scholarly journals Numerical investigation of V shaped three elements resonator for optical closed loop system

2019 ◽  
Vol 16 (3) ◽  
pp. 1392 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Numerical Investigation ◽  
Phase Angle ◽  
High Performance ◽  
Stability Parameter ◽  
Beam Radius ◽  
Curvature Radius ◽  
Negative Effects ◽  
System Parameters ◽  
Resonator System ◽  
The Stability

<span>This study have outlined numerical investigation of V shaped three element resonator. The stability parameter is measured against </span><span>back mirror curvature radius</span><span>, </span><span>back mirror phase angle</span><span>, </span><span>focusing length</span><span>, </span><span>focusing mirror phase angle</span><span>, </span><span>folding range</span><span> in both S plane and T plane. The stability parameter is changed in positive and negative trend under the operating system parameters. The stability parameter should be optimized in order to achieve high performance efficiency of resonator system. Beam radius variations are also measured versus </span><span>focusing range</span><span>, folding range, and back mirror phase angle. It is clear that the negative effects of increasing system parameters on beam radius variation in both S plane and T plane. </span>

scholarly journals Simulative Study of Simple Ring Resonator Based Brewster Plate for Power System operation Stability

2019 ◽  
Vol 16 (2) ◽  
pp. 1070 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Ring Resonator ◽  
Beam Radius ◽  
Curvature Radius ◽  
Spherical Mirror ◽  
Stability Parameters ◽  
Space Length ◽  
Simple Ring ◽  
Positive Effects ◽  
Operation Stability ◽  
Resonator System

<span>This study has outlined the simulative study of simple ring resonator based Brewster plate in the air. The obtained results are achieved with the variations of space length, curvature radius and phase angle of the </span><span>spherical mirror</span><span>. Beam radius criterion and stability parameters are measured with the variations of </span><span>refractive index</span><span> and thickness of Brewster plate in the air. The negative and positive effects of increasing operating parameters are observed on the performance of ring resonator system efficiency. </span>

scholarly journals Z shaped like resonator with crystal in the presence of flat mirror based standing wave ratio for optical antenna systems

2020 ◽  
Vol 17 (3) ◽  
pp. 1405 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed ◽  
Preecha Yupapin
Keyword(s):  
Standing Wave ◽  
Cavity Length ◽  
Beat Frequency ◽  
Stability Parameter ◽  
Beam Radius ◽  
Curvature Radius ◽  
Spherical Mirror ◽  
Optical Antenna ◽  
Flat Mirror ◽  
Intermode Beat

<span>This study has outlined the Z resonator shaped with Brewster crystal in the presence of flat mirror for measuring the standing wave ratio. Stability parameter and beam radius are simulated versus thickness, refractive index of the crystal and first and second folding ranges. Beam radius variations are studied against phase angle and curvature radius of spherical mirror in T and S planes. Intermode beat frequency of the system is 216.276 MHz and total cavity length is 693.078 mm. It is important the standing wave ratio is dependent on stability parameter and beam radius variations. </span>

scholarly journals Influence of device to device interconnection elements on the system behavior and stability

2020 ◽  
Vol 18 (2) ◽  
pp. 843 ◽  
Author(s):  
Iraj Sadegh Amiri ◽  
Ahmed Nabih Zaki Rashed ◽  
Preecha Yupapin
Keyword(s):  
Focal Length ◽  
Beam Radius ◽  
Curvature Radius ◽  
Spherical Mirror ◽  
System Operation ◽  
Thin Lens ◽  
Crystal Stability ◽  
Lens Focal Length ◽  
Resonator System ◽  
Tilted Plane

<p>This work has presented the<strong> </strong>interaction between tangential/sagittal cylindrical thin lens in the titled plane parallel crystal. Stability criterion parameters are measured under the control of curvature radius of a spherical mirror, the thickness of the tilted plane crystal, the refractive index of tilted plane crystal, the thickness for a plate of matter and phase angle of the sagittal cylindrical thin lens. Beam radius waist is plotted against the focal length of the tangential cylindrical thin lens. Focal length for both thin lens in resonator crystal is optimized to upgrade the resonator system operation efficiency.</p>

Dietary Vitamin and Stability of Oral Anticoagulation: Proposal of a Diet with Constant Vitamin K1 Content

