bluuebunny/crossref_metadata_2025 huggingface dataset:
Prospects for the use of waste cement industry in the production of clinker-free concrete
Authors: Sh Salamanova M , Yu Murtazayev S-A , Kh Alaskhanov A , Saydumov M S
Published: June 2021

The production of Portland cement clinker is accompanied by huge dust release and the accumulation of huge amounts of aspiration and clinker dust in the dust collection system. The rational use of this high-quality corrected fine-dispersed resource is an urgent task not only in technological, but also in ecological terms. Aspiration dust cannot be returned to the technological cycle. It is taken out of the cement plant, disrupting the ecological situation of valuable agricultural land and mountainous landscape. Taking into account the fact that it can be used in its natural form, without an additional mechanical intervention, this will expand the material and raw material base for the production of alkaline cements. This paper presents the results of studies of the particle size distribution of particles in samples of dispersed material and the determination of the shape and size of cement dust particles. The reactivity of the investigated powders of technogenic nature has been proved. These characteristics of cement dust electrostatic indicate feasibility of these powders dispersed as component binders ligaments alkaline activation.
On the assessment of the stress condition of a T-shaped frame supporting structure during the experimental process
Authors: Durakov S V , Bukovtsova A I , Kozhukhova N I
Published: June 2021

Due to the specifics of the distribution of forces in a two-span frame, it is necessary to increase the cross-sections of the central part of the girder, which negatively affects the consumption of steel for the production of the frame. To reduce the influence of the specifics of the distribution of internal forces on the weight indicators in the girder of a two-span frame, it is necessary to use innovative constructive ways of distributing forces in the girder of the frame, which affect the reduction of material consumption. Such structures include the two-span frame with T-shaped supports proposed in this article, the calculation method of which is based on the idea of combining functions. Since the design is a newly proposed one, it is necessary to identify its stress state. Experimental studies are one of the ways to identify the stress state. The experimental research methodology is presented in the article. This article proposes an assessment of the stress state of a new structural form of a frame with T-shaped support. The development of the section method and the finite difference method makes it possible to evaluate the stress state of the frame from the deformations measured in the experiment. The accuracy of this method is 2…6 %. The proposed technique will make it possible to assess the stress state of a new structural form of a frame with T-shaped support using measured deformations, which were determined as a result of experimental studies, as well as when assessing the stress state of operating frame structures.
Extraction of methylene blue coloring agent from model solutions with a plant-origin sorbent
Authors: Loktionova E V , Sysa O K , Loktionov V A
Published: June 2021

The production output of dyes and pigments in chemical industry is constantly increasing. Sewage waters, which contain synthetic and organic coloring agents, produce toxic effect, which is preconditioned by their low MAC values - below 0.001 mg/dm 2. The most promising method of the pigmented wastewater treatment, which allows reducing the pollutants’ content to the regulated permissible amount, is the adsorption method. This work presents research findings concerning sorption purification of test water media, containing methylene blue coloring agent, by using crop farming waste - chopped sunflower (Heliánthus ánnuus) stalks - as a sorption material. It has been determined that the maximum sorption capacity of chopped sunflower stalks biomass for this coloring agent is 0.245 mmol/dm 2. The processing of the received data has demonstrated that the obtained adsorption isotherm of methylene blue belongs to Type V isotherms according to classification by Brunauer-Deming-Deming-Teller (BDDT) or to the S-type, according to Giles’ classification. This adsorption process is the most accurately described by the Brunauer-Emmett-Teller model (BET), based on the concept of multilayer adsorption.
Fractal express methods evaluation of a breaking stress of concrete
Authors: Volchuk V M , Kotov M A
Published: June 2021

We have offered the methods of the operative evaluation of a breaking stress in testing strength on compression of heavy concrete of grade 400 with the use of fractal formalism. The methods are based on the setting of the relations of the values of a breaking stress and fractal measurement of concrete: 1. Areas with crushed stone prevailing (R2 = 0.7224); 2. Areas with sand prevailing (R2 = 0.6102); 3. Pin holes (R2 = 0.6874). During fractal experimenting the indexes of breaking were increased from 391.63 to 515.13 kH in reducing fractal dimension of areas 1 from 1.866 to 1.588; areas 3 from 1.826 to 1.684 and internal quality (boundary of its elements) from 1.617 to 1.353. Increase of fractal dimension was fixed only for areas containing sand (areas 2) from 1.755 to 1.944. These results make possible to apply fractal dimension as the indicator of structural changes of concrete in the prediction of its properties. In fractal modelling the accuracy of the results depends on the option of the task way for space metric that is proved by the obtained linear model (R2 = 0.9254), which describes the connection between the elements of macrostructure and strength criterion of concrete.

