nonlinear plane waveguide
Akhmediev, N. N.; Nabiev, R. F.; Popov, Yu. M.
1989-01-01
The three-dimensional problem of a symmetric nonlinear plane waveguide, which consist of a linear medium layer surrounded by nonlinear media, is investigated. The stationary solution of this problem is a mode whose field is falling to zero at infinity in all directions perpendicular to the propagation direction. The even, odd and assymetrical solutions of the problem are obtained.
Polyimide Aerogels with Three-Dimensional Cross-Linked Structure
Meador, Mary Ann B. (Inventor)
2016-01-01
A method for creating a three dimensional cross-linked polyimide structure includes dissolving a diamine, a dianhydride, and a triamine in a solvent, imidizing a polyamic acid gel by heating the gel, extracting the gel in a second solvent, supercritically drying the gel, and removing the solvent to create a polyimide aerogel.
Three-dimensional charge transport in organic semiconductor single crystals.
He, Tao; Zhang, Xiying; Jia, Jiong; Li, Yexin; Tao, Xutang
2012-04-24
Three-dimensional charge transport anisotropy in organic semiconductor single crystals - both plates and rods (above and below, respectively, in the figure) - is measured in well-performing organic field-effect transistors for the first time. The results provide an excellent model for molecular design and device preparation that leads to good performance.
Scattering and conductance quantization in three-dimensional metal nanocontacts
DEFF Research Database (Denmark)
Brandbyge, Mads; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet
1997-01-01
The transmission through three-dimensional nanocontacts is calculated in the presence of localized scattering centers and boundary scattering using a coupled-channel recursion method. Simple confining potentials are used to investigate how robust the observation of quantized conductance is with r...
Differential equations of the shell suspension. Three-dimensional problem
Гнатейко, Нонна Валентинівна
2016-01-01
Differential equations of suspension of gyroscope are constructed as a shell of rotation. Analytical material well-being of analysis of properties of suspension as a system with part parameters is created. Three-dimensional approach gives possibility for the comprehensive study of errors of devices of inertial navigation from position impedance status.
Three-Dimensional Printing Using a Photoinitiated Polymer
Muskin, Joseph; Ragusa, Matthew; Gelsthorpe, Thomas
2010-01-01
Printers capable of producing three-dimensional objects are becoming more common. Most of these printers are impractical for use in the chemistry classroom because of the expense incurred in fabricating a print head that must be controlled in three dimensions. We propose a simpler solution to this problem that allows the emerging technology of…
Three dimensional boundary layers on submarine conning towers and rudders
Gleyzes, C.
1988-01-01
Solutions for the definition of grids adapted to the calculation of three-dimensional boundary layers on submarine conning towers and on submarine rudders and fins are described. The particular geometry of such bodies (oblique shaped hull, curved fins) required special adaptations. The grids were verified on examples from a test basin.
Algebraic Ricci Solitons of three-dimensional Lorentzian Lie groups
Batat, Wafaa
2011-01-01
We classify Algebraic Ricci Solitons of three-dimensional Lorentzian Lie groups. All algebraic Ricci solitons that we obtain are sol-solitons. In particular, we prove that, contrary to the Riemannian case, Lorentzian Ricci solitons need not to be algebraic Ricci solitons.
Highly monodisperse bismuth nanoparticles and their three-dimensional superlattices.
Yarema, Maksym; Kovalenko, Maksym V; Hesser, Günter; Talapin, Dmitri V; Heiss, Wolfgang
2010-11-01
A simple and reproducible synthesis of highly monodisperse and ligand-protected bismuth nanoparticles (Bi NPs) is reported. The size of the single-crystalline and spherically shaped NPs is controlled between 11 and 22 nm mainly by the reaction temperature. The high uniformity of the NPs allows their self-assembly into long-range-ordered two- and three-dimensional superstructures.
Three-Dimensional Evolution of the Galactic Fountain
D'Avillez, M A
1999-01-01
Gas that escapes from the Galactic disk, rises into the halo, cools and falls back, constitutes a "Galactic Fountain". Three-Dimensional simulations show that such a fountain model reproduces many of the features that have been observed in the Galaxy and other galaxies such as M31 and M33. Here, these results are reported.
Resistive drift wave turbulence in a three-dimensional geometry
DEFF Research Database (Denmark)
Korsholm, Søren Bang; Michelsen, Poul; Naulin, V.
1999-01-01
The Hasegawa-Wakatani model describing resistive drift waves is investigated analytically and numerically in a three-dimensional periodic geometry. After an initial growth of the energy the drift waves couple nonlinearly to convective cells, which eventually dominate the system completely...
THE THREE DIMENSIONAL MODELS AND THEIR IDENTIFICATION MINING SUBSIDENCE
Institute of Scientific and Technical Information of China (English)
WUGe; SHENGuanghan; JIXiaoming; WANGQuanke
1995-01-01
The theory and method for selecting the three dimensional prediction models of mining subsidence are studied in this paper. Namely, based on system identification and statistics theory, an optimum mining subsidence prediction model can be selected. The method proved by a typical case has a good prospect for determining the physical model of rock mass for mining subsidence prediction.
Yttrium oxide based three dimensional metamaterials for visible light cloaking
Rai, Pratyush; Kumar, Prashanth S.; Varadan, Vijay K.; Ruffin, Paul; Brantley, Christina; Edwards, Eugene
2014-04-01
Metamaterial with negative refractive index is the key phenomenon behind the concept of a cloaking device to hide an object from light in visible spectrum. Metamaterials made of two and three dimensional lattices of periodically placed electromagnetic resonant cells can achieve absorption and propagation of incident electromagnetic radiation as confined electromagnetic fields confined to a waveguide as surface plasmon polaritons, which can be used for shielding an object from in-tune electromagnetic radiation. The periodicity and dimensions of resonant cavity determine the frequency, which are very small as compared to the wavelength of incident light. Till now the phenomena have been demonstrated only for lights in near infrared spectrum. Recent advancements in fabrication techniques have made it possible to fabricate array of three dimensional nanostructures with cross-sections as small as 25 nm that are required for negative refractive index for wavelengths in visible light spectrum of 400-700 nm and for wider view angle. Two types of metamaterial designs, three dimensional concentric split ring and fishnet, are considered. Three dimensional structures consisted of metal-dielectric-metal stacks. The metal is silver and dielectric is yttrium oxide, other than conventional materials such as FR4 and Duroid. High κ dielectric and high refractive index as well as large crystal symmetry of Yttrium oxide has been investigated as encapsulating medium. Dependence of refractive index on wavelength and bandwidth of negative refractive index region are analyzed for application towards cloaking from light in visible spectrum.
Automated analysis of three-dimensional stress echocardiography
K.Y.E. Leung (Esther); M. van Stralen (Marijn); M.G. Danilouchkine (Mikhail); G. van Burken (Gerard); M.L. Geleijnse (Marcel); J.H.C. Reiber (Johan); N. de Jong (Nico); A.F.W. van der Steen (Ton); J.G. Bosch (Johan)
2011-01-01
textabstractReal-time three-dimensional (3D) ultrasound imaging has been proposed as an alternative for two-dimensional stress echocardiography for assessing myocardial dysfunction and underlying coronary artery disease. Analysis of 3D stress echocardiography is no simple task and requires considera
Oblique water entry of a three dimensional body
Directory of Open Access Journals (Sweden)
Scolan Yves-Marie
2014-12-01
Full Text Available The problem of the oblique water entry of a three dimensional body is considered. Wagner theory is the theoretical framework. Applications are discussed for an elliptic paraboloid entering an initially flat free surface. A dedicated experimental campaign yields a data base for comparisons. In the present analysis, pressure, force and dynamics of the wetted surface expansion are assessed.
BIFURCATION OF PERIODIC ORBITS OF A THREE-DIMENSIONAL SYSTEM
Institute of Scientific and Technical Information of China (English)
LIU XUANLIANG; HAN MAOAN
2005-01-01
Consider a three-dimensional system having an invariant surface. By using bifurcation techniques and analyzing the solutions of bifurcation equations, the authors study the spacial bifurcation phenomena of a k multiple closed orbit in the invariant surface.The sufficient conditions of the existence of many closed orbits bifurcate from the k multiple closed orbit are obtained.
Three-dimensional stiffness of the carpal arch.
Gabra, Joseph N; Li, Zong-Ming
2016-01-01
The carpal arch of the wrist is formed by irregularly shaped carpal bones interconnected by numerous ligaments, resulting in complex structural mechanics. The purpose of this study was to determine the three-dimensional stiffness characteristics of the carpal arch using displacement perturbations. It was hypothesized that the carpal arch would exhibit an anisotropic stiffness behavior with principal directions that are oblique to the conventional anatomical axes. Eight (n=8) cadavers were used in this study. For each specimen, the hamate was fixed to a custom stationary apparatus. An instrumented robot arm applied three-dimensional displacement perturbations to the ridge of trapezium and corresponding reaction forces were collected. The displacement-force data were used to determine a three-dimensional stiffness matrix using least squares fitting. Eigendecomposition of the stiffness matrix was used to identify the magnitudes and directions of the principal stiffness components. The carpal arch structure exhibited anisotropic stiffness behaviors with a maximum principal stiffness of 16.4±4.6N/mm that was significantly larger than the other principal components of 3.1±0.9 and 2.6±0.5N/mm (pcarpal tunnel which is accounted for by the stiff transverse ligaments that tightly bind distal carpal arch. The minimal principal stiffness is attributed to the less constraining articulation between the trapezium and scaphoid. This study provides advanced characterization of the wrist׳s three-dimensional structural stiffness for improved insight into wrist biomechanics, stability, and function.
Three-Dimensional Space to Assess Cloud Interoperability
2013-03-01
major cloud providers, OpenStack and OpeNebula, to demonstrate the usage of the three-dimensional space and its benefits . We start this chapter with a...documentation:rel4.0:external_auth. [68] X. Gao, P. Shah, A. Yoga , A. Kodgire and X. Ni. Cloud storage survey [Online]. Available: http
Potential Flows From Three-Dimensional Complex Variables
Martin, E. Dale; Kelly, Patrick H.; Panton, Ronald L.
1992-01-01
Report presents investigation of several functions of three-dimensional complex variable, with emphasis on potential-flow fields computed from these functions. Part of continuing research on generalization of well-established two-dimensional complex analysis to three and more dimensions.
Three-dimensional simulations of viscoelastic instability in polymeric filaments
DEFF Research Database (Denmark)
Rasmussen, Henrik Koblitz; Hassager, Ole
1999-01-01
The three-dimensional Langrangian integral method is used to simulate the elastic end-plate instability that occurs in the rapid extension of some polymeric filaments between parallel plates. It is demonstrated that the upper convected Maxwell model describes the essential features of the instabi...
Approaching the Sequential and Three-Dimensional Organization of Genomes
T.A. Knoch (Tobias)
2006-01-01
textabstractGenomes are one of the major foundations of life due to their role in information storage, process regulation and evolution. To achieve a deeper unterstanding of the human genome the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic prope
Generation of a Desired Three-Dimensional Electromagnetic Field
DEFF Research Database (Denmark)
2005-01-01
The present invention relates to a method and a system for synthesizing a prescribed three-dimensional electromagnetic field based on generalized phase contrast imaging. Such a method and apparatus may be utilized in advanced optical micro and nano-manipulation, such as by provision of a multiple...
Computer Generated Holography as a Three-Dimensional Display Medium
1990-12-01
series of two dimensional images are reflected on an object screen resulting in an autostereoscopic , or true three dimensional, images. The advantages of...an attractive target to optimize. Jack Ritter has suggested a fast approximation to 3D Euclidean distance calculations (10:432). His methid uses no
Three-dimensional reconstruction of the otosclerotic focus
DEFF Research Database (Denmark)
Bloch, Sune Land; Sørensen, Mads Sølvsten
2010-01-01
The location and three-dimensional (3D) shapes of the otosclerotic foci suggest a general centripetal distribution of otosclerotic bone remodeling around the inner ear space, whereas the normal bone remodeling is distributed centrifugally. The existence of an inverse spatial relation between normal...
Three-dimensional topology optimized electrically-small conformal antenna
DEFF Research Database (Denmark)
Erentok, Aycan; Sigmund, Ole
2008-01-01
A three-dimensional (3D) conductor-based conformal electrically small antenna is obtained using a topology optimization method. The optimization method distributes a certain amount of conductive material to a designated design domain such that the material layout defines an electrically small...
A Novel Three-Dimensional Tool for Teaching Human Neuroanatomy
Estevez, Maureen E.; Lindgren, Kristen A.; Bergethon, Peter R.
2010-01-01
Three-dimensional (3D) visualization of neuroanatomy can be challenging for medical students. This knowledge is essential in order for students to correlate cross-sectional neuroanatomy and whole brain specimens within neuroscience curricula and to interpret clinical and radiological information as clinicians or researchers. This study implemented…
Optimal eavesdropping in cryptography with three-dimensional quantum states.
Bruss, D; Macchiavello, C
2002-03-25
We study optimal eavesdropping in quantum cryptography with three-dimensional systems, and show that this scheme is more secure against symmetric attacks than protocols using two-dimensional states. We generalize the according eavesdropping transformation to arbitrary dimensions, and discuss the connection with optimal quantum cloning.
Three-Dimensional Extension of a Digital Library Service System
Xiao, Long
2010-01-01
Purpose: The paper aims to provide an overall methodology and case study for the innovation and extension of a digital library, especially the service system. Design/methodology/approach: Based on the three-dimensional structure theory of the information service industry, this paper combines a comprehensive analysis with the practical experiences…
Three dimensional rigorous model for optical scattering problems
Wei, X.
2006-01-01
We present a three-dimensional model based on the finite element method for solving the time-harmonic Maxwell equation in optics. It applies to isotropic or anisotropic dielectrics and metals, and to many configurations such as an isolated scatterer in a multilayer, bi-gratings and crystals. We shal
Three-Dimensional Waves in Tilt Thermal Boundary Layers
Institute of Scientific and Technical Information of China (English)
TAO Jian-Jun; YUAN Xiang-Jiang
2009-01-01
We numerically and theoretically study the stabilities of tilt thermal boundary layers immersed in stratified air. An interesting phenomenon is revealed: the stationary longitudinal-roll mode becomes unstable to some oscillating state even when the Grashof number is smaller than its corresponding critical value. By stability analysis, this phenomenon is explained in terms of a new three-dimensional wave mode. The effect of the tilt angle on the stability of the boundary flows is investigated. Since the new three-dimensional wave is found to be the most unstable mode when the title angle is between 30° and 64°, it is expected to play an important role in the transition to turbulence.
Slightly Two or Three Dimensional Self-Similar Solutions
Sari, Re'em; Yalinewich, Almog; MacFadyen, Andrew
2011-01-01
Self similarity allows for analytic or semi-analytic solutions to many hydrodynamics problems. Most of these solutions are one dimensional. Using linear perturbation theory, expanded around such a one-dimensional solution, we find self-similar hydrodynamic solutions that are two- or three-dimensional. Since the deviation from a one-dimensional solution is small, we call these slightly two-dimensional and slightly three-dimensional self-similar solutions, respectively. As an example, we treat strong spherical explosions of the second type. A strong explosion propagates into an ideal gas with negligible temperature and density profile of the form rho(r,theta,phi)=r^{-omega}[1+sigma*F(theta,phi)], where omega>3 and sigma << 1. Analytical solutions are obtained by expanding the arbitrary function F(theta,phi) in spherical harmonics. We compare our results with two dimensional numerical simulations, and find good agreement.
Magnetic field intensification by three-dimensional explosion process
Hotta, H; Yokoyama, T
2012-01-01
We investigate an intensification mechanism for the magnetic field near the base of the solar convection zone that does not rely on differential rotation. Such mechanism in addition to differential rotation has been suggested by studies of flux emergence, which typically require field strength in excess of those provided by differential rotation alone. We study here a process in which potential energy of the superadiabatically stratified convection zone is converted into magnetic energy. This mechanism, know as explosion of magnetic flux tubes, has been previously studied in the thin flux tube approximation as well as two-dimensional MHD simulations, we expand the investigation to three-dimensional MHD simulations. Our main result is that enough intensification can be achieved in a three-dimensional magnetic flux sheet as long as the spatial scale of the imposed perturbation normal to the magnetic field is sufficiently large. When this spatial scale is small, the flux sheet tends to rise toward the surface, r...
Three-dimensional Microarchitecture of Adolescent Cancellous Bone
DEFF Research Database (Denmark)
Ding, Ming; Hvid, I; Overgaard, Søren
regarding three-dimensional (3-D) microarchitecture of normal adolescent cancellous bone. The objective of this study was to investigate 3-D microarchitecture of normal adolescent cancellous bone, and compared them with adult cancellous bone, thus seeking more insight into the subchondral bone adaptations...... of lateral condyle in the young adult. There were no statistical significances in the mechanical properties apart from the Young’s modulus of adolescent in anterior-posterior direction was significantly lower than the other groups. DISCUSSION: This is the first study on the 3-D microarchitecture of human...... of Orthopaedics & Traumatology and Institute of Forensic Medicine, Odense and Aarhus University Hospitals, Denmark. RESULTS: Three-dimensional reconstructions of cancellous bone from micro-CT imaging are shown in Figure 1. Our data showed that trabecular separation was significantly greater in the adolescence...
Three-Dimensional Dynamical Instabilities in Galactic Ionization Fronts
Whalen, D J; Whalen, Daniel J.; Norman, Michael L.
2007-01-01
Ionization front instabilities have long been of interest for their suspected role in a variety of phenomena in the galaxy, from the formation of bright rims and 'elephant trunks' in nebulae to triggered star formation in molecular clouds. Numerical treatments of these instabilities have historically been limited in both dimensionality and input physics, leaving important questions about their true evolution unanswered. We present the first three-dimensional radiation hydrodynamical calculations of both R-type and D-type ionization front instabilities in galactic environments (i.e., solar metallicity gas). Consistent with linear stability analyses of planar D-type fronts, our models exhibit many short-wavelength perturbations growing at early times that later evolve into fewer large-wavelength structures. The simulations demonstrate that both self-consistent radiative transfer and three-dimensional flow introduce significant morphological differences to unstable modes when compared to earlier two-dimensional ...
Three-dimensional metamaterials fabricated using Proton Beam Writing
Energy Technology Data Exchange (ETDEWEB)
Bettiol, A.A., E-mail: a.bettiol@nus.edu.sg [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Dr. 3, Singapore 117542 (Singapore); Turaga, S.P.; Yan, Y.; Vanga, S.K. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Dr. 3, Singapore 117542 (Singapore); Chiam, S.Y. [NUS High School for Maths and Science, 20 Clementi Avenue 1, Singapore 129957 (Singapore)
2013-07-01
Proton Beam Writing (PBW) is a direct write lithographic technique that has recently been applied to the fabrication of three dimensional metamaterials. In this work, we show that the unique capabilities of PBW, namely the ability to fabricate arrays of high resolution, high aspect ratio microstructures in polymer or replicated into metal, is well suited to metamaterials research. We have also developed a novel method for selectively electroless plating silver directly onto polymer structures that were fabricated using PBW. This method opens up new avenues for utilizing PBW for making metamaterials and other sub-wavelength metallic structures. Several potential applications of three dimensional metamaterials fabricated using PBW are discussed, including sensing and negative refractive index materials.
Three-dimensional theory for light-matter interaction
DEFF Research Database (Denmark)
Sørensen, Martin Westring; Sørensen, Anders Søndberg
2008-01-01
We present a full quantum mechanical three dimensional theory describing an electromagnetic field interacting with an ensemble of identical atoms. The theory is constructed such that it describes recent experiments on light-matter quantum interfaces, where the quantum fluctuations of light...... to a dressed state picture, where the light modes are solutions to the diffraction problem, and develop a perturbative expansion in the fluctuations. The fluctuations are due to quantum fluctuations as well as the random positions of the atoms. In this perturbative expansion we show how the quantum...... fluctuations are mapped between atoms and light while the random positioning of the atoms give rise to decay due to spontaneous emission. Furthermore we identify limits, where the full three dimensional theory reduce to the one dimensional theory typically used to describe the interaction....
Influence of stable stratification on three-dimensional isotropic turbulence
Metais, O.
The influence of a stable stratification on three-dimensional homogeneous turbulence is investigated by performing large eddy simulations with the subgrid scales procedure developed by Chollet and Lesieur for isotropic turbulence. Computational initial conditions close to those of the experiments performed by Itsweire, Helland and Van Atta allow the comparison of the experimental and numerical evolutions of density-stratified turbulent flows. Theoretical works by Riley, Metcalfe and Weisman and by Lilly suggest that low Froude number stably-stratified turbulence may be a nearly noninteracting superposition of wave and quasi-horizontal turbulent vortex motions. For our computations the stably-stratified turbulence seems to be a decaying three-dimensional turbulence pulsed by internal gravity waves. However some tendencies towards two-dimensional turbulence are observed.
Moyamoya disease: diagnosis with three-dimensional CT angiography
Energy Technology Data Exchange (ETDEWEB)
Tsuchiya, K. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Radiology, Kyorin Univ. School of Medicine, Tokyo (Japan)); Makita, K. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Radiology, Social Health Insurance Medical Center, Tokyo (Japan)); Furui, S. (Dept. of Radiology, National Defense Medical Coll., Saitama (Japan) Dept. of Diagnostic Radiology, Toranomon Kyosai Hospital, Tokyo (Japan))
1994-08-01
Our purpose was to assess the value of three-dimensional (3D) CT angiography in the diagnosis of moyamoya disease. We studied seven patients with moyamoya disease proved by conventional angiography. Three-dimensional (3D) CT angiography was performed using rapid sequence or helical (spiral) scanning in conjunction with a bolus injection of intravenous contrast medium. All seven patients could be diagnosed as having moyamoya disease on the basis of the following 3D CT angiographic findings: poor visualisation of the main trunks and/or major branches of anterior and middle cerebral arteries (7 patients); dilated leptomeningeal anastomotic channels from the posterior cerebral arteries (4); and demonstration of ''moyamoya vessels'' in the basal ganglia (2). Although conventional angiography remains the principal imaging technique for demonstrating anatomical changes in detail, less invasive 3D CT angiography provides a solid means of diagnosing moyamoya disease when it is suspected on CT, MRI, or clinical grounds. (orig.)
Three-Dimensional Modeling of Guide-Field Magnetic Reconnection
Hesse, Michael
2005-01-01
The dissipation mechanism of guide field magnetic reconnection remains a subject of intense scientific interest. On one hand, one set of recent studies have shown that particle inertia-based processes, which include thermal and bulk inertial effects, provide the reconnection electric field in the diffusion region. On the other hand, a second set of studies emphasizes the role of wave-particle interactions in providing anomalous resistivity in the diffusion region. In this presentation, we analyze three-dimensional PIC simulations of guide-field magnetic reconnection. Specific emphasis will be on the question whether thermal-inertia processes, mediated by the electron pressure tensor, remain a viable dissipation mechanism in fully three-dimensional systems.
Three dimensional calculation of flux of low energy atmospheric neutrinos
Lee, H.; Bludman, S. A.
1985-01-01
Results of three-dimensional Monte Carlo calculation of low energy flux of atmospheric neutrinos are presented and compared with earlier one-dimensional calculations 1,2 valid at higher neutrino energies. These low energy neutrinos are the atmospheric background in searching for neutrinos from astrophysical sources. Primary cosmic rays produce the neutrino flux peaking at near E sub=40 MeV and neutrino intensity peaking near E sub v=100 MeV. Because such neutrinos typically deviate by 20 approximately 30 from the primary cosmic ray direction, three-dimensional effects are important for the search of atmospheric neutrinos. Nevertheless, the background of these atmospheric neutrinos is negligible for the detection of solar and supernova neutrinos.
Three-dimensional hybrid networks based on aspartic acid
Indian Academy of Sciences (India)
Anupama Ghosh; R A Sanguramath
2008-01-01
Three-dimensional achiral coordination polymers of the general formula M2(D, L-NHCH (COO)CH2COO)2.C4H4N2 where M = Ni and Co and pyrazine acts as the linker molecule have been prepared under hydrothermal conditions starting with [M(L-NHCH(COO)CH2COO).3H2O] possessing a helical chain structure. A three-dimensional hybrid compound of the formula Pb2.5[N{CH(COO)CH2COO}22H2O] has also been prepared hydrothermally starting with aspartic acid and Pb(NO3)2. In this lead compound, where a secondary amine formed by the dimerisation of aspartic acid acts as the ligand, there is two-dimensional inorganic connectivity and one-dimensional organic connectivity.
Electroencephalographic (EEG) control of three-dimensional movement
McFarland, Dennis J.; Sarnacki, William A.; Wolpaw, Jonathan R.
2010-06-01
Brain-computer interfaces (BCIs) can use brain signals from the scalp (EEG), the cortical surface (ECoG), or within the cortex to restore movement control to people who are paralyzed. Like muscle-based skills, BCIs' use requires activity-dependent adaptations in the brain that maintain stable relationships between the person's intent and the signals that convey it. This study shows that humans can learn over a series of training sessions to use EEG for three-dimensional control. The responsible EEG features are focused topographically on the scalp and spectrally in specific frequency bands. People acquire simultaneous control of three independent signals (one for each dimension) and reach targets in a virtual three-dimensional space. Such BCI control in humans has not been reported previously. The results suggest that with further development noninvasive EEG-based BCIs might control the complex movements of robotic arms or neuroprostheses.
Single florescent nanodiamond in a three dimensional ABEL trap
Kayci, Metin; Radenovic, Aleksandra
2015-11-01
Three dimensional single particle trapping and manipulation is an outstanding challenge in various fields ranging from basic physics to life sciences. By monitoring the response of a trapped particle to a designed environment one can extract its characteristics. In addition, quantum dynamics of a spatially scanned well-known particle can provide environmental information. Precise tracking and positioning of such a particle in aqueous environment is crucial task for achieving nano-scale resolution. Here we experimentally demonstrate three dimensional ABEL trap operating at high frequency by employing a hybrid approach in particle tracking. The particle location in the transverse plane is detected via a scanning laser beam while the axial position is determined by defocused imaging. The scanning of the trapped particle is accomplished through a nano positioning stage integrated to the trap platform.
Identification of Jiangxi wines by three-dimensional fluorescence fingerprints
Wan, Yiqun; Pan, Fengqin; Shen, Mingyue
2012-10-01
A new assay of identifying wines was developed based on fingerprints of three-dimensional fluorescence spectra, and 30 samples from different manufacturers were analyzed. The techniques of principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to differentiate and evaluate the character parameters of wines' three-dimensional fluorescence spectra. At the same time, the back-propagation network (BPN) was applied to predict the attribution of unknown samples. The results of PCA and HCA showed that there was definite different information among the wine samples from different manufacturers. It was promising that the method could be applied to distinguish wine samples produced by different manufacturers. The proposed method could provide the criterion for the quality control of wines.
Atomic force microscope study of three-dimensional nanostructure sidewalls
Energy Technology Data Exchange (ETDEWEB)
Hussain, Muhammad Mustafa [SEMATECH, 2706 Montopolis Drive, Austin, TX 78741 (United States); Gondran, Carolyn F H [Advanced Technology Development Facility, 2706 Montopolis Drive, Austin, TX 78741 (United States); Michelson, Diane K [International SEMATECH Manufacturing Initiative, 2706 Montopolis Drive, Austin, TX 78741 (United States)
2007-08-22
Next generation planar and non-planar complementary metal oxide semiconductor (CMOS) structures are three-dimensional nanostructures with multi-layer stacks that can contain films thinner than ten atomic layers. The high resolution of transmission electron microscopy (TEM) is typically chosen for studying properties of these stacks such as film thickness, interface and interfacial roughness. However, TEM sample preparation is time-consuming and destructive, and TEM analysis is expensive and can provide problematic results for surface and interface roughness. Therefore, in this paper, we present the use of direct measurements of sidewall surface structures by conventional atomic force microscopy (AFM) as an alternative or complementary method for studying multi-layer film stacks and as the preferred method for studying FinFET sidewall surface roughness. In addition to these semiconductor device applications, this AFM sidewall measurement technique could be used for other three-dimensional nanostructures.
Three-dimensional radiation transfer modeling in a dicotyledon leaf
Govaerts, Yves M.; Jacquemoud, Stéphane; Verstraete, Michel M.; Ustin, Susan L.
1996-11-01
The propagation of light in a typical dicotyledon leaf is investigated with a new Monte Carlo ray-tracing model. The three-dimensional internal cellular structure of the various leaf tissues, including the epidermis, the palisade parenchyma, and the spongy mesophyll, is explicitly described. Cells of different tissues are assigned appropriate morphologies and contain realistic amounts of water and chlorophyll. Each cell constituent is characterized by an index of refraction and an absorption coefficient. The objective of this study is to investigate how the internal three-dimensional structure of the tissues and the optical properties of cell constituents control the reflectance and transmittance of the leaf. Model results compare favorably with laboratory observations. The influence of the roughness of the epidermis on the reflection and absorption of light is investigated, and simulation results confirm that convex cells in the epidermis focus light on the palisade parenchyma and increase the absorption of radiation.
Three Dimensional Iterative Reconstruction Techniques in Positron Tomography.
Sloka, Scott
The acquisition of positron tomographic data in three dimensions is an improvement over the two dimensional acquisition of data because the greater the number of measurements taken of a stochastic process, the more accurately determined the desired parameter may be. This research pursues the goal of three dimensional image reconstruction in Positron Tomography using an iterative approach. This thesis has followed a systematic approach to the exploration of a system for three dimensional iterative reconstruction. System design parameters were discussed such as the advantages and disadvantages of iterative vs analytic methods, the implementation of two, three dimensional iterative algorithms, the selection of a ray passing method, and the choice of an analytic method for comparison to the iterative methods. Several qualitative and quantitative tests were used/developed and performed to analyse and compare the results. Three dimensional reconstruction in Positron Tomography using two iterative techniques (ART and ML-EM) was demonstrated. The ML-EM algorithm was adapted to satisfy the objective of equalizing the estimates with the measurements via division of the sampling density. A new multi-objective function methodology was developed for two dimensions and its extension to three dimensions discussed. A smoothly-varying Gaussian phantom was created for comparing artifacts from different ray passing methods. The analysis of voxel trends over many iterations was used. The use of the output from a two dimensional filtered backprojection algorithm as the seed for three dimensional algorithms to accelerate the reconstruction the was explored. The importance of the selection of a good ray ordering in ART and its effects on the total squared error were explored. For the phantoms studied in this thesis, the ML -EM algorithm tended to perform better under most conditions. This algorithm is slower than ART to achieve both a low total squared error and good contrast, but the
Artificial three-dimensional niches deconstruct pancreas development in vitro.
Greggio, Chiara; De Franceschi, Filippo; Figueiredo-Larsen, Manuel; Gobaa, Samy; Ranga, Adrian; Semb, Henrik; Lutolf, Matthias; Grapin-Botton, Anne
2013-11-01
In the context of a cellular therapy for diabetes, methods for pancreatic progenitor expansion and subsequent differentiation into insulin-producing beta cells would be extremely valuable. Here we establish three-dimensional culture conditions in Matrigel that enable the efficient expansion of dissociated mouse embryonic pancreatic progenitors. By manipulating the medium composition we generate either hollow spheres, which are mainly composed of pancreatic progenitors, or complex organoids that spontaneously undergo pancreatic morphogenesis and differentiation. The in vitro maintenance and expansion of pancreatic progenitors require active Notch and FGF signaling, thus recapitulating in vivo niche signaling interactions. Our experiments reveal new aspects of pancreas development, such as a community effect by which small groups of cells better maintain progenitor properties and expand more efficiently than isolated cells, as well as the requirement for three-dimensionality. Finally, growth conditions in chemically defined biomaterials pave the way for testing the biophysical and biochemical properties of the niche that sustains pancreatic progenitors.
Three-Dimensional All-Dielectric Photonic Topological Insulator
Slobozhanyuk, Alexey; Ni, Xiang; Smirnova, Daria; Kivshar, Yuri S; Khanikaev, Alexander B
2016-01-01
The discovery of two-dimensional topological photonic systems has transformed our views on electromagnetic propagation and scattering of classical waves, and a quest for similar states in three dimensions, known to exist in condensed matter systems, has been put forward. Here we demonstrate that symmetry protected three-dimensional topological states can be engineered in an all-dielectric platform with the electromagnetic duality between electric and magnetic fields ensured by the structure design. Magneto-electric coupling playing the role of a synthetic gauge field leads to a topological transition to an insulating regime with a complete three-dimensional photonic bandgap. An emergence of surface states with conical Dirac dispersion and spin-locking is unimpeded. Robust propagation of surface states along two-dimensional domain walls defined by the reversal of magneto-electric coupling is confirmed numerically by first principle studies. It is shown that the proposed system represents a table-top platform f...
Time multiplexed pinhole array based lensless three-dimensional imager
Schwarz, Ariel; Wang, Jingang; Shemer, Amir; Zalevsky, Zeev; Javidi, Bahram
2016-06-01
We present an overview of multi variable coded aperture (MVCA) for lensless three-dimensional integral imaging (3D II) systems. The new configuration is based on a time multiplexing method using a variable pinholes array design. The system provides higher resolution 3D images with improved light intensity and signal to noise ratio as compared to single pinhole system. The MVCA 3D II system configuration can be designed to achieve high light intensity for practical use as micro lenslets arrays. This new configuration preserves the advantages of pinhole optics while solving the resolution limitation problem and the long exposure time of such systems. The three dimensional images are obtained with improved resolution, signal to noise ratio and sensitivity efficiency. This integral imaging lensless system is characterized by large depth of focus, simplicity and low cost. In this paper we present numerical simulations as well as experimental results that validate the proposed lensless imaging configuration.
Three-dimensional mapping of single-atom magnetic anisotropy.
Yan, Shichao; Choi, Deung-Jang; Burgess, Jacob A J; Rolf-Pissarczyk, Steffen; Loth, Sebastian
2015-03-11
Magnetic anisotropy plays a key role in the magnetic stability and spin-related quantum phenomena of surface adatoms. It manifests as angular variations of the atom's magnetic properties. We measure the spin excitations of individual Fe atoms on a copper nitride surface with inelastic electron tunneling spectroscopy. Using a three-axis vector magnet we rotate the magnetic field and map out the resulting variations of the spin excitations. We quantitatively determine the three-dimensional distribution of the magnetic anisotropy of single Fe atoms by fitting the spin excitation spectra with a spin Hamiltonian. This experiment demonstrates the feasibility of fully mapping the vector magnetic properties of individual spins and characterizing complex three-dimensional magnetic systems.
Three-Dimensional Structure of Solar Wind Turbulence
Chen, C H K; Schekochihin, A A; Horbury, T S; Wicks, R T; Bale, S D
2011-01-01
We have measured, for the first time, the three-dimensional structure of inertial range plasma turbulence in the fast solar wind with respect to a local, physically motivated coordinate system. We found that the incompressible Alfvenic fluctuations are three-dimensionally anisotropic, with the sense of this anisotropy changing from large to small scales. At the largest scales, the magnetic field correlations are longest in the local fluctuation direction, consistent with Alfven waves. At the smallest scales, they are longest along the local mean field direction and shortest in the direction perpendicular to the local mean field and the local field fluctuation. The compressive fluctuations are highly elongated along the local mean magnetic field direction, although axially symmetric perpendicular to it. Their large anisotropy may explain why they are not heavily damped.
All-optical three-dimensional electron pulse compression
Wong, Liang Jie; Rohwer, Timm; Gedik, Nuh; Johnson, Steven G
2014-01-01
We propose an all-optical, three-dimensional electron pulse compression scheme in which Hermite-Gaussian optical modes are used to fashion a three-dimensional optical trap in the electron pulse's rest frame. We show that the correct choices of optical incidence angles are necessary for optimal compression. We obtain analytical expressions for the net impulse imparted by Hermite-Gaussian free-space modes of arbitrary order. Although we focus on electrons, our theory applies to any charged particle and any particle with non-zero polarizability in the Rayleigh regime. We verify our theory numerically using exact solutions to Maxwell's equations for first-order Hermite-Gaussian beams, demonstrating single-electron pulse compression factors of $>10^{2}$ in both longitudinal and transverse dimensions with experimentally realizable optical pulses. The proposed scheme is useful in ultrafast electron imaging for both single- and multi-electron pulse compression, and as a means of circumventing temporal distortions in ...
