Uticaj gustine zasnivanja na prinos krme žutog zvezdana gajenog za kombinovano korišćenje

Birdsfoot trefoil grown for seed (cv. Bokor) was examined in agroecological conditions of Western Serbia during period 2007-2009. The goal was to determine herbage yield which could be achieved growing seed crop, using different interrow spacing (12.5, 25 and 50 cm) and various seeding rates (2, 4 and 8 kg ha-1). The highest hay yield was obtained in the third production year at the narrowest spacing and using the highest seeding rate (5.26 t ha-1). Total hay production during 3 years using birdsfoot trefoil seed crop for herbage yield ranged from 9.11 to 14.83 t ha-1 depending on row spacing and from 10.74 to 13.2 t ha-1 depending on seeding rate. The highest stand density (8 kg ha-1 seeding rate and 12.5 cm interrow spacing) produced the highest herbage yield of birdsfoot trefoil in the combined usage (for forage and seed production).Žuti zvezdan za proizvodnju semena, sorte Bokor, ispitivan je u agroekološkim uslovima zapadne Srbije, u periodu 2007-2009. godine. Ispitivana je količina biomase koja se može dobiti gajenjem žutog zvezdana za seme, pri zasnivanju na različitom međurednom rastojanju (12,5, 25 i 50 cm) i sa različitom normom semena (2, 4 i 8 kg ha-1). Najveći prinosi sena ostvareni su u trećoj godini gajenja useva na najužem međurednom rastojanju od 12,5 cm (6,56 t ha-1) i pri najvećoj količini semena od 8 kg ha-1 (5,73 t ha-1). Ukupna produkcija sena u trogodišnjem periodu korišćenja semenskog useva žutog zvezdana bila je od 9,11 do 14,83 ha-1 u zavisnosti od međurednog rastojanja i od 10,74 do 13,20 ha-1 u zavisnosti od setvene norme. Žuti zvezdan u kombinovanom korišćenju (za seme i krmu) je imao najveći potencijal za prinos krme pri većoj gustini zasnivanja (8 kg ha-1 i 12,5 cm međuredno rastojanje)

Finite-difference time-domain calculation of spontaneous emission lifetime in a microcavity

We developed a general numerical method to calculate the spontaneous emission lifetime in an arbitrary microcavity, using a finite-difference time-domain algorithm. For structures with rotational symmetry we also developed a more efficient but less general algorithm. To simulate an open radiation problem, we use absorbing boundaries to truncate the computational domain. The accuracy of this method is limited only by numerical error and finite reflection at the absorbing boundaries. We compare our result with cases that can be solved analytically and find excellent agreement. Finally, we apply the method to calculate the spontaneous emission lifetime in a slab waveguide and in a dielectric microdisk, respectively

Using a situation awareness approach to determine decision-making behaviour in squash

Situation awareness (SA) refers to the awareness of all relevant sources of information, an ability to synthesise this information using domain knowledge gained from past experiences and the ability to physically respond to a situation. Expert-novice differences have been widely reported in decision-making in complex situations although determining the small differences in expert behaviour are more elusive. This study considered how expert squash players use SA to decide on what shot to play. Matches at the 2010 (n = 14) and 2011 (n = 27) Rowe British Grand Prix were recorded and processed using Tracker software. Shot type, ball location, players' positions on court and movement parameters between the time an opponent played a shot prior to the player's shot to the time of the opponent's following shot were captured 25 times per second. Six SA clusters were named to relate to the outcome of a shot ranging from a defensive shot played under pressure to create time to an attempted winner played under no pressure with the opponent out of position. This new methodology found fine-grained SA differences in expert behaviour, even for the same shot type played from the same court area, beyond the usual expert-novice differences

Using a situation awareness approach to identify differences in the performance profiles of the world’s top two squash players and their opponents

