Model microemulsions containing vegetable oils part 1: Nonionic surfactant systems

Nonionic microemulsions containing triglycerides and fatty acid esters as lipophilic components have been studied. The phase inversion temperature (PIT) of the systems was determined by a conductometric method. Partial phase diagrams were constructed in the phase inversion temperature range. Water solubilization capacity of the nonionic surfactant systems studied was dependent on surfactant and oil types in analogy to ordinary hydrocarbon systems. The PIT:s increased with increased molecular weight for both esters and triglycerides.     

Analysis of Distribution of Nonmetallic Inclusions in Aluminum DC-Cast Billets and Slabs

Inclusion distribution was studied in commercial aluminum DC-cast billets and slabs using a newly developed deep-etching method. Analyses revealed a nonuniform distribution of nonmetallic inclusions across billet diameters and lengths, and also across slab thicknesses and widths. In as-cast billets, more inclusions were found at the beginning and end of the billet length; more were present near the cross-section center than near the surface. In slabs, inclusions were located mostly within 13 mm of the surface and in a band between the centerline and the surface. Few inclusions were found 60 to 100 mm from the slab surface or at the centerline. In addition, comparing slab quality after casting using three types of ceramic foam filters (CFFs; i.e., 30 ppi, 50 ppi, and 50 ppi + HF) revealed significant differences in inclusion size, number, and distribution. Casting slabs using a finer pore-size filter (50 ppi) reduced the number of non-metallic inclusions greatly. The inclusion distribution patterns observed in the solidified slabs are discussed in terms of melt flow during casting.     

Charge engineering of a protein domain to allow efficient ion-exchange recovery

We have created protein domains with extreme surface charge.These mutated domains allow for ion-exchange chromatographyunder conditions favourable for selective and efficient capture,using Escherichia coli as a host organism. The staphylococcalprotein A-derived domain Z (Z_wt) was used as a scaffold whenconstructing two mutants, Z_basic1 and Z_basic2, with high positivesurface charge. Far-ultraviolet circular dichroism measurementsshowed that they have a secondary structure content comparableto the parental molecule Z_wt. Although melting temperatures(T_m) of the engineered domains were lower than that of the wild-typeZ domain, both mutants could be produced successfully as intracellularfull-length products in E.coli and purified to homogeneity byion-exchange chromatography. Further studies performed on Z_basic1and Z_basic2 showed that they were able to bind to a cation exchangereven at pH values in the 9 to 11 range. A gene fusion betweenZ_basic2 and the acidic human serum albumin binding domain (ABD),derived from streptococcal protein G, was also constructed.The gene product Z_basic2–ABD could be purified using cation-exchangechromatography from a whole cell lysate to more than 90% purity.     

Selective proton labelling of amino acids in deuterated bovine calbindin D9K. A way to simplify 1H-NMR spectra

A technique for proton labelling of selected amino acids indeuterated calbindin D_9K, heterologously expressed in E.coli,was developed in order to simplify and obtain higher resolutionin ¹H-NMR spectra. The spectra from two double-labelling experiments,Val plus Ser and Val plus Leu, when compared to the uniformlyprotonated protein showed a dramatically simpler pattern withlow background signals and gave considerably sharper resonancesdue to reduced relaxation rates in the deuterated proteins.The selective proton labelling technique will enable detailedand rapid analysis of interesting domains of proteins and willalso make the analysis of larger proteins feasible.     

Method Developed for Quantitative Analysis of Inclusions in Solidified Aluminum Ingots

A deep-etching method was used to determine inclusions in solidified direct chill cast aluminum ingots. The technique was developed to allow easy quantification of the amount and size distribution of inclusions over billet lengths and cross sections. A pressure filtration (Prefil) test also was used to verify molten alloy cleanliness during casting, and the results of these measurements then were compared. The amount and distribution of nonmetallic inclusions were analyzed, as determined using a NaOH deep-etching method over billet lengths and cross sections. A higher inclusion count was observed at both billet ends, with more inclusions located nearer the billet section centerline. Furthermore, the inclusion density in the radial direction at every distance along the billet length was distributed inhomogeneously. Differences were observed between Prefil samples taken at different casting stages. The Prefil curves and metallographic analysis of Prefil residue obtained from melt samples, at an early casting stage or before degassing, indicate more oxides than in a melt sample taken under steady-state casting conditions. A reasonable correlation was established between the number of inclusions in the molten alloy (measured using Prefil and LiMCA) and the etch pits on deep-etched surfaces of billet cross sections.     

