bluuebunny/crossref_metadata_2025 huggingface dataset:
Lanthanides compete with calcium for binding to cadherins and inhibit cadherin-mediated cell adhesion
Authors: Brayshaw Lewis L , Smith Rosanna C G , Badaoui Magd , Irving James A , Price Stephen R
Published: March 2019

Lanthanides are rare-earth metals with a broad range of applications in biological research and medicine. In addition to their unique magnetic and spectroscopic properties, lanthanides are also effective mimics of calcium and can stimulate or inhibit the function of calcium-binding proteins. Cadherins are a large family of calcium-binding proteins that facilitate cell adhesion and play key roles in embryo development, tissue homeostasis and tumour metastasis. However, whether lanthanides can bind cadherins and functionally replace calcium binding has not been comprehensively explored. In this study, we investigated the effect of lanthanide binding on cadherin structure and function using terbium, which is a commonly used lanthanide for protein spectroscopy and a proposed anti-cancer agent. We demonstrate that terbium can compete with calcium for binding to calcium-binding sites in cadherins. Terbium binding to cadherins abolished their cell adhesive activity and rendered cadherins sensitive to proteolysis by trypsin. Molecular dynamics simulations indicate that replacement of calcium by terbium results in structural rearrangements and increases the flexibility of the cadherin ectodomain. These changes in structure and dynamics are likely to underlie the inability of lanthanide-bound cadherins to support cell adhesion. Taken together, our findings further knowledge on lanthanide interactions with calcium-binding proteins and provide new insight into the influence of metal chemistry on cadherin structure, dynamics and function.
Facile preparation of orange-emissive carbon dots for the highly selective detection of silver ions
Authors: Ma Yunxia , Lv Wenjuan , Chen Yonglei , Na Min , Liu Juanjuan , Han Yangxia , Ma Sudai , Chen Xingguo
Published: March 2019

We have prepared orange-emissive carbon dots, which serve as a highly selective fluorescent method for the detection of silver ions.
Hydrophilic “bridge” tannins for stabilizing the metal selenides onto activated carbon for binder-free and ultralong-life asymmetric supercapacitors
Authors: Li Yue , Cui Linlin , Jia Mengying , Xu Lanshu , Gao Jianmin , Jin Xiaojuan
Published: March 2019

Tannin-doped activated carbon by employing tannin as the structure coupling bridge between the two components could effectively tune the electronic structural states and result in strong coupling effects with NiCo2Se4.
Pressure-induced fluorescence enhancement of FAαPbBr2+α composite perovskites
Authors: Nguyen Lan Anh Thi , Minh Duong Nguyen , Yuan Ye , Samanta Sudeshna , Wang Lin , Zhang Dongzhou , Hirao Naohisa , Kim Jaeyong , Kang Youngjong
Published: March 2019

FAPbBr3 crystals were stabilized by the endotaxy passivation by FA4PbBr6 during high pressure compression.
Open-book-like triboelectric nanogenerators based on low-frequency roll–swing oscillators for wave energy harvesting
Authors: Zhong Wei , Xu Liang , Yang Xiaodan , Tang Wei , Shao Jiajia , Chen Baodong , Wang Zhong Lin
Published: March 2019

Open-book-like triboelectric nanogenerators enable highly effective wave energy harvesting with enhanced power and charge output for self-powered marine systems.
Nanoskiving fabrication of size-controlled Au nanowire electrodes for electroanalysis
Authors: Xu Muzhen , Zhang Yue , Wang Kai , Mao Jinpeng , Ji Wenliang , Qiu Wanling , Feng Taotao , Zhang Meining , Mao Lanqun
Published: March 2019

Nanoskiving, benefiting from its simple operation and high reproducibility, is a promising method to fabricate nanometer-size electrodes.
Two fluorescence quenching immunochromatographic assays based on carbon dots and quantum dots as donor probes for the determination of enrofloxacin
Authors: Li Shijie , Wang Yanan , Mu Xingqian , Sheng Wei , Wang Junping , Wang Shuo
Published: March 2019

Two fluorescence quenching lateral flow immunochromatographic assays were developed based on carbon dots (CDs) and quantum dots (QDs) as donor signal probes.
In situ fluorescent profiling of living cell membrane proteins at a single-molecule level
Authors: Fan Yuanyuan , Li Lu , Lu Meng , Si Haibin , Tang Bo
Published: March 2019

A signal amplification method is developed for visualization analysis of membrane proteins on living cells at a single-molecule level.
Localized surface plasmon enhanced electrocatalytic methanol oxidation of AgPt bimetallic nanoparticles with an ultra-thin shell
Authors: Bi Jinglei , Cai Hairui , Wang Bin , Kong Chuncai , Yang Shengchun
Published: March 2019

AgPt bimetallic hollow nanoparticles (AgPt-BHNPs) with an ultra-thin shell were synthesized.
Target-triggered dynamic hairpin assembly for signal amplification of microRNA and oncogenes and its application in live-cell imaging
Authors: Li Yuanfang , Yue Shuzhen , Qi Hongjie , Ding Caifeng , Song Weiling , Bi Sai
Published: March 2019

