scholarly journals Evaluation of certain pesticides and their alternatives against the black vine thrips, Retithrips syriacus (Mayet) (Thysanoptera: Thripidae) infesting grapevine

2020 ◽  
pp. 23-31
Author(s):  
Refat OH Allam ◽  
Amr MMM Badawy ◽  
Moustafa MS Bakry
Keyword(s):  
Zinc Oxide ◽  
Garlic Extract ◽  
The Other ◽  
Field Conditions ◽  
Toxic Compound ◽  
Other Hand ◽  
Initial Reduction ◽  
Commercial Vineyard ◽  
Grapevine Leaves ◽  
Lc50 And Lc90

The black vine thrips, Retithrips syriacus Mayet (Thripidae: Thysanoptera) is considered as pest. Adults and nymphs of this pest causes a serious damage to grapevine leaves. The experiments were carried out to evaluate the toxicity of seven pesticides on nymphs and adults of GVT on Flame seedless and Superior commercial vineyard varieties under laboratory and field conditions during 2016/2017 season. Data clearly indicate that the order of efficiency of the tested compounds were the same at both LC50 and LC90 levels. The tested insecticides could be descendingly arranged as follows: Radient, Pleo, Movento, Nanoparticles Zinc oxide, Marshal, KZ oil and Garlic extract. The corresponding LC50 values were 0.1, 0.24, 0.9, 0.92, 1.33, 1.45 and 1.5 ppm, while the LC90 values were 0.87, 1.07, 5.48, 10.92, 8.67, 6.42 and 11.26 ppm, respectively. On the other hand, χ2 values were 5.77, 2.93, 3.95, 3.08, 6.54, 2.87 and 1.51 respectively. Radient had the steepest toxicity line and Garlic extract had the flattest, however Pleo, Movento, Nanoparticles Zinc oxide, Marshal and KZ oil lie in between. This reflects the superiority of Radient and inferiority of Garlic extract. Radient was the most toxic compound, whereas Garlic extract was the least toxic one. the initial reduction of KZ oil (71.83, 72.80, 71.50 and 70.95) in both varieties and all of them are above 70% reduction. From these results, it should be suggested using of some effective alternatives such as KZ oil for controlling black vine thrips in compatible program with chemical insecticides instead of conventional individuals' insecticides. Keywords: Insecticides; Retithrips syriacus; Thrips; Grapevine

Influence of Intermittent Air Introduction on Formation of Zn Films by Mechanical Coating Technique

2013 ◽  
Vol 750 ◽  
pp. 138-141
Author(s):  
Liang Hao ◽  
Yun Lu ◽  
Hiromasa Sato ◽  
Hiroshi Asanuma ◽  
Fu Sheng Pan
Keyword(s):  
Zinc Oxide ◽  
Adhesion Strength ◽  
The Other ◽  
Coating Process ◽  
Sem Images ◽  
Coating Technique ◽  
Zno Nanocrystals ◽  
Other Hand ◽  
Mechanical Coating

The influence of intermittent air introduction on the formation of Zn films during mechanical coating process was investigated. A series of contrast experiments were carried out. The XRD and EDS results showed that Zn particles were slightly oxidized. The SEM images indicated that disk-like zinc oxide (ZnO) nanocrystals were formed. The formation of disk-like ZnO made the morphology of Zn films more uneven and irregular. On the other hand, it increased the adhesion strength of Zn films to Al2O3 balls and hence the exfoliation of Zn films was not found.

Cathodoluminescence of Diffusion Layer Synthesized by Coupling of β-Ga2O3 and ZnO

2006 ◽  
Vol 320 ◽  
pp. 121-124 ◽  
Author(s):  
Kenichi Suzuki ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Zinc Oxide ◽  
Diffusion Layer ◽  
Gallium Oxide ◽  
The Other ◽  
Energy Dispersive ◽  
X Ray ◽  
Eds Analysis ◽  
Other Hand ◽  
Zno Ceramics

Beta gallium oxide (β-Ga2O3) ceramics was coupled and reacted with zinc oxide (ZnO) ceramics at 1200oC for 24 h. Energy dispersive X-ray spectroscopy (EDS) analysis revealed the existence of diffusion layer near the interface between β-Ga2O3 and ZnO. Furthermore, the layer showed monochromatic and intense cathodoluminescence (CL) at 3.5 eV. On the other hand, very weak emissions were observed from the out of the layer. The compound in the layer is considered to be an attractive material for ultraviolet optoelectronics.

