新辊面包覆降低能耗

正纸与纸板生产属于能耗密集型产业,大部分能量用于流浆箱前的磨木、筛选等备浆工段以及烘干部的蒸发脱水。截至目前,人们研究的重点一直是如何降低这些工艺段的能耗。然而,通过强化压榨脱水,可大幅降低压榨部的传动能耗和烘干部的干燥能耗,由此而产生的成本效益也相当明显。     

Inhibitory effects of substrate and soluble end products on biohydrogen production of the alkalithermophile Caloramator celer: Kinetic,metabolic and transcription analyses

In this study the tolerance of the alkalithermophile Caloramator celer towards substrate (glucose) and soluble end product (acetate, formate and ethanol) inhibition was assessed employing nonlinear inhibition models. In addition, the effects of subinhibitory concentrations of end products on fermentative metabolism and regulation of 12 key genes involved in pyruvate catabolism were studied. Optimal growth and H₂ production were found at 50 mM of glucose and the critical substrate concentration was observed at 290–360 mM. Two inhibition models revealed that ethanol had a higher inhibitory effect on growth rate, whereas H₂ production kinetics was more sensitive towards increasing concentrations of acetate and formate. Acetate, the main soluble metabolite of the fermentation, inhibited the H₂ production by increasing the ionic strength in the medium. Subinhibitory concentrations of soluble end products induced changes in the metabolite profile of C. celer, specifically exogenous acetate (80 mM) and ethanol (40 mM) slightly increased the H₂ yield by 4 and 7%, respectively. However, despite the observed metabolic shifts, gene regulation was minimal and not always in agreement with the measured product yields. Overall, the results suggest that further optimization of the H₂ production process from C. celer should focus on methods to evolve adapted osmotolerant strains and/or remove soluble metabolites, especially acetate, from the culture.     

In vitro studies toward noninvasive glucose monitoring with optical coherence tomography

We use optical coherence tomography (OCT) to measure glucose-induced changes in Intralipid and in mouse skin samples in vitro. Mouse skin samples are cultured in a CO2 incubator before measurements are made with different amounts of added glucose concentrations. The results show that the glucose-induced changes in the OCT slope value vary between 20% and 52%/30 mM glucose in different mouse skin samples. This change is much larger than the change in 2% Intralipid (2.1%/30 mM) and in 5% Intralipid (0.86%/30 mM). Hence the results show that OCT has potential to monitor glucose-induced changes in tissues in vitro.     

Sedimentation Method in Calibrating Optical Particle Counters

The use of a horizontal elutriator in calibrating optical particle counters according to aerodynamic particle size has been studied. As elutriator a ceramic component with 4800 parallel square channels with dimensions of 0.1 × 0.1 × 15.2 cm has been used. The advantage of the present method is that the particle penetration characteristic of the elutriator can be easily changed simply by varying the flow rate. The elutriator has been used in studying the properties of an optical particle size analyzer (PMS Las-X). The relationship between the equivalent aerodynamic particle size and the corresponding particle size indicated by the analyzer has been determined by using Arizona road dust particles and dioctylphthalate particles. The practical size range of the method is D_p ≥ 0.3 μm.     

Bipolar Diffusion Charging of Soot Aggregates

Experimental measurements of bipolar diffusion charging efficiency over the range of 15–400 nm are compared for oil droplets, flame generated soot aggregates, and diesel engine exhaust particulate matter to explore possible effects of particle morphology. Charging efficiency is recorded using a tandem differential mobility analyzer (DMA) approach; the first DMA selects a monodisperse aerosol and the second compares the flux of these particles through a neutralizer versus an identical blank housing. Electrostatic precipitation of mobility selected soot particles onto TEM grids provides comparative data on changes in soot particle morphology with mobility diameter. The measurements yield soot charging efficiencies that slightly, but systematically, differ from those of equal mobility diameter oil droplets. Single positive charging of soot climbs to ～ 10% higher than oil droplets at 50 nm and then decreases to 15% lower by 400 nm as the soot develops a progressively more fractal-like structure. Negative charging exhibits the same pattern, except the variations are +15% and –10%, respectively. These trends, as well as those for double and triple charging, fall intermediate between Fuchs predictions and the model of Wen et al. (1984a) Wen, H. Y., Reischl, G. P. and Kasper, G. 1984a. Bipolar Diffusion Charging of Fibrous Aerosol Particles—I. Charging Theory. J. Aerosol Sci., 15: 89–101. [Crossref], [Web of Science ®] , [Google Scholar] for charging of fibrous particles.     

The Impact of Ethanol Fuel Blends on PM Emissions from a Light-Duty GDI Vehicle

This study explores the influence of ethanol on particulate matter (PM) emissions from gasoline direct injection (GDI) vehicles, a technology introduced to improve fuel economy and lower CO₂ emissions, but facing challenges to meet next-generation emissions standards. Because PM formation in GDI engines is sensitive to a number of operating parameters, two engine calibrations are examined to gauge the robustness of the results. As the ethanol level in gasoline increases from 0% to 20%, there is possibly a small (<20%) benefit in PM mass and particle number emissions, but this is within test variability. When the ethanol content increases to >30%, there is a statistically significant 30%–45% reduction in PM mass and number emissions observed for both engine calibrations. Particle size is unaffected by ethanol level. PM composition is primarily elemental carbon; the organic fraction increases from ～5% for E0 to 15% for E45 fuel. Engine-out hydrocarbon and NO_x emissions exhibit 10–20% decreases, consistent with oxygenated fuel additives. These results are discussed in the context of the changing commercial fuel and engine technology landscapes.

Copyright 2012 American Association for Aerosol Research     

Diplatinum(III) [Cl2(μ2-amidinate)4] compound derived from air oxidation of mononuclear cis-[Pt(NH3)2(amidine-κ)2] complex

The dinuclear platinum(III) complex [Pt₂Cl₂{μ₂-N(H)C(Et)N(H)}₄] (2) has been prepared by heating cis-[Pt(NH₃)₂{NHC(NH₂)Et}₂](Cl)₂ (cis-1) under aeration conditions in an EtOH/H₂O mixture at 70 °C for 2 d and it was characterized by elemental analyses (C, H, N), ESI⁺-MS, IR, ¹H and ¹³C NMR spectroscopies and also by X-ray diffraction. Complex 2 represents the second Pt^III dimer stabilized by the amidinate ligand ever known and it has a lantern-type structure with four amidinate ligands bridging two Pt^III centers with Pt–Pt distance of 2.4809(2) Å.     

Parallel integration of aligned carbon strings in polymer composite: Dielectrophoretic preparation,finite element simulation,and electrical characterization

We report on dielectrophoretic alignment of carbon black particles into radially arranged string‐like assemblies in oligourethane mixtures followed by photopolymerization. Using finite element modelling and optical microscopy we find significant difference in field distributions depending on the substrate beneath aligned films. On glass, the field is concentrated between the electrode tips leading to string‐like assemblies between the tips. On oxide covered silicon, the field is distributed along the electrode circumference leading to more distributed fractal assemblies. Using comprehensive dc resistance measurements and ac‐impedance spectroscopy we show that the resistance of the strings varies from 120 kΩ to 5 MΩ with a mean of 1.03 MΩ. Strings on oxide covered silicon show significantly higher resistances than the strings on glass. We also demonstrate the effect of aging and an increase in resistance through elongating aligned strings. POLYM. COMPOS., 36:1866–1874, 2015. © 2014 Society of Plastics Engineers