Cold tolerance of the spring-feeding larvae of the eyespotted bud moth,Spilonota ocellana(Lepidoptera: Tortricidae)

2017 ◽  
Vol 149 (3) ◽  
pp. 291-299 ◽  
Author(s):  
J.A. Swain ◽  
G.J.R. Judd ◽  
J.S. Cory
Keyword(s):  
Low Temperature ◽  
Larval Mortality ◽  
Malus Pumila ◽  
Supercooling Point ◽  
Spring Frost ◽  
Temperature Thresholds ◽  
The Mean ◽  
Freezing Temperatures ◽  
Freeze Tolerant ◽  
Lower Lethal Temperature

AbstractIn this study, we explore the low-temperature thresholds of a pest of apple (Malus pumilaMiller; Rosaceae), the eyespotted bud moth,Spilonota ocellanaDenis and Schiffermüller (Lepidoptera: Tortricidae), in the context of spring frost.Spilonota ocellanaoverwinters as a larva, resuming activity and feeding early in the growing season when it could be vulnerable to unexpected freezing temperatures. We determined that the mean supercooling point of spring instars did not differ for larvae within or outside leaf shelters and ranged from −9.1±0.2 °C for fourth instars, to −7.9±0.2 °C for sixth instars. Larval weight increased with instar and was positively related to the supercooling point. As some insects are freeze tolerant and able to recover from freezing, we also exposed larvae to brief freeze events between −4.5 °C and −9.5 °C and found that the median lower lethal temperature, was −7.3±0.4 °C across all instars; indicating thatS. ocellanaspring instars are susceptible to freezing temperatures above their supercooling point. These low-temperature thresholds suggest that in the spring, S. ocellanalarvae are chill susceptible, and a hard frost (<−7 °C) would be necessary to cause significant larval mortality.

EFFECT OF COOLING RATE ON THE FREEZING TEMPERATURES OF SUPERCOOLED INSECTS

1966 ◽  
Vol 44 (4) ◽  
pp. 655-659 ◽  
Author(s):  
R. W. Salt
Keyword(s):  
Cooling Rate ◽  
Water Samples ◽  
Freezing Temperature ◽  
Supercooling Point ◽  
Cephus Cinctus ◽  
Standard Rate ◽  
Rate Of Cooling ◽  
The Mean ◽  
Freezing Temperatures

Cooling rate affects the freezing temperature of water samples and of insects. Doubling the rate of cooling lowers the mean supercooling point of Cephus cinctus larvae 0.24 °C. Adoption of a standard rate of cooling of 1° per minute, or adjustment of other rates to this basis, is proposed.

scholarly journals Effects of Temperature on the Flow and Heat Transfer in Gel Fuels: A Numerical Study

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 821
Author(s):  
Qin-Liu Cao ◽  
Wei-Tao Wu ◽  
Wen-He Liao ◽  
Feng Feng ◽  
Mehrdad Massoudi
Keyword(s):  
Heat Transfer ◽  
Low Temperature ◽  
Transport System ◽  
Apparent Viscosity ◽  
Thermal Design ◽  
Straight Pipe ◽  
Heating Wall ◽  
Supply Pressure ◽  
Flow And Heat Transfer ◽  
The Mean

In general, rheological properties of gelled fuels change dramatically when temperature changes. In this work, we investigate flow and heat transfer of water-gel in a straight pipe and a tapered injector for non-isothermal conditions, which mimic the situations when gelled fuels are used in propulsion systems. The gel-fluid is modeled as a non-Newtonian fluid, where the viscosity depends on the shear rate and the temperature; a correlation fitted with experimental data is used. For the fully developed flow in a straight pipe with heating, the mean apparent viscosity at the cross section when the temperature is high is only 44% of the case with low temperature; this indicates that it is feasible to control the viscosity of gel fuel by proper thermal design of pipes. For the flow in the typical tapered injector, larger temperature gradients along the radial direction results in a more obvious plug flow; that is, when the fuel is heated the viscosity near the wall is significantly reduced, but the effect is not obvious in the area far away from the wall. Therefore, for the case of the tapered injector, as the temperature of the heating wall increases, the mean apparent viscosity at the outlet decreases first and increases then due to the high viscosity plug formed near the channel center, which encourages further proper design of the injector in future. Furthermore, the layer of low viscosity near the walls plays a role similar to lubrication, thus the supply pressure of the transport system is significantly reduced; the pressure drop for high temperature is only 62% of that of low temperature. It should be noticed that for a propellent system the heating source is almost free; therefore, by introducing a proper thermal design of the transport system, the viscosity of the gelled fuel can be greatly reduced, thus reducing the power input to the supply pressure at a lower cost.

