Effects of Sub-Lethal High Temperature on An Insect, Rhodnius Prolixus (Stål.)

1968 ◽  
Vol 48 (3) ◽  
pp. 455-463
Author(s):  
A. Y. K. OKASHA

1. The effect on moulting of exposing 1st-, 2nd-, 3rd- and 4th-stage larvae of Rhodnius to 36.5° C. immediately after feeding was studied. After transfer to normal temperature (28° C.) moulting is delayed; the duration of the delay is directly proportional to the period of exposure to high temperature. 2. Unfed larvae exposed to high temperature exhibit delayed moulting when placed at normal temperature after feeding, and prolonged exposure also inhibits micturition which normally occurs directly after feeding. 3. Since the Malpighian tubules appear to function normally, it is suggested that the inhibition of the mechanisms responsible for emptying the rectum results in the cessation of micturition. 4. The harmful effects on moulting of heat-treatment of unfed larvae can be eliminated by placing the exposed insects at normal temperature for an appropriate period before feeding. 5. Exposure to high temperature either before or after feeding results in the decrease and malformation of the sensory bristles and plaques in the next larval stage.

Author(s):  
M. Larsen ◽  
R.G. Rowe ◽  
D.W. Skelly

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.


Alloy Digest ◽  
1993 ◽  
Vol 42 (10) ◽  

Abstract ALTEMP HX is an austenitic nickel-base alloy designed for outstanding oxidation and strength at high temperatures. The alloy is solid-solution strengthened. Applications include uses in the aerospace, heat treatment and petrochemical markets. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-442. Producer or source: Allegheny Ludlum Corporation.


Alloy Digest ◽  
1992 ◽  
Vol 41 (5) ◽  

Abstract INCO ALLOY 330 is a nickel/iron/chromium austenitic alloy, not hardenable by heat treatment. It is a solid solution strengthened high-temperature alloy. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-403. Producer or source: Inco Alloys International Inc..


Alloy Digest ◽  
1974 ◽  
Vol 23 (4) ◽  

Abstract ALUMINUM 3004 is nominally an aluminum-manganese-magnesium alloy which cannot be hardened by heat treatment; however, it can be strain hardened by cold working. It has higher strength than Aluminum 3003 and good workability, weldability and resistance to corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-51. Producer or source: Various aluminum companies. Originally published June 1957, revised April 1974.


Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  

Abstract ALX is a composition of nonferrous materials with a cobalt base containing chromium, tungsten and carbon. This alloy is commonly supplied in the cast-to-shape form, having an as-cast hardness of Rockwell C60-62 and requiring no further heat treatment. ALX is also supplied as cast tool bit material and is useful where conventional high-speed steels or carbides do not function effectively. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, and machining. Filing Code: Co-35. Producer or source: Allegheny Ludlum Corporation.


Alloy Digest ◽  
1985 ◽  
Vol 34 (5) ◽  

Abstract ALUMINUM 319.0 is a general-purpose foundry alloy that is moderately responsive to heat treatment. It has excellent casting characteristics and good mechanical properties. Among its many uses are crankcases, housings, engine parts, typewriter frames and rear-axle housings. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as creep and fatigue. It also includes information on low and high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: Al-256. Producer or source: Various aluminum companies.


Alloy Digest ◽  
1958 ◽  
Vol 7 (7) ◽  

Abstract ALUMINUM 6151, formerly A51S Alloy, is an aluminum forging alloy combining good forgeability, strength, and resistance to corrosion. It responds to an age-hardening heat treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Al-67. Producer or source: Aluminum Company of America.


Alloy Digest ◽  
1969 ◽  
Vol 18 (6) ◽  

Abstract Ti-5A1-4FeCr is an alpha-beta type titanium alloy recommended for airframe components. It responds to an age-hardening heat treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-58. Producer or source: Titanium alloy mills.


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