bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical and experimental investigations on shape optimization of submerged floating tunnels with a discrete adjoint method
Authors: Zhou Jianjun , Liu Jiabin , Guo Anxin
Published: December 2023

The shape of the tube in submerged floating tunnels (SFTs) plays a critical role in determining their performance and safety in marine environments. In this study, a gradient optimization procedure based on the discrete adjoint method is performed to minimize the drag force under uniform currents action. The free form deformation approach is employed to parameterize the design variables. The physical mechanisms of the optimization process are revealed via unsteady numerical simulations and experimental tests. Moreover, the hydrodynamic performance of the tube with the optimal shapes subjected to a wave–current combination is also evaluated. The results show that the drag coefficient is significantly reduced through optimization by reducing the pressure amplitude in the negative-pressure area. Additionally, the lift oscillation is also suppressed to delay structural fatigue, owing to the strength reduction and increased distance of the wake vortex. The experimental analysis indicates the advantage of the optimal shape in reducing the loads under wave–current actions, accompanied by changes in the frequency distribution of the force and vortex structure. The elliptical shape of the SFT's tube provides significant advantages in drag reduction at high Reynold number. Suggestions on the shape design of the section of SFT are given according to different types of constraints.
Large-Z atoms in the strong-interaction limit of DFT: Implications for gradient expansions and for the Lieb–Oxford bound
Authors: Daas Kimberly J. , Kooi Derk P. , Benyahia Tarik , Seidl Michael , Gori-Giorgi Paola
Published: December 2023

We numerically study the strong-interaction limit of the exchange–correlation functional for neutral atoms and Bohr atoms as the number of electrons increases. Using a compact representation, we analyze the second-order gradient expansion, comparing it with the one for exchange (weak interaction limit). The two gradient expansions, at strong and weak interaction, turn out to be very similar in magnitude but with opposite signs. We find that the point-charge plus continuum model is surprisingly accurate for the gradient expansion coefficient at strong coupling, while generalized gradient approximations, such as Perdew–Burke–Ernzerhof (PBE) and PBEsol, severely underestimate it. We then use our results to analyze the Lieb–Oxford bound from the point of view of slowly varying densities, clarifying some aspects on the bound at a fixed number of electrons.
Continuum model for extraction and retention in porous media
Authors: Matias André F. V. , Valente-Matias Daniel F. , Neng Nuno R. , Nogueira José M. F. , Andrade José S. , Coelho Rodrigo C. V. , Araújo Nuno A. M.
Published: December 2023

Several natural and industrial processes involve the extraction or retention of a solute by a fluid invading a network of channels. Examples include aquifer contamination, chemical filtration, and coffee extraction. We propose a continuum equation to model these processes, parametrized by the Péclet number and the rate of mass transfer between the solid and the fluid. We study the time dependence of the extracted mass for different values of the parameter space. The continuum description is validated by combining extraction experiments with coffee and computational fluid dynamics. An analytical solution is derived for the limit of slow mass transfer, which is corroborated by numerical simulations.
Programmable oscillation of C60 inside carbon nanotubes subjected to strain gradient
Authors: Vaezi Mehran
Published: December 2023

Programmable locomotion of molecules inside the carbon nanotube (CNT) has a significant role in controlling the reactions and delivery systems based on nanotubes. Using molecular dynamics (MD) simulations as well as the theoretical approach, we evaluate the oscillation of C60 inside the CNTs that are subjected to strain gradients from both sides. The molecular dynamics simulations are implemented by LAMMPS open-source software. Using this program, the van der Waals (vdW) interactions are established between C60 and nanotube, and the simulations are performed in canonical ensemble. The strain gradient applied on CNT provides the restoring force of the oscillation of C60. The potential energy of fullerene finds the minimum value at the unstrained region of CNT, which makes it the equilibrium point of oscillation. The amplitude of the oscillations is shown to be related to the thermal energy of C60. The frequency of the oscillations depends on the magnitude of the strain gradient applied on the nanotubes. At higher strain gradients of CNTs, we observe the increase in the frequency due to the increase in the restoring force acting on the fullerene molecule. We exploit the strained carbon nanotubes to control the position of C60 inside the nanotube. It has been shown that by changing the strain gradient of CNT, it is possible to steer the locomotion of C60 to different points inside the nanotube.
Neuromorphic memristor based on amorphous InAlZnO film for synaptic behavior simulation
Authors: Xu Yimeng , Han Xu , Xu Weidong , Ye Caiyang , Dai Ziyi , Feng Xianjin , Qian Kai
Published: December 2023