Fate of Selected Pathogens Inoculated into Foods Prepared in Slow Cookers1,2

1979 ◽  
Vol 42 (11) ◽  
pp. 872-876 ◽  
Author(s):  
J. RITTER ◽  
J. O'LEARY ◽  
B. E. LANGLOIS
Keyword(s):  
Staphylococcus Aureus ◽  
Low Temperature ◽  
Salmonella Typhimurium ◽  
Clostridium Perfringens ◽  
Health Hazard ◽  
Green Bean ◽  
Vegetative Cells ◽  
Salmonella Choleraesuis ◽  
Navy Beans ◽  
The Mean

Staphylococcus aureus, Clostridium perfringens. Salmonella choleraesuis, and Salmonella typhimurium were inoculated (108 cells or spores) into two slow cookers containing green bean casserole, baked navy beans, chicken cacciatore, barbecued ribs or pork pot roast, and their fate determined after cooking. Heating patterns also were determined at three positions inside the two cookers. None of the foods cooked in either of the slow cookers contained detectable levels of S. aureus or salmonellae. The similarity between C. perfringens vegetative and spore counts indicate that only spores were present in the cooked foods. Except for the green bean casserole cooked using a low temperature setting, cooking resulted in a 0.44–1.67 and 0.36–1.54 log count reduction, respectively, of vegetative cells and spores of C. perfringens. Counts of vegetative cells and spores after cooking the green bean casserole were approximately .18 and .30 log counts higher than the uncooked counts. The mean times for the coldest areas in Cooker A to reach 50 C were 2.57 and 0.97 h, respectively, for the low (80 watts) and high (160 watts) temperature settings. The mean times for the coldest areas in Cooker B (removable liner) to reach 50 C were 2.35 and 0.52 h for the low (130 watts) and high (260 watts) temperature settings, respectively. Results suggest that when the recommended quantities of ingredients are used and the proper cooking procedure followed, foods prepared in the slow cookers studied do not present a health hazard.

3D Freeze Printing: Development of an Experimental Setup and Determination of 3D Printing Parameters

2020 ◽  
Author(s):  
Halil Tetik ◽  
Dong Lin
Keyword(s):  
3D Printing ◽  
Low Temperature ◽  
Temperature Gradient ◽  
Freeze Casting ◽  
Printing Process ◽  
Print Head ◽  
Freezing Temperatures ◽  
Fabrication Parameters ◽  
Printing Parameters

Abstract 3D freeze printing is a hybrid manufacturing method composed of freeze casting and inkjet-based printing. It is a facile method to fabricate lightweight, porous, and functional structures. Freeze casting is a well-known method for fabricating porous bodies and is capable of manipulating the micro-structure of the resulting product. Freeze casting simply involves solidification of a liquid suspension using low temperature and sublimation of the solvent using low temperature and pressure. After the sublimation of the solvent crystals, we obtain a porous structure where the pores are a replica of solvent crystal. Making use of the temperature gradient, as seen in unidirectional and bidirectional freeze casting, during the solidification with low temperature values, the solvent crystals grow along the temperature gradient. Furthermore, by manipulating the freezing kinetics during solidification, we can have a control on the average pore size distribution. For instance, when lower freezing temperatures result in finer pores with higher amount, higher freezing temperatures result in coarser pores with less amount. Also, the use of some additives inside the suspension leads to changes in the morphology of the solvent crystals as well as the resulting pores. However, the macro-structure of the fabricated body is highly dependent on the mold used during the process. In order to eliminate the dependency on the mold during the freeze casting process, our group recently combined this technique with inkjet-based 3D printing. With inkjet-based 3D printing, we fabricated uniform lines from single droplets, and complex 3D shapes from the lines. This provided us the ability of tailoring the macro structure of the final product without any dependency on a mold as seen in freeze casting. As a result of the 3D freeze printing process, we achieved fabricating lightweight, porous, and functional bodies with engineered micro and macro-structures. However, achieving fine droplets, and uniform lines by merging the droplets requires a good combination of fabrication parameters such as pressure adjustment inside the print head, print head speed, jetting frequency. Also, fabricating complex shapes from uniform lines requires well-adjusted parameters such as line thickness and layer height. In this study, we briefly explained the mechanics of the 3D freeze printing process. Following that we presented the development process of an open-source inkjet-based 3D printer. Finally, we explained the determination of inkjet dispensing and 3D printing parameters required for a high-quality 3D printing. During our experiments for the determination of fabrication parameters, we used a nanocellulose crystals-based ink due to its low cost and ease of preparation.

