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Abstract

The purpose of this paper is to develop a dynamic thermal model of a permanent magnet excited synchronous motor (PMSM). The model estimates the temperature at specific points of the machine during operation. The model is implemented using thermal network theory, whose parameters are determined by means of analytical approaches. Usually thermal models are initialized and referenced to room temperature. However, this can lead to incorrect results, if the simulations are performed when the electrical machine operates under “warm” conditions. An approach is developed and discussed in this paper, which captures the model in critical states of the machine. The model gives feedback by online measured quantities to estimate the initial temperature. The paper provides an extended dynamic thermal model, which leads to a more accurate and more efficient thermal estimation.

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Authors and Affiliations

Christelle Piantsop Mbo’O
Kay Hameyer
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Abstract

Development and demography of Adalia decempunctata L. were studied under laboratory conditions at seven constant temperatures (12, 16, 20, 24, 28, 32 and 36°C). First instar larvae failed to develop to second instar at 12°С and no development occurred at 36°C. The total developmental time varied from 47.92 days at 16°C to 15.94 days at 28°C and increased at 32°C. The lower temperature thresholds of 11.05 and 9.90°C, and thermal constants of 290.84 day-degree and 326.34 day-degree were estimated by traditional and Ikemoto-Takai linear models, respectively. The lower temperature threshold (Tmin) values estimated by Analytis, Briere-1, Briere-2 and Lactin-2 for total immature stages were 11.99, 12.24, 10.30 and 10.8°C, respectively. The estimated fastest developmental temperatures (Tfast) by the Analytis, Briere-1, Briere-2 and Lactin-2 for overall immature stages development of A. decempunctata were 31.5, 31.1, 30.7 and 31.7°C, respectively. Analytis, Briere-1, Briere-2 and Lactin-2 measured the upper temperature threshold (Tmax) at 33.14, 36.65, 32.75 and 32.61°C. The age-stage specific survival rate (sxj) curves clearly depicted the highest and lowest survival rates at 16 and 32°C for males and females. The age-specific fecundity (mx) curves revealed higher fecundity rate when fed A. gossypii at 24 and 28°C. The highest and lowest values of intrinsic rate of increase (r) were observed at 28 and 16°C (0.1945 d–1 and 0.0592 d–1, respectively). Also, the trend of changes in the finite rate of increase (λ) was analogous with intrinsic rate of increase. The longest and shortest mean generation time (T) was observed at 16 and 28°C, respectively and the highest net reproductive rates (R0) was estimated at 24 and 28°C. According to the results, the most suitable temperature seems to be 28°C due to the shortest developmental time, highest survival rate, and highest intrinsic rate of increase.

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Authors and Affiliations

Zahra Mojib-Haghghadam
Jalal Jalali Sendi
Arash Zibaee
Jafar Mohaghegh
Azadeh Karimi-Malati
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Abstract

This paper presents a review of geophysical studies of the crust and the lithosphere- asthenosphere boundary (LAB) in the ocean-continent transition in the area of Spitsbergen (Svalbard Archipelago) in high Arctic. Over last decades many investigations were performed during Polish geophysical expeditions, as well as in the framework of international cooperation with scientists from Germany, Japan, Norway and USA. We compiled here existing seismic, gravity and thermal models down to LAB depth along the 800 km long transect extending from the actively spreading Knipovich Ridge, across southern Spitsbergen to the Kong Karls Land Volcanic Province. The results of all methods are very consistent, although they are sensitive to different physical parameters: seismic wave velocities, densities and thermal. The thinnest lithosphere of only 12 km is found beneath the Knipovich Ridge. Only 50 km to the west and 50 km to the east of the ridge the LAB depth increases to about 30 km, and this value corresponds to the oceanic structure of the North Atlantic Ocean. Beneath southern Spitsbergen the LAB depth is about 55 km and increases to 90–100 km beneath continental structure of the Barents Sea. The uplift of the LAB close to distance of 700 km along transect could be correlated with Kong Karls Land Volcanic Province.

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Authors and Affiliations

Marek Grad
Jacek Majorowicz

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