DNA nanobrushes are constructed based on target-triggered dynamic hairpin assembly in both unidirectional and bilateral growth manners, and realize sensitive and selective detection of short miRNA and long target DNA, respectively.
Theoretical study on the light-emitting mechanism of circularly polarized luminescence molecules with both thermally activated delayed fluorescence and aggregation-induced emission
Authors: Yin Xiu , Fan Jian-Zhong , Liu Jie , Cai Lei , Sun Hao , Sun Yu-Ping , Wang Chuan-Kui , Lin Li-Li
Published: March 2019

The light-emitting mechanism of circularly polarized luminescence molecules with both TADF and AIE.
The effect of protons on the Mg2+ migration in an α-V2O5 cathode for magnesium batteries: a first-principles investigation
Authors: Ni Dixing , Shi Jing , Xiong Wan , Zhong Shuying , Xu Bo , Ouyang Chuying
Published: March 2019

Via first-principles calculations, we showed that the Mg-ion diffusion energy barrier in α-V2O5 can be substantially decreased through hydrogenation.
High local coordination symmetry around the spin center and the alignment between magnetic and symmetric axes together play a crucial role in single-molecule magnet performance
Authors: Yang Zhao-Fu , Tian Yong-Mei , Zhang Wan-Ying , Chen Peng , Li Hong-Feng , Zhang Yi-Quan , Sun Wen-Bin
Published: March 2019

A tetradentate 8-hydroxyquinoline-based acyl hydrazine ligand was used to construct a series of mono/di-nuclear dysprosium single-molecule magnets (SMMs) with nearly ideal pentagonal bipyramid coordination geometry (D5h).
One-step fabrication of trimetallic core–shell Au@PdAuCu mesoporous nanospheres for ethanol electrooxidation
Authors: Lv Hao , Sun Lizhi , Chen Xin , Xu Dongdong , Liu Ben
Published: March 2019

A one-step surfactant-directing method was reported to synthesize Au@PdAuCu mesoporous nanospheres with tailored Au cores, cylindrically opened mesochannels, and multimetallic shells. The resultant Au@PdAuCu mesoporous nanospheres exhibited enhanced electrocatalytic ethanol oxidation performance.
Aromatisation of bio-derivable isobutyraldehyde over HZSM-5 zeolite catalysts
Authors: Deischter Jeff , Schute Kai , Neves Dario S. , Ebert Brigitta E. , Blank Lars M. , Palkovits Regina
Published: March 2019

A novel efficient route to obtain aromatic products based on biomass feedstock was successfully demonstrated with high BTX yields.
A simple ketone as an efficient metal-free catalyst for visible-light-mediated Diels–Alder and aza-Diels–Alder reactions
Authors: Kollmann Jiri , Zhang Yu , Schilling Waldemar , Zhang Tong , Riemer Daniel , Das Shoubhik
Published: March 2019

An efficient metal-free homogeneous system has been developed for the Diels–Alder reaction between electron-rich dienophiles and dienes under visible-light conditions. The mechanism of this reaction has been proposed based on the experimental evidence.
Unravelling the growth mechanism of the co-precipitation of iron oxide nanoparticles with the aid of synchrotron X-Ray diffraction in solution
Authors: LaGrow Alec P. , Besenhard Maximilian O. , Hodzic Aden , Sergides Andreas , Bogart Lara K. , Gavriilidis Asterios , Thanh Nguyen Thi Kim
Published: March 2019

The formation mechanism of iron oxide nanoparticles reveals an initial segregation into ferrihydrite seeds and a Fe2+ rich growth reservoir.
Transformable nanotherapeutics enabled by ICG: towards enhanced tumor penetration under NIR light irradiation
Authors: Tang Yuxiang , Li Yihui , Li Si , Hu Hang , Wu Yuxin , Xiao Chen , Chu Zhiqin , Li Zifu , Yang Xiangliang
Published: March 2019

ICG@HES-SS-DOX NP was formed by crosslinking HES-SS-DOX with ICG. Exposed to NIR light, ICG degrades, leading to the dissociation of NP. The scattered HES-SS-DOX can penetrate deep in H22 tumor.
Nanoscale investigation of improved triboelectric properties of UV-irradiated ultrananocrystalline diamond films
Authors: Kim Jae-Eun , Panda Kalpataru , Choi Joong Il Jake , Park Jeong Young
Published: March 2019

The improved triboelectrical properties after UV exposure on UNCD films were investigated using AFM.
Untying thioether bond structures enabled by “voltage-scissors” for stable room temperature sodium–sulfur batteries
Authors: Chen Kejun , Li HuangJingWei , Xu Yan , Liu Kang , Li Hongmei , Xu Xiaowen , Qiu Xiaoqing , Liu Min
Published: March 2019

A steady sulfur cathode is central to realizing stable room temperature sodium–sulfur (RT Na–S) batteries.
Water-soluble chiral tetrazine derivatives: towards the application of circularly polarized luminescence from upper-excited states to photodynamic therapy
Authors: He Tingchao , Ren Can , Luo Yu , Wang Qi , Li Junzi , Lin Xiaodong , Ye Chuanxiang , Hu Wenbo , Zhang Junmin
Published: March 2019

A new family of water-soluble tetrazine derivatives exhibits the first example of CPL from upper-excited states and highly efficient ISC.
Integrated analyses of lncRNAs microarray profiles and mRNA–lncRNA coexpression in smooth muscle cells under hypoxic and normoxic conditions
Authors: Zhao Qinshuo , Sun Dating , Li Yuanyuan , Qin Jin , Yan JiangTao
Published: March 2019

Hypoxia may cause abnormal proliferation and migration of the vascular smooth muscle cells (VSMCs) from the media to the intima. This contributes to vessel narrowing and accelerates the process of atherosclerosis. The association of the aberrant expression of long noncoding RNAs (lncRNAs) with the development and progression of atherosclerosis is well known; however, it is not well investigated in hypoxic VSMCs. Using a microarray approach, we identified 1056 and 2804 differentially expressed lncRNAs and mRNAs, respectively, in hypoxic and normoxic mouse aorta smooth muscle (MOVAS) cells. Of them, we randomly chose several lncRNAs and validated the microarray data using the quantitative PCR (qPCR) assay. Advanced bioinformatics analyses indicated that the up-regulated mRNAs were mainly involved in inflammatory responses, lipid metabolism, clearance of amyloid-β peptide, citrate cycle (TCA cycle), TGF-β signaling, and chemokine signaling. The down-regulated mRNAs were mainly involved in the apoptosis pathway, glycerolipid metabolism, Wnt signaling pathway, and MAPK signaling pathway. The constructed coexpression network indicated interactions between 87 lncRNAs and ten mRNAs. In addition, we demonstrated that the silence of lncRNA NONMMUT002434 expression could abrogate the migration and proliferation of smooth muscle cells dramatically. Our data provide comprehensive evidence on the differential expression of lncRNAs and mRNAs in hypoxic MOVAS cells, which may be valuable biomarkers for atherosclerotic diseases, and thereby facilitating diagnosis of atherosclerosis.
On fitness: how do mutations shape the biology of cancer?
Authors: Majewski Ian J.
Published: March 2019

The theory of evolution by natural selection shapes our understanding of the living world. While natural selection has given rise to all the intricacies of life on the planet, those responsible for treating cancer have a darker view of adaptation and selection. Revolutionary changes in DNA sequencing technology have allowed us to survey the complexities that constitute the cancer genome, while advances in genetic engineering are allowing us to functionally interrogate these alterations. These approaches are providing new insights into how mutations influence cancer biology. It is possible that with time, this new knowledge will allow us to take control of the evolutionary processes that shape the disease, to develop more effective treatments.
The properties of the kinematically distinct components in NGC 448 and NGC 4365
Authors: Nedelchev B. , Coccato L. , Corsini E. M. , Sarzi M. , de Zeeuw T. , Pizzella A. , Dalla Bontà E. , Iodice E. , Morelli L.
Published: March 2019

Aims. We study the kinematically distinct components in two early-type galaxies NGC 448 and NGC 4365 aided by integral-field observations with the Multi-Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope. The former galaxy has previously been shown to host a counter-rotating stellar disc while the latter harbours a central (apparently) decoupled core that has been suggested to not be physically distinct from the main body and instead stems from the different orbital types in the core and main body due to its triaxial nature. We aim to measure the brightness profiles, kinematics, and stellar population properties of the peculiar kinematic structures in these galaxies and shed light on their true nature and formation mechanism.

Methods. We use a kinematic decomposition technique to separate the individual contributions to the spectra of the two distinct kinematic components observed at each spatial position in the field of view. Furthermore, by folding back the outcome of a photometric decomposition we reduce the intrinsic degeneracies in recovering the kinematics and the best-fitting stellar spectral templates. Finally, by extracting the Lick line-strength indices for the individual components and fitting them to single stellar population models we derive their ages, metallicities, andα/Fe overabundances.

Results. The two kinematically decoupled stellar components in NGC 448 have similar ages, but different chemical compositions. The distinct kinematic feature in NGC 448 has a nearly exponential surface-brightness light profile, dominates in the innermost ∼10″, is smaller in size, and is very likely an embedded counter-rotating disc as also indicated by its kinematics. It has higher metallicity than the main galaxy stellar body and lowerα/Fe overabundance. By contrast, we do not find evidence for true decoupling in the two distinct kinematic components in NGC 4365. This confirms earlier work suggesting that the kinematically distinct core is likely not a separate dynamical structure, but most certainly likely a projection effect stemming from the orbital structure of this galaxy that was previously found to be intrinsically triaxial in shape.

Conclusions. Our findings indicate that the kinematically decoupled component in NGC 448 is truly decoupled, has external origin, and was formed through either the acquisition of gas and a subsequent star-formation episode or from the direct accretion of stars from a companion. Conversely, the presence of a kinematically distinct component in NGC 4365 is not associated to a true kinematic decoupling and is instead most likely due to a projection effect stemming from the triaxial nature of this galaxy.
Enhancement of the Walbrzych Hard Coal Mines Geographic Information System for its application in studies of mining deformations
Authors: Blachowski Jan , Herkt Paulina
Published: March 2019