Three Dimensional Energy Transmitting Boundary in the Time Domain
Directory of Open Access Journals (Sweden)
Naohiro eNakamura
2015-11-01
Full Text Available Although the energy transmitting boundary is accurate and efficient for the FEM earthquake response analysis, it could be applied in the frequency domain only. In the previous papers, the author proposed an earthquake response analysis method using the time domain energy transmitting boundary for two dimensional problems. In this paper, this technique is expanded for three dimensional problems. The inner field is supposed to be a hexahedron shape and the approximate time domain boundary is explained, first. Next, two dimensional anti-plane time domain boundary is studied for a part of the approximate three dimensional boundary method. Then, accuracy and efficiency of the proposed method are confirmed by example problems.
Three-dimensional P velocity structure in Beijing area
Institute of Scientific and Technical Information of China (English)
于湘伟; 陈运泰; 王培德
2003-01-01
A detail three-dimensional P wave velocity structure of Beijing, Tianjin and Tangshan area (BTT area) was determined by inverting local earthquake data. In total 16 048 P wave first arrival times from 16048 shallow and mid-depth crustal earthquakes, which occurred in and around the BTT area from 1992 to 1999 were used. The first arrival times are recorded by Northern China United Telemetry Seismic Network and Yanqing-Huailai Digital Seismic Network. Hypocentral parameters of 1 132 earthquakes with magnitude ML=1.7~6.2 and the three-dimensional P wave velocity structure were obtained simultaneously. The inversion result reveals the complicated lateral heterogeneity of P wave velocity structure around BTT area. The tomographic images obtained are also found to explain other seismological observations well.
Three-dimensional natural convection in a narrow spherical shell
Liu, Ming; Egbers, Christoph
The convective motions in a shallow fluid layer between two concentric spheres in the presence of a constant axial force field have been studied numerically. The aspect ratio of the fluid layer to inner radius is beta =0.08, the Prandtl number Pra =37.5. A three-dimensional time-dependent numerical code is used to solve the governing equations in primitive variables. Convection in the sphe rical shell has then a highly three-dimensional nature. Characteristic flow patterns with a large number of banana-type cells, oriented in north-south direction and aligned in the azimuthal direction, are formed on the northern hemisphere, which grow gradually into the equatorial region accompanied by the generation of new cells as the Rayleigh number is increased. Various characteristics of these flows as well as their transient evolution are investigated for Rayleigh numbers up to 20 000.
Three-dimensional potential energy surface of Ar–CO
Energy Technology Data Exchange (ETDEWEB)
Sumiyoshi, Yoshihiro, E-mail: y-sumiyoshi@gunma-u.ac.jp [Division of Pure and Applied Science, Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510 (Japan); Endo, Yasuki [Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)
2015-01-14
A three-dimensional intermolecular potential energy surface of the Ar–CO complex has been determined by fitting most of the previously reported spectroscopic data, where observed transition frequencies by microwave, millimeter-wave, submillimeter-wave, and infrared spectroscopy were reproduced simultaneously within their experimental accuracies. A free rotor model Hamiltonian considering all the freedom of motions for an atom-diatom system was applied to calculate vibration-rotation energies. A three-dimensional potential energy surface obtained by ab initio calculations at the CCSD(T)-F12b/aug-cc-pV5Z level of theory was parameterized by a model function consisting of 46 parameters. They were used as initial values for the least-squares analysis of the experimental data. A total of 20 parameters were optimized to reproduce all the spectroscopic data.
Three Dimensional Numerical Relativity with a Hyperbolic Formulation
Bona, C; Seidel, E; Walker, P; Bona, Carles; Masso, Joan; Seidel, Edward; Walker, Paul
1998-01-01
We discuss a successful three-dimensional cartesian implementation of the Bona-Massó hyperbolic formulation of the 3+1 Einstein evolution equations in numerical relativity. The numerical code, which we call ``Cactus,'' provides a general framework for 3D numerical relativity, and can include various formulations of the evolution equations, initial data sets, and analysis modules. We show important code tests, including dynamically sliced flat space, wave spacetimes, and black hole spacetimes. We discuss the numerical convergence of each spacetime, and also compare results with previously tested codes based on other formalisms, including the traditional ADM formalism. This is the first time that a hyperbolic reformulation of Einstein's equations has been shown appropriate for three-dimensional numerical relativity in a wide variety of spacetimes.
Three-Dimensional Reconstruction of Erythrocyte in the Capillary
Fan, Yifang; Li, Zhiyu; Lin, Wentao; Wei, Yuan; Zhong, Xing; Newman, Tony; Lv, Changsheng; Fan, Yuzhou
2013-01-01
The dynamic analysis of erythrocyte deformability is used as an important means for early diagnosis of blood diseases and blood rheology. Yet no effective method is available in terms of three-dimensional reconstruction of erythrocytes in a capillary. In this study, ultrathin serial sections of skeletal muscle tissue are obtained from the ultramicrotome, the tomographic images of an erythrocyte in a capillary are captured by the transmission electron microscope, and then a method to position and restore is devised to demonstrate the physiological relationship between two adjacent tomographic images of an erythrocyte. Both the modeling and the physical verification reveal that this method is effective, which means that it can be used to make three-dimensional reconstruction of an erythrocyte in a capillary. An example of reconstructed deformation of erythrocyte based on the serial ultrathin sections is shown at the end of this paper.
Three-dimensional surface reconstruction from multistatic SAR images.
Rigling, Brian D; Moses, Randolph L
2005-08-01
This paper discusses reconstruction of three-dimensional surfaces from multiple bistatic synthetic aperture radar (SAR) images. Techniques for surface reconstruction from multiple monostatic SAR images already exist, including interferometric processing and stereo SAR. We generalize these methods to obtain algorithms for bistatic interferometric SAR and bistatic stereo SAR. We also propose a framework for predicting the performance of our multistatic stereo SAR algorithm, and, from this framework, we suggest a metric for use in planning strategic deployment of multistatic assets.
Electric transport in three-dimensional Skyrmion/monopole crystal
Zhang, Xiao-Xiao; Mishchenko, Andrey S.; De Filippis, Giulio; Nagaosa, Naoto
2016-01-01
We study theoretically the transport properties of a three-dimensional spin texture made from three orthogonal helices, which is essentially a lattice of monopole-antimonopole pairs connected by Skyrmion strings. This spin structure is proposed for MnGe based on the neutron scattering experiment as well as the Lorentz transmission electron microscopy observation. Equipped with a sophisticated spectral analysis method, we adopt finite temperature Green's function technique to calculate the lon...
Development of three-dimensional memory (3D-M)
Yu, Hong-Yu; Shen, Chen; Jiang, Lingli; Dong, Bin; Zhang, Guobiao
2016-10-01
Since the invention of 3-D ROM in 1996, three-dimensional memory (3D-M) has been under development for nearly two decades. In this presentation, we'll review the 3D-M history and compare different 3D-Ms (including 3D-OTP from Matrix Semiconductor, 3D-NAND from Samsung and 3D-XPoint from Intel/Micron).
Three dimensional momentum distributions of recoil-ions and photoelectrons
Energy Technology Data Exchange (ETDEWEB)
Ullrich, J.; Schmitt, W. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Doerner, R.; Jagutzki, O.; Mergel, V.; Moshammer, R.; Schmidt-Boecking, H.; Spielberger, L.; Unverzagt, M.; Vogt, T. [Frankfurt Univ. (Germany). Inst. fuer Kernphysik
1996-10-01
A novel high-resolution technique, the Multi-Electron-Recoil-Ion Momentum Spectroscopy, allows to determine in coincidence the three dimensional momentum vectors of the ion and up to three electrons created in any photo ionization event. At a solid angle of 4 {pi} the energy-resolutions for ions and electrons are {+-}2{mu} eV and {+-}10 meV, respectively. (orig.)
Three-dimensional conceptual model for service-oriented simulation
Wang, Wenguang; Zander, Justyna; Zhu, Yifan; 10.1631/jzus.A0920258
2009-01-01
In this letter, we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks. In particular, the model inspects the crossover between the disciplines of modeling and simulation, service-orientation, and software/systems engineering. Finally, two specific simulation frameworks are studied as examples.
Three-Dimensional Simulations of Deep-Water Breaking Waves
Brucker, Kyle A; Dommermuth, Douglas G; Adams, Paul
2014-01-01
The formulation of a canonical deep-water breaking wave problem is introduced, and the results of a set of three-dimensional numerical simulations for deep-water breaking waves are presented. In this paper fully nonlinear progressive waves are generated by applying a normal stress to the free surface. Precise control of the forcing allows for a systematic study of four types of deep-water breaking waves, characterized herein as weak plunging, plunging, strong plunging, and very strong plunging.
A practical three-dimensional dosimetry system for radiation therapy
Guo, Pengyi; Adamovics, John; Oldham, Mark
2006-01-01
There is a pressing need for a practical three-dimensional (3D) dosimetry system, convenient for clinical use, and with the accuracy and resolution to enable comprehensive verification of the complex dose distributions typical of modern radiation therapy. Here we introduce a dosimetry system that can achieve this challenge, consisting of a radiochromic dosimeter (PRESAGE™) and a commercial optical computed tomography (CT) scanning system (OCTOPUS™). PRESAGE™ is a transparent material with com...
Reentrance and ultrametricity in three-dimensional Ising spin glasses
Katzgraber, Helmut G.; Thomas, Creighton K.; Hartmann, Alexander K.
2012-02-01
We study the three-dimensional Edwards-Anderson Ising spin glass with bimodal disorder with a fraction of 22.8% antiferromagnetic bonds. Parallel tempering Monte Carlo simulations down to very low temperatures show that for this fraction of antiferromagnetic bonds the phase diagram of the system is reentrant, in agreement with previous results. Furthemore, using a clustering analysis, we analyze the ultrametric properties of phase space for this model.
Three-dimensional nonparaxial beams in parabolic rotational coordinates.
Deng, Dongmei; Gao, Yuanmei; Zhao, Juanying; Zhang, Peng; Chen, Zhigang
2013-10-01
We introduce a class of three-dimensional nonparaxial optical beams found in a parabolic rotational coordinate system. These beams, representing exact solutions of the nonparaxial Helmholtz equation, have inherent parabolic symmetries. Assisted with a computer-generated holography, we experimentally demonstrate the generation of different modes of these beams. The observed transverse beam patterns along the propagation direction agree well with those from our theoretical predication.
Absence of bilinear condensate in three-dimensional QED
Karthik, Nikhil
2016-01-01
There are plausibility arguments that QED in three dimensions has a critical number of flavors of massless two-component fermions, below which scale invariance is broken by the presence of bilinear condensate. We present numerical evidences from our lattice simulations using dynamical overlap as well as Wilson-Dirac fermions for the absence of bilinear condensate for any even number of flavors of two-component fermions. Instead, we find evidences for the scale-invariant nature of three-dimensional QED.
Powder blasting for three-dimensional microstructuring of glass
Belloy, E.; Sayah, A.; M.A.M. Gijs
2000-01-01
We report on powder blasting as a promising technology for the three-dimensional structuring of brittle materials. We investigate the basic parameters of this process, which is based on the erosion of a masked substrate by a high-velocity eroding powder beam, using glass substrates. We study the effect of various parameters on the etching rate, like the powder velocity and the mask feature size, which induces geometrical effects to the erosion process. We introduce oblique powder blasting and...
Three-dimensional magnetic reconnection through a moving magnetic null
Lukin, V. S.; Linton, M. G.
2011-01-01
A computational study of three-dimensional magnetic reconnection between two flux ropes through a moving reconnection site is presented. The configuration is considered in the context of two interacting spheromaks constrained by a perfectly conducting cylindrical boundary and oriented to form a single magnetic field null at its center. The initial magnetic field configuration is embedded into a uniform thermal plasma and is unstable to tilting. As the sphe...
Three-dimensional magnetic reconnection through a moving magnetic null
Lukin, V. S.; Linton, M. G.
2011-01-01
A computational study of three-dimensional magnetic reconnection between two flux ropes through a moving reconnection site is presented. The configuration is considered in the context of two interacting spheromaks constrained by a perfectly conducting cylindrical boundary and oriented to form a single magnetic field null at its center. The initial magnetic field configuration is embedded into a uniform thermal plasma and is unstable to tilting. As the spheromaks tilt, their magnetic fi...
Strategy for automatic and complete three-dimensional optical digitization
2012-01-01
This Letter proposes a new strategy of a three-dimensional (3D) scanning pipeline to achieve complete 3D digitization of complex objects in a real scene. This strategy consists of a one-dimensional array of optical 3D sensors combined with an automatically controlled turntable. An efficient calibration method for the sensor array is presented to guarantee the accuracy of the 3D measurement. Furthermore, an automatic registration technique is also proposed for aligning multiple range images ta...
THE SYSTEM SIMULATION OF THREE-DIMENSIONAL RADAR
Institute of Scientific and Technical Information of China (English)
Zhang Wei; Xiang Jingcheng; Wang Xuegang
2004-01-01
To provide a test platform for Electronic Warfare (EW) system, it is needed to simulate the radar received Intermediate Frequency (IF) signals and radar system functions.This letter gives a description of a radar system simulation software developed for frequencyphase scanning three-dimensional (3-D) radar. Experimental results prove that the software could be used for system evaluation and for training purposes as an attractive alternative to real EW system.
IF signals simulation of three-dimensional radar
Institute of Scientific and Technical Information of China (English)
Zhang Wei; Wang Xuegang; Zhu Zhaoda
2008-01-01
Based on the analysis of the principles of frequency-phase scanning 3-D (three-dimensional) radar and the scattering mechanism of 3-D radar, the target and clutter IF (intermediate frequency) signals model of frequencyphase scanning 3-D radar is presented. The IF signals model of different channels of 3-D radar is presented in one simple formula in which complex waveform effects are considered. The simulation results obtained during tests are also provided in the end.
Sectional and Ricci Curvature for Three-Dimensional Lie Groups
Directory of Open Access Journals (Sweden)
Gerard Thompson
2016-01-01
Full Text Available Formulas for the Riemann and Ricci curvature tensors of an invariant metric on a Lie group are determined. The results are applied to a systematic study of the curvature properties of invariant metrics on three-dimensional Lie groups. In each case the metric is reduced by using the automorphism group of the associated Lie algebra. In particular, the maximum and minimum values of the sectional curvature function are determined.
Entropy of three-dimensional BTZ black holes
Institute of Scientific and Technical Information of China (English)
GAO; Changjun; SHEN; Yougen
2004-01-01
The entropies of scalar field and neutrino field are calculated in the back ground of three-dimensional BTZ black hole.Considering statistical physics,we propose not to consider the superraradiant modes for bosons(Fermion fields do not displaysup perradiance).In fact,the nonsuperradiant modes do contribute exactly the area entropy for both bosons and fermions.The result shows that the neutrino field entropy is 3/2 times the scalar one.
Three-dimensional echocardiographic assessment of atrial septal defects
Directory of Open Access Journals (Sweden)
Charles German
2015-01-01
Full Text Available Echocardiography provides a useful tool in the diagnosis of many congenital heart diseases, including atrial septal defects, and aids in further delineating treatment options. Although two-dimensional echocardiography has been the standard of care in this regard, technological advancements have made three-dimensional echocardiography possible, and the images obtained in this new imaging modality are able to accurately portray the morphology, location, dimensions, and dynamic changes of defects and many other heart structures during the cardiac cycle.
Universally applicable three-dimensional hydrodynamic microfluidic flow focusing
Chiu, Yu-Jui; Cho, Sung Hwan; Mei, Zhe; Lien, Victor; Wu, Tsung-Feng; Lo, Yu-Hwa
2013-01-01
We have demonstrated a microfluidic device that can not only achieve three-dimensional flow focusing but also confine particles to the center stream along the channel. The device has a sample channel of smaller height and two sheath flow channels of greater height, merged into the downstream main channel where 3D focusing effects occur. We have demonstrated that both beads and cells in our device display significantly lower CVs in velocity and position distributions as well as reduced probabi...
Environmental, Transient, Three-Dimensional, Hydrothermal, Mass Transport Code - FLESCOT
Energy Technology Data Exchange (ETDEWEB)
Onishi, Yasuo [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bao, Jie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glass, Kevin A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Eyler, L. L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Okumura, Masahiko [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2015-03-28
The purpose of the project was to modify and apply the transient, three-dimensional FLESCOT code to be able to effectively simulate cesium behavior in Fukushima lakes/dam reservoirs, river mouths, and coastal areas. The ultimate objective of the FLESCOT simulation is to predict future changes of cesium accumulation in Fukushima area reservoirs and costal water. These evaluation results will assist ongoing and future environmental remediation activities and policies in a systematic and comprehensive manner.
A new three-dimensional general-relativistic hydrodynamics code
Baiotti, L.; Hawke, I.; Montero, P. J.; Rezzolla, L.
We present a new three-dimensional general relativistic hydrodynamics code, the Whisky code. This code incorporates the expertise developed over the past years in the numerical solution of Einstein equations and of the hydrodynamics equations in a curved spacetime, and is the result of a collaboration of several European Institutes. We here discuss the ability of the code to carry out long-term accurate evolutions of the linear and nonlinear dynamics of isolated relativistic stars.
A new three-dimensional general-relativistic hydrodynamics code
Baiotti, Luca; Montero, Pedro J; Rezzolla, Luciano
2010-01-01
We present a new three-dimensional general relativistic hydrodynamics code, the Whisky code. This code incorporates the expertise developed over the past years in the numerical solution of Einstein equations and of the hydrodynamics equations in a curved spacetime, and is the result of a collaboration of several European Institutes. We here discuss the ability of the code to carry out long-term accurate evolutions of the linear and nonlinear dynamics of isolated relativistic stars.
Three-dimensional conceptual model for service-oriented simulation
Institute of Scientific and Technical Information of China (English)
Wen-guang WANG; Wei-ping WANG; Justyna ZANDER; Yi-fan ZHU
2009-01-01
In this letter, we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks, In particular, the model inspects the crossover between the disciplines of modeling and simulation,service-orientation, and software/systems engineering. Finally, two specific simulation frameworks are studied as examples.
Three-dimensional vortex structures under breaking waves
WATANABE Yasunori; Saeki, Hiroshi; Hosking, Roger J.
2005-01-01
The large-scale vortex structures under spilling and plunging breakers are investigated, using a fully three-dimensional large-eddy simulation (LES). When an overturning jet projecting from the crest in a breaking wave rebounds from the water surface ahead, the vorticity becomes unstable in a saddle region of strain between the rebounding jet and a primary spanwise vortex, resulting in spanwise undulations of the vorticity. The undulations are amplified on a braid in this saddle region, leadi...
APPLICATIONS OF FRACTIONAL EXTERIOR DIFFERENTIAL IN THREE-DIMENSIONAL SPACE
Institute of Scientific and Technical Information of China (English)
陈勇; 闫振亚; 张鸿庆
2003-01-01
A brief survey of fractional calculus and fractional differential forms was firstly given. The fractional exterior transition to curvilinear coordinate at the origin were discussed and the two coordinate transformations for the fractional differentials for three-dimensional Cartesian coordinates to spherical and cylindrical coordinates are obtained, respectively. In particular, for v = m = 1 , the usual exterior transformations, between the spherical coordinate and Cartesian coordinate, as well as the cylindrical coordinate and Cartesian coordinate, are found respectively, from fractional exterior transformation.
MRFD Method for Scattering From Three Dimensional Dielectric Bodies
Directory of Open Access Journals (Sweden)
A. F. Yagli
2011-09-01
Full Text Available A three-dimensional multiresolution frequency domain (MRFD method is established to compute bistatic radar cross sections of arbitrarily shaped dielectric objects. The proposed formulation is successfully verified by computing the bistatic radar cross sections of a dielectric sphere and a dielectric cube. Comparing the results to those obtained from the finite difference frequency domain (FDFD method simulations and analytic calculations, we demonstrated the computational time and memory advantages of MRFD method.
Three-Dimensional DNA Nanostructures Assembled from DNA Star Motifs.
Tian, Cheng; Zhang, Chuan
2017-01-01
Tile-based DNA self-assembly is a promising method in DNA nanotechnology and has produced a wide range of nanostructures by using a small set of unique DNA strands. DNA star motif, as one of DNA tiles, has been employed to assemble varieties of symmetric one-, two-, three-dimensional (1, 2, 3D) DNA nanostructures. Herein, we describe the design principles, assembly methods, and characterization methods of 3D DNA nanostructures assembled from the DNA star motifs.
On a three-dimensional implementation of the baker's transformation
Carrière, Philippe
2007-11-01
A three-dimensional, steady flow configuration intended to mimic the baker's map is studied by means of numerical simulation. The Poincaré sections computed from a finite element solution of the velocity field show that the behavior is dominated by chaotic advection. The value obtained for the Lyapunov exponent is very close to the theoretical value of ln2 predicted by the baker's map.
Three dimensional modelling of ICRF launchers for fusion devices
Carter, M. D.; Rasmussen, D. A.; Ryan, P. M.; Hanson, G. R.; Stallings, D. C.; Batchelor, D. B.; Bigelow, T. S.; England, A. C.; Hoffman, D. J.; Murakami, M.; Wang, C. Y.; Wilgen, J. B.; Rogers, J. H.; Wilson, J. R.; Majeski, R.; Schilling, G.
1996-02-01
The three dimensional (3-D) nature of antennas for fusion applications in the ion cyclotron range of frequencies (ICRF) requires accurate modelling to design and analyse new antennas. In this article, analysis and design tools for radiofrequency (RF) antennas are successfully benchmarked with experiment, and the 3-D physics of the launched waves is explored. The systematic analysis combines measured density profiles from a reflectometer system, transmission line circuit modelling, detailed 3-D magnetostatics modelling and a new 3-D electromagnetic antenna model including plasma. This analysis gives very good agreement with measured loading data from the Tokamak Fusion Test Reactor (TFTR) Bay-M antenna, thus demonstrating the validity of the analysis for the design of new RF antennas. The 3-D modelling is contrasted with 2-D models, and significant deficiencies are found in the latter. The 2-D models are in error by as much as a factor of 2 in real and reactive loading, even after they are corrected for the most obvious 3-D effects. Three dimensional effects play the most significant role at low parallel wavenumbers, where the launched power spectrum can be quite different from the predictions of 2-D models. Three dimensional effects should not be ignored for many RF designs, especially those intended for fast wave current drive
Formation of three-dimensional Parylene C structures via thermoforming
Kim, B. J.; Chen, B.; Gupta, M.; Meng, E.
2014-06-01
The thermoplastic nature of Parylene C is leveraged to enable the formation of three-dimensional structures using a thermal forming (thermoforming) technique. Thermoforming involves the heating of Parylene films above its glass transition temperature while they are physically confined in the final desired conformation. Micro and macro scale three-dimensional structures composed of Parylene thin films were developed using the thermoforming process, and the resulting chemical and mechanical changes to the films were characterized. No large changes to the surface and bulk chemistries of the polymer were observed following the thermoforming process conducted in vacuum. Heat treated structures exhibited increased stiffness by a maximum of 37% depending on the treatment temperature, due to an increase in crystallinity of the Parylene polymer. This study revealed important property changes resulting from the process, namely (1) the development of high strains in thermoformed areas of small radii of curvature (30-90 µm) and (2) ˜1.5% bulk material shrinkage in thermoformed multilayered Parylene-Parylene and Parylene-metal-Parylene films. Thermoforming is a simple process whereby three-dimensional structures can be achieved from Parylene C-based thin film structures with tunable mechanical properties as a function of treatment temperature.
Interaction of two three-dimensional explosion bubbles
Institute of Scientific and Technical Information of China (English)
YAO Xiong-liang; ZHANG A-man; LIU Yu-chen
2007-01-01
The interaction of two underwater explosion bubbles was mathematically analyzed in this paper. Based on the assumption of potential flow, high-order curved elements were used to discretize the boundary integral equation and solve it. Assuming that gas inside the bubble follows the isentropic rule,the Euler-Lagrange method was used to trace the evolution of the bubble, and when calculating the singular integral, the singularity of the double-layer singular integral was eliminated by reconstructing a principal-value integral of double-layer potential so that a more precise result could be obtained. Elastic mesh technique (EMT) was also used when tracing the evolution of the bubble interface, and numerical smoothing wasn't needed. A comparison of calculations using this three-dimensional model with results of the Reyleigh-Plesset bubble model shows that the three-dimensional model and calculation method in this paper is practical. This three-dimensional model was applied to simulate the interaction of two bubbles under the action of gravity, and the dynamic characteristics of two bubbles near the surface was also analyzed. Bubbles influenced by surface effects and gravity present severe non-linearity. This paper provides a reference for research into the dynamics of multi-bubbles.
Three dimensional self-assembly at the nanoscale
Gracias, D. H.
2013-05-01
At the nanoscale, three dimensional manipulation and assembly becomes extremely challenging and also cost prohibitive. Self-assembly provides an attractive and possibly the only highly parallel methodology to structure truly three dimensional patterned materials and devices at this size scale for applications in electronics, optics, robotics and medicine. This is a concise review along with a perspective of an important and exciting field in nanotechnology and is related to a Nanoengineering Pioneer Award that I received at this SPIE symposium for my contributions to the 3D selfassembly of nanostructures. I detail a historical account of 3D self-assembly and outline important developments in this area which is put into context with the larger research areas of 3D nanofabrication, assembly and nanomanufacturing. A focus in this review is on our work as it relates to the self-assembly with lithographically patterned units; this approach provides a means for heterogeneous integration of periodic, curved and angled nanostructures with precisely defined three dimensional patterns.
Three-dimensional magnetic recording using ferromagnetic resonance
Suto, Hirofumi; Kudo, Kiwamu; Nagasawa, Tazumi; Kanao, Taro; Mizushima, Koichi; Sato, Rie
2016-07-01
To meet the ever-increasing demand for data storage, future magnetic recording devices will need to be made three-dimensional by implementing multilayer recording. In this article, we present methods of detecting and manipulating the magnetization direction of a specific layer selectively in a vertically stacked multilayer magnetic system, which enable layer-selective read and write operations in three-dimensional magnetic recording devices. The principle behind the methods is ferromagnetic resonance excitation in a microwave magnetic field. By designing each magnetic recording layer to have a different ferromagnetic resonance frequency, magnetization excitation can be induced individually in each layer by tuning the frequency of an applied microwave magnetic field, and this selective magnetization excitation can be utilized for the layer-selective operations. Regarding media for three-dimensional recording, when layers of a perpendicular magnetic material are vertically stacked, dipolar interaction between multiple recording layers arises and is expected to cause problems, such as degradation of thermal stability and switching field distribution. To solve these problems, we propose the use of an antiferromagnetically coupled structure consisting of hard and soft magnetic layers. Because the stray fields from these two layers cancel each other, antiferromagnetically coupled media can reduce the dipolar interaction.
Three-dimensional robust diving guidance for hypersonic vehicle
Zhu, Jianwen; Liu, Luhua; Tang, Guojian; Bao, Weimin
2016-01-01
A novel three-dimensional robust guidance law based on H∞ filter and H∞ control is proposed to meet the constraints of the impact accuracy and the flight direction under process disturbances for the dive phase of hypersonic vehicle. Complete three-dimensional coupling relative motion equations are established and decoupled into linear ones by feedback linearization to simplify the design process of the further guidance law. Based on the linearized equations, H∞ filter is introduced to eliminate the measurement noises of line-of-sight angles and estimate the angular rates. Furthermore, H∞ robust control is well employed to design guidance law, and the filtered information is used to generate guidance commands to meet the guidance goal accurately and robustly. The simulation results of CAV-H indicate that the proposed three-dimensional equations can describe the coupling character more clearly than the traditional decoupling guidance, and the proposed guidance strategy can guide the vehicle to satisfy different multiple constraints with high accuracy and robustness.
Three-dimensional illumination system for tomographic particle image velocimetry
Zhang, Fen; Song, Yang; Qu, Xiangju; Ji, Yunjing; Li, Zhenhua; He, Anzhi
2016-10-01
Tomographic particle image velocimetry (Tomo-PIV) is a new developed technique for three-component threedimensional (3C-3D) velocity measurement of the flow field based on the optical tomographic reconstruction method, and has been received extensive attention of the related industries. Three-dimensional light source illuminating the tracer particles of flow field is a critical application for tomographic particle image velocimetry. Three-dimensional light source not only determines the size of measurement volume and the range of the scope of application, but also has a great influence on the image quality. In this work, we propose a rectangular light amplification system using powell lens, prisms and two reflectors. The system can be optimized if given the system parameters based on the theoretical model. The rectangular light amplification system will be verified experimentally by measuring the cross section size of the illuminated light source. A 60mm×25mm cross section of rectangular three-dimensional light source can be obtained by using the rectangular light amplification system. The experiments demonstrate the the feasibility the proposed system.
Three-dimensional appearance of the lips muscles with three-dimensional isotropic MRI: in vivo study
Energy Technology Data Exchange (ETDEWEB)
Olszewski, Raphael; Reychler, H. [Universite Catholique de Louvain, Department of Oral and Maxillofacial Surgery, Cliniques Universitaires Saint Luc, Brussels (Belgium); Liu, Y.; Xu, T.M. [Peking University School and Hospital of Stomatology, Department of Orthodontics, Beijing (China); Duprez, T. [Universite Catholique de Louvain, Department of Radiology, Cliniques Universitaires Saint Luc, Brussels (Belgium)
2009-06-15
Our knowledge of facial muscles is based primarily on atlases and cadaveric studies. This study describes a non-invasive in vivo method (3D MRI) for segmenting and reconstructing facial muscles in a three-dimensional fashion. Three-dimensional (3D), T1-weighted, 3 Tesla, isotropic MRI was applied to a subject. One observer performed semi-automatic segmentation using the Editor module from the 3D Slicer software (Harvard Medical School, Boston, MA, USA), version 3.2. We were able to successfully outline and three-dimensionally reconstruct the following facial muscles: pars labialis orbicularis oris, m. levatro labii superioris alaeque nasi, m. levator labii superioris, m. zygomaticus major and minor, m. depressor anguli oris, m. depressor labii inferioris, m. mentalis, m. buccinator, and m. orbicularis oculi. 3D reconstruction of the lip muscles should be taken into consideration in order to improve the accuracy and individualization of existing 3D facial soft tissue models. More studies are needed to further develop efficient methods for segmentation in this field. (orig.)
Three-dimensional stochastic seepage field for embankment engineering
Institute of Scientific and Technical Information of China (English)
Ya-jun WANG; Wo-hua ZHANG; Chang-yu WU; Da-chun REN
2009-01-01
Owing to the complexity of get-engineering seepage problems influenced by different random factors, three-dimensional simulation and analysis of the stochastic seepage field plays an important role in engineering applications. A three-dimensional anisotropic heterogeneous steady random seepage model was developed on the basis of the finite element method. A statistical analysis of the distribution characteristics of soil parameters sampled from the main embankment of the Yangtze River in the Southern Jingzhou zone of China was conducted. The Kolomogorov-Smimov test verified the statistical hypothesis that the permeability coefficient tensor has a Gaussian distribution. With the help of numerical analysis of the stochastic seepage field using the developed model, various statistical and random characteristics of the stochastic seepage field of the main embankment of the Yangtze River in the Southern Jingzhou zone of China were investigated. The model was also examined with statistical testing. Through the introduction of random variation of the upstream and downstream water levels into the model, the effects of the boundary randomness due to variation of the downstream and upstream water levels on the variation of simulated results presented with a vector series of the random seepage field were analyzed. Furthermore, the combined influence of the variation of the soil permeability coefficient and such seepage resistance measures as the cut-off wall and relief ditch on the hydraulic head distribution was analyzed and compared with the results obtained by determinate analysis. Meanwhile, sensitivities of the hydraulic gradient and downstream exit height to the variation of boundary water level were studied. The validity of the simulated results was verified by stochastic testing and measured data. The developed model provides more detail and a full stochastic algorithm to characterize and analyze three-dimensional stochastic seepage field problems.
Three-dimensional numerical modeling of nearshore circulation
Institute of Scientific and Technical Information of China (English)
SUN Detong
2008-01-01
A three-dimensional nearshore circulation model was developed by coupling CH3D, a three-dimensional hydrodynamic model and REF/DIF, a nearsbore wave transformation model. The model solves the three-dimensional wave-averaged equations of motion. Wave-induced effects on circulation were introduced in the form of radiation stresses, wave-induced mass transport, wave-induced enhancement of bottom friction and wave-induced turbulent mixing. Effects of breaking waves were considered following Svendsen (1984a and 1984b) and Stive and Wind (1986). The model was successfully tested against the analytical solution of longshore currents by Longuet and Higgins (1970). The model successfully simulated the undertow as observed in a laboratory experiment by Stive and Wind (1982). In addition, the model was applied to a physical model by Mory and Hamm (1997) and successfully reproduced the eddy behind a detached breakwater as well as the longshore current on the open beach and the contiguous eddy in the open area of the wave tank. While the qualitative agreement between model results and experimental observations was very good, the quantitative agreement needs to be further improved. Albeit difficult to explain every discrepancy between the model re- suits and observations, in general, sources of errors are attributed to the lack of understanding and comprehensive description of following processes: (1) the horizontal and vertical distribution of radiation stress, especially for breaking waves; (2) the detailed structure of turbulence;(3)Wave-current interaction (not included at this moment) ; and (4)the wave- current boundary layer and the resulting bottom shear stress.
Three-dimensional multifunctional optical coherence tomography for skin imaging
Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Sasaoka, Tomoko; Yamanari, Masahiro; Sugiyama, Satoshi; Yasuno, Yoshiaki
2016-02-01
Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by a single scan. They respectively contrast the structure and morphology, vasculature, melanin content and collagen traits of the tissue.
Modified Three-Dimensional Multicarrier Optical Prime Codes
Directory of Open Access Journals (Sweden)
Rajesh Yadav
2016-01-01
Full Text Available We propose a mathematical model for novel three-dimensional multicarrier optical codes in terms of wavelength/time/space based on the prime sequence algorithm. The proposed model has been extensively simulated on MATLAB for prime numbers (P to analyze the performance of code in terms of autocorrelation and cross-correlation. The simulated outcome resembles the mathematical model and gives better results over other methods available in the literature as far as autocorrelation and cross-correlation are concerned. The proposed 3D optical codes are more efficient in terms of cardinality, improved security, and providing quality of services.
Three-dimensional reconstruction of the rat nephron
DEFF Research Database (Denmark)
Christensen, Erik Ilsø; Grann, Birgitte; Kristoffersen, Inger B.;
2014-01-01
This study gives a three-dimensional (3D) structural analysis of rat nephrons and their connections to collecting ducts. Approximately 4,500 2.5-μm-thick serial sections from the renal surface to the papillary tip were obtained from each of 3 kidneys of Wistar rats. Digital images were recorded...... and aligned into three image stacks and traced from image to image. Short-loop nephrons (SLNs), long-loop nephrons (LLNs), and collecting ducts (CDs) were reconstructed in 3D. We identified a well-defined boundary between the outer stripe and the inner stripe of the outer medulla corresponding...
Integrated three-dimensional reconstruction using reflectance fields
Directory of Open Access Journals (Sweden)
Maria-Luisa Rosas
2012-01-01
Full Text Available A method to obtain three-dimensional data of real-world objects by integrating their material properties is presented. The material properties are defined by capturing the Reflectance Fields of the real-world objects. It is shown, unlike conventional reconstruction methods, the method is able to use the reflectance information to recover surface depth for objects having a non-Lambertian surface reflectance. It is, for recovering 3D data of objects exhibiting an anisotropic BRDF with an error less than 0.3%.
