bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climate change shifts agropastoral-pastoral margins in Africa putting food security and livelihoods at risk
Authors: Nidumolu Uday , Gobbett David , Hayman Peter , Howden Mark , Dixon John , Vrieling Anton 
Published: August 2022

Abstract
Climate is one of the key factors determining the suitability of land for agricultural production and influencing the spatial transition between grazing and cropping-dominated farming systems in Africa. We identified the climate indices that best align with the margin between the Agropastoral and Pastoral Farming Systems in the historical climate (1981–2006). We then used global climate model results to assess how these agropastoral-pastoral margins are likely to shift by 2050 as a consequence of forecasted climate change. We found that the agropastoral-pastoral margin will retreat across Africa resulting in less area climatically suited for productive agropastoral practices. Depending on the climate model, climate index and projections used, the conversion of land currently suitable for agropastoral production to land suitable for pastoral production across the continent leads to a reduction of the current 4.43 M km2 of Agropastoral Farming Systems to between 1.2 M km2 and 3.6 M km2. This reduction of 27%–81% of the Agropastoral zone would threaten food security and livelihoods in those areas. While we did not assess this aspect, the retreat of the agropastoral-pastoral margin may be offset by the conversion of higher rainfall zones to suitability for agropastoral production which would expand the area suitable for the Agropastoral Farming System. Identifying the locations and vulnerability to the climatic shifts along agropastoral-pastoral margins can help policy makers and planners to define strategies for improving the long-term resilience of livelihoods to climate change.
Unprecedented Arctic sea ice thickness loss and multiyear-ice volume export through Fram Strait during 2010–2011
Authors: Li Xuewei , Yang Qinghua , Yu Lejiang , Holland Paul R , Min Chao , Mu Longjiang , Chen Dake 
Published: August 2022

Abstract
The satellite-observed sea ice thickness (SIT) records from 2003 to 2020 identify an extreme SIT loss during 2010–2011. Ice thickness budget analysis demonstrates that the thickness loss was associated with an extraordinarily large multiyear ice (MYI) volume export through the Fram Strait during the season of sea ice advance. High cloudiness led to positive anomalies of net longwave radiation, and positive net surface energy flux anomalies supported enhanced sea ice melt from June to August. Due to the MYI loss, the Arctic sea ice became more sensitive to subsequent atmospheric anomalies. The reduced surface albedo triggering a positive ice-albedo amplifying feedback and contributed to the accelerating loss of ice thickness. These tightly coupled events highlight that the increasingly younger and thinner Arctic sea ice is becoming more vulnerable to external forcing and created the precondition for the rapid reduction in sea ice extent in 2012.
Heat transfer in transversely coupled qubits: optically controlled thermal modulator with common reservoirs
Authors: Yang Yi-jia , Liu Yu-qiang , Yu Chang-shui 
Published: August 2022

Abstract
This paper systematically studied heat transfer through two transversely coupled qubits in contact with two types of heat reservoirs. One is the independent heat reservoir which essentially interacts with only a single qubit, the other is the common heat reservoir which is allowed to simultaneously interact with two qubits. Compared to independent heat reservoirs, common reservoirs always suppress heat current in most cases. However, the common environment could enhance heat current, if the dissipation rate corresponding to the higher eigenfrequency is significantly higher than that corresponding to the lower eigenfrequency. In particular, in the case of resonant coupling of two qubits and the proper dissipations, the steady state can be decomposed into a stationary dark state which does not evolve and contributes zero heat current, and a residual steady state which corresponds to the maximal heat current. This dark state enables us to control steady-state heat current with an external control field and design a thermal modulator. In addition, we find that inverse heat currents could be present in the dissipative subchannels between the system and reservoirs, which interprets the suppression roles of common heat reservoirs. We also calculate the concurrence of assistance (COA) of the system and find that heat current and COA have the same trend with temperature, which further indicates that entanglement can be regarded as a resource to regulate heat transport.
Determination of the parameters of the canonical working body of the straw chopper
Authors: Mamatov F M , Karimov R R , Gapparov Sh X , Karshiev F U , Choriyev R M 
Published: August 2022

Abstract
In the world, much attention is paid to the development and application of machine straw choppers. The aim of the study is to justify the parameters of a straw chopper in the form of a hyperboloid of polycaninic form. The basic principles and methods of classical mechanics, mathematical analysis and statistics were used in this study. The authors proposed and developed a straw chopper of polycanonical form. On the basis of theoretical studies analytical dependences for definition of the frontal area of a polycanonical straw shredder depending on its parameters are determined. Multifactorial experiments were carried out, on the basis of which the optimal parameters and mode of operation of the shredder were established: length of the working part 861 mm, angle of the tray installation 38° and rotor rotation frequency 727 rpm.
Research the parameters of cutter bar of the rotor of a green stalk forage chopper
Authors: Borotov A N 
Published: August 2022

