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The Berlin Joint Lab for Electrochemical Interfaces BElChem is located at the BESSY II synchrotron in Berlin, Germany, and co run by the Fritz Haber Institut, the Max Planck Institut of Chemical Energy Conversion and the Helmholtz Zentrum Berlin. BElChem focuses on providing a molecular level description of photo electrochemical interfaces that are of high relevance for solar fuel production and renewable energy storage. The CO2 reduction reaction CO2RR and the oxygen evolution reaction OER are of particular current interest. In BElChem, near ambient pressure X ray photoelectron spectroscopy NAP XPS and near ambient pressure hard X ray photoelectron spectroscopy NAP HAXPES will be used for the in situ and operando interrogation of the electronic structure and chemical composition of catalytically active solid gas and solid liquid interfaces. BElChem will also enable heterogeneous catalytic reactions, such as oxidation and hydrogenation reactions, to be investigated

Photodeposition is a specific method for depositing metallic co catalysts onto photocatalysts and was applied for immobilizing platinum nanoparticles onto cellulose, a photocatalytically inactive biopolymer. The obtained Pt cellulose catalysts show narrow and well dispersed nanoparticles with average sizes between 2 and 5 nm, whereby loading, size and distribution depend on the preparation conditions. The catalysts were investigated for the hydrogenation of para nitrophenol via transfer hydrogenation using sodium borohydride as the hydrogen source, and the reaction rate constant was determined using the pseudo first order reaction rate law. The Pt cellulose catalysts are catalytically active with rate constant values k from 0.09 10 amp; 8722;3 to 0.43 10 amp; 8722;3 min amp; 8722;1, which were higher than the rate constant of a commercial Pt Al2O3 catalyst k 0.09 10 amp; 8722;3 min amp; 8722;1 . Additionally, the Pt cellulose catalyst can be used for electrochemical hydrogenation of para nitrophenol where the hydrogen is electrocatalytically formed. The electrochemical hydrogenation is faster compared to the transfer hydrogenation k 0.11 min amp; 8722;1

Long diffusion lengths of photoexcited charge carriers are crucial for high power conversion efficiencies of photoelectrochemical and photovoltaic devices. Time resolved photoconductance measurements are often used to determine diffusion lengths in conventional semiconductors. However, effects such as polaron formation or multiple trapping can lead to time varying mobilities and lifetimes that are not accounted for in the conventional calculation of the diffusion length. Here, a generalized analysis is presented that is valid for time dependent mobilities and time dependent lifetimes. The diffusion length is determined directly from the integral of a photoconductivity transient and can be applied regardless of the nature of carrier relaxation. To demonstrate our approach, photoconductivity transients are measured from 100 fs to 1 s by the combination of time resolved terahertz and microwave spectroscopy for BiVO4, one of the most studied metal oxide photoanodes for photoelectrochemical water splitting. The temporal evolution of charge carrier displacement is monitored and converges after about 100 ns to a diffusion length of about 15 nm, which rationalizes the photocurrent loss in the corresponding photoelectrochemical device. The presented method is further validated on a amp; 8722;Si H, c amp; 8722;Si, and halide perovskite, which underlines its potential to determine the diffusion length in a wide range of semiconductors, including disordered materials

The spatial distribution and concentration of lanthanide activator and sensitizer dopant ions are of key importance for the luminescence color and efficiency of upconverting nanoparticles UCNPs . Quantifying dopant ion distributions and intermixing, and correlating them with synthesis methods require suitable analytical techniques. Here, X ray photoelectron spectroscopy depth profiling with tender X rays 2000 6000 eV , providing probe depths ideally matched to UCNP sizes, is used to measure the depth dependent concentration ratios of Er3 to Yb3 , [Er3 ] [Yb3 ], in three types of UCNPs prepared using different reagents and synthesis methods. This is combined with data simulations and inductively coupled plasma optical emission spectroscopy ICP OES measurements of the lanthanide ion concentrations to construct models of the UCNPs dopant ion distributions. The UCNP sizes and architectures are chosen to demonstrate the potential of this approach. Core only UCNPs synthesized with XCl3 6H2O precursors amp; 946; phase exhibit a homogeneous distribution of lanthanide ions, but a slightly surface enhanced [Er3 ] [Yb3 ] is observed for UCNPs prepared with trifluroacetate precursors amp; 945; phase . Examination of Yb core Er shell UCNPs reveals a co doped, intermixed region between the single doped core and shell. The impact of these different dopant ion distributions on the UCNP s optical properties is discussed to highlight their importance for UCNP functionality and the design of efficient UCNPs

