University of Bucharest
  • Bucharest, District 5, Romania
Recent publications
Public consultation is an essential component of the planning process to achieve sustainable development. However, there is still a lack of knowledge related to public engagement in consultation processes on urban planning matters. Thus, the aim of this study was to understand public needs in terms of planning urban space by exploring the content of online comments made by the public. We used, as a case study, urban planning in Bucharest, Romania. We assessed 1879 online comments submitted between 2008 and 2020 through a municipality-set online platform, to 220 out of the 1148 zonal urban plans issued during that period. The self-organizing map (SOM) method, an unsupervised artificial neural network, was used to visualize and cluster the online comments based on their content. Using this method, 13 clusters were found to show the general landscape of topics in online comments. These revealed three main and frequently discussed issues among the public: urban green spaces (i.e., saving or developing new green spaces), protection of cultural heritage (i.e., preserving the cultural heritage of the city) and administrative issues (i.e., lack of confidence in the decision-making and permit granting process). In terms of dynamics over the analyzed time period, the topics evolved from esthetic and cultural concerns to issues relating to administrative shortcomings and lack of urban green spaces. Furthermore, we investigated the relationship between plan characteristics and comments and found that the objective of the plan and its year of approval have a positive influence on the presence and number of comments. These results are important to produce higher quality urban projects that are better aligned with the public needs. We further suggest the need to support a sustainable urban spatial development by incorporating the real public needs.
In Europe, equity has become an important policy objective based on the recently adopted European Green Deal and the idea of “leaving no one behind”. However, the question remains as to what extent equity is a real concern in the implementation of territorial policies, including spatial planning, and other place-based strategies in the EU member states. In this paper, we determine if and how equity has become a concern in the strategic planning of green infrastructure (GI), and whether strategic plans are indeed relevant in responding to vulnerable groups’ needs. We focus on Romania, a post-communist country where ensuring GI availability and accessibility is often a challenge for cities. The strategic plans of 75 % of Romanian cities (N = 242 plans) were systematically evaluated using document content analysis. This revealed that equity is addressed rather superficially in strategic urban plans. While most aim at increasing the availability and attractiveness of GI, very few of them do so by explicitly addressing the needs of vulnerable groups. Interestingly, equity concerns in the plans are not correlated with actual green space availability. Our study contributes to discussions about the role of strategic urban planning in delivering equitable public spaces and provides a set of recommendations for policy- and decision-makers.
The interactions of ions with defective KTaO3 has been studied by irradiating pre- pmaged single crystal KTaO3 with 5 MeV C, 7 MeV Si and 12 MeV O ions at 300 K. By exploring these processes in KTaO3, the results show that, for a pre-damaged fractional disorder level of 0.3 and inelastic electronic energy loss, Se, ≥ 4.65 keV/nm (7 MeV Si ions), the synergistic interaction of Se with defects enables amorphous ion track creation. At lower values of Se (5 MeV C and 12 MeV O), minor increases in disorder are observed initially over a region of depth at an ion fluence of 10 ions/nm2, which may be due to dissolution of pre-existing interstitial or amorphous clusters; however, with further increase in ion fluence, a transition from irradiation-induced disorder production to ionization-induced damage recovery processes, not previously reported in KTaO3, is observed.
A 4-algebra is a commutative algebra A over a field k such that (a2)2=0, for all a∈A. We have proved recently [22] that 4-algebras play a prominent role in the classification of finite dimensional Bernstein algebras. Let A be a 4-algebra, E a vector space and π:E→A a surjective linear map with V=Ker(π). All 4-algebra structures on E such that π:E→A is an algebra map are described and classified by a global cohomological object GH2(A,V). Any such 4-algebra is isomorphic to a crossed product V#A and GH2(A,V) is a coproduct, over all 4-algebras structures ⋅V on V, of all non-abelian cohomologies Hnab2(A,(V,⋅V)), which are the classifying objects for all extensions of A by V. Several applications and examples are provided: in particular, GH2(A,k) and GH2(k,V) are explicitly computed and the Galois group Gal(V#A/V) of the extension V↪V#A is described.
