Zinc oxide-nickel cermet selective coatings obtained by sequential electrodeposition

The investigation of pulse electrodepositing modes influence on crystal structure, morphology and optical properties of ZnO has revealed the conditions in which quasi-one-dimensional (1D) ZnO nanorod arrays are formed as separate nanorods. Due to a sufficiently high resistance of zinc oxide, the electrodeposition of nickel on the fluorine doped tin oxide (FTO)/ZnO surfaces carried out in space between the ZnO nanorods. An incomplete filling of the gaps between nanorods by the nickel nanoparticles through subsequent Ni electrodeposition ensured the creation of ZnO–Ni graded cermets. The cermets, in which electrochemical filling of the spaces between ZnO nanorods by Ni, was performed in the pulse mode. It provided higher absorption of visible and near IR light. It was shown that the manufactured ZnO–Ni graded cermets have high light absorption combined with comparatively low thermal losses, so these cermets are promising cheap and affordable selective coatings for solar heat collectors

Structure, optical, electrical and thermoelectric properties of solution-processed Li-doped NiO films grown by SILAR

The article presents a new facial synthesis of Li-doped NiO films (NiO:Li) via an easy and cost-effective method Successive Ionic Layer Adsorption and Reaction (SILAR) with the processing of the obtained NiO films in a lithium-containing aqueous solution for their transformation after annealing into NiO:Li layers. Comparative analysis of crystal structure, optical, electrical and thermoelectric properties of the obtained NiO and NiO:Li 420-1050 nm thick films have reveiled a cubic rock-salt NiO structure, at that, NiO:Li samples are nanocrystalline single phased Li-NiO solid solutions. The fabricated NiO and NiO:Li films are p-type semiconductors with activation energy Ea = 0.1 eV and Ea = 0.25‒0.31 eV, respectively. The obtained in-plane Seebeck coefficients Z are in the range 0.20–0.33 mV/К. Notwithstanding the fact that the maximum values of the thermoelectric power factors P=2.2 μW/K2·m, are rather small, they were achieved if the hot end of the NiO:Li film was heated only to 115 °C. Thus, the produced in this work new low cost thermoelectric thin film material is suitable for a production of electrical energy for low-power devices due to absorption of low-potential heat

Advantages of cluster approach in managing the economy of the Russian Federation

The formation of new approaches to economic growth that will unite scientific, educational and production potentials, as well as lead to an increase in the competitiveness of enterprises, the region, the economy of the nation in general, both research and educational organizations, will have a further multiplier effect on the formation of an economy processes of a new order. This trend in the formation of modern approaches, and their successful implementation will result in the transition of the Russian economy to an economy of innovative type, more adjusted to relevant world trends and markets. The urgency of implementing cluster approaches in the development of the economy on the basis of innovative territorial clusters is dictated by the need to ensure a balanced and sustainable development of the domestic economic system through the promotion of innovation in individual territories. Such actively formed territories can now become clusters. In the modern world, clusters, with their completely different policy of realizing their activities, displaying the newest forms and competitiveness, become springboards' that help launch territories into the economy of the future. Today, the competitiveness of the economy of the region and the state depends not only on technical achievements or inventions, but also on organizational changes that contribute to the achievement by them of high commercial results, as well as on marketing innovations in the promotion and implementation of cluster policies

The Control Actions Structure Optimization in the Process of the Regions Housing and Communal Services Development

The purpose of the present research is to find areas of organizational and economic mechanisms that enhance the efficiency of regional utilities. A systematic approach to the analysis of the organizational and economic mechanism of Housing in the region, provides a systematic, comprehensive and effective investigation. Strategic Imperatives in the management of regional utilities are defined taking into account the crisis tendencies in the process of its development. Case utilities management is seen as the realization of the objectives of its development in different scenario conditions. With the help of mathematical modeling methods and parameters are determined by the structure of the control actions. The article proposes a methodology for calculating the article options strategy utilities management in the region, the results of modeling the trajectory of housing and communal services of the Republic of Adygea. Keywords: housing and communal services of the region, organizational and economic mechanism, management system, the trajectory of the development process JEL Classifications: L51; O18; R5

Solution-processed flexible broadband ZnO photodetector modified by Ag nanoparticles

