To see the other types of publications on this topic, follow the link: Dispersion.11.
Journal articles on the topic 'Dispersion.11'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Dispersion.11.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Duru, M., I. Melek, E. Seyfeli, et al. "QTC Dispersion and P-Wave Dispersion during Migraine Attacks." Cephalalgia 26, no. 6 (2006): 672–77. http://dx.doi.org/10.1111/j.1468-2982.2006.01081.x.
Full textAbstract:
The aim of this study was to investigate increase of QTc dispersion and P-wave dispersion during migraine attacks. Fifty-five patients (16–65 years of age, 49 women, six men) with migraine were included in our study. Heart rate, QTc interval, maximum and minimum QTc interval, QTc dispersion, maximum and minimum P-wave duration and P-wave dispersion were measured from 12-lead ECG recording during migraine attacks and pain-free periods. ECGs were transferred to a personal computer via a scanner and then used for magnification of x400 by Adobe Photoshop software. Maximum QTc interval (454 ± 24 ms vs. 429 ± 23 ms, P < 0.001), QTc interval (443 ± 26 ms vs. 408 ± 22 ms, P <0.001) and QTc dispersion (63 ± 18 ms vs. 43 ± 14 ms, P <0.001) were found significantly higher during migraine attacks compared with pain-free periods. Maximum P-wave duration (107 ± 11 ms vs. 100 ± 11 ms, P <0.001) and P-wave dispersion (45 ± 13 ms vs. 35 ± 13 ms, P <0.001) were found higher during migraine attacks than pain-free periods. We concluded that migraine attacks are associated with increased QTc and P-wave dispersion compared with pain-free periods.
2
Carlberg, Raymond G., and Carl J. Grillmair. "Testing for Dark Matter in the Outskirts of Globular Clusters." Astrophysical Journal 922, no. 2 (2021): 104. http://dx.doi.org/10.3847/1538-4357/ac289f.
Full textAbstract:
Abstract The proper motions of stars in the outskirts of globular clusters are used to estimate cluster velocity dispersion profiles as far as possible within their tidal radii. We use individual color–magnitude diagrams to select high-probability cluster stars for 25 metal-poor globular clusters within 20 kpc of the Sun, 19 of which have substantial numbers of stars at large radii. Of the 19, 11 clusters have a falling velocity dispersion in the 3–6 half-mass radii range, 6 are flat, and 2 plausibly have a rising velocity dispersion. The profiles are all in the range expected from simulated clusters that started at high redshift in a zoom-in cosmological simulation. The 11 clusters with falling velocity dispersion profiles are consistent with no dark matter above the Galactic background. The six clusters with approximately flat velocity dispersion profiles could have local dark matter, but are ambiguous. The two clusters with rising velocity dispersion profiles are consistent with a remnant local dark matter halo, but need membership confirmation and detailed orbital modeling to further test these preliminary results.
3
Haldar, Susanta, Ramachandran Gnanasekaran, and Pavel Hobza. "A comparison of ab initio quantum-mechanical and experimental D0 binding energies of eleven H-bonded and eleven dispersion-bound complexes." Physical Chemistry Chemical Physics 17, no. 40 (2015): 26645–52. http://dx.doi.org/10.1039/c5cp04427h.
Full text
4
Shehadi, Maher. "Particle dispersion analysis in an 11-row Boeing 767 cabin mockup." Science and Technology for the Built Environment 25, no. 7 (2019): 849–57. http://dx.doi.org/10.1080/23744731.2019.1573057.
Full text
5
André, P. S., Armando Pinto, J. L. Pinto, et al. "Chromatic Dispersion in Ge-Doped SiO2-Based Single Mode Fibres due to Temperature Dependence of the Ultraviolet Absorption: Numerical and Experimental Results." Materials Science Forum 514-516 (May 2006): 369–76. http://dx.doi.org/10.4028/www.scientific.net/msf.514-516.369.
Full textAbstract:
The main information transmission limitation in optical communications employing SiO2 optical fibres is imposed by the optical pulses temporal broadening, resulting from the dispersive properties of the transmission medium (chromatic dispersion). Usually, this dispersion is modelled assuming a -0.4 meV/°C dependence of the 11 eV gap energy. We have monitored the 4.3 eV absorption band, with temperature and obtained a thermal dependence of -0.026 meV/°C. With this value we can predict the first and second order chromatic dispersion for a wavelength of 1550 nm.
6
Aghanim, N., Y. Akrami, M. Ashdown, et al. "Planck intermediate results." Astronomy & Astrophysics 617 (September 2018): A48. http://dx.doi.org/10.1051/0004-6361/201731489.
Full textAbstract:
Using the Planck full-mission data, we present a detection of the temperature (and therefore velocity) dispersion due to the kinetic Sunyaev-Zeldovich (kSZ) effect from clusters of galaxies. To suppress the primary CMB and instrumental noise we derive a matched filter and then convolve it with the Planck foreground-cleaned “2D-ILC” maps. By using the Meta Catalogue of X-ray detected Clusters of galaxies (MCXC), we determine the normalized rms dispersion of the temperature fluctuations at the positions of clusters, finding that this shows excess variance compared with the noise expectation. We then build an unbiased statistical estimator of the signal, determining that the normalized mean temperature dispersion of 1526 clusters is 〈(ΔT/T)2 〉 = (1.64 ± 0.48) × 10−11. However, comparison with analytic calculations and simulations suggest that around 0.7 σ of this result is due to cluster lensing rather than the kSZ effect. By correcting this, the temperature dispersion is measured to be 〈(ΔT/T)2〉 = (1.35 ± 0.48) × 10−11, which gives a detection at the 2.8 σ level. We further convert uniform-weight temperature dispersion into a measurement of the line-of-sight velocity dispersion, by using estimates of the optical depth of each cluster (which introduces additional uncertainty into the estimate). We find that the velocity dispersion is 〈υ2〉 = (123 000 ± 71 000) (km s−1)2, which is consistent with findings from other large-scale structure studies, and provides direct evidence of statistical homogeneity on scales of 600 h−1 Mpc. Our study shows the promise of using cross-correlations of the kSZ effect with large-scale structure in order to constrain the growth of structure.
7
Zhang, Li Li, Yu Hong Chen, and Li Min Qi. "Dispersion Behavior of Silicon Carbide Whisker." Key Engineering Materials 602-603 (March 2014): 114–17. http://dx.doi.org/10.4028/www.scientific.net/kem.602-603.114.
Full textAbstract:
The dispersion stability of silicon carbide whisker (SiCw) which is by-product of SiC was researched using distilled water as dispersing medium, polyethylene imine (PEI), tetramethylammonium hydroxide (TMAH), poly(meth)acrylamide (PMAM) as the dispersants. The sedimentation and optical microscope technology are used to observe whisker dispersion ，FTIR and ZETA electric potential are used to explore its dispersion mechanism . The results show that the order of dispersion capacity of the dispersant was PEI> TMAH> PMAM.When 1.25vol% PEI was used as dispersant, SiCw can be dispersed homogeneously at pH=9 and 10, in the meanwhile, if TMAH was used, the added amount would be 0.75vol% in which the pH is in range of 11-12.
8
Liu, Ping, Jie Ren, and Yuhan Sun. "Synthesis, characterization and catalytic properties of SAPO-11 with high silicon dispersion." Catalysis Communications 9, no. 9 (2008): 1804–9. http://dx.doi.org/10.1016/j.catcom.2008.01.030.
Full text
9
Smith, Simon E. T., William Cerny, Christian R. Hayes, et al. "The Discovery of the Faintest Known Milky Way Satellite Using UNIONS." Astrophysical Journal 961, no. 1 (2024): 92. http://dx.doi.org/10.3847/1538-4357/ad0d9f.
