Pravne podlage, standardi in kriteriji za ocenjevanje toplotnih razmer pri delu v gozdu

In this discourse, the Slovene legal basis for thermal conditions at work, together with three international standards for studying thermal conditions SIST EN ISO 7730 (Thermal comfort), SIST EN 27243 (hot environments) and SIST EN ISO 11079 (cold environments), are presented. All three international standards list the criteria for evaluation of thermal conditions and represent the scientific research basis for studying work in practice. For efficient work safety, knowledge of the national legislation is implicit.V članku so predstavljene pravne podlage za urejanje toplotnih razmer na delovnem mestu v slovenski zakonodaji ter trije mednarodni standardi za preučevanje toplotnih razmer SIST EN ISO 7730 (toplotno udobje), SIST EN 27243 (vroča okolja) in SIST EN ISO 11079 (hladna okolja). Vsi trije mednarodni standardi podajajo kriterije za ocenjevanje toplotnih razmer in so osnova za znanstveno preučevanje in delo v praksi. Za učinkovito varstvo pri delu je nujno potrebno tudi poznavanje nacionalne zakonodaje

Forestry Ergonomics and Occupational Safety in High Ranking Scientific Journals from 2005–2016

The occupational safety and health change through time due to technological and social development. It is an obligation of scientific research to impartially and critically examine these changes and propose measures to reduce negative impacts on people. Since the forestry as an industry sector follows general changes, we tried to establish the situation in the field of occupational safety and health in forestry by reviewing the studies in the period 2005–2016. The review included studies, the results of which have been published particularly in scientific journals relating to the field of forestry and ergonomics with an impact factor. The findings show that the number of published articles in the field of occupational safety and health and ergonomics increases. Studies were mostly limited to only three continents, namely Europe and North and South America, and 26 countries in total. The majority of research was conducted in Canada, Brazil and Sweden. The largest number of research relates to traditional technologies of harvesting (chainsaw and skidder), whereas the Nordic states prevail in terms of modern, mechanized technologies. The study shows that international and intercontinental cooperation of researchers must be further stimulated in the field of research and education. It has been identified that there is a lack of studies addressing the issue of biomass production, forest road and skid trail construction, and some new technologies. There is a deficiency of cognitive studies, studies of workers’ burnout and comprehensive studies of ergonomics and productivity in the field of ergonomics. The uniform statistics of recording accidents will provide the research to be conducted in all forestry operations and enable the preparation of efficient preventive measures

Operator Exposure to Noise and Whole-Body Vibration in a Fully Mechanised CTL Forest Harvesting System in Karst Terrain

In recent decades fully mechanised cut-to-length forest harvesting systems have spread from flat and gentle to steep and rough terrain. To analyse the potential adverse impact of these changes on operator health, an observational study of exposure to noise and whole-body vibration (WBV) was carried out in karst terrain. The results showed that, in contrast to exposure to noise, the exposure of harvester and forwarder operators to WBV exceeds the daily exposure action value specified in the European Directive. Differences between work sites may contribute up to 8.7 dB(A) to noise exposure and up to 0.28 m/s2 and 6.0 m/s1.75 to WBV exposure when working with forwarders and harvesters. Aside from technical upgrades of machines, reduction of exposure to both WBV and noise, while simultaneously maintaining high productivity, requires careful selection of work sites and adapted work organisation

Superconducting quantum simulator for topological order and the toric code

Topological order is now being established as a central criterion for characterizing and classifying ground states of condensed matter systems and complements categorizations based on symmetries. Fractional quantum Hall systems and quantum spin liquids are receiving substantial interest because of their intriguing quantum correlations, their exotic excitations and prospects for protecting stored quantum information against errors. Here we show that the Hamiltonian of the central model of this class of systems, the Toric Code, can be directly implemented as an analog quantum simulator in lattices of superconducting circuits. The four-body interactions, which lie at its heart, are in our concept realized via Superconducting Quantum Interference Devices (SQUIDs) that are driven by a suitably oscillating flux bias. All physical qubits and coupling SQUIDs can be individually controlled with high precision. Topologically ordered states can be prepared via an adiabatic ramp of the stabilizer interactions. Strings of qubit operators, including the stabilizers and correlations along non-contractible loops, can be read out via a capacitive coupling to read-out resonators. Moreover, the available single qubit operations allow to create and propagate elementary excitations of the Toric Code and to verify their fractional statistics. The architecture we propose allows to implement a large variety of many-body interactions and thus provides a versatile analog quantum simulator for topological order and lattice gauge theories

