bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impacts of REDD+ on the social-ecological resilience of community forests
Authors: Hajjar Reem , Engbring Gretchen , Kornhauser Kailey 
Published: December 2020

Abstract
Reducing emissions from deforestation and forest degradation (REDD+) has emerged as an important and cost-effective climate change mitigation strategy internationally. In many localities around the world, REDD+ and related interventions have been superimposed on, and overlap with, existing decentralized institutional arrangements such as community forests. These interventions often modify local institutions through new rules and practices that comply with mostly carbon-related objectives, prompting questions about the compatibility of a top-down mechanism such as REDD+ with the decentralized approaches of community forestry. Thus, we asked: are REDD+ interventions in community forests enhancing or detracting from communities’ abilities to practice adaptive management and governance—key desired components of local social-ecological resilience and the ability of communities to respond to disturbance and global change? We conducted a systematic review of studies examining REDD+ interventions in community forests. We extracted data on 59 case studies reported on in 43 articles, stemming from 14 countries, with two thirds of the cases located in two countries alone. Our meta-analysis found that REDD+ has had mixed impacts on communities’ social-ecological resilience. Increases in network ties, connectivity across scales, and increased participation in decision making are indicators of enhanced potential for local adaptability. However, we also see that, through restrictions on local forest practices, rigidity in rules, and communities’ natural capital being locked into carbon contracts, REDD+ has limited communities’ ability to manage for uncertainty. While not representative of all existing REDD+ projects, our results suggest important implications for REDD+ policymakers and forest-reliant communities engaging in REDD+. Reconciling REDD+ goals with the need for forest communities to retain adaptive capacity will be a challenge moving forward, particularly if REDD+ compromises the ability of forest-reliant communities to respond to unexpected shocks or their ability to adapt to changing environmental or economic conditions.
Future changes in precipitation extremes over Southeast Asia: insights from CMIP6 multi-model ensemble
Authors: Ge Fei , Zhu Shoupeng , Luo Haolin , Zhi Xiefei , Wang Hao 
Published: December 2020

Abstract
Past assessments of coupled climate models have indicated that precipitation extremes are expected to intensify over Southeast Asia (SEA) under the global warming. Here, we use outputs from 15 climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to evaluate projected changes in precipitation extremes for SEA at the end of the 21st century. The results suggest that CMIP6 multi-model ensemble medians show better performances in characterizing precipitation extremes than individual models. Projected changes in precipitation extremes linked to rising greenhouse gas (GHG) emissions (represented by the latest proposed Shared Socioeconomic Pathways) increase significantly over the Indochina Peninsula and the Maritime Continent. Substantial changes in the number of very heavy precipitation days (R20mm) and the intensity of daily precipitation (SDII) indicate that such locally heavy rainfall is likely to occur over a short time and that more precipitation extremes over SEA are probable in a warmer future. This is consistent with projections from the Coordinated Regional Downscaling Experiment and CMIP5 models. The present study reveals the high sensitivity of the precipitation extremes over SEA, and highlights the importance of constrained anthropogenic GHG emissions in an ambitious mitigation scenario.
Fire reduces riverine DOC concentration draining a watershed and alters post-fire DOC recovery patterns
Authors: Wei Xinyuan , Hayes Daniel J , Fernandez Ivan 
Published: December 2020

Abstract
The loading of dissolved organic carbon (DOC) from soils to inland waters and ultimate transport to the ocean is a critical flux pathway in the terrestrial biosphere carbon cycle. Fires can significantly affect this flux through biogeochemical processes related to oxidation and mobilization of DOC in the soil. Therefore, in order to accurately estimate and model terrestrial carbon storage and export to the marine environment, we need to better understand the effects of fire on DOC flux. In this analysis, we compiled available observational data sets from seven watersheds across the conterminous United States generally spanning the years 1999–2019. We used these data sets to examine the effects of fire on riverine DOC concentration draining a watershed to study both the immediate impacts and the post-fire recovery patterns. Our results suggest that these fires result in an immediate decrease in riverine DOC concentration draining the watershed by 26 ± 15%, and the time required for DOC concentrations to recover to pre-fire levels was estimated to be, on average, approximately 9 months. During recovery, DOC concentration was 24 ± 11% lower than the long-term average for the watershed. In addition, the larger the proportion of the watershed that burned, the greater the concentration decrease and the longer the time period for post-fire recovery.
Stand for carrying out life tests of plunger hydraulic cylinders with energy recovery
Authors: Pelipenko A Yu , Rybak A T 
Published: December 2020

