Magnetic charge and ordering in kagome spin ice

We present a numerical study of magnetic ordering in spin ice on kagome, a two-dimensional lattice of corner-sharing triangles. The magnet has six ground states and the ordering occurs in two stages, as one might expect for a six-state clock model. In spin ice with short-range interactions up to second neighbors, there is an intermediate critical phase separated from the paramagnetic and ordered phases by Kosterlitz-Thouless transitions. In dipolar spin ice, the intermediate phase has long-range order of staggered magnetic charges. The high and low-temperature phase transitions are of the Ising and 3-state Potts universality classes, respectively. Freeze-out of defects in the charge order produces a very large spin correlation length in the intermediate phase. As a result of that, the lower-temperature transition appears to be of the Kosterlitz-Thouless type.Comment: 20 pages, 12 figures, accepted version with minor change

Benchmarking acid and base dopants with respect to enabling the ice V to XIII and ice VI to XV hydrogen-ordering phase transitions

Doping the hydrogen-disordered phases of ice V, VI and XII with hydrochloric acid (HCl) has led to the discovery of their hydrogen-ordered counterparts ices XIII, XV and XIV. Yet, the mechanistic details of the hydrogen-ordering phase transitions are still not fully understood. This includes in particular the role of the acid dopant and the defect dynamics that it creates within the ices. Here we investigate the effects of several acid and base dopants on the hydrogen ordering of ices V and VI with calorimetry and X-ray diffraction. HCl is found to be most effective for both phases which is attributed to a favourable combination of high solubility and strong acid properties which create mobile H3O+ defects that enable the hydrogen-ordering processes. Hydrofluoric acid (HF) is the second most effective dopant highlighting that the acid strengths of HCl and HF are much more similar in ice than they are in liquid water. Surprisingly, hydrobromic acid doping facilitates hydrogen ordering in ice VI whereas only a very small effect is observed for ice V. Conversely, lithium hydroxide (LiOH) doping achieves a performance comparable to HF-doping in ice V but it is ineffective in the case of ice VI. Sodium hydroxide, potassium hydroxide (as previously shown) and perchloric acid doping are ineffective for both phases. These findings highlight the need for future computational studies but also raise the question why LiOH-doping achieves hydrogen-ordering of ice V whereas potassium hydroxide doping is most effective for the 'ordinary' ice Ih.Comment: 18 pages, 7 figures, 1 tabl

ДЕТЕРМІНАНТИ ІННОВАЦІЙНОЇ АКТИВНОСТІ В КОНТЕКСТІ СОЦІАЛЬНО-ЕКОНОМІЧНОГО ЗРОСТАННЯ

The national economy transition to innovative activities, connected with social and economic growth requires considerable determinants, which represent a competitive area for further social and economic growth in the context of globalization. The impacts on innovative activities are considerable in the context of understanding the complexity of social and economic growth within both the national and global level. Despite numerous researches and available achievements in the field of the nature and essence of innovative activities in the context of social and economic growth, there are still a lot of different questions, concerning their determinants. The purpose of the current study is to determine a wide range of approaches to define both innovative activities and socio-economic growth, considering the nature of innovative activities and different determinants on theoretical as well as on the empirical levels. Results from earlier studies demonstrate a strong and consistent association between micro economic determinants and innovative activities. But above mentioned points of views are pretty limited and do not include some important determinants for innovative activities and further socio-economic growth. The current study is different from prior ones. Firstly, it looks at investigated determinants, which influence on the innovative activities and socio-economic growth, empirically. Secondly, it considers for a vast amount of practical approaches, which create the possibility to consider and combine the determinants of innovative activities. Thirdly, this paper investigates the issue associated with innovative activities, connected with social and economic growth nowadays. Thus, the authors provide empirical models, which are developed in accordance with appropriate tendencies in national economy.Представлено эмпирические исследования внутренних и внешних детерминант инновационной деятельности и социально-экономического роста. Ряд предыдущих исследований было сосредоточено на характеристиках и сущности инновационной деятельности и социально-экономического роста. Приведенное исследование призвано обосновать детерминанты инновационной активности в контексте социально-экономического роста. Во-первых, осуществлено эмпирические исследования факторов, которые влияют на инновационную деятельность. Во-вторых, статья представляет ряд практических подходов, которые создают возможность рассмотрения и сочетание признаков инновационной деятельности и социально-экономического роста. В-третьих, в исследовании получили развитые эмпирические модели, которые учитывают тенденции инновационной деятельности и социально-экономического роста в Украине.Зміна вектора розвитку національної економіки на інноваційний зумовила трансформацію моделей соціального та економічного зростання. Це вимагає диференціації детермінант, які є конкурентоспроможною сферою для подальшого соціально-економічного зростання в умовах глобалізації. Стаття репрезентує емпіричні дослідження внутрішніх і зовнішніх детермінантів інноваційної діяльності та соціально-економічного зростання. Низка попередніх досліджень була зосереджена на характеристиках і сутності інноваційної діяльності та соціально-економічного зростання. Проте для наявних праць характерна низка досить вагомих обмежень, що пов’язано із недостатнім урахуванням деяких важливих детермінант для інноваційної діяльності та подальшого соціально-економічного зростання. Незважаючи на численні дослідження та наявні досягнення щодо сутності та сутності інноваційної діяльності в контексті соціально-економічного зростання, ще існує багато різних питань, що стосуються їхніх детермінант. Наведене дослідження покликане обґрунтувати детермінанти інноваційної активності в контексті соціально-економічного зростання та відрізняється за своїми концептуальними характеристиками від наявних теорій. У процесі аналізу визначено широкий спектр підходів до диференціації як інноваційної діяльності, так і соціально-економічного зростання. По-перше, здійснено емпіричні дослідження чинників, які впливають на інноваційну діяльність. По-друге, стаття презентує низку практичних підходів, які створюють можливість розгляду і поєднання ознак інноваційної діяльності та соціально-економічного зростання. По-третє, у дослідженні розвинуто емпіричні моделі, які враховують тенденції інноваційної діяльності та соціально-економічного зростання в Україні. Таким чином, наведено емпіричні моделі, які розробляються відповідно до відповідних тенденцій у національній економіці

