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Production of lactic acid from paper sludge has been performed by simultaneous saccharification and fermentation (SSF). The SSF process design was based on experimental data obtained from cellulose hydrolysis and fermentation. The SSF process was employed to avoid an excessively dense solution when the sludge content of the feed was higher than 15%; this is one of several benefits of SSF. The enzyme system used for hydrolysis of paper sludge for production of glucose was optimized. CMCase and α-glucosidase with activities of 2.5 and 10 U mL-1, respectively, were found to be optimum for hydrolyzing 5% sludge. In batch SSF 16 g L-1 lactic acid was produced from 5% paper sludge with an yield of 80%. Paper sludge which served as a feed seemed to have a buffering effect during SSF, probably because of the inorganic ash component in the sludge. The final product concentration by SSF was observed to be limited by the cellulose content of the system, which can probably be resolved by intermittent feeding of the paper sludge. SSF of paper sludge fed in batch mode, with intermittent feeding, produced lactic acid at 162 g L-1, with a yield of 74% and a productivity of 1.4 g L-1 h-1. The lactic acid production performance of the modified bioreactor improved after removal of indigestible solid materials from the upper compartment, which enabled the feed of paper sludge to be increased. A mathematical model is described which predicts glucose and subsequent lactic acid production on the basis of the rate expressions of each step of the SSF process. Saccharification kinetics were determined by experiments on enzymatic cellulose hydrolysis, by use of a Michaelis-Menten equation; growth kinetics of L. rhamnosus were determined by use of a Monod expression which incorporated lactic acid inhibition. The kinetic model is expected to predict the performance of the SSF process. For further use of the lactic acid, i.e. polylactic acid, it must be recovered and purified. Results from application of the simulated moving-bed (SMB) process for separation of lactic acid and acetic acid are given, as are several methods of lactic acid purification. [ABSTRACT FROM AUTHOR]

High contents of fillers such as kaolin or calcium carbonate limit the use of waste paper, especially in tissue paper production. In order to determine the effect of flotation reagents on the removal of fillers, adsorption, zeta potential, and particle size measurement,s as well as flotation experiments using model dispersions of calcium carbonate, kaolin, and cellulose fibers were carried out. The adsorption of the cationic polymer starts at low initial concentrations on the negatively charged filler surfaces and cellulose fibers. However, due to the steeper slope of the adsorption isotherm on the fillers, the polymer is preferentially adsorbed on the fillers. Furthermore, the adsorption of the polymer causes an increase in the particle size of the fillers. Anionic surfactants are generally better suited for waste paper systems containing calcium carbonate than for those with kaolin. This is due to the fact that the adsorption onto calcium carbonate occurs at lower concentrations than that onto kaolin. Calcium ions dissolved in the pulp improve the adsorption of anionic surfactant onto kaolin and are necessary for a sufficiently high recovery of the fillers. [ABSTRACT FROM AUTHOR]

Biotechnology for Solving Slime Problems in the Pulp and Paper Industry includes the following topics: biofilms, glycocalyx; microbial extracellular polysaccharides; organisms within the slime; slime control, biocides, cleaning; surface-active agents in slime control, synthetic surfactants, biosurfactants, alternative biocide-free growth control methods, enzymatic slime deposit control, bacteriophages, introduction of competing micro-organisms; biological equilibrium; and biodispersants. [ABSTRACT FROM AUTHOR]

Pitch problems in pulp mills are often caused by the resinous materials (pitch) in wood which comprise approximately 2-8% of total composition depending upon the species and time of year. Traditional methods to control pitch problems include natural seasoning of wood before pulping and/or adsorption and dispersion of the pitch particles with chemicals in the pulping and papermaking processes, accomplished by adding fine talc, dispersants and other kinds of chemicals. Within the last five years, two new and different methods of combatting pitch, both of which are biotechnological in basis, have been developed independently and are now used industrially. Hata and colleagues of Nippon Paper Industries developed a pitch control method using the enzyme lipase, which catalyzes the hydrolysis of triglycerides. Farrell and colleagues of Sandoz Chemicals Biotech (now known as Clariant) developed a method of pitch control and biocontrol using a fungus developed in the laboratory from the same type of organisms which cause natural aging, the Ascomycetes. This fungus is non-colored and prevents the staining and decrease of brightness normally associated with aged wood. [ABSTRACT FROM AUTHOR]

The regularities of adsorption of lignosulphonates from water solutions onto cellulose, kaolin, TiO2 and CaCO3 was studied and the high values of the non-electrical portion of free energy of adsorption were shown, which provide effective adsorption of polymer on the surfaces charged similarly with lignosulphonates. Modification of lignosulphonates with siliconorganic oligomers increased significantly their affinity to cellulose and kaolin due to changing hydrophobicity and introducing of new active centers in the lignosulphonates macromolecules. Comparative study of compatibility of lignosulphonates and modified lignosulphonates with polyacrylamide was carried out. Keywords: lignosulphonates; adsorption; cellulose; kaolin; modification; siliconorganic oligomers; compatibility with polyacrylamide [ABSTRACT FROM AUTHOR]

Despite the most notorious medical disaster caused by thalidomide in medical history, huge numbers of papers have been published about this drug since its formulation in 1956. While most of the early studies specifically concerned teratogenicity, recently there has been a resurgence of interest in thalidomide because of its potential for treating a number of otherwise intractable diseases, such as leprosy, human immunodeficiency virus replication in acquired immune deficiency syndrome, and cancer. Although the pharmacological aspects of the drug have been frequently reviewed, reviews focusing on thalidomide synthesis are rare. Here, the synthesis of thalidomide is reviewed in chronological order from the first report. We first aim to give an overview of the most conventional aspects of thalidomide. Subsequently, we will focus on the synthesis of racemic thalidomide, which is now commercially available. Finally, we will describe the asymmetric synthesis of thalidomide. To our knowledge, all the papers and patents concerning thalidomide synthesis have been introduced. Because of the number of papers and patents, we will not mention the preparation of thalidomide derivatives. [ABSTRACT FROM AUTHOR]