Abstract
This article proposes a solution to the problem of energy saving during life tests of plunger hydraulic cylinders. The author proposes a test stand using recovery. The purpose of the article is to disclose the device and the principle of operation of the hydromechanical system of the stand. Mathematical model of hydraulic drive of stand based on theory of volume stiffness is disclosed. Mathematical simulation results confirm and indicate the feasibility of recuperation in the test stand. In order to design a stand with the best energy indicators, it is proposed to carry out mathematical modeling of the hydromechanical drive of the stand, determine the numerical and structural parameters of the elements of the hydraulic system and mechanical transmission. The obtained theoretical results of mathematical modeling were applied and used in the design and manufacture of an experimental stand for resource tests of plunger hydraulic cylinders with energy recovery.
Investigation of the real gas conversion method for a low-temperature methane compressor
Authors: Sokolov M , Kozhukhov Y , Sadovsky N , Petrov A , Kartashov S , Ivanov V 
Published: December 2020

Abstract
In this work, a study was made of methods for converting a real gas from a full-scale compressor to a model one for low-temperature pure methane using the equations of state of a real gas Benedict-Webb-Rubin and Peng-Robinson. In the course of the work, the features of recalculation methods were studied, a model of an air compressor was selected, corresponding in parameters to a model of a low-temperature methane compressor using the theory of similarity, using similarity criteria. Also, in this work, the features of the application of various equations of state were studied when describing the model of a low-temperature methane compressor, as well as the features that arise when this model is converted to an air model analogue. Data were obtained on the possibility of applying the proposed methods on real units, and the invariance of the method with respect to the used equations of state of a real gas for pure methane at temperatures from 150 to 300 K and a division of 0.2 MPa was proved. At the final stage of the work, comparative characteristics of two models of natural methane compressors were obtained, based on different equations of real gas, describing the medium and two models of model compressors using air as a working medium and being model analogs of the above units.
Mechanisms of construction machines and selection of steels for the manufacture of welded metal structures
Authors: Scherbakov Alexander , Babanina Anna , Solovyeva Elena , Aleksandrovskiy Maxim 
Published: December 2020

AbstractThe paper is devoted to the study of the working mechanisms of construction machines from the point of view of the selection of structural steels for the manufacture of welded metal structures. Special attention is paid to the operational reliability and durability of modern construction machines. It was found that the most suitable for the manufacture of welded structures are complex-alloyed low-carbon steels. They have high strength (σ0.2≥600 MPa, σB≥800 MPa), are characterized by sufficient plasticity and increased resistance to brittle fracture at low temperatures. In the selection process, special attention was paid to the properties that structural steels should simultaneously have, specifically: low sensitivity to various stress concentrators; adaptability to perform service functions that are envisaged in the development of the project and directly in the process of manufacturing the welded metal structure, good weldability. The experiments were carried out using the example of low-carbon and low-alloy steels. Special attention was paid to the analysis of the optimal modes of thermal cycling with the aim of obtaining final structures with a given degree of dispersion, typical of real metal structures. Taking into account the requirements for the reliability of construction machines in operating conditions at high and low temperatures, as well as taking into account various operational characteristics, the expediency of using ferromagnetic structural steels was substantiated.
Constructive and technological modernization of the aircraft beam
Authors: Lyudmirsky Yu G , Shchepkin V V , Assaulenko S S 
Published: December 2020

Abstract
The directions of modernization of welded structures, previously created and serially produced in the aerospace, transport and other industries, are considered. For this, it is proposed to use thermally hardened aluminum alloys as the base metal, and to obtain permanent joints, instead of argon-arc welding, use friction stir welding (FSW), which is performed in the solid phase and has many advantages. Purpose of the work: to show the usefulness of constructive and technological modernization of previously designed and manufactured structures, taking into account the latest achievements in welding, in particular, when creating structures from aluminum alloys using FSW. An example of the modernization of an aircraft beam made of AMg6 aluminum alloy with the help of a FSW is given, which clearly demonstrates how the shape and geometry of the structure are interrelated with the technology of its manufacture.The presented structural and technological options for the modernization of the beam ensured: a decrease in welding stresses and deformations, an increase in the cyclic strength of a structure, savings in materials, labor, time and a decrease in the cost of manufactured products.
Empirical studies of structural material with given parameters at various fire factors
Authors: Eremina Tatiana , Korolchenko Dmitrii , Minailov Denis 
Published: December 2020

Abstract
The results are given of numerical experiments on heating of steel structures of buildings roofing by solving a heat engineering problem in conditions of non-stationary heat influence at standard temperature mode according to GOST 30247.0 and at fire temperature mode. The estimation of equivalent duration of fire for steel roofing structures is made. For modeling of heating of steel structures the computational system allowing to carry out thermal engineering calculation of a structure on the basis of its program model was used. For estimation of fire temperature modes the software package “Fire Dynamics Simulator” (FDS) was used, which implements the field mathematical model.
Dispersion analysis of factors affecting parameters of threaded connection “buttress” of oil-and-gas pipelines
Authors: Tsybryi I K , Vyalikov I L , Koval N S , Ignatenko V I 
Published: December 2020