Neuromorphic computing that emulates brain behaviors can address the challenge of von Neumann bottleneck and is one of the crucial compositions of next-generation computing. Here, the polynary oxide of amorphous InAlZnO (a-IAZO)-based memristor is employed as electronic synapse with essential properties of biological synapse, including spiking timing-dependent plasticity, paired-pulse facilitation, long-term depression/potentiation, and Pavlov associative memory. Especially, the a-IAZO memristor properties are quite sensitive to the oxygen vacancy content, which exhibit stable switching and narrow distribution of Set/Reset voltage due to the oxygen vacancy content decrease after high-temperature annealing in air, showing promise for memristor performance enhancement. This work promotes the development of high-performance memristors with polynary oxide for neuromorphic computing and opens a path for a-IAZO film application in optoelectronics.
Superlattice-like films with high thermal stability and ultralow power consumption via adding graphite carbon nanolayers
Authors: Zeng Xiaotian , Zhu Xiaoqin , Hu Yifeng
Published: December 2023

The effect of graphite carbon nanolayers on the phase change performance and microstructure of Zn15Sb85 film was systematically studied. After the addition of graphite carbon nanolayers, superlattice-like films exhibit better thermal stability and data retention, especially [C(4 nm)/Zn15Sb85(10 nm)]5 superlattice-like film. The phase change memory based on [C(4 nm)/Zn15Sb85(10 nm)]5 has fast operating speed and ultralow power consumption. During the aging process, the electronic structure of [C(4 nm)/Zn15Sb85(10 nm)]5 superlattice-like film remains almost unchanged. The results of x-ray diffraction and transmission electron microscopy indicate that the addition of graphite carbon nanolayers reduces the grain size. The formation of new C–Sb and C–Zn bonds was speculated through energy dispersion spectroscopy and x-ray photoelectron spectroscopy. The results indicate that graphite carbon nanolayers play an important role in improving the thermal stability, operating speed, reducing power consumption, and resistance drift of Zn15Sb85 films.
Higher-order topological states in dual-band valley sonic crystals
Authors: Li Jin , Deng ChengXin , Zhang Kun , Lu Qiao , Yang Hai
Published: December 2023

As a quantum state of frequency extrema in the momentum space of acoustic systems, sonic valley pseudospin provides a new degree of freedom for controlling acoustic waves. Higher-order topological insulators (HOTIs) have extended the traditional bulk-edge correspondence principle and are a crucial concept for classic wave regulation. However, HOTIs in valley sonic crystals (VSCs) only appear in a single bandgap, which limits the multi-frequency selectivity of the corner state and is not conducive to the design of multi-frequency acoustic communication devices. Here, we demonstrate “Y-shaped” acoustic crystals with C3 symmetry that form a double-band VSC, and the topological phase transitions in both low- and high-frequency band gaps coincide. We realize theoretically and experimentally higher-order states in dual-band valley sonic crystals. Our work enriches the application of HOTIs in acoustic multi-frequency regulatory systems and provides different avenues for designing of multi-band acoustic devices.
The early Baba Malay continuum
Authors: Lee Nala H.
Published: December 2023