Prevalence of gastrointestinal helminths in ruminants in Ukraine: a 5-year meta-analysis

The production of environmentally friendly livestock products is currently receiving much attention, especially in the European Union. The problem of monitoring the quality and safety of meat and milk in modern conditions is relevant not only for Ukraine but also for the world community. The scientific substantiation of the methods of research on meat for sale subject to invasive diseases is especially important, as the product may pose risks to the consumer. One of the criteria for assessing the welfare of a herd is the prevalence of helminthiases in cattle. Ruminant parasitoses in Ukraine have always been and remain a separate, often significant, problem for veterinary specialists. Helminths have evolved to use a wide range of ecological niches. In this study, we tried to quantify the prevalence of helminthiases among ruminants (cattle, sheep and goats) in Ukraine. The relevant studies were searched for in the online databases. The meta-analysis included 15 publications from January 2015 to December 2020 which reported the spread of parasites in Ukraine. The research results show that the infestation of ruminants with gastrointestinal helminths on the territory of Ukraine is 56.7%. Egger’s regression test revealed no significant publication bias. During the period of pastured farming, stable parasitocenoses are formed in the body of ruminants. The parasitoses are caused by helminths (gastrointestinal strongyles, liver flukes, paramphistomas, dicrocelia). They are recorded in monoinvasions or mixed invasions. Ruminants, according to helminthological examination in different climatic zones, are constantly infested with trematodes. In Ukraine, the presence of three species of flukes has been confirmed in ruminants: Fasciola hepatica, Dicrocoelium dendriticum and Paramphistomum cervi. Parasitization by those species negatively affects the profitability of dairy farming. Trematodes cause significant economic losses: reduced milk productivity of cows, reduced live weight gain of young animals, negative impact on reproduction. At the same time, fascioliasis is socially significant and dangerous to humans. According to the analyzed literature sources, two types of cestodes have been registered in Ukraine: Moniezia benedeni and M. expansa. The epizootic situation regarding nematodes is just as fraught. That is the most numerous group of helminths, their fauna is represented by the following species: Strongyloides papillosus, Nematodirus spathiger, Bunostomum spp., Oesophagostomum radiatum, Haemonchus contortus, Toxocara vitulorum, Trichuris skrjabini, T. ovis and T. globulosa. It is proven that in cattle parasitocenoses are recorded more often than monoinvasions. The highest rates of prevalence of infection were observed when polyinvasion included gastrointestinal strongyles, namely from the order Strongylida. Strongyloides papillosus is the most common taxonomic representative, while Fasciola hepatica has the lowest prevalence of infection, especially in sheep. Updated data on helminthiasis will expand the screening strategy to maintain the health of farm ruminants and reduce economic losses

Spin correlations in Ca3Co2O6: A polarised-neutron diffraction and Monte Carlo study