In this work, we present flexible broadband photodetectors (PDs) fabricated by a deposition of nanostructured zinc oxide (ZnO) films on polyimide (PI) substrates by using cheap and scalable aqueous method Successive Ionic Layer Adsorption and Reaction (SILAR). In order to increase the long-wavelength absorption of the nanostructured ZnO layer, we created its intrinsic defects, including oxygen vacancies by post-treatment at 300 °C in vacuum and thus the light-sensitive material ZnO/PI was obtained. Then we applied silver nanoparticles (Ag NPs) from a silver sol onto a nanostructured ZnO film, which were visualized using SEM in the form of spheres up to 100 nm in size that increased the photocurrent and figures of merit of thus obtained light-sensitive material ZnO_Ag/PI due to localized surface plasmon resonance and double Schottky barriers at the Ag-ZnO interface. To fabricate photodetectors based on a photoconductive effect, these ZnO/PI and ZnO_Ag/PI materials were equipped with ohmic aluminum contacts. The spectral responsivity (Rλ up to 275 A/W to UV light) of solution-processed flexible broadband photodetector based on ZnO_Ag/PI material at different wavelengths of light and light power densities is better than Rλ of the ZnO/PI photodetector, and at least an order of magnitude higher than Rλ of photodetectors based on nanostructured zinc oxide described in recent articles. The external quantum efficiency (EQE) of both PDs in this study in UV–Vis-NIR spectra is very high in the range from 1∙102 to 9∙104 % and is better or of the same order of magnitude as the EQE data of modern flexible broadband high-sensitivity PDs based on nanostructured heterostructures containing ZnO. The specific detectivity in UV–Vis-NIR spectra is large for ZnO/PI (from 3.5∙1010 to 1∙1012 Jones) and especially for ZnO_Ag/PI (from 1.6∙1011 to 8.6∙1013 Jones), which indicates the ability of the PDs based on light-sensitive materials ZnO/PI and ZnO_Ag/PI to recognize a very weak light signal

Non-destructive control of PVD coating surface defects

Nanostructured ZrN coatings were deposited by the vacuum arc method with partial separation of the plasma flow from macroparticles using a curvilinear magnetic filter. With the proposed deposition parameters, a ZrN coating with an fcc lattice and (111) texture is formed. Theoretical studies are carried out to assess the defects of the surface layer in the presence of an adsorbed impurity of an fcc lattice with the surface orientation plane (111), and the characteristics of surface waves in the ZrN coating are considered. Equations are obtained for the dispersion laws and parameters of the splitting off of the surface wave from the zone of bulk vibrations in the nearest-neighbor approximation.Розглянуто параметри осадження наноструктурного покриття ZrN вакуумно-дуговим методом із частковою сепарацією плазмового потоку від макрочасток за допомогою криволінійного магнітного фільтра. При запропонованих параметрах нанесення формується покриття ZrN з ГЦК-ґратками та орієнтаційною площиною поверхні (111). Виконано теоретичні дослідження для оцінки дефектності поверхневого шару в вигляді адсорбованих домішок та розглянуто характеристики поверхневих хвиль у покритті ZrN. Отримано вирази для законів дисперсії та параметрів відщеплення поверхневої хвилі від зони об'ємних коливань при врахуванні найближчих сусідів

Crystal Structure of Nanoscale Tin Dioxide Films Produced by Magnetron Sputtering

Investigation of direct current magnetron sputtering parameters effects on the crystal structure of gas sensitive tin dioxide films has revealed that the change in the substrate temperature and in the film thickness leads to the transition from the condensation of metastable conglomerates of amorphous globules to the ≈15 nm SnO₂ crystallites with three-dimensional shape and well-defined edges. The dependence of the SnO₂ structure from the working Ar-O₂ gas mixtures and from their humidity evidences the significant role of the adsorption in the kinetics of the magnetron sputtering of tin dioxide. Due to the adsorption the morphological and dimensional characteristics of the tin dioxide films demonstrate the anomalous stability of the amorphous globules with their enhanced specific surface energy and the stabilization of the amorphous state, selectively retained even after the SnOv film reach in general the critical thickness of the crystallization

