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This article examines whether the new labor organization annual financial report (Form LM-2) has significantly improved transparency of union finances over the old form by providing useful and easily understood information to union members, government, and the public. The new form, filed by unions with $250,000 or more in annual receipts, was first published by the U.S. Department of Labor's Office of Labor-Management Standards in December 2002. After reviewing the changes made in the new LM-2 form, the authors then use data drawn from a stratified random sample of union filings under the new LM-2 form to determine what additional gain in transparency has actually occurred.

A 3.1-4.8 GHz ultra-wideband (UWB) receiver front-end for high data rate, short-range communication is presented. The receiver, based on the Multi Band OFDM Alliance (MBOA) standard proposal, consists of a zero-IF receive chain and an ultra-fast frequency-hopping synthesizer. The combination of high-linearity RF circuits, aggressive baseband filtering and low local oscillator spurs from the synthesizer results in an interference-robust receiver, having the ability to co-exist with systems operating in the 2.4-GHz and 5-GHz ISM bands. The packaged device shows an overall noise figure of 4.5 dB and has a measured input IP3 of -6 dBm and input IP2 of +25 dBm. Spurious tones generated by the synthesizer are below -45 dBc and -50 dBc in the 2.4-GHz and 5-GHz ISM bands, respectively. The hopping speed is well below the required 9.5 ns. The complete receive chain has been realized in a 0.25 /spl mu/m BiCMOS technology and draws 78mA from a 2.5-V supply.

A new subsite stepped multiresistor test structure is introduced. This test structure is used for studying and improving small resistance mismatch patterns in resistor ladders for high-resolution analog-to-digital converter applications. By utilizing wafer prober subsite movements and contact pad cross connections in the test structures, in combination with a Kelvin measurement method and dedicated statistical data evaluation technique, this approach enables identification of very small (

Several amorphous narrow molecular weight fractions of poly(aryl ether ether ketone) or PEEK have been heated from below their glass transition temperature to above their final melting point. The semicrystalline morphology induced by cold crystallization and its thermal evolution are studied by time-resolved simultaneous small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction, and differential scanning calorimetry. The long period and the crystalline and the amorphous thicknesses are computed from the correlation function of the SAXS curves. The evolution of the structural parameters of the various semicrystalline samples can be reconciled with the existence of a single distribution of lamellae which undergoes reorganization during the continuous heating. The reorganization process as well as the semicrystalline morphology depends on the molecular weight of the fractions. The amorphous thickness strongly increases with the molecular weight while the thermal evolution of the thickness of the crystalline layers is similar for all fractions. These experimental results support the view that the larger degree of entanglements of the high molecular weight samples impedes the reorganization mechanism with the consequence that the apparent melting temperature decreases with increasing average molecular weight.

Multiarm star polymers represent a valuable model system for investigating the dynamics of tethered chains, spherical brushes, or grafted colloidal spheres. Because of their topology, the multiarm ...

The morphology of several semicrystalline poly(aryl ether ether ketone) (PEEK) samples with narrow molecular weight distributions and of a commercial sample of PEEK has been investigated by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS). The use of different molecular weights allows us to enlarge the macroscopic crystallinity range usually attainable for the commercial PEEK grades. WAXD and DSC data are in good agreement to estimate the weight degree of crystallinity values ranging from ∼15% for the highest molecular weight sample to ∼55% for the lowest molecular weight sample. Most of the investigated samples exhibit the well-known double melting behavior with a low and a high melting endotherm. This behavior is interpreted in the light of a melting−recrystallization mechanism which is strongly affected by the presence of entanglements in the amorphous zones. The analysis of the SAXS data shows that, under constant annealing ...

Barriers to rotation have been calculated by molecular mechanics, using the force field MM+, for a fragment of PEEK and its methyl, ethyl, isopropyl, tert-butyl and di-tert-butyl, substituted derivatives. The barrier for the nearer C—O bond increases from 2.0 kcal/mol in KEEK to 16 kcal/mol in dibutyl substituted KEEK as the bulkiness of the substituent increases. The rotation barrier of the further C—O bond is not affected by the substituent. Keywords: rotation barriers, PEEK, molecular mechanics.