Abstract
In the context of increasing volumes of oil-and-gas production, quality and tightness assurance of oil-and-gas pipes has become a very urgent problem. The most common methods of pipe connecting are coupling and streamline joints with application of conic, trapezoidal and triangular threads, including buttress ones. The accuracy of thread profile production has a significant impact on interchangeability of items during assembly and their connection reliability, including tightness. In the process of production of items under consideration, various factors, such as technological heredity, rigidity of the processing equipment, its adjustment and installation and others, influence the thread production process. The given article introduces the results of carried-out studies on the impact of the duration of threaded machine operation and the lot of pipe blanks on the main parameters of the thread, such as thread tension by threaded gauge, thread length from the end without black crested threads, etc. The degree of each factor influencing the corresponding parameter was established on the basis of dispersion analysis.
Comparative analysis of structural parameters of bolt-rivet rods
Authors: Chernykh E V , Zaides S A 
Published: December 2020

Abstract
The article presents the general characteristics of bolt-rivet joints. The main structural parameters of bolt-rivet rods affecting premature shank tearing are given. Stages of rod installation process into hole are described and critical moments of shank tearing are determined. A graph showing the variation of the rod retraction force depending on the thickness of the package is obtained, and basic parameters are determined for comparing two types of rods with different design, but the same purpose. Methods of determining shank tear- off forces, as well as stresses arising in the neck during retraction, using Femap software product are considered. Maximum stress values are calculated on the example of two types of rods and analysis of possible shank tear is carried out at available parameters of neck. In conclusion, it is noted that with the help of IT-technology it is possible to improve not only the design of joints, but also the technology of their implementation, by changing the design of fasteners.
Problems and mechanisms to improve the Russian aviation industry’s productivity in the sharing economy
Authors: Schmeleva A N , Bezdelov S A 
Published: December 2020

Abstract
Currently, the pandemic has had an extremely negative impact on the economy, especially in the aviation industry. The airfreight’s frequency has not fully recovered. The situation requires appropriate systemic measures to address it. The article describes the organizational and economic mechanisms to improve the Russian aviation’s productivity and identifies the need to review approaches to assess the Russian aviation industry, considering that it has not achieved the target indicators set by the state program. There are two main directions: inclusion of the section “Evaluation of Integrated Aircraft Industry Structures (IS) Efficiency” into the state program, as well as a detailed evaluation of competitiveness and product portfolio of the aircraft industry’s IS, development of IS competitiveness strategy both in the domestic and foreign markets. There have also been considered the prospects of using crowdlending platforms in Russia as an alternative financial instrument to banks in the helicopter technology’s P2B and B2B segments. There several factors facilitating this practice’s development: the world sharing economy’s active position; tightened requirements for customers and a decline in bank loans; the lack of profitable lending programs for small and medium-sized entrepreneurship; the regulations of crowdfunding platforms introduced in 2020; citizens’ growing involvement in various IT platforms, including investment ones.
Analysis of the use of a combine harvester equipped with a precision farming system in rice growing conditions
Authors: Garkuha S , Skazhennik M , Chizhikov V , Kiselev E , Petrushin A 
Published: December 2020

Abstract
On the basis of the Federal State Budget Scientific Institution “Federal Scientific Rice Centre”, studies were conducted to evaluate the effectiveness of the use of the TUCANO 580 combine equipped for harvesting rice with the P420 pick-up. It was established that the combine successfully worked on threshing rice with a shift capacity of about 20 tons per hour. The performance indicators of the combine met the agro-technical requirements (ATT) and amounted to: the total grain loss for the combine 1.99%, including for the thresher 1.55% and for the pick-up 0.44%. Crushing and breaking of bunker grain amounted to 1.2%, which corresponds to the ATT standard - not more than 4.0%. The content of weed impurities was 0,8% (for ATT no more than 5.0%). Along with this, a technique was developed for processing data from a multispectral camera based on the results of surveying by an unmanned aerial vehicle (BVS) and the Sentinel-2A satellite. Based on spectral images, experimental fields, digital maps of the spatial distribution of the normalized relative vegetation index (NDVI) have been created. According to the CLAAS TELEMATICS system, yield maps were constructed. The digital topographic basis of the test ranges was adjusted with the addition of the necessary vector layers based on the results of processing the spectral survey. As a result of the work, a positive assessment of the efficiency of the combine is given, the basis for the creation of a geoinformation base in the information system for the application of precision technologies in agriculture is prepared.
Equalization of the moisture content of the mixture for obtaining fertilizers from high-moisture waste of poultry farming by extrusion
Authors: Potapov M A , Kurochkin A A , Frolov D I 
Published: December 2020