АНТИОТРАЖАЮЩИЕ ПОКРЫТИЯ ИЗ ЭЛЕКТРООСАЖДЕННЫХ МАССИВОВ ОКСИДА ЦИНКА ДЛЯ СОЛНЕЧНЫХ ЭЛЕМЕНТОВ

Surfaces of current photovoltaic devices are characterized by a high refractive index, so they tend to significant reflection of light. This explains the need for an antireflective coating (AR). In this paper, for the first time we demonstrate the possibility of creating the AR in the form of nano-scale zinc oxide array with a parabolic profile by its pulse electrodeposition from aqueous electrolytes. The study of the influence of the zinc oxide deposition mode on their optical properties such as transparency and reflection in the visible region at different angles of radiation, the optical band gap and Urbach energy were performed using a spectrophotometer SF-2000 equipped with specular and diffuse reflection attachment SFO-2000. Structural characteristics, namely, lattice parameters, microstrains, residual stress and texture were analyzed by X-ray diffractometry. Morphology of the grown arrays was investigated by intermittent-contact atomic force microscopy (AFM) using a NanoLaboratory Ntegra Prima NT-MDT setup. Optimization of the pulse electrodeposition mode allowed to adjust the size of parabolic nipples and thus to create AR moth-eye structure based on the electrodeposited zinc oxide arrays, which is suitable for use in photovoltaic devices. Bibliography. 7, Table. 1, Fig. 5.Поверхности современных фотоэлектрических преобразователей характеризуются довольно высоким коэффициентом преломления, поэтому им свойственно значительное отражение света, для устранения которого прибегают к нанесению антиотражающих покрытий (АП). В данной работе впервые показана возможность создания АП в виде наноразмерных массивов оксида цинка с параболическим профилем методом импульсного электрохимического осаждения из водных электролитов. Исследование влияния режимов осаждения массивов оксида цинка на такие его оптические свойства как прозрачность и отражение в видимой области при различных углах облучения, на оптическую ширину запрещенной зоны и на энергию Урбаха выполняли с помощью спектрофотометра СФ-2000, оснащенного приставкой зеркального и диффузного отражения СФО-2000. Структурные характеристики, а именно, параметры кристаллической решетки, микронапряжения, остаточные напряжения и текстура анализировались по данным рентген-дифрактометрических исследований. Морфологию выращиваемых массивовисследовали полуконтактным методом атомной силовой микроскопии (АСМ) на установке «НаноЛаборатория Нтегра Прима NT-MDT». Оптимизация режимов импульсного электроосаждения позволила скорректировать размеры параболических нановыступов и таким образом обеспечить создание на основе электроосажденных массивов оксида цинка пригодного для использования в фотоэлектрических преобразователях АП с эффектом глаза ночной бабочки. Библ. 7, табл. 1, рис. 5.Поверхні сучасних фотоелектричних перетворювачів характеризуються досить високим коефіцієнтом заломлення, тому їм властиво значне відображення світла, для усунення якого вдаються до нанесення антивідбиваючих покриттів (АП). У даній роботі вперше показана можливість створення АП у вигляді нанорозмірних масивів оксиду цинку з параболічним профілем методом імпульсного електрохімічного осадження з водних електролітів. Дослідження впливу режимів осадження масивів оксиду цинку на такі його оптичні властивості як прозорість і відображення у видимій області при різних кутах опромінення, на оптичну ширину забороненої зони та на енергію Урбаха виконували за допомогою спектрофотометра СФ-2000, оснащеного приставкою дзеркального і дифузного віддзеркалення СФО-2000 . Структурні характеристики, а саме, параметри кристалічної решітки, мікронапруги, залишкові напруги і текстура аналізувалися за даними рентген-дифрактометричних досліджень. Морфологію вирощуваних масивів досліджували напівконтактним методом атомної силової мікроскопії (АСМ) на установці «НаноЛабораторія Нтегра Прима NT-MDT». Оптимізація режимів імпульсного електроосадження дозволила скорегувати розміри параболічних нановиступов і таким чином забезпечити створення на основі електроосадженних масивів оксиду цинку придатного для використання в фотоелектричних перетворювачах АП з ефектом ока нічного метелика. Бібл. 7, табл. 1, мал. 5

Boron isotope sensitivity to seawater pH change in a species of Neogoniolithon coralline red alga

