Large Reserves Research Articles

Allocation problem in cross-platform ride-hail integration

We consider a ride-hail system in which a third-party integrator receives ride requests and allocates them to ride service platforms. The ride allocation problem (RAP) is modeled as a Stackelberg game. The integrator, as the leader, chooses the allocation that maximizes its profit, by pricing the rides such that no platform (i.e., follower) can find a more profitable allocation. In pursuit of self-interest, the integrator may refuse to match as many rides as the platforms are willing to serve, thereby injecting an artificial scarcity into the system. To protect the platforms from over exploitation, an exogenous reserve price is introduced to bound their per capita profit from below. We formulate RAP as a bilevel pricing problem, and convert it to a single-level problem by dualizing the lower level. When artificial scarcity is eliminated and all reserve prices are set to zero, we prove the single-level problem can be turned into a mixed integer-linear program that equals its linear relaxation, thus becoming polynomially solvable. Moreover, this version of RAP is shown to be related to cooperative assignment games. Numerical experiments confirm that artificial scarcity negatively affects matching productivity and social welfare. The integrator is favored to take most profits, and leveraging artificial scarcity strengthens its dominance. Moreover, the tighter the supply, the more the integrator benefit from artificial scarcity. The reserve price helps redistribute benefits from the integrator to the platforms. However, demanding an excessively large reserve price may depress the platforms’ profits, while undermining system efficiency.

Water Quality Index by Multivariate Statistical Technique to Estimate the Temporal Decay of the Watercourses

Objective: This study aims to add some variables that characterize the water quality in a water quality index (WQIacp), observing the events of precipitation and land use watersheds. Method: The water samples were characterized in 180 local rivers, and they were monthly analyzed. To ellaborate the WQIacp, a multifactorial analysis statistic and the weighted least squares method were used. Results and Discussion: The first factor explained 42.68% of variance, and variables apparent color and total coliform variables showed higher scores in the formation of the WQIacp. According to the analysis, it´s observed that there is a strong correlation between areas that have higher rates of remaining with the municipalities that have a better WQIacp. Cluster analysis of the municipalities, considering the remaining native vegetation, shows that in the extreme north of Goiás are the cities with the largest reserves. In central and southern part of the state lie the most deforested municipalities. Finally, in the northwestern, part of central and southern of Goiás State, are those cities that present inequality related to the the amount of native vegetation. The worst WQIacp indexes for municipalities evaluated, -1.00 and -0.96, are in the center of Goiás, in Meia Ponte River and João Leite River, respectively, near the city of Goiânia, while the best is in northern of Goiás, 0.68, in Campos Belos in Santa Tereza River. It is still observed that for all the years analyzed, there is an improvement in water quality in the dry season. The average rates grow from April on and get lower from October on, in the beginning of the rainy season. This loss of water quality during flooding is represented mainly by varying color, total coliforms and turbidity, which have scores 0.200, 0.187 and 1.179, respectively. Research Implications: The creation of a water quality index helps in diagnosing and comparing the quality of water sources, facilitating decision-making by managers of Sanitation Concessionaires. Originality/Value: This study contributes to the literature, proposing a methodology based on descriptive statistics to create a water quality index, which can assist managers in decision-making.

Эколого-биологическая характеристика медоносных растений Удмуртской Республики

Abstract. The purpose is to analyze honey–bearing resources, biological forms and species diversity of natural, cultural and adventitious honey-bearing flora in the territory of the Udmurt Republic to create a scheme-map of the honey conveyor. Methods. In the study of this issue “Methods of conducting research in beekeeping” (2003), “Plant determinant of Udmurtia” were used. Results. As of January 1, 2023, the area of agricultural land in all land categories amounted to 1838.3 thousand ha, or 43.7 %, non-gricultural land – 2367.8 thousand hectares, or 56.3 % of the total land fund of the Udmurt Republic. The area of coniferous plants has increased by an average of 38 % since 1966, and hardwood by 35 %. The dynamics of the increase in areas for many species is positive – pine, spruce, ash, elm, alder, linden, willows. The life forms of honey plants of the republic have a different ratio: the largest number of 73 species are grasses (65.2 %), 29 are trees (25.8 %) and 10 are shrubs (9 %). When analyzing data on the flowering of honey plants in Udmurtia, most plants bloom in the off-season – 72.5 %, 25.8 % – in summer, spring. There are plants of prolonged flowering, and honey plants that bloom only in September are absent. The main honey-bearing crop is small-leaved linden. It has a large honey reserve; its specific weight of honey reserve is 90.92 %. To develop the honey reserve of the Udmurt Republic, it is necessary to have a number of bee colonies 4.5 times higher than the current level, which is 224.75 thousand bee colonies. Scientific novelty. Beekeeping in the Udmurt Republic is a promising area of agriculture in the development of forest and agricultural lands, the possibility of improving it and using the export of bees to the honey harvest, taking into account the flowering time of honeybees of natural and agricultural honeybees and active nomads.

