scholarly journals The pattern of stolon growth, onset of bulking, and time-span of stolonisation and tuberisation by cv. Pierwiosnek, an early potato variety

2015 ◽  
Vol 30 (1) ◽  
pp. 51-69
Author(s):  
B. Lis-Kaczyńska ◽  
A. Listowski
Keyword(s):  
Potato Variety ◽  
Growth Conditions ◽  
Time Span ◽  
Tuber Initiation ◽  
Growth Time ◽  
Early Potato ◽  
Initiation Frequency ◽  
Growth Differences

Experiments were performed to check the course of stalonisation growth of the stolons and of the tuberisation in three experiments in which the plants of an early potato cv. Pierwiosnek grew under different conditions, including different lengths of the day. The following were inwestigated: the rate of stolon emergence, stolon growth, differences of the pattern of stolon growth, time-span of stolonisation and of tuber initiation, frequency of particular patterns of stolon growth in relation to the time of stolen emergence, intensity of terminal and laterel tuberisation, and of the branching of the stolons. The differences in the growth conditions in each of the three experiments enabled us to check the of variability of the particular features during the development of the stolons.

scholarly journals A Computational Model of Bidirectional Axonal Growth in Micro-Tissue Engineered Neuronal Networks (micro-TENNs)

2018 ◽  
Author(s):  
Toma Marinov ◽  
Liang Yuchi ◽  
Dayo O. Adewole ◽  
D. Kacy Cullen ◽  
Reuben H. Kraft
Keyword(s):  
White Matter ◽  
Computational Model ◽  
Large Scale ◽  
Three Dimensional ◽  
Growth Conditions ◽  
Growth Time ◽  
Directional Growth ◽  
System Reconstruction ◽  
Realistic Neuron

AbstractMicro-Tissue Engineered Neural Networks (Micro-TENNs) are living three-dimensional constructs designed to replicate the neuroanatomy of white matter pathways in the brain, and are being developed as implantable microtissue for axon tract reconstruction or as anatomically-relevant in vitro experimental platforms. Micro-TENNs are composed of discrete neuronal aggregates connected by bundles of long-projecting axonal tracts within miniature tubular hydrogels. In order to help design and optimize micro-TENN performance, we have created a new computational model including geometric and functional properties. The model is built upon the three-dimensional diffusion equation and incorporates large-scale uni- and bi-directional growth that simulates realistic neuron morphologies. The model captures unique features of 3D axonal tract development that are not apparent in planar outgrowth, and may be insightful for how white matter pathways form during brain development. The processes of axonal outgrowth, branching, turning and aggregation/bundling from each neuron are described through functions built on concentration equations and growth time distributed across the growth segments. Once developed we conducted multiple parametric studies to explore the applicability of the method and conducted preliminary validation via comparisons to experimentally grown micro-TENNs for a range of growth conditions. Using this framework, this model can be applied to study micro-TENN growth processes and functional characteristics using spiking network or compartmental network modeling. This model may be applied to improve our understanding of axonal tract development and functionality, as well as to optimize the fabrication of implantable tissue engineered brain pathways for nervous system reconstruction and/or modulation.

scholarly journals X-ray investigation of polytype distribution in InAs nanowires during MBE growth

2014 ◽  
Vol 70 (a1) ◽  
pp. C748-C748
Author(s):  
Ullrich Pietsch ◽  
Andreas Biermanns ◽  
Emmanouil Dimakis ◽  
Lutz Geelhaar ◽  
Anton Davydok ◽  
...  
Keyword(s):  
Time Evolution ◽  
Stacking Faults ◽  
Growth Conditions ◽  
Growth Mode ◽  
Ex Situ ◽  
Growth Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Liquid Indium

The monolithic integration of III-V semiconductors with Si is the ideal way to combine the superior optoelectronic properties of the compound semiconductors with the mature Si technology. This integration can be realized by growing epitaxially dislocation-free III-V NWs on Si substrates either in the vapor-liquid-solid (VLS) or in the vapor-solid (VS) mode associated with the presence or absence, respectively, of group-III liquid droplets on the NW tips [1]. In this work, we investigate the correlation between the growth mode and the forming polytypes in InAs NWs grown on Si(111). The growth was performed in the molecular beam epitaxy chamber of beamline 11XU at Spring8 [2], while the structural dynamics was probed by in situ x-ray diffraction. Specifically, the time evolution of the formation of wurtzite (WZ) and zincblende (ZB) polytypes was monitored during the NW growth. Despite the As-rich growth conditions, a spontaneous build-up of liquid In on Si was found to be present in the nucleation phase, where the InAs nuclei mainly grow in the WZ phase with low number of stacking faults. Shortly after the nucleation, the liquid In is consumed by the excessive As, and the growth continues in the VS mode with an increasing density of stacking faults forming in the NW crystal. The time evolution of the liquid Indium signal (Fig. (a)) correlates well with the time evolution of wurzite growth rate (Fig (b)). The latter saturates at a time where the liquid indium disappers, i.e. where the VLS changes into the VS mode, whereas the zinc-blende polytypes grow almost continuous in both VLS and VS growth mode. The dynamics of stacking faults density was determined quantitatively by ex-situ X-ray diffraction measuring thestacking fault induced increase of the peak width of wurtzite reflections at InAs nanowire samples of different length ; i.e. growth time [3].

