From geotechnical maps to three-dimensional models

It is generally preferable to store geotechnical and geological investigation material for possible future use. Old material may be even more valuable than new results in some cases. If the location data for site investigations cannot be identified reliably, it is usually advisable to refrain from using the data at all. Quaternary maps compiled by the Geological Survey of Finland are available for the entire country. Some municipalities in areas where foundation conditions play a prominent part in the safety and economy of building have worked up their own foundation survey materials into regional geotechnical maps. The use of geotechnical data for planning has always required a three-dimensional viewpoint. 3D analysis requires a joint GIS-type database. These still generally consist of binary files, although a relational database solution is recommended for the management of large bodies of data in particular. The general principle as regards old investigations is that their costs have already been covered, whereas overwise separate search and maintenance costs will be involved. Data users are themselves responsible for the results of older site investigations. One important feature is that geotechnical data can be combined with information obtained from other systems.     

Enzymatic synthesis of site-specifically (alpha 1-3)-fucosylated polylactosamines containing either a sialyl Lewis (x), a VIM-2, or a sialylated and internally difucosylated sequence

By using two different reaction pathways, we generated enzymatically three sialylated and site-specifically alpha 1-3-fucosylated polylactosamines. Two of these are isomeric hexasaccharides Neu5Ac(alpha 2-3)Gal(beta 1-4)GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)] GlcNAc and Neu5Ac(alpha 2-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-3)Gal(beta 1-4) GlcNAc, containing epitopes that correspond to VIM-2 and sialyl Lewis (x), respectively. The third one, nonasaccharide Neu5Ac(alpha 2-3)Gal(beta 1-4)GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)] GlcNAc(beta 1-3)Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc, is a sialylated and internally difucosylated derivative of a trimeric N-acetyllactosamine. All three oligosaccharides have one fucose-free N-acetyllactosaminyl unit and can be used as acceptors for recombinant alpha 1-3-fucosyltransferases in determining the biosynthesis pathways leading to polyfucosylated selectin ligands.     

Improving the Accuracy of Structural Hot‐spot Stress Approach

A method for extending the applicability of the structural hot‐spot stress method for fatigue assessment of welded structures is discussed. The structural hot‐spot stress method for plate structures, as currently presented in commonly used design guidance documents, cannot account for the effect of weld size, and load carrying fillet welds are assessed using a different S‐N curve as compared to non‐load carrying fillet welds. This paper presents a proposal to linearize the local stress distribution through the plate thickness in the plane of the weld toe. This proposal considers the forces transmitted by the weld itself. A bilinear stress distribution, which partially captures the local effect of the weld, is derived from the non‐linear stress distribution. The non‐linear distribution is based on equilibrium and the stress in the fillet weld. A simple procedure is presented to determine the bilinear curve from the nominal weld stress. This is a great advantage in finite element analysis when only nominal base plate stress and nominal weld stresses need to be determined. When compared to the more conventional structural stress approach, the new method also has the advantage that extrapolation is not required. The same weld stresses can also be used in the analysis of the root cracks. The proposed method was scaled to correspond to the traditional structural hot‐spot stress method using detailed linear elastic fracture mechanics simulations. The method is only applied to fully load‐carrying welds here but can also be used for partial load‐carrying welds. A symmetric splice plate having a fully loaded fillet weld is presented as an example case. The influence of base plate thickness is studied as well.     

Inkjet Printed Large‐Area Flexible Few‐Layer Graphene Thermoelectrics

Graphene‐based organic nanocomposites have ascended as promising candidates for thermoelectric energy conversion. In order to adopt existing scalable printing methods for developing thermostable graphene‐based thermoelectric devices, optimization of both the material ink and the thermoelectric properties of the resulting films are required. Here, inkjet‐printed large‐area flexible graphene thin films with outstanding thermoelectric properties are reported. The thermal and electronic transport properties of the films reveal the so‐called phonon‐glass electron‐crystal character (i.e., electrical transport behavior akin to that of few‐layer graphene flakes with quenched thermal transport arising from the disordered nanoporous structure). As a result, the all‐graphene films show a room‐temperature thermoelectric power factor of 18.7 µW m^?1 K^?2, representing over a threefold improvement to previous solution‐processed all‐graphene structures. The demonstration of inkjet‐printed thermoelectric devices underscores the potential for future flexible, scalable, and low‐cost thermoelectric applications, such as harvesting energy from body heat in wearable applications.     