The architecture of this 12 b ADC is based on a three-stage conversion, using cascaded folding and interpolating techniques. Compared to other multi-stage ADC architectures, folding and interpolating ADCs are based on non-linear analog pre-processing. This architecture is an attractive solution for high-resolution ADCs, as extremely linear circuit topologies are not required. To increase the resolution of folding and interpolating ADCs above the published 8 b examples, without raising the number of parallel input stages or the number of comparators in the fine-comparator, a cascaded folding and interpolating architecture is introduced. The ADC achieves 64 dB signal-to-noise ratio (SNR) and 75 dB spurious-free dynamic range (SFDR), while quantizing a 15 MHz full-scale input signal at 50 MSample/s. The 7.0 mm/sup 2/ ADC is fabricated in a 13 GHz, 1 /spl mu/m BiCMOS process and dissipates 300 mW from a single 5.0 V supply. The device is mounted in a standard 44-pin plastic package.

The large scale architecture of polymers is recognized to create special properties in functional polymers. One of the more striking examples is the ability of certain diblock copolymers to associate into micelles in a selective solvent for one of the blocks.(1) The insoluble block forms a dense core that is kept in solution by a soluble corona. The diblock micelle has the overall conformation of a star polymer.(2,3) However, the self-association of block copolymers into micelles depends strongly on the chemical nature of the two blocks, on the respective sizes of the blocks and on the selective solvent. In general, it is observed that the molecular weight of the insoluble block must be kept low in order to form micelles. This is especially true when water or a polar solvent is used as the selective good solvent.(1,4) Otherwise, a cloudy unstable two phase system is produced. The association number of diblocks in micelles varies considerably and makes their systematic study difficult. The associa...

The title polymers have been prepared by nucleophilic substitution of 2,3-dimethyl- and trimethylhydroquinone, and 3,3′-dimethyl- and 3,3′,5,5′-tetramethylbiphenol with difluorobenzophenone. These polymers have been brominated to various degrees of substitution. The dimethyl PEEK can only be monobrominated; trimethyl PEEK yields mono- and dibromomethyl functional groups in the ratio 2:1. These results can be explained by steric hindrance to dibromination of the vicinal methyl groups. Dimethyl- and tetramethylbiphenyl PEEK can be dibrominated completely.

The lateral structures of dried adsorbed binary mixtures of star polymers were investigated. Blends of protonated and deuterated polybutadiene stars were prepared from cyclohexane solutions and adsorbed onto silicon substrates. The number of arms and the molecular weight of the arms was varied. With grazing incidence small angle scattering techniques (GISAS) and scanning force microscopy (SFM), different dominant in-plane length scales were determined. The morphology of these structures is dominated by blob-like structures created from single stars or agglomerates of star polymers.

Digital cellular standards have emerged over the last 20 years. Today, 2G systems like GSM/EDGE are providing worldwide coverage for voice and basic data services. The increasing demand of about 4 billon users has led to high demand for low cost multi-standard, multi-mode and multi-band terminals. RF integration using reconfigurable circuits is a key technology to achieve the required technical performance as well as the even more important cost position. Another important commercial aspect of mobile communication systems is the efficient usage of the available spectrum by cognitive radio techniques. The key for this view of cognitive radio is a reconfigurable RF frontend providing the required flexibility. Therefore the wireless forum will investigate the current status and R&D trends in reconfigurable systems focusing on non-4G based reconfigurable RF and reconfigurable data converters. Target systems include cognitive radio and multi-mode/multi-standard systems including short range systems like Bluetooth and WLAN. The forum will cover reconfigurable RF front-ends, their corresponding reconfigurable A/D converters as well as performance on demand concepts and adaptive power consumption.

