High Temperature Ageing of Fe-based Nanocrystalline Ribbons

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000260-000265 ◽  
Author(s):  
Christian Martin ◽  
Rémi Robutel ◽  
Cyril Buttay ◽  
Fabien Sixdenier ◽  
Pascal Bevilacqua ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperature Stress ◽  
Complex Permeability ◽  
Magnetic Flux Density ◽  
Low Permeability ◽  
High Permeability ◽  
Design Considerations ◽  
Temperature Ageing ◽  
The Impact

The impact of long-term high-temperature stress on nanocrystalline Finemet materials is measured by keeping samples at 200 °C for 1300 hours. The standard industrialized, high permeability Finemet materials as well as the recently available low permeability Finemet materials are investigated. Characterizations are performed at different frequencies, temperatures and magnetic field excitations on both aged and non-aged samples. Their complex permeability is also measured during the ageing test. Irreversible changes are pointed out on permeability, coercive field and magnetic flux density at saturation. Regarding the design considerations for high temperature power electronics, the suitability of these materials is demonstrated but an ageing effect has to be considered nonetheless. The presented data can be extrapolated to several thousand hours at 200 °C using the presented empiric ageing law.

scholarly journals Assessing Stream-Aquifer Connectivity in a Coastal California Watershed

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 416
Author(s):  
Bwalya Malama ◽  
Devin Pritchard-Peterson ◽  
John J. Jasbinsek ◽  
Christopher Surfleet
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Water Level ◽  
Time Series Data ◽  
Series Data ◽  
Low Permeability ◽  
Pumping Tests ◽  
Stream Flows ◽  
The Impact

We report the results of field and laboratory investigations of stream-aquifer interactions in a watershed along the California coast to assess the impact of groundwater pumping for irrigation on stream flows. The methods used include subsurface sediment sampling using direct-push drilling, laboratory permeability and particle size analyses of sediment, piezometer installation and instrumentation, stream discharge and stage monitoring, pumping tests for aquifer characterization, resistivity surveys, and long-term passive monitoring of stream stage and groundwater levels. Spectral analysis of long-term water level data was used to assess correlation between stream and groundwater level time series data. The investigations revealed the presence of a thin low permeability silt-clay aquitard unit between the main aquifer and the stream. This suggested a three layer conceptual model of the subsurface comprising unconfined and confined aquifers separated by an aquitard layer. This was broadly confirmed by resistivity surveys and pumping tests, the latter of which indicated the occurrence of leakage across the aquitard. The aquitard was determined to be 2–3 orders of magnitude less permeable than the aquifer, which is indicative of weak stream-aquifer connectivity and was confirmed by spectral analysis of stream-aquifer water level time series. The results illustrate the importance of site-specific investigations and suggest that even in systems where the stream is not in direct hydraulic contact with the producing aquifer, long-term stream depletion can occur due to leakage across low permeability units. This has implications for management of stream flows, groundwater abstraction, and water resources management during prolonged periods of drought.

scholarly journals Alterations of Endogenous Hormones, Antioxidant Metabolism, and Aquaporin Gene Expression in Relation to γ-Aminobutyric Acid-Regulated Thermotolerance in White Clover

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1099
Author(s):  
Hongyin Qi ◽  
Dingfan Kang ◽  
Weihang Zeng ◽  
Muhammad Jawad Hassan ◽  
Yan Peng ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Temperature ◽  
Temperature Stress ◽  
White Clover ◽  
High Temperature Stress ◽  
Aminobutyric Acid ◽  
Endogenous Hormones ◽  
Gaba Level ◽  
Antioxidant Metabolism ◽  
The Impact

Persistent high temperature decreases the yield and quality of crops, including many important herbs. White clover (Trifolium repens) is a perennial herb with high feeding and medicinal value, but is sensitive to temperatures above 30 °C. The present study was conducted to elucidate the impact of changes in endogenous γ-aminobutyric acid (GABA) level by exogenous GABA pretreatment on heat tolerance of white clover, associated with alterations in endogenous hormones, antioxidant metabolism, and aquaporin-related gene expression in root and leaf of white clover plants under high-temperature stress. Our results reveal that improvement in endogenous GABA level in leaf and root by GABA pretreatment could significantly alleviate the damage to white clover during high-temperature stress, as demonstrated by enhancements in cell membrane stability, photosynthetic capacity, and osmotic adjustment ability, as well as lower oxidative damage and chlorophyll loss. The GABA significantly enhanced gene expression and enzyme activities involved in antioxidant defense, including superoxide dismutase, catalase, peroxidase, and key enzymes of the ascorbic acid–glutathione cycle, thus reducing the accumulation of reactive oxygen species and the oxidative injury to membrane lipids and proteins. The GABA also increased endogenous indole-3-acetic acid content in roots and leaves and cytokinin content in leaves, associated with growth maintenance and reduced leaf senescence under heat stress. The GABA significantly upregulated the expression of PIP1-1 and PIP2-7 in leaves and the TIP2-1 expression in leaves and roots under high temperature, and also alleviated the heat-induced inhibition of PIP1-1, PIP2-2, TIP2-2, and NIP1-2 expression in roots, which could help to improve the water transportation and homeostasis from roots to leaves. In addition, the GABA-induced aquaporins expression and decline in endogenous abscisic acid level could improve the heat dissipation capacity through maintaining higher stomatal opening and transpiration in white clovers under high-temperature stress.

