Improvement in Surface Morphology and Crystal Epitaxial CaF2 on Si (100) Through two Mbe Growth Stages

1988 ◽  
Vol 116 ◽  
Author(s):  
Yoshihiro Morimoto ◽  
Shoichiro Matsumoto ◽  
Shoji Sudo ◽  
Kiyoshi Yoneda
Keyword(s):  
Surface Morphology ◽  
Smooth Surface ◽  
Growth Stage ◽  
Early Growth ◽  
Crystal Quality ◽  
Growth Stages ◽  
Optimum Conditions ◽  
Si Substrate ◽  
Mbe Growth

AbstractWe report the first study on improvement in surface morphology and crystal quality of as—grown epitaxial CaF2 film on a (100) Si substrate grown through two MBE growth stages without any post-growth treatment. The degree of improvement in surfacemorphology and crystal quality depends not only on the thickness of an initial thin CaF2 film grown at the early growth stage of 550ºC but also on both the subsrate temperature and thickness of a sequential grown CaF2 film used for thesecond growth stage. Under optimum conditions, the CaF2 films exhibited high quality with an RBS/channeling minimum yield of 4%, together with a very smooth surface morphology without any other nuclel or cracks.

Crystal Quality and Surface Morphology Improvement of Movpe-Grown GaAs-on-Si Using Tertiarybutylarsine

1992 ◽  
Vol 281 ◽  
Author(s):  
S. MIYAGAKI ◽  
S. Ohkubo ◽  
K. Takai ◽  
N. Takagi ◽  
M. Kimura ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Buffer Layer ◽  
Vapor Phase ◽  
Metalorganic Vapor Phase Epitaxy ◽  
Layer Growth ◽  
Vapor Phase Epitaxy ◽  
Crystal Quality ◽  
Si Substrate ◽  
Gaas Films

ABSTRACTWe developed GaAs heteroepitaxy on a Si substrate by metalorganic vapor phase epitaxy (MOVPE) using tertiarybutylarsine (TBAs). In buffer layer growth at 450°C, the surface morphology and crystal quality of TBAs-grown films were slightly inferior to those of AsH3-grown films. At buffer layer growth below 400°C, the quality of TBAs-grown films improved. The GaAs films we grew using TBAs had a better quality than those grown using AsH2.

Control of Early Watergrass (Echinochloa Oryzoides) and Late Watergrass (Echinochloa Phyllopogon) with Cyhalofop, Clefoxydim, and Penoxsulam Applied Alone and in Mixture with Broadleaf Herbicides

2006 ◽  
Vol 20 (4) ◽  
pp. 992-998 ◽  
Author(s):  
Christos A. Damalas ◽  
Kico V. Dhima ◽  
Ilias G. Eleftherohorinos
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Application Rate ◽  
Early Growth ◽  
Rice Fields ◽  
Growth Stages ◽  
Early Growth Stage ◽  
Late Growth ◽  
Echinochloa Phyllopogon

Experiments were conducted to study the effect of application rate, growth stage, and tank-mixing azimsulfuron or bentazon on the activity of cyhalofop, clefoxydim, and penoxsulam against two morphologically distinctEchinochloaspecies from rice fields in Greece. Mixtures of penoxsulam with MCPA were also evaluated. Cyhalofop (300 to 600 g ai/ha) applied at the three- to four-leaf growth stage provided 62 to 85% control of early watergrass but 41 to 83% control of late watergrass averaged over mixture treatments. Control ranged from 37 to 80% for early watergrass and from 35 to 78% for late watergrass when cyhalofop was applied at the five- to six-leaf growth stage averaged over mixture treatments. Mixtures of cyhalofop with azimsulfuron or bentazon reduced efficacy on both species irrespective of growth stage or cyhalofop application rate compared with cyhalofop alone. Clefoxydim (100 to 250 g ai/ha) applied alone at the three- to four-leaf growth stage provided 98 to 100% control of early watergrass and 91 to 100% control of late watergrass; when clefoxydim was applied alone at the five- to six-leaf growth stage the control obtained was 91 to 100% for early watergrass and 79 to 100% for late watergrass. Mixtures of clefoxydim with azimsulfuron or bentazon reduced efficacy on late watergrass at the early growth stage and on both species at the late growth stage. Penoxsulam (20 to 40 g ai/ha) applied alone provided 94 to 100% control of both species at both growth stages. Mixtures of MCPA with penoxsulam reduced efficacy on late watergrass at the early growth stage and on both species at the late growth stage. Mixtures of penoxsulam with azimsulfuron or bentazon reduced efficacy only on late watergrass at the late growth stage.

