X-Ray Spectroscopy — The Driving Force to Understand and Develop Catalysis

Catalysis is involved in about 90% of manmade chemicals. The development of novel or improved catalysts requires fundamental understanding of the commanding steps of a catalytic reaction. In simple terms, a catalytic transformation depends on the coupling between catalyst electronic structure and reagents’ molecular orbitals. Herein, we report a spectroscopic technique capable of determining the electronic structure of metal containing catalysts under working conditions. The technique is called photon-in photon-out X-ray spectroscopy and can be employed to characterize materials, unveil substrate adsorption parameters, and follow changes in electronic structure during catalytic reactions

Model organizacyjny związku komunalnego. W kierunku uelastycznienia ustawowej regulacji

The whole article is built around the thesis stating that the legal regulation of the organizational model of the municipal union is inflexible, which hinders the practical use of the institution. Local government laws using cogent norms do not give space to cooperating municipalities and/or counties to implement "tailor-made" organizational solutions, i.e. taking into account the conditions of the area (geographical, political, economic, social, etc.). These laws should therefore be amended. In addition to the normative analysis and de lege lata conclusions, several demands to the legislator were also presented, each exemplified by a proposed statutory provision.Artykuł zbudowano wokół tezy stanowiącej, że ustawowa regulacja modelu organizacyjnego związku komunalnego jest sztywna, co utrudnia praktyczne wykorzystanie instytucji. Ustrojowe ustawy samorządowe posługujące się normami o charakterze kogentywnym nie pozostawiają miejsca współdziałającym gminom i/lub powiatom na wdrażanie rozwiązań organizacyjnych „szytych na miarę”, czyli uwzględniających uwarunkowania danego obszaru (geograficzne, polityczne, gospodarcze, społeczne itd ). Należy zatem te ustawy w określony sposób zmienić Obok analizy normatywnej i wniosków de lege lata zaprezentowano także kilka postulatów do ustawodawcy, a każdy egzemplifikowano propozycją przepisu ustawowego

Performance of a laboratory von Hámos type x-ray spectrometer in x-ray absorption spectroscopy study on 3d group metals

With the recent progress regarding the development of x-ray instrumentation, compact x-ray spectrometers are becoming more and more popular as they allow x-ray absorption spectroscopy (XAS) and x-ray emission spectroscopy (XES) studies at the research institutes laboratories. Such setups provide a cost-effective tool for routine sample characterization with unlimited access and are of great utility in feasibility studies preceding the experiments at synchrotrons and x-ray free-electron lasers (XFELs). Herein, we present the operation and capabilities of the von Hamos type x-ray spectrometer in x-ray absorption spectra measurement for various 3d metal elements. Results allowed us to establish the photon counting performance of the setup, demonstrating a possible range of applications of the in-house x-ray spectroscopy apparatus

Laboratory von H\'amos X-ray Spectroscopy for Routine Sample Characterization

High energy resolution, hard X-ray spectroscopies are powerful element selective probes of the electronic and local structure of matter, with diverse applications in chemistry, physics, biology and materials science. The routine application of these techniques is hindered by the complicated and slow access to synchrotron radiation facilities. Here we propose a new, economic, easily operated laboratory high resolution von H\'amos type X-ray spectrometer, which offers rapid transmission experiments for X-ray absorption, and is also capable of recording X-ray emission spectra. The use of a cylindrical analyzer crystal and a position sensitive detector enabled us to build a maintenance free, flexible setup with low operational costs, while delivering synchrotron grade signal to noise measurements in reasonable acquisition times. We demonstrate the proof of principle and give examples for both measurement types. Finally, tracking of a several day long chemical transformation, a case better suited for laboratory than synchrotron investigation, is also presented

Współpraca THINK TANKÓW z organami administracji publicznej przy stanowieniu prawa

The paper “Cooperation between THINK TANKS and public administration in legislation process” presents the problem of think tanks participation in the process of administrative legislation. Nowadays their contribution to the execution of public functions of legislation is undoubtedly very beneficial. It is also preferred to use the results of parallel activities of administrative authorities and think tanks. As the analysis of existing legislation shows, the think tanks that are involved in the legislative process may use a wide variety of legal institutions. In addition, they possess a valuable base of experts and financial resources. To summarize, this paper shows that cooperation with think tanks allows the administration to achieve higher quality services at lower financial cost

First white beam on a von Hámos spectrometer at the PolyX beamline of SOLARIS

Synchrotrons are brilliant sources of X-ray radiation used in a variety of methods to study the structure of matter and dynamics of processes on the atomic scale. X-ray spectroscopy methods at synchrotrons are typically combined with the beam monochromatization which guarantees better energy resolution but also reduces orders of magnitude the photon flux incident on the sample and thus wastes the vast majority of the photons produced. Here we report on the commissioning of an X-ray spectrometer at the PolyX beamline of SOLARIS specialized in application of white, broadband and monochromatic X-ray beam in multimodal microimaging, microtomography and microscpectroscopic studies. The spectrometer was used to acquire good quality Fe K-edge X-ray absorption spectrum over about 120 eV-range within seconds. In this work we present the first X-ray absorption spectrum measured using a synchrotron white beam in combination with a von Hámos geometry-based spectrometer

In situ high energy resolution off-resonant spectroscopy applied to a time-resolved study of single site Ta catalyst during oxidation

In the present work high energy resolution off-resonant X-ray spectroscopy (HEROS) was employed at a synchrotron to study a silica supported Ta(V) bisalkyl catalyst activated in hydrogen. The Ta Lα1 HEROS spectra were measured during oxidation of the starting complex and the relative species’ concentration was successfully retrieved as a function of time using the fingerprint HEROS spectra measured for the unoxidized and the oxidized catalyst. Based on the experimental data and theory- based calculations, it was shown that oxidation of the active Ta catalyst leads to the formation of mono- and di-meric species on the SiO2 surface. The obtained results were compared to those of the previously reported time-resolved HEROS study on an inactive silica supported Ta(V) bisalkyl catalyst’s concentration evolution during its oxidation Błachucki et al. (2015). The study allowed observation of an immediate transition of the active Ta catalyst from its unoxidized form to the oxidized one. This finding is dissimilar to the result of the study on the inactive Ta catalyst, where the oxidation led through an intermediate step