Geographic information systems (GIS) have been increasingly used in augmenting studies of mining and post-mining areas such as surface deformation analyses, risk assessment associated with old mining sites, identification of old mining sites and other. Up-to-date and complete geodatabase is an indispensable element of any geoinformation system facilitating such geospatial analyses. In this paper the process of verification and integration of Walbrzych Hard Coal Mines geodatabase and project of enhancing the Deformation Information System for these mines with web map application of underground workings and query tools developed with free and open source software (FOSS) have been described. The interactive map allows users to interact and obtain precise information on location and characteristics of underground mining and the query tools streamline pre-processing operations necessary for geospatial analyses.
A review of methods of cartographic presentation of urban space
Authors: Bac-Bronowicz Joanna , Wojciechowska Gabriela
Published: March 2019

The aim of the article is to present selected solutions applied in urban planning, which, even contemporarily, can be used as models. The paper presents a review of selected concepts of model cities from the antiquity to contemporary times. The article presents methods of creating three-dimensional city models (or their flat presentations in so-called two and a half dimensions), including the historical conceptualization, portraying both the practical and aesthetical features of former map projections. Referring to historical examples, the article also includes historical and contemporary urban 3D models corresponding to analyzed conceptions.
Changes in the conduct of administrative proceedings in the scope of cadaster database
Authors: Sudoł Ewa
Published: March 2019

One of the components of the national spatial information infrastructure database (National Geographic Information System) at the district level is the records database of land and buildings. It is a state register that contains databases related to space and procedures and techniques for collecting, updating, processing and sharing information. A legal system regulating the procedures for keeping, updating and making available subject and object information included in the cadastres database is determined by the proper functioning of the land and buildings register (as part of the geodetic resource). The basis of department work in the field of keeping land and buildings records are primarily provisions of the Codex of Administrative Procedure of the Geodetic and Cartographic Law and regulations in the register of land and buildings. On 1 June 2017, a new Codex of Administrative Procedure came into force. In this paper have been presented the most important changes in conducting of administrative procedures in the field of geodesy at the district level after the aforementioned legal amendment. This paper touched the topics related to, among others, issued principle of resolving doubts in favor of the party (Article 7a), silent settlement of the case (Article 122a), administrative simplified proceedings (Chapter 14), appeal proceedings (Chapter 10). There have been presented examples of the most frequently conducted cases in the field of land and buildings registration in district country with particular emphasis on changes introduced by the latest legal amendments in connection with detailed regulations. The author focused on the logical interpretation of legal changes in order to show the problems connected with their application in practice (from the point of view of the proceedings and local government administration).
Application of new measurement technology for deformation study of structures in mining areas
Authors: Gruchlik Piotr , Kowalski Andrzej
Published: March 2019

Despite of classic geodetic measurements, which are used in mine surveying at the beginning, more new technology are applied to measure deformation of structures and surface in mining areas. In the article new technologies are described for utilitarian aims based on strain sensors, laser, scanners and drones. The application of new technologies are especially useful when direct access to measured object is impossible using classic methods and in situation where continuous or quasi-continuous measurement is necessary. In Central Mining Institute the research has been conducted to understand the phenomenon of surface deformation induced by underground mining comparing predicted and measured values before and after extraction. In the last 20 years the mining technology has changed and dynamics of structure and surface deformation induced by mining. The second reason of technology development is necessity to instantly inform users of land and structures about changes using for instance the Internet.
Approximation of the process of changes in deformation of land surface using artificial neural networks
Authors: Mrówczyńska Maria , Sztubecki Jacek
Published: March 2019

Artificial neural networks are an interesting method for modelling phenomena, including spatial phenomena, which are difficult to describe with known mathematical models. The properties of neural networks enable their practical application for solving such problems as: approximation, interpolation, identification and classification of patterns, compression, prediction, etc. The article presents the use of multilayer feedforward artificial neural networks for describing the process of changes in land surface deformation in the area of the Legnica-Głogów Copper Mining Centre, located in the southern part of the Fore Sudetic Monocline. Results provided by geodesic monitoring, which consists of land surveying and interpreting data obtained in this way, are undoubtedly significant in terms of identifying the impact of mining on the land surface the results of measurements carried out by precise levelling in the years 19672014 were used to determine changes in land deformation in the Legnica-Głogów Copper Mining Centre. The concept of a flexible reference system was used to assess the stability of points in the measurement and control network stabilized in order to determine vertical displacements. However, the reference system itself was identified on the basis of the critical value of the increment of the square of the norm of corrections to the observations.
Stability test of TCRP1201+ total station parameters and its setup
Authors: Odziemczyk Waldemar
Published: March 2019

Monitoring systems utilising automated electronic total stations are an important element of controlling safety levels of numerous engineering structures. In order to ensure appropriate credibility of the obtained data, it is crucial to maintain the stability of both the parameters of the used instrument as well as of its setup. This study presents the results of research on the stability of the Leica TCRP1201+ instrument’s basic parameters and three selected tripods manufactured using different materials. In the case of the total station the inspected values included Hz-collimation, V-collimation, and tilt compensation errors. Two of the head tilt components and torsion were examined for each of the tripods. The research was carried out in three-day sessions in conditions of large temperature fluctuations. Graphs presenting the changes in the studied values were supplemented with analysis of correlation between the said changes and the changes in temperature. The conclusions section of the study includes suggestions on how to avoid the negative effects of changes in the geometry of the measuring device.
Examination of vertical displacements at non-permanently fixed points
Authors: Gradka Robert
Published: March 2019