Effect of parasitism by Anaphes sp. (Hymenoptera: Mymaridae) on the cold hardiness of Listronotus oregonensis (Coleoptera: Curculionidae) eggs

1993 ◽  
Vol 71 (4) ◽  
pp. 759-764 ◽  
Author(s):  
Thierry Hance ◽  
Guy Boivin
Keyword(s):  
Low Temperature ◽  
Cold Hardiness ◽  
Egg Parasitoids ◽  
Local Extinction ◽  
Short Photoperiod ◽  
Supercooling Point ◽  
Listronotus Oregonensis ◽  
Overwintering Site

The cold hardiness of egg parasitoids is critical to their survival in winter because these organisms have little control in the choice of their overwintering site. The supercooling points of Listronotus oregonensis eggs increased from −24.9 to −22.1 °C as eggs matured. When these eggs were parasitized by Anaphes sp., their supercooling point remained stable at −22.9 °C throughout the development of the parasitoid. Anaphes sp. maintained its cold hardiness by increasing its levels of glycerol and fructose. When the parental generation was exposed to a combination of low temperature and short photoperiod, the supercooling point of the daughter generation (F1) was significantly decreased. A further decrease in the supercooling point was observed when F1 individuals were stored at 3 °C for 14 or 20 days. These data show that local extinction of populations overwintering in nonsheltered habitats is probably common in southwestern Quebec.

Low temperature induced male sterility in Sorghum bicolor

1971 ◽  
Vol 11 (50) ◽  
pp. 352 ◽  
Author(s):  
RW Downes ◽  
DR Marshall
Keyword(s):  
Low Temperature ◽  
Male Sterility ◽  
Temperature Regime ◽  
Flag Leaf ◽  
Pollen Sterility ◽  
Male Sterile ◽  
Low Degree ◽  
The Mean ◽  
Mother Cells ◽  
Breeding And Genetics

Male sterility was induced in sorghum by exposing plants to a temperature regime of 18/13�C (day-night temperatures) during meiosis in the pollen mother cells. This normally occurs at the time the last (flag) leaf is emerging and elongating. The majority of genotypes examined were rendered completely male sterile by the low temperature regime. However, some genotypes retained a low degree of pollen fertility. The low temperatures appeared to have little, if any, effect on female fertility. The available evidence indicates that it is the night temperature, rather than the mean temperature, which is critical for the induction of pollen sterility. The potential uses of this method of inducing male sterility in plant breeding and genetics programs are briefly discussed.

ROSETTE VEGETATIVE GROWTH OF LOWBUSH BLUEBERRY RELATED TO FREEZING TEMPERATURES

1988 ◽  
Vol 68 (2) ◽  
pp. 549-551 ◽  
Author(s):  
I. V. HALL ◽  
P. D. HILDEBRAND
Keyword(s):  
Low Temperature ◽  
Vegetative Growth ◽  
Leaf Expansion ◽  
Stages Of Development ◽  
Vaccinium Angustifolium ◽  
Potted Plants ◽  
Vegetative Buds ◽  
Lowbush Blueberry ◽  
Freezing Temperatures ◽  
Natural Stands

