Competitively priced hydrogen via high-efficiency nuclear electrolysis

A fully dedicated nuclear-electrolytic hydrogen-production facility, based on advanced (1985) technology, has been synthesized and assessed at the conceptual level. The facility integrates 1) an HTGR operating a binary shaftpower-extraction cycle at 980°C (1800 F) top temperature, 2) direct d.c, electricity generation via acyclic generators, and 3) high-current density, high-pressure electrolyzers based on the solid polymer electrolyte approach. All subsystems are close-coupled and optimally interfaced. Pipeline-pressure hydrogen and coproduct oxygen are produced at 6900 kPa (1000 psi). On consistent costing bases, the advanced facility concept was found to provide hydrogen costs that were approximately half those associated with conventional, contemporary-technology nuclear electrolysis. Representative costs were $4.81/GJ ($5.07/million Btu) vs $9.36/GJ ($9.88/million Btu). The nuclear heat-to-hydrogen energy conversion efficiency for the advanced system was estimated as 43%, vs 25% for the baseline present-day approach.     

Different populations of inositol 1,4,5-trisphosphate receptors expressed in the bovine adrenal cortex

The inositol 1,4,5-trisphosphate (InsP3) receptor forms a tetrameric channel responsible for the release of Ca2+ from intracellular stores. In the present study we showed that the experimental approach used to separate bound and free ligands may discriminate between two populations of InsP3 binding sites in bovine adrenal cortex microsomes. A large population of low affinity sites and a small population of high affinity sites were detected with centrifugation and filtration approaches, respectively. Both populations were found in the supernatant and the cytoskeleton fractions of Triton X-100 solubilized microsomes. After treatment of microsomes with thimerosal, an alkylating reagent known to increase InsP3 receptor affinity, the filtration and the centrifugation approaches yielded identical results. With selective anti-InsP3 receptor antibodies, we showed that types 1, 2 and 3 InsP3 receptors are present in intact microsomes and in the cytoskeleton fraction. Binding studies on immunoprecipitated receptors revealed that anti-type 1 antibody recognizes a large population of low affinity sites whereas anti-type 2 antibody recognizes a small population of high affinity sites. Our results indicate that the three types of InsP3 receptors are expressed at different levels in the bovine adrenal cortex. The presence of different types of InsP3 receptors with different ligand binding affinities and their association with the cytoskeleton offer a convenient way for the cell to simultaneously regulate its intracellular Ca2+ concentration and reorganize the spatial distribution of its Ca2+ stores.     

Protein profiling of oral brush biopsies: S100A8 and S100A9 can differentiate between normal, premalignant, and tumor cells

In oral mucosa lesions it is frequently difficult to differentiate between precursor lesions and already manifest oral squamous cell carcinoma. Therefore, multiple scalpel biopsies are necessary to detect tumor cells already in early stages and to guarantee an accurate follow‐up. We analyzed oral brush biopsies (n = 49) of normal mucosa, inflammatory and hyperproliferative lesions, and oral squamous cell carcinoma with ProteinChip Arrays (SELDI) as a non‐invasive method to characterize putative tumor cells. Three proteins were found that differentiated between these three stages. These three proteins are able to distinguish between normal cells and tumor cells with a sensitivity of 100% and specificity of 91% and can distinguish inflammatory/hyperproliferative lesions from tumor cells with a sensitivity of up to 91% and specificity of up to 90%. Two of these proteins have been identified by immunodepletion as S100A8 and S100A9 and this identification was confirmed by immunocytochemistry. For the first time, brush biopsies have been successfully used for proteomic biomarker discovery. The identified protein markers are highly specific for the distinction of the three analyzed stages and therewith reflect the progression from normal to premalignant non‐dysplastic and finally to tumor tissue. This knowledge could be used as a first diagnostic step in the monitoring of mucosal lesions.     

