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Pulse transit time

Berc Kalanyan, William A Kimes, Ryan Beams, Stephan J Stranick, Elias Garratt, Irina Kalish, Albert V Davydov, Ravindra K Kanjolia, James E Maslar
High volume manufacturing of devices based on transition metal dichalcogenide (TMD) ultra-thin films will require deposition techniques that are capable of reproducible wafer-scale growth with monolayer control. To date, TMD growth efforts have largely relied upon sublimation and transport of solid precursors with minimal control over vapor phase flux and gas-phase chemistry, which are critical for scaling up laboratory processes to manufacturing settings. To address these issues, we report a new pulsed metalorganic chemical vapor deposition (MOCVD) route for MoS2 film growth in a research-grade single-wafer reactor...
August 8, 2017: Chemistry of Materials: a Publication of the American Chemical Society
Yuly Vesga, Carlos Diaz, Jeanne Crassous, Florencio E Hernandez
Herein, we report on the theoretical-experimental analysis of the two photon absorption and circular dichroism spectra of 1-(2-pyridyl)-4-methoxy-carbo[6]helicene derivative (P6). The primary outcomes of our investigation on this particular helicene derivative with a donor-acceptor motif on one end led to two important conclusions: 1) The lengthening of the π-electron delocalization within the helical core of P6 predominantly increases the contribution of the magnetic transition dipole moment to the TPCD signal; 2) The electric transition quadrupole moment contribution to the TPCD signal is enhanced by the intramolecular charge transfer (ICT) produced by the donor-acceptor combination on one end of the molecule...
March 15, 2018: Journal of Physical Chemistry. A
Ruwei Zhao, Guoru Li, Baitao Zhang, Jingliang He
As a new member of transition metal dichalcogenides (TMDs), rhenium disulfide (ReS2 ), with a nearly unchanged direct bandgap from bulk to monolayer form, is attractive in physics and material fields. By using the optically driving deposition method, the ReS2 saturable absorber (SA) has been fabricated with a modulation depth and saturation fluence of 6.9% and 27.5 μJ/cm2 , respectively. Based on the ReS2 -SA, a multi-wavelength bright-dark pulse pair from a mode-locked fiber laser has been observed experimentally for the first time, to the best of our knowledge...
March 5, 2018: Optics Express
Mark Golberg, Joaquin Ruiz-Rivas, Sagi Polani, Yevgeny Beiderman, Zeev Zalevsky
Blood pressure (BP) is usually measured either invasively, by an intra-arterial catheter, or noninvasively, by a cuff-based sphygmomanometer. While the invasive method is continuous and more accurate, it has the risk of infection and generally is not comfortable for the patient. On the other hand, the cuff-based measurement is safer but less reliable and infrequent. Therefore, a reliable continuous noninvasive BP measurement is highly desirable. In this work, we propose a remote optical system, based on temporal analysis of secondary reflected speckle patterns, for computing a subject's pulse transit time (PTT)...
March 1, 2018: Applied Optics
Isinsu Baylam, Sarper Ozharar, Alphan Sennaroglu
We report on an experimental demonstration of a 1200-nm pumped Tm3+ :Lu2 O3 ceramic laser. By using a gain-switched, tunable Cr4+ :forsterite laser, the excitation spectrum was measured, with optimum pumping bands centered near 1198 nm, 1204 nm, and 1211 nm. The highest slope efficiency of 21.5% was obtained at the pump wavelength of 1204 nm. Comparative energy efficiency measurements performed near 1200-nm and 800-nm pumping further showed that nearly 40% improvement was obtained in slope efficiency measured with respect to the incident pump energy for 1200-nm pumping...