Such methods provide a satisfactory in practical purposes operative prediction for the values of breaking stress of concrete of grade 400 with significant reduction of time and money expenditures on full-scale testing and the application of microscopy.
Quality assurance in the design of heating systems in green building
Authors: Vinogradova N A , Plekhanova S V
Published: June 2021

The article considered the issue of thermal stabilization of buildings, formed a mathematical model for the room. The applied systems of thermoactive structures are described, their strengths and weaknesses are determined. Other methods of “passive” cooling systems are considered, it is determined that the main air conditioning systems are not fully used is technically and economically feasible, however, as complementary systems for the off-season must be taken into account. The heat supply system using a heat pump and a low-potential source (sewage) is described. This system allows for more efficient use of the evaporative-condensation cycle by operating with a smaller temperature difference between the heat pump flow and the low potential source. It is shown that the main attention should be paid to the development of alternative heating systems and the use of renewable energy sources. A significant part of the equipment used cannot always be considered as part of the overall strategy for the formation of an ecological building. The use of forms of heating based on low-potential sources will improve the environmental performance of residential and industrial buildings.
Comparison of the effectiveness of mineral and mixed coagulants in the lightening of water from a surface source
Authors: Grishin B M , Laskov N N , Perelygin Y P
Published: June 2021

The results of experimental studies of the coagulation treatment of the Sura River water in the autumn period and during high water with the use of mixed coagulants based on aluminum sulfate (AS), polyaluminum chloride “AQUA-AURAT 18” (PACl) and organic coagulant FL 4540 are presented. When treating river water with a low temperature, the use of mixed organic and mineral coagulants allows for a more significant reduction in the turbidity of the settled water compared to mineral coagulants AS and PACl at the same doses. Mixed coagulants with a weight ratio of FL 4540: AS (or FL 4540: PACl) equal to 1:4 have a greater efficiency of action compared to coagulants with a ratio of organic and mineral parts equal to 1:1. When treating low-turbidity water with a low temperature in the autumn period, the highest effect of clarification by settling was obtained using mixed coagulants based on PACl and FL 4540. At a standard mixing time of the initial river water with coagulants of 2 min, the use of a mixed coagulant K3 based on PACl and FL 4540 allows getting the same lightening effect as when using only PACl, but with doses lower by 30%. Experimental data on the coagulation treatment of the source water with low alkalinity and increased turbidity during the flood showed the greatest effectiveness of the mixed coagulant K1 based on AS and FL 4540, the use of which, with a mixing time of 2 minutes with the source water, reduces the dose of AS by 10% with the same settling effect. Increasing the mixing time with water to 15 minutes increases the effectiveness of the mixed coagulants, which in this case can reduce the doses of AS and PACl by 1.6-2 times without compromising the quality of clarified water by settling.
Estimation of the residual resource of several buildings and structures as a single object
Authors: Korolkov D I , Bolodyan G I , Gravit M V
Published: June 2021

In this article, the author raises the problem of assessing the residual resource of an object, which consists of several buildings and structures. Four different approaches to solving this problem are presented. The advantages and disadvantages of these approaches are presented. The areas of their application are indicated. Within the framework of these approaches, one can use the direct enumeration method, the combinatorial method, the algebra of logic, the general logical-probabilistic method. The author has developed two possible options for calculating the residual resource of these objects using the general logical-probabilistic method. It is proposed to develop a Methodology for calculating the residual life of such objects before the survey. The author indicates the main points that must be prescribed in the developed Methodology. An example of calculating an object consisting of five buildings is given. The scheme of functional integrity is constructed according to the general logical-probabilistic method. In the program complex “Arbiter” the static and probabilistic-time calculation of the given scheme is performed. Then the calculation of the object as a whole was carried out according to the “2 of 5” system. As a result, the value of the probability of failure-free operation and the residual resource of the object as a whole is shown.
Complex application of ash of hydraulic removal and modified additives such as CMA, CM-2 in the production of non-autoclaved foam concrete
Authors: Dusembinov D S , Lukpanov R E , Tsygulyov D V , Yenkebayev S B
Published: June 2021