The aim of this paper was to analyze vertical displacements in four different test areas, with various types of surfaces, without permanently stabilized measuring: points and control network, using the same measurement method. The first stage involved measuring selected test areas with a number of measuring points that reliably reflect the surface and to construct the DEM. The second stage involves acquiring of a grid of control points, evenly distributed in the test area, used to assess the accuracy of the DEM. The last stage involved the analysis of the acquired results, including the application of an original program to calculate vertical displacements. In order to conduct the analysis the “blind test” was introduced, which allowed to perform formal analyses, i.e. verification of the accuracy of models constructed based on direct measurements. In this program (based on the IDW interpolation method), the study of the dependence of introducing fixed points (given measurement error), to measured survey points was carried out. It was possible to determine vertical displacements between measurements in each area, calculate the accuracy of the mapping of the terrain surface, fit the DEM into the actual terrain, as well as obtain the parameters of the approximate planes.
CFD simulation of ejector: is it worth to use real gas models?
Authors: Vu Nguyen Van , Kracik Jan
Published: March 2019

This paper presents progress of evaluation existing ejector of previous work with different gases, included real gas. This work was done by the Ansys simulation tool. The paper also discussed about the two solvers used for simulating real gas difluoromethane (R32). The results showed that entrainment ratios are almost not influenced by different gases but by the working conditions. Secondly, the solver pressure-based can obtain comparable results with the density-based one, while it is much more stable and solution converges faster than the density-based.
How much can be saved by changing the regulation of the apartment house boiler room
Authors: Novotný Petr , Hujer Jan
Published: March 2019

Boiler room for apartment building is in operation since 2009 and data are collected for cost evaluation. Question arises after a minor reconstruction. How much energy has been saved? The article selects and processes data that was available. It shows that the importance of the heating circuit pump control cannot be underestimated or overestimated. The article derives savings from gathered data.
Development of an anti-flood board to protect the interiors and exteriors of the infrastructure
Authors: Petru Michal , Srb Pavel , Sevcik Ladislav , Martinec Tomas , Kulhavy Petr
Published: March 2019

This article deals with the development of an anti-flood board to protect the interior and exterior of various infrastructures, such a houses, cottages or industrial buildings. It was designed prototypes and assembled numerical simulations. In Central Europe and in particular in the Czech Republic, floods are an integral part of the natural water cycle and cause great loss of life and great property damage. The development of new types of mobile anti-flood boards is very important as the design solution is developed for flood protection with regard to minimizing weight, cost of production, easy manipulation, simplicity and speed of installation.
New boundary conditions for fluid interaction with hydrophobic surface
Authors: Pochylý František , Fialová Simona , Havlásek Michal
Published: March 2019

Solution of both laminar and turbulent flow with consideration of hydrophobic surface is based on the original Navier assumption that the shear stress on the hydrophobic surface is directly proportional to the slipping velocity. In the previous work a laminar flow analysis with different boundary conditions was performed. The shear stress value on the tube walls directly depends on the pressure gradient. In the solution of the turbulent flow by the k-ε model, the occurrence of the fluctuation components of velocity on the hydrophobic surface is considered. The fluctuation components of the velocity affect the size of the adhesive forces. We assume that the boundary condition for ε depending on the velocity gradients will not need to be changed. When the liquid slips over the surface, non-zero fluctuation velocity components occur in the turbulent flow. These determine the non-zero value of the turbulent kinetic energy K. In addition, the fluctuation velocity components also influence the value of the adhesive forces, so it is necessary to include these in the formulation of new boundary conditions for turbulent flow on the hydrophobic surface.
Dynamic interferometric measurement with extended unambiguity range in flow measurement
Authors: Psota Pavel , Doleček Roman , Lédl Vít , Vít Tomáš
Published: March 2019

This paper reports on a new approach to measure dynamic processes in fluid mechanics using interferometry with extended dynamic range. A key factor is the use of two wavelengths and the recording of interferograms from both wavelengths in one frame. Phase map evaluation is based on the Fourier transform. The difference between the obtained phase fields creates a synthetic phase whose dynamic range also covers large changes of the measured quantity.
Numerical simulation of airflow around the evaporator in the closed space
Authors: Puchor Tomáš , Banovčan Roman , Lenhard Richard
Published: March 2019

The article deals with a numerical simulation of the forced airflow around a evaporator with the finned tubes in the electrotechnical box, by finite volume method in the program ANSYS Workbench. The work contains an analysis of the impact of forced airflow on the evaporator with the various seated the electrical components. The aim of the work is to find out the most effective way of heat dissipation by forced convection from the electrical components in the closed space with lowest pressure loss.
Manipulation of the swirling flow instability in hydraulic turbine diffuser by different methods of water injection
Authors: Rudolf Pavel , Litera Jiří , Alejandro Ibarra Bolanos Germán , Štefan David
Published: March 2019

Vortex rope, which induces substantial pressure pulsations, arises in the draft tube (diffuser) of Francis turbine for off-design operating conditions. Present paper focuses on mitigation of those pulsations using active water jet injection control. Several modifications of the original Susan-Resiga’s idea were proposed. All modifications are driven by manipulation of the shear layer region, which is believed to play important role in swirling flow instability. While some of the methods provide results close to the original one, none of them works in such a wide range. Series of numerical experiments support the idea that the necessary condition for vortex rope pulsation mitigation is increasing the fluid momentum along the draft tube axis.
Processing of Cells’ Trajectories Data for Blood Flow Simulation Model*
Authors: Slavík Martin , Kovalčíková Kristína , Bachratý Hynek , Bachratá Katarína , Smiešková Monika
Published: March 2019

