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The increasing worldwide demand for antimicrobial agents has significantly contributed to the alarming rise of antimicrobial resistance, posing a grave threat to human life. Consequently, there is a pressing need to explore uncharted environments, seeking out novel antimicrobial compounds that display exceptionally efficient capabilities. Hot springs harbor microorganisms possessing remarkable properties, rendering them an invaluable resource for uncovering groundbreaking antimicrobial compounds. In this study, thermophilic bacteria were isolated from Mahallat Hot Spring, Iran. Out of the 30 isolates examined, 3 strains exhibited the most significant antibacterial activities against Escherichia coli and Staphylococcus aureus. Furthermore, the supernatants of the isolated strains exhibited remarkable antibacterial activity, displaying notable resistance to temperatures as high as 75 °C for 30 min. It was determined that the two strains showed high similarity to the Bacillus genus, while strain Kh3 was classified as Saccharomonospora azurea. All three strains exhibited tolerance to NaCl. Bacillus strains demonstrated optimal growth at pH 5 and 40 °C, whereas S. azurea exhibited optimal growth at pH 9 and 45 °C. Accordingly, hot springs present promising natural reservoirs for the isolation of resilient strains possessing antibacterial properties, which can be utilized in disease treatment or within the food industry.

The increasing worldwide demand for antimicrobial agents has significantly contributed to the alarming rise of antimicrobial resistance, posing a grave threat to human life. Consequently, there is a pressing need to explore uncharted environments, seeking out novel antimicrobial compounds that display exceptionally efficient capabilities. Hot springs harbor microorganisms possessing remarkable properties, rendering them an invaluable resource for uncovering groundbreaking antimicrobial compounds. In this study, thermophilic bacteria were isolated from Mahallat Hot Spring, Iran. Out of the 30 isolates examined, 3 strains exhibited the most significant antibacterial activities against Escherichia coli and Staphylococcus aureus. Furthermore, the supernatants of the isolated strains exhibited remarkable antibacterial activity, displaying notable resistance to temperatures as high as 75 °C for 30 min. It was determined that the two strains showed high similarity to the Bacillus genus, while strain Kh3 was classified as Saccharomonospora azurea. All three strains exhibited tolerance to NaCl. Bacillus strains demonstrated optimal growth at pH 5 and 40 °C, whereas S. azurea exhibited optimal growth at pH 9 and 45 °C. Accordingly, hot springs present promising natural reservoirs for the isolation of resilient strains possessing antibacterial properties, which can be utilized in disease treatment or within the food industry.

Hydrogen peroxide is commonly used as a low-toxicity liquid rocket propellant (oxidizer). Hydrodynamic bearings lubricated by this propellant may be applicable in rocket engine pumps. In this paper, a hydrodynamic tilting-pad journal bearing lubricated by highly concentrated (87wt%) hydrogen peroxide was proposed. Furthermore, an experimental validation of the performance of this bearing with pads made of PEEK material (polyetheretherketone) was carried out on the developed high-speed measuring device. To verify the endurance of this bearing, measurements were performed at different peroxide flow rates from 100% to 20% of the nominal flow rate. The tests were also conducted under excessive vibrations induced by the misalignment of the test rotor with the drive connected by a flexible coupling. In addition to vibration measurement, the wear of the bearing sliding surfaces and lubricant temperature variations were evaluated. The measured results were compared with the calculated data. For this purpose, a two-dimensional computational model based on the thermo-elasto-hydrodynamic lubrication theory was presented. To improve the solution convergence, Newton's method was used to calculate the equilibrium tilt of the pads. The involved bearings operated smoothly at the mentioned misalignment even at 20% peroxide flow, only slight foaming occurred at the outlet.

Hydrogen peroxide is commonly used as a low-toxicity liquid rocket propellant (oxidizer). Hydrodynamic bearings lubricated by this propellant may be applicable in rocket engine pumps. In this paper, a hydrodynamic tilting-pad journal bearing lubricated by highly concentrated (87wt%) hydrogen peroxide was proposed. Furthermore, an experimental validation of the performance of this bearing with pads made of PEEK material (polyetheretherketone) was carried out on the developed high-speed measuring device. To verify the endurance of this bearing, measurements were performed at different peroxide flow rates from 100% to 20% of the nominal flow rate. The tests were also conducted under excessive vibrations induced by the misalignment of the test rotor with the drive connected by a flexible coupling. In addition to vibration measurement, the wear of the bearing sliding surfaces and lubricant temperature variations were evaluated. The measured results were compared with the calculated data. For this purpose, a two-dimensional computational model based on the thermo-elasto-hydrodynamic lubrication theory was presented. To improve the solution convergence, Newton's method was used to calculate the equilibrium tilt of the pads. The involved bearings operated smoothly at the mentioned misalignment even at 20% peroxide flow, only slight foaming occurred at the outlet.

Hydrogen peroxide is commonly used as a low-toxicity liquid rocket propellant (oxidizer). Hydrodynamic bearings lubricated by this propellant may be applicable in rocket engine pumps. In this paper, a hydrodynamic tilting-pad journal bearing lubricated by highly concentrated (87wt%) hydrogen peroxide was proposed. Furthermore, an experimental validation of the performance of this bearing with pads made of PEEK material (polyetheretherketone) was carried out on the developed high-speed measuring device. To verify the endurance of this bearing, measurements were performed at different peroxide flow rates from 100% to 20% of the nominal flow rate. The tests were also conducted under excessive vibrations induced by the misalignment of the test rotor with the drive connected by a flexible coupling. In addition to vibration measurement, the wear of the bearing sliding surfaces and lubricant temperature variations were evaluated. The measured results were compared with the calculated data. For this purpose, a two-dimensional computational model based on the thermo-elasto-hydrodynamic lubrication theory was presented. To improve the solution convergence, Newton's method was used to calculate the equilibrium tilt of the pads. The involved bearings operated smoothly at the mentioned misalignment even at 20% peroxide flow, only slight foaming occurred at the outlet.

Hydrogen peroxide is commonly used as a low-toxicity liquid rocket propellant (oxidizer). Hydrodynamic bearings lubricated by this propellant may be applicable in rocket engine pumps. In this paper, a hydrodynamic tilting-pad journal bearing lubricated by highly concentrated (87wt%) hydrogen peroxide was proposed. Furthermore, an experimental validation of the performance of this bearing with pads made of PEEK material (polyetheretherketone) was carried out on the developed high-speed measuring device. To verify the endurance of this bearing, measurements were performed at different peroxide flow rates from 100% to 20% of the nominal flow rate. The tests were also conducted under excessive vibrations induced by the misalignment of the test rotor with the drive connected by a flexible coupling. In addition to vibration measurement, the wear of the bearing sliding surfaces and lubricant temperature variations were evaluated. The measured results were compared with the calculated data. For this purpose, a two-dimensional computational model based on the thermo-elasto-hydrodynamic lubrication theory was presented. To improve the solution convergence, Newton's method was used to calculate the equilibrium tilt of the pads. The involved bearings operated smoothly at the mentioned misalignment even at 20% peroxide flow, only slight foaming occurred at the outlet.