The idea of linking stressors, services providing units (SPUs), and ecosystem services (ES) is ubiquitous in the literature, although is currently not applied in areas contaminated with heavy metals (HMs), This integrative literature review introduces the general form of a deterministic conceptual model of the cross-scale effect of HMs on biogeochemical services by SPUs with a feedback loop, a cross-scale heuristic concept of resilience, and develops a method for applying the conceptual model. The objectives are 1) to identify the clusters of existing research about HMs effects on ES, biodiversity, and resilience to HMs stress, 2) to map the scientific fields needed for the conceptual model's implementation, identify institutional constraints for inter-disciplinary cooperation, and propose solutions to surpass them, 3) to describe how the complexity of the cause-effect chain is reflected in the research hypotheses and objectives and extract methodological consequences, and 4) to describe how the conceptual model can be implemented. A nested analysis by CiteSpace of a set of 16,176 articles extracted from the Web of Science shows that at the highest level of data aggregation there is a clear separation between the topics of functional traits, stoichiometry, and regulating services from the typical issues of the literature about HMs, biodiversity, and ES. Most of the resilience to HMs stress agenda focuses on microbial communities. General topics such as the biodiversity-ecosystem function relationship in contaminated areas are no longer dominant in the current research, as well as large-scale problems like watershed management. The number of Web of Science domains that include the analyzed articles is large (26 up to 87 domains with at least ten articles, depending on the sub-set), but thirteen domains account for 70–80% of the literature. The complexity of approaches regarding the cause-effect chain, the stressors, the biological and ecological hierarchical level and the management objectives was characterized by a detailed analysis of 60 selected reviews and 121 primary articles. Most primary articles approach short causal chains, and the number of hypotheses or objectives by article tends to be low, pointing out the need for portfolios of complementary research projects in coherent inter-disciplinary programs and innovation ecosystems to couple the ES and resilience problems in areas contaminated with HMs. One provides triggers for developing innovation ecosystems, examples of complementary research hypotheses, and an example of technology transfer. Finally one proposes operationalizing the conceptual methodological model in contaminated socio-ecological systems by a calibration, a sensitivity analysis, and a validation phase.
TiO2-activated carbon composites with mesoporous structure were prepared by sol-gel method using different titanium precursors (titanium tetraisopropoxide, tetraethyl orthotitanate) and surfactants (Brij 58 and activated carbon). Two different activated carbons (AC and ACP), obtained from ground coffee, were activated in different conditions with orto-phosphoric acid. Finaly the obtained supports were dopped with Ag (1%). The crystalline structure, morphology, mesoporous structure, surface composition and optical properties of Ag/Ag2O/C/P/TiO2 photocatalysts were characterized by X-ray diffraction (XRD), BET surface area measurements, scanning and transmission electron microscopy (SEM, TEM), X-ray photoelectron spectroscopy (XPS), Raman, diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) techniques. A significant effect of activated carbon and titanium precursor on TiO2 crystalline phase was evidenced. Thus, XRD and TEM evidenced amorphization of TiO2 structure for samples with high phosphorus percent in activated carbon. As well, a small amount of rutile, together anatase, stood out for samples obtained from tetraethyl orthotitanate. XPS spectra revealed the presence of Ag¹⁺, Ag⁰, C-C, C-O, C-P, and P-O species on the surface with significant effect on adsorption and photocatalytic degradation of Brilliant Blue FCF dye and antibiotic Ciprofloxacin. The best activity and no toxicity of the obtained water after Ciprofloxacin photodegradation was evidenced for the sample with higher P content. The obtained results highlighted that activated carbon play an outstanding role in the mechanism of dye and antibiotic photodegradation influencing both the adsorption of organic molecules and photocatalytic performances of p-n Ag2O/TiO2 heteroconjunction from composite materials.
