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2022 ◽  
Author(s):  
Yue Peng ◽  
Yong Yang ◽  
Yuesong Jia ◽  
Bo Rao ◽  
Ming Zhang ◽  
...  

Abstract Collisional-merging is a way to form high-performance field-reversed configuration (FRC) plasma. An experiment device named HUST-FRC (HFRC) is under construction in Huazhong University of Science and Technology, which will be used to investigate the FRC formation through collisional-merging. In this research, a magnetohydrodynamics (MHD) simulation software called USim is used to study the effect of the initial density of plasma, the amplitude of the bias magnetic field, the configuration of the bias field, the rise time of the main field and the magnetic field ripple on the plasma parameters to facilitate the designing and operations of HFRC. Preliminary simulation results show that cusp configuration, lower ripple, higher initial density, an initial bias field of -0.15 T or -0.2 T, and a rise time of 4 μs are conducive to the formation of high-performance FRC plasma in HFRC device.


2022 ◽  
Vol 14 (4) ◽  
pp. 95-102
Author(s):  
A. Zh. Fursova ◽  
A. S. Derbeneva ◽  
M. S. Tarasov ◽  
M. V. Vasil’eva ◽  
J. A. Gamza ◽  
...  

The purpose of the study was to assess the changes of biomarkers of diabetic macular edema activity by optical coherence tomography angiography (OCTA) data and the relationship of these biomarkers with the response to anti-VEGF therapy during a two-year follow-up. Material and methods. The study included 59 patients (101) eyes, averagely aged 60.27 ± 9.50 years. The average number of intravitreal injections of aflibercept over the treatment period was 12.87 ± 3.50. The initial size of the foveolar avascular zone (FAZ) area — 0.37 ± 0.22 mm2 , and the acircularity index — 0.56 ± 0.14 remained unchanged after 5 months: 0.36 ± 0.24 mm2  and 0.56 ± 0.12, respectively, and being practically in the same level in 12 and 24 months. The large FAZ area, noted in the group where disorganization of retinal inner layers (DRIL) was observed (0.39 ± 0.21 mm2 ), correlated with a lower visual acuity (r = 0.67, p = 0.003). The acircularity index remained unchanged; no significant differences were found in the DRIL patient groups. After 5 loading injections, the average initial density of vessels in the macular region increased from 12.33 ± 3.86 mm to 12.75 ± 1.14 mm, after 1 year it was 13.48 ± 1.15 mm, after 2 years — 13.25 ± 3.39 mm. The average density of retinal perfusion increased at the 5th month from 29.81 ± 10.85 % to 31.55 ± 2.34 %, after 12 months to 32.91 ± 3.45, and by the end of the observation period to 31.41 ± 9.79 %. In the DRIL group, the baseline vascular density and mean perfusion volume were significantly lower: 11.17 ± 2.09 mm vs. 13.49 ± 1.14 mm and 28.40 ± 4.53 % vs. 31.20 ± 2.44 %). Conclusion. DRIL, a biomarker reflecting impaired capillary blood flow in the superficial capillary plexus and correlating with functional results, can be used as a predictor of antiangiogenic therapy effectiveness. After antiangiogenic therapy with DMO, the microcirculation indices (FAZ and acircularity) remained stable, and the vascular density and perfusion volume tended to increase, which testifies to the absence of ischemic damage.


2022 ◽  
Author(s):  
Tanja Golke ◽  
Patrick Mucher ◽  
Patricia Schmidt ◽  
Astrid Radakovics ◽  
Manuela Repl ◽  
...  

Background: Peripheral blood mononuclear cells (PMBCs) are a versatile material for clinical routine as well as for research projects. However, their isolation via density gradient centrifugation is still time-consuming. When samples are taken beyond usual laboratory handling times, it may sometimes be necessary to pause the isolation process. Our aim was to evaluate the impact of delays up to 48 hours after the density gradient centrifugation on PBMC yield, purity and viability. Methods: PBMCs were isolated from samples of 20 donors, either with BD Vacutainer CPT tubes (CPT) or with the standard Ficoll method. Isolation was paused after initial density gradient centrifugation for 0, 24, or 48 hours. PBMC yield, purity and viability were compared. Results: The yield did not change significantly over time when CPT were used (55%/52%/47%), but did after isolation with the standard method (62%/40%[p<0.0001]/53%[p<0.01]). Purity was only affected if CPT were used (95%/93%[p=n.s./92%[p<0.05] vs. 97% for all time points with standard method). Whereas viable PBMCs decreased steadily for CPT isolates (62%/51%[p<0.001]/36%[p<0.0001]), after standard Ficoll gradient isolation, cell apoptosis was more pronounced already after 24h delay, and viability did not further decrease after 48h (64%/44%[p<0.0001]/40%[p<0.0001]). Conclusions: In conclusion, our data suggests that post-centrifugation delays of up to 48h might have only a minor effect on cell yield and purity. However, at the same time, a relevant decrease in cell viability was observed, which could be partially compensated by the use of CPT if the isolation was resumed latest the day after blood withdrawal.