The study of the properties of matter at extreme conditions (>109 Pa, >104 K0) is imperative for understanding phenomena where such states are reached in planetary astrophysics and confined fusion. To achieve such states of matter, what is often described as warm dense plasma, extremely high energy density deposition should be realized. One of the techniques used to explore matter under extreme conditions is the underwater electrical explosion of wire and wire arrays accompanied by the generation of strong shock waves., QC 20230424

In this study, quantitative analyses focusing on the mangrove, Rhizophora sp. (R sp.), have been conducted to understand the 1) effect of the choice of bulk drag coefficient, CD, on the wave attenuation results, 2) sensitivity of the wave attenuation model to the complex root system of Rhizophora sp. at various water levels, and 3) contribution analyses of the root, trunk, and canopy of R sp. tree to wave dampening. The results of these analyses are then used to craft recommendations that can guide future research.

Warm dense matter (WDM) is the state of matter at high pressures and temperatures. WDM is relevant both for practical applications and for fundamental science. The practical significance is due to the generation of the WDM state in experiments on nuclear fusion and the creation of new materials under extreme conditions. From the point of view of fundamental science, the relevance of WDM is due to the extreme conditions in the interiors of planets and stars. Many questions regarding the interplay of quantum degeneracy, thermal excitations, and strong correlations effects in WDM remain open. To solve this problem, we use an externally perturbed WDM to investigate how electronic structure and excitations are affected by thermal excitations and density inhomogeneities. The results are reported in our recent articles [1-4], where we presented: a study of the quality of various exchange-correlation functionals in the KS-DFT method [1,2]; the change in electronic excitations due to strong inhomogeneity and thermal effects [3]; and a new KS-DFT based methodology for the investigation of the non-linear response of electrons across temperature regimes relevant for WDM [4]. [1] Z. Moldabekov, T. Dornheim, M. Boehme, J. Vorberger, A. Cangi, J. Chem.Phys. 155 (2021) 124116. [2] Z. Moldabekov, T. Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105 (2022) 035134. [3] Z. Moldabekov, T. Dornheim, A. Cangi, Sci. Rep. 12 (2022) 1093. [4] Z. Moldabekov, J. Vorberger, T. Dornheim, J. Chem. Theory Comput. 18 (2022) 2900

The article discusses the gene “Monoamine oxidase” (MAO), which is considered to be the “Warrior’s genome”. This gene is associated with human behavioral response in extreme conditions. Genotyping of athletes was carried out and the frequency of occurrence of genotypes in the group of athletes was established. Preliminary data have been obtained that can be used to formulate a hypothesis and plan studies related to the MAO gene on large samples of athletes., В статье рассматривается ген «Моноаминоксидаза» (МАО), который принято считать «Геном воина». Данный ген имеет связь с поведенческой реакцией человека в экстремальных условиях. Было проведено генотипирование спортсменов и установлена частота встречаемости генотипов в группе спортсменов. Получены предварительные данные, которые могут быть использованы для формулировки гипотезы и планирования исследований связанных с геном МАО на больших выборках спортсменов.

Tesis por compendio, [ES] Esta tesis doctoral presenta un estudio de compresores scroll con inyección de vapor (SCVI) para bombas de calor que operan en climas fríos o para aplicaciones de calentamiento de agua a alta temperatura. Para ello, se comparó experimentalmente un SCVI con un compresor de dos etapas de pistones (TSRC) trabajando con R-407C en condiciones extremas. La comparación se realizó en términos de eficiencias del compresor, capacidad, COP y rendimientos estacionales tanto para el modo calefacción como para el modo refrigeración. Los resultados proporcionan una idea general sobre el rango de aplicación de los compresores estudiados y sobre las diferencias en los rendimientos de los compresores. Sin embargo, se identificaron varias limitaciones en la caracterización de los compresores y en el análisis del ciclo. Esto motivó a profundizar en el estudio del ciclo de compresión de dos etapas y sus componentes. El siguiente paso fue realizar un análisis teórico de los ciclos de compresión de dos etapas para aplicaciones de calefacción, en donde se identificó a la presión intermedia y a la relación de inyección como los parámetros del sistema más influyentes sobre el COP. La presión intermedia se optimizó para dos configuraciones de inyección (tanque de separación y economizador) utilizando varios refrigerantes. Basándose en los resultados de la optimización, se propuso una correlación que permite obtener la presión intermedia óptima del ciclo, considerando la influencia del subenfriamiento a la salida del condensador. Además, se analizó la influencia del diseño de los componentes del sistema sobre el COP del ciclo. Posteriormente, el estudio se profundizó a nivel de componentes. El factor más crítico en el sistema es el rendimiento del compresor. Por lo tanto, el siguiente paso fue evaluar la influencia de varios sistemas de compresión con inyección de vapor sobre el COP. Se tomaron en cuenta tres tecnologías de compresores, un SCVI, un TSRC y un compresor scroll de dos etapas, [CA] Aquesta tesi doctoral presenta un estudi de compressors scroll amb injecció de vapor (SCVI) per a bombes de calor que operen en climes freds o per a aplicacions d'escalfament d'aigua a alta temperatura. Per a això, es va comparar experimentalment un SCVI amb un compressor de dues etapes de pistons (TSRC) treballant amb R-407C en condicions extremes. La comparació es va realitzar en termes d'eficiències del compressor, capacitat, COP i rendiments estacionals tant per al mode calefacció com per al mode refrigeració. Els resultats proporcionen una idea general sobre el rang d'aplicació dels compressors estudiats i sobre les diferències en els rendiments dels compressors. No obstant això, es van identificar diverses limitacions en la caracterització dels compressors i en l'anàlisi del cicle. Això va motivar a aprofundir en l'estudi del cicle de compressió de dues etapes i els seus components. El següent pas va ser realitzar una anàlisi teòrica dels cicles de compressió de dues etapes per a aplicacions de calefacció, on es va identificar la pressió intermèdia i la relació d'injecció com els paràmetres del sistema més influents sobre el COP. La pressió intermèdia es va optimitzar per a dues configuracions d'injecció (tanc de separació i economitzador) utilitzant diversos refrigerants. Basant-se en els resultats de l'optimització, es va proposar una correlació que permet obtindre la pressió intermèdia òptima del cicle, considerant la influència del subrefredament a l'eixida del condensador. A més, es va analitzar la influència del disseny dels components del sistema sobre el COP del cicle. Posteriorment, l'estudi es va aprofundir a nivell de components. El factor més crític en el sistema és el rendiment del compressor. Per tant, el següent pas va ser avaluar la influència de diversos sistemes de compressió amb injecció de vapor sobre el COP. Es van prendre en compte tres tecnologies de compressors, un SCVI, un TSRC i un compressor scroll de dues etapes (TSSC). Aqueste, [EN] This Ph.D. thesis presents a study of scroll compressors with vapor-injection (SCVI) for heat pumps operating in cold climates or in high-temperature water heating applications. To do so, firstly, an SCVI was experimentally compared with a two-stage reciprocating compressor (TSRC) working with R-407C under extreme conditions. The comparison was made in terms of compressor efficiencies, capacity, COP, and seasonal COP, both for heating and cooling modes. The results give a general idea about the application range of the studied compressors and the differences in the compressors' performance. Nevertheless, several restrictions in the compressors' characterization and the cycle analysis were identified. This motivated us to deepen in the study of the two-stage compression cycle and its components. The next step was performing a theoretical analysis of two-stage compression cycles for heating applications, where the intermediate pressure and the injection ratio were identified as the most influential system parameters on the COP. The intermediate pressure was optimized for two vapor-injection configurations (flash tank and economizer) using several refrigerants. Based on the optimization results, a correlation was proposed that allows obtaining the optimal intermediate pressure of the cycle, considering the influence of the subcooling at the condenser outlet. In addition, a theoretical analysis of the influence of the design of the system components on the COP of the cycle was performed. Once the thermodynamic analysis of the two-stage cycle was carried out, the study was deepened at the component level. The most critical factor in the system is the compressor performance. Hence, the next step was evaluating the influence of several compression systems with vapor-injection on the COP. Three compressor technologies were taken into account, an SCVI, a TSRC and a two-stage scroll compressor (TSSC). These compressor technologies were characterized and modeled in order

