Search results for "Analytical"
showing 10 items of 9586 documents
Angular Regioselectivity in the Reactions of 2-Thioxopyrimidin-4-ones and Hydrazonoyl Chlorides : Synthesis of Novel Stereoisomeric Octahydro[1,2,4]t…
2020
The regioselective synthesis of cis and trans stereoisomers of variously functionalized octahydro[1,2,4]triazolo[4,3-a]quinazolin-5-ones was performed. The 2-thioxopyrimidin-4-ones used in the synthesis reacted with hydrazonoyl chlorides in a regioselective manner to produce the angular regioisomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones rather than the linear isomers [1,2,4]triazolo[4,3-a]quinazolin-5-ones. The synthesis process took place with electronic control. The angular regiochemistry of the products was confirmed by X-ray experiments and two-dimensional NMR studies.
Production and extraction of astaxanthin from Phaffia rhodozyma and its biological effect on alcohol-induced renal hypoxia in Carassius auratus
2015
The effect of astaxanthin (3,3â²-dihydroxy-s-carotene-4,4â²-dione) on alcohol-induced morphological changes in Carassius auratus, as an experimental model, was determined. The yeast Phaffia rhodozyma was used as a source of astaxanthin. The animals were divided into three groups for 30 days: one group was treated with ethanol at a dose of 1.5% mixed in water, the second one with EtOH 1.5% and food enriched with astaxanthin from P. rhodozyma, and the third was a control group. After a sufficient experimental period, the samples were processed using light microscopy and evaluated by histomorphological and histochemical staining, and the data were supported by immunohistochemical analysis, u…
Determination of sorption properties of heavy metals in various biosorbents
2018
Various techniques of determination of properties of physicochemical processes of heavy metal sorption in biosorbents were analysed. The methods of preparing and storing samples, conditions of experiment performance, as well as the methods of data interpretation were discussed. Two procedures of study were analysed: (1) in the static system of biosorbent-solution contact and (2) in the system of dynamic flow of solution. Copper cation sorption was studied. The effect of consecutive stages of the study on the quality of final results was shown. A high degree of uncertainty of the sorption capacity assessment was reported, which was dependent on the manner of conducting the study. The applica…
Analytical approach for the problems of dynamics and stability of a moving web
2015
Problems of dynamics and stability of a moving web, modelled as an elastic rod or string, and axially travelling between rollers (supports) at a constant velocity, are studied using analytical approaches. Transverse, longitudinal and torsional vibrations of the moving web are described by a hyperbolic second-order partial differential equation, corresponding to the string and rod models. It is shown that in the framework of a quasi-static eigenvalue analysis, for these models, the critical point cannot be unstable. The critical velocities of one-dimensional webs, and the arising non-trivial solution of free vibrations, are studied analytically. The dynamical analysis is then extended into t…
ANALYTICAL PROCEDURES FOR THE DETERMINATION OF TRACE AMOUNTS OF XENOBIOTICS IN ENVIRONMENTAL WATER SAMPLES
2016
Wciąż wzrastające zanieczyszczenie środowiska związane z działalnością człowieka stanowi poważny problem ekologiczny współczesnego świata. Ksenobiotyki to substancje obce i potencjalnie szkodliwe dla organizmów żywych. Obecność niektórych z nich w środowisku wodnym może nieść za sobą poważne konsekwencje. Do najbardziej niebezpiecznych należą antybiotyki oraz pestycydy. Rozwój nauki i techniki umożliwił kontrolowanie tych substancji w środowisku naturalnym. Oznaczanie śladowych ilości ksenobiotyków w próbkach wód środowiskowych jest złożonym procesem, wymagającym zastosowania odpowiedniej metody ekstrakcyjnej i analitycznej. Złożoność matrycy oraz obecność substancji współobecnych stanowi d…
Requirements for using simulation to design and assess wireless ATM handover solutions
1999
Wireless ATM (WATM) has been widely considered as a solution for broadband wireless services. Handover is one of the most important mobility support functions in the WATM network. Many handover solutions have been proposed, analysed, and benchmarked. Simulations have been broadly used to assess these solutions. However, there are many dilemmas in how simulation has been applied as a research methodology: heterogeneous simulation systems used, lack of comparison with other related work, biased conclusions, and unavailability of simulation models and systems to researchers. The WATM research community lacks a standard and commonly acceptable methodology for applying simulation. To address thi…
1982
3D survey in complex archaeological environments: An approach by terrestrial laser scanning
2018
Abstract. The survey of archaeological sites by appropriate geomatics technologies is an important research topic. In particular, the 3D survey by terrestrial laser scanning has become a common practice for 3D archaeological data collection. Even if terrestrial laser scanning survey is quite well established, due to the complexity of the most archaeological contexts, many issues can arise and make the survey more difficult. The aim of this work is to describe the methodology chosen for a terrestrial laser scanning survey in a complex archaeological environment according to the issues related to the particular structure of the site. The developed approach was used for the terrestrial laser s…
SCAN-TO-BIM FOR THE MANAGEMENT OF HERITAGE BUILDINGS: THE CASE STUDY OF THE CASTLE OF MAREDOLCE (PALERMO, ITALY)
2020
Abstract. Conservation and preservation of heritage buildings require the knowledge and sharing of a great deal of data and information about buildings. Such information comes from the different disciplines involved in the restoration and maintenance processes. The integration and use of all this information in a single working environment is a key factor for the success of historical building conservation and management projects. Heritage (or Historic) Building Information Modelling (HBIM) is nowadays the most appropriate tool to collect and manage all data related to Architectural Heritage. The HBIM process requires an in-depth knowledge of the historical building that can be achieved usi…
THE VIRTUALIZATION OF CH FOR HISTORICAL RECONSTRUCTION: THE AR FRUITION OF THE FOUNTAIN OF ST. GEORGE SQUARE IN VALLETTA (MALTA)
2020
Abstract. Improving accessibility to Cultural Heritage (CH) is an increasingly urgent challenge today. It is not only a matter of physical inaccessibility but also temporal, considering that part of CH now lost. Fortunately, the most modern technological tools are helping to break down both space and time barriers. In facts, recent advances in representation, 3D modelling and survey methodologies opened new scenarios for valorization and conservation of CH. In particular, the improvement of quality in resolution and sensor sensitivity of cameras allowed to achieve the right level of 3D reconstruction through digital photogrammetry procedures. In the same field, terrestrial laser scanners (T…