The chlor-alkali industry is one of the largest electrochemical operations in the world, the main products being chlorine and sodium hydroxide generated simultaneously by the electrolysis of sodium chloride solutions. The chlor-alkali industry serves the commodity chemical business, chlorine and sodium hydroxide (also called caustic soda) being indispensable intermediates in the chemical industry [1-10]. [ABSTRACT FROM AUTHOR]

Due to its relative simplicity, Finite Difference (FD) analysis was historically the first numerical technique for boundary value problems in mathematical physics. The excellent review paper by V. Thomée [Tho01] traces the origin of FD to a 1928 paper by R. Courant, K. Friedrichs and H. Lewy, and to a 1930 paper by S. Gerschgorin. However, the Finite Element Method (FEM) that emerged in the 1960s proved to be substantially more powerful and flexible than FD. The modern techniques of hp-adaption, parallel multilevel preconditioning, domain decomposition have made FEM ever more powerful (Chapter 3). Nevertheless, FD remains a very valuable tool, especially for problems with relatively simple geometry. [ABSTRACT FROM AUTHOR]

Carbon dioxide is a potential carbon resource abundant on earth. It is also a green house gas with a rapidly increasing atmospheric concentration during the last two centuries. Chemical fixation of CO2 is an attractive technique for utilization of carbon resources, as well as for the reduction of the atmospheric concentration of CO2. Nevertheless, CO2 is the stablest among carbon based substances under the environmental conditions. It has not been incorporated as a major industrial material. Carbon dioxide can be electrochemically reduced to useful products under mild conditions. However, the energy conversion efficiency, defined as the ratio of the free energy of the products obtained in electrochemical CO2 reduction and that consumed in the reduction, would be roughly 30 to 40%. Such a low efficiency may discourage practical application of CO2 reduction in the very near future. However, the significance of the CO2 reduc- tion will be reevaluated in various aspects of science in future, since many interesting facts in basic electrochemistry have been revealed by recent studies. At the moment, electrochemical reduction of CO2 is an interesting as well as an important topic in chemistry. Fundamental studies of the electrochemical reduction of CO2 started as early as the 19th century, and have been further promoted by many workers in recent years. Numerous reports have been published in the last two decades. At the same time, confusions and contradictions are found in this field. This article attempts to provide a review of CO2 reduction at metal electrodes. Several review papers have already appeared, which contain the history and classical works of CO2 reduction. Thus this paper will not repeat the historical aspects of CO2 reduction. This chapter will review recent progress, putting emphasis on basic problems and particularly on electrocatalytic aspects. [ABSTRACT FROM AUTHOR]

Different dehydration techniques are widely used to stabilize fruits. Numerous papers about dehydration methods such as air drying (AD) or osmotic dehydration (OD) are being published around the world. Vacuum impregnation (VI) pre-treatment may be used as a tool both to improve mass transfer and to develop engineered products (Fito et al., 2001). In this paper, a solid food is considered as a monophasic and homogenous system, and product humidity is considered as the main variable related to quality characteristics of the final product being correlated with process conditions (mainly air temperature and velocity). Nowadays, consumers are much more demanding, calling for products with good texture, color and nutritional value. Quality is becoming a more complex concept that affects the functionality of the product (Fito and Chiralt, 2003). In this situation, foods have to be defined by considering some of the structural, sensorial, physical-chemical and nutritive aspects. The changes in every considered characteristic, along with drying processes, need to be taken into account, and mechanistic correlations among these characteristics and process variables must be established (Torreggiani and Bertolo, 2001). A new methodology that allows us to consider structural, physical- chemical and nutritive aspects when defining a fruit, while also analyzing phase transitions, structural changes and transport phenomena in a systematic way (SAFES) (Fito et al., 2006) has been applied to dehydration of apple by combined methods. [ABSTRACT FROM AUTHOR]

Environmentally assisted cracks in line-pipe steels are initiated either as a result of stresses in combination with environmental effects, as in stress corrosion cracking (SCC), or as a result of trapped hydrogen in the steel, as in hydrogen-induced cracking (HIC). To understand better the mechanism of the crack initiation process, key metallurgical and environmental elements that can affect the cracking phenomena were investigated and are reviewed in this paper. The complexity of both cracking phenomena results from the dependence of SCC and HIC on multiple metallurgical, mechanical, and environmental parameters that may all influence both crack initiation and propagation; e.g., composition, microstructure, and nonmetallic inclusions in the steel, applied stress, water chemistry in the field, and ionic concentrations in the groundwater near the pipe surface to name a few for SCC. In addition, for HIC phenomena, one can add the concentration of hydrogen sulfide (H2S) in the fluids transported in the pipe as well as concentration of CO2, pH, etc. In this paper, cracking of linepipe steels is analyzed critically, with particular attention to the crack initiation process. The paper is divided into two parts: The first part covers SCC and the second covers HIC. [ABSTRACT FROM AUTHOR]

This paper exposes some ideas how blind people can get better access to the structure of chemical formulas. The first chapters outline the problems of blind people, who work in chemical areas. A further part of this paper discusses the state of the art in access to chemistry. Starting form this level of information ideas on a new approach will be shown how a blind user can navigate through chemical formulas. [ABSTRACT FROM AUTHOR]

