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  • 1.
    Andersson, Kent
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Bang, Martin
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Marcus, Carina
    SAAB Aerosystems.
    Persson, Björn
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Sturesson, Peter
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Jensen, Eva
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Hult, Gunnar
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Military utility: A proposed concept to support decision-making2015In: Technology in society, ISSN 0160-791X, E-ISSN 1879-3274, Vol. 43, p. 23-32Article in journal (Refereed)
    Abstract [en]

    A concept called Military Utility is proposed for the study of the use of technology in military operations. The proposed concept includes a three-level structure representing key features and their detailed components. On basic level the Military Utility of a technical system, to a military actor, in a specific context, is a compound measure of the military effectiveness, of the assessed technical system's suitability to the military capability system and of the affordability. The concept is derived through conceptual analysis and is based on related concepts used in social sciences, the military domain and Systems Engineering. It is argued that the concept has qualitative explanatory powers and can support military decision-making regarding technology in forecasts, defense planning, development, utilization and the lessons learned process. The suggested concept is expected to contribute to the development of the science of Military-Technology and to be found useful to actors related to defense.

  • 2.
    Andersson, Tobias
    Swedish National Defence College.
    Elhybridteknik i bandvagnssystemet: Den militära nyttan i logistikfunktionen2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Fossil fuels are finite resources and in a report from 2013, the Swedish Defence Material Administration encourages the Swedish Armed Forces to start planning for the transition to alternative propulsion systems to reduce its dependency of fossil fuels. The most promising technology to bridge the gap between pure electric propulsion and today’s internal combustion engine is hybrid electric technology. This essay examines the implications a series hybrid solution would have on military logistics. The method used includes analysis of both scientific reports and of survey answers from personnel in the SAF with several years of experience working with the tracked vehicle Bandvagn 309. The analysis of the survey answers is completed with interviews with these people and others working at BAE Systems who contributes with technical expertise. The essay will conclude that a series hybrid solution would have a positive impact on military logistics even though it is hard to specify how great the effect would be due to technical uncertainties and the fact that the technology is yet to be tested in combat.

  • 3.
    Berglund, Martin
    et al.
    Uppsala University.
    Sturesson, Peter
    Swedish Defence University, Department of Military Studies, Military-Technology Division. Uppsala University.
    Persson, Anders
    Uppsala University.
    Thornell, Greger
    Uppsala University.
    Manufacturing Miniature Langmuir probes by Fusing Platinum Bond Wires2015In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 10, article id 105012Article in journal (Refereed)
    Abstract [en]

    This paper reports on a novel method for manufacturing microscopic Langmuir probes with spherical tips from platinum bond wires by fusing for plasma characterization in microplasma sources. Here, the resulting endpoints, formed by droplets on the ends of a fused wire, are intended to act as spherical Langmuir probes. For studying the fusing behavior, bond wires were wedge bonded over a 2 mm wide slit, to emulate the final application, and fused with different voltages and currents. For electrical isolation, a set of wires were coated with a 4 μm thick layer of Parylene before they were fused. After fusing, the gap size, as well as the shape and area of the ends of the remaining stubs were measured. The yield of the process was also investigated, and the fusing event was studied using a high-speed camera for analyzing its dynamics. Four characteristic tip shapes were observed: spherical, folded, serpentine shaped and semi-spherical. The stub length leveled out at  ~400 μm as the fusing power increased. The fusing of the coated wires required a higher power to yield a spherical shape. Finally, a Parylene coated bond wire was integrated into a stripline split-ring resonator (SSRR) microplasma source, and was fused to form two Langmuir probes with spherical endpoints. These probes were used for measuring the IV characteristics of a plasma generated by the SSRR. In a voltage range between  −60 V and 60 V, the fused stubs exhibited the expected behavior of spherical Langmuir probes, and will be considered for further integration.

  • 4.
    Bhatt, Parth
    et al.
    Instituto Tecnológico de Aeronáutica, Brasilien.
    Yano, Edgar Toshiro
    Instituto Tecnológico de Aeronáutica, Brasilien.
    Amorim, Joni
    Högskolan i Skövde.
    Gustavsson, Per
    Swedish National Defence College, Department of Military Studies, Command & Control Studies Division. George Mason University, USA.
    A Cyber Security Situational Awareness Framework to Track and Project Multistage Cyber Attacks2014In: Proceedings of the 9th International Conference on Cyber Warfare & Security, Academic Conferences Limited, 2014Conference paper (Refereed)
  • 5.
    Bruzelius, Nils
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Bull, Peter
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Bäck, Lars
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Eklund, Jonas
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Heilert, Kenny
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Liwång, Hans
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Stensson, Patrik
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Svantesson, Carl-Gustaf
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Lärobok i Militärteknik, vol. 5: Farkostteknik2010Book (Other academic)
  • 6.
    Bull, Peter
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Ögren, Petter
    Totalförsvarets forskningsinstitut, FOI.
    Grahn, P.
    Totalförsvarets forskningsinstitut, FOI.
    Hillerström, G.
    Totalförsvarets forskningsinstitut, FOI.
    Johansson, P.
    Totalförsvarets forskningsinstitut, FOI.
    Jändel, M.
    Totalförsvarets forskningsinstitut, FOI.
    Karlholm, J.
    Totalförsvarets forskningsinstitut, FOI.
    Karlsson, R.
    Totalförsvarets forskningsinstitut, FOI.
    Lundgren, L.
    Totalförsvarets forskningsinstitut, FOI.
    Löfgren, Lars
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Mårtensson, T.
    Totalförsvarets forskningsinstitut, FOI.
    Nilsson, P.
    Totalförsvarets forskningsinstitut, FOI.
    Näsström, F.
    Totalförsvarets forskningsinstitut, FOI.
    Rensfelt, A.
    Totalförsvarets forskningsinstitut, FOI.
    Robinson, J.
    Totalförsvarets forskningsinstitut, FOI.
    Schubert, J.
    Totalförsvarets forskningsinstitut, FOI.
    Sparf, M.
    Totalförsvarets forskningsinstitut, FOI.
    Svenmarck, P.
    Totalförsvarets forskningsinstitut, FOI.
    Thoren, P.
    Totalförsvarets forskningsinstitut, FOI.
    Ulvklo, M.
    Totalförsvarets forskningsinstitut, FOI.
    Förstudie obemannade farkoster2012Report (Other (popular science, discussion, etc.))
    Abstract [en]

    Unmanned vehicles are being used in many conflicts around the world today. This report gives a broad overview of the field of unmanned vehicles, and includes suggestions of how a future research activity within the field might look like.

