Salvage surgery for continent ileostomies (CI) after a first successful revision: more long-term blame on the reservoir than the nipple valve

Purpose The aim of the study was to investigate the underlying cause of long-term complications in patients requiring at least one revision surgery of a continent ileostomy (CI) and to analyze functional outcome. Methods Only patients with CI at least one revision were included in the retrospective data analysis. Four different classes of complications (Cl A–D) were defined: Cl A = Nipple valve (NV), Cl B = pouch, Cl C = outlet (stoma), and Cl D = afferent loop (AL). Associations between underlying disease and origin of complications were analyzed. Cumulative probabilities were calculated using Kaplan–Meier analysis. Results A total of 77 patients were identified with a follow-up of 30 years, requiring 133 surgeries for 148 complications (c.). Cl A 49 c. (33.1%), Cl B 50 c. (33.8%), Cl C 39 c. (26.4%), and Cl D 10 c. (6.8%). Cl A and C complications were not correlated to underlying disease, whereas Cl B and D complications were only found in ulcerative colitis (UC) and Crohn’s disease (CD). The cumulative probability of a second revision showed a linear rise, reaching 62.5% after 20 years. Cl A and B complications both reached 42.1%. Eleven (14.3%) patients (10 Cl B) had pouch failure in a follow-up period of 11.5 ± 8.7 years (1–31 years), whereas 66 (85.7%) had successful revisional surgery. Overall CI survival was 78.8% at 44 years. Conclusion CI survival is limited by inflammatory complications of the pouch based on the underlying disease and not by mechanical limitations of the NV

冬季の日本海側地域における大気汚染降下物に関する研究

取得学位：学術博士(XX)，学位授与番号：学博甲第25号，学位授与年月日：平成2年3月25

Aerothermal characterization of the CALLISTO vehicle during descent

Aerothermal loads are a design driving factor during launcher development as the thermal loads directly in- fluence TPS design and trajectory. Recent developments in reusable launch vehicles (RLV) (e.g. SpaceX, Blue Origin) have added the dimension of refurbishment to the challenges the thermal design must con- sider. For disposable launchers the heat flux due to base heating during ascent needs to be considered for aft thermal protections system (TPS) and structural design. With the current European long term strategy[1] moving towards a reusable first stage - aerothermal loads may significantly change. The CAL- LISTO vehicle is a flight demonstrator for future reusable launcher stages and their technologies. The program involves three countries and their space organizations: CNES for France, DLR for Germany and JAXA for Japan. The first tests will be conducted in 2024 from CSG, Europe’s Spaceport. The challenge is to develop, all along the project, the skills of the partners. This know-how includes products and vehicle design, ground segment set up, and post-flight operations for vehicle recovery then reuse [2–5]. For the CALLISTO vehicle the highest heat fluxes are mainly due to heating from hot exhaust gases and heated air in proximity of the aft bay and on the exposed structures like legs and fins. The development of the plume extension is different for the considered re-entry, when compared to Falcon 9, or the studies presented in [6–8]. As shown by Dumont et al.[9] the plume remains relatively concentrated at the aft end of the vehi- cle due to high atmospheric pressure and only very low fractions of actual exhaust gas species enclosing the vehicle. In the current study we conducted computational fluid dynamics (CFD) studies in order to determine the aerothermal loads on the vehicle during descent through the landing approach corridor for both phase B and phase C aeroshapes. The database development for vehicle phase B and phase C are described in detail and analyzed for some of the most prominent interfaces. The final phase C database presented allows interpolation of interface heatfluxes for the entire flight domain (M, ρ) at varying angle of attack (between 180 deg and 160 deg). Further the sensitivity of the plume-vehicle interaction to angle of attack, chemistry, thrust vector deflection and engine throttling are investigated for a critical Mach number indicating further area of improvement for future databases

Aerothermal analysis of plume interaction with deployed landing legs of the CALLISTO vehicle

The current European long term strategy aims at moving towards reusable launch vehicles (RLV) for the first stages of launchers. In accordance with this strategy the German Aerospace Center (DLR) has entered into a collaboration with the Japan Aerospace Exploration Agency (JAXA) and the French Space Agency (CNES) for the development of RLV relevant technologies. A part of this collaboration is a vertical take off and vertical landing (VTVL) reusable subscale launcher first stage demonstrator - the Cooperative Action Leading to Launcher Innovation in Stage Toss back Operations (CALLISTO). The mission of the CALLISTO vehicle is to return to the launch pad using retro propulsion and an Approach and Landing System (ALS) with extendable landing legs. This development leads to additional aerothermal design questions compared to traditional launchers. In the case of CALLISTO the highest heat fluxes are caused by heating from hot exhaust gases of the aft bay section. This especially affects the unfolded ALS during the final phase of the landing approach. The arising heat fluxes, therefore, influence the structural design and the thermal protection system (TPS) of the ALS. In this study we conduct computational fluid dynamics (CFD) investigations using Reynolds averaged Navier Stokes (RANS) methods of the aerothermal loads on the ALS during the landing phase. We use the Spalart-Allmaras turbulence model and frozen chemistry for the simulations. We analyse the flow field as well as the surface distributions. We investigate the necessity of simulations including the plume for these analyses. We use analyses of the flow fields as well as the surface distributions to investigate the influence of angle of attack, angle of roll, atmospheric conditions, flight speed and thrust level