The natural world is filled with rough surfaces. Roughness is, however, a relative term. One may describe a sheet of paper as being smooth to the touch, whereas on an atomic scale one would observe deep valleys and tall mountains in the landscape. Of particular scientific interest in the past few decades have been surfaces that exhibit this rough behavior on a nanometer scale, often referred to as thin film surfaces. Numerous studies have been carried out investigating processes to create thin films, characterize them, and test their physical properties [187]. The physics behind the growth and structure of these surfaces has been shown to be very interesting and challenging due to the complexities of the growth processes and surface structures [8, 40, 104, 112]. Specifically, surface and interface roughness controls many important physical and chemical properties of films. For example, the electrical conductivity of thin metal films depends very much on surface and interface roughness [135], and the reliability of a Si MOSFET (metal-oxide-semiconductor fieldeffect transistor)channel depends on the roughness of the gate oxide—silicon interface [82]. Also, interface roughness has a profound effect on the magnetic hysteresis of a magnetic film [115], and controls optical losses in optical waveguides [130]. Rough surfaces can increase the effective area for advanced charge storage devices [19], as well as promote capillary forces through wicking in modern heat pipe design [51]. These properties of thin films are exploited in a number of applications, including semiconductor devices [153], solar cells [127 ], and thin-film transistor (TFT) displays [73]. [ABSTRACT FROM AUTHOR]

The direct use of terahertz (THz) spectral features in screening for explosives, drugs, and other contraband is limited since adjacent materials may obscure the signature of a suspect material. This paper describes a system that overcomes this problem by combining tomographic imaging with THz spectroscopy. This paper identifies a set of 30-GHz-wide windows in the atmospheric water vapour absorption up to 3 THz: data collected in these bands permit the reconstruction of an object with 1-cm resolution. Images of the distribution of innocuous and suspect material within the object are generated by an algorithm providing an optimised filter. The spectral characteristics of any region within the object may also be examined. Practical issues associated with implementing this system are discussed. [ABSTRACT FROM AUTHOR]

The main components of a proton exchange membrane (PEM) fuel cell are the gas diffusion layer, membrane and catalyst. Gas diffusion layers (GDLs) are commercially available in various forms such as carbon paper or woven carbon fabrics. These are placed on either side of the membrane in a fuel cell. A GDL should allow the flow of reactant gases H2, air/oxygen and product gases to pass through it. The water formed in a cell should not choke the pores of this paper or fabric and so they are pre-coated with polytetrafluoroethylene (PTFE), which changes the GDL material from hydrophilic to hydrophobic. PTFE is also commonly called Teflon. The platinum catalysts for both the anode and cathode side can be coated on the surface of a GDL. The hydrogen or oxygen reacts in three phases: interface-gas phase (hydrogen or oxygen), liquid phase (water) and solid phase (catalyst). The carbon paper or fabric serves as a structural support for the electrocatalyst layer as well as current collector. Some of the GDLs available on the market are not coated with PTFE and are thinner in size. In such cases, the user has to coat the GDL with PTFE. [ABSTRACT FROM AUTHOR]

As illustrated throughout this book, surface plasmons (SPs) are well known for their capabilities of concentrating light in subwavelength volumes and also for guiding light along the surface of a metal. But this does not exhaust the phenomena related to SPs. Even the scientific community working on this subject was greatly surprised in 1998 by the suggestion that SPs could enhance the transmission of light through subwavelength holes. That seminal paper reported that, when subwavelength holes are disposed on a metallic film forming a two-dimensional (2D) array, the transmission of light through this structure is greatly enhanced at some particular wavelengths. [ABSTRACT FROM AUTHOR]

The study of the photochemistry and photophysics of octahedral and pseudo-octahedral Cr(III) complexes has a rich history. An initial discussion is devoted to a general appraisal of the state of these two subjects up to December 1998, after providing a framework of state energy levels and radiative and non-radiative relaxation processes relevant to Cr(III) systems. The remaining sections cover some of the more active areas in the Cr(III) field, such as ultrafast dynamics, photosubstitution, thermally activated excited state relaxation, energy transfer, and photoactivated redox processes (both intermolecular and intramolecular). Each of these sections begins with an overview of the subject area, and then one or more representative papers from the recent literature are selected for more detailed discussion. [ABSTRACT FROM AUTHOR]

This work presents a review of studies on the process economics of ethanol production from lignocellulosic materials published since 1996. Our objective was to identify the most costly process steps and the impact of various parameters on the final production cost, e.g. plant capacity, raw material cost, and overall product yield, as well as process configuration. The variation in estimated ethanol production cost is considerable, ranging from about 0.13 to 0.81 US$ per liter ethanol. This can be explained to a large extent by actual process differences and variations in the assumptions underlying the techno-economic evaluations. The most important parameters for the economic outcome are the feedstock cost, which varied between 30 and 90 US$ per metric ton in the papers studied, and the plant capacity, which influences the capital cost. To reduce the ethanol production cost it is necessary to reach high ethanol yields, as well as a high ethanol concentration during fermentation, to be able to decrease the energy required for distillation and other downstream process steps. Improved pretreatment methods, enhanced enzymatic hydrolysis with cheaper and more effective enzymes, as well as improved fermentation systems present major research challenges if we are to make lignocellulose-based ethanol production competitive with sugar- and starch-based ethanol. Process integration, either internally or externally with other types of plants, e.g. heat and power plants, also offers a way of reducing the final ethanol production cost. [ABSTRACT FROM AUTHOR]

