scholarly journals Analysis of Omni-directivity Error of Electromagnetic Field Probe using Isotropic Antenna

2016 ◽  
Vol 16 (6) ◽  
pp. 287-293
Author(s):  
Rene Hartansky
Keyword(s):  
Electromagnetic Field ◽  
Systematic Error ◽  
Shape Change ◽  
Mutual Arrangement ◽  
Directional Characteristic ◽  
Frequency Dependent ◽  
Directional Characteristics ◽  
Different Types

Abstract This manuscript analyzes the omni-directivity error of an electromagnetic field (EM) probe and its dependence on frequency. The global directional characteristic of a whole EM probe consists of three independent directional characteristics of EM sensors - one for each coordinate. The shape of particular directional characteristics is frequency dependent and so is the shape of the whole EM probe’s global directional characteristic. This results in systematic error induced in the measurement of EM fields. This manuscript also contains quantitative formulation of such errors caused by the shape change of directional characteristics for different types of sensors depending on frequency and their mutual arrangement.

Movement of Calcium Ions and their Role in the Activation of Platelets

1978 ◽  
Vol 40 (02) ◽  
pp. 212-218 ◽  
Author(s):  
P Massini ◽  
R Käser-Glanzmann ◽  
E F Lüscher
Keyword(s):  
Plasma Membrane ◽  
Platelet Activation ◽  
Calcium Ions ◽  
Binding Sites ◽  
Shape Change ◽  
Release Reaction ◽  
Dense Bodies ◽  
Activated Platelets ◽  
Different Types ◽  
Ca Ions

SummaryThe increase of the cytoplasmic Ca-concentration plays a central role in the initiation of platelet activation. Four kinds of movements of Ca-ions are presumed to occur during this process: a) Ca-ions liberated from membranes induce the rapid shape change, b) Vesicular organelles release Ca-ions into the cytoplasm which initiate the release reaction, c) The storage organelles called dense bodies, secrete their contents including Ca-ions to the outside during the release reaction, d) At the same time a rearrangement of the plasma membrane occurs, resulting in an increase in its permeability for Ca-ions as well as in an increase in the number of Ca-binding sites.Since most processes occurring during platelet activation are reversible, the platelet must be equipped with a mechanism which removes Ca-ions from the cytoplasm. A vesicular fraction obtained from homogenized platelets indeed accumulates Ca actively. This Ca- pump is stimulated by cyclic AMP and protein kinase; it may be involved in the recovery of platelets after activation.It becomes increasingly clear that the various manifestations of platelet activation are triggered by a rise in the cytoplasmic Ca2+-concentration. The evidence for this and possible mechanisms involved are discussed in some detail in the contributions by Detwiler et al. and by Gerrard and White to this symposium. In this article we shall discuss four different types of mobilization of Ca-ions which occur in the course of the activation of platelets. In addition, at least one transport step involved in the removal of Ca2+ must occur during relaxation of activated platelets.

Study of the significance of the ph of the substrate of the biogas installation during treating it with a low-frequency electromagnetic field

2021 ◽  
pp. 106-114
Author(s):  
M.M. Zablodsky ◽  
◽  
P.B. Klendiy ◽  
O. P. Dudar ◽  
◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Induction ◽  
Ph Value ◽  
Low Frequency ◽  
Decisive Role ◽  
Methane Fermentation ◽  
Different Types ◽  
Substrate Ph ◽  
Fermentation Substrate ◽  
Industrial Frequency

The article considers the issue of studying the value of pH, substrate in the process of methane fermentation in the mesophilic regime and the influence of the electromagnetic field of industrial frequency. The aim is to investigate the influence of electromagnetic fields on the pH value of the substrate during fermentation. Different types of microorganisms are involved in the process of methanogenesis, and the decisive role in it is played by methane-forming archaea, which are most sensitive to pH and should be in the range of 6.5 - 8. Therefore, it is necessary to check the effect of low frequency electromagnetic field on substrate pH. The study was performed for 25 days on two substrates, one of which was exposed to a low-frequency electromagnetic field with an electromagnetic induction of 3.5 mT. The research results show that the pH value of the substrate exposed to the electromagnetic field during the methane fermentation process was within acceptable limits, and the second substrate decreased, that is, it was acidified. Key words: methane fermentation, substrate, pH value, electromagnetic field

scholarly journals Ecología y evolución de la polinización por engaño

2017 ◽  
pp. 57
Author(s):  
Reyna A. Castillo ◽  
Carlos Cordero ◽  
César A. Domínguez
Keyword(s):  
Theoretical Framework ◽  
Evolutionary Perspective ◽  
Frequency Dependent ◽  
Selective Pressures ◽  
Deceit Pollination ◽  
Different Types ◽  
Main Components

In this work we reviewed the biology of deceit pollination from an ecological and evolutionary perspective. Species pollinated by deceit are characterized because a percentage of their flowers do not produce rewards, and therefore these species get the advantages derived from pollinators without paying the costs. In this review, we first described the different types of deceit occurring in nature, as well as the selective pressures involved on its evolution. We then reviewed and discussed the theoretical framework of deceit pollination and the relevant aspects of its main components: frequency-dependent se lection, flower resemblance, and the sensorial capacities of pollinators.

