Measurements of Corona Discharge in Non-Uniform Field Freon GAP

2014 ◽  
Vol 7 (4) ◽  
pp. 47-61
Author(s):  
A. S. Hasaani ◽  
Hassan J. Mohammed
Keyword(s):  
Corona Discharge ◽  
Pressure Range ◽  
Outer Diameter ◽  
Uniform Field ◽  
Design Considerations ◽  
Wide Range ◽  
Onset Voltage ◽  
Inner Diameter ◽  
Gap Spacing ◽  
High Degree

Corona Discharge have been recorded in pin-to pin electrode at gas pressure gaps with high degree of non-uniformity electric field. For a wide range of experimental applicability the pin to pin electrode was used over pressure range from 1bar to 3bar and gap spacing from 0 to 5mm.High –pressure dc corona discharge experiments have been carried out in a 16cm long glass chamber with an inner diameter and outer diameter are 16.8cm, and 19cm respectively. Corona onset voltage and breakdown voltages were reached. The design considerations of the setup allow to use pin to pin electrode type geometries. Electronegative gases such as air, Freon (R22), were separately used for low temperature corona generation. The experiments have been carried out under ambient Laboratory conditions of temperature (19-24 oC), and humidity. The present experiment were studies the relation between the (V-P) and (V-d), on other hand, we study the relation between the current and applied voltage.

scholarly journals Design and Performance Analysis of Multi-Spring Maker

2019 ◽  
Vol 9 (1) ◽  
pp. 2782-2784
Keyword(s):  
Performance Analysis ◽  
World Wide ◽  
Outer Diameter ◽  
Mechanical Device ◽  
Compression Spring ◽  
Wide Range ◽  
Tension And Compression ◽  
Inner Diameter ◽  
Compression Springs ◽  
And Performance

In this industrial world, wide range of power operated machines is used for the production of springs. But this is the simple mechanism arrangement for the production of torsion and compression springs. This machine is operated by manual method. This machine can produce both the tension and compression springs of different Diameter and different length. It can make a spring with the help of the shaft. The wire which is used for producing the spring moves around the shaft to make a suitable spring. This self-movement is achieved by the keyway of the shaft. A handle is used to operate the rolling machine manually. The outer Diameter of the shaft is the inner Diameter of the spring. The torsion and compression spring is a mechanical device which is used to store energy and release it when needed.

Understanding Conformational Entropy in Small Molecules

2020 ◽  
Author(s):  
Lucian Chan ◽  
Garrett Morris ◽  
Geoffrey Hutchison
Keyword(s):  
Small Molecules ◽  
Degrees Of Freedom ◽  
Absolute Error ◽  
Low Energy ◽  
Standard Entropy ◽  
Free Energies ◽  
Conformational Entropy ◽  
Wide Range ◽  
High Degree ◽  
Empirical Corrections

The calculation of the entropy of flexible molecules can be challenging, since the number of possible conformers grows exponentially with molecule size and many low-energy conformers may be thermally accessible. Different methods have been proposed to approximate the contribution of conformational entropy to the molecular standard entropy, including performing thermochemistry calculations with all possible stable conformations, and developing empirical corrections from experimental data. We have performed conformer sampling on over 120,000 small molecules generating some 12 million conformers, to develop models to predict conformational entropy across a wide range of molecules. Using insight into the nature of conformational disorder, our cross-validated physically-motivated statistical model can outperform common machine learning and deep learning methods, with a mean absolute error ≈4.8 J/mol•K, or under 0.4 kcal/mol at 300 K. Beyond predicting molecular entropies and free energies, the model implies a high degree of correlation between torsions in most molecules, often as- sumed to be independent. While individual dihedral rotations may have low energetic barriers, the shape and chemical functionality of most molecules necessarily correlate their torsional degrees of freedom, and hence restrict the number of low-energy conformations immensely. Our simple models capture these correlations, and advance our understanding of small molecule conformational entropy.