The paper presents studies on the use of ash of hydraulic removal in combination with modifier additives in the production of non-autoclaved foam concrete. The research is aimed at obtaining high-quality non-autoclaved foam concrete based on industrial waste with high construction and technical properties. The main objective of the paper is to determine the quality indicators of non-autoclaved foam concrete, according to standard methods, corresponding to the normative and technical documentation. The studies were carried out under laboratory conditions on certified and calibrated test equipment. The industrial waste considered in the paper, the ash of hydraulic removal and food industry waste, are common waste in all countries of the world, which gives high relevance to the research topic within the framework of waste disposal. The conducted studies confirmed the effectiveness of the integrated use of waste, to obtain the best result. As it is known, ash reduces the thermal conductivity, which is a positive effect, but at the same time reduces the strength of the material and frost resistance. In the paper it was proved that with the use of oil processing waste, it is possible to obtain an increase in frost resistance due to volumetric hydrophobization, as well as with the use of alcohol production waste, a significant increase in strength is achieved, due to the plasticizing effect of the casein contained (polymer components) in the composition of alcohol production waste. The obtained results of the study on thermal conductivity, strength and frost resistance confirm the effectiveness of the use of ash in combination with modified additives based on food industry waste CM-2 and CMA-P. In conclusion, a comparative analysis of the effectiveness of the use of industry waste the ash of hydraulic removal in combination with modified CM-2 and CMA-P additives is carried out.
Ensuring environmental safety when using polymer waste in technologies for obtaining building materials
Authors: Pugin K G
Published: June 2021

The production of building materials uses large amounts of primary natural resources. Mineral and organic components of the natural environment are used as raw materials, which leads to degradation and disruption of the habitat of living organisms. One of the possible methods to reduce the consumption of natural resources is the use of industrial and consumer wastes as raw materials, which include polymer waste. The high resource potential of polymer waste as a fuel is shown. Waste can replace coal coke, which is used in ferrous metallurgy technologies. The analysis of several technologies for the use of polymer waste as an inert filler and as a bituminous binder in the production of asphalt concrete and building mixtures has been carried out. The classification of various groups of polymer waste by melting temperature and chemical composition is presented. The analysis of technological processes for the use of polymer waste made it possible to conclude that considerable attention is paid to the extraction of economic benefits without environmental assessment of the safety of the technologies used. An environmental assessment of polymer waste disposal technologies has been proposed, which will allow at the stage of technology development to assess the environmental risks arising from the production and operation of the resulting product. It is proposed to select the temperature range in the technological processes for obtaining secondary products as indicators of the formation of environmental risks when using polymer waste.
Thermal conditions of a single-pipe heating system of an apartment block
Authors: Seminenko A S , Elistratova Y V , Kireev V M , Goncharov I V
Published: June 2021

The heating system is one of the life support systems. The discrepancy between the thermal (temperature) conditions of the living quarters is one of the most urgent complaints of residents of apartment blocks in most regions of the Russian Federation. The object of the study is a single-pipe water heating system of a 14-storey apartment block with an overhead distribution, for which the heat output is determined to compensate for heat losses under various initial conditions (outdoor air temperature and infiltration airflow rate). As a result of the calculation of the thermal conditions, deviations in the indoor air temperature of living quarters from the permissible range are determined. To eliminate violations of the microclimate parameters, this paper considers ways to increase the heat transfer of heating appliances by increasing the area of the heating appliance, as well as increasing the flow rate of the heat-transfer agent passing through the appliance. The results of the calculation of the thermal conditions showed the impossibility of eliminating the violation of the thermal conditions by these methods: depending on the temperature of the outdoor air in the living quarters, there is an excess or lack of heat. To eliminate the thermal and hydraulic disarrangement, a mechanical method for adjusting the heat transfer is proposed by switching off the sections of the heating appliance with an increased number of them. Taking into account the recommendations on the need to ensure that the length of the radiator corresponds to 50-70% of the length of the window opening, this method is functional for use.
Research and operating experience of long-burning boilers in the North-East of Russia
Authors: Slobodchikov Egor
Published: June 2021

In Yakutia, there is a tendency to build individual houses in rural areas. Due to the complex geographical location, economic problems and transport and logistics difficulties, it is not possible to connect many settlements to centralized sources of energy supply. Therefore, the demand for efficient autonomous sources of thermal generation due to the use of local solid fuels has recently increased. Practice shows that heat generators of imported and national manufacturers are not adapted to work at low outdoor temperatures. In the climatic conditions of the North-East of Russia, one of the important tasks is to increase the reliability and efficiency of heat generation sources; this is a necessary condition for ensuring comfortable working and living conditions for a person.
The use of waste in the composition of organic-mineral mixtures used in road construction
Authors: Pugin K G , Pugina V K
Published: June 2021

The construction of highways requires a large amount of building materials. Organo-mineral mixtures, which include asphalt concrete, are the main building material for the construction of the upper layers of the road structure. In order to reduce the cost of asphalt concrete, part of the natural mineral raw materials may be replaced by industrial waste. Previous studies show that waste from various industries in terms of their physical and mechanical properties are not inferior to natural raw materials used in road construction. When using the material resource of waste, environmental issues are additionally resolved by reducing the volume of waste disposal at landfills. The studies carried out have shown that the composition of the asphalt concrete mixture, in which drill cuttings are used, as a mineral powder, meet the requirements for asphalt concrete. Studies have shown that waste plastics HDPE and LDPE can be considered as reinforcing and modifying elements in the structure of asphalt concrete. Asphalt concrete, which includes plastic waste, meets the requirements for asphalt concrete used for road construction.
Estimation of deformations of steel constructions of cranes based on photogrammetry
Authors: Yu Ganshkevich A , Shikhov N S , Stoyantsov N M
Published: June 2021

