Coexistence of ferro- and antiferromagnetic order in Mn-doped Ni2_2MnGa

Ni-Mn-Ga is interesting as a prototype of a magnetic shape-memory alloy showing large magnetic field induced strains. We present here results for the magnetic ordering of Mn-rich Ni-Mn-Ga alloys based on both experiments and theory. Experimental trends for the composition dependence of the magnetization are measured by a vibrating sample magnetometer (VSM) in magnetic fields of up to several tesla and at low temperatures. The saturation magnetization has a maximum near the stoichiometric composition and it decreases with increasing Mn content. This unexpected behaviour is interpreted via first-principles calculations within the density-functional theory. We show that extra Mn atoms are antiferromagnetically aligned to the other moments, which explains the dependence of the magnetization on composition. In addition, the effect of Mn doping on the stabilization of the structural phases and on the magnetic anisotropy energy is demonstrated.Comment: 4 pages, 3 figure

CHANGING OF OAK TREES BY THEIR COMPANIONS IN BILA TSERKVA FOREST GREEN ZONE UNDER THE IMPACT OF MINERAL SURFACE MINING AND RECREATION

Досліджено, що у лісовому масиві у міру наближення до гранітного кар'єру погіршуються умови росту і розвитку дуба звичайного. Пришвидшується всихання не лише стиглих, але і пристигаючих і середньовікових дубняків. Порушені узлісся та рідини захоплюють осика і липа, поширюються дернина, клен татарський, зарості глоду, бузини і шипшини. Менше впливає на деревостани рекреація. Охарактеризовано лісівничо-таксаційні та просторові особливості зміни дуба першого ярусу його супутниками, стійкішими до висушування ґрунтового покриву. Зроблено спробу прогнозу розвитку деревостанів.Исследовано, что в лесном массиве с приближением к гранитному карьеру ухудшаются условия роста и развития дуба обыкновенного. Ускоряется усыхание не только спелых, но и приспевающих и средневозрастных дубняков. Нарушенные опушки и редины захватывают осина и липа, распространяются дернина, клен татарский, заросли боярышника, бузины и шиповника. Меньше влияет на древостои рекреация. Охарактеризованы лесоводственно-таксационные и пространственные особенности смены дуба первого яруса его спутниками, более устойчивыми к иссушению почвенного покрова. Сделана попытка прогноза развития древостоев.It is shown that in a forest, approaching the granite quarry, conditions of growth and development of oak deteriorate. The drying of maturing and middle-aged oak stands, as well as ripe trees, accelerates. Aspen and linden trees capture destroyed edges and sparse forests; sod, Tatarian maple and hawthorn thickets, elderberry and dog-rose spread. Recreation has less impact on stands. Forestry-taxation and spatial peculiarities of changing of oak trees in first tier by their companions that more resistant to drying up of the soil cover are described. An attempt of forecast the development of forest stands was made

Analysis of losses in the mixing section of the central air conditioner using the entropy-statistical method

The article presents an entropy-statistical analysis of losses in the mixing section of a central air conditioner. The temperature and humidity of the outdoor and recirculating air were measured. The methodology for determining losses using the entropy-statistical method is presented in the work. The calculation of losses in the mixing section of the central air conditioner due to the mixing of air flows depending on the flow rate of the supply and recirculation air as well as due to hydraulic losses. A comparative analysis of the results is carried out and the distribution diagrams of the component losses are presented. Proposed conclusions regarding the way to reduce losses

Analysis of losses in the mixing section of the central air conditioner using the entropy-statistical method

The article presents an entropy-statistical analysis of losses in the mixing section of a central air conditioner. The temperature and humidity of the outdoor and recirculating air were measured. The methodology for determining losses using the entropy-statistical method is presented in the work. The calculation of losses in the mixing section of the central air conditioner due to the mixing of air flows depending on the flow rate of the supply and recirculation air as well as due to hydraulic losses. A comparative analysis of the results is carried out and the distribution diagrams of the component losses are presented. Proposed conclusions regarding the way to reduce losses

Building of a digital model of aluminum electrolysis modes

The article discusses the issues of constructing a digital model of aluminum electrolysis modes. This model allows to achieve the specified criteria of the production process on the basis of scientific processing of historical data accumulated during the industrial production of aluminum at factories using a mathematical apparatus as well as to obtain recommendations on the values of control parameters. The study is aimed at achieving the business goals of the company's management in particular on increasing of the profits by improving the quality and quantity of products with reduced production costs

Self modelling calculations of the form of the weld pool in electron beam welding

Translated from Russian (Fiz. Khim. Obrab. Mater. 1988 v. 22(4) p. 111-115)Available from British Library Document Supply Centre- DSC:9023.19(VR-Trans--4168)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Dominant hydrogen complex in natural anatase TiO2

A study combining vibrational spectroscopy and first-principles theory is presented for a hydrogen-related defect in natural anatase TiO2 that is characterized by an O–H vibrational mode at 3373 cm−1 (10 K). Based on complementary Raman scattering, IR absorption, electron paramagnetic resonance, and secondary ion mass spectrometry data supported also by ab initio calculations, it is tentatively proposed that the defect responsible for the 3373 cm−1 line includes two hydroxyl units located next to a substitutional iron atom, FeTiH2. The defect may exist in at least two charge states, whereby the 3373 cm−1 line is associated with the positive charge state of the complex

Calculations of thermal processes in continuous and pulsed-periodic regimes of laser welding of metals

Translated from Russian (Fiz. Khim. Obrab. Mater. 1988 v. 22(4) p. 56-62)Available from British Library Document Supply Centre- DSC:9023.19(VR-Trans--4159)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo