Binary-coded and real-coded genetic algorithm in pipeline flow optimization

The mathematical model for the liquid-gas mixture flow in pipelines is an initial-boundary value problem for a nonlinear hyperbolic conservation law system. This hyperbolic conservation law system together with boundary conditions is numerically solved using the essentially non-oscillatory (ENO) schemes. The optimization problem is a boundary control problem, i.e. boundary conditions that cause pressure values in the pipeline as close as possible to the desired ones are to be found, considering given constraints. The applied optimization method is the genetic algorithm (GA) with two different variable-to-chromosome coding strategies: binary coding and real coding. The results of both GA strategies applied to two pipeline flow optimization problems are presented and compared

Model upravljanja kompetencijama vodstva u metalurškim tvrtkama

The purpose of presented research was to develop feasible model for leadership competence management in metallurgical companies. Results of the research are presented in the form of a structured procedure for leadership competence development and performance review. Analysis of entry requirements for employment in metallurgical companies synthesized presented set of leadership competences and matrix for calculation of leadership success was developed. With usage of these two tools it is possible to quantify the leadership performance which represents great advantage in leadership benchmarking process. During the research additional set of problems was defined. These problems were addressed heuristically in the framework of this research.Svrha predstavljenog istraživanja bila je razvoj ostvarivog modela upravljanja kompetencijama vodstva u metalurškim tvrtkama. Rezultati istraživanja predstavljeni su u obliku strukturirane procedure razvoja kompetencija vodstva i prosudbe izvršenja. Analiza ulaznih zahtjeva pri zapošljavanju u metalurškim kompanijama sintetizirala je predstavljeni set kompetencija vodstva te je razvijene matrica izračuna uspjeha vodstva. Korištenjem navedenih alata moguće je kvantificirati prosudbu izvršenja što predstavlja veliku prednost u procesu usporedbe vodstva s najboljima. Tijekom istraživanja definiran je dodatni set problema. Predloženo je heurističko rješenje tih problem u okviru ovog istraživanja

Navarivanje vijenaca monoblok točka (MBT) čelika R7T za željeznička vozila

The steel R7T monoblock wheel material properties are defined by the International Declaration UIC 812-3. Taking into consideration the resurfacing of the rim, the analyzed conditions for the resurfacing, as well as the analysis of the chemical compounds, mechanical characteristics (material hardness, pulling strength, and tenacity), ultrasound and metallographic testing, which proved that the resurfaced rim area has the required characteristics, according to the Declaration UIC 812-3.Svojstva materijala monobloka točkova čelika R7T su određeni po međunarodnoj objavi UIC 812-3. Na temelju navarivanja vijencaovih točkova, istraživanih uvjeta za navarivanje, te ispitivanjem kemijskog sastava, mehničkih svojstava (tvrdoće, vlačne čvrstoće, žilavosti), ultrazvučnim i metalograpskim ispitivanjima, dokazano je da navareni sloj vijenca ima osobine sukladne traženim po objavi UIC 812-3

Review of Technologies for the Recovery of Phosphorus from Waste Streams

Phosphorus is essential to the growth of living organisms, and, therefore, its presence is considered vital for all forms of life. Research shows that phosphate rock reserves are reducing. Phosphate rock is used as raw material for the production of phosphate-based fertilizers, and its lack of supply could have adverse effects on the global food supply. New resources that can be a potential replacement for phosphate rock in the production of fertilizers and other phosphorus-containing substances are investigated. This paper provides an overview of technology implementations, methods, and processes, as well as the latest achievements in the field of phosphorus recovery from waste streams. Different methods of phosphorus regeneration from sewage sludge and solid waste, and forms of phosphate regeneration are described. In addition, an overview of the following methods is given: nanonucleation, adsorption and ion exchange, solar evaporation, biological assimilation of P, and membrane technologies

Family Relationships in Prediction of Ageing

This paper presents a study of the predictive value of family relationships from genealogies, and its impact on the delayed ageing. The study comprised adult population over 18 years of age of two urban family practices (N = 1700). The study sample included all patients (total = 581; 57.3% female, 42.7% male) having sought medical assistance of any kind in the period of three consecutive months. The study was performed in two stages. The selection of patients according to the results of the 25th and 75th percentiles of the memory component analysis was done in stage I. The comparison of life history and events across a genealogy in the groups of the 25th and 75th percentile memory deficit was done in stage II. The method used in stage I was a psychological test – Pictures of Object Test (POT) to test the memory deficit. In stage II, personal life histories and description of the genealogies were obtained by individuals’ associations expressed in the form of a free text which was then analyzed statistically (SPAD-T), and the results were correlated to data read on the developed genogram. The statistical text analysis of life-events recall and the correlation across a genealogy showed a difference in the patterns of family relationships across a genealogy in the two study groups, and their predictive value for prevention in family practice

Family Relationships in Prediction of Ageing

This paper presents a study of the predictive value of family relationships from genealogies, and its impact on the delayed ageing. The study comprised adult population over 18 years of age of two urban family practices (N = 1700). The study sample included all patients (total = 581; 57.3% female, 42.7% male) having sought medical assistance of any kind in the period of three consecutive months. The study was performed in two stages. The selection of patients according to the results of the 25th and 75th percentiles of the memory component analysis was done in stage I. The comparison of life history and events across a genealogy in the groups of the 25th and 75th percentile memory deficit was done in stage II. The method used in stage I was a psychological test – Pictures of Object Test (POT) to test the memory deficit. In stage II, personal life histories and description of the genealogies were obtained by individuals’ associations expressed in the form of a free text which was then analyzed statistically (SPAD-T), and the results were correlated to data read on the developed genogram. The statistical text analysis of life-events recall and the correlation across a genealogy showed a difference in the patterns of family relationships across a genealogy in the two study groups, and their predictive value for prevention in family practice

Oblique surface waves at an interface of metal-dielectric superlattice and isotropic dielectric

We investigate the existence and the dispersion characteristics of surface waves that propagate at an interface between metal-dielectric superlattice and isotropic dielectric. Within the long wavelength limit, when the effective-medium approximation is valid, the superlattice behaves like a uniaxial plasmonic crystal with the main optical axes perpendicular to the metal-dielectric interfaces. We demonstrate that if such a semi-infinite plasmonic crystal is cut normally to the layer interfaces and brought into the contact with semi-infinite dielectric, a new type of surface modes can appear. The propagation of such modes obliquely to the optical axes occurs under favorable conditions that regard thicknesses of the layers, as well as the proper choice of dielectric permittivity of the constituent materials. We show that losses within the metallic layers can be substantially reduced by making the layers sufficiently thin. At the same time, a dramatic enlargement of the range of angles for oblique propagation of the new surface modes is observed. This can lead, however, to the field non-locality and consequently to the failure of the effective-medium approximation.Comment: 4 pages, 3 figure

Theoretical study of metal borides stability

We have recently identified metal-sandwich (MS) crystal structures and shown with ab initio calculations that the MS lithium monoboride phases are favored over the known stoichiometric ones under hydrostatic pressure [Phys. Rev. B 73, 180501(R) (2006)]. According to previous studies synthesized lithium monoboride tends to be boron-deficient, however the mechanism leading to this phenomenon is not fully understood. We propose a simple model that explains the experimentally observed off-stoichiometry and show that compared to such boron-deficient phases the MS-LiB compounds still have lower formation enthalpy under high pressures. We also investigate stability of MS phases for a large class of metal borides. Our ab initio results suggest that MS noble metal borides are less unstable than the corresponding AlB$_2$-type phases but not stable enough to form under equilibrium conditions.Comment: 14 pages, 15 figure