This paper discusses a pulse electroplating method for developing tin (Sn)-decorated gas diffusion electrodes (GDEs) for the electrochemical conversion of carbon dioxide (CO2) to formate. The pulse-plated Sn electrodes achieved current densities up to 388 mA/cm2, more than two-fold greater than conventionally prepared electrodes (150 mA/cm2), both at a formate selectivity of 80%. Optical and microscopic analyses indicate improvements in deposition parameters could further enhance performance by reducing the catalyst particle size.

The International Simple Glass (ISG) is considered as reference benchmark glass and is used in the frame of an international collaboration for the study of the dissolution mechanisms of high-level vitrified nuclear waste.

In this work the forward dissolution rate of the ISG was determined in different alkaline solutions, as a simulation of the disposal conditions foreseen by the Belgian concept for geological disposal of vitrified waste. The determination of the forward dissolution rate was done by measuring the Si released from the glass in solution in tests performed at 30 °C in four different KOH solutions with pH varying from 9 to 14 and in artificial cementitious water at pH 13.5.

The forward dissolution rates determined for the ISG in high pH solutions are in good agreement with the results obtained for a lower pH range.

The rates obtained in this study, moreover, were compared with the rates measured in the same conditions for SON68 glass from a previous work. The values obtained for the two glasses are comparable in artificial cementitious water and in KOH at moderately alkaline pH. At higher pH, ISG glass shows a lower forward dissolution rate with respect to SON68 (0.20 g·m-2·d for ISG and 0.35 g·m-2 d for SON68 at pH 14).

To better understand light induced changes in polymeric coatings commonly used to protect metal artifacts, this work details the decomposition of thin (∼100nm) nitrocellulose-based lacquer films on silver, copper, and gold. Samples were exposed to various wavelengths of light including, UVA (∼340nm), UVB (312nm), and UVC (254nm), under controlled temperature and humidity. Decomposition was characterized using reflection absorption spectroscopy (RAS) and monitoring infrared absorbance bands. The loss of NO2 functional groups was observed and the decrease was fit to a simple two step autocatalytic model involving primary and secondary decomposition steps. The decomposition rate under UVC light exposure was rapid and similar for all substrates. Rate constants for the primary and secondary steps were similar in magnitude and only mildly dependent on temperature. For UVB light exposure, all reaction rates were much slower and secondary decomposition was much faster relative to the primary decomposition step. Decomposition under all conditions resulted in the formation of oxidized species with an infrared spectrum similar to that of carboxylic acids.

Arc welding processes such Gas Tungsten (GTAW), Gas Metal (GMAW) and Submerged Arc (SAW) are typically used in order to produce a weld joint in stainless steels (SS). However, welding thermal cycle generates a sensitization by formation of chromium carbides. In addition, the heat affected zone (HAZ) is also susceptible to sensitization and fracture of the weldment. Weld bead geometric parameters such depth penetration, fusion zone (FZ) width and size of HAZ are mainly determined by welding operation parameters. This research work studies the influence of welding current, welding speed and arc gap on the width and grain size in the HAZ produced by a single pass of autogenous GTAW process applied to a plate butt-welded joint of AISI 304 SS. The welded specimens were prepared for analysis by light optical (LOM) and scanning electron (SEM) microscopies to identify the interfaces between FZ-HAZ and base material as well as the grain growth in the HAZ. Adams equation for 2-D heat distribution was used to estimate theoretically the width of the HAZ. Furthermore, computational simulation which solved a convective-diffusion problem of the volumetric heat applied during the weld pool formation allowed to correlate the thermal gradient and the molten material flow of the FZ with the welding depth penetration, and width and grain size in the HAZ. The results demonstrated that the high heat input generates an important grain growth in the HAZ caused by low heat diffusion in the adjacent material to the fusion line. Welding speed was the main factor in the thermal gradient changes. Simulation results indicate that outward recirculating flow in the molten metal produced by surface tension forces is responsible for the shallow penetration of the autogenous GTAW process. Theoretical and computational estimations of the HAZ are in good agreement with the experimental results.