Orthorhombic fulleride (CH3NH2)K3C60 close to Mott-Hubbard instability: Ab initio study

We study the electronic structure and magnetic interactions in methylamine-intercalated orthorhombic alkali-doped fullerene (CH3NH2)K3C60 within the density functional theory. As in the simpler ammonia intercalated compound (NH3)K3C60, the orthorhombic crystal-field anisotropy \Delta lifts the t1u triple degeneracy at the \Gamma point and drives the system deep into the Mott-insulating phase. However, the computed \Delta and conduction electron bandwidth W cannot alone account for the abnormally low experimental N\'eel temperature, T_N = 11 K of the methylamine compound, compared to the much higher value T_N = 40 K of the ammonia one. Significant interactions between CH3NH2 and C60^{3-} are responsible for the stabilization of particular pseudo-Jahn-Teller fullerene-cage distortions and the ensuing low-spin S = 1/2 state. These interactions also seem to affect the magnetic properties, as interfullerene exchange interactions depend on the relative orientation of pseudo-Jahn-Teller distortions of neighboring C60^{3-} molecules. For the ferro-orientational order of CH3NH2-K^+ groups we find an apparent reduced dimensionality in magnetic exchange interactions, which may explain the suppressed N\'eel temperature. The disorder in exchange interactions caused by orientational disorder of CH3NH2-K^+ groups could further contribute to this suppression.Comment: 8 pages, 5 figures, 1 tabl

Studying Light-Harvesting Models with Superconducting Circuits

The process of photosynthesis, the main source of energy in the animate world, converts sunlight into chemical energy. The surprisingly high efficiency of this process is believed to be enabled by an intricate interplay between the quantum nature of molecular structures in photosynthetic complexes and their interaction with the environment. Investigating these effects in biological samples is challenging due to their complex and disordered structure. Here we experimentally demonstrate a new approach for studying photosynthetic models based on superconducting quantum circuits. In particular, we demonstrate the unprecedented versatility and control of our method in an engineered three-site model of a pigment protein complex with realistic parameters scaled down in energy by a factor of $10^5$. With this system we show that the excitation transport between quantum coherent sites disordered in energy can be enabled through the interaction with environmental noise. We also show that the efficiency of the process is maximized for structured noise resembling intramolecular phononic environments found in photosynthetic complexes.Comment: 8+12 pages, 4+12 figure

Realization of a quantum random generator certified with the Kochen-Specker theorem

Random numbers are required for a variety of applications from secure communications to Monte\ua0Carlo simulation. Yet randomness is an asymptotic property, and no output string generated by a physical device can be strictly proven to be random. We report an experimental realization of a quantum random number generator (QRNG) with randomness certified by quantum contextuality and the Kochen-Specker theorem. The certification is not performed in a device-independent way but through a rigorous theoretical proof of each outcome being value indefinite even in the presence of experimental imperfections. The analysis of the generated data confirms the incomputable nature of our QRNG

Observation of the Crossover from Photon Ordering to Delocalization in Tunably Coupled Resonators

Networks of nonlinear resonators offer intriguing perspectives as quantum simulators for non-equilibrium many-body phases of driven-dissipative systems. Here, we employ photon correlation measurements to study the radiation fields emitted from a system of two superconducting resonators, coupled nonlinearly by a superconducting quantum interference device (SQUID). We apply a parametrically modulated magnetic flux to control the linear photon hopping rate between the two resonators and its ratio with the cross-Kerr rate. When increasing the hopping rate, we observe a crossover from an ordered to a delocalized state of photons. The presented coupling scheme is intrinsically robust to frequency disorder and may therefore prove useful for realizing larger-scale resonator arrays

Poročila

Pregled znanstvenega, strokovnega in pedagoškega dela prof. Franca Lovrenčaka  ob njegovi 80-letnici Ob 550-letnici rojstva kartografa in horografa Pietra Coppa In memoriam Marjan Tkalčič (1949–2020) Vpogled v socialno geografijo Challenges of Tourism Development in Protected Areas of Croatia and Slovenia Routledge International Handbook of Rural Studies Origination. The Geographies of Brands and Branding Brands and Branding Geographie