Cerebellotrigeminal Dermal Dysplasia (Gómez-López-Hernández Syndrome)

2018 ◽  
Vol 16 (05) ◽  
pp. 362-368 ◽  
Author(s):  
Federica Sullo ◽  
Agata Polizzi ◽  
Stefano Catanzaro ◽  
Selene Mantegna ◽  
Francesco Lacarrubba ◽  
...  
Keyword(s):  
De Novo ◽  
Chromosomal Rearrangements ◽  
Number Of Patients ◽  
Wide Range ◽  
Visual Problems ◽  
Neurodevelopmental Abnormalities ◽  
Clinical Triad ◽  
High Degree ◽  
Motor Handicap

Cerebellotrigeminal dermal (CTD) dysplasia is a rare neurocutaneous disorder characterized by a triad of symptoms: bilateral parieto-occipital alopecia, facial anesthesia in the trigeminal area, and rhombencephalosynapsis (RES), confirmed by cranial magnetic resonance imaging. CTD dysplasia is also known as Gómez-López-Hernández syndrome. So far, only 35 cases have been described with varying symptomatology. The etiology remains unknown. Either spontaneous dominant mutations or de novo chromosomal rearrangements have been proposed as possible explanations. In addition to its clinical triad of RES, parietal alopecia, and trigeminal anesthesia, CTD dysplasia is associated with a wide range of phenotypic and neurodevelopmental abnormalities.Treatment is symptomatic and includes physical rehabilitation, special education, dental care, and ocular protection against self-induced corneal trauma that causes ulcers and, later, corneal opacification. The prognosis is correlated to the mental development, motor handicap, corneal–facial anesthesia, and visual problems. Follow-up on a large number of patients with CTD dysplasia has never been reported and experience is limited to few cases to date. High degree of suspicion in a child presenting with characteristic alopecia and RES has a great importance in diagnosis of this syndrome.

scholarly journals Controlling Teleportation-Based Locomotion in Virtual Reality with Hand Gestures: A Comparative Evaluation of Two-Handed and One-Handed Techniques

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 715
Author(s):  
Alexander Schäfer ◽  
Gerd Reis ◽  
Didier Stricker
Keyword(s):  
Virtual Reality ◽  
Virtual Worlds ◽  
User Preferences ◽  
Interaction Techniques ◽  
Hand Gestures ◽  
Wide Range ◽  
Effectiveness And Efficiency ◽  
High Degree ◽  
Additional Hardware ◽  
Comprehensive Study

Virtual Reality (VR) technology offers users the possibility to immerse and freely navigate through virtual worlds. An important component for achieving a high degree of immersion in VR is locomotion. Often discussed in the literature, a natural and effective way of controlling locomotion is still a general problem which needs to be solved. Recently, VR headset manufacturers have been integrating more sensors, allowing hand or eye tracking without any additional required equipment. This enables a wide range of application scenarios with natural freehand interaction techniques where no additional hardware is required. This paper focuses on techniques to control teleportation-based locomotion with hand gestures, where users are able to move around in VR using their hands only. With the help of a comprehensive study involving 21 participants, four different techniques are evaluated. The effectiveness and efficiency as well as user preferences of the presented techniques are determined. Two two-handed and two one-handed techniques are evaluated, revealing that it is possible to move comfortable and effectively through virtual worlds with a single hand only.

scholarly journals Morphological Changes in Lamellar Macular Holes According to SD-OCT Examination over a Long Observation Period

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1145
Author(s):  
Magdalena Kal ◽  
Izabela Chojnowska-Ćwiąkała ◽  
Mateusz Winiarczyk ◽  
Monika Jasielska ◽  
Jerzy Mackiewicz
Keyword(s):  
Retinal Thickness ◽  
Morphological Changes ◽  
Outer Diameter ◽  
Corrected Visual Acuity ◽  
Macular Holes ◽  
Kolmogorov Smirnov ◽  
Inner Diameter ◽  
Observation Period ◽  
Sd Oct

Background: The aim of this study was to evaluate the quantitative morphological changes in lamellar macular holes (LMHs) based on SD-OCT examinations and to assess the correlations among minimal retinal thickness (MRT), reading vision (RV), and best corrected visual acuity (BCVA) over a 36-month follow-up period. Methods: A group of 40 patients (44 eyes) with LMH was evaluated, with an average age of 69.87 (SD = 10.14). The quantitative parameters monitored in the follow-up period (at 0, 3, 6, 12, 18, 24, 30, and 36 months) were tested for normality of distribution by Shapiro–Wilk and Kolmogorov–Smirnov tests. Results: The RV and BCVA values were stable, and no significant changes were found at any of the check-ups during the 36-month follow-up period (BCVA p = 0.435 and RV p = 0.0999). The analysis of individual quantitative LMH parameters during the 36-month follow-up period did not demonstrate statistically significant differences: MRT (p = 0.461), Max RT temporal (p = 0.051), Max RT nasal (p = 0.364), inner diameter (ID) (p = 0.089), and outer diameter (OD) (p = 0.985). Conclusions: The observations at 0, 6, 12, 18, 24, 30, and 36 months revealed moderate and significant correlations between RV and MRT. No significant correlation between BCVA and MRT was observed.

