Optimization of pH value and aluminium sulphate quantity in the chemical treatment of molasses

The aim of this investigation was to find the optimal working conditions for the chemical treatment of molasses that guarantee coagulation and precipitation of undesired macromolecules. Twenty experiments were performed, within the limits: 3.5pH8.5 and 0.1 mol Al/lc0.5 mol Al/l, on samples of molasses treated with Al₂(SO₄)₃ as a precipitant. The efficiency of the treatment was controlled through measuring both the zeta potential and solution absorbance at 560 nm. By analysing the experimental results, it was concluded that the optimum lies within reduced limits of: 4pH7 and 0.2 mol Al/lc0.4 mol Al/l, which covers nine experimental points. Based on these measurements, a mathematical model of absorbance changes was defined, in terms of pH and Al₂(SO₄)₃ quantity. The model was taken as the objective function, and the optimal calculated values were obtained: pH=5.3 and c=0.34 mol Al/l. They guarantee a minimal absorbance value of: 0.124 at 560 nm.     

Pulsed flow for enhanced cleaning in food processing

The use of slow (～1 Hz) flow oscillation imposed on a stationary flow of liquid has been shown to enhance shear stresses imposed on a surface and to mitigate fouling or enhance cleaning. Examples of the application of pulsed flow are presented in this paper. A new measuring technique in combination with tailored CFD simulations was developed for monitoring the cleaning of complex piping equipment with pulsed flow. A time-independent and isotropic approach to model the wall shear stress is introduced. The optical monitoring procedure uses a model food soil consisting of starch as matrix material and phosphorescent zinc sulfide crystals as optical tracer. Investigations of pulsed flow cleaning published prior to this work focused on tests with straight pipes, whereas difficulties in industrial cleaning operations more often arise while operating piping systems and plant components with complex geometries. Therefore cleaning experiments were performed in a CIP test rig simulating industrial cleaning processes. The results with pulsed flow show an enhancement of cleaning efficiency at locations difficult to access using stationary flow.     

Multi-response design of Nd:YAG laser drilling of Ni-based superalloy sheets using Taguchi��s quality loss function, multivariate statistical methods and artificial intelligence

This paper presents a hybrid design strategy for the determination of the optimum laser drilling parameters which simultaneously meets the requirements for seven quality characteristics (responses) of the holes produced during pulsed Nd:YAG laser drilling of a thin sheet of nickel-based superalloy Nimonic 263. The process was designed using two approaches based on the experimental data. In the first approach, the quality losses of seven correlated responses were uncorrelated into a set of components using the principal component analysis; then the grey relational analysis was applied to synthesise components into a synthetic performance measure. Since this approach considered only parameter values used in the experiment, the second approach was developed to find the global optimal parameters solution using an artificial neural network to model the relation between parameters and a synthetic performance measure, and a genetic algorithm to perform a search for the global optimum in a continual multidimensional space. The analysis of the application indicated that the proposed approaches gave a better result, in terms of the optimal parameter settings that yield the maximal synthetic performance measure, than several commonly used methods for multi-response process parameters design. The results demonstrated that the robust Nd:YAG laser drilling of Ni-based superalloy sheets was designed with respect to the requirements for seven quality characteristics of the drilled holes, by using the proposed strategy.     

Application of supervised self-organizing maps in breast cancer diagnosis by total synchronous fluorescence spectroscopy

Data from total synchronous fluorescence spectroscopy (TSFS) measurements of normal and malignant breast tissue samples are introduced in supervised self-organizing maps, a type of artificial neural network (ANN), to obtain diagnosis. Three spectral regions in both TSFS patterns and first-derivative TSFS patterns exhibited clear differences between normal and malignant tissue groups, and intensities measured from these regions served as inputs to neural networks. Histology findings are used as the gold standard to train self-organizing maps in a supervised way. Diagnostic accuracy of this procedure is evaluated with sample test groups for two cases, when the neural network uses TSFS data and when the neural network uses data from first-derivative TSFS. In the first case diagnostic sensitivity of 87.1% and specificity of 91.7% are found, while in the second case sensitivity of 100% and specificity of 94.4% are achieved.     

Folgen des Globalen Wandels für das Grundwasser in Süddeutschland – Teil 2: Sozioökonomische Aspekte

In order to account for complex interactions between humans climate and the water cycle, the research consortium GLOWA-Danube (www.glowa-danube.de) has developed the simulation system DANUBIA which consists of 17 coupled models. DANUBIA was applied to investigate various impacts of global-change between 2011 and 2060 in the Upper Danube Catchment. This article describes part 2 of an article series with investigations of socio-economic aspects, while part 1 (Barthel et al. in Grundwasser 16(4), doi:10.1007/s007-011-01794, 2011) deals with natural-spatial aspects. The principles of socio-economic actor-modeling and interactions between socio-economic and natural science model components are described here. We present selected simulations that show impacts on groundwater from changes in agriculture, tourism, economy, domestic water users and water supply. Despite decreases in water consumption, the scenario simulations show significant decreases in groundwater quantity. On the other hand, groundwater quality will likely be influenced more severely by land use changes compared to direct climatic causes. However, overall changes will not be dramatic.     

