Influence Of Growth Parameters On Interface Broadening In Mbe-Grown Interfaces: A Non Destructive Study By Magneto-Optics

1995 ◽  
Vol 406 ◽  
Author(s):  
W. Grieshaber ◽  
A. Haury ◽  
J. Cibert ◽  
Y. Merle d'Aubigné ◽  
A. Wasiela
Keyword(s):  
Quantum Wells ◽  
Significant Influence ◽  
Growth Parameters ◽  
Optical Technique ◽  
Mn Content ◽  
Non Destructive

AbstractWe present a detailed study of the influence of growth parameters on the broadening of CdTe-CdMnTe interfaces using a new magneto-optical technique [1,2] in MBE-grown quantum wells and superlattices. For growth temperatures up to about 300°C the Mn content decreases exponentially at the CdTe on CdMnTe interface and conversely the Cd one decreases exponentially at the CdMnTe on CdTe interface. At temperatures exceeding 300°C an additional broadening takes place which acts equally on both interfaces. Growth interruptions and modified flux stoechiometry do not exhibit significant influence on the broadening.

AES and EELFS Studies of Initial Stages of Growth of GaAs/InAs/GaAs Heterostructures.

1988 ◽  
Vol 144 ◽  
Author(s):  
F. D. Schowengerdt ◽  
F. J. Grunthaner ◽  
John K. Liu
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Growth Parameters ◽  
High Energy ◽  
Model Calculations ◽  
Mbe Growth ◽  
Quantum Well Structures ◽  
Stages Of Growth ◽  
Double Heterostructures ◽  
Composition And Structure

ABSTRACTWe report on a systematic study of the composition and structure of GaAs/InAs/GaAs quantum wells using Auger Electron Spectroscopy (AES), Extended Energy Loss Fine Structure (EELFS), and Reflection High Energy Electron Diffraction (RHEED) techniques. Double heterostructures with InAs thickness ranging from 2 to 10 monolayers, capped by 2 to 10 monolayers of GaAs, were grown by MBE using a variety of techniques, including those employing sequential, interrupted, and delayed shutter timing sequences. AES peak ratios are compared with model calculations to monitor compositional development of the multilayers. The AES results are correlated with RHEED measurements to determine MBE growth parameters for optimal control of the stoichiometry and surface morphology. EELFS was used to monitor strain in the buried InAs layers. The AES results show departure from smooth laminar growth of layers of stoichiometric InAs on GaAs at temperatures below 420 C and above 470 C. AES results on the quantum well structures suggest floating InAs layers on top of the GaAs and/or facet formation in the GaAs layers. The EELFS results, when compared to bulk InAs, indicate the presence of strain in the buried InAs quantum well.

scholarly journals Assessment of fruit firmness of pepper using non-destructive physical measurements, in response to different growing and pruning technologies

2003 ◽  
Vol 9 (1) ◽  
Author(s):  
D. Tompos ◽  
S. Istella ◽  
T. Ignát
Keyword(s):  
Significant Influence ◽  
Quality Parameters ◽  
European Market ◽  
Fruit Firmness ◽  
Physical Measurements ◽  
Vegetable Products ◽  
Important Quality ◽  
Non Destructive ◽  
Pruning Methods

The European market demands vegetable products of the highest quality and this commercial quality must be maintained till the goods reach the customer. One of these important quality parameters is the fruit firmness of pepper. The experiments were aimed at to find out the influence of different growing methods (soil or rockwool-based) and pruning technologies (to 1, 2, 3 or 4 shoots) on the yield and fruit firmness of three pepper varieties (HO F1, Karpia Fl and Pritavit F1) which are common in Hungary. Fruit firmness was measured by the non-destructive impact method. On the basis of the results, in unheated forcing the pruning to 1, 2 or 3 shoots can be suggested for all three varieties, as well as the utilisation of rockwool in their growing. The non-destructive impact method has been found suitable for testing the fruit firmness of pepper varieties. In the experiments involving different growing mediums pepper stands were found to show significant differences, however the different pruning methods had no significant influence on fruit firmness.

scholarly journals Application of Phosphorus and Calcium to Improve Physiological Response of Groundnut (Arachis hypogaea L.)

