Exclusive ηc\eta_c production from small-xx evolved Odderon at a electron-ion collider

We compute exclusive $\eta_c$ production in high energy electron-nucleon and electron-nucleus collisions that is sensitive to the Odderon. In perturbative QCD the Odderon is a $C$-odd color singlet consisting of at least three $t$-channel gluons exchanged with the target. By using the Color Glass Condensate effective theory our result describes the Odderon exchange at the high collision energies that would be reached at a future electron-ion collider. The Odderon distribution is evolved to small-$x$ using the Balitsky-Kovchegov evolution equation with running coupling corrections. We find that while at low momentum transfers $t$ the cross section off a proton is dominated by the Primakoff process, the Odderon becomes relevant at larger momentum transfers of $|t|\geq1.5$ GeV$^2$. We point that the Odderon could also be extracted at low-$t$ using neutron targets since the Primakoff component is strongly suppressed. In the case of nuclear targets, the Odderon cross section becomes enhanced thanks to the mass number of the nuclear target. The gluon saturation effect induces a shift in the diffractive pattern with respect to the Primakoff process that could be used as a signal for the Odderon.Comment: a few typos corrected, a few references added, matches the published versio

Medium induced Lorentz symmetry breaking effects in nonlocal Polyakov–Nambu–Jona-Lasinio models

In this paper we detail the thermodynamics of two flavor nonlocal Polyakov–Nambu–Jona-Lasinio models for different parametrizations of the quark interaction regulators. The structure of the model is upgraded in order to allow for terms in the quark selfenergy which violate Lorentz invariance due to the presence of the medium. We examine the critical properties, the phase diagram as well as the equation of state. Furthermore, some aspects of the Mott effect for pions and sigma mesons are discussed explicitly within a nonlocal Polyakov–Nambu–Jona-Lasinio model. In particular, we continued the meson polarization function in the complex energy plane and under certain approximations, we were able to extract the imaginary part as a function of the meson energy. We were not able to calculate the dynamical meson mass, and therefore resorted to a technical study of the temperature dependence of the meson width by replacing the meson energy with the temperature dependent spatial meson mass. Our results show that while the temperature behavior of the meson widths is qualitatively the same for a wide class of covariant regulators, the special case where the nonlocal interactions are introduced via the instanton liquid model singles out with a drastically different behavior.Instituto de Física La Plat

The structure of above-ground biomass of wild cherry (Prunus avium L.) in lowland Croatian forests

U radu su prikazane sastavnice strukture ukupne nadzemne biomase stabala divlje trešnje (Prunus avium L.) na području spačvanskog bazena u Upravi šuma Podružnica Vinkovci. Istraživanja su obavljena na 120 primjernih stabala divlje trešnje, prsnih promjera od 10 do 72 cm i visine od 10,8 do 34,4 m. Drvni sortimenti izrađeni su prema Hrvatskim normama proizvoda iskorištavanja šuma iz 1995. godine.Sortimentna struktura primjernih stabala divlje trešnje pokazuje znatna odstupanja u odnosu na tablice sortimentne strukture za voćkarice koje koristi trgovačko društvo „Hrvatske šume“ d.o.o. Zagreb. Udio trupaca za furnir kreće se od 9,29 % u debljinskom stupnju 37,5 cm do najviše 19,50 % u debljinskom stupnju 67,5 cm. Pilanski trupci prvog razreda kakvoće kreću se u rasponu od 12,04 % (72,5 cm) do 19,89 % (32,5 cm), a drugog razreda kakvoće od 17,30 % (62,5 cm) do 26,89 % (32,5 cm). Drvni sortiment tanke oblovine zastupljen je u debljinskom stupnju 17,5 cm sa 17,44 % te u debljinskom stupnju 22,5 cm sa 15,90 %, dok je u višim debljinskim stupnjevima značajno manje zastupljen. Udio prostornog drva je najveći u prvom debljinskom stupnju 88,76 % (12,5 cm) te u sljedeća dva sa 67,44 % i 47,71 %, a najmanji je u debljinskom stupnju 67,5 cm sa 27,01 %. Prosječni udio prostornoga drva iznosi 42,09 %. Otpad se u ukupnoj strukturi krupnog drva kreće od 11,24 % (12,5 cm) do 19,12 % (27,5 cm), a prosječno iznosi 16,47 %. Dvostruka debljina kore kreće se u rasponu od 0,53 cm do 3,37 cm, odnosno prosječno 1,66 ± 0,57 cm, a postotni udio kore kreće se od 4,77 % do 16,46 %, sa srednjom vrijednošću od 9,02 ± 2,01 %. Utvrđeni su i parametri Schumacher-Hallove jednadžbe, gustoća drva, udio vode, obujam granjevine (promjera <7 cm) te struktura ukupne nadzemne biomase.The paper presents the structure of the total above-ground biomass of wild cherry (Prunus avium L.) trees in the area of the Spačva basin in the Vinkovci Forest Administration. The research was performed on 120 samples of wild cherry trees with a diameter at breast height (DBH) ranging from 10 to 72 cm and tree height ranging from 10.8 to 34.4 m. Timber assortments were processed according to the Croatian Standards for Forest Exploitation Products from 1995.The assortment structure of sample wild cherry trees shows significant deviations in relation to the assortment structure tables used by the company ”Croatian Forests” Ltd. Zagreb. The share of veneer logs ranges from 9.29% (37.5 cm) to a maximum of 19.50% in the diameter class of 67.5 cm. Sawmill logs of the first quality class range from 12.04% (72.5 cm) to 19.89% (32.5 cm), and of the second quality class from 17.30% (62.5 cm) to 26, 89% (32.5 cm). Thin roundwood assortment is represented in the diameter class of 17.5 cm with 17.44% and immediately in the next with 15.90%, while in the higher diameter classes it is significantly less represented. The share of stacked wood (firewood and pulpwood) is the highest in the first diameter class, 88.76% (12.5 cm) and in the next two with 67.44% and 47.71%, and is the lowest in the diameter class 67.5 cm with share of 27.01%. The average share of stacked wood is 42.09%. Waste in the total structure ranges from 11.24 (12.5 cm) to 19.12% (27.5 cm), and is on average 16.47%. Double bark thickness ranges from 0.53 cm to 3.37 cm, with an average of 1.66 ± 0.57 cm, and the percentage of bark share ranges from 4.77% to 16.46%, with a mean value of 9.02 ± 2.01%.The parameters of the Schumacher-Hall equation, wood density, moisture content, branch volume (diameter <7 cm) and the structure of total aboveground biomass were also determined