The paper considers the results of the application of photogrammetry to assess the deformations of rod and plate elements of the steel constructions of hoisting machines, the analysis of the main problems arising in their processing and the proposed solutions to ensure the necessary accuracy. The authors, based on their own research and practical experiences application in the use of photogrammetry, carried out accuracy rating the magnitude of deformations. Based on a brief review of normative documents, proposals for rationing the permissible values of measurement errors are given. The paper also considers the problems that may arise in the assessment of the deformed state of design status and proposes approaches to solving these problems. One of the problems solved in the study was to assess the magnitude of the deformation of the rear belt of support of blocks of equalizing polyspast, resulting from an emergency situation during the operation of the crane KPL-16-30. In addition to assessing the overall deformed state of the entire element, the deformation in some sections of the structure was assessed. The application of some approaches to estimating the deformation of rod structure elements based on modeling the shape of the a curved axis of a beam or rod. Also considered the experience of deflection measurement the deflection of the 0.5 t electric hoists guide in the laboratory of hoisting machines. The authors shared their inspecting of the wagon tippler No. 2 examination. In addition to the assessment of transverse deformations, the task was to check the possible torsion of the metal structure of the moving part. In the process of work some problems were also revealed, the solution of which will make it possible to provide the necessary accuracy of measurements. When evaluating the approximation accuracy, the authors propose to use several approaches.
Impact of the stress-strain state of the soil on the stability of the retaining wall
Authors: Kozyukova N V , Zhambakina Z M , Akishev U K , Sarsenbaev N B
Published: June 2021

The results of the survey and calculation of the stability of retaining walls along highways located near the incline of the slope are presented. The analysis of the results of the numerical solution for modeling the interaction of the slope and the retaining wall shows that the most dangerous areas are the zones of development of maximum horizontal deformations at the retaining walls due to shear deformations. The zone, where shear deformations are spread, covers a large volume of slope soils. Collapsing soils, sinking from their own weight on the slope during water saturation, worsen the initial value of the adhesion, the angle of internal friction, the modulus of deformation, changing the stress-strain state. The trajectories of the movement of particles of collapsing soil when the stress-strain state of the slope on the retaining wall changes show that the movement of soil particles occurs at the boundary of collapsing and non-collapsing loams. Numerical calculations carried out under the PLAXIS program showed that in the water-saturated state, the slope is a landslide. The retaining wall on the incline of the slope, made of collapsing soils, is not stable and the sliding of the soil occurs only in the layers of collapsing soils of the slope.
Investigation of stressed state of shell structure
Authors: Strelnikov V N , Sukov M G
Published: June 2021

The main fundamental difference of wave gears from all other meshing gears is the presence of a flexspline which is implemented in the form of a shell structure, and which, by means of a wave generator located on the input shaft, modifies the rotational motion of the wave generator into permanent elastic wave deformations of the flexspline, which are then transformed in the rotation of the output shaft. The design features of harmonic gear drives provide them with a number of significant advantages, such as smaller dimensions and weight, in comparison with conventional ones, including planetary gear train of the same torque. They have the highest kinematic accuracy, including damping behavior and low level of noise and vibration. A unique feature of harmonic gear drives is the ability to transfer rotation into a sealed space with almost zero fluid leakage. Harmonic gear drives are capable of carrying out large gear ratios in one stage: for steel flexspline, from a minimum of about 60 to a maximum of 300. At the same time, their efficiency is quite high - in the reduction mode of 80 … 90 %, as in planetary gears with the same gear ratio. When operating in the torque multiplication mode, the efficiency noticeably declines. The disadvantage of harmonic gear drives is a relatively low frequency of the wave generator rotation, approximately within the range of 1500 … 3500 min 1 with the radii of small flexspline from 125 to 25 mm, respectively. Therefore, the power of harmonic gear drives, despite the high transmitted torques, is limited to relatively small values - from 0.1 to 48 kW. Their service life is limited to approximately 104 hours; a year and a half with continuous operation throughout the day. Specific weight and cost of harmonic drives is 1.5 +2 times lower than those of planetary type, which represents technical and economic advantages and commercial interest for road and construction machinery.
Dependence of the temperature of the beginning of the heating season on the energy efficiency class of the building
Authors: Svirin M V , Kosilov D M , Seminenko A S
Published: June 2021