Simulations of the red blood cells (RBCs) flow as a movement of elastic objects in a fluid, are developed to optimize microfluidic devices used for a blood sample analysis for diagnostic purposes in the medicine. Tracking cell behaviour during simulation helps to improve the model and adjust its parameters. For the optimization of the microfluidic devices, it is also necessary to analyse cell trajectories as well as likelihood and frequency of their occurrence in a particular device area, especially in the parts, where they can affect circulating tumour cells capture. In this article, we propose and verify several ways of processing and analysing the typology and trajectory stability in simulations with single or with a large number of red blood cells (RBCs) in devices with different topologies containing cylindrical obstacles.
Numerical simulation of minor losses coefficient on the example of elbows
Authors: Emil Smyk , Dariusz Mrozik , Łukasz Olszewski , Kazimierz Peszyński
Published: March 2019

Determining of minor losses coefficient is very complicated problem. Analytical methods are often very difficult and experimental methods are very expensive and time-consuming. Consequently, the use of numerical methods seems to be a good solution, but there are no publications describing this issue. Therefore, the paper is describing the numerical method of determining the minor loss coefficient ξ on the example of elbows with circular cross-section.
Experimental study of the flow field disturbance in the vicinity of single sensor hot-wire anemometer
Authors: Sobczyk Jacek
Published: March 2019

Preliminary experimental study of the flow field disturbance in the vicinity of single sensor normal hot-wire anemometer (SN) probe was carried out. Regular 2D particle image velocimetry (PIV) setup equipped with micro lens and distance rings was applied to measurements of macroscopic flow around microscopic elements. Experimental results revealed complexity of the flow around the wire and its strong dependence on both – the velocity magnitude and the probe orientation in relation to freestream direction. Examination of the velocity fields in the vicinity of SN probe suggests that it may not be such a “point” measurement method as it is commonly assumed to be.
Analysis of mean and fluctuating helicity measured by TomoPIV in swirling jet
Authors: Stepanov Rodion , Frick Peter , Dulin Vladimir , Markovich Dmitriy
Published: March 2019

Important role of helicity was theoretically predicted for the generation of large-scale magnetic fields and atmospheric vortices. Helicity can lead to a reduction of turbulent dissipation in the atmosphere or in a specific constrained flow, e.g. in pipe. We use the TomoPIV data (42 cube of grid points, resolution 0.84 mm) to measure 3D velocity field of turbulent swirling flows. We study spatial distribution of the mean and fluctuating components of energy and helicity. We find that helical turbulence excitation and decay along stream of the jet strongly depend on the inflow swirl. We observe spatial separation of turbulent flow with different sign of helicity while integrated values are conserves. It is shown that large scale swirling flow induces helicity at the small scales. Our results bring valuable materials for benchmark the modern numerical simulations with turbulent closure technique.
Impact of different thickness of the smooth heated surface on flow boiling heat transfer
Authors: Strąk Kinga , Piasecka Magdalena
Published: March 2019

This paper presents a comparison of the performance of three smooth heated surfaces with different thicknesses. Analysis was carried out on an experimental setup for flow boiling heat transfer. The most important element of the setup was the test section with a rectangular minichannel, 1.7 mm deep, 16 mm wide and 180 mm long, oriented vertically. The heated element for the FC-72 Fluorinert flowing in the minichannel was designated as a Haynes-230 alloy plate (0.10 mm and 0.45 mm thick) or a Hastelloy X alloy plate (0.65 mm thick). Infrared thermography was used to measure the temperature of the outer plate surface. The local values of the heat transfer coefficient for stationary state conditions were calculated using a simple one-dimensional method. The experimental results were presented as the relationship between the heat transfer coefficients in the subcooled boiling region and the distance along the minichannel length and boiling curves. The highest local heat transfer coefficients were recorded for the surface of 0.10 mm thick heated plate at the outlet and 0.45 mm thick plate at the minichannel inlet. All boiling curves were typical in shape.
The heat transfer coefficient determination with the use of the Beck-Trefftz method in flow boiling in a minichannel
Authors: Strąk Kinga , Maciejewska Beata , Piasecka Magdalena
Published: March 2019

In this paper, the solution of the two-dimensional inverse heat transfer problem with the use of the Beck method coupled with the Trefftz method is proposed. This method was applied for solving an inverse heat conduction problem. The aim of the calculation was to determine the boiling heat transfer coefficient on the basis of temperature measurements taken by infrared thermography. The experimental data of flow boiling heat transfer in a single vertical minichannel of 1.7 mm depth, heated asymmetrically, were used in calculations. The heating element for two refrigerants (FC-72 and HFE-7100, 3M) flowing in the minichannel was the plate enhanced on the side contacting with the fluid. The analysis of the results was performed on the basis of experimental series obtained for the same heat flux and two different mass flow velocities. The results were presented as infrared thermographs, heated wall temperature and heat transfer coefficient as a function of the distance from the minichannel inlet. The results was discussed for the subcooled and saturated boiling regions separately.
Numerical Study of Shaft-Seal Parameters for Various Geometry Configurations and Operation Regimes
Authors: Straka Petr
Published: March 2019

