scholarly journals On the production and formation of pearls

1833 ◽  
Vol 2 ◽  
pp. 278-278
Keyword(s):  
External Surface ◽  
Central Cell ◽  
Common Mode ◽  
Inner Surface ◽  
The Common

In his examinations of the organs of generation of the large freshwater muscle, the author often met with seed pearls, either in the ovarium, or connected with the shell upon which the ovarium lay; and he remarked at the same time that all Oriental pearls have a brilliant central cell, which in the common mode of boring them is destroyed, but which may be beautifully exhibited by carefully splitting the pearl into halves: this cell is just large enough to contain an ovum, which is formed upon a pedicle like the yolk of the pullet’s egg, and is similarly discharged when completely formed. Thence Sir Everard concludes, that a pearl is formed upon the external surface of an ovum, which having been blighted, does not pass with the others into the oviduct, but remains attached to its pedicle in the ovarium, and in the following season receives a coat of pearl at the same time that the inner surface of the shell receives its annual supply. This conclusion, he observes, is verified by some pearls being spherical while others are pyramidal, in consequence of the pedicle, as well as the ovum, having been enamelled with nacre. This paper concludes with an extract from one of the early volumes of the Philosophical Transactions, in which a corresponding account of the growth of pearls is announced by Arnoldi in 1673.

scholarly journals Clinical significance of accessory foramina in adult human mandible

2017 ◽  
Vol 5 (6) ◽  
pp. 2449
Author(s):  
Nisha Goyal ◽  
Maneesha Sharma ◽  
Rasalika Miglani ◽  
Anil Garg ◽  
P. K. Gupta
Keyword(s):  
External Surface ◽  
Inferior Alveolar Nerve ◽  
The Body ◽  
Facial Skeleton ◽  
Lingual Foramen ◽  
Adult Human ◽  
Common Location ◽  
Inner Surface ◽  
The Common ◽  
Accessory Foramina

Background: The mandible is the strongest and largest bone of facial skeleton. It consists of one horseshoe-shaped body and a pair of rami. On external surface of body in the midline there is a faint ridge i.e. symphysis menti indicating the line of fusion of two halves of mandible during development. The aim of this study is to describe the position and incidence of accessory foramina on the inner surface of the body and rami of both sides of mandible to provide simple important reliable surgical landmarks.Methods: The present study was conducted on 100 dried adult human mandibles. Bones which had deformities, asymmetries, external pathological changes and fractures were excluded from the present study.Results: In 97% cases at least one accessory foramen was observed on inner surface of mandible. The accessory lingual foramen was found to be constant finding with incidence of 81%. Frequency of infraspinous or sublingual foramen was 58%, of lateral foramen was 50% and that of accessory mandibular foramen was 39%.Conclusions: The anatomical knowledge about the common location and incidence of accessory foramina in mandible are important for surgeons and anaesthetists performing surgeries in the area around mandible. These accessory foramina transmit neurovascular bundles which provide accessory innervations to the roots of teeth.  Thus proper knowledge of accessory foramina are important in relation to achieving complete inferior alveolar nerve block and for avoiding injury to neurovascular bundle passing through them.

Tunable balanced to balanced filtering power divider with high common-mode suppression

Frequenz ◽  
2020 ◽  
Vol 74 (7-8) ◽  
pp. 263-270
Author(s):  
Cao Zeng ◽  
Xue Han Hu ◽  
Feng Wei ◽  
Xiao Wei Shi
Keyword(s):  
Return Loss ◽  
High Selectivity ◽  
Power Divider ◽  
Center Frequency ◽  
Differential Mode ◽  
Common Mode ◽  
Mode Suppression ◽  
The Common ◽  
Equal Power ◽  
Good Agreement

AbstractIn this paper, a tunable balanced-to-balanced in-phase filtering power divider (FPD) is designed, which can realize a two-way equal power division with high selectivity and isolation. A differential-mode (DM) passband with a steep filtering performance is realized by applying microstrip stub-loaded resonators (SLRs). Meanwhile, six varactors are loaded to the SLRs to achieve the center frequency (CF) and bandwidth adjustment, respectively. U-type microstrip lines integrated with stepped impedance slotline resonators are utilized as the differential feedlines, which suppress the common-mode (CM) intrinsically, making the DM responses independent of the CM ones. A tuning center frequency from 3.2 to 3.75 GHz and a fractional bandwidth (12.1–17.6%) with more than 10 dB return loss and less than 2.3 dB insertion loss can be achieved by changing the voltage across the varactors. A good agreement between the simulated and measured results is observed. To the best of authors' knowledge, the proposed balanced-to-balanced tunable FPD is first ever reported.