Biofuels for use in the transportation sector have been produced on a significant scale since the 1970s, using a variety of technologies. The biofuels widely available today are predominantly sugar- and starch-based bioethanol, and oilseed- and waste oil-based biodiesel, although new technologies under development may allow the use of lignocellulosic feedstocks. Measures to promote the use of biofuels include renewable fuel mandates, tax incentives, and direct funding for capital projects or fleet upgrades. This paper provides a review of the policies behind the successful establishment of the biofuel industry in countries around the world. The impact of direct funding programs and excise tax exemptions are examined using the United States as a case study. It is found that the success of five major bioethanol producing states (Illinois, Iowa, Nebraska, South Dakota, and Minnesota) is closely related to the presence of funding designed to support the industry in its start-up phase, while tax exemptions on bioethanol use do not influence the development of production capacity. The study concludes that successful policy interventions can take many forms, but that success is equally dependent upon external factors, which include biomass availability, an active industry, and competitive energy prices. [ABSTRACT FROM AUTHOR]

Phenothiazine derivatives as well as flavonoids belong to heterocyclic compounds that exert numerous effects on biological systems. The structure of these compounds enables their specific interactions with different membrane proteins and also nonspecific interactions with the lipid phase of membranes. In the present review we focus on the influence of phenothiazines and flavonoids on lipid bilayers and other model systems, and on two groups of membrane proteins: transporters involved in the phenomenon of multidrug resistance and ion channels. Most of the compounds described in this paper interact with membranes and affect different properties of lipid bilayers. Modification of membrane properties should contribute to mechanisms underlying certain types of biological activity of the discussed molecules. Structural features essential for the modulatory effects exerted by phenothiazines and flavonoids on multidrug transporters are presented. Also various types of response of voltage-gated and chemically activated ion channels to the presence of heterocyclic compounds are reviewed. [ABSTRACT FROM AUTHOR]

Petroleum asphaltenes are extremely complex and are difficult to characterize. Asphaltenes are a solubility class, defined as that portion of the oil (or organic material) that is soluble in toluene and insoluble in normal heptane. (Sometimes, other alkane solvents are used to define this solubility class, the most common other solvent being, normal pentane.) Asphaltenes present numerous problems during production, transportation, and processing of crude oils because they are on the higher polarity and molecular weight end of the crude oil compositional spectrum. As a result, this solubility class has been widely studied. There are over a thousand papers on various aspects of asphaltenes, including their chemistry, molecular weight, solubility, phase behavior, reactivity, etc.1-4 [ABSTRACT FROM AUTHOR]

We discuss examples and methods for using NMR diffusion measurements to obtain information about molecular sizes, their distributions, and dynamics. Scaling relationships between chain lengths and diffusion constants are derived and tested on diffusion measurements of many samples, including crude oils that are high in saturates. The diffusion constants of asphaltenes are also measured as a function of asphaltene concentration, indicating the formation of asphaltene aggregates at a concentration of approximately 0.2 g/L, and the sizes of the individual asphaltene molecules and aggregates are obtained. The examples and methods discussed in this paper can become the basis for in situ characterization of crude oils. [ABSTRACT FROM AUTHOR]

In this paper, the discovery and synthesis of the explosive 1,1-diamino-2,2-dinitroethene (FOX-7) are described, together with an account of its structural, spectroscopic, and explosive properties. The chemical reactivity of FOX-7 towards nucleophilic substitution (transamination), electrophilic substitution, and acid-base properties is explored, as is its thermal behavior (phase transformations and thermal decomposition). The molecular structure and physical properties of FOX-7 are compared with those of its three isomers (as yet unsynthesized), as derived by theoretical calculations. Finally, the physical properties of FOX-7 are compared to those of various energetic molecules that are structurally related to FOX-7. [ABSTRACT FROM AUTHOR]

Seven cellulase preparations from Penicillium and Trichoderma spp. were evaluated for their ability to hydrolyze the cellulose fraction of hardwoods (yellow poplar and red maple) pretreated by organosolv extraction, as well as model cellulosic substrates such as filter paper. There was no significant correlation among hydrolytic performance on pretreated hardwood, based on glucose release, and filter paper activity. However, performance on pretreated hardwood showed significant correlations to the levels of endogenous β-glucosidase and xylanase activities in the cellulase preparation. Accordingly, differences in performance were reduced or eliminated following supplementation with a crude β-glucosidase preparation containing both activities. These results complement a previous investigation using softwoods pretreated by either organosolv extraction or steam explosion. Cellulase preparations that performed best on hardwood also showed superior performance on the softwood substrates. [ABSTRACT FROM AUTHOR]

This paper presents the hypothesis that algal remains were precursors of the fullerenes in the hard carbonaceous rock Shungite (Russia), in carbonaceous matter from the hard rocks of the Black Member of the Onaping Formation at Sudbury (Canada), and in solid, hard bitumens from Mitov (Czech Republic). The paper argues further that PAHs from the biogenic matter were transformed, perhaps by cyclomerization followed by zip-up, during the geologic metamorphic stages experienced by these rocks. [ABSTRACT FROM AUTHOR]

The first report on the discovery of neptunium was in 1940 by McMillan and Abelson (1940), although McMillan did the preliminary work in 1939 and published his findings (McMillan, 1939). He did not claim that a new element had been discovered until confirmatory measurements had been undertaken in the following year. The production of neptunium was accomplished by placing a layer of uranium trioxide on paper with several aluminum or paper foils and then exposing this to neutrons from a cyclotron. Examination of the uranium paper sample containing the non-recoiling fraction displayed that two new radioactive components had been created. One component displayed a 23 min half-life, later identified as U-239, while the second exhibited a 2.3 day half-life. Both components decayed via β particle emission. Preliminary chemical analysis was performed to determine the behavior of the 2.3 day component and resulted in the contradictory assignment of this component as that exhibiting an atomic number of 93, but not being transuranic in nature (Segrè, 1939). Segrè noted in his paper that his conclusions were contradictory. However, the following quotation is from his paper, "The necessary conclusion seems to be that the 23 minute uranium decays into a very long-lived 93 and that transuranic elements have not yet been observed." The primary stumbling block to the proper assignment of the material as transuranic in nature was the lack of observation of any alpha decay activity that would emanate from the daughter product of the beta decay of this new material with an atomic number 93. It was this work by (1939) that led McMillan and Abelson to revisit the chemical analysis and determine its properties in greater depth. [ABSTRACT FROM AUTHOR]

