Категории симметрии и асимметрии в науке о языке

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The practical importance of accounting education for future managers

There is an opinion that accounting is a work on the chronological processing of the data of business transactions that have already occurred at the enterprise. Many applicants are not interested in the accounting profession, considering it narrowly focused, boring, and unprestigious. Although, graduates of accounting specialties have applied knowledge and the ability to implement them in their specialty, as accounting is required by all business entities, without exception, from an individual entrepreneur to transnational corporations. Knowledge and skills in accounting disciplines allow graduates to choose a large number of specialties from an accountant to a financial director or an auditor. Thus, the subject of the research is a set of theoretical and methodological issues regarding the importance of accounting knowledge for managers of various levels of enterprise administration. The purpose of the article is a theoretical justification of the methodological aspects of the importance of acquiring accounting competencies by managers of enterprises

Lithium Manganese Sulfates as a New Class of Supercapattery Materials at Elevated Temperatures

To make supercapattery devices feasible, there is an urgent need to find electrode materials that exhibit a hybrid mechanism of energy storage. Herein, we provide a first report on the capability of lithium manganese sulfates to be used as supercapattery materials at elevated temperatures. Two compositions are studied: monoclinic Li$_2$Mn(SO$_4$)$_2$ and orthorhombic Li$_2$Mn$_2$(SO$_4$)$_3$, which are prepared by a freeze-drying method followed by heat treatment at 500 °C. The electrochemical performance of sulfate electrodes is evaluated in lithium-ion cells using two types of electrolytes: conventional carbonate-based electrolytes and ionic liquid IL ones. The electrochemical measurements are carried out in the temperature range of 20–60 °C. The stability of sulfate electrodes after cycling is monitored by in-situ Raman spectroscopy and ex-situ XRD and TEM analysis. It is found that sulfate salts store Li+ by a hybrid mechanism that depends on the kind of electrolyte used and the recording temperature. Li$_2$Mn(SO$_4$)$_2$ outperforms Li$_2$Mn$_2$(SO$_4$)$_3$ and displays excellent electrochemical properties at elevated temperatures: at 60 °C, the energy density reaches 280 Wh/kg at a power density of 11,000 W/kg. During cell cycling, there is a transformation of the Li-rich salt, Li$_2$Mn(SO$_4$)$_2$, into a defective Li-poor one, Li$_2$Mn$_2$(SO$_4$)$_3$, which appears to be responsible for the improved storage properties. The data reveals that Li$_2$Mn(SO$_4$)$_2$ is a prospective candidate for supercapacitor electrode materials at elevated temperatures

A Cubic Mg2MnO4 Cathode for non-aqueous Magnesium Batteries

The feasibility of cubic Mg2MnO4 (c-Mg2MnO4) cathode for rechargeable magnesium batteries is scrutinized by both theoretical and experimental methods. To exploit the high valence state of Mn4+ upon magnesium insertion in c-Mg2MnO4, we substituted Mn3+ (0.645 Å) by the larger Mg2+ (0.72 Å) and studied a series of Mg1+yMn3+2-2yMn4+yO4. The results prove that this Mg/Mn substitution results in a progressive increase of the unit cell parameter “a” due to the increasement in the average oxidation of Mn. We also distinguish the importance of having Mn(IV) in c-Mg2MnO4 vs. the known Mn(III) in tetragonal MgMn2O4 (t-MgMn2O4). The geometry optimization and energy calculations on the c-Mg2MnO4 system are carried out within the density functional theory (DFT) calculations indicating the Mg insertion occurs at 2.23 V with a volume expansion of ca. 8.7 %. Galvanostatic curves revealed a two-step profile with an average voltage of 2.1 V and 160 mA h g−1 (0.5 Mg2+)

Review and new perspectives on non-layered manganese compounds as electrode material for Sodium-Ion batteries

After more than 30 years of delay compared to lithium-ion batteries, sodium analogs are now emerging in the market. This is a result of the concerns regarding sustainability and production costs of the former, as well as issues related to safety and toxicity. Electrode materials for the new sodium-ion batteries may contain available and sustainable elements such as sodium itself, as well as iron or manganese, while eliminating the common cobalt cathode compounds and copper anode current collectors for lithium-ion batteries. The multiple oxidation states, abundance, and availability of manganese favor its use, as it was shown early on for primary batteries. Regarding structural considerations, an extraordinarily successful group of cathode materials are layered oxides of sodium, and transition metals, with manganese being the major component. However, other technologies point towards Prussian blue analogs, NASICON-related phosphates, and fluorophosphates. The role of manganese in these structural families and other oxide or halide compounds has until now not been fully explored. In this direction, the present review paper deals with the different Mn-containing solids with a non-layered structure already evaluated. The study aims to systematize the current knowledge on this topic and highlight new possibilities for further study, such as the concept of entatic state applied to electrodes

