Problems of the starting and operating of hydraulic components and systems in low ambient temperature: Part II Determining the clearance between cooperating elements during the hydraulic components start-up in extremely low ambient temperatures on the grounds of experimental research

Abstract A large number of hydraulic devices and systems are started in low ambient temperatures. A good example of such a device is the hoisting winch on the ship. Starting hydraulic drive units in thermal shock conditions (rapid supply of hot oil to the cold unit) may lead to incorrect operation of the actuating system, for instance, due to the loss of clearance between cooperating elements. The article presents methods to prevent the disappearance of effective clearance in a hydraulic motor started in thermal shock conditions. For this reason, the structure of the hydraulic satellite motor was complemented by elements creating special channels through which hot oil could flow and additionally heat fixed parts of the motor. This solution ensures faster heating of motor housing, thus decreasing the temperature difference between the housing and the satellites during motor start-up in thermal shock conditions.

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Reindeer breathe less and save water in the cold

Rangifer ◽

10.7557/2.10.3.864 ◽

1990 ◽

Vol 10 (3) ◽

pp. 243

Author(s):

Kjell J. Nilssen ◽

Arne Rognmo ◽

Arnoldus Schytte Blix

Keyword(s):

Ambient Temperature ◽

Rangifer Tarandus ◽

Treadmill Exercise ◽

Minute Volume ◽

Oxygen Extraction ◽

Running Speed ◽

Ambient Temperatures ◽

Svalbard Reindeer ◽

Respiratory Minute Volume ◽

Low Ambient Temperature

Simultaneous measurements of metabolic rate, respiratory minute volume, respiratory frequency, and oxygen extraction from the inspired air were obtained during treadmill exercise in Svalbard reindeer (Rangifer tarandus platyrhynchus) and Norwegian reindeer (Rangifer tarandus tarandus). The experiments were carried out both in summer and winter at ambient temperatures and running speeds ranging from +12 to -30 °C and 3.7 to 9.0 knvh1, respectively. We found that respiratory minute volume was generally lower in summer than in winter for a similar ambient temperature, and also that respiratory minute volume was reduced at low ambient temperature both in summer and winter. The change in respiratory minute volume was inversely related to oxygen extraction, the latter being at its highest at the lowest ambient temperature and running speed in summer. Reduction of respiratory minute volume, and hence respiratory water loss, at low ambient temperature is likely to contribute significantly to the survival of these species, particularly in winter when the animals can only replace body water with snow at low temperature.

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Light-Response Bric-A-Brack/Tramtrack/Broad proteins mediate cryptochrome 2 degradation in response to low ambient temperature

The Plant Cell ◽

10.1093/plcell/koab219 ◽

2021 ◽

Author(s):

Libang Ma ◽

Xu Li ◽

Zhiwei Zhao ◽

Yuhao Hao ◽

Ruixin Shang ◽

...

Keyword(s):

High Temperature ◽

Ambient Temperature ◽

Protein Stability ◽

Blue Light ◽

Light Response ◽

26S Proteasome ◽

Negative Regulator ◽

Ambient Temperatures ◽

Temperature Responses ◽

Low Ambient Temperature

Abstract Cryptochromes (crys) are photolyase-like blue-light receptors first discovered in Arabidopsis thaliana and later identified in all major evolutionary lineages. Crys are involved in not only blue light responses but also in temperature responses; however, whether and how cry protein stability is regulated by temperature remains unknown. Here, we show that cry2 protein abundance is modulated by ambient temperature and cry2 protein is degraded under low ambient temperature via the 26S proteasome. Consistent with this, cry2 shows high levels of ubiquitination under low ambient temperatures. Interestingly, cry2 degradation at low ambient temperatures occurs only under blue light and not under red light or dark conditions, indicating blue-light-dependent degradation of cry2 at low ambient temperature. Furthermore, low ambient temperature promotes physical interaction of Light-Response Bric-a-Brack/Tramtrack/Broad (LRB) proteins with cry2 to modulate its ubiquitination and protein stability in response to ambient temperature. LRBs promote high-temperature-induced hypocotyl elongation by modulating the protein stability of cry2 protein. These results indicate that cry2 accumulation is regulated by not only blue light but also ambient temperature, and LRBs are responsible for cry2 degradation at low ambient temperature. The stabilization of cry2 by high temperature makes cry2 a better negative regulator of temperature responses.

