Many different bacteria have essential roles in the process ofrecycling organic waste, making them useful tools when it comes toestablishing artificial ecosystems, a key technology to master inthe expansion of human space travel.In order to further investigate bacteria growth conditions duringspace travel, the MOREBAC experiment was formulated. The objectivewas to design an experimental setup and develop measurementequipment with the capability of confirming successfulresuscitation of freeze-dried bacteria in space by measuringbacteria growth, on-board the student-built MIST-satellite.The experimental setup prototype consisted of an acrylic chipwherein the bacteria would be placed during experiments and anoptical measurements configuration using a photosensor with thepurpose of detecting bacteria cell growth. For experimentalenvironment monitoring, a temperature sensor and a pressure sensorwere calibrated.An Arduino Nano microcontroller was programmed to control allelectrical components during measurements. During the opticaldensity measurements blue dyed water and E.coli bacteria innutrition media were used as test samples.Provided varying blue dye or bacteria cell concentrations, in theform of dilution series and growth-over-time-series, the equipmentproved capable of producing measurements that indicate the opticaldensity of the test sample.Furthermore, a prototype experiment protocol simulating eventsthat will occur in the final experiment design, was implementedand was able to produce real-time monitoring graphs of optical,temperature and pressure measurements, as well as documentation ofall events and measurement data. / MOREBAC / MIST

The onset of fire within a compartment can pose a hazard to the occupants and the structure containing the compartment. Fire suppression systems aim to either extinguish or suppress an incipient fire before loss of life or damage to the structure can occur. The geometry and use of the compartment as well as the fuel packages within must be taken into account when choosing an appropriate fire suppression system. This thesis explores novel suppression methods inside of compartments. Los Alamos National Laboratories came to the University of Texas Fire Research Group (UTFRG) to characterize and investigate the fire danger inside of nuclear gloveboxes. The first suppression method discussed explores activation tests of a commercial automatic fire suppression system (Fire Foe [superscript TM]) containing heptaflouropropane (FE-36) fire suppressant conducted within a glovebox at the UTFRG's burn structure. Temperature and time to activation data of ten tests at four different fire sizes, three 13 kW, one 20 kW, three 25 kW, and three 50 kW, was taken. Gas temperatures from experiments were compared against NIST's Fire Dynamics Simulator (FDS) gas temperatures with good agreement. The time and spatially averaged net heat flux on a virtual Fire Foe [superscript TM] tube from the FDS simulations were passed to a thermo-physical, semi-empirical, sub-model to predict activation with poor agreement from experimental activation times. A Bayesian parameter inference was later run on the sub-model. While the Bayesian inference approach is able to match sub-model temperatures to experimental temperatures, some non-physical values for heat transfer coefficients and view factors were observed at the lower heat release rate fires. Micro combustion calorimetry (MCC) was used to determine heat of combustion of glovebox glove material and cone calorimetry tests were run to find ignition time versus incident heat flux. Using standard ignition time models, effective model parameters were calibrated. Thermal characterization of the glove material showed that the heat of combustion found from MCC was within the range of heats of combustion for other non-halogenated materials found in the literature. Analysis of the time to ignition tests showed that the glove material should be modeled as thermally thick when one would expect thin behavior. This behavior was attributed to possible heat losses from the back of the glove material. Dry water is expected to have similar suppression characteristics as water mist systems because the dry water particle sizes are on the order of water mist droplet sizes. The major benefit with dry water is the low pressures needed to drive the aerosol. An issue encountered with the dry water was flowing it in the way one would flow normal water. It was found that at low normal and shear stresses, the dry water clathrates would release the water held inside. A possible low shear delivery mechanism was discussed that avoids the ratholing effect. A continuous dry water production system was also designed. Filter loading tests were conducted to determine the quality of the dry water collected from the batch and continuous cases. It was observed that the ratio of water to silica for the continuous case reaches the batch value and is similar to results found in the literature. For the batch dry water it was observed that the particle size of the dried clathrates does vary with rotational speed of the blender and is independent of the type of water used (tap or deionized). / text

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17161号 / 工博第3651号 / 新制||工||1554(附属図書館) / 29900 / 京都大学大学院工学研究科電子工学専攻 / (主査）教授 藤田 静雄, 教授 髙岡 義寛, 教授 川上 養一 / 学位規則第4条第1項該当