March 10, 2018: Applied Optics
Jun Du, Mahesh S Kodikara, Graeme J Moxey, Mahbod Morshedi, Adam Barlow, Cristóbal Quintana, Genmiao Wang, Robert Stranger, Chi Zhang, Marie P Cifuentes, Mark G Humphrey
1-Nitronaphthalenyl-4-alkynyl and 9-nitroanthracenyl-10-alkynyl complexes [M](C[triple bond, length as m-dash]C-4-C10 H6 -1-NO2 ) ([M] = trans-[RuCl(dppe)2 ] (6b), trans-[RuCl(dppm)2 ] (7b), Ru(PPh3 )2 (η5 -C5 H5 ) (8b), Ni(PPh3 )(η5 -C5 H5 ) (9b), Au(PPh3 ) (10b)) and [M](C[triple bond, length as m-dash]C-10-C14 H8 -9-NO2 ) ([M] = trans-[RuCl(dppe)2 ] (6c), trans-[RuCl(dppm)2 ] (7c), Ru(PPh3 )2 (η5 -C5 H5 ) (8c), Ni(PPh3 )(η5 -C5 H5 ) (9c), Au(PPh3 ) (10c)) were synthesized and their identities were confirmed by single-crystal X-ray diffraction studies...
March 7, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Phoebe Tengdin, Wenjing You, Cong Chen, Xun Shi, Dmitriy Zusin, Yingchao Zhang, Christian Gentry, Adam Blonsky, Mark Keller, Peter M Oppeneer, Henry C Kapteyn, Zhensheng Tao, Margaret M Murnane
It has long been known that ferromagnets undergo a phase transition from ferromagnetic to paramagnetic at the Curie temperature, associated with critical phenomena such as a divergence in the heat capacity. A ferromagnet can also be transiently demagnetized by heating it with an ultrafast laser pulse. However, to date, the connection between out-of-equilibrium and equilibrium phase transitions, or how fast the out-of-equilibrium phase transitions can proceed, was not known. By combining time- and angle-resolved photoemission with time-resolved transverse magneto-optical Kerr spectroscopies, we show that the same critical behavior also governs the ultrafast magnetic phase transition in nickel...
March 2018: Science Advances
Arjang Talattof, Gordon L Amidon
Fasted-state gastrointestinal (GI) fluid transit is typically represented as a first-order, deterministic process (averaged and viewed as a continuous approximation). It is, however, most likely a discrete process involving fluid packets interrupted by variable time periods of little to no fluid emptying. In this report we present a physiologically based pulsed-packet gastric fluid emptying model and evaluate it with respect to recent gastrointestinal fluid volume emptying results, published gastric emptying of various dosage forms, and gastric fluid emptying as a function of GI motility...
March 5, 2018: Molecular Pharmaceutics
Elisa Biasin, Tim B van Driel, Gianluca Levi, Mads G Laursen, Asmus O Dohn, Asbjørn Moltke, Peter Vester, Frederik B K Hansen, Kasper S Kjaer, Tobias Harlang, Robert Hartsock, Morten Christensen, Kelly J Gaffney, Niels E Henriksen, Klaus B Møller, Kristoffer Haldrup, Martin M Nielsen
Time-resolved X-ray scattering patterns from photoexcited molecules in solution are in many cases anisotropic at the ultrafast time scales accessible at X-ray free-electron lasers (XFELs). This anisotropy arises from the interaction of a linearly polarized UV-Vis pump laser pulse with the sample, which induces anisotropic structural changes that can be captured by femtosecond X-ray pulses. In this work, a method for quantitative analysis of the anisotropic scattering signal arising from an ensemble of molecules is described, and it is demonstrated how its use can enhance the structural sensitivity of the time-resolved X-ray scattering experiment...
March 1, 2018: Journal of Synchrotron Radiation
Miklós Antal Werner, Eugene Demler, Alain Aspect, Gergely Zaránd
We propose to apply a modified version of the excitation scheme introduced by Volchkov et al. on bosons experiencing hyperfine state dependent disorder to address the critical state at the mobility edge of the Anderson localization transition, and to observe its intriguing multifractal structure. An optimally designed, spatially focused external radio frequency pulse can be applied to generate transitions to eigenstates in a narrow energy window close to the mobility edge, where critical scaling and multifractality emerge...