Tesis por compendio, [ES] Esta tesis doctoral presenta un estudio de compresores scroll con inyección de vapor (SCVI) para bombas de calor que operan en climas fríos o para aplicaciones de calentamiento de agua a alta temperatura. Para ello, se comparó experimentalmente un SCVI con un compresor de dos etapas de pistones (TSRC) trabajando con R-407C en condiciones extremas. La comparación se realizó en términos de eficiencias del compresor, capacidad, COP y rendimientos estacionales tanto para el modo calefacción como para el modo refrigeración. Los resultados proporcionan una idea general sobre el rango de aplicación de los compresores estudiados y sobre las diferencias en los rendimientos de los compresores. Sin embargo, se identificaron varias limitaciones en la caracterización de los compresores y en el análisis del ciclo. Esto motivó a profundizar en el estudio del ciclo de compresión de dos etapas y sus componentes. El siguiente paso fue realizar un análisis teórico de los ciclos de compresión de dos etapas para aplicaciones de calefacción, en donde se identificó a la presión intermedia y a la relación de inyección como los parámetros del sistema más influyentes sobre el COP. La presión intermedia se optimizó para dos configuraciones de inyección (tanque de separación y economizador) utilizando varios refrigerantes. Basándose en los resultados de la optimización, se propuso una correlación que permite obtener la presión intermedia óptima del ciclo, considerando la influencia del subenfriamiento a la salida del condensador. Además, se analizó la influencia del diseño de los componentes del sistema sobre el COP del ciclo. Posteriormente, el estudio se profundizó a nivel de componentes. El factor más crítico en el sistema es el rendimiento del compresor. Por lo tanto, el siguiente paso fue evaluar la influencia de varios sistemas de compresión con inyección de vapor sobre el COP. Se tomaron en cuenta tres tecnologías de compresores, un SCVI, un TSRC y un compresor scroll de dos etapas, [CA] Aquesta tesi doctoral presenta un estudi de compressors scroll amb injecció de vapor (SCVI) per a bombes de calor que operen en climes freds o per a aplicacions d'escalfament d'aigua a alta temperatura. Per a això, es va comparar experimentalment un SCVI amb un compressor de dues etapes de pistons (TSRC) treballant amb R-407C en condicions extremes. La comparació es va realitzar en termes d'eficiències del compressor, capacitat, COP i rendiments estacionals tant per al mode calefacció com per al mode refrigeració. Els resultats proporcionen una idea general sobre el rang d'aplicació dels compressors estudiats i sobre les diferències en els rendiments dels compressors. No obstant això, es van identificar diverses limitacions en la caracterització dels compressors i en l'anàlisi del cicle. Això va motivar a aprofundir en l'estudi del cicle de compressió de dues etapes i els seus components. El següent pas va ser realitzar una anàlisi teòrica dels cicles de compressió de dues etapes per a aplicacions de calefacció, on es va identificar la pressió intermèdia i la relació d'injecció com els paràmetres del sistema més influents sobre el COP. La pressió intermèdia es va optimitzar per a dues configuracions d'injecció (tanc de separació i economitzador) utilitzant diversos refrigerants. Basant-se en els resultats de l'optimització, es va proposar una correlació que permet obtindre la pressió intermèdia òptima del cicle, considerant la influència del subrefredament a l'eixida del condensador. A més, es va analitzar la influència del disseny dels components del sistema sobre el COP del cicle. Posteriorment, l'estudi es va aprofundir a nivell de components. El factor més crític en el sistema és el rendiment del compressor. Per tant, el següent pas va ser avaluar la influència de diversos sistemes de compressió amb injecció de vapor sobre el COP. Es van prendre en compte tres tecnologies de compressors, un SCVI, un TSRC i un compressor scroll de dues etapes (TSSC). Aqueste, [EN] This Ph.D. thesis presents a study of scroll compressors with vapor-injection (SCVI) for heat pumps operating in cold climates or in high-temperature water heating applications. To do so, firstly, an SCVI was experimentally compared with a two-stage reciprocating compressor (TSRC) working with R-407C under extreme conditions. The comparison was made in terms of compressor efficiencies, capacity, COP, and seasonal COP, both for heating and cooling modes. The results give a general idea about the application range of the studied compressors and the differences in the compressors' performance. Nevertheless, several restrictions in the compressors' characterization and the cycle analysis were identified. This motivated us to deepen in the study of the two-stage compression cycle and its components. The next step was performing a theoretical analysis of two-stage compression cycles for heating applications, where the intermediate pressure and the injection ratio were identified as the most influential system parameters on the COP. The intermediate pressure was optimized for two vapor-injection configurations (flash tank and economizer) using several refrigerants. Based on the optimization results, a correlation was proposed that allows obtaining the optimal intermediate pressure of the cycle, considering the influence of the subcooling at the condenser outlet. In addition, a theoretical analysis of the influence of the design of the system components on the COP of the cycle was performed. Once the thermodynamic analysis of the two-stage cycle was carried out, the study was deepened at the component level. The most critical factor in the system is the compressor performance. Hence, the next step was evaluating the influence of several compression systems with vapor-injection on the COP. Three compressor technologies were taken into account, an SCVI, a TSRC and a two-stage scroll compressor (TSSC). These compressor technologies were characterized and modeled in order

Billion atom molecular dynamics (MD) using quantum-Accurate machine-learning Spectral Neighbor Analysis Potential (SNAP) observed long-sought high pressure BC8 phase of carbon at extreme pressure (12 Mbar) and temperature (5,000 K). 24-hour, 4650 node production simulation on OLCF Summit demonstrated an unprecedented scaling and unmatched real-world performance of SNAP MD while sampling 1 nanosecond of physical time. Efficient implementation of SNAP force kernel in LAMMPS using the Kokkos CUDA backend on NVIDIA GPUs combined with excellent strong scaling (better than 97% parallel efficiency) enabled a peak computing rate of 50.0 PFLOPs (24.9% of theoretical peak) for a 20 billion atom MD simulation on the full Summit machine (27,900 GPUs). The peak MD performance of 6.21 Matom-steps/node-s is 22.9 times greater than a previous record for quantum-Accurate MD. Near perfect weak scaling of SNAP MD highlights its excellent potential to advance the frontier of quantum-Accurate MD to trillion atom simulations on upcoming exascale platforms., QC 20220602Part of proceedings: ISBN 978-145038442-1

