273 research outputs found
Examination of mother-child agreement and its influencing factors in symptom reports and quality of life of depressed and non depressed children
A new species of Tetranycopsis is described and the genus Mesobryobia (Acari: Tetranychidae, Bryobiinae) reported from Hungary for the first time
A new Tetranycopsis species, Tetranycopsis vertesiensis sp. n., is described from Central-Hungary on grasses (Poaceae) based on females. The new species differs from the previously described congeners in the length of dorsal setae, all setae (except v1 and v2) similar in shape and length and number of setae on femur of leg I (10), which is a unique character combination within the genus Tetranycopsis. The first Central-European record of the genus Mesobryobia is presented. Specimens of Mesobryobia terpoghossiani (Bagdasarian, 1959) were collected in two different places in Hungary
A biominĹ‘sĂtĂ©s hatása a fogyasztĂłk Ă©rzĂ©kelĂ©sĂ©re Ă©s attitűdjĂ©re csokoládĂ©k esetĂ©n
A biominĹ‘sĂtĂ©s hatása a fogyasztĂłk Ă©rzĂ©kelĂ©sĂ©re Ă©s attitűdjĂ©re csokoládĂ©k esetĂ©n
Polimerek degradációjának mértékét és mechanizmusát meghatározó tényezők, valamint a stabilizálás egyes kérdéseinek vizsgálata = Study of the factors determining the extent and mechanism of polymer degradation, as well as certain aspects of its stabilization
A poliolefinek degradáciĂłját számos tĂ©nyezĹ‘ befolyásolja. A kutatás cĂ©lja összefĂĽggĂ©sek megállapĂtása volt a poliolefinek - elsĹ‘sorban a polietilĂ©nek - előállĂtási körĂĽlmĂ©nyei, a polimer por szerkezete, a feldolgozás során lejátszĂłdĂł kĂ©miai reakciĂłk, a feldolgozott polimer tulajdonságai, valamint a stabilizátorok tĂpusa Ă©s hatĂ©konysága között. A kitűzött cĂ©l elĂ©rĂ©sĂ©hez kĂĽlönbözĹ‘ analitikai mĂłdszereket dolgoztunk ki. Ă–sszefĂĽggĂ©st állapĂtottunk meg a kĂĽlönbözĹ‘ katalizátorokkal előállĂtott lineáris polietilĂ©nek kĂ©miai szerkezete, tulajdonságai Ă©s stabilitása között. MegállapĂtottuk, hogy a polimer feldolgozása során lejátszĂłdĂł kĂ©miai reakciĂłk irányát Ă©s sebessĂ©gĂ©t, továbbá a stabilizátorok fogyását a polimer por vinil koncentráciĂłja, valamint a polimerbe beĂ©pĂĽlt oxigĂ©ntartalmĂş csoportok jelentĹ‘sen befolyásolják. Feltártuk a kĂĽlönbözĹ‘ mĂłdszerekkel vizsgált szilárdsági jellemzĹ‘k Ă©s a polimer kĂ©miai szerkezete, valamint reolĂłgiai tulajdonságai közötti összefĂĽggĂ©seket. Meghatároztuk három kĂĽlönbözĹ‘ kĂ©miai szerkezetű foszfortartalmĂş stabilizátor hatĂ©konyságát lineáris polietilĂ©nekben, Ă©s elemeztĂĽk a hatásmechanizmust. Feltártuk az antioxidáns molekulák közötti specifikus kölcsönhatások szerepĂ©t a hatĂ©konyságban. Tanulmányoztuk a stabilizátorok hidrolitikus stabilitását Ă©s annak hatását a polimer tulajdonságaira, valamint a környezetre. | The degradation of polyolefins is determined by different parameters. The aim of the work was determining relationships between the polymerization conditions of polyolefins - first of all polyethylenes -, the chemical structure of the polymer powder, the chemical reactions during processing, the properties of the polymer processed, as well as the type and the efficiency of antioxidants. Different analytical methods were developed. Relationships were established among the chemical structure of linear polyethylene powder polymerized by different catalysts, the properties and the stability of the polymer processed. It was found that the direction and the rate of chemical reactions, as well as the stabilizer consumption during processing are affected strongly by the vinyl group content of the nascent polymer powder and the oxygen containing groups built in the polymer chain. Relationships were established between the mechanical properties of the film determined by different methods, as well as the chemical structure and the rheological characteristics of the polymer. The efficiency of three phosphorous antioxidants of different chemical structure was determined in linear polyethylenes, and their stabilization mechanism was analyzed. The role of specific interaction between antioxidants in the stabilization efficiency was determined. The hydrolytic stability of antioxidants, as well as its effect on the polymer properties and the environment was studied
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