As the world's power needs grow, the demand for power from renewable resources, such as wind or solar is increasing. One major drawback associated with these renewable resources is that the power output is dependent on environmental factors, such as cloud cover and wind speeds. This allows the possibility of either power output exceeding or falling short of forecast levels that may lead to grid instabilities. Therefore, Large Scale Energy Storage (LSES) systems are critical to store excess power when the output exceeds demand in order to supplement output power when it falls short of demand.¹ The Zinc/Bromine Redox Flow Battery (RFB) is a promising technology because of previously reported long cycle-life (CL) capability, high efficiencies, low cost materials, and scalable operating conditions.² The excellent energy storage performance of the Zinc/Bromine system was confirmed by measuring both Faradaic and Coulombic electrochemical cell efficiency dependence on temperature of a bench scale Zinc/Bromine flow cell. At room temperature, near 75% Faradaic efficiency was measured when cycling the system between 20% and 100% State of Charge (SOC), which is in good agreement with published values,³ and was measured to be over 80% efficient when operating at an elevated temperature of 50°C. To elucidate capital and operational costs, key system operation parameters especially focused on degradation mechanisms were investigated. Since deep discharge cycling is perceived as highly damaging to electrochemical systems, a system was cycled between 0% and 5% (SOC) 10,000 times. Performance was quantified by measuring the frequency factor (i[subscript 0]) and relative activation energy (α) for the reactions using Tafel scans. No statistically significant degradation or change to the electrodes was observed during the zero point cycling experiment. However, it was found that under conventional operation damage to the electrodes does accumulate, presumably due to the highly oxidative environment caused by the presence of high concentrations of dissolved bromine or tri-bromide. While the performance of both electrodes shows decreases in frequency factor attributed to the damage process, the bromide oxidation process seems to be more damaging (i.e., at the positive electrode during the charging process). Long term measurements show a degradation of the electrocatalytic parameters at an applied overpotential of 100 mV from ca. 40 mA/cm² to ca. 5 mA/cm² at the positive electrode and from ca. 20 mA/cm² to ca. 10 mA/cm² for the negative electrode. A degradation rate model was proposed to predict the service life expectancy of graphite electrodes in a bromine system based on processes showing a combined second order reaction rate coupled with a negative first order reaction rate. The model can be used to predict the cost of energy when operating any device using graphite electrodes, based on the operating power ratio, defined here as the quotient between operating power and system rated power. This damage could be partially reversed by exposing the electrode surfaces to concentrated potassium hydroxide dissolved in isopropanol, presumably due to exfoliation of the electrocatalytic surface leading to the exposure of a clean surface with electrocatalytic performance close to the original. Further, a chemical pretreatment for the graphite surface imparting enhanced stability in aqueous bromine systems was developed that shows negligible damage when similar amounts of current have passed through the electrode surface. After bromide oxidation equivalent to passing ca. 10 Ah/cm² the treated surface showed a change in steady state current density at an applied overpotential of 100 mV from ca. 50 mA/cm² to ca. 48 mA/cm². / Graduation date: 2013 / Access restricted to the OSU Community at author's request from April 1, 2013 - April 1, 2015

Ingestion of cold (<10°C) compared to warm (>37°C) fluid has been suggested to attenuate heat storage levels during exercise. However, modulations in sweat output may yield differences in evaporative heat loss that are greater than differences in heat transfer with the ingested fluid. The purpose of the thesis was to evaluate thermoregulatory control and human heat balance, and compare thermometrically derived values of heat storage with those derived from partitional calorimetry following water ingestion of varying temperature during exercise. We found that water ingestion of 50°C compared to 1.5°C decreases heat storage in thermoneutral environments, and further exacerbates the error of thermometric heat storage estimations. Differences in heat storage were attributed exclusively to disproportionate reductions in whole-body and local sweat output and thus evaporative heat loss potential. Ingested fluid temperature only minimally altered skin blood flow and did not influence dry heat exchange with the ambient environment.