Purpose The pressure exerted on a squash player is a consequence of the quality of a shot coupled with the ability of the player to return the ball, namely, the coupling of the two players’ situation awareness (SA) abilities. SA refers to an awareness of all relevant sources of information, the ability to synthesize this information using domain knowledge and the ability to physically respond to a situation. Methods Matches involving the two best players in the world (n = 9) at the 2011 Rowe British Grand Prix, held in Manchester, United Kingdom were recorded and processed using Tracker software. Shot type, ball location, players’ positions on court and movement parameters between the time an opponent played a shot prior to the player’s shot to the time of the opponent’s following shot were captured 25 times per second. All shots (excluding serves and rally ending shots) produced five main SA clusters, similar to those presented by Murray et al. (2018), except a greater proportion of shots were categorized in the greater pressure clusters and less in the lower pressure ones. Results Individual matches were presented using cluster performance profile infographics which demonstrated how individual player’s performance profiles differed between matches. Conclusion It is suggested that it is the coupling, of the two player’s behaviors, that makes the examination of tactics so challenging. This inherently means that performance profiles vary in subtle ways, making consistent profiles that are independent of the opponent very unlikely for elite players. This approach should be further modified to determine within match changes in performance

Study on a standard for grounding systems realization

Grounding systems of objects inside power facilities are very often realized as structures consisting of protective electrodes’ system placed in the object foundation, and neutral electrodes’ system placed at a specified distance from the object. Official standards and publications recommend a minimal value for the distance between the protective and the neutral part of grounding structures, so that the influence of one on another can be neglected. We analyze several practical implementations of grounding structures and demonstrate that the minimal distance is actually much smaller than that recommended by the standards

Control design for inhomogeneous broadening compensation in single-photon transducers

A transducer of single photons between microwave and optical frequencies can be used to realize quantum communication over optical fiber links between distant superconducting quantum computers. A promising scalable approach to constructing such a transducer is to use ensembles of quantum emitters interacting simultaneously with electromagnetic fields at optical and microwave frequencies. However, inhomogeneous broadening in the transition frequencies of the emitters can be detrimental to this collective action. In this article, we utilise a gradient-based optimization strategy to design the temporal shape of the laser field driving the transduction system to mitigate the effects of inhomogeneous broadening. We study the improvement of transduction efficiencies as a function of inhomogeneous broadening in different single-emitter cooperativity regimes and correlate it with a restoration of superradiance effects in the emitter ensembles. Furthermore, to assess the optimality of our pulse designs, we provide certifiable bounds on the design problem and compare them to the achieved performance

Synthesis and characterization of crosslinked polyurethanes

Two polyurethane samples, crosslinked with aliphatic hyperbranched polyester, were synthesized and examined in this work. The sample PUPDMS-EO was prepared using ethylene oxide-poly(dimethylsiloxane)-ethylene oxide as macrodiol, while the synthesis of PUPTMO was performed using poly(tetramethyleneoxide). The obtained results show that thermal stability of these networks can be improved by introducing the siloxane sequences. However, the sample PUPDMS-EO has at the same time much lower crosslinking density than PUPTMO.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Effects of rule changes on physical demands and shot characteristics of elite-standard men’s squash and implications for training

The physical demands and rally characteristics of elite-standard men's squash have not been well documented since recent rule changes (scoring and tin height). This information is needed to design optimal training drills for physical conditioning, provided here based on an analysis of movement and shot information. Matches at the 2010 (n = 14) and 2011 (n = 27) Rowe British Grand Prix were analysed. Rallies were split into four ball-in-play duration categories using the 25th (short), 75th (medium), 95th percentiles (long) and maximum values. Cohen’s d and Chi squared tests of independence evaluated effects of rally and rule changes on patterns of play. The proportion of long, middle and short shots was related to the duration of the rally with more shots played in the middle and front of the court in short rallies (phi = 0.12). The frequencies of shots played from different areas of the court have not changed after the adoption of new rules but there is less time available to return shots that reflects the attacking nature of match play for elite-standard men players. Aspiring and current elite-standard players need to condition themselves to improve their ability to cope with these demands using the ghosting patterns presented that mimic demands of modern match play