Carbon nuclear magnetic resonance characterization of ethylene-propylene-1-octadecene terpolymers and comparison with ethylene-propylene-1-hexene and 1-decene terpolymers

In this paper, we report the complete ¹³C NMR characterization of a set of ethylene-propylene-1-octadecene terpolymers obtained with the metallocenic system rac-ethylene bis-indenyl zirconium dichloride, using different comonomer ratios. A detailed study of ¹³C NMR chemical shifts, triad sequence distributions, monomer average sequence lengths and reactivity ratios for these terpolymers is presented. The incorporations of 1-octadecene were superior of those obtained using 1-hexene and 1-decene in the same conditions. Catalytic activities of terpolymers of ethylene-propylene and α-olefins (α-olefins:1-hexene, 1-decene and 1-octadecene) were compared showing that they increase with the amount of propylene in the feed.     

Effect of adhesive type and composite viscosity on the dentin bond strength

Objectives: Evaluate the influence of composite resins viscosity and type of cure of the adhesive systems on the bond strength of composite resins submitted to artificial aging.

Methods: Dentin specimens (n = 240) were divided into 2 groups: Group GC: GrandioSO, and Group GF: GrandioSO Heavy Flow. These groups were subdivided into 6: FM: Futurabond M – light cured, FDCC: Futurabond Dual Cure – chemical cured, FDCL: Futurabond Dual Cure – light cured, CS3: Clearfil S3 – light cured, CDCC: Clearfil Dual Cure – chemical cured, and CDCL: Clearfil Dual Cure – light cured. Resin blocks were build up on the dentin surface. Half of samples on each group were cut to obtain resin/dentin sticks (1 × 1 mm). The other half was first submitted to thermomechanical aging. The dentin/resin sticks were submitted to microtensile bond strength test and the results were analyzed using three-way ANOVA and Tukey’s test (α = 5%).

Results: ANOVA showed significant influence for adhesive (p = 0.0000) and aging (p = 0.0001). No significant influence of the composite viscosity on bond strength was observed (ANOVA: p = 0.0861). For adhesive, the results of Tukey’s test (MPa) were CDCC: 13.44 (±5.13)a; FM: 14,01 (±2.71)a; CDCL: 14.51 (±4.98)a; FDCC: 18.66 (±7.13)b; CS3: 18.80 (±6.50)b; FDCL: 19.18 (±7.39)b. For aging: AGED: 14.99 (±6.32)a; NOT AGED: 17.87 (±5.97)b.

Conclusion: Composite resin viscosities did not influence on the bond strength. Type of cure of the adhesives had influence on the bond strength. Thermomechanical aging decreased the bond strength.     

Efficiency of optimized bifurcating tree-like and parallel microchannel networks in the cooling of electronics

A bifurcating tree-like network consists of a single inlet channel, which bifurcates over several levels to uniformly distributed microchannels that are vertically connected to a second network for fluid return. Here we introduce a one-dimensional model that considers convective heat transfer from the solid into the liquid as well as entrance and mixing effects. The performance of the bifurcating network is compared with that of a parallel microchannel cold plate branching from a single tapered manifold channel in terms of a constant volume flow rate, pressure gradient, and required pumping power. We optimized both networks independently with regard to global boundary conditions for cooling microprocessors and found a significantly superior performance for the parallel channel cooler. For a constant flow rate, the parallel channel network achieves a more than fivefold higher performance coefficient than the bifurcating tree-like network, while almost four times more heat can be removed for a constant pressure gradient across the networks.     

Pore Structure of Coffee Beans Affected by Roasting Conditions

Hot-air roasting of coffee beans not only forms color and flavor compounds but also leads to a complete alteration of the bean microstructure. The resulting pore structure controls mass transfer phenomena during roasting and storage. The principal objective of the present project was to investigate the influence of different roasting conditions on volume increase and pore-structure development. Coffee beans were roasted in 2 different, well-defined roasting processes to equal degree of roast. Volumetry, mercury porosimetry, and electron microscopy were employed to study structural product properties. The roasting conditions were found to have a major impact on microstructure. High-temperature roasted coffees had greater bean volume, pore volume and larger micropores in the cell walls as compared to low-temperature roasted beans.     