The contribution deals with numerical modelling of flow through the shaft labyrinth seal for various geometric configurations and operating states. The objective is to obtain dependency of the mass flow rate through the seal and the outlet flow angle from the seal on the pressure ratio and the rotation speed for various seal clearances and other geometrical parameters. The results will be used as a background for modification of the test-rig for axial turbine stage.
Local velocity scaling in an impeller discharge flow in T400 vessel agitated by tooth impeller in a fully turbulent region
Authors: Šulc Radek , Ditl Pavel , Fořt Ivan , Jašíkova Darina , Kotek Michal , Kopecký Václav , Kysela Bohuš
Published: March 2019

Hydrodynamics and flow field were measured in an agitated vessel using 2-D Time Resolved Particle Image Velocimetry (2-D TR PIV). The experiments were carried out in a fully baffled cylindrical flat bottom vessel 400 mm in inner diameter agitated by a tooth impeller 133 mm in diameter. The velocity fields were measured in the impeller discharge flow for impeller rotation speeds from 300 rpm to 700 rpm and three liquids of different viscosities (i.e. (i) distilled water, ii) a 28% vol. aqueous solution of glycol, and iii) a 43% vol. aqueous solution of glycol), corresponding to the impeller Reynolds number in the range 68 000 < Re < 221 000. This Re range secures the fully-developed turbulent flow of agitated liquid. In accordance with the theory of mixing, the dimensionless mean and fluctuation velocities in the measured directions were found to be constant and independent of the impeller Reynolds number. On the basis of the test results the spatial distributions of dimensionless velocities were calculated. The radial turbulence intensity was found to be in the majority in the range from 0.3 to 0.9, which corresponds to the high level of this quantity.
Using the adsorption chillers for utilisation of waste heat from rotary kilns
Authors: Sztekler Karol , Kalawa Wojciech , Nowak Wojciech , Stefański Sebastian , Krzywański Jarosław , Grabowska Karolina
Published: March 2019

Waste heat utilisation and its reclamation is important for increasing the efficiency of the electric power production and for decreased consumption of primary energy. Waste heat can be utilised for the electric power production or for manufacturing and processing purposes. According to long-term forecasts, the consumption of electric power with current consumption of about 150 TWh, can be increased to about 230 TWh in around 2040, what may lead to the increased energy consumption from fuels and the increased emission of harmful contaminants to the atmosphere. The cement subsector, next to the glass industry, is among the most power-consuming industries, and it consumes about 12-15% of total energy consumed by industry in total, whereas the CO2 emission from such industry exceeds about 5% in worldwide scale. In the cement sector, there is an increasing need for useful reclamation of waste energy, in order to obtain high energy-saving factors, and hence the financial and environmental benefits. In this paper the chances for waste energy reclamation from a rotary kiln are presented, with means of the used adsorption chillers.
Instantaneous fluid force acting on a circular cylinder control by a small rod
Authors: Tsutsui Takayuki
Published: March 2019

Two unique bluff body flow control methods using a small rod have been proposed in previous studies. The first is the forced reattachment method, which is a type of separated shear layer control. This method reduces drag and generates a lift. The second is the front rod method, which involves the placement of a small rod upstream of the bluff body to control the incoming flow and reduce drag. This paper describes the features of the instantaneous fluid force achieved using these flow control methods. These methods were experimentally applied to a cylinder, and the instantaneous pressure field and the flow visualizations of these methods are presented. When the forced reattachment method was applied, a lift force was generated, and the vibration was less than that in the case of the front rod method. When the front rod method was applied, the drag force was reduced by over 50% in comparison with those in the uncontrolled case and the case with the forced reattachment method.
On 3D Flow Structure of the Boundary Layer on the Suction Side of a Plate
Authors: Uruba Václav , Procházka Pavel , Skála Vladislav
Published: March 2019

Experimental study of the structure of the boundary layer on the suction side of a plate is to be presented. The flat plate with rounded edges and angle of attack of 7° is used. The boundary layer flow will be explored using the time-resolved PIV technique, measuring plane was located very close to the wall. Analysis of the flow dynamics is to be presented using the POD technique applied on both velocity and vorticity fields.
Description of saturation curves and boiling process of dry air
Authors: Vestfálová Magda , Petříková Markéta , Šimko Martin
Published: March 2019

Air is a mixture of gases forming the gas wrap of Earth. It is formed by dry air, moisture and other pollutants. Dry air is a substance whose thermodynamic properties in gaseous state, as well as the thermodynamic properties of its main constituents in gaseous state, are generally known and described in detail in the literature. The liquid air is a bluish liquid and is industrially used to produce oxygen, nitrogen, argon and helium by distillation. The transition between the gaseous and liquid state (the condensation process, resp. boiling process), is usually displayed in the basic thermodynamic diagrams using the saturation curves. The saturation curves of all pure substances are of a similar shape. However, since the dry air is a mixture, the shapes of its saturation curves are modified relative to the shapes corresponding to the pure substances. This paper deals with the description of the dry air saturation curves as a mixture, i.e. with a description of the process of phase change of dry air (boiling process). The dry air saturation curves are constructed in the basic thermodynamic charts based on the values obtained from the literature. On the basis of diagrams, data appearing in various publications are interpreted and put into context with boiling process of dry air.
Numerical and experimental study of fluid flow in simplified blade cascade with prescribed harmonic motion
Authors: Vimmr Jan , Bublík Ondřej , Pecka Aleš , Pešek Luděk , Procházka Pavel
Published: March 2019

