Dynamic explicitly specified behaviors in distributed agent-based industrial solutions

Currently, the manufacturing domain is primarily characterized by the flexibility, adaptability and robustness of the production system. The manufacturing flow processes lead to shorter cycle times to efficiently meet customer needs. Mentioned features can be more easily achieved in a distributed system, such as holonic or multi-agent system, which becomes strongly influenced by the advancement of semantic technologies. In the majority of existing multi-agent based control systems, which are responsible for acting, sensing, computing and production planning, the ontology (necessary for knowledge bases and communication) is usually hard-coded directly in the agent code. In this case, the hard-coded system behavior can be hardly maintained??usually system reprogramming is needed from time to time to satisfy customer requirements. In this paper we discuss the necessity of explicit definition of both declarative and procedural knowledge and propose explicit procedural knowledge handling. Sharing and distribution of such knowledge is discussed and illustrated on an implemented transportation system example. We also introduce the utilization of discussed architecture for explicit specification of agent behavior in failures patterns handling and smart grid configuration scenario. Such a solution greatly increases the possibility of system integration, openness, flexibility, and extensibility, all without having to restart the running distributed system. The topic discussed in this paper shows the ability of the dynamic reconfigurable multi-agent system to participate in development of industrial control systems and solutions.     

Initial sintering stage of thoria powder investigated by emanation thermal analysis

The initial stage of free sintering of thoria (ThO₂) has been investigated by means of emanation thermal analysis. Thoria powder (having surface area of 18 m² g^–1) was prepared from thorium oxalate (homogeneously labelled by²²⁸Th) by heating to 500 ° C. The release of²²⁰Rn was studied at various temperatures. The curves of radon diffusion release measured during isothermal heating of thoria powder at four temperatures (705, 735, 780 and 825 ° C) have been used for investigating the kinetics of the surface changes of thoria powder during the initial stage of sintering. The experimental data evaluated obey the kinetic law E _p S _eff = const ×t ⁿ , whereE _p is the emanating power due to the diffusion of radon in intergranular space and open pores,S _eff is the effective surface area,t is time andn equals 0.64. The effective surface areaS _eff has been proposed as a new parameter characterizing the active surface of powdered solid and its changes during sintering.     

Lasioglossins: Three Novel Antimicrobial Peptides from the Venom of the Eusocial Bee Lasioglossum laticeps (Hymenoptera: Halictidae)

Three novel structurally related pentadecapeptides, named lasioglossins, were isolated from the venom of the eusocial bee Lasioglossum laticeps. Their primary sequences were established as H‐Val‐Asn‐Trp‐Lys‐Lys‐Val‐Leu‐Gly‐Lys‐Ile‐Ile‐Lys‐Val‐Ala‐Lys‐NH₂ (LL‐I), H‐Val‐Asn‐Trp‐Lys‐Lys‐Ile‐Leu‐Gly‐Lys‐Ile‐Ile‐Lys‐Val‐Ala‐Lys‐NH₂ (LL‐II) and H‐Val‐Asn‐Trp‐Lys‐Lys‐Ile‐Leu‐Gly‐Lys‐Ile‐Ile‐Lys‐Val‐Val‐Lys‐NH₂ (LL‐III). These lasioglossins exhibited potent antimicrobial activity against both Gram‐positive and Gram‐negative bacteria, low haemolytic and mast cell degranulation activity, and a potency to kill various cancer cells in vitro. The lasioglossin CD spectra were measured in the presence of trifluoroethanol and sodium dodecyl sulfate solution and indicated a high degree of α‐helical conformation. NMR spectroscopy, which was carried out in trifluoroethanol/water confirmed a curved α‐helical conformation with a concave hydrophobic and convex hydrophilic side. To understand the role of this bend on biological activity, we studied lasioglossin analogues in which the Gly in the centre of the molecule was replaced by other amino acid residues (Ala, Lys, Pro). The importance of the N‐terminal part of the molecule to the antimicrobial activity was revealed through truncation of five residues from both the N and C termini of the LL‐III peptide. C‐terminal deamidation of LL‐III resulted in a drop in antimicrobial activity, but esterification of the C terminus had no effect. Molecular modelling of LL‐III and the observed NOE contacts indicated the possible formation of a bifurcated H‐bond between hydrogen from the Lys15 CONH peptide bond and one H of the C‐terminal CONH₂ to the Ile11 oxygen atom. Such interactions cannot form with C‐terminal esterification.     