Full textAbstract:
Abstract We present the discovery of Ursa Major III/UNIONS 1, the least luminous known satellite of the Milky Way, which is estimated to have an absolute V-band magnitude of + 2.2 − 0.3 + 0.4 mag, equivalent to a total stellar mass of 16 − 5 + 6 M ⊙. Ursa Major III/UNIONS 1 was uncovered in the deep, wide-field Ultraviolet Near Infrared Optical Northern Survey (UNIONS) and is consistent with an old (τ > 11 Gyr), metal-poor ([Fe/H] ∼ −2.2) stellar population at a heliocentric distance of ∼10 kpc. Despite its being compact (r h = 3 ± 1 pc) and composed of few stars, we confirm the reality of Ursa Major III/UNIONS 1 with Keck II/DEIMOS follow-up spectroscopy and identify 11 radial velocity members, eight of which have full astrometric data from Gaia and are co-moving based on their proper motions. Based on these 11 radial velocity members, we derive an intrinsic velocity dispersion of 3.7 − 1.0 + 1.4 km s−1 but some caveats preclude this value from being interpreted as a direct indicator of the underlying gravitational potential at this time. Primarily, the exclusion of the largest velocity outlier from the member list drops the velocity dispersion to 1.9 − 1.1 + 1.4 km s−1, and the subsequent removal of an additional outlier star produces an unresolved velocity dispersion. While the presence of binary stars may be inflating the measurement, the possibility of a significant velocity dispersion makes Ursa Major III/UNIONS 1 a high-priority candidate for multi-epoch spectroscopic follow-ups to deduce the true nature of this incredibly faint satellite.
10
Tyagi, Preeti, Thomas Schrinner, Steffen Richter, Amiya Ray, and Harlad Grossmann. "Factors influencing polymeric granule-assisted dispersion of ultraviolet ink." January 2017 15, no. 1 (2016): 19–29. http://dx.doi.org/10.32964/tj15.1.19.
Full textAbstract:
The objective of this research is to identify and evaluate the factors influencing polymeric granuleassisted dispersion of ultraviolet (UV) ink particles. First time, granule-assisted alternative dispersion was observed during adsorption deinking. By optimizing and combining this alternative dispersion process with pulping, we aim to minimize the energy consumption in the dispersion process and thus reduce the environmental impact of the paper recycling process on carbon footprint. For experimental confirmation, a combination of printed paper and polymeric granules was selected such that ink detached from the fibers would not be adsorbed onto the surface of polymeric granules. Factors that affect the mechanical dispersion process were chosen and varied for optimization of the newly developed dispersion method. Results show that at 15% consistency, temperature 45°C, and mass ratio of oven dry pulp and granules of 1:1.5 (200 g pulp and 300 g granules), the granule-assisted dispersion process gives optimum results for reduction of specks size. All experiments were carried out at rotor speed 2 of Hobart pulper (INGEDE Method 11 “Assessment of print product recyclability–Deinkability test”). These optimized parameters are similar to the optimized parameters of adsorption deinking, which give a further option to combine both of the steps (adsorption deinking and granule assisted dispersion) into one. We also demonstrated that the polymeric granule-assisted dispersion method is a viable replacement for the conventional dispersion process by assuring no alteration in fiber length, water retention value of pulp, and strength properties of the handsheets.
11
Guo, Feiyu, Yinfeng Dong, Yiping Wang, Xingyu Zhang, and Qingshuang Su. "Estimation of wave velocity and analysis of dispersion characteristics based on wavelet decomposition." Vibroengineering Procedia 53 (November 27, 2023): 20–26. http://dx.doi.org/10.21595/vp.2023.23749.
Full textAbstract:
Due to the complexity of the crustal medium and stratigraphic boundaries, seismic waves typically exhibit attenuation and dispersion after propagation through the medium. By studying the regularity of seismic wave dispersion, soil layer information can be extracted. Current spectral decomposition techniques take less account of signal filtering processing of seismic waves, and the complexity of the stratigraphy tends to reduce the accuracy of dispersion analysis. Based on the above, a new method for calculating the dispersion characteristics of a site from surface and downhole ground vibration recordings is proposed, which is simpler than the spectra analysis of surface waves (SASW) method and eliminates the need for multiple pickups and additional equipment. This method is based on wavelet decomposition and seismic wave filtering, and a numerical simulation example is established to verify the effectiveness of the method. Then, the records of the Tohoku earthquake on March 11, 2011 are used as actual strong earthquake examples for filtering and dispersion analysis. Finally, it is concluded that the seismic wave dispersion analysis method based on wavelet decomposition can effectively filter and analyze seismic waves in specific frequency bands.
12
Sareen, Shweta, Vishal Mutreja, Satnam Singh, and Bonamali Pal. "Highly dispersed Au, Ag and Cu nanoparticles in mesoporous SBA-15 for highly selective catalytic reduction of nitroaromatics." RSC Advances 5, no. 1 (2015): 184–90. http://dx.doi.org/10.1039/c4ra10050f.
Full textAbstract:
This paper demonstrates homogeneous dispersion of Au, Ag and Cu nanoparticles (size ∼ 5, 11 and 13 nm) into the mesopores of 3-aminopropyltriethoxysilane modified SBA-15 for improved catalytic reduction of m-dinitrobenzene to m-phenylenediamine.
13
Cho, M. J., Sang Heum Youn, Jae Jun Kim, Kyu Hong Hwang, Jong Kook Lee, and Mikio Iwasa. "Dispersion of ZrO2 Particles in the Al2O3/ZrO2 Ceramics by the Partial Chemical Dispersion Processes." Key Engineering Materials 317-318 (August 2006): 77–80. http://dx.doi.org/10.4028/www.scientific.net/kem.317-318.77.
Full textAbstract:
To improve the mechanical properties of Al2O3/ZrO2 composites, the homogeneous dispersion of ultra low size ZrO2 particles in Al2O3 ceramics have been controlled by partial dispersion of ZrO2 by chemical processes such as coprecipitation or polymeric precursor method(Pechini process). So nanosized Zr/Y hydroxide were coprecipitated or polymerized directly to the surfaces of commercial sub-micron size α-alumina powder(Sumitomo: AES-11(0.4 μm)) using ZrOCl2 /Y(NO3)3 solution. By the partial coprecipitation method, dispersion of relatively small sized ZrO2 in Al2O3/ZrO2 composites could be achieved at 1500~1600° C of sintering temperature. In case of the polyesterization of Zr/Y(NO3)3-citric acid solution in ethylene glycol directly to the commercial sub-micron size α-alumina powder, more homogeneous dispersion of relatively low sized ZrO2 in Al2O3/ZrO2 composites could be obtained at 1450~1600°C of sintering temperature range and their mechanical strength was more enhanced.
14
Cordioli, Michele, Andrea Ranzi, Giulio A. De Leo, and Paolo Lauriola. "A Review of Exposure Assessment Methods in Epidemiological Studies on Incinerators." Journal of Environmental and Public Health 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/129470.
Full textAbstract:
Incineration is a common technology for waste disposal, and there is public concern for the health impact deriving from incinerators. Poor exposure assessment has been claimed as one of the main causes of inconsistency in the epidemiological literature. We reviewed 41 studies on incinerators published between 1984 and January 2013 and classified them on the basis of exposure assessment approach. Moreover, we performed a simulation study to explore how the different exposure metrics may influence the exposure levels used in epidemiological studies. 19 studies used linear distance as a measure of exposure to incinerators, 11 studies atmospheric dispersion models, and the remaining 11 studies a qualitative variable such as presence/absence of the source. All reviewed studies utilized residence as a proxy for population exposure, although residence location was evaluated with different precision (e.g., municipality, census block, or exact address). Only one study reconstructed temporal variability in exposure. Our simulation study showed a notable degree of exposure misclassification caused by the use of distance compared to dispersion modelling. We suggest that future studies (i) make full use of pollution dispersion models; (ii) localize population on a fine-scale; and (iii) explicitly account for the presence of potential environmental and socioeconomic confounding.
15
Chng, Soon Siang, Minmin Zhu, Zehui Du, et al. "Dielectric dispersion and superior thermal characteristics in isotope-enriched hexagonal boron nitride thin films: evaluation as thermally self-dissipating dielectrics for GaN transistors." Journal of Materials Chemistry C 8, no. 28 (2020): 9558–68. http://dx.doi.org/10.1039/d0tc02253e.
Full textAbstract:
The isotope-enriched h-BN films exhibited a dielectrics dispersion with low dielectric loss, below 1.3%. Their optical band gaps depend on isotopic composition (5.54 to 5.79 eV). Thermal conductivity of pure B<sup>10/11</sup>N are enhanced by around 231%.
