VARIABLES ASSOCIATED WITH PHEROMONE TRAPS FOR MONITORING SPRUCE BUDWORM POPULATIONS (LEPIDOPTERA: TORTRICIDAE)

1981 ◽  
Vol 113 (6) ◽  
pp. 527-537 ◽  
Author(s):  
Mark W. Houseweart ◽  
Daniel T. Jennings ◽  
C. J. Sanders
Keyword(s):  
Sex Attractant ◽  
Spruce Budworm ◽  
High Density ◽  
Trapping Efficiency ◽  
Low Density ◽  
Pheromone Traps ◽  
Trap Efficiency ◽  
Ca 50 ◽  
Trap Placement

AbstractThe effects of three trap variables (age, saturation, and density) on catches of male spruce budworm moths were tested using Pherocon 1CP® traps baited with synthetic sex attractant in high-density budworm populations in Maine and low-density populations in Ontario. As trap age increased, the number of moths captured decreased significantly; traps aged 2, 10, and 16 days caught an average of 5.4, 28, and 27% fewer moths than unaged traps. Traps functionally saturate and trapping efficiency diminishes in both high and low density populations after ca. 50 moths are caught, although maximum observed catch was 193 moths/day. Density or spacing of traps also affects trap efficiency. Traps spaced 5 m apart may act as a single attraction source. Interference between traps was evident for traps spaced 10, 20, and 30 m apart, while traps spaced at 40 m had the least interference. However, interference at all spacings was noted during peak moth flight in 1978 when mean catch was ca. 140 moths/trap/day.Pherocon 1CP traps can be used for detecting and monitoring spruce budworm populations; however, influences of trap age, timing of trap placement, trap saturation, spacing of traps, and lure strength should be taken into account.

EVALUATION OF SEX ATTRACT ANT TRAPS FOR MONITORING SPRUCE BUDWORM POPULATIONS (LEPIDOPTERA: TORTRICIDAE)

1978 ◽  
Vol 110 (1) ◽  
pp. 43-50 ◽  
Author(s):  
C. J. Sanders
Keyword(s):  
Sex Attractant ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Low Density ◽  
Commercial Sex

AbstractFour commercial sex attractant traps were evaluated for monitoring low density spruce budworm (Choristoneura fumiferana (Clem.)) populations. Factors considered were color, the number of male budworm caught, durability of traps and their ability to exclude non-target insects and debris. The Pherocon 1CP was superior to 3-M Brand Sectar 1 and XC-26; Pherocon 1C was least suitable. Interpretation of the numbers captured may be confounded by the fact that trapped males repel other males.

FACTORS AFFECTING CATCH IN PHEROMONE TRAPS FOR MONITORING THE WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS FREEMAN

1990 ◽  
Vol 122 (6) ◽  
pp. 1119-1130 ◽  
Author(s):  
J.D. Sweeney ◽  
J.A. McLean ◽  
R.F. Shepherd
Keyword(s):  
Larval Density ◽  
Basal Area ◽  
Spruce Budworm ◽  
Trapping Efficiency ◽  
Choristoneura Occidentalis ◽  
Pheromone Traps ◽  
Western Spruce Budworm ◽  
Trap Design ◽  
Factors Affecting ◽  
The Mean

AbstractThe effects of trap design, lure concentration, lure age, and trap maintenance on the catch of western spruce budworm moths, Choristoneura occidentalis Freeman, in pheromone traps were tested in light to moderate infestations near Ashcroft, B.C. High cumulative moth catches reduced the trapping efficiency of both the sticky traps and the non-sticky Uni-traps relative to traps from which the moths were removed every 2 days. Correlations between the total season’s catch and larval density per plot in the same and following generations were not significant (P>0.05) for any of the eight combinations of trap design, lure concentration, and maintenance regimen tested. However, by dividing the mean moth catch in Uni-traps by either the basal area or foliage biomass per hectare in each plot, correlations with the following year’s larval density were significant (r2 = 0.77–0.98; P<0.05; n=5).

Quantitative defect studies in semiconductor TEM samples prepared by low angle ion milling

1995 ◽  
Vol 53 ◽  
pp. 512-513
Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf
Keyword(s):  
Sample Preparation ◽  
Milling Time ◽  
High Density ◽  
Low Density ◽  
Ion Milling ◽  
High Quality ◽  
Variable Angle ◽  
Major Disadvantage ◽  
Induced Defects

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).