From the early eighth century CE Byzantine shops next to the Synagogue and Bath-Gymnasium Complex at Sardis, Turkey, were excavated from 1958 to 1969 more than 50 pounds, or about 350 panes of transparent flat glass sheets interpreted as window glass. Examination using optical microscopy showed little variation in size, shape, thickness, edge shape, tool marks, bubble and cord elongation and alignment. Microstructural and compositional variation of weathered surfaces and unweathered cross sections were studied using scanning electron microscopy with energy dispersive x-ray analysis (SEM-EDS). Differential thermal analysis (DTA) was used to determine glass transition temperature range. Three traditional window-forming methods have been described in the glass technology literature: crown, plate and cylinder. The Sardis glass is most similar to criteria expected for cylinder glass, but significant differences were documented. Consistently patterned characteristics evidence a developed technological practice. Replicative tests were conducted using various forming sequences. Wooden and ceramic two-piece molds were made to overblow one or both ends, and hot glass threads were used to thermal shock the cylinder ends and to make a vertical crack that allowed opening during a reheating and slumping operation. These reconstructed methods fit the observed microstructural and macrostructural characteristics of the glass sheets. Analysis of glass manufacturing methods in antiquity contribute to the historical knowledge of craft practices and to the interpretation of industrial debris excavated at markets and industrial workshops.

The present paper examines nanoporous material – carbon fabrics, which is used as electrodes in rechargeable energy storage capacitors (ultracapacitors). The fabrics structure, impurities composition, the influence of impurity types on ultracapacitor characteristics and the influence of thermal treatments on the impurities concentration are studied. The analysis of the ultracapacitor equivalent circuit with the studied material is made and the capacitor charge-discharge characteristics are investigated.

The performed studies resulted in determination of the investigated carbon material structure, determination of impurities composition of carbon material and change of impurities content depending on thermal treatment in vacuum. The optimum temperature range for treatment in vacuum is established. The equivalent circuit of the ultracapacitor is analyzed and its charge-discharge characteristics are investigated. The chosen equivalent circuit makes it possible to estimate the influence of pores different size on the ultracapacitor charge-discharge characteristics that is important for its application in energy storage devices.

We have produced plasma activated water (PAW) using air, O2, N2, He and Ar atmospheric pressure dielectric barrier discharge plasma irradiation to deionized water. Then, PAW was kept for 1 hour or 1 day at room temperature to reduce concentrations of short lifetime reactive oxygen species and reactive nitrogen species before supplying to plants. O2, air and N2 PAW induces growth enhancement of plants. For 1 hour PAW supply the longest seedling length after 3 days cultivation is 1.62, 1.38, 1.13, 1.12, and 1.04 times long for air, O2, He, N2, and Ar plasmas compared with the length for thecontrol, whereas for 1 day PAW supply it is 1.52, 1.28, 1.13, 1.10, and 1.08 times long for air, O2, He, N2 and Ar. Therefore, long lifetime reactive oxygen nitrogen species in PAW is effective for the growth enhancement.

For a wide range of bandgaps of solar cell materials, the potential contribution of upconversion materials was calculated and related to various configurations of the solar cell and upconversion layers. Moreover, by comparing these various strategies with the potential of a dual junction tandem cell configuration, a compelling case is made for upconverters.

At idealized 100% conversion efficiency, the upconverter with a single junction cell is more efficient than a dual junction tandem cell. It was also found that a single junction cell with an upconverter that is ‘only’ 80% efficient has a similar efficiency as an ideal dual junction cell. This result shows that upconverters are certainly a route worthwhile to pursue, especially because the single junction cells plus upconverters could have more cost reduction potential than dual junction cell configurations.

Additionally, it was investigated if an upconverter that uses two different photon energies would create a large surplus in efficiency. For a cell band gap of 1.55 eV a theoretical maximum efficiency (here defined as Voc*Isc) of 54.5% was calculated. Although there is a further increase in efficiency compared to converters with a single conversion energy, very careful bandgap tuning with a tolerance < 0.02 eV is required, which makes this system rather sensitive for material and solar spectrum fluctuations and it is suggested that a simple upconverter material is a more favorable strategy.