Improvement in electrocatalytic behavior of hydrothermally prepared SrBi2O4 with g-CN toward OER activity

The depletion of fossil fuel reservoirs has led to a serious concern related to the energy industry, with by-products generated from their combustion harming the environment. Hence, it is crucial to find an alternative to fossil fuels that has large reserves. The spinel is an efficient class that can provide reliable source of fuel by coupling with graphitic carbon nitride (g-CN). Herein, we hydrothermally developed the non-transition metal-based spinel with g-CN composite for oxygen evolution reaction (OER) activity. The resulting samples were thoroughly characterized using various analytical techniques. All characterizations verify the phase structure of the SrBi2O4/g-CN composite. The nitrogen (N2) adsorption-desorption isotherm indicated a mesoporous structure based on the adsorption isotherm. In addition, the integration of unique-shaped nanoparticles decorated on graphitized carbon nitride nanosheets helps in reducing initial potentials for the OER procedure. Due to their unique mesoporous configuration, SrBi2O4/g-CN catalysts illustrate remarkable electrical conductivity and electrocatalytic activity. The SrBi2O4/g-CN composite exhibited less overpotential (η) of 193 mV at current density (Cd) of 10 mA/cm2 compared to SrBi2O4. The SrBi2O4/g-CN composite revealed remarkable durability and lesser Tafel value of 33 mV/dec. All of the outstanding results obtained from the electrochemical activity suggest as potential electrocatalyst and it can be employed in future energy conversion and water related applications.

Removal of benzo[a]pyrene from the soil by adsorption coupled with degradation on saponin-modified bentonite immobilized crude enzymes

Bentonite is a non-metallic mineral with montmorillonite as the main component. It is an environmentally friendly mineral material with large reserves, wide distribution, and low price. Bentonite can be easily modified organically using the surfactant saponin to obtain saponin-modified bentonite (Sap-BT). This study investigates the immobilization of crude enzymes obtained from Trametes versicolor by physical adsorption with Sap-BT. Thus, saponin-modified bentonite immobilized crude enzymes (CE-Sap-BT) were developed to remove benzo[a]pyrene. Immobilization improves the stability of free enzymes. CE-Sap-BT can maintain more than 80% of activity at 45 °C and after storage for 15 d. Additionally, CE-Sap-BT exhibited a high removal rate of benzo[a]pyrene in soil, with 65.69% after 7 d in highly contaminated allotment soil and 52.90% after 6 d in actual soil contaminated with a low concentration of benzo[a]pyrene at a very low laccase dosage (0.1 U/3 g soil). The high catalytic and removal performance of CE-Sap-BT in contaminated sites showed more excellent practical application value.

Bioengineered 3D ovarian model for long-term multiple development of preantral follicle: bridging the gap for poly(ε-caprolactone) (PCL)-based scaffold reproductive applications