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Sleep-waking pattern and body temperature in hypoxia at selected ambient temperatures

Journal of Applied Physiology ◽

10.1152/jappl.1984.57.5.1564 ◽

1984 ◽

Vol 57 (5) ◽

pp. 1564-1568 ◽

Cited By ~ 9

Author(s):

B. Hale ◽

D. Megirian ◽

M. J. Pollard

Keyword(s):

Body Temperature ◽

Ambient Temperature ◽

Core Temperature ◽

Ambient Temperatures ◽

State Changes ◽

Maximum Minimum ◽

Mild Hypoxia ◽

Low Ambient Temperature

We studied the effect of mild hypoxia (15% O2) and low ambient temperature (Ta = 15 degrees C) on the rat's sleep-waking pattern (SWP) and maximum-minimum core temperature (max-min Tb). Mild hypoxia at neutral Ta (29 degrees C) disrupted the SWP in the same way as low Ta during normoxia: both affected the pattern of frequency of state changes (P less than 0.01), not the pattern of epoch durations. Mild hypoxia and low Ta together caused a degree of disruption of the SWP which was the sum of each alone, i.e., additive. Although both mild hypoxia and low Ta significantly depressed max-min Tb, low Ta exerted a greater effect than mild hypoxia. Together they further depressed max-min Tb in an additive way. We conclude that mild hypoxia disrupts the rat's SWP independent of central thermoregulatory mechanisms at neutral Ta, that the effects of mild hypoxia and low Ta on the SWP are additive at the stimulus levels used, and that Ta, not inspired O2, determines Tb.

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Technical and economic aspects of starting a selected power unit at low ambient temperatures

Open Engineering ◽

10.1515/eng-2021-0059 ◽

2021 ◽

Vol 11 (1) ◽

pp. 606-616

Author(s):

Wojciech Lewicki

Keyword(s):

Ambient Temperature ◽

Power Unit ◽

Armed Forces ◽

Transport Sector ◽

Compression Ignition Engine ◽

Ambient Temperatures ◽

Start Up ◽

Cylinder Liners ◽

The Impact

Abstract The article presents research on the impact of a 359 compression-ignition engine starting at low ambient temperatures. This engine is used in vehicles such as STAR 200, 244, and 226. The purpose of these tests was to determine the amount of wear depending on the ambient temperature and the number of starts, as well as to compare the wear at start-up with the wear occurring during tests on the dynamometer (long-term test for reliability) and wear occurring during the operation of the engine in the vehicle, and the impact of the number of starts and ambient temperature on diesel engine for the life of the vehicle to be repaired. The results of the author’s research showed that a minimum of the number of starts at low ambient temperatures has an impact on the number of kilometers driven by the car during operation to replace the cylinder liners (engine repair). Apart from the Polish armed forces and armies of other countries in which this type of vehicle is still used, the direct recipients of the research results are also other entities from the logistics transport sector for which further use of this power unit especially at low ambient temperatures is of fundamental economic importance.

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Technical and economic aspects of starting a selected power unit at low ambient temperatures

Open Engineering ◽

10.1515/eng-2020-0218 ◽

2021 ◽

Vol 11 (1) ◽

pp. 606-616

Author(s):

Wojciech Lewicki

Keyword(s):

Ambient Temperature ◽

Power Unit ◽

Armed Forces ◽

Transport Sector ◽

Compression Ignition Engine ◽

Ambient Temperatures ◽

Start Up ◽

Cylinder Liners ◽

The Impact

Abstract The article presents research on the impact of a 359 compression-ignition engine starting at low ambient temperatures. This engine is used in vehicles such as STAR 200, 244, and 226. The purpose of these tests was to determine the amount of wear depending on the ambient temperature and the number of starts, as well as to compare the wear at start-up with the wear occurring during tests on the dynamometer (long-term test for reliability) and wear occurring during the operation of the engine in the vehicle, and the impact of the number of starts and ambient temperature on diesel engine for the life of the vehicle to be repaired. The results of the author’s research showed that a minimum of the number of starts at low ambient temperatures has an impact on the number of kilometers driven by the car during operation to replace the cylinder liners (engine repair). Apart from the Polish armed forces and armies of other countries in which this type of vehicle is still used, the direct recipients of the research results are also other entities from the logistics transport sector for which further use of this power unit especially at low ambient temperatures is of fundamental economic importance.

