نتایج جستجو برای: diode

تعداد نتایج: 20961  

1999
Carl E. Wieman Leo Hollberg

We present a review of the use of diode lasers in atomic physics with an extensive list of references. We discuss the relevant characteristics of diode lasers and explain how to purchase and use them. We also review the various techniques that have been used to control and narrow the spectral outputs of diode lasers. Finally we present a number of examples illustrating the use of diode lasers i...

Introduction Evaluation of the delivered dose of externally wedged photon beams by external diode dosimeters during the treatment process requires the estimation of exit surface dose correction factors in various wedge angles and field sizes. Materials and Methods A system of absorbed dose evaluation, using p-type diode dosimeters placed on the exit surface of a phantom, was characterized for e...

1998
ERIC R. CARLSON

Abstruct-The two-diode subfmrmordcallypumped stripline mixer hasa pair of diodesshunt mounted with oppositepolarities in a striplfne circuit betweenthe sigsudand local oscillator inputs. The circuit haslow noiseand conversion10ssand substantialAM local oscillator noise cancellation.The load oscfflator frequency is abmsthaff the signal frequency.A novel diode chip, the notch-front dfodq which ha...

2001
Valdir C. Colussi A. Sam Beddar Timothy J. Kinsella Claudio H. Sibata

The AAPM Task Group 40 reported that in vivo dosimetry can be used to identify major deviations in treatment delivery in radiation therapy. In this paper, we investigate the feasibility of using one single diode to perform in vivo dosimetry in the entire radiotherapeutic energy range regardless of its intrinsic buildup material. The only requirement on diode selection would be to choose a diode...

2011
ALEXANDER ZEMLIAK ANDREY OSTROVSKY SERGIO VERGARA EVGENIY MACHUSSKIY

The analysis and optimization of the npvnp avalanche diode have been realized on basis of the nonlinear model and special optimization procedure. This type of the diode that was named as Double Avalanche Region (DAR) IMPATT diode includes two avalanche regions inside the diode. The phase delay which was produced by means of the two avalanche regions and the drift region v is sufficient to obtai...

In this research, tunability of a commercial diode laser has extended to about more than ± 11 nm using a V-shaped external-cavity fabricated around the laser. Although under normal condition it can be tuned up to about ± 4 nm just by changing its temperature and injection current. Such modified diode laser has then used in a difference-frequency generation (DFG) experimental setup as pump sourc...

Introduction: Skin cancer has been increased day by day, but it can be cured if it diagnosed early. After reviewing the scientific literature about 980 nm diode laser, and its multiple advantages on skin diseases. We studied in this paper the effectiveness of this type of laser on the progression of skin cancer among hamsters which were exposed to carcinogen on the bac...

2013
Yangjun Zhang Mengqing Yuan Qing Huo Liu

This paper investigates Ultra Wide Band (UWB) response of a self-actuated electromagnetic wave shield based on a diode grid both in frequency and time domain. The investigation is first carried out on a shield valid for an incident wave polarized at a specific direction only, then extended to a shield effective for an incident wave polarized at an arbitrary direction. In the frequency domain, t...

2007
Jurianto Joe Michael Chia Yan Wah Ashok K. Marath

Zero bias Schottky diode model for low RF input power (≤ 0 dBm at antenna input port) and moderate DC current (≥ 30 μA) RECtifying anTENNAs (RECTENNAs) is investigated. The model provides diode parameters at the desired output DC current level to be matched with the antenna so that optimum power transfer from antenna to the diode occurs. The model relies primarily on DC V-I diode characteristic...

Journal: :journal of dentistry, tehran university of medical sciences 0
sm. abtahi z. khamverdy

statement of the problem: various methods such as light emitting diode (led) have been used to enhance the polymerization of resin-based orthodontic adhesives. there is a lack of information on the advantages and disadvantages of different light curing systems. purpose: the aim of this study was to compare the effect of led and halogen light curing systems on the shear bond strength of orthodon...

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