Wyniki wyszukiwania - Biblioteka Nauki

1

Numerical simulation and theoretical analysis of the 3D viscous flow in centrifugal impellers

100%

Kang S. , Hirsch C.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2001

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tom Vol. 5, No 4

433-458

EN

This paper investigates the three-dimensional viscous ow in centrifugal impellers through theoretical analysis and numerical simulations, which is a summary of the authors' recent work. A quantitative evaluation of the dierent contributions to the streamwise vorticity is performed, namely, the passage vortices along the endwalls due to the ow turning; a passage vortex generated by the Coriolis forces proportional to the local loading and mainly active in the radial parts of the impeller; blade surface vortices due to the meridional curvature. In the numerical simulation the NASA Large Scale Centrifugal Compressor (LSCC) impeller with vaneless diuser is computed at three ow rates. An advanced Navier-Stokes solver, EURANUS/TURBO is applied with an algebraic turbulence model of Badwin-Lomax and a linear k-" model for closure, for dierent meshes. An in-depth validation has been performed based on the measured data. An excellent agreement is obtained for most of the data over a wide region of the ow passage. Structures of the 3D ow in the blade passage and the tip region, and their variations with ow rate as well, are analysed based on the numerical results.

2

Compatible mappings of type (C) and common fixed point theorems of Gregus type

80%

Pathak H. , Cho Y. , Kang S. , Madharia B.

Demonstratio Mathematica

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1998

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tom Vol. 31, nr 3

499-518

EN

In this paper, we introduce the concept of compatible mappings of type (C) in normed spaces and compare these mappings with compatible mappings of type (A) and compatible mappings of type (B). In the sequel, we establish a common fixed point theorem for two pairs of compatible mappings of type (C) for Gregus type contraction condition. Our main result improves, extends and modifies several known results.

3

Effect of urea and molasses supplementation on quality of cassava top silage

80%

Kang S. , Wanapat M. , Nunoi A.

Journal of Animal and Feed Sciences

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2018

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tom 27

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nr 1

EN

The aim of the study was to evaluate the nutritive value and fermentation efficiency of cassava top silage using in vitro gas production technique. The four-month plants were harvested, chopped into 2–3 cm pieces and ensiled with 0, 0.5 and 1% urea (U), and 0, 0.5, 1 and 2% molasses (M) (on the basis of the crop dry matter (DM)). Silage pH increased with U supplementation but decreased by addition of 2% of M, so the lowest pH values were observed in: U0M0–2 and then in U0.5M2 and U1M2 groups. The U supplementation increased crude protein content in cassava top silage in a dose-dependent manner. There was observed U × M interaction for neutral and acid detergent fibre contents (NDF and ADF, respectively) – when added together the M decreased these parameters in a dose-dependent manner, and the lowest value of NDF was observed in U1M2 group, and of ADF – for U0M2, U0.5M2 and U1M2 groups. The cumulative gas production was increased when either U or M were added, and the highest value was observed in U0.5M2 and U1M2 groups. In addition, the true digestibility was increased when M was added and the NDF digestibility was the highest in M2 groups. Fermented pH was increased by U supplementation while protozoa populations were similar among treatments. So, supplementation with 0.5–1% of U and 2% of M may increase cassava top silage quality and the in vitro fermentation efficiency. However studies evaluating cassava top silage influence on animal growth performance are recommended.

4

Responses of tillering Stipa breviflora traits to a long-term grazing gradient

70%

Li J. , Han G. , Kang S. , Zhang X. , Li C.

Acta Societatis Botanicorum Poloniae

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2022

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tom 91

5

Real-time optical demultiplexing with the chirped pulses

51%

Li Y. , Zhang X. , Yuan J. , Kang Z. , Sang X. , Kang S. , Kang X. , Yan B. , Wang K. , Yu C.