Evaluation of different linker regions for multimerization and coupling chemistry for immobilization of a proteinaceous affinity ligand

Alkaline conditions are generally preferred for sanitizationof chromatography media by cleaning-in-place (CIP) protocolsin industrial biopharmaceutical processes. The use of such rigorousconditions places stringent demands on the stability of ligandsintended for use in affinity chromatography. Here, we describeefforts to meet these requirements for a divalent proteinaceoushuman serum albumin (HSA) binding ligand, denoted ABD*dimer.The ABD*dimer ligand was constructed by genetic head-to-taillinkage of two copies of the ABD* moiety, which is a monovalentand alkali-stabilized variant of one of the serum albumin-bindingmotifs of streptococcal protein G. Dimerization was performedto investigate whether a higher HSA-binding capacity could beobtained by ligand multimerization. We also investigated theinfluence on alkaline stability and HSA-binding capacity ofthree variants (VDANS, VDADS and GGGSG) of the inter-domainlinker. Biosensor binding studies showed that divalent ligandscoupled using non-directed chemistry demonstrate an increasedmolar HSA-binding capacity compared with monovalent ligands.In contrast, equal molar binding capacities were observed forboth types of ligands when using directed ligand coupling chemistryinvolving the introduction and recruitment of a unique C-terminalcysteine residue. Significantly higher molar binding capacitieswere also detected when using the directed coupling chemistry.These results were confirmed in affinity chromatography bindingcapacity experiments, using resins containing thiol-coupledligands. Interestingly, column sanitization studies involvingexposure to 0.1 M NaOH solution (pH 13) showed that of all thetested constructs, including the monovalent ligand, the divalentligand construct containing the VDADS linker sequence was themost stable, retaining 95% of its binding capacity after 7 hof alkaline treatment. Received May 12, 2003; revised October 8, 2003; accepted October 21, 2003     

The Use of Oxygen Isotopic Labeling to Understand Oxidation Mechanisms

Oxidation of Metals - Isotopic labeling is a powerful tool to evaluatetransport and reaction mechanisms of oxidation. Theevaluation can answer the essential question inhigh-temperature oxidation:...     

Proposed future underground projects in sweden

The author describes a number of underground projects proposed by Swedish architects, engineers and planners. These include an underground wind tunnel built in rock, an underground museum, underground gas storage facility, an underwater traffic tunnel for Stockholm, and a large conference center under Stockholm, an underground concert hall in Jönköping, underground grain storage and oil storage facilities in rock caverns, and an underground pipeline to bring fuel to Stockholm airport, underground peak power-stations, and an underground waste treatment facility.     

Culture related to road traffic safety: A comparison of eight countries using two conceptualizations of culture

The majority of previous cross-country studies of human factors relevant to traffic safety have not operationalized and measured culture. Also studies in this vein have mostly been carried out in Europe and the United States. The aim of the study was to examine country cluster differences, based on the Culture's Consequences framework, in road traffic risk perception, attitudes towards traffic safety and driver behaviour in samples from Norway, Russia, India, Ghana, Tanzania, Uganda, Turkey and Iran. An additional aim was to examine cluster differences in road traffic culture as symbol use and to investigate whether this theoretical cultural framework predicts risk perception, attitudes towards traffic safety and driver behaviour in the country clusters. The sample consisted of a total of 2418 individuals who were obtained by convenience sampling in the different countries. The countries segmented into four Culture's Consequences clusters; Norway, Russia and India, Sub-Saharan Africa, and Near East countries. The findings showed that Norwegians reported overall safer attitudes towards traffic safety and driver behaviour than the remaining country clusters. Individuals in Africa reported the highest risk perception. The countries also differed substantially in road traffic culture as symbol use. Contrary to established cultural theory, prediction models revealed that cultural factors were stronger predictors of driver behaviour than of risk perception. Also, the social cognitive risk constructs (i.e. risk perception and attitudes) solely explained variance in driver behaviour in the Norwegian and Russia/India clusters. Previous empirical efforts, which aimed to demonstrate that culture is important for the risk perception criterion, may have focused on a criterion variable that is not strongly related to driver behaviour. Furthermore, countermeasures aimed to influence social cognition may have stronger applicability in countries with a more individualistic western cultural orientation.