High-Pressure Reverse Osmosis for Industrial Water Recycling: Permeate-Sided Pressure Drop as Performance-Limiting Factor

In the chemical industry large amounts of saline wastewater occur. Its disposal into rivers is a considerable burden to the ecosystem. To strive for a circular economy and enable a viable raw material recycling, energy-efficient concentration processes are requisite. High-pressure reverse osmosis meets this criterion, but its industrial application demands suitable membrane elements that withstand the exceptional operation conditions and provide sufficient performance. Hence, new requirements regarding the design of spiral-wound elements arise. To identify those, specific performance-limiting effects need a better understanding.     

Ultrafast Atomic Diffusion Paths in Fine-Grained Nickel Obtained by Spark Plasma Sintering

Metallurgical and Materials Transactions A - Short-circuit diffusion in fine-grained Ni samples processed by Spark Plasma sintering has been investigated by the radiotracer technique. Ni grain...     

Nanocrystal-encoded fluorescent microbeads for proteomics: antibody profiling and diagnostics of autoimmune diseases

The first application of nanocrystal (NC)-encoded microbeads to clinical proteomics is demonstrated by multiplexed detection of circulating autoantibodies, markers of systemic sclerosis. Two-color complexes, consisting of NC-encoded, antigen-covered beads, anti-antigen antibody or clinical serum samples, and dye-tagged detecting antibodies, were observed using flow cytometry assays and on the surface of single beads. The results of flow cytometry assays correlated with the ELISA technique and provided clear discrimination between the sera samples of healthy donors and patients with autoimmune disease. Microbead fluorescence signals exhibited narrow distribution regardless of their surface antigen staining, without the need of any fluorescence compensation-a parameter determining the limit of sensitivity of flow cytometry assays. In single bead measurements, less than 30 dye-labeled antibodies interacting with the topoI-specific antibodies at the surface of a bead have been detected by the emission of dye excited through the FRET from NCs. In this format, the antibody-bead interaction reaction turns specifically the fluorescence signal from dye label off and on, additionally increasing autoantibody detection sensitivity.     

Characterization of high refractive index semiconductor films by surface plasmon resonance

Si-based surface plasmon resonance (SPR) in the Kretschmann-Raether geometry is considered as a platform for the optical measurement of high refractive index films. The implementation of the SPR effect becomes possible due to the relatively high index of refraction of Si compared to most materials. As examples we study the SPR responses for some important semiconductor-based films, including laser-ablated porous silicon and thin germanium films. Using SPR data, we determine the refractive indices of these films for different parameters (thickness and porosity) and ambiences. We also discuss novel SPR biosensor architectures with the use of these solid films.     

Theoretical limit of localized surface plasmon resonance sensitivity to local refractive index change and its comparison to conventional surface plasmon resonance sensor

In this paper, the theoretical sensitivity limit of the localized surface plasmon resonance (LSPR) to the surrounding dielectric environment is discussed. The presented theoretical analysis of the LSPR phenomenon is based on perturbation theory. Derived results can be further simplified assuming quasistatic limit. The developed theory shows that LSPR has a detection capability limit independent of the particle shape or arrangement. For a given structure, sensitivity is directly proportional to the resonance wavelength and depends on the fraction of the electromagnetic energy confined within the sensing volume. This fraction is always less than unity; therefore, one should not expect to find an optimized nanofeature geometry with a dramatic increase in sensitivity at a given wavelength. All theoretical results are supported by finite-difference time-domain calculations for gold nanoparticles of different geometries (rings, split rings, paired rings, and ring sandwiches). Numerical sensitivity calculations based on the shift of the extinction peak are in good agreement with values estimated by perturbation theory. Numerical analysis shows that, for thin (≤10 nm) analyte layers, sensitivity of the LSPR is comparable with a traditional surface plasmon resonance sensor and LSPR has the potential to be significantly less sensitive to temperature fluctuations.     

Toward Low-Cost,High-Energy Density,and High-Power Density Lithium-Ion Batteries

Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by ~70% from 2008 to 2015, the current battery pack cost ($268/kWh in 2015) is still >2 times what the USABC targets ($125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. This article discusses three major aspects for cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.     

