Heuristic optimization applied to an intrinsically difficult problem - Birds formation flight

The conversion of CO2 to fuels is of significant importance in enabling the production of sustainable fuels, contributing to alleviating greenhouse gas emissions. While there are a number of key steps required to convert CO2, the initial step of adsorption and activation by the catalyst is critical. Well-known metal oxides such as oxidised TiO2 or CeO2 are unable to promote this step. In addressing this difficult problem, recent experimental work shows the potential for bismuth-containing materials to activate and convert CO2, but the origin of this activity is not yet clear. Additionally, nanostructures can show enhanced activity towards CO2. In this paper we present density functional theory (DFT) simulations of CO2 activation on heterostructured materials composed of extended rutile and anatase TiO2 surfaces modified with nanoclusters with Bi2O3 stoichiometry. These heterostructures show low coordinated Bi sites in the nanoclusters and a valence band edge that is dominated by Bi-O states. These two factors mean that supported Bi2O3 nanoclusters are able to adsorb and activate CO2. Computed adsorption energies lie in the range of -0.54 eV to -1.01 eV. In these strong adsorption modes, CO2 is activated, in which the molecule bends giving O-C-O angles of 126 - 130o and elongation of C-O distances up to 1.28 Å, with no carbonate formation. The electronic properties show a strong CO2-Bi-oxygen interaction that drives the interaction of CO2 to induce the structural distortions. Bi2O3-TiO2 heterostructures can be reduced to form Bi2+ and Ti3+ species. The interaction of CO2 with this electron-rich, reduced system can produce CO directly, reoxidising the heterostructure or form an activated carboxyl species (CO2-) through electron transfer from the heterostructure to CO2. These results highlight that a semiconducting metal oxide modified with suitable metal oxide nanoclusters can activate CO2, thus overcoming the difficulties associated with the difficult first step in CO2 conversion.

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Biochemical Markers in Patients with Readmission for Congestive Heart Failure

Revista de Chimie ◽

10.37358/rc.18.7.6395 ◽

2018 ◽

Vol 69 (7) ◽

pp. 1687-1691

Author(s):

Razan Al Namat ◽

Mihai Constantin ◽

Ionela Larisa Miftode ◽

Andrei Manta ◽

Antoniu Petris ◽

...

Keyword(s):

Heart Failure ◽

Congestive Heart Failure ◽

Rural Areas ◽

Discharge Planning ◽

Difficult Problem ◽

Uncontrolled Hypertension ◽

Medical Attention ◽

Family Doctors ◽

Increased Risk ◽

Risk Patients

Repetitive or recurrent hospitalizations are a general major health issue in patients with chronic disease. Congestive heart failure, is associated with a high incidence and presence of early rehospitalization, but variables in order to identify patients at increased risk and also an analysis of potentially remediable factors contributing to readmission have not been previously reported and it remains still a difficult problem. We retrospectively assessed 100 patients aged between 48-85 years old, of which 75% were men, who had been hospitalized with documentation of congestive heart failure in St. Spiridon County Emergency Hospital. They were hospitalized between 2010-2017. Even if recurrent heart failure was the most common cause for readmission or rehospitalization, other cardiac disorders and noncardiac illnesses were also accounted for readmission. Predictive factors of an increased probability of readmission included prior patient�s medical heart failure history, heart failure decompensation precipitated or accelerated by an ischaemic episode, atrial fibrillation or uncontrolled hypertension. Factors contributing to preventable readmissions included noncompliance with medications or diet, inadequate discharge planning or follow-up, failure of both social support system and the seek of a promp medical attention when symptoms reappeared. We also identified an inappropriate colaboration with family doctors especially for the patients from rural areas. Patients were more likely to cite side effects of prescribed medications rather than nonadherence as a precipitating factor for readmission. Thus, we can appreciate that early rehospitalization in patients with congestive heart failure may be avoidable in up to 50% of cases. Identification of high risk patients is possible and also necessary shortly after admission in order to identify nonpharmacological interventions designed to decrease readmission frequency.

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COMPLEX PROSTHETIC REHABILITATION OF THE PATIENT WITH MALIGNANT TUMOR OF OROPHARYNGEAL REGION DURING ANTITUMOR TREATMENT: CASE REPORT

Problems in oncology ◽

10.37469/0507-3758-2019-65-2-287-293 ◽

2019 ◽

Vol 65 (2) ◽

pp. 287-293

Author(s):

Yekaterina Izhnina ◽

Yekaterina Kochurova ◽

Natalya Lapina ◽

Karina Seferyan

Keyword(s):

Case Report ◽

Malignant Tumor ◽

Methodological Approach ◽

Difficult Problem ◽

Prosthetic Rehabilitation ◽

Anatomic Structure

Treatment of patients with malignant tumor of oropharyngeal region is a difficult problem due to the last detection of diseases and complex anatomic structure, despite the emergence new and improvement methods of the treatment of cancer of oropharyngeal region. Complex rehabilitation of this patients presents great difficulties due to the disturbance of breath, swallowing, speech, and the lack of a single methodological approach to treatment. It is needs to improve the effectiveness of prosthetic care for patients with malignant tumor of oropharyngeal region.

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Smooth Constrained Heuristic Optimization of a Combinatorial Chemical Space

10.21236/ada620145 ◽

2015 ◽

Author(s):

Berend C. Rinderspacher

Keyword(s):

Chemical Space ◽

Heuristic Optimization

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Urban stormwater: the analysis of the failure of the alternative techniques and the management of quality

Water Science & Technology ◽

10.2166/wst.1995.0009 ◽

1995 ◽

Vol 32 (1) ◽

pp. 33-39

Author(s):

E. Alfakih ◽

S. Barraud ◽

Y. Azzout ◽

B. Chocat

Keyword(s):

Stormwater Management ◽

Difficult Problem ◽

Management Approach ◽

Alternative Technique ◽

Urban Stormwater ◽

Urban Stormwater Management ◽

Porous Pavement ◽

Alternative Techniques ◽

Design Construction

The implementation of alternative techniques in urban stormwater management is a difficult problem in terms of choice, design, construction, and operating. We applied a quality management approach to try and have a better understanding of these techniques. The quality of an alternative technique in urban stormwater management is defined; the factors that lead to failures were identified and analysed. In order to reduce these factors, tools were developed, and measures that allow the achievement of the necessary standard of quality are suggested. In this article, all the illustrations refer to the porous pavement technique.

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