Baba Malay today is an endangered creole perceived to be a less flexible, easily identifiable language entity with static ascribed qualities. An investigation of resources from the late 1800s and early 1900s shows that such a characterization of early Baba Malay is not possible. Three novels and twenty letters demonstrate a wide range of variation, lexically and grammatically, emphasizing a wide creole continuum that plausibly existed in the heydays of the language. The wide range of variation can be understood to be detracting from, and aligning with the creole’s substrate and lexifier languages, or with the language that was gaining dominance during that time, English. The linguistic ideologies of early Baba Malay speakers and competing pressures in their group identities explain the considerable variation found.
Prioritizing Animal Welfare in AAI Hospital Programs
Authors: Foss Cynnie H.E.
Published: December 2023

A successful animal-assisted intervention (AAI) program in a hospital setting must include careful planning and monitoring. It requires in-depth knowledge of the hospital environment, training for teams beyond what is provided through registering agencies, understanding animal welfare needs and indicators, training all involved staff and volunteers, and prioritizing the safety of all involved. There is a need for AAI organizations to create standards of practice and offer professional certifications to cultivate legitimacy for AAI programs and ensure that all participants realize that animal welfare is paramount for successful and sustainable programs in a healthcare environment and beyond. These issues are explored in the following case report with examples given to help illustrate the unique aspects that must be considered when implementing AAI in a hospital setting.

Information

© The Author 2023
Understanding and managing seed degeneration in potato: Implications for potato resilient seed system and food security. A review
Authors: Tessema Lemma , Tesfaye Mamaru
Published: December 2023

Understanding seed degeneration in potato farming systems requires updated and pertinent information across different cropping systems and circumstances to find ways to deal with the problem. As a vegetatively propagated crop, potato is susceptible to pathogens and pest accumulation in seed tubers over successive cycles of vegetative propagation especially, where small-scale farmers replant their source seed for several production seasons. Seed degeneration in potatoes is a complex phenomenon, caused by a variety of soil, vector, and seed-borne pathogens resulting reduction in yield and quality of the crop. By providing an extensive overview of the current state of knowledge on the impacts and coping strategies of potato seed degeneration, mostly in the global south, this review aims to help underpin such relevant information and better development of the seed sector. This review article also provides insights on seed system bottlenecks leading to seed degeneration which impact food security and the livelihoods of smallholder farmers in developing countries including Ethiopia. We discussed the causes of seed degeneration and possible approaches to conquer the problem under smallholders’ perspective for sustainable potato production and improved food security.
The political economy of the climate crisis in Southern Africa
Authors: Mkodzongi Grasian
Published: December 2023

This article maps out the dynamics of the climate crisis that is unfolding globally, but whose consequences have a disproportionate impact on countries in sub-Saharan Africa and the wider global South. Although these countries have contributed insignificant amounts of greenhouse gas emissions (compared to their industrialised counterparts), their populations are the major victims of climate change, whose disastrous impacts were recently witnessed in Zimbabwe during Cyclone Idai and in South Africa during the Durban floods. In addition, Southern Africa is experiencing climate change-induced droughts, depleting water in major dams and undermining hydroelectric power generation, especially in Zambia and Zimbabwe. As a result, the region is experiencing dangerous power outages affecting agriculture and other key industries. This article adopts a novel decolonial perspective to make sense of these extreme weather events, arguing that the climate crisis is already affecting the livelihoods of many people in Southern Africa and that it is often the poor and vulnerable who suffer most from the impacts of climate change. There is thus a need for industrialised countries to contribute towards the costs of climate change mitigation since they are historically responsible for most of the carbon emissions.
Autonomous projects in the face of the global fishing market: women fish processors in Senegal in a context of climate emergency
Authors: Moreno-Maestro Susana
Published: December 2023

