scholarly journals A novel design of an electromagnetically levitated vibrational viscometer for biomedical and clinical applications

2019 ◽  
pp. 819-831
Author(s):  
ALİ AKPEK
Keyword(s):  
Cardiovascular Diseases ◽  
Kinematic Viscosity ◽  
Accurate Determination ◽  
Clinical Applications ◽  
Limited Resources ◽  
Viscosity Behavior ◽  
The World ◽  
Electromagnetically Levitated ◽  
Novel Design

Accurate determination of the viscosity behavior of fluids is extremely important, especially for biomedical and clinical applications. For example, blood viscosity is used to detect cardiovascular diseases in patients. Like blood, all body fluids and biochemical solvents used in biomedical studies are very limited resources. Therefore, a viscometer that is especially focused for biomedical and clinical applications should have the ability to obtain viscosity results from a reservoir as small as possible, in a range as wide as possible and in a period of time as short as possible. The measurements must be accurate even when the fluid temperatures shift swiftly and the test fluids pass throughout the viscometer continuously. Thus, it would be a huge advantage if a viscometer had the capability to measure simultaneously dynamic viscosity, kinematic viscosity, static viscosity, and density. However, there is no viscometer in the world that can achieve these goals. In this study, a novel electromagnetically levitated vibrational viscometer is designed to solve this problem.

The Foundation and Early Development of the Nautical Almanac

1965 ◽  
Vol 18 (4) ◽  
pp. 391-401 ◽  
Author(s):  
Eric G. Forbes
Keyword(s):  
Eighteenth Century ◽  
Present Article ◽  
Early Development ◽  
Accurate Determination ◽  
Practical Possibility ◽  
The World ◽  
Nevil Maskelyne ◽  
Nautical Almanac ◽  
Different Parts

Soon after the middle of the eighteenth century, improvements in the design and construction of astronomical and nautical instruments, coupled with the increased accuracy of tables of the Moon's motion, at last made the accurate determination of longitude at sea by lunar distance a practical possibility. The Astronomer Royal, Nevil Maskelyne, was quick to appreciate the importance of publishing the calculated solar and lunar ephemerides, together with other relevant tables and explanations, in the form of a Nautical Almanac, which was first printed under his supervision in 1766 and immediately distributed to mariners in different parts of the world. The present article is concerned with the circumstances relating to the origin and development of this publication during the first fifty years of its existence.

Radiocarbon dating of Chinese Ancient Tea Trees

Radiocarbon ◽  
2019 ◽  
Vol 61 (6) ◽  
pp. 1741-1748
Author(s):  
Jia Chen ◽  
Hongtao Shen ◽  
Kimikazu Sasa ◽  
Haihui Lan ◽  
Tetsuya Matsunaka ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Radial Growth ◽  
Accurate Determination ◽  
Annual Rings ◽  
The World ◽  
Automated Sample Preparation ◽  
The University

ABSTRACTThe jungles of Linyun and Longlin Autonomous Prefecture, located in the heart of the southwestern Guangxi Zhuang Autonomous Region of China, are home to the oldest tea trees (Camellia sinensis) in the world. In the absence of regular annual rings, radiocarbon (14C) dating is one of the most powerful tools that can assist in the determination of the ages and growth rates of these plants. In this work, cores were extracted from large ancient tea trees in a central Longlin rain forest; extraction of carbon was performed with an automated sample preparation system. The 14C levels in the tree cores were measured using accelerator mass spectrometry (AMS) at the University of Tsukuba. These measurements indicated that contrary to conventional views, the ages of trees in these forests range up to ~700 years, and the growth rate of this species is notably slow, exhibiting a long-term radial growth rate of 0.039±0.006 cm/yr. It was demonstrated that 14C analyses provide accurate determination of ages and growth rates for subtropical wild tea trees.

A proposed radar method for non-destructive investigation of Egyptian pyramids

2021 ◽  
Vol 63 (1) ◽  
pp. 12-19
Author(s):  
S Ivashov ◽  
T D Bechtel ◽  
V Razevig ◽  
L Capineri ◽  
M Inagaki
Keyword(s):  
Literature Review ◽  
Accurate Determination ◽  
Recent Event ◽  
Cultural Objects ◽  
The Public ◽  
Ancient Egyptian ◽  
The World ◽  
Great Pyramid ◽  
Non Destructive

The study of ancient Egyptian monuments attracts the attention of experts from around the world. A recent event that confirms this is the discovery, using muon sensors, of previously unknown cavities in the Great Pyramid of Giza (or Khufu's Pyramid). Since it is unfeasible to directly confirm this discovery by drilling, another independent non-destructive method is necessary to confirm this discovery and provide accurate determination of the locations and shapes of the cavities. Following a literature review of the different methods used in evaluating cultural objects, this paper analyses a possible framework for simulation of a holographic radar for detecting openings or other unknown structures of interest to archaeologists/Egyptologists and the public.

scholarly journals Determination of the beginning the Steady-State for controlled processes in monitoring systems with limited resources

2018 ◽  
Vol 245 ◽  
pp. 10002 ◽  
Author(s):  
Vladimir Leontiev ◽  
Alexander Sorokin ◽  
Sergey Saradzhishvili
Keyword(s):  
Steady State ◽  
Control Systems ◽  
Boiling Point ◽  
Inertial Sensors ◽  
Accurate Determination ◽  
Limited Resources ◽  
Physical Processes ◽  
Suggested Approach ◽  
The Moment

