On closed sets with convex projections under somewhere dense sets of directions

Let k,n ∈ N with k< n and let

Natural noise and external wake field seeding in a proton-driven plasma accelerator

We discuss the level of natural shot noise in a proton bunch-driven plasma accelerator. The required seeding for the plasma wake field must be larger than the cumulative shot noise. This is the necessary condition for the axial symmetry of the generated wake and the acceleration quality. We develop an analytical theory of the noise field and compare it with multi-dimensional simulations. It appears that the natural noise wake field generated in plasma by the available at CERN super-protons-synchrotron (SPS) bunches is very low, at the level of a few 10 kV/m. This fortunate fact eases the requirements on the seed. Our three dimensional simulations show that even a few tens MeV electron bunch precursor of a very moderate intensity is sufficient to seed the proton bunch self-modulation in plasma.Comment: 5 pages, 5 figure

Implementarea programului Dspace-CRIS în Repozitoriul Instituțional IRMS - Nicolae Testemițanu SUMPh

Background. Institutional Repository IRMS - Nicolae Testemitanu SUMPh is an archive of scientific publications by university staff based on Dspace. For further development and expansion, new opportunities are needed, namely, obtaining relevant information about the studies conducted and their results. Objective of the study. The work aims to describe the experience of implementing the free open-source extension DSpace-CRIS in the current IRMS repository - Nicolae Testemitanu SUMPh. Material and Methods. It was made an analysis of scientific publications and technical literature on the use of the DSpace-CRIS extension, to further introduce the extension into the repository. It has been identified the best and acceptable criteria which can be used to implement this extension. The research was based on a comparison and analysis of the repositories of educational institutions using DSpaceCRIS. Results. Implementation of the CRIS-Dspace extension in the institutional repository IRMS Nicolae Testemitanu SUMPh will allow to monitor, systematize and keep records of the results of research activities of Nicolae Testemitanu SUMPh university employees. Create profiles of researchers, department pages, project grants and awards, research results reports; establish the relationship between the author, unit and the result of scientific activity. Conclusion. The implementation of the extension DSpace-CRIS will allow to monitor and record the results of the research activities of Nicolae Testemitanu SUMPh university employees. Will ensure the availability and improve the ranking of the university. Introducere. Repozitoriul instituțional IRMS Nicolae Testemițanu SUMPh reprezintă o arhivă de publicații științifice a angajaților Universității, bazată pe platforma DSpace. Diversificarea funcționalității Repozitoriului presupune dezvoltarea și extinderea acestuia prin implementarea unor noi programe, cum ar fi Dspace -CRIS-ul etc. Acest fapt este confirmat de bunele practici ale repozitoriilor instituționale de peste hotarele țarii. Scopul lucrării. Scopul lucrării este de a analiza, descrie și a scoate în evidență specificul implementării programului DSpace-CRIS în repozitoriul IRMS - Nicolae Testemițanu SUMPh. Material și Metode. În vederea atingerii scopului a fost realizată analiză publicațiilor științifice și tehnice privind aplicarea sistemului DSpace-CRIS. A fost efectuată o analiză comparativă a repozitoriilor care funcționează în baza acestei extensii în vederea identificării și aplicării celor mai bune practici de aplicare și funcționare. Rezultate. Aplicarea sistemului DspaceCRIS- în repozitoriul instituțional IRMS - SUMPh Nicolae Testemițanu va permite o organizare și monitorizare mai eficientă a rezultatelor activității de cercetare a angajaților USMF „Nicolae Testemițanu”. Concluzii. Implementarea suplimentului DSpace-CRIS va avea un impact pozitiv asupra managementului științific, vizibilității Universității și a fiecărui cercetător în parte

On a characterization of normal and countably paracompact spaces via set-avoiding selections

summary:We give a characterization of normal and countably paracompact spaces via continuous set-avoiding selections

Overview of Plasma Lens Experiments and Recent Results at SPARC_LAB

Beam injection and extraction from a plasma module is still one of the crucial aspects to solve in order to produce high quality electron beams with a plasma accelerator. Proper matching conditions require to focus the incoming high brightness beam down to few microns size and to capture a high divergent beam at the exit without loss of beam quality. Plasma-based lenses have proven to provide focusing gradients of the order of kT/m with radially symmetric focusing thus promising compact and affordable alternative to permanent magnets in the design of transport lines. In this paper an overview of recent experiments and future perspectives of plasma lenses is reported

