Wyniki wyszukiwania - Biblioteka Nauki

1

Wpływ naturalnego i przyspieszonego starzenia na właściwości ochronne powłok zabezpieczających beton przed karbonatyzacją

100%

Kozak A.

|

tom nr 1

14-17

PL

W pracy omówiono wyniki badań wybranych organicznych powłok ochronnych stosowanych do ochrony betonu przed karbonatyzacją, poddanych procesom naturalnego i przyspieszonego starzenia. Badaniami objęto powłoki poliuretanowe i epoksydowe starzone w atmosferze miejsko-przemysłowej (Kraków) i górskiej (Tatranska Strba, Słowacja) oraz w warunkach przyśpieszonych w komorze starzeniowej. Na podstawie przeprowadzonych badań stwierdzono, że w wyniku starzenia w środowisku naturalnym oraz w komorze starzeniowej nastąpiły wyraźne zmiany we właściwościach mechanicznych powłok ochronnych. W celu wyjaśnienia przyczyn zmian, zastosowano spektroskopię w podczerwieni.

EN

The paper deals with test results of organic coatings used as concrete protection against carbonation. Coatings were subjected to natural and artificial weathering. Polyurethane and epoxy coatings were weathered in municipal-industrial atmosphere (Cracow), mountain one (Tatranska Strba, Slovakia) and in weathering chamber. Based on results obtained it was found that as a result of weathering in natural environments and in the weathering chamber considerable changes of mechanical properties of coatings occurred. In order to explain causes of these changes, infra-red spectroscopy was used.

2

Badania procesów mikrobiologicznej degradacji polimerów stosowanych w technologii płynów wiertniczych

100%

Kapusta P. , Turkiewicz A.

|

2009

|

tom Tom 11

1213-1224

PL

Od wielu lat stosowane są w przemyśle naftowym liczne polimery, które służą przede wszystkim do obniżenia filtracji płuczki wiertniczej, a także spełniają inne funkcje jak np., zwiększenie lub zmniejszenie lepkości, flokulacja zwiercin, ograniczenie hydratacji przewiercanych skał ilastych i inne. Polimery, które znalazły zastosowanie w technologii płuczek wiertniczych są produktami rozpuszczalnymi w wodzie, które w środowisku wodnym silnie pęcznieją i tworzą roztwory o dużej lepkości. W porównaniu z konwencjonalnymi materiałami stosowanymi do sporządzania płuczek wiertniczych polimery są lepszymi materiałami, ponieważ podlegają degradacji i tym samym nie stwarzają poważnego zagrożenia dla środowiska naturalnego [11]. Niemniej jednak znajdują się one w odpadach wiertniczych, umieszczanych po wierceniu w dołach urobkowych lub wywożonych z wiertni na zbiorcze obszary składowania odpadów przemysłowych. Oprócz zastosowania do wodnodyspersyjnych płuczek wiertniczych, związki polimerowe są wykorzystywane również jako składniki płynów zabiegowych (szczelinujących), a także zaczynów cementowych.