BackgroundAssisted Reproductive Technologies (ARTs) have been validated in human and animal to solve reproductive problems such as infertility, aging, genetic selection/amplification and diseases. The persistent gap in ART biomedical applications lies in recapitulating the early stage of ovarian folliculogenesis, thus providing protocols to drive the large reserve of immature follicles towards the gonadotropin-dependent phase. Tissue engineering is becoming a concrete solution to potentially recapitulate ovarian structure, mostly relying on the use of autologous early follicles on natural or synthetic scaffolds. Based on these premises, the present study has been designed to validate the use of the ovarian bioinspired patterned electrospun fibrous scaffolds fabricated with poly(ε-caprolactone) (PCL) for multiple preantral (PA) follicle development.MethodsPA follicles isolated from lamb ovaries were cultured on PCL scaffold adopting a validated single-follicle protocol (Ctrl) or simulating a multiple-follicle condition by reproducing an artificial ovary engrafted with 5 or 10 PA (AO5PA and AO10PA). The incubations were protracted for 14 and 18 days before assessing scaffold-based microenvironment suitability to assist in vitro folliculogenesis (ivF) and oogenesis at morphological and functional level.ResultsThe ivF outcomes demonstrated that PCL-scaffolds generate an appropriate biomimetic ovarian microenvironment supporting the transition of multiple PA follicles towards early antral (EA) stage by supporting follicle growth and steroidogenic activation. PCL-multiple bioengineering ivF (AO10PA) performed in long term generated, in addition, the greatest percentage of highly specialized gametes by enhancing meiotic competence, large chromatin remodeling and parthenogenetic developmental competence.ConclusionsThe study showcased the proof of concept for a next-generation ART use of PCL-patterned scaffold aimed to generate transplantable artificial ovary engrafted with autologous early-stage follicles or to advance ivF technologies holding a 3D bioinspired matrix promoting a physiological long-term multiple PA follicle protocol.

The Main Controlling Factors of the Cambrian Ultra-Deep Dolomite Reservoir in the Tarim Basin

The genesis of deep-to-ultra-deep dolomite reservoirs in the Tarim Basin is crucial for exploration and development. The Cambrian subsalt dolomite reservoirs in the Tarim Basin are widely distributed, marking significant prospects for ultra-deep reservoir exploration. Based on big data methodologies, this study collects and analyzes porosity and permeability data of carbonate reservoirs in the western Tarim Basin, specifically targeting the Cambrian deep-oil and gas-reservoir research. Through an examination of the sedimentary evolution and distribution of carbonate–evaporite sequences, and considering sedimentary facies, stratigraphic sediment thickness, fault zone distribution, and source-reservoir assemblages as primary reference factors, the study explores the macro-distribution patterns of porosity and permeability, categorizing three favorable reservoir zones. The controlling factors for the development of Cambrian carbonate reservoirs on the western part of the Tarim Basin are analyzed from the perspectives of sedimentary and diagenetic periods. Factors such as tectonic activity, depositional environment, microbial activity, and pressure dissolution are analyzed to understand the main causes of differences in porosity and permeability distribution. Comprehensive analysis reveals that the porosity and permeability of the Series2 carbonate reservoirs are notably high, with extensive distribution areas, particularly in the Bachu–Tazhong and Keping regions. The geological pattern of “Three Paleo-uplifts and Two Depressions” facilitated the formation of inner-ramp and intra-platform shoals, creating conducive conditions for the emergence of high-porosity reservoirs. The characteristics of reservoir development are predominantly influenced by diagenetic and tectonic activities. The Miaolingian is chiefly affected by diagenesis, featuring high permeability but lower porosity and smaller distribution range; dolomitization, dissolution, and filling processes under a dry and hot paleoclimate significantly contribute to the formation and preservation of reservoir spaces. In the Furongian, the Keping and Bachu areas display elevated porosity and permeability levels, along with substantial sedimentary thickness. The conservation and development of porosity within thick dolomite sequences are mainly governed by high-energy-particulate shallow-shoal sedimentary facies and various dissolution actions during diagenesis, potentially indicating larger reserves.