Discrete canonical analysis of three dimensional gravity with cosmological constant
Berra-Montiel, J
2014-01-01
We discuss the interplay between standard canonical analysis and canonical discretization in three-dimensional gravity with cosmological constant. By using the Hamiltonian analysis, we find that the continuum local symmetries of the theory are given by the on-shell space-time diffeomorphisms, which at the action level, corresponds to the Kalb-Ramond transformations. At the time of discretization, although this symmetry is explicitly broken, we prove that the theory still preserves certain gauge freedom generated by a constant curvature relation in terms of holonomies and the Gauss's law in the lattice approach.
Observation of three dimensional optical rogue waves through obstacles
Energy Technology Data Exchange (ETDEWEB)
Leonetti, Marco, E-mail: marco.leonetti@roma1.infn.it [Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Viale Regina Elena, 291 00161 Roma (RM) (Italy); Conti, Claudio [ISC-CNR and Department of Physics, University Sapienza, P.le Aldo Moro 5, I-00185 Roma (Italy)
2015-06-22
We observe three-dimensional rogue waves in the speckle distribution of a spatially modulated optical beam. Light is transmitted beyond a partially reflecting obstacle generating optical rogue waves at a controlled position in the shadow of the barrier. When the barrier transmits only 0.07% of the input laser power, we observe the mostly localized event. These results demonstrate that an optimum amount of spatial non-homogeneity maximizes the probability of a gigantic event while the technique we exploit enables to control light behind a fully reflective wall.
Three-dimensional structure of brain tissue at submicrometer resolution
Saiga, Rino; Mizutani, Ryuta; Inomoto, Chie; Takekoshi, Susumu; Nakamura, Naoya; Tsuboi, Akio; Osawa, Motoki; Arai, Makoto; Oshima, Kenichi; Itokawa, Masanari; Uesugi, Kentaro; Takeuchi, Akihisa; Terada, Yasuko; Suzuki, Yoshio
2016-01-01
Biological objects are composed of submicrometer structures such as cells and organelles that are essential for their functions. Here, we report on three-dimensional X-ray visualization of cells and organelles at resolutions up to 100 nm by imaging microtomography (micro-CT) equipped with Fresnel zone plate optics. Human cerebral tissue, fruit fly cephalic ganglia, and Escherichia coli bacteria labeled with high atomic-number elements were embedded in epoxy resin and subjected to X-ray microtomography at the BL37XU and BL47XU beamlines of the SPring-8 synchrotron radiation facility. The obtained results indicated that soft tissue structures can be visualized with the imaging microtomography.
Three-dimensional nanojunction device models for photovoltaics
Wangperawong, Artit; Bent, Stacey F.
2011-06-01
A model is developed to describe the behavior of three-dimensionally nanostructured photovoltaic devices, distinguishing between isolated radial pn junctions and interdigitated pn junctions. We examine two specific interdigitated architectures, the point-contact nanojunction and the extended nanojunction, which are most relevant to experimental devices reported to date but have yet to be distinguished in the field. The model is also applied to polycrystalline CdTe devices with inverted grain boundaries. We demonstrate that for CdTe/CdS solar cells using low-quality materials, the efficiency of the extended nanojunction geometry is superior to other designs considered.
Three-Dimensional Magnetohydrodynamic Simulation of Slapper Initiation Systems
Energy Technology Data Exchange (ETDEWEB)
Christensen, J S; Hrousis, C A
2010-03-09
Although useful information can be gleaned from 2D and even 1D simulations of slapper type initiation systems, these systems are inherently three-dimensional and therefore require full 3D representation to model all relevant details. Further, such representation provides additional insight into optimizing the design of such devices from a first-principles perspective and can thereby reduce experimental costs. We discuss in this paper several ongoing efforts in modeling these systems, our pursuit of validation, and extension of these methods to other systems. Our results show the substantial dependence upon highly accurate global equations of state and resistivity models in these analyses.
Synthesis of three-dimensional hierarchical cobalt hydroxide microstructures
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
β-Co(OH)2 with three-dimensional (3-D) structures was prepared by a simple hydrothermal method. It was found that the amount of cetyltrimethylammonium bromide (CTAB), the pH value, and the reaction time all had an important influence on the formation of this morphology. The products were characterized by X-ray diffraction, energy-dispersive X-ray analysis, and scanning electron microscopy. A possible mechanism of the formation of the 3-D microstructures of β-Co(OH)2 was proposed.
Analysis and visualization of complex unsteady three-dimensional flows
Van Dalsem, William R.; Buning, Pieter G.; Dougherty, F. Carroll; Smith, Merritt H.
1989-01-01
Flow field animation is the natural choice as a tool in the analysis of the numerical simulations of complex unsteady three-dimensional flows. The PLOT4D extension of the widely used PLOT3D code to allow the interactive animation of a broad range of flow variables was developed and is presented. To allow direct comparison with unsteady experimental smoke and dye flow visualization, the code STREAKER was developed to produce time accurate streaklines. Considerations regarding the development of PLOT4D and STREAKER, and example results are presented.
Seismic waves in a three-dimensional block medium
Aleksandrova, N. I.
2016-08-01
We study numerically the propagation of seismic waves in a three-dimensional block medium. The medium is modelled by a spatial lattice of masses connected by elastic springs and viscous dampers. We study Lamb's problem under a surface point vertical load. The cases of both step and pulse load are considered. The displacements and velocities are calculated for surface masses. The influence of the viscosity of the dampers on the attenuation of perturbations is studied. We compare our numerical results for the block medium with known analytical solutions for the elastic medium.
Proton beam writing of three-dimensional microcavities
Energy Technology Data Exchange (ETDEWEB)
Vanga, S.K., E-mail: sudheer@nus.edu.sg [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Bettiol, A.A. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)
2013-07-01
Optical micro cavities exhibit high quality factors due to the circulation of resonant optical fields within the cavity. Polymers are good materials for the fabrication of micro cavities for practical applications due to the availability of various refractive indices and their low cost. Polymer micro cavities generally yield low Q-factors compared to semiconductor materials because of inherent material absorption losses, and their Q-factors are limited by the low index contrast between the polymer and the substrate material. In the present work, three dimensional micro cavities were fabricated in SU-8 using proton beam writing to enhance the index contrast by isolating the cavities from the substrate.
Multiple scattering of light in three-dimensional photonic quasicrystals.
Ledermann, Alexandra; Wiersma, Diederik S; Wegener, Martin; von Freymann, Georg
2009-02-01
Recent experiments on three-dimensional icosahedral dielectric photonic quasicrystals have shown several unexpected features: transmitted femtosecond pulses developed a trailing "diffusive" exponential tail and the sum of (zeroth-order) transmittance and reflectance was well below unity. These experimental findings have previously been ascribed to sample imperfections. Here, we analyze these findings by using 3D periodic approximants of the ideal photonic quasicrystals. We show that the experimental observations can be explained in terms of multiple scattering of light within these structures, i.e., in terms of intrinsic rather than purely extrinsic quasicrystal properties.
Three-Dimensional Analysis of Frequency-Chirped FELs
Energy Technology Data Exchange (ETDEWEB)
Huang, Z.; Ding, Y.; Wu, J.; /SLAC
2010-09-14
Frequency-chirped free-electron lasers (FELs) are useful to generate a large photon bandwidth or a shorter x-ray pulse duration. In this paper, we present a three-dimensional analysis of a high-gain FEL driven by the energy-chirped electron beam. We show that the FEL eigenmode equation is the same for a frequency-chirped FEL as for an undulator-tapered FEL. We study the transverse effects of such FELs including mode properties and transverse coherence.
High-resolution three-dimensional imaging of dislocations.
Barnard, J S; Sharp, J; Tong, J R; Midgley, P A
2006-07-21
Dislocations and their interactions govern the properties of many materials, ranging from work hardening in metals to device pathology in semiconductor laser diodes. However, conventional electron micrographs are simply two-dimensional projections of three-dimensional (3D) structures, and even stereo microscopy cannot reveal the true 3D complexity of defect structures. Here, we describe an electron tomographic method that yields 3D reconstructions of dislocation networks with a spatial resolution three orders of magnitude better than previous work. We illustrate the method's success with a study of dislocations in a GaN epilayer, where dislocation densities of 1010 per square centimeter are common.
Three-dimensional imaging of direct-written photonic structures
Marshall, Graham D; Thayil, Anisha; Withford, Michael J; Booth, Martin
2010-01-01
Third harmonic generation microscopy has been used to analyze the morphology of photonic structures created using the femtosecond laser direct-write technique. Three dimensional waveguide arrays and waveguide-Bragg gratings written in fused-silica and doped phosphate glass were investigated. A sensorless adaptive optical system was used to correct the optical aberrations occurring in the sample and microscope system, which had a lateral resolution of less than 500 nm. This non-destructive testing method creates volume reconstructions of photonic devices and reveals details invisible to other linear microscopy and index profilometry techniques.
Three-dimensional array foci of generalized Fibonacci photon sieves
Zhang, Junyong; Zhu, Jianqiang; Lin, Zunqi
2015-01-01
We present a new kind of photon sieves on the basis of the generalized Fibonacci sequences. The required numbers and locations of axial foci can be designed by generalized Fibonacci photon sieves (GFiPS). Furthermore, the three-dimensional array foci can be controllable and adjustable by the optical path difference scaling factor (OPDSF) when the amplitude modulation is replaced with the phase modulation. Multi-focal technologies can be applied to nano-imaging, THZ, laser communications, direct laser writing, optical tweezers or atom trapping, etc.
Ising Model Coupled to Three-Dimensional Quantum Gravity
Baillie, C F
1992-01-01
We have performed Monte Carlo simulations of the Ising model coupled to three-dimensional quantum gravity based on a summation over dynamical triangulations. These were done both in the microcanonical ensemble, with the number of points in the triangulation and the number of Ising spins fixed, and in the grand canoncal ensemble. We have investigated the two possible cases of the spins living on the vertices of the triangulation (``diect'' case) and the spins living in the middle of the tetrahedra (``dual'' case). We observed phase transitions which are probably second order, and found that the dual implementation more effectively couples the spins to the quantum gravity.
On three-dimensional trace anomaly from holographic local RG
Kikuchi, Ken; Suzuki, Akihiro
2016-01-01
Odd-dimensional quantum field theories (QFTs) can have nonzero trace anomalies if external fields are introduced and some ingredients needed to make Lorentz scalars with appropriate mass dimensions (or weights) are supplied. We have studied a three-dimensional QFT and explicitly computed the trace of the stress tensor using the holographic local renormalization group (RG). We have checked some properties of vector beta functions and the Wess-Zumino consistency condition, however, found the anomalies vanish on fixed points. We clarify what is responsible for the vanishing trace anomalies.
A Novel Woodpile Three-Dimensional Terahertz Photonic Crystal
Institute of Scientific and Technical Information of China (English)
LIU Huan; YAO Jian-Quan; ZHENG Fang-Hua; XU De-Gang; WANG Peng
2007-01-01
A novel woodpile lattice structure is proposed. Based on plane wave expansion (PWE) method, the complete photonic band gaps (PBGs) of the novel woodpile three-dimensional (3D) terahertz (THz) photonic crystal (PC) with a decreasing symmetry relative to a face-centred-tetragonal (fct) symmetry are optimized by varying some structural parameters and the highest band gap ratio can reach 27.61%. Compared to the traditional woodpile lattice, the novel woodpile lattice has a wider range of the Riling ratios to gain high quality PBGs, which provides greater convenience for the manufacturing process. The novel woodpile 3D PC will be very promising for materials of THz functional components.
Critical exponents of a three dimensional O(4) spin model
Kanaya, K; Kanaya, K; Kaya, S
1995-01-01
By Monte Carlo simulation we study the critical exponents governing the transition of the three-dimensional classical O(4) Heisenberg model, which is considered to be in the same universality class as the finite-temperature QCD with massless two flavors. We use the single cluster algorithm and the histogram reweighting technique to obtain observables at the critical temperature. After estimating an accurate value of the inverse critical temperature \\Kc=0.9360(1) we make non-perturbative estimates for various critical exponents by finite-size scaling analysis. They are in excellent agreement with those obtained with the 4-\\epsilon expansion method with errors reduced to about halves of them.
Canonical and symplectic analysis for three dimensional gravity without dynamics
Escalante, Alberto
2016-01-01
In this paper a detailed Hamiltonian analysis of three-dimensional gravity without dynamics proposed by V. Hussain is performed. We report the complete structure of the constraints and the Dirac brackets are explicitly computed. In addition, the Faddeev-Jackiw symplectic approach is developed; we report the complete set of Faddeev-Jackiw constraints and the generalized brackets, then we show that the Dirac and the generalized Faddeev-Jackiw brackets coincide to each other. Finally, the similarities and advantages between Faddeev-Jackiw and Dirac's formalism are briefly discussed.
Three-dimensional visual illusion of graphic painting
Institute of Scientific and Technical Information of China (English)
于静
2012-01-01
Visual illusion is the visual design of a special category.It is a set of technology and art in one of a unique form of artistic expression.Visual illusion can give people a taste of the spirit, with strong cultural con- tent and artistic appeal.So by this way of painting, it has a clever and unique perspective. Aspect If the plane can be realistic paintings to life, then the three-dimensional, two-dimensional space can be called even more powerful by aspects.
CATIA Core Tools Computer Aided Three-Dimensional Interactive Application
Michaud, Michel
2012-01-01
CATIA Core Tools: Computer-Aided Three-Dimensional Interactive Application explains how to use the essential features of this cutting-edge solution for product design and innovation. The book begins with the basics, such as launching the software, configuring the settings, and managing files. Next, you'll learn about sketching, modeling, drafting, and visualization tools and techniques. Easy-to-follow instructions along with detailed illustrations and screenshots help you get started using several CATIA workbenches right away. Reverse engineering--a valuable product development skill--is also covered in this practical resource.
Three-dimensional measurement of a tightly focused laser beam
Directory of Open Access Journals (Sweden)
Xiangsheng Xie
2013-02-01
Full Text Available The spatial structure of a tightly focused light field is measured with a double knife-edge scanning method. The measurement method is based on the use of a high-quality double knife-edge fabricated from a right-angled silicon fragment mounted on a photodetector. The reconstruction of the three-dimensional structures of tightly focused spots is carried out with both uniform and partially obstructed linearly polarized incident light beams. The optical field distribution is found to deviate substantially from the input beam profile in the tightly focused region, which is in good agreement with the results of numerical simulations.
Three-dimensional wake potential in a streaming dusty plasma
Indian Academy of Sciences (India)
M Salahuddin; M K Islam; A K Banerjee; M Salimullah; S K Ghosh
2003-09-01
The oscillatory wake potential for a slowly moving or static test dust particulate in a ﬁnite temperature, collisionless and unmagnetized dusty plasma with a continuous ﬂow of ions and dust particles has been studied. The collective resonant interaction of the moving test particle with the low-frequency and low-phase-velocity dust-acoustic mode is the origin of the periodic attractive force between the like polarity particulates along and perpendicular to the streaming ions and dust grains resulting into dust-Coulomb crystal formation. This wake potential can explain the three-dimensional dust-Coulomb crystal formation in the laboratory conditions.
Optimal control of three-dimensional steamflooding processes
Energy Technology Data Exchange (ETDEWEB)
Liu, Wei; Fred Ramirez, W. (Dept. of Chemical Engineering, Univ. of Colorado, Boulder, CO (United States))
1994-06-01
A system science approach using optimal control theory of distributed parameter systems has been developed to determine operating strategies that maximize the economic profitability of the steamflooding processes. Necessary conditions of optimization are established by using the discrete form of calculus of variations and Pontryagin's Maximum Principle. The performance of this approach is investigated through two actual three-dimensional steamflooding projects. The optimization results show this method yields significant improvements over the original operating strategies. These improvements cannot be achieved through traditional design methods
Ordinary polarization singularities in three-dimensional optical fields.
Freund, Isaac
2012-06-15
In generic three-dimensional optical fields the canonical point polarization singularities are points of circular polarization, C points on C lines, and points of linear polarization, L points on L lines. These special points are surrounded by a sea of ordinary points. In planes oriented normal to the principle axes of the polarization ellipse at the point, every ordinary point is also a singularity, here an ordinary polarization singularity, or O point. Interactions between O points, between O points and C points, and between O points and L points are described that highlight the fact that a consistent description of optical fields containing C and L lines must include O points.
Three-Dimensional Model for Strip Hot Rolling
Institute of Scientific and Technical Information of China (English)
ZHANG Guo-min; XIAO Hong; WANG Chun-hua
2006-01-01
A three-dimensional model for strip hot rolling was developed, in which the plastic deformation of strip, the thermal crown of rolls, roll deflection and flattening were calculated by rigid-plastic finite element method, finite difference method, influential function method and elastic finite element method respectively. The roll wear was taken into consideration. The model can provide detailed information such as rolling pressure distribution, contact pressure distribution between backup rolls and work rolls, deflection and flattening of work rolls, lateral distribution of strip thickness, and lateral distribution of front and back tensions. The finish rolling on a 1 450 mm hot strip mill was simulated.
Three-dimensional edge extraction in optical scanning holography
Zong, Yonghong; Zhou, Changhe; Ma, Jianyong; Jia, Wei; Wang, Jin
2016-10-01
Edge extraction has found applications in various image processing fields, such as in pattern recognition. In this paper, a new method is proposed for edge extraction of three-dimensional objects in optical scanning holography (OSH). Isotropic and anisotropic edge extraction of 3D objects is simulated using spiral phase plates in OSH operating in an incoherent mode. We propose to use a delta function and a spiral phase plate as the pupil functions to realize isotropic and anisotropic edge extraction. Our computer simulations show the capability of extracting the edges of a given 3D object by spiral phase filtering in OSH.
Three-dimensional imaging for a very large excavator
Energy Technology Data Exchange (ETDEWEB)
Roberts, J.; Winstanley, G.; Corke, P. [CSIRO, Kenmore, Qld. (Australia). Manufacture and & Infrastructure Technology
2003-08-01
We describe the development of a three-dimensional (3D) imaging system for a 3500 tonne mining machine (dragline). Draglines are large walking cranes used for removing the dirt that covers a coal seam. Our group has been developing a dragline swing automation system since 1994. The system so far has been 'blind' to its external environment. The work presented in this paper attempts to give the dragline an ability to sense its surroundings. A 3D digital terrain map (DTM) is created from data obtained from a two-dimensional laser scanner while the dragline swings. Experimental data from an operational dragline are presented.
Electrified magnetic catalysis in three-dimensional topological insulators
Gorbar, E. V.; Miransky, V. A.; Shovkovy, I. A.; Sukhachov, P. O.
2016-09-01
The gap equations for the surface quasiparticle propagators in a slab of three-dimensional topological insulator in external electric and magnetic fields perpendicular to the slab surfaces are analyzed and solved. A different type of magnetic catalysis is revealed with the dynamical generation of both Haldane and Dirac gaps. Its characteristic feature manifests itself in the crucial role that the electric field plays in dynamical symmetry breaking and the generation of a Dirac gap in the slab. It is argued that, for a sufficiently large external electric field, the ground state of the system is a phase with a homogeneous surface charge density.
Seismic waves in a three-dimensional block medium
Aleksandrova, Nadezhda
2016-01-01
We study numerically the propagation of seismic waves in a three-dimensional block medium. The medium is modeled by a spatial lattice of masses connected by elastic springs and viscous dampers. We study Lamb's problem under a surface point vertical load. The cases of both step and pulse load are considered. The displacements and velocities are calculated for surface masses. The influence of the viscosity of the dampers on the attenuation of perturbations is studied. We compare our numerical results for the block medium with known analytical solutions for the elastic medium.
Three dimensional free convection couette flow with transpiration cooling
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Free convection flow between two vertical parallel plates with transverse sinusoidal injection of the fluid at the stationary plate and its corresponding removal by constant suction through the plate in uniform motion has been analyzed. Due to this type of injection velocity, the flow becomes three-dimensional. Analytical expressions for the velocity, temperature, skin friction and rate of heat transfer were obtained. The important characteristics of the problem, namely the skin friction and the rate of heat transfer are discussed in detail with the help of graphs.
The Electron in Three-Dimensional Momentum Space
Mantovani, L.; Bacchetta, A.; Pasquini, B.
2016-07-01
We study the electron as a system composed of an electron and a photon and derive the leading-twist transverse-momentum-dependent distribution functions for both the electron and photon in the dressed electron, thereby offering a three-dimensional description of the dressed electron in momentum space. To obtain the distribution functions, we apply both the formalism of light-front wave function overlap representation and the diagrammatic approach; we discuss the comparison of our results between light-cone gauge and Feynman gauge, discussing the role of the Wilson lines to obtain gauge-independent results. We provide examples of plots of the computed distributions.
Three-dimensional characterization of stress corrosion cracks
DEFF Research Database (Denmark)
Lozano-Perez, S.; Rodrigo, P.; Gontard, Lionel Cervera
2011-01-01
Understanding crack propagation and initiation is fundamental if stress corrosion cracking (SCC) mechanisms are to be understood. However, cracking is a three-dimensional (3D) phenomenon and most characterization techniques are restricted to two-dimensional (2D) observations. In order to overcome...... the best spatial resolution. To illustrate the power of these techniques, different parts of dominant stress corrosion cracks in Ni-alloys and stainless steels have been reconstructed in 3D. All relevant microstructural features can now be studied in detail and its relative orientation respect...
New Discrete Element Models for Three-Dimensional Impact Problems
Institute of Scientific and Technical Information of China (English)
SHAN Li; CHENG Ming; LIU Kai-xin; LIU Wei-Fu; CHEN Shi-Yang
2009-01-01
Two 3-D numerical models of the discrete element method(DEM)for impact problems are proposed.The models can calculate not only the impact problems of continuum and non-continuum,but also the transient process from continuum to non-continuum.The stress wave propagation in a concrete block and a dynamic splitting process of a marble disc under impact loading are numerically simulated with the proposed models.By comparing the numerical results with the corresponding results obtained by the finite element method(FEM)and the experiments,it is proved that the models are reliable for three-dimensional impact problems.
Three-dimensional versus two-dimensional vision in laparoscopy
DEFF Research Database (Denmark)
Sørensen, Stine Maya Dreier; Savran, Mona M; Konge, Lars;
2016-01-01
BACKGROUND: Laparoscopic surgery is widely used, and results in accelerated patient recovery time and hospital stay were compared with laparotomy. However, laparoscopic surgery is more challenging compared with open surgery, in part because surgeons must operate in a three-dimensional (3D) space...... through a two-dimensional (2D) projection on a monitor, which results in loss of depth perception. To counter this problem, 3D imaging for laparoscopy was developed. A systematic review of the literature was performed to assess the effect of 3D laparoscopy. METHODS: A systematic search of the literature...
Three Dimensional Transformations in the Film Subtitle Translation
Institute of Scientific and Technical Information of China (English)
陈志海
2015-01-01
Film plays an indispensable part in cultural exchange. However, current scholars’studies on the film subtitle transla⁃tion are less than literary translation. There exists no systematic strategy and theory guiding it, and there still exists some problems. This paper introduces eco-translatology to film subtitle translation. Eco-translatology proposes that translation is an alternative cy⁃cle of translators’adaptation and selection activities in translational eco-environment. The translation method focuses on three-dimensional transformation, namely linguistic, cultural and communicative dimensions.
Three Dimensional Digital Image Processing using Edge Detectors
Directory of Open Access Journals (Sweden)
John Schmeelk
2005-11-01
Full Text Available This paper provides an introduction to three dimensional image edge detection and its relationship to partial derivatives, convolutions and wavelets. We are especially addressing the notion of edge detection because it has far reaching applications in all areas of research to include medical research. A patient can be diagnosed as having an aneurysm by studying an angiogram. An angiogram is the visual view of the blood vessels whereby the edges are highlighted through the implementation of edge detectors. This process is completed through convolution, wavelets and matrix techniques. Some illustrations included will be vertical, horizontal, Sobel and wavelet edge detectors.
The three-dimensional crystal structure of cholera toxin
Energy Technology Data Exchange (ETDEWEB)
Zhang, Rong-Guang; Westbrook, M.L.; Nance, S.; Spangler, B.D. [Argonne National Lab., IL (United States); Scott, D.L. [Yale Univ., New Haven, CT (United States). Dept. of Molecular Biophysics and Biochemistry; Westbrook, E.M. [Northwestern Univ., Evanston, IL (United States)
1996-02-01
The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB{sub 5} enterotoxin (choleragen). We have solved the three-dimensional structure of choleragen at 2.5 {Angstrom} resolution and compared the refined coordinates with those of choleragenoid (isolated B pentamer) and the heat-labile enterotoxin from Escherichia coli (LT). The crystalline coordinates provide a detailed view of the stereochemistry implicated in binding to GM1 gangliosides and in carrying out ADP-ribosylation. The A2 chain of choleragen, in contrast to that of LT, is a nearly continuous {alpha}-helix with an interpretable carboxyl tail.
The application of three-dimensional photoelasticity to impact problems
Energy Technology Data Exchange (ETDEWEB)
Kostin, I.C. [Moscow State Univ. of Civil Engeneering (Russian Federation); Fedorov, A.V. [Mining School of Nantes (France)
1995-12-31
A method is proposed for the solution of three-dimensional dynamic problems in geometrically complex structural configurations under impact. The methodology developed employs the generation of photoelastically observable stress wave propagation in a birefringent material applied to the external surfaces of a structure. This work demonstrated the extension of this technique to impact loading. Problems of practical engineering application, such as the gluing of birefringent material to test models were examined experimentally. Pulsed magnetic fields generated by capacitor discharge were employed on typical complex engineering models to demonstrate that the methodology is adequate for solving practical impact problems.
On three-dimensional trace anomaly from holographic local RG
Kikuchi, Ken; Hosoda, Hiroto; Suzuki, Akihiro
2017-01-01
Odd-dimensional quantum field theories (QFTs) can have nonzero trace anomalies if external fields are introduced and some ingredients needed to make Lorentz scalars with appropriate mass dimensions (or weights) are supplied. We have studied a three-dimensional QFT and explicitly computed the trace of the stress tensor using the holographic local renormalization group (RG). We have checked some properties of vector beta functions and the Wess-Zumino consistency condition; however, we have found that the anomalies vanish on fixed points. We clarify what is responsible for the vanishing trace anomalies.
Black holes in three-dimensional dilaton gravity theories
Sá, P M; Lemos, J P S; Sa, Paulo M; Kleber, Antares; Lemos, Jose P S
1995-01-01
Three dimensional black holes in a generalized dilaton gravity action theory are analysed. The theory is specified by two fields, the dilaton and the graviton, and two parameters, the cosmological constant and the Brans-Dicke parameter. It contains seven different cases, of which one distinguishes as special cases, string theory, general relativity and a theory equivalent to four dimensional general relativity with one Killing vector. We study the causal structure and geodesic motion of null and timelike particles in the black hole geometries and find the ADM masses of the different solutions.
Architecture and Applications of Functional Three-Dimensional Graphene Networks
DEFF Research Database (Denmark)
Dey, Ramendra Sundar; Chi, Qijin
2015-01-01
building blocksfor the bottom-up architecture of various graphene based nanomaterials. Th eassembly of functionalized GNS into three-dimensional (3D) porous graphenenetworks represents a novel approach. Resulting 3D porous graphene materialsposses unique physicochemical properties such as large surface...... based on the accomplishmentsrecently reported. Th e chapter will include: (1) a brief introduction to grapheneand its nanocomposites, (2) the major methods to assemble 3D porous graphenenetworks, (3) structural characteristics of 3D porous graphene, (4) some typicalexamples of their applications...
AN EXAMPLE OF THREE-DIMENSIONAL PROGRESSIVE SLOPE FAILURE
Institute of Scientific and Technical Information of China (English)
王家臣; 骆中洲
1995-01-01
In fact, the failure of any slope takes place progressively, but the progressive failure mechanism has not been emphasized sufficently in the present stability analysis of slopes. This paper provides an example of the progressive slope failure which took place at Pingzhuang west surface coal mine and was numbered the 26th slide. The three-dimensional reliability model for progressive slope failure is used to study the failure process of the 26th slide. The outcomes indicate that the progressive failure is indeed the failure mechanism of the slide.
Characterization of a novel phantom for three-dimensional in vitro cell experiments
Energy Technology Data Exchange (ETDEWEB)
Altman, Michael B; Pelizzari, Charles A; Aydogan, Bulent; Reft, Chester S; Chmura, Steven J [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, IL (United States); Vesper, Benjamin J; Radosevich, James A [Center for Molecular Biology of Oral Diseases, College of Dentistry, University of Illinois at Chicago, Chicago, IL (United States); Smith, Brett D; Stinauer, Michelle A [Department of Radiation Oncology, University of Illinois at Chicago, Chicago, IL (United States); Roeske, John C [Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL (United States)
2009-03-07
A novel intensity-modulated radiation therapy (IMRT) phantom for use in three-dimensional in vitro cell experiments, based on a commercially available system (CIRS Inc., Norfolk, VA), was designed and fabricated. The water-equivalent plastic phantom can, with a set of water-equivalent plastic inserts, enclose 1-3 multi-well tissue culture plates. Dosimetry within the phantom was assessed using thermoluminescence dosimeters (TLDs) and film. The phantom was loaded with three tissue culture plates, and an array of TLDs or a set of three films was placed underneath each plate within the phantom, and then irradiated using an IMRT plan created for it. Measured doses from each dosimeter were compared to those acquired from the treatment planning system. The percent differences between TLD measurements and the corresponding points in the treatment plan ranged from 1.3% to 2.9%, differences which did not show statistical significance. Average point-by-point percent dose differences for each film plane ranged from 1.6% to 3.1%. The percentage dose difference for which 95% of the points in the film matched those corresponding to the calculated dose plane to within 3.0% ranged from 2.8% to 4.2%. The good agreement between predicted and measured dose shows that the phantom is a useful and efficient tool for three-dimensional in vitro cell experiments. (note)
X-ray Emissions from Three-dimensional Magnetohydrodynamic Coronal Accretion Flows
Kawanaka, Norita; Mineshige, Shin
2008-01-01
We calculate the radiation spectrum and its time variability of the black hole accretion disk-corona system based on the three-dimensional magnetohydrodynamic simulation. In explaining the spectral properties of active galactic nuclei (AGNs), it is often assumed that they consist of a geometrically thin, optically thick disk and hot, optically thin corona surrounding the thin disk. As for a model of the corona, we adopt the simulation data of three-dimensional, non-radiative MHD accretion flows calculated by Kato and coworkers, while for a thin disk we assume a standard type disk. We perform Monte Carlo radiative transfer simulations in the corona, taking into account the Compton scattering of soft photons from the thin disk by hot thermal electrons and coronal irradiation heating of the thin disk, which emits blackbody radiation. By adjusting the density parameter of the MHD coronal flow, we can produce the emergent spectra which are consistent with those of typical Seyfert galaxies. Moreover, we find rapid ...
Automated photogrammetry for three-dimensional models of urban spaces
Leberl, Franz; Meixner, Philipp; Wendel, Andreas; Irschara, Arnold
2012-02-01
The location-aware Internet is inspiring intensive work addressing the automated assembly of three-dimensional models of urban spaces with their buildings, circulation spaces, vegetation, signs, even their above-ground and underground utility lines. Two-dimensional geographic information systems (GISs) and municipal utility information exist and can serve to guide the creation of models being built with aerial, sometimes satellite imagery, streetside images, indoor imaging, and alternatively with light detection and ranging systems (LiDARs) carried on airplanes, cars, or mounted on tripods. We review the results of current research to automate the information extraction from sensor data. We show that aerial photography at ground sampling distances (GSD) of 1 to 10 cm is well suited to provide geometry data about building facades and roofs, that streetside imagery at 0.5 to 2 cm is particularly interesting when it is collected within community photo collections (CPCs) by the general public, and that the transition to digital imaging has opened the no-cost option of highly overlapping images in support of a more complete and thus more economical automation. LiDAR-systems are a widely used source of three-dimensional data, but they deliver information not really superior to digital photography.
A Three-Dimensional Map of Milky-Way Dust
Green, Gregory M; Finkbeiner, Douglas P; Rix, Hans-Walter; Martin, Nicolas; Burgett, William; Draper, Peter W; Flewelling, Heather; Hodapp, Klaus; Kaiser, Nicholas; Kudritzki, Rolf Peter; Magnier, Eugene; Metcalfe, Nigel; Price, Paul; Tonry, John; Wainscoat, Richard
2015-01-01
We present a three-dimensional map of interstellar dust reddening, covering three-quarters of the sky out to a distance of several kiloparsecs, based on Pan-STARRS 1 and 2MASS photometry. The map reveals a wealth of detailed structure, from filaments to large cloud complexes. The map has a hybrid angular resolution, with most of the map at an angular resolution of 3.4' to 13.7', and a maximum distance resolution of ~25%. The three-dimensional distribution of dust is determined in a fully probabilistic framework, yielding the uncertainty in the reddening distribution along each line of sight, as well as stellar distances, reddenings and classifications for 800 million stars detected by Pan-STARRS 1. We demonstrate the consistency of our reddening estimates with those of two-dimensional emission-based maps of dust reddening. In particular, we find agreement with the Planck 353 GHz optical depth-based reddening map to within 0.05 mag in E(B-V) to a depth of 0.5 mag, and explore systematics at reddenings less tha...
Three-dimensional imaging using differential synthetic aperture interferometry
Zhang, Ning; Zhou, Yu; Sun, Jianfeng; Zhi, Ya'nan; Lu, Zhiyong; Xu, Qian; Sun, Zhiwei; Liu, Liren
2014-09-01
Synthetic aperture radar interferometry (InSAR) can gain three-dimensional topography with high spatial resolution and height accuracy using across track interferometry[1]. Conventional InSAR produce three-dimensional images from SAR data. But when the working wavelength transit from microwave to optical wave, the transmission antenna and receive antenna become very sensitive to platform vibration and beam quality[2]. Through differential receive antenna formation, we can relax the requirement of platform and laser using synthetic aperture imaging ladar (SAIL) concept[3]. Line-of-sight motion constraints are reduced by several orders of magnitude. We introduce two distinctive forms of antenna formation according to the position of interferogram. The first architecture can simplify the interferogram processing and phase extraction algorithm under time-division multiplex operation. The second architecture can process the 2D coordinate and height coordinate at the same time. Using optical diffraction theory, a systematic theory of side-looking SAIL is mathematically formulated and the necessary conditions for assuring a correct phase history are established[4]. Based on optical transformation and regulation of wavefront, a side-looking SAIL of two distinctive architectures is invented and the basic principle, systematic theory, design equations and necessary conditions are presented. It is shown that high height accuracy can be reached and the influences from atmospheric turbulence and unmodeled line-of-sight motion can be automatically compensated.
Frozen Gaussian approximation for three-dimensional seismic wave propagation
Chai, Lihui; Tong, Ping; Yang, Xu
2016-09-01
We present a systematic introduction on applying frozen Gaussian approximation (FGA) to compute synthetic seismograms in three-dimensional earth models. In this method, seismic wavefield is decomposed into frozen (fixed-width) Gaussian functions, which propagate along ray paths. Rather than the coherent state solution to the wave equation, this method is rigorously derived by asymptotic expansion on phase plane, with analysis of its accuracy determined by the ratio of short wavelength over large domain size. Similar to other ray-based beam methods (e.g. Gaussian beam methods), one can use relatively small number of Gaussians to get accurate approximations of high-frequency wavefield. The algorithm is embarrassingly parallel, which can drastically speed up the computation with a multicore-processor computer station. We illustrate the accuracy and efficiency of the method by comparing it to the spectral element method for a three-dimensional (3D) seismic wave propagation in homogeneous media, where one has the analytical solution as a benchmark. As another proof of methodology, simulations of high-frequency seismic wave propagation in heterogeneous media are performed for 3D waveguide model and smoothed Marmousi model respectively. The second contribution of this paper is that, we incorporate the Snell's law into the FGA formulation, and asymptotically derive reflection, transmission and free surface conditions for FGA to compute high-frequency seismic wave propagation in high contrast media. We numerically test these conditions by computing traveltime kernels of different phases in the 3D crust-over-mantle model.
