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Background Third-generation cephalosporins (3GCs) may be susceptible in vitro to Enterobacter spp. and Klebsiella aerogenes. However, treatment with mainly fourth-generation cephalosporins or carbapenems is currently recommended. Diversification of antimicrobial agents in therapy is required to avoid the selection pressure of resistant organisms by broad-spectrum antimicrobial agents. Aims This study investigated the clinical efficacy of 3GC therapy for Enterobacter spp. and Klebsiella aerogenes bacteremia in a multicenter, retrospective, observational study. Methods Patients with Enterobacter spp. or Klebsiella aerogenes detected in blood cultures and treated with a susceptible antimicrobial agent were included in the study. Propensity score matching was performed to align patient background bases, and clinical outcomes between the 3GC and non-3GC groups were compared. Treatment success was defined as having no need for treatment escalation or the addition of other antimicrobial agents, no recurrence, or no death within 30 days. Results The study included 188 cases, of which 57 and 131 were included in the 3GC and non-3GC treatment groups, respectively; 53 patients in each group were matched by propensity score matching. There were no significant differences between groups in rates of switching to a susceptible antimicrobial or adding another agent, relapse within 30 days, or death within 30 days. In the 3GC group, source control was associated with favorable clinical outcomes. Conclusions Definitive 3GC therapy for susceptible Enterobacter spp. and Klebsiella aerogenes bacteremia is as clinically effective and valuable a targeted therapy as non-3GC therapy and can be implemented under conditions in which infection source control measures are in place.

The foundation for effective dam safety assurance is an appropriate and well-designed regulatory framework that captures the legal, institutional, technical, and financial elements in the reality of a particular jurisdiction. Aging infrastructure, diminishing returns on new projects, changes in climate and weather patterns, and shifting trends of human settlement require ever-increasing attention in the effort to ensure the safety of dams and downstream communities. Establishing and maintaining a regulatory framework that is fit for purpose is, therefore, necessary for assuring the quality of dam design, construction, and operations. The framework also ensures that safety measures are reflective of the risks inherent in managing these structures and the context in which they are developed. Such frameworks need to be developed as part of a holistic strategy for water management that is integrated in basin and regional planning processes. The purpose of this Decision Support Tool is to guide countries and jurisdictions through various considerations in designing and updating their regulatory environment for dam safety assurance. This Decision Support Tool aggregates information derived from a comprehensive review and comparative analysis of regulatory frameworks in 51 countries. It presents a typology of situations that correlate with regulatory framework options along a continuum from minimum to maximum assurance of safety. It then presents hypothetical examples of how the Decision Support Tool can be used by countries and jurisdictions to assess their own situations and which regulatory options may be appropriate to consider for improving dam safety assurance.

By using small-angle neutron scattering (SANS) reinforced by scanning electron microscopy, the fine structure of catalysts for polymer electrolyte fuel cells has been investigated. The experimental data resulting from contrast variation with mixed light and heavy water (H2O/D2O) are well described by a core–shell model with fluctuations in concentration between water and Nafion. In particular, SANS obtained with the mixed water ratio 30/70, which corresponds to a matching point between mixed water and Nafion, shows a broad scattering maximum, which is attributed to a 5 nm-thick Nafion shell on the surface of the larger carbon particles. After swelling by water, the ionomer layer absorbs water at the 17 wt% level. By changing the H2O/D2O ratio, it was further confirmed that the catalyst with the ionomer exhibits water repellence, whereas the bare catalyst without the ionomer is wetted by water. Because it is very difficult to extract more information, for instance regarding the Pt–Nafion interactions, by means of small-angle scattering, reflectometry and grazing-incidence scattering experiments with neutrons should be attempted on a model catalyst prepared on a flat substrate.

An attempt has been made to combine small-angle scattering of X-rays or neutrons with scanning electron microscopy in reciprocal space, in order to establish a structural analysis method covering a wide range of sizes from micro- to macro-scales. A system with a binary contrast, in which scattering objects with a homogeneous density are dispersed in vacuum (or air), is considered. A topological surface image, detected by secondary electron emission, is converted by means of a Fourier transform into a two-dimensional scattering amplitude in reciprocal space. The method was first tested by studying a dilute system of monodisperse SiO2 particles, with respect to calibrations for brightness inversion, noise reduction and two-dimensional Fourier transform, to obtain a scattering amplitude that agrees well with the analytical amplitude for a spherical particle. Secondly, the microstructure of a carbon-supported Pt catalyst for polymer electrolyte fuel cell applications was examined with the combined method, covering length scales from 10 µm down to nanometres. After two-dimensional Fourier transformation, the secondary electron emission images with low magnification are able to overcome the limitation of the minimum wavenumber (q min) detectable by ultra-small-angle scattering.