Analysis Of Future Health Insurance Premium Reserve Calculations Using The Commissioners Method With Woolhouse Formula

A premium reserve is the amount of funds that the insurance company needs to prepare for the payment of liability benefits when a claim occurs. One method of calculating premiums is the commissioners method which is an extension of the prospective reserve method.The main factor in the actuarial calculation is the mortality rate that can be determined using the WOOLHOUSE mortality law. This study aims to determine the size of the life insurance premiums reserve using the commisioners method and the WOLHOUSE mortality laws. The calculation of the premium reserve is linked to the determination of a person's chances of survival over a period of years of WOALHOUSE law which is then used to find the value of the insurance, the initial annuity value, the annual premium, the modified premiums based on the Commissioners method, and the amount of the premie reserve at the end of the year. The study was conducted on a 25-year-old woman who was enrolled in a dwiguna life insurance program with a 25 year liability period and a 23 year premium payment period at a 4% interest rate with a liability of Rs. 500,000,000. The results of the analysis showed that the large reserves of premiums obtained at the end of the period of liability with the Commissioners method and the WOOLHOUSE mortality law are equal to the given reservation value, so that the insurance company is prepared to give the amount of reservation promised to the policyholder.

Blowing against the Wind? a narrative approach to central Bank foreign exchange intervention

Most countries in the world use foreign exchange intervention, but measuring the success of the policy is difficult. By using a narrative approach, I identify interventions when the central bank manages to influence the exchange rate based on pure luck. I separate them from interventions when the central bank actually impacted the exchange rate. Because intervention records are daily aggregates, an intervention might appear to have changed the direction of the exchange rate, when it is more likely to have been caused by market news. This analysis allows to have a better understanding of how successful central bank operations really are. I use new daily data on Bank of England interventions in the 1980 s and 1990 s. Some studies find that interventions work in up to 80 % of cases. Yet, by accounting for intraday market moving news, I find in adverse conditions, the Bank of England managed to influence the exchange rate only in 8 % of cases. I use natural language processing to confirm the validity of the narrative approach. Using lasso and a VAR analysis, I investigate what makes the Bank of England intervene. I find that only movement on the Deutschmark and not US dollar exchange rate made the Bank intervene. Also, I find that interest rate hikes were mostly a tool for currency management and accompanied by large reserve sales.

Мировой рынок химических средств защиты растений: потенциальные потери урожая, тренды и перспективы производства пестицидов для экономики России

To ensure its food security and economic growth, Russia needs to monitor the global pesticide market because constant monitoring predicts supply stability and provides annual high yields. The article describes the current issues associated with agricultural pesticide, analyzes the development directions on the global pesticide market, and predicts its impact on the Russian economy. To analyze the global market of chemical plant protection products, the authors applied an integrated approach based on analysis, synthesis, analogy, comparison, and forecasting. The research relied on the domestic laws and standards issued by the Ministry of Agriculture and the Federal Service for Veterinary and Phytosanitary Surveillance. Other sources included statistics obtained from foreign agencies (Phillips McDougal; Kynetec; NBS, China; Chemexcil, India) and Russian institutions (Rosstat, BusinesStat, Zerno.ru, etc.). The review included articles published in scientific and analytical databases, i.e., eLIBRARY.RU, AgroXXI, and AgroPages in 2018–2024. The analysis concentrated on India, China, and the Russian Federation. It covered absolute and relative harvest losses, as well as the market share of importing countries and key suppliers on Russian pesticide market. The demand for chemical pesticides continues to grow, despite restrictions or prohibitions of some hazardous pesticides. Some active ingredients were partially unavailable while finished formulations were subjected to import quotas. In 2024, Russia will be using as many chemical plant protection products as in 2023 since the domestic warehouses store large reserves. The weather conditions are likely to ensure optimal plant growth. Russian farmers will harvest about 142 million tons of grain, including 92–95 million tons of wheat. If repeated annually, this research may reduce the risk of harvest losses and allow the state to adopt prompt regulation measures to obtain high-quality products, thus increasing the domestic consumption and export potential.

CONDITIONS OF THE OAK FORESTS GROWTH AND CULTIVATION ON THE TOP SURFACES AND SLOPES OF THE NEAR-VOLGA AND ERGENI UPLANDS AND THE PLAINS OF THE SAL-MANYCH INTERFLUVE