scholarly journals Mullins–Sekerka stability analysis for melting-freezing waves in helium

1994 ◽  
Vol 5 (1) ◽  
pp. 21-37
Author(s):  
Joseph D. Fehribach
Keyword(s):  
Surface Tension ◽  
Growth Rate ◽  
Stability Analysis ◽  
Original Problem ◽  
The Other ◽  
Field Conditions ◽  
System Of Equations ◽  
Far Field ◽  
Other Hand ◽  
The Stability

This paper considers the stability of melt-solid interfaces to eigenfunction perturbations for a system of equations which describe the melting and freezing of helium. The analysis is carried out in both planar and spherical geometries. The principal results are that when the melt is freezing, under certain far-field conditions, the interface is stable in the sense of Mullins and Sekerka. On the other hand, when the solid is melting (at least when the melting is sufficiently fast), the interface is unstable. In some circumstances these instabilities are oscillatory, with amplitude and growth rate increasing with surface tension and frequency. The last section considers the original problem of Mullins and Sekerka in the present notation.

scholarly journals Influence of photoperiod on the accumulation of allantoin in comfrey plants

2001 ◽  
Vol 13 (1) ◽  
pp. 49-54 ◽  
Author(s):  
ANA HORTÊNCIA FONSÊCA CASTRO ◽  
MARIA CLÁUDIA MARX YOUNG ◽  
AMAURI ALVES DE ALVARENGA ◽  
JOSÉ DONIZETI ALVES
Keyword(s):  
Medicinal Plant ◽  
The Other ◽  
Field Conditions ◽  
Average Content ◽  
Symphytum Officinale ◽  
Other Hand

In order to evaluate the influence of photoperiod on the accumulation of allantoin in comfrey (Symphytum officinale L.), a well known medicinal plant, an experiment was conducted during July and August, 1998. Cuttings obtained from 90 day old plants were submitted to four photoperiods (8, 12, 16 and 20 hours). After 60 days, allantoin content in roots and rhizomes was evaluated. The results showed that increases in photoperiod promoted an increment in the average content of allantoin in roots (0.06%, 0.303%, 1.213% and 4.78%). On the other hand, in rhizomes, allantoin accumulation decreased (9.65%, 7.14%, 0.55%) when the photoperiod was increased from 8 to 12 and 16 hours, respectively, stabilizing on a 20-hour photoperiod (0.53%). Plants cultivated under field conditions presented 2.55% and 2.63% allantoin content in rhizomes and roots, respectively. Based on the fact that in comfrey the roots are considered to be sites of allantoin synthesis, the results demonstrated that photoperiod could influence both the synthesis of allantoin in these organs as well as its accumulation in the rhizomes.

Detoxification of Citrinin and Ochratoxin A by Hydrogen Peroxide

1994 ◽  
Vol 77 (3) ◽  
pp. 631-637 ◽  
Author(s):  
Sophie G Fouler ◽  
Alka B Trivedi ◽  
Naofumi Kitabatake
Keyword(s):  
Hydrogen Peroxide ◽  
Ochratoxin A ◽  
Hela Cells ◽  
Room Temperature ◽  
The Other ◽  
Toxic Compound ◽  
Other Hand ◽  
Alkaline Conditions

Abstract The effects of hydrogen peroxide on citrinin and ochratoxin A toxicity were examined using HeLa cells. The citrinin was completely detoxified by prior incubation with 0.05% hydrogen peroxide for 30 min at room temperature, and the toxic compound(s) that resulted from heating citrinin at 100°C were also detoxified upon reheating it with hydrogen peroxide. On the other hand, ochratoxin A was not detoxified by hydrogen peroxide at room temperature, but its toxicity was reduced by heating ochratoxin A with hydrogen peroxide under alkaline conditions.

