scholarly journals Photogrammetric Measurement and Analysis of the Shape Profile of Pneumatic Artificial Muscles

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 72
Author(s):  
Jonathan M. Chambers ◽  
Norman M. Wereley
Keyword(s):  
Image Data ◽  
Geometric Shape ◽  
Cylindrical Shape ◽  
Correction Factors ◽  
Profile Data ◽  
Simple Method ◽  
Shape Approximation ◽  
Specialized Equipment ◽  
Photogrammetric Method ◽  
Internal Volume

Inaccuracies in modeling of the geometric shape of PAMs has long been cited as a probable source of error in modeling and design efforts. The geometric shape and volume of PAMs is commonly approximated using a cylindrical shape profile, even though its shape is non-cylindrical. Correction factors—based on qualitative observations of the PAM’s general shape—are often implemented to compensate for error in this cylindrical shape approximation. However, there is little evidence or consensus on the accuracy and form of these correction factors. Approximations of the shape profile are also used to calculate the internal volume of PAMs, as experimental measurements of the internal volume require intrusive testing methods and specialized equipment. This research presents a photogrammetric method for measuring the shape profile and internal volume of PAMs. A test setup, method of image data acquisition, and a preliminary analysis of the image data, is presented in this research. A 22.2 mm (7/8 in) diameter PAM is used to demonstrate the photogrammetric procedure and test its accuracy. Analysis of the tested PAM characterizes trends of the shape profile with respect to pressure and contraction. The common method of estimating the diameter—through the use of the cylindrical approximation and initial geometry of the PAM—is tested by comparison to the measured shape profile data. Finally, a simple method of calculating the internal volume using the measured shape profile data is developed. The presented method of acquiring photogrammetric measurements of PAM shape produces an accurate characterization of its shape profile, thereby mitigating uncertainty in PAM shape in analysis and other efforts.

scholarly journals A Rapid Bacteriophage DNA Extraction Method

2018 ◽  
Vol 1 (3) ◽  
pp. 27 ◽  
Author(s):  
Džiuginta Jakočiūnė ◽  
Arshnee Moodley
Keyword(s):  
Dna Extraction ◽  
Illumina Miseq ◽  
Extraction Methods ◽  
Resistant Bacteria ◽  
Simple Method ◽  
Antibiotic Resistant ◽  
Phage Dna ◽  
Specialized Equipment ◽  
Miseq Platform ◽  
Dna Extraction Methods

Bacteriophages (phages) are intensely investigated as non-antibiotic alternatives to circumvent antibiotic resistance development as well as last resort therapeutic options against antibiotic resistant bacteria. As part of gaining a better understanding of phages and to determine if phages harbor putative virulence factors, whole genome sequencing is used, for which good quality phage DNA is needed. Traditional phage DNA extraction methods are tedious and time consuming, requiring specialized equipment e.g., an ultra-centrifuge. Here, we describe a quick and simple method (under four hours) to extract DNA from double stranded DNA (dsDNA) phages at titers above 1.0 × 1010 plaque-forming units (PFU)/mL. This DNA was suitable for library preparation using the Nextera XT kit and sequencing on the Illumina MiSeq platform.

scholarly journals A simple method to measure CLOCK-BMAL1 DNA binding activity in tissue and cell extracts

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1316 ◽  
Author(s):  
Maud Gillessen ◽  
Pieter Bas Kwak ◽  
Alfred Tamayo
Keyword(s):  
Dna Binding ◽  
Binding Activity ◽  
Casein Kinase I ◽  
Simple Method ◽  
Dna Binding Activity ◽  
Tissue Extracts ◽  
Cell Extracts ◽  
Specialized Equipment ◽  
Dna Binding Assay

The proteins CLOCK and BMAL1 form a heterodimeric transcription factor essential to circadian rhythms in mammals.  Daily rhythms of CLOCK-BMAL1 DNA binding activity are known to oscillate with target gene expression in vivo. Here we present a highly sensitive assay that recapitulates native CLOCK-BMAL1 DNA binding rhythms from crude tissue extracts, which we call the Clock Protein-DNA Binding Assay (CPDBA). This method can detect less than 2-fold differences in DNA binding activity, and can deliver results in two hours or less using 10 microliters or less of crude extract, while requiring neither specialized equipment nor expensive probes. To demonstrate the sensitivity and versatility of this assay, we show that enzymatic removal of phosphate groups from proteins in tissue extracts or pharmacological inhibition of casein kinase I in cell culture increased CLOCK-BMAL1 DNA binding activity by ~1.5 to ~2 fold, as measured by the CPDBA. In addition, we show that the CPDBA can measure CLOCK-BMAL1 binding to reconstituted chromatin. The CPDBA is a sensitive, fast, efficient and versatile probe of clock function.