Diacylglycerols and PMA induce actin polymerization and distinct shape changes in lymphocytes: relation to fluid pinocytosis and locomotion

1989 ◽  
Vol 93 (3) ◽  
pp. 457-465
Author(s):  
H.U. Keller ◽  
V. Niggli ◽  
A. Zimmermann
Keyword(s):  
Actin Polymerization ◽  
Shape Change ◽  
Second Messengers ◽  
Cell Periphery ◽  
Response Curves ◽  
Blood Lymphocytes ◽  
Different Types ◽  
Net Uptake ◽  
Very High ◽  
Shape Changes

Shape changes have been determined in human blood lymphocytes stimulated with OAG, diC8, PMA, colchicine or the hexapeptide fNLPNTL in short-term assays (30 min). Distinct types of shape-change responses were observed. Colchicine was active in generating a relatively small proportion of polarized lymphocytes (front-tail polarity). OAG, diC8 and PMA produced different types of shape change (non-polar cells with surface projections), and these were closely associated with an increase in actin polymerization and a shift of F-actin into the projections at the cell periphery. The diacylglycerols OAG and diC8 produced biphasic dose-response curves leading to rounding up of cells at very high stimulant concentrations. PMA produced no comparable biphasic response when tested over a much wider concentration range. Though the nonpolar cells with surface projections generated by OAG, diC8 or PMA showed vigorous shape changes, they lacked significant locomotor activity. alpha-Phorbol, 4 alpha-PDD, lumicolchicine or fNLPNTL were inactive. Small blood lymphocytes stimulated by OAG, diC8 or PMA showed a very small increase in the net uptake of FITC-dextran by fluid pinocytosis. Unlike neutrophils, which show a high net uptake, lymphocytes did not concentrate FITC-dextran in large granules, indicating that they do not develop a ‘storage’ compartment in the form of large vesicles. However, small fluorescent spots were consistently found in at least a fraction of blood lymphocytes. The results indicate that stimulated surface movement may be instrumental in fluid pinocytosis. Diacylglycerols may act as second messengers to induce pinocytosis, shape changes and altered actin polymerization in lymphocytes.

Springback Analysis in Hybrid Material Deformation

2018 ◽  
Author(s):  
Elizabeth M. Mamros ◽  
Chetan P. Nikhare
Keyword(s):  
Hybrid Materials ◽  
Material Properties ◽  
Shape Change ◽  
Single Layer ◽  
Metal Composite ◽  
Composite Sandwich ◽  
Composite Layers ◽  
Different Types ◽  
Reduction Methods ◽  
Manufacturing Problems

In the automotive and aerospace industries, cost and overall weight are major opponents that are affecting design opportunities. Research to investigate possible cost and weight reduction methods is continuously being performed focusing especially on the hybrid materials being used to manufacture parts. Currently, different types of metals with polymers are being chosen to make punched parts, but the deformation of the materials has not been fully investigated. The way that the material deforms will dictate the material properties held by the subsequent parts. Without knowing these material properties, it is difficult to prevent manufacturing problems during various processes. One major problem encountered when forming solid metal parts is that when the die is removed, the deformed parts change shape due to the elastic properties of the material. This shape change is called springback. This undesirable result causes the parts to be the incorrect shape and to not align correctly during assembly. One possible solution would be to investigate the material properties of trilayer hybrid materials consisting of metal and composite layers adjoined by adhesive. Trilayer channels will be tested by punching and measuring the resulting springback. Two different trilayer design setups will be tested, composite metal composite sandwich and metal composite metal sandwich, and will be compared with the deformation in a single layer metal channel. The outcome of these tests will determine which trilayer design will have the greatest success in reducing the undesirable springback effects.