    The overview is focussed on both systems and capabilities, as well as activities that are relevant for the Swedish Armed forces. By applying the capability areas defined in the armed forced development plan (FMUP) to both commercial systems and possible scenarios, we strive to limit the scope of the report to the most relevant topics.

    The recommendations are based upon a review of the development documents of the Swedish Armed Forces, as well as visits to units operating unmanned systems today, and the overview described above. The suggestions are as fol- lows. Broad, cross-disciplinary projects focussing on system types, e.g. UAV, UGV etc, should be formed. These should be interacting with the procure- ment process, and different level of planning activities. They should also bring together competencies across FHS and FOI, survey current research state-of- the-art, through competitions, conferences and collaborations, and transfer the results to the armed forces through demonstrations and simulations of sys- tems and subsystems. Simulations in particular are well suited to illustrate the benefits and drawbacks of a particular unmanned systems, as the interaction with such systems is mostly carried out through the computers of the control stations, even for the real systems. In this way, participants from the armed forces can get a feeling for both threats and possibilities associated with the different future and contemporary systems, which will be of use to both tactic development and procurement activities.

  • 7.
    Colonese, Emilia
    et al.
    Instituto Tecnológico de Aeronáutica, Brasilien.
    Parente de Oliveira, Jose
    Instituto Tecnológico de Aeronáutica, Brasilien.
    Yano, Edgar
    Instituto Tecnológico de Aeronáutica, Brasilien.
    Amorim, Joni
    Högskolan i Skövde.
    Andler, Sten
    Högskolan i Skövde.
    Gustavsson, Per
    Swedish National Defence College, Department of Military Studies, Command & Control Studies Division.
    Cyber Security for Middleware System Architectures2014In: Proceedings of the 9th International Conference on Cyber Warfare & Security, Academic Conferences Limited, 2014Conference paper (Refereed)
  • 8. Grahn, Sven
    et al.
    Pålsson, Kristina
    Lärobok i Militärteknik, vol. 7: Rymdteknik2007 (ed. 1)Book (Other academic)
  • 9.
    Ivarsson, Olle
    Swedish National Defence College.
    Systemjämförelse – NH-90 och MH-60R2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In 2001 Swedish FMV ordered 18 NH-90 medium heavy helicopters from NH industries. The purpose of the procurement was that the new helicopter 14 would become the Swedish armed forces new primary medium helicopter, able to solve both ground and naval missions. The deal consisted of 5 naval versions of helicopter 14 and 13 helicopters for ground operations. The naval version of helicopter 14 was supposed to replace the Swedish helicopter 4, which was decommissioned 2011. Helicopter 14 was planned to be delivered at 2011, but because of delays it is now predicted to be delivered at 2019.  

    Therefore in this assignment a system analysis has been conducted to determine which helicopter system the Swedish armed forces in theory would have profited most to procure. Helicopter 14 system, or the American commercial off the shelf solution, MH-60R Seahawk. The assignment has be conducted to conclude which of these two system solutions would be the most optimal for preforming anti-submarine warfare under Swedish conditions. But also external factors in the procurement will be examined such as procurement methods, political effects, both positive and negative and also aspects of multinational cooperation’s.        

    The results of the system analysis showed that helicopter 14 was the best system for the Swedish armed forces. However there was few decisive differences between the two systems, therefor more factors should be taken into account during the procurement of a new helicopter system, such as procurement methods, defense cooperation’s and extending the lifetime of the previous system.     

  • 10.
    Johnsson, Fredrik
    et al.
    SWEDEC.
    Vretblad, Bengt
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Experimentally developed model for the design of protective measures against shaped charge jet penetration during EOD operations2014In: ISMS Annual Connference 2014: Armed Forces for 2020 and beyond Roles, 2014Conference paper (Refereed)
    Abstract [en]

    The wide use of light anti-tank weapons, such as rocket propelled grenades and the scattering of sub-munitions lead toa greatnumber of explosive remnants of war (ERW) containing shaped charge warheadsin different conflict areas. A serious problem is that, the explosive ordnance disposal (EOD) personnel lack adequate means for the design of protective measures against the jetfrom clearance of shaped charge ammunition. In this paper, based on a master thesis in military technology,a previously suggested calculation model1, is developed further. The objectiveis to create a tool that can be applied to EOD operationsand meet military requirements by consideration of the limited information availability, the short time frames, the working methods and the technology level that are characteristic for such operations.

    Full-scale experiments have been conducted to clarify the effects of conditions that are typical for EOD operations: protective measures built from sandbags with a long standoff distance to the ordnance. The results indicate that the hydrodynamic penetration theory is not suitable for these conditions,and,furthermore, thata sandbag construction provides significantly better protection against the jet than a homogeneous gravel construction.

    By disturbance analysis, the sensitivity of the individual parameters in the model is studied for typical errors. Subsequently, Monte Carlo simulation has been used to analyse the cumulative effect these errors can cause. The simulation results have then been the used to determine the model ́s margin of safety.

    To achieve the desired military utility it should be possible to use the model under field conditions, with limited time frames and without access to advanced calculating means. This has resulted in a simple diagram included in a completedesign tool.It is proposed to implement the toolin regulations and curricula for EOD operations in order to remedy today’s lack of decision support

  • 11.
    Karlsson, Andreas
    Swedish National Defence College.
    En undersökning om hur Robotsystem 70 skytten presterar i kyla2009Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this essay it has been studied how cold environment can affect the gunner of the RBS 70.

    In this study, the method of testing a hypothesis has been used. Hypothesis: “The Gunner is affected by cold to such an extent that a hit is not probable”

    The hypothesis is used in helping to answer the following two questions:

    1.      To what level is the RBS 70 Gunner affected by cold?

    2.      How can the Swedish AD Regiment improve its use of equipment in order to   reduce the effects of cold weather, on the RBS 70 gunners’ ability to aim?

     A test was performed to verify or falsify the hypothesis. Seven people from the Swedish AD Regiment fired simulated missiles both indoors and outdoors, in different temperatures. The results show that the missiles fired indoors at 20°C had an approximated direct hit-ratio of 94 percent. The firings where the thumb temperatures were the lowest had a lot lower direct hit ratio.