Periodontal Damage after thermal inhalation injury – the impact of high temperature inhalation injury on long term periodontal health

Burns ◽  
2021 ◽  
Author(s):  
Robert Schappacher ◽  
Matthias Rapp ◽  
Claus-Martin Muth ◽  
Jan Nölke ◽  
Lance Amrehn ◽  
...  
Keyword(s):  
High Temperature ◽  
Inhalation Injury ◽  
Periodontal Health ◽  
The Impact

Long Term Degradation Behavior of Impact Properties of Hydraulic Forged Superalloy 718 during Exposure at High Temperature

2007 ◽  
Vol 26-28 ◽  
pp. 1071-1074
Author(s):  
Young Seok Song ◽  
M.R. Lee ◽  
Jeong Tae Kim
Keyword(s):  
High Temperature ◽  
Impact Energy ◽  
Melting Process ◽  
Hydraulic Press ◽  
Degradation Behavior ◽  
Impact Properties ◽  
Hardness Tests ◽  
Temperature Exposure ◽  
The Impact

To check long term degradation behavior of hydraulic forged superalloy 718 during exposure at high temperature, an Alloy 718 ingot with a diameter of 400mm was manufactured by the vacuum melting process, VIM followed by VAR. The ingot was broken down for uniform microstructure and mechanical properties by a controlled cogging process using a hydraulic press. To investigate long term degradation behavior of impact properties and hardness, the specimens were exposed to 600oC, 650oC and 700oC for holding times up to 12,112 hours. Impact energy absorption tests were performed at room temperature. The fractured area and the microstructure of the impact specimens were observed by OEM and SEM and Brinell hardness tests were also performed. The changes of impact energy and hardness are remarkably different for each temperature condition. The results suggest that the impact properties and hardness of Ni based superalloy 718 is strongly related to temperature and time during high temperature exposure.

Simulation Experimental Study on Aeolotropism Affects the Recovery of Low Permeable Sub Layer Reservoir

2015 ◽  
Vol 733 ◽  
pp. 174-177
Author(s):  
Xin Yuan Zhao ◽  
Yi Kun Liu ◽  
Feng Jiao Wang ◽  
Ru Ya Chen ◽  
Jin Ming Wang
Keyword(s):  
Recovery Rate ◽  
Water Flooding ◽  
Displacement Rate ◽  
Low Permeability ◽  
High Permeability ◽  
Water Displacement ◽  
Sand Body ◽  
Rock Cores ◽  
Layer Analysis ◽  
The Impact

In order to reveal the impact of reservoir heterogeneity on its recovery and by taking the interlayer heterogeneous and inner layer sand superimposition model (two forms of complexity situation) into account, water flooding experiments have been conducted on parallel connected rock cores, which are selected and artificially casted cores with different permeability, at different injection rates. Experimental results suggested that water displacement recovery is kept decreasing with the increasing of interlayer heterogeneity. when the interlayer permeability ratio (ratio of high permeability versus low permeability) is at about 6.5 and water displacement rate is set at 0.5ml/min, 1ml/min, 1.5ml/min, 2ml/min, respectively, the water flooding experiments indicated that the low permeability recovery increased significantly and low permeability layer became main producer with the increasing of water displacement rate, on the opposite, the high permeability recovery showed no little big change. Laboratory experiments on the model of layer sand body superimposition revealed that the recovery rate of FTRLPTPL model is about 5%~10% higher than that of FTPLPTRL model.(FTRLPTPL is briefed from that flooding from the thick and rich in oil layer and produced from the thin and poor in oil layer. FTPLPTRL is briefed from that flooding from the thin and poor in oil layer and produced from the thick and rich in oil layer.) Analysis on the experiments in different reservoir inner situation told us that recovery enhancement of low permeability layer can play a significant role in increasing the overall recovery rate.