Simulation Research on Matching of Spray and Combustion Chamber Geometry in Diesel Engine

2011 ◽  
Vol 199-200 ◽  
pp. 193-197 ◽  
Author(s):  
Cheng Cheng Zhang ◽  
Qian Wang ◽  
Zhi Xia He ◽  
Ping Jiang
Keyword(s):  
Temperature Field ◽  
Diesel Engine ◽  
Combustion Chamber ◽  
Shape Change ◽  
Emission Characteristics ◽  
Mixed Gas ◽  
Combustion Chambers ◽  
Simulation Research ◽  
Different Types ◽  
Combustion Processes

In order to investigate the influence of combustion chamber geometry on spray and combustion characteristics in diesel engine, universal CFD software STAR-CD is applied to simulate the combustion processes in three different types of combustion chambers of diesel engine. The effect of combustion chamber geometry on in–cylinder air motion, temperature field and exhaust emissions are researched in this paper. Comparing with experimental results, calculation models are proved to be validity. The results show that differences of combustion chamber shape change the characteristic of flow field in cylinder, which affects the formation of mixed gas and determines the combustion and emission characteristics.

scholarly journals The impact of different types of wave action on the destruction of stable gel-containing water-oil emulsions

2018 ◽  
Vol 84 (7) ◽  
pp. 7-15
Author(s):  
Yu. N. Romanova ◽  
N. S. Musina ◽  
T. A. Maryutina
Keyword(s):  
Electromagnetic Field ◽  
Original Method ◽  
Complete Separation ◽  
Wave Action ◽  
Permanent Magnetic Field ◽  
Oil Emulsion ◽  
Real Samples ◽  
Different Types ◽  
Oil Emulsions ◽  
The Impact

An original method of wave sample preparation of commercial stable gel-containing water-oil emulsions is developed to separate water and oil phases present in the composition for their subsequent analysis. Real samples of commercial stable water-oil emulsions, differing in composition (water content, «gel», iron sulphide and mechanical impurities) are studied. The effect of the intensity and duration of the wave action of different nature on the completeness of phase separation in the real samples of commercial emulsions of different composition are studied. A possibility in principal of isolating oil and water phases from the composition of stable water-oil emulsions stabilized by gel-like associates under wave action (magnetostatic and electromagnetic field, ultrasonic vibrations) is shown. When the water-oil emulsion is exposed to a permanent magnetic field with an induction range of 0.1 – 0.57 T for 1 – 3 minutes, the degree of water isolation from the emulsion samples under study varies from 48 % to 71 %, depending on the composition of the emulsion under study. Similar results are obtained under the effect of electromagnetic field with an induction of 0.1 – 1.0 T. For complete separation of water and oil phases from gel-containing water-oil emulsions, we proposed to use ultrasonic treatment combined with addition of a suspension prepared from aluminum oxide nanopowder in acetonitrile which provide complete destruction of «gel» and 100 % separation of water and oil phases.

scholarly journals Technical note: CO<sub>2</sub> is not like CH<sub>4</sub> – limits of and corrections to the headspace method to analyse <i>p</i>CO<sub>2</sub> in water

2020 ◽  
Author(s):  
Matthias Koschorreck ◽  
Yves T. Prairie ◽  
Jihyeon Kim ◽  
Rafael Marcé
Keyword(s):  
Systematic Error ◽  
Headspace Analysis ◽  
Technical Note ◽  
Simple Application ◽  
Carbonate System ◽  
Experimental Conditions ◽  
Potential Error ◽  
Chemical Theory ◽  
Different Types ◽  
Chemical Equilibration

Abstract. Headspace analysis of CO2 frequently has been used to quantify the concentration of CO2 in freshwater. According to basic chemical theory, not considering chemical equilibration of the carbonate system in the sample vials will result in a systematic error. In this paper we provide a method to quantify the potential error resulting from simple application of Henry's law to headspace CO2 samples. By analysing the potential error for different types of water and experimental conditions we conclude that the error incurred by headspace analysis of CO2 is less than 5 % for samples with pH 

Enriching Agronomic Experiments with Data Provenance

2017 ◽  
Vol 8 (3) ◽  
pp. 21-38
Author(s):  
Sergio Manuel Serra da Cruz ◽  
Jose Antonio Pires do Nascimento
Keyword(s):  
Systematic Error ◽  
Statistical Data ◽  
Scientific Workflow ◽  
Computational Experiments ◽  
Data Provenance ◽  
Computational Approaches ◽  
Integration Platform ◽  
Workflow System ◽  
Scientific Experiments ◽  
Different Types

Reproducibility is a major feature of Science. Even agronomic research of exemplary quality may have irreproducible empirical findings because of random or systematic error. The ability to reproduce agronomic experiments based on statistical data and legacy scripts are not easily achieved. We propose RFlow, a tool that aid researchers to manage, share, and enact the scientific experiments that encapsulate legacy R scripts. RFlow transparently captures provenance of scripts and endows experiments reproducibility. Unlike existing computational approaches, RFlow is non-intrusive, does not require users to change their working way, it wraps agronomic experiments in a scientific workflow system. Our computational experiments show that the tool can collect different types of provenance metadata of real experiments and enrich agronomic data with provenance metadata. This study shows the potential of RFlow to serve as the primary integration platform for legacy R scripts, with implications for other data- and compute-intensive agronomic projects.

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