Activitatea CI Infomedica în contextul pandemiei COVID-19

Biblioteca Ştiinţifică Medicală, USMF „Nicolae Testemiţanu”Background. In the context of the COVID-19 pandemic, the activity of IC Infomedica was carried out in a special regime. The transition to online activity has demonstrated the professional capacity of librarians. The sanitary crisis imposed the operative reorientation of the libraries regarding the service. Objective of the study. To assess the degree of satisfaction of the IC Infomedica users regarding the quality of remote services provided during the pandemic period. Material and Methods. At the documentation stage, were analyzed the practices and experience of the libraries in the country and abroad and the activity reports of the Center during the pandemic period. At the documentation stage, the practices and experience of libraries in the country and abroad and the activity reports of the Center during the pandemic period were analyzed. Results. In the conditions of the COVID-19 crisis, IC Infomedica managed to adapt quickly to the new normalities. The distance activity was organized coherently and efficiently. The efforts have been made to provide information services, scientometrics, beneficiary training. The recommendations on optimizing the quality of services and the professional activity of the IC are based on the opinions of the respondents. Conclusion. The pandemic period highlighted the insufficiency of skills and competencies in the use of information technologies and resources for different categories of users, which determined the Library to act in order to form the information literacy of SML users.Introducere. În legătură cu pandemia Covid-19, activitatea CI Infomedica s-a desfășurat în regim special. Trecerea la activitatea în regim online a demonstrat capacitatea profesională a bibliotecarilor. Criza sanitară a impus reorientarea operativă a bibliotecilor, privind deservirea beneficiarilor. Scopul lucrării. Reflectarea activităţii CI Infomedica în perioada pandemică. Material și Metode. La etapa de documentare au fost analizate practicile și experiența bibliotecilor din țară și peste hotare și rapoartele de activitate a Centrului în perioada pandemică (martie 2020-septembrie 2021). În vederea evaluării calității serviciilor online prestate de CI Infomedica, au fost chestionați utilizatorii deserviți în perioada pandemică. Rezultate. În condițiile crizei COVID-19, CI Infomedica a reușit să se adapteze rapid noilor normalității. Activitatea la distanță a fost organizată coerent și eficient. Eforturile au fost depuse în vederea prestării serviciilor informaționale, scientometrice, a formării beneficiarilor. Recomandările privind optimizarea calității serviciilor și a activității profesionale a CI sunt bazate pe opiniile respondenților. Concluzii. Perioada pandemică a evidențiat insuficiența abilităţilor şi a competențelor de utilizare a tehnologiilor și a resurselor informaționale, la diferite categorii de utilizatori, lucru care a determinat Biblioteca să acţioneze în vederea formării culturii informaţiei utilizatorilor BŞM

Generation of angular-momentum-dominated electron beams from a photoinjector

Various projects under study require an angular-momentum-dominated electron beam generated by a photoinjector. Some of the proposals directly use the angular-momentum-dominated beams (e.g. electron cooling of heavy ions), while others require the beam to be transformed into a flat beam (e.g. possible electron injectors for light sources and linear colliders). In this paper, we report our experimental study of an angular-momentum-dominated beam produced in a photoinjector, addressing the dependencies of angular momentum on initial conditions. We also briefly discuss the removal of angular momentum. The results of the experiment, carried out at the Fermilab/NICADD Photoinjector Laboratory, are found to be in good agreement with theoretical and numerical models.Comment: 8 pages, 7 figures, submitted to Phys. Rev. ST Accel. Beam

Quantifying the Detrimental Impacts of Land-Use and Management Change on European Forest Bird Populations

The ecological impacts of changing forest management practices in Europe are poorly understood despite European forests being highly managed. Furthermore, the effects of potential drivers of forest biodiversity decline are rarely considered in concert, thus limiting effective conservation or sustainable forest management. We present a trait-based framework that we use to assess the detrimental impact of multiple land-use and management changes in forests on bird populations across Europe. Major changes to forest habitats occurring in recent decades, and their impact on resource availability for birds were identified. Risk associated with these changes for 52 species of forest birds, defined as the proportion of each species' key resources detrimentally affected through changes in abundance and/or availability, was quantified and compared to their pan-European population growth rates between 1980 and 2009. Relationships between risk and population growth were found to be significantly negative, indicating that resource loss in European forests is an important driver of decline for both resident and migrant birds. Our results demonstrate that coarse quantification of resource use and ecological change can be valuable in understanding causes of biodiversity decline, and thus in informing conservation strategy and policy. Such an approach has good potential to be extended for predictive use in assessing the impact of possible future changes to forest management and to develop more precise indicators of forest health

Причины и последствия провала внешнеполитической стратегии России на Украине

This article analyzes Russian foreign policy in Ukraine during the political crisis in 2013-2014 years, which (crisis) led to the military coup against legitimately elected Ukrainian President Viktor Yanukovych and to the Civil War start. Special attention is paid to the mistakes and miscalculations of Russian foreign policy in Ukraine and its alternative schemes, the use of which would preserve political stability in Ukraine and ensure the successful realization of Russia's national interests.Статья посвящена анализу российской внешней политики на Украине в период политического кризиса 2013-2014 гг., приведшего к вооруженному свержению законно избранного президента В. Януковича и началу гражданской войны. Особое внимание автор уделяет ошибкам и просчетам российской внешнеполитической стратегии на Украине и ее альтернативным схемам, использование которых позволило бы сохранить внутриполитическую стабильность на Украине и успешно реализовать российские интересы