2021 ◽  
Author(s):  
H. Davari ◽  
B. Farokhi ◽  
M. Ali Asgarian

Abstract A particle-in-cell simulation is modeled and run on a dusty plasma to determine the effect of the magnetic field on the process dust-particle charging through electron-ion plasma. The electric field is solved through the Poisson equation, and the electron-neutral elastic scattering, excitation, and ionization processes are modeled through Monte Carlo collision method. The effects obderved from the initial density of the plasma, the initial temperature of the electrons, and the changing magnetic field are included in this simulation model. In the dust particle charging process, saturation time and saturation charge are compared. An increase in the magnetic field cannot reduce time to reach the saturation state. Determinig the magnetic field boundaries which depend on the physical properties of the plasma, which can be contributive in some areas of dusty(complex) plasma. The applications of the results obtaind here for fusion plasma conditions and space and laboratory plasmas are discussed. The results here can be applied in future simulation models with a focus on the dust particle movement and their effect on plasma, leading to the modeling of different astrophysical plasmas thorough laboratory experiments.


2021 ◽  
Author(s):  
Yinbin Lu ◽  
Chenwei Liang

In the filling and transportation processes of liquefied natural gas (LNG), the safety of LNG storage tanks is compromised because of rollover phenomenon. As such, the rollover factors of LNG in a storage tank should be identified to prevent or weaken the rollover intensity of LNG. In this study, the rollover behavior of LNG in a storage tank is numerically simulated. The density of the two layers in a LNG storage tank is related to temperature in our numerical model. It is found that the greater the significant initial density difference (range of 1-12 kg·m-3) is, the more obvious the LNG rollover will be. A density difference of 7.5 kg·m-3 is found as the critical density difference in the present work. When the initial density difference exceeds the critical density difference, the LNG rollover coefficients increase dramatically. Moreover, an LNG rollover model with two daughter models is proposed, which are divided by the critical initial density difference, i.e., a cubic relationship between rollover coefficients and the initial density difference when the density difference is less than 7.5 kg·m-3 and secondly, a linear relationship between the rollover coefficient and the double exponential functions when the density difference is larger than 7.5 kg·m-3.


2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Tariq Mahmood ◽  
Mei Sun

AbstractThis paper considers the initial-boundary value problem of the one-dimensional full compressible nematic liquid crystal flow problem. The initial density is allowed to touch vacuum, and the viscous and heat conductivity coefficients are kept to be positive constants. Global existence of strong solutions is established for any $H^{2}$ H 2 initial data in the Lagrangian flow map coordinate, which holds for both vacuum and non-vacuum case. The key difficulty is caused by the lack of the positive lower bound of the density. To overcome such difficulty, it is observed that the ratio of $\frac{\rho _{0(y)}}{\rho (t,y)}$ ρ 0 ( y ) ρ ( t , y ) is proportional to the time integral of the upper bound of temperature and vector director field, along the trajectory. Density weighted Sobolev type inequalities are constructed for both temperature and director field in terms of $\frac{\rho _{0(y)}}{\rho (t,y)}$ ρ 0 ( y ) ρ ( t , y ) and small dependence on their dissipation estimates. Besides this, to deal with cross terms arising due to liquid crystal flow, higher order priori estimates are established by using effective viscous flux.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anusha Dravid ◽  
Brad Raos ◽  
Darren Svirskis ◽  
Simon J. O’Carroll

AbstractNeuronal models are a crucial tool in neuroscientific research, helping to elucidate the molecular and cellular processes involved in disorders of the nervous system. Adapting these models to a high-throughput format enables simultaneous screening of multiple agents within a single assay. SH-SY5Y cells have been widely used as a neuronal model, yet commonly in an undifferentiated state that is not representative of mature neurons. Differentiation of the SH-SY5Y cells is a necessary step to obtain cells that express mature neuronal markers. Despite this understanding, the absence of a standardised protocol has limited the use of differentiated SH-SY5Y cells in high-throughput assay formats. Here, we describe techniques to differentiate and re-plate SH-SY5Y cells within a 96-well plate for high-throughput screening. SH-SY5Y cells seeded at an initial density of 2,500 cells/well in a 96-well plate provide sufficient space for neurites to extend, without impacting cell viability. Room temperature pre-incubation for 1 h improved the plating homogeneity within the well and the ability to analyse neurites. We then demonstrated the efficacy of our techniques by optimising it further for neurite outgrowth analysis. The presented methods achieve homogenously distributed differentiated SH-SY5Y cells, useful for researchers using these cells in high-throughput screening assays.