This article aims to analyse the difficult relationship between the needs of the Senegalese state to obtain economic compensation for the over-exploitation of natural resources, the right to food sovereignty of the local population, and the survival of the environment. It focuses on the fisheries agreements signed by Senegal with the European Union (EU) and how these have an impact on the conditions of people who make a living from the sector, analysing the situation and the self-organising of women involved in fish processing, an activity that sustains their autonomy and their ongoing reproduction as a collective. Declared goals of sustainable fishing in the latest protocol implementing the EU–Senegal Fisheries Agreement (2019–2024) are at odds with the actual over-exploitation of the marine environment. The commitment expressed in Article 2 of the agreement to ‘promote sustainable fishing and protect marine biodiversity’ contrasts with the lived experiences of women fish processors, expressed in denunciations of campaigns such as Greenpeace Afrique’s AnaSamaJën (where is my fish?). Based on the assumption that overfishing is a form of extractivism that undermines food sovereignty and the sustainability of local societies, this article first analyses the agreements signed between Senegal and the EU, including their clear anthropocentric ontology (Escobar 2017) and discusses how the state takes up the financial, environmental and food challenges posed by climate change. The second part, based on fieldwork and interviews with women fish processors and other actors in the sector, shows how these international agreements affect their economic and social conditions as well as their resistance, where social struggles and environmental thinking are linked.
Heusler-alloy-based magnetoresistive sensor with synthetic antiferromagnet
Authors: Khamtawi R , Saenphum N , Chantrell R W , Chureemart J , Chureemart P
Published: December 2023

Heusler alloy has been widely utilized in magnetoresistive sensors to enhance the device performance. In this work, we theoretically investigate the performance of Heusler-alloy-based magnetoresistive sensors with a synthetic antiferromagnet (SAF) layer. The atomistic model combined with the spin accumulation model will be used in this work. The former is used to construct the reader stack and investigate the magnetization dynamics in the system. The latter is employed to describe the spin transport behavior at any position of the structure. We first perform simulations of the exchange bias (EB) phenomenon in the IrMn/

C

o
2

F
e
S
i

(CFS) system providing a high EB field. Then, a realistic reader stack of IrMn/CFS/Ru/CFS/Ag/CFS is constructed via an atomistic model. Subsequently, the resistance–area product (RA) and magnetoresistance (MR) ratio of the reader can be calculated by using the spin accumulation model. As a result of the spin transport behavior in the Heusler-alloy-based reader stack including SAF structure at 0 K, an enhancement of the MR ratio up to 120

%

and RA

<
40
m

Ω
⋅
μ

m
2

can be observed. This study demonstrates the important role of the Heusler alloy and SAF layer in the development of magnetoresistive sensors for the application of readers in hard disk drives with an areal density beyond 2 Tb in−2.
Enhanced ultraviolet photo-detecting by constructing TiO2/KNbO3 heterojunction
Authors: Song Jianqiao , Bai Zhaowen , Wang Gang , Li Jiang , Zhang Xinmiao , Jin Mengjing , Zhao Haixing , Chang Peng , Pan Xiaojun
Published: December 2023

The demands of the ultraviolet (UV) radiation monitoring is rising in fields of human health and survival surroundings. Among many types of UV detectors, the photoelectrochemical (PEC) type UV detectors based on solar sensitized cells have gained a lot attention because of their fast response, low cost, simple manufacturing process, self-powered and so on. The heterojunction can accelerate the separation and migration of photogenerated carriers and then improve the photoresponse of UV detectors. In this work, the nanostructure KNbO3 (KNO) films were modified by chemical bath deposition to form a TiO2/KNO heterojunction. Compared with the UV detectors based on pure KNO and TiO2, the responsivity of the developed PEC UV photodetectors based on TiO2/KNO reached 11.99 mA W−1 under UV illumination of 35 mW cm−2 @ 365 nm, which is higher than that of the pure KNO UV detector (1.26 mA W−1) and the TiO2 UV detector (3.96 mA W−1). Besides, the lifetime of photogenerated carrier, response time and recovery time of the detector are all promoted. The results can be attributed to the formation of a TiO2/KNO heterojunction, in which the generated built-in electric field can promote the separation of photogenerated carriers and hinder the recombination of photogenerated electron–hole pairs, thus improving the detection performance of the UV detectors.
A 3D-printed fence-surface plasma source for skin treatment and its potential for personalized medical application
Authors: Zhao Yajun , Liu Yuzhuang , Liu Zhiyan , Zhang Xu , Zhang Li , Jin Shanshan , Fang Zhi
Published: December 2023

