scholarly journals Analysis of a method for measuring deposit impedance parameters using charge amplifier and lock-in voltmeter

2021 ◽  
Author(s):  
Dariusz Robert Wiśniewski

Parameters such as capacitance and conductivity are measured to describe the properties of a medium, including its moisture content. These methods do not deliver highly accurate results in materials that are characterized by low homogeneity, varied porosity, high conductivity and high water content. This study proposes a more accurate method for estimating the parameters of any medium. In the experimental setup, a charge amplifier and a phase-sensitive voltmeter were applied to determine resistance and capacitance parameters of a medium based on the signals received by the measuring system. The proposed method can be applied to non-homogeneous media containing both dielectric and conductive materials. The described measuring system is composed of two flat electrodes whose size can be adapted to the dimensions of the analyzed medium. A method for processing the sensing signal to determine the impedance characteristics of a medium with the use of a phase-sensitive voltmeter was described. The measuring system was modeled in Matlab/Simulink, and the results were discussed.   

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1077-1088 ◽  
Author(s):  
Kaarina Kekäläinen ◽  
Henrikki Liimatainen ◽  
Floriane Biale ◽  
Jouko Niinimäki

AbstractCellulose nanofibrils (NF) are usually produced by disintegration processes at low solids content (<5%). However, the high water content reduces the capacity of production, increases the transportation costs of NF suspensions and narrows the possible applications of NF. The goal of the present study was to test a grinding technique based on oscillatory ball milling. Bleached kraft pulp cellulose was nanofibrillated at high solids contents (≥50%), which was obtained from 2,2,6,6-tetramethylpiperidine-1-oxyl radical-oxidized pulp. The grinding method was only successful when the charge density was at least 0.5 mmol g-1. NFs and cellulose nanocrystals were identified at a charge density of 1.1 mmol g-1and a solids content of 50%. The size reduction of the formed particles was observed by means of flow fractionation and imaging and viscosity measurements after increasing the charge density from 0.3 to 1.1 mmol g-1. A solids content increment and a charge density decrement resulted in particles with low aspect ratio rather than in nanofibrils. Wide angle X-ray diffraction measurements showed the transformation of crystalline cellulose into amorphous material in the case of grounding at 93% solids content.


2011 ◽  
Vol 250-253 ◽  
pp. 3785-3789
Author(s):  
Qiang Qiang Miao ◽  
Zheng Han Chen ◽  
Qing Qing Zhu ◽  
Zhi Hua Yao ◽  
Jun Hao Zhang

Measuring system of soil moisture and water bedload LGD-Ⅲ was used in those tests . Infiltration law of one dimensional vertical soil poles were carried out profound studies,under different density and a constant water head . At the same time,the course of wetness front along with time pass away, infiltration law along with time pass away and different high water content along with time pass away were made a comprehensive studies , under different dry density. According to a great deal of test data, the relationship between wetness front and time was given to a function under different dry density.


Holzforschung ◽  
2012 ◽  
Vol 66 (7) ◽  
pp. 877-881 ◽  
Author(s):  
Jukka Antikainen ◽  
Tapani Hirvonen ◽  
Jussi Kinnunen ◽  
Markku Hauta-Kasari

Abstract Heartwood detection for Scotch pine (Pinus sylvestris) is possible via several different methods, such as X-ray and infrared cameras. X-ray systems are often very expensive and need huge modifications of sawmill equipment for implementation. Infrared cameras are more affordable but can only be applied for fresh samples with high water content. This article describes a novel imaging method for heartwood detection for Scotch pine, which is based on the fluorescence information emitted of pinosylvin type stilbene and its monomethyl ether. Fluorescence imaging is a low-cost method for measuring heartwood content in real time on an industrial line. The method is applicable for fresh and dried samples. This paper will show the results of fluorescence matrices of Scotch pine. Measurements were made with a bispectrometer system to obtain suitable wavelengths for the excitation and detection of fluorescence. A reliable measuring system is described, which is suited for on-line measurements on an industrial line. An algorithm will also be presented, which is useful for quantification of heartwood and sapwood.