Ultrasound is an imaging tool with a broad range of applications such as medical diagnostics, underwater exploration and nondestructive evaluation of materials. As early as the first half of the 19th century, sound waves had been used for underwater navigation and ranging. However, the history of modern acoustics began with the establishment of the theory of sound by Lord Rayleigh, and the discovery of piezoelectric effect by the Curie brothers, both in the late 1800s. Acoustical devices have been used for practical underwater imaging applications since World War I. Use of ultrasound in medicine started in the 1930s, and initially was confined to therapy, particularly in tissue heating. The first use of ultrasound as a medical diagnostic tool was for transmission imaging of brain tumors in the early 1940s. In the following years, sonic energy reflection from within soft tissue histological elements was reported, pioneering pulse-echo ultrasound imaging. Linear transducer arrays with electronic scanning started replacing fixed-focus mechanical sector scanners in the 1970s, providing greatly improved resolution and faster image formation. The details of the history of ultrasound imaging and transducer technologies can be found in several books [1, 2] and papers [3]-[6]. [ABSTRACT FROM AUTHOR]

At present, many areas of industry have strong tendencies towards miniaturization of products. Mechanical components of these products as a rule are manufactured using conventional large-scale equipment or micromechanical equipment based on microelectronic technology (MEMS). The first method has some drawbacks because conventional largescale equipment consumes much energy, space and material. The second method seems to be more advanced but has some limitations, for example, two-dimensional (2D) or 2.5-dimensional shapes of components and materials compatible with silicon technology. Here we consider an alternative technology of micromechanical device production. This technology is based on micromachine tools (MMT) and microassembly devices, which can be produced as sequential generations of microequipment. The first generation can be produced by conventional large-scale equipment. The machine tools of this generation can have overall sizes of 100-200 mm. Using microequipment of this generation, second generation microequipment having smaller overall sizes can be produced. This process can be repeated to produce generations of micromachine tools having overall sizes of some millimeters. In this work we analyze the problems of microequipment miniaturization and give some results of first generation microequipment prototyping. Amicromachining center having an overall size of 130 × 160 × 85mm3 was produced and characterized. This center has allowed us to manufacture micromechanical details having sizes from 50 µm to 5 mm. These details have complex three-dimensional shapes (for example, screw, gear, graduated shaft, conic details, etc.), and are made from different materials, such as brass, steel, different plastics etc. Earlier in a Japanese project micromachine tools and micromanipulators were created with expensive elements of precision technology. The high cost of such microequipment slows down its promotion to the market. We propose another method of micromachine tool and micromanipulator creation. We do not use the expensive elements. To obtain the necessary precision we utilize the natural advantages of equipment of small size. The error analysis of the microequipment made in this work shows that the miniaturization of the microequipment automatically leads to decreasing of the errors of the micromachine tools. Examples of the developed microequipment prototypes are given. We have started to investigate and to make prototypes of the assembly microdevices controlled by a computer vision system. In this paper we also describe an example of the applications (microfilters) for the proposed technology. [ABSTRACT FROM AUTHOR]

During the last half of the 19th century, chlorine, used almost exclusively in the textile and paper industry, was made [1] by reacting manganese dioxide with hydrochloric acid 1$$ MnO_2 + 4HCl\xrightarrow{{100 - 110^\circ C}}MnCl_2 + Cl_2 + 2H_2 O $$ [ABSTRACT FROM AUTHOR]

Fullerenes, in particular C60, can form covalent intermolecular bonds (“polymerize”) when treated at high temperature under high pressure. This contribution briefly reviews some recent advances in this field. Short overviews are given of the pressure-temperature phase diagrams of pristine C60 and C70 and of their physical properties under high pressure. The paper has its main emphasis on the structures and properties of the one- and two-dimensional (chains and planes) polymeric phases of C60 created in the range 1–9 GPa (10–90 kbar) and up to 1100 K. Their structures, as obtained from studies on polymerized single crystals, the treatment conditions used to obtain well-defined structures, and some selected physical properties, including the surprising discovery of ferromagnetism, are discussed. The paper presents the results of both ex situ and in situ structural studies. Three-dimensional polymers, and the possibility to create well-defined three-dimensional structures by high-pressure treatment of low-dimensional polymers, are also discussed. Finally, a short section devoted to higher fullerenes discusses the polymeric forms of C70, including the ordered zigzag chain phase recently created under hydrostatic pressure conditions. [ABSTRACT FROM AUTHOR]

Besides superconductivity, high-Tc materials show a number of unconventional phases. In one of these phases doped holes tend to organize themselves in quasi-one-dimensional structures, so-called "stripes". In this paper we analyze some aspects of his phenomenon and its relation with superconductivity. In the first part, we show the important role of the long-range part of the Coulomb interaction, showing that the latter can favor Cooper-pair tunneling between stripes, thus enhancing superconducting correlations. In the second part of the paper, we analyze some features of recent angle-resolved photoemission experiments for LaSrCuO and LaNdSrCuO materials, and show how these can be understood in the light of the stripe picture, supporting the existence of (possibly) dynamic stripes in LaSrCuO. In addition, the analysis allows to distinguish between different stripes geometries and to determine their doping dependence. [ABSTRACT FROM AUTHOR]