A 3D-printed fence-surface electrode that has the potential for personalized medical application is fabricated in this study. The framework of the 3D-printed fence electrode could be any shape to fit the outline of the target. Here, the fence electrode with an area of 50 × 50 mm is made as an example to study the discharge characteristic and the affecting factors (number of bars and the curvature of the electrode). The results show that more bars of the fence electrode with the same area will have a larger discharge current and a more uniform glowing area, which is consistent with the numerical results. When introducing the human load, it will not affect the original discharge between the fence and the ground electrodes but will add discharging channels between the fence electrode and the human load when the load contacts the fence electrode. In the worst case, the maximum root-mean-square of the discharge current flowing through the human model is 5.9 mA, which is still lower than the safety thresholds. The highest temperature rise on the surface of the fence electrode is 35.226.55 °C at the condition of 15 bars for 7 kV, 3 min running. It needs a 60 s treatment for Escherichia coli and Staphylococcus aureus to get a sterilization rate of 99.99% while it needs about 180 s treatment for Pseudomonas aeruginosa to get the same rate. Finally, the procedure for designing a personalized fence-surface plasma source is illustrated and the electrodes used to fit the calf and heel are made. The discharge of the personalized fence-electrode is stable and could be used in personalized plasma medicine in the future.
Fate of false vacuum in non-perturbative regimes
Authors: Frasca Marco , Ghoshal Anish , Okada Nobuchika
Published: December 2023

We use some exact results in scalar field theory to revise the analysis by Coleman and Callan about false vacuum decay and propose a simple non-perturbative formalism. We introduce an exact Green’s function which incorporates non-perturbative corrections in the strong coupling regimes of the theory. The solution of the scalar field theory involves the Jacobi elliptical function and has been used to calculate the effective potential for any arbitrary coupling values. We demonstrate the use of this formalism in a simple λ
ϕ
4 theory, and show that the effective potential exhibits a false minimum at the origin. We then calculate the false vacuum decay rate in the thin wall approximation, and suggest simple analytic formulae that may be useful for the analysis for the first-order phase transition beyond the perturbative regime. In our methodology, we show that the standard results obtained in perturbation theory are reproduced by making the coupling values very small.
First-principles and machine learning investigation on A4BX6 halide perovskites
Authors: Zheng Pan , Huang Yiru , Zhang Lei
Published: December 2023

The A4BX6 molecular halide perovskites have received attention owing to their interesting optoelectronic properties at the molecular scale; however, a comprehensive dataset of their atomic structures and electronic properties and associated data-driven investigation are still unavailable now, which makes it difficult for inverse materials design for semiconductor applications (e.g. wide band gap semiconductor). In this manuscript, we employ data-driven methods to predict band gaps of A4BX6 molecular halide perovskites via machine learning. A large virtual design database including 246 904 A4BX6 perovskite samples is predicted via machine learning, based on the model trained using 2740 first-principles results of A4BX6 molecular halide perovskites. In addition, symbolic regression-based machine learning is employed to identify more physically intuitive descriptors based on the starting first-principles dataset of A4BX6 molecular halide perovskites. In addition, different ranking methods are employed to offer a comprehensive feature importance analysis for the halide perovskite materials. This study highlights the efficacy of machine learning-assisted compositional design of A4BX6 perovskites, and the multi-dimensional database established here is valuable for future experimental validation toward perovskite-based wide band gap semiconductor materials.
Analysis of a sand and dust storm event in Termez, Surkhandarya Region, Uzbekistan: impacts and insights
Authors: Khamidjonov S K , Doniyorova X S
Published: December 2023