16
Akamatsu, K., T. Kawamura, and S. Deki. "Composition dependence on dispersion of Au/Cu bimetallic nanoparticles in nylon 11 thin films." European Physical Journal D 16, no. 1 (2001): 305–8. http://dx.doi.org/10.1007/s100530170116.
Full text
17
Upadhyaya, J. C., D. K. Sharma, D. Prakash, and S. C. Upadhyaya. "Three-particle forces in the lattice dynamics of some hexagonal close-packed metals." Canadian Journal of Physics 72, no. 1-2 (1994): 61–72. http://dx.doi.org/10.1139/p94-011.
Full textAbstract:
A lattice dynamical model is developed by applying the Clark–Gazis–Wallis-type three-particle forces in the hexagonal close-packed (hcp) system. The model is then applied in the study of the phonon dispersion in four hep metals, namely, Be, Tb, Ho, and Lu. The present scheme gives the dynamical matrix element Im D12 (q, 11) to be nonzero and explains the peculiar behaviour of dispersion branches along ΓKM direction in these hep metals. Further more, a single expression for C44 is found and the Cauchy discrepancy (C13-C44) is entirely ascribed to the three-particle forces.
18
Cai, Huimei, Shuilin Ji, Juzhou Zhang, et al. "Determination of 11 photoinitiators and their migration into tea and milk by gas chromatography-tandem mass spectrometry (MSPD-GC-MS/MS)." Analytical Methods 9, no. 20 (2017): 2957–63. http://dx.doi.org/10.1039/c7ay00156h.
Full textAbstract:
Based on the use of multi-walled carbon nanotubes (MWCNTs) in matrix solid-phase dispersion (MSPD) extraction, a novel, rapid and reliable method was developed for the analysis of 11 photoinitiators used in food packaging ink followed by quantitation by gas chromatography-tandem mass spectrometry.
19
Xu, Jing, and Min Chen. "Study on Dispersion Behavior of Al2O3/ZrO2 Composite Powder." Applied Mechanics and Materials 395-396 (September 2013): 100–103. http://dx.doi.org/10.4028/www.scientific.net/amm.395-396.100.
Full textAbstract:
nanocomposite used widely with the development of nanotechnology, and the dispersion of different composition is important. ZrO2 often used as the second phase to improve the toughness of Al2O3 ceramics[1,. nanoAl2O3 and ZrO2 are added to water to prepare suspension, and PVP was used as dispersant to improve the dispersion of suspension. The suspension of Al2O3 and ZrO2 adjusted from 2 to 11 with the addition of dispersant is 0.5%. The flocculation of suspension was observed after 3h, 6h, 12h and 24h. Result shows that two kinds suspension dispersant better in acid liquid than in alkaline and natural liquid. The pH values that are choose as the best dispersion and flocculation are 5 and 7. Morphology and element distribution of composite powder are tested in the SEM. Results show that the composite powder is finely disseminated.
20
Sims, J. Jason, Allison P. Winecoff, and Michael R. Ujhelyi. "Lidocaine Does Not Affect Myocardial Electrical Heterogeneity: Implications for Low Proarrhythmic Actions." Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy 17, no. 6 (1997): 1267–73. http://dx.doi.org/10.1002/j.1875-9114.1997.tb03091.x.
Full textAbstract:
An area of unidirectional conduction block is one requirement for reentrant arrhythmias to occur. Functional block caused by dispersion of repolarization and refractoriness is the most probable mechanism of drug‐induced unidirectional conduction block. We assessed the effects of lidocaine on spatial dispersion of myocardial repolarization and refractoriness in the intact porcine heart. Monophasic action potential duration at 90% repolarization, effective refractory period (ERP), and ventricular fibrillation cycle length (VFCL) were measured at two endocardial and one epicardial sites at baseline and during a treatment phase with D5W (n=11) or lidocaine 10 mg/kg/hour (n=12). Dispersion was calculated as the difference between the maximum and minimum values of the three recording sites. Lidocaine produced significant changes in ERP, VFCL, paced QRS duration, and intraventricular conduction time. It did not change basal levels of dispersion in repolarization and refractoriness. Lidocaine produced changes in myocardial electrophysiology that are uniform across the myocardium and thus did not change myocardial electrical heterogeneity. This may be a mechanism of the agent's lower proarrhythmic effects compared with other sodium channel blockers that increase myocardial electrical heterogeneity.
21
Tukaiev, S., D. Kashpur, N. Pogorilska, M. Makarchuk, I. Zyma, and J. M. A. Ferreira. "Negative factors of personality hardiness that effect on ability to control situation and cope with the stress." European Psychiatry 67, S1 (2024): S826—S827. http://dx.doi.org/10.1192/j.eurpsy.2024.1725.
Full textAbstract:
IntroductionPersonality hardiness expresses the characteristics that help to overcome stress and achieve well-being.ObjectivesThis study focused on the Hardiness as the important personality trait, which allow coping with stress and the relationship of empathy, emotional sensitivity and the personality hardiness.Methods88 healthy volunteers, students aged 17 to 26 years (mean age = 19, SD = 1,69), participated in this study. We used Cloninger’s Temperament and Character Inventory (TCI), the Maddi Hardiness Survey (adapted by Leontyev), Buss Perry Aggression Questionnaire (BPAQ), the Barratt impulsiveness scale (BIS-11), Maslach Burnout Inventory (MBI), the Questionnaire Measure of Emotional Empathy (QMEE).Results The cluster analysis was used to identify groups of hardy personalities. We demonstrated a negative relationship between hardiness and depression and burnout. It revealed significant differences between these groups by the following traits: Attention (BIS-11), Self-Control (BIS-11), Cognitive Complexity (BIS-11), Hostility (BPAQ), Exploratory activity (NS1 TCI), Shyness of strangers (HA3 TCI), Resourcefulness (S3 TCI). Regression analysis was used to identify Hardiness factors and to build the following regression models. For the first group the models describe 100% of dispersion (R-square=1,000, Durbin-Watson statistic = 1,419) and are:Control = -16,998 - 2,922*С2 + 3,549*С5 + 3,264*CI + 0,723*ST2 + 0,747*S4 - 0,306*SC + 0,166*RD3 - 0,020*C — 0,003*NS2, where C2 – scale Empathy (TCI), C5 – scale Principles (TCI), CI – cognitive instability, ST2 – Transpersonal identification scale (TCI), S4 – Self-acceptance (TCI), SC – Self-Control (BIS-11), RD3 – Social attachment (TCI), C – Cooperativeness (TCI), NS2 – Impulsive decision making (TCI). The Hardiness model described 50% (R-square=0,456) of dispersion:Hardiness = 63,527 – 4,080*C2, where C2 –Empathy scale (TCI) (p=0,003).The regression models of the second group explain 50% of group dispersion (R-square=0,512) and are Independent variables significance p<0,05:Challenge = 12,484 + 0,389*SC + 0,197*EE — 0,702*RD1 — 0,206*A,where SC- Self-Control scale (BIS-11), EE – Emotional Empathy (Personality test of Emotional Empathy), RD1 – Sentimentality scale (TCI), A – Anger (BPAQ).The Hardiness model describes 35% of dispersion (R-square=0,364, Durbin-Watson statistic = 2,066): Hardiness = 100,352 + 0,941*SC — 0,527*H, where SC – Self-Control scale (BIS-11) (p=0,009), H – Hostility scale (BPAQ) (p=0,021).ConclusionsThus, the attention and self-control problems, hostility, cognitive complexity and shyness have a negative impact on hardiness.Our results suggest that the excessive use of empathy leads to decrease of ability to control situation and cope with the stress.Disclosure of InterestNone Declared
22
Lou, Qing, Deborah L. Janks, Katherine M. Holzem, et al. "Right ventricular arrhythmogenesis in failing human heart: the role of conduction and repolarization remodeling." American Journal of Physiology-Heart and Circulatory Physiology 303, no. 12 (2012): H1426—H1434. http://dx.doi.org/10.1152/ajpheart.00457.2012.
