A high capacity tunable retransmission type frequency coded chipless radio frequency identification system

This article presents a 12‐bit frequency coded chipless RFID system in the frequency range of 3 to 6 GHz. The system consists of a fully printable chipless tag and a pair of high‐gain reader antennas. The tag also incorporates its own antennas to improve the read range. Information is encoded into frequency spectrum using a multi‐resonant circuit. The circuit consists of multiple microstrip U and L‐shaped open stub resonators patterned in a unique configuration. The proposed configuration aids in capturing more data in a reduced space as well as tunable frequency operation. Tag and reader antennas utilize techniques such as stepped impedance feeding line, defective partial ground plane, and stair‐step patch structure to achieve wide‐band impedance bandwidth in miniature size. The results of the wireless measurements in the non‐anechoic environment show that the proposed system has a reading range of more than 20 cm. The presented system possesses great potential for low‐cost short‐range inventory tracking.     

Use of plant stanol ester margarine among persons with and without cardiovascular disease: Early phases of the adoption of a functional food in Finland

Background

The plant stanol ester margarine Benecol^® is a functional food that has been shown to lower effectively serum total and LDL-cholesterol. The purpose of this post-marketing study is to characterize users of plant stanol ester margarine with and without cardiovascular disease.

Methods

A cohort of plant stanol ester margarine users was established based on a compilation of 15 surveys conducted by the National Public Health Institute in Finland between 1996–2000. There were 29 772 subjects aged 35–84 years in the cohort. The users of plant stanol ester margarine were identified by the type of bread spread used.

Results

The plant stanol ester margarine was used as bread spread by 1332 (4.5%) subjects. Almost half (46%) of the users reported a history of cardiovascular disease. Persons with cardiovascular disease were more likely to use plant stanol ester margarine (8%) than persons without cardiovascular disease (3%). Users with and without cardiovascular disease seemed to share similar characteristics.In particular, they were elderly people with otherwise healthy life-styles and diet. They were less likely smokers, more likely physically active and less likely obese than nonusers. The users reported being in good or average health in general and having used cholesterol-lowering drugs.

Conclusion

Plant stanol ester margarine seems to be used by persons for whom it was designed and in a way it was meant: as part of efforts for cardiovascular disease risk reduction.

     

IMPROVEMENTS IN THE SURFACE CHARACTERISTICS OF STAINLESS STEEL WORKPIECES BY BURNISHING WITH AN AMORPHOUS DIAMOND-COATED TIP

Burnishing is a cold working process that can be used to improve surface finish and surface hardness of workpieces. Conventionally, diamond or hard metal burnishing tools are used. In the present work, a novel burnishing tool was created by depositing amorphous diamond coating (AD) on a stainless steel tip. This tool was used to improve the surface finish and surface hardness of Nitronic-50 HS stainless steel workpieces. Nitronic-50 HS is used in a wide range of applications in industry. The burnishing process was carried out at different burnishing parameters (force, revolution speed, feed and number of tool passes). Burnishing parameters had a significant effect on the finishing process and they had to be optimized to achieve the best results. Remarkable improvements in surface finish (70% decrease in roughness) and hardness (25% increase) could be achieved with this tool and process in the surface finishing of Nitronic-50 stainless steel workpieces. From the tribological point of view, the AD-coated tip performed slightly better than a corresponding tip modified from a commercial polycrystalline diamond tip. AD coating seems to be very suitable for use in mechanical surface finishing tools such as a burnishing tip.     

Effect of biological wastewater treatment on the molecular weight distribution of soluble organic compounds and on the reduction of BOD, COD and P in pulp and paper mill effluent

Pulp and paper mill wastewater was characterizated, before (influent) and after (effluent) biological wastewater treatment based on an activated sludge process, by microfiltration (8, 3, 0.45 and 0.22mum) and ultrafiltration (100, 50, 30 and 3kDa) of the wastewater samples into different size fractions. Various parameters were measured on each fraction: molecular weight distribution (MWD) using high performance size exclusion chromatography (HPSEC), total organic carbon (TOC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (Tot-P), phosphate phosphorus (PO(4)-P), electrical conductivity, pH, turbidity, charge quantity and zeta potential. The MWD, TOC and COD(Cr) results indicated that the majority of the material present in both the influent and effluent was in the medium molecular weight (MW) range (i.e. MW<10kDa) with three main MW sub-fractions. There were no significant differences in the range of the MWD between the influent and effluent samples. The magnitude of the MWD in the effluent was about one half that in the influent, the greatest reduction being in the 6kDa fraction. The 3kDa fractions of both the influent and effluent showed a considerable increase in BOD(7), probably due to the removal of compounds harmful to bacteria in 3kDa ultrafiltration. Influent turbidity decreased considerably in microfiltration (8-0.22mum). As the turbidity was removed by 0.22mum filtration, the anionic charge quantity started to decrease. Particles in the influent and effluent contained 19-29% and 14-20% of the total phosphorus, respectively. The major phosphorus fraction was in the form of soluble phosphate.     