CDMA bus-based on-chip interconnect infrastructure

As technology scales toward deep submicron, the integration of complete system-on-chip (SoC) designs consisting of large number of Intellectual Property (IP) blocks (cores) on the same silicon die is becoming technically feasible. Until recently, the design-space exploration for SoCs has been mainly focused on the computational aspects of the problem. However, as the number of IP blocks on a single chip and their performance continue to increase, a shift from computation-based to communication-based designs becomes mandatory. As a result, the communication architecture plays a major role in the area, performance and energy consumption of the overall systems [Pasricha S, Dutt N. On-chip communication architectures: system on chip interconnect. Amsterdam: Elsevier Inc.; 2008, Kim J, Verbauwhede I, Chang MCF. Design of an interconnect architecture and signaling technology for parallelism in communication. IEEE Trans VLSI Syst 2007;15(8):881-94].This article presents a structure of a wrapper as a component of Code Division Multiple Access, CDMA, based shared bus architecture in a SoC. Two types of wrappers can be identified, master and slave. A master wrapper is located between the arbiter and CDMA coded physical interconnect, while a slave connects the CDMA coded bus with memory/peripheral module. In the proposal, only bus lines that carry address and data signals are CDMA coded. We implemented a pair of master-slave wrapper described in VHDL and confirmed its functionality using testbenches. Also we synthesized wrappers using a Xilinx Spartan and Virtex devices to determine resource requirements in respect to a number of equivalent gates, communication bandwidth, latency and power consumption. Specifically we involved a Design_Quality, DQ, metric for wrapper performance evaluation. A pair of master-slave wrapper seems to occupy appropriate space, in average 2000 equivalent gates, considering CPU cost of about 30,000 gates, what is less than 8% of hardware overhead per CPU. We also present experimental results which show that benefits of involving CDMA coding relates both to decreasing a number of bus lines and accomplishing simultaneous multiple master-slave connections at relatively low-power consumption and high communication bandwidth. Convenient range indices R_W and R_R to determine data transfer rate for Write and Read operations in multiprocessor bus systems that use TDMA and CDMA data transfer techniques. The obtained results show that increased data transfer latencies involved by CDMA data transfer are compensated by simultaneous master-slave transfers.     

Effect of Wood Welding Process on Chemical Constituents of Australian Eucalyptus

Thermochemical changes occurring during wood welding were investigated in Eucalyptus saligna and Eucalyptus pilularis. Unwelded reference wood and material from welded interface were compared via Py-GC/MS, thermogravimetric analyses, X-ray photoelectron spectroscopy, and attenuated total reflection Fourier transform infrared spectroscopy to explain differences in mechanical properties of welded wood between species. It appeared that the species originally containing more condensed substructures also provided stronger joints. The condensation index after welding allowed validating that the adhesive properties of lignin are more accessible in such species. The presence of more carbonyl functions, attributed to carbohydrate solicitation during welding process, potentially made lignin less accessible. Changes following welding were evidenced by the contribution of extractive compounds, fatty acid chains, and terpenoids, possibly reacting with hydroxyl groups and leading to adhesive properties by chemical linkage through new covalent bonds formation. Results corroborate the better mechanical properties of E. saligna, providing stronger joints possibly due to more accessible adhesive properties by esterification between lignin and fatty acid.     

Variable neighborhood search based approaches to a vehicle scheduling problem in agriculture

A vehicle scheduling problem (VSP) that arises from sugar beet transportation within minimum working time under the set of constraints reflecting a real‐life situation is considered. A mixed integer quadratically constrained programming (MIQCP) model of the considered VSP and reformulation to a mixed integer linear program (MILP) are proposed and used within the framework of Lingo 17 solver, producing optimal solutions only for small‐sized problem instances. Two variants of the variable neighborhood search (VNS) metaheuristic—basic VNS (BVNS) and skewed VNS (SVNS) are designed to efficiently deal with large‐sized problem instances. The proposed VNS approaches are evaluated and compared against Lingo 17 and each other on the set of real‐life and generated problem instances. Computational results show that both BVNS and SVNS reach all known optimal solutions on small‐sized instances and are comparable on medium‐ and large‐sized instances. In general, SVNS significantly outperforms BVNS in terms of running times.     

Purification and properties of polyphosphatase from Saccharomyces cerevisiae cytosol

A homogenous polyphosphatase preparation was obtained from Saccharomyces cerevisiae cytosol with a 3·8% yield and 3540-fold purification. The enzyme hydrolysed polyphosphate (polyP) with various chain lengths, including polyP₃, and split P_i off the end of the chain. It was inactive with respect to ATP, PP_i, and p-nitrophenylphosphate. Its specific activity with polyP₁₅ was 283 U/mg protein. The polyphosphatase was a monomeric protein with a molecular mass of 40 kDa. This enzyme was inactive without divalent cations and with Cu²⁺ and Ca²⁺. The ability of other divalent cations to activate the enzyme decreased in the following order: Co²⁺>Mn²⁺>Mg²⁺>Zn²⁺. A kinetic model of the hydrolysis of polyP₃ and action of Mg²⁺ is proposed. © 1998 John Wiley & Sons, Ltd.