DSC data show that anionically prepared monodisperse 1,2-polybutadiene (>99% 1,2; 1,2-PBd) and polyisoprene (93% 1,4; PI) are miscible but the glass transition region is very broad for blends with high 1,2-PBd content. The viscoelastic properties of the blends have been studied over a wide temperature range. Individual relaxations of the components are observed. The blends are thermorheologically complex because the temperature dependence of the 1,2-PBd relaxation is stronger than that of PI. Analysis of the temperature dependence of the relaxation times suggests that each component in the blend experiences its own T g

The replication of adenovirus DNA requires, in addition to several host factors, three virus-encoded proteins: a DNA binding protein, the precursor of the terminal protein (pTP), and a DNA polymerase (Ad poi). Ad poi and pTP form a tight complex that is necessary for the initiation step in DNA replication. To perform mutation scanning of the adenovirus type 5 pTP and Ad poi a series of in-frame linker insertions of a 12-mer oligonucleotide d(CCCATCGATGGG) were introduced into cloned viral DNA fragments containing coding sequences of these proteins. The insertions are located at recognition sites for several blunt end-cutting restriction endonucleases. Forty different sites were mutagenized and the mutated genes were transferred to a plasmid that contains the left 42% of the adenovirus genome. They were rebuilt into the viral genome by means of in vivo recombination between plasmid DNA and digested adenovirus DNA-TP complex. The resulting viral genomes were tested for viability and rescued virus was analyzed for the presence of the inserted linker oligonucleotide. This procedure resulted in recovery of a number of viable virus mutants with insertions in the pTP or Ad poi genes, all of which are phenotypically silent. The other mutations did not allow virus production. The positions of these apparent lethal codon insertion mutations were useful to identify regions of functional importance in both proteins. It can be concluded that the precursor-specific region of pTP plays an important role in virus multiplication.

A series of aromatic polyethersulfones based on biphenol and dichlorodi phenylsulfone have been prepared and fractionated. The fractions have been character ized by light scattering and intrinsic viscosity measurements. The characteristic ratio C ∝ = 1.96 which is in agreement with the freely rotating nature of the polyethersulfone chain. The molecular weight dependence of the glass transition temperature is established. The low temperature β-transition is at -113°C when measured at 1 rad/s with a mechanical spectrometer.

The linear viscoelastic properties of a series of RADEL R polyethersulfone fractions have been studied. The molecular weight of the fractions ranged from 2.4 X 103 to 7.2 X 104. The RADEL R polyethersulfone is a thermorheologically complex material. After correction to iso-free volume, it has been found that 1/0∝M3.4,w in agreement with the relation expected for entangled flexible polymers. Below Mw = 10 000, 1/0∝ M2.0 w. From integration under the loss peak of high molecular weight fractions it is found that the plateau modulus G°N=3.6x 107. It is calculated that at 282°C the molecular weight between entanglements is Me=1550. The high plateau modulus is related to the molecular parameters of RADEL R polyethersulfone. Both the Graessley-Edwards model and the Lin model are discussed for a number of polymers that contain phenylene groups in the main chain.

A fully integrated transceiver for 3-band OFDM UWB is presented. It has been implemented in a 0.25/spl mu/m SiGe BiCMOS process, and has a die area of less than 4mm2. The power consumption is 47mA, 43mA, and 27mA at 2.7V supply for receiver, transmitter, and synthesizer respectively. The chip features DC offset cancellation, a loop-back test mode, a single input/output pin for antenna connection, a 1GHz baseband clock output and is robust against interferers from cellular and ISM bands. The measured EVM is 8%, while the overall NF is 4.5dB and the iIP3 is -6dBm.

