Spectrophotometric determination of chromium as the chromium-peroxo-4-(2-pyridylazo)resorcinol complex

Der ternäre Chrom-Peroxo-PAR-Komplex weist einen scheinbaren molaren Extinktionskoeffizienten von 6280 l · mol −1 · cm −1 auf, wenn er aus 0,1 M schwefelsaurer Lösung mit Ethylacetat extrahiert wird. Das Beersche Gesetz wird bis zu 6,0 μg Cr/ml befolgt. Die Bedingungen für eine optimale Farbbildung, die Zusammensetzung des Komplexes, die Wirkung verschiedener Begleitionen und die Anwendung auf Stähle werden beschrieben. The ternary complex chromium-peroxo-PAR exhibits an apparent molar absorptivity of 6280 l mol −1 cm −1 when extracted into ethyl acetate from 0.1 M sulfuric acid solution. Beer's law is followed for solutions containing up to 6.0 μg Cr ml −1 . Conditions for optimum color formation, complex composition, effects of diverse ions, and application to the determination of chromium in steels are described.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46457/1/216_2004_Article_BF00480608.pd

Equity and justice in global warming policy

Many countries are implementing or at least considering policies to counter increasingly certain negative impacts from climate change. An increasing amount of research has been devoted to the analysis of the costs of climate change and its mitigation, as well as to the design of policies, such as the international Kyoto Protocol, post-Kyoto negotiations, regional initiatives, and unilateral actions. Although most studies on climate change policies in economics have considered efficiency aspects, there is a growing literature on equity and justice. Climate change policy has important dimensions of distributive justice, both within and across generations, but in this paper we survey only studies on the intragenerational aspect, i.e.., within a generation. We cover several domains including the international, regional, national, sectoral and inter-personal, and examine aspects such as the distribution of burdens from climate change, climate change policy negotiations in general, implementation of climate agreements using tradable emission permits, and the uncertainty of alternatives to emission reductions

Synthesis and characterization of adenine base grafted polyacrylamides as polynucleotide analogs

The adenine base grafted polyacrylamides and their corresponding monomer model compounds were prepared and examined. The results suggest that the monomer model compounds exist in a preferred conformation, whereas the adenine base grafted polyacrylamides exist in a limited ordered conformation in an aqueous medium.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38814/1/080241218_ftp.pd

Synthesis and characterization of uracil base grafted polyacrylamides as polynucleotide analogs Dedicated to Professor Dr. Georg Manecke on the occasion of his 70th birthday, June 13, 1986.

In conjunction with the previous studies of the adenine base grafted polyacrylamides, the uracil base grafted polyacrylamides and their monomer model compounds were prepared. In this case, however, an amine bond instead of an amide bond was used to attach the pendants onto the amino active site. A wider range of grafting efficiency (45–90%) and a smaller hypochromic effect were observed. This increase in grafting efficiency is responsible for the observed increase in percent hypochromicity. The reactivity ratios of the monomer model compounds with complementary bases, e.g., uracil and adenine, were estimated from a Finemann–Ross plot. Continuous mixing experiments involving the synthetic polyacrylamides with complementary bases suggested that polymer–polymer mixtures form base-paired complexes that stabilize the stacked conformation only in neutral aqueous solution. Electrostatic repulsion prÈvented such stability in acidic or alkaline aqueous solution. The collective information from NMR, UV, and CD spectra suggested that uracil based grafted poly(2-amino-2-methylpropyl)acrylamide (PDMPA) and poly(2-amino-2-methylbutyl)acrylamide (PDMBA) exist in limited ordered conformation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38813/1/080241217_ftp.pd

Synthesis and characterization of poly(2-amino-2-methylpropyl)acrylamide, poly(2-amino-2-methylbutyl)acrylamide, and copolymers of polyacrylamide

Polyacrylamides possessing an amino group at the terminus of the branch chain as the potential site for amino acid and/or nucleic acid base grafting have been prepared. This type of polyacrylamide would provide a substantial spacing distance between the polymer main chain and pendant groups. Poly(2-amino-2-methylpropyl)acrylamide (PDMPA) and optically active poly(2-amino-2-methylbutyl)acrylamide (PDMBA) were characterized using vapor phase osmometry (VPO), gel permeation chromatography (GPC), and dilute solution viscometry. In addition, copolymers of poly(2-amino-2-methylpropyl)acrylamide with N -vinylpyrrolidinone, N -vinylimidazole, and H(5)-vinylimidazole, were prepared.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38815/1/080241219_ftp.pd

Synthesis and characterization of poly(2-amino-2-methylpropyl)acrylamide, poly(2-amino-2-methylbutyl)acrylamide, and copolymers of polyacrylamide

Polyacrylamides possessing an amino group at the terminus of the branch chain as the potential site for amino acid and/or nucleic acid base grafting have been prepared. This type of polyacrylamide would provide a substantial spacing distance between the polymer main chain and pendant groups. Poly(2-amino-2-methylpropyl)acrylamide (PDMPA) and optically active poly(2-amino-2-methylbutyl)acrylamide (PDMBA) were characterized using vapor phase osmometry (VPO), gel permeation chromatography (GPC), and dilute solution viscometry. In addition, copolymers of poly(2-amino-2-methylpropyl)acrylamide with N -vinylpyrrolidinone, N -vinylimidazole, and H(5)-vinylimidazole, were prepared.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38815/1/080241219_ftp.pd