1997 ◽  
Vol 77 (03) ◽  
pp. 504-509 ◽  
Author(s):  
Sarah L Booth ◽  
Jacqueline M Charnley ◽  
James A Sadowski ◽  
Edward Saltzman ◽  
Edwin G Bovill ◽  
...  
Keyword(s):  
Dietary Intake ◽  
Vitamin K ◽  
High Performance ◽  
Case Reports ◽  
Food Composition ◽  
Dietary Guidelines ◽  
Dietary Vitamin ◽  
Vitamin K1 ◽  
The Stability ◽  
The Impact

SummaryCase reports cited in Medline or Biological Abstracts (1966-1996) were reviewed to evaluate the impact of vitamin K1 dietary intake on the stability of anticoagulant control in patients using coumarin derivatives. Reported nutrient-drug interactions cannot always be explained by the vitamin K1 content of the food items. However, metabolic data indicate that a consistent dietary intake of vitamin K is important to attain a daily equilibrium in vitamin K status. We report a diet that provides a stable intake of vitamin K1, equivalent to the current U.S. Recommended Dietary Allowance, using food composition data derived from high-performance liquid chromatography. Inconsistencies in the published literature indicate that prospective clinical studies should be undertaken to clarify the putative dietary vitamin K1-coumarin interaction. The dietary guidelines reported here may be used in such studies.

Photochemical stability of warfarin potassium in powdered pharmaceutical tablets

2021 ◽  
Vol 32 (2) ◽  
pp. 115-129
Author(s):  
Emi Horiguchi-Babamoto ◽  
Makoto Otsuka
Keyword(s):  
High Performance ◽  
Partial Least Squares Regression ◽  
Pediatric Patients ◽  
Reversed Phase ◽  
Least Squares Regression ◽  
Brand Name ◽  
Pharmaceutical Tablets ◽  
Light Stability ◽  
Warfarin Potassium ◽  
The Stability

BACKGROUND: Warfarin potassium (Wf) commercial tablets originally formulated for adults are ground before administration to pediatric patients and elderly patients with dysphagia. OBJECTIVE: The present study investigated the effect of tablet grinding on the photostability of four types of commercial Wf tablets and predicted the photostability of the tablet powders by chemometric analysis. METHODS: The photodegradation of Wf content was evaluated by reversed-phase column high-performance liquid chromatography with ultraviolet (HPLC-UV). RESULTS: The bulk Wf powder was relatively photostable, whereas ground Wf tablets underwent substantial photodegradation. The photostability of the ground powders of a brand-name Wf commercial tablet and three generic Wf commercial tablets was quantitatively assessed and compared. In certain cases, the Wf in all the three ground generic tablets was less photostable than in the ground brand-name tablets. After 28 days of light irradiation, the Wf content decreased to 69.79% in the brand-name tablets, while it was 31.90% in some generic tablets. To clarify the factors influencing the relative photostability in various Wf formulations, we analyzed the intermolecular interactions between the active ingredient and the excipients by partial least-squares regression analysis based on photostability screening for each additive. CONCLUSION: The results suggested that the additives light anhydrous silicic acid and povidone adversely affect the stability of Wf tablets. In addition, the light stability of ground tablets was affected considerably by their formulation.

scholarly journals Inhibition or Facilitation? Contrasted Inter-Specific Interactions in Sphagnum under Laboratory and Field Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1554
Author(s):  
Chao Liu ◽  
Zhao-Jun Bu ◽  
Azim Mallik ◽  
Yong-Da Chen ◽  
Xue-Feng Hu ◽  
...  
Keyword(s):  
Field Experiment ◽  
Species Interactions ◽  
Laboratory Experiments ◽  
Resource Competition ◽  
Specific Interactions ◽  
Interaction Type ◽  
Negative Effects ◽  
Experiment Data ◽  
The Stability ◽  
Positive Effect

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

Experimentally Determined Stability Parameters of a Subsonic Cascade Oscillating Near Stall

1978 ◽  
Vol 100 (1) ◽  
pp. 111-120 ◽  
Author(s):  
F. O. Carta ◽  
A. O. St. Hilaire
Keyword(s):  
Phase Angle ◽  
Incidence Angle ◽  
Minor Effect ◽  
Significant Finding ◽  
Force Coefficient ◽  
Stability Parameters ◽  
Free System ◽  
Pressure Transducers ◽  
Moment Coefficient ◽  
The Stability

Tests were performed on a linear cascade of airfoils oscillating in pitch about their midchords at frequencies up to 17 cps, at free-stream velocities up to 200 ft/s, and at interblade phase angles of 0 deg and 45 deg, under conditions of high aerodynamic loading. The measured data included unsteady time histories from chordwise pressure transducers and from chordwise hot films. Unsteady normal force coefficient, moment coefficient, and aerodynamic work per cycle of oscillation were obtained from integrals of the pressure data, and indications of the nature and extent of the separation phenomenon were obtained from an analysis of the hot-film response data. The most significant finding of this investigation is that a change in interblade phase angle from 0 deg to 45 deg radically alters the character of the unsteady blade loading (which governs its motion in a free system) from stable to unstable. Furthermore, the stability or instability is governed primarily by the phase angle of the pressure distribution (relative to the blade motion) over the forward 10–15 percent of the blade chord. Reduced frequency and mean incidence angle changes were found to have a relatively minor effect on stability for the range of parameters tested.