A review of copper fertilizer management for optimum yield and quality of crops in the Canadian Prairie provinces

2006 ◽  
Vol 86 (3) ◽  
pp. 605-619 ◽  
Author(s):  
S. S. Malhi ◽  
R. E. Karamanos
Keyword(s):  
Seed Yield ◽  
Growth Stage ◽  
Field Experiments ◽  
Seed Quality ◽  
Soil Analysis ◽  
Growth Stages ◽  
Canadian Prairie ◽  
Cu Deficiency ◽  
Yield And Quality

Deficiency of copper (Cu) in Canadian prairie soils is not widespread, but whenever it occurs it can cause a drastic reduction in seed yield and quality of most cereals, especially wheat. Field experiments conducted in western Canada indicated that broadcast-incorporation of granular Cu fertilizers prior to seeding at 3-5.6 kg Cu ha-1 was usually sufficient to prevent Cu deficiency in wheat, and improve seed yield and quality. At lower rates (< 2.0 kg Cu ha-1), broadcast-incorporation of granular Cu fertilizers was not effective, while surface spray-broadcast followed by incorporation of liquid Cu fertilizers was much more effective in increasing seed yield of wheat in the first year of application. Surface broadcast without incorporation and seedrow-placed granular Cu fertilizers were much less effective in improving seed yield of wheat than their foliar or soil-incorporated applications. In the growing season, foliar applications of Cu at 0.20 to 0.28 kg Cu ha-1 to wheat at the Feekes 6 (first node of stem visible at base of shoot or stem elongation), Feekes 10 (sheath of last leaf completely grown or flag-leaf) and early boot growth stages were very effective in restoring seed yield, while Cu applications at the Feekes 2 (four-leaf) or Feekes 10.5 (complete heading) growth stage did not have a consistent effect to correct damage caused by Cu deficiency. Some Cu fertilizers (e.g., Cu oxide) were less effective than others in preventing/correcting Cu deficiency. Soil application at relatively high rates produced residual benefits in increasing seed yield for a number of years. The sensitivity of crops to Cu deficiency is usually in the order (wheat, flax, canary seed) > (barley, alfalfa) > (timothy seed, oats, corn) > (peas, clovers) > (canola, rye, forage grasses). Stem melanosis in wheat was associated with deficiency of Cu in soil, and the disease was reduced substantially with Cu application. A high level of available P in soil was observed to induce/increase severity of Cu deficiency in wheat. Soil analysis for diethylene triamine pentacetic acid- (DTPA) extractable Cu in soil can be used as a good diagnostic tool to predict Cu deficiency, but there was a poor relationship between total Cu concentration in shoots and the degree of Cu deficiency in crops. Application of Cu fertilizers to wheat on Cu-deficient soils also generally improved seed quality. Key words: Application time, Cu source, foliar application, granular Cu, growth stage, placement method, rate of Cu, seedrow-placed Cu, soil incorporation, wheat

Effect of gas flow rate on surface morphology and crystal quality of ZnTe epilayers grown on GaAs substrates

2011 ◽  
Vol 46 (4) ◽  
pp. 551-554 ◽  
Author(s):  
Qixin Guo ◽  
Masaki Nada ◽  
Yaliu Ding ◽  
Katsuhiko Saito ◽  
Tooru Tanaka ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Flow Rate ◽  
Gas Flow ◽  
Crystal Quality ◽  
Gas Flow Rate ◽  
Gaas Substrates

scholarly journals Using 77Se-Labelled Foliar Fertilisers to Determine How Se Transfers Within Wheat Over Time

2021 ◽  
Vol 8 ◽  
Author(s):  
Chandnee Ramkissoon ◽  
Fien Degryse ◽  
Scott Young ◽  
Elizabeth H. Bailey ◽  
Michael J. McLaughlin
Keyword(s):  
Growth Stage ◽  
Practical Knowledge ◽  
Stem Elongation ◽  
Early Growth ◽  
Sodium Selenate ◽  
Growth Stages ◽  
Young Leaves ◽  
Urea Inclusion ◽  
Heading Stage ◽  
Over Time