Direct-writing organic three-dimensional nanofibrous structure
Wang, Han; Zheng, Gaofeng; Li, Wenwang; Wang, Xiang; Sun, Daoheng
2011-02-01
Direct-writing technology based on Near-Field Electrospinning (NFES) was used to fabricate an organic three-dimensional nanofibrous circle on the patterned silicon substrate. In NFES, straight jet without splitting and chaotic motion was utilized to direct-write orderly nanofiber. When the collector movement speed was lower than electrospinning rate, the relaxed nanofiber would be lead into the pendulum motion by the electrical field force and Coulomb repulsion force from the residual charges on the collector. When the relative air humidity is lower than 35%, individual nanofiber with larger elastic resistance would reveal a good self-assembly performance. Owing to the guidance of the electric field force at the edge of the micro-pattern, a nanofiber was deposited layer by layer to format a 3D nanofibrous circle on the top surface of the micro-pattern. The dimension scale of 3D nanofibrous circle was smaller than 30 µm. With the help of a microscope, a 3D nanofibrous circle can be deposited precisely on the strip micro-pattern with width of 4 µm. Furthermore, a 3D nanofibrous circle in different shapes can be obtained by using special micro-patterns. This organic three-dimensional nanofibrous circle has created a new aspect for the fabrication of organic micro/nanosystems.
Tailoring thermal conductivity via three-dimensional porous alumina.
Abad, Begoña; Maiz, Jon; Ruiz-Clavijo, Alejandra; Caballero-Calero, Olga; Martin-Gonzalez, Marisol
2016-12-09
Three-dimensional anodic alumina templates (3D-AAO) are an astonishing framework with open highly ordered three-dimensional skeleton structures. Since these templates are architecturally different from conventional solids or porous templates, they teem with opportunities for engineering thermal properties. By establishing the mechanisms of heat transfer in these frameworks, we aim to create materials with tailored thermal properties. The effective thermal conductivity of an empty 3D-AAO membrane was measured. As the effective medium theory was not valid to extract the skeletal thermal conductivity of 3D-AAO, a simple 3D thermal conduction model was developed, based on a mixed series and parallel thermal resistor circuit, giving a skeletal thermal conductivity value of approximately 1.25 W·m(-1)·K(-1), which matches the value of the ordinary AAO membranes prepared from the same acid solution. The effect of different filler materials as well as the variation of the number of transversal nanochannels and the length of the 3D-AAO membrane in the effective thermal conductivity of the composite was studied. Finally, the thermal conductivity of two 3D-AAO membranes filled with cobalt and bismuth telluride was also measured, which was in good agreement with the thermal model predictions. Therefore, this work proved this structure as a powerful approach to tailor thermal properties.
Three-dimensional shock wave diffraction off a discontinuous edge
Cooppan, S.; Skews, B.
2017-03-01
The interaction of three-dimensional vortex flows was investigated through vortex shedding off a discontinuous edge. Two wedges of 14.5° wedge angle (up and downstream edges) were separated by an offset. The size of the offset (5, 10, and 20 mm) and the Mach number (Mach 1.32, 1.42, and 1.6) were the key parameters investigated. Experimental images were taken and computational simulations were run; a close relation was found between the two. This enabled the three-dimensional effects of the flow to be studied and analysed. It was found, as the offset increased in size, the vortices shed off the up and downstream edges took a longer time to merge and the strength of the interaction was weaker. The vortex topology changed with a larger offset; the downstream vortex was thinner (in terms of cross-sectional diameter) adjacent to the offset, which is an indication of a change in density, than the rest of the vortex along the downstream diffraction edge. This particular feature was more prevalent at lower Mach numbers. The effect of a higher Mach number was to increase the rate of dissipation of the vortices, lengthen the shear layer due to the higher upstream velocity, and make the vortex profile elliptical.
Tailoring thermal conductivity via three-dimensional porous alumina
Abad, Begoña; Maiz, Jon; Ruiz-Clavijo, Alejandra; Caballero-Calero, Olga; Martin-Gonzalez, Marisol
2016-12-01
Three-dimensional anodic alumina templates (3D-AAO) are an astonishing framework with open highly ordered three-dimensional skeleton structures. Since these templates are architecturally different from conventional solids or porous templates, they teem with opportunities for engineering thermal properties. By establishing the mechanisms of heat transfer in these frameworks, we aim to create materials with tailored thermal properties. The effective thermal conductivity of an empty 3D-AAO membrane was measured. As the effective medium theory was not valid to extract the skeletal thermal conductivity of 3D-AAO, a simple 3D thermal conduction model was developed, based on a mixed series and parallel thermal resistor circuit, giving a skeletal thermal conductivity value of approximately 1.25 W·m-1·K-1, which matches the value of the ordinary AAO membranes prepared from the same acid solution. The effect of different filler materials as well as the variation of the number of transversal nanochannels and the length of the 3D-AAO membrane in the effective thermal conductivity of the composite was studied. Finally, the thermal conductivity of two 3D-AAO membranes filled with cobalt and bismuth telluride was also measured, which was in good agreement with the thermal model predictions. Therefore, this work proved this structure as a powerful approach to tailor thermal properties.
Transect-based Three-Dimensional Road Modeling and Visualization
Institute of Scientific and Technical Information of China (English)
LI Qingquan; TANG Luliang; ZUO Xiaoqing; LI Hanwu
2004-01-01
On the basis of the study on road elements and the existing three-dimensional road data models, this paper puts forward the transect-based road modeling, resolves the modeling of the simplest road with two road transects, and fulfils the visualization of the road. OpenGL is applied as the tool of visualization. The map texture technology, LOD algorithm and dynamic multi-differentiating texture technology are of benefit to the construction of 3D road GIS, and improve the speed of roaming and effective visualization. This paper also disusses the combination of 2D digitall road map and 3D road scene, and the dynamic response between them. Finally, on the basis of the research on the transect-based road model, this paper develops the three-dimensional road geographic information system called virtual road ( VRoad ), which not only supplies road designers with a set of tool which can turn the designed 2D road data into 3D road and the high road assistant function area in computer, but also supplies the road management with a set of tool which can realize the road real time and interactive roaming, high-efficiency management.
A biorthogonality relationship for three-dimensional couple stress problem
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
The duality solution for elasticity and the biorthogonality relationship have been well researched. Now the couple stress theory becomes a new research spot but there is few research for the biorthogonality relationship for couple stress theory comparing to classical elasticity. A new state vector is presented for three dimensional couple stress problems of prismatic structures. A new biorthogonality relation- ship of couple stress is discovered. The dual partial differential equations of couple stress problem are derived by the new state vector. By two important identical equations the new biorthogonality rela- tionship is proved based on the method of separation of variables. The symplectic orthogonality rela- tionship to three dimensional couple stress theory may be decomposed into two independently and symmetrically orthogonality relationships. The new biorthogonality relationship includes the symplec- tic orthogonality relationship. The biorthogonality relationship of couple stress may also be degener- ated into the theory of elasticity. The new state vector and biorthogonality relationship provide theo- retic foundation for the research on the schemes of separation of variables and eigenfunction expan- sion of couple stress theory.
Three Dimensional Quantum Geometry and Deformed Poincare Symmetry
Joung, E; Noui, K
2008-01-01
We study a three dimensional non-commutative space emerging in the context of three dimensional Euclidean quantum gravity. Our starting point is the assumption that the isometry group is deformed to the Drinfeld double D(SU(2)). We generalize to the deformed case the construction of the flat Euclidean space as the quotient of its isometry group ISU(2) by SU(2). We show that the algebra of functions becomes the non-commutative algebra of SU(2) distributions endowed with the convolution product. This construction gives the action of ISU(2) on the algebra and allows the determination of plane waves and coordinate functions. In particular, we show that: (i) plane waves have bounded momenta; (ii) to a given momentum are associated several SU(2) elements leading to an effective description of an element in the algebra in terms of several physical scalar fields; (iii) their product leads to a deformed addition rule of momenta consistent with the bound on the spectrum. We generalize to the non-commutative setting the...
Three-dimensional scene capturing for the virtual reality display
Dong, Jingsheng; Sang, Xinzhu; Guo, Nan; Chen, Duo; Yan, Binbin; Wang, Kuiru; Dou, Wenhua; Xiao, Liquan
2016-10-01
A virtual reality shooting and display system based on multiple degrees of freedom camera is designed and demonstrated. Three-dimensional scene display and the wide angle display can be achieved easily and quickly through the construction with the proposed system. The range of the viewing scene can be broaden with the image stitching process, and the display in the demonstrated system can achieve the effect of wide angle for applications of image mosaic. In the meantime, the system can realize 3D scene display, which can effectively reduce the complexity of the 3D scene generation, and provide a foundation for adding interactive characteristics for the 3D scene in the future. The system includes an adjustable bracket, computer software, and a virtual reality device. Multiple degrees of freedom of the adjustable bracket are developed to obtain 3D scene source images and mosaic source images easily. 5 degrees of freedom are realized, including rotation, lifting, translation, convergence and pitching. To realize the generation and display of three-dimensional scenes, two cameras are adjusted into a parallel state. With the process of image distortion eliminating and calibration, the image is transferred to the virtual reality device for display. In order to realize wide angle display, the cameras are adjusted into "V" type. The preprocessing includes image matching and fusion to realize image stitching. The mosaic image is transferred for virtual reality display with its image reading and display functions. The wide angle 3D scene display is realized by adjusting different states.
Nanoscale three-dimensional imaging of the human myocyte.
Sulkin, Matthew S; Yang, Fei; Holzem, Katherine M; Van Leer, Brandon; Bugge, Cliff; Laughner, Jacob I; Green, Karen; Efimov, Igor R
2014-10-01
The ventricular human myocyte is spatially organized for optimal ATP and Ca(2+) delivery to sarcomeric myosin and ionic pumps during every excitation-contraction cycle. Comprehension of three-dimensional geometry of the tightly packed ultrastructure has been derived from discontinuous two-dimensional images, but has never been precisely reconstructed or analyzed in human myocardium. Using a focused ion beam scanning electron microscope, we created nanoscale resolution serial images to quantify the three-dimensional ultrastructure of a human left ventricular myocyte. Transverse tubules (t-tubule), lipid droplets, A-bands, and mitochondria occupy 1.8, 1.9, 10.8, and 27.9% of the myocyte volume, respectively. The complex t-tubule system has a small tortuosity (1.04±0.01), and is composed of long transverse segments with diameters of 317±24nm and short branches. Our data indicates that lipid droplets located well beneath the sarcolemma are proximal to t-tubules, where 59% (13 of 22) of lipid droplet centroids are within 0.50μm of a t-tubule. This spatial association could have an important implication in the development and treatment of heart failure because it connects two independently known pathophysiological alterations, a substrate switch from fatty acids to glucose and t-tubular derangement.
Three dimensional visualisation of human facial exposure to solar ultraviolet.
Downs, Nathan; Parisi, Alfio
2007-01-01
A three dimensional computer model of the human face has been developed to represent solar ultraviolet exposures recorded by dosimeter measurements on a manikin headform under low cloud conditions and various solar zenith angles. Additionally, polysulfone dosimeters have been successfully miniaturised to provide the detailed measurements required across the face. The headform used in this research was scanned at 709 individual locations to make a wireframe mesh consisting of 18 vertical contours and 49 horizontal contours covering half the manikin's frontal facial topography. Additionally, the back of the headform and neck have also been scanned at 576 locations. Each scanned location has been used as a viable dosimeter position on the headform and represents a grid intersection point on the developed computer wireframe. A series of exposures recorded by dosimeters have been translated into three dimensional exposure ratio maps, representing ambient solar ultraviolet exposure. High dosimeter density has allowed for the development of individual topographic contour models which take into account complex variation in the face and improve upon previously employed techniques which utilise fewer dosimeters to interpolate exposure across facial contours. Exposure ratios for solar zenith angle ranges of 0 degrees -30 degrees, 30 degrees -50 degrees, and 50 degrees -80 degrees have been developed.
Three-dimensional percolation modeling of self-healing composites.
Dementsov, Alexander; Privman, Vladimir
2008-08-01
We study the self-healing process of materials with embedded "glue"-carrying cells, in the regime of the onset of the initial fatigue. Three-dimensional numerical simulations within the percolation-model approach are reported. The main numerical challenge taken up in the present work has been to extend the calculation of the conductance to three-dimensional lattices. Our results confirm the general features of the process: The onset of material fatigue is delayed, by development of a plateaulike time dependence of the material quality. We demonstrate that, in this low-damage regime, the changes in the conductance and thus in similar transport and response properties of the material can be used as measures of the material quality degradation. A new feature found for three dimensions, where it is much more profound than in earlier-studied two-dimensional systems, is the competition between the healing cells. Even for low initial densities of the healing cells, they interfere with each other and reduce each other's effective healing efficiency.
Three-dimensional Echocardiography in Valvular Heart Disease.
Kurklinsky, Andrew; Mankad, Sunil
2012-01-01
Recent technologic advances in 3-dimensional (3D) echocardiography, using parallel processing to scan a pyramidal volume, have allowed for a superior ability to describe valvular anatomy using both transthoracic and transesophageal echocardiography. Although still in evolution and at an early phase of adaptation with respect to its clinical application, 3D echocardiography has emerged as an important clinical tool in the assessment of valvular heart disease. Three-dimensional echocardiography provides unique perspectives of valvular structures by presenting "en face" views of valvular structures, allowing for a better understanding of the topographical aspects of pathology, and a refined definition of the spatial relationships of intracardiac structures. Three-dimensional echocardiography makes available indices not described by 2D echocardiography and has been demonstrated to be superior to 2D echocardiography in a variety of valvular disease scenarios. The information gained from 3D echocardiography has especially made an impact in guiding clinical decisions in the evaluation of mitral valve (MV) disease. The decision of early surgery in degenerative MV disease is based on the suitability of repair, and the suitability of repair is generally based on echocardiography. The superior understanding of MV anatomy afforded by 3D echocardiography has been shown to be quite valuable in this setting. This review will describe the contemporary use of 3D echocardiography in the assessment of valvular heart disease, including MV, aortic, tricuspid, and prosthetic valve abnormalities. This article illustrates how 3D echocardiography can complement current echocardiography techniques in the management of valvular heart disease.
Three-dimensional Majorana fermions in chiral superconductors.
Kozii, Vladyslav; Venderbos, Jörn W F; Fu, Liang
2016-12-01
Using a systematic symmetry and topology analysis, we establish that three-dimensional chiral superconductors with strong spin-orbit coupling and odd-parity pairing generically host low-energy nodal quasiparticles that are spin-nondegenerate and realize Majorana fermions in three dimensions. By examining all types of chiral Cooper pairs with total angular momentum J formed by Bloch electrons with angular momentum j in crystals, we obtain a comprehensive classification of gapless Majorana quasiparticles in terms of energy-momentum relation and location on the Fermi surface. We show that the existence of bulk Majorana fermions in the vicinity of spin-selective point nodes is rooted in the nonunitary nature of chiral pairing in spin-orbit-coupled superconductors. We address experimental signatures of Majorana fermions and find that the nuclear magnetic resonance spin relaxation rate is significantly suppressed for nuclear spins polarized along the nodal direction as a consequence of the spin-selective Majorana nature of nodal quasiparticles. Furthermore, Majorana nodes in the bulk have nontrivial topology and imply the presence of Majorana bound states on the surface, which form arcs in momentum space. We conclude by proposing the heavy fermion superconductor PrOs4Sb12 and related materials as promising candidates for nonunitary chiral superconductors hosting three-dimensional Majorana fermions.
Three-dimensional finite element analysis of platform switched implant
2017-01-01
PURPOSE The purpose of this study was to analyze the influence of the platform switching concept on an implant system and peri-implant bone using three-dimensional finite element analysis. MATERIALS AND METHODS Two three-dimensional finite element models for wide platform and platform switching were created. In the wide platform model, a wide platform abutment was connected to a wide platform implant. In the platform switching model, the wide platform abutment of the wide platform model was replaced by a regular platform abutment. A contact condition was set between the implant components. A vertical load of 300 N was applied to the crown. The maximum von Mises stress values and displacements of the two models were compared to analyze the biomechanical behavior of the models. RESULTS In the two models, the stress was mainly concentrated at the bottom of the abutment and the top surface of the implant in both models. However, the von Mises stress values were much higher in the platform switching model in most of the components, except for the bone. The highest von Mises values and stress distribution pattern of the bone were similar in the two models. The components of the platform switching model showed greater displacement than those of the wide platform model. CONCLUSION Due to the stress concentration generated in the implant and the prosthodontic components of the platform switched implant, the mechanical complications might occur when platform switching concept is used. PMID:28243389
Three-dimensional flow and turbulence structure in electrostatic precipitator
DEFF Research Database (Denmark)
Ullum, Thorvald Uhrskov; Larsen, Poul Scheel; Özcan, Oktay
2002-01-01
Stereo PIV is employed to study the three-dimensional velocity and turbulence fields in a laboratory model of a negative corona, barbed-wire, smooth-plate, electrostatic precipitator (figure 1). The study is focused on determining the parametric effects of axial development, mean current density Jm...... and bulk velocity U0 on secondary flows and turbulence levels and structures due to the action of the three-dimensional electrostatic field on the charged gas. At constant bulk velocity (U0 = 1 m/s) and current density (Jm = 0.4 mA/m2), secondary flows in the form of rolls of axial vorticity with swirl...... of normal Reynolds stresses. The effects of U0 and Jm on S and Tu (at fixed position between 6th and 7th electrode) are reasonably correlated by the electrohydrodynamic modulus NEHD = (Jm/bi)ly/(½rU02), where bi denotes the ion mobility and ly the electrode-plate distance....
A biorthogonality relationship for three-dimensional couple stress problem
Institute of Scientific and Technical Information of China (English)
LUO JianHui; LI QiuSheng; LIU GuangDong
2009-01-01
The duality solution for elasticity and the biorthogonality relationship have been well researched. Now the couple stress theory becomes a new research spot but there is few research for the biorthogonality relationship for couple stress theory comparing to classical elasticity. A new state vector is presented for three dimensional couple stress problems of prismatic structures. A new biorthogonality relation-ship of couple stress is discovered. The dual partial differential equations of couple stress problem are derived by the new state vector. By two important identical equations the new biorthogonality rela-tionship is proved based on the method of separation of variables. The symplectic orthogonality rela-tionship to three dimensional couple stress theory may be decomposed into two independently and symmetrically orthogonality relationships. The new biorthogonality relationship includes the symplectic orthogonality relationship. The biorthogonality relationship of couple stress may also be degenerated into the theory of elasticity. The new state vector and biorthogonality relationship provide theoretic foundation for the research on the schemes of separation of variables and eigenfunction expansion of couple stress theory.
Three-dimensional recurring patterns in excitable media
Energy Technology Data Exchange (ETDEWEB)
Biton, Y. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Rabinovitch, A., E-mail: avinoam@bgu.ac.il [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Braunstein, D. [Physics Department, Sami Shamoon College of Engineering, Beer-Sheva (Israel); Friedman, M. [Department of Information Systems Engineering, Ben-Gurion University, Beer-Sheva 84105 (Israel); Aviram, I. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)
2011-06-13
A new method to create three-dimensional periodic patterns in excitable media is presented. The method is demonstrated and the patterns are obtained with the help of two types of 3D 'spiral pairs' generators, which are respectively based on a 'corner effect' and a 'unidirectional propagation' processes. The results portray time-repeating patterns resembling fruits or potteries. The method is easy to implement and can be used to form other types of 3D patterns in excitable media. The question of periodicity of the patterns thus obtained is resolved by calculating the singular lines (filaments) around which they evolve and showing their unique reattachment property. Actual realizations could be conceived e.g. in chemical reactions such as Belousov-Zhabotinsky. Possible severe cardiac arrhythmias following the appearance of such patterns in the action potential of the heart are considered. -- Highlights: → New method to create three-dimensional periodic patterns in excitable media. → Singular lines (filaments) for the corner effect are presented. → Filaments are shown to exhibit periodic behavior.
Three-dimensional protonic conductivity in porous organic cage solids
Liu, Ming; Chen, Linjiang; Lewis, Scott; Chong, Samantha Y.; Little, Marc A.; Hasell, Tom; Aldous, Iain M.; Brown, Craig M.; Smith, Martin W.; Morrison, Carole A.; Hardwick, Laurence J.; Cooper, Andrew I.
2016-09-01
Proton conduction is a fundamental process in biology and in devices such as proton exchange membrane fuel cells. To maximize proton conduction, three-dimensional conduction pathways are preferred over one-dimensional pathways, which prevent conduction in two dimensions. Many crystalline porous solids to date show one-dimensional proton conduction. Here we report porous molecular cages with proton conductivities (up to 10-3 S cm-1 at high relative humidity) that compete with extended metal-organic frameworks. The structure of the organic cage imposes a conduction pathway that is necessarily three-dimensional. The cage molecules also promote proton transfer by confining the water molecules while being sufficiently flexible to allow hydrogen bond reorganization. The proton conduction is explained at the molecular level through a combination of proton conductivity measurements, crystallography, molecular simulations and quasi-elastic neutron scattering. These results provide a starting point for high-temperature, anhydrous proton conductors through inclusion of guests other than water in the cage pores.
Three-dimensional angular domain optical projection tomography
Ng, Eldon; Vasefi, Fartash; Roumeliotis, Michael; Kaminska, Bozena; Carson, Jeffrey J. L.
2011-03-01
Angular Domain Imaging (ADI) has been previously demonstrated to generate projection images of attenuating targets embedded within a turbid medium. The imaging system employs a silicon micro-tunnel array positioned between the sample and the detection system to reject scattered photons that have deviated from the initial propagation direction and to select for ballistic and quasi-ballistic photons that have retained their forward trajectory. Two dimensional tomographic images can be reconstructed from ADI projections collected at a multitude of angles. The objective of this work was to extend the system to three dimensions by collecting several tomographic images and stacking the reconstructed slices to generate a three dimensional volume representative of the imaging target. A diode laser (808nm, CW) with a beam expander was used to illuminate the sample cuvette. An Angular Filter Array (AFA) of 80 μm × 80 μm square-shaped tunnels 2 cm in length was used to select for image forming quasi-ballistic photons. Images were detected with a linear CCD. Our approach was to use a SCARA robot to rotate and translate the sample to collect sufficient projections to reconstruct a three dimensional volume. A custom designed 3D target consisting of 4 truncated cones was imaged and reconstructed with filtered backprojection and iterative methods. A 0.5 mm graphite rod was used to collect the forward model, while a truncated pseudoinverse was used to approximate the backward model for the iterative algorithm.
Three Dimensional Culture of Human Renal Cell Carcinoma Organoids.
Directory of Open Access Journals (Sweden)
Cynthia A Batchelder
Full Text Available Renal cell carcinomas arise from the nephron but are heterogeneous in disease biology, clinical behavior, prognosis, and response to systemic therapy. Development of patient-specific in vitro models that efficiently and faithfully reproduce the in vivo phenotype may provide a means to develop personalized therapies for this diverse carcinoma. Studies to maintain and model tumor phenotypes in vitro were conducted with emerging three-dimensional culture techniques and natural scaffolding materials. Human renal cell carcinomas were individually characterized by histology, immunohistochemistry, and quantitative PCR to establish the characteristics of each tumor. Isolated cells were cultured on renal extracellular matrix and compared to a novel polysaccharide scaffold to assess cell-scaffold interactions, development of organoids, and maintenance of gene expression signatures over time in culture. Renal cell carcinomas cultured on renal extracellular matrix repopulated tubules or vessel lumens in renal pyramids and medullary rays, but cells were not observed in glomeruli or outer cortical regions of the scaffold. In the polysaccharide scaffold, renal cell carcinomas formed aggregates that were loosely attached to the scaffold or free-floating within the matrix. Molecular analysis of cell-scaffold constructs including immunohistochemistry and quantitative PCR demonstrated that individual tumor phenotypes could be sustained for up to 21 days in culture on both scaffolds, and in comparison to outcomes in two-dimensional monolayer cultures. The use of three-dimensional scaffolds to engineer a personalized in vitro renal cell carcinoma model provides opportunities to advance understanding of this disease.
Three-Dimensional Turbulent Reconnection Induced by the Plasmoid Instability
Bhattacharjee, A.; Huang, Y. M.
2014-12-01
It has been established that the Sweet-Parker current layer in high-Lundquist-number reconnection is unstable to the super-Alfvenic plasmoid instability. Past two-dimensional magnetohydrodynamic simulations have demonstrated that the plasmoid instability leads to a new regime in which the Sweet-Parker current layer evolves into a chain of plasmoids connected by secondary current sheets and the averaged reconnection rate becomes nearly independent of the Lundquist number. In a three-dimensional configuration with a guide field, the additional degree of freedom allows plasmoid instabilities to grow at oblique angles [S. Baalrud et al. Phys. Plasmas 19, 022101 (2012)] and develop the complex dynamics of flux ropes which overlap, cause field-line stochasticization, and self-generate a turbulent state. Three-dimensional simulations in the high-Lundquist-number regime show the formation of cigar-shaped eddies elongated in the direction of the local magnetic field, which is a signature of anisotropic MHD turbulence. Furthermore, the energy fluctuation spectra are found to satisfy power laws in the inertial range. The averaged 3D reconnection rate in the self-generated turbulent state is of the order of a hundredth of the characteristic Alfven speed, which is an order of magnitude lower than the reconnection rate reported in recent studies of externally driven 3D turbulent reconnection. The physical reasons for these differences will be discussed.
Vocal Fold Pathologies and Three-Dimensional Flow Separation Phenomena
Apostoli, Adam G.; Weiland, Kelley S.; Plesniak, Michael W.
2013-11-01
Polyps and nodules are two different pathologies, which are geometric abnormalities that form on the medial surface of the vocal folds, and have been shown to significantly disrupt a person's ability to communicate. Although the mechanism by which the vocal folds self-oscillate and the three-dimensional nature of the glottal jet has been studied, the effect of irregularities caused by pathologies is not fully understood. Examining the formation and evolution of vortical structures created by a geometric protuberance is important, not only for understanding the aerodynamic forces exerted by these structures on the vocal folds, but also in the treatment of the above-mentioned pathological conditions. Using a wall-mounted prolate hemispheroid with a 2:1 aspect ratio in cross flow, the present investigation considers three-dimensional flow separation induced by a model vocal fold polyp. Building on previous work using skin friction line visualization, both the velocity flow field and wall pressure measurements around the model polyp are presented and compared. Supported by the National Science Foundation, Grant No. CBET-1236351 and GW Center for Biomimetics and Bioinspired Engineering (COBRE).
Three-dimensional bioprinting in tissue engineering and regenerative medicine.
Gao, Guifang; Cui, Xiaofeng
2016-02-01
With the advances of stem cell research, development of intelligent biomaterials and three-dimensional biofabrication strategies, highly mimicked tissue or organs can be engineered. Among all the biofabrication approaches, bioprinting based on inkjet printing technology has the promises to deliver and create biomimicked tissue with high throughput, digital control, and the capacity of single cell manipulation. Therefore, this enabling technology has great potential in regenerative medicine and translational applications. The most current advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review, including vasculature, muscle, cartilage, and bone. In addition, the benign side effect of bioprinting to the printed mammalian cells can be utilized for gene or drug delivery, which can be achieved conveniently during precise cell placement for tissue construction. With layer-by-layer assembly, three-dimensional tissues with complex structures can be printed using converted medical images. Therefore, bioprinting based on thermal inkjet is so far the most optimal solution to engineer vascular system to the thick and complex tissues. Collectively, bioprinting has great potential and broad applications in tissue engineering and regenerative medicine. The future advances of bioprinting include the integration of different printing mechanisms to engineer biphasic or triphasic tissues with optimized scaffolds and further understanding of stem cell biology.
Three-dimensional vision sensors for autonomous robots
Uchiyama, Takashi; Okabayashi, Keizyu; Wakitani, Jun
1993-09-01
A three dimensional measurement system, which is important for developing autonomous robots is described. Industrial robots used in today's plants are of the preprogrammed teaching playback type. It is necessary to develop autonomous robots which can work based on sensor information for intelligent manufacturing systems. Moreover, practical use of robots which work in unstructured environments such as outdoors and in space is expected. To realize this, a function to measure objects and the environment three-dimensionally is a key technology. Additional important requirements for robotic sensors are real-time processing and compactness. We have developed smart 3-D vision sensors for the purpose of realizing autonomous robots. These are two kinds of sensors with different functions corresponding to the application. One is a slitted light range finder ( SLRF ) to measure stationary objects. The other is a real-time tracking vision ( RTTV ) which can measure moving objects at high speed. SLRF uses multiple slitted lights which are generated by a semiconductor laser through an interference filter and a cylindrical lens. Furthermore, we developed a liquid crystal shutter with multiple electrodes. We devised a technique to make coded slitted light by putting this shutter in front of the light source. As a result, using the principle of triangulation, objects can be measured in three dimensions. In addition, high-speed image input was enabled by projecting multiple slitted light at the same time. We have confirmed the effectiveness of the SLRF applied to a hand-eye system using a robot.
Three-dimensional protonic conductivity in porous organic cage solids
Liu, Ming; Chen, Linjiang; Lewis, Scott; Chong, Samantha Y.; Little, Marc A.; Hasell, Tom; Aldous, Iain M.; Brown, Craig M.; Smith, Martin W.; Morrison, Carole A.; Hardwick, Laurence J.; Cooper, Andrew I.
2016-01-01
Proton conduction is a fundamental process in biology and in devices such as proton exchange membrane fuel cells. To maximize proton conduction, three-dimensional conduction pathways are preferred over one-dimensional pathways, which prevent conduction in two dimensions. Many crystalline porous solids to date show one-dimensional proton conduction. Here we report porous molecular cages with proton conductivities (up to 10−3 S cm−1 at high relative humidity) that compete with extended metal-organic frameworks. The structure of the organic cage imposes a conduction pathway that is necessarily three-dimensional. The cage molecules also promote proton transfer by confining the water molecules while being sufficiently flexible to allow hydrogen bond reorganization. The proton conduction is explained at the molecular level through a combination of proton conductivity measurements, crystallography, molecular simulations and quasi-elastic neutron scattering. These results provide a starting point for high-temperature, anhydrous proton conductors through inclusion of guests other than water in the cage pores. PMID:27619230
Three-dimensional saltating processes of multiple sediment particles
Institute of Scientific and Technical Information of China (English)
Hsiao-Wen WANG; Hong-Yuan LEE; Po-Ning LEE
2009-01-01
The purpose of this study was to investigate the interacting mechanism between the saltating particles near a channel bed.A three-dimensional real-time flow visualization technique was developed to measure the interparticle collision behaviors during the saltating process.Based on the experimental data,the distribution of the collision points was found to be symmetric.This confirms the assumption that the projections of the collision points onto the reasonable plane are uniformly distributed.A three-dimensional saltating model was also developed.This model produced satisfactory results.The model is able to simulate the continuous saltating trajectories of several particles.The simulated dimensionless saltating height,longitudinal and vertical saltation velocity components were found to increase as the dimensionless particle diameter and the dimensionless flow transport capacity parameter increase,while the simulated lateral saltation velocity component varies inversely with the dimensionless flow transport capacity parameter.A regression equation for the bed load transport rate was also obtained.
Three-dimensional flows in a transonic compressor rotor
Reid, Lonnie; Celestina, Mark L.; Dewitt, Kenneth; Keith, Theo
1991-01-01
This study involves an experimental and numerical investigation of the three-dimensional flows in a transonic compressor rotor. A variety of data which could be used, in a complementary fashion, to validate/calibrate the computational fluid dynamics turbomachinery code and improve understanding of the flow physics, were acquired. Detailed radial survey data which consisted of total pressure, total temperature, static pressure and flow angle were obtained at stations upstream and downstream of the rotor blade. Detailed velocity and turbulence profiles were obtained upstream of the rotor and used as the upstream boundary conditions for the numerical analysis. Calibrated flush-mounted hot film probes were used to measure wall shear stress on the hub and casing walls upstream of the rotor. The blade-to-blade shear-stress angle distributions were obtained at two axial locations on the rotor casing, using flush-mounted hot film probes. A numerical analysis conducted using a three-dimensional Navier-Stokes code was compared with the experimental results.
Topology of Flow Separation on Three-Dimensional Bodies
Chapman, Gary T.; Yates, Leslie A.
1991-01-01
In recent years there has been extensive research on three-dimensional flow separation. There are two different approaches: the phenomenological approach and a mathematical approach using topology. These two approaches are reviewed briefly and the shortcomings of some of the past works are discussed. A comprehensive approach applicable to incompressible and compressible steady-state flows as well as incompressible unsteady flow is then presented. The approach is similar to earlier topological approaches to separation but is more complete and in some cases adds more emphasis to certain points than in the past. To assist in the classification of various types of flow, nomenclature is introduced to describe the skin-friction portraits on the surface. This method of classification is then demonstrated on several categories of flow to illustrate particular points as well as the diversity of flow separation. The categories include attached, two-dimensional separation and three different types of simple, three-dimensional primary separation, secondary separation, and compound separation. Hypothetical experiments are utilized to illustrate the topological terminology and its role in characterizing these flows. These hypothetical experiments use colored oil injected onto the surface at singular points in the skin-friction portrait. Actual flow-visualization information, if available, is used to corroborate the hypothetical examples.
Energy Technology Data Exchange (ETDEWEB)
Cavinato, Christianne C.; Campos, Leticia L., E-mail: ccavinato@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B., E-mail: bhsouza@unifesp.b, E-mail: daros.kellen@unifesp.b, E-mail: rbitel-li.ddi@epm.b [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagem; Giordani, Adelmo J. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Servico de Radioterapia
2011-07-01
This work aims to compare the dose-response of the Fricke xylenol gel (FXG) dosimeter developed at IPEN using 270 Bloom gelatin from porcine skin made in Brazil evaluated using the magnetic resonance imaging (MRI) technique with the dosimetric response evaluated using the optical absorption (OA) spectrophotometry technique, in order to verify the possibility of quality assurance (QA) and reproducibility of FXG dosimeter to be carried out routinely using the OA technique for three-dimensional conformal radiotherapy (3DCRT) application using a 6 MV photons linear accelerator. The response in function of the absorbed dose of FXG dosimeter developed at IPEN presents linear behavior in clinical interest dose range when irradiated with Co-60 gamma radiation and 6 MV photons and evaluated using the MRI and OA techniques. The results indicate that the optical technique can be used for QA of FXG dosemeter when used in the possible application in QA of 3DCRT. (author)
Three-dimensional stability of growing boundary layers
Nayfeh, A. H.
1980-01-01
A theory is developed for the linear stability of three-dimensional growing boundary layers. The method of multiple scales is used to derive partial-differential equations describing the temporal and spatial evolution of the complex amplitudes and wavenumbers of the disturbances. In general, these equations are elliptic unless certain conditions are satisfied. For a monochromatic disturbance, these conditions demand that the ratio of the components of the complex group velocity be real and thereby relate the direction of growth of the disturbance to the disturbance wave angle. For a nongrowing boundary layer, this condition reduces to d-alpha/d-beta being real, in agreement with the result obtained by using the saddle-point method. For a wavepacket, these conditions demand that the components of the group velocity be real.