Ethene hydroformylation on Co/SiO2 catalysts

The results from ethene hydroformylation at 173°C showed that a Co(acac)₃/SiO₂ catalyst prepared from Co(acac)₃ precursor by gas‐phase deposition was three times as active as a catalyst prepared by impregnation from cobalt nitrate, but oxo‐selectivities were similar. The high propanal selectivities on the Co(acac)₃/SiO₂ seem to be related to the presence of highly dispersed active sites favouring CO insertion. As dispersion is decreased from 23 to 8% due to increasing metal content (from 5 to 16 wt%), oxo‐selectivity decreased from 39 to 25%. The activity of Co(acac)₃/SiO₂ remained unchanged during 68 h on stream. The gas‐phase deposition technique described here is a promising method for the preparation of active, selective and stable heterogeneous hydroformylation catalysts. This revised version was published online in July 2006 with corrections to the Cover Date.     

Modified bounded homotopies to enable a narrow bounding zone

The aim of this paper is to introduce modifications that enhance the usability of the bounded homotopy methods proposed by Paloschi [1995. Bounded homotopies to solve systems of algebraic nonlinear equations. Computers and Chemical Engineering 19, 1243-1254; 1997. Bounded homotopies to solve systems of sparse algebraic nonlinear equations. Computers and Chemical Engineering 21, 531-541], especially in the area of chemical engineering. In modified bounded homotopies, the homotopy path is tracked by exploiting mapped variables instead of unmapped ones. Path tracking based on mapped variables makes it significantly easier to track the bounded homotopy path even though the bounding zone has to be narrow. Mapping also improves the bounding effect of bounded homotopies and makes it possible to avoid unreasonable variable values in homotopy path tracking. The performance of the modifications is illustrated with test cases. These examples clearly show that the modifications enlarge the capability and accuracy of bounded homotopies when solving both small- and large-scale sets of nonlinear equations describing chemical engineering problems.     

Development of an Efficient Acid Digestion Procedure Utilizing High-Pressure Asher Technique for the Determination of Iodine and Metallic Elements in Milk Powder

An effective wet digestion procedure for the determination of total iodine contents in milk powder samples was developed utilizing a high-pressure asher technique. The optimized method based on a two-stage digestion procedure. In the first stage, 500 mg samples were digested at 300 °C for 2 h using 15.2 mol L^?1 HNO₃ (5 mL) and 30 % H₂O₂ (3 mL). After the first digestion stage, digestion vessels were allowed to cool down and 1.2 mL of 20 % (w/v) Na₂S₂O₈ solution was added as an additional oxidizing agent to the samples. After that, the vessels were closed, and they were heated at 100 °C for 30 min, resulting in clear and colorless sample solutions. Iodine concentrations in the digested samples were measured with inductively coupled plasma mass spectrometry. The accuracy of the optimized method was confirmed by analyzing milk powder reference material (BCR-151, milk powder). The obtained value for iodine (5.29?±?0.37 mg kg^?1, n?=?6) was in good agreement with the certified value (5.35?±?0.14 mg kg^?1). Furthermore, the results obtained for reference material showed that the developed method can be applied also for the determination of other elements, e.g., copper, iron, and lead in the digested milk powder samples.     

Thermal tuning of laser pulse parameters in passively Q-switched Nd:YAG lasers

Modifying the output pulses of a passively Q-switched Nd:YAG laser, operating at 1064 nm, was realized by heating the laser crystal. With the demonstrated laser setups, a 100 K temperature rise led to a more than 50% increase in the pulse energy and a more than 10% decrease in the pulse length. This method offers an effective way to tune the output of the laser without mechanical adjustment or a change of components.