Applying Bayesian Inference to Estimate Uncertainties in the Aerodynamic Database of CALLISTO

The three national space centers DLR, CNES & JAXA have joined their efforts in the project CALLISTO to develop and mature key technologies for future operational Reusable Launch Vehicles (RLVs). The goal of this project is to develop, manufacture and test a reusable Vertical-Takeoff Vertical-Landing (VTVL) first stage demonstrator, which will be operated at the European Spaceport in French Guiana from late 2024. One important aspect in the development of RLVs, but also of aerospace vehicles in general, is the generation of an Aerodynamic Database (AEDB) which characterizes the aerodynamic flying qualities of the vehicle. These databases are commonly aggregated from Computational Fluid Dynamics (CFD) simulations and Wind Tunnel Tests (WTTs) via simple heuristic models. Whereas this classical approach is suitable for the estimation of nominal aerodynamic coefficients, the quantification of uncertainties in this pre-flight data with respect to the final flight behavior is still a difficult task that involves a lot of human expert knowledge and "gut feeling". Particularly for launch vehicles, these uncertainties are however essential to ensure robust guidance and control algorithms, as well as sufficient vehicle performance for a selected mission profile. For CALLISTO, in parallel to a classical approach, a new methodology has now been tested to estimate these uncertainties within the AEDB: To apply Bayesian Inference to predict a probability distribution over the aerodynamic coefficients, conditional on the available test and simulation results and on prior knowledge. This methodology has already been well-established in other data science domains, but for aerospace engineering only very few use-cases are known so far. With this new approach an objectively traceable modelling of the aerodynamic uncertainties should be possible. This paper presents the current development state of the Bayesian aerodynamic uncertainties model of CALLISTO. After problem definition and a short introduction to the underlying dataset, the paper mainly focuses on the used modelling techniques and the applicability of Bayesian methods to the aerodynamic characterization problem. Selected results are shown for Bayesian models and compared against the classical modelling approach, while advantages and disadvantages of the Bayesian methodology are discussed. It is shown that the implemented Bayesian Gaussian process model can infer the typical characteristics of the AEDB from the available datasets, while having comparable prediction qualities as the reference model. Observed differences in the variance and bias characteristics are discussed for both models

Nutritional Value of the Duckweed Species of the Genus Wolffia (Lemnaceae) as Human Food

Species of the genus Wolffia are traditionally used as human food in some of the Asian countries. Therefore, all 11 species of this genus, identified by molecular barcoding, were investigated for ingredients relevant to human nutrition. The total protein content varied between 20 and 30% of the freeze-dry weight, the starch content between 10 and 20%, the fat content between 1 and 5%, and the fiber content was ~25%. The essential amino acid content was higher or close to the requirements of preschool-aged children according to standards of the World Health Organization. The fat content was low, but the fraction of polyunsaturated fatty acids was above 60% of total fat and the content of n-3 polyunsaturated fatty acids was higher than that of n-6 polyunsaturated fatty acids in most species. The content of macro- and microelements (minerals) not only depended on the cultivation conditions but also on the genetic background of the species. This holds true also for the content of tocopherols, several carotenoids and phytosterols in different species and even intraspecific, clonal differences were detected in Wolffia globosa and Wolffia arrhiza. Thus, the selection of suitable clones for further applications is important. Due to the very fast growth and the highest yield in most of the nutrients, Wolffia microscopica has a high potential for practical applications in human nutrition

CALLISTO: towards reusability of a rocket stage: current status

JAXA, CNES and DLR have decided to cooperate to develop and fly a scaled reusable VTVL rocket stage called CALLISTO (Cooperative Action Leading to Launcher Innovation in Stage Toss - back Operations). This vehicle is paving the way for future reusable launch vehicles in Europe and in Japan. During phase B important progress in term of methods and operation philosophy specific to RLV have been made. Amongst other progresses, that will ease the development of future operational VTVL, in the domain of aerodynamic modelling, GNC landing leg deployment but also flight domain definitions are presented. These are concrete results which can at least partly be useful for other RLV projects

Towards a Reusable First Stage Demonstrator: CALLISTO - Technical Progresses & Challenges

In order to investigate the capabilities of a reusable launch system, JAXA, CNES and DLR have jointly initiated the project CALLISTO ("Cooperative Action Leading to Launcher Innovation for Stage Toss-back Operations"). The goal of this cooperation is to launch, recover and reuse a first stage demonstrator to increase the maturity of technologies necessary for future operational reusable launch vehicles (RLV) and to build up know-how on such vehicles under operational and developmental aspects. As the project has now turned into the detailed design phase, significant technical progresses have been made in definition, analysis and testing of systems and subsystems. The CALLISTO vehicle itself constitutes a subscale vertical take-off vertical landing (VTVL) stage with an overall length of 13.5 m and a take-off mass of less than 4 tons, which is propelled by a throttleable LOX/LH2 engine. It is capable to perform up to 10 consecutive flights during the planned flight campaign in French Guiana. Globally, the development effort on this system is equally shared between the three project partners. This paper presents the recent achievements in development of the key technologies for the reusable launch vehicle. While the design of critical subsystems has reached PDR level, detailed analyses and first breadboard tests have been performed successfully. These results are presented and discussed within the perimeter of the CALLISTO development roadmap. Possible technical challenges are indicated and their resolution methods are examined. Finally, the upcoming development steps are described which are foreseen to move forward to the qualification and maiden flight campaign