The heat supply of most Russian cities is provided by centralized sources of thermal energy. During the operation of buildings, the transition period of the year is not given due attention. The transition periods of the year (before and after the heating season) complicate the task of providing thermal comfort in the rooms of residential and community buildings. The paper deals with the problem of microclimate troubles in multistorey residential buildings during transition periods. The purpose of this work is to test the hypothesis that there is a dependency of the temperature of the beginning of the heating season, depending on its energy efficiency class. For the thermal conditions of the rooms, the classical dependences of the thermal balance, technical thermodynamics and the theory of heat and mass transfer are used. On the example of a nine-storey apartment block, a calculation was carried out, as a result of which the rational temperature of the beginning of the heating season for various energy efficiency classes was determined, as well as the internal air temperature at the outdoor air temperature equal to 8°C (the existing value of the temperature of the beginning and end of the heating season). The results obtained confirm the hypothesis of the study that there is a dependency of the rational temperature of the beginning of the heating season for a particular building, depending on its energy efficiency class. At the temperature of the beginning of the heating season, the internal air temperature of 20°C will be achievable with a deviation of -41.182%, which corresponds to energy efficiency class A (excluding heat gain from solar radiation). It is established that at the current temperature of the beginning of the heating season, the internal air temperature of 20°C will be achievable with a deviation of -41.182%, which corresponds to energy efficiency class A, for buildings of a lower class, the temperature of the beginning of the heating season is not optimal.
Bases of calculation and design of asynchronous diesel generators for autonomous system of power supply
Authors: Absalyamov D R , Avsyukevich D A , Litvinova N B , Druzhinin P V
Published: June 2021

The article discusses the characteristics of diesel generator sets currently used in autonomous power supply systems. The modes of operation of synchronous generators and their overload capacity are analyzed. The overloading capacity of diesel generator sets (DGS) can be significantly increased when used as an electromechanical energy converter of asynchronous generators (AG). The initial algorithm for their selection involves calculating the optimal value of the rotor speed and choosing the range of rotation frequency. The value of the optimal value of the rotational speed is determined depending on the method of maintaining the constancy of the current frequency when calculating the parameters of an autonomous asynchronous semiconductor cascade, which is understood as an AG together with its excitation and control system. The dependences of individual terms of electrical power losses on the operating mode of an autonomous asynchronous semiconductor stage are considered. After determining the optimal speed, the possible AG power is selected. Then, from a number of powers, its nominal power is selected. After determining the rated power, the minimum and maximum values of the rotational speed, it is possible to determine the optimal operating modes of the diesel generator set with the AG. As a criterion of optimality, the specific effective fuel consumption of the diesel generator set is taken. This approach to the choice of the type of diesel generator set when designing autonomous power supply systems requires a detailed consideration of the technical and economic characteristics of the units. The proposed design principles can ensure the most complete use of the positive properties of a diesel engine and an electromechanical energy conversion system, as a result of which to improve the technical and economic characteristics of autonomous power supply systems.
Research of aerodynamic properties of some building models
Authors: Gadaborsheva T B , Torgashina S N , Stepanova I E , Chicherov K O
Published: June 2021

The paper provides a brief analysis of the history of urban development, depending on the consideration of natural and climatic conditions, in particular, the movement of air masses. The construction practice is taken into account when accounting wind conditions, which primarily involves the effective placement of industrial enterprises, sanitary break zones, residential development and public space. Theoretical studies of the aerodynamic properties of two models of buildings of simple shape, based on some experimental data, are presented. Comparing the flow directions calculated theoretically with the directions measured experimentally by different authors, it is confirmed that the proposed theoretical methods well reflect the actual picture of the flow around a rectangular profile by an air flow. For the considered models No. 1 and No. 2, according to the test results, it was determined that the pressure on the windward planes (walls) of different heights depends on the ratio between the thickness of the boundary layer and the height of the building, respectively, buildings of small height are almost entirely located in the boundary layer, i.e. in the layer of air, which, touching the surface of the earth, is slowed down due to the roughness of the underlying surface, as the speed of air movement decreases as it approaches the surface of the earth, and on the surface it is zero.
Effect of low-level jet on turbine aerodynamic blade loading using large-eddy simulations
Authors: Gadde Srinidhi N. , Liu Luoqin , Stevens Richard J. A. M.
Published: June 2021