Cu2SnSe3 (CTSe) is a polyvalent material that can be used as an absorber layer for thin film solar cells or as a starting layer for the synthesis of CZTSe or CZTSSe compounds. Obtaining CTSe single phase films with optimized properties for thin film solar cells is a difficult task. A systematic study using both metallic and binary chalcogenides precursors for the formation of the CTSe phase was not performed. The films consisting of four different stacks (Sn\Cu, SnSe2\Cu, Sn\Cu2Se, and SnSe2\Cu2Se) were prepared by magnetron sputtering on soda lime glass (SLG) and molybdenum (Mo) coated SLG substrates, followed by annealing at 550 °C under Sn + Se atmosphere. X-ray diffraction and Raman spectroscopy results indicated the formation of a single CTSe phase in most of the stacks deposited on both substrates. Scanning electron microscopy images showed compact surfaces with large grains in the films deposited on Mo substrate, while the films on SLG have more voids on their surfaces. The elemental analysis measured by energy dispersive spectroscopy revealed stoichiometric films on Mo, and copper and tin rich compositions on SLG substrates. The band gap values inferred by conventional spectroscopy are between 0.81 and 1.95 eV. It was found that the SnSe2\Cu and Sn\Cu2Se stacks are preferred for the formation of a single CTSe phase, with dense surface morphology, a stoichiometric composition, and an optimal absorber layer band gap. This study opens the way to comprehend the formation reactions during the selenization of metallic and binary chalcogenides precursors towards the optimization of kesterite absorber for photovoltaic device fabrication.
Background: Nations marked by a Marxist-Leninist ideology have suffered greatly due to a culture of abuse emphasized by the absolute absence of psychology, thus contributing to a diminished ability in recognizing the consequences of traumatic experiences. Objective: To improve the assessment of the presence and severity of posttraumatic stress disorder (PTSD) in such a cultural context, our paper aimed at developing an alternative self-report measure for PTSD - the Post Traumatic Symptom Scale (PTSs), developed by clinicians with wide relevant expertise, based on the natural language people use to describe its subjective experience. This research used multiple samples consistent with the corresponding objectives. Mokken Scale Analysis and the Classical Test Theory were both employed. The proposed scale was tested against five competing PTSD models, whilst also investigating the symptoms' clusters in two different samples by using, to our knowledge, a network analysis approach for the first time. Method: The results indicated excellent psychometric properties regarding internal consistency and temporal reliability, as well as convergent and discriminant validity. The results of MSA showed that the scale fully conforms to the assumptions of the monotone homogeneity model, interpreted as positive evidence for its use in clinical purposes. The factor analyses pointed that the newer models outperformed the standard DSM-5 model, with bifactor models displaying better fit indexes than second-order models. Finally, a distinct pattern of symptom activation in the high-risk group (i.e. first-responders) was found, bringing support for symptoms overlapping between PTSD and affective disorders, thus reinforcing the idea of bridge symptoms which has significant clinical implications. Results: This study presents an alternative sound instrument for measuring PTSD symptomatology focused on how people naturally describe their subjective experiences. Theoretical and practical implications are discussed alongside limitations. Highlights: The construction of PTSs encompasses cultural trauma and one's subjective experience.PTSs was tested against the five major competing models of PTSD.Network analyses suggest different patterns in a student sample vs. a first-responders one, with the accent on the negative alterations in cognitions and mood (NACM) model.
Environmental Impact Assessment (EIA) emerged as a regulatory procedure and is now implemented worldwide. EIA aims to increase the sustainability of economic activities by decreasing the impact on environmental components. Transparency of the evaluation process is a key feature of the procedure, and this is achieved predominantly by encouraging participation in public debates. Public participation is essential for EIA's effectiveness, particularly in transboundary projects. This study evaluates whether media coverage of certain projects with transboundary environmental impacts increases public participation during EIA. We analyzed how online media covered the stories about four major projects subject to the EIA procedure in Romania (i.e., reactors 3 and 4 of Cernavoda Nuclear Power Plant, Oltenita used oil recycling facility, Certej mining project, management of Moldova Noua tailing ponds). We focused on articles published between 2010 and 2020, covering stories about the four projects. We further extracted the stakeholders involved in the projects using social network analysis. We extracted the main topics of articles discussing the four projects using deep categorization tools. The polarities of titles and contents of the articles were assessed using sentiment analysis tools. Our findings indicate that EIA is a media subject only when NGOs become important actors in the process and the industry generated local industrial disasters in the past; otherwise, the media rarely debate the environmental impact of projects. Without NGO reactions, Romanian readers are fed with political and economic aspects driven by large projects rather than environmental issues. The outcome of the current study is significant for understanding what triggers NGOs and the media to take a stand against major projects. Projects involving activities that generated ecological disasters in Romania's recent history are strongly opposed by NGOs and the public. In such cases, environmental and EIA topics are more often included in media stories. However, projects with undeniable environmental impact but without a negative background in Romania do not reach the public agenda, and the media stories do not focus on environmental aspects either, leading to limited public participation within the EIA procedure.