Latent fingerprints on paper and other porous surfaces can be developed using chemical methods so that they become visible to the naked eye and available as forensic evidence (1,2). Ninhydrin is the most commonly used reagent for developing fingerprints as it reacts with amino acids present in ecrine sweat to give the strong purple color familiar when it is used as a stain for protein. Another compound used is 1,8-diazafluorene-9-one (DFO), which gives fingerprints that fluoresce, and is claimed to be more sensitive. Paper evidence, such as checks and banknotes, are treated by immersing the paper in a tray of a solution of the reagents and allowing to dry. The solution can also be brushed onto cardboard or wallpaper. The latent fingerprints are then developed by heating the paper in a specially adapted oven at 80°C and 65% relative humidity. DFO-treated surfaces, however, are treated at 100°C with no added humidity (3). [ABSTRACT FROM AUTHOR]

Fluidized bed adsorption has been introduced as an integrative technology combining clarification, concentration, and initial purification in a single step. In the paper presented here, the use of fluidized adsorbents in the primary recovery of proteins starting from unclarified broths is reviewed. First the principle of fluidizing adsorbent, particles is discussed, subsequently possible experimental procedures for whole broth adsorption are demonstrated. The system parameters governing the performance of the sorption process in a fluidized bed are discussed in the second part of the paper and considerations on how operating parameters and process design influence the limiting steps are provided. Finally, examples for the successful operation of whole broth adsorption, employing fluidized adsorbents are shown and conditions are defined under which this technology may be an alternative to traditional protein purification methods. [ABSTRACT FROM AUTHOR]

This paper is a survey on methods which have been developed and applied in the field of dynamical modelling, analysis, monitoring and control design of bioprocesses over the past fifteen years. A key feature of the paper is to show how to incorporate the well-known knowledge about the dynamics of biochemical processes (basically, the reaction network and the material balances) in monitoring and control algorithms. These are moreover capable of dealing with the process uncertainty (in particular on the reaction kinetics) by introducing, for instance in the control algorithms, an adaptation scheme. [ABSTRACT FROM AUTHOR]

This paper is an attempt to demonstrate the close interrelationship between the scientific and business aspects of biotechnology and natural flavours, and especially how the market pull and technical push dynamics can be effectively integrated. After all, it is consumers' insistent demand for ‘natural flavours' and other food ingredients, and also for environmentally friendly products and "green" processes in general, that has greatly stimulated the application of enzymes and microorganisms as catalysts for flavour production. However, this is a highly fragmented and segmented industry; with very many and quite different companies involved, and a very wide range of flavour-conferring molecules, all of which can be permutated or combined creatively so as to meet the requirements of particular product requirements. Hence there are very many diverse and important factors at work which I hope to illustrate in this paper. These include manufacturing, regulatory, patenting, product labelling, raw materials supply and quality, applications and formulation factors that help make this such a challenging and fascinating area to work in. This close interrelationship of scientific and market forces is demonstrated by the following key questions that have to be answered in order for innovation to take place. Can we make the product in good quality and cost-effectively? Is it safe to use? Is there a big enough demand? Can we make and use it exclusively? [ABSTRACT FROM AUTHOR]

Organochlorines have been a matter of concern in the pulp and paper industry for the last two decades. These compounds are produced mainly by the reactions between residual lignin present in wood fibres and the chlorine used for bleaching. Some of the organochlorine compounds are found to be toxic, mutagenic, persistent, bioaccumulating and cause harm in biological systems. Earlier measures taken by the pulp and paper industry to solve the chlorine problem have focussed on improving effluent treatment methods. Today, the emphasis of research and development work in this area has shifted more towards improving the processes. In the search to produce pulp with non-polluting chemicals, more efficient pulping methods reducing the amount of residual lignin passing to the bleaching process and alternative bleaching methods, are being developed. There are also possibilities for treating effluent with microorganisms and enzymes to remove the dechlorinated organic material. Each option has inherent advantages and disadvantages with regard to capital costs, operating costs, ease of retrofit, fabrication and installation time. Impact on other mill unit operations is also considered in choosing the best options. Many factors have to be considered in choosing an effective and economical bleaching/treatment process that meets all the environmental guidelines. This review describes the environmental impact of organochlorines, use of enzymatic and biological bleaching for reducing the generation of organochlorine compounds, and treatment of bleach plant effluents by biological and enzymatic methods. Advantages and limitations of various biotechnological methods are discussed. [ABSTRACT FROM AUTHOR]

One of natures most important biological processes is the degradation of lignocellulosic materials to carbon dioxide, water and humic substances. This implies possibilities to use biotechnology in the pulp and paper industry and consequently, the use of microorganisms and their enzymes to replace or supplement chemical methods is gaining interest. This chapter describes the structure of wood and the main wood components, cellulose, hemicelluloses and lignins. The enzyme and enzyme mechanisms used by fungi and bacteria to modify and degrade these components are described in detail. Techniques for how to assay for these enzyme activities are also described. The possibilities for biotechnology in the pulp and paper industry and other fiber utilizing industries based on these enzymes are discussed. [ABSTRACT FROM AUTHOR]