2021 ◽  
pp. 103-111
Author(s):  
Henry Tamba Nyuma ◽  
William S. Kollie ◽  
Cornel. L. Rweyemamu ◽  
John S. Fayiah
Keyword(s):  
Significant Influence ◽  
Physiological Response ◽  
Growth Parameters ◽  
Raw Materials ◽  
Smallholder Farmers ◽  
Application Rate ◽  
Crop Growth ◽  
Area Index ◽  
Net Assimilation ◽  
Crop Biomass

Genotype, environment and agronomic practices are key determinants of crop   growth and productivity which are important to provide food, feed, raw materials and income to small holder farmers in Africa. The study was conducted at Crop museum, Sokoine University of Agriculture, Morogoro, Tanzania to investigate physiological response of groundnut to calcium and phosphorus nutrition among three improved groundnut genotypes Mangaka (G1), Masasi (G2) and Pendo (G3) with three levels of phosphorus and at calcium control (T0), 125 kg/ha (T1) and 55 kg/ha (T2) supplied from Diammonium Phosphate (DAP) and Minjingu mazao, respectively.  Significant (P< 0.05) influence of calcium was observed on leaf area index (LAI) 4.03; crop biomass 88.79 g/plant; number of nodules 66.22, and crop growth rate (CGR) 15.05 g m2/day. Whereas phosphorus had significant influence on net assimilation rate (NAR) 10.84 g m2/day. Similarly, groundnut genotype (Masasi) had significant influence on LAI (3.95); CGR (13.04 g m2/day); NAR (12.36 g m2/day) and number of nodes (64.93). However, there was no significant effect of genotype on crop biomass recorded from the investigation. Growth  parameters were significant influenced by genotype and fertilizer interactions with Significant (P=0.2) interaction effect for crop biomass observed between G3 x T1, whileG3 x T2 significantly affected number of nodules and G2 x T1 had Significant interaction effects on CGR and NAR. This is an indication that investment in improved genotype and appropriate application rate of fertilizers has the potential to enhance yield and income of smallholder farmers.

X-Rays for Fluid Flow Inspection

2004 ◽  
Author(s):  
D. Chambellan ◽  
O. Gal ◽  
S. Legoupil ◽  
A. Vabre
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Specific Gravity ◽  
Void Fraction ◽  
X Rays ◽  
Optical Technique ◽  
X Ray ◽  
Non Destructive Evaluation ◽  
Intensive Use ◽  
Non Destructive

X-rays techniques are widely used in the non-destructive evaluation field for mechanical inspection. However, development of new x-ray detectors and sources over the last decade has let to an intensive use of this technique in other fields. In this paper, we describe the use of X-rays techniques in the field of fluid flow engineering (fluidics and heat transfer). This technique is very attractive since measurements can be performed even if pressure, temperature require the use of opaque walls. In addition the X-ray technique is well suited to multiphase flows where optical technique can not be used if void fraction is larger than few percents. Specific gravity, mass or void fraction are the main accessible parameters.

scholarly journals Non-Destructive Measurement of Three-Dimensional Plants Based on Point Cloud

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 571 ◽  
Author(s):  
Yawei Wang ◽  
Yifei Chen
Keyword(s):  
Plant Growth ◽  
Point Cloud ◽  
Growth Parameters ◽  
Leaf Shape ◽  
Three Dimensional ◽  
3D Point Cloud ◽  
Surface Integral ◽  
Plant Model ◽  
Destructive Measurement ◽  
Non Destructive

In agriculture, information about the spatial distribution of plant growth is valuable for applications. Quantitative study of the characteristics of plants plays an important role in the plants’ growth and development research, and non-destructive measurement of the height of plants based on machine vision technology is one of the difficulties. We propose a methodology for three-dimensional reconstruction under growing plants by Kinect v2.0 and explored the measure growth parameters based on three-dimensional (3D) point cloud in this paper. The strategy includes three steps—firstly, preprocessing 3D point cloud data, completing the 3D plant registration through point cloud outlier filtering and surface smooth method; secondly, using the locally convex connected patches method to segment the leaves and stem from the plant model; extracting the feature boundary points from the leaf point cloud, and using the contour extraction algorithm to get the feature boundary lines; finally, calculating the length, width of the leaf by Euclidean distance, and the area of the leaf by surface integral method, measuring the height of plant using the vertical distance technology. The results show that the automatic extraction scheme of plant information is effective and the measurement accuracy meets the need of measurement standard. The established 3D plant model is the key to study the whole plant information, which reduces the inaccuracy of occlusion to the description of leaf shape and conducive to the study of the real plant growth status.