Off-white water pots have had sustained traditional acceptance for a long period of time in Jodhpur compared to red colored water pots imported from the neighboring Gujarat state. Both types of pots hold 20 liters of potable water. The fluorescence spectroscopy reveals dominance of silica, alumina and iron oxide in red pots from Gujarat whereas off-white pots from Rajasthan also have a slight excess of CaO and MgO. Fourier transform infrared spectroscopy reveals a firing temperature of 800 °C for off-white pots, which is comparatively less than that for red pots. A lower amount of Fe2O3 and higher MgO in off-white compared to red water pots is responsible for the color differentiation. Off-white pots show a better degree of cooling compared to red pots. Better resistance to load was observed in off-white pots compared to red pots. This study may imply influence of hidden techno-functional aspects towards sustainability of off-white pots in Jodhpur, Rajasthan.

Different aging heat treatments were performed in a Titanium alloy using as aging media metallic baths in comparison to typical furnace aging. As a first step, a Duplex Aging (DA) consisted of solubilization followed by quenching to room temperature after aging heat treatment in different metallic baths (Zn, Sn and Bi). A second procedure was Alternative Aging (AA) which consisted of solubilization and direct aging inside three different aforementioned baths. Microstructural aging variations begins at half hour until 30 h at 550°C inside metallic bath of Zn, Sn or Bi. Both kinds of aging promoted a microstructural variation and so on microhardness values. Microstructural analysis by Optical Microscopy showed a structural refinement after AA treatment. The highest hardness value of 375 HVN was achieved in Alternative Aging with Zn bath, which was found to be dependent on laminar α phase refining. Moreover, after AA treatment for 0.5, 1, 2, 3, 4, 10 and 30 h at 550°C in the metallic bath of Zn and Sn, the results indicated similar hardness values in different times, resulting in the fastest kinetic for Sn metallic bath at 2 h compared to that 4 h in Zn metallic bath. The observed increase in micro-hardness is not very attractive, it is recommended to use large aging times in order to stabilize final spacing of microstructural features in AA treatment.

Palladium germanide thin films were investigated for infrared plasmonic applications. Palladium thin films were deposited onto amorphous germanium thin films and subsequently annealed at a range of temperatures. X-ray diffraction was used to identify stoichiometry, and Scanning Electron Micrographs, along with Energy Dispersive Spectroscopy (EDS) was used to characterize composition and film quality. Resistivity was also measured for analysis. Complex permittivity spectra were measured from 0.3 to 15 µm using IR ellipsometry. From this, surface plasmon polariton (SPP) characteristics such as propagation length and mode confinement were calculated and used to determine appropriate spectral windows for plasmonic applications with respect to film characteristics. Films were evaluated for use with on-chip plasmonic components.

Ni-Zr alloy thin films were processed by DC magnetron sputtering of high purity Ni and Zr targets in ultrahigh vacuum at ambient temperature, with the substrate being subjected to either 0 V or -60 V bias. Some of the as-deposited films were annealed in vacuum at 700°C for 1 h. Surface profilometer and atomic force microscope were used to measure the film thickness and surface roughness, respectively. X-ray diffraction and cross-sectional TEM analysis have shown dispersion of nano-sized Ni3Zr dispersed in nanocrystalline Ni matrix. Nano-indentation and scratch tests conducted at 2 mN load have shown variation of hardness, Young′s modulus, scratch resistance, and coefficient of friction with substrate bias and annealing due to changes in grain size and surface roughness.

In recent years, tissue engineering has been utilized as an alternative approach to organ transplantation. Success rate of tissue regeneration influenced by the biomaterials, cell sources, growth factors and scaffold fabrication. Design and precise fabrication of scaffolds are required to support cells to expand and migrate to 3D environment. Common scaffold fabrication techniques use heat, adhesives, molds or light. In this research, “inverse-photolithography” which is a light based fabrication technique was used to generate the scaffolds. In order to control the interior architecture of the scaffold “a single vertical strut” and “a y-shape” were fabricated with the 3D printer by using the dissolvable filament. Then, the strut and the y-shape were immersed into the photo-curable solution which is poly(ethylene glycol) diacrylate (PEGDA) and photo-initiator mixture. UV light with the 365nm wavelength was placed up-side down under the solution. Photo-curable mixture was exposed to the UV light for 3 minutes to cure the entire scaffold. Solidified scaffold with the strut and y-shape inside was kept in the limonene solution. Limonene penetrated through the open ended strut and y-shape and it dissolved the 3D printed strut and y-shape away leaving the fabricated PEGDA based scaffolds. This preliminary research showcases, the 3D scaffolds with the controlled interior design, can be fabricated with the “inverse-photolithography” technique.

