Individual Professional Practice in the Company

Bakalářská práce popisuje absolvování individuální odborné praxe ve společnosti Railsformers s.r.o. Odborná praxe byla zaměřena na oblast vývoje aplikace pro Internet věcí (IoT). Aplikace v maximální možné míře využívá otevřené technologie, operační systém Linux, platformu Docker a jazyk Ruby. Cílem praxe je vývoj prototypu brány mezi různými technologiemi, využívanými v Internetu věcí. Součástí praxe je výběr vhodné hardwarové platformy, výběr vhodného operačního systému, tvorba základního aplikačního rozhraní pro správu platformy a implementace aplikace obsluhující samotnou bránu.This Bachelor's thesis describes a professional practice at the company Railsformers s.r.o. The professional practice has been focused on development of application for Internet of Things (IoT). Application maximizes usage of open technologies, Linux operating systém, Docker platform and Ruby language. The main goal of professional practice is development of IoT gateway prototype for connection between different interfaces. Parts of practice are: selection of hardware platform, selection of operating systém, creation of basic application interface for maintenance and implementation of application for gateway itself.460 - Katedra informatikyvýborn

How the United States and Russia Have Interacted with Syria Since Its Use of Chemical Weapons

Syria has been locked in a civil war for over a decade, with thousands of people dead, many of them civilians. The Syrian Civil War has caused a humanitarian crisis, drawing the attention of international humanitarian aid actors and now the United States. After a chemical weapons attack against the Syrian civilians by the Assad Regime, former Presidents Barack Obama and Donald Trump led punitive strikes against the Syrian government. After years of the United States weaving in and out of the Syrian crisis, the time has come for international actors to carefully analyze the intentions of the United States

On the origin of internal rotation in ammonia borane

The internal rotation in ammonia borane (AB) was studied on the basis of natural orbitals for chemical valence (NOCV) and eigenvectors for Pauli repulsion (NOPR). We found that the total hyperconjugation stabilization (ca. 5kcalmol − 1 ), based on the charge transfer from the occupied σ (B – H) orbitals into the empty σ *(N – H), slightly favors the staggered conformation over the eclipsed one; however, the barrier to internal rotation in ammonia borane can be understood predominantly in a ‘ classical ’ way, as originating from the steric (Pauli) repulsion contributions (of the kinetic origin) that act solely between N – HandB – H bonds. Repulsion be- tween the lone pair of ammonia and the adjacent B – H bonds was found to be dominant in absolute terms; however, it does not determine the rotational barrier. Similar conclusions on the role of CH ↔ HC repulsion appeared to be valid for isoelectronic ethane

Theoretical description of halogen bonding : an insight based on the natural orbitals for chemical valence combined with the extended-transition-state method (ETS-NOCV)

In the present study we have characterized the halogen bonding in selected molecules H 3 N – ICF 3 ( 1- NH 3 ), (PH 3 ) 2 C – ICF 3 ( 1-CPH 3 ), C 3 H 7 Br – (IN 2 H 2 C 3 ) 2 C 6 H 4 ( 2-Br ), H 2 – (IN 2 H 2 C 3 ) 2 C 6 H 4 ( 2-H 2 ) and Cl – (IC 6 F 5 ) 2 C 7 H 10 N 2 O 5 ( 3-Cl) , containing from one halogen bond ( 1-NH 3 , 1-CPH 3 ) up to four connections in 3-Cl (the two Cl – HN and two Cl – I), based on recently proposed ETS- NOCV analysis. It was found based on the NOCV- deformation density components that the halogen bonding C – X ... B (X-halogen atom, B-Lewis base), contains a large degree of covalent contribution (the charge transfer to X ... B inter-atomic region) supported further by the electron dona- tion from base atom B to the empty σ *(C – X) orbital. Such charge transfers can be of similar importance compared to the electrostatic stabilization. Further, the covalent part of halogen bonding is due to the presence of σ -hole at outer part of halogen atom (X). ETS-NOCV approach allowed to visualize formation of the σ -hole at iodine atom of CF 3 I molecule. It has also been demonstrated that strongly elec- trophilic halogen bond donor, [C 6 H 4 (C 3 H 2 N 2 I) 2 ][OTf] 2 , can activate chemically inert isopropyl bromide ( 2-Br ) moiety via formation of Br – I bonding and bind the hydrogen mol- ecule ( 2-H 2 ). Finally, ETS-NOCVanalysis performed for 3- Cl leads to the conclusion that, in terms of the orbital- interaction component, the strength of halogen (Cl – I) bond is roughly three times more important than the hydrogen bonding (Cl – HN)

Nature of beryllium, magnesium, and zinc bonds in carbene ⋯MX2⋯MX_2 (M = Be, Mg, Zn; X = H, Br) dimers revealed by the IQA, ETS-NOCV and LED methods

The nature of beryllium–, magnesium– and zinc–carbene bonds in the cyclopropenylidene⋯MX [Formula: see text] (M = Be, Mg, Zn; X = H, Br) and imidazol-2-ylidene⋯MBr [Formula: see text] dimers is investigated by the joint use of the topological QTAIM-based IQA decomposition scheme, the molecular orbital-based ETS-NOCV charge and energy decomposition method, and the LED energy decomposition approach based on the state-of-the-art DLPNO-CCSD(T) method. All these methods show that the C⋯M bond strengthens according to the following order: Zn < Mg [Formula: see text] Be. Electrostatics is proved to be the dominant bond component, whereas the orbital component is far less important. It is shown that QTAIM/IQA underestimates electrostatic contribution for zinc bonds with respect to both ETS-NOCV and LED schemes. The [Formula: see text] carbene→MX [Formula: see text] donation appears to be much more important than the MX [Formula: see text] carbene back-donation of [Formula: see text] symmetry. The substitution of hydrogen atoms by bromine (X in MX [Formula: see text]) strengthens the metal–carbene bond in all cases. The physical origin of rotational barriers has been unveiled by the ETS-NOCV approach

ETS-NOCV description of σ-hole bonding

The ETS-NOCVanalysis was applied to describe the σ -hole in a systematic way in a series of halogen com- pounds, CF 3 -X ( X 0 I, Br, Cl, F), CH 3 I, and C(CH3) n H 3-n -I ( n 0 1,2,3), as well as for the example germanium-based systems. GeXH 3 , X 0 F,Cl,H.Further,theETS-NOCV analysis was used to characterize bonding with ammonia for these systems. The results show that the dominating contribution to the deformation density, Δ ρ 1 , exhibits the negative-value area with a minimum, corresponding to σ - hole. The “ size ” (spatial extension of negative value) and “ depth ” (minium value) of the σ -hole varies for different X in CF 3 -X, and is influenced by the carbon substituents (fluorine atoms, hydrogen atoms, methyl groups). The size and depth of σ -hole decreases in the order: I, Br, Cl, F in CF 3 -X. In CH 3 -I and C(CH3) n H 3-n -I, compared to CF 3 -I, introduction of hydrogen atoms and their subsequent replacements by methyl groups lead to the systematic de- crease in the σ -hole size and depth. The ETS-NOCV σ -hole picture is consistent with the existence the positive MEP area at the extension of σ -hole generating bond. Finally, the NOCV deformation density contours as well as by the ETS orbital-interaction e nergy indicate that the σ -hole-based bond with ammonia contains a degree of covalent contribu- tion. In all analyzed systems, it was found that the electro- static energy is approximately two times larger than the orbital-interaction term, confirming the indisputable role of the electrostatic stabilization in halogen bonding and σ -hole bonding