Coulomb Excitation of Proton-rich N = 80 Isotones at HIE-ISOLDE

A projectile Coulomb-excitation experiment was performed at the radioactive ion beam facility HIE-ISOLDE at CERN. The radioactive ¹⁴⁰Nd and ¹⁴²Sm ions were post accelerated to the energy of 4.62 MeV/A and impinged on a 1.45 mg/cm²-thin ²⁰⁸Pb target. The γ rays depopulating the Coulomb-excited states were recorded by the HPGe-array MINIBALL. The scattered charged particles were detected by a double-sided silicon strip detector in forward direction. Experimental γ-ray intensities were used for the determination of electromagnetic transition matrix elements. Preliminary results for the reduced transition strength of the B(M1;23+→21+)=0.35(19)μN2 of ¹⁴⁰Nd and a first estimation for ¹⁴²Sm have been deduced using the Coulomb-excitation calculation software GOSIA. The 2³₊ states of ¹⁴⁰Nd and ¹⁴²Sm show indications of being the main fragment of the proton-neutron mixed-symmetry 2⁺₁,ms state

Voluntary depositing and institutional open access culture

The New Bulgarian University (NBU) Scholar Electronic Repository (SER) is the first open access institutional repository in Bulgaria. Following the “green route”, the archive promotes self-archiving practice to authors and reveals a more robust and reliable alternative to long-term preservation and additionally granting higher visibility of their materials. It has two unique features: 1.) Depositing is voluntary; 2.) Original content is submitted in a range of different languages. The article presents a survey of self-archiving practices for the Scholar Electronic Repository. An overview is given of the strict meta-data control which is crucial for storing and backing-up authors’ materials. A detailed summary of the systematic approach to authors’ awareness and training is presented. Eventual pros and cons of several promotional infrastructure designs are discussed, including monthly seminars, real-time training and interactive LibGuides online. A six-month monitoring of submitted data and self-created records is performed to improve training, tracing typical mistakes. The frequency of submitting an alternative abstract is also considered, in a different language (not accompanying the original text), as an extra effort from authors. A distinctive difference in approach and experience of authors, who have attended training and those, who have not, has been detected. The Repository team assists the depositing process by adding end-user services. The Web 2.0 RSS facility directly issues information about new titles into the Library blog and the mobile version of the Library web site. Announcements are posted into the Library blog and on the Facebook page to increase the impact and stimulate the accessibility of archived items (paintings, exhibitions, music art, videos). Meta-data from the NBU Repository are transferred to other information systems to raise the visibility and popularity of University research assets. In conclusion – the first of its kind institutional repository in Bulgaria offers proven and functional practices for the newly-launched five repositories in the country. The daily experience of developing the online archive provides evidence that it opens ample opportunities for university libraries from countries with poor information infrastructure and suffering from a language barrier might foster to join the green-on institutional repositories line

Graphene-Based Composites for Thermoelectric Applications at Room Temperature

The thermoelectric materials that operate at room temperature represent a scientific challenge in finding chemical compositions with three optimized, independent parameters, namely electrical and thermal conductivity and the Seebeck coefficient. Here, we explore the concept of the formation of hybrid composites between carbon-based materials and oxides, with the aim of modifying their thermoelectric performance at room temperature. Two types of commercially available graphene-based materials are selected: N-containing reduced graphene oxide (NrGO) and expanded graphite (ExGr). Although the NrGO displays the lowest thermal conductivity at room temperature, the ExGr is characterized by the lowest electrical resistivity and a negative Seebeck coefficient. As oxides, we choose two perspective thermoelectric materials: p-type Ca3Co4O9 and n-type Zn0.995Al0.005O. The hybrid composites were prepared by mechanical milling, followed by a pelleting. The thermoelectric efficiency was evaluated on the basis of its measured electrical resistivity, Seebeck coefficient and thermal conductivity at room temperature. It was found that that 2 wt.% of ExGr or NrGO leads to an enhancement of the thermoelectric activity of Ca3Co4O9, while, for Zn0.995Al0.005O, the amount of ExGr varies between 5 and 20 wt.%. The effect of the composites’ morphology on the thermoelectric properties is discussed on the basis of SEM/EDS experiments