    The greatest issue lowering the gunners thumb temperature was the temperature of the joystick of the sight. The conclusions are that the joystick, which is made of aluminium, must be isolated to avoid cooling the gunners’ thumb. Otherwise it will be harder to hit the target at a low temperature.

  • 12.
    Khaji, Zahra
    et al.
    Uppsala University.
    Sturesson, Peter
    Swedish Defence University, Department of Military Studies, Military-Technology Division. Division of Microsystems Technology, Dept. of Engineering Sciences and Ångström Space Technology Centre, Dept. of Engineering Sciences, Uppsala University, Uppsala, Sweden.
    Klintberg, Lena
    Uppsala University.
    Hjort, Klas
    Uppsala University.
    Thornell, Greger
    Division of Microsystems Technology, Dept. of Engineering Sciences and Ångström Space Technology Centre, Dept. of Engineering Sciences, Uppsala University, Uppsala, Sweden.
    Manufacturing and characterization of a ceramic microcombustor with integrated oxygen storage and release element2015In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 10, article id 104006Article in journal (Refereed)
    Abstract [en]

    A microscale ceramic high-temperature combustor with a built-in temperature sensor and source of oxygen has been designed, manufactured and characterized. The successful in situ electroplating and oxidation of copper, and the use of copper oxide as the source of oxygen were demonstrated. It was shown that residual stresses from electroplating, copper oxidation and oxide decomposition did not cause much deformation of the substrate but influenced mainly the integrity and adhesion of the metal films. The process had influence on the electrical resistances, however. Calibration of the temperature sensor and correlation with IR thermography up to 1000 °C revealed a nearly linear sensor behavior. Demonstration of combustion in a vacuum chamber proved that no combustion had occurred before release of oxygen from the metal oxide resource.

  • 13.
    Knaust, Stefan
    et al.
    Uppsala University.
    Khaji, Zahra
    Uppsala University.
    Sturesson, Peter
    Swedish Defence University, Department of Military Studies, Military-Technology Division. Uppsala University.
    Klintberg, Lena
    Uppsal University.
    Characterization of dielectric properties of polycrystalline aluminum nitride for high temperature wireless sensor nodes2013In: Journal of Physics: Conference Series / [ed] Paul Mitcheson, London: Institute of Physics (IOP), 2013Conference paper (Refereed)
    Abstract [en]

    An aluminium nitride (AlN) passive resonance circuit intended for thermallymatched high temperature wireless sensor nodes (WSN) was manufactured using thick-lmtechnology. Characterization was done for temperatures up to 900C in both a hot-chuck forfrequencies below 5 MHz, and using wireless readings of resonating circuits at 15 MHz, 59 MHz,and 116 MHz. The substrate for the circuits was sintered polycrystalline AlN. Using a simpliedmodel for the resonators where the main contribution of the frequency-shift was considered tocome from a shift of the dielectric constant for these frequencies, the temperature dependency ofthe dielectric constant for AlN was found to decrease with increasing frequency up to 15 MHz.With an observed frequency shift of 0.04% at 15 MHz, and up to 0.56% at 59 MHz over atemperature range of 900C, AlN looks as a promising material for integration of resonancecircuits directly on the substrate.

  • 14.
    Liwång, Hans
    KTH, Farkostteknik, Skeppsteknik.
    Evaluating SHIPFLOW as a tool for calculating transverse dynamic stability and maneuvering drift forces on two semi-planning hulls1999Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 15.
    Liwång, Hans
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Applications Section.
    Exposure, vulnerability and recoverability in relation to a ship's intact stability2019In: Ocean Engineering, ISSN 0029-8018, E-ISSN 1873-5258, Vol. 187Article in journal (Refereed)
    Abstract [en]

    Intact stability describes a ship's stability in waves to avoid incidents. Operational safety measures are an important aspect of a holistic safety approach for intact stability. The aim of this study is to provide a structure of the relationship between key elements of the intact stability risk concept. Such a structure has implications for risk assessment and risk management. The developed structure is discussed in relation to the proposed second generation intact stability criteria, which highlights how the measures relate to safety. The definitions are also analyzed in relation to seven incidents. Operational decisions and the human element are shown to have strong ties to exposure, vulnerability and recoverability. However, the results herein show that the interdependency between risk and operational decisions differ between the three areas; the effective measures are thus different. The actual exposure, vulnerability and recoverability for a ship is not known nor can it be fully assessed. However, all three aspects of intact stability safety must be considered in a structured manner to reach a cost effective intact stability.

  • 16.
    Liwång, Hans
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Risk-based ship security analysis – an approach based on civilian and military methods2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The demands on maritime operations today are increasingly higher in terms of control, efficiency and cost. The margins for accidents and security incidents are therefore decreasing. In the area of ship safety the regulations, guidelines and methods have a history and culture of systematic research, development and implementation. In contrast, international security is highly politicized and therefore not as transparent. The result is that a tradition of ship security is not as well established.

    The overall aim of this thesis is to propose a method for ship security analysis that increases the overall safety of the crew and the ship. The objective is to develop a method that is systematic in order to ensure that assessment and response are complete and effective, and that the process is documented to provide evidence of decision-making.

    The method used is probabilistic risk assessment where quantitative analysis is central. The proposed approach is consistent with the requirements of maritime safety work. However, in the work here, the proposed methods are specifically tested for security cases. This is because hazards (without intent) and threats (with intent) evolve in different ways into risk. Therefore, they must be analysed differently in order to capture the causal relationship.

    The proposed approach consists of three steps: the first step consists of a threat description that documents qualitative and quantitative aspects that together describe how the threat most likely will act in relation to the ship’s vulnerability; the second step uses the threat description to define the system studied as well as the scenarios that collectively describe the harmful consequences; the third step evaluates the risk with tools from probabilistic risk assessment.

    The overall conclusion is that the proposed method brings the procedure and results of ship security analysis into the open and therefore allows for criticism, improvements and shared risk knowledge, not possible with less structured methods. The results also show that the calculated probabilities agree with available statistics, which indicates that the analysis succeeds in describing the central causal relationships of the scenarios modelled.