This paper describes the basic approach for determination of the steady-state conditions of physical processes such as boiling or other phase transitions in control systems with limited resources. In this research, we consider the particular case of a control system that should determine the moment when the water temperature reaches boiling point. In different systems, the accurate determination of the boiling point is important, because it results in other functions such as switching off or transitioning to other states. Hence, we explore the possibility of applying our approach in systems with limited resources, using cheap temperature inertial sensors. During the investigation, we encountered a delay in identifying the boiling point, caused by inertia. These issues demonstrate the need for the further improvement of the suggested approach in this particular case. However, generally our results indicate the applicability of this approach for control systems.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Reduction of Potassium in Kidney Proximal Tubules to Aid in Electron Probe X-Ray Microanalysis of Calcium

1985 ◽  
Vol 43 ◽  
pp. 474-475
Author(s):  
A. LeFurgey ◽  
P. Ingram ◽  
L.J. Mandel
Keyword(s):  
Smooth Muscle ◽  
Proximal Tubule ◽  
Electron Probe ◽  
Clinical Applications ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Target Cells ◽  
X Ray ◽  
Freeze Dried

For quantitative determination of subcellular Ca distribution by electron probe x-ray microanalysis, decreasing (and/or eliminating) the K content of the cell maximizes the ability to accurately separate the overlapping K Kß and Ca Kα peaks in the x-ray spectra. For example, rubidium has been effectively substituted for potassium in smooth muscle cells, thus giving an improvement in calcium measurements. Ouabain, a cardiac glycoside widely used in experimental and clinical applications, inhibits Na-K ATPase at the cell membrane and thus alters the cytoplasmic ion (Na,K) content of target cells. In epithelial cells primarily involved in active transport, such as the proximal tubule of the rabbit kidney, ouabain rapidly (t1/2= 2 mins) causes a decrease2 in intracellular K, but does not change intracellular total or free Ca for up to 30 mins. In the present study we have taken advantage of this effect of ouabain to determine the mitochondrial and cytoplasmic Ca content in freeze-dried cryosections of kidney proximal tubule by electron probe x-ray microanalysis.

Fast calibration of CBED patterns for quantitative analysis

1993 ◽  
Vol 51 ◽  
pp. 674-675
Author(s):  
M.A. Gribelyuk ◽  
M. Rühle
Keyword(s):  
Reciprocal Lattice ◽  
Accurate Determination ◽  
Incident Beam ◽  
Crystal Thickness ◽  
Structure Model ◽  
Beam Direction ◽  
Transmitted Beam ◽  
Reciprocal Vector ◽  
On Line

A new method is suggested for the accurate determination of the incident beam direction K, crystal thickness t and the coordinates of the basic reciprocal lattice vectors V1 and V2 (Fig. 1) of the ZOLZ plans in pixels of the digitized 2-D CBED pattern. For a given structure model and some estimated values Vest and Kest of some point O in the CBED pattern a set of line scans AkBk is chosen so that all the scans are located within CBED disks.The points on line scans AkBk are conjugate to those on A0B0 since they are shifted by the reciprocal vector gk with respect to each other. As many conjugate scans are considered as CBED disks fall into the energy filtered region of the experimental pattern. Electron intensities of the transmitted beam I0 and diffracted beams Igk for all points on conjugate scans are found as a function of crystal thickness t on the basis of the full dynamical calculation.

Computer-Assisted High-Re Solution TEM

1990 ◽  
Vol 48 (1) ◽  
pp. 162-163
Author(s):  
F.A. Ponce ◽  
H. Hikashi
Keyword(s):  
Signal To Noise Ratio ◽  
Accurate Determination ◽  
Computer Software ◽  
Video Camera ◽  
Image Contrast ◽  
Objective Lens ◽  
Computer Assisted ◽  
Optical Parameters ◽  
Astigmatism Correction

The determination of the atomic positions from HRTEM micrographs is only possible if the optical parameters are known to a certain accuracy, and reliable through-focus series are available to match the experimental images with calculated images of possible atomic models. The main limitation in interpreting images at the atomic level is the knowledge of the optical parameters such as beam alignment, astigmatism correction and defocus value. Under ordinary conditions, the uncertainty in these values is sufficiently large to prevent the accurate determination of the atomic positions. Therefore, in order to achieve the resolution power of the microscope (under 0.2nm) it is necessary to take extraordinary measures. The use of on line computers has been proposed [e.g.: 2-5] and used with certain amount of success.We have built a system that can perform operations in the range of one frame stored and analyzed per second. A schematic diagram of the system is shown in figure 1. A JEOL 4000EX microscope equipped with an external computer interface is directly linked to a SUN-3 computer. All electrical parameters in the microscope can be changed via this interface by the use of a set of commands. The image is received from a video camera. A commercial image processor improves the signal-to-noise ratio by recursively averaging with a time constant, usually set at 0.25 sec. The computer software is based on a multi-window system and is entirely mouse-driven. All operations can be performed by clicking the mouse on the appropiate windows and buttons. This capability leads to extreme friendliness, ease of operation, and high operator speeds. Image analysis can be done in various ways. Here, we have measured the image contrast and used it to optimize certain parameters. The system is designed to have instant access to: (a) x- and y- alignment coils, (b) x- and y- astigmatism correction coils, and (c) objective lens current. The algorithm is shown in figure 2. Figure 3 shows an example taken from a thin CdTe crystal. The image contrast is displayed for changing objective lens current (defocus value). The display is calibrated in angstroms. Images are stored on the disk and are accessible by clicking the data points in the graph. Some of the frame-store images are displayed in Fig. 4.

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