Numerical Investigation of the Solidity Effect on Linear Compressor Cascades

2014 ◽  
Author(s):  
J. Sans ◽  
M. Resmini ◽  
J.-F. Brouckaert ◽  
S. Hiernaux
Keyword(s):  
Numerical Investigation ◽  
State Of The Art ◽  
Leading Edge ◽  
Operating Conditions ◽  
Compressor Cascade ◽  
Minimum Loss ◽  
Low Speed ◽  
High Mach ◽  
The Stability ◽  
The Impact

Solidity in compressors is defined as the ratio of the aerodynamic chord over the peripheral distance between two adjacent blades, the pitch. This parameter is simply the inverse of the pitch-to-chord ratio generally used in turbines. Solidity must be selected at the earliest design phase, i.e. at the level of the meridional design and represents a crucial step in the whole design process. Most of the existing studies on this topic rely on low-speed compressor cascade correlations from Carter or Lieblein. The aim of this work is to update those correlations for state-of-the-art controlled diffusion blades, and extend their application to high Mach number flow regimes more typical of modern compressors. Another objective is also to improve the physical understanding of the solidity effect on compressor performance and stability. A numerical investigation has been performed using the commercial software FINE/Turbo. Two different blade profiles were selected and investigated in the compressible flow regime as an extension to the low-speed data on which the correlations are based. The first cascade uses a standard double circular arc profile, extensively referenced in the literature, while the second configuration uses a state-of-the-art CDB, representative of low pressure compressor stator mid-span profile. Both profiles have been designed with the same inlet and outlet metal angles and the same maximum thickness but the camber and thickness distributions, the stagger angle and the leading edge geometry of the CDB have been optimized. The determination of minimum loss, optimum incidence and deviation is addressed and compared with existing correlations for both configurations and various Mach numbers that have been selected in order to match typical booster stall and choke operating conditions. The emphasis is set on the minimum loss performance at mid-span. The impact of the solidity on the operating range and the stability of the cascade are also studied.

Stability of dronabinol capsules when stored frozen, refrigerated, or at room temperature

2016 ◽  
Vol 73 (14) ◽  
pp. 1088-1092 ◽  
Author(s):  
Michael F. Wempe ◽  
Alan Oldland ◽  
Nancy Stolpman ◽  
Tyree H. Kiser
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Oxidative Degradation ◽  
Storage Condition ◽  
Sesame Oil ◽  
Forced Degradation ◽  
Product Packaging ◽  
Time Points ◽  
The Stability ◽  
Minimal Reduction

Abstract Purpose Results of a study to determine the 90-day stability of dronabinol capsules stored under various temperature conditions are reported. Methods High-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was used to assess the stability of dronabinol capsules (synthetic delta-9-tetrahydrocannabinol [Δ9-THC] mixed with high-grade sesame oil and other inactive ingredients and encapsulated as soft gelatin capsules) that were frozen, refrigerated, or kept at room temperature for three months. The dronabinol capsules remained in the original foil-sealed blister packs until preparation for HPLC–UV assessment. The primary endpoint was the percentage of the initial Δ9-THC concentration remaining at multiple designated time points. The secondary aim was to perform forced-degradation studies under acidic conditions to demonstrate that the HPLC–UV method used was stability indicating. Results The appearance of the dronabinol capsules remained unaltered during frozen, cold, or room-temperature storage. Regardless of storage condition, the percentage of the initial Δ9-THC content remaining was greater than 97% for all evaluated samples at all time points over the three-month study. These experimental data indicate that the product packaging and the sesame oil used to formulate dronabinol capsules efficiently protect Δ9-THC from oxidative degradation to cannabinol; this suggests that pharmacies can store dronabinol capsules in nonrefrigerated automated dispensing systems, with a capsule expiration date of 90 days after removal from the refrigerator. Conclusion Dronabinol capsules may be stored at room temperature in their original packaging for up to three months without compromising capsule appearance and with minimal reduction in Δ9-THC concentration.

Sign in / Sign up

Export Citation Format

Share Document