  • 17.
    Liwång, Hans
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Risk-based ship security analysis: a decision-support approach2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The protection of shipping does not come without hazards and threats for military forces, individual civilian ship operators and crews. With particular focus on security threats, this thesis is about how to prepare for such operations without introducing unnecessary risks, i.e., supporting conscious risk-taking related to ship security. It examines both civilian and military aspects of maritime security and therefore draws from the experience of both fields.

    Maritime safety regulations, guidelines and methods have a history and culture of systematic research, development and implementation. In contrast, international security is highly politicised and therefore less transparent. Unfortunately, comprehensive studies of ship security risk are rare. Moreover, applying risk-based approaches to security areas requires special considerations, and the limited research in this field has led to a knowledge gap.

    To reduce the identified challenges with respect to security risk analysis, the goal of this thesis is to improve security decision support by defining an approach to ship security analysis. To increase overall safety, this approach must facilitate compromises between traditional maritime safety and maritime security. Accordingly, the objective is to develop an approach that is both systematic and gives the decision maker an appropriate picture of the security risks. To examine the requirements for a security decision-support approach, the work in the appended papers studies both threats to naval vessels and the security threat posed to commercial vessels by pirates. The results of the studies can be used to further develop military doctrines and civilian guidelines.

    This study shows that the description and quantification of the (concept of) operation in the risk analysis is central for implementing both security and naval ship survivability. In addition, the crew’s risk perception, procedural safeguards and how the implemented risk controls are perceived have an important role not only in risk analysis but also in deciding the effectiveness of implemented controls. It is also concluded that only using expected values—not collecting and using uncertainties—in the analysis can lead to misleading results. Therefore, the uncertainty treatment offered by a quantitative approach is crucial for risk understanding, especially if the aim is to find robust control options or to support the development of a resilient culture.

  • 18.
    Liwång, Hans
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Pejlert, Lars
    Miller, Steve
    Gustavsson, Jan-Erik
    Management of High Speed Machinery Signatures to Meet Stealth Requirement in the Royal Swedish Navy Visby Class Corvette (YS2000)2001In: IGTI 2001, 2001, p. 2001-GT-0214-Conference paper (Other academic)
    Abstract [en]

    Over the years, the word stealth has been used more and more when discussing design and operational characteristics in military applications. New and more challenging techniques are constantly being applied to minimize signatures and thus hinder or delay detection and identification.The Visby Class Corvette is a multipurpose combat ship with 600 tons displacement. The hull is a sandwich construction of a PVC core with carbon fiber/vinyl laminate. The propulsion system consists of two identical CODOG machinery systems, each driving a KaMeWa 125 size Water Jet Unit.The Ship has special requirements for all signatures, i.e. Radar-, Hydro acoustics-, IR- and Magnetic Signature.The High Speed Machinery is twin Honeywell TF50A Gas Turbines, cantilever mounted side by side on the Main Reduction Gearbox housing. The Main Reduction Gearbox is a dual input high performance marine Gearbox designated MA -107 SBS, designed and manufactured by Cincinnati Gear Co.The Low Speed Machinery is a MTU 16 V 2000 TE90 Diesel Engine connected to the MRG by a power take in shaft.Combustion Air for the Gas Turbines is ducted from the shipside Air Inlet Screen (radar screen) via 3-stage separating filters. The Exhausts from the twin Gas Turbines are combined into one Exhaust Pipe and ducted to the ship transom above the Water Jet stream.Very little can be changed in the Gas Turbine, but high quality such as well balanced rotating part contributes to reduce the signatures. However, the main work has to be accomplished by the building shipyard in cooperation with the Gas Turbine manufacturer. The Main Reduction Gearbox is more available for changes to reduce signatures, but even for the Gearbox the building shipyard has to take design and installation measures.The HSM installation consist mainly of the Gas Turbine Engine, the Main Reduction Gear, Water Jets Unit and surrounding equipment such as main shaft, bearings and so on. The emphasis in this paper is on the GT, MRG and their effect on some of the more well known signatures i.e. RCS, IR, Hydro acoustics and Magnetic. Also some design measures are discussed.

  • 19.
    Liwång, Hans
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Ringsberg, Jonas W.
    Chalmers Univeristy of Technology.
    Ship security analysis: the effect of ship speed and effective lookout2013In: Proceedings of the ASME 32nd International Conference on Ocean, Offshore and Arctic Engineering (OMAE 2013), ASME Press, 2013Conference paper (Refereed)
    Abstract [en]

    The threat of piracy to commercial shipping is a concern for the protection and safeguarding of human lives, property and environment. Therefore, ships under piracy threat should follow security measures suggested by the International Maritime Organization (IMO) and the Contact Group on Piracy off the Coast of Somali. It is, therefore, important to choose the proper security measures for the right situation.

    This study presents a simulation model that can be used for probabilistic risk assessments regarding the operation of commercial ships. This investigation specifically studies the pirate approach phase and quantifies the effect of ship speed and effective lookout. The purpose of introducing probabilistic risk assessment into the analysis of pirate attacks is to meet safety goals more effectively through a well-balanced combination of proactive and reactive measures whilst keeping focus on the intended over all purpose of the particular ship.

    The study presents collected and documented knowledge regarding pirate capability, intention and likelihood to perform attacks. The knowledge is collected from experts with experience from the situation off the Horn of Africa. The collected information is input to an influence analysis that identifies the network of influences that govern the skiff approach. The simulation model describes piracy characteristics and decision making on the threatened ship, the characteristics and countermeasures of the ship under attack, as well as weather.

    Based on a comparison with available statistics the overall conclusion of the work is that the threat analysis and the simulation model can quantify and explain how the studied risk control options affect the probability of a successful approach. The result therefore exemplifies how a quantified ship security analysis can support the recommendations in industry guidelines and also enable recommendations that to a greater extent can facilitate an educated decision by the ship operators.

  • 20.
    Liwång, Hans
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Ringsberg, Jonas W.
    Chalmers University of Technology.
    Norsell, Martin
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Quantitative risk analysis: Ship security analysis for effective risk control options2013In: Safety Science, ISSN 0925-7535, E-ISSN 1879-1042, Vol. 58, p. 98-112Article in journal (Refereed)
    Abstract [en]

    This study reviews ship security assessment. The objectives are to explore the possibilities for quantifying and performing a more thorough ship security risk analysis than that described in the International Ship and Port Facility Security code and to evaluate to what extent this more detailed analysis increases ship security and facilitate the effective selection of risk control options.

