Low Loss,High NA Chalcogenide Glass Fibers for Broadband Mid‐Infrared Supercontinuum Generation

High‐purity Ge–As–Se and Ge–As–S chalcogenide glasses were prepared by modified physical and chemical purification techniques. Using the purified glasses, step‐index fibers with a small core (~5.5 μm) and large numerical aperture (~1.3) were fabricated. When a 13.5‐cm‐long fiber was pumped with 320 fs pulses at a repetition rate of 10.5 MHz at 4.1 μm, supercontinuum spanning from ~1.8 to ~9.8 μm with a dynamic range of ±10 dB and an average power of ~3 mW was generated.     

Flood Hazards

The phenomenon of virtual space is fundamental to the way human beings relate perceptually, behaviorally, and existentially to their world. Virtuality is the presence of what is not literally present, and it thus enables the immanence of building to be annealed to the past and future, analogous form, and hypothetical possibility. In sum, virtuality is synonymous with “architecture” proper, as opposed to building simple. Through the use of gesture, the non-present is made present and given a secret status ruled by a non-classical or “grotesque” order. The principle of our access to the virtual is based on the act of reading, where the movement from the actual to the virtual is simultaneously a spatial and a philosophical transformation. Reading is not simply the translation of phonetic or iconographic characters into their linguistic equivalents, but a restructuring of the space of appearance. The origins and evolution of this “space of reading” are characterized by a distinctive architecture, and the architecture of inhabitable spaces is conditioned by this distinctive architecture: the architecture of reading is the means of reading architecture.     

High Brightness 2.2–12 μm Mid‐Infrared Supercontinuum Generation in a Nontoxic Chalcogenide Step‐Index Fiber

An environment friendly nonlinear chalcogenide glass fiber with a Ge‐Sb‐Se core and a Ge‐Se cladding is fabricated for bright broadband mid‐infrared (MIR) supercontinuum (SC) generation. The fabricated Ge‐Sb‐Se/Ge‐Se fiber with a core diameter of 6 μm shows zero group velocity dispersion at ~4.2 μm and ~7.3 μm. By pumping the fiber with a length of 11 cm at 4.485 μm with 330 fs pulses, we achieve a SC covering the 2.2–12 μm spectral range and with an output average power of ~17 mW. This bright broadband SC source is promising for high‐resolution MIR spectroscopy.     

Properties of phyllosilicate-based porous ceramics shaped by conventional tape casting and freeze tape casting

Silicate ceramics were shaped using tape casting (TC) and freeze tape casting (FTC) processes from three clays labeled HCR, KORS, and KCR. These clays exhibited mass content of 77% halloysite–10 Å, 29% kaolinite, and 98% kaolinite minerals, respectively. After casting the slurries, the dried tapes were sintered at 1200°C. The microstructure changes were characterized before and after sintering using scanning electron microscopy. The apparent porosity of TC samples was lower (36–47 vol.%) compared to values obtained with FTC samples (67–79 vol.%). The latter samples exhibited a highly textured porosity, with micron-sized pores aligned perpendicular to the tape surfaces. Upon sintering, the porosity of TC samples tended to decrease conversely to the case of FTC samples. Such behavior seemed related to the simultaneous effect of organic additives and ice templating. Consequently, the FTC samples showed a relatively low mechanical strength of 3–7 MPa and thermal conductivity of .14– .22 W m⁻¹ K⁻¹. After sintering, the mullite crystallization contributed to strengthen the bulk materials, helping to compensate for the detrimental effect of porosity on the stress to rupture and on thermal conductivity values.     

Determination of total dietary fibre and available carbohydrates: A rapid integrated procedure that simulates in vivo digestion

The new definition of dietary fibre introduced by Codex Alimentarius in 2008 includes resistant starch and the option to include non‐digestible oligosaccharides. Implementation of this definition required new methodology. An integrated total dietary fibre method was evaluated and accepted by AOAC International and AACC International (AOAC Methods 2009.01 and 2011.25; AACC Method 32–45.01 and 32–50.01, and recently adopted by Codex Alimentarius as a Type I Method. However, in application of the method to a diverse range of food samples and particularly food ingredients, some limitations have been identified. One of the ongoing criticisms of this method was that the time of incubation with pancreatic α‐amylase/amyloglucosidase mixture was 16 h, whereas the time for food to transit through the human small intestine was likely to be approximately 4 h. In the current work, we use an incubation time of 4 h, and have evaluated incubation conditions that yield resistant starch and dietary values in line with ileostomy results within this time frame. Problems associated with production, hydrolysis and chromatography of various oligosaccharides have been addressed resulting in a more rapid procedure that is directly applicable to all foods and food ingredients currently available.