The controls of water and O2 availability, microbial activity and temperature on acid (H2SO4) production rates in commercial-scale sulphur (S0) blocks were quantified and recommendations were made for minimizing H2SO4 production in S0 blocks. Acidic drainage from the S0 blocks (pH 0.4-1.0) was attributed to mixing of fresh infiltrating water and low-pH resident water (mean pH=-2.1) with resident water comprising ~4-8% of the drainage. Although clean S0 is strongly hydrophobic, preferential water infiltration occurred rapidly through fractured S0 blocks in which the bulk hydraulic conductivity was estimated to be similar to gravel or clean sand (Ks=1x10-1 to 1x10-3 m/s). Microbial colonization of fracture faces generated localized hydrophilic conditions that helped create preferential pathways for water infiltration. Liquid water contact (compared to water vapour) was essential for S0 oxidation (i.e., H2SO4 production), therefore H2SO4 production in the S0 blocks was limited to fractures and friable S0 through which water flowed. H2SO4 production was greatest in the upper 1 m of the S0 block (70 to >97% of annual H2SO4 production) and the result of autotrophic microbial S0 oxidation.<p> S0 oxidation rates were very sensitive to temperature and increased by a factor of 4.3 for a temperature increase of 10°C (Q10). Therefore minimizing temperature (<5°C) in S0 blocks would be an effective strategy for controlling H2SO4 production. Heat released during S0 oxidation did have a measurable effect on in situ temperatures and should be considered in the design of insulated cover systems. Although autotrophic microbial activity was insensitive to O2 concentrations when they were >1 vol.%, the total mass production rate of H2SO4 is approximately proportional to the O2 concentration at the surface of the S0 block (assuming in situ O2 concentrations decrease to <1 vol. %). Therefore, cover systems that minimize the surficial O2 concentration are recommended.<p> Cover systems limiting H2O infiltration would be effective for minimizing the volume of acidic drainage, but may have no impact on H2SO4 production rates within the block. In this study, H2O infiltration through a typical soil cover (~95% efficiency) would easily satisfy the annual H2O demand for H2SO4 production (2.6 mm/m2 in the upper 1 m). Greater near-surface H2SO4 production rates may appear to make surficial biocide application an attractive option for minimizing S0-oxidizing microbial activity, however, this approach might simply drive the zone of H2SO4 production to greater depths and have no affect on the total mass production of H2SO4.

With an increase in the amount of information being exchanged every day, there is a need for storage repositories and faster networks to retrieve data with a minimum amount of time delay. Keeping this in mind, inroads have been made in developing different types of storage network technologies including Direct Attached Storage (DAS), Network Attached Storage (NAS), and Storage Area Network (SAN). Developments have also been made in building faster and parallel Input/Output (I/O) peripheral interface systems such as the Small Computer System Interface (SCSI). With the help of SCSI high-speed bus systems that quickly transfer large amounts of data requested by the user have been made, which is a very important need in storage are networks. Internet SCSI (iSCSI) protocol is a Small Computer System Interface (SCSI) transport protocol developed by the Internet Engineering Task Force (IETF), which maps block-oriented storage data over Transmission Control Protocol/Internet Protocol (TCP/IP) networks. This iSCSI storage technology is a viable solution utilizing IP networks for low-cost implementation of managing storage networks. Unlike the file access mechanism provided by protocols such as Network File System (NFS), iSCSI implementation has a block access mechanism to provide better performance and throughput. Remote Direct Memory Access (RDMA) technology provided by Internet Wide Area RDMA Protocol (iWARP), which runs over TCP/IP networks provides efficient data transfers. RDMA protocol is primarily chosen because it efficiently uses storage I/O (Input/Output) systems by providing a Zero Copy transfer mechanism. Implementing iSCSI over RDMA-enabled network adapters exploits RDMA operations for efficient data transfers using the existing infrastructure. This thesis involves the implementation and performance evaluation of iSCSI over RDMA, a process that maps iSCSI This study analyzes, the performance of SAN storage devices, demonstrating that iSCSI over RDMA performs better than running only iSCSI. In addition, the low cost and ease with which an iSCSI over RDMA can be managed make it superior to iSCSI, considering the performance gained. The iSCSI target from iSCSI Enterprise Target (IET) installed in a Fedora Core 5 machine with a 2.6.16 kernel was used to evaluate the iSCSI. The Initiator, was built using a Fedora Core 5 source iSCSI Initiator in a Fedora Core 5 machine with a 2.6.16 kernel and Microsoft iSCSI Initiator in a Microsoft server 2003 machine [1] [2]. This research used RNICs developed by Ammasso Corporation, to directly place data into Initiator buffers using Zero Copy transfer. Hence, unnecessary multiple copying procedures are eliminated, there by memory bus utilization and improving performance, which definitely impacts the overall performance of a system when there is large amount of data being transferred as occurs with iSCSI. The iSCSI over RDMA protocol implementation gives high performance and low overhead for I/O storage. / Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical and Computer Engineering. / "July 2006." / Includes bibliographic references (leaves 43-46)

