Temperature state of soils of peat plateaus in the sporadic permafrost area (European Northeast of Russia).

2018 ◽  
Vol XXII (5) ◽  
Keyword(s):  
Temperature State ◽  
Peat Plateaus

scholarly journals Analysis of long-term temperature monitoring of multiple wind turbines

2021 ◽  
pp. 002029402110130
Author(s):  
Xian Wang ◽  
Qian-cheng Zhao ◽  
Xue-bing Yang ◽  
Bing Zeng
Keyword(s):  
Wind Turbines ◽  
Temperature Rise ◽  
Performance Optimization ◽  
Wind Farm ◽  
Engineering Practice ◽  
Multiple Perspectives ◽  
Temperature State ◽  
Condition Monitoring Systems ◽  
Historical Temperature

The historical temperature data logged in the supervisory control and data acquisition (SCADA) system contains a wealth of information that can assist with the performance optimization of wind turbines (WTs). However, mining and using these long-term data is difficult and time-consuming due to their complexity, volume, etc. In this study, we tracked and analyzed the 5-year trends of major SCADA temperature rise variables in relation to the active power of four WTs in a real wind farm. To uncover useful information, an extended version of the bins method, which calculates the standard deviation (SD) as well as the average, is proposed and adopted. The implications of the analysis for engineering practice are discussed from multiple perspectives. The research results demonstrate a change in the patterns of the main temperature rise variables in a real wind farm, completeness of the monitoring of the WT internal temperature state, influence of wind turbine aging on temperature signals, a correlation between different measurement points, and a correlation between signals from different years. The knowledge gained from this research provides a reference for the development of more practical and comprehensive condition monitoring systems and methods, as well as better operation maintenance strategies.

scholarly journals Simulation of Diffusion Processes in Chemical and Thermal Processing of Machine Parts

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 698
Author(s):  
Kateryna Kostyk ◽  
Michal Hatala ◽  
Viktoriia Kostyk ◽  
Vitalii Ivanov ◽  
Ivan Pavlenko ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Temperature Distribution ◽  
Thermal Treatment ◽  
Diffusion Processes ◽  
Nitrogen Concentration ◽  
The Body ◽  
Functional Dependencies ◽  
Technological Parameters ◽  
Gas Nitriding ◽  
Temperature State

To solve a number of technological issues, it is advisable to use mathematical modeling, which will allow us to obtain the dependences of the influence of the technological parameters of chemical and thermal treatment processes on forming the depth of the diffusion layers of steels and alloys. The paper presents mathematical modeling of diffusion processes based on the existing chemical and thermal treatment of steel parts. Mathematical modeling is considered on the example of 38Cr2MoAl steel after gas nitriding. The gas nitriding technology was carried out at different temperatures for a duration of 20, 50, and 80 h in the SSHAM-12.12/7 electric furnace. When modeling the diffusion processes of surface hardening of parts in general, providing a specifically given distribution of nitrogen concentration over the diffusion layer’s depth from the product’s surface was solved. The model of the diffusion stage is used under the following assumptions: The diffusion coefficient of the saturating element primarily depends on temperature changes; the metal surface is instantly saturated to equilibrium concentrations with the saturating atmosphere; the surface layer and the entire product are heated unevenly, that is, the product temperature is a function of time and coordinates. Having satisfied the limit, initial, and boundary conditions, the temperature distribution equations over the diffusion layer’s depth were obtained. The final determination of the temperature was solved by an iterative method. Mathematical modeling allowed us to get functional dependencies for calculating the temperature distribution over the depth of the layer and studying the influence of various factors on the body’s temperature state of the body.

Development of Laminar Plasma Shielded HF-ERW Process: Advanced Welding Process of HF-ERW 3

2012 ◽  
Author(s):  
Hideki Hamatani ◽  
Funinori Watanabe ◽  
Nobuo Mizuhashi ◽  
Sunao Takeuchi ◽  
Yoshiaki Hirota ◽  
...  
Keyword(s):  
High Temperature ◽  
Welding Process ◽  
Air Entrainment ◽  
Plasma Jets ◽  
Control Technique ◽  
Monitoring Methods ◽  
Line Pipe ◽  
Temperature State ◽  
Weld Area ◽  
Cold Gas

High frequency - electric resistance welded (HF-ERW) pipe has been successfully used for many years for a number of applications. The benefits of HF-ERW pipe are considerable, including a higher dimensional tolerance and lower prices than seamless pipe and UO pipe. The conventional weld seam produced by HF-ERW, however, often has a relatively low toughness. We have developed an automatic heat input control technique based on ERW phenomena that relies on optical and electrical monitoring methods and has been shown to result in a significant improvement in the toughness. Shielding of the weld area must also be considered as a key factor in the formation of a sound weld. It has been shown that an inert cold gas (e.g., at room temperature) shielding technique is effective for maintaining a stable low oxygen state in the weld area that inhibits the formation of penetrator, a pancake oxide inclusions. Compared to the cold gas shielding technique, high temperature gas shielding, due to its higher kinetic viscosity coefficient, should make it easier to sustain a higher laminar flow, thus leading to a rather low air entrainment in the shielding gas. In addition, plasma is a much higher temperature state (∼6000 K), and the dissociated gases can react with the entrained oxygen; plasma jets should, therefore, enhance the overall shielding effects. Moreover, oxides on the strip edges can be expected to melt and/or be reduced by the high temperature plasma jets. Nippon Steel has developed a plasma torch that can generate a long and wide laminar argon – nitrogen – (hydrogen) jet. This paper describes the results obtained from our investigation of the effects of a plasma jet shield on the weld area of high strength line pipe with a yield strength grade of X65. Preliminary attempts in applying this novel shielding technique has been found, as expected, to demonstrate extremely low numbers of weld defects and a good low temperature toughness of the HF-ERW seam.