Influence of fully submerged permanent magnets in the evaluation of heat transfer and performance analysis of single slope glass solar still

2021 ◽  
pp. 095765092110310
Author(s):  
Ajay Kumar Kaviti ◽  
Akkala Siva Ram ◽  
Amit Kumar Thakur
Keyword(s):  
Heat Transfer ◽  
Permanent Magnets ◽  
Outer Diameter ◽  
Solar Still ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Inner Diameter ◽  
Evaporative Heat Transfer ◽  
And Performance ◽  
Depth Water

In this experimental study, permanent magnets with three different sizes (M-1: 32 mm inner diameter, 70 mm outer diameter and 15 mm thick, M-2: 25 mm inner diameter, 60 mm outer diameter and 10 mm thick, M-3: 22 mm inner diameter, 45 mm outer diameter and 9 mm thick) are fully submerged in the single-slope glass solar still. The performance of magnetic solar stills (MSS) with three different sizes at 2 cm depth water to ensure that magnets are fully submerged is compared with conventional solar still (CSS) at the location 17.3850°N, 78.4867°E. Tiwari model is adapted to calculate the heat transfer coefficients (HTC), internal and exergy efficiencies. MSS with M-1, M-2 and M-3 significantly enhanced the convective, radiative, and evaporative heat transfer rate for the 2 cm depth of water. This is due to the desired magnetic treatment of water, which reduces the surface tension and increases the hydrogen bonds. The MSS's total internal HTC, instantaneous efficiencies led CSS by 25.52%, 28.8%, respectively, with M-1. Having various magnetic fields due to different magnets sizes increases MSS's exergetic efficiency by 33.61% with M-1, 33.76% with M-2, and 42.25% with M-3. Cumulative yield output for MSS with M-1, M-2, and M-3 is 21.66%, 17.64%, 15.78% higher than CSS. The use of permanent magnets of different sizes in the MSS is a viable, economical and straight forward technique to enhance productivity.

Krypton 85 myocardial blood flow: precordial scintillation versus coronary sinus sampling

1965 ◽  
Vol 209 (4) ◽  
pp. 705-710 ◽  
Author(s):  
Michael D. Klein ◽  
Lawrence S. Cohen ◽  
Richard Gorlin
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Coronary Sinus ◽  
Human Subjects ◽  
Radioactive Decay ◽  
Empirical Correction ◽  
Wide Range ◽  
Actual Flow ◽  
Flow Through ◽  
High Degree

Myocardial blood flow in human subjects was assessed by comparative simultaneous measurement of krypton 85 radioactive decay from coronary sinus and precordial scintillation. Empirical correction of postclearance background from precordial curves yielded a high degree of correlation between flows derived from the two sampling sites (r = .889, P < .001). Comparison of left and right coronary flows in nine subjects revealed similarity in flow through the two vessels over a wide range of actual flow values (r = .945, P < .001).

Self-Organized, Tubular Hybrid Vascular Tissue Composed of Vascular Cells and Collagen for Low-Pressure-Loaded Venous System

1995 ◽  
Vol 4 (6) ◽  
pp. 597-608 ◽  
Author(s):  
Jiro Hirai ◽  
Takehisa Matsuda
Keyword(s):  
Vascular Tissue ◽  
Venous System ◽  
Seeding Density ◽  
Outer Diameter ◽  
Type I ◽  
Dependent Manner ◽  
Mixed Solution ◽  
Vascular Cells ◽  
Collagen Concentration ◽  
Inner Diameter

