Orbiter/payload contamination control assessment support

The development and integration of 16 payload bay liner filters into the existing shuttle/payload contamination evaluation (SPACE) computer program is discussed as well as an initial mission profile model. As part of the mission profile model, a thermal conversion program, a temperature cycling routine, a flexible plot routine and a mission simulation of orbital flight test 3 are presented

Internationalization process of Finnish-based startups and SMEs in emerging China:motives and entry strategies

Abstract. The purpose of this research is to study the internationalization process of Finnish-based startups and SMEs in emerging Chinese market. More closely, this study intents to reveal certain characteristics that Finnish-based firms possess in the context of motives and entry mode choices on internationalization. Therefore, this research offers no further explanation on the success or failure of internationalization but offers knowledge about the fundamental foundation which firms use to internationalize. Theoretical framework of this research is based on existing internationalization theories and key concepts regarding international expansion such as entry modes and foreign business culture. Empirical data collection of this research is conducted via qualitative methods in form of a case study within questionnaire and interviews. Primary data consists of 11 case firms without industry-specific limitations. Most of the case firms are newly born and can be addressed as born globals due to their internationalization from inception. Still, there are SMEs with solid domestic market position amongst the case firms. Academic journals, articles and books are observed to provide holistic substance understanding on the research topic. Findings suggest that extant previous experience on international markets decreases the time-embedded resources on internationalization to China. Aspects concerning China seem to condense on personal and business networks which are valued over the contractual agreements. Finnish-based firms motives for market entry are concerned by the market size and business opportunities. Surprisingly, startups and small enterprises tend to enter the market with high-commitment entry modes and in contrast medium-sized firms enter with low-commitment modes. Results of this study provide insight on internationalization as a phenomenon and can be used to evaluate the process of Finnish-based startups and SMEs. Because of the lack of limitations on industry-specific features, findings are useful to address internationalization in general, but sector-wise consideration is to be conducted. This research suggests further studies to concentrate on SMEs and startups as individual research targets. These differ highly on their backgrounds and perceived goals on foreign market entry and therefore should be separated from each other. Additionally, more research is needed to explain the importance on trust-based mutual network over the contractual agreements

Experimental investigation of contamination prevention techniques to cryogenic surfaces on board orbiting spacecraft

Within the simulation limitations of on-orbit conditions, it was demonstrated that a helium purge system could be an effective method for reducing the incoming flux of contaminant species. Although a generalized purge system was employed in conjunction with basic telescope components, the simulation provided data that could be used for further modeling and design of a specific helium injection system. Experimental telescope pressures required for 90% attenuation appeared to be slightly higher (factor of 2 to 5). Cooling the helium purge gas and telescope components from 300 to 140 K had no measurable effect on stopping efficiency of a given mass flow of helium from the diffuse injector

Orbiter/payload contamination control assessment support

The development and use of a contamination math model of the shuttle orbiter which incorporates specific shuttle orbiter configurations and contamination sources is described. These configurations and sources represent the latest design of the shuttle orbiter and its sources. The results of model predictions for many lines-of-sight and individual and grouped sources are presented. Support trade studies primarily concerned with the supplemental flash evaporator location and operation are presented

Sensitivity of idealised baroclinic waves to mean atmospheric temperature and meridional temperature gradient changes

The sensitivity of idealised baroclinic waves to different atmospheric temperature changes is studied. The temperature changes are based on those which are expected to occur in the Northern Hemisphere with climate change: (1) uniform temperature increase, (2) decrease of the lower level meridional temperature gradient, and (3) increase of the upper level temperature gradient. Three sets of experiments are performed, first without atmospheric moisture, thus seeking to identify the underlying adiabatic mechanisms which drive the response of extra-tropical storms to changes in the environmental temperature. Then, similar experiments are performed in a more realistic, moist environment, using fixed initial relative humidity distribution. Warming the atmosphere uniformly tends to decrease the kinetic energy of the cyclone, which is linked both to a weaker capability of the storm to exploit the available potential energy of the zonal mean flow, and less efficient production of eddy kinetic energy in the wave. Unsurprisingly, the decrease of the lower level temperature gradient weakens the resulting cyclone regardless of the presence of moisture. The increase of the temperature gradient in the upper troposphere has a more complicated influence on the storm dynamics: in the dry atmosphere the maximum eddy kinetic energy decreases, whereas in the moist case it increases. Our analysis suggests that the slightly unexpected decrease of eddy kinetic energy in the dry case with an increased upper tropospheric temperature gradient originates from the weakening of the meridional heat flux by the eddy. However, in the more realistic moist case, the diabatic heating enhances the interaction between upper- and low-level potential vorticity anomalies and hence helps the surface cyclone to exploit the increased upper level baroclinicity.Peer reviewe

The summer 2018 heatwave in Finland

Peer reviewe

The extratropical transition of Hurricane Ophelia (2017) as diagnosed with a generalized omega equation and vorticity equation