Electron Density and Effective Atomic Number Measurement by Using a Newly Developing Photon Counting CT System

2020 ◽  
Vol 38 ◽  
pp. 93-99
Author(s):  
Hiroshi Sakurai ◽  
Kazushi Hoshi ◽  
Yosuke Harasawa ◽  
Daiki Ono ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Electron Density ◽  
Atomic Number ◽  
Photon Counting ◽  
Effective Atomic Number ◽  
Image Data ◽  
Detector Response ◽  
Simple Method ◽  
Attenuation Coefficients ◽  
X Ray ◽  
Ct System

We developed the photon counting CT system by using a conventional laboratory X-ray source and a CdTe line sensor. Attenuation coefficients were obtained from the measured CT image data. Our suggested method for deriving the electron density and effective atomic number from the measured attenuation coefficients was tested experimentally. The accuracy of the electron densities and effective atomic numbers are about <5 % (the averages of absolute values are 2.6 % and 3.1 %, respectively) for material of 6< Z and Zeff <13. Our suggested simple method, in which we do not need the exact source X-ray spectrum and detector response function, achieves comparable accuracy to the previous reports.

scholarly journals To help practitioner: monitoring treatment of osteoporosis in study of bone mineral density on different axial densitometers

2020 ◽  
Vol 2 (37) ◽  
pp. 22-28
Author(s):  
O. A. Nikitinskaya ◽  
N. V. Toroptsova
Keyword(s):  
Preventive Measures ◽  
Initial Assessment ◽  
Correction Factors ◽  
Mineral Density ◽  
Simple Method ◽  
Treatment Of Osteoporosis ◽  
X Ray ◽  
T Score ◽  
Bone Densitometer ◽  
Monitoring Treatment

Dual-energy X-ray absorptiometry is recognized as the ‘gold standard’ for the diagnosis of osteoporosis. This method is used not only for the initial assessment of the state of the IPC, but also for further monitoring of treatment or preventive measures. It allows you to compare the data of a patient with successive measurements during a long observation. However, it is impossible to evaluate the results of studies in dynamics on devices of different manufacturers without standardizing indicators or introducing correction factors. A simple method for recalculating the T-score obtained on a Dexxum 3 apparatus (OsteoSys, South Korea) is presented in order to compare it with a similar indicator of a bone densitometer Lunar Prodigy (GE Healthcare, USA).

scholarly journals Synergy Between LiDAR and Image Data in Context of Building Extraction

2014 ◽  
Vol XL-1 ◽  
pp. 89-93
Author(s):  
A. P. Dal Poz
Keyword(s):  
Image Data ◽  
Airborne Lidar ◽  
Lidar Data ◽  
Theoretical Studies ◽  
Building Extraction ◽  
Building Roof ◽  
Photogrammetric Method ◽  
Airborne Lidar Data

This paper compares the paradigms of LiDAR and aerophotogrammetry in the context of building extraction and briefly discusses a photogrammetric strategy for refining building roof polyhedrons previously extracted from LiDAR data. In general, empirical and theoretical studies have confirmed that LiDAR-based methodologies are more suitable in extracting planar roof faces and ridges of the roof, whereas the aerophotogrammetry are more suitable in extracting building roof outlines. In order to exemplify how to explore these properties, it is presented a photogrammetric method for refining 3D building roof contours extracted from airborne LiDAR data. Examples of application are provided for this refining approach.

Manufacturing Slurry and Rheocasting of Hypereutectic Al-Si-Cu-Mg Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 420-425
Author(s):  
Yasuhiro Uetani ◽  
Nanako Mori ◽  
Masayoshi Dohi ◽  
Kenji Matsuda ◽  
Susumu Ikeno
Keyword(s):  
Primary Silicon ◽  
Mg Alloy ◽  
Peak Hardness ◽  
Cylindrical Shape ◽  
Pressure Casting ◽  
Melt Temperature ◽  
Simple Method ◽  
Gravity Casting ◽  
Semi Solid ◽  
Silicon Particles