The noble metals ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, and gold form a variety of complexes M(P) LL′ with tetrapyrrole ligands which are studied in many laboratories because their coordination chemistry and catalytic power is similar to that of the corresponding iron and cobalt tetrapyrroles forming the prosthetic groups in heme proteins and vitamin B12. Apart from the corrins and corroles which are treated in the second article of this volume, the main interest is devoted to noble metal complexes of porphyrins, but complexes of hydroporphyrins, porphyrin analogs, homologs, porphyrinoids, and phthalocyanines are also mentioned where appropriate. The treatise is organized into four main topics: metal insertion ("equatorial coordination chemistry", Sect. 2, formation of the M(P) entity), substitution and redox reactions ("axial coordination chemistry", Sect. 3, exchange of axial ligands L and L′), organometallic chemistry (a special case of axial coordination chemistry, Sect. 4), and notes on current special chemical topics like electrochemistry, catalysis, supramolecular chemistry, and biological applications. Where possible, the material is compressed in schemes and tables giving a synopsis of consecutive reactions of Ru/Os and Rh/Ir dyads. The two other dyads, Pd/Pt and Ag/Au, are so strongly governed by the square planar d8 configuration that they are practically devoid of axial coordination chemistry. The redox reactions of the Ru/Os dyad live on the switches between d6-d5 and d6-d4-d2 configurations mostly with octahedral geometry about the metal, those of the Rh/Ir dyad on the switches between the d6-d7-d8 configurations, giving rise to octahedral, square-pyramidal, and square planar geometries. The occurrence of the dinuclear or mononuclear Rh d7 systems give a special touch of radical chemistry to the organometallic chemistry of rhodium porphyrins which is expected to be fruitful to organometallic chemistry as a whole. Although a broad overview was intended, many entries are just given in keywords or tables in order to give the reader a chance to get more information. Nevertheless, out of nearly 500 papers scrutinized, only nearly 400 references appear in order to keep the volume and the writing time within certain limits, and any research group missing a paper in this review is asked for patience with the authors. [ABSTRACT FROM AUTHOR]

Planar liquid chromatography (PLC) involves the separation of mixtures on thin layers of adsorbents that are usually coated on glass, plastic, or aluminium sheets. The most common form of planar liquid chromatography is thin-layer chromatography (TLC); and this particular technique is the easiest, cheapest, and most widely used method for the isolation of natural products. TLC is one of the oldest forms of chromatography, the simplest example being the school experiment of spotting a plant extract near the bottom of thin strips of blotting paper and "developing" in a jar with water or alcohol. As the water moves up the blotting paper, the dark extract is separated into its component colors of light and dark greens and yellows. [ABSTRACT FROM AUTHOR]

This paper deals with the electrokinetic study of the solid components of the washing process, such as carbon black and polyester and polyester-cotton fabrics, under the influence of the cellulose ethers as antiredeposition agents and surfactants in the washing solution to explain the deposition results presented in a former paper by the same author. The components of the wash liquor studied were various cellulose ethers, used as antiredeposition agents (CMC, HPMC, HBMC and MHEC), and the anionic surfactant sodium dodecylbenzene sulfonate and the non-ionic surfactant Triton X-100 by separate and in different mixture ratios with a builder such as nitrilotriacetic (sodium salt) (NTA). The potential energy between carbon black particles and fabrics (polyester and polyester-cotton) was assessed by the theory of heterocoagulation, in an attempt to explain the different behavior of the antiredeposition agent during the washing process. [ABSTRACT FROM AUTHOR]

The paper discusses the role of surfactants in latex polymerization and in post-emulsification of binders, such as alkyd resins. The advantage of polymerizable surfactants as emulsifier is pointed out. The paper further discusses competitive adsorption between surfactants and between surfactant and associative thickener in paint formulations. [ABSTRACT FROM AUTHOR]

Fifty-seven years ago, Hans Meerwein published a paper, "über die Gleichgewichts-Isomerie zwischen Bornylchlorid, Isobornylchlorid and Camphenchlorhydrat 1)", which had immense consequences for the development of physical organic chemistry. The paper contains the first proposal of carbonium ions as intermediates in molecular rearrangements. It also provided the basis for the later proposal of a nonclassical ion as an intermediate2, in place of the pair of rapidly equilibrating classical cations utilized by Meerwein1). Consequently, this publication opened the door to major research efforts by numerous chemists throughout the world. It is the purpose of this review to discuss the question of whether it is the Meerwein concept of equilibrating cations or the Wilson proposal of a mesomeric nonclassical cation that best accounts for the fascinating behavior of 2-norbornyl cations. [ABSTRACT FROM AUTHOR]

Flocculation processes are of great importance for numerous industrial processes, such as paper manufacture, mining, and the treatment of industrial and municipal waste waters. Polymeric flocculants having molecular weights up to 1 · 107 g/mol are generally used for this purpose. The flocculation mechanism (bridging, charge-mosaic) is determined by the chain length, the charge density and the molecular weight of the polymeric flocculant. There is a closely defined optimum for the dosing rates of flocculants, from both an ecological and an economic point of view. The specific choice of flocculants therefore requires a reliable measuring method with which tests of effectiveness can be carried out, ideally under service conditions. This paper describes a fiber-optic flocculation sensor (FOFS) for measuring the flocculation state in flowing systems, which has proved useful in practice for both laboratory flocculation tests and as a measuring component of control systems for dosing equipment. The focus of this contribution is the use of the FOFS for assessing the effectiveness of polymeric flocculants in relation to waste water treatment. [ABSTRACT FROM AUTHOR]

Coupled thermo-hydro-chemo-mechanical (THCM) behavior of soils is important in a number of geoenvironmental engineering applications including nuclear waste disposal, landfill engineering, freeze-thaw cycles and fate and contaminant transport. As part of ongoing research and development in this field a number of key developments have been undertaken at the Geoenvironmental Research Centre (GRC), Cardiff, UK, with particular focus on the numerical simulation of these phenomena. This paper outlines some of these developments set within the context of the numerical finite-element model developed at the GRC – COMPASS, and discusses the theoretical and numerical implementation and comparison of numerical simulations with experimental data. In particular the development of the effects of temperatures elevated above 100°C on gas pressure and water phase change and consequently the moisture movement; frozen ground behavior with particular reference to seasonal freeze-thaw cycles with frost heave and ice segregation possibly leading to solifluction; reactive thermo-hydro-chemical-mechanical models including geochemical behavior with focus on the osmotic potential; and High Performance Computing (HPC) have been included. [ABSTRACT FROM AUTHOR]

