A HIGH TEMPERATURE CONTROL CIRCUIT

1948 ◽  
Vol 26a (3) ◽  
pp. 145-148 ◽  
Author(s):  
Bruce C. Lutz ◽  
John H. Wood

This is an electronic circuit useful in the control of electric air-bath furnaces having a long time lag. The control is accomplished by means of a relay that shunts a portion of the resistance in series with the furnace winding. The thermometric device is a thermocouple connected in series with a mirror-type galvanometer and a variable voltage supplied by a potentiometer. The setting of the potentiometer selects the temperature at which the device will control. A light beam falling on the mirror is reflected to one of two photocells. One photocell closes the shunt by means of the described circuit and increases the current in the furnace. This condition is maintained until the beam moves across the second photocell, when the shunt is again opened. The device will control temperatures over 1000 °C. within a precision of ± 2 °C. over any desired length of time.

Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.


Alloy Digest ◽  
1989 ◽  
Vol 38 (1) ◽  

Abstract UNS NO6455 is a nickel-chromium-molybdenum alloy with outstanding high-temperature stability as shown by high ductility and corrosion resistance even after long-time aging in the range 1200-1900 F. The alloy also has excellent resistance to stress-corrosion cracking and to oxidizing atmospheres up to 1900 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-367. Producer or source: Nickel and nickel alloy producers.


Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  

Abstract UNS No. R54620 is an alpha-beta titanium alloy. It has an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high strength is required. It has outstanding advantages for long-time use at temperatures to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-86. Producer or source: Titanium alloy mills.


Filomat ◽  
2017 ◽  
Vol 31 (20) ◽  
pp. 6247-6267 ◽  
Author(s):  
Elham Shamsara ◽  
Zahra Afsharnezhad ◽  
Reihaneh Mostolizadeh

Developing accurate mathematical models for host immune response in immunosuppressive diseases such as HIV and HTLV-1 are essential to achieve an optimal drug therapy regime. Since for HTLV-1 specific CTL response typically occurs after a time lag, we consider a discontinuous response function to better describe this lagged response during the early stage of the infectious, thus the system of HTLV-1 model will be a discontinuous system. For analyzing the dynamic of the system we use Filippov theory and find conditions in which the Filippov system undergoes a Hopf bifurcation. The Hopf bifurcation help us to find stable and unstable periodic oscillations and can be used to predict whether the CTL response can return to a steady state condition. Also, Hopf bifurcation in sliding mode is investigated. In this case the solutions will remain in the hyper-surface of discontinuity and as a consequence the disease cannot progress, at least for a long time. Finally we use numerical simulations to demonstrate the results by example.


2014 ◽  
Vol 28 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Thomas E. Lovejoy

One of the fundamental challenges of climate change is that we contribute to it increment by increment, and experience it increment by increment after a considerable time lag. As a consequence, it is very difficult to see what we are doing to ourselves, to future generations, and to the living planet as a whole. There are monumental ethical issues involved, but they are obscured by the incremental nature of the process and the long time frame before reaching the concentration of greenhouse gases and the ensuing accumulation of radiant heat—and consequent climate change—that ensues.


RSC Advances ◽  
2014 ◽  
Vol 4 (36) ◽  
pp. 18924-18929 ◽  
Author(s):  
Xun Hu ◽  
Lijun Zhang ◽  
Dehua Dong ◽  
Gongxuan Lu

A reactor with constant-temperature and stepwise decreasing-temperature zones is developed, which can catalyze steam reforming of bio-oil derived organics and methane to produce hydrogen-rich gas with only trace CO in a wide temperature region.


1970 ◽  
Vol 41 (7) ◽  
pp. 1092-1094
Author(s):  
E. J. White ◽  
J. R. Clarke

2002 ◽  
Vol 333 (1-2) ◽  
pp. 165-169 ◽  
Author(s):  
Y.Q Zhao ◽  
H.L Qu ◽  
K.Y Zhu ◽  
H Wu ◽  
C.L Liu ◽  
...  

2005 ◽  
Vol 288 (6) ◽  
pp. C1390-C1401 ◽  
Author(s):  
Richard Bouley ◽  
Herbert Y. Lin ◽  
Malay K. Raychowdhury ◽  
Vladimir Marshansky ◽  
Dennis Brown ◽  
...  

Vasopressin (VP) increases urinary concentration by signaling through the vasopressin receptor (V2R) in collecting duct principal cells. After downregulation, V2R reappears at the cell surface via an unusually slow (several hours) “recycling” pathway. To examine this pathway, we expressed V2R-green fluorescent protein (GFP) in LLC-PK1a cells. V2R-GFP showed characteristics similar to those of wild-type V2R, including high affinity for VP and adenylyl cyclase stimulation. V2R-GFP was located mainly in the plasma membrane in unstimulated cells, but it colocalized with the lysosomal marker Lysotracker after VP-induced internalization. Western blot analysis of V2R-GFP showed a broad 57- to 68-kDa band and a doublet at 46 and 52 kDa before VP treatment. After 4-h VP exposure, the 57- to 68-kDa band lost 50% of its intensity, whereas the lower 46-kDa band increased by 200%. The lysosomal inhibitor chloroquine abolished this VP effect, whereas lactacystin, a proteasome inhibitor, had no effect. Incubating cells at 20°C to block trafficking from the trans-Golgi network reduced V2R membrane fluorescence, and a perinuclear patch developed. Cycloheximide reduced the intensity of this patch, showing that newly synthesized V2R-GFP contributed significantly to its appearance. Cycloheximide also inhibited the reappearance of cell surface V2R after downregulation. We conclude that after downregulation, V2R-GFP is delivered to lysosomes and degraded. Reappearance of V2R at the cell surface depends on new protein synthesis, partially explaining the long time lag needed to fully reestablish V2R at the cell surface after downregulation. This degradative pathway may be an adaptive response to allow receptor-ligand association in the hypertonic and acidic environment of the renal medulla.


Sign in / Sign up

Export Citation Format

Share Document