Hurricane Ophelia was a category 3 hurricane which underwent extratropical transition and made landfall in Europe as an exceptionally strong post-tropical cyclone in October 2017. In Ireland, Ophelia was the worst storm in 50 years and resulted in significant damage and even loss of life. In this study, the different physical processes affecting Ophelia’s transformation from a hurricane to a mid-latitude cyclone are studied. For this purpose, we have developed software that uses OpenIFS model output and a system consisting of a generalized omega equation and vorticity equation. By using these two equations, the atmospheric vertical motion and vorticity tendency are separated into the contributions from different physical processes: vorticity advection, thermal advection, friction, diabatic heating, and the imbalance between the temperature and vorticity tendencies. Vorticity advection, which is often considered an important forcing for the development of mid-latitude cyclones, is shown to play a small role in the re-intensification of the low-level cyclone. Instead, our results show that the adiabatic upper-level forcing was strongly amplified by moist processes, and thus, the diabatic heating was the dominant forcing in both the tropical and extratropical phases of Ophelia. Furthermore, we calculated in more detail the diabatic heating contributions from different model parameterizations. We find that the temperature tendency due to the convection scheme was the dominant forcing for the vorticity tendency during the hurricane phase, but as Ophelia transformed into a mid-latitude cyclone, the microphysics temperature tendency, presumably dominated by large-scale condensation, gradually increased becoming the dominant forcing once the transition was complete. Temperature tendencies caused by other diabatic processes, such as radiation, surface processes, vertical diffusion, and gravity wave drag, were found to be negligible in the development of the storm.Hurricane Ophelia was a category 3 hurricane which underwent extratropical transition and made landfall in Europe as an exceptionally strong post-tropical cyclone in October 2017. In Ireland, Ophelia was the worst storm in 50 years and resulted in significant damage and even loss of life. In this study, the different physical processes affecting Ophelia's transformation from a hurricane to a mid-latitude cyclone are studied. For this purpose, we have developed software that uses OpenIFS model output and a system consisting of a generalized omega equation and vorticity equation. By using these two equations, the atmospheric vertical motion and vorticity tendency are separated into the contributions from different physical processes: vorticity advection, thermal advection, friction, diabatic heating, and the imbalance between the temperature and vorticity tendencies. Vorticity advection, which is often considered an important forcing for the development of mid-latitude cyclones, is shown to play a small role in the re-intensification of the low-level cyclone. Instead, our results show that the adiabatic upper-level forcing was strongly amplified by moist processes, and thus, the diabatic heating was the dominant forcing in both the tropical and extratropical phases of Ophelia. Furthermore, we calculated in more detail the diabatic heating contributions from different model parameterizations. We find that the temperature tendency due to the convection scheme was the dominant forcing for the vorticity tendency during the hurricane phase, but as Ophelia transformed into a mid-latitude cyclone, the microphysics temperature tendency, presumably dominated by large-scale condensation, gradually increased becoming the dominant forcing once the transition was complete. Temperature tendencies caused by other diabatic processes, such as radiation, surface processes, vertical diffusion, and gravity wave drag, were found to be negligible in the development of the storm.Peer reviewe

The Effectiveness of a Personal Computer Aviation Training Device (PCATD), a Flight Training Device (FTD), and an Airplane in Conducting Instrument Proficiency Checks

This project evaluated the effectiveness of a personal computer aviation training device (PCATD), a flight training device (FTD) and an airplane for conducting an instrument proficiency check (IPC). The study compared the performance of pilots receiving an IPC in a PCATD, in a FTD and in an airplane (IPC #1) with performance on a later IPC in an airplane (IPC #2). Chi-square tests were used to analyze the IPC #1 and IPC #2 data to determine whether the treatment (assignment to group) had an effect on the pass/fail ratio for the IPC #1 and IPC #2 flights respectively. The treatment effect on the IPC #1 and IPC #2 pass/fail ratios were not statistically significant. A series of planned-comparison tests were performed both between the experimental groups and between subjects within each experimental group. The PCATD group was compared to the Airplane group and to the FTD group, the Airplane group to the FTD group. None of these comparisons showed statistically significant (a \u3c .05) differences between groups. These findings provide compelling evidence for permitting the use of PCATDs to give IPCs

OZO v.1.0 : software for solving a generalised omega equation and the Zwack-Okossi height tendency equation using WRF model output

A software package (OZO, Omega-Zwack-Okossi) was developed to diagnose the processes that affect vertical motions and geopotential height tendencies in weather systems simulated by the Weather Research and Forecasting (WRF) model. First, this software solves a generalised omega equation to calculate the vertical motions associated with different physical forcings: vorticity advection, thermal advection, friction, diabatic heating, and an imbalance term between vorticity and temperature tendencies. After this, the corresponding height tendencies are calculated with the Zwack-Okossi tendency equation. The resulting height tendency components thus contain both the direct effect from the forcing itself and the indirect effects (related to the vertical motion induced by the same forcing) of each physical mechanism. This approach has an advantage compared with previous studies with the Zwack-Okossi equation, in which vertical motions were used as an independent forcing but were typically found to compensate the effects of other forcings. The software is currently tailored to use input from WRF simulations with Cartesian geometry. As an illustration, results for an idealised 10-day baroclinic wave simulation are presented. An excellent agreement is found between OZO and the direct WRF output for both the vertical motion and the height tendency fields. The individual vertical motion and height tendency components demonstrate the importance of both adiabatic and diabatic processes for the simulated cyclone. OZO is an open-source tool for both research and education, and the distribution of the software will be supported by the authors.Peer reviewe