A 1b 51h-order complex CTDeltaSigma modulator with integrated IF mixer for AM/FM/IBOC car radio receivers is presented. The 118dB DR in AM mode enables the realization of the receiver without a VGA and an external AM channel filter. It is fabricated in a 0.18mum CMOS process and consumes 210mW from a 1.8V supply

Preface. Acknowledgement. Foreword. Section 1. Introduction. 1.1 Ambient Intelligence: the Next Wave In Consumer Electronics. 1.2 The Physical Basis Of Ambient Intelligence.- Section 2. Wireless communication. 2.1 Circuits And Technologies For Wireless Sensor Networks. 2.2 In Home A/V Networks. 2.3 Body Area Networks: The ascent of autonomous wireless microsystems. 2.4 Wireless Communication Systems.- Section 3. Smart Sensors. 3.1 Interconnect and packaging technologies for realizing miniaturized smart devices. 3.2 Image Sensors for Ambient Intelligence. 3.3 Microsystem Technology For Ambient Intelligence.- Section 4. Low Power Electronics and System Architecture. 4.1 Low Energy Digital Circuit Design. 4.2 Analog Interface Circuits-the limit for AmI applications. 4.3 Vector Processing as an Enabler for Ambient Intelligence. 4.4 Xtreme Low Power Technology Development using a Virtual Design. Flow: Enabling technologies for Ambient Intelligence applications.- Section 5. Energy Supply and Management. 5.1 Energy Scavenging in Support of Ambient Intelligence: Techniques, Challenges, and Future Directions. 5.2 Power Management Options For AmI Applications. 5.3 Rechargeable Batteries: Efficient energy storage devices for wireless electronics.- Section 6. Enabling Technologies and Devices. 6.1 Personal Healthcare Devices. 6.2 Carbon nanotube field-effect transistors - the importance of being small. 6.3 Hardware For Ambient Sound Reproduction. 6.4 Secret Key Generation From Classical Physics: Physical Uncloneable Functions.- Section 7. Conclusions. 7.1 Conclusion and Key Challenges.

We examine the vitrification and melting of asymmetric star polymer mixtures by combining rheological measurements with mode coupling theory. We identify two types of glassy states, a single glass, in which the small component is fluid in the glassy matrix of the big one, and a double glass, in which both components are vitrified. Addition of small-star polymers leads to melting of both glasses, and the melting curve has a nonmonotonic dependence on the star-star size ratio. The phenomenon opens new ways for externally steering the rheological behavior of soft matter systems. © 2005 The American Physical Society.

The dynamics of colloidal star - linear homopolymer mixtures is investigated by photon correlation spectroscopy. In dilute star solutions, osmotic forces due to the added polymers lead initially to a shrinkage of the stars and eventually, at higher polymer concentrations, to stable star clusters. Furthermore, concentrated glassy star solutions melt upon addition of small amounts of linear polymers, as manifested by the remarkable speed-up of the star self-diffusion. Quantitative description of the experimental findings is provided by calculations of the effective star-star pair potential. © EDP Sciences.

The ongoing miniaturization of electronic circuits and the corresponding exponential increase in embedded computational power is reaching the point where it becomes viable to integrate electronics into people environments. Ambient intelligence refers to an electronic environment that is sensitive and responsive to the presence of people. Such an environment should be (1) ubiquitous: surrounding the user by a multitude of interconnected systems; (2) transparent: integrated and hidden into the background; (3) intelligent: adapting to the people that live in it. The potential to distribute functionality over a network of devices is determined by the power resources of the device and upon considering these demands it appears helpful to further classify in-home ambient intelligence "devices" into three distinct classes: the "watt-node", "milli-watt-node", and "micro-watt-node". In this paper we try to map the system needs associated with these nodes, differing by orders of magnitude with respect to the amount of information to be processed as well as the available power, on to requirements for Si process technology choices.

A continuous-time /spl Sigma//spl Delta/ ADC with merged channel filter and programmable-gain functionality is presented. Interferers above full-scale can be applied without jeopardizing reception of weak desired signals. The merged design occupies 0.14 mm/sup 2/ in 0.18 /spl mu/m CMOS, consumes 2 mW, and achieves 89 dB of dynamic range (DR) in a 1 MHz bandwidth.