Hydraulic conductivity behavior of soilcrete specimens created from dredging sand, cement, and bentonite

2021 ◽  
Author(s):  
Hoang-Hung Tran-Nguyen ◽  
Bich Thi Luong ◽  
Phong Duy Nguyen ◽  
Khanh Duy Tuan Nguyen
Keyword(s):  
Hydraulic Conductivity ◽  
Mekong Delta ◽  
Research Data ◽  
Low Permeability ◽  
High Permeability ◽  
Seepage Flows ◽  
Southern Vietnam ◽  
Hydraulic Gradients ◽  
Conductivity Behavior

Abstract Dredging sand is an inexpensive material utilized to rise elevations of highway embankments and earth levee bodies in the Southern Vietnam. However, high permeability of the dredging sand can cause failures due to seepage flows during annual flood seasons. The dredging sand mixing cement with or without bentonite is expected to be suitable low permeability as an impermeable material. However, hydraulic conductivity of soilcrete and bentonite specimens created from dredging sand taken in the Mekong delta has limit research data. This study aims at better understanding the hydraulic conductivity of dredging sand samples taken in Dong Thap province mixed with cement and bentonite. The effects of the hydraulic conductivity of soilcrete and bentonite soilcrete specimens on time, cement contents, bentonite contents, cement types, and hydraulic gradients were investigated. The tests followed the ASTM D5084 standard using the both falling head-constant tailwater and falling head-rising tailwater methods. The results indicate that: (1) the hydraulic conductivity of the soilcrete and bentonite specimens decreased with increasing in testing duration and cement contents; (2) the hydraulic conductivity of the soilcrete specimens was lower 104 to 105 times than that of the compacted sand; (3) the hydraulic conductivity of the bentonite soilcrete specimens was lower 10 times than those of the soilcrete specimens; (5) the PCS cement can induce long-term reduction of soilcrete hydraulic; (6) effect of hydraulic gradients on soilcrete hydraulic conductivity was ignorable; (6) the soilcrete hydraulic conductivity varies from 10− 9 to 10− 10 m/s.

Electromagneto-mechanical model of high temperature superconductor insert magnets in ultra high magnetic fields

2022 ◽  
Author(s):  
Frederic Trillaud ◽  
Edgar Berrospe-Juarez ◽  
Vı́ctor M. R. Zermeño ◽  
Francesco Grilli
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Magnetic Field ◽  
Mechanical Model ◽  
Safety Margin ◽  
Magnetic Flux Density ◽  
Mechanical Degradation ◽  
Relative Deformation ◽  
Induced Field ◽  
The Impact

Abstract Second-Generation High Temperature Superconducting (2G HTS) tapes are considered to be the main candidates for the development of future ultra high DC magnetic field magnets. In such application, the usability of the HTS magnets can be strongly impaired by large screening currents developed in the flat strip of the tapes. These currents lead to the generation of a Screening Current Induced Field (SCIF) that can deteriorate the performance by affecting the stability and the homogeneity of the magnetic field. Besides the SCIF, there is also the likely mechanical degradation of the tapes under the action of large Lorentz forces. The mechanical degradation and the presence of large screening currents intertwine to affect the reliable operation of 2G HTS magnets. To study those combined issues, an electromagneto-mechanical model based on tensile mechanical characterization of short samples was built to simulate the coupled electromagnetic and mechanical behaviour of insert magnets made of 2G HTS tapes under very high magnetic field. The coupling is carried out by considering the dependence of the n index and the critical current density Jc on the local relative deformation in addition to the magnetic flux density. The case study is the Little Big Coil (LBC, version 3) which broke the world record of the strongest continuous magnetic field achieved to this date. An analysis of the electromagneto-mechanical behavior of the LBC is conducted on the basis of information extracted from literature to show that the proposed model can assess the current magnitude at which the insert magnet quenched. Additionally, it is shown that the model can also provide some insights on the impact of the mechanical degradation of the tape on the SCIF hysteresis loop. The studies are conducted on the original LBC and on versions that include additional modifications such as harnessing and co- winding with rigid metallic tapes. These modifications are employed to limit the mechanical degradation of the HTS insert magnet under ultra high magnetic field. They are expected to deliver extra safety margin to 2G HTS insert magnets.

scholarly journals High-Temperature and Drought Stress Effects on Growth, Yield and Nutritional Quality with Transpiration Response to Vapor Pressure Deficit in Lentil

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 95
Author(s):  
Noureddine El Haddad ◽  
Hasnae Choukri ◽  
Michel Edmond Ghanem ◽  
Abdelaziz Smouni ◽  
Rachid Mentag ◽  
...  
Keyword(s):  
High Temperature ◽  
Drought Stress ◽  
Vapor Pressure ◽  
Grain Yield ◽  
Protein Content ◽  
Temperature Stress ◽  
Nutritional Quality ◽  
Vapor Pressure Deficit ◽  
High Temperature Stress ◽  
The Impact