The accurate simulation of additional interactions at the ATLAS experiment for the analysis of proton–proton collisions delivered by the Large Hadron Collider presents a significant challenge to the computing resources. During the LHC Run 2 (2015–2018), there were up to 70 inelastic interactions per bunch crossing, which need to be accounted for in Monte Carlo (MC) production. In this document, a new method to account for these additional interactions in the simulation chain is described. Instead of sampling the inelastic interactions and adding their energy deposits to a hard-scatter interaction one-by-one, the inelastic interactions are presampled, independent of the hard scatter, and stored as combined events. Consequently, for each hard-scatter interaction, only one such presampled event needs to be added as part of the simulation chain. For the Run 2 simulation chain, with an average of 35 interactions per bunch crossing, this new method provides a substantial reduction in MC production CPU needs of around 20%, while reproducing the properties of the reconstructed quantities relevant for physics analyses with good accuracy.
A natural coupling of a circuit with an electromagnetic device is possible if special boundary conditions, called Electric Circuit Element (ECE), are used for the electromagnetic field formulation. This contribution shows how these ECE boundary conditions can be implemented into the 3D-finite element method for solving coupled full-wave electromagnetic (EM) field-circuit problems in the frequency domain. The frequency response allows the extraction of a reduced order model of the analyzed device, accounting for all the EM field effects. The implementation is based on a weak formulation that uses the electric field strength E strictly inside the domain and a scalar potential V defined solely at the boundary. Edge elements for E are used inside the three-dimensional domain and nodal elements for V are used on its two-dimensional boundary. The weak formulation is described and implemented in the free environment Open Numerical Engineering LABoratory (onelab) . The validation is carried out on 3D examples.
We construct a type of transverse deformation of a Vaisman manifold, which preserves the canonical foliation. For this construction we only need a basic 1-form with certain properties. We show that such basic 1-forms exist in abundance.
Nowadays, the flexible localization solution for various devices for work safety is one of the most demanding research questions. Notably, it is expected to provide an acceptable level of precision in different types of environments empowered by wearable technology and the Interent of Things (IoT) devices. Existing leading localization technologies are adapted for certain conditions, e.g., Wi-Fi, BLE, UWB are used for indoor areas and various GNSS-based ones for outdoor. This work focuses on investigating the LoRaWAN (868 MHz band) as a potential candidate to bridge this gap, being one of the most reliable and recognized communication technologies for the Industrial Internet of Things (IIoT). In the past, the research community had a lot of critics with respect to the applicability of LoRaWAN for localization, while the vision is facing a tremendous change over the past two years. The purpose of this work is to assess the feasibility of LoRaWAN as a localization solution for work safety applications in the industrial scenario from different angles. The work is based on two measurement campaigns conducted at the Brno University of Technology (BUT), Brno, Czech Republic, and University Politechnica in Bucharest (UPB), Bucharest, Romania. The campaigns cover both indoor and outdoor scenarios, provide the practical limitations of the positioning in standalone and k-NN powered localization systems. According to the results, LoRaWAN-based localization with relatively dense gateways deployment allows for achieving a meter-level accuracy, which may be suitable for the localization of workers.
Introduction The ascent of a route can be defined as being climbed on-sight or red-point. Climbing performance is measured by the grade of the personal best route that the athlete has ever climbed. Methodology The study examined 17 youth climbers (10 male and 7 female). The inclusion criteria were age (less than 20 years), a minimum of three sessions per week, a minimum 7a climbing grade and participation in national or international competitions. We used the Cognitrom battery and applied tests measuring spatial orientation and reactivity. Results Climbing experience explained 42.7% of the variance of on-sight performance, and 49.5% of the variance of red-point performance. Image generation has a negative on both on-sight and red-point performance, lowering the prediction with 0.5% for on-sight climbing and with 1.5% for red-point climbing. Discussion Experience can predict climbing performance with a better prediction for red-point performance than on-sight with almost 7%. A high level of image generation ability can lead to viewing more approaches for passing the crux, but in a moment of physical and mental breakdown, can lead to failure. Red-pointing is less demanding than on-sight from physiological and psychologycal points of view. On-sight climbing requires greater levels of cognitive skills, such as route intepretation strategies, spatial orientation, motric memory, problem-solving skills, but also greater levels of psychological skills such as stress management, risk management, coping anxiety.