At the Savannah River Site (SRS) low activity salt solution is stabilized via encapsulation within a grout termed saltstone. Saltstone is emplaced into large (multi-million gallon) concrete storage facilities referred to as Saltstone Disposal Units (SDUs). Technetium-99 (99Tc) is a long-lived radionuclide contained in the low activity salt waste and subsequently incorporated into the grout waste form: it is considered a significant contributor to risk with respect to the long-term radiation exposure of the environment surrounding the SDUs. In the reducing, high pH environment within the grout, 99Tc is expected to be relatively immobile since it exists in a reduced Tc(IV) oxidation state in the form of sparingly soluble sulfides (TcSx) or hydrated oxides (TcO2.xH2O). However, in the presence of O2 (associated with the future infiltration of air or oxygenated ground waters into the saltstone monolith) it is possible for redox-sensitive Tc(IV) to transition into highly soluble (and mobile) Tc(VII) species, pertechnetate (TcO4-), which is more readily transported to the surrounding environment. Traditional approaches to quantifying the leaching behavior of 99Tc from cementitious matrices have involved partitioning experiments using size-reduced (crushed/ground) saltstone samples, and determination of the 99Tc fraction immobilized by the cementitious solids. Such experiments create artificially high solid-solution contact areas that likely result in higher 99Tc leachate concentrations than would be expected for intact, monolithic samples. In the current study a new technique, termed the Dynamic Leaching Method (DLM), is being used to investigate the 99Tc leaching behavior of monolithic saltstone samples. The data derived using this technique is intended to inform the SRS Saltstone Disposal Facility (SDF) Performance Assessment (PA) which models the long-term transport of radionuclides from the SDUs to the environment. The DLM utilizes a flexible-wall permeameter to achieve saturated leaching under an elevated hydraulic gradient in an effort to simulate the transport of groundwater through saltstone. Initial findings indicate that the 99Tc concentrations in the leachate are on the order of 1E-08 mol/L which suggests that the saltstone leaching behavior is controlled by the solubility of TcO2.xH2O compounds.

In the present study, we have attempted to produce the porous Ti–Al intermetallic based alloys by pressure-sintering of the elemental powders of Ti and Al through a combustion reaction, with a NaCl space holder to achieve the development of a highly porous structure. The powders of Ti (particle size: <45 μm) and Al (particle size: <45 μm) were mixed to various total compositions of Ti–0-40 Al (at.%), and NaCl (particle size: 300-400 μm) was mixed with the Ti/Al powder to give a highly porous structure. The mixed powder was sintered at 700 oC under a constant pressure of 30 MPa to form cylindrical specimens with a diameter of 20 mm. The soaking of the specimens in pure water allows for the removal of NaCl (with a volume fraction of 60 %) and the formation of the pores to achieve a controlled relative density of 0.4. The present process can produce porous Ti–Al alloys with various compositions. In as-sintered Ti–Al specimens, an inhomogeneous microstructure consisting of Ti particles surrounded by the a Ti–Al alloy layer (various Ti–Al intermetallic phases) was observed. The as-sintered specimens exhibited the brittle behavior under compression, which is independent of their Al content. However, in a Ti–20Al alloy heat-treated at 1300 °C, a nearly Ti3Al single-phase microstructure appeared in the porous specimen. The heat-treated porous Ti–20Al alloy shows both a high plateau-strength level of approximately 100 MPa and a high plateau-end strain over 50%, resulting in a high absorption energy. The present results demonstrate that controlling the microstructure for the formation of the Ti3Al single-phase would be an effective method to achieve high energy absorption capacity of the porous Ti–Al alloy.

The ordering of polarization field of inhomogeneous ferroelectric systems were investigated. We found that these systems exhibit rather complex polarization ordering behaviors with the coexistence of polar and toroidal ordering, and particularly, a novel and tunable polar-toroidal phase transformation under external mechanical, electrical or thermal fields. Accompanying with this polar-toroidal phase transformation, there is a large change of polarization and strain. As a result, large eletromechanical and thermomechanical performance can be achieved in these systems. The polar/toroidal phase boundaries can be regarded a new kind of morphotropic phase boundary (MPB). The polar-toroidal phase transformation in nanoscale ferroelectric systems should provide us a novel strategy to develop energy conversion nanodevices.