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Nuts, anchor, self-locking, fixed, single lug, reduced series, with counterbore, with MJ threads, classifications: 1100 MPa (at ambient temperatures)/235°C, 1100 MPa (at ambient temperature)/315°C, 1100 MPa (at ambient temperature)/425°C. Dimensions

10.3403/01640506u ◽

2015 ◽

Keyword(s):

Ambient Temperature ◽

Ambient Temperatures

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Influence of Ambient Temperature on Radiative and Convective Heat Dissipation Ratio in Polymer Heat Sinks

Polymers ◽

10.3390/polym13142286 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2286

Author(s):

Jan Kominek ◽

Martin Zachar ◽

Michal Guzej ◽

Erik Bartuli ◽

Petr Kotrbacek

Keyword(s):

Heat Transfer ◽

Ambient Temperature ◽

Convective Heat ◽

Heat Dissipation ◽

High Surface ◽

Heat Sinks ◽

Fourth Power ◽

Molding Process ◽

Ambient Temperatures ◽

University Of Technology

Miniaturization of electronic devices leads to new heat dissipation challenges and traditional cooling methods need to be replaced by new better ones. Polymer heat sinks may, thanks to their unique properties, replace standardly used heat sink materials in certain applications, especially in applications with high ambient temperature. Polymers natively dispose of high surface emissivity in comparison with glossy metals. This high emissivity allows a larger amount of heat to be dissipated to the ambient with the fourth power of its absolute surface temperature. This paper shows the change in radiative and convective heat transfer from polymer heat sinks used in different ambient temperatures. Furthermore, the observed polymer heat sinks have differently oriented graphite filler caused by their molding process differences, therefore their thermal conductivity anisotropies and overall cooling efficiencies also differ. Furthermore, it is also shown that a high radiative heat transfer leads to minimizing these cooling efficiency differences between these polymer heat sinks of the same geometry. The measurements were conducted at HEATLAB, Brno University of Technology.

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Insufficient Stability of Clavulanic Acid in Widely Used Child-Appropriate Formulations

Antibiotics ◽

10.3390/antibiotics10020225 ◽

2021 ◽

Vol 10 (2) ◽

pp. 225

Author(s):

Ines Mack ◽

Mike Sharland ◽

Janneke M. Brussee ◽

Sophia Rehm ◽

Katharina Rentsch ◽

...

Keyword(s):

Ambient Temperature ◽

Clavulanic Acid ◽

Storage Conditions ◽

Essential Medicines ◽

Active Components ◽

Middle Income ◽

Ambient Temperatures ◽

Essential Medicines List ◽

Dispersible Tablets ◽

The Stability

Amoxicillin-clavulanic acid (AMC) belongs to the WHO Essential Medicines List for children, but for optimal antimicrobial effectiveness, reconstituted dry powder suspensions need to be stored in a refrigerated environment. Many patients in low- and middle-income countries who are sold AMC suspensions would be expected not to keep to the specified storage conditions. We aimed to assess the stability of both ingredients in liquid formulations and dispersible tablets, combined with nationally representative data on access to appropriate storage. Degradation of amoxicillin (AMX) and clavulanic-acid (CLA) was measured in suspensions and dispersible tablets commercially available in Switzerland at different ambient temperatures (8 °C vs. 28 °C over 7 days, and 23 °C vs. 28 °C over 24 h, respectively). Data on access to refrigeration and electricity were assessed from the USAID-funded Demographic and Health Survey program. In suspensions, CLA degraded to a maximum of 12.9% (95% CI −55.7%, +29.9%) at 8°C and 72.3% (95% CI −82.8%, −61.8%) at a 28 °C ambient temperature during an observation period of 7 days. Dispersible tablets were observed during 24 h and CLA degraded to 15.4% (95% CI −51.9%, +21.2%) at 23 °C and 21.7% (−28.2%, −15.1%) at a 28 °C ambient temperature. There is relevant degradation of CLA in suspensions during a 7-day course. To overcome the stability challenges for all active components, durable child-appropriate formulations are needed. Until then, prescribers of AMC suspensions or pharmacists who sell the drug need to create awareness for the importance of proper storage conditions regarding effectiveness of both antibiotics and this recommendation should be reflected in the WHO Essential Medicines List for children.

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