HNBR is commonly used in elastomer components that undergo severe mechanical loading under harsh thermal and chemical environments. Elastomer applications for oil and gas often feature high strains, high strain rates, wide temperature ranges, contact with organic solvents as well as high pressures. As a consequence of its acrylonitrile content and its high level of hydrogenation, HNBR is suitable for many oil and gas sealing applications. However, it is not always clear how HNBR compounds respond under these extreme conditions, where it often performs above expectation. Of particular interest is the origin of its high levels of mechanical toughness. This paper aims to further understand this behaviour by characterising a typical oil and gas elastomer at high temperatures under a range of different ageing conditions. A fracture mechanics-based fatigue study where cyclic fatigue test results are contrasted with the tear resistance results from trouser tear tests. These are undertaken on typical HNBR engineering compounds with different levels of carbon black filler to explore their tear and fatigue resistance at different conditions including temperature and ageing. Results indicate a surprisingly complex cyclic fatigue and static tear behaviour for these materials. Results can often feature experimental scatter due to significant transitioning regions between smooth and knotty tearing. Ageing and testing at elevated temperatures appear to encourage knotty tearing behaviour and ageing can on occasion be seen to help develop even tougher materials. DSC and X-Ray diffraction tests are used to explore the potential mechanisms behind this behaviour, HNBR is commonly used in elastomer components that undergo severe mechanical loading under harsh thermal and chemical environments. Elastomer applications for oil and gas often feature high strains, high strain rates, wide temperature ranges, contact with organic solvents as well as high pressures. As a consequence of its acrylonitrile content and its high level of hydrogenation, HNBR is suitable for many oil and gas sealing applications. However, it is not always clear how HNBR compounds respond under these extreme conditions, where it often performs above expectation. Of particular interest is the origin of its high levels of mechanical toughness. This paper aims to further understand this behaviour by characterising a typical oil and gas elastomer at high temperatures under a range of different ageing conditions. A fracture mechanics-based fatigue study where cyclic fatigue test results are contrasted with the tear resistance results from trouser tear tests. These are undertaken on typical HNBR engineering compounds with different levels of carbon black filler to explore their tear and fatigue resistance at different conditions including temperature and ageing. Results indicate a surprisingly complex cyclic fatigue and static tear behaviour for these materials. Results can often feature experimental scatter due to significant transitioning regions between smooth and knotty tearing. Ageing and testing at elevated temperatures appear to encourage knotty tearing behaviour and ageing can on occasion be seen to help develop even tougher materials. DSC and X-Ray diffraction tests are used to explore the potential mechanisms behind this behaviour

Operating in the downhole oil and gas environment exposes elastomers to extreme conditions which leads to the progressive degradation of mechanical properties resulting in sub-optimal performance and premature failure. An R&D project was initiated with the aim of developing high performance elastomer compounds that demonstrate an increase in fatigue lifetime and thermal and chemical stability. The strategy focused on development of innovative tests to evaluate mechano-physical properties under environmental and cyclic fatigue conditions more representative of the actual operating environment than standard test conditions and new materials development. Significant progress has been made on understanding chemical and physical processes that lead to elastomer failure considering specific test-fluid and thermal conditions. Development of specific protocols will enable more comprehensive elastomer-fluid compatibility analyses to be performed in the future. The study describes an approach to describe elastomer ageing behaviour in realistic conditions and to quantify the contribution of chemical and physical processes. This will enable optimized materials selection and lifetime predictions to be performed for materials developed for specific operational condition, Operating in the downhole oil and gas environment exposes elastomers to extreme conditions which leads to the progressive degradation of mechanical properties resulting in sub-optimal performance and premature failure. An R&D project was initiated with the aim of developing high performance elastomer compounds that demonstrate an increase in fatigue lifetime and thermal and chemical stability. The strategy focused on development of innovative tests to evaluate mechano-physical properties under environmental and cyclic fatigue conditions more representative of the actual operating environment than standard test conditions and new materials development. Significant progress has been made on understanding chemical and physical processes that lead to elastomer failure considering specific test-fluid and thermal conditions. Development of specific protocols will enable more comprehensive elastomer-fluid compatibility analyses to be performed in the future. The study describes an approach to describe elastomer ageing behaviour in realistic conditions and to quantify the contribution of chemical and physical processes. This will enable optimized materials selection and lifetime predictions to be performed for materials developed for specific operational condition

Neglecting extremes and designing buildings for the past or most likely weather conditions is not the best approach for the future. Robust design techniques can, however, be a viable option for tackling future challenges. The concept of robust design was first introduced by Taguchi in the 1940s. The result of the design process is a product that is insensitive to the effect of given sources of variability, even though the sources themselves are not eliminated. A robust design optimization (RDO) method is for the first time proposed in this paper, for supporting architects and engineers in the design of buildings with robust energy performance under climate change and extreme conditions. The simplicity and the low computational demand of the process underlies the feasibility and applicability of this method, which can be used at any stage of the design process. The results show that the performance of the optimum solution not only has a 81.5% lower variation (less sensitivity to climate uncertainty) but at the same time has a 14.4% lower mean energy use value compared with a solution that is compliant with a recent construction standard (ASHRAE 90.1-2016). Less sensitivity to climate uncertainty means greater robustness to climate change whilst maintaining high performance.

Modern technology for the processing of spent fuel assemblies (SFA) and radioactive waste (RW) is utilized in radiation protection cells. Under the conditions of exposure to high radiation fields, there is an intense destruction of various assemblies of actuators made of organic materials, including insulation of motor windings, which leads to frequent equipment failures requiring repair or replacement. Within the limits of the existing need, a project is being developed, with the purpose of creation of a radiation-resistant asynchronous electric motor with ceramic insulation for operation in. The proposed technical solutions make possible to increase the service life of the engine operating under the influence of radiation fields in radiation protection chambers by 4-5 times. Operation under an extreme condition requires an assessment of the engine itself. Considering a non-standard cooling system is of crucial importance for such projects. © 2019 Published under licence by IOP Publishing Ltd.

Магістерська дисертація: 106 с., 44 рис., 24 табл., 2 додатки, 19 джерел Актуальність теми зумовлена потребою автоматизації методів порятунку життя членів екіпажу яхти при випадінні за борт та відсутності ефективних аналогів. Метою роботи є підвищення ефективності пошуково-рятувальних заходів у випадку екстремальних умов яхтингу за рахунок створення апаратно-програмного комплексу, засади якого були покладені в попередній роботі. Для досягнення поставленої мети розв’язуються такі завдання: дослідження концепції розшуку членів екіпажу; розробка архітектури комплексу; моделювання роботи програмно-апаратного комплексу; вдосконалення роботи архітектури комплексу, на основі отриманих результатів досліджень; розробка програмної складової комплексу; інтеграція розробленого алгоритму в алгоритми роботи яхти; створення інтерфейсу користувача. Об’єктом дослідження є позиціонування члену екіпажу в умовах яхтингу. Предметом дослідження є виявлення місцезнаходження і факту випадіння члену екіпажу в умовах яхтингу. Методами дослідження є методи математичного аналізу – для вибору моделі архітектури комплексу, та математичної статистики – для обробки результатів; Наукова новизна одержаних результатів полягає у побудові архітектури взаємодії складових частин апаратно-програмного комплексу. Практичне значення одержаних результатів. Архітектура запропонованого комплексу дозволяє провести ефективні автоматизовані пошуково-рятувальні заходи у випадку випадіння члену екіпажу за межі яхти при екстремальних умовах, на відміну від не працездатних в більшості випадків аналогічних рішень., Master's dissertation: 106 pages, 44 figures, 24 tables, 2 attachments, 19 sources The urgency of the topic is determined by the necessity in method automation of saving the life of the yacht crew members, when they falling down, out from the board and lack of effective counterparts. The purpose of this work is to increase the effectiveness of search and rescue methods in the event of extreme conditions of yachting through the creation of hardware and software complex, the basis of which was laid in the previous work. To achieve this goal, the following tasks are solved: research of the positioning concept of crew members; architecture development of the complex; work simulation of the software and hardware complex; improvement of the complex architecture, based on the results of research; development of software component of the complex; integration of the developed algorithm in the algorithms of the yacht; creating a user interface. The object of research is the positioning a crew member in yachting conditions. The subject is identification of the location and the fact of a crew member falling in yachting conditions. Methods of research There are methods of mathematical analysis - for choosing the model architecture of the complex, and mathematical statistics - for the processing of results; The scientific novelty of the obtained results is the architecture construction of the components interaction inside the developed hardware and software complex. The practical value of the results. The architecture of the proposed complex allows to carry out effective automated search and rescue actions in the event of the loss of a crew member outside the yacht under extreme conditions, in contrast to the non-able-bodied similar solutions, in most cases.

