An overview of the different inhibitors formed by pre-treatment of lignocellulosic materials and their inhibition of ethanol production in yeast and bacteria is given. Different high temperature physical pre-treatment methods are available to render the carbohydrates in lignocellulose accessible for ethanol fermentation. The resulting hydrolyzsates contain substances inhibitory to fermentation—depending on both the raw material (biomass) and the pre-treatment applied. An overview of the inhibitory effect on ethanol production by yeast and bacteria is presented. Apart from furans formed by sugar degradation, phenol monomers from lignin degradation are important co-factors in hydrolysate inhibition, and inhibitory effects of these aromatic compounds on different ethanol producing microorganisms is reviewed. The furans and phenols generally inhibited growth and ethanol production rate (QEtOH) but not the ethanol yields (YEtOH) in Saccharomyces cerevisiae. Within the same phenol functional group (aldehyde, ketone, and acid) the inhibition of volumetric ethanol productivity was found to depend on the amount of methoxyl substituents and hence hydrophobicity (log P). Many pentose-utilizing strains Escherichia coli, Pichia stipititis, and Zymomonas mobilis produce ethanol in concentrated hemicellulose liquors but detoxification by overliming is needed. Thermoanaerobacter mathranii A3M3 can grow on pentoses and produce ethanol in hydrolysate without any need for detoxification.

Inhibition of ethanol-producing yeast and bacteria by degradation products produced during pre-treatment of biomass.

Fermentation of lignocellulosic hydrolysates. I: inhibition and detoxification

Global energy consumption due to friction in passenger cars

Ethanol produced from various lignocellulosic materials such as wood, agricultural and forest residues has the potential to be a valuable substitute for, or complement to, gasoline One of the major resources in the Northern hemisphere is softwood This paper reviews the current status of the technology for ethanol production from softwood, with focus on hemicellulose and cellulose hydrolysis, which is the major problem in the overall process Other issues of importance, eg overall process configurations and process economics are also considered

A review of the production of ethanol from softwood

The recent development in the field of superhard materials with Vickers hardness of ⩾40 GPa is reviewed. Two basic approaches are outlined including the intrinsic superhard materials, such as diamond, cubic boron nitride, C3N4, carbonitrides, etc. and extrinsic, nanostructured materials for which superhardness is achieved by an appropriate design of their microstructure. The theoretically predicted high hardness of C3N4 has not been experimentally documented so far. Ceramics made of cubic boron nitride prepared at high pressure and temperature find many applications whereas thin films prepared by activated deposition from the gas phase are still in the stage of fundamental development. The greatest progress has been achieved in the field of nanostructured materials including superlattices and nanocomposites where superhardness of ⩾50 GPa was reported for several systems. More recently, nc-TiN/SiNx nanocomposites with hardness of 105 GPa were prepared, reaching the hardness of diamond. The principles of de...

https://mediatum.ub.tum.de/doc/958917/file.pdf

The search for novel, superhard materials

Design and evaluation of tribological coatings

This paper discusses the basic design and special applications of wide-area monitoring and control systems, which complement classical protection systems and Supervisory Control and Data Acquisition/Energy Management System applications. Systemwide installed phasor measurement units send their measured data to a central computer, where snapshots of the dynamic system behavior are made available online. This new quality of system information opens up a wide range of new applications to assess and actively maintain system's stability in case of voltage, angle or frequency instability, thermal overload, and oscillations. Recent developed algorithms and their design for these application areas are introduced. With practical examples, the benefits in terms of system security are shown.

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Design Aspects for Wide-Area Monitoring and Control Systems

ME-C:H coatings in motor vehicles

This paper addresses online estimation of electromechanical oscillatory modes in power systems using dynamic data such as currents, voltages and angle differences measured on-line across transmission lines. These measurements are provided by newly installed phasor measurement units (PMUs). Here, the collected data are evaluated with the main objective to detect the dominant frequency and damping of oscillations during normal operation of the power system. The goal is to give the transmission operator qualitative and quantitative information about actual oscillations in the power system as well as about related properties, such as stability margins. The approach is demonstrated on a model of a real power system. Several problems and limitations of the approach are pointed out as well.

Detection of oscillations in power systems using Kalman filtering techniques

Four different multilayered coatings TiN/CrN, TiN/MoN, TiN/NbN and TiN/TaN, were deposited on cemented carbide A hybrid PVD process consisting of ion plating (TiN) and magnetron sputtering (CrN, MoN, NbN and TaN) was used The chemical and phase composition, morphology and microstructure of the coatings were assessed using auger electron spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy, respectively In addition, all coatings were characterised with respect to their residual stress, hardness, cohesion/adhesion and abrasive wear resistance A PVD TiN coating was used as a reference throughout the investigation All coatings exhibited a cubic NaCl structure Furthermore, all multilayered coatings, except TiN/MoN, were found to have a strongly preferred (200) orientation TiN/MoN displayed a mixture consisting of (111), (200) and (220) orientations TiN displayed a (111)-preferred orientation It was found that the mechanical and tribological properties of the multilayered TiN/metal nitride coatings, in general, were superior to those of homogenous TiN The overall best performance was found for the TiN/CrN coating, whereas TiN/TaN showed the highest abrasive wear resistance

Mats Larsson

Papers

Design and evaluation of tribological coatings

Design Aspects for Wide-Area Monitoring and Control Systems

ME-C:H coatings in motor vehicles

Detection of oscillations in power systems using Kalman filtering techniques

Mechanical and tribological properties of multilayered PVD TiN/CrN, TiN/MoN, TiN/NbN and TiN/TaN coatings on cemented carbide