We present polarised-neutron diffraction measurements of the Ising-like spin-chain compound Ca3Co2O6 above and below the magnetic ordering temperature TN. Below TN, a clear evolution from a single-phase spin-density wave (SDW) structure to a mixture of SDW and commensurate antiferromagnet (CAFM) structures is observed on cooling. For a rapidly-cooled sample, the majority phase at low temperature is the SDW, while if the cooling is performed sufficiently slowly, then the SDW and the CAFM structure coexist between 1.5 and 10 K. Above TN, we use Monte Carlo methods to analyse the magnetic diffuse scattering data. We show that both intra- and inter-chain correlations persist above TN, but are essentially decoupled. Intra-chain correlations resemble the ferromagnetic Ising model, while inter-chain correlations resemble the frustrated triangular-lattice antiferromagnet. Using previously-published bulk property measurements and our neutron diffraction data, we obtain values of the ferromagnetic and antiferromagnetic exchange interactions and the single-ion anisotropy.Comment: 10 pages, 7 figure

GINA - A Polarized Neutron Reflectometer at the Budapest Neutron Centre

The setup, capabilities and operation parameters of the neutron reflectometer GINA, the recently installed "Grazing Incidence Neutron Apparatus" at the Budapest Neutron Centre, are introduced. GINA, a dance-floor-type, constant-energy, angle-dispersive reflectometer is equipped with a 2D position-sensitive detector to study specular and off-specular scattering. Wavelength options between 3.2 and 5.7 {\AA} are available for unpolarized and polarized neutrons. Spin polarization and analysis are achieved by magnetized transmission supermirrors and radio-frequency adiabatic spin flippers. As a result of vertical focusing by the five-element (pyrolytic graphite) monochromator the reflected intensity from a 20x20 mm sample has doubled. GINA is dedicated to studies of magnetic films and heterostructures, but unpolarized options for non-magnetic films, membranes and other surfaces are also provided. Shortly after its startup, reflectivity values as low as 3x10-5 have been measured on the instrument. The facility is now open for the international user community, but its development is continuing mainly to establish new sample environment options, the spin analysis of off-specularly scattered radiation and further decrease of the background

Nutrition of soldiers in battle conditions: the evolution from Zaporizhzhia Sich until today.

Nutrition of military personnel in the field or during combat operations is of great importance for maintaining force performance. An indispensable element in the provision of service personnel with food is individual “dry rations”, which are most often formed based on the nutrition of one soldier for one to three days. Of interest was the question of how the nutrition of the service personnel changed in combat operations meanwhile. Objective – to study the historical aspect of nutrition in battle conditions during the period from the Zaporizhzhia Sich to the present day. Materials and methods – literary sources, regulatory documents, research results. The information retrieval and the theoretical analysis method are used. The literature data, legislative and regulatory documents, the results of scientific research related to the nutrition of Ukrainian service personnel in the combat operations for the period from XVII-XXI centuries are analyzed. The evolution of “dry operational ration” over several centuries took place depending on the development of the food industry: from dry products that do not spoil with long-term keepeng (crackers, cereals, dry meat, dry fish), dry food concentrates and canned foods to ready-to-eat first and second courses. The caloric content of dry rations from the middle of the twentieth century ranged from 3100 kcal to 3350 kcal. In the Ukrainian army it is from 3,500 kcal to 3,800 kcal, and only for Joint Force Operation (JFO) – 4,100. Until recently, the energy value (calorific value) of dry rations was calculated without taking into account the actual energy consumption of service personnel in carrying out combat operations. Further studies on improving the nutritional standards of service personnel should be aimed, first of all, at establishing real energy costs when they perform their mission, including military ones

A Connectivity-Based Eco-Regionalization Method of the Mediterranean Sea

International audienceEcoregionalization of the ocean is a necessary step for spatial management of marine resources. Previous ecoregionalization efforts were based either on the distribution of species or on the distribution of physical and biogeochemical properties. These approaches ignore the dispersal of species by oceanic circulation that can connect regions and isolates others. This dispersal effect can be quantified through connectivity that is the probability, or time of transport between distinct regions. Here a new regionalization method based on a connectivity approach is described and applied to the Mediterranean Sea. This method is based on an ensemble of Lagrangian particle numerical simulations using ocean model outputs at 1/12u resolution. The domain is divided into square subregions of 50 km size. Then particle trajectories are used to quantify the oceanographic distance between each subregions, here defined as the mean connection time. Finally the oceanographic distance matrix is used as a basis for a hierarchical clustering. 22 regions are retained and discussed together with a quantification of the stability of boundaries between regions. Identified regions are generally consistent with the general circulation with boundaries located along current jets or surrounding gyres patterns. Regions are discussed in the light of existing ecoregionalizations and available knowledge on plankton distributions. This objective method complements static regionalization approaches based on the environmental niche concept and can be applied to any oceanic region at any scale