     

In vitro incorporation of14C-acetate into lipids of hamster flank organ (Costovertebral organ) sebaceous glands and epidermis

Following in vitro incubation of flank organs from male golden Syrian hamsters with sodium [1-¹⁴C] acetate, sebaceous glands and appendage-freed epidermis were obtained by treating the flank organ tissue with calcium chloride. This method permitted the study of incorporation of carbon-14 into the lipids of these skin components. Extracted lipids were identified by thin layer chromatography and autoradiography and were quantitated by liquid scintillation counting. Mono-, di-, and triglycerides, free sterols, fatty acids, wax monoesters, and squalene were identified as products of sebaceous gland metabolism of labeled acetate. In marked contrast, little incorporation of¹⁴C into triglycerides by the epidermal preparations was noted, although the epidermal lipids showed higher relative proportions of free sterols and polar lipids (including phospholipids). Accumulation of sterol esters did not occur. In both preparations phosphatidylcholine represented the major labeled phospholipid.     

Imaging and Diffraction Study of Continuous α-Fe2O3 Films on (0001)Al2O3

Continuous α-Fe₂O₃ films grown on bulk (0001)Al₂O₂ substrates by low-pressure chemical vapor deposition have been studied by transmission electron microscopy and the observations compared to those obtained from discontinuous films at an earlier stage of the growth process. Plan-view specimens revealed significant thermal stress in the continuous films, while cross-sectional specimens showed that cracking occurs in thicker films. The free surface of the film and the film/substrate interface appeared sharp and flat, apart from growth ledges and steps. Weak-beam imaging revealed a hexagonal misfit dislocation network consisting of perfect edge dislocations. Fine structure in the selected-area diffraction patterns which corroborates these observations is also discussed. The misfit network of partial dislocations previously observed in the discontinuous films was not observed for the continuous films, indicating an effect of film thickness, growth rate, or surface preparation on the Fe₂O₃/(0001)Al₂O₃ interface structure.     

Allocation of energy inputs among the end-uses in the US petroleum and coal products industry

This paper models the allocation of energy inputs in the US petroleum and coal products industry by allocating combustible fuel and renewable energy inputs among generic end-uses, including intermediate conversions through onsite power and steam generation. This analysis, called an energy end-use model, showed that 72% of the fuel input in the US petroleum and coal products industry goes to onsite steam and power generation, whereas 28% goes directly to end-uses. Eight percent of the boiler output is used for power generation, 72% goes directly to end-uses, and 20% is waste heat. Among the end-uses, process heating is the biggest energy user with a total energy consumption of 2338 PJ, whereas machine drive is the biggest electricity consumer with a consumption of 168 PJ. This paper also provides estimates of the uncertainty of the data. The approach to create this model is applicable to all other industries for which data is available and the model is consistent with US Department of Energy data for 1998. When used in conjunction with similar models for other years, it can be used to identify the changes and trends in energy utilization even at the prime mover level of detail.     

Δ6 Desaturase mRNA Abundance in HepG2 Cells Is Suppressed by Unsaturated Fatty Acids

The effect of unsaturated fatty acids on the abundance of Δ6 desaturase (D6D) mRNA and the fatty acid composition of HepG2 cell membranes was examined. Supplementation of HepG2 cells with oleic acid (18:1n-9, OA), linoleic acid (18:2n-6, LA), α-linolenic acid (18:3n-3, ALA), arachidonic acid (20:4n-6, AA) or eicosapentaenoic acid (20:5n-3, EPA) reduced D6D mRNA abundance by 39 ± 6.6, 40 ± 2.2, 31 ± 5.2, 55 ± 4.8, and 52 ± 5.0%, respectively, compared with control cells. Despite the reduction in D6D mRNA abundance, the level of D6D conversion products (20:3n-9, EPA and AA) in OA, ALA and LA supplemented cells, respectively, was elevated above that in control cells. Our results suggest that although unsaturated fatty acids decrease the abundance of D6D mRNA by as much as 50%, the conversion of polyunsaturated fatty acids and accumulation of long chain polyunsaturated fatty acids (LCPUFA) in HepG2 cell phospholipids continues to occur.