Relating texture properties and composition of bovine fat tissue

The relationship of various texture variables and fatty acid composition was studied in bovine kidney fat. Fat samples were obtained from 6 × 5 Brown Swiss bulls fed on one out of six diets containing different fats in order to achieve a high variability in depot fat composition. Melting curves, solid fat content, fatty acid composition, and three mechanical variables (cutting, extrusion, and adhesion force) were determined to characterize texture properties. Additionally, four sensory texture attributes (firmness, adhesiveness, friability, spreadability) were evaluated by manual inspection. Discriminant analyses showed that fatty acid composition as well as melting behaviour together with solid fat content are suitable to classify kidney fat according to the fat used in nutrition. Data obtained by mechanical and sensory texture measurements were less discriminative. All these texture attributes were closely correlated with each other. Extrusion force showed highest correlations with sensory attributes and therefore was considered to be most suitable to describe kidney fat characteristics beside melting behaviour and solid fat content. According to stepwise regression analyses, stearic acid, oleic acid, and fatty acids ≤ C₁₆ were important to explain the texture characteristics of the fats analyzed. Melting behaviour and solid fat content could be best described by fatty acid composition (R² = 0.73—0.94). However, in sensory and mechanical attributes, fatty acid composition on average accounted only for 54% of the variation with the closest relationship found for extrusion force (R² = 0.78).     

Effects of composite viscosity and adhesive curing mode on marginal sealing of restorations

Objectives: Evaluate the influence of composite viscosity, adhesive systems curing mode and artificial aging on marginal sealing of composite resin restorations. Methods: 240 cavities were prepared in bovine incisors. Teeth were divided in two groups: GR – GrandioSO (Voco), conventional viscosity and GF – GrandioSO Heavy Flow (Voco), low viscosity. Each group was divided into 6 subgroups: FM – Futura Bond M (Voco), FDCL and FDCC – Futura Bond DC (Voco), light and chemical cured, CS – Clearfil S³ Bond (Kuraray), CDCL and CDCC – Cleafil DC (Kuraray), light and chemical cured. Half of all specimens were subjected to mechanical (300.000) and thermal cycling (1.000). Marginal gap was measured in an optical microscope. For microleakage, specimens were stained in 50% ammoniacal silver nitrate. Results: For marginal gap mean (μm), significant differences were shown for all factors (p = 0.000). Results for resin were GR: 28.1 and GF: 40.6; for adhesive CDCC: 28.67, CDCL: 32.25, CS: 34.12, FDCL: 36.10, FM: 36.50 and FDCC: 38.46; and for artificial aging WITHOUT: 29.05 and WITH: 39.65. For microleakage mean (mm), there were also differences for all factors (p = 0.000). Results for resin were GR: 2.68 and GF: 3.46; for adhesive FM: 2.85, CDCC: 3.00, FDCL: 3.08, CDCL: 3.15, CS: 3.16 and FDCC: 3.19; and for artificial aging WITHOUT: 2.66 and WITH: 3.48. Conclusion: Composite with conventional viscosity resulted in narrower marginal gaps and less microleakage. CDCC showed less marginal gap formation. The presence of thermo-mechanical cycling increased the values of gap and microleakage.     

Biofiltration of wastewater treatment plant effluent: effective removal of pharmaceuticals and personal care products and reduction of toxicity

This study investigates biofiltration for the removal of dissolved organic carbon (DOC), pharmaceuticals and personal care products (PPCPs), and for the reduction of non-specific toxicity expressed as baseline toxicity equivalent concentration (baseline-TEQ). Two filtering media, sand and granular activated carbon, were tested. The influence of pre-ozonation and empty-bed contact time (EBCT, from 30 to 120 min) was determined. The experiments were performed at a pilot-scale with real WWTP effluent. A previous study showed that biological activity had developed on the filtering media and dissolved organic removal had reached a steady state before sampling commenced. The results show that biological activated carbon (BAC) has a good potential for the removal of DOC (35-60%), PPCPs (>90%) and baseline-TEQ (28-68%) even without pre-ozonation. On the contrary, the sand shows limited improvement of effluent quality. Varying the EBCT does not influence the performance of the BAC filters; however, dissolved oxygen concentration could be a limiting factor. The performances of the BAC filters were stable for over two years suggesting that the main mechanism of organic matter and PPCPs removal is biodegradation. It is concluded that BAC filtration without pre-ozonation could be implemented as a low cost advanced treatment option to improve WWTP effluent chemical quality.