Dam safety is central to public protection and economic security. However, the world has an aging portfolio of large dams, with growing downstream populations and rapid urbanization placing dual pressures on these important infrastructures to provide increased services and to do it more safely. To meet the challenge, countries need legal and institutional frameworks that are fit for purpose and can ensure the safety of dams. Such frameworks enable dams to provide water supplies to meet domestic and industrial demands, support power generation, improve food security, and bolster resilience to floods and droughts, helping to build safer communities. Laying the Foundations: A Global Analysis of Regulatory Frameworks for the Safety of Dams and Downstream Communities is a systematic review of dam regimes from a diverse set of 51 countries with varying economic, political, and cultural circumstances. These case studies inform a continuum of legal, institutional, technical, and financial options for sustainable dam safety assurance. The findings from the comparative analysis will inform decision makers about the merits of different options for dam safety and help them systematically develop the most effective approaches for the country context. By identifying the essential elements of good practices guided by portfolio characteristics, this tool can help identify gaps in existing legal, institutional, technical, and financial frameworks to enhance the regulatory regime for ensuring the safety of dams and downstream communities.

To elucidate a bulk membrane (Nafion®) with respect to channel connectivity or mass transfer (water or ions) through the channels, we propose to utilize time-resolved neutron reflectivity and deuterium exchange method. We performed the experiment on time-of-flight spectrometer iMATERIA at pulsed neutron spallation source J-PARC in Tokai, Japan. To exchange water (D2O or H2O) in the film during RF measurements, we specially designed a sample environment with Si substrates. A bulk film (50 μm thickness) is sandwiched by Si substrate (5 mm thickness) and Al mesh plate. The incident neutron incomes from edge of Si substrate and reflects at a front surface of bulk film. When we exchange water (D2O or H2O), water flows through Al mesh and starts to diffuse in the film. When exchanged water reaches to a front surface of the film, critical angle for total reflection (or critical wave number) changes, according to the chemical composition and therefore the averaged coherent scattering length (bav) at the front surface. Consequently, diffusion coefficient is determined from time-dependence in bav.

To observe details of three phase contact in a fuel cell catalyst layer and water distribution, we performed grazing incidence small-angle neutron scattering (GISANS) and neutron reflectivity (NR). We prepared a model catalyst on silicon(Si) substrates on which platinum(Pt) and Nafion thin layers are stacked. We employed two machines (KWS-1 and iMATERIA, respectively), which are monochromatic at FRM-II Germany and time-of-flight at J-PARC Japan. In case of Pt flat surface, which was prepared by sputtering, the influence due to humidification was observed in the vertical direction; a water layer could be confirmed between the Pt layer and the Nafion layer, increase in the thickness of the Nafion layer and increase in the water content of Nafion thin layer could be confirmed. The horizontal direction, on the other hand, water channels (microphase separation of Nafion) could not be observed in the core of thin Nafion layer. We also prepared the specimen, first Pt nano-particles are implanted in a surface of Si substrate and second Nafion thin layer covers by spin coating.

Under India’s DRIP program over 5,000 large dams are to be rehabilitated in accordance with modern dam safety standards. In order to prioritize the rehabilitation works for such a large number of dams, India’s Central Water Commission, needed a risk screening tool to allow for a portfolio risk screening. The tool was developed by simplifying sound principles of risk analysis followed by a comprehensive validation process. The application of the tool is relatively easy and the process of generating risk index for a single dam may take as little as few hours to 1-2 days, depending on the availability of data and personnel familiar with the dam making the tool ideal for helping to prioritize dam safety remedial projects for India’s dam safety program and for other large portfolio’s around the world.

