scholarly journals Piezoelectric surface acoustical phonon limited mobility of electrons in graphene on a GaAs substrate

2013 ◽  
Vol 87 (7) ◽  
Author(s):  
S. H. Zhang ◽  
W. Xu ◽  
S. M. Badalyan ◽  
F. M. Peeters
Keyword(s):  
Gaas Substrate ◽  
Limited Mobility ◽  
Acoustical Phonon

Cristal-growth dynamics of n-doped gaAs

1992 ◽  
Vol 50 (2) ◽  
pp. 1544-1545
Author(s):  
Pham V. Huong ◽  
Stéphanie Bouchet ◽  
Jean-Claude Launay
Keyword(s):  
Crystal Growth ◽  
Spatial Resolution ◽  
Epitaxial Layer ◽  
Outer Surface ◽  
Gaas Substrate ◽  
Structural Modification ◽  
Growth Dynamics ◽  
Argon Laser ◽  
High Anisotropy ◽  
Crystal Gaas

Microstructure of epitaxial layers of doped GaAs and its crystal growth dynamics on single crystal GaAs substrate were studied by Raman microspectroscopy with a Dilor OMARS instrument equipped with a 1024 photodiode multichannel detector and a ion-argon laser Spectra-Physics emitting at 514.5 nm.The spatial resolution of this technique, less than 1 μm2, allows the recording of Raman spectra at several spots in function of thickness, from the substrate to the outer deposit, including areas around the interface (Fig.l).The high anisotropy of the LO and TO Raman bands is indicative of the orientation of the epitaxial layer as well as of the structural modification in the deposit and in the substrate at the interface.With Sn doped, the epitaxial layer also presents plasmon in Raman scattering. This fact is already very well known, but we additionally observed that its frequency increases with the thickness of the deposit. For a sample with electron density 1020 cm-3, the plasmon L+ appears at 930 and 790 cm-1 near the outer surface.

Interfacial properties of GaSb/InAs superlattices

1993 ◽  
Vol 51 ◽  
pp. 826-827
Author(s):  
M. E. Twigg ◽  
B. R. Bennett ◽  
J. R. Waterman ◽  
J. L. Davis ◽  
B. V. Shanabrook ◽  
...  
Keyword(s):  
Gaas Substrate ◽  
Molecular Beam ◽  
Infrared Detector ◽  
Interfacial Properties ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
X Ray ◽  
Short Period ◽  
High Optical Absorption

Recently, the GaSb/InAs superlattice system has received renewed attention. The interest stems from a model demonstrating that short period Ga1-xInxSb/InAs superlattices will have both a band gap less than 100 meV and high optical absorption coefficients, principal requirements for infrared detector applications. Because this superlattice system contains two species of cations and anions, it is possible to prepare either InSb-like or GaAs-like interfaces. As such, the system presents a unique opportunity to examine interfacial properties.We used molecular beam epitaxy (MBE) to prepare an extensive set of GaSb/InAs superlattices grown on an GaSb buffer, which, in turn had been grown on a (100) GaAs substrate. Through appropriate shutter sequences, the interfaces were directed to assume either an InSb-like or GaAs-like character. These superlattices were then studied with a variety of ex-situ probes such as x-ray diffraction and Raman spectroscopy. These probes confirmed that, indeed, predominantly InSb-like and GaAs-like interfaces had been achieved.

Structural properties of GaAs/InGaAs/GaAs (001) and InGaAs/GaAs (001) heterostructures and correlation with electronic properties

1990 ◽  
Vol 48 (4) ◽  
pp. 602-603
Author(s):  
J.M. Bonar ◽  
R. Hull ◽  
R. Malik ◽  
R. Ryan ◽  
J.F. Walker
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Gaas Substrate ◽  
Critical Thickness ◽  
Lattice Mismatch ◽  
Band Offset ◽  
Misfit Dislocations ◽  
Gaas Substrates ◽  
Gaas Structure ◽  
Low X

In this study we have examined a series of strained heteropeitaxial GaAs/InGaAs/GaAs and InGaAs/GaAs structures, both on (001) GaAs substrates. These heterostructures are potentially very interesting from a device standpoint because of improved band gap properties (InAs has a much smaller band gap than GaAs so there is a large band offset at the InGaAs/GaAs interface), and because of the much higher mobility of InAs. However, there is a 7.2% lattice mismatch between InAs and GaAs, so an InxGa1-xAs layer in a GaAs structure with even relatively low x will have a large amount of strain, and misfit dislocations are expected to form above some critical thickness. We attempt here to correlate the effect of misfit dislocations on the electronic properties of this material.The samples we examined consisted of 200Å InxGa1-xAs layered in a hetero-junction bipolar transistor (HBT) structure (InxGa1-xAs on top of a (001) GaAs buffer, followed by more GaAs, then a layer of AlGaAs and a GaAs cap), and a series consisting of a 200Å layer of InxGa1-xAs on a (001) GaAs substrate.

Reconstruction Of Urban Parks Of Culture And Rest Of The Soviet Period

2019 ◽  
pp. 61-65
Keyword(s):  
Public Space ◽  
Senior Citizens ◽  
Urban Parks ◽  
Public Spaces ◽  
Historical Background ◽  
Soviet Period ◽  
Limited Mobility ◽  
Functional Zoning ◽  
Functional Areas ◽  
The City

This article analyzes the main problems of urban public spaces, because today public spaces can determine the future of cities. It is noted that parks are multifunctional public spaces in the urban environment, as they are an important element of the citywide system of landscaping and recreation, perform health, cultural, educational, aesthetic and environmental functions. The article notes that the need for easily accessible and well-maintained urban parks remains, however, the state of parks in many cities of Russia remains unsatisfactory, requiring reconstruction. A brief historical background of the Park of Culture and Rest of the Soviet period in Omsk is expounded, the analysis of the existing territory of the Park is presented. It is revealed that the Park, being the largest public space in Omsk, does not meet the requirements of modern urbanism, although it represents a great potential for designing the space for the purpose of recreation of citizens. Performed functional zoning scheme of the territory of the Park in question, where its division into functional areas destined for active recreational users of the Park is presented, considered the interests of senior citizens, people with limited mobility, etc. Reconstruction of Parks of the Soviet period can provide the city with additional recreational opportunities, as well as increase its tourist attractiveness.