Abstract
Currently, special attention is being paid to the development of cattle-raising, fisheries and poultry in Uzbekistan. Cattle-raising, fisheries and poultry feeding green forage providing their intensive increasing as well decreases the gathering of additional oil in them. Therefore, a chopping device was produced to cut green crops, such as clover, maize as well legumes. Since the quantity and arrangement of cutter-bars in the rotor depends on the quantity and placement of the cut feeds to be of same length, the quantity of cutter-bars has been explored theoretical and experimental researches. According to theoretical researches, the greater the quantity of cutter-bars in the feed chopping rotor, the greater the work efficiency and the shorter the length of cutting. During the experiments, when the quantity of rotations of the rotor was 1500 rpm and the quantity of rotating of the chopper was 175 rpm, 6 cutter-bars were installed on a rotor with a diameter of 200 mm. It was found that metal consumption and cost were reduced compared to 8 cutter-bars. It is recommended to install 6 cutter-bars on a rotor with a diameter of 200 mm.
Method of prediction of vibration emissions and transition of the technical state of a centrifugal pumping unit
Authors: Bekchanov F A , Atajanov A U , Babajanov L K , Yusupov F F 
Published: August 2022

Abstract
From many factors, the reliable operation of a centrifugal pump unit largely depends on the reliability of the electric motor, which is the main link of the centrifugal pump unit and an important factor in the failure-free operation of the centrifugal pump unit, which depends on the reliability of rolling bearings. This article is devoted to the study of the methodology for predicting vibration emissions and the transition of the technical state of a centrifugal pump unit to the states “Requires action” and “Unacceptable". Experimentally tested and confirmed the operability of the method for isolating vibration emissions in the flow of measuring the vibration of a centrifugal pump unit, separating a smooth increase in vibration from its emission. The technique for detecting and controlling the process of staged accumulation of damage and failure of parts by increasing the amplitudes of vibration emissions has been tested, which provides long-term and prompt proactive diagnostics throughout the entire period of operation, and the performance of the proposed diagnostic method has been confirmed.
Some ecological problems of providing the population with high-quality drinking water
Authors: Sambursky G A , Leont’eva S V , Molchanova Ya P , Nikitina S V 
Published: August 2022

Abstract
Issues of state policy in the field of improving the availability and safety of drinking water supply are focused most often on water treatment technologies. Tariff policy, being hostage to the political conjuncture, limits the possibilities of sustainable development of water supply, which requires a very balanced approach to the choice of technologies. To justify the choice of water treatment technologies in certain local conditions, an assessment of technological approaches based on the methodology of assessing the risk to public health together with a proper feasibility study should be carried out. Assessment of the population’s satisfaction with water supply services makes it possible to form various trajectories of drinking water supply to the population. Based on the analysis, taking into account modern international experience, it is necessary to consider the factor of formation of behavioural practice of safe water supply. Thus, the justification of solutions for the organization of drinking water supply for the end user requires taking into account the formed behavioural motives.
Construction of low-pressure hydraulic structures
Authors: Paluanov D T 
Published: August 2022

Abstract
The issues of construction of low-pressure hydraulic structures to provide sustainable water resources to the economy in areas where there is a shortage of water resources were considered. Based on the structure of areas with difficult geological conditions, a “dam-heterogeneous soil” model has been developed, which is affected by the weight of the structure and the hydrostatic pressure of the water. The developed model is implemented in the adoption of the optimal technical solution to the problem of the presence of deformable and ductile soils on the construction site under the requirements of regulatory documents. The results of the theoretical research were compared with the results of natural research and the results were proved to be close to each other.
Analysis of fractional and chemical composition of chartak reservoir sludge sediments
Authors: Xoshimov S , Qosimov T , Ortikov I , Hoshimov A 
Published: August 2022