Methods of Testing Discrete Semiconductors in the 1149.4 Environment

This paper describes measurement methods for testing discrete semiconductors in the environment defined by the IEEE 1149.4 standard for a mixed-signal bus. First, the paper introduces and illustrates measurement procedures for obtaining such essential electrical parameters of diodes and transistors as can be used for testing and identification. Then, the procedures are carried out and the achieved measurement results presented. To demonstrate the usability of the measurement procedures, the paper then presents test methods and measurement results for discrete component blocks. The results indicate that testing and measuring some of the electrical parameters of discrete semiconductors is possible in the 1149.4 environment. These parameters allow the determination of whether the component under test is working properly or not. Our tests only covered the semiconductors’ DC features, disregarding their AC features. Also discussed are limitations of the 1149.4 environment in discrete semiconductor testing.

Compensatory fertilization of Scots pine stands polluted by heavy metals

The results from four compensatory fertilization experiments located at different distances (0.5, 2, 4 and 8 km) along a heavy metal deposition gradient extending from the Harjavalta Cu-Ni smelter in SW Finland are presented. The experiments were established in middle-age Scots pine stands growing on dryish sites of sorted glaciofluvial sediments. The soil type in all the experiments is ferric podsol. The treatments in the experiments consisted of liming, a powdered slow-release mineral mixture and stand-specific fertilization which comprised at least methylene urea and ammonium nitrate.Monitoring of deposition and soil solution and studies on soil chemical and microbiological properties, on the nutrient status of trees and needle litterfall, on fine root dynamics and on the growth of the tree stands were carried out during a 5-year period.There was a severe shortage of exchangeable Ca and Mg in the organic layer of the most polluted stands. Although the uppermost mineral soil layer had relatively high exchangeable Ca and Mg concentrations, the trees were not able to utilize these nutrient reserves presumably due to the toxic effects of Cu and Ni on the plant roots and mycorrhizas.The treatments that included limestone markedly decreased the Cu and Ni concentrations in the soil solution and soil organic layer, presumably due to immobilisation through precipitation or absorption. The Ca and Mg concentrations correspondingly increased, which certainly contributed to the partial recovery of fine root and stand growth. The powdered mineral mixture and the combination of methylene urea and ammonium nitrate had no short-term effect on the microbial biomass and activity. All the fertilizer treatments increased volume growth in the most polluted stand. The stand-specific fertilization increased needle mass in heavily polluted stands, but the response of the needle mass to fertilizer treatments was low in the less polluted stands. No clear evidence was found to support the role of nutrient status in tree resistance.     

The State and Self-help Housing in Urban Finland, 1920 to 1950

This paper examines self-help housing and state housing policies in urban Finland from 1920 to 1950. In Finland self-help housing consisted primarily of self-building of one- and two-family houses. It is often assumed that self-building used to be the typical urban form of housing production. It was certainly the form that housing reformers preferred. However, most urban housing production was private speculative production. Self-building became relatively important only when other production was depressed. The state supported self-building by providing subsidised housing finance. Of the three successive housing finance systems examined, only the last concerned only self-building. The loan policies also included an attempt to control the quality and design of self-built housing. The policies were, however, so limited that they did not have a large impact on urban housing in normal times. In Finland, as in many other countries, the government's attitude towards self-building can be characterised as guarded support.     

Characterisation of Fractions Obtained by Isoamylolysis and Ion‐exchange Chromatography of Cationic Waxy Maize Starch

Isoamylase hydrolysates of wet‐ (WC) and dry‐cationised (DC) waxy maize starch were fractionated by ion‐exchange chromatography on CM‐Sepharose into an unbound and four bound fractions. The amount of bound dextrins was higher in the WC than in the DC sample. The fractions were characterised by gel‐permeation chromatography and proton‐NMR spectroscopy. The unbound fraction from the WC sample consisted mainly of linear chains formed from amylopectin. The dextrins in the bound fractions contained increased amounts, from 1.2—7.9, of cationic substituents per molecule and the degree of polymerisation increased with the density of substituents. Dextrins weakly bound to CM‐Sepharose had a linear structure, whereas more tightly bound fractions were mixtures of linear and branched dextrins. In the latter, the debranching was incomplete because of sterical hindrance by substituents at or close to the branch points. Most of the dextrins were partly hydrolysed by β‐amylase, but the more highly substituted fractions possessed also a population of β‐amylase resistant dextrins, suggesting substituents at the non‐reducing ends.