Low-level jets (LLJs) are winds with high-shear and large wind energy potential. We perform large-eddy simulations (LES) with actuator line modeling of a turbine operating in a moderately stable boundary layer in the presence of LLJs. We find that the turbine tip and root vortices break down quickly when the LLJ is above the turbine rotor swept area. In contrast, the wake recovery is slow, and the vortices are stable when the LLJ is in the middle or even below the rotor swept area. The LLJ shear causes significant azimuthal variation in the external aerodynamic blade loading, increasing fatigue loading on the turbines. We observe that both tangential and axial forces on the blades are highest when the blade directly interacts with the LLJ. Azimuthal variation in the tangential forces on the blades is the highest when the LLJ is above the rotor swept area, i.e. when the turbine operates in the positive shear region of LLJ, with the blade tip interacting with the LLJ.
Validation of wind turbine wakes modelled by the Meso-NH LES solver under different cases of stability
Authors: Jézéquel E , Cathelain M , Masson V , Blondel F
Published: June 2021

In wind farms, the wakes of upstream turbines impact the downstream ones in terms of power production, loads, and fatigue. The wake properties depend on many parameters such as the stratification, Coriolis force, large-scale forcing and orography. To simulate this interdependence, the actuator line method (ALM) has been implemented in the atmospheric code Meso-NH, which is an LES research code developed by the French weather services. This implementation has already been validated for the blade force distribution on the NewMexico case (uniform inflow in a wind tunnel) and for the interaction with the atmosphere on the Horns Rev photo case. The work presented here aims at completing the validation in a realistic atmospheric boundary layer (ABL), with a focus on velocity deficit and wake meandering. It is based on the international SWiFT benchmark which compares the results of many numerical models with LiDAR measurements in the wake of a single turbine for three cases of atmospheric stability: neutral, unstable and stable. The good results show the capacity of Meso-NH/ALM to generate realistic wakes in a representative ABL.
Comparison of large-eddy simulations of wakes with wind farm wake parametrizations using the Weather Research and Forecasting model
Authors: Peña Alfredo , Mirocha Jeffrey D.
Published: June 2021

Wind farm parametrizations are nowadays commonly used to predict the output of wind farms in real-time numerical weather prediction mesoscale models. However, their accuracy both to reproduce the wind speed and turbulent kinetic energy fields behind turbines is a matter of debate. Here, and to the authors knowledge for the first time for a single turbine, the in-built wind farm parametrization of the Weather Research and Forecasting model is evaluated using detailed large-eddy simulations of the wake performed with a generalized actuator disk model that was implemented in the same modeling system. Thus, a fairer evaluation is achieved compared to previous works, as we try to set the simulations as similar as possible within the same modeling framework. We find that both types of simulations can be used to provide similar inflow conditions to the turbine. Most importantly, by comparing the detailed-wake results, within the area where the turbine is placed, with the mesoscale results at the analogous position, velocity deficits can differ up to 50%. However, within the same area, the vertical profile of turbine-generated TKE is nearly identical between the two types of simulations. Our findings demonstrate that the generalized actuator disk implementation can provide us with a solid foundation for evaluation of wind farm parametrizations within weather models.
A level-set framework for the wind turbine wake analysis: from high-fidelity unsteady simulations to 1D momentum theory
Authors: Houtin—Mongrolle F. , Benard P. , Lartigue G. , Moureau V.
Published: June 2021

In the context of yawed wind turbine wakes, the validity of the so-called 1D momentum theory is arguable. The 1D momentum theory emerges from an inviscid, steady and irrotational analysis of the streamtube surrounding a wind turbine while the wake aerodynamics under yaw is modified. In this work, the mean flow streamtube around a single DTU 10MW wind turbine, under yaw misalignement and turbulent inflow is investigated with Large-Eddy Simulation combined to the Actuator Line method. The simulations are performed on a highly resolved grid counting billions of elements. The streamtube construction from the mean flow is based on the transport of accurate conservative level set functions. Integration of local flow quantities within the streamtube presents similarities when the streamtube expansion occurs past the turbine until the velocity deficit starts to recover. Mean kinetic energy and momentum budget are then presented to explain the yawed wake recovery and deflection process. Background turbulence plays a key role in the recovery process while the deflection of the wake is impacted by pressure forces on the streamtube. From these budgets, four wake regions showing similar flow dynamics are defined and correlated to local flow structures.
Mortality-based damages per ton due to the on-road mobile sector in the Northeastern and Mid-Atlantic U.S. by region, vehicle class and precursor
Authors: Arter Calvin A , Buonocore Jonathan , Chang Charles , Arunachalam Saravanan
Published: June 2021

On-road vehicular emissions contribute to the formation of fine particulate matter and ozone which can lead to increased adverse health outcomes near the emission source and downwind. In this study, we present a transportation-specific modeling platform utilizing the community multiscale air quality model (CMAQ) with the decoupled direct method (DDM) to estimate the air quality and health impacts of on-road vehicular emissions from five vehicles classes; light-duty autos, light-duty trucks (LDT), medium-duty trucks, heavy-duty trucks (HDT), and buses (BUS), on PM2.5 and O3 concentrations at a 12 × 12 kilometer scale for 12 states and Washington D.C. as well as four large metropolitan statistical areas in the Northeast and Mid-Atlantic U.S. in 2016. CMAQ-DDM allows for the quantification of sensitivities from individual precursor emissions (NO