Planted oak forests in the south of European Russia are of great conservation and economic importance. The widespread practice of their creation in dry steppes and semideserts dates back to the 1950-1970s and allows to form oak (Quercus robur L.) plantations with longevity up to 40-60 years. The aim of the study is to investigate the growth features of oak trees under different soil-climatic and biocenotic conditions and to suggest methods to increase their longevity.The research was carried out in 2011-2016 in the south of the Near-Volga Upland, the northern part of the Ergeni Upland and lowland plains of the Sal-Manych interfluve at 28 temporary sample plots using common methods of forest inventory and regression data analysis.It has been established that the viability of oak is limited by unfavorable topographic position of plantations, increased climate dryness (HC 0,4-0,6), high content of soil carbonates and shallow-lying horizon of their accumulation, as well as the presence of shrub layer and other competitors for moisture. Under these conditions, afforestation of depressions on the plains and shady slopes with pure plantations of oak and other species without shrubs should gain advantage. The methods of their creation should be modified depending on the topographic position of particular forest area and the climate dryness.So, the main soil cultivation in depressions could last 1-2 years, applying the system of black fallow with plantation plowing. It is advisable to keep 3,5-4,0-meter row spacing, frequent tending, and intensive clearing of young tree stands. Maturer plantations need careful sanitary-selective cuttings, mainly the low-type ones, and preservation of high canopy density. Poor water availability and deterioration of plantations should be prevented by construction of dams.Reclamation plantations of low marketability are created on flat areas after 2-3 years of deeper basic tillage. The carbonate horizon should be loosened and a large moisture reserve is needed. Row spacing of 2,5-3,0 meters is reasonable, accelerating the canopy closure. The area of tree nutrition is expanded by low-intensive uniformly selective cuttings, forming more open stands. The longevity of oak in already existing plantations could be increased by eliminating its competitors, such as living ground cover, shrubs and associated species.

Application of porous carbon nanoelectrode materials for lithium-ion batteries

Abstract In order to achieve carbon neutrality and gradually improve the current global warming environmental situation, the world’s major research teams are committed to developing lithium-ion batteries with better performance, trying to use in various new energy facilities, such as electric vehicles, which can effectively reduce polluting gas emissions. Nowadays, many electrode materials that can improve the performance of lithium-ion batteries have been continuously emerging, such as carbon nanotubes and silicon-based nanomaterials. However, carbon nanotube electrode materials have the disadvantages of high irreversible capacity, voltage lag and high manufacturing cost, while silicon-based nanomaterials also have the drawbacks of volume expansion and poor electrical conductivity. Based on the mature research of carbon materials, extensive raw material sources and large reserves, completely non-toxic and low comprehensive cost, this research analyzes three new porous carbon nanoelectrode materials with high development potential, and shows their electrochemical performance advantages, such as high charge-discharge specific capacity, excellent rate performance, and low charge transfer impedance.

Preparation and microwave dielectric properties of calcite (CaCO3) ceramics

Calcite, as the thermodynamically stable phase of calcium carbonate, is a promising low-cost candidate as low-εr microwave dielectric ceramics because of its large natural reserve and the strong covalency of C–O bond, while it is difficult to be densified due to the decomposition at about 627 °C. In the present work, calcite ceramics with the relative density of 87.8 % and low Qf value of 5,600 GHz were prepared by the room-temperature cold sintering, and the pressure-less sintering at 400–600 °C was conducted subsequently. The pressure-less sintering only increases the relative density slightly, while the microstructural evolution including the formation of uniform grains and significant grain growth were observed with increasing the sintering temperature, leading to a dramatic increase in Qf value. The best microwave dielectric properties with εr = 7.60, Qf = 20,200 GHz, and τf = −154 ppm/°C at around 12 GHz were obtained in the calcite ceramic sintered at 600 °C, indicating the applicable possibility of carbonate ceramics in microwave communications.

Analysis of the Impact of Forces in Hanger Rods on Power Boiler Operation

Hanger rods intended for boiler suspensions on a metal structure require a special design approach that considers the total weight of the boiler structure that is to be carried. Unfortunately, a large reserve in the rods’ carrying capacity does not always guarantee the failure-free operation of a boiler. For this reason, it is very important to monitor the forces acting in the rods. Any negligence in this matter might cause a local excess of stresses in the boiler pressure part and result in periodic shutdowns of the boiler. Therefore, in order not to let this happen, adequate computational methods have to be developed. To date, the methods described in the literature and in design requirements have concentrated, first of all, on analyses of the boiler individual subassemblies or on small boiler units supported from the bottom at just a few points. The aim of this paper was to conduct a numerical analysis for a real high-capacity power boiler. The computations were performed based on experimentally measured forces in the hanger rods, and the results were verified by comparing the areas of stress concentration against the area where the boiler structure was regularly damaged.