Abstract
In the present era, when climate change has become a global problem, efficient use of water resources is becoming an important task. Natural field research was conducted in Chartak reservoir. In order to determine the amount of turbidity entering with the flow, the characteristic tributaries were determined along the length of the reservoir, and in each tributary, samples were taken using a bathometer at different times of the season and filtered in laboratory conditions. According to the analysis of the results, the average amount of incoming turbidity was 0.3-0.5 g/l, and the amount of outgoing turbidity was 0.05-0.08 g/l. Samples of the sediments that sank into the reservoir bowl were taken and their fractional and chemical composition was analyzed in the laboratory of “Gidroproekt” JSC. According to the fractional composition of muddy sediments, particles with a diameter of 1.0-0.5 mm are 13.98%, particles with a diameter of 0.5-0.25 mm are 11, 49%, particles with a diameter of 0.25-0.10 mm - 7.56%, particles with a diameter of 0.10-0.05mm - 10.48%, particles with a diameter of 0.05-0.01 mm - 26.8%, it was found that particles with a diameter of 0.01-0.005 mm make up 13.34%, and particles with a diameter of 0.005-0.002 mm make up 16.42%. If we pay attention to the distribution and share of sediments on the walls, 35-40% of particles with a large fraction (d=1.0-0.1 mm) and 50-60% are particles with a small fraction (d=0.05-0.001mm). It is based on the presence of particles rich in microelements useful for agricultural fields in sediments. If we pay attention to the distribution and share of sediments on the walls, 35-40% of particles with a large fraction (d=1.0-0.1 mm) and 50-60% are particles with a small fraction (d=0.05-0.001mm). It is based on the presence of particles rich in microelements useful for agricultural fields in sediments. If we pay attention to the distribution and share of sediments on the walls, 35-40% of particles with a large fraction (d=1.0-0.1 mm) and 50-60% are particles with a small fraction (d=0.05-0.001mm). It is based on the presence of particles rich in microelements useful for agricultural fields in sediments.
Theoretical study of the accumulation of mechanical mixtures in the engine lubrication system
Authors: Ganiboyeva E , Khakimov B , Shermuxamedov X P , Rakhimov Yu 
Published: August 2022

Abstract
The work in the field of oil obsolescence, theoretical identification of active additives contained in the oil as a benchmark for evaluating the main operational properties of oil, as well as a theoretical assessment of the properties of oil oxidation resistance and the resource of its active elements, depending on the intensity of the eating of engine details and the amount of elements. The sharply changing climate and high pollination conditions of the republic, a sharp increase in the amount of water and mechanical mixtures, which in turn can lead to a premature departure of motor oils used in it, such as viscosity, corrosion resistance, oxidation resistance, washing and other properties, and acceleration of engine eating. Due to the overload of the tractor, theoretically determined that mechanical mixtures and asphalt products containing oxidation products containing motor oil in the engine maintenance system increased by 1.2%.
Inherent strain based estimate of the residual deformations for printed MS1 and 316L parts
Authors: Gonda V , Felde I , Horváth R , Réger M 
Published: August 2022

Abstract
In this study, the effect of the magnitude of inherent strain is examined for the simulated deformations of printed specimens, where the material grade is either of MS1 or 316L steel powders. While both material qualities are steel grades, and the same sets of inherent strain values with different magnitude and directional variations are defined in the simulations, allowing isotropic and orthotropic behaviour too, the resulting deformation in the printed part may also be strongly influenced by the mechanical properties of the different steel grades.
Characterisation of defects in die cast aluminium parts
Authors: Horváth R. , Réger M. , Oláh F. 
Published: August 2022

Abstract
In this paper, the results of computed tomography and destructive testing of a die cast, gas tight aluminium part are compared and analysed with the aim of refining the porosity map. The mapping of the continuity defects detected by the two methods makes it possible to estimate the number, shape and distribution of continuity defects on and in the immediate vicinity of the machined surface, and to compare the characteristics of continuity defects detected by non-destructive and sequential fine machining. Based on the results of the CT scan of a given casting, we also performed destructive testing to find defects in a selected part of the casting by sequential fine machining. The basic criterion for the choice of the cutting parameters was to minimize the plastic deformation (smearing) on the machined surface, i.e. to clearly identify porosity. We then investigated the position, shape and other characteristics of porosity on the surfaces. The results and differences resulting from the two different methods are also analysed.
Finite element simulation of micro-milling of hardened tool steel
Authors: Balázs B Z , Takács M 
Published: August 2022

Abstract
The demand for miniature components has been growing steadily in recent years. One of the most important technologies to produce such small components is micro-milling. Although the technology is highly researched, there are still many difficulties due to the size reduction, which makes the finite element simulation, as well as the exploration of cutting process challenging. The aim of the research was to investigate the micro-milling process, especially those features, that can be measured very complicated due to the small sizes at the experiments, such as the cutting temperature, and stresses, by means of finite element simulation. The results show that the cutting temperatures are smaller than in the case of conventional size machining, moreover, the stresses do not show significant changes during the cutting edge impact. Finally, the results were validated by the experimental results through comparing cutting force components, which shows a good agreement.
Recording acoustic spectrum for residual stress determination and assigning natural frequency ranges for vibration stress relief
Authors: Rutscher A , Kiri A 
Published: August 2022