Full textAbstract:
Increased dispersion of repolarization has been suggested to underlie increased arrhythmogenesis in human heart failure (HF). However, no detailed repolarization mapping data were available to support the presence of increased dispersion of repolarization in failing human heart. In the present study, we aimed to determine the existence of enhanced repolarization dispersion in the right ventricular (RV) endocardium from failing human heart and examine its association with arrhythmia inducibility. RV free wall preparations were dissected from five failing and five nonfailing human hearts, cannulated and coronary perfused. RV endocardium was optically mapped from an ∼6.3 × 6.3 cm2 field of view. Action potential duration (APD), dispersion of APD, and conduction velocity (CV) were quantified for basic cycle lengths (BCL) ranging from 2,000 ms to the functional refractory period. We found that RV APD was significantly prolonged within the failing group compared with the nonfailing group (560 ± 44 vs. 448 ± 39 ms, at BCL = 2,000 ms, P < 0.05). Dispersion of APD was increased in three failing hearts (161 ± 5 vs. 86 ± 19 ms, at BCL = 2,000 ms). APD alternans were induced by rapid pacing in these same three failing hearts. CV was significantly reduced in the failing group compared with the nonfailing group (81 ± 11 vs. 98 ± 8 cm/s, at BCL = 2,000 ms). Arrhythmias could be induced in two failing hearts exhibiting an abnormally steep CV restitution and increased dispersion of repolarization due to APD alternans. Dispersion of repolarization is enhanced across the RV endocardium in the failing human heart. This dispersion, together with APD alternans and abnormal CV restitution, could be responsible for the arrhythmia susceptibility in human HF.
23
Sert, Ahmet, Cem Gokcen, Ebru Aypar, and Dursun Odabas. "Effects of atomoxetine on cardiovascular functions and on QT dispersion in children with attention deficit hyperactivity disorder." Cardiology in the Young 22, no. 2 (2011): 158–61. http://dx.doi.org/10.1017/s1047951111001211.
Full textAbstract:
AbstractBackgroundAtomoxetine is a central norepinephrine reuptake inhibitor used to treat attention deficit/hyperactivity disorder. The effects of atomoxetine on cardiovascular functions and QT dispersion in children with attention deficit/hyperactivity disorder have not been previously reported. The aim of this study was to analyse cardiovascular functions and QT dispersion on the surface electrocardiogram of children with attention deficit/hyperactivity disorder during atomoxetine therapy.MethodsA total of 40 children – with a mean age of 8.6 plus or minus 2.3 years and a median age of 11 years; ranged from 8 to 14 years – with attention deficit/hyperactivity disorder – with six girls and 34 boys – were included in the study. We recorded the mean systolic and diastolic blood pressure, heart rate, corrected QT interval, QT dispersion, and left ventricular systolic functions at baseline and 5 weeks after atomoxetine therapy.ResultsAtomoxetine decreased baseline mean systolic and diastolic blood pressure; baseline mean heart rate decreased; and baseline mean corrected QT interval and QT dispersion mildly increased. Atomoxetine decreased baseline mean ejection fraction and baseline mean shortening fraction.ConclusionThe results of our study suggest that atomoxetine does not cause clinically significant alterations in QT dispersion, systolic and diastolic blood pressure, heart rate, corrected QT interval, and left ventricular systolic functions during short-term treatment in children with attention deficit/hyperactivity disorder.
24
Lin, Xing Jun, Suzelle Barrington, Guangcai Gong та Denis Choinière. "Simulation of odour dispersion downwind from natural windbreaks using the computational fluid dynamics standard k-ε modelA paper submitted to the Journal of Environmental Engineering and Science." Canadian Journal of Civil Engineering 36, № 5 (2009): 895–910. http://dx.doi.org/10.1139/s08-057.
Full textAbstract:
If natural windbreaks create air turbulence and can help disperse odours from livestock operations, their dispersion effect has not been extensively researched. This paper introduces a model simulating odour dispersion downwind from natural windbreaks. The standard k-ε model of the FLUENT software was used to incorporate the effect of climatic conditions and windbreak structure. The model was calibrated for wind velocity recovery, odour concentration (OC) from field observations and inertial resistance. Once calibrated, the model accurately reproduced the odour plume developing downwind from the windbreak. The correlation between OC for 11 field trials and that simulated were statistically significant (P < 0.01), indicating that the model was accurate. The model demonstrated that a windbreak did alter the magnitude and direction of the wind velocity, thus creating a pressure jump across its width. This pressure jump produces a strong downwind turbulence forming a mixing layer capable of enhancing odour dispersion.
25
Mahmoodlu, Mojtaba G., Amir Raoof, and Martinus Th van Genuchten. "Effect of soil textural characteristics on longitudinal dispersion in saturated porous media." Journal of Hydrology and Hydromechanics 69, no. 2 (2021): 161–70. http://dx.doi.org/10.2478/johh-2021-0004.
Full textAbstract:
Abstract This study focuses on the effects of soil textural heterogeneity on longitudinal dispersion under saturation conditions. A series of solute transport experiments were carried out using saturated soil columns packed with two filter sands and two mixtures of these sands, having d50 values of 95, 324, 402, and 480 µm, subjected to four different steady flow rates. Values of the dispersion coefficient (D) were estimated from observed in-situ distributions of calcium chlo-ride, injected as a short nonreactive tracer pulse, at four different locations (11, 18, 25, 36 cm). Analyses of the observed distributions in terms of the standard advection-dispersion equation (ADE) showed that D increased nonlinearly with travel distance and higher Peclet numbers+. The dispersion coefficient of sand sample S1 with its largest average particle size (d 50) was more affected by the average pore-water velocity than sample S4 having the smallest d 50. Results revealed that for a constant velocity, D values of sample S1 were much higher than those of sample S4, which had the smallest d 50. A correlation matrix of parameters controlling the dispersion coefficient showed a relatively strong positive relationship between D and the Peclet number. In contrast, almost no correlation was evident between D and porosity as well as grain size. The results obtained with the four sandy matrices were consistent and proved that the dispersion coefficient depends mainly on the particle size.
26
Habib, Unsia, Mohammed E. Ali Mohsin, Zahid Iqbal Khan, et al. "Mechanical, Thermal, and Flammability Properties of Eco-Friendly Nanocomposites from Recycled PET/PA-11 Blends Reinforced with Graphene Nanoplatelets." Polymers 17, no. 8 (2025): 1038. https://doi.org/10.3390/polym17081038.
Full textAbstract:
This study investigates the development of sustainable nanocomposites using recycled polyethylene terephthalate (RPET) and polyamide 11 (PA-11) blends reinforced with graphene nanoplatelets (GNPs). RPET/PA-11 blends were compatibilized with 2 phr Joncryl® and processed using melt blending followed by injection moulding. The effects of varying GNP contents (1–4 phr) on mechanical, thermal, and flame-retardant properties were analysed. The nanocomposite with 1 phr GNPs exhibited an optimal balance of mechanical, flame-retardant, and thermal properties, along with improved dispersion compared to higher GNP loadings. Higher GNP concentrations led to increased stiffness but also promoted agglomeration, which negatively impacted tensile and impact strength. Thermal analysis revealed that GNPs influenced the cold crystallization behaviour of RPET, while the TGA results indicated a moderate enhancement in thermal stability. The maximum degradation temperature (Tmax) increased from 410.38 °C to 430.06 °C with 1 phr GNPs but declined at higher loadings. Similarly, flammability tests showed an improvement in the limiting oxygen index (LOI) from 19 to 24. Morphological analysis confirmed that GNPs facilitated PA-11 dispersion within the RPET matrix, particularly at lower GNP concentrations (1 phr). These findings highlight the potential of RPET/PA-11/GNP nanocomposites for multifunctional applications, providing an optimal balance between mechanical performance, thermal stability, and flame resistance. This research highlights the synergistic effect of GNPs in achieving sustainable, high-performance materials, addressing the challenges of plastic waste management and the need for eco-friendly engineering solutions for industries such as automotive, packaging, and construction.
27
Tolasz, Radim, Radek Čekal, Anna Lamačová, and Hana Škáchová. "The year 2022 in Czechia." Meteorologické zprávy 76, no. 1 (2023): 1–15. http://dx.doi.org/10.59984/mz2023.01.01.
