An Investigation of Drying Process of Shelled Pistachios in a Newly Designed Fixed Bed Dryer System by Using Artificial Neural Network

In this paper, the drying of Siirt pistachios (SSPs) in a newly designed fixed bed dryer system and the prediction of drying characteristics using artificial neural network (ANN) are presented. Drying characteristics of SSPs with initial moisture content (MC) of 42.3% dry basis (db) were studied at different air temperatures (60, 80, and 100 °C) and air velocities (0.065, 0.1, and 0.13 m/s) in a newly designed fixed bed dryer system. Obtained results of experiments were used for ANN modeling and compared with experimental data. Falling rate period was observed during all the drying experiments; constant rate period was not observed. Furthermore, in the presented study, the application of ANN for predicting the drying time (DT) for a good quality product (output parameter for ANN modeling) was investigated. In order to train the ANN, experimental measurements were used as training data and test data. The back propagation learning algorithm with two different variants, so-called Levenberg–Marguardt (LM) and scaled conjugate gradient (SCG), and tangent sigmoid transfer function were used in the network so that the best approach can be determined. The most suitable algorithm and neuron number in the hidden layer are found out as LM with 15 neurons. For this number level, after the training, it is found that Root-mean squared (RMS) value is 0.3692, and absolute fraction of variance (R²) value is 99.99%. It is concluded that ANNs can be used for prediction of drying SSPs as an accurate method in similar systems.     

The effect of the electron irradiation on the series resistance of Au/Ni/6H-SiC and Au/Ni/4H-SiC Schottky contacts

The effect of electron irradiation on Au/Ni/6H-SiC and Au/Ni/4H-SiC Schottky contacts has been studied by current voltage (I-V) characterization at room temperature. The diodes have been subjected to the electron irradiation at various energies (6, 12 and 15 MeV) and influence of the electron irradiation on the diode parameters such as barrier height, ideality factor, and series resistance has been studied. Cheung functions, Norde model and conductance method have been used to determine the diode parameters. The ideality factor of the diodes is greater than unity indicating activation of some other current transport mechanism(s). The series resistances of the diodes increase by increasing electron energy. The reverse current increases for the Au/Ni/6H-SiC diode after each electron irradiation experiment, while decreasing trend is observed for Au/Ni/4H-SiC diode. Decrease in the barrier height of Au/Ni/4H-SiC diode is observed and mainly attributed to the increase of the reverse current, while the decrease of the forward current is caused by increase in series resistance, for high electron irradiation energies.     

Die bulgarische Sojabohne

Ohne ZusammenfassungMitteilung aus dem Chemischen Institut der Universität Sofia.     

Radioactivity and heavy metal concentrations in food samples from Rize, Turkey

BACKGROUND: Rize in Turkey was contaminated by the Chernobyl accident in 1986. A comprehensive study was planned and carried out to determine the radioactivity levels and heavy metal concentrations in four food categories collected in Rize in 2008, 2009 and 2010. RESULTS: Tomato showed the highest concentration of ²³⁸U, at 9.43 ± 0.128 Bq kg^?1, whereas the lowest concentration of 0.20 ± 0.02 Bq kg^?1 was measured in aubergine samples. The highest concentration of ²³²Th was measured at 3.22 ± 0.29 Bq kg^?1 in grape samples. ⁴⁰K was found to contribute the highest activity in all the food samples. The highest activity concentration of ¹³⁷Cs was 10.20 ± 4.19 Bq kg^?1, for parsley. The average contribution range of each of the heavy metals to the dietary intake was 0.13–9.14, 0.27–34.63, 0.05–3.62, 0.11–14.97, 0.78–8.51 and 0.01–1.57 mg, respectively, for Mn, Fe, Cu, Zn, Ni and As. CONCLUSION: The range of radioactivity levels in food samples of the present study is of no risk to public health. Heavy metal concentrations of Mn, Fe, Cu, Zn, Ni and As obtained were far below the established values by FAO/WHO limits. Copyright © 2011 Society of Chemical Industry     

Slicing from formal semantics: Chisel—a tool for generic program slicing

We describe Chisel, a tool that synthesizes a program slicer directly from a given algebraic specification of a programming language operational semantics \(\mathcal {S}\). \(\mathcal {S}\) is assumed to be a rewriting logic specification, given in Maude, while the program is a ground term of this specification. Chisel takes \(\mathcal {S}\) and synthesizes language constructs, i.e., instructions, that produce features relevant for slicing, e.g., data dependency. We implement syntheses adjusted to each feature as model checking properties over an abstract representation of \(\mathcal {S}\). The syntheses results are used by a traditional interprocedural slicing algorithm that we parameterize by the synthesized language features. We present the tool on two language paradigms: high-level, imperative and low-level, assembly languages. Computing program slices for these languages allows for extracting traceability properties in standard compilation chains and makes our tool fitting for the validation of embedded system designs. Chisel’s slicing benchmark evaluation is based on benchmarks used in avionics.     

Cardinality Networks: a theoretical and empirical study

We introduce Cardinality Networks, a new CNF encoding of cardinality constraints. It improves upon the previously existing encodings such as the sorting networks of Eén and Sörensson (JSAT 2:1–26, 2006) in that it requires much less clauses and auxiliary variables, while arc consistency is still preserved: e.g., for a constraint x ₁?+?...?+?x _n ?≤?k, as soon as k variables among the x _i ’s become true, unit propagation sets all other x _i ’s to false. Our encoding also still admits incremental strengthening: this constraint for any smaller k is obtained without adding any new clauses, by setting a single variable to false. Here we give precise recursive definitions of the clause sets that are needed and give detailed proofs of the required properties. We demonstrate the practical impact of this new encoding by careful experiments comparing it with previous encodings on real-world instances.     

A mixed-integer programming formulation and Lagrangean relaxation for the cross-dock door assignment problem

In a cross-dock, goods are unloaded from incoming trucks, consolidated according to their destinations, and then, loaded into outgoing trucks with little or no storage in between. In this paper, we study the cross-dock door assignment problem in which the assignment of incoming trucks to strip doors, and outgoing trucks to stack doors is determined, with the objective of minimising the total material handling cost. We present a new mixed integer programming formulation which is embedded into a Lagrangean relaxation that exploits the special structure of the problem to obtain bounds on the optimal solution value. A primal heuristic is used at every iteration of the Lagrangean relaxation to obtain high quality feasible solutions. Computational results obtained on benchmark instances (with up to 20 origins and destinations, and 10 strip and stack doors) and on a new and more difficult set of instances (with up to 50 origins and destinations, and 30 strip and stack doors) confirm the efficiency of the algorithm.     

Cubic group-III nitride-based nanostructures—basics and applications in optoelectronics

Molecular beam epitaxy (MBE) of cubic group-III nitrides is a direct way to eliminate the polarization effects which inherently limits the performance of optoelectronic devices containing quantum well or quantum dot active regions. In this contribution the latest achievement in the MBE of phase-pure cubic GaN, AlN, InN and their alloys will be reviewed. A new reflected high-energy electron beam (RHEED) control technique enables to carefully adjust stoichiometry and to severely reduce the surface roughness, which is important for any hetero-interface. The structural, optical and electrical properties of cubic nitrides and AlGaN/GaN will be presented. We show that no polarization field exists in cubic nitrides and demonstrate 1.55 μm intersubband absorption in cubic AlN/GaN superlattices. Further the progress towards the development and fabrication of cubic hetero-junction field effect transistors (HFETs) is discussed.