content

contents
NATURAL AND TECHNICAL SCIENCES
Antoniya Dimitrova, Svetlana Genieva, Lyubomir Vlaev, Application of isoconversional method in non-isothermal thermogravimetry	7
Dobromir Yordanov, Petko Petkov, Slavi Ivanov, Yanko Dimitrov, Generalized kinetic model of biodiesel production	15
Dobromir Yordanov, Petko Petkov, Slavi Ivanov, Yanko Dimitrov, Prolongation of the model of biodiesel production by prognostication of concentrations of final products with rate constants of saponification process	19
Zdravka Nikolaeva, Dimo Hristozov, Rusi Pavlov, A laboratory set-up for determination of the light’s refraction coefficient	24
Stefka Kasarova, Nina Sultanova, Ivan Nikolov, Comparative refractometric and dispersive characteristics of optical plastics and optical glasses	30
Liliya Staneva, Modeling the passing of amplitude-modulation signals through parallel oscillating system	36
Lyubka Chepanova, Ivanka Madgarova, Zara Aneva, Validation of a spectrophotometric method for determination of total phosphorus in soils and sediments using a microwave-assisted digestion	39
N. Halachev, R. Iankova, St. Manolov, B. Nikolova-Mladenova, D. Ivanov, Study on salicylaldehyd aroyl hydrazones. I. Electrostatic potentials as a mesure of their reactivity	44
N. Halachev, R. Iankova, St. Manolov, B. Nikolova-Mladenova, D. Ivanov, Study on salicylaldehyd aroyl hydrazones. II. Proton affinity and correlations with the electrostatic potentials of the compounds	52
Yoana Alexandrova, Investigation of the transport characteristics of carboxylic ion exchange membrane	57
Stoiko Petrov, Violeta Slavova, Investigation of the transport characteristics of ultra filtering polymer membranes chemically modified by alcoholic solutions and copper (II) cations	61
Yordanka Tasheva, Petko Petkov, Influence of the parameters of ska instalation on the quality of the obtained product	65
Yordanka Tasheva, Petko Petkov, Influence of raw material in ska instalation on the quality of obtained product	69
Lyubcho Lyubchev, Dimitar Rusev, Russy Pavlov, Irena Markovska-Minova, New design of a direct-flow cyclone from a return vortical stream	73
Lyubcho Lyubchev, Dimitar Rusev, Russy Pavlov, Irena Markovska-Minova, Process engineering and pilot installation for production of glass microspheres	77
Angel Zvezdov, Alla El Shemeri, Dilyana Zvezdova, Small water treatment ion-exchange device for softening of salty natural waters befor nanofiltration or reverse osmosis membrane processes	82
Angel Zvezdov, Allа Ell Shemeri, Stanislava Pavlova, Diliana Zvezdova, Threе chamber small water treatment device	88
Vasil Bobev, Rumyana Mateva, Research of tehnological process for multimodal transport	94
ECONOMIC SCIENCES
Ivan Dimitrov, Supply chain management strategies	97
Ivan Dimitrov, Organizations relationships in supply chains	106
Velika Bineva, A check-list research of the relationships between supplier selection and business process improvement in organization	112
Velika Bineva, Supplier selection decision as basis for business process improvement in organization	119
Rumyana Stoycheva, Modern ergonomic parameters and requirements for the organization of labor and rest	125
Rumyana Stoycheva, Directive of european union for safety and health at work and modern ergonomic requirements for the labor process	133
George Dimitrov, Marketing of the sports-entertaining services in tourist centres	139
George Dimitrov, A pogramming and organization of the sport entertaining activity in tourist's centers	147
Doncho Keremidchiev, Evaluating the power of a workplace in Proff. Dr Assen Zlatarov University, Bourgas	155