Author(s):  
Dr. Sarvesh Chandra Yadav

<p>The effects of overtaking disturbances behind the flow on the propagation of diverging cylindrical shock Waves through an ideal gas in presence of a magnetic field having =constant=  and an Initial density distribution  where  is a constant,  is the density at the plane / exes of symmetry: The analytical formula for flow variables representing both the position form viz; weak and strong cases at shock waves have been obtained. Their numerical estimates at permissible shock front locations have been obtained.</p> <p>There numerical estimates at permissible shock front location's have been Calculated and compared with earlier result describing in Free Propagation through figures. After inclusion of E.O.D. noted that there is no change at flow variable with parameters and . However, the trends of variation with propagation distance r, for shock strength, shock velocity and particle velocity are not change in case of weak shock with work Magnetic field<strong>(wswmf).</strong></p>


Author(s):  
Chenxi Du ◽  
Xianzhi Ao ◽  
Bingxian Luo ◽  
Jingjing Wang ◽  
Chong Chen ◽  
...  

Abstract The solar energetic particle (SEP) event is a kind of hazardous space weather phenomenon, so its quantitative forecast is of great importance from the aspect of space environmental situation awareness. We present here a set of SEP forecast tools, which consists of three components: 1) a simple polytropic solar wind model to estimate the background solar wind conditions at the inner boundary of 0.1AU (about 20 R⊙); 2) an ice-cream-cone model to estimate the erupted CME parameters; and 3) the improved Particle Acceleration and Transport in the Heliosphere (iPATH) model to calculate particle fluxes and energy spectra. By utilizing the above models, we have simulated six realistic SEP events from August 14, 2010 to September 10, 2014, and compared the simulated results to the GOES spacecraft observations. The results show that the simulated fluxes of > 10MeV particles agree with the observations while the simulated fluxes of > 100MeV particles are higher than the observed data. One of the possible reasons is that we have adopted a simple method in the model to calculate the injection rate of energetic particles. Furthermore, we have conducted the ensemble numerical simulations over these events and investigated the effects of different background solar wind conditions at the inner boundary on SEP events. The results imply that the initial CME density plays an important role in determining the power spectrum, while the effect of varying background solar wind temperature is not significant. Naturally, we have examined the influence of CME initial density on the numerical prediction results for virtual SEP cases with different CME ejection speeds. The result shows that the effect of initial CME density variation is inversely associated with CME speed.


Bioenergy ◽  
2021 ◽  
Author(s):  
Ya. D. Fuchylo ◽  
I. D. Ivaniuk ◽  
Ya. P. Makukh ◽  
V. Yu. Yukhnovskyi ◽  
S. O. Remeniuk ◽  
...  

Goal. Study of peculiarities of growing pine stands and prospects of their use in agroforestry of Zhytomyr Polissia on the example of agricultural lands of Malyn Vocational College. Methods. Field, laboratory, analytical, statistical. Results. On sod-podzolic sandy soils of Zhytomyr Polissia pine seedlings after three years of cultivation were 55.7 ± 3.43 cm in height. The maximum increase in height was observed during the third year of cultivation of the plantation, when at the beginning of the growing season with herbicide Targon Plus the impact of cereal vegetation reduced to a minimum, resulting in improved seedling growth conditions. The high preservation of pine plants and their intensive growth allow us to make optimistic forecasts about the feasibility of growing them as a forest component of agricultural landscapes, especially given the presence of biotically stable 15-year-old pine plantations created by similar agricultural techniques. They were laid at an initial density of 7.1 thousand seedlings per 1 ha, and later thinned to 2982 and 1691 plants/ha, respectively. With almost the same productivity indicators, higher tree height (by 17.0%) and larger average diameter (by 23.8%) allow thinner plantations to have a more positive impact on adjacent agricultural lands, grow more intensively and have higher productivity in the future. This indicates the expediency of pine plantations in the region of research as a forestry component of agrolandscapes a density at the age of 15 years of about 1700 trees per 1 ha.


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