Propulsion system of a hybrid electric ship is powered by the main engine and a motor coupled to the propeller shaft via a gearbox. The motor provides a power boost when the propulsion load is high and extracts excess power working as a generator at low loading conditions. The power boost comes from the auxiliary engine which is used to supply service loads as well. When excess power is taken out from the shaft it is delivered to the ship power system requiring the auxiliary engine to reduce its power. Consequently, auxiliary engine experiences frequent changes resulting in frequency sags or swells. In extreme conditions these could result in blackouts. In addition, changes in service loads could also lead to frequency deviations causing serious power quality issues. This paper proposes a novel model predictive control (MPC) based strategy to address this issue and thereby improve the power quality. The proposed strategy uses a battery energy storage system to absorb load changes and regulate the frequency of the ship power system. The same approach is tested with the PI controllers as well for performance comparisons. Simulation results are presented to verify the efficacy of the proposed frequency regulation strategy.

This project takes place in the north of Norway, on an Island called Senja. With its beautiful nature and reliable resource of fish it attracts tourists in the summer time and seasonal workers in the fishing industry during the winter. How can communal housing for tourists and workers act as a hub in the local community? Around this question a cluster of different functions has been developed that serves the whole community as well as the communal housing with private living units.

The initiative (since 2014) project described in this paper is a product of a joint innovative research and implementation effort of the Civil Engineering and Architecture Institute, Ural Federal University, the Science and Engineering Centre "Reliability and Safety of Large Systems and Machines", Ural Branch Russian Academy of Sciences (both Yekaterinburg), Start-up OptiCits, Barcelona, Spain and the Old Dominion University, Norfolk, VA, USA. The project is based on using the MAICS convergent technology [1] to create a versatile multi-purpose tool for optimizing the science and art of risk based governance of resilience-smart and sustainable city infrastructure and communities operating in usual and extreme conditions. The tool being developed is tailored to the needs of the City of Yekaterinburg-the capital of the Urals Region and allegedly the third most important and vibrant city of Russia. It is also being offered to the Yekaterinburg City Administration as an every-day decision-support work-tool and addendum to the Strategic Program "Yekaterinburg 2030 - a Safe City"[2] during preparation of the city for winning and conducting the World Expo-2025. Authors believe that the findings of this research would also be useful to the Sverdlovsk Oblast cities of every size and type of communities that inhabit them, including, first and foremost, Nizhny Tagil, Kamensk Uralsky, Serov, Pervouralsk, Revda, Verkhnyaya Pyshma, multiple mono-cities et al. The project also incorporates block-chain technology, smart contracts and digital currency as an effective tool for implementing the project. © 2018 Institute of Physics Publishing. All rights reserved.

One of the recent trends in materials science and technology is the research of the behavior of the materials under the extreme conditions both on the theoretical and experimental basis. There are limitations of the experimental methods, however, theoretical approach can be used as a supplement to the experimental results. As a consequence, in the last two decades a vast number of structure prediction calculations have been performed on chemical systems, focusing on the high-pressure and high temperature phases. In this work, we would like to present several computational studies and their connection to the actual synthesis routes: lead sulfide (PbS), barium sulfide (BaS), and aluminum nitride (AlN). The investigated compounds were calculated on ab initio level using the most advanced tools in quantum chemistry and computational material science including Hartree-Fock Theory, Density Functional Theory (DFT) and Hybrid (B3LYP) Approximation. Their structural, mechanical, elastic and vibrational properties have been investigated and in addition, we show structure candidates as the function of size, pressure and temperature and not previously observed in any of the investigated materials thus creating new possibilities for synthesis of advanced materials with improved physical, chemical, and/or mechanical properties. © 2018 The Authors.

This project takes place in the north of Norway, on an Island called Senja. With its beautiful nature and reliable resource of fish it attracts tourists in the summer time and seasonal workers in the fishing industry during the winter. How can communal housing for tourists and workers act as a hub in the local community? Around this question a cluster of different functions has been developed that serves the whole community as well as the communal housing with private living units.

Components in aircraft engines and gas turbines are exposed to extreme conditions in order to increase performance and efficiency of the overall engine, hence there is an increasing need for cost-effective and time-efficient repair strategies. Presented here are two novel approaches to the repair of Nickel-based components. The hybrid brazing process involves the application of a repair coating, a nickel-based filler material, a NiCoCrAlY and an aluminium layer, by thermal spraying followed by a heat treatment and combined brazing-aluminizing process. This significantly shortens the conventional repair brazing process and yields superior results. Single-crystal additive repair by laser cladding is applied for the repair of small or large defects in single-crystal turbine blades by enabling monocrystalline solidification of the cladded material by use of a temperature gradient, thereby allowing for the regeneration of these expensive components. The novel approach that combines layer-wise addition of material and laser melting enables the formation of highly monocrystalline structures.

One of the recent trends in materials science and technology is the research of the behavior of the materials under the extreme conditions both on the theoretical and experimental basis. There are limitations of the experimental methods, however, theoretical approach can be used as a supplement to the experimental results. As a consequence, in the last two decades a vast number of structure prediction calculations have been performed on chemical systems, focusing on the high-pressure and high temperature phases. In this work, we would like to present several computational studies and their connection to the actual synthesis routes: lead sulfide (PbS), barium sulfide (BaS), and aluminum nitride (AlN). The investigated compounds were calculated on ab initio level using the most advanced tools in quantum chemistry and computational material science including Hartree-Fock Theory, Density Functional Theory (DFT) and Hybrid (B3LYP) Approximation. Their structural, mechanical, elastic and vibrational properties have been investigated and in addition, we show structure candidates as the function of size, pressure and temperature and not previously observed in any of the investigated materials thus creating new possibilities for synthesis of advanced materials with improved physical, chemical, and/or mechanical properties.