The increase in atmospheric carbon dioxide (CO2) observed since the industrial revolution has reduced surface ocean pH by ∼0.1 pH units, with further change in the oceanic system predicted in the coming decades. Calcareous organisms can be negatively affected by extreme changes in seawater pH (pHsw) such as this due to the associated changes in the oceanic carbonate system. The boron isotopic composition (δ11B) of biogenic carbonates has been previously used to monitor pH at the calcification site (pHcf) in scleractinian corals, providing mechanistic insights into coral biomineralisation and the impact of variable pHsw on this process. Motivated by these investigations, this study examines the δ11B of the high-Mg calcite skeleton of the coralline red alga Neogoniolithon sp. to constrain pHcf, and investigates how this taxon’s pHcf is impacted by ocean acidification. δ11B was measured in multiple algal replicates (n = 4–5) cultured at four different pCO2 scenarios – averaging (±1σ) 409 (±6), 606 (±7), 903 (±12) and 2856 (±54) μatm, corresponding to average pHsw (±1σ) of 8.19 (±0.03), 8.05 (±0.06), 7.91 (±0.03) and 7.49 (±0.02) respectively. Results show that skeletal δ11B is elevated relative to the δ11B of seawater borate at all pHsw treatments by up to 18‰. Although substantial variability in δ11B exists between replicate samples cultured at a given pHsw (smallest range = 2.32‰ at pHsw 8.19, largest range = 6.08‰ at pHsw 7.91), strong correlations are identified between δ11B and pHsw (R2 = 0.72, p < 0.0001, n = 16) and between δ11B and B/Ca (R2 = 0.72, p < 0.0001, n = 16). Assuming that skeletal δ11B reflects pHcf as previously observed for scleractinian corals, the average pHcf across all experiments was 1.20 pH units (0.79 to 1.56) higher than pHsw, with the magnitude of this offset varying parabolically with decreasing pHsw, with a maximum difference between pHsw and pHcf at a pHsw of 7.91. Observed relationships between pHsw and calcification rate, and between pHsw and pHcf, suggest that coralline algae exhibit some resilience to moderate ocean acidification via increase of pHcf relative to pHsw in a similar manner to scleractinian corals. However, these results also indicate that pHcf cannot be sufficiently increased by algae exposed to a larger reduction in pHsw, adversely impacting calcification rates of coralline red algae

Boron isotopes in foraminifera : systematics, biomineralisation, and CO2 reconstruction

Funding: Fellowship from University of St Andrews, $100 (pending) from Richard Zeebe, UK NERC grants NE/N003861/1 and NE/N011716/1.The boron isotope composition of foraminifera provides a powerful tracer for CO2 change over geological time. This proxy is based on the equilibrium of boron and its isotopes in seawater, which is a function of pH. However while the chemical principles underlying this proxy are well understood, its reliability has previously been questioned, due to the difficulty of boron isotope (δ11B) analysis on foraminferal samples and questions regarding calibrations between δ11B and pH. This chapter reviews the current state of the δ11B-pH proxy in foraminfera, including the pioneering studies that established this proxy’s potential, and the recent work that has improved understanding of boron isotope systematics in foraminifera and applied this tracer to the geological record. The theoretical background of the δ11B-pH proxy is introduced, including an accurate formulation of the boron isotope mass balance equations. Sample preparation and analysis procedures are then reviewed, with discussion of sample cleaning, the potential influence of diagenesis, and the strengths and weaknesses of boron purification by column chromatography versus microsublimation, and analysis by NTIMS versus MC-ICPMS. The systematics of boron isotopes in foraminifera are discussed in detail, including results from benthic and planktic taxa, and models of boron incorporation, fractionation, and biomineralisation. Benthic taxa from the deep ocean have δ11B within error of borate ion at seawater pH. This is most easily explained by simple incorporation of borate ion at the pH of seawater. Planktic foraminifera have δ11B close to borate ion, but with minor offsets. These may be driven by physiological influences on the foraminiferal microenvironment; a novel explanation is also suggested for the reduced δ11B-pH sensitivities observed in culture, based on variable calcification rates. Biomineralisation influences on boron isotopes are then explored, addressing the apparently contradictory observations that foraminifera manipulate pH during chamber formation yet their δ11B appears to record the pH of ambient seawater. Potential solutions include the influences of magnesium-removal and carbon concentration, and the possibility that pH elevation is most pronounced during initial chamber formation under favourable environmental conditions. The steps required to reconstruct pH and pCO2 from δ11B are then reviewed, including the influence of seawater chemistry on boron equilibrium, the evolution of seawater δ11B, and the influence of second carbonate system parameters on δ11B-based reconstructions of pCO2. Applications of foraminiferal δ11B to the geological record are highlighted, including studies that trace CO2 storage and release during recent ice ages, and reconstructions of pCO2 over the Cenozoic. Relevant computer codes and data associated with this article are made available online.Publisher PDFPeer reviewe