High temperature and water deficit are among the major limitations reducing lentil (Lens culinaris Medik.) yield in many growing regions. In addition, increasing atmospheric vapor pressure deficit (VPD) due to global warming causes a severe challenge by influencing the water balance of the plants, thus also affecting growth and yield. In the present study, we evaluated 20 lentil genotypes under field conditions and controlled environments with the following objectives: (i) to investigate the impact of temperature stress and combined temperature-drought stress on traits related to phenology, grain yield, nutritional quality, and canopy temperature under field conditions, and (ii) to examine the genotypic variability for limited transpiration (TRlim) trait in response to increased VPD under controlled conditions. The field experiment results revealed that high-temperature stress significantly affected all parameters compared to normal conditions. The protein content ranged from 23.4 to 31.9%, while the range of grain zinc and iron content varied from 33.1 to 64.4 and 62.3 to 99.3 mg kg−1, respectively, under normal conditions. The grain protein content, zinc and iron decreased significantly by 15, 14 and 15% under high-temperature stress, respectively. However, the impact was more severe under combined temperature-drought stress with a reduction of 53% in protein content, 18% in zinc and 20% in iron. Grain yield declined significantly by 43% in temperature stress and by 49% in the combined temperature-drought stress. The results from the controlled conditions showed a wide variation in TR among studied lentil genotypes. Nine genotypes displayed TRlim at 2.76 to 3.51 kPa, with the genotypes ILL 7833 and ILL 7835 exhibiting the lowest breakpoint. Genotypes with low breakpoints had the ability to conserve water, allowing it to be used at later stages for increased yield. Our results identified promising genotypes including ILL 7835, ILL 7814 and ILL 4605 (Bakria) that could be of great interest in breeding for high yields, protein and micronutrient contents under high-temperature and drought stress. In addition, it was found that the TRlim trait has the potential to select for increased lentil yields under field water-deficit environments.

scholarly journals Screening of Indian Mustard (Brassica juncea L. Czern and Coss) Genotypes with Respect to Seedling Growth Physiology under Salinity and High-Temperature Stress

2021 ◽  
pp. 97-108
Author(s):  
Satya Narayan Prasad ◽  
. Kavita ◽  
. Kiran ◽  
Trisha Sinha
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Seedling Growth ◽  
Growth Parameters ◽  
Indian Mustard ◽  
High Temperature Stress ◽  
Seedling Stage ◽  
Growth Physiology ◽  
Vigour Index ◽  
The Impact

The experiment was carried out to screen mustard genotypes under individual and combined salinity and high-temperature stress at seedling stage. Seeds after being sown in soil-filled trays were subjected to two levels of salinity stress i.e. 4.0 dSm-1 and 6.0 dSm-1, and high-temperature (40℃), and their performances were also compared with control (1.2 dSm-1). Contrasting sets of genotypes were selected on the basis of seedling growth parameters such as germination percentage, seedling length, dry weight of seedlings, vigour index-I and vigour index-II, recorded in 15-day-old seedlings. With consideration to the genotypic variations observed under all the treatments, genotypes CS2009-347 and CS-52 were identified as tolerant, and genotypes CS2009-256 and CS2009-145 were identified as susceptible under salinity and high-temperature stress conditions. The results also revealed that the impact of salinity and high-temperature in combination on mustard at seedling stage was more detrimental than that of their effects under individual conditions. These findings of genotypic variations in terms of tolerance in seedling stage of Indian mustard might be helpful in selection of genotypes with improved tolerance to salinity and high-temperature.

Influence of High-Temperature Ageing on Mechanical Properties of Low Alloy Steel Clad Plate Welded Joints

2016 ◽  
Vol 878 ◽  
pp. 51-55
Author(s):  
Zhi Ling Wang ◽  
Xiang Li
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Fusion Zone ◽  
Welded Joints ◽  
Base Layer ◽  
Filling Material ◽  
Welding Wire ◽  
Joint Fusion ◽  
Temperature Ageing ◽  
The Impact

In this paper, the mechanical properties of welded joints of Q345R/304 stainless steel clad plates after high temperature ageing were studied. E309Nb welding rod, ER310 welding wire, and ER309L welding wire were used as cladding filling materials, and ER50-6 welding wire was used as base-layer filling material. The mechanical properties of welded joints were characterized by micro-hardness measurement and mechanics performance testing respectively, after ageing treatment at 600°C for 100 hours. Test results showed that there was lower carbon diffusion in the ER309L joint-base layer and transition layer than those of other two joints after high temperature ageing, and the hardness value had little change around ER309L joint-fusion zone. The microstructure of ER309L joint-fusion zone was different from that of other two joints. The impact test after high temperature ageing indicateed the impact toughness of three welding joints decreased obviously, and the weld zone of ER309L joint presented a worst toughness, which leded to the occurrence of brittle fracture.

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