Surgical accuracy of three-dimensional virtual planning
DEFF Research Database (Denmark)
Stokbro, Kasper; Aagaard, Esben; Torkov, Peter;
2016-01-01
This retrospective study evaluated the precision and positional accuracy of different orthognathic procedures following virtual surgical planning in 30 patients. To date, no studies of three-dimensional virtual surgical planning have evaluated the influence of segmentation on positional accuracy...... and transverse expansion. Furthermore, only a few have evaluated the precision and accuracy of genioplasty in placement of the chin segment. The virtual surgical plan was compared with the postsurgical outcome by using three linear and three rotational measurements. The influence of maxillary segmentation...... was analyzed in both superior and inferior maxillary repositioning. In addition, transverse surgical expansion was compared with the postsurgical expansion obtained. An overall, high degree of linear accuracy between planned and postsurgical outcomes was found, but with a large standard deviation. Rotational...
Hamiltonian thermodynamics of three-dimensional dilatonic black hole
Dias, Gonçalo A S
2008-01-01
The action for a class of three-dimensional dilaton-gravity theories with a cosmological constant can be recast in a Brans-Dicke type action, with its free $\\omega$ parameter. These theories have static spherically symmetric black holes. Those with well formulated asymptotics are studied through a Hamiltonian formalism, and their thermodynamical properties are found out. The theories studied are general relativity ($\\omega\\to\\infty$), a dimensionally reduced cylindrical four-dimensional general relativity theory ($\\omega=0$), and a theory representing a class of theories ($\\omega=-3$). The Hamiltonian formalism is setup in three dimensions through foliations on the right region of the Carter-Penrose diagram, with the bifurcation 1-sphere as the left boundary, and anti-de Sitter infinity as the right boundary. The metric functions on the foliated hypersurfaces are the canonical coordinates. The Hamiltonian action is written, the Hamiltonian being a sum of constraints. One finds a new action which yields an unc...
A Review of Three-Dimensional Printing in Tissue Engineering.
Sears, Nick A; Seshadri, Dhruv R; Dhavalikar, Prachi S; Cosgriff-Hernandez, Elizabeth
2016-08-01
Recent advances in three-dimensional (3D) printing technologies have led to a rapid expansion of applications from the creation of anatomical training models for complex surgical procedures to the printing of tissue engineering constructs. In addition to achieving the macroscale geometry of organs and tissues, a print layer thickness as small as 20 μm allows for reproduction of the microarchitectures of bone and other tissues. Techniques with even higher precision are currently being investigated to enable reproduction of smaller tissue features such as hepatic lobules. Current research in tissue engineering focuses on the development of compatible methods (printers) and materials (bioinks) that are capable of producing biomimetic scaffolds. In this review, an overview of current 3D printing techniques used in tissue engineering is provided with an emphasis on the printing mechanism and the resultant scaffold characteristics. Current practical challenges and technical limitations are emphasized and future trends of bioprinting are discussed.
Accurate complex scaling of three dimensional numerical potentials.
Cerioni, Alessandro; Genovese, Luigi; Duchemin, Ivan; Deutsch, Thierry
2013-05-28
The complex scaling method, which consists in continuing spatial coordinates into the complex plane, is a well-established method that allows to compute resonant eigenfunctions of the time-independent Schrödinger operator. Whenever it is desirable to apply the complex scaling to investigate resonances in physical systems defined on numerical discrete grids, the most direct approach relies on the application of a similarity transformation to the original, unscaled Hamiltonian. We show that such an approach can be conveniently implemented in the Daubechies wavelet basis set, featuring a very promising level of generality, high accuracy, and no need for artificial convergence parameters. Complex scaling of three dimensional numerical potentials can be efficiently and accurately performed. By carrying out an illustrative resonant state computation in the case of a one-dimensional model potential, we then show that our wavelet-based approach may disclose new exciting opportunities in the field of computational non-Hermitian quantum mechanics.
Reconstructing the three-dimensional local dark matter velocity distribution
Kavanagh, Bradley J
2016-01-01
Directionally sensitive dark matter (DM) direct detection experiments present the only way to observe the full three-dimensional velocity distribution of the Milky Way halo local to Earth. In this work we compare methods for extracting information about the local DM velocity distribution from a set of recoil directions and energies in a range of hypothetical directional and non-directional experiments. We compare a model independent empirical parameterisation of the velocity distribution based on an angular discretisation with a model dependent approach which assumes knowledge of the functional form of the distribution. The methods are tested under three distinct halo models which cover a range of possible phase space structures for the local velocity distribution: a smooth Maxwellian halo, a tidal stream and a debris flow. In each case we use simulated directional data to attempt to reconstruct the shape and parameters describing each model as well as the DM particle properties. We find that the empirical pa...
Three-dimensional structural characterization of nonwoven fabrics.
Venu, Lalith B Suragani; Shim, Eunkyoung; Anantharamaiah, Nagendra; Pourdeyhimi, Behnam
2012-12-01
Nonwoven materials are found in a gamut of critical applications. This is partly due to the fact that these structures can be produced at high speed and engineered to deliver unique functionality at low cost. The behavior of these materials is highly dependent on alignment of fibers within the structure. The ability to characterize and also to control the structure is important, but very challenging due to the complex nature of the structures. Thus, to date, focus has been placed mainly on two-dimensional analysis techniques for describing the behavior of nonwovens. This article demonstrates the utility of three-dimensional (3D) digital volumetric imaging technique for visualizing and characterizing a complex 3D class of nonwoven structures produced by hydroentanglement.
Optimal tetrahedral mesh generation for three-dimensional point set
Institute of Scientific and Technical Information of China (English)
秦开怀; 吴边; 关右江; 葛振州
1997-01-01
Three-dimensional (3D) tnangulation is a basic topic in computer graphics. It is considered very difficult to obtain the global optimal 3D triangulatlon, such as the triangulation which satisfies the max-min solid angle criterion A new method called genetic tetrahedral mesh generation algorithm (GTMGA for short) is presented. GT-MGA is based on the principle of genetic algorithm and aims at the global optimal triangulation. With a multi-objective fitness function, GTMGA is able to perform optimizations for different requirements. New crossover operator and mutation operator, polyhedron crossover and polyhedron mutation, are used in GTMGA. It is shown by the experimental results that GTMGA works better than both the 3D Delaunay triangulation and the algorithm based on local transformations.
A Three-Dimensional Cooperative Guidance Law of Multimissile System
Directory of Open Access Journals (Sweden)
Xing Wei
2015-01-01
Full Text Available In order to conduct saturation attacks on a static target, the cooperative guidance problem of multimissile system is researched. A three-dimensional guidance model is built using vector calculation and the classic proportional navigation guidance (PNG law is extended to three dimensions. Based on this guidance law, a distributed cooperative guidance strategy is proposed and a consensus protocol is designed to coordinate the time-to-go commands of all missiles. Then an expert system, which contains two extreme learning machines (ELM, is developed to regulate the local proportional coefficient of each missile according to the command. All missiles can arrive at the target simultaneously under the assumption that the multimissile network is connected. A simulation scenario is given to demonstrate the validity of the proposed method.
Three-dimensional combustion in type Ia supernovae
Khokhlov, A M; Wheeler, J C
1996-01-01
Turbulent combustion is three-dimensional. Turbulence in a Type Ia supernova is driven on large scales by the buoyancy of burning products. The turbulent cascade penetrates down to very small scales, and makes the rate of deflagration independent of the microphysics. The competition between the turbulent cascade and the freeze-out of turbulent motions due to stellar expansion determines the largest scale participating in the cascade. This sets the bulk rate of a deflagration in a supernova. The freeze-out limits the bulk rate of deflagration to a value that makes a powerful explosion impossible. Two-dimensional simulations cannot capture these essential elements of turbulent combustion, even in principle. A powerful delayed detonation explosion can take place if the burning makes a transition to a detonation. A deflagration to detonation transition (DDT) can occur in a layer of mixed cold fuel and hot burning products created either inside an active turbulent burning region by a high intensity of turbulence, ...
Mapping three-dimensional temperature in microfluidic chip.
Wu, Jinbo
2013-11-25
Three-dimensional (3D) temperature mapping method with high spatial resolution and acquisition rate is of vital importance in evaluating thermal processes in micro-environment. We have synthesized a new temperature-sensitive functional material (Rhodamine B functionalized Polydimethylsiloxane). By performing optical sectioning of this material, we established an advanced method for visualizing the micro-scale 3D thermal distribution inside microfluidic chip with down to 10 ms temporal resolution and 2 ~ 6 °C temperature resolution depending the capture parameters. This method is successfully applied to monitor the local temperature variation throughout micro-droplet heat transfer process and further reveal exothermic nanoliter droplet reactions to be unique and milder than bench-top experiment.
Characterization of highly anisotropic three-dimensionally nanostructured surfaces
Schmidt, Daniel
2013-01-01
Generalized ellipsometry, a non-destructive optical characterization technique, is employed to determine geometrical structure parameters and anisotropic dielectric properties of highly spatially coherent three-dimensionally nanostructured thin films grown by glancing angle deposition. The (piecewise) homogeneous biaxial layer model approach is discussed, which can be universally applied to model the optical response of sculptured thin films with different geometries and from diverse materials, and structural parameters as well as effective optical properties of the nanostructured thin films are obtained. Alternative model approaches for slanted columnar thin films, anisotropic effective medium approximations based on the Bruggeman formalism, are presented, which deliver results comparable to the homogeneous biaxial layer approach and in addition provide film constituent volume fraction parameters as well as depolarization or shape factors. Advantages of these ellipsometry models are discussed on the example ...
Three-dimensional structure of a sunspot light bridge
Felipe, T; Khomenko, E; Kuckein, C; Ramos, A Asensio; Balthasar, H; Berkefeld, T; Denker, C; Feller, A; Franz, M; Hofmann, A; Kiess, C; Lagg, A; Nicklas, H; Suárez, D Orozco; Yabar, A Pastor; Rezaei, R; Schlichenmaier, R; Schmidt, D; Schmidt, W; Sigwarth, M; Sobotka, M; Solanki, S K; Soltau, D; Staude, J; Strassmeier, K G; Volkmer, R; von der Lühe, O; Waldmann, T
2016-01-01
Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar physics. Light bridges are commonly present during sunspot decay, but a comprehensive picture of their role in the removal of photospheric magnetic field is still missing. We study the three dimensional configuration of a sunspot and in particular its light bridge during one of the last stages of its decay. We present the magnetic and thermodynamical stratification inferred from full Stokes inversions of the photospheric Si I 10827 \\AA\\ and Ca I 10839 \\AA\\ lines obtained with the GREGOR Infrared Spectrograph of the GREGOR telescope at Observatorio del Teide, Tenerife, Spain. The analysis is complemented by a study of continuum images covering the disk passage of the active region, which are provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. The sunspot shows a light bridge with penumbral continuum intensity that separates the c...
Three-dimensional pharmacophore screening for fentanyl derivatives
Institute of Scientific and Technical Information of China (English)
Ming Liu; Zhiguo Sun; Wenxiang Hu
2012-01-01
Fentanyl is a highly selective μ-opioid receptor agonist with high analgesic activity. Three-dimensional pharmacophore models were built from a set of 50 fentanyl derivatives. These were employed to elucidate ligand-receptor interactions using information derived only from the ligand structure to identify new potential lead compounds. The present studies demonstrated that three hydrophobic regions, one positive ionizable region and two hydrogen bond acceptor region sites located on the molecule seem to be essential for analgesic activity. The results of the comparative molecular field analysis model suggested that both steric and electrostatic interactions play important roles. The contributions from steric and electrostatic fields for the model were 0.621 and 0.379, respectively. The pharmacophore model provides crucial information about how well the common features of a subject molecule overlap with the hypothesis model, which is very valuable for designing and optimizing new active structures.
Scale invariance of parity-invariant three-dimensional QED
Karthik, Nikhil; Narayanan, Rajamani
2016-09-01
We present numerical evidences using overlap fermions for a scale-invariant behavior of parity-invariant three-dimensional QED with two flavors of massless two-component fermions. Using finite-size scaling of the low-lying eigenvalues of the massless anti-Hermitian overlap Dirac operator, we rule out the presence of a bilinear condensate and estimate the mass anomalous dimension. The eigenvectors associated with these low-lying eigenvalues suggest critical behavior in the sense of a metal-insulator transition. We show that there is no mass gap in the scalar and vector correlators in the infinite-volume theory. The vector correlator does not acquire an anomalous dimension. The anomalous dimension associated with the long-distance behavior of the scalar correlator is consistent with the mass anomalous dimension.
Three dimensional dynamic mode decomposition of premixed turbulent jet flames
Grenga, Temistocle; Macart, Jonathan; Mueller, Michael
2016-11-01
Analysis of turbulent combustion DNS data largely focuses on statistical analyses. However, turbulent combustion is highly unsteady and dynamic. In this work, Dynamic Mode Decomposition (DMD) will be explored as a tool for dynamic analysis of turbulent combustion DNS data, specifically a series of low Mach number spatially-evolving turbulent planar premixed hydrogen/air jet flames. DMD decomposes data into coherent modes with corresponding growth rates and oscillatory frequencies. The method identifies structures unbiased by energy so is particularly well suited to exploring dynamic processes at scales smaller than the largest, energy-containing scales of the flow and that may not be co-located in space and time. The focus of this work will be on both the physical insights that can potentially be derived from DMD modes and the computational issues associated with applying DMD to large three-dimensional DNS datasets.
Electric transport in three-dimensional skyrmion/monopole crystal
Zhang, Xiao-Xiao; Mishchenko, Andrey S.; De Filippis, Giulio; Nagaosa, Naoto
2016-11-01
We study theoretically the transport properties of a three-dimensional spin texture made from three orthogonal helices, which is essentially a lattice of monopole-antimonopole pairs connected by skyrmion strings. This spin structure is proposed for MnGe based on neutron scattering experiments as well as Lorentz transmission electron microscopy observations. Equipped with a sophisticated spectral analysis method, we adopt the finite temperature Green's function technique to calculate the longitudinal dc electric transport in such a system. We consider conduction electrons interacting with spin waves of the topologically nontrivial spin texture, wherein fluctuations of monopolar emergent magnetic fields enter. We study in detail the behavior of electric resistivity under the influence of temperature, external magnetic field, and a characteristic monopole motion, especially a novel magnetoresistivity effect describing the latest experimental observations in MnGe, wherein a topological phase transition signifying strong correlations is identified.
DNA Origami with Complex Curvatures in Three-Dimensional Space
Energy Technology Data Exchange (ETDEWEB)
Han, Dongran; Pal, Suchetan; Nangreave, Jeanette; Deng, Zhengtao; Liu, Yan; Yan, Hao
2011-04-14
We present a strategy to design and construct self-assembling DNA nanostructures that define intricate curved surfaces in three-dimensional (3D) space using the DNA origami folding technique. Double-helical DNA is bent to follow the rounded contours of the target object, and potential strand crossovers are subsequently identified. Concentric rings of DNA are used to generate in-plane curvature, constrained to 2D by rationally designed geometries and crossover networks. Out-of-plane curvature is introduced by adjusting the particular position and pattern of crossovers between adjacent DNA double helices, whose conformation often deviates from the natural, B-form twist density. A series of DNA nanostructures with high curvature—such as 2D arrangements of concentric rings and 3D spherical shells, ellipsoidal shells, and a nanoflask—were assembled.
Three-dimensional THz lumped-circuit resonators.
Todorov, Yanko; Desfond, Pascal; Belacel, Cherif; Becerra, Loïc; Sirtori, Carlo
2015-06-29
Our work describes a novel three dimensional meta-material resonator design for optoelectronic applications in the THz spectral range. In our resonant circuits, the capacitors are formed by double-metal regions cladding a dielectric core. Unlike conventional planar metamaterials, the electric field is perpendicular to the surface and totally confined in the dielectric core. Furthermore, the magnetic field, confined in the inductive part, is parallel to the electric field, ruling out coupling through propagation effects. Our geometry thus combines the benefit of double-metal structures that provide parallel plate capacitors, while maintaining the ability of meta-material resonators to adjust independently the capacitive and inductive parts. Furthermore, in our geometry, a constant bias can be applied across the dielectric, making these resonators very suitable for applications such as ultra-low dark current THz quantum detectors and amplifiers based on quantum cascade gain medium.
Three-dimensional antenna models for fusion experiments
Carter, M. D.; Wang, C. Y.; Hogan, J. T.; Harris, J. H.; Hoffman, D. J.; Rasmussen, D. A.; Ryan, P. M.; Stallings, D. S.; Batchelor, D. B.; Beaumont, B.; Hutter, T.; Saoutic, B.
1996-02-01
The development of the RANT3D code has permitted the systematic study of the effect of three-dimensional structures on the launched power spectrum for antennas in the ion cyclotron range of frequencies. The code allows the septa between current straps to be modeled with arbitrary heights and permits the antenna to interact with other structures in the tokamak. In this paper we present comparisons of calculated loading with the Tokamak Fusion Test Reactor and Tore Supra experiments, demonstrate the effects on loading caused by positioning uncertainties for an antenna in Tore Supra, and show electric field patterns near the Tore Supra antenna. A poloidal component in the static magnetic field for the plasma response is included in the near-field calculations using the warm plasma code, GLOSI. Preliminary estimates for the heat flux on the bumper limiters during typical operation in Tore Supra are also presented.
Three-dimensional antenna models for fusion experiments
Energy Technology Data Exchange (ETDEWEB)
Carter, M.D.; Wang, C.Y.; Hogan, J.T.; Harris, J.H.; Hoffman, D.J.; Rasmussen, D.A.; Ryan, P.M.; Stallings, D.S.; Batchelor, D.B. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8071, (United States); Beaumont, B.; Hutter, T.; Saoutic, B. [Association Euratom-CEA, Department de Recherche sur la Fusion Controlee, Centre d`Etudes de Cadarache, 13108 Saint Paul Lez Durance, Cedex (France)
1996-02-01
The development of the RANT3D code has permitted the systematic study of the effect of three-dimensional structures on the launched power spectrum for antennas in the ion cyclotron range of frequencies. The code allows the septa between current straps to be modeled with arbitrary heights and permits the antenna to interact with other structures in the tokamak. In this paper we present comparisons of calculated loading with the Tokamak Fusion Test Reactor and Tore Supra experiments, demonstrate the effects on loading caused by positioning uncertainties for an antenna in Tore Supra, and show electric field patterns near the Tore Supra antenna. A poloidal component in the static magnetic field for the plasma response is included in the near-field calculations using the warm plasma code, GLOSI. Preliminary estimates for the heat flux on the bumper limiters during typical operation in Tore Supra are also presented. {copyright} {ital 1996 American Institute of Physics.}
Visualising very large phylogenetic trees in three dimensional hyperbolic space
Directory of Open Access Journals (Sweden)
Liberles David A
2004-04-01
Full Text Available Abstract Background Common existing phylogenetic tree visualisation tools are not able to display readable trees with more than a few thousand nodes. These existing methodologies are based in two dimensional space. Results We introduce the idea of visualising phylogenetic trees in three dimensional hyperbolic space with the Walrus graph visualisation tool and have developed a conversion tool that enables the conversion of standard phylogenetic tree formats to Walrus' format. With Walrus, it becomes possible to visualise and navigate phylogenetic trees with more than 100,000 nodes. Conclusion Walrus enables desktop visualisation of very large phylogenetic trees in 3 dimensional hyperbolic space. This application is potentially useful for visualisation of the tree of life and for functional genomics derivatives, like The Adaptive Evolution Database (TAED.
Microassembly of semiconductor three-dimensional photonic crystals.
Aoki, Kanna; Miyazaki, Hideki T; Hirayama, Hideki; Inoshita, Kyoji; Baba, Toshihiko; Sakoda, Kazuaki; Shinya, Norio; Aoyagi, Yoshinobu
2003-02-01
Electronic devices and their highly integrated components formed from semiconductor crystals contain complex three-dimensional (3D) arrangements of elements and wiring. Photonic crystals, being analogous to semiconductor crystals, are expected to require a 3D structure to form successful optoelectronic devices. Here, we report a novel fabrication technology for a semiconductor 3D photonic crystal by uniting integrated circuit processing technology with micromanipulation. Four- to twenty-layered (five periods) crystals, including one with a controlled defect, for infrared wavelengths of 3-4.5 microm, were integrated at predetermined positions on a chip (structural error crystals for such short wavelengths have not been reported before. This technology offers great potential for the production of optical wavelength photonic crystal devices.
Three-dimensional ocean sensor networks: A survey
Wang, Yu; Liu, Yingjian; Guo, Zhongwen
2012-12-01
The past decade has seen a growing interest in ocean sensor networks because of their wide applications in marine research, oceanography, ocean monitoring, offshore exploration, and defense or homeland security. Ocean sensor networks are generally formed with various ocean sensors, autonomous underwater vehicles, surface stations, and research vessels. To make ocean sensor network applications viable, efficient communication among all devices and components is crucial. Due to the unique characteristics of underwater acoustic channels and the complex deployment environment in three dimensional (3D) ocean spaces, new efficient and reliable communication and networking protocols are needed in design of ocean sensor networks. In this paper, we aim to provide an overview of the most recent advances in network design principles for 3D ocean sensor networks, with focuses on deployment, localization, topology design, and position-based routing in 3D ocean spaces.
Three-dimensional optical tomography of the premature infant brain
Energy Technology Data Exchange (ETDEWEB)
Hebden, Jeremy C [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London (United Kingdom); Gibson, Adam [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London (United Kingdom); Yusof, Rozarina Md [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London (United Kingdom); Everdell, Nick [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London (United Kingdom); Hillman, Elizabeth M C [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London (United Kingdom); Delpy, David T [Department of Medical Physics and Bioengineering, University College London, 11-20 Capper Street, London (United Kingdom); Arridge, Simon R [Department of Computer Science, University College London, Gower Street, London (United Kingdom); Austin, Topun [Department of Paediatrics and Child Health, University College London, 5 University Street, London (United Kingdom); Meek, Judith H [Department of Paediatrics and Child Health, University College London, 5 University Street, London (United Kingdom); Wyatt, John S [Department of Paediatrics and Child Health, University College London, 5 University Street, London (United Kingdom)
2002-12-07
For the first time, three-dimensional images of the newborn infant brain have been generated using measurements of transmitted light. A 32-channel time-resolved imaging system was employed, and data were acquired using custom-made helmets which couple source fibres and detector bundles to the infant head. Images have been reconstructed using measurements of mean flight time relative to those acquired on a homogeneous reference phantom, and using a head-shaped 3D finite-element-based forward model with an external boundary constrained to match the measured positions of the sources and detectors. Results are presented for a premature infant with a cerebral haemorrhage predominantly located within the left ventricle. Images representing the distribution of absorption at 780 nm and 815 nm reveal an asymmetry consistent with the haemorrhage, and corresponding maps of blood volume and fractional oxygen saturation are generally within expected physiological values.
Three-dimensional tertiary structure of yeast phenylalanine transfer RNA
Kim, S. H.; Sussman, J. L.; Suddath, F. L.; Quigley, G. J.; Mcpherson, A.; Wang, A. H. J.; Seeman, N. C.; Rich, A.
1974-01-01
Results of an analysis and interpretation of a 3-A electron density map of yeast phenylalanine transfer RNA. Some earlier detailed assignments of nucleotide residues to electron density peaks are found to be in error, even though the overall tracing of the backbone conformation of yeast phenylalanine transfer RNA was generally correct. A new, more comprehensive interpretation is made which makes it possible to define the tertiary interactions in the molecule. The new interpretation makes it possible to visualize a number of tertiary interactions which not only explain the structural role of most of the bases which are constant in transfer RNAs, but also makes it possible to understand in a direct and simple fashion the chemical modification data on transfer RNA. In addition, this pattern of tertiary interactions provides a basis for understanding the general three-dimensional folding of all transfer RNA molecules.
Three-Dimensional Printing of Drug-Eluting Implants
DEFF Research Database (Denmark)
Water, Jorrit Jeroen; Bohr, Adam; Bøtker, Johan Peter
2015-01-01
The aim of the present work was to investigate the potential of three-dimensional (3D) printing as a manufacturing method for products intended for personalized treatments by exploring the production of novel polylactide-based feedstock materials for 3D printing purposes. Nitrofurantoin (NF......) and hydroxyapatite (HA) were successfully mixed and extruded with up to 30% drug load with and without addition of 5% HA in polylactide strands, which were subsequently 3D-printed into model disc geometries (10 × 2 mm). X-ray powder diffraction analysis showed that NF maintained its anhydrate solid form during...... of custom-made, drug-loaded feedstock materials for 3D printing of pharmaceutical products for controlled release....
Optimized Fourier representations for three-dimensional magnetic surfaces
Energy Technology Data Exchange (ETDEWEB)
Hirshman, S.P.; Meier, H.K.
1984-11-01
The selection of an optimal parametric angle theta describing a closed magnetic flux surface is considered with regard to accelerating the convergence rate of the Fourier series for the Cartesian coordinates x(theta,phi) identical with R - R/sub 0/ and y(theta,phi) identical with Z - Z/sub 0/. Geometric criteria are developed based on the Hamiltonian invariants of Keplerian orbits. These criteria relate the rate of curve traversal (tangential speed) to the curvature (normal acceleration) so as to provide increased angular resolution in regions of largest curvature. They are, however, limited to either convex or starlike domains and do not provide rapid convergence for complex domains with alternating convex and concave regions. A generally applicable constraint criterion, based directly on minimizing the width of the x and y Fourier spectra, is also derived. A variational principle is given for implementing these constraints numerically. Application to the representation of three-dimensional magnetic flux surfaces is discussed.
Applications of three-dimensional carbon nanotube networks
Directory of Open Access Journals (Sweden)
Manuela Scarselli
2015-03-01
Full Text Available In this paper, we show that it is possible to synthesize carbon-based three-dimensional networks by adding sulfur, as growth enhancer, during the synthesis process. The obtained material is self-supporting and consists of curved and interconnected carbon nanotubes and to lesser extent of carbon fibers. Studies on the microstructure indicate that the assembly presents a marked variability in the tube external diameter and in the inner structure. We study the relationship between the observed microscopic properties and some potential applications. In particular, we show that the porous nature of the network is directly responsible for the hydrophobic and the lipophilic behavior. Moreover, we used a cut piece of the produced carbon material as working electrode in a standard electrochemical cell and, thus, demonstrating the capability of the system to respond to incident light in the visible and near-ultraviolet region and to generate a photocurrent.
Three-dimensional structure of brain tissue at submicrometer resolution
Energy Technology Data Exchange (ETDEWEB)
Saiga, Rino; Mizutani, Ryuta, E-mail: ryuta@tokai-u.jp [Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa 259-1292 (Japan); Inomoto, Chie; Takekoshi, Susumu; Nakamura, Naoya; Tsuboi, Akio; Osawa, Motoki [Tokai University School of Medicine, Isehara, Kanagawa 259-1193 (Japan); Arai, Makoto; Oshima, Kenichi; Itokawa, Masanari [Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506 (Japan); Uesugi, Kentaro; Takeuchi, Akihisa; Terada, Yasuko; Suzuki, Yoshio [Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, Hyogo 679-5198 (Japan)
2016-01-28
Biological objects are composed of submicrometer structures such as cells and organelles that are essential for their functions. Here, we report on three-dimensional X-ray visualization of cells and organelles at resolutions up to 100 nm by imaging microtomography (micro-CT) equipped with Fresnel zone plate optics. Human cerebral tissue, fruit fly cephalic ganglia, and Escherichia coli bacteria labeled with high atomic-number elements were embedded in epoxy resin and subjected to X-ray microtomography at the BL37XU and BL47XU beamlines of the SPring-8 synchrotron radiation facility. The obtained results indicated that soft tissue structures can be visualized with the imaging microtomography.
Is a three-dimensional-printed tooth filling possible?
Directory of Open Access Journals (Sweden)
Muhammet Kerim Ayar
2016-01-01
Full Text Available Introduction: Three-dimensional (3-D printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce treatment costs and technique-sensitivity of the placement of restorative material. The Hypothesis: Here, the hypothesis that a 3-D-printed tooth filling approach could be an alternative to traditional approaches to treatment of decayed teeth is proposed. Evaluation of the Hypothesis: The actual implementation of the 3-D-printed tooth filling technique in the practice of restorative dentistry was discussed in this manuscript.
Three dimensional sensitivity characterization of plasmonic nanorods for refractometric biosensors.
Leitgeb, V; Trügler, A; Köstler, S; Krug, M K; Hohenester, U; Hohenau, A; Leitner, A; Krenn, J R
2016-02-07
An experimental three dimensional characterization of the local refractive index sensitivity of plasmonic gold nanorods is performed by controlled apposition of lithographic nanostructures. We show up to seven times higher sensitivity values to local changes in the refractive index at the particle tip than center. In addition, successive deposition of defined nm-thin dielectric layers on nanorods covered with stripe masks allows us to study the sensitivity decrease normal to the particle surface separately for different particle sites. Clear trends to a stronger sensitivity decay at sites of higher local sensitivity are demonstrated experimentally and theoretically. Our sensitivity characterization provides an important tool to find the most suitable particle type and particle site for specific bio-sensing applications.
Voro++: a three-dimensional Voronoi cell library in C++
Energy Technology Data Exchange (ETDEWEB)
Rycroft, Chris
2009-01-15
Voro++ is a free software library for the computation of three dimensional Voronoi cells. It is primarily designed for applications in physics and materials science, where the Voronoi tessellation can be a useful tool in the analysis of densely-packed particle systems, such as granular materials or glasses. The software comprises of several C++ classes that can be modified and incorporated into other programs. A command-line utility is also provided that can use most features of the code. Voro++ makes use of a direct cell-by-cell construction, which is particularly suited to handling special boundary conditions and walls. It employs algorithms which are tolerant for numerical precision errors, and it has been successfully employed on very large particle systems.
Three-dimensional protein structure prediction: Methods and computational strategies.
Dorn, Márcio; E Silva, Mariel Barbachan; Buriol, Luciana S; Lamb, Luis C
2014-10-12
A long standing problem in structural bioinformatics is to determine the three-dimensional (3-D) structure of a protein when only a sequence of amino acid residues is given. Many computational methodologies and algorithms have been proposed as a solution to the 3-D Protein Structure Prediction (3-D-PSP) problem. These methods can be divided in four main classes: (a) first principle methods without database information; (b) first principle methods with database information; (c) fold recognition and threading methods; and (d) comparative modeling methods and sequence alignment strategies. Deterministic computational techniques, optimization techniques, data mining and machine learning approaches are typically used in the construction of computational solutions for the PSP problem. Our main goal with this work is to review the methods and computational strategies that are currently used in 3-D protein prediction.
Three-dimensional rogue waves in nonstationary parabolic potentials.
Yan, Zhenya; Konotop, V V; Akhmediev, N
2010-09-01
Using symmetry analysis we systematically present a higher-dimensional similarity transformation reducing the (3+1) -dimensional inhomogeneous nonlinear Schrödinger (NLS) equation with variable coefficients and parabolic potential to the (1+1) -dimensional NLS equation with constant coefficients. This transformation allows us to relate certain class of localized exact solutions of the (3+1) -dimensional case to the variety of solutions of integrable NLS equation of the (1+1) -dimensional case. As an example, we illustrated our technique using two lowest-order rational solutions of the NLS equation as seeding functions to obtain rogue wavelike solutions localized in three dimensions that have complicated evolution in time including interactions between two time-dependent rogue wave solutions. The obtained three-dimensional rogue wavelike solutions may raise the possibility of relative experiments and potential applications in nonlinear optics and Bose-Einstein condensates.
Transport in three-dimensional topological insulators: Theory and experiment
Culcer, Dimitrie
2012-02-01
This paper reviews recent theoretical and experimental work on transport due to the surface states of three-dimensional topological insulators. The theoretical focus is on longitudinal transport in the presence of an electric field, including Boltzmann transport, quantum corrections and weak localization, as well as longitudinal and Hall transport in the presence of both electric and magnetic fields and/or magnetizations. Special attention is paid to transport at finite doping, and to the π-Berry phase, which leads to the absence of backscattering, Klein tunneling and half-quantized Hall response. Signatures of surface states in ordinary transport and magnetotransport are identified. The review also covers transport experiments of the past years, tracing its evolution from the initial obscuring of surface transport by bulk transport to the increasing success of experimental work in identifying transport due to the surface states. Current and likely future experimental challenges are given prominence and the present status of the field is assessed.
Three-dimensional chemotaxis model for a crawling neutrophil.
Song, Jihwan; Kim, Dongchoul
2010-11-01
Chemotactic cell migration is a fundamental phenomenon in complex biological processes. A rigorous understanding of the chemotactic mechanism of crawling cells has important implications for various medical and biological applications. In this paper, we propose a three-dimensional model of a single crawling cell to study its chemotaxis. A single-cell study of chemotaxis has an advantage over studies of a population of cells in that it provides a clearer observation of cell migration, which leads to more accurate assessments of chemotaxis. The model incorporates the surface energy of the cell and the interfacial interaction between the cell and substrate. The semi-implicit Fourier spectral method is applied to achieve high efficiency and numerical stability. The simulation results provide the kinetic and morphological traits of a crawling cell during chemotaxis.
Discriminating the structure of rotated three-dimensional figures.
Barfield, W; Salvendy, G
1987-10-01
Visualizing the structure of transformed (by rotation) three-dimensional (3-D) figures is an important aspect of information processing for computer-graphics tasks. However, little research exists to establish the speed and accuracy in which subjects perform discrimination tasks for transformed images and the effects of rotation variables on perceiving transformed images. This research tests the effects of figural complexity, angles and axes of rotation on the speed and accuracy in which subjects discriminate the structure of rotated 3-D wireframe images. Results show that response times are affected more by angles than axes of rotation, the specific form of the image affects error rates, and the number of 90 degrees bends which determine the structure of an image may be an inadequate measure of form complexity for the task described here.
Three dimensional simulation for bayou choctaw strategic petroleum reserve (SPR).
Energy Technology Data Exchange (ETDEWEB)
Ehgartner, Brian L. (Sandia National Laboratories, Albuquerque, NM); Park, Byoung Yoon; Lee, Moo Yul
2006-12-01
Three dimensional finite element analyses were performed to evaluate the structural integrity of the caverns located at the Bayou Choctaw (BC) site which is considered a candidate for expansion. Fifteen active and nine abandoned caverns exist at BC, with a total cavern volume of some 164 MMB. A 3D model allowing control of each cavern individually was constructed because the location and depth of caverns and the date of excavation are irregular. The total cavern volume has practical interest, as this void space affects total creep closure in the BC salt mass. Operations including both cavern workover, where wellhead pressures are temporarily reduced to atmospheric, and cavern enlargement due to leaching during oil drawdowns that use water to displace the oil from the caverns, were modeled to account for as many as the five future oil drawdowns in the six SPR caverns. The impacts on cavern stability, underground creep closure, surface subsidence, infrastructure, and well integrity were quantified.
Inner mechanics of three-dimensional black holes.
Detournay, Stéphane
2012-07-20
We investigate properties of the inner horizons of certain black holes in higher-derivative three-dimensional gravity theories. We focus on Bañados-Teitelboim-Zanelli and spacelike warped anti-de Sitter black holes, as well as on asymptotically warped de Sitter solutions exhibiting both a cosmological and a black hole horizon. We verify that a first law is satisfied at the inner horizon, in agreement with the proposal of Castro and Rodriguez [arXiv:1204.1284]. We then show that, in topologically massive gravity, the product of the areas of the inner and outer horizons fails to be independent on the mass, and we trace this to the diffeomorphism anomaly of the theory.
Human gesture recognition using three-dimensional integral imaging.
Javier Traver, V; Latorre-Carmona, Pedro; Salvador-Balaguer, Eva; Pla, Filiberto; Javidi, Bahram
2014-10-01
Three-dimensional (3D) integral imaging allows one to reconstruct a 3D scene, including range information, and provides sectional refocused imaging of 3D objects at different ranges. This paper explores the potential use of 3D passive sensing integral imaging for human gesture recognition tasks from sequences of reconstructed 3D video scenes. As a preliminary testbed, the 3D integral imaging sensing is implemented using an array of cameras with the appropriate algorithms for 3D scene reconstruction. Recognition experiments are performed by acquiring 3D video scenes of multiple hand gestures performed by ten people. We analyze the capability and performance of gesture recognition using 3D integral imaging representations at given distances and compare its performance with the use of standard two-dimensional (2D) single-camera videos. To the best of our knowledge, this is the first report on using 3D integral imaging for human gesture recognition.