Correction of functional constipation in patients with limited mobility after stroke

2019 ◽  
Vol 1 (6) ◽  
pp. 53-55
Author(s):  
M. S. Turchina ◽  
M. V. Bukreeva ◽  
L. Yu. Korolyova ◽  
Zh. E. Annenkova ◽  
L. G. Polyakov
Keyword(s):  
Quality Of Life ◽  
Chronic Constipation ◽  
Functional Constipation ◽  
Cerebrovascular Diseases ◽  
Medical Rehabilitation ◽  
Stroke Patients ◽  
Limited Mobility ◽  
Complete Restoration ◽  
The World

Currently, the problem of early rehabilitation of stroke patients is important, since in terms of the prevalence of cerebrovascular diseases and disability after suffering a stroke, Russia is one of the first places in the world. The complex of medical rehabilitation of such patients should provide for the early and most complete restoration of all body functions, patient education for lost skills, re-socialization of the patient and improvement of the quality of life. One of the factors contributing to a significant reduction in the quality of life after a stroke is the development of chronic constipation. The article reflects the modern methods of correction of chronic constipation in patients with limited mobility.

Clinical approbation of remote monitoring in treatment of patients in hospital and home care for patients with limited mobility

2020 ◽  
pp. 44-49
Author(s):  
A. A. Eryomenko ◽  
N. V. Rostunova ◽  
S. A. Budagyan ◽  
L. S. Sorokina
Keyword(s):  
High Risk ◽  
Home Care ◽  
Remote Monitoring ◽  
Emergency Situation ◽  
Home Treatment ◽  
Clinical Testing ◽  
Telemedicine System ◽  
Medical Supervision ◽  
Limited Mobility

The article describes the experience of clinical testing of the personal telemedicine system (PTS) ‘Obereg’ for remote monitoring of patients with the consequences of severe conditions in leading Russian clinics. It is shown that such patients are at high risk of complications when transferred from the ICU to a normal ward with limited medical supervision and lack of instrumentation. The use of remote monitoring using the personal telemedicine system ‘Obereg’ allows to solve this problem. The results of the use of PTS ‘Obereg’ for the organization of monitoring in the home patronage of patients with limited mobility are presented. It is indicated that such devices should be used in an emergency situation similar to a coronavirus pandemic to monitor patients who are in infectious boxes and on home treatment.

(InAs)1/(GaAs)2short period superlattice strained single quantum well laser on GaAs substrate

1993 ◽  
Vol 29 (1) ◽  
pp. 98-99 ◽  
Author(s):  
H. Kurakake ◽  
T. Uchida ◽  
H. Soda ◽  
S. Yamazaki
Keyword(s):  
Quantum Well ◽  
Gaas Substrate ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Quantum Well Laser

scholarly journals Photoconductive Antennas: Effects of Crystallographic Orientation of GaAs Substrate and the Period of Plasmon Grid on THz Antenna Performance (Ann. Phys. 8/2021)

2021 ◽  
Vol 533 (8) ◽  
pp. 2170025
Author(s):  
Arseniy M. Buryakov ◽  
Maxim S. Ivanov ◽  
Dinar I. Khusyainov ◽  
Anastasia V. Gorbatova ◽  
Vladislav R. Bilyk ◽  
...  
Keyword(s):  
Crystallographic Orientation ◽  
Gaas Substrate ◽  
Photoconductive Antennas ◽  
Antenna Performance ◽  
Thz Antenna

scholarly journals Tropism of Sub-Axial Cervical Facet Joints Is Not Related to Segmental Movement during Active Movement or Therapist-Perceived Symptomatic Locations

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 739
Author(s):  
Neil Tuttle ◽  
Kerrie Evans ◽  
Clarice Sperotto dos Santos Rocha
Keyword(s):  
Cervical Spine ◽  
Neck Pain ◽  
Active Movement ◽  
Facet Joints ◽  
Segmental Mobility ◽  
Limited Mobility ◽  
Translational Movement ◽  
The Difference ◽  
Cervical Facet ◽  
The Relationship

Tropism, or asymmetry, of facet joints in the cervical spine has been found to be related to degenerative changes of the joints and discs. Clinicians often assume that differences in segmental mobility are related to tropism. The aims of this study were to determine the relationship between asymmetry of facet joints in the sub-axial cervical spine and (1) segmental mobility and (2) spinal levels perceived by therapists to have limited mobility. Eighteen participants with idiopathic neck pain had MRIs of their cervical spine in neutral and at the end of active rotation. Angular movement and translational movement of each motion segment was calculated from 3D segmentations of the vertebrae. A plane was fitted to the facet on each side. Tropism was considered to be the difference in the orientation of the facet planes and ranged from 1 to 30° with a median of 7.7°. No relationships were found between the extent of tropism and either segmental movement or locations deemed to be symptomatic. Tropism in the sub-axial cervical spine does not appear to be related to segmental mobility in rotation or to levels deemed to be symptomatic.

Sign in / Sign up

Export Citation Format

Share Document