Ingestion of cold (<10°C) compared to warm (>37°C) fluid has been suggested to attenuate heat storage levels during exercise. However, modulations in sweat output may yield differences in evaporative heat loss that are greater than differences in heat transfer with the ingested fluid. The purpose of the thesis was to evaluate thermoregulatory control and human heat balance, and compare thermometrically derived values of heat storage with those derived from partitional calorimetry following water ingestion of varying temperature during exercise. We found that water ingestion of 50°C compared to 1.5°C decreases heat storage in thermoneutral environments, and further exacerbates the error of thermometric heat storage estimations. Differences in heat storage were attributed exclusively to disproportionate reductions in whole-body and local sweat output and thus evaporative heat loss potential. Ingested fluid temperature only minimally altered skin blood flow and did not influence dry heat exchange with the ambient environment.

Cloud computing enables data centres to provide resource sharing across multiple tenants. This sharing, however, usually comes at a cost in the form of reduced isolation between tenants, which can lead to inconsistent and unpredictable performance. This variability in performance becomes an impediment for clients whose services rely on consistent, responsive performance in cloud environments. The problem is exacerbated for applications that rely on cloud storage systems as performance in these systems is a ffected by disk access times, which often dominate overall request service times for these types of data services. In this thesis we introduce MicroFuge, a new distributed caching and scheduling middleware that provides performance isolation for cloud storage systems. To provide performance isolation, MicroFuge's cache eviction policy is tenant and deadline-aware, which enables the provision of isolation to tenants and ensures that data for queries with more urgent deadlines, which are most likely to be a ffected by competing requests, are less likely to be evicted than data for other queries. MicroFuge also provides simplifi ed, intelligent scheduling in addition to request admission control whose performance model of the underlying storage system will reject requests with deadlines that are unlikely to be satisfi ed. The middleware approach of MicroFuge makes it unique among other systems which provide performance isolation in cloud storage systems. Rather than providing performance isolation for some particular cloud storage system, MicroFuge can be deployed on top of any already deployed storage system without modifying it. Keeping in mind the wide spectrum of cloud storage systems available today, such an approach make MicroFuge very adoptable. In this thesis, we show that MicroFuge can provide signifi cantly better performance isolation between tenants with di fferent latency requirements than Memcached, and with admission control enabled, can ensure that more than certain percentage of requests meet their deadlines.

The project has been performed in a close collaboration with Hörsam who works in the field of hearing technology. In a first meeting with the company, the Project group was showed a few existing storage boxes for hearing aids. The company thought they were unnecessarily large with plenty of unused space and wanted a new, smarter solution to be developed. The project began with user studies in which audiologists, maintenance technicians, future users and others were interviewed. The purpose was to obtain their views on today's storage boxes and to find out how well the users maintained their hearing aids. It proved to be a large lack of knowledge regarding the management of hearing aids within the users. As a result, new ways to clean their hearing aids were found. The group decided, therefore, to include extra batteries and cleaning articles in the storage box. It would give the user a sense of security, knowing they have everything they need in one place. If earwax or moisture gets stuck in the sound channels to the hearing aid, the sound will disappear completely or partially. It is similarly, if the batteries run out. Hearing aid batteries last only about two weeks after activation and they are very small and difficult to handle for people with stiff joints. In the current situation, there are a variety of cleaning articles with different designs. Each hearing aid manufacturers have basically their own kit. Despite this, it is the same tools that are recommended by all. This is a brush, a loop, a cloth, a long needle and an air blower. In some cases the use of a rod with a magnet helps to facilitate replacement of batteries. The batteries are magnetic and therefore easily stuck on the rod, which help the user to handle the batteries. After several suggestions of solutions the result became a storage box that the group has chose to call Skötsam. It has a soft and handy shape that offers the user a good grip. Skötsam is fitted for both those who only have one hearing aid and for those who have one to each ear. In the battery compartment there is space for at least two extra batteries, depending on its size. The different cleaning articles are located in a smart and clever way, while all functions are easy to use. In a comparison with today's storage boxes Skötsam have seven new features. It has been tested by future users with successful results. Even audiologists and technicians and others who have tried Skötsam are very satisfied with the result. All the requests and demands set out during the project have been met.