Особенности сжигания композиционных водоугольных топлив

Russia has large coal reserves, on the average up to 173 billion tons. Although, the share of coal generation in Russia is relatively small (about 20–22 %), it reaches 65 % in the Siberian Federal District. Russia cannot deny coal, but it is necessary to update and improve energy efficiency of Thermal Power Plants (TPP) and boiler houses that burn coal. Currently, technologies have been developed to produce and use composite coal-water fuel (CWF) with various additives, primarily of organic origin to improve its target characteristics. A study of the characteristics of such coal-water suspensions has proved the promising outlook of their use as fuel in large and small Thermal Power Plants, both from an economic and environmental safety points of view. However, the lack of experimental data on the issues of combustion of composite coal-water fuel in bench-scale and semi-industrial conditions hinders the further development of CWF technology. Thus, it is relevant to study the features of combustion of composite coal-water fuels from coals of varying degrees of metamorphism. To prepare experimental batches of composite CWF, raw coals and coal slurries of various stages of metamorphism (grades D, SS, T) have been used. They were burned in a bench-scale semi-industrial plant. The research results have been processed using the methods of mathematical statistics and regression analysis. The influence of mechanical activation of CWF on the viscosity and temperature of its ignition and combustion has been established. The features of combustion of composite coal-water fuel using pneumomechanical injectors of two types are determined. The composition of harmful emissions during the combustion of CWF has been determined. The possibility to use composite coal-water fuel to ignite high-power boilers has been established. It has been proved that the combustion of CWF is environmentally safer compared to the combustion of coal and other types of fuel.

FORESTRY AND STAND MENSURATION CHARACTERISTICS OF OAK STANDS IN RECREATIONAL AND HEALTH FORESTS OF THE LEFT-BANK STEPPE

The study of forestry and stand mensuration characteristics of oak stands in the recreational and health forests of the Left-Bank Steppe was carried out based on forest management materials. The distribution of oak stands in recreational and recreational forests of the region by location, origin, forest types, age groups and classes, health status classes, and relative completeness was analyzed. Indicators of the use of forest site capacity by modal oak stands within forest areas of green zones around settlements (forestry part of forests of green zones) were calculated. It was found that oak groves in the recreational and recreational forests of the Left-Bank Steppe occupy an area of more than 73 thousand hectares or 39% of the total area of recreational and recreational forests of the Left-Bank of Ukraine. Artificial oak plantations predominate, the share of which is 52.9%. Sprouted oak stands occupy 42.5% of the area, and natural seeded stands occupy 4.6%. The largest reserve (195 m3·ha–1) is characterized by natural seed stands. Forests in the conditions of dry birch and sapwood predominate — 25,9 thousand hectares, which is 35.4% of the total area of oak stands in study region. In terms of area and stock, medieval plantations prevail, the share of which is 60.7% of the total area and 56.6% of their total stock. The predominance of oak stands growing according to the II and III site classes (62.7%) and characterized by a relative completeness of 0.7–0.8 (63.7%) was noted. It was established that the relative completeness of oak stands, starting from the VII age class, gradually decreases. The rate of use of forest plant potential by oak trees within the forests of green zones around settlements (forestry part) compared to local highly productive stands amounts to 76%. Losses of wood due to the insufficient degree of use of land fertility were estimated at 916.7 thousand m3.