Sb2Se3 has emerged as an important photoelectrochemical (PEC) and photovoltaic (PV) material due to its rapid rise in photoconversion efficiencies. However, despite its binary nature, Sb2Se3 has a complex defect chemistry, which reduces the maximum photovoltage that can be obtained. Thus, it is important to understand these defects and to develop passivation strategies in order to further improve this material. In this work, a comprehensive investigation of the charge carrier dynamics of Sb2Se3 and the influence of sulfur treatment on its optoelectronic properties was performed using time resolved microwave conductivity (TRMC), photoluminescence (PL) spectroscopy and low frequency Raman spectroscopy (LFRS). The key finding in this work is that upon sulfur treatment of Sb2Se3, the carrier lifetime is increased by the passivation of deep defects in Sb2Se3 in both the surface region and the bulk, which is evidenced by increased charge carrier lifetime of TRMC decay dynamics, increased radiative recombination efficiency and decreased deep defect level emission (PL), and improved long-range order in the material (LFRS). These findings provide crucial insights into the defect passivation mechanisms in Sb2Se3 paving the way for developing highly efficient PEC and PV devices.

Photoelectrochemical water splitting is a promising route to produce hydrogen from solar energy. However, corrosion of photoelectrodes remains a fundamental challenge for their implementation. Here, we reveal different dissolution behaviors of BiVO4 photoanode in pH-buffered borate, phosphate, and citrate (hole-scavenger) electrolytes, studied in operando employing an illuminated scanning flow cell. We demonstrate that decrease in photocurrents alone does not reflect the degradation of photoelectrodes. Changes in dissolution rates correlate to the evolution of surface chemistry and morphology. The correlative measurements on both sides of the liquid-semiconductor junction provide quantitative comparison and mechanistic insights into the degradation processes.