scholarly journals A New Approach to the PWM Modulation for the Multiphase Matrix Converters Supplying Loads with Open-End Winding

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 466
Author(s):  
Pawel Szczepankowski ◽  
Natalia Strzelecka ◽  
Enrique Romero-Cadaval
Keyword(s):  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Simulation Software ◽  
Common Mode ◽  
New Approach ◽  
Matrix Converters ◽  
Load Voltage ◽  
Common Mode Voltage ◽  
The Common ◽  
Open End Winding

This article presents three variants of the Pulse Width Modulation (PWM) for the Double Square Multiphase type Conventional Matrix Converters (DSM-CMC) supplying loads with the open-end winding. The first variant of PWM offers the ability to obtain zero value of the common-mode voltage at the load’s terminals and applies only six switches within the modulation period. The second proposal archives for less Total Harmonic Distortion (THD) of the generated load voltage. The third variant of modulation concerns maximizing the voltage transfer ratio, minimizing the number of switching, and the common-mode voltage cancellation. The discussed modulations are based on the concept of sinusoidal voltage quadrature signals, which can be an effective alternative to the classic space-vector approach. In the proposed approach, the geometrical arrangement of basic vectors needed to synthesize output voltages is built from the less number of vectors, which is equal to the number of the matrix converter’s terminals. The PWM duty cycle computation is performed using only a second-order determinant of the voltages coordinate matrix without using trigonometric functions. A new approach to the PWM duty cycles computing and the load voltage synthesis by 5 × 5 and 12 × 12 topologies has been verified using the PSIM simulation software.

scholarly journals Opposite Triangle Carrier with SVPWM for Common-Mode Voltage Reduction in Dual Three Phase Motor Drives

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 282
Author(s):  
Seon-Ik Hwang ◽  
Jang-Mok Kim
Keyword(s):  
Electromagnetic Interference ◽  
Pulse Width Modulation ◽  
Motor Drives ◽  
Common Mode ◽  
Pwm Inverter ◽  
Common Mode Voltage ◽  
Voltage Vector ◽  
Three Phase ◽  
The Common ◽  
Zero Voltage

The common-mode voltage (CMV) generated by the switching operation of the pulse width modulation (PWM) inverter leads to bearing failure and electromagnetic interference (EMI) noises. To reduce the CMV, it is necessary to reduce the magnitude of dv/dt and change the frequency of the CMV. In this paper, the range of the CMV is reduced by using opposite triangle carrier for ABC and XYZ winding group, and the change in frequency in the CMV is reduced by equalizing the dwell time of the zero voltage vector on ABC and XYZ winding group of dual three phase motor.

Complex Protection of Pipelines Using Silicate Materials Based on Local Raw Materials of the Far East

2019 ◽  
Vol 945 ◽  
pp. 46-52 ◽  
Author(s):  
Elena A. Yatsenko ◽  
B.M. Goltsman ◽  
A.V. Ryabova
Keyword(s):  
Oil And Gas ◽  
External Surface ◽  
Raw Materials ◽  
Foam Glass ◽  
Russian Far East ◽  
Far East ◽  
The Far East ◽  
Inner Surface ◽  
Oil And Gas Pipelines ◽  
The Russian Far East

Modern trends in the development of the oil and gas infrastructure of the Russian Far East are considered. The main threats in the operation of oil and gas pipelines are described. The technology of complex protection of pipeline surfaces is proposed. Protection of the inner surface is achieved through the use of silicate enamel coatings, protection of the external surface – through the use of foam glass. On the basis of local silicate raw materials the technology of the described materials is developed, and their main properties are determined. Recommendations on the application of the developed technology for the protection of pipelines are given.

Methodology for the Common Mode Analysis

2007 ◽  
Author(s):  
Zdzislaw H. Klim ◽  
Marek Balazinski
Keyword(s):  
Mode Analysis ◽  
Common Mode ◽  
The Common
Sign in / Sign up

Export Citation Format

Share Document