Cathodoluminescence of Diffusion Layer Synthesized by Coupling of α-Al2O3 and ZnO

2006 ◽  
Vol 11-12 ◽  
pp. 163-166
Author(s):  
Kenichi Suzuki ◽  
Yuichiro Kuroki ◽  
Tomoichiro Okamoto ◽  
Masasuke Takata
Keyword(s):  
Zinc Oxide ◽  
Aluminum Oxide ◽  
Diffusion Layer ◽  
The Other ◽  
Energy Dispersive ◽  
X Ray ◽  
Eds Analysis ◽  
Other Hand ◽  
Α Al2o3 ◽  
Zno Ceramics

Alpha aluminum oxide (α-Al2O3) ceramics was coupled and reacted with zinc oxide (ZnO) ceramics at 1200°C for 24 h. Energy dispersive X-ray spectroscopy (EDS) analysis revealed the existence of step-shaped distribution of Al and Zn near the interface between α-Al2O3 and ZnO. Intense ultraviolet (3.75 eV) emission was clearly observed from the layer. On the other hand, very weak emissions were observed outside the layer near the interface. The compound in the layer is considered to be an attractive material for ultraviolet optoelectronics.

scholarly journals A comparison of overshoot modelling with observations of polar mesospheric summer echoes at radar frequencies of 56 and 224 MHz

2015 ◽  
Vol 33 (6) ◽  
pp. 737-747 ◽  
Author(s):  
O. Havnes ◽  
H. Pinedo ◽  
C. La Hoz ◽  
A. Senior ◽  
T. W. Hartquist ◽  
...  
Keyword(s):  
No Reduction ◽  
The Other ◽  
Rapid Reduction ◽  
Electron Heating ◽  
Vhf Radar ◽  
Radar Observations ◽  
Other Hand ◽  
Initial Reduction ◽  
Summer Echoes ◽  
Identical Behaviour

Abstract. We have compared radar observations of polar mesospheric summer echoes (PMSEs) modulated by artificial electron heating, at frequencies of 224 MHz (EISCAT VHF) and 56 MHz (MORRO). We have concentrated on 1 day of observation, lasting ~ 3.8 h. The MORRO radar, with its much wider beam, observes one or more PMSE layers all the time while the VHF radar observes PMSEs in 69% of the time. Statistically there is a clear difference between how the MORRO and the VHF radar backscatter reacts to the heater cycling (48 s heater on and 168 s heater off). While MORRO often reacts by having its backscatter level increased when the heater is switched on, as predicted by Scales and Chen (2008), the VHF radar nearly always sees the "normal" VHF overshoot behaviour with an initial rapid reduction of backscatter. However, in some heater cycles we do see a substantial recovery of the VHF backscatter after its initial reduction to levels several times above that just before the heater was switched on. For the MORRO radar a recovery during the heater-on phase is much more common. The reaction when the heater was switched off was a clear overshoot for nearly all VHF cases but less so for MORRO. A comparison of individual curves for the backscatter values as a function of time shows, at least for this particular day, that in high layers above ~ 85 km height, both radars see a reduction of the backscatter as the heater is switched on, with little recovery during the heater-on time. These variations are well described by present models. On the other hand, the backscatter in low layers at 81–82 km can be quite different, with modest or no reduction in backscatter as the heater is switched on, followed by a strong recovery for both radars to levels several times above that of the undisturbed PMSEs. This simultaneous, nearly identical behaviour at the two very different radar frequencies is not well described by present modelling.

scholarly journals Phase transition in a system of random sparse Boolean equations

2010 ◽  
Vol 45 (1) ◽  
pp. 93-105
Author(s):  
Thorsten Schilling ◽  
Pavol Zajac
Keyword(s):  
Phase Transition ◽  
Partial Solution ◽  
Large System ◽  
The Other ◽  
System Of Equations ◽  
Algebraic Cryptanalysis ◽  
Other Hand ◽  
Initial Reduction

ABSTRACT Many problems, including algebraic cryptanalysis, can be transformed to a problem of solving a (large) system of sparse Boolean equations. In this article we study 2 algorithms that can be used to remove some redundancy from such a system: Agreeing, and Syllogism method. Combined with appropriate guessing strategies, these methods can be used to solve the whole system of equations. We show that a phase transition occurs in the initial reduction of the randomly generated system of equations. When the number of (partial) solutions in each equation of the system is binomially distributed with probability of partial solution p, the number of partial solutions remaining after the initial reduction is very low for p’s below some threshold pt, on the other hand for p > pt the reduction only occurs with a quickly diminishing probability.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

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