Selectively Promoting or Preventing Osteoblast Growth on Titanium Functionalized with Polyelectrolyte Multilayers

Titanium plays an important role in medical applications, such as hip joint implants or fixation plates. These implants must perform differently depending on their clinical application. In particular, the osseointegrative properties required of the implant vary with clinical application. The present work is aimed at the functionalization of titanium surface using polyelectrolyte multilayers consisting of natural biopolymers and testing their cell adhesive properties with respect to the osseointegration capacity. Multilayered coatings were created from chitosan (Chi), hyaluronic acid (HA), and gelatine (Gel) through layer‐by‐layer deposition. Cell adhesion, proliferation, and viability were tested in vitro with the human osteoblast cell line CAL‐72 at timescales up to 7 d. Two multilayer coatings consisting of alternated chitosan/gelatin or chitosan/hyaluronic acid layers with the outmost layer of gelatin (Chi/Gel) or hyaluronic acid (Chi/HA), respectively, were tested. The experimental results showed that surfaces functionalized with Chi/Gel and Chi/HA multilayers demonstrated a good initial adhesion of osteoblasts. After 4 d culturing, osteoblast cells were almost completely detached from the substrates functionalized with Chi/HA multilayers. In contrast to Chi/HA, the proliferation of osteoblasts on substrates with Chi/Gel multilayer coatings was statistically significantly higher compared to the control titanium. We have shown that the growth of osteoblasts can be enhanced or completely prevented on a titanium surface functionalized with polyelectrolyte multilayers consisting of natural biopolymers, as desired. Both multilayer coatings, Chi/Gel and Chi/HA, have potential for applications in the field of titanium implants, where rapid osseointegration is essential, and/or where no ingrowth of the implant is desired, respectively.     

Structure,thermal, and mechanical properties of DDM‐hardened epoxy/benzoxazine hybrids: Effects of epoxy resin functionality and ETBN toughening

Bifunctional, trifunctional, and tetrafunctional epoxy (EP) resins were hardened with stoichiometric amount of 4,4′‐diaminodiphenyl methane in presence and absence of benzoxazine (BOX). The EP/BOX ratio of the hybrid systems was constant, viz. 50/50 wt %. For the bifunctional EP, the EP/BOX range covered the ratios 75/25 and 25/75 wt %, as well. Epoxy‐terminated liquid nitrile rubber (ETBN) was incorporated in 10 wt % in the systems with trifunctional and tetrafunctional EP, and in 10, 15, and 20 wt % in the EP/BOX with bifunctional EP to improve their toughness. Information on the structure and morphology of the hybrid systems was received from differential scanning calorimetric, dynamic‐mechanical thermal analysis, atomic force microscopic, and scanning electron microscopic studies. The flexural, fracture mechanical properties, thermal degradation, and fire resistance of the EP/BOX and EP/BOX/ETBN hybrids were determined. It was found that some homopolymerized BOX was built in the EP/BOX conetwork in form of nanoscale inclusions, whereas ETBN formed micron scaled droplets of sea‐island structure. Incorporation of BOX improved the charring and fire resistance, enhanced the flexural modulus and strength, reduced the glass transition (T_g), the fracture toughness, and energy. Additional modification with ETBN decreased the charring, fire resistance, flexural modulus and strength, as well as T_g, however, improved the fracture toughness and especially the fracture energy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

A probability model of system downtime with implications for optimal warranty design

Traditional approaches toward modeling the availability of a system often do not formally take into account uncertainty over the parameter values of the model. Such models are then frequently criticized because the observed reliability of a system does not match that predicted by the model. This paper extends a recently published segregated failures model so that, rather than providing a single figure for the availability of a system, uncertainty over model parameter values is incorporated and a predictive probability distribution is given. This predictive distribution is generated in a practical way by displaying the uncertainties and dependencies of the parameters of the model through a Bayesian network (BN). Permitting uncertainty in the reliability model then allows the user to determine whether the predicted reliability was incorrect due to inherent variability in the system under study, or due to the use of an inappropriate model. Furthermore, it is demonstrated how the predictive distribution can be used when reliability predictions are employed within a formal decision‐theoretic framework. Use of the model is illustrated with the example of a high‐availability computer system with multiple recovery procedures. An BN is produced to display the relations between parameters of the model in this case and to generate a predictive probability distribution of the system's availability. This predictive distribution is then used to make two decisions under uncertainty concerning the offered warranty policies on the system: a qualitative decision and an optimization over a continuous decision space. Copyright © 2009 John Wiley & Sons, Ltd.