Foliar selenium (Se) fertilisation has been shown to be more efficient than soil-applied fertilisation, but the dynamics of absorption and translocation have not yet been explored. An experiment was undertaken to investigate time-dependent changes in the absorption, transformation, and distribution of Se in wheat when 77Se-enriched sodium selenate (Sefert) was applied to the leaves at a rate of 3.33 μg Se per kg soil (equivalent to 10 g ha−1) and two growth stages, namely stem elongation, Zadoks stage 31/32 (GS1), and heading stage, Zadoks stage 57 (GS2). The effect of urea inclusion in foliar Se fertilisers on the penetration rates of Se was also investigated. Wheat was harvested at 3, 10, and 17 days and 3, 10, and 34 days after Se applications at GS1 and GS2, respectively. Applying foliar Se, irrespective of the formulation, brought grain Se concentration to a level high enough to be considered adequate for biofortification. Inclusion of N in the foliar Se solution applied at an early growth stage increased recoveries in the plants, likely due to improved absorption of applied Se through the young leaves. At a later growth stage, the inclusion of N in foliar Se solutions was also beneficial as it improved the assimilation of applied inorganic Se into bioavailable selenomethionine, which was then rapidly translocated to the grain. The practical knowledge gained about the optimisation of Se fertiliser formulation, method, and timing of application will be of importance in refining biofortification programs across different climatic regimes.

Effect of growth stage at cutting on yield and quality of lucerne cultivars from different dormancy groups in northern Victoria

1987 ◽  
Vol 27 (1) ◽  
pp. 55 ◽  
Author(s):  
RH Slarke ◽  
WK Mason
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Dry Matter ◽  
Growth Stage ◽  
In Vitro Digestibility ◽  
Growth Stages ◽  
Flower Bud ◽  
Yield And Quality

At Kyabram, Victoria, the effects of growth stage at cutting on dry matter (DM) yield and quality of lucerne was determined during the warm season haymaking period for cultivars with contrasting winter dormancy characteristics. Growth stages at cutting were pre-flower bud, flower-bud, 10% bloom and full bloom. Cultivars were winter non-dormant CUF 101 and Pioneer Brand 572, semi-winter dormant Pioneer Brand 581 and winter dormant Pioneer Brand 545. Cultivar responses or interactions between cultivar and growth stage at cutting were not significant (P>0.05) for dry matter yield, crude protein or in vitro digestibility. Cutting of the pre-flower bud stage, compared with cutting at the 10% bloom stage, reduced DM yield by 18% (16.4 v. 13.5 t/ha), but increased crude protein content of the lucerne from 19.3 to 24%. The total protein yield per hectare was not affected by cutting stages from pre-flower bud stage to 10% bloom. Cutting lucerne at the flower bud stage rather than at 10% bloom gave increased protein content and digestibility with only a moderate yield decline. However, more frequent cutting was unsatisfactory as it decreased the density of the stand and increased the proportion of weeds and so could not be recommended.

Response of Asiatic Dayflower (Commelina communis) to Glyphosate and Alternatives in Soybean

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Santiago M. Ulloa ◽  
Micheal D. K. Owen
Keyword(s):  
Growth Stage ◽  
Field Research ◽  
Early Growth ◽  
Growth Stages ◽  
Anecdotal Evidence ◽  
Single Application ◽  
Emergence Period ◽  
Early Growth Stage ◽  
Greenhouse Experiments ◽  
Corn Plants

Asiatic dayflower has recently become a troublesome weed in eastern Iowa. This weed demonstrates an extended emergence period and there is anecdotal evidence of glyphosate tolerance. Thus, Asiatic dayflower is difficult to manage in glyphosate-resistant (GR) corn and soybean. Greenhouse experiments were conducted to evaluate the response of Asiatic dayflower to glyphosate applied at different rates and growth stages. Field research was conducted in 2005 and 2006 to evaluate different herbicides for Asiatic dayflower control in soybean. PRE herbicides were applied at planting and POST herbicides were applied 21 and 42 d after planting (DAP). In addition, shikimate accumulation in response to glyphosate was compared among Asiatic dayflower and GR and non-GR corn and soybean. Under greenhouse conditions, a single application of glyphosate (0.84 kg ae ha−1) did not control Asiatic dayflower. Only the highest rate evaluated, 13.44 kg ae ha−1 (16X), was lethal to Asiatic dayflower. Even when applied at an early growth stage (two leaves) and using high rates (3.36 kg ae ha−1), glyphosate controlled Asiatic dayflower just 28%. In the field, metribuzin and KIH-485 controlled Asiatic dayflower 80 and 73%, respectively. Early POST applications (21 DAP) of cloransulam or lactofen controlled Asiatic dayflower 80 and 67%, respectively. A single glyphosate application of 0.86 kg ae ha−1 controlled Asiatic dayflower approximately 50%. Glyphosate-treated Asiatic dayflower and non-GR corn and soybeans accumulated shikimate after application. GR corn and soybeans did not accumulate shikimate in response to glyphosate. Twenty-one days after treatment, all the non-GR soybean and corn plants died; however, Asiatic dayflower plants survived.