By this paper we aim to emphasize the regulatory framework and the content of non-financial reporting, as well as the importance of presenting this information, which facilitate the development and/or the consolidation of a responsible business model. The professional accountants have a major responsibility in the capital employment process and must have an integrated thinking by their role in the audit councils and the audit commissions, as financial managers, and within the positions in the financial field in order to inform the organisations’ decision-makers and the investors with regard to the opportunities and risks related to sustainability.
We study the existence of nontrivial and of representable (dual) weak complementations, along with the lattice congruences that preserve them, in different constructions of bounded lattices, then use this study to determine the finite (dual) weakly complemented lattices with the largest numbers of congruences, along with the structures of their congruence lattices. It turns out that, if n≥7 is a natural number, then the four largest numbers of congruences of the n–element (dual) weakly complemented lattices are: 2n-2+1, 2n-3+1, 5·2n-6+1 and 2n-4+1, which yields the fact that, for any n≥5, the largest and second largest numbers of congruences of the n–element weakly dicomplemented lattices are 2n-3+1 and 2n-4+1. For smaller numbers of elements, several intermediate numbers of congruences appear between the elements of these sequences.
We discuss a recently proposed family of statistical network models—relational hyperevent models (RHEMs)—for analyzing team selection and team performance in scientific coauthor networks. The underlying rationale for using RHEM in studies of coauthor networks is that scientific collaboration is intrinsically polyadic, that is, it typically involves teams of any size. Consequently, RHEM specify publication rates associated with hyperedges representing groups of scientists of any size. Going beyond previous work on RHEM for meeting data, we adapt this model family to settings in which relational hyperevents have a dedicated outcome, such as a scientific paper with a measurable impact (e.g., the received number of citations). Relational outcome can on the one hand be used to specify additional explanatory variables in RHEM since the probability of coauthoring may be influenced, for instance, by prior (shared) success of scientists. On the other hand, relational outcome can also serve as a response variable in models seeking to explain the performance of scientific teams. To tackle the latter, we propose relational hyperevent outcome models that are closely related with RHEM to the point that both model families can specify the likelihood of scientific collaboration—and the expected performance, respectively—with the same set of explanatory variables allowing to assess, for instance, whether variables leading to increased collaboration also tend to increase scientific impact. For illustration, we apply RHEM to empirical coauthor networks comprising more than 350,000 published papers by scientists working in three scientific disciplines. Our models explain scientific collaboration and impact by, among others, individual activity (preferential attachment), shared activity (familiarity), triadic closure, prior individual and shared success, and prior success disparity among the members of hyperedges.
A new cosmological theory is proposed in the theoretical framework of modified gravity theories which is based on a tachyonic field non-minimally coupled with a specific topological invariant constructed with third order contractions of the Riemann tensor. After proposing the action of the cosmological model, the modified Friedmann relations and the Klein–Gordon equations are obtained, describing the corresponding geometrical corrections to the Einstein–Hilbert action. The physical features of the cosmological system are investigated by adopting the dynamical system analysis in the case of an exponential function for the geometrical coupling term. The investigation revealed that the cosmological system can explain the current accelerated expansion of the Universe and the matter dominated epoch, showing a high compatibility to the recent history of our Universe for various values of the coupling coefficients.
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7,671 members
Octavian D. Pavel
  • Department of Organic Chemistry, Biochemistry and Catalysis
Nicolae Cotfas
  • Faculty of Physics
Florentina Hristea
  • Department of Computer Science
Surugiu Camelia
  • Faculty of Administration and Business
90 Panduri Street, 050663, Bucharest, District 5, Romania
Head of institution
Marian Preda
+40-21- 313 17 60