Optica Applicata

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2018

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tom Vol. 48, nr 4

621--632

EN

A scheme for real-time optical demultiplexing is proposed by utilizing the time-broadened and linearly chirped pulses instead of the conventional mode-locked pulses. The copies of the optical-time-division-multiplexed signal are acquired through a dual-pump parametric gate and used as the parametric multicast block. Simulation results show that the demultiplexing from 160 Gb/s down to sixteen 10 Gb/s tributaries can be achieved only by using a sampling source of 10 GHz. The proposed scheme can effectively reduce the complexity of parallel processing, and find important applications in the high-speed all-optical signal processing.

6

Snowmelt runoff modelling under projected climate change patterns in the gilgit river basin of northern Pakistan

51%

Adnan M. , Nabi G. , Kang S. , Zhang G. , Adnan R. M. , Anjum M. N. , Iqbal M. , Ali A. F.

Polish Journal of Environmental Studies

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2017

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tom 26

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nr 2

EN

Pakistan is home to three of the world’s largest mountain ranges in the Upper Indus Basin (UIB), where the majority of Pakistan’s water resources are located: the Himalayan, Karakorum, and Hindu-Kush. This work estimated the (snow+glacier) and rainfall runoff from one of the major tributaries, the Gilgit River, nestled within the UIB of Pakistan. The snowmelt runoff model (SRM) derived by the cryospheric data from the MODIS (moderate resolution imaging spectroradiometer) was employed to predict the daily discharges of the Gilgit. The SRM was successfully calibrated, and the simulation was undertaken from 2005 to 2010, with a coefficient of model efficiency ranging from 0.84-0.94. The average contributions of (snow+glacier) and rainfall to the stream flows of the Gilgit from 2001-10 were 78.35% and 21.65%, respectively, derived from the SRM. The representative concentration pathways (RCP) 4.5 and 8.5 scenarios of the Intergovernmental Panel on Climate Change (IPCC) AR5 were used to investigate the effects of the changes in temperature on climate of the Gilgit catchment. Under the RCP 4.5 scenario, the air temperature of Gilgit will increase by 3°C, whereas the increase in precipitation will be minor. Under the RCP 8.5 scenario (overshooting scenario), air temperature will increase by 10.7°C, whereas precipitation will decrease between 2010 and the end of the 21st century in the Gilgit catchment. The application of the RCP 4.5 and 8.5 mean temperature scenarios in the SRM suggested that with increases in mean temperature of 3.02ºC and 10.7ºC, respectively, the average annual runoff in the Gilgit will increase by 67.03 and 177.5%, respectively, compared with the observed runoff by the end of the 21st century. This increased surface runoff from snow/glacier melt can potentially be utilized by planning new storage areas at appropriate locations to harness additional water.

7

A proteomic analysis of the effect of MAPK pathway activation on L-glutamate-induced neuronal cell death

51%

Kang S. , Kim E. Y. , Bahn Y. J. , Chung J. W. , Lee D. H. , Park S. G. , Yoon T. S. , Park B. C. , Bae K. H.

Cellular and Molecular Biology Letters

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2007

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tom 12

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nr 1

EN

Oxidative stress has been implicated in the pathogenesis of neuronal degenerative diseases. It is also widely known that oxidative stress induces mitogen-activated protein kinase (MAPK) signaling cascades. In this study, we used proteomic analysis to investigate the role of the MAPK pathway in oxidative stress-induced neuronal cell death. The results demonstrated that several proteins, including eukaryotic translation elongation factor 2 (eEF2) and enolase I, showed a differential expression pattern during the neuronal cell death process, and this was MAPK pathway dependent. Several chaperone and cytoskeletal proteins including heat shock protein 70, calreticulin, vimentin, prolyl 4-hydroxylase β polypeptide, and transgelin 2 were up-or down-regulated, despite their expressions not depending on the MAPK pathway. These findings strongly suggest that the expressions of proteins which play protective roles are independent of the MAPK pathway. On the other hand, eEF2 and enolase I may be the downstream targets of the MAPK pathway.