February 26, 2018: Scientific Reports
B A Akselrod, L A Tolstova, T A Pshenichniy, S V Fedulova
BACKGROUND: Estimated continuous cardiac output (esCCOTM) based on pulse wave transit time is one of alternative non-invasive CO measurement techniques. METHODS: Randomized study included 23 scheduled patients operated upon due to cardiovascular diseases. Cardiac index (CI) was measured Comparative analyses of esCCO and others CO measurement methods used intraoperative was carried out. In the first group (n = 9) esCCO was compared with transpulmonary thermodilution (PiCCO-plus); in the second group (n = 8) - with pulmonary artery thermodilution; in the third group (n = 6) - with transoesophageal echocardiography (velocity-time integral)...
September 2017: Anesteziologiia i Reanimatologiia
M Doser, S Aghion, C Amsler, G Bonomi, R S Brusa, M Caccia, R Caravita, F Castelli, G Cerchiari, D Comparat, G Consolati, A Demetrio, L Di Noto, C Evans, M Fanì, R Ferragut, J Fesel, A Fontana, S Gerber, M Giammarchi, A Gligorova, F Guatieri, S Haider, A Hinterberger, H Holmestad, A Kellerbauer, O Khalidova, D Krasnický, V Lagomarsino, P Lansonneur, P Lebrun, C Malbrunot, S Mariazzi, J Marton, V Matveev, Z Mazzotta, S R Müller, G Nebbia, P Nedelec, M Oberthaler, N Pacifico, D Pagano, L Penasa, V Petracek, F Prelz, M Prevedelli, B Rienaecker, J Robert, O M Røhne, A Rotondi, H Sandaker, R Santoro, L Smestad, F Sorrentino, G Testera, I C Tietje, E Widmann, P Yzombard, C Zimmer, J Zmeskal, N Zurlo
The efficient production of cold antihydrogen atoms in particle traps at CERN's Antiproton Decelerator has opened up the possibility of performing direct measurements of the Earth's gravitational acceleration on purely antimatter bodies. The goal of the AEgIS collaboration is to measure the value of g for antimatter using a pulsed source of cold antihydrogen and a Moiré deflectometer/Talbot-Lau interferometer. The same antihydrogen beam is also very well suited to measuring precisely the ground-state hyperfine splitting of the anti-atom...
March 28, 2018: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Christopher L Follett, Stephanie Dutkiewicz, David M Karl, Keisuke Inomura, Michael J Follows
In the North Pacific Subtropical Gyre (NPSG), an annual pulse of sinking organic carbon is observed at 4000 m between July and August, driven by large diatoms found in association with nitrogen fixing, heterocystous, cyanobacteria: Diatom-Diazotroph Associations (DDAs). Here we ask what drives the bloom of DDAs and present a simplified trait-based model of subtropical phototroph populations driven by observed, monthly averaged, environmental characteristics. The ratio of resource supply rates favors nitrogen fixation year round...
February 15, 2018: ISME Journal
Tsuyoshi Matsuda, Hirohiko Kimura, Hiroyuki Kabasawa, Masayuki Kanamoto
On arterial spin-labeled (ASL) images, areas of bright intravascular signal will appear when the post labeling delay time is shorter than arterial transit time. Vascular suppression (VS) schemes reduce artefactual bright signal by dephasing intravascular labeled spins. However, existing VS methods, such as Motion-Sensitized Driven-Equilibrium (MSDE), decrease the uniformity of the signal intensity distribution and extend the echo time. The purpose of this study is to compare VS using a Delays Alternating with Nutation for Tailored Excitation (DANTE) preparation pulse, with MSDE for ASL imaging on a flow phantom and volunteer data...
February 12, 2018: Magnetic Resonance Imaging
Mehmet Dogan, Tolga Han Efe, Tolga Cimen, Cem Ozisler, Mehmet Ali Felekoglu, Ahmet Goktug Ertem, Mehmet Erat, Omer Yiginer, Murat Tulmac
OBJECTIVES: Systemic sclerosis (SSc) is a chronic, inflammatory, and autoimmune connective tissue disease that is associated with vascular lesions, and fibrosis of the skin and visceral organs. Cardiac complications may occur as a secondary effect of SSc as a result of pulmonary arterial hypertension and interstitial lung disease. The objective of this study was to assess whether the pulmonary pulse transit time (pPTT) could serve as a diagnostic marker for pulmonary arterial alterations in patients with SSc, prior to development of pulmonary hypertension...