The vision of ambient intelligence opens a world of unprecedented experiences: the interaction of people with electronic devices is changed as context awareness, natural interfaces and ubiquitous availability of information are realized. We analyze the consequences of the ambient intelligence vision for embedded systems by mapping the involved technologies on a power-information graph. Based on differences in power consumption, three types of devices are introduced: the autonomous or microWatt-node, the personal or milliWatt-node and the static or Watt-node. Ambient intelligent functions are realized by a network of these devices with the computing, communication and interface electronics realized in Silicon IC technologies. The tri-partition of the ambient intelligence system hierarchy into microWatt nodes, milliWatt nodes, and Watt nodes introduces four major issues for embedded systems design.

In the first part of this paper the function of Analog to Digital (AD) and Digital to Analog (DA) converters in communication systems is discussed. The relation between the system data rate and the converter data rate is explored and the impact on the power dissipation in the AD and DA converter is shown. The second part describes the realisation of a DA converter for cable upstream application.

Background digital offset extraction and analog compensation remove offset of the critical analog components. The calibrated two-step ADC achieves -70 dB THD in the Nyquist band with a 2.5 V supply. The ADC in 0.25 μm CMOS measures 1.0 mm/sup 2/ and dissipates 295 mW.

We examined the cytotoxic effects of free daunorubicin (DNR) and liposome-encapsulated DNR on multidrug-resistant (MDR1) leukemia cells of patients with acute leukemias who had failed primary induction treatment that included DNR. This was analyzed ex-vivo with DNR concentrations and exposure times that normally can be achieved in-vivo for both drugs with induction treatment. The leukemic blasts of patients both with drug-resistant AML and drug-resistant ALL were, ex-vivo, very sensitive to DNR concentrations and exposure times that can be achieved in-vivo by liposome-encapsulated DNR. However, under identical conditions, free DNR and liposome-encapsulated DNR had a similar cytotoxic profile, arguing against a unique mechanism of cytotoxicity by the liposomal constructure. These data suggest that liposome-encapsulated DNR may be preferable to free DNR for the treatment of acute leukemias.

To set an example for the organization, the senior management team at Abbott Northwestern Hospital used quality tools and techniques to improve a highly visible, problematic system--the operating budget process. Team members narrowed the root cause to a faulty, nonintegrated assumption process and identified additional problems, such as inadequate communication, unclear accountabilities, and lengthy timetables. Then, the team streamlined the budget process from a 6-month to a 10-week cycle, which aligned the process with one of the organization's shared quality goals--reducing cycle time.Cycle time was reduced by 60 percent, from an average of 6 months to 10 weeks. Budget accuracy, which is measured by how close initial budget submissions come to targeted net income projections, improved by $12 million or 500 percent. The amount of rework, which is measured by the number of budget revisions made prior to Board approval, dropped from eight revisions to four. Overall satisfaction and familiarity with the budget process increased by 40 percent among managers and supervisors.

A series of adenovirus type 5 precursor terminal protein (pTP) and DNA polymerase (Ad pol) genes with linker insertion mutations were separately introduced into the vaccinia virus genome under the control of a late vaccinia virus promoter. The recombinant viruses were used for overexpression of the mutant genes in HeLa cells. In total, 22 different mutant pTP and 10 different Ad pol vaccinia virus recombinants were constructed, including some that expressed carboxyl-terminus-truncated forms of both proteins and one that produced the mutant H5ts149 Ad pol. To investigate the structure-function relationships of both proteins, extracts from cells infected with the recombinant viruses were tested for in vitro complementation of the initiation and elongation steps in adenovirus DNA replication. The results were in accordance with those of earlier in vivo experiments with these insertion mutants and indicate that multiple regions of both proteins are essential for adenovirus DNA replication. The carboxyl termini of both pTP and Ad pol were shown to be essential for proper functioning of these proteins during initiation of adenovirus DNA replication. Three different DNA replication-negative pTP mutants were shown to have residual activity in the initiation assay, suggesting not only that pTP is required for initiation but also that it may play a role in DNA replication after the deoxycytidylation step.