Sand and dust storms (SDS) are classified as global natural disasters and cause significant environmental and social problems. The article presents a study of a sand and dust storm that occurred on June 9, 2023, in Termez, Surkhandarya region, Uzbekistan. The research employed a multi-faceted approach, utilizing Landsat satellite imagery, and ground truth data collected through EKOLAB equipment. Additionally, a survey was conducted among the residents of the affected area to gather insights into the social impacts of the SDS event, and recommendations were developed by the authors to mitigate its consequences. The study aims to provide a holistic understanding of SDS occurrence in the region and its effects on the local population.
Geospatial model of negative processes of agricultural land as a means of digitalization of the educational and experimental farm
Authors: Esaulko A N , Odintsov S V , Loshakov A V , Ivannikov D I , Kotova A S
Published: December 2023

The article discusses the creation of a series of maps of negative processes for the purpose of digitalization of the Educational and Experimental Farm of the Stavropol State Agrarian University when assessing the degree of degradation of agricultural lands. The article is devoted to the problem of studying modern methods for assessing the condition of agricultural lands subject to negative processes. As a result of the research, the main negative processes were established, the degrees of their development and the intensity of their spread were determined. The main task of creating a geospatial model is to determine the current state of agricultural land and the possibility of their further use in agriculture. As a result, the prospects for the economic use of agricultural land were determined based on a comprehensive assessment of the qualitative condition of the land, a geospatial model will identify the dangers of the development of negative processes and a system of practical recommendations for planning the economic use of agricultural land.
Physical and geographical features of the toponyms of Uzbekistan
Authors: Mirakmalov M T , Ibragimova R A , Avezov M M , Okhunjonova D K
Published: December 2023

This article focuses on the study of physical and geographical aspects of toponymy, which involves the naming and renaming of geographical objects based on the natural features of a place. The research in this field prioritizes the normalization and standardization of geographical names, compilation of a state register of geographical names, proper use of names, publication of toponymic dictionaries, and transliteration of geographical names. In this regard, the present paper analyzes scientific research on toponyms from various regions worldwide, including Uzbekistan. A classification system of geographical names and physical and geographical features of toponyms specific to the regions of Uzbekistan has been developed and recommended, taking into account the natural characteristics of the place. Additionally, thematic toponymic maps have been developed.
Current state of biodiversity and hydrological-hydrochemical regime of the Mezhdurechensk reservoir of the Republic of Karakalpakstan
Authors: Temirbekov R , Mirzambetov N , Musaev A , Israilova I , Kaipov I , Turlibaev Z
Published: December 2023

The paper is devoted to the quantitative and qualitative indicators of the zooplankton of the Mezhdurechensky reservoir. The hydrological and hydrochemical regime of the Mezhdurechensky reservoir, which is highly dynamic and completely depends on the volume of river flow, has been studied. The species composition of the fish population of the Mezhdurechensk reservoir is given.
Influence of the shape of the disc slots of the seeder on the suction force of the vacuum for precise sowing of seeds
Authors: Saidova Mukhayyokhon , Alimova Feruza , Tursunbaev Sarvar , Kulmuradov Dilshod , Boltaeva Mohichekhra
Published: December 2023

The article analyzes the influence of the shape of the disc slots of the seeder on the suction force of the vacuum.Currently, pneumatic devices for various soil and climatic conditions are accurate with a cellular method of sowing seeds and the development of a seed drill design, in which 3 seeds are sown in each nest, targeted scientific research is being conducted to substantiate the parameters, ensuring its functioning at the level of agrotechnical requirements.In order to study the influence of the shape of the nests of the lander disk on the vacuum suction force, experimental studies were conducted using the lander disk of three different variants. Based on the conducted experiments, the authors drew their conclusions.
Assessment of sustainable innovative development of petroleum and gas chemical complex enterprises considering the impact of industrial risks
Authors: Zotov Maksim
Published: December 2023