Microwave-assisted synthesis of carboxymethylcellulose – based polymeric surfactants

Summary Carboxymethylcellulose (CMC, DS_CM = 1) was partially hydrophobized in order to prepare polymeric surfactants by the transesterification reaction using the methyl ester of the fatty acid complex of rapeseed oil (MERO). The chemical modification was performed in different reaction media (i) DMF/TSA and (ii) H₂O/DMF with and without K₂CO₃ as catalyst, at various reaction conditions and using microwave radiation with controlled power as heating source. The obtained MERO-hydrophobized CMC (MH-CMC) comprising mixed fatty acyl esters were characterized by FT-IR and NMR spectroscopic techniques, which indicated a very low degree of esterification (DS < 0.1). The derivatives showed, in spite of moderate surface tension-lowering effects, excellent emulsifying activity for ‘oil in water’ type emulsions as well as good performance properties including washing power and antiredeposition efficiency. The results suggested that surface-active MH-CMC derivatives can be prepared under microwave heating at reaction times in the range of several minutes, what is a great advantage in comparison to transesterification reactions lasting up to 6 h at conventional heating. The novel CMC esters represent biodegradable polymeric surfactants with potential applications in manufacture of consumer products and in industrial processes.     

Dielectric Properties and Phase Transition Behavior of xPMN-(1 − x)PZT Ceramic Systems

The dielectric properties and phase transition behavior of the pseudo-ternary xPb(Mg_1/3Nb_2/3)O₃-(1 – x)Pb(Zr,Ti)O₃ solid solution system were investigated as a function of the Pb(Mg_1/3Nb_2/3)O₃ (PMN) content and Ti/Zr ratio for selected compositions. The investigations have demonstrated a general trend in broadening of the phase transition and increasing diffusivity with increasing PMN content. For the morphotropic phase boundary (MPB) compositions, the dielectric permittivity maximum, its temperature (T _m) and the Curie-Weiss constant were found to decrease with increasing Mg_1/3Nb_2/3 concentration. When a Ti/Zr ratio was constant and equal to 53/47, temperature-dependent investigations demonstrated that the dielectric parameters involved in a modified Curie-Weiss law increase monotonically with increasing PMN content and T _m moves toward room temperature with average rate of –4.1°C/mol% as well. A phase transition in 0.5PMN-0.5Pb(Zr_0.47Ti_0.53)O₃ and 0.25PMN-0.75Pb(Zr_0.60Ti_0.40)O₃ ceramic systems exhibited a diffused behavior with a characteristic frequency dependence of T _m. From pyroelectric measurement, an unusual spontaneous polarization behavior at about 215 K is reported for some MPB compositions.     

Simulation programming system siproversion for desk-top computer compucorp 625 in basic language

The paper presents a successful implementation of a flowsheeting package with many features of third generation simulators on a handy and cheap desk-top computer. This version is still powerful enough to solve industrial problems of reasonable size and it is especially suitable for operative calculation in places where it is difficult and/or expensive to reach a terminal network, i.e. branch offices or plants sites.     

Trends in identification

The paper refers to methods used for identification of linear and nonlinear systems. Deterministic and stochastic approaches are distinguished and specific features concerning parameters, structure and state estimation are briefly discussed from the point of view of possible advantages and difficulties for identification. Attention is paid to different final goals of identification with respect to the convenience of the methods in question. The most important trends in identification approaches are argued by unsolved problems of identification, by the complexity of numerical calculations and of practical applications. The significance of the uncertainty in structure, parameters or noise and the possible application of the a priori knowledge of the analysed system are taken into consideration.     

Solution of nonlinear boundary value problems—XI: One-parameter imbedding methods

One-parameter imbedding techniques are used to solve a standard nonlinear boundary value problem appearing in reaction engineering. The one-parameter imbedding technique is formulated in a general form, the resulting procedures are classified as the one-loop and multi-loop methods. Twelve multi-loop and two one-loop procedures are suggested to solve the problem in question. The behaviour of all methods proposed as well as the numerical results are discussed also for the case of multiple solutions.