Search results for " materia"

Organocatalisi: sviluppo di nuovi materiali supportati riciclabili ed ottimizzazione di reazioni in fase omogenea.

2011

Merging Features from Green's Functions and Time Dependent Density Functional Theory: A Route to the Description of Correlated Materials out of Equil…

2016

We propose a description of nonequilibrium systems via a simple protocol that combines exchange-correlation potentials from density functional theory with self-energies of many-body perturbation theory. The approach, aimed to avoid double counting of interactions, is tested against exact results in Hubbard-type systems, with respect to interaction strength, perturbation speed and inhomogeneity, and system dimensionality and size. In many regimes, we find significant improvement over adiabatic time dependent density functional theory or second Born nonequilibrium Green's function approximations. We briefly discuss the reasons for the residual discrepancies, and directions for future work.

Suite of Statistical Models Forecasting Latvian GDP

2014

Abstract We develop a suite of statistical models to forecast Latvian GDP. We employ various univariate and multivariate econometric techniques to obtain short-term GDP projections and to assess the performance of the models. We also comprise the information contained in components of GDP and obtain short-term GDP projections from disaggregated perspective. We run out-of-sample forecasting procedures to evaluate GDP projections and to assess forecasting accuracy of all individual statistical models. We conclude that factor and bridge models are among the best individually performing models in the suite. Forecasting accuracy obtained using disaggregated models of factor and bridge models is …

Recent Advances in the Chemistry of 1,2,4-Oxadiazoles

2015

1,2,4-Oxadiazoles experienced an almost 80-year long period of scientific lethargy before they tickled the curiosity of chemists. The study of chemical and photochemical reactivity of 1,2,4-oxadiazoles opened the way to a series of applications in heterocyclic synthesis. Today, 1,2,4-oxadiazoles are known in medicinal chemistry for their use as bioisosters of esters and amides. Furthermore, fluorinated 1,2,4-oxadiazoles have been applied in materials science either by themselves or for the targeted modification of polymers and macromolecules. Overall, the synthesis of 1,2,4-oxadiazoles can be planned to fine-tune their properties for featured applications. Their versatility, either as start…

DFT Prediction of Enhanced Reducibility of Monoclinic Zirconia upon Rhodium Deposition.

2018

Oxides are an important class of materials and are widely used, for example, as supports in heterogeneous catalysis. In a number of industrial catalytic processes, oxide supports actively participate in chemical transformations by releasing lattice oxygen anions. While this is intuitively understood for reducible oxides, the reducibility of irreducible oxides may be modified via nanoengineering or upon inclusion of foreign species. Our calculations predict that the ability of irreducible monoclinic zirconia to release oxygen improves substantially upon deposition of rhodium. Through a comprehensive screening of Rh/ZrO2 with different size of the rhodium species, we find that a Rh adatom and…

Oxygen Vacancy Formation and Migration within the Antiphase Boundaries in Lanthanum Scandate-Based Oxides: Computational Study.

2022

The study was performed with the financial support from the Latvian Council of Science under the grant agreement LZP-2020/2-0009. Calculations were performed at the HLRS, University of Stuttgart, within the project 12939 DEFTD. The Institute of Solid State Physics, University of Latvia (Latvia), as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Frame-work Programme H2020-WIDESPREAD-01-2016-2017-Teaming Phase2 under grant agreement No. 739508, project CAMART2.

The p-Type Doping of ZnO: Mirage or Reality?

2015

This chapter deals with a critical review on p-type doping of ZnO. In the past 15 years, ZnO has attracted considerable attention due to its unique properties, which make it a promising material for optoelectronic devices applications. However, a reliable p-type ZnO doping remains a major challenge because of self-compensation effects; thus, despite the advantages of these devices, the fabrication of ZnO-based devices is hampered by the lack of a stable p-type doping. A careful and critical analysis of the results reported in literature raises many doubts about the correctness of the doping-type assignments and, in general, the values of the electrical parameters reported. A historical surv…

Feedback and Communication in Active Hydrogel Spheres with pH Fronts: Facile Approaches to Grow Soft Hydrogel Structures

2021

Abstract Compartmentalized reaction networks regulating signal processing, communication and pattern formation are central to living systems. Towards achieving life‐like materials, we compartmentalized urea‐urease and more complex urea‐urease/ester‐esterase pH‐feedback reaction networks into hydrogel spheres and investigate how fuel‐driven pH fronts can be sent out from these spheres and regulated by internal reaction networks. Membrane characteristics are installed by covering urease spheres with responsive hydrogel shells. We then encapsulate the two networks (urea‐urease and ester‐esterase) separately into different hydrogel spheres to devise communication, pattern formation and attracti…

One-dimensional nanostructures as electrode materials for water electrolysis

2010

„Miasto to jak mieszkanie. Nasze”. Powojenne strategie oswajania miast Ziem Zachodnich i Północnych na przykładzie Wrocławia

2018

Treść artykułu prezentuje trzy istotne zagadnienia. Pierwszym z nich jest refleksja nad praktykami zamieszkiwania (dwelling) miasta – pojęcia rozszerzającego zakres ba- dań nad przestrzenią miejską o kategorie związane z socjologią codzienności – przede wszystkim dotyczącego materialnego środowiska życia ludzi widzianego z perspektywy dyskursów niedominujących. Drugim z zagadnień jest analiza strategii oswajania ob- cego kulturowo dziedzictwa materialnego Ziem Zachodnich i Północnych, za pomocą kategorii zamieszkiwania i na przykładzie wspomnień mieszkańców Wrocławia. Trzecim aspektem są pytania stanowiące punkt wyjścia dla przyszłych projektów badawczych au- torki, postawione w wyniku prze…