We have determined the exact nature of two thermosensitive (ts) adenovirus mutants, H5ts19 and H5ts149, which map to different genes in the E2 transcription unit. The H5ts19 mutation appears to stem from a single base-pair change of A-T to G-C at position 1840 (numbering as in ref. 1), corresponding to codon 154 of the gene coding for DBP. This results in a glutamine-to-arginine change in the amino-terminal domain of the protein. H5ts19 is defective in a late stage of infection, during virus assembly. This phenotype strongly differs from that described for the limited number of known DBP mutants, indicating that DBP is not only functional during DNA replication, but also plays a role in the late phase of the infection cycle. The defect of the (N group) mutant H5ts149 affects the initiation of viral DNA replication. Marker rescue experiments followed by nucleotide sequence analysis of H5ts149 DNA revealed a single point mutation in the gene coding for the Ad pol. A transition of C-G to A-T at position 7563 (numbering as in ref. 2) changes amino acid residue 411 of Ad pol, a leucine residue, to phenylalanine. This mutation is located in a region conserved among various DNA polymerases, which suggests an important role of this domain in DNA replication.

The organization of the chloroplast ribosomal RNA genes in Spirodela oligorhiza has been determined. We have therefore characterized two cloned BamHI fragments containing the genes for the large and small rRNA genes, and two PstI fragments, each containing one of the two large, invertedly repeated regions of chloroplast DNA. Characterization was performed by restriction endonuclease mapping, DNA/RNA hybridization and electronmicroscopic R-loop analysis. The results show that the rRNA genes are present in the order 16S, 23S, 4.5S and 5S. The 16S (1.5 kb) and 23S (2.9 kb) rRNA genes are separated by a spacer of 2.25 kb. There appears to be a close resemblance between the organization of the chloroplast rRNA genes in Spirodela oligorhiza and other higher plants so far examined.

The base sequence of Spirodela oligorhiza chloroplast DNA coding for 4.5S and 5S ribosomal RNA, the flanking regions and the spacer between these two genes has been determined. We have compared these sequences with the corresponding ones in other higher plants. Besides a high degree of homology, some interesting differences are found.

The dependence of grafting on the type of initiator has been examined in the case of three polymer–monomer systems: polystyrene–methyl methacrylate, polymethyl methacrylate–vinyl acetate, and polyethyl α-chloroacrylate–vinyl acetate. The different initiators used in these experiments were benzoyl peroxide (Bz2O2), azobisisobutyronitrile (AIBN), di-tert-butyl peroxide (DTBP), and tert-butyl hydroperoxide (TBHP). In each case the graft copolymers were separated from the homopolymers by fractional precipitation or by extraction. In the case of the system polystyrene–methyl methacrylate, an appreciable degree of grafting as well as formation of graft copolymer occur in the presence of Bz2O2; in contrast, the grafting is low with DTBP and doubtful with AIBN. For the other two systems no noticeable differences occurred as function of the initiator. In the case of polyethyl α-chloroacrylate the amount of graft copolymer is exceptionally high owing to the sensitivity of this polymer to a radical attack; this sensitivity results in the partial insolubility of the graft copolymers in the presence of TBHP and DTBP, but not in the presence of AIBN.