Both rapid and stable semi-solid slurry preparation of hypereutectic Al-14.8%Si-4.5%Cu-1.1%Mg alloy (in mass%) with fine solid granules as well as finely dispersed primary silicon particles was tried using a simple method newly developed, where the low-superheat melt passes through a gap between a rotating regular octagonal rotor and a circumscribed chill block. By examining effects of melt temperature running out from tundish, gap distance and rotational speed of rotor on solidification structure of the semi-solid slurry manufactured, the optimum making condition of the targeted semi-solid slurry was found out. Mean sizes of solid granules and primary silicon particles within the slurry, which had been made quickly with the good reproducibility, were 45μm and 20μm, respectively. Subsequently the obtained semi-solid slurries were rheocast into a cylindrical shape cavity by the use of a high pressure casting machine. It has been shown that the rheocast samples have peak hardness value between the gravity casting and the hot-extrusion, but a good age-hardenability somewhat higher than that of gravity casting.

A Method of Estimating Natural and Fishing Mortalities

1958 ◽  
Vol 15 (4) ◽  
pp. 749-758 ◽  
Author(s):  
J. E. Paloheimo
Keyword(s):  
Age Groups ◽  
Mortality Rates ◽  
Correction Factors ◽  
Fishing Mortality ◽  
Age Classes ◽  
Simple Method ◽  
Virtual Population ◽  
Population Size Estimates ◽  
Available Information ◽  
Size Estimates

A simple method of estimating instantaneous natural and fishing mortality rates is given. It uses the maximum of the available information. The method requires data on numbers caught by age-classes, and data on (effective) effort for a series of years. For each year-class is calculated the weighted sum of catches from all age-groups from a given age on, and these sums are used as estimates of year-class strengths. The weighting factors depend on the instantaneous fishing and natural mortality rates; the best values of mortality rates are arrived at by iteration. When statistics are not complete a correction factor can be applied. This method is compared with Fry's "virtual" population size estimates; in both cases the basic statistics are catches. We have, however, introduced correction factors to allow for varying fishing intensities and incomplete statistics at older ages.

scholarly journals Validation of a Locally Designed Computed Tomography Dose Phantom: A Comparison Study with a Standard Acrylic Phantom in South-South, Nigeria

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Anwuli Christiana Tobi ◽  
Chukwuka Emmanuel Mokobia ◽  
Joyce Ekeme Ikubor ◽  
Akintayo Daniel Omojola
Keyword(s):  
Computed Tomography ◽  
Cylindrical Shape ◽  
Correction Factors ◽  
Energy Agency ◽  
Dose Length Product ◽  
Ct Dose ◽  
Volume Computed Tomography ◽  
The Mean ◽  
Computed Tomography Dose Index ◽  
Dose Measurements

Purpose: The aim of this study was to determine the mean volume computed tomography dose index (CTDIvol) for the standard head and body phantoms and locally designed head and body phantoms respectively. Similarly, this study determined and compared the displayed mean CTDIvol and Dose Length Product (DLP) for the above phantoms from the CT monitor. In addition, the percentage deviations of both phantoms were compared with the recommended limits from the International Atomic Energy Agency (IAEA) and the American College of Radiologists (ACR). Materials and Methods: Dose measurements were made using a standard polymethymethacrylate (PMMA) phantom for head and body as well as a locally designed phantom with four CT scanners using thermoluminescence dosimeters (TLDs). The locally designed phantoms were made using a PMMA sheet, which was bent to give the desired cylindrical shape and was made like the standard phantoms. The constructed phantom was filled with water and the TLD chips were inserted into the center and peripheries of the phantoms to obtain the absorbed doses. Results: The CTDIvol for the standard head and body phantom for center A was 66.97 and 21.85mGy and for B was 23.39 and 6.29mGy respectively. Similarly, the CTDIvol for the constructed head and body phantom for center A was 63.91 and 19.84mGy and for B was 24.67 and 6.30mGy respectively. The uncertainty between the standard and constructed head phantoms for centers A and B was 4.6 and 5.5% respectively, while that of the standard and constructed body phantoms for centers A and B was 9.2 and 0.0% respectively. The maximum percent deviation from the console CTDIvol and DLP values with the four phantoms for centers A and B was within ±20%. The mean correction factors for the head and body were 0.998 and 1.05 respectively. Conclusion: The uncertainties obtained in this study were within the IAEA and ACR recommended value of ±20%. The constructed phantom proved useful for CT dose measurements.

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