EN

Various polymer compounds are widely used in oil industry. Synthetic and semi-synthetic polymers are components of drilling fluids. Microbial degradation of these compounds is the subject of special interest. There is a demand for degradation of drilling wastes. The ability of bacteria isolated from drilling muds and reservoir waters to degrade polymers was investigated in laboratory and simulated reservoir conditions. Natural polymers are the products of microorganisms' activity. They consist of the monomers units linked by glycosidic bonds (like in starch, guaran-guar gum and xanthan gum). Many commercially important polymers are synthesized by chemical modifications of naturally occurring polymers. Prominent examples of semi synthetic polymers widely applied in oil and gasindustry are carboxymethylcelullose (CMC), hydroxyethylcelullose (HEC) and carboxymethyl starch (CMS). This polymers are typical components of water-based polymer drilling fluids. Comparing natural and modified polymers, the last ones posses better resistant to bacteria' activity, low impurity content and better solubility. Aerobic and anaerobic bacteria, which use the examined polymers in metabolic processes, were isolated from the drilling muds, water basis (dedicated to prepare drilling fluids) and brine water. To conduct the experiments, we used microbiological media containing addition of individual polymers as the source of carbon. The quantity of polymer's addiction corresponded to its concentration in drilling mud. All products applied in our researches, were listed below: Rotomag (starch modified by alkaline-thermal treatment), Polvitex Z (carboxymethyl starch-sodium salt), Polofix LV (low-viscosity carboxymethylcelullose), Tylose HV (high-viscosity carboxymethylcelullose), Guar gum (chemical modified product), PHPA (partially hydrolyzed polyacrylamide). The microorganisms were isolated in the media containing the polymer in determined concentration. The total amount of microorganisms were determined by plates-assay, the growth kinetics were determined by turbidity of solution. The hydrogen sulphide production was essential parameter to determine the metabolic activity of sulfate-reducing bacteria. The quantities of produced gas were determined in iodometric manner. Polysaccharides degradation were determined by colorimetry method. Comparing the sample containing degraded polymer to the sample with non-degraded polymer was conducted after 14-day incubation. In this way we estimated susceptibility degradation of examined polymers by bacteria strains. To determine PHPA degradation, at first we refined the sample by ion-change chromatography and then we conducted the turbidity measurement. Results of the studies showed the ability of bacterial strains apply to elimination drilling wastes in oil and gas industry.

3

A novel method and device for plastic mulch retriever

100%

Khazimov K. M. , Niyazbayev A. K. , Shekerbekova Z. S. , Urymbayeva A. A. , Mukanova G. A. , Bazarbayeva T. A. , Nekrashevich V. F. , Khazimov M. Z. , Khazimov K. M. , Niyazbayev A. K. , Shekerbekova Z. S. , Urymbayeva A. A. , Mukanova G. A. , Bazarbayeva T. A. , Nekrashevich V. F. , Khazimov M. Z.

|

2021

4

Maldi – metoda do zastosowań w analizie strukturalnej polimerów

84%

Swinarew B. , Swinarew A. S.

|

tom [Z] 68, 7-8

645--660

EN

Polymers as one of the fastest growing groups of widespread use of synthetic materials are characterized by a great diversity of structures. Structural characterization of polymers generally includes: an assessment of the average molecular weight (Mn) and the molar mass distribution (PD) to determine the structure of repeating units (mers) sequence analysis of the copolymer, identification of the end groups, the detection and identification of contaminants and substances present in the composition of the polymer asa dopant. Modern mass spectrometry (MS) offers the opportunity to study the smallest structural details of macromolecular materials [1–10]. Because of the variety of potential structures of polymer analysis process is to answer a few questions by a certain pattern. The first step is to determine the chemical structure of the polymer backbone. The second step is to identify whether the chains have branching points and define the degree of branching. The third important step is to correct end groups identification, also for the detection of cyclic oligomers that can be present. The structural studies can be made by mass spectrometer using reflectron mode. In the essence, the method involves three steps. The first analysis is performed with standard mass spectrum of the sample. Then the precursor ion (parent ion) is selected, which is subjected to further analysis by MS changed voltages and reflectron mode. This paper aims to present the issues related to the detailed analysis and characterization of polymeric materials produced on a large scale. Before, for materials such as poly(propylene), poly(ethylene), poly(styrene), polycarbonate, etc., increasing demands on the mechanical and technological parameters were placed. Maintaining a high level of products is associated with a very rigorous process control of the manufacturing, processing and transportation at every stage. The optimal tool for the structural characteristics of these polymeric materials is the defense technique MALDI-TOF MS (Matrix-Assisted Laser Desorption/Ionization Time- -Of-Flight Mass Spectrometer) due to its versatility, speed and extremely high precision. Below, we present some aspects of MALDI MS analysis of polymeric materials and composites. Note, that the following literature review focuses on the recent developments in the field of preparation of the samples, to achieve high mass resolution, the identification of polymers and copolymers, the accuracy of the molar mass determination and the identification of functional end groups, sequence analysis of the copolymer.

5

Folie biodegradowalne

84%

Jakucewicz S.

|

tom R. 61, nr 8

459-464