Problem statement. The process of co-operation dump working bodies with the developed soil is one of determinative duty cycle machines for earth-moving transport works. Character passing of process carries out the considerable influence on the construction of earth-moving transport machines. Passing process of cooperation dump working body machine with soil depends on the technological setting machine, namely from a kind of a robot, that is executed by a machine, physical and mechanical properties of soil and method of his destruction, geometrical parameters of working body, parameters of the mode digging (depth of cutting, cutting corner, corner setting of working organ in a plan and etc.), that determine power and power parameters of working process machine. Possibility optimization of geometrical parameters telescopic working body of bulldozer to different ground to the terms and technological operations will allow rationally to use hauling and coupling descriptions of machine, promote her productivity and universality. Purpose. There is a review and analysis of existent theories of cooperation of dump working bodies with soil and development, on their basis, algorithm of optimization calculation geometrical parameters of dump bulldozer telescopic type depending on the ground terms and hauling and coupling descriptions of base machine, determination of his productivity at digging and portage soil. Conclusions. On the basis of hauling balance the algorithm optimization of geometrical parameters dump bulldozer telescopic type is worked out after the generalized criterion optimization ПNG depending on engine of base machine and physical and mechanical properties of the developed environment power., Постановка проблемы. Процесс взаимодействия отвальных рабочих органов с разрабатываемым грунтом является одним из определяющих факторов рабочего цикла машин для землеройнотранспортных работ. Характер процесса значительно влияет на конструкцию землеройно-транспортных машин. Процесс взаимодействия отвального рабочего органа машины с грунтом зависит от технологического назначения машины, а именно от вида работ, которые выполняются машиной, физико-механических свойств грунта и способа его разрушения, геометрических параметров рабочего органа, параметров режима копания (глубины резания, угла резания, угла установки рабочего органа в плане и т. д.), которые определяют силовые и энергетические параметры рабочего процесса машины. Возможность оптимизации геометрических параметров телескопического рабочего органа бульдозера к различным грунтовым условиям и технологическим операциям позволит рационально использовать тягово-сцепные характеристики машины, повысить её производительность и универсальность. Цель статьи − обзор и анализ существующих теорий взаимодействия отвальных рабочих органов с грунтом и разработка, на их основе алгоритма оптимизационного расчета геометрических параметров отвала бульдозера телескопического типа в зависимости от грунтовых условий и тягово-сцепных характеристик базовой машины, определение его производительности при копании и транспортировании грунта. Выводы. На основании тягового баланса разработан алгоритм оптимизации геометрических параметров отвала бульдозера телескопического типа по обобщенному критерию оптимизации ПNG в зависимости от мощности двигателя базовой машины и физико-механических свойств разрабатываемой среды., Постановка проблеми. Процес взаємодії відвальних робочих органів із ґрунтом, що розроблюється, − один із визначальних факторів робочого циклу машин для землерийно-транспортних робіт. Характер процесу суттєво впливає на конструкцію землерийно-транспортних машин. Процесу взаємодії відвального робочого органу машини з ґрунтом залежить від технологічного призначення машини, тобто від виду робіт, що виконуються машиною, фізико-механічних властивостей ґрунту та способу його руйнування, геометричних параметрів робочого органа, параметрів режиму копання (глибини різання, кута різання, кута установки робочого органа в плані і тощо.), які визначають силові та енергетичні параметри робочого процесу машини. Можливість оптимізації геометричних параметрів телескопічного робочого органа бульдозера до різноманітних ґрунтових умов та технологічних операцій дозволить раціонально використовувати тягово-зчіпні характеристики машини, підвищити її продуктивність та універсальність. Мета статті − огляд і аналіз існуючих теорій взаємодії відвальних робочих органів із ґрунтом та розроблення, на їх основі, алгоритму оптимізаційного розрахунку геометричних параметрів відвала бульдозера телескопічного типу залежно від ґрунтових умов та тягово-зчіпних характеристик базової машини, визначення його продуктивності під час копанні та транспортування ґрунту. Висновок. На основі тягового балансу розроблено алгоритм оптимізації геометричних параметрів відвала бульдозера телескопічного типу за узагальненим критерієм оптимізації ПNG залежно від потужності двигуна базової машини та фізико-механічних властивостей середовища, що розроблюється.

This paper presents the updated Polish Neuroendocrine Tumour Network expert panel recommendations on the management of neuroendocrine neoplasms (NENs) of the stomach and duodenum, including gastrinoma. The recommendations discuss the epidemiology, pathogenesis, and clinical presentation of these tumours as well as their diagnosis, including biochemical, histopathological, and localisation diagnoses. The principles of treatment are discussed, including endoscopic, surgical, pharmacological, and radionuclide treatments. Finally, there are also recommendations on patient monitoring.

This study presents the revised Polish guidelines regarding the management of patients suffering from neuroendocrine neoplasms (NENs) of the small intestine and appendix. The small intestine, especially the ileum, is the most common location for these neoplasms. Most are well differentiated and slow growing. Their symptoms may be atypical, which can result in delayed or accidental diagnosis. Appendicitis is usually the first manifestation of NEN in this location. Typical symptoms of carcinoid syndrome occur in approximately 20-30% of patients suffering from small intestinal NENs with distant metastases. The main cause of death in patients with carcinoid syndrome is carcinoid heart disease. The most useful laboratory test is the determination of chromogranin A, while concentration of 5-hydroxyindoleacetic acid is helpful in the diagnostics of carcinoid syndrome. For visualisation, ultrasound, computed tomography, magnetic resonance imaging, colonoscopy, video capsule endoscopy, double-balloon enteroscopy, and somatostatin receptor scintigraphy may be used. A detailed his-tological report is crucial for the proper diagnostics and therapy of NENs of the small intestine and appendix. The treatment of choice is surgical management, either radical or palliative. The pharmacological treatment of the hormonally active and non-active small intestinal NENs as well as NENs of the appendix is based on long-acting somatostatin analogues. In patients with generalised NENs of the small intestine in progress during the SSA treatment, with good expression of somatostatin receptors, the first-line treatment should be radio-isotope therapy, while targeted therapies, such as everolimus, should be considered afterwards. When the above therapies are exhausted, in certain cases chemotherapy may be considered.