Full textAbstract:
The article summarizes main events in the months of 2022 in meteorology, climatology, hydrology and ambient air quality. The average annual temperature of 9.2 °C with a deviation of +0.9 °C above the 1991–2020 normal (and +1.7 °C from the 1961–1990 normal) classifies the year as a temperature normal year. The annual precipitation amount of 630 mm classifies the year as normal compared to both the 1961–1990 and 1991–2020 normals. The highest and lowest temperatures, significant precipitation events and, where applicable, higher wind speeds and snowfall, and groundwater statistics are shown for each month. If the level of flood activity in Czechia was reached, it is also listed in the overview. With respect to the air quality, cases exceeding the limit values for human health protection, and smog situations declared are listed. Compared to the 10-year average (2012–2021) the dispersion conditions were significantly better in 2022. Good dispersion conditions, as expressed by the ventilation index for the whole country, were recorded in 320 days (88%), moderately poor dispersion conditions in 42 days (11%) and poor dispersion conditions in three days (1%) in 2022.
28
Tolasz, Radim, Radek Čekal, Anna Lamačová, and Hana Škáchová. "The year 2022 in Czechia." Meteorologické zprávy 76, no. 1 (2023): 1–15. http://dx.doi.org/10.59984/mz.2023.01.01.
Full textAbstract:
The article summarizes main events in the months of 2022 in meteorology, climatology, hydrology and ambient air quality. The average annual temperature of 9.2 °C with a deviation of +0.9 °C above the 1991–2020 normal (and +1.7 °C from the 1961–1990 normal) classifies the year as a temperature normal year. The annual precipitation amount of 630 mm classifies the year as normal compared to both the 1961–1990 and 1991–2020 normals. The highest and lowest temperatures, significant precipitation events and, where applicable, higher wind speeds and snowfall, and groundwater statistics are shown for each month. If the level of flood activity in Czechia was reached, it is also listed in the overview. With respect to the air quality, cases exceeding the limit values for human health protection, and smog situations declared are listed. Compared to the 10-year average (2012–2021) the dispersion conditions were significantly better in 2022. Good dispersion conditions, as expressed by the ventilation index for the whole country, were recorded in 320 days (88%), moderately poor dispersion conditions in 42 days (11%) and poor dispersion conditions in three days (1%) in 2022.
29
Wang, Sheng Qin, Mohit Sharma, and Yew Wei Leong. "Polyamide 11/Clay Nanocomposite Using Polyhedral Oligomeric Silsesquioxane Surfactants." Advanced Materials Research 1110 (June 2015): 65–68. http://dx.doi.org/10.4028/www.scientific.net/amr.1110.65.
Full textAbstract:
This paper reports polyamide 11 (PA11)/layered silicate (clay) nanocomposite using polyhedral oligomeric silsesquioxane (POSS) surfactants. POSS functionalized with amino, ammonium and guanidinium groups were synthesized and used to facilitate the intercalation of polymer chains between silicate layers thereby to improve the dispersion of clay in polymer matrix. Nanocomposites from the blends of POSS-modified clay and PA11 were thus formulated via melting compounding and their mechanical and physical properties were characterized.
30
Iz, Muhammet, Jinhyok Lee, Myungchan Choi, Yumi Yun, and Jongwoo Bae. "The Effect of Polyamide 11 on the Thermal Stability and Light Transmittance of Silicone-Based Thermoplastic Vulcanizates." Polymers 16, no. 3 (2024): 324. http://dx.doi.org/10.3390/polym16030324.
Full textAbstract:
The effect of polyamide 11 (PA11) on the thermal stability and light transmittance properties of silicone-based thermoplastic vulcanizates (TPVs) has been investigated. The blends were prepared through a dynamic vulcanization process by adding 15, 30, and 45 wt% PA11 to the silicon-based TPVs, respectively. The effect of PA11 on the dispersion of silicone rubber in the TPVs after dynamic vulcanization was characterized by a scanning electron microscope (SEM), the thermal stability of the compounds was evaluated through the changes in mechanical performance in the thermo-oxidative aging process, and the light transmittance of TPVs was measured by a haze meter. The results showed that adding PA11 to silicone-based TPVs caused a decrease in the size of the silicone rubber particles after dynamic vulcanization, resulting in improved dispersion. Due to this, by increasing the compatibility between the segments through silicone’s effective dispersion, the amount of light absorption was reduced, and the amount of light transmittance was increased. Finally, according to the results of the thermal aging test, it was found that TPVs with 30 and 45 wt% PA11, respectively, showed outstanding thermal resistance after aging at 160 °C and 168 h and did not melt down.
31
Mubarak, Sadia, Sidra Hamid, Bushra Riaz, Mamoona Shafiq, and Zubia Razzaq. "EFFECT OF SEVERITY OF ISCHEMIA ON QT DISPERSION IN PATIENTS WITH CORONARY ARTERY DISEASE." Pakistan Journal of Physiology 18, no. 4 (2022): 11–13. http://dx.doi.org/10.69656/pjp.v18i4.1515.
Full textAbstract:
Background: Coronary artery disease (CAD) is the most prevalent cause of death due to myocardial ischemia. QT dispersion is a marker of increased risk for myocardial ischemia events. The objective of this study was to find out the effect of severity of ischemia on ventricular repolarization heterogeneity by measuring and comparing QT dispersion in single, double and triple coronary artery disease patients. Methods: This cross-sectional comparative study was conducted in the Department of Physiology, Army Medical College (AMC) in collaboration with Electrophysiology Department, Armed Forces Institute of Cardiology (AFIC). Forty patients aged 55±8 Yrs with CAD were included in the study. Holter monitors were used to attain ECG recordings digitally with ten electrodes. For exploration of digital QT dispersion data CardioScan Luxury version was used. Results: Out of 40 patients 18 (45%) had single, 16 (40%) double, and 6 (15%) had triple vessel disease. A significant difference was noted on comparison across mean values of QT dispersion in three groups with single, double and triple vessels coronary artery disease (p=0.01). There was also a remarkable difference of QT dispersion between single and triple vessel disease patients (p=0.007). Conclusion: Ventricular repolarization heterogeneity increases with the ischemia. Patients with triple vessel disease are more prone to risk of developing life threatening arrhythmias. Pak J Physiol 2022;18(4):11-3
32
Balkhi, Rim Al, Maurice Beghetti, and Beat Friedli. "Time course of appearance of markers of arrhythmia in patients with tetralogy of Fallot before and after surgery." Cardiology in the Young 14, no. 4 (2004): 360–66. http://dx.doi.org/10.1017/s1047951104004020.
Full textAbstract:
Sudden death and ventricular tachycardia are known to occur late after correction of tetralogy of Fallot. Abnormal dispersion of the QT interval, ventricular late potentials, and prolongation of the QRS complex, alone or in combination, are useful markers of the risk for such complications. Our present prospective study investigates the time course of appearance of two markers, dispersion of QT and JT, and ventricular late potentials, before and after corrective surgery. Dispersion of QT and JT, and signal averaged electrocardiographic parameters, were determined sequentially in 20 patients before, a mean of 9 ± 3 days after, and again 35 ± 11 days post-operatively. Dispersion of QT was already abnormal before surgery in two-fifths of the patients, but increased markedly in the later post-operative period. Ventricular late potentials were absent before surgery and in the immediate post-operative period, but were found in one-fifth of patients 1 month later. We conclude that abnormal dispersion of QT is, to some extent, a fact of the natural history of tetralogy of Fallot, but is significantly amplified by surgery. Ventricular late potentials, on the other hand, are absent before surgery, but appear with some delay after the operation, probably as a result of scarring rather than the surgical incision itself. Long-term follow-up is needed to assess the significance of these findings.
33
Mamatha, T., Md Zubair, N. Sarah Nasreen, and Md Ahmeduddin. "Formulation and Evaluation of Oro dispersible Tablets of Fosinopril Sodium." Dhaka University Journal of Pharmaceutical Sciences 14, no. 1 (2015): 11–16. http://dx.doi.org/10.3329/dujps.v14i1.23729.