Cavity quantum electrodynamics with three-dimensional photonic bandgap crystals
Vos, W L
2015-01-01
This paper gives an overview of recent work on three-dimensional (3D) photonic crystals with a "full and complete" 3D photonic band gap. We review five main aspects: 1) spontaneous emission inhibition, 2) spatial localization of light within a tiny nanoscale volume (aka "a nanobox for light"), 3) the introduction of a gain medium leading to thresholdless lasers, 4) breaking of the weak-coupling approximation of cavity QED, both in the frequency and in the time-domain, 5) decoherence, in particular the shielding of vacuum fluctuations by a 3D photonic bandgap. In addition, we list and evaluate all known photonic crystal structures with a demonstrated 3D band gap.
High temperature three-dimensional photoplasticity: Procedures and application
Song, Baoyun; He, Youliang; Bai, Guangrun
1998-05-01
Polycarbonate, because of its extreme toughness, pronounced yield behavior, and the ability to flow extensively prior to fracture, is suitable material for photoplastic analysis and is widely used in recent years. In most cases where the deformations are small, photoplastic experiments are usually conducted at room temperature. But in some applications where the model materials are due to undergo large deformations, to avoid too early occurrence of brittleness, the models should be heated to a higher temperature to improve their deformabilities. This paper investigates the possibility of the utility of high temperature photoplasticity to the simulation of complicated metal forming processes and gives the approprate test temperature of polycarbonate as a photoplastic material. As an example, the three-dimensional strain distributions in the die chamber of continuous cladding process are evaluated.
Lattice kinetic simulations in three-dimensional magnetohydrodynamics.
Breyiannis, G; Valougeorgis, D
2004-06-01
A lattice kinetic algorithm to simulate three-dimensional (3D) incompressible magnetohydrodynamics is presented. The fluid is monitored by a distribution function, which obeys a scalar kinetic equation, subject to an external force due to the imposed magnetic field. Following the work of J. Comput. Phys. 179, 95 (2002)], the magnetic field is represented by a different three-component vector distribution function, which obeys a corresponding vector kinetic equation. Discretization of the 3D phase space is based on a 19-bit scheme for the hydrodynamic part and on a 7-bit scheme for the magnetic part. Numerical results for magnetohydrodynamic (MHD) flow in a rectangular duct with insulating and conducting walls provide excellent agreement with corresponding analytical solutions. The scheme maintains in all cases tested the MHD constraint inverted Delta.B=0 within machine round-off error.
Three-Dimensional Numerical Modeling of Magnetohydrodynamic Augmented Propulsion Experiment
Turner, M. W.; Hawk, C. W.; Litchford, R. J.
2009-01-01
Over the past several years, NASA Marshall Space Flight Center has engaged in the design and development of an experimental research facility to investigate the use of diagonalized crossed-field magnetohydrodynamic (MHD) accelerators as a possible thrust augmentation device for thermal propulsion systems. In support of this effort, a three-dimensional numerical MHD model has been developed for the purpose of analyzing and optimizing accelerator performance and to aid in understanding critical underlying physical processes and nonideal effects. This Technical Memorandum fully summarizes model development efforts and presents the results of pretest performance optimization analyses. These results indicate that the MHD accelerator should utilize a 45deg diagonalization angle with the applied current evenly distributed over the first five inlet electrode pairs. When powered at 100 A, this configuration is expected to yield a 50% global efficiency with an 80% increase in axial velocity and a 50% increase in centerline total pressure.
Three-Dimensional Image Compression With Integer Wavelet Transforms
Bilgin, Ali; Zweig, George; Marcellin, Michael W.
2000-04-01
A three-dimensional (3-D) image-compression algorithm based on integer wavelet transforms and zerotree coding is presented. The embedded coding of zerotrees of wavelet coefficients (EZW) algorithm is extended to three dimensions, and context-based adaptive arithmetic coding is used to improve its performance. The resultant algorithm, 3-D CB-EZW, efficiently encodes 3-D image data by the exploitation of the dependencies in all dimensions, while enabling lossy and lossless decompression from the same bit stream. Compared with the best available two-dimensional lossless compression techniques, the 3-D CB-EZW algorithm produced averages of 22%, 25%, and 20% decreases in compressed file sizes for computed tomography, magnetic resonance, and Airborne Visible Infrared Imaging Spectrometer images, respectively. The progressive performance of the algorithm is also compared with other lossy progressive-coding algorithms.
Three-dimensional characterization of stress corrosion cracks
Energy Technology Data Exchange (ETDEWEB)
Lozano-Perez, S., E-mail: sergio.lozano-perez@materials.ox.ac.u [University of Oxford, Department of Materials, Parks Road, Oxford OX1 3PH (United Kingdom); Rodrigo, P. [Universidad Rey Juan Carlos, Dpto. de Ciencia e Ingenieria de Materiales, c/ Tulipan s.n., 28933 Mostoles (Madrid) (Spain); Gontard, Lionel C. [Danish Technical University, Center for Electron Nanoscopy, Matematiktorvet Building 307, Room 115, 2800 Kogens Lyngby (Denmark)
2011-01-31
Understanding crack propagation and initiation is fundamental if stress corrosion cracking (SCC) mechanisms are to be understood. However, cracking is a three-dimensional (3D) phenomenon and most characterization techniques are restricted to two-dimensional (2D) observations. In order to overcome this problem, different approaches to extract 3D information have been used in the recent years. In this work we will present the benefits of using 3D focused ion beam (FIB) slicing and electron tomography. 3D FIB slicing offers a fast and high throughput characterization while electron tomography offers the best spatial resolution. To illustrate the power of these techniques, different parts of dominant stress corrosion cracks in Ni-alloys and stainless steels have been reconstructed in 3D. All relevant microstructural features can now be studied in detail and its relative orientation respect to the strain direction and grain boundary plane accurately measured.
Three Dimensional Modeling of an MRI Actuated Steerable Catheter System.
Liu, Taoming; Cavuşoğlu, M Cenk
2014-01-01
This paper presents the three dimensional kinematic modeling of a novel steerable robotic ablation catheter system. The catheter, embedded with a set of current-carrying micro-coils, is actuated by the magnetic forces generated by the magnetic field of the MRI scanner. This paper develops a 3D model of the MRI actuated steerable catheter system by using finite differences approach. For each finite segment, a quasi-static torque-deflection equilibrium equation is calculated using beam theory. By using the deflection displacements and torsion angles, the kinematic modeling of the catheter system is derived. The proposed models are evaluated by comparing the simulation results of the proposed model with the experimental results of a proof-of-concept prototype.
Modified gravity in three dimensional metric-affine scenarios
Bambi, Cosimo; Rubiera-Garcia, D
2015-01-01
We consider metric-affine scenarios where a modified gravitational action is sourced by electrovacuum fields in a three dimensional space-time. Such scenarios are supported by the physics of crystalline structures with microscopic defects and, in particular, those that can be effectively treated as bi-dimensional (like graphene). We first study the case of $f(R)$ theories, finding deviations near the center as compared to the solutions of General Relativity. We then consider Born-Infeld gravity, which has raised a lot of interest in the last few years regarding its applications in astrophysics and cosmology, and show that new features always arise at a finite distance from the center. Several properties of the resulting space-times, in particular in presence of a cosmological constant term, are discussed.
Three dimensional direct numerical simulation of complex jet flows
Shin, Seungwon; Kahouadji, Lyes; Juric, Damir; Chergui, Jalel; Craster, Richard; Matar, Omar
2016-11-01
We present three-dimensional simulations of two types of very challenging jet flow configurations. The first consists of a liquid jet surrounded by a faster coaxial air flow and the second consists of a global rotational motion. These computations require a high spatial resolution and are performed with a newly developed high performance parallel code, called BLUE, for the simulation of two-phase, multi-physics and multi-scale incompressible flows, tested on up to 131072 threads with excellent scalability performance. The method for the treatment of the fluid interfaces uses a hybrid Front Tracking/Level Set technique that defines the interface both by a discontinuous density field as well as by a local triangular Lagrangian mesh. Coriolis forces are taken into account and solved via an exact time-integration method that ensures numerical accuracy and stability. EPSRC UK Programme Grant EP/K003976/1.
Three-dimensional reconstruction of the intra-cluster medium
Puchwein, E; Puchwein, Ewald; Bartelmann, Matthias
2005-01-01
We propose and test a new method based on Richardson-Lucy deconvolution to reconstruct three-dimensional gas density and temperature distributions in galaxy clusters from combined X-ray and thermal Sunyaev-Zel'dovich observations. Clusters are assumed to be axially symmetric and arbitrarily inclined with respect to the line-of-sight. No equilibrium assumption other than local thermal equilibrium is needed. We test the algorithm with synthetic observations of analytically modeled and numerically simulated galaxy clusters and discuss the quality of the density and temperature reconstructions in idealised situations and in presence of observational noise, deviations from axial symmetry and cluster substructure. We find that analytic and numerical gas density and temperature distributions can be accurately reconstructed in three dimensions, even if observational noise is present. We also discuss methods for determining the inclination angle from data and show that it can be constrained using X-ray temperature map...
Three-dimensional micro- and nanometre composite aluminium patterns
Institute of Scientific and Technical Information of China (English)
Zhao Xiao-Wei; Zhang Zeng-Xing; Xiang Yan-Juan; Zhou Wei-Ya; Wang Gang; Jiang Peng; Gao Yan; Wang Jian-Xiong; Song Li; Liu Dong-Fang; Liu Li-Feng; Dou Xin-Yuan; Luo Shu-Dong
2005-01-01
Three-dimensional micro- and nanometre composite aluminium patterns are constructed on Al substrate by using photolithography, reactive ion etching and anodization. A layer of patterned SiO2 mask is introduced as resist on the surface of Al foil, and during anodization the tilted nanopores and remaining Al microstructure are formed underneath the SiO2 mask. The existence of SiO2 mask leads to the deflection of electric field and effect on the transportation of ions, which results in the formation of laterally tilted nanopores, while the nanopores go down directly when being far from the boundaries of SiO2. The vertical and lateral anodization processes proceeding simultaneously construct the Al microstructure under the patterned SiO2 mask.
3N Scattering in a Three-Dimensional Operator Formulation
Glöckle, W; Elster, Ch; Golak, J; Skibinski, R; Witala, H
2009-01-01
A recently developed formulation for a direct treatment of the equations for two- and three-nucleon bound states as set of coupled equations of scalar functions depending only on vector momenta is extended to three-nucleon scattering. Starting from the spin-momentum dependence occurring as scalar products in two- and three-nucleon forces together with other scalar functions, we present the Faddeev multiple scattering series in which order by order the spin-degrees can be treated analytically leading to 3D integrations over scalar functions depending on momentum vectors only. Such formulation is especially important in view of awaiting extension of 3N Faddeev calculations to projectile energies above the pion production threshold and applications of chiral perturbation theory 3N forces, which are to be most efficiently treated directly in such three-dimensional formulation without having to expand these forces into a partial wave basis.
Three-dimensional extinction mapping using Gaussian random fields
Sale, S E
2014-01-01
We present a scheme for using stellar catalogues to map the three-dimensional distributions of extinction and dust within our Galaxy. Extinction is modelled as a Gaussian random field, whose covariance function is set by a simple physical model of the ISM that assumes a Kolmogorov-like power spectrum of turbulent fluctuations. As extinction is modelled as a random field, the spatial resolution of the resulting maps is set naturally by the data available; there is no need to impose any spatial binning. We verify the validity of our scheme by testing it on simulated extinction fields and show that its precision is significantly improved over previous dust-mapping efforts. The approach we describe here can make use of any photometric, spectroscopic or astrometric data; it is not limited to any particular survey. Consequently, it can be applied to a wide range of data from both existing and future surveys.
On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers
LeBoeuf, Richard L.; Mehta, Rabindra D.
1995-01-01
In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged ('real') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.
Secure three-dimensional data transmission and display.
Matoba, Osamu; Javidi, Bahram
2004-04-10
An optical three-dimensional (3D) display system interfaced with digital data transmission is proposed. In this system, an original 3D object is encrypted by use of a random phase mask and then the encrypted pattern is recorded as a digital hologram. The digital hologram key is also recorded for optical decryption. Both the encrypted digital hologram and the digital hologram key are transmitted to a receiver through a conventional communication data channel. At the receiver, the 3D scene is reconstructed and displayed optically in a retrieval system based on a joint-transform correlation. Experimental results are presented. We investigate the influence of quantization of the joint power spectrum in the optical correlator on the quality of the reconstructed image.
Split Bregman's algorithm for three-dimensional mesh segmentation
Habiba, Nabi; Ali, Douik
2016-05-01
Variational methods have attracted a lot of attention in the literature, especially for image and mesh segmentation. The methods aim at minimizing the energy to optimize both edge and region detections. We propose a spectral mesh decomposition algorithm to obtain disjoint but meaningful regions of an input mesh. The related optimization problem is nonconvex, and it is very difficult to find a good approximation or global optimum, which represents a challenge in computer vision. We propose an alternating split Bregman algorithm for mesh segmentation, where we extended the image-dedicated model to a three-dimensional (3-D) mesh one. By applying our scheme to 3-D mesh segmentation, we obtain fast solvers that can outperform various conventional ones, such as graph-cut and primal dual methods. A consistent evaluation of the proposed method on various public domain 3-D databases for different metrics is elaborated, and a comparison with the state-of-the-art is performed.
Recursive three-dimensional model reconstruction based on Kalman filtering.
Yu, Ying Kin; Wong, Kin Hong; Chang, Michael Ming Yuen
2005-06-01
A recursive two-step method to recover structure and motion from image sequences based on Kalman filtering is described in this paper. The algorithm consists of two major steps. The first step is an extended Kalman filter (EKF) for the estimation of the object's pose. The second step is a set of EKFs, one for each model point, for the refinement of the positions of the model features in the three-dimensional (3-D) space. These two steps alternate from frame to frame. The initial model converges to the final structure as the image sequence is scanned sequentially. The performance of the algorithm is demonstrated with both synthetic data and real-world objects. Analytical and empirical comparisons are made among our approach, the interleaved bundle adjustment method, and the Kalman filtering-based recursive algorithm by Azarbayejani and Pentland. Our approach outperformed the other two algorithms in terms of computation speed without loss in the quality of model reconstruction.
Three-Dimensional Reconstruction of the Mouse Nephron
DEFF Research Database (Denmark)
Zhai, Xiao-Yue; Thomsen, Jesper Skovhus; Birn, Henrik;
2006-01-01
contributed to a 27% average increase in the lengths of the corresponding segments, (2) the thick-walled tubules incorporated in the central part of the vascular bundles in the inner stripe of the outer medulla were identified as thick ascending limbs of long-looped nephrons, and (3) three types of short......, including the spatial course of the tubules, lengths of different segments of nephrons, histotopography of tubules and vascular bundles, and epithelial ultrastructure at well-defined positions along Henle’s loop and the distal convolution of nephrons. Three-dimensional reconstruction of 200 nephrons...... and collecting ducts was performed on aligned digital images, obtained from 2.5-µm-thick serial sections of mouse kidneys. Important new findings were highlighted: (1) A tortuous course of the descending thin limbs of long-looped nephrons and a winding course of the thick ascending limbs of short-looped nephrons...
Controlling Random Lasing with Three-Dimensional Plasmonic Nanorod Metamaterials.
Wang, Zhuoxian; Meng, Xiangeng; Choi, Seung Ho; Knitter, Sebastian; Kim, Young L; Cao, Hui; Shalaev, Vladimir M; Boltasseva, Alexandra
2016-04-13
Plasmonics has brought revolutionary advances to laser science by enabling deeply subwavelength nanolasers through surface plasmon amplification. However, the impact of plasmonics on other promising laser systems has so far remained elusive. Here, we present a class of random lasers enabled by three-dimensional plasmonic nanorod metamaterials. While dense metallic nanostructures are usually detrimental to laser performance due to absorption losses, here the lasing threshold keeps decreasing as the volume fraction of metal is increased up to ∼0.07. This is ∼460 times higher than the optimal volume fraction reported thus far. The laser supports spatially confined lasing modes and allows for efficient modulation of spectral profiles by simply tuning the polarization of the pump light. Full-field speckle-free imaging at micron-scales has been achieved by using plasmonic random lasers as the illumination sources. Our findings show that plasmonic metamaterials hold potential to enable intriguing coherent optical sources.
Three-dimensional cell culture models for investigating human viruses.
He, Bing; Chen, Guomin; Zeng, Yi
2016-10-01
Three-dimensional (3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover, these models bridge the gap between traditional two-dimensional (2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition, 3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.
IRIS: A Generic Three-Dimensional Radiative Transfer Code
Ibgui, L; Lanz, T; Stehlé, C
2012-01-01
We present IRIS, a new generic three-dimensional (3D) spectral radiative transfer code that generates synthetic spectra, or images. It can be used as a diagnostic tool for comparison with astrophysical observations or laboratory astrophysics experiments. We have developed a 3D short-characteristic solver that works with a 3D nonuniform Cartesian grid. We have implemented a piecewise cubic, locally monotonic, interpolation technique that dramatically reduces the numerical diffusion effect. The code takes into account the velocity gradient effect resulting in gradual Doppler shifts of photon frequencies and subsequent alterations of spectral line profiles. It can also handle periodic boundary conditions. This first version of the code assumes Local Thermodynamic Equilibrium (LTE) and no scattering. The opacities and source functions are specified by the user. In the near future, the capabilities of IRIS will be extended to allow for non-LTE and scattering modeling. IRIS has been validated through a number of te...
Engineering three-dimensional cell mechanical microenvironment with hydrogels.
Huang, Guoyou; Wang, Lin; Wang, Shuqi; Han, Yulong; Wu, Jinhui; Zhang, Qiancheng; Xu, Feng; Lu, Tian Jian
2012-12-01
Cell mechanical microenvironment (CMM) significantly affects cell behaviors such as spreading, migration, proliferation and differentiation. However, most studies on cell response to mechanical stimulation are based on two-dimensional (2D) planar substrates, which cannot mimic native three-dimensional (3D) CMM. Accumulating evidence has shown that there is a significant difference in cell behavior in 2D and 3D microenvironments. Among the materials used for engineering 3D CMM, hydrogels have gained increasing attention due to their tunable properties (e.g. chemical and mechanical properties). In this paper, we provide an overview of recent advances in engineering hydrogel-based 3D CMM. Effects of mechanical cues (e.g. hydrogel stiffness and externally induced stress/strain in hydrogels) on cell behaviors are described. A variety of approaches to load mechanical stimuli in 3D hydrogel-based constructs are also discussed.
Three-dimensional morphology of the human embryonic brain
Directory of Open Access Journals (Sweden)
N. Shiraishi
2015-09-01
Full Text Available The morphogenesis of the cerebral vesicles and ventricles was visualized in 3D movies using images derived from human embryo specimens between Carnegie stage 13 and 23 from the Kyoto Collection. These images were acquired with a magnetic resonance microscope equipped with a 2.35-T superconducting magnet. Three-dimensional images using the same scale demonstrated brain development and growth effectively. The non-uniform thickness of the brain tissue, which may indicate brain differentiation, was visualized with thickness-based surface color mapping. A closer view was obtained of the unique and complicated differentiation of the rhombencephalon, especially with regard to the internal view and thickening of the brain tissue. The present data contribute to a better understanding of brain and cerebral ventricle development.
New developments in: three-dimensional planning for orthognathic surgery.
Popat, Hashmat; Richmond, Stephen; Drage, Nicholas A
2010-03-01
The limitations of plain film radiographs are well documented and the recent introduction of cone beam computed tomography (CBCT) imaging has been a breakthrough in enabling three-dimensional (3D) visualization of the bony skeleton and dentition. There are many reported applications for CBCT in the field of orthodontics and maxillofacial surgery, including the localization of impacted teeth and implant site assessment. More recently, by augmenting CBCT volumes of the maxilla, mandible and dentition, a virtual 3D patient can be created, which can allow planning of orthognathic surgery entirely in 3D. A commercially available software package for 3D orthognathic planning (Maxilim(R), Medicim NV, Belgium) is independently reviewed, familiarizing the reader with the technique for creating a virtual 3D patient, outlining the advantages and disadvantages of the software and concluding on the feasibility of its routine use in clinical practice.
Three-dimensional surface imaging system for assessing human obesity
Xu, Bugao; Yu, Wurong; Yao, Ming; Pepper, M. Reese; Freeland-Graves, Jeanne H.
2009-10-01
The increasing prevalence of obesity suggests a need to develop a convenient, reliable, and economical tool for assessment of this condition. Three-dimensional (3-D) body surface imaging has emerged as an exciting technology for the estimation of body composition. We present a new 3-D body imaging system, which is designed for enhanced portability, affordability, and functionality. In this system, stereo vision technology is used to satisfy the requirement for a simple hardware setup and fast image acquisition. The portability of the system is created via a two-stand configuration, and the accuracy of body volume measurements is improved by customizing stereo matching and surface reconstruction algorithms that target specific problems in 3-D body imaging. Body measurement functions dedicated to body composition assessment also are developed. The overall performance of the system is evaluated in human subjects by comparison to other conventional anthropometric methods, as well as air displacement plethysmography, for body fat assessment.
Three-Dimensional Ocean Sensor Networks: A Survey
Institute of Scientific and Technical Information of China (English)
WANG Yu; LIU Yingjian; GUO Zhongwen
2012-01-01
The past decade has seen a growing interest in ocean sensor networks because of their wide applications in marine research,oceanography,ocean monitoring,offshore exploration,and defense or homeland security.Ocean sensor networks are generally formed with various ocean sensors,autonomous underwater vehicles,surface stations,and research vessels.To make ocean sensor network applications viable,efficient communication among all devices and components is crucial.Due to the unique characteristics of underwater acoustic channels and the complex deployment environment in three dimensional (3D) ocean spaces,new efficient and reliable communication and networking protocols are needed in design of ocean sensor networks.In this paper,we aim to provide an overview of the most recent advances in network design principles for 3D ocean sensor networks,with focuses on deployment,localization,topology design,and position-based routing in 3D ocean spaces.
Three-dimensional simulation of polytropic accretion discs
Energy Technology Data Exchange (ETDEWEB)
Molteni, D. (Palermo Univ. (Italy). Ist. di Fisica); Belvedere, G.; Lanzafame, G. (Catania Univ. (Italy). Ist. di Astronomia)
1991-04-15
We carried out three-dimensional simulations of the formation and evolution of accretion discs in close binary systems, using the Smoothed Particle Hydrodynamics method to solve the fluid dynamic equations. Although the runs presented here refer to an ideal gas with different polytropic indexes, and constitute the first stage of more physically complex forthcoming simulations, they nevertheless give some interesting results; the disc structure and dynamics are in agreement with standard models only for small {gamma}-values; as a consequence of the z-resolution is found that disc formation is inhibited for {gamma} {ge} 1.2, which means that some 2D simulations of polytropic discs are meaningless; the disc is slightly asymmetric in the x-y plane and its profile is irregular and pulsating at the outer boundary. (Author).
Ideal three-dimensional electrode structures for electrochemical energy storage.
Chabi, Sakineh; Peng, Chuang; Hu, Di; Zhu, Yanqiu
2014-04-16
Three-dimensional electrodes offer great advantages, such as enhanced ion and electron transport, increased material loading per unit substrate area, and improved mechanical stability upon repeated charge-discharge. The origin of these advantages is discussed and the criteria for ideal 3D electrode structure are outlined. One of the common features of ideal 3D electrodes is the use of a 3D carbon- or metal-based porous framework as the structural backbone and current collector. The synthesis methods of these 3D frameworks and their composites with redox-active materials are summarized, including transition metal oxides and conducting polymers. The structural characteristics and electrochemical performances are also reviewed. Synthesis of composite 3D electrodes is divided into two types - template-assisted and template-free methods - depending on whether a pre-made template is required. The advantages and drawbacks of both strategies are discussed.
Three dimensional MOF-sponge for fast dynamic adsorption.
Li, Huizeng; Li, Mingzhu; Li, Wenbo; Yang, Qiang; Li, Yanan; Gu, Zhenkun; Song, Yanlin
2017-02-22
Nowadays, environmental pollution is a big problem. Metal organic frameworks (MOFs) provide a novel strategy for exhaust gases adsorption and toxic pollutants removal. We proposed a facile and versatile method to prepare a highly efficient three dimensional MOF-sponge by coating MOF crystals on polyurethane sponge surface, mimicking the porous structure of the marine animal, sponge. Owing to combination of the spatial structure of the commercial sponge and the excellent adsorption capacity of MOF coatings, the MOF-sponge possessed good permeability and high dynamic adsorption capacity. Dynamic adsorption ability of the prepared Cu3(BTC)2-sponge was demonstrated by flowing gas-mixtures of NH3/N2 and an aquatic solution of Rhodamine B through it, with a capacity of 101.6 mg g(-1) and 8.8 mg g(-1) for NH3 and Rhodamine B, respectively.
A New Three-Dimensional Track Fit with Multiple Scattering
Berger, Niklaus; Kozlinskiy, Alexandr; Schöning, Andre
2016-01-01
Modern semiconductor detectors allow for charged particle tracking with ever increasing position resolution. Due to the reduction of the spatial hit uncertainties, multiple Coulomb scattering in the detector layers becomes the dominant source for tracking uncertainties. In this case long range correlations can be ignored, and the track fit can consequently be formulated as a sum of independent fits to hit triplets. In this paper we present an analytical solution for a three-dimensional triplet(s) fit in a homogeneous magnetic field based on a multiple scattering model. Track fitting of hit triplets is performed using a linearization ansatz. The momentum resolution is discussed for a typical spectrometer setup. Furthermore the track fit is compared with other track fits for two different pixel detector geometries, namely the Mu3e experiment at PSI and a typical high-energy collider experiment. For a large momentum range the triplets fit provides a significant better performance than a single helix fit. The tri...
Persistent currents in three-dimensional shell-doped nanorings
Institute of Scientific and Technical Information of China (English)
Xu Ning; Ding Jian-Wen; Chen Hong-Bo; Ma Ming-Ming
2009-01-01
The persistent current in three-dimensional (P×N2) nanorings as a function of the unit cell number (P), the channel number (M = N2), surface disorder (ξ), and temperature (T) is theoretically investigated in terms of rotational symmetry. On the whole, the typical current increases linearly with (<3) but decreases exponentially with P, while wide fluctuations exist therein. In the presence of surface disorder, the persistent current decreases with ξ in the regime of weak disorder but increases in the regime of strong disorder. In addition, it is found that the persistent current in perfect rings decreases exponentially with temperature even at T < T*, while in most disorder rings, the typical current decreases slightly with temperature at T < T*.
Three-Dimensional Genome Organization and Function in Drosophila
Schwartz, Yuri B.; Cavalli, Giacomo
2017-01-01
Understanding how the metazoan genome is used during development and cell differentiation is one of the major challenges in the postgenomic era. Early studies in Drosophila suggested that three-dimensional (3D) chromosome organization plays important regulatory roles in this process and recent technological advances started to reveal connections at the molecular level. Here we will consider general features of the architectural organization of the Drosophila genome, providing historical perspective and insights from recent work. We will compare the linear and spatial segmentation of the fly genome and focus on the two key regulators of genome architecture: insulator components and Polycomb group proteins. With its unique set of genetic tools and a compact, well annotated genome, Drosophila is poised to remain a model system of choice for rapid progress in understanding principles of genome organization and to serve as a proving ground for development of 3D genome-engineering techniques. PMID:28049701
An exactly solvable three-dimensional nonlinear quantum oscillator
Energy Technology Data Exchange (ETDEWEB)
Schulze-Halberg, A. [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary, Indiana 46408 (United States); Morris, J. R. [Department of Physics, Indiana University Northwest, 3400 Broadway, Gary, Indiana 46408 (United States)
2013-11-15
Exact analytical, closed-form solutions, expressed in terms of special functions, are presented for the case of a three-dimensional nonlinear quantum oscillator with a position dependent mass. This system is the generalization of the corresponding one-dimensional system, which has been the focus of recent attention. In contrast to other approaches, we are able to obtain solutions in terms of special functions, without a reliance upon a Rodrigues-type of formula. The wave functions of the quantum oscillator have the familiar spherical harmonic solutions for the angular part. For the s-states of the system, the radial equation accepts solutions that have been recently found for the one-dimensional nonlinear quantum oscillator, given in terms of associated Legendre functions, along with a constant shift in the energy eigenvalues. Radial solutions are obtained for all angular momentum states, along with the complete energy spectrum of the bound states.
GPU-ACCELERATED FEM SOLVER FOR THREE DIMENSIONAL ELECTROMAGNETIC ANALYSIS
Institute of Scientific and Technical Information of China (English)
Tian Jin; Gong Li; Shi Xiaowei; Le Xu
2011-01-01
A new Graphics Processing Unit (GPU) parallelization strategy is proposed to accelerate sparse finite element computation for three dimensional electromagnetic analysis.The parallelization strategy is employed based on a new compression format called sliced ELL Four (sliced ELL-F).The sliced ELL-F format-based parallelization strategy is designed for hastening many addition,dot product,and Sparse Matrix Vector Product (SMVP) operations in the Conjugate Gradient Norm (CGN) calculation of finite element equations.The new implementation of SMVP on GPUs is evaluated.The proposed strategy executed on a GPU can efficiently solve sparse finite element equations,especially when the equations are huge sparse (size of most rows in a coefficient matrix is less than 8).Numerical results show the sliced ELL-F format-based parallelization strategy can reach significant speedups compared to Compressed Sparse Row (CSR) format.
Hydrogel microfabrication technology toward three dimensional tissue engineering
Directory of Open Access Journals (Sweden)
Fumiki Yanagawa
2016-03-01
Full Text Available The development of biologically relevant three-dimensional (3D tissue constructs is essential for the alternative methods of organ transplantation in regenerative medicine, as well as the development of improved drug discovery assays. Recent technological advances in hydrogel microfabrication, such as micromolding, 3D bioprinting, photolithography, and stereolithography, have led to the production of 3D tissue constructs that exhibit biological functions with precise 3D microstructures. Furthermore, microfluidics technology has enabled the development of the perfusion culture of 3D tissue constructs with vascular networks. In this review, we present these hydrogel microfabrication technologies for the in vitro reconstruction and cultivation of 3D tissues. Additionally, we discuss current challenges and future perspectives of 3D tissue engineering.
Three-dimensional flow measurements in a tesla turbine rotor
Fuchs, Thomas; Schosser, Constantin; Hain, Rainer; Kaehler, Christian
2015-11-01
Tesla turbines are fluid mechanical devices converting flow energy into rotation energy by two physical effects: friction and adhesion. The advantages of the tesla turbine are its simple and robust design, as well as its scalability, which makes it suitable for custom power supply solutions, and renewable energy applications. To this day, there is a lack of experimental data to validate theoretical studies, and CFD simulations of these turbines. This work presents a comprehensive analysis of the flow through a tesla turbine rotor gap, with a gap height of only 0.5 mm, by means of three-dimensional Particle Tracking Velocimetry (3D-PTV). For laminar flows, the experimental results match the theory very well, since the measured flow profiles show the predicted second order parabolic shape in radial direction and a fourth order behavior in circumferential direction. In addition to these laminar measurements, turbulent flows at higher mass flow rates were investigated.
Three-dimensional periodic dielectric structures having photonic Dirac points
Energy Technology Data Exchange (ETDEWEB)
Bravo-Abad, Jorge; Joannopoulos, John D.; Soljacic, Marin
2015-06-02
The dielectric, three-dimensional photonic materials disclosed herein feature Dirac-like dispersion in quasi-two-dimensional systems. Embodiments include a face-centered cubic (fcc) structure formed by alternating layers of dielectric rods and dielectric slabs patterned with holes on respective triangular lattices. This fcc structure also includes a defect layer, which may comprise either dielectric rods or a dielectric slab with patterned with holes. This defect layer introduces Dirac cone dispersion into the fcc structure's photonic band structure. Examples of these fcc structures enable enhancement of the spontaneous emission coupling efficiency (the .beta.-factor) over large areas, contrary to the conventional wisdom that the .beta.-factor degrades as the system's size increases. These results enable large-area, low-threshold lasers; single-photon sources; quantum information processing devices; and energy harvesting systems.
Three-dimensional laser-assisted processing of bioceramics
Comesaña, R.; Lusquiños, F.; del Val, J.; Malot, T.; Riveiro, A.; Quintero, F.; Boutinguiza, M.; Aubry, P.; Pou, J.
The study of calcium phosphate bioceramics processing by rapid prototyping based on laser cladding was tackled in this work. This technique shows a great potential to provide a three-dimensional tailored implant adapted to the specific problem of each patient. Working window to produce stable geometrical features and repeatable microstructures was established by real time process monitoring and characterization of the processed material. The relationships between the processing parameters and the obtained properties are discussed, in addition to the biological behaviour of the produced parts. The obtained calcium phosphate phases (oxyapatite, tricalcium phosphate, tetracalcium phosphate and amorphous calcium phosphate) are found to favorably influence the degradability of the precursor hydroxyapatite in Tris-HCl buffer which is a good sign of the favorable behavior of this type of materials when implanted 'in vivo'.
Three-dimensional microfabrication through a multimode optical fiber
Morales-Delgado, Edgar E; Conkey, Donald B; Stasio, Nicolino; Psaltis, Demetri; Moser, Christophe
2016-01-01
Additive manufacturing, also known as 3D printing, is an advanced manufacturing technique that allows the fabrication of arbitrary macroscopic and microscopic objects. All 3D printing systems require large optical elements or nozzles in proximity to the built structure. This prevents their use in applications in which there is no direct access to the area where the objects have to be printed. Here, we demonstrate three-dimensional microfabrication based on two-photon polymerization (TPP) with sub diffraction-limited resolution through an ultra-thin, 50 mm long printing nozzle of 560 micrometers in diameter. Using wavefront shaping, femtosecond infrared pulses are focused and scanned through a multimode optical fiber (MMF) inside a photoresist that polymerizes via two-photon absorption. We show the construction of arbitrary 3D structures of 500 nm resolution on the other side of the fiber. To our knowledge, this is the first demonstration of microfabrication through a multimode optical fiber. Our work represen...
Three-dimensional simulation of a microplasma pump
Wang, Chin-Cheng; Roy, Subrata
2009-09-01
We present a three-dimensional simulation of dielectric barrier discharge (DBD) using the finite element based multiscale ionized gas (MIG) flow code. The two-species hydrodynamic plasma model coupled Poisson equation and Navier-Stokes equation are solved using MIG flow code to predict complicated flow structure inside a plasma induced micropump. The advantage of such a micropump is rapid on/off switching without any moving parts. Results show a reasonable distribution for ion and electron densities as well as an electric field. The key factors of microplasma pump design are the location of actuators and input voltage. The flow rate of the microplasma pump is on the order of ml min-1. Such a flow rate may be beneficial for micropropulsion in space.
A resolution measure for three-dimensional microscopy.
Chao, Jerry; Ram, Sripad; Abraham, Anish V; Ward, E Sally; Ober, Raimund J
2009-05-01
A three-dimensional (3D) resolution measure for the conventional optical microscope is introduced which overcomes the drawbacks of the classical 3D (axial) resolution limit. Formulated within the context of a parameter estimation problem and based on the Cramer-Rao lower bound, this 3D resolution measure indicates the accuracy with which a given distance between two objects in 3D space can be determined from the acquired image. It predicts that, given enough photons from the objects of interest, arbitrarily small distances of separation can be estimated with prespecified accuracy. Using simulated images of point source pairs, we show that the maximum likelihood estimator is capable of attaining the accuracy predicted by the resolution measure. We also demonstrate how different factors, such as extraneous noise sources and the spatial orientation of the imaged object pair, can affect the accuracy with which a given distance of separation can be determined.