Abstract
We have developed a new technique for diagnostics in connection with vibration stress relief. The measurement images developed by us with a unique acoustic spectrum recording are not only suitable for determining the natural frequencies of metal castings, but can also be deduced from them the dislocation in the crystal structure and residual stress, which can cause deformation later. From the changes between the measurement images, the effect of different machining even resting and aging on the casting can be seen. Furthermore, the required input frequency for vibration stress relief can be easily determined from the measured images. Some of the main advantages are the process obtained quickly, easily and immediately. The research will be continued, we are working further development, including the acoustic diagnostic system, the VSR equipment, the recording software with an online platform.
Analysis of the strength difference effect on tailor welded blanks’ springback
Authors: Béres G J , Tisza M 
Published: August 2022

Abstract
Tailor welded blanks (TWBs) are becoming widespread in the automotive industry due to their advantages, such as the possibility of weight reduction or the material usage optimising, resulting from the application. However, their main disadvantage is that the construction design and the simulation of the mechanical processes (like weld line movement, sheet springback, etc) are more complex. Predicting the mechanical response can only be done by accurately estimating the weld properties, which greatly increases the material testing requirements. Moreover, it often does not coincide with the matter of the field of material forming. In this study we focus on the simplified description of the springback of TWBs, to reveal which parameters have the primary influence on this process. Three kinds of DP steels with different strengths were welded to a mild steel grade one by one. Using these pairs we have varied both the strength difference between each sides and the average strength of the blanks, too. Uniaxial tensile tests were performed for the mechanical characterisation of each material, as well as right-angled bends perpendicular to the weld line were carried out to monitor the springback tendency of the samples. Our results show that a transition zone develops near to the weld line, independently from the strength difference between the TWB’s components. This zone is well-defined by linear functions, in which, the parameters are consistent with the physical content of the springback phenomenon.
Surface roughness prediction applying artificial neural network at micro machining
Authors: Adizue U L , Balazs B Z , Takacs M 
Published: August 2022

Abstract
Micro machining forms an integral part of modern manufacturing technology. In order to satisfy the most important demands, like cost reduction, quality improvement, and production efficiency, this process has to be implemented into the framework of Industry 4.0, too. Defect reduction of products can be realized by beneficial trends of Industry 4.0, such as application of sensors driven AI based predictive models. Surface roughness is one of the main indicators, which can be used for evaluation of the machined surface. The aim of this research is to develop a predictive surface roughness model in the case of micro milling of hard materials. Most important scientific knowledge related to micro milling, and application possibilities of AI based predictive models in the case of chip removal processes were summarised. Micro milling experiments on hot work tool steel (AISI H13) were carried out in order to determine the effect of different cutting parameters on surface roughness. The effects of the cutting parameters were investigated by the analysis of variance (ANOVA). Two-layer feedforward artificial neural network (ANN) based model was trained, validated and tested by means of experimental results. It was found that the trained model has an average MSE, RMSE and R values of 0.00063850, 0.019116835 and 0.9948, while the additional validation test provided 0.00038148, 0.019531513 and 0.8545, respectively, which are statistically significant. The developed model can effectively predict the surface roughness under the investigated circumstances.
The synthesis of a liver tissue mimicking solution for microwave medical applications
Authors: Farhat Iman , Farrugia Jonathan , Farrugia Lourdes , Bonello Julian , Pollacco Daphne , Sammut Charles 
Published: August 2022

Abstract
This paper presents the synthesis of a mixture solution that is equivalent to ex-vivo liver tissue dielectric characteristics between 500 MHz and 5 GHz. The mimicking solution was synthesized using concentrations of two chemicals, the solute which is referred to as the inclusion phase and the solvent, referred to as the host phase. The inclusion phase consisted of bovine serum albumin (BSA) powder and the host phase consisted of a phosphate-buffered saline (PBS) solution with a concentration of Triton X-100 (TX-100). The dielectric properties of these two phases were substituted into Bruggeman's two-phase mixture equation to estimate the dielectric properties of excised liver. Furthermore, the study exploits Bruggeman’s equation to investigate the impact of tissue dehydration levels on the dielectric properties of an excised tissue. The effect of dehydration has been characterised as a function of time based on the loss-on-drying technique (a substance is heated until it is completely dry). Dielectric parameters were measured as a function of frequency using the Slim Form open-ended coaxial probe at a constant room temperature of circa 25 °C. Measured dielectic data were fitted to the Cole-Cole model and good agreement with the mimicking solutions was obtained. These results indicate that these solutions can be used to model the human body phantoms for microwave medical applications.