February 14, 2018: Lung
Rosemary S C Horne, Genevieve Shandler, Knarik Tamanyan, Aidan Weichard, Alexsandria Odoi, Sarah N Biggs, Margot J Davey, Gillian M Nixon, Lisa M Walter
BACKGROUND: Up to 50% of overweight/obese children have obstructive sleep apnea (OSA) compared to up to 6% of normal weight children. We compared cardiovascular variables between normal weight and overweight/obese children with and without OSA, and controls. METHODS: Seventy-four referred children and 24 normal weight non-snoring controls (8-18 years) were recruited. Referred children were grouped according to their obstructive apnea hypopnea index (OAHI): OSA (>1 event/h) or primary snoring (PS ≤ 1 event/h) and whether they were normal weight (BMI z-score <1...
January 2018: Sleep Medicine
John Dewhurst, Peter Elliott, Sam Shallcross, Eberhard K U Gross, Sangeeta Sharma
Laser pulses induce spin preserving optical transitions that we show generate dramatic changes in the magnetic structure of materials, including a switching of magnetic order from anti-ferromagnetic (AFM) to transient ferromagnetic (FM) in a multi-sub-lattice systems. The microscopic mechanism underpinning this ultra-fast switching of magnetic order is dominated by charge flow from one magnetic sub-lattice to another. As this spin modulation is purely optical in nature (i.e. not mediated indirectly via the spin-orbit interaction) this is one of the fastest means of manipulating spins by light...
February 9, 2018: Nano Letters
Bin Sun, Yuxia Zhang, Rui Zhang, Haohai Yu, Guowei Zhou, Huaijin Zhang, Jiyang Wang
NiO, a 3d transition-metal oxide with the strong electron correlation, has attracted great physical attention due to the spin-orbit splitting of 3d electrons. By taking advantage of electron transition process originated from 3d spin-orbit splitting, it may be applied to many photonics areas by linear or nonlinear optical response. To further broaden the photonics applications of NiO, we originally explore the nonlinear optical response, saturable absorption, during the electronic transition due to 3d spin-orbit splitting under a strong optical field and successfully applied in the ultrafast photonics as a mode-locker for the generation of visible laser pulses, which is the result of dynamic balancing process by the electron transition arising from ground state (3A2g) to excited state (1Eg) of spin-orbit splitting in the Ni2+ 3d configurations...
January 22, 2018: Optics Express
Jingjing Ju, Haiyi Sun, Xingkai Hu, Yonghong Liu, Yaoxiang Liu, Jingwei Wang, Cheng Wang, Tie-Jun Wang, Xueliang Guo, Jiansheng Liu, See Leang Chin, Ruxin Li, Zhizhan Xu
Water condensation and precipitation induced by 22-TW 800-nm laser pulses at 1 Hz in an open cloud chamber were investigated in a time-resolved manner. Two parts of precipitation in two independent periods of time were observed directly following each laser shot. One part started around the filament zone at t < 500 μs and ended at t ≅ 1.5 ms after the arrival of the femtosecond laser pulse. The other following the laser-induced energetic air motion (turbulence), started at t ≅ 20 ms and ended at t ≅ 120 ms...
February 5, 2018: Optics Express
Yibin Zhang, Richard B Miles
Tagging is demonstrated in argon and nitrogen gases using a femtosecond laser with pulse energies of approximately 70 μJ through a nonresonant ionization process at 267 nm. The signal fluorescence lifetime in pure argon and nitrogen-argon mixtures are measured and found to be long enough to make mean velocity and turbulence measurements in a subsonic flow. In pure argon, the dominating processes involve atomic transitions between 700 and 900 nm. In argon-nitrogen mixtures, nitrogen quenches atomic argon species and the dominant radiating processes are transitions in the nitrogen second positive system...
February 1, 2018: Optics Letters
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