For intensive production systems like the Blue Ridge Aquaculture (BRA), based in Martinsville, VA, there are significant economic incentives to reuse the waste by diverting it into a cropping system that would increase the total productivity and total resource-reuse efficiency, and decrease the environmental, ecological, and financial costs of aquacultural waste disposal. In order to facilitate the reuse of effluent from the tilapia production at the BRA, a green house was developed. On this site, sludge waste from recirculating aquaculture was separated and composted using a vermicomposting technique and the resulting compost was utilized as an amendment to conventional greenhouse potting mixes. These aquacultural waste products were compared to conventional greenhouse culture of a common ornamental annual plant. It was hypothesized that (1) vermicomposted aquaculture sludge would increase the growth of plants over conventional greenhouse potting mixes, and (2) recycled aquacultural wastewater can serve as a quality source of irrigation water, and plant response would differ with irrigation method. Plant growth and 11 out of 12 plant tissue nutrients were greater when compost was increased in the substrate. Plant root growth and 3 out of 12 tissue nutrients were increased when irrigated with wastewater. Plant shoot mass and total mass was greater when irrigated by ebb and flow irrigation compared to overhead mist irrigation, and 4 out of 12 tissue nutrients were greater when irrigated with mist irrigation. Overall plant performance was greatest with 15% vermicomposted sludge in the substrate and watered with wastewater by ebb and flow irrigation. / Master of Science

Gallium oxide (Ga2O3) has been the subject of extensive research activity due to its ultrawide bandgap and large breakdown field, which make it promising for next-generation applications in deep ultraviolet detection and power electronics. β-Ga2O3 is the most thermally stable and well-studied polymorph of Ga2O3. However, during the past decade, the metastable orthorhombic κ-Ga2O3 has emerged as an equally impressive candidate material owing to its high crystal symmetry and ferroelectric and spontaneous polarization properties. Several studies have reported the growth and characterization of κ-Ga2O3 films using different epitaxial growth methods. However, the existing literature still lacks reports on the processing of this material for future device applications. Therefore, in this thesis, we investigate the effects of high-temperature treatment and plasma exposure on the structural and optical properties of mist chemical vapor deposition (mist-CVD)-grown κ-Ga2O3 films. Using high-temperature X-ray diffraction (HT-XRD), we show that the films remain phase-pure up to an annealing temperature of 800 ˚C, after which β-phase peaks start to appear and eventually show a complete transition to β-Ga2O3 at 875 ˚C. Additionally, we show using detailed high-resolution transmission electron microscopy (HRTEM) and XRD analyses that annealing at 700 ˚C in ambient air is effective in improving the crystal quality of the κ-Ga2O3 layer by relieving in-plane strains and epitaxial stacking faults. Moreover, since dry etching is needed for the anisotropic patterning of materials for device applications, it is necessary to investigate the effects of plasma exposure on the near-surface properties of the material in order to keep its damage to a minimum. Therefore, we studied the impacts of plasma exposure during dry etching on the chemical structure, crystallinity, and optical properties of κ-Ga2O3 by using a variety of characterization methods. We observed how varying the etching parameters using BCl3/Ar can affect the near-surface properties of the material, which play a key role in modifying the performance of future devices. Specifically, we found that both RIE/ICP power and BCl3/Ar ratio can influence the surface stoichiometry and the concentration of native defect density, which affect the material’s structural and optical properties. Additionally, we reported for the first time on κ-Ga2O3 ICP-RIE process optimization using a BCl3/Ar gas mixture. By tuning the process parameters, the optimized recipe had a high etch rate of 130 nm/min, showed a surface roughness reduction of 56%, and produced vertical sidewall profiles for ridge device structures.

No description available.