    The study focuses on Somali-based maritime piracy, using piracy on the Indian Ocean as a case study. Data are collected using questionnaires and interviews with civilian and military security experts who possess firsthand experience of piracy off the coast of Somalia. The data are collected specifically for this study and describe and quantify the threat’s capability, intent and likelihood of exploiting a ship’s vulnerability. Based on the collected description of the threat, the study analyzes and describes: probability of detection by pirates, probability of successful approach, and probability of successful boarding.

    The performed work shows good agreement between calculated probabilities and frequencies in the cited incident reports. Also, the developed scenarios describe the most important influences on the analyzed areas. The research therefore shows that the proposed risk-based approach, which uses structurally collected and documented information on the threat, can increase ship security by assisting in selecting risk control options. The approach also allows for a better understanding of the causal relationship between threat and risk than that provided in today’s security analysis by ship owners, for example. This understanding is crucial to choosing effective and robust risk control options.

  • 21.
    Liwång, Hans
    et al.
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Applications Section.
    Rosén, Anders
    KTH Royal Institute of Technology, Stockholm, Sweden.
    A framework for investigating the potential for operational measures in relation to intact stability2018In: Proceedings of the 13th International conference on stability of ships and ocean vehicles / [ed] Naoya Umeda, Toru Katayama, Atsuo Maki, Kobe, 2018, p. 488-499Conference paper (Refereed)
    Abstract [en]

    Operational safety measures are an important aspect of a holistic safety approach for intact stability. With the aim to facilitate and further investigate potential operational measures this researchaims to describe a framework for prioritizing intact stability issues suitable for being addressed withoperational safety measures. The proposed framework identifies that there are different potentialsand uncertainties in relation to operational safety measures dependent on the operation type understudy. It is demonstrated that there is not one solution that facilitates operational measures and thereliability of potential measures varies.

  • 22.
    Liwång, Hans
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division. Chalmers University of Technology, Gothenburg, Sweden.
    Sörenson, Karl
    Swedish Defence University, Department of Military Studies, War Studies Division, Sektionen för marina operationer (KV Marin). Royal Institute of Technology, Stockholm, Sweden.
    Österman, Cecilia
    Linnaeus University, Kalmar Maritime Academy, Kalmar, Sweden.
    Ship security challenges in high-risk areas: manageable or insurmountable?2015In: WMU Journal of Maritime Affairs (JoMA), ISSN 1651-436X, E-ISSN 1654-1642, Vol. 14, no 2, p. 201-217Article in journal (Refereed)
    Abstract [sv]

    Piracy can lead to risks so high that they, according to the International Maritime Organization, are tolerable only if risk reduction is not practicable or is disproportionate to the benefits achieved. Therefore, there is a need for reducing ship security risks in relation to antagonistic threats such as piracy. The aim of this study is to identify challenges for ship operators when developing their ship security management. Furthermore, this study also investigates two central aspects in the analysis: understanding the threat and understanding how a security threat affects the crew and operation of the ship. It is clear from the analysis that the importance of subjective aspects beyond a ship operators’ direct control is high. This seems to be the fact for all aspects of the risk management process. The situation is also dynamic as the security risk, as well as the risk perception, can change dramatically even though there are no actual operational changes. As a result, the ship security management process is highly iterative and depends on situations on board as well as conditions out of the ship operator’s control. In order to make ship security manageable, the risk management has to put particular focus on methodological understanding, relevant system understanding and well-defined risk acceptance criteria as well as on including all levels of the organization in the risk reduction implementation and on a continuous monitoring.

  • 23.
    Liwång, Hans
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Westin, Jonas
    Swedish Defence University.
    Wikingsson, Jon
    Swedish Defence University.
    Norsell, Martin
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Minimising Risk from Armed Attacks: The new naval ship code's effects2010Conference paper (Other academic)
  • 24.
    Nilsson, Göran
    Swedish National Defence College.
    Unmanned Combat Aerial Vehicles: Teknik och etik: Ett självständigt arbete om obemannade flygande farkoster och deras militära nytta och moraliska dilemman2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Unmanned aerial vehicles, popularly known as drones, have been up to debate since the start of the war on terror, 11th September 2001, and there are still a lot of questions about their use and moral legitimacy. There are a lot of useful applications for this kind of vehicle for example, situational awareness, searching for lost people and attack missions. This study is going to investigate how these vehicles are being used within attack missions and and what their military utility are. Since there are a lot of different opinions on the system in war and conflict, the aim for this study is to make the ethics more concrete and evaluate what military utility this system gives.

    The moral aspects of UCAV, Unmanned Combat Aerial Vehicle, in conflict and war differ a lot from person to person. Those who are against this kind of system mean that the UCAV, in itself, is a threat and not as much to how it is used. Supporters of the system, on the other hand, argue that similar tactics have been used in war since the 1960s hence the system does not need any change in ethics and morals. However the system has got a negative reputation because of they way it is being used.

    This study shows that it is morally right to use UCAVs when the conflict or war meets a majority of the seven criteria of Just War Theory. However it is not as simple as that, there are a lot more factors that come in play. The population of the nation and its interests in the conflict or war, the threat level and what kind of profit the nation will acquire through it are important factors. If all of these criteria are met then the use of UCAVs for attack missions can be seen as morally just.

  • 25.
    Persson, Anders
    et al.
    Uppsala University, Division of Microsystems Technology, Uppsala, Sweden; Uppsala University, Ångström Space Technology Centre, Uppsala, Sweden.
    Berglund, Martin
    Uppsala University, Division of Microsystems Technology, Uppsala, Sweden; Uppsala University, Ångström Space Technology Centre, Uppsala, Sweden.
    Khaji, Zahra
    Uppsala University, Division of Microsystems Technology, Uppsala, Sweden.
    Sturesson, Peter
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Systems Section. Uppsala University, Division of Microsystems Technology, Uppsala, Sweden; Uppsala University, Ångström Space Technology Centre, Uppsala, Sweden.
    Söderberg, Johan
    Uppsala University, Division of Microsystems Technology, Uppsala, Sweden; Uppsala University, Ångström Space Technology Centre, Uppsala, Sweden.
    Thornell, Greger
    Uppsala University, Division of Microsystems Technology, Uppsala, Sweden; Uppsala University, Ångström Space Technology Centre, Uppsala, Sweden.
    Optogalvanic spectroscopy with microplasma sources: Current status and development towards a lab on a chip2016In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 26, no 10, article id 104003Article in journal (Refereed)
    Abstract [en]