X

, SO2, NH3, volatile organic compounds, and PM2.5) in each state to pollution levels and health effects in downwind states. In the region we considered, LDT are responsible for the most PM2.5-attributable premature mortalities at 1234 with 46% and 26% of those mortalities from directly emitted primary particulate matter and NH3, respectively; and O3-attributable premature mortalities at 1129 with 80% of those mortalities from NO

X

emissions. Based on a detailed source-receptor matrix of sensitivities with subsequent monetization of damages that we computed, we find that the largest damages-per-ton estimate is approximately $4 million per ton of directly emitted primary particulate matter from BUS in the New York-Newark-Jersey City metropolitan statistical area. We find that on-road vehicular NH3 emissions are the second largest contributor to PM2.5 concentrations and health impacts in the study region, and that reducing 1 ton of NH3 emissions from LDT is ∼75 times and from HDT is ∼90 times greater in terms of damages reductions than a 1 ton reduction of NO

X

. By quantifying the impacts by each combination of source region, vehicle class, and emissions precursor this study allows for a comprehensive understanding of the largest vehicular sources of air quality-related premature mortalities in a heavily populated part of the U.S. and can inform future policies aimed at reducing those impacts.
Reversing ocean acidification along the Great Barrier Reef using alkalinity injection
Authors: Mongin Mathieu , Baird Mark E , Lenton Andrew , Neill Craig , Akl John
Published: June 2021

The Great Barrier Reef (GBR) is a globally significant coral reef system supporting productive and diverse ecosystems. The GBR is under increasing threat from climate change and local anthropogenic stressors, with its general condition degrading over recent decades. In response to this, a number of techniques have been proposed to offset or ameliorate environmental changes. In this study, we use a coupled hydrodynamic-biogeochemical model of the GBR and surrounding ocean to simulate artificial ocean alkalinisation (AOA) as a means to reverse the impact of global ocean acidification on GBR reefs. Our results demonstrate that a continuous release of 90 000 t of alkalinity every 3 d over one year along the entire length of the GBR, following the Gladstone-Weipa bulk carrier route, increases the mean aragonite saturation state (

Ω

a
r

) across the GBR’s 3860 reefs by 0.05. This change offsets just over 4 years (∼4.2) of ocean acidification under the present rate of anthropogenic carbon emissions. The injection raises

Ω

a
r

in the 250 reefs closest to the route by

⩾
0.15

, reversing further projected Ocean Acidification. Following cessation of alkalinity injection

Ω

a
r

returns to the value of the waters in the absence of AOA over a 6 month period, primarily due to transport of additional alkalinity into the Coral Sea. Significantly, our study provides for the first time a model of AOA applied along existing shipping infrastructure that has been used to investigate shelf scale impacts. Thus, amelioration of decades of OA on the GBR is feasible using existing infrastructure, but is likely to be extremely expensive, include as yet unquantified risks, and would need to be undertaken continuously until such time, probably centuries in the future, when atmospheric CO2 concentrations have returned to today’s values.
How well can a seasonal forecast system represent three hourly compound wind and precipitation extremes over Europe?
Authors: Owen Laura E , Catto Jennifer L , Dunstone Nick J , Stephenson David B
Published: June 2021

Extreme precipitation and winds can have a severe impact on society, particularly when they occur at the same place and time. In this study the Met Office’s Global Seasonal forecast system version 5 (GloSea5) model ensembles are evaluated against the reanalysis dataset ERA5, to find out how well they represent three hourly extreme precipitation, extreme wind and extreme co-occurring events over Europe. Although substantial differences in magnitude are found between precipitation and wind extremes between the datasets, the conditional probability of exceedance above the 99th percentile, which measures the co-occurrence between the two extremes, compares well spatially over Europe. However, significant differences in frequency are found around and over some areas of high topography. Generally GloSea5 underestimates this co-occurrence over sea. The model’s co-occurring events at individual locations investigated occur with very similar synoptic patterns to ERA5, indicating that the compound extremes are produced for the correct reasons.
Two-photon lithography of fluorescence-encoded quick-read micro-code for anti-counterfeiting applications
Authors: Jaiswal Arun , Rani Sweta , Singh Gaurav Pratap , Saxena Sumit , Shukla Shobha
Published: June 2021