Autostereoscopic three-dimensional display based on two parallax barriers.
Luo, Jiang-Yong; Wang, Qiong-Hua; Zhao, Wu-Xiang; Li, Da-Hai
2011-06-20
An autostereoscopic three-dimensional (3D) display composed of a flat-panel display, two parallax barriers, and a backlight panel is proposed. Parallax barrier 1, located between the backlight panel and the flat-panel display, divides the lights to create the perception of stereoscopic images. Parallax barrier 2, located between the flat-panel display and the viewers, acts as the function of decreasing the cross talk of the stereoscopic images. The operation principle of the display and the calculation equations for the parallax barriers are described in detail. An autostereoscopic 3D display prototype is developed. The prototype presents high-quality stereoscopic images. At the optimal viewing distance, it presents stereoscopic images without cross talk. At other viewing distances, it has less cross talk than a conventional autostereoscopic 3D display based on one parallax.
Augmented reality three-dimensional display with light field fusion.
Xie, Songlin; Wang, Peng; Sang, Xinzhu; Li, Chengyu
2016-05-30
A video see-through augmented reality three-dimensional display method is presented. The system that is used for dense viewpoint augmented reality presentation fuses the light fields of the real scene and the virtual model naturally. Inherently benefiting from the rich information of the light field, depth sense and occlusion can be handled under no priori depth information of the real scene. A series of processes are proposed to optimize the augmented reality performance. Experimental results show that the reconstructed fused 3D light field on the autostereoscopic display is well presented. The virtual model is naturally integrated into the real scene with a consistence between binocular parallax and monocular depth cues.
Application of a three-dimensional display in diagnostic imaging.
Baxter, B; Hitchner, L E; Anderson, R E
1982-10-01
An autostereoscopic viewing device for tomographic scans that allows a physician to examine multiple computed tomography sections with each section properly positioned in three dimensions has been constructed and tested. Images produced on the device allow the observer to utilize both motion parallax and stereoscopic depth cues as if viewing a real three-dimensional (3D) object. These 3D images can be very striking because of the ease with which one can form a true impression of depth relationships. We describe operating principles of the viewing device and the appearance of images produced on it. Stereo photographs made from 3D images displayed on the device are included to illustrate potential applications and problems.
A three-dimensional magnetostatics computer code for insertion devices.
Chubar, O; Elleaume, P; Chavanne, J
1998-05-01
RADIA is a three-dimensional magnetostatics computer code optimized for the design of undulators and wigglers. It solves boundary magnetostatics problems with magnetized and current-carrying volumes using the boundary integral approach. The magnetized volumes can be arbitrary polyhedrons with non-linear (iron) or linear anisotropic (permanent magnet) characteristics. The current-carrying elements can be straight or curved blocks with rectangular cross sections. Boundary conditions are simulated by the technique of mirroring. Analytical formulae used for the computation of the field produced by a magnetized volume of a polyhedron shape are detailed. The RADIA code is written in object-oriented C++ and interfaced to Mathematica [Mathematica is a registered trademark of Wolfram Research, Inc.]. The code outperforms currently available finite-element packages with respect to the CPU time of the solver and accuracy of the field integral estimations. An application of the code to the case of a wedge-pole undulator is presented.
Applications of three-dimensional printing technology in urological practice.
Youssef, Ramy F; Spradling, Kyle; Yoon, Renai; Dolan, Benjamin; Chamberlin, Joshua; Okhunov, Zhamshid; Clayman, Ralph; Landman, Jaime
2015-11-01
A rapid expansion in the medical applications of three-dimensional (3D)-printing technology has been seen in recent years. This technology is capable of manufacturing low-cost and customisable surgical devices, 3D models for use in preoperative planning and surgical education, and fabricated biomaterials. While several studies have suggested 3D printers may be a useful and cost-effective tool in urological practice, few studies are available that clearly demonstrate the clinical benefit of 3D-printed materials. Nevertheless, 3D-printing technology continues to advance rapidly and promises to play an increasingly larger role in the field of urology. Herein, we review the current urological applications of 3D printing and discuss the potential impact of 3D-printing technology on the future of urological practice.
Three-dimensional information encryption and anticounterfeiting using digital holography.
Shiu, Min-Tzung; Chew, Yang-Kun; Chan, Huang-Tian; Wong, Xin-Yu; Chang, Chi-Ching
2015-01-01
In this work, arbitrary micro phase-step digital holography with optical interferometry and digital image processing is utilized to obtain information about an image of a three-dimensional object and encrypting keys. Then, a computer-generated hologram is used for the purpose of holographic encryption. All information about the keys is required to perform the decryption, comprising the amplitude and phase distribution of the encrypting key, the distance of image reconstruction, zero-order term elimination, and twin-image term suppression. In addition to using identifiable information on different image planes and linear superposition processing hidden within the encrypted information, not only can we convey an important message, but we can also achieve anticounterfeiting. This approach retains the strictness of traditional holographic encryption and the convenience of digital holographic processing without image distortion. Therefore, this method provides better solutions to earlier methods for the security of the transmission of holographic information.
Holographic Three-Dimensional Fluids with Nontrivial Vorticity
Leigh, Robert G; Petropoulos, P Marios
2011-01-01
Three-dimensional fluids with nontrivial vorticity can be described holographically. It is well-known that the Kerr-AdS geometry gives rise to a cyclonic flow. Here we note that Taub--NUT--AdS4 geometries give rise to a rotating fluid with vortex flow. The Randers and Zermelo forms of the boundary metrics provide alternative descriptions of the fluid by inertial co-moving or by accelerated observers. Such fluids possess acoustic horizons. Moreover, light propagation on the boundary Taub--NUT fluid will encounter an optical horizon associated with closed timelike curves. In the latter case the Misner string introduces a multi-valuedness of the scalar fluctuations which can be attributed to the anyonic nature of the boundary vortex.
Scaling behaviour of three-dimensional group field theory
Magnen, Jacques; Rivasseau, Vincent; Smerlak, Matteo
2009-01-01
Group field theory is a generalization of matrix models, with triangulated pseudomanifolds as Feynman diagrams and state sum invariants as Feynman amplitudes. In this paper, we consider Boulatov's three-dimensional model and its Freidel-Louapre positive regularization (hereafter the BFL model) with a `ultraviolet' cutoff, and study rigorously their scaling behavior in the large cutoff limit. We prove an optimal bound on large order Feynman amplitudes, which shows that the BFL model is perturbatively more divergent than the former. We then upgrade this result to the constructive level, using, in a self-contained way, the modern tools of constructive field theory: we construct the Borel sum of the BFL perturbative series via a convergent `cactus' expansion, and establish the `ultraviolet' scaling of its Borel radius. Our method shows how the `sum over triangulations' in quantum gravity can be tamed rigorously, and paves the way for the renormalization program in group field theory.
Moving through three-dimensional phase diagrams of monoclonal antibodies.
Rakel, Natalie; Baum, Miriam; Hubbuch, Jürgen
2014-01-01
Protein phase behavior characterization is a multivariate problem due to the high amount of influencing parameters and the diversity of the proteins. Single influences on the protein are not understood and fundamental knowledge remains to be obtained. For this purpose, a systematic screening method was developed to characterize the influence of fluid phase conditions on the phase behavior of proteins in three-dimensional phase diagrams. This approach was applied to three monoclonal antibodies to investigate influences of pH, protein and salt concentrations, with five different salts being tested. Although differences exist between the antibodies, this extensive study confirmed the general applicability of the Hofmeister series over the broad parameter range analyzed. The influence of the different salts on the aggregation (crystallization and precipitation) probability was described qualitatively using this Hofmeister series, with a differentiation between crystallization and precipitation being impossible, however.
The Lagrangian Deformation Structure of Three-Dimensional Steady Flow
Lester, Daniel R; Borgne, Tanguy Le; de Barros, Felipe P J
2016-01-01
Fluid deformation and strain history are central to wide range of fluid mechanical phenomena ranging from fluid mixing and particle transport to stress development in complex fluids and the formation of Lagrangian coherent structures (LCSs). To understand and model these processes it is necessary to quantify Lagrangian deformation in terms of Eulerian flow properties, currently an open problem. To elucidate this link we develop a Protean (streamline) coordinate transform for steady three-dimensional (3D) flows which renders both the velocity gradient and deformation gradient upper triangular. This frame not only simplifies computation of fluid deformation metrics such as fi?nite-time Lyapunov exponents (FTLEs) and elucidates the deformation structure of the flow, but moreover explicitly recovers kinematic and topological constraints upon deformation such as those related to helicity density and the Poincar\\'{e}-Bendixson theorem. We apply this transform to several classes of steady 3D flow, including helical ...
Three-dimensional axisymmetric flow-focusing device using stereolithography.
Morimoto, Yuya; Tan, Wei-Heong; Takeuchi, Shoji
2009-04-01
This paper describes a three-dimensional microfluidic axisymmetric flow-focusing device (AFFD) fabricated using stereolithography. Using this method, we can fabricate AFFDs rapidly and automatically without cumbersome alignment needed in conventional methods. The AFFDs are able to be fabricated reproducibly with a micro-sized orifice of diameter around 250 mum. Using this device, we are able to produce monodisperse water-in-oil (W/O) droplets with a coefficient of variation (CV) of less than 4.5%, W/O droplets with encapsulated microbes (CV < 4.9%) and oil-in-water (O/W) droplets (CV < 3.2%) without any surface modifications. The diameter of these droplets range from 54 to 244 mum with respect to the flow rate ratio of the fluids used; these results are in good agreement with theoretical behavior. For applications of the AFFD, we demonstrate that these devices can be used to produce double emulsions and monodisperse hydrogel beads.
THREE DIMENSIONAL PRINTING IN THE SOUTH AFRICAN INDUSTRIAL ENVIRONMENT
Directory of Open Access Journals (Sweden)
D. Dimitrov
2012-01-01
Full Text Available
ENGLISH ABSTRACT: The current development of the rapid prototyping industry in South Africa is characterised by the strong dominance and fast growth in sales of three dimensional printers. Although it reflects the international trend, it seems that the industrial community lacks a clear appreciation of the real strength of this technology, especially with respect to the large variety of devices available today on the market. This paper surveys the current state and capabilities of three dimensional printing (3DP. Based on its technical background – the ink-jet printing known from the printer and plotter industry – a classification structure is developed and proposed. Different printing techniques and process concepts, together with their advantages and limitations, are described and analysed. Typical examples from three completely different application areas – manufacturing, medicine, and architecture – are presented and discussed. Some basic considerations for an informed selection of the right technology for a particular application are then presented.
AFRIKAANSE OPSOMMING: Sterk groei in die verkope van drie dimensionele drukkers (3DP kenmerk die onlangse groei in die snelle prototipe industrie in Suid-Afrika. Ten spyte daarvan dat hierdie ‘n internasionale tendens reflekteer, blyk dit dat die werklike waarde van die tegnologie nog nie ten volle waardeer word in die industriële gemeenskap nie, veral aangesien daar so ‘n groot verskeidenheid masjiene in die mark beskikbaar is. ‘n Oorsig oor die huidige stand en vermoë van drie dimensionele drukkers word hier gegee. ‘n Klassifikasiestruktuur – gebaseer op die inkspuitdrukkertegnologie – word ontwikkel en voorgestel. Verskillende druktegnieke en konsepprosesse word ontleed. Daar word ook gekyk na die voor- en nadele hiervan. Tipiese voorbeelde van drie verskillende toepassings (vervaardiging, medies, en argitektuur word aangebied en bespreek. Basiese riglyne vir
Symmetry enrichment in three-dimensional topological phases
Ning, Shang-Qiang; Liu, Zheng-Xin; Ye, Peng
2016-12-01
While two-dimensional symmetry-enriched topological phases (SETs ) have been studied intensively and systematically, three-dimensional ones are still open issues. We propose an algorithmic approach of imposing global symmetry Gs on gauge theories (denoted by GT) with gauge group Gg. The resulting symmetric gauge theories are dubbed "symmetry-enriched gauge theories" (SEG), which may be served as low-energy effective theories of three-dimensional symmetric topological quantum spin liquids. We focus on SEGs with gauge group Gg=ZN1×ZN2×⋯ and onsite unitary symmetry group Gs=ZK1×ZK2×⋯ or Gs=U (1 ) ×ZK 1×⋯ . Each SEG(Gg,Gs) is described in the path-integral formalism associated with certain symmetry assignment. From the path-integral expression, we propose how to physically diagnose the ground-state properties (i.e., SET orders) of SEGs in experiments of charge-loop braidings (patterns of symmetry fractionalization) and the mixed multiloop braidings among deconfined loop excitations and confined symmetry fluxes. From these symmetry-enriched properties, one can obtain the map from SEGs to SETs . By giving full dynamics to background gauge fields, SEGs may be eventually promoted to a set of new gauge theories (denoted by GT*). Based on their gauge groups, GT*s may be further regrouped into different classes, each of which is labeled by a gauge group Gg*. Finally, a web of gauge theories involving GT,SEG,SET, and GT* is achieved. We demonstrate the above symmetry-enrichment physics and the web of gauge theories through many concrete examples.
Three-Dimensional Morphology of a Coronal Prominence Cavity
Gibson, S. E.; Kucera, T. A.; Rastawicki, D.; Dove, J.; deToma, G.; Hao, J.; Hill, S.; Hudson, H. S.; Marque, C.; McIntosh, P. S.; Rachmeler, L.; Reeves, K. K.; Schmieder, B.; Schmit, D. J.; Seaton, D. B.; Sterling, A. C.; Tripathi, D.; Williams, D. R.; Zhang, M.
2010-01-01
We present a three-dimensional density model of coronal prominence cavities, and a morphological fit that has been tightly constrained by a uniquely well-observed cavity. Observations were obtained as part of an International Heliophysical Year campaign by instruments from a variety of space- and ground-based observatories, spanning wavelengths from radio to soft-X-ray to integrated white light. From these data it is clear that the prominence cavity is the limb manifestation of a longitudinally-extended polar-crown filament channel, and that the cavity is a region of low density relative to the surrounding corona. As a first step towards quantifying density and temperature from campaign spectroscopic data, we establish the three-dimensional morphology of the cavity. This is critical for taking line-of-sight projection effects into account, since cavities are not localized in the plane of the sky and the corona is optically thin. We have augmented a global coronal streamer model to include a tunnel-like cavity with elliptical cross-section and a Gaussian variation of height along the tunnel length. We have developed a semi-automated routine that fits ellipses to cross-sections of the cavity as it rotates past the solar limb, and have applied it to Extreme Ultraviolet Imager (EUVI) observations from the two Solar Terrestrial Relations Observatory (STEREO) spacecraft. This defines the morphological parameters of our model, from which we reproduce forward-modeled cavity observables. We find that cavity morphology and orientation, in combination with the viewpoints of the observing spacecraft, explains the observed variation in cavity visibility for the east vs. west limbs
Visualization of three-dimensional nephron structure with microcomputed tomography.
Bentley, Michael D; Jorgensen, Steven M; Lerman, Lilach O; Ritman, Erik L; Romero, J Carlos
2007-03-01
The three-dimensional architecture of nephrons in situ and their interrelationship with other nephrons are difficult to visualize by microscopic methods. The present study uses microcomputed X-ray tomography (micro-CT) to visualize intact nephrons in situ. Rat kidneys were perfusion-fixed with buffered formalin and their vasculature was subsequently perfused with radiopaque silicone. Cortical tissue was stained en bloc with osmium tetroxide, embedded in plastic, scanned, and reconstructed at voxel resolutions of 6, 2, and 1 microm. At 6 microm resolution, large blood vessels and glomeruli could be visualized but nephrons and their lumens were small and difficult to visualize. Optimal images were obtained using a synchrotron radiation source at 2 microm resolution where nephron components could be identified, correlated with histological sections, and traced. Proximal tubules had large diameters and opaque walls, whereas distal tubules, connecting tubules, and collecting ducts had smaller diameters and less opaque walls. Blood vessels could be distinguished from nephrons by the luminal presence of radiopaque silicone. Proximal tubules were three times longer than distal tubules. Proximal and distal tubules were tightly coiled in the outer cortex but were loosely coiled in the middle and inner cortex. The connecting tubules had the narrowest diameters of the tubules and converged to form arcades that paralleled the radial vessels as they extended to the outer cortex. These results illustrate a potential use of micro-CT to obtain three-dimensional information about nephron architecture and nephron interrelationships, which could be useful in evaluating experimental tubular hypertrophy, atrophy, and necrosis.
Three-dimensional metrology inside a vacuum chamber
Costille, Anne; Beaumont, Florent; Prieto, Eric; Carle, Michael; Fabron, Christophe
2016-07-01
Several three dimensional coordinates systems are proposed by companies to provide accurate measurement of mechanical parts in a volume. None of them are designed to perform the metrology of a system in a vacuum chamber. In the frame of the test of NISP instrument from ESA Euclid mission, the question was raised to perform a three dimensional measurement of different parts during the thermal test of NISP instrument into ERIOS chamber done at Laboratoire d'Astrophysique de Marseille (LAM). One of the main objectives of the test campaign will be the measurement of the focus position of NISP image plane with respect to the EUCLID object plane to ensure a good focalisation of NISP instrument after integration on the payload. A Metrology Verification System (MVS) has been proposed. Its goal is to provide at operational temperature the measurement of references frames set on a EUCLID telescope simulator and NISP, the knowledge of the coordinates of the object point source provided by the telescope simulator and the measurement of the angle between the telescope simulator optical axis and NISP optical axis. The MVS concept is based on the use of a laser tracker, outside the vacuum chamber, that measures reflectors inside the vacuum chamber through a curved window. We will present preliminary results that show the possibility to perform this type of measurements and the accuracy reached in this configuration. An analysis of the contributors to the measurement error budget of the MVS is proposed, based on the current knowledge of the MVS performance and constraints during the TB/TV tests.
Tian, Yaolan; Isotalo, Tero J.; Konttinen, Mikko P.; Li, Jiawei; Heiskanen, Samuli; Geng, Zhuoran; Maasilta, Ilari J.
2017-02-01
We demonstrate a method to fabricate narrow, down to a few micron wide metallic leads on top of a three-dimensional (3D) colloidal crystal self-assembled from polystyrene (PS) nanospheres of diameter 260 nm, using electron-beam lithography. This fabrication is not straightforward due to the fact that PS nanospheres cannot usually survive the harsh chemical treatments required in the development and lift-off steps of electron-beam lithography. We solve this problem by increasing the chemical resistance of the PS nanospheres using an additional electron-beam irradiation step, which allows the spheres to retain their shape and their self-assembled structure, even after baking to a temperature of 160 °C, the exposure to the resist developer and the exposure to acetone, all of which are required for the electron-beam lithography step. Moreover, we show that by depositing an aluminum oxide capping layer on top of the colloidal crystal after the e-beam irradiation, the surface is smooth enough so that continuous metal wiring can be deposited by the electron-beam lithography. Finally, we also demonstrate a way to self-assemble PS colloidal crystals into a microscale container, which was fabricated using direct-write 3D laser-lithography. Metallic wiring was also successfully integrated with the combination of a container structure and a PS colloidal crystal. Our goal is to make a device for studies of thermal transport in 3D phononic crystals, but other phononic or photonic crystal applications could also be envisioned.
Establishment of a Kind of Three-dimensional Thunderstorm Cloud Electrification-Discharge Mode
Institute of Scientific and Technical Information of China (English)
无
2011-01-01
[Objective] The research aimed to study the establishment of a kind of three-dimensional thunderstorm cloud electrification-discharge mode.[Method] Based on a kind of three-dimensional strong convective cloud mode,several parameterization schemes of electrification-discharge mechanism which were mature and had experimental basis were coupled into the strong convective cloud mode.The three-dimensional strong convective mode could simulate electrification-discharge process,and the three-dimensional thundersto...
Three-Dimensional Problems of Thermoviscoplasticity: Focus on Ukrainian Research (Review)
Shevchenko, Yu. N.; Savchenko, V. G.
2016-05-01
Methods and results of studying the three-dimensional viscoplastic stress-strain state of engineering structures under thermomechanical loading are presented. The following classes of thermoviscoelastic problems are considered: axisymmetric problems, nonaxisymmetric problems for bodies of revolution, three-dimensional problems for arbitrarily shaped bodies, three-dimensional problems for isotropic and anisotropic bodies of revolution
Oscillatory cellular patterns in three-dimensional directional solidification.
Tourret, D; Debierre, J-M; Song, Y; Mota, F L; Bergeon, N; Guérin, R; Trivedi, R; Billia, B; Karma, A
2015-10-01
We present a phase-field study of oscillatory breathing modes observed during the solidification of three-dimensional cellular arrays in microgravity. Directional solidification experiments conducted onboard the International Space Station have allowed us to observe spatially extended homogeneous arrays of cells and dendrites while minimizing the amount of gravity-induced convection in the liquid. In situ observations of transparent alloys have revealed the existence, over a narrow range of control parameters, of oscillations in cellular arrays with a period ranging from about 25 to 125 min. Cellular patterns are spatially disordered, and the oscillations of individual cells are spatiotemporally uncorrelated at long distance. However, in regions displaying short-range spatial ordering, groups of cells can synchronize into oscillatory breathing modes. Quantitative phase-field simulations show that the oscillatory behavior of cells in this regime is linked to a stability limit of the spacing in hexagonal cellular array structures. For relatively high cellular front undercooling (i.e., low growth velocity or high thermal gradient), a gap appears in the otherwise continuous range of stable array spacings. Close to this gap, a sustained oscillatory regime appears with a period that compares quantitatively well with experiment. For control parameters where this gap exists, oscillations typically occur for spacings at the edge of the gap. However, after a change of growth conditions, oscillations can also occur for nearby values of control parameters where this gap just closes and a continuous range of spacings exists. In addition, sustained oscillations at to the opening of this stable gap exhibit a slow periodic modulation of the phase-shift among cells with a slower period of several hours. While long-range coherence of breathing modes can be achieved in simulations for a perfect spatial arrangement of cells as initial condition, global disorder is observed in both
Experimental and three-dimensional finite element investigation of fatigue
Bomidi, John A. R.
Materials often fail at cyclic loads that are lower than their ultimate strength or even their yield strength due to progressive internal material degradation; commonly known as fatigue. Moreover, there is a wide scatter in observed fatigue lives of mechanical components operating under identical loading conditions. The randomness of fatigue failure is considered to be linked to basic microstructural effects such as random microstructure topology and the initiation/growth of cracks along inter/transgranular planes. Several modeling approaches have been previously presented ranging from 2D discrete element to 3D Finite Element methods with explicit representation of microstructure topology and continuum damage mechanics to capture dispersion in rolling contact fatigue life and fatigue spalling. There is, however, a need to compare the modeling approach with experimental fatigue test conditions in order to verify and as required enhance the modeling approach to capture observed fatigue failure. This dissertation presents experimental test results and three-dimensional modeling approach that capture fatigue failure. The three-dimensional modeling approach is enhanced according to the experimental observations to consider inter/trans granular failure, different modes of fatigue initiation and propagation and finally for considering effect of plasticity in fatigue of rolling contacts. The following phenomena have been investigated: (1) Fatigue of microbeams: (a )Results of fatigue life and failure from 3D modeling of intergranular fatigue in microbeams are compared with experimental observations reported in literature (2) Tensile fatigue of thin sheets: (a) A test rig with a new grip and alignment system is developed to address the challenges associated with thin sheet testing and conduct fatigue experiments. (b) The 3D fatigue model is enhanced to capture the dominant transgranular fatigue observed in the experiments. The observed and modeled fatigue life and failure
Three-Dimensional Visualization of Interfacial Phenomena Using Confocal Microscopy
Shieh, Ian C.
Surfactants play an integral role in numerous functions ranging from stabilizing the emulsion in a favorite salad dressing to organizing the cellular components that make life possible. We are interested in lung surfactant, which is a mixture of lipids and proteins essential for normal respiration because it modulates the surface tension of the air-liquid interface of the thin fluid lining in the lungs. Through this surface tension modulation, lung surfactant ensures effortless lung expansion and prevents lung collapse during exhalation, thereby effecting proper oxygenation of the bloodstream. The function of lung surfactant, as well as numerous interfacial lipid systems, is not solely dictated by the behavior of materials confined to the two-dimensional interface. Rather, the distributions of materials in the liquid subphase also greatly influence the performance of interfacial films of lung surfactant. Therefore, to better understand the behavior of lung surfactant and other interfacial lipid systems, we require a three-dimensional characterization technique. In this dissertation, we have developed a novel confocal microscopy methodology for investigating the interfacial phenomena of surfactants at the air-liquid interface of a Langmuir trough. Confocal microscopy provides the excellent combination of in situ, fast, three-dimensional visualization of multiple components of the lung surfactant system that other characterization techniques lack. We detail the solutions to the numerous challenges encountered when imaging a dynamic air-liquid interface with a high-resolution technique like confocal microscopy. We then use confocal microscopy to elucidate the distinct mechanisms by which a polyelectrolyte (chitosan) and nonadsorbing polymer (polyethylene glycol) restore the function of lung surfactant under inhibitory conditions mimicking the effects of lung trauma. Beyond this physiological model, we also investigate several one- and two-component interfacial films
TWO- AND THREE-DIMENSIONAL SIMULATIONS OF ASTEROID OCEAN IMPACTS
Directory of Open Access Journals (Sweden)
Michael Gittings
2003-01-01
Full Text Available We have performed a series of two-dimensional and three-dimensional simulations of asteroid impacts into an ocean using the SAGE code from Los Alamos National Laboratory and Science Applications International Corporation. The SAGE code is a compressible Eulerian hydrodynamics code using continuous adaptive mesh refinement for following discontinuities with a fine grid while treating the bulk of the simulation more coarsely. We have used realistic equations of state for the atmosphere, sea water, the oceanic crust, and the mantle. In two dimensions, we simulated asteroid impactors moving at 20 km/s vertically through an exponential atmosphere into a 5 km deep ocean. The impactors were composed of mantle material (3.32 g/cc or iron (7.8 g/cc with diameters from 250m to 10 km. In our three-dimensional runs we simulated asteroids of 1 km diameter composed of iron moving at 20 km/s at angles of 45 and 60 degrees from the vertical. All impacts, including the oblique ones, produce a large underwater cavities with nearly vertical walls followed by a collapse starting from the bottom and subsequent vertical jetting. Substantial amounts of water are vaporized and lofted high into the atmosphere. In the larger impacts, significant amounts of crustal and even mantle material are lofted as well. Tsunamis up to a kilometer in initial height are generated by the collapse of the vertical jet. These waves are initially complex in form, and interact strongly with shocks propagating through the water and the crust. The tsunami waves are followed out to 100 km from the point of impact. Their periods and wavelengths show them to be intermediate type waves, and not (in general shallow-water waves. At great distances, the waves decay as the inverse of the distance from the impact point, ignoring sea-floor topography. For all impactors smaller than about 2 km diameter, the impacting body is highly fragmented and its remains lofted into the stratosphere with the water
Two- and Three-Dimensional Simulations of Asteroid Ocean Impacts
Gisler, G.; Weaver, R. P.; Mader, C. L.; Gittings, M. L.
2003-01-01
We have performed a series of two-dimensional and three-dimensional simulations of asteroid impacts into an ocean using the SAGE code from Los Alamos National Laboratory and Science Applications International Corporation. The SAGE code is a compressible Eulerian hydrodynamics code using continuous adaptive mesh refinement for following discontinuities with a fine grid while treating the bulk of the simulation more coarsely. We have used tabular equations of state for the atmosphere, water, the oceanic crust, and the mantle. In two dimensions, we simulated asteroid impactors moving at 20 km/s vertically through an exponential atmosphere into a 5 km deep ocean. The impactors were composed of mantle material (3.32 g/cc) or iron (7.8 g/cc) with diameters from 250m to 10 km. In our three-dimensional runs we simulated asteroids of 1 km diameter composed of iron moving at 20 km/s at angles of 45 and 60 degrees from the vertical. All impacts, including the oblique ones, produce large underwater cavities with nearly vertical walls followed by a collapse starting from the bottom and subsequent vertical jetting. Substantial amounts of water are vaporized and lofted high into the atmosphere. In the larger impacts, significant amounts of crustal and even mantle material are lofted as well. Tsunamis up to a kilometer in initial height are generated by the collapse of the vertical jet. These waves are initially complex in form, and interact strongly with shocks propagating through the water and the crust. The tsunami waves are followed out to 100 km from the point of impact. Their periods and wavelengths show them to be intermediate type waves, and not (in general) shallow-water waves. At great distances, the waves decay faster than the inverse of the distance from the impact point, ignoring sea-floor topography. For all impactors smaller than about 2 km diameter, the impacting body is highly fragmented and its remains lofted into the stratosphere with the water vapor and crustal
Leadership and organizational ethics: the three dimensional African perspectives.
Mathooko, Jude Mutuku
2013-01-01
This paper addresses the past, present and future aspects of African leadership and organizational ethics that have, are and will be key for any organization to sustain its systems and structures. Organizational ethics revolves around written and/or unwritten guidelines, ethical values, principles, rules and standards, that are drawn from the harmonious coexistence with the biosphere and it is how these elements are applied that dictates the style of leadership and the ethical thinking of the leaders. Africa has a wide range of complexities which are compounded by, inter alia, tribal divisiveness, selfish leadership, wealth inequality, and massive unemployment. Africans tend to draw their leadership and ethical practices and reflections from the events in the environment with which they have interacted for many years. However, in order to fully address and understand the African perspective in leadership and organizational ethics, a broad comprehension of the African diverse and complex landscape is needed through unravelling of the three dimensional existence of the people. African ethics, developed over time, unifies organizations and leadership since it is part of life and is practised, sub-consciously or unconsciously, by the people as they transform from one practice to the other, and during intergenerational transitions. Globalization, liberalization, technological changes and advancement, and market changes are rapidly transforming the environment in which organizations operate. In such a situation, an effective and true leader cannot be rigid but should be flexible, with the ability to use different leadership styles whenever the situation calls for it. Only those leaders with a three-dimensional perspective live inspiring lives, live with a cause and adopt organizational ethics and leadership styles that will stand the test of time. Despite Africa being the cradle of humankind, leadership and organizational ethics is still in its infancy and wanting, even
Three-dimensional wedge filling in ordered and disordered systems
Energy Technology Data Exchange (ETDEWEB)
Greenall, M J [Department of Mathematics, Imperial College London, 180 Queen' s Gate, London SW7 2BZ (United Kingdom); Parry, A O [Department of Mathematics, Imperial College London, 180 Queen' s Gate, London SW7 2BZ (United Kingdom); Romero-Enrique, J M [Department of Mathematics, Imperial College London, 180 Queen' s Gate, London SW7 2BZ (United Kingdom)
2004-04-21
We investigate interfacial structural and fluctuation effects occurring at continuous filling transitions in 3D wedge geometries. We show that fluctuation-induced wedge covariance relations that have been reported recently for 2D filling and wetting have mean-field or classical analogues that apply to higher-dimensional systems. Classical wedge covariance emerges from analysis of filling in shallow wedges based on a simple interfacial Hamiltonian model and is supported by detailed numerical investigations of filling within a more microscopic Landau-like density functional theory. Evidence is presented that classical wedge covariance is also obeyed for filling in more acute wedges in the asymptotic critical regime. For sufficiently short-ranged forces mean-field predictions for the filling critical exponents and covariance are destroyed by pseudo-one-dimensional interfacial fluctuations. We argue that in this filling fluctuation regime the critical exponents describing the divergence of length scales are related to values of the interfacial wandering exponent {zeta}(d) defined for planar interfaces in (bulk) two-dimensional (d = 2) and three-dimensional (d = 3) systems. For the interfacial height l{sub w} {approx} {theta}-{alpha}){sup -{beta}}{sub w}, with {theta} the contact angle and {alpha} the wedge tilt angle, we find {beta}{sub w} = {zeta}(2)/2(1-{zeta}(3)). For pure systems (thermal disorder) we recover the known result {beta}{sub w} = 1/4 predicted by interfacial Hamiltonian studies whilst for random-bond disorder we predict the universal critical exponent {beta} {approx} even in the presence of dispersion forces. We revisit the transfer matrix theory of three-dimensional filling based on an effective interfacial Hamiltonian model and discuss the interplay between breather, tilt and torsional interfacial fluctuations. We show that the coupling of the modes allows the problem to be mapped onto a quantum mechanical problem as conjectured by previous authors
Transport of molecular fluids through three-dimensional porous media
Adler, Pierre; Pazdniakou, Aliaksei
2014-05-01
The main purpose of this study is to extend the analysis which has been made for the double layer theory (summarized by [1]) to situations where the distance between the solid walls is of the order of several molecular diameters. This is of a large interest from a scientific viewpoint and for various engineering applications. The intermolecular forces and their influence on fluid structure and dynamics can be taken into account by using the mesoscopic scale models based on the Boltzmann equation [2]. The numerical methods derived from these models are less demanding in computational resources than conventional molecular dynamics methods and therefore long time evolution of large samples can be considered. Three types of fluid particles are considered, namely the anions, the cations and the solvent. They possess a finite diameter which should be at least a few lattice units. The collision frequency between particles is increased by the pair correlation function for hard spheres. The lattice Boltzmann model is built in three dimensions with 19 velocities; it involves two relaxation times. The particle distribution functions are discretized over a basis of Hermite polynomial tensors. Electric forces are included and a Poisson equation is simultaneously solved by a successive over-relaxation method. The numerical algorithm is detailed; it is devised in order to be able to address any three-dimensional porous media. It involves the determination of the densities of each particle species, of the overall density and of the equilibrium distribution function. Then, the electric forces are determined. Collision operators are applied as well as the boundary conditions. Finally, the propagation step is performed and the algorithm starts a new loop. The influence of parameters can be illustrated by systematic calculations in a plane Poiseuille configuration. The drastic influence of the ratio between the channel width and the particle sizes on the local densities and the
Modelling for three dimensional coalescence of two bubbles
Han, R.; Li, S.; Zhang, A. M.; Wang, Q. X.
2016-06-01
This paper is concerned with the three dimensional (3D) interaction and coalescence of two bubbles subject to buoyancy and the dynamics of the subsequent joined bubble using the boundary integral method (BIM). An improved density potential method is implemented to control the mesh quality. It helps to avoid the numerical instabilities, which occur after coalescence. Numerical convergence tests are conducted in terms of mesh sizes and time steps. The 3D numerical model agrees well with an axisymmetric BIM model for axisymmetric cases as well as experimental results captured by high-speed camera. The bubble jetting, interaction, and coalescence of the two bubbles depend on the maximum bubble radii, the centre distance between two bubbles at inception, and the angle β between the centre line and the direction of buoyancy. We investigate coalescence of two bubbles for β = 0, π/4, and π/2, respectively, and at various centre distances at inception. Numerical results presented include the bubble and jet shapes, the velocity, and pressure fields surrounding the bubbles, as well as the time histories of bubble volumes, jet velocities, and positions of centroid of the bubble system.
Three-dimensional ultrasound assessment of endometrial receptivity: a review
Directory of Open Access Journals (Sweden)
Alcázar Juan
2006-11-01
Full Text Available Abstract Three-dimensional ultrasound (3D US is a new imaging modality, which is being introduced into clinical practice. Although this technique will not probably replace two-dimensional ultrasound, it is being increasingly used. It has been reported that 3D US is a very high reproducible technique. The endometrium has been paid special attention when using this technique. The aim of this paper is to address some technical aspects of 3D US and to review critically its current status in evaluating endometrial function with special focus in its role in predicting pregnancy in assisted reproductive techniques. In spontaneous cycles endometrial volume grows during follicular phase remaining constant through the luteal phase. Endometrial vascularization increases during follicular phase peaking 2–3 days before ovulation, decreasing thereafter and increasing again during mid and late luteal phase. Data from studies analysing the role of 3D US for predicting IVF outcome are controversial. An explanation for these controversial findings might be different design of reported studies, specially the timing of ultrasound evaluation.
