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1.
Wireless Networks - Localization is regarded as one of the important challenges in the internet of things and Wireless Sensor Networks. The failure to localize sensors properly causes data loss and... 相似文献
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Wojciech Polkowski Natalia Sobczak Rafał Nowak Artur Kudyba Grzegorz Bruzda Adelajda Polkowska Marta Homa Patrycja Turalska Merete Tangstad Jafar Safarian Elmira Moosavi-Khoonsari Alejandro Datas 《Journal of Materials Engineering and Performance》2018,27(10):5040-5053
For a successful implementation of newly proposed silicon-based latent heat thermal energy storage systems, proper ceramic materials that could withstand a contact heating with molten silicon at temperatures much higher than its melting point need to be developed. In this regard, a non-wetting behavior and low reactivity are the main criteria determining the applicability of ceramic as a potential crucible material for long-term ultrahigh temperature contact with molten silicon. In this work, the wetting of hexagonal boron nitride (h-BN) by molten silicon was examined for the first time at temperatures up to 1750 °C. For this purpose, the sessile drop technique combined with contact heating procedure under static argon was used. The reactivity in Si/h-BN system under proposed conditions was evaluated by SEM/EDS examinations of the solidified couple. It was demonstrated that increase in temperature improves wetting, and consequently, non-wetting-to-wetting transition takes place at around 1650 °C. The contact angle of 90° ± 5° is maintained at temperatures up to 1750 °C. The results of structural characterization supported by a thermodynamic modeling indicate that the wetting behavior of the Si/h-BN couple during heating to and cooling from ultrahigh temperature of 1750 °C is mainly controlled by the substrate dissolution/reprecipitation mechanism. 相似文献
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Elmira Khusnutdinova Anastasiya Petrova Zulfia Zileeva Ulyana Kuzmina Liana Zainullina Yulia Vakhitova Denis Babkov Oxana Kazakova 《International journal of molecular sciences》2021,22(18)
A series of A-ring modified oleanolic and ursolic acid derivatives including C28 amides (3-oxo-C2-nicotinoylidene/furfurylidene, 3β-hydroxy-C2-nicotinoylidene, 3β-nicotinoyloxy-, 2-cyano-3,4-seco-4(23)-ene, indolo-, lactame and azepane) were synthesized and screened for their cytotoxic activity against the NCI-60 cancer cell line panel. The results of the first assay of thirty-two tested compounds showed that eleven derivatives exhibited cytotoxicity against cancer cells, and six of them were selected for complete dose–response studies. A systematic study of local SARs has been carried out by comparative analysis of potency distributions and similarity relationships among the synthesized compounds using network-like similarity graphs. Among the oleanane type triterpenoids, C2-[4-pyridinylidene]-oleanonic C28-morpholinyl amide exhibited sub-micromolar potencies against 15 different tumor cell lines and revealed particular selectivity for non-small cell lung cancer (HOP-92) with a GI50 value of 0.0347 μM. On the other hand, superior results were observed for C2-[3-pyridinylidene]-ursonic N-methyl-piperazinyl amide 29, which exhibited a broad-spectrum inhibition activity with GI50 < 1 μM against 33 tumor cell lines and <2 μM against all 60 cell lines. This compound has been further evaluated for cell cycle analysis to decipher the mechanism of action. The data indicate that compound 29 could exhibit both cytostatic and cytotoxic activity, depending on the cell line evaluated. The cytostatic activity appears to be determined by induction of the cell cycle arrest at the S (MCF-7, SH-SY5Y cells) or G0/G1 phases (A549 cells), whereas cytotoxicity of the compound against normal cells is nonspecific and arises from apoptosis without significant alterations in cell cycle distribution (HEK293 cells). Our results suggest that the antiproliferative effect of compound 29 is mediated through ROS-triggered apoptosis that involves mitochondrial membrane potential depolarization and caspase activation. 相似文献
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Determining the Main Factors in Declining the Urmia Lake Level by Using System Dynamics Modeling 总被引:4,自引:2,他引:4
Urmia Lake in Iran is the second largest saline lake in the world. This ecosystem is the home for different species. Due to
various socio-economical and ecological criteria, Urmia Lake has important role in the Northwestern part of the country but
it has faced many problems in recent years. Because of droughts, overuse of surface water resources and dam constructions,
water level has decreased in such a way that one quarter of the lake has changed to saline area in the last 10 years. The
purpose of this research is to determine the main factors which reduce the lake’s water level. To this end, a simulation model,
based on system dynamics method, is developed for the Urmia Lake basin to estimate the lake’s level. After successful verification
of the model, results show that (among the proposed factors) changes in inflows due to the climate change and overuse of surface
water resources is the main factor for 65% of the effect, constructing four dams is responsible for 25% of the problem, and
less precipitation on lake has 10% effect on decreasing the lake’s level in the recent years. In the future, the model also
can be used by managers as a decision support system to find the effects of building new dams or other infrastructures. 相似文献
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Seyed Morteza Babamir Elmira Hassanzade Mona Azimpour 《Concurrency and Computation》2015,27(17):5261-5287
In a multithreaded program, competition of threads for shared resources raises the deadlock possibility, which narrows the system liveness. Because such errors appear in specific schedules of concurrent executions of threads, runtime verification of threads behavior is a significant concern. In this study, we extended our previous approach for prediction of runtime behavior of threads may lead to an impasse. Such a prediction is of importance because of the nondeterministic manner of competing threads. The prediction process tries to forecast future behavior of threads based on their observed behavior. To this end, we map observed behavior of threads into time‐series data sets and use statistical and artificial intelligence methods for forecasting subsequent members of the sets as future behavior of the threads. The deadlock prediction is carried out based on probing the allocation graph obtained from actual and predicted allocation of resources to threads. In our approach, we use an artificial neural network (ANN) because ANNs enjoy the applicable performance and flexibility in predicting complex behavior. Using three case studies, we contrasted results of the current and our previous approaches to demonstrate results. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Partition coefficients of six migrants between four simulated foods (water, 10% ethanol, 3% acetic acid, 95% ethanol) and air were determined by the phase ratio variation (PRV) method using headspace analyses by gas chromatography. The migrants were ethyl acetate, methyl ethyl ketone, propyl alcohol, butyraldehyde, acetaldehyde and acetonitrile. The results showed that migrant absorption by the four food simulants was highly dependent on the physicochemical properties of migrants and foods, such as polarity, solubility and hydrogen-bonding. 相似文献
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The Journal of Supercomputing - Software evolution is a natural phenomenon due to the changing requirements. Understanding the program structure is a significant and complicated factor in... 相似文献
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