To benefit from the many advantages of organic semiconductors like flexibility, transparency, and small thickness, electronic devices should be entirely made from organic materials. This means, additionally to organic LEDs, organic solar cells, and organic sensors, we need organic transistors to amplify, process, and control signals and electrical power. The standard lateral organic field effect transistor (OFET) does not offer the necessary performance for many of these applications. One promising candidate for solving this problem is the vertical organic field effect transistor (VOFET). In addition to the altered structure of the electrodes, the VOFET has one additional part compared to the OFET – the source-insulator. However, the influence of the used material, the size, and geometry of this insulator on the behavior of the transistor has not yet been examined. We investigate key-parameters of the VOFET with different source insulator materials and geometries. We also present transmission electron microscopy (TEM) images of the edge area. Additionally, we investigate the charge transport in such devices using drift-diffusion simulations and the concept of a vertical organic light emitting transistor (VOLET). The VOLET is a VOFET with an embedded OLED. It allows the tracking of the local current density by measuring the light intensity distribution.

We show that the insulator material and thickness only have a small influence on the performance, while there is a strong impact by the insulator geometry – mainly the overlap of the insulator into the channel. By tuning this overlap, on/off-ratios of 9x105 without contact doping are possible.

As the global populations grow, water demand and pollution of water resources will increase. As a consequence, water borne disease outbreaks are on the rise and current disinfection methods have been shown to be ineffective in inactivating all pathogens during water treatment. Aluminum oxide nanoparticles (Al2O3 NPs) have been shown to poses antimicrobial properties. Also, Al2O3 has high thermal and chemical stability, which makes these NPs an excellent candidate for water treatment applications. Thus, the objective of this work is to assess the bactericidal properties of Al2O3 NPs synthesized using a polyol-based process in presence of polyvinylpyrrolidone (PVP). For practical applications nanoparticles must be immobilized in a medium to ensure that particles are not dispersed into the treated water. For this reason, synthesized nanoparticles were dispersed in electrospun polyacrylonitrile (PAN) membranes to also evaluate the bacterial removal capacity. X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) analysis suggests that synthesized nanoparticles are γ-Al2O3 after annealing at 800°C for 6 hours. Scanning Electron Microscopy (SEM) characterization was used to determine the morphology and size of synthesized nanoparticles. Composite electrospun membranes were also characterized by XRD, FT-IR, and SEM. The bactericide activity of the synthesized γ-Al2O3 NPs and commercially available Al2O3 particles was evaluated by the disc diffusion method against E. coli bacteria. Also, Al2O3-PAN composite electrospun membranes bacterial filtration capacity was tested. Both synthesized and industrially produced particles exhibited antibacterial activity against E. coli, but polyol-based synthesized nanoparticles demonstrated better bactericide properties. The bacterial removal capacity of PAN and PAN/Al2O3 fibers was comparable to that of paper filters.

Types of melter feed materials affect glass production rates. This study focuses on the effects of alumina sources on melting behavior of high-alumina high-level-waste melter feeds containing different alumina sources, namely, gibbsite, boehmite, and corundum. The heat flow from the glass melt to the cold cap, a floating layer of the reacting feed, is partially hindered by a foam layer at the bottom of the cold cap. Volume expansion tests and thermoanalytical methods revealed that a slow-melting feed with corundum foamed extensively, whereas a fast-melting feed with boehmite had a low reaction heat and produced less stable foam. The foam thickness, a critical factor for the rate of melting, estimated using the relationship between the heat conductivity and foam porosity was in reasonable agreement with experimental observation.

Magnetic bioseparation is an important area of biotechnology. Various techniques are used with a wide range of possible applications in bioscience research. Magnetic micro- or nanospheres can be functionalized with appropriate ligands, such as antibodies, with a high affinity to the target, like cells, bacteria or DNA/RNA. In order to realize magnets with efficient separation capabilities, it is important to have a strong force FM acting on the magnetic bodies. FM is proportional to the product of the magnetic field and the field gradient. Many permanent magnets on the market have large magnetic fields, but relatively weak field gradients. GIAMAG magnets have unique and patented designs that produce both very large magnetic fields and high field gradients, resulting in the most forceful magnetic separators available on the market.