In this paper, a numerical simulation and experimental measurements of compressible viscous fluid flow in simplified blade cascade are compared. The cascade consists of five flat plates three of which perform prescribed harmonic motion. The computed unsteady velocity field is compared with experimental measurements at selected points. Moreover, the power spectral density corresponding to the frequency of harmonic motion is computed for both the numerical and experimental data and compared. The numerical simulation was performed using the developed in-house CFD software based on the discontinuous Galerkin method, which offers high order of accuracy.
Flow behaviour and structure of heterogeneous particles-water mixture in horizontal and inclined pipes
Authors: Vlasák Pavel , Chára Zdeněk , Konfršt Jiří
Published: March 2019

The effect of slurry velocity and mean concentration of heterogeneous particle-water mixture on flow behaviour and structure in the turbulent regime was studied in horizontal and inclined pipe sections of inner diameter D = 100 mm. The stratified flow pattern of heterogeneous particle-water mixture in the inclined pipe sections was revealed. The particles moved mostly near to the pipe invert. Concentration distribution in ascending and descending vertical pipe sections confirmed the effect of fall velocity on particle-carrier liquid slip velocity and increase of in situ concentration in the ascending pipe section. Slip velocity in two-phase flow, which is defined as the velocity difference between the solid and liquid phase, is one of mechanism of particle movement in two-phase flow. Due to the slip velocity, there is difference between transport and in situ concentrations, and the slip velocity can be determined from comparison of the in situ and transport concentration. For heterogeneous particle-water mixture flow the slip velocity depends on the flow structure.
PIV measurements of airflow past multiple cylinders
Authors: Wodziak Waldemar , Sobczyk Jacek
Published: March 2019

Flow characteristics in vicinity of six circular cylinders aligned inline was investigated experimentally by means of PIV method. Experiments were conducted in a low speed closed circuit wind tunnel. Inflow velocity was 1.2 m/s which corresponds to Re=1600 based on the cylinder diameter. Spacing ratio between cylinders L/D was 1.5. Instantaneous and averaged velocity fields were presented. Experiments were designed in order to use their results as a test case for future numerical calculations.
Pilot study about the micro hydropower generation by use of flow induced vibration phenomenon
Authors: Yokoi Yoshifumi
Published: March 2019

In order to construct a micro power generation system using a piezo-electric element, power generation was tried using excitation oscillation of the bluff cylinder by the vortex shedding from the bluff cylinder. The bluff cylinder consists of a board spring section in which the piezo-electric element was attached, and a body section. The bluff cylinder was inserted into the water flow, the shape and the submersion depth of the bluff cylinder, and the flow velocity were varied, and the power generation characteristic was investigated. As a result, it was found that it can generate electricity by vortex excitation. It was found that the length and the submersion depth of the body section influence power generation. It was shown that the power generation characteristic changes with cross-sectional shape of the bluff cylinder. The most suitable state was the case where the submersion depth was set to 140 mm with a circular cylinder with a span length of 250 mm. It is important to choose the power generation object which suited the use purpose.
A vendor–buyer inventory model with lot-size and production rate dependent lead time under time value of money
Authors: Sarkar Sumon , Giri Bibhas Chandra , Sarkar Ashis Kumar
Published: March 2019

The paper studies an integrated vendor–buyer model with shortages under stochastic lead time which is assumed to be variable but depends on the buyer’s order size and the vendor’s production rate. The replenishment lead time and the market demand uncertainty are assumed to be reduced by changing the regular production rate of the vendor at the risk of paying additional cost. Shortages are partially backlogged and the backlogging rate depends on the length of the buyer’s replenishment lead time. The proposed model is formulated to obtain the net present value (NPV) of the expected total cost of the integrated system through optimization of (i) the buyer’s order quantity, (2) the buyer’s safety factor, and (3) the vendor’s production rate. Theoretical results are derived to demonstrate the existence and uniqueness of the optimal solution. Through extensive numerical study, some valuable managerial insights are obtained.
Supraglottiskarzinom: Erfahrungen mit der transoralen
Roboter-Chirurgie
Authors: Kapsreiter Markus
Published: March 2019

Karabulut B et al. Comparison of functional and oncological treatment outcomes
after transoral robotic surgery and open surgery for supraglottic laryngeal
cancer. J Laryngol Otol 2018; 132: 832–836

Die Behandlungsmöglichkeiten eines Supraglottiskarzinoms umfassen offene
Supraglottis-Laryngektomie, transorale Lasertherapie, transorale
Roboterchirurgie und Chemotherapie. Ärzte der HNO-Klinik des
Ümraniye-Krankenhauses in Istanbul verglichen die Behandlungsergebnisse bei
Patienten mit supraglottischen Tumoren des Larynxkarzinoms, die mittels
einer transoralen robotischen Laryngektomie und einer offenen Laryngektomie
behandelt wurden.