Determination of organic silicon compounds in biogas from wastewater treatments plants,landfills, and co-digestion plants

The study determined the organic silicon compounds in biogases from landfills, wastewater treatment plants (WWTPs), and biogas plants processing different organic material. The aim was to provide information for gas utilisation applications, as siloxanes are reported to shorten the life time of engines when biogas is used for energy production. In total, 48 samples were measured. The total concentration of organic silicon compounds in landfill and WWTP gases varied from 77 to 2460 μg/m³ while the concentrations in biogases from biogas plants varied from 24 to 820 μg/m³. The total concentration of organic silicon compounds was lowest (24 μg/m³) in the biogas plant processing grass and maize, and highest (2460 μg/m³) in one of the studied WWTP. The most common compounds in WWTPs and in biogas plants processing also sewage sludge were D4 and D5 while in landfills the most common compounds were D4 and L2 followed by trimethyl silanol. The effect of condensation of biogas on concentrations of organic silicon compounds was studied in one of the landfills and a negligible effect on concentrations was detected.     

Intrusion detection: managing the risk of connectivity

New tools work at both the host and network levels to block attacks from within and beyond the enterprise     

Fatty acids of a salami-type sausage made of Baltic herring fillets, pork and lard

 The fatty acid composition of "fish wurst", a fermented salami-type sausage made of pork, lard and Baltic herring fillets (Clupea harengus var. membras) was investigated. Changes in the proportions of the 35 most abundant fatty acids were examined throughout the 1-month ripening period followed by a 4-month storage period. The fat composition of the product was stable (32–35%) and retained the characteristics of the main ingredients: oleic acid (37.4%, mean of three production batches) palmitic acid (23.7%) and linoleic acid (10.7%) from lard and fish, stearic acid (11.7%) mainly from lard, and palmitoleic acid (3.0%) and long-chain (C20–C24), polyunsaturated fatty acids (c.a. 6%) mainly from fish. During the 4-week ripening period a statistically significant increase (P≤0.05) was detected in the proportions of minor fatty acids only, i.e. eicosenoic acid (20 : 1n-9), eicosadienoic acid (20 : 2n-6), docosadienoic acid (22 : 2n-6) and docosatrienoic acid (22 : 3n-3). During the 4-month storage of the ripe sausage, the fatty acid composition stabilized. Only the proportion of stearic acid increased significantly during storage, from 11.7% to 12.5%. Received: 23 January 1998 / Revised version: 1 April 1998     

Recent operational experiences of FILMTEC NF270 membrane in Europe

Nanofiltration (NF) is an attractive technology for potable and industrial water treatment because NF operates between ultrafiltration (UF) and reverse osmosis (RO) membranes. NF is designed to remove a high percentage of organic contaminants (humic acids, pesticides, color bodies) while passing a medium to high percentage of salt. Compared to UF membranes, the NF product water quality is significantly better; compared to comparable RO treatment systems NF systems require lower operating pressures. Due to these features, NF is increasingly used in a broad range of water treatment applications. The general applications include softening, as well as color, organics and micro-organism removal. DOW FILMTEC NF270-400 is one the most frequently used elements in water treatment and this paper presents examples of three recent NF270-400 installations in Europe. The first two plants, Eupen and Stembert, are located in Belgium and produce potable water from surface water. The third one is a Scandinavian plant which purifies groundwater for a brewery and soft drink production. The presented operation results prove NF to be a highly competitive technique for low cost water treatment.     

Signaled Step Size for Downlink Power Control of Dedicated Channels in UTRA TDD

This paper discusses downlink inner loop power control of dedicated channels in UTRA TDD. The current UTRA TDD downlink power control is similar to one in UTRA FDD mode, that comprises of closed inner loop and quality based outer loop. However, due to the time division feature and associated fexibility with asymmetry of TDD, the inner loop can not react as fast as in FDD and it is affected by rapid changes in environment. Therefore, the effect of the inner loop algorithm to the performance of UTRA TDD network is studied in this paper. Especially, the use of asymmetric step sizes for power up and power down commands is evaluated in contrast to the conventional symmetric power adjustment. Since it would be beneficial for the downlink inner loop power control to reach the target SIR as fast as possible, the power control step size based on the difference between the UE measured SIR and target SIR would be the most desirable power adjustment. Since the effectiveness of this type of an algorithm depends on available signaling bandwidth that is used, a study is carried out to find the tradeoff between the signaling bandwidth and related network performance.Janne Kurjenniemi was born in Jyväskylä, Finland, in March 1974. He received the M.Sc. in telecommunications in 2001 from the University of Jyväskylä, Jyväskyl, Finland. He is working as a Researcher at the Department of Mathematical Information Technology, University of Jyväskylä. His research interests include radio resource management for wireless communication systems.Otto-Aleksanteri Lehtinen was born in Tampere, Finland, in September 1971. He received the Master of Science in Technology in 1999 from the Helsinki University of Technology, Department of Electrical engineering (major in radio technology, minor signal processing and computer devices). His research interests include radio resource management for wireless communication systems.Tapani Ristaniemi was born in Kauhava, Finland, in 1971. He received the M.Sc. in mathematics in 1995, Ph.Lic. in applied mathematics in 1997, and Ph.D. in telecommunications in 2000 from the University of Jyväskylä, Jyväskylä, Finland. During 2001–2003 he was a professor of telecommunications at the Department of Mathematical Information Technology, University of Jyväskylä. In 2003 he joined the Institute of Communications Engineering in the Tampere University of Technology, Finland, where he has been a professor of wireless data communications. His research interests include signal processing for communications and radio resource management for wireless networks.     