Anti-counterfeiting tags are a simple and easy way to avoid duplication/forgery of valuable products; however, counterfeiting has evolved over time, with the help of newer technologies to clone and reproduce exact signatures, tags, barcodes, etc that are difficult to identify. To prevent such counterfeiting, it is imperative to obtain advanced and encoded anti-counterfeiting technologies with constant research and innovation. With this motivation, we have designed a sub-micron-scale patterned, fluorescent anti-counterfeiting tag based on an emissive layer embedded in a non-emissive polymer layer. The fabrication of the embedded structure is achieved using step-by-step writing of emissive and non-emissive layers using two-photon lithography. Interestingly, the encoded message is visible under ultraviolet illumination, and the structure is invisible under white light illumination. The proposed method can be extended for multilayer patterning with spatial positioning of different encoded messages along the height of the structure to incorporate layered security.
Eulerianity of Fourier coefficients of automorphic forms
Authors: Gourevitch Dmitry , Gustafsson Henrik , Kleinschmidt Axel , Persson Daniel , Sahi Siddhartha
Published: June 2021

We study the question of Eulerianity (factorizability) for Fourier coefficients of automorphic forms, and we prove a general transfer theorem that allows one to deduce the Eulerianity of certain coefficients from that of another coefficient. We also establish a ‘hidden’ invariance property of Fourier coefficients. We apply these results to minimal and next-to-minimal automorphic representations, and deduce Eulerianity for a large class of Fourier and Fourier–Jacobi coefficients. In particular, we prove Eulerianity for parabolic Fourier coefficients with characters of maximal rank for a class of Eisenstein series in minimal and next-to-minimal representations of groups of ADE-type that are of interest in string theory.
The Earldom Endowments of 1337: Political Thought and the Practice of Kingship in Late Medieval England
Authors: Raven Matt
Published: June 2021

This article examines Edward III’s earldom creations of March 1337 and the endowments given to these earls by Edward III in order to support their newly acquired rank. It re-evaluates the form of these grants and the governmental processes they stimulated within a context of ideological assumptions about the inalienability of the lands and rights thought to pertain to the Crown by contemporaries, as applicable to the English polity of the mid-fourteenth century. By viewing the grants of 1337 within this intellectual, political and economic context, this article argues that the endowments supporting the earldom creations were shaped by the pressures of inalienability and public finance; that these ideas were highly prominent; and that political practice in the mid-fourteenth century correlated to and reinforced the validity and importance of these concepts. Ultimately, this article uses the example of the earldom creations of 1337 and the endowments given in support of these elevations to demonstrate the mutual interdependence of comital and royal power in mid-fourteenth century England and to show how ideas concerning political structures paralleled and grew out of political practices.
Primary care provider perspectives on and utilization of a mandatory prescription drug monitoring program in New York City
Authors: Harocopos Alex , Allen Bennett , Chernick Rachel
Published: June 2021

Background

The ways in which prescription drug monitoring programs (PDMPs) have been integrated into primary care practice remain understudied, and research into physician utilization of PDMPs in states where PDMP use is mandated remains scant.

Objectives

To characterize primary care physician perspectives on and utilization of a mandatory PDMP in New York City.

Methods

We conducted face-to-face, in-depth interviews with primary care physicians who reported that they currently prescribed opioid analgesic medication. We used a thematic analytic approach to characterize physician perspectives on the PDMP mandate and physician integration of mandatory PDMP use into primary care practice.

Results

Primary care providers demonstrated a continuum of PDMP utilization, ranging from consistent use to the specifications of the mandate to inconsistent use to no use. Providers reported a range of perspectives on the purpose and function of the PDMP mandate, as well as a lack of clarity about the mandate and its enforcement.

Conclusion

Findings suggest a need for increased clinical and public health education about the use of PDMPs as clinical tools to identify and treat patients with potential substance use disorders in primary care.
Marcellus Shale Gas Boom and Forestry Employment: Evidence from West Virginia
Authors: Gazal Kathryn A , Arano Kathleen G
Published: June 2021

Advancement in drilling technology has increased natural gas extraction activities from the Marcellus shale deposit resulting in a shale gas boom in many regions, including West Virginia. This boom has created a significant labor demand shock to local economies experiencing the boom. A number of studies have shown that a shale gas boom directly increases employment and the income of those working in the industry. However, the boom can also have an adverse impact on other sectors through the resource movement effect and intersector labor mobility, pulling workers away from a related sector like forestry. Thus, an econometric model of employment in the forestry sector was developed to investigate the impact of the Marcellus shale gas boom in West Virginia. There is evidence of a labor movement effect with forestry employment negatively affected by the Marcellus shale boom. Specifically, the overall marginal effect of the shale boom on forestry employment is approximately 435 fewer jobs. However, the extent of the decline is slightly moderated by a higher relative wage between gas and forestry, perhaps suggesting diminishing returns and overall slack in the local labor market.