The paper deals with the design and a prototype implementation of a collaborative repository of scientific learning objects based on an efficient mechanism of filing and retrieving distributed knowledge on the Grid. The proposed repository can deal with a large variety of different learning contents. Its prototype implementation, developed for Chemistry contents, is part of an extended architecture consisting of a federation of autonomous local repositories. The federation is led by a coordinator who keeps track of the repository in which the learning objects are directly stored or referenced. In each repository server, a locally hosted Web Portal allows a easy management of the repository through a CMS front-end. [ABSTRACT FROM AUTHOR]

Many crystalline materials cannot be prepared in a suitable form for conventional single-crystal diffraction studies, and hence the successful structure characterisation and rationalisation of these materials and their properties often relies on the ability to gain this information from powder diffraction data. Although the refinement stage of the structure determination process can be carried out fairly routinely, structure solution is associated with several intrinsic difficulties. However, the recent development of direct-space structure solution methods has enabled the study of a wide range of materials using powder diffraction data, many of structural complexity only made tractable by these advances in methodology. This paper aims to guide you through the structure determination from powder diffraction process, highlighting the application of direct-space methods (and the global optimisation techniques on which they are based), including experimental and structural considerations, and examples illustrating the impact that powder diffraction has had on the structural study of both organic and inorganic materials. [ABSTRACT FROM AUTHOR]

Hydrogen bonds are well known for governing the molecular association and crystal packing, as well as for their contribution to the chemical and physical properties of substances. They affect the properties of materials as versatile as amphibole minerals, KDP-type (—OH⋯O= bonded) ferroelectrics or biopolymers (e.g. cellulose). While the classical examples of such materials usually concentrate on the —OH⋯O= bonds, recently analogical and completely new features were observed in —NH⋯N= bonded substances. The key factor for understanding these new properties is the structural coupling between molecular arrangements and H-atom position in the NH⋯N hydrogen bonds. In this paper the very weak NH⋯N involving Nsp3 nitrogen atoms in secondary and tertiary amines has been compared. Clear preferences for the molecular orientation depending on the H-atomposition have been revealed for the small, weakly interacting molecules for the molecular crystals of aziridine, C2H5N, and difluoroamine, HNF2. This coupling explains the microscopic mechanisms accompanying reorientations or inversions of the ammonium groups and molecular rearrangements, which are essential for understanding dynamics of protons in H-bonds, or spontaneous polarization and phase transitions in NH⋯N hydrogen-bonded materials. The directional preferences of NH⋯N hydrogen bonds can be employed for engineering transformable crystal structures, for predicting physical properties of crystals built of small molecules, for analyzing the molecular associations and conformations of larger molecules and biopolymers, or validating structural determinations. On the other hand, specific features of molecular structure, conformation or molecular arrangement in aggregates and crystal structure can compete with the subtle orientational preferences induced by NH⋯N bonds. Such systematic conformational preferences in molecular aggregates exist in the structures of piperazine, piperidine and morpholine. [ABSTRACT FROM AUTHOR]

In this paper we will focus on the crystal engineering of molecular materials exhibiting magnetic and/or electrical properties. The complexity of these materials needs of a precise design of the molecular building blocks, a control of the intermolecular interactions (hydrogen bonds, host/guest interactions, etc.) and a mastery in crystallization techniques in order to design crystal structures exhibiting useful physical properties. We will illustrate this concept through some relevant examples based on two-component hybrid materials. [ABSTRACT FROM AUTHOR]

The milk fat globule membrane (MFGM) is the membrane surrounding lipid droplets during their secretion in the alveolar lumen of the lactating mammary gland. MFGM proteins represent only 1-4% of total milk protein content; nevertheless, the MFGM consists of a complex system of integral and peripheral proteins, enzymes, and lipids. Despite their low classical nutritional value, MFGMproteins have been reported to play an important role in various cellular processes and defense mechanisms in the newborn. Using a proteomic approach, such as high-resolution, two-dimensional electrophoresis followed by direct protein identification by mass spectrometry, it has been possible to comprehensively characterize the subcellular organization of MFGM. This chapter covers the description of MFGM proteomics from the first studies about 10 years ago through the most recent papers. Most of the investigations deal with MFGMs from human and cow milk. [ABSTRACT FROM AUTHOR]

As an interface between different biological compartments, membranes guarantee an efficient exchange of matter, energy and/or signals. For this purpose, such an interface has to be designed as a very dynamic system, yet with a non-random distribution of its components, lipids and proteins. A delicate balance of lipid and protein interactions is the basis of tightly regulated mechanisms to concentrate molecules at the site of interest at a specific time and, thereby, exclude unwanted components. In order to elucidate this highly intricate architecture, the top-down approach—by looking at the intact cell—is best complemented by a bottom-up strategy, by building the whole complexity starting from a minimal number of components. Within this framework, model membranes are key systems to isolate the biological machinery and identify its function. In this paper, we review research on biomimetic membranes for optical microspectroscopy. In particular, we focus on giant unilamellar vesicles (GUVs), and their application to studies on domain assembly and on membrane curvature and deformations. In order to build complexity, efforts must be made towards mimicking cellular compositions, by using GUVs with native lipid compositions, to reconstitute (complexes of) membrane proteins and to include components of an artificial cytoskeleton underneath the bilayer. Novel exciting avenues lie ahead in the arena of membrane biophysics, many of which are strongly coupled to the promising developments of optical technologies. [ABSTRACT FROM AUTHOR]