High Mobility Nitrides

2001 ◽  
Vol 693 ◽  
Author(s):  
K. Scott ◽  
A. Butcher ◽  
Marie Wintrebert-Fouquet ◽  
Patrick P.–T. Chen ◽  
Trevor L. Tansley ◽  
...  
Keyword(s):  
Indium Nitride ◽  
High Mobility ◽  
Lag Time ◽  
Growth Conditions ◽  
Growth Time ◽  
Ion Sputtering ◽  
System A ◽  
Polycrystalline Thin Films ◽  
Reactive Ion Sputtering ◽  
Stable Material

AbstractThe highest mobility nitrides ever grown were indium nitride polycrystalline thin films. The original reactive ion sputtering unit used to produce those films is still in existence and has been substantially upgraded. In this paper we describe some of the parameters that are important for high purity indium nitride growth, while providing the most recent results for films grown with the upgraded system. A long lag time (greater than 100 hours of growth time) has been observed before obtaining stable material properties for a given set of growth conditions.

Accumulated day-degrees as a measure of physiological age and the relationships with growth and yield in early potato varieties

1983 ◽  
Vol 101 (3) ◽  
pp. 613-631 ◽  
Author(s):  
P. J. O'Brien ◽  
E. J. Allen ◽  
J. N. Bean ◽  
R. L. Griffith ◽  
Susan A. Jones ◽  
...  
Keyword(s):  
Growth And Yield ◽  
Physiological Age ◽  
Tuber Initiation ◽  
Early Potato ◽  
Effective Measure ◽  
Potato Varieties ◽  
Field Growth ◽  
And Storage ◽  
Sprout Growth ◽  
Young Seed

SUMMARYData from nine experiments from 1973 to 1981 which examined the effects of physiological age on sprout and field growth of early potato varieties are reported. Length of longest sprout per tuber and all aspects of field growth were related to number of daydegrees > 4 °C experienced by the seed after onset of sprout growth (measured as the appearance of a 3 mm sprout). It is, therefore, suggested that this scale is an effective measure of physiological age. In Home Guard and Maris Bard, increasing age of seed tubers resulted in earlier emergence and tuber initiation, larger early leaf areas and increased early tuber yields. As growth proceeded young seed produced the largest and most persistent leaf areas and the yields surpassed those of older seed and in some experiments yields decreased with increasing age at the final harvests.Optimum ages for specific harvesting periods were determined from regressions of tuber yield on age. In both varieties, they decreased with delay in harvesting. However, optimum ages differed in the two varieties and the implications for production and storage of seed and testing of varieties are discussed.

Properties of Thick n- and p-Type Epitaxial Layers of 4H-SiC Grown by Hot-Wall CVD on Off- and On-Axis Substrates

2006 ◽  
Vol 527-529 ◽  
pp. 183-186 ◽  
Author(s):  
Jawad ul Hassan ◽  
Christer Hallin ◽  
Peder Bergman ◽  
Erik Janzén
Keyword(s):  
Material Properties ◽  
Carrier Lifetime ◽  
Growth Conditions ◽  
Deep Levels ◽  
Growth Time ◽  
Epitaxial Layers ◽  
Electrical Measurements ◽  
P Type ◽  
Thick Layers

Thick epitaxial layers of 4H-SiC both n- and p-type were grown using horizontal Hot- Wall CVD (HWCVD). No large difference in the carrier lifetime was observed for the layers grown on n- and p-type substrates. The carrier lifetime usually increases with the increasing thickness of the epilayer. To investigate if the growth conditions and material properties are changing during the longer growth time a sample was prepared with uniformly varying epilayer thickness from 20μm on one side to 110μm on other side. Results of optical and electrical measurements, the variation in background impurities and other deep levels are discussed. Furthermore, the properties of thick layers grown on on-axis substrates are presented.

scholarly journals Nanostructure ITO and Get More of It. Better Performance at Lower Cost

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1974 ◽  
Author(s):  
Manel López ◽  
Juan Luis Frieiro ◽  
Miquel Nuez-Martínez ◽  
Martí Pedemonte ◽  
Francisco Palacio ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Growth Conditions ◽  
Growth Time ◽  
Two Phase ◽  
Nanostructured Surfaces ◽  
Flat Film ◽  
Phase Temperature ◽  
Temperature Activation ◽  
Dependent Growth ◽  
And Performance