Friction stir welding (FSW) has many advantages rather than fusion welding, but details of internal phenomena during its processes have not yet been clarified. In this study, a thermo-mechanically coupled process model was developed to investigate FSW phenomena inside a tool and workpiece. As a workpiece, 6061-T6 aluminum alloy was employed. The system of FSW process model includes several thermal boundaries. Among heat flows through these boundaries, heat transfers into the exterior of the system become more sensitive to tool and workpiece temperatures than heat transfers within the system. This paper especially focused on a heat transfer coefficient at a workpiece bottom, and optimized it through experiments and finite element method (FEM) analyses. The tool temperatures during FSW were measured with a special tooling system with imbedded thermocouples within a tool. As a result, an analysis model that is able to investigate details at a wide range of traverse speeds was developed for practical high speed welding. Then, the accuracy of developed FEM model was validated with them. Finally, the temperatures and stress distribution around workpiece/tool interfaces were investigated with the developed model.

The heterogeneous performance of polymer electrolyte fuel cell in space and time was discussed for operation at high current density. The cell voltage, detected by a segmented electrode, varies along a gas flow channel from upper to bottom stream and oscillates in time, which is referred as a respiration mode. At the higher current, the cell voltage at different positions started to be synchronized, as the current density increases. In order to investigate a role of water on the respiration, we employed a new method of contrast variation for small-angle neutron scattering (SANS) using deuterium (D2) gas as a fuel. By using D2, we introduce special scattering contrast in a polymer electrolyte film (Nafion®), when the film is originally swollen by H2O. After switching from H2 to D2 gas (humidified with H2O), we found that SANS intensity significantly decreases about 40% at the q-position of scattering maximum (qm) originating from the water-microdomains in the polymer electrolyte. After quantitative analyses of the scattering intensity, it was elucidated that 20 wt% of the total water is occupied by D2O as a steady state. At around the average intensity, SANS intensity oscillates with a time interval ∼100sec, which corresponds to the respiration mode found for voltage. The respiration behavior is considered as a non-linear & non-equilibrium phenomenon in an open system, where water flooding plays a role of feedback to decelerate fuel transportation and chemical reaction of water generation.

A fast-rising pulsed power generator (PPG) using a coaxial magnetic pulse compression (MPC) system has been developed. Two kinds of magnetic cores, a Co-based amorphous metal and a nanocrystalline Fe-based soft magnetic metal, have been used in the coaxial MPC system to evaluate losses of magnetic cores and leakage current of a saturable inductor. The PPG produced a pulsed-high-current of 3.7 kA with a risetime of 7 ns (20–80%) at a repetition frequency of 1000 pulses per second. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Conventional ozonizer with a high ozone output using silent or surface discharges needs a cooling system and a dielectric barrier, and therefore becomes a large machine. A compact ozonizer without the cooling system and the dielectric barrier has been developed by using a pulsed power generated discharge. The wire to plane electrodes made of metal have been used. However, the ozone output was low. Here, a compact and high repetition rate pulsed power generator is used as an electric source of a compact ozonizer. The ozone output of 6.1 g/h and the ozone yield of 86 g/kWh are achieved at 500 pulses per second, input average power of 280 W and an air flow rate of 20 L/min.

It has been reported that the direct dimethyl ether fuel cell (DDFC) that uses the Pt–Ru catalyst on the anode has a lower performance than that using the Pt catalyst on the anode at ordinary temperature and pressure. We investigated the performance of the DDFC in detail using a cell equipped with a reference electrode. The anode performance of the Pt–Ru catalyst was higher than that of the Pt catalyst at current densities lower than 100 mA/cm 2 and was affected by the steam in the low potential region. The performance of the cell was improved with the anode bubbler and increased temperature. Moreover, it has been understood that an increase in the water content does not lower the resistance of the cell, but reduces the resistance by the reaction process based on the result of the impedance measurement.

To visualize water in the catalyst of polymer electrolyte fuel cells (PEFCs), backscattered electron (BSE) imaging by means of scanning electron microscopy was employed. To confine a wet specimen of catalyst, an environmental wet cell was manufactured with a silicon nitride thin film (∼100 nm) as the beam window. By supplying humidified gas into the cell, a change in BSE brightness was detected in the catalyst attached to the silicon nitride window. As humidification proceeded, the BSE image became darker and returned brighter by switching to a dry gas. Monte Carlo simulations were performed to evaluate the energy and number of BSE obtained after passing through water with thickness d. Combining the results of the Monte Carlo simulation successfully converted the change in brightness to the change in thickness from d = 100 nm to d = 3 μm. This established method of evaluating water with a thickness resolution of the order of Δd = 100 nm can be applied to in situ observations of the catalyst in a PEFC during operation.