Systems operating in a medical environment need to maintain high standards regarding availability and performance. Large amounts of images are stored and studied to determine what is wrong with a patient. This puts hard requirements on the storage of the images. In this thesis, ways of incorporating distributed storage into a medical system are explored. Products, inspired by the success of Google, Amazon and others, are experimented with and compared to the current storage solutions. Several “non-relational databases” (NoSQL) are investigated for storing medically relevant metadata of images, while a set of distributed file systems are considered for storing the actual images. Distributed processing of the stored data is investigated by using Hadoop MapReduce to generate a useful model of the images' metadata.

The present work reports a study of the effects of the formation of a nanostructure induced by high-energy ball milling, compositions, and various catalytic additives on the hydrogen storage properties of LiNH2-LiH and LiNH2-MgH2 systems. The mixtures are systematically investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and a Sieverts-type apparatus. The results indicate that microstructural refinement (particle and grain size) induced by ball milling affects the hydrogen storage properties of LiNH2-LiH and LiNH2-MgH2 systems. Moreover, the molar ratios of the starting constituents can also affect the dehydrogenation/hydrogenation properties. In the LiNH2-LiH system, high-energy ball milling is applied to the mixtures of LiNH2 and LiH with molar ratios of 1:1, 1:1.2 and 1:1.4 LiH. The lowest apparent activation energy is observed for the mixture of LiNH2-LiH (1:1.2) milled for 25 h. The major impediment in the LiNH2-LiH system is the hydrolysis and oxidation of LiH, which causes a fraction of LiH to be inactive in the intermediate reaction of NH3+LiH→LiNH2+H2. Therefore, the LiNH2-LiH system always releases NH3, as long as a part of LiH becomes inactive, due to hydrolysis/oxidation, and does not take part in the intermediate reaction. To prevent LiH from undergoing hydrolysis/oxidation during desorption/absorption, 5 wt. % graphite is incorporated in the (LiNH2+1.2LiH) system. The DSC curve of the mixture does not show a melting peak of retained LiNH2, indicating that graphite can prevent or at least substantially reduce the oxidation/hydrolysis of LiH. Moreover, compared to the mixture without graphite, the mixture with graphite shows more hydrogen capacity, thus this mixture desorbs ~5 wt.% H2, which is close to the theoretical capacity. This system is fully reversible in the following reaction: LiNH2+LiH→Li2NH+H2. However, the equilibrium temperature at the atmospheric pressure of hydrogen (0.1 MPa H2) is 256.8°C for (LiNH2+1.2LiH) mixture, which is too high for use in onboard applications. To overcome the thermodynamic barrier associated with the LiNH2/LiH system, LiH is substituted by MgH2; therefore, the (LiNH2+nMgH2) (n=0.55, 0.6 and 0.7) system is investigated first. These mixtures are partially converted to Mg(NH2)2 and LiH by the metathesis reaction upon ball milling. In this system, hydrogen is desorbed in a two-step reaction: [0.5xMg(NH2)2+xLiH]+[(1-x)LiNH2+(0.5-0.5x)MgH2]→0.5Li2Mg(NH)2+1.0H2 and 0.5Li2Mg(NH)2+MgH2→0.5Mg3N2+LiH+H2. Moreover, this system is fully reversible in the following reaction: Li2Mg(NH)2+2H2→ Mg(NH2)2+2LiH. Step-wise desorption tests show that the enthalpy and entropy change of the first reaction is -46.7 kJ/molH2 and 136.1 J/(molK), respectively. The equilibrium temperature at 0.1 bar H2 is 70.1°C, which indicates that this system has excellent potential for onboard applications. The lowest apparent activation energy of 71.7 kJ/mol is observed for the molar ratio of 1:0.7MgH2 milled for 25 h. This energy further decreases to 65.0 kJ/mol when 5 wt.% of n-Ni is incorporated in the system. Furthermore, the molar ratio of MgH2/LiNH2 is increased to 1.0 and 1.5 to increase the limited hydrogen storage capacity of the (LiNH2+0.7MgH2) mixture. It has been reported that the composition changes can enhance the hydrogen storage capacity by changing the dehydrogenation/hydrogenation reaction pathways. However, theoretically predicted LiMgN is not observed, even after dehydrogenation at 400°C. Instead of this phase, Li2Mg(NH)2 and Mg3N2 are obtained by dehydrogenation at low and high temperatures, respectively, regardless of the milling mode and the molar ratio of MgH2/LiNH2. The only finding is that the molar ratio of MgH2/LiNH2 can significantly affect mechano-chemical reactions during ball milling, which results in different reaction pathways of hydrogen desorption in subsequent heating processes; however, the reaction’s product is the same regardless of the milling mode, the milling duration and their composition. Therefore, the (LiNH2+0.7MgH2) mixture has the greatest potential for onboard applications among Li-Mg-N-H systems due to its high reversible capacity and good kinetic properties.