A tubular, hierarchically structured hybrid vascular tissue composed of vascular cells and collagen was prepared. First, a cold mixed solution of bovine aortic smooth muscle cells (SMCs) and Type I collagen was poured into a tubular glass mold composed of a mandrel and a sheath (example of dimensions: inner diameter, 1.5 mm; outer diameter, 7 mm; length, 7 cm). Upon incubation at 37°C, an SMC-incorporated collagenous gel was formed. After the sheath was removed, the resulting fragile tissue, when cultured in medium, thinned in a time-dependent manner to form an opaque, dense tissue. Higher SMC seeding density and lower initial collagen concentration induced more rapid and prominent shrinkage of the tissue. Morphologic investigation showed that over time, bipolarly elongated SMCs and collagen fiber bundles became positioned around the mandrel. Both components became circumferentially oriented. When the mandrel was removed, a tubular hybrid medial tissue was formed. A hybrid vascular tissue with a hierarchical structure was constructed by seeding endothelial cells onto the inner surface of the hybrid medial tissue. Prepared tissues tolerated luminal pressures as great as 100 mmHg and mechanical stress applied during an anastomotic procedure. This method allowed us to prepare a tubular hybrid medial tissue of predetermined size (inner diameter, wail thickness, and length) by selecting appropriate mold design, initial collagen concentration, and SMC seeding density. Such hybrid vascular tissues may provide physiological functions when implanted into the venous system.

scholarly journals Nucleation in continuous flow cooling sonocrystallization for coiled capillary crystallizers

2021 ◽  
Author(s):  
Mira Schmalenberg ◽  
Lena K. Weick ◽  
Norbert Kockmann
Keyword(s):  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Cell ◽  
Deionized Water ◽  
Small Scale ◽  
Non Invasive ◽  
Ultrasonic Bath ◽  
Continuous Crystallization ◽  
Wide Range ◽  
Inner Diameter

AbstractNucleation in continuously operated capillary coiled cooling crystallizers is experimentally investigated under the influence of ultrasound. It was found that there is no sharp boundary but rather a transition zone for nucleation under sonication. For this purpose, a tube with an inner diameter of 1.6 mm and a length of 6 m was winded in a coiled flow inverter (CFI) design and immersed into a cooled ultrasonic bath (37 kHz). The CFI design was chosen for improved radial mixing and narrow residence time distribution, which is also investigated. Amino acid l-alanine dissolved in deionized water is employed in a supersaturation range of 1.10 to 1.46 under quiet and sonicated conditions. Nucleation is non-invasive detected using a flow cell equipped with a microscope and camera. Graphical abstract Since the interest and demand for small-scale, continuous crystallization increases, seed crystals were generated in a coiled tube via sonication and optically investigated and characterized. No distinct threshold for nucleation could be determined in a wide range of supersaturations of l-alanine in water

Historical Dynamics

2018 ◽  
Author(s):  
Peter Turchin
Keyword(s):  
Religious Conversion ◽  
Synthetic Approach ◽  
Dynamical Processes ◽  
Factors Affecting ◽  
Historical Processes ◽  
Wide Range ◽  
Historical Dynamics ◽  
State Breakdown ◽  
Political Economic ◽  
High Degree

Many historical processes are dynamic. Populations grow and decline. Empires expand and collapse. Religions spread and wither. Natural scientists have made great strides in understanding dynamical processes in the physical and biological worlds using a synthetic approach that combines mathematical modeling with statistical analyses. Taking up the problem of territorial dynamics—why some polities at certain times expand and at other times contract—this book shows that a similar research program can advance our understanding of dynamical processes in history. The book develops hypotheses from a wide range of social, political, economic, and demographic factors: geopolitics, factors affecting collective solidarity, dynamics of ethnic assimilation/religious conversion, and the interaction between population dynamics and sociopolitical stability. It then translates these into a spectrum of mathematical models, investigates the dynamics predicted by the models, and contrasts model predictions with empirical patterns. The book's highly instructive empirical tests demonstrate that certain models predict empirical patterns with a very high degree of accuracy. For instance, one model accounts for the recurrent waves of state breakdown in medieval and early modern Europe. And historical data confirm that ethno-nationalist solidarity produces an aggressively expansive state under certain conditions (such as in locations where imperial frontiers coincide with religious divides). The strength of the book's results suggests that the synthetic approach advocated can significantly improve our understanding of historical dynamics.

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