One of the recent trends in materials science and technology is the research of the behavior of the materials under the extreme conditions both on the theoretical and experimental basis. There are limitations of the experimental methods, however, theoretical approach can be used as a supplement to the experimental results. As a consequence, in the last two decades a vast number of structure prediction calculations have been performed on chemical systems, focusing on the high-pressure and high temperature phases. In this work, we would like to present several computational studies and their connection to the actual synthesis routes: lead sulfide (PbS), barium sulfide (BaS), and aluminum nitride (AlN). The investigated compounds were calculated on ab initio level using the most advanced tools in quantum chemistry and computational material science including Hartree-Fock Theory, Density Functional Theory (DFT) and Hybrid (B3LYP) Approximation. Their structural, mechanical, elastic and vibrational properties have been investigated and in addition, we show structure candidates as the function of size, pressure and temperature and not previously observed in any of the investigated materials thus creating new possibilities for synthesis of advanced materials with improved physical, chemical, and/or mechanical properties. © 2018 The Authors.

Venus is our closest planet, but we know much less about it than about Mars. The main reason for this is the extreme conditions, with a dense atmosphere of mainly CO2 at 92 bar atmosphere and 460 °C temperature at the surface. Only six spacecraft have succeeded to land on Venus and transmit data back to Earth; however none survived for long due to the high temperature. Venera-13 has the record, with 127 minutes at the surface of Venus in 1982. There are many compelling reasons to learn more about the sister planet of Earth, which requires measurements over months rather than minutes on the surface of Venus. Perhaps the single-most challenging task for long-term data taking on the surface of Venus is to build electronics that can operate at temperatures up to 500 °C without cooling. It seems that such technology must be based on wide bandgap semiconductors, such as GaN, SiC or diamond. At KTH, research with SiC devices and integrated circuits has been done for more than 20 years, demonstrating high voltage devices and digital integrated circuit operation at 600 °C. In 2014 the project Working On Venus launched, with funding from Knut and Alice Wallenberg Foundation. The goal is to demonstrate all the electronics for a complete working lander, with all electronics from sensors through amplifiers and analog-to-digital converters to microcontroller with memory and radio, including power supply. The particular sensors the project has in mind are seismic, gas and image sensors. So far, a 200 device level integration has been demonstrated at 500 °C and a 5000+ device level 4 bit microcontroller is being fabricated in an in-house bipolar technology. As for all devices for space, radiation is another concern. SiC integrated circuits have survived exposure to 3 MeV protons with fluences of 1013 cm-2 and gamma rays with doses of 332 Mrad. The dedicated project SUPERHARD IC will study manufacture methods for radiation hardened instrument components that could go beyond Venus, f, QC 20181214

The article deals with the problem of improving the effectiveness of rifle cadet training at military universities as the basis of their mental readiness to overcome obstacles and difficulties in extreme situations and conditions. The requirements for the professional training of cadets, including the ability to possess a firearm and use it in different situations increase. Rifle training, one of the main sections of the military training, aimed at instilling all members rifle arms solid skills sure possession in all situations, В статье рассматривается проблема повышения эффективности стрелковой подготовки курсантов военных вузов как основа формирования их психической готовности к преодолению препятствий и трудностей в экстремальных ситуациях и условиях. Возрастают требования к профессиональной подготовке курсантов, в том числе к умению владеть огнестрельным оружием и применять его в различной обстановке. Стрелковая подготовка военнослужащих, являющаяся одним из основных разделов военного обучения, направлена на привитие всем военнослужащим твердых навыков уверенного владения стрелковым оружием в любых ситуациях

A new simulation tool aimed at characterizing the thermal behavior of parabolic trough collectors over a wide range of pressures and gas mixtures in the vacuum chamber is presented in this study. The model is able to accurately predict overall efficiency and heat losses obtained in a number of experimental sources based on both on-sun and off-sun testing, with vacuum in the annulus and no hydrogen. Excellent agreement of the simulations with experiments including different gas compositions, especially with high hydrogen concentrations, is achieved through the use of molecular dynamics results for the determination of the accommodation coefficient of the mixture. Additional experiments were carried out to validate the accuracy of the model over a range of pressures between 10-4 and 130 mbar. The accurate modelling of rarefied gas dynamics presented here also leads to an excellent agreement between simulations and experiments over the whole pressure range. An accurate determination of the performance in such extreme conditions is critical for an adequate Operation & Maintenance strategy, as well as the development of effective predictive and preventives plans., QC 20160519

The current paper presents a comparative study between a scroll compressor with vapor-injection (SCVI) and a two-stage reciprocating compressor (TSRC) operating under extreme conditions. The present work is divided into two parts: in the first part, both compressors are compared in terms of compressor efficiency, volumetric efficiency, coefficient of performance (COP), and cooling capacity with R407C refrigerant; in the second part, the seasonal performances of both compressors working in cooling and heating modes are estimated and analyzed. Results show that the SCVI presents better efficiency and COP than the TSRC for pressure ratios below 7.5. This compressor can be used in air conditioning systems and heat pumps which work under moderate temperature conditions. For higher pressure ratios, the TSRC has better efficiency which subsequently gives higher COP. This type of compressor is more suited to be used in sanitary hot water systems operating in harsh climates and in low-temperature freezing systems (under −20°C).

The current paper presents a comparative study between a scroll compressor with vapor-injection (SCVI) and a two-stage reciprocating compressor (TSRC) operating under extreme conditions. The present work is divided into two parts: in the first part, both compressors are compared in terms of compressor efficiency, volumetric efficiency, coefficient of performance (COP), and cooling capacity with R407C refrigerant; in the second part, the seasonal performances of both compressors working in cooling and heating modes are estimated and analyzed. Results show that the SCVI presents better efficiency and COP than the TSRC for pressure ratios below 7.5. This compressor can be used in air conditioning systems and heat pumps which work under moderate temperature conditions. For higher pressure ratios, the TSRC has better efficiency which subsequently gives higher COP. This type of compressor is more suited to be used in sanitary hot water systems operating in harsh climates and in low-temperature freezing systems (under −20°C).

Despite the large interest in the emotional and volitional self-regulation, most of the work is devoted to a general approach without experimental use of specific methods of self-regulation. Have practical experience in this field need to theoretical understanding, Несмотря на большой интерес к проблеме эмоционально-волевой саморегуляции, большинство работ посвящено общим подходам без учета экспериментального использования конкретных методов саморегуляции. Имеющиеся практические наработки в этой области нуждаются в теоретическом осмыслении

