Fast and robust spin manipulation in a quantum dot by electric fields

We apply an invariant-based inverse engineering method to control by time-dependent electric fields electron spin dynamics in a quantum dot with spin-orbit coupling in a weak magnetic field. The designed electric fields provide a shortcut to adiabatic processes that flips the spin rapidly, thus avoiding decoherence effects. This approach, being robust with respect to the device-dependent noise, can open new possibilities for the spin-based quantum information processing.Comment: 7 pages, 6 figures, with supplemental material. Errors in the published version have been correcte

A Simulation Model Outline for the Hungarian Forest Sector

The model presented in this paper describes the structure of the Hungarian forest sector. The planning of the sector at a national and company level as well as the mechanism of regulation concerning production, investments, and consumption are also investigated and the exports and imports linked. One of the most important objectives is to create this model in order to study the behavior of the system so as to aid the decision making both in strategic and tactical areas. Apart from forestry the model also includes the wood processing activities

ANALYSIS OF FACTORS INFLUENCING TRAVEL CONSUMER SATISFACTION AS REVEALED BY ONLINE COMMUNICATION PLATFORMS

The objective of the present empirical study is to determine the factors influencing the tourism consumer satisfaction, as it results from the evaluations posted on virtual platforms. The communication platform chosen as study is the Romanian website Amfostacolo.ro. In this case, the travel consumer satisfaction is expressed by the score of the ratings posted on the virtual platform Amfostacolo.ro and the decision to recommend or not the unit / destination. Considering the peculiarities of the communication platform studied, the elements influencing the score indicating satisfaction there can be identified as components of tourism supply and the characteristics of the reviewer. Data processing has been carried out with ordinary least squares (OLS), structural equation modeling (confirmatory factor analysis, path analysis), cluster analisys and polytomous logistic regression. The results broadly confirm the hypotheses, namely that: the type of stay and the age of the reviewer influence the satisfaction of the consumer more than the destination and number of stars of the accommodation, the age group of the reviewer influences the destination yet it is uncertain about the influence of the variables related to the holiday (the type of stay and the number of stars of the accommodation), the meal service influences more than other attributes the consumer satisfaction and the recommendation of the reviewer is influenced by the characteristics related to his person and the holiday consumed

SPORT: A new sub-nanosecond time-resolved instrument to study swift heavy ion-beam induced luminescence - Application to luminescence degradation of a fast plastic scintillator

We developed a new sub-nanosecond time-resolved instrument to study the dynamics of UV-visible luminescence under high stopping power heavy ion irradiation. We applied our instrument, called SPORT, on a fast plastic scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean electronic stopping power of 2.6 MeV/\mu m. As a consequence of increasing permanent radiation damages with increasing ion fluence, our investigations reveal a degradation of scintillation intensity together with, thanks to the time-resolved measurement, a decrease in the decay constant of the scintillator. This combination indicates that luminescence degradation processes by both dynamic and static quenching, the latter mechanism being predominant. Under such high density excitation, the scintillation deterioration of BC-400 is significantly enhanced compared to that observed in previous investigations, mainly performed using light ions. The observed non-linear behaviour implies that the dose at which luminescence starts deteriorating is not independent on particles' stopping power, thus illustrating that the radiation hardness of plastic scintillators can be strongly weakened under high excitation density in heavy ion environments.Comment: 5 figures, accepted in Nucl. Instrum. Methods

The molecular mechanism of cotranslational membrane protein recognition and targeting by SecA

Cotranslational protein targeting is a conserved process for membrane protein biogenesis. In Escherichia coli, the essential ATPase SecA was found to cotranslationally target a subset of nascent membrane proteins to the SecYEG translocase at the plasma membrane. The molecular mechanism of this pathway remains unclear. Here we use biochemical and cryoelectron microscopy analyses to show that the amino-terminal amphipathic helix of SecA and the ribosomal protein uL23 form a composite binding site for the transmembrane domain (TMD) on the nascent protein. This binding mode further enables recognition of charged residues flanking the nascent TMD and thus explains the specificity of SecA recognition. Finally, we show that membrane-embedded SecYEG promotes handover of the translating ribosome from SecA to the translocase via a concerted mechanism. Our work provides a molecular description of the SecA-mediated cotranslational targeting pathway and demonstrates an unprecedented role of the ribosome in shielding nascent TMDs

Comparison of pyrethrins extraction methods efficiencies

Extraction efficiency of insecticidal active compounds from dried Dalmatian pyrethrum flowers (Chrysanthemum cinerariaefolium /Trevir/Vis) was tested using different techniques and solvents. The research included six treatments which are the combination of two techniques (soxtec and ultrasound) and three different solvents (hexane, ethanol and petroleum ether). Dalmatian pyrethrum is a perennial herb native to Croatia. Its powder prepared from dried flower heads has been used as naturalinsecticide for centuries in traditional Croatian farming systems. It has no toxicity to man and animals but possesses ecological benefits that have led to increasing worldwide production of this natural insecticide. Nowadays, it is cultivated mainly at higher altitudes in tropical countries such as Kenya, Tanzania and Rwanda. The present investigation was directed in identifying a simple and reliable extraction treatment using solvents with lower cost and toxicity and an adequate method for the identification and separation of active compounds (pyrethrins) with possible application in enterprises or industry. Best developed method was used for determination of pyrethrin content in three different natural populations of Chrysanthemum. The results revealed high content of total pyrethrins inpopulations grown in Croatia. Developed method and good quality product give a possibility for this culture to become again an exporting and economically valid product for Croatia