    Miniaturized optogalvanic spectroscopy (OGS) shows excellent prospects for becoming a highly sensitive method for gas analysis in micro total analysis systems. Here, a status report on the current development of microwave-induced microplasma sources for OGS is presented, together with the first comparison of the sensitivity of the method to conventional single-pass absorption spectroscopy. The studied microplasma sources are stripline split-ring resonators, with typical ring radii between 3.5 and 6mm and operation frequencies around 2.6 GHz. A linear response (R2 = 0.9999), and a stability of more than 100 s are demonstrated when using the microplasma source as an optogalvanic detector. Additionally, saturation effects at laser powers higher than 100 mW are observed, and the temporal response of the plasma to periodic laser perturbation with repletion rates between 20 Hz and 200 Hz are studied. Finally, the potential of integrating additional functionality with the detector is discussed, with the particular focus on a pressure sensor and a miniaturized combustor to allow for studies of solid samples.

  • 26.
    Persson, Björn
    Swedish Defence University, Department of Military Studies, Military-Technology Division. KTH Royal Institute of Technology.
    Assessment of Aircraft Radar Cross-Section for Detection Analysis2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Hiding from and surprising an opponent are tactics that have been used in warfare throughout history. They were features that aircraft originally possessed when they were first used in military operations. However, development of military technology is an endless struggle between advances in technology and counter technology. During World War II this struggle led to the development of a new technology called radar, which was designed to detect sea vessels and aircraft at a distance and deny them the element of surprise. This laid the foundation for modern air defenses and simultaneously created a need for aircraft to penetrate such defenses. Central to the tactics and technological development that followed from the deployment of radar on the modern battlefield is the radar cross-section (RCS) of aircraft, which dictates the range at which aircraft can be detected by radar. In this thesis some aspects of the RCS of aircraft in radar detection are investigated. A combination of experimental measurement of aircraft and digital model development of the RCS of aircraft has been used.

    From flight experiments, the uncertainty in aspect angle to a threat sensor, due to aircraft dynamics, is quantified for various aircraft. In addition, the RCS fluctuation behavior of a military jet trainer is investigated by dynamic in-flight measurement. The monostatic and bistatic RCS of an F-117 are modeled and findings show that spline interpolation provides superior accuracy when interpolating the RCS data. Smooth and conservative RCS models are suggested and a new RCS sampling scheme is presented. A model based on experimental data is suggested for determining the range of aspect angles that an aircraft is likely to orient towards a threat sensor, and experimental RCS data is compared to the classical Swerling radar target models.

    Possible consequences for military operations and the design of military systems are discussed and considerations for modeling the interaction between air defenses and aircraft penetrating those defenses are given.  

    This thesis should be of interest to military actors and the defense industry, since the analyses of the ability to detect aircraft using radar are important for military operations and their planning.

     

  • 27.
    Persson, Björn
    Swedish Defence University, Department of Military Studies, Military-Technology Division. KTH.
    Radar Target Modeling Using In-Flight RCS Measurements2017In: Journal of Aircraft, ISSN 0021-8669, E-ISSN 1533-3868, Vol. 54, no 1, p. 284-291Article in journal (Refereed)
    Abstract [en]

    A flight experiment with the Saab 105 aircraft and the radar cross-section measurement system Arken has been performed at C and Ku bands. Two types of trajectories were flown and the flight state was recorded using inertial and satellite navigation equipment.  The data was used to recreate the flight in a simulator where aspect angles and range to the measurement system could be calculated. The measured radar cross-section as a function of time is presented and compared to various statistical fluctuation models, including the distributions used in Swerling cases. Findings show that the Generalized Pareto distribution fits the measured data best and that Swerling Case 2 is also a good candidate for describing the dynamics of the radar cross-section at Ku-band when the aircraft approaches the radar head on. The measured radar cross-section data was analyzed using the Fast Fourier Transform from which fluctuation rates for different carrier frequencies and trajectories could be estimated.

  • 28.
    Persson, Björn
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division. KTH.
    Bull, Peter
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Empirical Study of Flight-Dynamic Influences on Radar Cross-Section Models2016In: Journal of Aircraft, ISSN 0021-8669, E-ISSN 1533-3868, Vol. 53, no 2, p. 463-474Article in journal (Refereed)
    Abstract [en]

    In this work, measurements and a method for analyzing flight-dynamic effects on radar cross-section models for aircraft are presented. Flight-dynamic effects need to be considered when designing combat aircraft and creating target models for radar simulators. The work is based on flight data from three different types of aircraft: Piper PA-28 Archer II, Boeing 737, and Saab JAS 39 Gripen. Using inertial navigation and global-positioning systems, the motions of the three aircraft are recorded in flight. From the data, aspect angles toward a radar station located in the extension of the intended flight path are generated using a simulator. It is found that the major contribution to perturbations in aspect angles is due to the rotational degrees of freedom and that bivariate normal distributions are a good candidate for approximating the uncertainty in aspect angles for all three aircraft types. It is also found that each rotational degree of freedom is close to a normal distribution but that the parameter values of the distribution vary with altitude and aircraft type.

  • 29.
    Pettersson, Alexander
    Swedish Defence University.
    Additiv tillverkning för högre teknisk tillgänglighet i internationella insatsområden2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this paper the military utility of additive manufacturing of spare parts during international deployment is explored. We also analyze the effect that additive manufacturing has on technical availability.

    International deployment can be tough for logistical reasons and this leads to a difficulty in supplying ground troops with spare parts. If the spare parts cannot be acquired in the deployment area these have to be shipped from central distribution centers or be ordered directly from the industries. Some spare parts are uncommon and not stored in distribution centers but only get manufactured on order. This type of production can lead to delivery times of up to 40-50 weeks. With additive manufacturing this process could be shortened to 4-10 weeks.

    Conclusions that can be drawn is that additive manufacturing has military utility and can give a higher technical availability, given that a few technical difficulties are resolved. At this point there is a shortcoming in the number of qualified materials for printing spare parts for regular vehicles and this makes it difficult for the industry to approve of spare parts constructed with additive manufacturing. The winning in technical availability is directly linked to how difficult the deployment area is to reach for logistical units. Additive manufacturing has a higher positive effect in areas that are hard to reach.