This study assesses the state of the petrochemical complex sustainable innovative development considering the influence of industrial risks. It is assumed that the comprehensive introduction of innovations with various types of effects in the long term will improve not only the economic indicators of the region, but also the social and environmental ones through the introduction of sustainable innovations. It should be also noted that within the framework of existing world and domestic practice, issues with the integration of indicators for the safe and accident-free operation of enterprises of the petrochemical complex remain poorly studied. The work investigates the main economic, social, and environmental indicators of the complex under consideration. An analysis of accident rates at enterprises was carried out. The main causes of emergency events have been identified and measures to reduce them have been proposed. As a result it is concluded that the development of the petrochemical complex in the long term should be safe and based on the introduction of sustainable innovations.
Interrelation of wear rates of accelerator gear teeth
Authors: Irgashev B A , Mirzaev N N , Irgashev A
Published: December 2023

This paper considers the interrelation of wear rate of the accelerating gear pinion head and teeth foot, which depends on the number of pinion teeth involved in the meshing and gear ratio. Patterns of wear rate changes occurring between the head and the gear teeth leg, hardened by volume hardening, hardening by high-frequency current, cementation and nitriding, in the presence and absence of abrasive particles in the working environment, when the gear ratio has an increasing (accelerating) tendency, have been established.
The influence of the front section teeth lengths on the agrotechnical and energy performance of a two-stage vibratory gear hardware for land
Authors: Umurzakov A X , Imomov M X , Maxmudov F R , Mamasoliyeva S X
Published: December 2023

This article presents the research tests of agrotechnical and energetic performance based on the development of the construction of the oscillating gear harrow, which is processed in two stages before planting, and the results of the field test of its front section tooth lengths. In addition, the uniformity of the compression spring installed in the unit, their change graphs at different tooth lengths are given.
Productivity analysis of agricultural UAVs by field crop spraying
Authors: Kovalev I V , Kovalev D I , Astanakulov K D , Podoplelova V A , Borovinsky D V , Shaporova Z E
Published: December 2023

The article presents an analysis of the performance of agricultural UAVs when spraying field crops. Based on an analysis of the current state of technology for using UAVs in precision agriculture, a model for calculating UAV performance has been developed, based on the time structure of the crop spraying process, including the time of spraying, replenishment of mineral fertilizers or pesticides, and UAV flight. It is noted that for an agricultural UAV, when used in a precision farming system, the equation of existence must relate the take-off mass, the functional components of the take-off mass and the parameters of the sprayer, ensuring differentiated application of pesticides and fertilizers. Based on the proposed performance model of agricultural UAVs, recommendations are given for choosing the type of UAV for spraying crops. This model allows us to generalize methods for testing the production performance of agricultural UAVs, build models of production efficiency and provide proposals for technological solutions to improve these performance characteristics.
Results of extensive tests of a hanging brush grade equipped with track softeners and field soft devices
Authors: Tukhtakuziev A , Rasuljonov A R , Barlibaev Sh N , Kimsanov Sh
Published: December 2023

The article presents the structure, technological work process, values of basic parameters, technical description, and results of field tests of a comprehensive suspended screed-leveler equipped with devices that can quickly and easily adjust the pressure on the soil and create a soft soil layer on the surface of the field. According to the results of the tests, the working depth of the trail softener was 19.6 cm and 19.3 cm. At speeds of 6-8 km/h, the performance of a comprehensive roller-leveler equipped with track softeners and a device that creates a soft soil layer on the surface of the field is 4.96-6.24 ha/h in the main time, the performance in the operational time is 3, 77-4.74 ha/h, fuel consumption was 4.0-4.4 kg/ha. These remarks confirm that the pilot copy of the comprehensive roller-leveller, equipped with track softeners and a device that creates a soft soil layer on the field surface, performed the specified technological process reliably and qualitatively, and its performance fully corresponds to the initial requirements.
Analysis of system parameters in a microprocessor performance model of a swarm of agricultural spraying UAVs
Authors: Kovalev I V , Kovalev D I , Astanakulov K D , Voroshilova A A , Podoplelova V A , Borovinsky D V
Published: December 2023