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第24010号 / エネ博第446号 / 新制||エネ||84(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー応用科学専攻 / (主査)教授 平藤 哲司, 教授 土井 俊哉, 教授 藤本 仁 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Mitochondria shape cytosolic Ca2+ (cCa2+) transients. Ca2+ entry into the mitochondria is driven by the highly negative mitochondrial membrane potential and through a highly selective channel, the Mitochondrial Calcium Uniporter (MCU). Mitochondrial Ca2+ (mCa2+) is utilized by the matrix dehydrogenases for maintaining cellular bioenergetics. The TCA cycle-derived NADH and FADH2 are mCa2+ dependent thus, feed into the electron transport chain (ETC) to generate ATP. Either loss of mCa2+ or metabolite uptake by the mitochondria results in a bioenergetic crisis and mitochondrial dysfunction. Reciprocally, sudden elevation of cCa2+ under conditions of stroke or ischemia/reperfusion injury (I/R) drives excessive mCa2+ overload that in turn leads to the opening of a large channel, the mitochondrial permeability transition pore (PTP) that triggers necrotic cell death. Thus, Ca2+ and metabolite equilibrium is essential to maintain a healthy mitochondrial pool. Our laboratory has previously showed that loss of mCa2+ uptake leads to decreased ATP generation and cell survival through autophagy. Although metabolite scarcity also results in similar reduction in ATP generation, the molecular mechanisms by which metabolites control mitochondrial ion homeostasis remain elusive. Deprivation of glucose or supplementation of mitochondrial pyruvate carrier (MPC) transport blocker UK5099 and or carnitine-dependent fatty acid blocker etomoxir triggered an increase in the expression of MICU1, a regulator of the mitochondrial calcium uniporter (MCU) but not the MCU core subunit. Consistently, either RNAi-mediated deletion of MPC isoforms or dominant negative human mutant MPC1 R97W showed significant induction of MICU1 protein abundance and inhibition of MCU-mediated mCa2+ uptake. Moreover, TCA cycle substrate-dependent MICU1 expression is under the control of EGR1 transcriptional regulation. Reciprocally, the MICU1 dependent inhibition of mCa2+ uptake exhibited lower NADH production and oxygen consumption and ATP production. The reduction of mitochondrial pyruvate by MPC knockdown is linked to higher production of mitochondrial ROS and elevated autophagy markers. These studies reveal an unexpected regulation of MCU-mediated mCa2+ flux machinery involving major TCA cycle substrate availability and possibly MICU1 to control cellular switch between glycolysis and oxidative phosphorylation. While mCa2+ is required for energy generation, sustained elevation of mCa2+ results in mitochondrial swelling and necrotic death. Hence, it was thought that preventing mCa2+ overload can be protective under conditions of elevated cCa2+. Contrary to this, mice knocked-out for MCU, that demonstrated no mCa2+ uptake and hence no mitochondrial swelling, however failed protect cells from I/R- mediated cell death. MCU-/- animals showed a similar infarct size comparable to that of control animals, suggesting that prevention of MCU-mediated mCa2+ overload alone is not sufficient to protect cells from Ca2+ -induced necrosis. The absence of mCa2+ entry revealed an elevation in the upstream cCa2+ transients in hepatocytes from MCUDHEP. Ultra-structural analysis of liver sections from MCU-/- (MCUDHEP) and MCUfl/fl animals revealed stark contrast in the shape of mitochondria: MCUfl/fl liver sections showed long and filamentous mitochondria (spaghetti-like) while MCUDHEP mitochondria were short and circular (donut-like). Furthermore, challenging MCUfl/fl and MCUDHEP hepatocytes with ionomycin caused a marked increase in cCa2+ and a simultaneous change in mitochondrial shape (from spaghetti to donut), a phenomenon we termed mitochondrial shape transition (MiST) that was independent of mitochondrial swelling. The cCa2+-mediated MiST is induced by an evolutionarily conserved mitochondrial surface EF-hand domain containing Miro1. Glutamate and Ca2+ -stress driven cCa2+ mobilization cause MiST in neurons that is suppressed by expression of Miro1 EF1 mutants. Miro1-dependent MiST is essential for autophagosome formation that is attenuated in cells harboring Miro1 EF1 mutants. Remarkably, loss of cCa2+ sensitization by Miro1 prevented MiST and mitigated autophagy. These results demonstrate that an interplay of ions and metabolites function in concert to regulate mitochondrial shape that in turn dictates the diverse mitochondrial processes from ATP generation to determining mechanisms of cell death. / Biomedical Sciences