The paper deals with the results of the varietal macro trials on soya in 2013 i 2014 at the location Aleksandrovac, micro trial with fertilizers at the location Aleksandrovac in 2014 and micro trial with fertilizers at the location Banja Luka in 2013. Both vegetation seasons have been characterised with very extreme weather conditions. Achieved yields (536 - 1.216 kg ha-1) in the varietal macro trial in very dry vegetation season 2013 were significantly lower than the yields (3.022 - 4.133 kg ha-1) in very rainy season in 2014. The traits of permeable, alluvial soil had dominant influence on the yield results in Aleksandrovac in the both years. The micro trials with the fertilizers were performed on the variety Sonja. Raising doses of fertilizer (MAP 100-200-300 kg ha-1, N10:P30:K20 200-300 -400 kg ha-1 and N15:P15:K15 200-400-600 kg ha-1) in 2014 did not result with economically justified grain yield increase. Similar results were obtained at the location Banja Luka in the previous year, what impose the need for more detailed study of this agrotechnical operation in the future., U radu su analizirani rezultati sortnih makroogleda na soji u 2013 i 2014. godini na lokalitetu Aleksandrovac, mikroogleda sa đubrenjem na navedenom lokalitetu u 2014. godini, te mikroogleda sa đubrenjem na lokalitetu Banja Luka u 2013. godini. Obe sezone karakterisale su vrlo ekstremne vremenske prilike. Ostvareni prinosi zrna (536 - 1.216kg ha-1) u sortnom makroogledu u vrlo sušnoj 2013. godini bili su značajno niži u odnosu na prinose (3.022 - 4.133 kg ha-1) u izuzetno kišnoj 2014. godini. Osobine propusnog, aluvijalnog zemljišta imale su presudan uticaj na prinose zrna u obe godine. Ogledi sa različitim đubrivima praćeni su na banjalučkoj sorti Sonja. Rastuće doze đubriva u 2014. godini nisu dovele do ekonomski opravdanog povećanja prinosa zrna u odnosu na kontrolu. Slični rezultati dobijeni su i u prethodnoj godini na lokalitetu Banja Luka, što upućuje na neophodnost detaljnijeg proučavanja ove agrotehničke mere.

The necessity of taking into account in the analysis of heart rate variability, individual-typological characteristics of autonomic regulation. The aim of the work was to study the dynamics of mental and functional states servicemen depending on individual typological features of autonomic regulation and correction of these conditions donozologicheskims methods, Показана необходимость учета при анализе вариабельности сердечного ритма, индивидуально-типологических особенностей вегетативной регуляции. Целью работы явилось изучение динамики психических и функциональных состояний военнослужащих в зависимости от индивидуально-типологических особенностей вегетативной регуляции и коррекция данных состояний донозологическими методами

The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final downselection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supranuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m2 effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study., QC 20150611

The interest in two stage cycles has increased in the last years and some compressor manufacturers have commercialized compressors adapted to work in these conditions. Nevertheless, the information supplied by them usually is limited to certain design conditions defined by the application and extrapolation to other conditions is not straightforward. In this article a test campaign of an injection scroll compressor is presented. This test campaign was divided in two parts, on the first one a wide range of evaporating and condensing pressures for the intermediate conditions recommended by the manufacturer were measured, and the compressor behavior was systematically compared with single stage compressor of the same volume. On the second part an experimental study of the influence of the intermediate conditions on the performance have been done. The study has included the evaluation of the separate influence of intermediate gas superheat, intermediate pressure and wet injection.

The interest in two stage cycles has increased in the last years and some compressor manufacturers have commercialized compressors adapted to work in these conditions. Nevertheless, the information supplied by them usually is limited to certain design conditions defined by the application and extrapolation to other conditions is not straightforward. In this article a test campaign of an injection scroll compressor is presented. This test campaign was divided in two parts, on the first one a wide range of evaporating and condensing pressures for the intermediate conditions recommended by the manufacturer were measured, and the compressor behavior was systematically compared with single stage compressor of the same volume. On the second part an experimental study of the influence of the intermediate conditions on the performance have been done. The study has included the evaluation of the separate influence of intermediate gas superheat, intermediate pressure and wet injection.

Through genome mining, we identified a gene encoding a putative serine protease of the thermitase subgroup of subtilases (EC 3.4.21.66) in the thermophilic bacterium Coprothermobacter proteolyticus. The gene was functionally expressed in Escherichia coli, and the enzyme, which we called proteolysin, was purified to near homogeneity from crude cell lysate by a single heat treatment step. Proteolysin has a broad pH tolerance and is active at temperatures of up to 80 degrees C. In addition, the enzyme shows good activity and stability in the presence of organic solvents, detergents, and dithiothreitol, and it remains active in 6 M guanidinium hydrochloride. Based on its stability and activity profile, proteolysin can be an excellent candidate for applications where resistance to harsh process conditions is required.

This paper describes an investigation on the usefulness of Bayesian Networks in the safety assessment of dune coasts. A network has been created that predicts the erosion volume based on hydraulic boundary conditions and a number of cross-shore profile indicators. Field measurement data along a large part of the Dutch coast has been used to train the network. Corresponding storm impact on the dunes was calculated with an empirical dune erosion model named duros+. Comparison between the Bayesian Network predictions and the original duros+ results, here considered as observations, results in a skill up to 0.88, provided that the training data covers the range of predictions. Hence, the predictions from a deterministic model (duros+) can be captured in a probabilistic model (Bayesian Network) such that both the process knowledge and uncertainties can be included in impact and vulnerability assessments., Hydraulic Engineering, Civil Engineering and Geosciences

This paper describes an investigation on the usefulness of Bayesian Networks in the safety assessment of dune coasts. A network has been created that predicts the erosion volume based on hydraulic boundary conditions and a number of cross-shore profile indicators. Field measurement data along a large part of the Dutch coast has been used to train the network. Corresponding storm impact on the dunes was calculated with an empirical dune erosion model named duros+. Comparison between the Bayesian Network predictions and the original duros+ results, here considered as observations, results in a skill up to 0.88, provided that the training data covers the range of predictions. Hence, the predictions from a deterministic model (duros+) can be captured in a probabilistic model (Bayesian Network) such that both the process knowledge and uncertainties can be included in impact and vulnerability assessments., Hydraulic Engineering, Civil Engineering and Geosciences

Peer Reviewed, Postprint (author's final draft)

We have performed fundamental experimental and theoretical studies of insensitive energetic materials (FOX 7, HMX, RDX, TATB and PETN) with the aim of better-ascertaining their behavior under extreme conditions as well as seeking to understand more about what makes them relatively stable in the hope of designing better explosives in the future. We have also developed novel methods to study these important materials which we feel will aid future studies of insensitive munitions.

When dealing with high-tech equipment, accurate positioning is of the utmost importance to ensure durability and a productive lifetime. Unexpected high friction or wear of positioning mechanisms can lead to unnecessary down-time or products that are not up to specification. To ensure a sufficient lifetime, it is necessary to know beforehand how the sliding and rolling contacts will behave over time. This demand becomes more stringent when the machine operates at extreme conditions, e.g. vacuum or extremely low temperatures. Traditional greases and mineral oil based lubricants do not perform adequately in such extreme environments, as they either contaminate the vacuum or do not provide sufficient film thickness. TNO recently developed a unique measuring application, the TNO cryotribometer, in order to measure friction and wear of position mechanisms at harsh conditions. Preliminary results show that the contact pressure and the sliding velocity influenced the friction level greatly. This set-up is currently used to find and analyze different material combinations, which demonstrate a constant friction level under cryogenic vacuum conditions. © 2011 SPIE.

The current work focuses on the study of the influence of pressure and temperature on three important thermodynamic properties: speed of sound, compressibility and density of common diesel fuels. The sample fuels studied were conventional diesel (Repsol Elite), Rape Methyl Ester (typical bio-diesel used in Spain) and a fuel used especially for winter season (Arctic). Speed of sound and densities has been determined experimentally. The third property, bulk modulus, has been calculated from the other two. Speed of sound measurements have been carried out in wide range of temperatures (298 < T/K < 343) and pressures (15 < p/MPa < 180), which represent the typical values used in injection systems for diesel engines. Hence, a particular configuration was coupled to the high-pressure injection system, obtaining accurate measurements at these extreme conditions. A detailed description of the method is presented; also, the obtained results are listed, with an uncertainty of ~0.3%. Density measurements have been performed over a broad range of temperatures (298 < T/K < 343), using two commercial devices, obtaining an overall uncertainty of ~0.6%. © 2010 Elsevier Ltd. All rights reserved.