Abstract
The article examines the problem of processing poultry waste using extrusion technology. Bird droppings contain elements necessary for plant nutrition. This chemical composition makes it a valuable organic raw material for use as organic fertilizer. However, manure requires processing before being introduced into the soil. The main goal of the study is to reduce the moisture content of the mixture of high-moisture poultry waste to a level sufficient for high-quality extrusion into fertilizer. Reducing the moisture content of the mixture is possible by mixing them with vegetable fillers. Litter components or plant waste were selected as fillers. As a result of measuring the moisture content of the components of the mixture, it was determined: poultry manure with litter (PP) turned out to be the least wet and can be used for processing by extrusion; bird droppings from young stock (PM) and bird droppings from adult birds (PV) can be used for extrusion processing when mixed with vegetable fillers in a ratio of 1: 1 and 1: 2, respectively.
Research of the location of fixing blocks in the design of engineering structures
Authors: Borisova V , Borisova V , Volkova Y 
Published: December 2020

Abstract
A static model of loads in the mast, cables and blocks fixing its position is investigated. In contrast to the existing installation methods, in which instead of blocks, piles are used, located on the shore and uniquely fixing the mast, in the problem under consideration it is not possible to install piles. Therefore, the blocks are installed directly into the water and are not attached to the bottom by anything. Fixation occurs due to the force of friction between the block and the bottom of the reservoir and the force of gravity. Static equilibrium is considered at ultimate dynamic loads, which were specified in the problem statement.
Machine Wear Calculation Module in Computer-Aided Design Systems
Authors: Dykha A , Sorokatyi R , Pasichnyk O , Yaroshenko P , Skrypnyk T 
Published: December 2020

Abstract
It has been established that computer-aided design systems are currently an effective tool in engineering practice. Based on the methods of computer modeling, it is possible to assess the performance of any technical system in a given period of time. The operability of almost all technical systems is associated with the analysis of the process of wear of its elements. For the numerical modeling of wear processes, an iterative approach is proposed, which involves consideration of a number of discrete states through which the tribosystem passes during its operation. To characterize tribosystems, the method uses a unified mathematical apparatus to simulate the wear of various friction units. This takes into account a wide range of operating factors that limit the physical characteristics of wear processes and their changes in the process of functioning. An algorithm of interaction of the module for calculating the wear of an element with a computer-aided design system and an example of its implementation are presented.
Analysis of the influence of theoretical head coefficient on the low-flow centrifugal compressor stage characteristics
Authors: Yablokov A , Kozhukhov Y , Sadovskiy N , Yanin I , Nguyen M H 
Published: December 2020

Abstract
The article presents the results of a numerical study of the influence of the theoretical head coefficients on the characteristics of a low-flow stage of a centrifugal compressor. The study was conducted in the Ansys CFX 19.2 software package. As a result of a numerical study, it was found that the drop in the efficiency of the compressor stage with an increase in the theoretical head coefficient is associated with a decrease in the efficiency of the stationary elements due to the increased absolute speed behind the impeller. At the same time, an increase in the theoretical head coefficient leads to a decrease in losses associated with the coefficient 1 + β1k + βfr and therefore, an increase in the polytropic efficiency of the impeller is observed at values of the theoretical head coefficient ψt ≤0.64.
Exploring the possibilities of using machine vision in the construction industry
Authors: Konikov Alexander , Sudakova Anna 
Published: December 2020

Abstract
In many areas of the economy, including the construction industry, new IT technologies are being successfully introduced - Cloud computing, Big Data, Internet of Things etc. A significant place among these technologies is taken by the direction of “Machine Vision”. This technology allows to bring to a qualitatively different level a number of important applications in the construction industry and therefore deserves the close attention of specialists. For example, with the help of machine vision it is possible to consider and analyze the smallest defects invisible to the human eye (for example, when controlling the quality of an important element of construction structures - welds). The result is not affected by fatigue or inattention of the staff, you can work 24 hours, there are other advantages discussed in the article. The best effect is achieved with the complex application of new IT technologies. The most promising is the use of machine vision in combination with IoT and Big Data technologies. The paper explores the possibility of using machine vision in the construction industry as a stand-alone solution and in combination with other new IT technologies. The possibility of using unmanned aerial vehicles (drones) equipped with a machine vision system is being considered - for monitoring construction sites and surrounding areas.