Three-dimensional structure of the wild-type RHDV
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The three-dimensional (3D) structure of the wild-type rabbit hemorrhagic disease virus (RHDV) has been determined to a resolution of 3.2 nm by electron cryomicroscopy and computer image reconstruction techniques. The 3D density map exhibits characteristic structural features of a calicivirus: a T=3 icosahedral capsid with 90 arch-like capsomeres at the icosahedral and local 2-fold axes and 32 large surface hollows at the icosahedral 5- and 3-fold axes. This result confirms that the RHDV isolated in China is a member of the Caliciviridae family. A rather continuous capsid shell was found without channels. However, our RHDV structure also reveals some distinct structural charac-teristics not observed in other caliciviruses, including inter-connected capsomeres and the lack of protuberance on the base of each of the surface hollows. Two types of particles were identified with similar outer capsid structure but dif-ferent density distributions inside the capsid shells, which could not be distinguished by conventional negative staining electron microscopy. As the genomic and subgenomic RNAs are both packaged into particles for RHDV, we suggest that the two types of particles identified correspond to those con-taining either the genomic or subgenomic RNAs, respec-tively.
Figure-ground organization based on three-dimensional symmetry
Michaux, Aaron; Jayadevan, Vijai; Delp, Edward; Pizlo, Zygmunt
2016-11-01
We present an approach to figure/ground organization using mirror symmetry as a general purpose and biologically motivated prior. Psychophysical evidence suggests that the human visual system makes use of symmetry in producing three-dimensional (3-D) percepts of objects. 3-D symmetry aids in scene organization because (i) almost all objects exhibit symmetry, and (ii) configurations of objects are not likely to be symmetric unless they share some additional relationship. No general purpose approach is known for solving 3-D symmetry correspondence in two-dimensional (2-D) camera images, because few invariants exist. Therefore, we present a general purpose method for finding 3-D symmetry correspondence by pairing the problem with the two-view geometry of the binocular correspondence problem. Mirror symmetry is a spatially global property that is not likely to be lost in the spatially local noise of binocular depth maps. We tested our approach on a corpus of 180 images collected indoors with a stereo camera system. K-means clustering was used as a baseline for comparison. The informative nature of the symmetry prior makes it possible to cluster data without a priori knowledge of which objects may appear in the scene, and without knowing how many objects there are in the scene.
On the dynamics of the three dimensional planetary systems
Antoniadou, Kyriaki I; Hadjidemetriou, John D
2013-01-01
Over the last decades, there has been a tremendous increase in research on extrasolar planets. Many exosolar systems, which consist of a Star and two inclined Planets, seem to be locked in 4/3, 3/2, 2/1, 5/2, 3/1 and 4/1 mean motion resonance (MMR). We herewith present the model used to simulate three dimensional planetary systems and provide planar families of periodic orbits (PO), which belong to all possible configurations that each MMR has, along with their linear horizontal and vertical stability. We focus on depicting stable spatial families (most of them up to mutual inclination of $60^\\circ$) generated by PO of planar circular families, because the trapping in MMR could be a consequence of planetary migration process. We attempt to connect the linear stability of PO with long-term stability of a planetary system close to them. This can stimulate the search of real planetary systems in the vicinity of stable spatial PO-counterbalanced by the planets' orbital elements, masses and MMR; all of which could...
Application of Three-dimensional Body Measurement System
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
The configuration principles and functions of the non-contact three-dimensional (3D) body measurement system (BMS)developed by the Textile/Clothing Technology Corporation ([TC]2) are described in this paper. The advantages of this new system, compared with traditional contact body measurement instruments ( Martin instruments ) are discussed by selecting 40 female undergraduates of Donghua University as the scan objects. In the experiments both the Martin instruments and [TC]2 BMS were used respectively. According to the data of different position ( Bust Circumference, Full Waist, Full Hips, Bust Height, Front Waist Height and Back Waist Height) obtained from both of the methods we can get the correlation coefficient which is close to 1, indicating that the results of both methods have comparability. Finally some suggestions for the further applications of the non-contact BMS in the apparel development of China are given. Ke ywords : Body measurement, anth ro pormetr y , non- contact 3D body measurement system, apparel industry, made-tomeasure (MTM).
Three-Dimensional scanning transmission electron microscopy of biological specimens
De Jonge, Niels
2010-01-18
A three-dimensional (3D) reconstruction of the cytoskeleton and a clathrin-coated pit in mammalian cells has been achieved from a focal-series of images recorded in an aberration-corrected scanning transmission electron microscope (STEM). The specimen was a metallic replica of the biological structure comprising Pt nanoparticles 2-3 nm in diameter, with a high stability under electron beam radiation. The 3D dataset was processed by an automated deconvolution procedure. The lateral resolution was 1.1 nm, set by pixel size. Particles differing by only 10 nm in vertical position were identified as separate objects with greater than 20% dip in contrast between them. We refer to this value as the axial resolution of the deconvolution or reconstruction, the ability to recognize two objects, which were unresolved in the original dataset. The resolution of the reconstruction is comparable to that achieved by tilt-series transmission electron microscopy. However, the focal-series method does not require mechanical tilting and is therefore much faster. 3D STEM images were also recorded of the Golgi ribbon in conventional thin sections containing 3T3 cells with a comparable axial resolution in the deconvolved dataset. © 2010 Microscopy Society of America.
Three dimensional inviscid compressible calculations around axial flow turbine blades
Fourmaux, Antoine; Petot, Bertrand
1991-12-01
The application of a three dimensional (3D) method to the prediction of steady inviscid compressible flows in highly loaded stator bladings is presented. The complete set of Euler equations is solved by a finite difference method using a time marching two step Lax-Wendorff algorithm. The treatment of the boundary conditions is based on the use of the characteristic relations. This technique offers a great versatility and allows to prescribe conditions close to the physics of flows encountered in turbomachines. The code was adapted in order to build a 3D design tool able to run in different types of turbine blade geometries. Two types of multidomain structured meshes were tested (H+0+H and H+C). The H+C type of grid was finally choosen for industrial applications. Two applications to turbine nozzles are presented. The first is a low pressure turbine vane with evolutive flow path outer diameter. The results demonstrate the ability to predict flow features that cannot be computed via the classical two dimensional approach. The second is a high pressure inlet guide vane at transonic conditions. The strong radial evolution of pressure distribution and the trailing edge flow pattern are correctly predicted.
Three dimensional simulations of viscous folding in diverging microchannels
Xu, Bingrui; Shin, Seungwon; Juric, Damir
2016-01-01
Three dimensional simulations on the viscous folding in diverging microchannels reported by Cubaud and Mason are performed using the parallel code BLUE for multi-phase flows. The more viscous liquid L_1 is injected into the channel from the center inlet, and the less viscous liquid L_2 from two side inlets. Liquid L_1 takes the form of a thin filament due to hydrodynamic focusing in the long channel that leads to the diverging region. The thread then becomes unstable to a folding instability, due to the longitudinal compressive stress applied to it by the diverging flow of liquid L_2. Given the long computation time, we were limited to a parameter study comprising five simulations in which the flow rate ratio, the viscosity ratio, the Reynolds number, and the shape of the channel were varied relative to a reference model. In our simulations, the cross section of the thread produced by focusing is elliptical rather than circular. The initial folding axis can be either parallel or perpendicular to the narrow di...
Modeling Three-Dimensional Chromosome Structures Using Gene Expression Data.
Xiao, Guanghua; Wang, Xinlei; Khodursky, Arkady B
2011-03-01
Recent genomic studies have shown that significant chromosomal spatial correlation exists in gene expression of many organisms. Interestingly, coexpression has been observed among genes separated by a fixed interval in specific regions of a chromosome chain, which is likely caused by three-dimensional (3D) chromosome folding structures. Modeling such spatial correlation explicitly may lead to essential understandings of 3D chromosome structures and their roles in transcriptional regulation. In this paper, we explore chromosomal spatial correlation induced by 3D chromosome structures, and propose a hierarchical Bayesian method based on helical structures to formally model and incorporate the correlation into the analysis of gene expression microarray data. It is the first study to quantify and infer 3D chromosome structures in vivo using expression microarrays. Simulation studies show computing feasibility of the proposed method and that, under the assumption of helical chromosome structures, it can lead to precise estimation of structural parameters and gene expression levels. Real data applications demonstrate an intriguing biological phenomenon that functionally associated genes, which are far apart along the chromosome chain, are brought into physical proximity by chromosomal folding in 3D space to facilitate their coexpression. It leads to important biological insight into relationship between chromosome structure and function.
Three dimensional multilayer solenoid microcoils inside silica glass
Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Si, Jinhai; Hou, Xun
2016-01-01
Three dimensional (3D) solenoid microcoils could generate uniform magnetic field. Multilayer solenoid microcoils are highly pursued for strong magnetic field and high inductance in advanced magnetic microsystems. However, the fabrication of the 3D multilayer solenoid microcoils is still a challenging task. In this paper, 3D multilayer solenoid microcoils with uniform diameters and high aspect ratio were fabricated in silica glass. An alloy (Bi/In/Sn/Pb) with high melting point was chosen as the conductive metal to overcome the limitation of working temperature and improve the electrical property. The inductance of the three layers microcoils was measured, and the value is 77.71 nH at 100 kHz and 17.39 nH at 120 MHz. The quality factor was calculated, and it has a value of 5.02 at 120 MHz. This approach shows an improvement method to achieve complex 3D metal microstructures and electronic components, which could be widely integrated in advanced magnetic microsystems.
A three-dimensional atlas of human tongue muscles.
Sanders, Ira; Mu, Liancai
2013-07-01
The human tongue is one of the most important yet least understood structures of the body. One reason for the relative lack of research on the human tongue is its complex anatomy. This is a real barrier to investigators as there are few anatomical resources in the literature that show this complex anatomy clearly. As a result, the diagnosis and treatment of tongue disorders lags behind that for other structures of the head and neck. This report intended to fill this gap by displaying the tongue's anatomy in multiple ways. The primary material used in this study was serial axial images of the male and female human tongue from the Visible Human (VH) Project of the National Library of Medicine. In addition, thick serial coronal sections of three human tongues were rendered translucent. The VH axial images were computer reconstructed into serial coronal sections and each tongue muscle was outlined. These outlines were used to construct a three-dimensional (3D) computer model of the tongue that allows each muscle to be seen in its in vivo anatomical position. The thick coronal sections supplement the 3D model by showing details of the complex interweaving of tongue muscles throughout the tongue. The graphics are perhaps the clearest guide to date to aid clinical or basic science investigators in identifying each tongue muscle in any part of the human tongue.
Three-dimensional data assimilation for ionospheric reference scenarios
Gerzen, Tatjana; Wilken, Volker; Minkwitz, David; Hoque, Mainul M.; Schlüter, Stefan
2017-02-01
The reliable estimation of ionospheric refraction effects is an important topic in the GNSS (Global Navigation Satellite Systems) positioning and navigation domain, especially in safety-of-life applications. This paper describes a three-dimensional ionosphere reconstruction approach that combines three data sources with an ionospheric background model: space- and ground-based total electron content (TEC) measurements and ionosonde observations. First the background model is adjusted by F2 layer characteristics, obtained from space-based ionospheric radio occultation (IRO) profiles and ionosonde data, and secondly the final electron density distribution is estimated by an algebraic reconstruction technique.The method described is validated by TEC measurements of independent ground-based GNSS stations, space-based TEC from the Jason 1 and 2 satellites, and ionosonde observations. A significant improvement is achieved by the data assimilation, with a decrease in the residual errors by up to 98 % compared to the initial guess of the background. Furthermore, the results underpin the capability of space-based measurements to overcome data gaps in reconstruction areas where less GNSS ground-station infrastructure exists.
Slow axial drift in three-dimensional granular tumbler flow
Zaman, Zafir; D'Ortona, Umberto; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.
2013-07-01
Models of monodisperse particle flow in partially filled three-dimensional tumblers often assume that flow along the axis of rotation is negligible. We test this assumption, for spherical and double cone tumblers, using experiments and discrete element method simulations. Cross sections through the particle bed of a spherical tumbler show that, after a few rotations, a colored band of particles initially perpendicular to the axis of rotation deforms: particles near the surface drift toward the pole, while particles deeper in the flowing layer drift toward the equator. Tracking of mm-sized surface particles in tumblers with diameters of 8-14 cm shows particle axial displacements of one to two particle diameters, corresponding to axial drift that is 1-3% of the tumbler diameter, per pass through the flowing layer. The surface axial drift in both double cone and spherical tumblers is zero at the equator, increases moving away from the equator, and then decreases near the poles. Comparing results for the two tumbler geometries shows that wall slope causes axial drift, while drift speed increases with equatorial diameter. The dependence of axial drift on axial position for each tumbler geometry is similar when both are normalized by their respective maximum values.
Three-dimensional ghost imaging lidar via sparsity constraint
Gong, Wenlin; Zhao, Chengqiang; Yu, Hong; Chen, Mingliang; Xu, Wendong; Han, Shensheng
2016-05-01
Three-dimensional (3D) remote imaging attracts increasing attentions in capturing a target’s characteristics. Although great progress for 3D remote imaging has been made with methods such as scanning imaging lidar and pulsed floodlight-illumination imaging lidar, either the detection range or application mode are limited by present methods. Ghost imaging via sparsity constraint (GISC), enables the reconstruction of a two-dimensional N-pixel image from much fewer than N measurements. By GISC technique and the depth information of targets captured with time-resolved measurements, we report a 3D GISC lidar system and experimentally show that a 3D scene at about 1.0 km range can be stably reconstructed with global measurements even below the Nyquist limit. Compared with existing 3D optical imaging methods, 3D GISC has the capability of both high efficiency in information extraction and high sensitivity in detection. This approach can be generalized in nonvisible wavebands and applied to other 3D imaging areas.
A Three-Dimensional Model of the Yeast Genome
Noble, William; Duan, Zhi-Jun; Andronescu, Mirela; Schutz, Kevin; McIlwain, Sean; Kim, Yoo Jung; Lee, Choli; Shendure, Jay; Fields, Stanley; Blau, C. Anthony
Layered on top of information conveyed by DNA sequence and chromatin are higher order structures that encompass portions of chromosomes, entire chromosomes, and even whole genomes. Interphase chromosomes are not positioned randomly within the nucleus, but instead adopt preferred conformations. Disparate DNA elements co-localize into functionally defined aggregates or factories for transcription and DNA replication. In budding yeast, Drosophila and many other eukaryotes, chromosomes adopt a Rabl configuration, with arms extending from centromeres adjacent to the spindle pole body to telomeres that abut the nuclear envelope. Nonetheless, the topologies and spatial relationships of chromosomes remain poorly understood. Here we developed a method to globally capture intra- and inter-chromosomal interactions, and applied it to generate a map at kilobase resolution of the haploid genome of Saccharomyces cerevisiae. The map recapitulates known features of genome organization, thereby validating the method, and identifies new features. Extensive regional and higher order folding of individual chromosomes is observed. Chromosome XII exhibits a striking conformation that implicates the nucleolus as a formidable barrier to interaction between DNA sequences at either end. Inter-chromosomal contacts are anchored by centromeres and include interactions among transfer RNA genes, among origins of early DNA replication and among sites where chromosomal breakpoints occur. Finally, we constructed a three-dimensional model of the yeast genome. Our findings provide a glimpse of the interface between the form and function of a eukaryotic genome.
Three-dimensional characteristics of SFC type MHD generator
Energy Technology Data Exchange (ETDEWEB)
Oikawa, Shun' ichi; Kayukawa, Naoyuki
1988-03-20
Concerning a Faraday type MHD generator with power output 100 MWe, a parabolic three-dimensional analysis was made on the SFC type and the conventional UFC type of the applied magnetic field, comparing the electrical and fluid fields of both types. Results are as follows: (1) In Faraday type MHD generator, Hall current which is an ineffective current is suppressed by SFC magnetic field coordination. (2) In the case of UFC, a current concentration to the central anode which occurs in the large Faraday type MHD generator does not occur in the case of SFC type. (3) In SFC, a secondary flow in the electrode boundary, especially in the vicinity of the anode is weak. (4) In addition to the velocity overshoot in the dielectric wall boundary layer, in the case of SFC, it generates in the electric wall. As a result, concentrated arc columns are suppressed by the acceleration of heat transfer to the electrode wall. (13 figs, 1 tab, 13 refs)
Three dimensional boundary element solutions for eddy current nondestructive evaluation
Yang, Ming; Song, Jiming; Nakagawa, Norio
2014-02-01
The boundary integral equations (BIE) method is a numerical computational method of solving linear partial differential equations which have been formulated as integral equations. It can be applied in many areas of engineering and science including fluid mechanics, acoustics, electromagnetics, and fracture mechanics. The eddy current problem is formulated by the BIE and discretized into matrix equations by the method of moments (MoM) or the boundary element method (BEM). The three dimensional arbitrarily shaped objects are described by a number of triangular patches. The Stratton-Chu formulation is specialized for the conductive medium. The equivalent electric and magnetic surface currents are expanded in terms of Rao-Wilton-Glisson (RWG) vector basis function while the normal component of magnetic field is expanded in terms of the pulse basis function. Also, a low frequency approximation is applied in the external medium. Additionally, we introduce Auld's impedance formulas to calculate impedance variation. There are very good agreements between numerical results and those from theory and/or experiments for a finite cross-section above a wedge.
Three dimensional simulations of viscous folding in diverging microchannels
Xu, Bingrui; Chergui, Jalel; Shin, Seungwon; Juric, Damir
2016-11-01
Three dimensional simulations on the viscous folding in diverging microchannels reported by Cubaud and Mason are performed using the parallel code BLUE for multi-phase flows. The more viscous liquid L1 is injected into the channel from the center inlet, and the less viscous liquid L2 from two side inlets. Liquid L1 takes the form of a thin filament due to hydrodynamic focusing in the long channel that leads to the diverging region. The thread then becomes unstable to a folding instability, due to the longitudinal compressive stress applied to it by the diverging flow of liquid L2. We performed a parameter study in which the flow rate ratio, the viscosity ratio, the Reynolds number, and the shape of the channel were varied relative to a reference model. In our simulations, the cross section of the thread produced by focusing is elliptical rather than circular. The initial folding axis can be either parallel or perpendicular to the narrow dimension of the chamber. In the former case, the folding slowly transforms via twisting to perpendicular folding, or it may remain parallel. The direction of folding onset is determined by the velocity profile and the elliptical shape of the thread cross section in the channel that feeds the diverging part of the cell.
Lagrangian chaos in three- dimensional steady buoyancy-driven flows
Contreras, Sebastian; Speetjens, Michel; Clercx, Herman
2016-11-01
Natural convection plays a key role in fluid dynamics owing to its ubiquitous presence in nature and industry. Buoyancy-driven flows are prototypical systems in the study of thermal instabilities and pattern formation. The differentially heated cavity problem has been widely studied for the investigation of buoyancy-induced oscillatory flow. However, far less attention has been devoted to the three-dimensional Lagrangian transport properties in such flows. This study seeks to address this by investigating Lagrangian transport in the steady flow inside a cubic cavity differentially-heated from the side. The theoretical and numerical analysis expands on previously reported similarities between the current flow and lid-driven flows. The Lagrangian dynamics are controlled by the Péclet number (Pe) and the Prandtl number (Pr). Pe controls the behaviour qualitatively in that growing Pe progressively perturbs the integable state (Pe =0), thus paving the way to chaotic dynamics. Pr plays an entirely quantitative role in that Pr1 amplifies and diminishes, respectively, the perturbative effect of non-zero Pe. S.C. acknowledges financial support from Consejo Nacional de Ciencia y Tecnología (CONACYT).
Three-dimensional effects for radio frequency antenna modeling
Energy Technology Data Exchange (ETDEWEB)
Carter, M.D.; Batchelor, D.B.; Stallings, D.C.
1993-12-31
Electromagnetic field calculations for radio frequency (rf) antennas in two dimensions (2-D) neglect finite antenna length effects as well as the feeders leading to the main current strap. The 2-D calculations predict that the return currents in the sidewalls of the antenna structure depend strongly on the plasma parameters, but this prediction is suspect because of experimental evidence. To study the validity of the 2-D approximation, the Multiple Antenna Implementation System (MAntIS) has been used to perform three-dimensional (3-D) modeling of the power spectrum, plasma loading, and inductance for a relevant loop antenna design. Effects on antenna performance caused by feeders to the main current strap and conducting sidewalls are considered. The modeling shows that the feeders affect the launched power spectrum in an indirect way by forcing the driven rf current to return in the antenna structure rather than the plasma, as in the 2-D model. It has also been found that poloidal dependencies in the plasma impedance matrix can reduce the loading predicted from that predicted in the 2-D model. For some plasma parameters, the combined 3-D effects can lead to a reduction in the predicted loading by as much as a factor of 2 from that given by the 2-D model, even with end-effect corrections for the 2-D model.
Three-dimensional effects for radio frequency antenna modeling
Carter, M. D.; Batchelor, D. B.; Stallings, D. C.
1994-10-01
Electromagnetic field calculations for radio frequency (rf) antennas in two dimensions (2-D) neglect finite antenna length effects as well as the feeders leading to the main current strap. The 2-D calculations predict that the return currents in the sidewalls of the antenna structure depend strongly on the plasma parameters, but this prediction is suspect because of experimental evidence. To study the validity of the 2-D approximation, the Multiple Antenna Implementation System (MAntIS) has been used to perform three-dimensional (3-D) modeling of the power spectrum, plasma loading, and inductance for a relevant loop antenna design. Effects on antenna performance caused by feeders to the main current strap and conducting sidewalls are considered. The modeling shows that the feeders affect the launched power spectrum in an indirect way by forcing the driven rf current to return in the antenna structure rather than the plasma, as in the 2-D model. It has also been found that poloidal dependencies in the plasma impedance matrix can reduce the loading predicted from that predicted in the 2-D model. For some plasma parameters, the combined 3-D effects can lead to a reduction in the predicted loading by as much as a factor of 2 from that given by the 2-D model, even with end-effect corrections for the 2-D model.
Three-dimensional effects for radio frequency antenna modeling
Energy Technology Data Exchange (ETDEWEB)
Carter, M.D.; Batchelor, D.B.; Stallings, D.C. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37821-8071 (United States))
1994-10-15
Electromagnetic field calculations for radio frequency (rf) antennas in two dimensions (2-D) neglect finite antenna length effects as well as the feeders leading to the main current strap. The 2-D calculations predict that the return currents in the sidewalls of the antenna structure depend strongly on the plasma parameters, but this prediction is suspect because of experimental evidence. To study the validity of the 2-D approximation, the Multiple Antenna Implementation System (MAntIS) has been used to perform three-dimensional (3-D) modeling of the power spectrum, plasma loading, and inductance for a relevant loop antenna design. Effects on antenna performance caused by feeders to the main current strap and conducting sidewalls are considered. The modeling shows that the feeders affect the launched power spectrum in an indirect way by forcing the driven rf current to return in the antenna structure rather than the plasma, as in the 2-D model. It has also been found that poloidal dependencies in the plasma impedance matrix can reduce the loading predicted from that predicted in the 2-D model. For some plasma parameters, the combined 3-D effects can lead to a reduction in the predicted loading by as much as a factor of 2 from that given by the 2-D model, even with end-effect corrections for the 2-D model.
A three-dimensional measurement method for medical electric endoscope
Zhou, Tingting; Tao, Pei; Yuan, Bo; Wang, Liqiang
2017-01-01
One method for three-dimensional (3D) measurement based on structured light is proposed for the medical electric endoscope in the present study. The structured light of black and white strips is generated by that the point sources illuminate the grating mask plate. Four point sources are aligned linearly by a certain space and they are lighted sequentially. Then four images of modulated fringes by the height of object with different phase shifts can be obtained. The algorithm proposed by Wang Z is employed to extract the accurate phase shift from the fringe images since the phase shift cannot be exactly set as π/2 by hardware. An experimental prototype endoscope was built according to the proposed method. One high-definition CMOS camera module developed by ourselves was used to acquire the endoscopic images and the structured light was generated by four fiber LEDs and a transmission grating with a pitch of 0.1 mm. one C# program was designed to light up LEDs in turn, acquire the phase shifted images and calculate the 3D information. The experimental results indicate that its precise of depth measurement at the working distance of 40 mm is better than 0.5 mm and its consuming time of 3D depth calculation is less than 0.5 s.
EXPERIMENTS OF THREE-DIMENSIONAL FLOW STRUCTURE IN BRAIDED RIVERS
Institute of Scientific and Technical Information of China (English)
HUA Zu-lin; GU Li; CHU Ke-jian
2009-01-01
The braided river is a typical river pattern in nature, but there is a paucity of comprehensive data set describing the three-dimensional flow field in the braided river. A physical model experiment was used to study the flow characteristics in the typical braided river with a mid-bar between two anabranches. In the experiment, two kinds of mid-bar with the ratios of its length to maximal width of 3 and 5 were considered. Moreover, the mid-bar could be moved to adjust the width of two anabranches. The detailed measurements of velocity were conducted using an acoustic Doppler velocimeter over a grid defined throughout the whole braided river region, including the bifurcation, two anabranches and the confluence. In two kinds of mid-bar braided models, a separation zone was observed in the anabranch of the model in which the ratio of length to maximal width of mid-bar is 3, however the separation zone was not found in another model in which the ratio is 5. In addition, the opposite secondary cells were observed at the bend apex of anabranch in two models, and different longitudinal velocity distributions in the entrance region of anabranch account for this opposite flow structure. Finally, turbulent kinetic energy were shown and compared in different situations. The high turbulence occurs at the place with strong shear, especially at the boundary of the separation zone and the high velocity passing flow.
Parallax multi-viewer autostereoscopic three-dimensional display
Sha, Lingdao; Schonfeld, Dan; Li, Qun
2014-03-01
It is a widely held belief that in the long run, three-dimensional (3D) display should supply stereo to multiple viewers without wearing any viewing aids and free to move. Over the last few decades, great e®orts have been made to approach auto-stereoscopic (AS) display for multiple viewers. Spatial multiplexing technique has ¯rst been employed to accommodate multiple viewers simultaneously in stereoscopic planar display. However, resolution of each view image decreases as the number of viewers increases. Recent development of high-speed liquid crystal display (LCD), which is capable of operating 240-Hz frame rate, makes feasible multi-viewer display via time multiplexing and improving image quality at the same time. In this paper, we propose a display adjustment algorithm that enables high-quality auto-stereoscopic display for multiple viewers. The proposed method relies on spatio-temporal parallax barrier to channel desired stereo pair to corresponding viewers according to their locations. We subsequently conduct simulations that demonstrate the e®ectiveness of the proposed method.
Standing Kink modes in three-dimensional coronal loops
Energy Technology Data Exchange (ETDEWEB)
Pascoe, D. J.; De Moortel, I., E-mail: dpascoe@mcs.st-andrews.ac.uk [School of Mathematics and Statistics, University of St. Andrews, St. Andrews KY16 9SS (United Kingdom)
2014-04-01
So far, the straight flux tube model proposed by Edwin and Roberts is the most commonly used tool in practical coronal seismology, in particular, to infer values of the (coronal) magnetic field from observed, standing kink mode oscillations. In this paper, we compare the period predicted by this basic model with three-dimensional (3D) numerical simulations of standing kink mode oscillations, as the period is a crucial parameter in the seismological inversion to determine the magnetic field. We perform numerical simulations of standing kink modes in both straight and curved 3D coronal loops and consider excitation by internal and external drivers. The period of oscillation for the displacement of dense coronal loops is determined by the loop length and the kink speed, in agreement with the estimate based on analytical theory for straight flux tubes. For curved coronal loops embedded in a magnetic arcade and excited by an external driver, a secondary mode with a period determined by the loop length and external Alfvén speed is also present. When a low number of oscillations is considered, these two periods can result in a single, non-resolved (broad) peak in the power spectrum, particularly for low values of the density contrast for which the two periods will be relatively similar. In that case (and for this particular geometry), the presence of this additional mode would lead to ambiguous seismological estimates of the magnetic field strength.
Three-dimensional lattice Boltzmann model for electrodynamics.
Mendoza, M; Muñoz, J D
2010-11-01
In this paper we introduce a three-dimensional Lattice-Boltzmann model that recovers in the continuous limit the Maxwell equations in materials. In order to build conservation equations with antisymmetric tensors, like the Faraday law, the model assigns four auxiliary vectors to each velocity vector. These auxiliary vectors, when combined with the distribution functions, give the electromagnetic fields. The evolution is driven by the usual Bhatnager-Gross-Krook (BGK) collision rule, but with a different form for the equilibrium distribution functions. This lattice Bhatnager-Gross-Krook (LBGK) model allows us to consider for both dielectrics and conductors with realistic parameters, and therefore it is adequate to simulate the most diverse electromagnetic problems, like the propagation of electromagnetic waves (both in dielectric media and in waveguides), the skin effect, the radiation pattern of a small dipole antenna and the natural frequencies of a resonant cavity, all with 2% accuracy. Actually, it shows to be one order of magnitude faster than the original Finite-difference time-domain (FDTD) formulation by Yee to reach the same accuracy. It is, therefore, a valuable alternative to simulate electromagnetic fields and opens lattice Boltzmann for a broad spectrum of new applications in electrodynamics.
Three Dimensional Movements Of The Upper Cervical Spine
Panjabi, Manohar M.; Dvorak, Jiri; Duranceau, Joanne; Yamamoto, Isao
1989-04-01
Ten fresh cadaveric whole cervical spine specimens (occiput to C7) were studied using well established techniques to document the movements in flexion, extension, left and right lateral bending and left and right axial rotation. Pure moments of maximum 1.5 newton meters were applied incrementally and three dimensional movements of the bones were recorded using stereophotogrammetry. Each moment was applied individually and in a three load/unload cycles. The motion measurements were made on the third load cycle. Parameters of neutral zone, elastic zone and range of motion were computed. Neutral zones for flexion/extension, right/left lateral bending and right/left axial rotation were respectively: 1.1, 1.5 and 1.6 (occiput-C1); and 3.2, 1.2 and 29.6 degrees (C1-C2). Ranges of motion for flexion, extension, lateral bending (one side) and axial rotation (one side) were respectively: 3.5, 21.0, 5.5 and 7.2 degrees (occiput-Cl joint) and 11.5, 10.9, 6.7 and 38.9 degrees (CI-CZ joint). The highest intervertebral motion in the spine was the axial rotation at the Cl-C2 joint, neutral zone constituting 75% of this motion.
Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.
Energy Technology Data Exchange (ETDEWEB)
Warne, Larry Kevin; Jorgenson, Roy Eberhardt
2014-10-01
This report examines the localization of high frequency electromagnetic fi elds in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This report treats both the case where the opposing sides, or mirrors, are convex, where there are no interior foci, and the case where they are concave, leading to interior foci. The scalar problem is treated fi rst but the approximations required to treat the vector fi eld components are also examined. Particular att ention is focused on the normalization through the electromagnetic energy theorem. Both projections of the fi eld along the scarred orbit as well as point statistics are examined. Statistical comparisons are m ade with a numerical calculation of the scars run with an axisymmetric simulation. This axisymmetric cas eformstheoppositeextreme(wherethetwomirror radii at each end of the ray orbit are equal) from the two -dimensional solution examined previously (where one mirror radius is vastly di ff erent from the other). The enhancement of the fi eldontheorbitaxiscanbe larger here than in the two-dimensional case. Intentionally Left Blank
Hierarchical, Three-Dimensional Measurement System for Crime Scene Scanning.
Marcin, Adamczyk; Maciej, Sieniło; Robert, Sitnik; Adam, Woźniak
2017-02-02
We present a new generation of three-dimensional (3D) measuring systems, developed for the process of crime scene documentation. This measuring system facilitates the preparation of more insightful, complete, and objective documentation for crime scenes. Our system reflects the actual requirements for hierarchical documentation, and it consists of three independent 3D scanners: a laser scanner for overall measurements, a situational structured light scanner for more minute measurements, and a detailed structured light scanner for the most detailed parts of tscene. Each scanner has its own spatial resolution, of 2.0, 0.3, and 0.05 mm, respectively. The results of interviews we have conducted with technicians indicate that our developed 3D measuring system has significant potential to become a useful tool for forensic technicians. To ensure the maximum compatibility of our measuring system with the standards that regulate the documentation process, we have also performed a metrological validation and designated the maximum permissible length measurement error EMPE for each structured light scanner. In this study, we present additional results regarding documentation processes conducted during crime scene inspections and a training session.
The three-dimensional matrix -- An evolution in project management
Energy Technology Data Exchange (ETDEWEB)
Glidewell, D.
1996-09-01
In the Functional Department Dimension, functional departments such as project management, design, and construction would be maintained to maximize consistency among project teams, evenly allocate training opportunities, and facilitate the crossfeeding of lessons learned and innovative ideas. Functional departments were also determined to be the surest way of complying uniformly with all project control systems required by the Department of Energy (Sandia`s primary external customer). The Technical Discipline dimension was maintained to enhance communication within the technical disciplines, such as electrical engineering, mechanical engineering, civil engineering, etc., and to evenly allocate technical training opportunities, reduce technical obsolescence, and enhance design standards. The third dimension, the Project Dimension, represents the next step in the project management evolution at Sandia, and together with Functional Department and Technical Discipline Dimensions constitutes the three-dimensional matrix. It is this Project Dimension that will be explored thoroughly in this paper, including a discussion of the specific roles and responsibilities of both management and the project team.
Three Dimensional CFD Analysis of the GTX Combustor
Steffen, C. J., Jr.; Bond, R. B.; Edwards, J. R.
2002-01-01
The annular combustor geometry of a combined-cycle engine has been analyzed with three-dimensional computational fluid dynamics. Both subsonic combustion and supersonic combustion flowfields have been simulated. The subsonic combustion analysis was executed in conjunction with a direct-connect test rig. Two cold-flow and one hot-flow results are presented. The simulations compare favorably with the test data for the two cold flow calculations; the hot-flow data was not yet available. The hot-flow simulation indicates that the conventional ejector-ramjet cycle would not provide adequate mixing at the conditions tested. The supersonic combustion ramjet flowfield was simulated with frozen chemistry model. A five-parameter test matrix was specified, according to statistical design-of-experiments theory. Twenty-seven separate simulations were used to assemble surrogate models for combustor mixing efficiency and total pressure recovery. ScramJet injector design parameters (injector angle, location, and fuel split) as well as mission variables (total fuel massflow and freestream Mach number) were included in the analysis. A promising injector design has been identified that provides good mixing characteristics with low total pressure losses. The surrogate models can be used to develop performance maps of different injector designs. Several complex three-way variable interactions appear within the dataset that are not adequately resolved with the current statistical analysis.
Three Dimensional Vapor Intrusion Modeling: Model Validation and Uncertainty Analysis
Akbariyeh, S.; Patterson, B.; Rakoczy, A.; Li, Y.
2013-12-01
Volatile organic chemicals (VOCs), such as chlorinated solvents and petroleum hydrocarbons, are prevalent groundwater contaminants due to their improper disposal and accidental spillage. In addition to contaminating groundwater, VOCs may partition into the overlying vadose zone and enter buildings through gaps and cracks in foundation slabs or basement walls, a process termed vapor intrusion. Vapor intrusion of VOCs has been recognized as a detrimental source for human exposures to potential carcinogenic or toxic compounds. The simulation of vapor intrusion from a subsurface source has been the focus of many studies to better understand the process and guide field investigation. While multiple analytical and numerical models were developed to simulate the vapor intrusion process, detailed validation of these models against well controlled experiments is still lacking, due to the complexity and uncertainties associated with site characterization and soil gas flux and indoor air concentration measurement. In this work, we present an effort to validate a three-dimensional vapor intrusion model based on a well-controlled experimental quantification of the vapor intrusion pathways into a slab-on-ground building under varying environmental conditions. Finally, a probabilistic approach based on Monte Carlo simulations is implemented to determine the probability distribution of indoor air concentration based on the most uncertain input parameters.