2014 ◽  
Vol 953-954 ◽  
pp. 1467-1470
Author(s):  
Guang Fu Li

When oil field entered into the high water content period, liquid production capacity of oil wells had large fluctuation and poor regularity, which leaded to the error of human reading and bottom water density in the measurement process, the difficulty of measuring oil wells is gradually increasing. Therefore, the measurement of low producing well has aroused extensive attention. How to research and establish a suitable measuring device for low producing well, improve measurement accuracy and management level of intermittent oil wells has become a serious problem in oil production. Using automatic oil measuring system can improve the accuracy of measurement, which achieved the automatic measurement for the fluid and gas production and moisture content of oil wells.


Author(s):  
A. Bykov ◽  
D. Palatov ◽  
I. Studenov ◽  
D. Chupov

The article provides information about the features of spring feeding of sterlet in the spawning grounds of the middle course of the Northern Dvina river in may 2019. The main and secondary groups of forage objects in the diet of this species of sturgeon are characterized. The article considers the variability of the sterlet food composition with an increase in the size of fish from 30 to 60 cm. In the process of fish growth in the diet of the Severodvinsk sterlet, the main components in terms of occurrence and mass in all size groups are the larvae of Brooks and chironomids. A minor occurrence was the larvae of midges, biting midges, stoneflies, mayflies and small clams. To random and seasonal food are the larvae of water bugs, butterflies, flies, beetles and eggs of other fish. The feeding intensity of the smaller sterlet (30–40 cm) was significantly higher than that of the fish in the size groups 40–50 and 50–60 cm. Fundamental changes in the diet of the Severodvinsk sterlet for the main food objects for more than sixty years of observations have not been established. During periods of high water content of the Northern Dvina due to seasonal changes in the structure of benthic communities, the value of Brooks in the diet of sterlet increases and the proportion of chironomids decreases.


2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.


2019 ◽  
Vol 67 (7) ◽  
pp. 4803-4810 ◽  
Author(s):  
Xiong Wang ◽  
Tao Qin ◽  
Yexian Qin ◽  
Ahmed H. Abdelrahman ◽  
Russell S. Witte ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shun-ichiro Karato ◽  
Bijaya Karki ◽  
Jeffrey Park

AbstractOceans on Earth are present as a result of dynamic equilibrium between degassing and regassing through the interaction with Earth’s interior. We review mineral physics, geophysical, and geochemical studies related to the global water circulation and conclude that the water content has a peak in the mantle transition zone (MTZ) with a value of 0.1–1 wt% (with large regional variations). When water-rich MTZ materials are transported out of the MTZ, partial melting occurs. Vertical direction of melt migration is determined by the density contrast between the melts and coexisting minerals. Because a density change associated with a phase transformation occurs sharply for a solid but more gradually for a melt, melts formed above the phase transformation depth are generally heavier than solids, whereas melts formed below the transformation depth are lighter than solids. Consequently, hydrous melts formed either above or below the MTZ return to the MTZ, maintaining its high water content. However, the MTZ water content cannot increase without limit. The melt-solid density contrast above the 410 km depends on the temperature. In cooler regions, melting will occur only in the presence of very water-rich materials. Melts produced in these regions have high water content and hence can be buoyant above the 410 km, removing water from the MTZ. Consequently, cooler regions of melting act as a water valve to maintain the water content of the MTZ near its threshold level (~ 0.1–1.0 wt%). Mass-balance considerations explain the observed near-constant sea-level despite large fluctuations over Earth history. Observations suggesting deep-mantle melting are reviewed including the presence of low-velocity anomalies just above and below the MTZ and geochemical evidence for hydrous melts formed in the MTZ. However, the interpretation of long-term sea-level change and the role of deep mantle melting in the global water circulation are non-unique and alternative models are reviewed. Possible future directions of studies on the global water circulation are proposed including geodynamic modeling, mineral physics and observational studies, and studies integrating results from different disciplines.


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