Razvoj i umjeravanje prijenosnoga sustava za mjerenje osovinskih opterećenja vozila – mjerenja na forvarderu

U radu je istražen prijenosni sustav vaga WLS 101/R2K korišten za izmjeru osovinskih optereć enja forvardera Valmet 840.2 radi što preciznijega utvrđivanja količine šumske biomase. Zbog uočenih odstupanja u izmjerenoj masi tereta prijenosnoga sustava vaga i kontrolnoga mjerenja (kolna vaga) istraženo je kako značajke tovara (zakrivljenost oblovine i količina drva), niveliranje osovina vozila te značajke podloge utječu na izmjeru mase vaganjem. Mjerenja su provedena u tri serije: 1) mjerenja iste vrste tovara na neravnoj i ravnoj podlozi, 2) mjerenja pet različitih vrsta tovara uz istodobno istraživanje utjecaja horizontalnosti osovina, 3) mjerenja iste vrste tovara uz korištenje metalnoga okvira za umetanje para prijenosnih vaga radi centriranja kotača forvardera na mjernu površinu vage. Najmanja odstupanja mjernih vrijednosti (<2% u odnosu na kontrolno mjerenje mase kolnom vagom) postignuta su korištenjem metalnoga okvira za umetanje para prijenosnih vaga. Također je utvrđeno da je neprecizno postavljanje kotača vozila na površinu vaga uzrok najvećih pogrešaka u mjerenju mase tereta

Razvoj i umjeravanje prijenosnoga sustava za mjerenje osovinskih opterećenja vozila – mjerenja na forvarderu

U radu je istražen prijenosni sustav vaga WLS 101/R2K korišten za izmjeru osovinskih optereć enja forvardera Valmet 840.2 radi što preciznijega utvrđivanja količine šumske biomase. Zbog uočenih odstupanja u izmjerenoj masi tereta prijenosnoga sustava vaga i kontrolnoga mjerenja (kolna vaga) istraženo je kako značajke tovara (zakrivljenost oblovine i količina drva), niveliranje osovina vozila te značajke podloge utječu na izmjeru mase vaganjem. Mjerenja su provedena u tri serije: 1) mjerenja iste vrste tovara na neravnoj i ravnoj podlozi, 2) mjerenja pet različitih vrsta tovara uz istodobno istraživanje utjecaja horizontalnosti osovina, 3) mjerenja iste vrste tovara uz korištenje metalnoga okvira za umetanje para prijenosnih vaga radi centriranja kotača forvardera na mjernu površinu vage. Najmanja odstupanja mjernih vrijednosti (<2% u odnosu na kontrolno mjerenje mase kolnom vagom) postignuta su korištenjem metalnoga okvira za umetanje para prijenosnih vaga. Također je utvrđeno da je neprecizno postavljanje kotača vozila na površinu vaga uzrok najvećih pogrešaka u mjerenju mase tereta

Detailed experimental comparison of energy efficiency between proportional and direct driven hydraulic system

This paper investigates the energy efficiency of a Direct Driven Hydraulic (DDH) system and a proportional electrohydraulic system. A detailed analysis of their energy efficiency is carried out based on experimental results obtained in laboratory conditions using a fully loaded cylinder and sine wave reference trajectory. To ensure fairness in the testing process, the same cylinder with the same initial conditions is used for both systems. The cylinder velocity is estimated online using a novel algebraic differentiator approach based on measured cylinder position. The power of each component is calculated from the obtained measurements, and the energy efficiency of the system is given, along with the losses for each component. Based on the obtained results, it is concluded that the efficiency of the DDH system with a fully loaded cylinder is 28%, while that of the proportional electrohydraulic system is 4%. The significantly higher energy efficiency of the DDH system is attributed to its use of a power-on-demand approach, in contrast to the proportional electrohydraulic system

Applicability of hydraulic dynamometer for measuring load mass on forwarders

In the last few years, with the start of wood biomass production from wood residues, the need for determining the quantity of extracted wood residuals on a landing site has appeared. The beginning of intensive usage of wood residues for wood biomass starts in lowland forest where all wood residues are extracted with forwarders. There are several ways to determine load mass on a forwarder, first and probably most accurate is the use of load cells which are installed between forwarder undercarriage and loading space. In Croatia, as far as it is known, there is no forwarder with such equipment, although manufacturers offer the installation of such equipment when buying a new forwarder. The second option is using a portable measuring platform (axle scale) which was already used for research of axle loads of trucks and forwarders. The data obtained with the measuring platform are very accurate, while its deficiency is relatively great mass, large dimensions and high price. The third option is determining mass by using hydraulic dynamometer which is installed on crane between the rotator and the telescopic boom. The production and installation of such a system is very simple, and with the price it can easily compete with previously described measuring systems. The main deficiency of this system is its unsatisfying accuracy. The results of assortment mass measuring with hydraulic dynamometer installed on a hydraulic crane and discussion on factors influencing obtained results will be presented in this paper