The controls of water and O2 availability, microbial activity and temperature on acid (H2SO4) production rates in commercial-scale sulphur (S0) blocks were quantified and recommendations were made for minimizing H2SO4 production in S0 blocks. Acidic drainage from the S0 blocks (pH 0.4-1.0) was attributed to mixing of fresh infiltrating water and low-pH resident water (mean pH=-2.1) with resident water comprising ~4-8% of the drainage. Although clean S0 is strongly hydrophobic, preferential water infiltration occurred rapidly through fractured S0 blocks in which the bulk hydraulic conductivity was estimated to be similar to gravel or clean sand (Ks=1x10-1 to 1x10-3 m/s). Microbial colonization of fracture faces generated localized hydrophilic conditions that helped create preferential pathways for water infiltration. Liquid water contact (compared to water vapour) was essential for S0 oxidation (i.e., H2SO4 production), therefore H2SO4 production in the S0 blocks was limited to fractures and friable S0 through which water flowed. H2SO4 production was greatest in the upper 1 m of the S0 block (70 to >97% of annual H2SO4 production) and the result of autotrophic microbial S0 oxidation.<p> S0 oxidation rates were very sensitive to temperature and increased by a factor of 4.3 for a temperature increase of 10°C (Q10). Therefore minimizing temperature (<5°C) in S0 blocks would be an effective strategy for controlling H2SO4 production. Heat released during S0 oxidation did have a measurable effect on in situ temperatures and should be considered in the design of insulated cover systems. Although autotrophic microbial activity was insensitive to O2 concentrations when they were >1 vol.%, the total mass production rate of H2SO4 is approximately proportional to the O2 concentration at the surface of the S0 block (assuming in situ O2 concentrations decrease to <1 vol. %). Therefore, cover systems that minimize the surficial O2 concentration are recommended.<p> Cover systems limiting H2O infiltration would be effective for minimizing the volume of acidic drainage, but may have no impact on H2SO4 production rates within the block. In this study, H2O infiltration through a typical soil cover (~95% efficiency) would easily satisfy the annual H2O demand for H2SO4 production (2.6 mm/m2 in the upper 1 m). Greater near-surface H2SO4 production rates may appear to make surficial biocide application an attractive option for minimizing S0-oxidizing microbial activity, however, this approach might simply drive the zone of H2SO4 production to greater depths and have no affect on the total mass production of H2SO4.