Fe-substituted mordenite, Al-mordenite (Al end-member) and Fe-mordenite (Fe end-member) were synthesized in the Na2O-Al2O3-Fe2O3-SiO2-H2O system under TEA (tetraethylammonium) as a template by hydrothermal method. The hydrothermal process was performed in a stainless Morey bomb at 150°C. The continuous solid solution of Fe into Al-site in mordenite was obtained for mordenites with Al-Fe molar ratio (75/25, 50/50, 25/75). The mordenite crystal with Al-end member showed a tablet-like structure with 10μm diameter and 5μm thickness. The morphology of Fe-substituted mordenite was platelet shaped with 10μm in size. Fiber-like Fe-mordenite grew up to 30μm in length and 5μm in diameter. TEA was decomposed in air atmosphere at 440-450°C for Al-mordenite, Fe-mordenite, and Fe-substituted mordenites.

It is clear that a tetragonal phase transforms to the monoclinic and rhombohedral phases in grinding of ZrO 2 doped with 3 mol% Y 2 O 3 . The grinding process also changes the roughness of the surface. Because surface roughness and structural changes in the deformed surface layer should influence the mechanical properties of ZrO 2 Y 2 O 3 , the bending strength σ b of ground specimens is presented as a function of both the volume of martensitic transformed phase and the roughness of the surface. Then, σ b is assumed to be equal to σ o (1 + ϵ m + r + γ ), where σ o is the original bending strength of the sintered material polished to a surface roughness of 0.1 μm, and ϵ m + r and γ are the degrees of influences caused by phase transformation and surface roughness. Furthermore, ϵ m + r and γ were defined respectively by the following equations of 1.71(V m −1.3) 100 and −0.55(R max 100 , where V m is the volumetric percentage (vol%) of monoclinic phase, and R max is the roughness of the abraded surface. The bending strength increased as much as 2–14% because of phase transformation and decreased as much as 2–5% because of an increase in surface roughness. The degrees of influence of ϵ m and ϵ r by both phase transformations were approximately 6 and 5.8%.

Zirconia is regarded as the structural materials of machine element which provide the distinct properties of tenacity by the martensitic transformation from a tetragonal phase to the monoclinic or rhombohedral phases under the plastic deformation and the brittle fracture. The present paper makes clear the relationships between both fracture modes and the phase transformations. In several machining processes which form the surface with both fracture modes, it is experimentally examined how the surface roughness and the phase transformation influence to the toughening of ZrO2-Y2O3. The phase transformation plays an important role in grinding and shotpeening, but the surface roughness influences much to the toughening of ZrO2-Y2O3 in oscillated wet-lapping. In grinding, a tetragonal phase equivalently transforms to the monoclinic and rhombohedral phases, but a monoclinic phase is mostly presented in oscillated wet-lapping and shotpeening. It was made clear that the plastic deformation related to the transformation of tetragonal phase to a rhombohedral phase, as well as the brittle fracture related to the transformation of tetragonal phase to a monoclinic phase.

All solid-state pulsed power generators, which are operated with long lifetime, compactness and high reliability, have been developed to be used for industrial applications, such as excimer laser, high energy density plasma (EUV sources) and pulse ozonizer. Moreover, requirements of these applications are repetitive operation and fast risetime voltage. Recently, semiconductor power device technology has improved the performance of fast high voltage switching and low switching loss. In particular, insulated gate bipolar transistor (IGBT) is highly efficient semiconductor switching device. However, the IGBT switch is still not sufficient to drive the pulse laser and the pulse ozonizer itself. In practical systems, semiconductor switches are used with the assistance of magnetic switches. We have studied and developed high repetition rate small size pulsed power generator for generation of discharge plasma. This generator consists of an IGBT switch circuit, a step-up pulse transformer and multi-stage magnetic pulse compression circuit (MPC) at the last magnetic pulse compression stage, has a coaxial configuration. This fast-rising pulsed power generator using a coaxial MPC has been developed for fast rise time output current. We use two kinds of magnetic core materials, a Co-based amorphous alloy and a nanocrystalline Fe-based soft magnetic alloy. Two kinds of magnetic cores were investigated in the coaxial MPC to evaluate loss of the magnetic cores, leakage current of saturable inductors, and circuit inductance. The pulsed power generator produced a pulsed-high-current of 3.7 kA with a rise time of 7 ns at a repetition rate of 1000 pulses per second (pps). This generator is able to generate an output voltage of about 20 kV with voltage rise time of less than 10 ns. We did the operation test and generate the streamer discharge with 1000 pps.