  • 30.
    Sigholm, Johan
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division.
    Larsson, Emil
    Svenska Dagbladet, Stockholm, Sweden.
    Determining the Utility of Cyber Vulnerability Implantation: The Heartbleed Bug as a Cyber Operation2014In: Military Communications Conference (MILCOM), 2014 IEEE, IEEE conference proceedings, 2014, p. 110-116Conference paper (Refereed)
    Abstract [en]

    Flaws in computer software or hardware that are as yet unknown to the public, known as zero-day vulnerabilities, are an increasingly sought-after resource by actors conducting cyber operations. While the objective pursued is commonly defensive, as in protecting own systems and networks, cyber operations may also involve exploiting identified vulnerabilities for intelligence collection or to produce military effects. The weapon zing and stockpiling of such vulnerabilities by various actors, or even the intentional implantation into cyberspace infrastructure, is a trend that currently resembles an arms race. An open question is how to measure the utility that access to these exploitable vulnerabilities provides for military purposes, and how to contrast and compare this to the possible adverse societal consequences that withholding disclosure of them may result in, such as loss of privacy or impeded freedom of the press. This paper presents a case study focusing on the Heart bleed bug, used as a tool in an offensive cyber operation. We introduce a model to estimate the adoption rate of an implanted flaw in Open SSL, derived by fitting collected real-world data. Our calculations show that reaching a global adoption of at least 50 % would take approximately three years from the time of release, given that the vulnerability remains undiscovered, while surpassing 75 % adoption would take an estimated four years. The paper concludes that while exploiting zero-day vulnerabilities may indeed be of significant military utility, such operations take time. They may also incur non-negligible risks of collateral damage and other societal costs.

  • 31.
    Sturesson, Peter
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Systems Section. Ångström Space Technology Centre (ÅSTC), Uppsala University, Sweden.
    Sense, Actuate and Survive: Ceramic Microsystems for High-Temperature Aerospace Applications2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In aerospace applications, but also in manufacturing, mining, energy industry and natural hazards, high temperature, corrosion, erosion and radiation, challenge the performance and being of hardware.

    In this work, high-temperature co-fired ceramic (HTCC) alumina and platinum have been used for a range of devices intended for aerospace applications at up to 1000°C.

    The thermomechanics of a pressure sensor was investigated, and the interfacing was attained by wireless powering and reading. However, read range was limited and sensitivity decreased with temperature. Silver, electroplated after sintering, was found to remedy this until it eventually alloyed with platinum.

    Copper was electroplated and oxidized for oxygen storage in a microcombustor, intended for sample preparation for optogalvanic spectroscopy (OGS) to indicate extraterrestrial life. Despite delamination, caused by residual stresses, the device operated successfully.

    Conversely, pre-firing metallization by integration of platinum wires was studied. Freely suspended, and despite heat-induced shape irregularities, these were found advantageous over screen printed elements for gas heating, and temperature and pressure sensing. By fusing off the wires, spherical tips, allowing for impedance monitoring of microplasma sources in, e.g., OGS, were formed.

    Microplasma sources can also be used for gas heating. This, together with screen printed and suspended resistive heaters, was evaluated in a microthruster, showing that plasma heating is the most effective, implying fuel consumption reduction in satellite propulsion.

    In conclusion, HTCC alumina microdevices are thermally stable and could benefit several aerospace applications, especially with the complementary metallization schemes devised here.

    Future developments are expected to include both processing and design, all with the intention of sensing, actuating and surviving in high-temperature environments.

  • 32.
    Sturesson, Peter
    et al.
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Systems Section.
    Bull, Peter
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Applications Section.
    On the Applicability and Military Utility of Microsystems in Military Jet EnginesManuscript (preprint) (Other academic)
  • 33.
    Sturesson, Peter
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division. Uppsala University.
    Khaji, Zahra
    Uppsala University.
    Knaust, Stefan
    Uppsala University.
    Sundqvist, Johan
    Uppsala University.
    Klintberg, Lena
    Uppsala University.
    Thornell, Greger
    Uppsala University.
    Thermomechanical stability and integrability of an embedded ceramic antenna with an integrated sensor element for wireless reading in harsh environments2013In: Journal of Physics: Conference Series / [ed] Paul Mitcheson, London: Institute of Physics (IOP), 2013Conference paper (Refereed)
    Abstract [en]

    This paper reports on the design, manufacturing and evaluation of a small, wirelessly powered and read resonating antenna circuit with an integrated pressure sensor. The work aims at developing miniature devices suitable for harsh environments, where high temperature prevents the use of conventional, silicon-based microdevices. Here, the device is made of alumina with platinum as conducting material. Ceramic green tapes were structured using high-precision milling, metallized using screen printing, and subsequently laminated to form stacks before they were sintered. The device’s frequency shift as a function of temperature was studied up to 900°C. The contributions to the shift both from the thermomechanical deformation of the device at large, and from the integrated and, so far, self-pressurized sensor were sorted out. A total frequency shift of 3200 ppm was observed for the pressure sensor for heating over the whole range. Negligible levels of thermally induced radius of curvature were observed. With three-point bending, a frequency shift of 180 ppm was possible to induce with a curvature of radius of 220 m at a 10 N load. The results indicate that a robust pressure sensor node, which can register pressure changes of a few bars at 900°C and wirelessly transmit the signal, is viable.

  • 34.
    Sturesson, Peter
    et al.
    Swedish Defence University, Department of Military Studies, Military-Technology Division. Uppsala University.
    Khaji, Zahra
    Uppsala University.
    Stefan, Knaust
    Uppsala University.
    Klintberg, Lena
    Uppsala University.
    Thornell, Greger
    Uppsala University.
    Thermomechanical properties and performance of ceramic resonators for wireless pressure reading at high temperatures2015In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 25, no 9, article id 095016Article in journal (Refereed)
    Abstract [en]

    This paper reports on the design, fabrication, and thermomechanical study of ceramic LC resonators for wireless pressure reading, verified at room temperature, at 500 °C and at 1000 °C for pressures up to 2.5 bar. Five different devices were fabricated from high-temperature co-fired ceramics (HTCC) and characterized. Alumina green tape sheets were screen printed with platinum paste, micromachined, laminated, and fired. The resulting samples were 21 mm  ×  19 mm with different thicknesses. An embedded communicator part was integrated with either a passive backing part or with a pressure-sensing element, including an 80 µm thick and 6 mm diameter diaphragm. The study includes measuring thermally and mechanically induced resonance frequency shifts, and thermally induced deformations. For the pressure sensor device, contributions from changes in the relative permittivity and from expanding air trapped in the cavity were extracted. The devices exhibited thermomechanical robustness during heating, regardless of the thickness of the backing. The pressure sensitivity decreased with increasing temperature from 15050 ppm bar−1 at room temperature to 2400 ppm bar−1 at 1000 °C, due to the decreasing pressure difference between the external pressure and the air pressure inside the cavity.