Scanning Electron Microscopic and Electrophoretic Observations on Barium Sulphate Used to Adsorb Clotting Factors

1975 ◽  
Vol 33 (02) ◽  
pp. 256-270
Author(s):  
R. M Howell ◽  
S. L. M Deacon
Keyword(s):  
Electron Microscopy ◽  
Factor Xa ◽  
Barium Sulphate ◽  
High Density ◽  
Low Density ◽  
Factor X ◽  
Clotting Factors ◽  
Electron Microscopic ◽  
Complementary Techniques ◽  
Scanning Electron

SummaryElectron microscopy and particle electrophoresis were found to be complementary techniques with which to complete the physical data from an earlier study on barium sulphates used to adsorb clotting factors from serum. The differences revealed by scanning electron microscopy (S. E. M.) in the physical shape of low and high density grades of barium sulphate particles appear to be of greater significance than charge as expressed by electrophoretic mobility, in determining whether or not precursor or preformed factor Xa is eluted.This conclusion was based on the finding that at pH values close to 7, where the adsorption from serum occurs, all samples with the exception of natural barytes were uncharged. However as the high-density, or soil-grade, was found by S. E. M. to consist of large solid crystals it was suggested that this shape might induce activation of factor X as a result of partial denaturation and consequent unfolding of the adsorbed protein. In contrast, uptake of protein into the centre of the porous aggregates revealed by S. E. M. pictures of low-density or X-ray grade barium sulphate may afford protection against denaturation and exposure of the enzyme site.The porous nature of particles of low-density barium sulphate compared with the solid crystalline forms of other grades accounts not only for its lower bulk density but also for its greater surface/gram ratio which is reflected by an ability to adsorb more protein from serum.Neither technique produced evidence from any of the samples to indicate the presence of stabilising agents sometimes used to coat particles in barium meals.

scholarly journals Low-Temperature Mechanical Properties of High-Density and Low-Density Polyethylene and Their Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1821
Author(s):  
Ildar I. Salakhov ◽  
Nadim M. Shaidullin ◽  
Anatoly E. Chalykh ◽  
Mikhail A. Matsko ◽  
Alexey V. Shapagin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Impact Strength ◽  
Relative Elongation ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Elongation At Break ◽  
Subzero Temperatures ◽  
Izod Impact

Low-temperature properties of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and their blends were studied. The analyzed low-temperature mechanical properties involve the deformation resistance and impact strength characteristics. HDPE is a bimodal ethylene/1-hexene copolymer; LDPE is a branched ethylene homopolymer containing short-chain branches of different length; LLDPE is a binary ethylene/1-butene copolymer and an ethylene/1-butene/1-hexene terpolymer. The samples of copolymers and their blends were studied by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), 13С NMR spectroscopy, and dynamic mechanical analysis (DMA) using testing machines equipped with a cryochamber. It is proposed that such parameters as “relative elongation at break at −45 °C” and “Izod impact strength at −40 °C” are used instead of the ductile-to-brittle transition temperature to assess frost resistance properties because these parameters are more sensitive to deformation and impact at subzero temperatures for HDPE. LLDPE is shown to exhibit higher relative elongation at break at −45 °C and Izod impact strength at −20 ÷ 60 °C compared to those of LDPE. LLDPE terpolymer added to HDPE (at a content ≥ 25 wt.%) simultaneously increases flow properties and improves tensile properties of the blend at −45 °C. Changes in low-temperature properties as a function of molecular weight, MWD, crystallinity, and branch content were determined for HDPE, LLDPE, and their blends. The DMA data prove the resulting dependences. The reported findings allow one to understand and predict mechanical properties in the HDPE–LLDPE systems at subzero temperatures.

scholarly journals High-density Néel-type magnetic skyrmion phase stabilized at high temperature

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Hee Young Kwon ◽  
Kyung Mee Song ◽  
Juyoung Jeong ◽  
Ah-Yeon Lee ◽  
Seung-Young Park ◽  
...  
Keyword(s):  
High Temperature ◽  
High Density ◽  
Low Density ◽  
Memory Devices ◽  
Magnetic Multilayer ◽  
Multilayer Systems ◽  
Micromagnetic Simulations ◽  
Transmission Electron ◽  
Ultrahigh Density ◽  
Lorentz Transmission Electron Microscopy

AbstractThe discovery of a thermally stable, high-density magnetic skyrmion phase is a key prerequisite for realizing practical skyrmionic memory devices. In contrast to the typical low-density Néel-type skyrmions observed in technologically viable multilayer systems, with Lorentz transmission electron microscopy, we report the discovery of a high-density homochiral Néel-type skyrmion phase in magnetic multilayer structures that is stable at high temperatures up to 733 K (≈460 °C). Micromagnetic simulations reveal that a high-density skyrmion phase can be stabilized at high temperature by deliberately tuning the magnetic anisotropy, magnetic field, and temperature. The existence of the high-density skyrmion phase in a magnetic multilayer system raises the possibility of incorporating chiral Néel-type skyrmions in ultrahigh-density spin memory devices. Moreover, the existence of this phase at high temperature shows its thermal stability, demonstrating the potential for skyrmion devices operating in thermally challenging modern electronic chips.

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