The kinetics of cyclopolymerization and cyclo-copolymerization of vinyl cinnamate were studied. The mechanism of chain propagation during the cyclopolymerization of vinyl cinnamate was considered. By determination of the residual unsaturation of the polymer (I.R. and U.V. spectrometry and bromometry) at different monomer concentrations, it was possible to evaluate the ratio of the cyclization rate constant to the vinyl propagation rate constant; it is equal to 13. In the range of low monomer concentrations the polymerization of vinyl cinnamate is of first order with respect to monomer concentration, and of one half order with respect to initiator concentration. At monomer concentration higher than three mole·1.minus;1 the reaction becomes independent of monomer concentration, and first order with respect to the initiator. Modified copolymer composition equations were derived taking due account of the different reactivity of the monomer radical before and after cyclization; consequently three reactivity ratios r1, r2, and r3 have been defined, and the experimental methods for their evaluation determined. On the basis of these equations the following reactivity ratios have been evaluated: vinyl cinnamate(M1)-vinyl acetate r3 = 1.2 ± 0.1 and r2 = 0.04; M1-vinyl pyrrolidone r3 = 1.15–1.30 and r1 = 0.01; M1-methacrylonitrile r3 = 0.15 and r2 = 4; M1-styrene r1 = 0.25 ± 0.1 and r2 = 1.25 ± 0.1. The interpretation of these data suggests formation of a pseudo-cyclic benzyl radical stabilized by resonance before addition of the second vinyl monomer. Die Kinetik der Cyclopolymerisation und Cyclo-Copolymerisation von Zimtsaurevinylester wurde studiert. Zuerst wurde der Mechanismus des Kettenwachstums wahrend der Cyclopolymerisation von Zimtsaurevinylester betrachtet. Die Bestimmung der restlichen Doppelbindungen im Polymeren (durch IR- und UV-Spektroskopie und Bromometrie) erlaubte die Bestimmung des Verhaltnisses von Cyclisierungs- zu Vinylwachstums-Geschwindigkeitskonstanten; es ergibt sich zu 13. Im Bereich kleiner Monomerkonzentrationen ist die Polymerisation von Zimtsaurevinylester eine Reaktion 1. Ordnung bezuglich Monomerkonzentration und 0,5. Ordnung bezuglich Initiatorkonzentration; sind die Monomerkonzentrationen groser als 3 Mole·l−1, wird die Reaktion von der Monomerkonzentration unabhangig und 1. Ordnung bezuglich des Initiators. Unter entsprechender Berucksichtigung der unterschiedlichen Reaktivitat des Monomerradikals vor und nach der Zyklisierung wurden modifizierte Copolymerisationsgleichungen aufgestellt; 3 Copolymerisationsparameter rl, r2 und r3 wurden definiert, und die experimentellen Methoden zu ihrer Bestimmung wurden angegeben. Auf Grund dieser Gleichungen wurden als Wert der Copolymerisationsparameter bestimmt: Zimtsaurevinylester (MI)-Vinylacetat r3 = 1,2 ± 0,l und r2 = 0,04; M1-Methacrylnitril r1 = 0,15 und r2 = 4; M1-Styrol rl = 0,25 ± 0,l und r2 = 1,25 ± 0,l. Eine Diskussion dieser Werte legt die Bildung eines pseudo-cyclischen Benzylradikals nahe, das durch Resonanz stabilisiert ist, bevor das 2. Vinylmonomere addiert wird.

The base sequence of Spirodela oligorhiza chloroplast DNA coding for 4.5S and 5S ribosomal RNA, the flanking regions and the spacer between these two genes has been determined. We have compared these sequences with the corresponding ones in other higher plants. Besides a high degree of homology, some interesting differences are found.

Publisher Summary This chapter reports the experimental techniques and results obtained in the study of polymeric alloys. Polymeric alloys are formed when two polymers are thoroughly mixed in one body. The lattice model for liquid–polymer mixtures was extended to the mixture of two polymers. A thermodynamic theory, which considers the free energy change on mixing two infinitely long completely separated blocks without consideration of domain morphology, gives for the mean free energy of mixing per segment. It is found that during casting from solution, the presence of solvent at the point of polymer immobilization may influence the type of morphology that is thermodynamically favored. The presence of a solvent preferential for one of the blocks tends to produce the morphology according to the volume fraction of the solvated block. The use of the solubility parameter is restricted to polymer pairs whose interactions are determined solely by dispersion forces. It is observed that in the metastable region, between the binodal and spinodal, phase separation is expected to proceed by nucleation and growth.