Full textAbstract:
The purpose of present research was to formulate and evaluate oro dispersible tablets (ODTs) of fosinopril sodium (FS). It has been developed at 20 mg dose and was prepared using different types of superdisintegrants such as (sodium starch glycolate, Ac-Di-Sol, crospovidone (CP), different types of subliming agents such as ammonium bicarbonate (AB) and camphor at different concentrations by direct compression method. The formulations were evaluated for uniformity of weight, content, hardness, friability, wetting time, in vitro dispersion time and dissolution rate. All formulations showed satisfactory mechanical strength, uniform weight, uniform drug content, and lesser wetting time and dispersion time. All the formulations showed more than 90% of drug release within 15 minutes. Among 10 formulations, formulation A5 (consisting of 2 % CP) and F4 (consisting of 15 % AB) were found to yield best results in terms of wetting time, in vitro dispersion time and dissolution rate.Dhaka Univ. J. Pharm. Sci. 14(1): 11-16, 2015 (June)
34
Asano, Kazunori. "Wear Behavior of In Situ Mg2Si Particle-Dispersed Magnesium Alloys." Materials Science Forum 909 (November 2017): 100–105. http://dx.doi.org/10.4028/www.scientific.net/msf.909.100.
Full textAbstract:
Magnesium alloys, in which the in-situ Mg2Si particles were dispersed, were fabricated by a casting process, and the dry sliding wear behavior of the alloys was investigated. Optical microscopy revealed that the polygonal Mg2Si particles were homogeneously dispersed in the alloys. Mg2Si particle volume fractions in the alloys were 7 and 11 vol%. Although the wear loss of the alloy decreased due to the particle-dispersion, there was no difference in the wear loss between the alloys with different volume fractions. The worn surfaces of the particle-dispersed alloys were covered with the crumbled Mg2Si particles, which would prevent seizure between the alloy and the steel counterpart, leading to an improvement in the wear resistance of the alloy. The particle-dispersion slightly decreased the scatter of the coefficient of friction during the wear for the low sliding speed and load, but the effect of the dispersion was not clearly observed for the high speed and load.
35
Leng, Ng Chiew, and Chew Cheng Meng. "Making sense of students’ errors in solving problems related to measures of dispersion." International Journal of Evaluation and Research in Education (IJERE) 12, no. 2 (2023): 924. http://dx.doi.org/10.11591/ijere.v12i2.24580.
Full textAbstract:
The importance of statistical learning has been widely discussed. However, little effort has been made to understand the difficulties of students in learning measure of dispersion, which is the key component to statistical learning. The present study sought to identify the reasons behind the errors committed in solving problems related to measures of dispersion, by examining students’ errors in the diagnostics tests, followed by in depth interviews to elicit their thinking and understanding. There were 85 grade-11 high school students involved in the first phase of the quantitative research and 10 students with weak performance were subsequently selected for the second phase qualitative research. The interviews were conducted using the contingent teaching model. The findings indicated that students’ committing errors in solving problems related to measure of dispersion due to lacking statistical vocabulary knowledge, weak symbol sense, rote learning, low statistical reasoning and statistical thinking ability. The results of the study and proper remedials are discussed.
36
Leng, Ng Chiew, and Chew Cheng Meng. "Making sense of students' errors in solving problems related to measures of dispersion." International Journal of Evaluation and Research in Education (IJERE) 12, no. 2 (2023): 924–40. https://doi.org/10.11591/ijere.v12i2.24580.
Full textAbstract:
The importance of statistical learning has been widely discussed. However, little effort has been made to understand the difficulties of students in learning measure of dispersion, which is the key component to statistical learning. The present study sought to identify the reasons behind the errors committed in solving problems related to measures of dispersion, by examining students’ errors in the diagnostics tests, followed by in depth interviews to elicit their thinking and understanding. There were 85 grade-11 high school students involved in the first phase of the quantitative research and 10 students with weak performance were subsequently selected for the second phase qualitative research. The interviews were conducted using the contingent teaching model. The findings indicated that students’ committing errors in solving problems related to measure of dispersion due to lacking statistical vocabulary knowledge, weak symbol sense, rote learning, low statistical reasoning and statistical thinking ability. The results of the study and proper remedials are discussed.
37
Di Lorenzo, Maria Laura, Alessandra Longo, and René Androsch. "Polyamide 11/Poly(butylene succinate) Bio-Based Polymer Blends." Materials 12, no. 17 (2019): 2833. http://dx.doi.org/10.3390/ma12172833.
Full textAbstract:
The manuscript details the preparation and characterization of binary blends of polyamide 11 (PA 11) and poly(butylene succinate) (PBS), with PA 11 as the major component. The blends are fully bio-based, since both components are produced from renewable resources. In addition, PBS is also biodegradable and compostable, contrarily to PA 11. In the analyzed composition range (up to 40 m% PBS), the two polymers are not miscible, and the blends display two separate glass transitions. The PA 11/PBS blends exhibit a droplet-matrix morphology, with uniform dispersion within the matrix, and some interfacial adhesion between the matrix and the dispersed droplets. Infrared spectroscopy indicates the possible interaction between the hydrogens of the amide groups of PA 11 chains and the carbonyl groups of PBS, which provides the compatibilization of the components. The analyzed blends show mechanical properties that are comparable to neat PA 11, with the benefit of reduced material costs attained by addition of biodegradable PBS.
38
Fairris, David. "Unions and Wage Inequality in Mexico." ILR Review 56, no. 3 (2003): 481–97. http://dx.doi.org/10.1177/001979390305600307.
Full textAbstract:
This paper offers empirical evidence on the impact of trade unions on wage inequality in Mexico. The results indicate that unions were a strongly equalizing force affecting the dispersion of wages in 1984, but were only half as effective at reducing wage inequality in 1996. Not only did the unionized percentage of the labor force fall considerably over the period, unions also lost some of their ability to reduce wage dispersion among the workers they continued to represent. Had unions maintained in 1996 the same structural power they possessed in 1984, the rise in wage inequality in the formal sector of the labor market between those years would have been reduced by roughly 11%.
39
Mukherjee, Biplab. "EFFECT OF MIXING ENERGY, MIXING TIME AND SETTLING TIME ON DISPERSION EFFECTIVENESS IN TWO BENCH-SCALE TESTING SYSTEMS." International Oil Spill Conference Proceedings 2008, no. 1 (2008): 651–56. http://dx.doi.org/10.7901/2169-3358-2008-1-651.
Full textAbstract:
ABSTRACT Dispersion experiments were conducted in baffled-flask and paddle-jar mixing systems at five energy dissipation rates ranging from 4.8 × 10−4 to 1.6 × 10−1 J/kg-s. The objective of these experiments was to investigate the effects of mixing energy, mixing time, and settling time on dispersion effectiveness and size distribution of the chemically dispersed oil droplets. Two separate combinations of evaporatively weathered Mars crude oil premixed with dispersants differing in hydrophile-lipophile balance (HLB) (12 and 10) but having the same chemical composition (Tween 80 and Span 80 in dodecane) were used. Dispersion effectiveness increased with energy dissipation rate to a maximum and then leveled for all cases studied. In the baffled flask, dispersion effectiveness reached a maximum of 82 ± 5% irrespective of oil-dispersant combination. In the paddle jar, the maximum value of dispersion effectiveness was oil-dispersant specific, being at 87 ± 9% and 30 ± 11% for dispersant HLB 12 and 10, respectively. Mixing time did not seem to have a significant effect on dispersion effectiveness in comparison to the effects of energy dissipation rates and oil-dispersant combinations. The normalized volume distributions of the dispersed oil droplets were tri-modal in both systems, suggesting that multiple mechanisms of droplet formation occurred. The largest droplet mode disappeared from the size distribution in dispersions produced in the baffled flask when the mixing energy was &gt;1.6 × 10−2 J/kg-s. A similar behavior was also observed in the paddle jar for the oil-dispersant combination of HLB 12, but not for HLB 10. Inclusion of a settling period of 20 minutes before collecting sample decreased the dispersion effectiveness in paddle jar but no significant changes were observed in the baffled flask system. The differences observed were due to the differences in the size distributions of the dispersed oil droplets generated in these two systems.
40
Yetkin, Ertan, Kubilay Senen, Mehmet Ileri, et al. "Diurnal Variation of QT Dispersion in Patients With and Without Coronary Artery Disease." Angiology 52, no. 5 (2001): 311–16. http://dx.doi.org/10.1177/000331970105200503.