Machining of Micro-Channels on Brittle Glass Using an Abrasive Slurry Jet

2010 ◽  
Vol 443 ◽  
pp. 639-644 ◽  
Author(s):  
King Lun Pang ◽  
Thai Nguyen ◽  
Jing Ming Fan ◽  
Jun Wang
Keyword(s):  
Surface Morphology ◽  
Smooth Surface ◽  
Particle Concentration ◽  
Machined Surface ◽  
Large Wave ◽  
Abrasive Slurry Jet ◽  
Ductile Mode ◽  
Micro Channels ◽  
Wave Patterns

This paper presents a study of using an abrasive slurry jet for the machining of micro channels on brittle glasses. The machined surface morphology and channel dimensions are used to assess the technology. Surface morphology was found featuring with two types of wave patterns; one was along the channels with large wave lengths as a result of the jet deflection during the motion of nozzle, and the other was due to viscous flow that resulted in smooth surface eroded predominantly by ductile mode. The investigation showed that using higher jet pressure and higher particle concentration enables to create channels with higher depth, although these widened the channels and degraded the surface quality in some cases by inducing a larger number of pit fragments on the surface. With proper control of the operating parameters, this technology can be used for machining micro channels on brittle materials with high quality of surface finish.

Soybean Sensitivity to Drift Rates of Imazosulfuron

2014 ◽  
Vol 28 (3) ◽  
pp. 443-453 ◽  
Author(s):  
Sandeep S. Rana ◽  
Jason K. Norsworthy ◽  
Robert C. Scott
Keyword(s):  
Growth Stage ◽  
Yield Loss ◽  
Field Trials ◽  
Application Rate ◽  
Early Growth ◽  
Growth Stages ◽  
Sulfonylurea Herbicide ◽  
Full Bloom ◽  
Close Proximity ◽  
Different Growth Stages

Imazosulfuron is a sulfonylurea herbicide recently labeled in U.S. rice at a maximum rate of 336 g ai ha−1. Soybean is prone to drift of herbicides from rice fields in the southern United States because these crops are often grown in close proximity. Field trials were conducted to determine the effect of low rates of imazosulfuron applied to nonsulfonylurea-resistant soybean at different growth stages. Soybean was treated at the vegetative cotyledonary (VC); vegetative second trifoliate (V2); vegetative sixth trifoliate (V6); and reproductive full bloom (R2) growth stages with 1/256 (1.3 g ha−1) to 1/4 (84.1 g ha−1) times (X) the maximum labeled rate of imazosulfuron. Soybean was injured regardless of application rate or timing. At 2 wk after treatment (WAT), imazosulfuron injured soybean 23 to 79, 44 to 76, 32 to 68, and 14 to 50% when applied at the VC, V2, V6, and R2 growth stages, respectively, where the highest injury was caused by the highest imazosulfuron rate (1/4X). However, by 20 wk after planting (WAP), soybean treated with imazosulfuron at the VC and V2 growth stages had only 0 to 17% and 8 to 53% injury, respectively. At higher rates [1/8 (42 g ha−1) and 1/4X] of imazosulfuron, soybean treated at the VC growth stage recovered more from injury than did soybean treated at the V2 growth stage. Soybean treated with imazosulfuron at the V6 and R2 growth stages had better recovery from the injury at the lower two rates [1/256 and 1/128X (2.6 g ha−1)] than at the higher rates [1/64 (5.3 g ha−1) to 1/4X]. Imazosulfuron, at all rates tested, delayed soybean maturity by 1 to 4, 2 to 6, 1 to 12, and 3 to 16 d for the VC, V2, V6, and R2 growth stages, respectively. Yield loss was greater when imazosulfuron was applied at V6 and R2 compared to applications at VC and V2. Results from this research indicate that imazosulfuron can severely injure soybean regardless of the growth stage at which drift occurs; however, soybean injured by imazosulfuron at early growth stages (VC and V2) has a better chance of recovery over time compared to drift at later growth stages (V6 and R2).

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