Interpolating Coherent States for Heisenberg-Weyl and Single-Photon SU(1,1) Algebras

New quantal states which interpolate between the coherent states of the Heisenberg_Weyl and SU(1,1) algebras are introduced. The interpolating states are obtained as the coherent states of a closed and symmetric algebra which interpolates between the two algebras. The overcompleteness of the interpolating coherent states is established. Differential operator representations in suitable spaces of entire functions are given for the generators of the algebra. A nonsymmetric set of operators to realize the Heisenberg-Weyl algebra is provided and the relevant coherent states are studied.Comment: 13 pages nd 5 ps figure

INFLUENCE OF SPACING SIZE AND SHAPE ON QUALITY COMPONENTS OF CELERIAC CULTIVARS (APIUM GRAVEOLENS VAR. RAPACEUM MILL.)

Celer korjenaš za prodaju u svješem stanju i za preradu mora zadovoljiti potrebne standarde kakvoće. Na svojstva koja određuju kakvoću mogu utjecati klimatski i edafski čimbenici, kultivari i načini uzgoja. Organogena tla u Vranskom bazenu i klimatski uvjeti koji omogućuju dugu vegetaciju povoljni su za rast celera. Kako to utječe na kakvoću korijena u 3 kultivara i 5 načina sadnje cilj je ovog istraživanja. U dvogodišnjem pokusu na lokaciji Jankolovica posađena su 3 kultivara: Nemona, Volltreffer i Praški orijaš uz 2 razmaka redova i 3 razmaka u trakama uz sklop: 8.3, 10.0, 11.1, 12.5 i 13.3 biljke/m2. U vrijeme berbe iz svakog od 5 ponavljanja ustanovljen je udio standardnih korjenova i njihova prosječna masa. Standardni korijeni su zatim klasirani po promjeru u 3 kategorije (6 do 8, 8 do 10 i >10 cm). Korijeni su uzdužno razrezani i ustanovljena je pojava unutrašnjih šupljina za svaku kategoriju te postotak suhe tvari refraktometrom, što je pokazatelj kakvoće za preradu. Prosječna masa tržnog korijena statistički se nije razlikovala. Kultivar Volltreffer bio je nešto krupniji (374 g) od kultivara Nemona (334 g) i Praški orijaš (319 g). Povećanjem broja biljaka po m2 prosječna masa tržnog korijena se lagano smanjivala (od 370 do 259 g) u dvogodišnjem prosjeku za sva tri kultivara. Najmanje sitnog korijena (promjera 6 do 8 cm) u ukupnoj masi bilo je u kultivara Volltreffer 23.5 %, zatim Praškog orijaša 31,0 % i Nemona 40.5 %. Za sva tri kultivara povećanjem sklopa udio sitnih korjenova se povećavao (od 26.5 na 39%). Prosječna masa sitnih (promjera 6-8 cm) bila je 208 do 249 g, srednjih (promjera 8 do 10 cm) 366 do 398 g i krupnih (>10 cm) od 586 do 653 g. Najmanju masu u svim kategorijama imao je Praški orijaš. U svim krupnoćama povećanjem sklopa prosječna masa se malo smanjuje. Pojava šupljina u sredini korijena može biti negativno svojstvo. U prvoj godini bilo je više šupljih korjenova nego u drugoj godini istraživanja, krupni korjenovi imali su više šupljina od sitnih, a u većem sklopu bilo ih je manje. Postotak suhe tvari refraktometrom kretao se u prosjeku od 5 do 7 % a bio je najveći u Praškog orijaša. Na osnovi ovih svojstava ne može se izdvojiti najpovoljniji kultivar, niti sklop koji bi doprinio boljoj kakvoći.Celeriac quality components are influenced by cultivars, growing methods, climatic factors and soil quality. Muck soils of the Vrana area and long growing period as a result of the Mediterranean climate are favorable for celeriac production. Two years experiment was conducted with 3 cultivars: Nemona, Volltreffer and Praški orijaš planted in 2 row distance and 3 bend with 8.3, 10.0, 11.1, 12.5, and 13.3 plants/m2 respectively and 5 replications. During harvest following quality components mean root weight and mean weight were investigated After classification according to diameter (6-8, 8-10 and >10cm), incidence of internal holes (>1 cm) and the dry matter content (Brix) were established. According to ANOVA, mean root weight there were no significant differences between cultivars and spacings (Volltreffer 374 g, Nemona 334 g and Praški orijaš 319 g). With the increase of the number of plants/m2 the root mean weight slightly decreased (370 to 259 g). The lowest percentage of small roots was found in Volltreffer 23.5 %, at Praški orijaš 31.0 % and Nemona 40.5 %. With the increase of the number of plants/m2 the percentage of small roots increased too (from 26.5 to 39 %). Mean weight of small roots was 208 to 249 g, medium 366 to 398 g and large 586 to 653 g. Praški orijaš had the smalest mean weight in all sizes. With spacing decrease mean weight in all sizes slightly decreased. In the first year experiment more internal were was found than in the second year which suggests the influence of climatic factors. More internal holes were found in larger roots than in smaller categories. The same tendency was shown with larger spacings. The dry matter content was from 5 to 7 %. The highest values were found in Praški orijaš cultivar. According to presented experimental results it is not possible to suggest the best cultivar and planting method in respect to quality components