Full textAbstract:
QT dispersion defined as interlead QT variability in a 12-lead electrocardiogram was proposed by Day and associates as a simple method to evaluate the repolarization heterogenicity of the ventricular myocardium. The frequency of onset of myocardial infarction and sudden death has been reported to have a circadian variation, with a peak incidence in the early morning hours. The authors investigated whether there is diurnal variation of QT interval and QT interval dispersion in healthy subjects and in patients with coronary artery disease. The study popula tion consisted of two groups. Group I consisted of 62 subjects without coronary artery disease and group II consisted of 82 patients with coronary artery disease. Twelve-lead ECG was recorded for each patient in the morning (between 7 AM and 8 AM), afternoon (between 3 PM and 5 PM) and at night (between 11 PM and 1 AM), on the day after performance of coronary angiography. QTc dispersion was significantly higher in patients with coronary artery disease than in healthy subjects in the morning hours and afternoon (p< 0.001). Although the differ ences were much prominent in group I than group II, both QTc dispersion of morning and afternoon were significantly greater than those at night. There were no statistically significant differences between group I and group II at nighttime with respect to maximum QTc , minimum QTc intervals, and QTc dispersion (p>0.05). In conclusion, QT dispersion shows diurnal variation with an increase in the morning hours in both patients with coronary artery disease and subjects without coronary artery disease. The mechanism of diurnal variation of QT dispersion in patients with coronary artery disease is quite different from that of healthy subjects.
41
Rahman, Mohammad Mizanur, Rami Suleiman, Md Hasan Zahir, Aasif Helal, A. Madhan Kumar, and Md Bashirul Haq. "Multi Self-Healable UV Shielding Polyurethane/CeO2 Protective Coating: The Effect of Low-Molecular-Weight Polyols." Polymers 12, no. 9 (2020): 1947. http://dx.doi.org/10.3390/polym12091947.
Full textAbstract:
We prepared a series of polyurethane (PU) coatings with defined contents using poly(tetramethylene oxide)glycol (PTMG) with two different molecular weights (i.e., Mn = 2000 and 650), as well as polydimethyl siloxane (PDMS) with a molecular weight of Mn 550. For every coating, maximum adhesive strength and excellent self-healing character (three times) were found using 6.775 mol% mixed with low-molecular-weight-based polyols (PU-11-3-3). Defined 1.0 wt% CeO2 was also used for the PU-11-3-3 coating (i.e., PU-11-3-3-CeO2) to obtain UV shielding properties. Both the in situ polymerization and blending processes were separately applied during the preparation of the PU-11-3-3-CeO2 coating dispersion. The in situ polymerization-based coating (i.e., PU-11-3-3-CeO2-P) showed similar self-healing properties. The PU-11-3-3-CeO2-P coating also showed excellent UV shielding in real outdoor exposure conditions.
42
Verma, R., and P. K. Garg. "ANALYSIS OF SPATIO-TEMPORAL URBAN DYNAMICS IN 11 SMART CITIES OF UTTAR PRADESH, INDIA." International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVI-4/W5-2021 (December 23, 2021): 557–64. http://dx.doi.org/10.5194/isprs-archives-xlvi-4-w5-2021-557-2021.
Full textAbstract:
Abstract. Urban planning in smart cities needs to be done in a “Smart” way. One way is to analyze the urbanisation pattern by spatio-temporal change detection techniques. Classified data such as, for years 1985, 1995 and 2005 Decadal Land use data for India and for year 2015, Copernicus Global Land service Dynamic Land Cover layers (CGLS-LC100 products) are used to perform multi-temporal analysis of the 11 smart cities of Uttar Pradesh state of India namely "Agra", "Aligarh", "Bareilly", "Jhansi", "Kanpur", "Lucknow", "Moradabad", "Prayagraj", "Rampur", "Saharanpur" and "Varanasi". Dynamics of Urban expansion are studied utilizing concepts of Landscape Metrics calculated by FRAGSTATS and also Shannon’s Entropy Values (Hn) over the 11 smart cities. Largest Patch Index (LPI), Landscape Shape Index (LSI), Aggregation Index (AI) and Mean Euclidean Nearest Neighbor Distance (ENN_MN) are metrics used to characterize urbanisation. Results indicate rise in value of LSI over the years from 1985 and with sudden increase in year 2015 for Built-up patches, corroborating more complexity in shapes of Built-up patches in all 11 cities. Kanpur, showing large values of LPI indicates the sudden increase of Built-up land use class over the years. The decreasing value of ENN_MN over the years indicates less centrality for built-up pixels in urbanisation. AI is unchanged for Built-up patches for 1985–1995 but decrease in year 2015 indicates less compactness which is due to dispersion of built-up pixels. High values of Hn over the years indicating dispersion of urbanisation in all 11 smart cities except Agra, also validates results.
43
Jung, Jae-Heon, So-Yeong Lee, Joo Choi, and Ho-Sang Sohn. "Dispersion Behavior of Blast Furnace Sludge for Valuable Metal Recovery." Korean Journal of Metals and Materials 59, no. 5 (2021): 295–303. http://dx.doi.org/10.3365/kjmm.2021.59.5.295.
Full textAbstract:
Blast furnace sludge, which comes from the iron making process, contains many valuable materials including iron, carbon, and zinc, etc. Because a cohesive agent is added during filtration, fine sludge particles are agglomerated together. Therefore, This makes it necessary to disperse the sludge in solution before separating or recovering valuable materials. In this study, the effects of solid/liquid (g/L) ratio, ultrasonic dispersion conditions, the pH of solvent, and the concentration of dispersant on the dispersion of sludge were investigated by measuring the interfacial properties (zeta potential and hydrodynamic size) of sludge particles. High absolute value of zeta potential and small hydrodynamic size suggests that the sludge particles in the solution presents good dispersion. The absolute value of zeta potential increased gradually at high solid/liquid ratio and ultrasonic dispersion intensity. But when the sludge in solution was dispersed for more than 30 minutes, the absolute value of the zeta potential decreased due to increasing contact and interaction between the particles. Optimal dispersion operations were conducted and when the pH of the solution was adjusted to 11, the zeta potential value was measured to be -44.8 mV. This means that the sludge formed the most stable dispersed phase. The lowest zeta potential was measured to be -46.4 mV with the addition of sodium hexametaphosphate (NaPO3)6 in the solution. It is thought that the sodium hexametaphosphate reduced ionic strength by removing alkali metal ions from the solution of sludge.
44
Tyukanko, Vitaliy, Alexandr Demyanenko, Antonina Dyuryagina, Kirill Ostrovnoy, and Marianna Lezhneva. "Optimization of the Composition of Silicone Enamel by the Taguchi Method Using Surfactants Obtained from Oil Refining Waste." Polymers 13, no. 21 (2021): 3619. http://dx.doi.org/10.3390/polym13213619.
Full textAbstract:
The aim of this work is to optimize the composition of a two-component silicone enamel consisting of an aluminum pigment and a polyphenylsiloxane polymer to obtain the maximum dispersion of the pigment in the coating. The following products were used as surfactants: AS-1, PEPA, and Telaz. To assess the effect of surfactants on the dispersion of the pigment, computer-optical microscopy was used. The results of the studies showed that all the studied surfactants cause an improvement in the dispersion of the pigment. According to the degree of influence on the dispersion of the pigment, surfactants can be arranged in a row: PEPA > Telaz > AS-1. When the PEPA content in the enamel is 0.25 g/dm3, a decrease in the diameter of the pigment particles by 46% (from 26 to 14 microns) is recorded, with an increase in their specific amount by 2 times (from 258 to 550 pcs). Optimal enamel compositions allow a reduction in the corrosion rate by 11 times (from 0.6 to 0.053 mm/year) and improvement to the decorative properties of coatings (roughness, gloss, etc.). The effectiveness of the AS-1 product (obtained from oil refining waste) as a dispersant additive in silicone enamel has been proven.
45
Niu, Xinxiang, Xiaoyong Hu, Cuicui Lu, Yan Sheng, Hong Yang, and Qihuang Gong. "Broadband dispersive free, large, and ultrafast nonlinear material platforms for photonics." Nanophotonics 9, no. 15 (2020): 4609–18. http://dx.doi.org/10.1515/nanoph-2020-0420.