Optical Technique for Characterization of High Energy Ion Implanted Materials

1992 ◽  
Vol 268 ◽  
Author(s):  
Gustavo E Aizenberg ◽  
Pieter L Swart ◽  
Beatrys M Lacquet
Keyword(s):  
Refractive Index ◽  
Digital Signal ◽  
Amorphous Layer ◽  
High Energy ◽  
Optical Technique ◽  
Concentration Peak ◽  
Non Destructive ◽  
Reflectance Data ◽  
Ion Implanted

ABSTRACTA new method for the characterization of high energy ion-implanted materials has been developed. The refractive index and thickness of the amorphous layer produced by ion-implantation as well as the recrystallized layer formed by annealing of the ionimplanted samples can be determined by means of this non-destructive optical technique.For frequencies where the carriers do not respond, the measured reflectance is bilinear transformed, and further digital signal processing yields information about thickness and refractive index of the abovementioned layers. When working at optical frequencies where the carriers can respond to the electromagnetic field the physical position of the peak concentration follows directly from the processed reflectance data. Simulated and experimental data have been analyzed. The position of the boundaries between the amorphous, recrystallized and substrate zones, as well as the position of the carrier concentration peak can be determined for various steps of annealing. The algorithm has the advantage of being simple and time efficient.

Nanoscale Features Grown by MBE on Nonplanar Patterned Si Substrates

1995 ◽  
Vol 380 ◽  
Author(s):  
Karl D. Hobart ◽  
Fritz J. Kub ◽  
Henry F. Gray ◽  
Mark E. Twigg ◽  
Doewon Park ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Growth Parameters ◽  
Multiple Quantum ◽  
Electron Microscopies ◽  
Si Substrates ◽  
Transmission Electron ◽  
Low Dimensional ◽  
20 Nm ◽  
Nanoscale Features ◽  
Qualitative Changes

ABSTRACTSi growth by molecular beam epitaxy on nonplanar patterned Si substrates is studied as a function of growth parameters. The substrates consist of a truncated pyramid template with {111} sides and (100) tops formed by anisotropic etching of Si(100). For growth temperatures ≤ 550°C no qualitative changes in the morphology of the template are observed. At growth temperatures between 650–700°C {113} facets begin to form on the (100) surface and reduce the lateral dimensions of the (100) facet to < 20 nm. At high temperatures (∼800°C) {113} facets remain stable and {111} facets no longer exist. The small (100) mesa formed at medium temperatures by facet reduction is exploited through the growth of Si/Si 1-xGex multiple quantum wells leading to low-dimensional structures. Observations are quantified by scanning electron and transmission electron microscopies.

Aluminium Doping of 4H-SiC Grown with HexaMethylDiSilane

2005 ◽  
Vol 483-485 ◽  
pp. 121-124 ◽  
Author(s):  
C. Sartel ◽  
Véronique Soulière ◽  
Marcin Zielinski ◽  
Yves Monteil ◽  
Jean Camassel ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Parameters ◽  
Growth Conditions ◽  
P Systems ◽  
P System ◽  
Aluminium Concentration ◽  
P Type ◽  
Non Destructive ◽  
Aluminium Doping

We report on the study of the p-type doping of 4H-SiC material using HexaMethylDiSilane/TriMethylAluminium/Propane (HMDS/TMA/P) system in place of the usual Silane/TriMethylAluminium/Propane (S/TMA/P) precursors. The influence of growth parameters such as TMA flow, growth rate or C/Si ratio is investigated. The aluminium incorporation level is deduced from both by C(V) (mercury probe) and SIMS measurements. The presence of aluminium in the layers is confirmed by non-destructive optical micro-Raman experiments. Good quality p-type, aluminium doped 4H-SiC layers can be grown using HMDS/TMA/P system. The amount of aluminium in the layers can be controlled by choosing the growth conditions and an aluminium concentration as high as 2x1019 at.cm-3 has been reached.Finally, comparing the two HMDS/TMA/P and S/TMA/P systems, no difference in aluminium incorporation has been found.

Sign in / Sign up

Export Citation Format

Share Document