Preparation of Humic Acid from Weathered Coal by Mechanical Energy Activation and Its Properties

Humic acid (HA) is rich in functional groups with high activity, which can effectively improve the soil environment. The large reserves of weathered coal in China provide sufficient raw material guarantee for HA extraction and utilization. At present, the activation side of weathered coal is still the main technical difficulty that restricts HA extraction. In this study, the weathered coal from Inner Mongolia was used as the raw material, and the mechanical energy was used to activate the weathered coal through a planetary ball mill, which improved the extraction rate of HA and optimized the molecular structure and composition of HA. The effects of four parameters, namely, ball material ratio, ball milling time, ball milling speed, and ball size, on the free HA content of weathered coal were investigated, the HA was extracted by alkaline extraction method, and the activated weathered coal and the extracted HA were characterized. The results showed that a ball material ratio of 9:1, a ball milling speed of 200 r/min, a ball milling time of 200 min, a milling ball size of Ф5:Ф10:Ф15 = 48:42:45 and 56:42:37 are the optimal parameters for the mechanical energy activation, and the HA extraction rate of activated weathered coal under these conditions reached 82.3%, which was 15% higher than that of the unactivated one. Moreover, the aroma of the ball-milled weathered coal increased, the content of oxygenated functional groups increased, and the molecular weight and aroma of HA increased. This provides scientific theoretical guidance for the preparation of HA with high aromaticity and large molecular weight from weathered coal.

Właściwości i zastosowanie gruzińskiego naturalnego filipsytu

Oceanic and terrestrial sedimentary phillipsites make up very large reserves, but the use of this natural zeolite is not so wide comparing to clinoptilolite, and purpose of our study was to characterize the phillipsites of the Georgian deposits and highlight their possible application. It is shown that natural phillipsite can be used as a raw material for the synthesis of phase-pure zeolite NaX with Si/Al~1.5-1.7 in the form of octahedral crystallites with uniform micrometric (2-7 μm) dimensions, characterized by high specific surface area (590-770 m2/g) and volume of pores (0.58 cm3/g) including uniform zeolitic micropores and channels with an average diameter of 55 nm, which opens up the prospect of its use in catalysis. It has been established that natural phillipsite is a suitable carrier of bioactive metals: silver-, copper-, and zinc-containing micro-mesoporous materials have been prepared using ion-exchange reactions between zeolite and a salt of a transition metal; the products contain up to 235 mg/g of silver, 85 mg/g of copper, and 87 mg/g of zinc, and in the Kirby-Bauer disk-diffusion test show strong bacteriostatic activity against such microorganisms as gram-negative bacterium Escherichia coli, gram-positive bacteria Staphylococcus aureus and Bacillus subtilis, fungal pathogenic yeast Candida albicans and a fungus Aspergilus niger. The use of bactericidal materials obtained on the basis of natural phillipsite is possible both for water purification and disinfection, and as fillers in the production of polymeric materials, paper and cardboard.

РОБОТИЗАЦИЯ ПРОИЗВОДСТВА СЕЛЬСКОХОЗЯЙСТВЕННОЙ ТЕХНИКИ

Increasing labor productivity at agricultural engineering enterprises in modern conditions is impossible without the use of robots, which should replace human labor in technological operations with dangerous and harmful production processes. (Research purpose) The research purpose is evaluating the use of robotics by enterprises of the agricultural machinery industry in the production. (Materials and methods) Conducted an assessment of the use of robotics tools when visiting enterprises in the agricultural engineering industry. (Results and discussion) It has been established that for a sustainable presence and strengthening of their positions in the market, companies producing agricultural machinery are increasing the volume of research and development work on the designs and production technologies of modern machines. It was noted that an increase in labor productivity in modern conditions is impossible without the use of robots, which are designed to replace human labor at work with harmful and dangerous production factors in procurement, when cleaning blanks, with thermal and physical methods of surface treatment of products made of various materials, when painting, as well as in order to reduce defects. It was determined that the use of robotization tools by enterprises of the agricultural machinery industry does not exceed three percent of the total volume of technological operations performed. Robotics tools are used mainly in welding operations. Loading and unloading, replacement of working tools on numerically controlled machines, as well as many other technological operations remain practically not covered. (Conclusions) The conducted studies have shown that machine-building companies have large reserves for using robotics tools in performing technological operations in order to reduce production costs and increase labor productivity. As measures to support the introduction of robots into production, grants are allocated by the Russian Digital Economy and Skolkovo foundations, preferential loans through the industrial development Fund "Digitalization of Industry".

Research on marginal-restraint mandrel-free spinning of large thin-walled aluminum alloy domes with large bottom reserves

Research on marginal-restraint mandrel-free spinning of large thin-walled aluminum alloy domes with large bottom reserves