The current work focuses on the study of the influence of pressure and temperature on three important thermodynamic properties: speed of sound, compressibility and density of common diesel fuels. The sample fuels studied were conventional diesel (Repsol Elite), Rape Methyl Ester (typical bio-diesel used in Spain) and a fuel used especially for winter season (Arctic). Speed of sound and densities has been determined experimentally. The third property, bulk modulus, has been calculated from the other two. Speed of sound measurements have been carried out in wide range of temperatures (298 < T/K < 343) and pressures (15 < p/MPa < 180), which represent the typical values used in injection systems for diesel engines. Hence, a particular configuration was coupled to the high-pressure injection system, obtaining accurate measurements at these extreme conditions. A detailed description of the method is presented; also, the obtained results are listed, with an uncertainty of ~0.3%. Density measurements have been performed over a broad range of temperatures (298 < T/K < 343), using two commercial devices, obtaining an overall uncertainty of ~0.6%. © 2010 Elsevier Ltd. All rights reserved.

Up to now just deterministic gust shapes are specified in standards; e.g. the Extreme Operating Gust (IEC) is given by a Mexican hat like shape. In this paper gust shapes will be determined by application of so-called constrained stochastic simulation. This method specifies how to efficiently generate time series around some specific event (e.g. a local maximum) in a normal (Gaussian) process. In this way the generated gusts have the correct stochastic properties of turbulence (like generated wind fields for fatigue analysis). In constrained stochastic simulation a random signal can be generated which satisfies some condition, e.g. a maximum value or jump at some time instant. Usually the condition is applied on the external condition, i.e. the wind or waves (for offshore wind turbines). In this paper the condition of a maximum value, at some time instant, will be applied to the response instead (the blade root flapping moment). Assuming a linearised model of the wind turbine, the accompanying wind input leading to the extreme response, can be derived. By performing load simulations the proposed method is validated. In the future a probabilistic approach of extreme loading may replace the present deterministic procedure in standards., Aerospace Design, Integration and Operations, Aerospace Engineering

Up to now just deterministic gust shapes are specified in standards; e.g. the Extreme Operating Gust (IEC) is given by a Mexican hat like shape. In this paper gust shapes will be determined by application of so-called constrained stochastic simulation. This method specifies how to efficiently generate time series around some specific event (e.g. a local maximum) in a normal (Gaussian) process. In this way the generated gusts have the correct stochastic properties of turbulence (like generated wind fields for fatigue analysis). In constrained stochastic simulation a random signal can be generated which satisfies some condition, e.g. a maximum value or jump at some time instant. Usually the condition is applied on the external condition, i.e. the wind or waves (for offshore wind turbines). In this paper the condition of a maximum value, at some time instant, will be applied to the response instead (the blade root flapping moment). Assuming a linearised model of the wind turbine, the accompanying wind input leading to the extreme response, can be derived. By performing load simulations the proposed method is validated. In the future a probabilistic approach of extreme loading may replace the present deterministic procedure in standards., Aerospace Design, Integration and Operations, Aerospace Engineering

Classical molecular dynamics (CMD) calculations are fast but are heavily dependent on the potential feasibility. On the other hand, first-principles (ab initio) molecular dynamics (AIMD) does not use any empirical knowledge, but can be extremely time consuming. As both techniques have been applied to study melting at extreme conditions, a comparison of the methods is motivated. Furthermore, when melting is studied with MD, the use of coexistent solid and liquid structures (two-phase) in the initial simulation configuration, instead of a only a solid structure (one-phase), can have a significant impact. In this work, comparisons have been made between CMD and AIMD methods applied to one- and two-phase systems for the melting of Ne at high pressure., QC 20141024

Recently, a novel type of ion-beam induced deformation of metal nanoobjects has been found. Under heavy ion irradiation, Au nanospheres in a silica matrix first elongate into rods. At higher fluences they combine into nanowires that continue to grow during irradiation. Such anisotropically shaped metal nanoparticles may have great potential in a wide range of fields. For example, nanorods exhibit a split plasmon resonance, with one of the bands shifting into the infrared. Arrays of such particles have a great potential as nanophotonic guides in the (infra)red, an important telecom wavelength regime, but outside the range of plasmon resonances of spherical metal particles. Here, we present a model and atomistic computer simulations of this ion beam shaping. The experimental lower threshold for ion beam shaping of 6 keV/nm ion energy deposition along the ion track coincides with the theoretically required energy for melting of SiO2 in the ion track of a few nanometer diameter. Heating occurs on a timescale of a few tens of fs. Thus, temperature gradients of several billion Kelvin per cm can be reached. The Au nanosphere experiences such an extreme environment if it is touched by an ion track. These extreme conditions are similar to femtosecond laser processing of Au layers where frozen nanojets have been observed. Laser-induced nanojet formation and ion beam shaping have obviously the same driving force: Based on atomistic simulations we prove that thermocapillarity drives material of a Au nanosphere, which is touched by an ion track, from the hot equator to the colder pole regions(Thermocapillarity is the driving force for the wellknown Marangoni effect). Additionally, the transiently extreme high temperature in the molten SiO2 ion track dissolves Au, which diffuses fast and precipitates during cooling into tiny Au clusters. Superposition of tracks leads to a highly anisotropic “track diffusion” transport of Au from short nanorods to longer ones

Recently, a novel type of ion-beam induced deformation of metal nanoobjects has been found. Under heavy ion irradiation, Au nanospheres in a silica matrix first elongate into rods. At higher fluences they combine into nanowires that continue to grow during irradiation. Such anisotropically shaped metal nanoparticles may have great potential in a wide range of fields. For example, nanorods exhibit a split plasmon resonance, with one of the bands shifting into the infrared. Arrays of such particles have a great potential as nanophotonic guides in the (infra)red, an important telecom wavelength regime, but outside the range of plasmon resonances of spherical metal particles. Here, we present a model and atomistic computer simulations of this ion beam shaping. The experimental lower threshold for ion beam shaping of 6 keV/nm ion energy deposition along the ion track coincides with the theoretically required energy for melting of SiO2 in the ion track of a few nanometer diameter. Heating occurs on a timescale of a few tens of fs. Thus, temperature gradients of several billion Kelvin per cm can be reached. The Au nanosphere experiences such an extreme environment if it is touched by an ion track. These extreme conditions are similar to femtosecond laser processing of Au layers where frozen nanojets have been observed. Laser-induced nanojet formation and ion beam shaping have obviously the same driving force: Based on atomistic simulations we prove that thermocapillarity drives material of a Au nanosphere, which is touched by an ion track, from the hot equator to the colder pole regions(Thermocapillarity is the driving force for the wellknown Marangoni effect). Additionally, the transiently extreme high temperature in the molten SiO2 ion track dissolves Au, which diffuses fast and precipitates during cooling into tiny Au clusters. Superposition of tracks leads to a highly anisotropic “track diffusion” transport of Au from short nanorods to longer ones