scholarly journals Multiband transport and nonmetallic low-temperature state of K0.50 Na0.24 Fe1.52 Se2

2014 ◽  
Vol 90 (2) ◽  
Author(s):  
Hyejin Ryu ◽  
F. Wolff-Fabris ◽  
J. B. Warren ◽  
M. Uhlarz ◽  
J. Wosnitza ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature State

Characterizing waste disposal sites by using multi-spectral satellite imagery

2021 ◽  
Author(s):  
Gaetana Ganci ◽  
Annalisa Cappello ◽  
Giuseppe Bilotta ◽  
Giuseppe Pollicino ◽  
Luigi Lodato
Keyword(s):  
Soil Moisture ◽  
Surface Temperature ◽  
Waste Disposal ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
The State ◽  
Dump Site ◽  
Temperature State ◽  
Surrounding Areas

<p>The application of remote sensing for monitoring, detecting and analysing the spatial and extents and temporal changes of waste dumping sites and landfills could become a cost-effective and powerful solution. Multi-spectral satellite images, especially in the thermal infrared, can be exploited to characterize the state of activity of a landfill.  Indeed, waste disposal sites, during the period of activity, can show differences in surface temperature (LST, Land Surface Temperature), state of vegetation (estimated through NDVI, Normalized Difference Vegetation Index) or soil moisture (estimated through NDWI, Normalized Difference Water Index) compared to neighboring areas. Landfills with organic waste typically show higher temperatures than surrounding areas due to exothermic decomposition activities. In fact, the biogas, in the absence or in case of inefficiency of the conveying plants, rises through the layers of organic matter and earth (landfill body) until it reaches the surface at a temperature of over 40 ° C. Moreover, in some cases, leachate contamination of the aquifers can be identified by analyzing the soil moisture, through the estimate of the NDWI, and the state of suffering of the vegetation surrounding the site, through the estimate of the NDVI. This latter can also be an indicator of soil contamination due to the presence of toxic and potentially dangerous waste when buried or present nearby. To take into account these facts, we combine the LST, NDVI and NDWI indices of the dump site and surrounding areas in order to characterize waste disposal sites. Preliminary results show how this approach can bring out the area and level of activity of known landfill sites. This could prove particularly useful for the definition of intervention priorities in landfill remediation works.</p>

scholarly journals On the dimorphism and the pressure–temperature state diagram of racemic m-nisoldipine, a dihydropyridine calcium ion antagonist

2018 ◽  
Vol 76 (5) ◽  
pp. 341-347 ◽  
Author(s):  
K. Li ◽  
G. Gbabode ◽  
G. Coquerel ◽  
R. Céolin ◽  
I.B. Rietveld
Keyword(s):  
Calcium Ion ◽  
State Diagram ◽  
Temperature State

scholarly journals Strong degradation of palsas and peat plateaus in northern Norway during the last 60 years

2016 ◽  
Author(s):  
Amund F. Borge ◽  
Sebastian Westermann ◽  
Ingvild Solheim ◽  
Bernd Etzelmüller
Keyword(s):  
Aerial Imagery ◽  
Aerial Images ◽  
Moderate Increase ◽  
Permafrost Degradation ◽  
Northern Norway ◽  
Temperature And Precipitation ◽  
Important Pathway ◽  
The 1950S ◽  
Lateral Erosion ◽  
Peat Plateaus

Abstract. Palsas and peat plateaus are permafrost landforms occurring in subarctic mires which constitute sensitive ecosystems with strong significance for vegetation, wildlife, hydrology and carbon cycle. We have systematically mapped the occurrence of palsas and peat plateaus in the northernmost county of Norway (Finnmark, ~ 50 000 km2) by manual interpretation of aerial images from 2005–2014 at a spatial resolution of 250 m2. At this resolution, mires and wetlands with palsas or peat plateaus occur in about 850 km2 of Finnmark, with the actual palsas and peat plateaus underlain by permafrost covering a surface area of approximately 110 km2. Secondly, we have quantified the lateral changes of the extent of palsas and peat plateaus for four study areas located along a NW–SE transect through Finnmark by utilizing repeat aerial imagery from the 1950s to the 2010s. The results of the lateral changes reveal a total decrease of 33–71 % in the areal extent of palsas and peat plateaus during the study period, with the largest lateral change rates observed in the last decade. However, the results indicate that degradation of palsas and peat plateaus in northern Norway has been a consistent process during the second half of the 20th century and possibly even earlier. Significant rates of degradation are observed in all investigated time periods since the 1950s, and thermokarst landforms observed on aerial images from the 1950s suggest that lateral degradation was already an ongoing process at this time. The results of this study show that lateral erosion of palsas and peat plateaus is an important pathway for permafrost degradation in the sporadic permafrost zone in northern Scandinavia. While the environmental factors governing the rate of erosion are not yet fully understood, we note a moderate increase in both air temperature and precipitation during the last few decades in the region.

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