When potted plants of lowbush blueberries were subjected to temperatures of −2 °C for periods of 0.5–4.0 h, a rosette of leaves arising from vegetative buds was induced similar to that observed in natural stands of Vaccinium angustifolium Ait. Vegetative buds at various stages of development from green tip (2 mm) to the point of leaf expansion were equally susceptible to the low temperature injury. Variation in susceptibility among seven clones tested (Brunswick, 71–14, ME-3, NB3, 895, 752, and 694) was not observed.Key words: Lowbush blueberry, low-temperature injury

On the low-temperature limit of the mean square amplitude matrix

1972 ◽  
Vol 12 (3) ◽  
pp. 471-477 ◽  
Author(s):  
Ø. Ra
Keyword(s):  
Low Temperature ◽  
Temperature Limit ◽  
Mean Square ◽  
The Mean ◽  
Amplitude Matrix

EFFECT OF MEAN PORE SIZE ON THE LOW-TEMPERATURE ADSORPTION OF NITROGEN ON ALUMINA

1960 ◽  
Vol 38 (6) ◽  
pp. 783-786 ◽  
Author(s):  
J. L. Blumenthal ◽  
S. Sourirajan ◽  
Ken Nobe
Keyword(s):  
Low Temperature ◽  
Pore Size ◽  
Pore Radius ◽  
Capillary Condensation ◽  
Pressure Ratio ◽  
Relative Pressure ◽  
The Third ◽  
Two Samples ◽  
Adsorption Of Nitrogen ◽  
The Mean

The effect of mean pore size on the low-temperature adsorption of nitrogen on two samples of alumina has been studied. The mean pore radius of one sample of alumina was 37 Å, and that of the other was 3100 Å. The two adsorption isotherms at −195.8 °C have been plotted in terms of the volume of gas adsorbed per square meter of surface area vs. relative pressure ratio. The data have been found to fall into three distinct regions. In the first region extending up to the relative pressure ratio of 0.3, the two isotherms are nearly identical. In the second region extending from the relative pressure ratio of 0.3 to 0.75, the isotherm for the small mean pore size alumina lies above that for the large mean pore size sample. In the third region extending from the relative pressure ratio of 0.75 up to saturation, the isotherm for the small mean pore size sample tends to level off whereas that for the large mean pore size sample rises rapidly with increase in the relative pressure ratio. The above experimental observations have been explained on the basis of capillary condensation.

scholarly journals Distribution of Xylella fastidiosa in Sycamore Associated with Low Temperature and Host Resistance

Plant Disease ◽  
2004 ◽  
Vol 88 (9) ◽  
pp. 951-958 ◽  
Author(s):  
T. S. M. Henneberger ◽  
K. L. Stevenson ◽  
K. O. Britton ◽  
C. J. Chang
Keyword(s):  
Low Temperature ◽  
Host Resistance ◽  
Xylella Fastidiosa ◽  
Temperature Treatment ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bacterial Populations ◽  
Low Temperature Treatment ◽  
Detection Frequency ◽  
Temperature Thresholds ◽  
Viable Bacteria

Experiments were conducted in the field and laboratory to determine effects of low temperatures on Xylella fastidiosa populations in American sycamore. Roots and shoots from naturally infected trees at two locations were collected monthly. Sap extracted from the samples was tested by enzyme-linked immunosorbent assay for presence of X. fastidosa and was diluted and plated on periwinkle wilt medium to determine populations of viable bacteria. Cumulative rainfall and hours below temperature thresholds (-5 to 10°C) were recorded at each site. Bacterial populations in shoots were negatively correlated with cumulative hours below -5°C air temperature (r= -0.96). In roots, bacterial populations were only weakly correlated with cumulative hours below soil temperature thresholds (-0.61 < r <-0.25). Bacterial populations were not correlated with monthly rainfall. In the laboratory, resistant and susceptible sycamore trees were inoculated with X. fastidiosa and held in the dark at 5°C or 22°C. After 12 weeks, inoculated stem sections were collected and sap was extracted and tested as described previously. Stems that tested positive for X. fastidiosa were divided into additional samples and tested as described above. Results of the laboratory study indicated no significant effects of low-temperature treatment (5°C) or host resistance on viable bacteria. Bacterial detection frequency and population size were greatest near the inoculation point and the primary direction of early bacterial spread was acropetal.

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