  • 35.
    Sturesson, Peter
    et al.
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Systems Section. Ångström Space Technology Centre, Dept. of Engineering Sciences, Uppsala University, Sweden; Division of Microsystems Technology, Dept. of Engineering Sciences, Uppsala University, Sweden.
    Klintberg, Lena
    Division of Microsystems, Dept. of Engineering Sciences, Uppsala University.
    Thornell, Greger
    Ångström Space Technology Centre, Dept. of Engineering Sciences, Uppsala University, Sweden; Division of Microsystems Technology, Dept. of Engineering Sciences, Uppsala University, Sweden.
    Pirani Microgauge Fabricated of High-Temperature Co-fired Ceramics with Integrated Platinum Wires2019In: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 285, p. 8-16Article in journal (Refereed)
    Abstract [en]

    This paper presents the integration and pressure sensor operation of platinum bond wires in High- Temperature Co-fired alumina (HTCC). Devices were fabricated with a 50 μm diameter wire suspended across a 500 μm wide cavity in green-body state HTCC, electrically connected to screen printed alumina conductors. The substrate shrinkage during sintering to a cavity width of 400 μm causes the wire element to elevate from the cavity ́s bottom surface. Resulting devices were compared with reference devices, containing screen-printed sensor elements, as Pirani gauges operated at 100 °C in constant-resistance mode, and in dynamic mode with a feeding current of 1 A in a pressure range from 10-4 Torr to atmospheric pressure. Also, devices with wire lengths between 500 and 3500 μm were operated and studied in constant-resistance and dynamic mode. Lastly, a device is demonstrated in operation at a mean temperature of 830 °C. The results include wire elements with a consistent elevation from their substrate surfaces, with irregularities along the wires. The wire devices exhibit a faster pressure response in dynamic mode than the reference devices do but operate similarly in constant-resistance mode. Increasing the wire element length shows an increasing dynamic pressure range but a decreasing maximum sensitivity. The sensitivity is retained in high temperature mode, but the dynamic range is extended from about 10 Torr to about 700 Torr.

  • 36.
    Sturesson, Peter
    et al.
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Systems Section.
    Seton, Ragnar
    Uppsala Universitet.
    Klintberg, Lena
    Uppsala University.
    Thornell, Greger
    Uppsala University.
    Persson, Anders
    Uppsala Universitet.
    Effect of Resistive and Plasma Heating on the Specific Impulse of a Ceramic Cold Gas Thruster2019In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 28, no 2, p. 235-244Article in journal (Refereed)
    Abstract [en]

    Research and development of small satellites has continued to expand over the last decades. However, propulsion systems with adequate performance have persisted to be a great challenge. In this paper, the effects of three different heaters on the specific impulse and overall thrust efficiency of a cold gas microthruster are presented. They consisted of a conventional, printed resistive thick-film element, a freely suspended wire, and a stripline split-ring resonator microplasma source and were integrated in a single device made from high-temperature co-fired ceramics (HTCC). The devices were evaluated in two setups, where the first measured thrust and the other shock cell geometry. In addition, the resistive elements were evaluated as gas temperature sensors. The microplasma source was found to provide the greatest improvement in both specific impulse and thrust efficiency, increasing the former from an un- heated level of 44 s to 55 s when heating with a power of 1.1 W. This corresponded to a thrust efficiency of 53 %. This could be compared to the results from the wire and printed heaters which were 50 s and 18 %, and 45 s and 14 %, respectively. The combined results also showed that imaging the shock cells of a plasma heated thruster was a simple and effective way to determine its performance compared to the traditional thrust balance method.

  • 37.
    Sturesson, Peter
    et al.
    Swedish Defence University, Department of Military Studies, Science of Command and Control and Military Technology Division, Military Technology Systems Section. Uppsala Univ, Dept Engn Sci, Angstrom Space Technol Ctr, Sweden; Uppsala Univ, Dept Engn Sci, Div Microsyst Technol, Sweden.
    Zahra, Khaji
    Uppsala Univ, Dept Engn Sci, Div Microsyst Technol, Sweden.
    Lena, Klintberg
    Uppsala Univ, Dept Engn Sci, Div Microsyst Technol, Sweden.
    Greger, Thornell
    Uppsala Univ, Dept Engn Sci, Angstrom Space Technol Ctr, Sweden; Uppsala Univ, Dept Engn Sci, Div Microsyst Technol, Sweden.
    Ceramic Pressure Sensor for High Temperatures: Investigation of the Effect of Metallization on Read Range2017In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 17, no 8, p. 2411-2421Article in journal (Refereed)
    Abstract [en]

    A first realization of membranes by draping a graphite insert with ceramic green body sheets, and a study on the relationship between circuit metallization, made by double- layer screen-printing of platinum and electroplating of silver on top of platinum, and the practical read range of ceramic LC resonators for high-temperature pressure measurements, are presented. As a quality factor reference, two-port microstrip meander devices were positively evaluated. To study interdiffusion between silver and platinum, test samples were annealed at 500, 700, and 900 °C for 4, 36, 72, and 96 hours. The LC resonators were fabricated with both metallization methods, and the practical read range at room temperature was evaluated. Pressure sensitive membranes were characterized for pressures up to 2.5 bar at room temperature, 500 and up to 900°C. Samples electroplated with silver exhibited performance equal to or better than double-layer platinum samples for up to 60 hours at 500°C, 20 hours at 700°C, and for 1 hour at 900°C, which was correlated with the degree of interdiffusion as determined from cross- sectional analysis. The LC resonator samples with double-layer platinum exhibited a read range of 61 mm, and the samples with platinum and silver exhibited a read range of 59 mm. The lowest sheet resistance, and, thereby, the highest read range of 86 mm, was obtained with a silver electroplated LC resonator sample after 36 hours of annealing at 500°C. 

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