Full textAbstract:
AbstractBroadband dispersion free, large and ultrafast nonlinear material platforms comprise the essential foundation for the study of nonlinear optics, integrated optics, intense field optical physics, and quantum optics. Despite substantial research efforts, such material platforms have not been established up to now because of intrinsic contradictions between large nonlinear optical coefficient, broad operating bandwidth, and ultrafast response time. In this work, a broadband dispersion free, large and ultrafast nonlinear material platform based on broadband epsilon-near-zero (ENZ) material is experimentally demonstrated, which is designed through a novel physical mechanism of combining structural dispersion and material dispersion. The broadband ENZ material is constructed of periodically nanostructured indium tin oxide (ITO) films, and the structure is designed with the help of theoretical predictions combined with algorithm optimization. Within the whole broad ENZ wavelength range (from 1300 to 1500 nm), a wavelength-independent and large average nonlinear refractive index of −4.85 × 10−11 cm2/W, which is enlarged by around 20 times than that of an unstructured ITO film at its single ENZ wavelength, and an ultrafast response speed at the scale of Tbit/s are experimentally reached simultaneously. This work not only provides a new approach for constructing nonlinear optical materials but also lays the material foundation for the application of nanophotonics.
46
Gilbert, Karoline M., Amanda C. N. Quirk, Puragra Guhathakurta, et al. "The TREX Survey: Kinematical Complexity Throughout M33's Stellar Disk and Evidence for a Stellar Halo*." Astrophysical Journal 924, no. 2 (2022): 116. http://dx.doi.org/10.3847/1538-4357/ac3480.
Full textAbstract:
Abstract We present initial results from a large spectroscopic survey of stars throughout M33's stellar disk. We analyze a sample of 1667 red giant branch (RGB) stars extending to projected distances of ∼11 kpc from M33's center (∼18 kpc, or ∼10 scale lengths, in the plane of the disk). The line-of-sight velocities of RGB stars show the presence of two kinematical components. One component is consistent with rotation in the plane of M33's H i disk and has a velocity dispersion (∼19 km s−1), consistent with that observed in a comparison sample of younger stars, while the second component has a significantly higher velocity dispersion. A two-component fit to the RGB velocity distribution finds that the high-dispersion component has a velocity dispersion of 59.3 − 2.5 + 2.6 km s−1 and rotates very slowly in the plane of the disk (consistent with no rotation at the <1.5σ level), which favors interpreting it as a stellar halo rather than a thick disk population. A spatial analysis indicates that the fraction of RGB stars in the high-velocity-dispersion component decreases with increasing radius over the range covered by the spectroscopic sample. Our spectroscopic sample establishes that a significant high-velocity-dispersion component is present in M33's RGB population from near M33's center to at least the radius where M33's H i disk begins to warp at 30′ (∼7.5 kpc) in the plane of the disk. This is the first detection and spatial characterization of a kinematically hot stellar component throughout M33's inner regions.
47
Yoo, Seung Hwa, H. J. Wang, Sung Tag Oh, Sung Goon Kang, and Yong Ho Choa. "Synthesis and Densification of CNTs/Fe/Al2O3 Nanocomposite Powders by Chemical Vapor Deposition." Key Engineering Materials 317-318 (August 2006): 665–68. http://dx.doi.org/10.4028/www.scientific.net/kem.317-318.665.
Full textAbstract:
CNTs/Fe/Al2O3 nanocomposites were prepared by thermal CVD and SPS methods. The dispersion of CNTs in the Fe/Al2O3 matrix were controlled by an attrition milling process. FESEM analysis revealed that the CNTs of 5 vol.% were homogeneously dispersed in the Fe/Al2O3. The effects of CNTs dispersion on the mechanical and electrical properties of the specimens were investigated. Fracture strength and electrical conductivity of 5 vol.% CNTs/Fe/Al2O3 specimen were measured at 641 MPa and 2.93 10-11 mS/m, whereas that of a 20 vol.% CNTs/Fe/Al2O3 specimen were 208 MPa and 8.46 10-7 mS/m, respectively. In comparison with an Al2O3 monolith, the specimen with 5 vol.% CNTs showed enhanced fracture strength and increased electrical conductivity.
48
Tătaru, L., T. A. Hrăniciuc, F. Stătescu, N. Marcoie, C. M. Vârlan (Toma), and R. Mitroi. "Hydrodynamic modelling and simulation of the variation of the water quality parameters of the Bahlui River." IOP Conference Series: Materials Science and Engineering 1304, no. 1 (2024): 012032. http://dx.doi.org/10.1088/1757-899x/1304/1/012032.
Full textAbstract:
Abstract For the simulation of hydrodynamic changes and pollutant dispersion in the study area, an appropriate model was applied using the DHI series software. Flows were modelled using the hydrodynamic model and the hydrological model, and water quality was modelled using MIKE 11 ECO LAB. The paper presents a simulation for the water quality of the Bahlui River. Mike 11 contains a GIS map and simulation editors. Water quality parameters such as temperature, dissolved oxygen and biochemical oxygen demand were simulated. Modelling results can be used as a planning tool to help decision makers during different phases.
49
Lopez-Rodriguez, Enrique, Alejandro S. Borlaff, Rainer Beck, et al. "Extragalactic Magnetism with SOFIA (SALSA Legacy Program): The Magnetic Fields in the Multiphase Interstellar Medium of the Antennae Galaxies*." Astrophysical Journal Letters 942, no. 1 (2022): L13. http://dx.doi.org/10.3847/2041-8213/acaaa2.
Full textAbstract:
Abstract Mergers are thought to be a fundamental channel for galaxy growth, perturbing the gas dynamics and the magnetic fields (B-fields) in the interstellar medium (ISM). However, the mechanisms that amplify and dissipate B-fields during a merger remain unclear. We characterize the morphology of the ordered B-fields in the multiphase ISM of the closest merger of two spiral galaxies, the Antennae galaxies. We compare the inferred B-fields using 154 μm thermal dust and 11 cm radio synchrotron emission polarimetric observations. We find that the 154 μm B-fields are more ordered across the Antennae galaxies than the 11 cm B-fields. The turbulent-to-ordered 154 μm B-field increases at the galaxy cores and star-forming regions. The relic spiral arm has an ordered spiral 154 μm B-field, while the 11 cm B-field is radial. The 154 μm B-field may be dominated by turbulent dynamos with high 12CO(1–0) velocity dispersion driven by star-forming regions, while the 11 cm B-field is cospatial with high H i velocity dispersion driven by galaxy interaction. This result shows the dissociation between the warm gas mainly disturbed by the merger, and the dense gas still following the dynamics of the relic spiral arm. We find a ∼8.9 kpc scale ordered B-field connecting the two galaxies. The base of the tidal tail is cospatial with the H i and 12CO(1–0) emission and has compressed and/or sheared 154 μm and 11 cm B-fields driven by the merger. We suggest that amplified B-fields, with respect to the rest of the system and other spiral galaxies, may be supporting the gas flow between both galaxies and the tidal tail.
50
Cho, Yong Heui. "Analytical Dispersion Equations of a Lossy Coaxial Waveguide in the Microwave and Visible Spectra." Journal of Electromagnetic Engineering and Science 21, no. 2 (2021): 119–25. http://dx.doi.org/10.26866/jees.2021.21.2.119.
Full textAbstract:
Analytical hybrid-mode dispersion relations of a lossy coaxial waveguide were rigorously analyzed using a mode-matching technique. In order to model a practical coaxial line with inevitable losses, we adopted an all-dielectric coaxial waveguide surrounded by the perfect electric conductor (PEC) boundary. The rigorous dispersion characteristics of the TM<sub>01</sub>, TE<sub>01</sub>, and EH<sub>11</sub> modes were investigated for lossy coaxial waveguides filled with different electrical conductivities. Based on the exact solutions, approximate but accurate dispersion equations were proposed for the TM<sub>0<i>p</i></sub>, TE<sub>0<i>p</i></sub> , EH<sub><i>mp</i></sub>, and HE<sub><i>mp</i></sub> modes in order to estimate and compare the behaviors of complex propagation constants in the microwave and visible spectra.