Low-temperature aerosol flow reactor method for preparation of surface stabilized pharmaceutical nanocarriers

Nanoparticles can be used to improve the delivery of many drugs, especially peptides and proteins. Although several methods are available for polymeric nanoparticle preparation, there are few single-stage processes that produce dry, solid nanoparticles that can be easily re-dispersed in pharmaceutical vehicles. The aerosol flow reactor method is a single-stage process that has been used for the preparation of multicomponent, coated nanoparticles under uniform temperature and gas flow field. However, it is traditionally used with high synthesis temperatures. In the present study, the aerosol flow reactor method was further optimized for processing and surface stabilization of pharmaceutical nanoparticles containing temperature sensitive biomolecules. In the developed method, drug-loaded carrier nanoparticles consisting of a biodegradable polymer (Eudragit L100) and a drug (phenylephrine hydrochloride) were first produced by aerosol droplet drying and subsequently coated in the gas phase. The carrier particles were coated with l-leucine in order to inhibit agglomeration of the nanoparticles in solutions before administration. In the coating process, a side stream of l-leucine vapor was directed into the main aerosol flow containing the drug-loaded carriers. The mixing with the main flow at ambient temperature induced a supersaturation of l-leucine vapor and condensation on the carrier particles. The results demonstrate that solid, hydrodynamically stable drug-loaded polymeric nanoparticles can be produced with a thin l-leucine coating. The low process temperature enables the surface engineering of particles loaded with temperature sensitive drugs or bioactive materials to be utilized for drug delivery purposes.     

IgA class serum antibodies against three different Klebsiella serotypes in ankylosing spondylitis

BACKGROUND: Over the past decade, the 585-nm pulsed dye laser (PDL) has been used successfully to treat a variety of cutaneous vascular lesions as well as hypertrophic scars. Laser scar revision has been revolutionized by the recent development of high-energy, pulsed carbon dioxide (CO2) laser systems. These new CO2 lasers allow controlled vaporization of thin layers of skin while minimizing damage to surrounding dermal structures. OBJECTIVE: To determine the effect of a high-energy, pulsed CO2 laser alone and in combination with a 585-nm PDL on nonerythematous hypertrophic scars. METHODS: Twenty patients with nonerythematous hypertrophic scars were treated with a high-energy, pulsed CO2 laser. One-half of each scar was additionally treated with the 585-nm PDL laser. Sequential clinical and photographic analyses were performed independently by two blinded assessors. In addition, erythema reflectance spectrometry measurements were obtained from the scars before and at regular postoperative intervals. RESULTS: Global assessment scores and erythema spectrometry measurements were significantly improved after laser treatment. Combination CO2 and PDL laser treatment resulted in more significant improvement than CO2 laser irradiation alone. CONCLUSION: Concomitant use of the high-energy, pulsed CO2 and PDL laser systems was superior to CO2 laser vaporization alone for revision of nonerythematous hypertrophic scars. Once again, the vascular specificity of the 585-nm PDL has been linked to improvement in hypertrophic scar tissue.     

Flexographically printed fluidic structures in paper

This Technical Note demonstrates a simple method based on flexographic printing of polystyrene to form liquid guiding boundaries and layers on paper substrates. The method allows formation of hydrophobic barrier structures that partially or completely penetrate through the substrate. This unique property enables one to form very thin fluidic channels on paper, leading to reduced sample volumes required in point-of-care diagnostic devices. The described method is compatible with roll-to-roll flexography units found in many printing houses, making it an ideal method for large-scale production of paper-based fluidic structures.     

Authentication of Particulate Air Samples by Aerosol

A method was developed for the protection of aerosol filters against tampering that can be applied to any particulate sampler. In this method, tagged particles are dispersed into the sampled aerosol volume by liquid atomization to guarantee homogeneous distribution of the tag and deposition into the filter matrix. The tagged aerosols are collected insitu, together with the sampled dust particles. The tag can be measured in different ways. This feature can be used for self protection of the method. The authentication of the individual filters is preserved through the lifetime of the filter sample. Long-term field tests of the equipment indicate reliable performance.     

High-frequency periodic time-domain waveform measurement system

A system is presented for the accurate measurement of high-frequency periodic time-domain voltage and current waveforms of a nonlinear microwave device. The measurements are performed in the time domain using a high-speed sampling oscilloscope. The results are Fourier-transformed into the frequency domain for error correction and then back into the time domain. An error-correction algorithm is presented that makes it possible to obtain accurate waveforms in spite of nonideal system components. Practical difficulties in measurement-system characterization are also discussed. An accurate circuit model for the measurement fixture is developed and its element values are determined. Measurement results are given showing the waveforms in a microwave transistor operated in the nonlinear region. The errors caused by signal processing are discussed