Satellites are evolving around the globe, expanding our possibility to explore space and many other applications. This thesis project is a model satellite used for teaching purposes in the course IE120V Electronics and Programming for Space Applications provided at KTH Royal Institute of Technology. The model can be used to teach Science, technology, engineering, and mathematics (STEM) in high school. The satellite is inspired by the MIniature Student saTellite (MIST) project carried out by the KTH Royal Institute of Technology, and hence this project will be called ”MiniMIST.” The MiniMIST aims to perform functions carried out on practical satellites. The onboard computer performs real-time image capturing, reads temperature from the surroundings, and analyzes power from solar panels and the power supply (batteries). The ground station setup is used to communicate with the satellite (MiniMIST) and receive data to be viewed and analyzed. The ESP32-Wrover was used as the main computer to run the MiniMIST. It was programmed with MicroPython and C++. Client-server communication using HTTP protocol emulated the communication between the ground station and MiniMIST with Web-Server communication. The ground station is a web page programmed using HTML, CSS, and JavaScript along with the AJAX framework. The thesis aims to build a working prototype of MiniMIST by dividing it into three sections: Hardware design, onboard computer software, and ground station software. / Satelliter utvecklas runt om i världen, vilket utökar vår möjlighet att utforska rymden och många andra applikationer. Detta examensarbete är en modellsatellit som används för undervisningsändamål i kursen IE120V Elektronik och programmering för rymdtillämpningar som ges vid Kungliga Tekniska Högskolan. Modellen kan användas för att lära ut naturvetenskap, teknik, ingenjörskap och matematik (STEM) på gymnasiet. Satelliten är inspirerad av projektet MIniature Student saTellite (MIST) som genomförts av Kungliga Tekniska Högskolan, och därför kommer detta projekt att kallas ”MiniMIST”. MiniMIST syftar till att utföra funktioner som utförs på praktiska satelliter. Datorn ombord utför bildtagning i realtid, läser av temperatur från omgivningen och analyserar ström från solpaneler och strömförsörjningen (batterier). Markstationsinställningen används för att kommunicera med satelliten (MiniMIST) och ta emot data som ska ses och analyseras. ESP32-Wrover användes som huvuddator för att köra MiniMIST. Den programmerades med MicroPython och C++. Klient-serverkommunikation med hjälp av HTTP-protokoll emulerade kommunikationen mellan markstationen och MiniMIST med webbserverkommunikation. Markstationen är en webbsida programmerad med HTML, CSS och JavaScript tillsammans med AJAX-ramverket. Avhandlingen syftar till att bygga en fungerande prototyp av MiniMIST genom att dela upp den i tre sektioner: Hårdvarudesign, inbyggd datormjukvara och markstationsmjukvara.

This thesis presents the work of adding support for a communications protocol in a space application. The work is a part of KTHs MIST (MIniature STudent Satellite) project which aims at sending an experimental satellite into space. Each experiment on the satellite is designed as a subsystem. These subsystems need to be able to communicate with the main computer on the satellite in order to transfer the results of the experiments down to earth. In efforts prior to the current thesis, a special communications protocol has been specified to solve this problem. That protocol is called MSP (MIST Space Protocol). This paper describes the efforts to add support for MSP to two of the satellite’s experiments. These two experiments are called SiC in Space and Piezo-LEGS. However, since Piezo-LEGS is incompatible with the I2C bus in which MSP runs on top of, it must communicate through the SiC experiment. Which parts of the protocol that need to be supported by each experiment are defined. The result of the work is that the experiments can communicate with the main computer through the MSP protocol. / Denna kandidatuppsats beskriver arbetet med att implementera MSP protokollet för de två experimenten SiC och Piezo-LEGS. Syftet med MIST projektet är att skicka upp en experimentsatellit i omloppsbanan runt jorden. I satelliten finns ett antal experiment. De två experiment som arbetet ar fokuserat på är ”SiC in Space” och ”Piezo-LEGS”. SiC-experimentets syfte är att man ska göra mätningar på en kiselkarbid (SiC) transistor i rymdens vacuum. Syftet med Piezo-LEGS experimentet är att man vill mäta hur prestandan för en piezoelektrisk motor påverkas i rymden. Inom MIST-projektet har ett kommunikationsprotokoll som kallas MSP utvecklats för kommunikation mellan satellitens huvuddator och experimenten. I detta arbete har MSP protokollet implementerats för experimenten SiC och Piezo-LEGS Eftersom Piezo-LEGS experimentet är inte kompatibel med I2C bussen som används av MSP protokollet, utan istället använder sig utav ASCII-kommandon via RS-485, måste MSP kommandona översättas till ASCII-kommandon utav SiC.