In this paper, we investigated how different growth conditions (i.e., temperature, growth time, and composition) allows for trading off cost (i.e., In content) and performance of nanostructured indium tin oxide (ITO) for biosensing applications. Next, we compared the behavior of these functionalized nanostructured surfaces obtained in different growth conditions between each other and with a standard thin film as a reference, observing improvements in effective detection area up to two orders of magnitude. This enhanced the biosensor’s sensitivity, with higher detection level, better accuracy and higher reproducibility. Results show that below 150 °C, the growth of ITO over the substrate forms a homogenous layer without any kind of nanostructuration. In contrast, at temperatures higher than 150 °C, a two-phase temperature-dependent growth was observed. We concluded that (i) nanowire length grows exponentially with temperature (activation energy 356 meV) and leads to optimal conditions in terms of both electroactive surface area and sensitivity at around 300 °C, (ii) longer times of growth than 30 min lead to larger active areas and (iii) the In content in a nanostructured film can be reduced by 10%, obtaining performances equivalent to those found in commercial flat-film ITO electrodes. In summary, this work shows how to produce appropriate materials with optimized cost and performances for different applications in biosensing.

Influence of Growth Conditions on the Formation of Fish-Bone GNFs by CVD Using Ni Foam as Catalyst

2007 ◽  
Vol 121-123 ◽  
pp. 153-158
Author(s):  
W.Z. Huang ◽  
X.B. Zhang ◽  
F.Z. Kong ◽  
Y. Li ◽  
D. Lu ◽  
...  
Keyword(s):  
Gas Flow ◽  
Bone Structure ◽  
Growth Conditions ◽  
Fish Bone ◽  
High Yield ◽  
Growth Time ◽  
Hydrogen Treatment ◽  
Ni Foam ◽  
Simple Method ◽  
Optimized Conditions

GNFs with fish-bone structure were first produced by a simple method. To optimize the growth conditions, different hydrogen treatment of the catalyst, different growth time and growth temperature, as well as different gas flow rate were employed. The effects of these growth conditions on the morphology and yield of GNFs were studied in details. It is found that fish-bone GNFs with high yield and high purity can be produced under the optimized conditions.

Influence of Growth Conditions on Morphology of ZnO Nanorods by Low-Temperature Hydrothermal Method

2016 ◽  
Vol 675-676 ◽  
pp. 53-56
Author(s):  
Supawadee Pokai ◽  
Puenisara Limnonthakul ◽  
Mati Horprathum ◽  
Sukon Kalasung ◽  
Pitak Eiamchai ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Hydrothermal Method ◽  
Zno Nanorods ◽  
Cost Effective ◽  
Growth Conditions ◽  
Growth Time ◽  
Thermoelectric Device ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray

Zinc oxide (ZnO) nanorods (NRs) promise high potentials in several applications, such as photovoltaic device, thermoelectric device, sensor and solar cell. In this research, the vertical alignment of ZnO NRs was fabricated by hydrothermal method with various precursor concentrations and growth time on different seed layers (ZnO and Au), which deposited on silicon wafer substrate (100). The crystalline structure and morphology of ZnO NRs have been characterized by x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) techniques, respectively. The x-ray diffraction pattern shows that the prepared samples have a strong preferred orientation (002) plane. FE-SEM images of the ZnO NRs, it found that the density and aspect ratio were strongly influenced by the seed layer and precursor concentration. In addition, the aspect ratio of ZnO NRs was increased with increasing growth time. This study provides a cost effective method for the fabrication of well aligned ZnO NRs for nano-electronic devices.

scholarly journals GaN and InGaN Nanowires on Si Substrates by Ga-Droplet Molecular Beam Epitaxy

2008 ◽  
Vol 1080 ◽  
Author(s):  
Kevin Goodman ◽  
Kejia Wang ◽  
Xiangning Luo ◽  
John Simon ◽  
Tom Kosel ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Molecular Beam Epitaxy Growth ◽  
Growth Time ◽  
Band Edge Emission ◽  
Si Substrates ◽  
Gan Nanowires ◽  
Transmission Electron ◽  
Microscopy Images

ABSTRACTMolecular beam epitaxy growth of GaN and InGaN nanowires is accomplished on Si (111) substrates using Ga-droplet nucleation. Typical diameters range from 25-80 nm and lengths can be varied by increasing the growth time; the growth rate is ∼0.25 microns/hour. The nanowires have been characterized structurally and optically. Photoluminescence spectra show band-edge emission of GaN nanowires centered at 362 nm at 290 K. Transmission electron microscopy images unveil that the nanowires are highly crystalline, and grow along the 0001 polar direction. Indium has also been successfully incorporated into GaN nanowires by modifying the growth conditions; the InGaN nanowires emit at ∼520 nm, which provides a possible route to solving strain related problems of high In-composition InGaN based efficient green emitters.

Sign in / Sign up

Export Citation Format

Share Document