The article develops a method for analyzing system parameters in a microprocessor performance model of a swarm of agricultural spraying UAVs. It is shown that the use of models for assessing the efficiency of UAV operation at various stages of the life cycle is possible on the basis of unified approaches to constructing a network model of UAV transport and technological cycles. The microprocessor performance model proposed by the authors provides a search for optimal solutions based on engineering programming approaches. Analysis of the influence of system parameters on the main criterion that determines the microprocessor performance of the system is performed based on a number of assumptions regarding the correspondence of predicted and actual parameter values. The main directions in modeling the microprocessor performance of UAVs are identified, for which sensitivity analysis of system parameters is the most important.
Calculation of the deformation values of the ammortizer in the compound angle gear transmission
Authors: Djuraev A Dj , Abduvakhobov D A , Khabibullaev D H , Ulmasov S A
Published: December 2023

The article presents the method of calculating the axial deformations of the rubber bush used in the bevel gear with the recommended composition and the formulas for determining the axial deformations. Based on the analysis of the connection graphs, the recommended values of its parameters were determined. The article presents the results of an analysis of the design features and disadvantages of cylindrical gears. An effective design scheme for a helical cylindrical gear transmission with elastic elements has been developed, allowing it to absorb peak values of oscillations of torques and axial force components arising from the meshing of wheel teeth, as well as cycling noise indicators.
Ecological characteristics of algoflora of Lake Khadicha and monitoring water quality
Authors: Kobulova B B , Yazdonov U T , Aitbayeva K K , Tashpulatov Y Sh
Published: December 2023

Lake Khadicha is a unique natural body of water which is used for growing commercial fish. In recent years, due to heavy loads of abiotic and anthropogenic factors, the lake water has become highly saline. This phenomenon greatly affects the biodiversity of aquatic organisms, in addition to algae. During 2019-2021, the algae flora of Lake Khadicha was studied. 216 species of algae were identified as part of the algal flora. Their relationship with external factors such as water temperature, salinity, pH and organic matter was studied.
Influence of supported filtration on channel safety (based on the example of Swanley channel)
Authors: Ikramova M , Akhmedkhodjaeva I , Otakhonov M , Ishpulatov Z
Published: December 2023

The article examines the problem of destruction and deformation of the banks of the Swanley Canal under the influence of backed-up groundwater filtration. An analysis of the current state of the canal and the dynamics of changes in groundwater levels along the canal bed was carried out. A hydraulic calculation of filtration flow was carried out and a method was proposed to reduce the negative impact of groundwater levels on the integrity of the canal.
Contact allergies to dental materials in patients
Authors: Forkel Susann , Schubert Steffen , Corvin Lisa , Heine Guido , Lang Claudia C V , Oppel Eva , Pföhler Claudia , Treudler Regina , Bauer Andrea , Sulk Mathias , Kränke Birger , Schäkel Knut , Heratizadeh Annice , Worm Margitta , Witte Jana , Geier Johannes , Buhl Timo
Published: December 2023

Background

Concerns regarding contact allergies and intolerance reactions to dental materials are widespread among patients. Development of novel dental materials and less frequent amalgam use may alter sensitization profiles in patients with possible contact allergy.

Objectives

To analyse current sensitization patterns to dental materials in patients with suspected contact allergy.

Methods

This retrospective, multicentre analysis from the Information Network of Departments of Dermatology (IVDK) selected participants from 169 834 people tested in 2005–2019 and registered with (i) an affected area of ‘mouth’ (and ‘lips’/‘perioral’), (ii) with the dental material in question belonging to one of three groups (dental filling materials, oral implants or dentures or equivalents) and (iii) with patch-testing done in parallel with the German baseline series, (dental) metal series and dental technician series.

Results

A total of 2730 of 169 834 tested patients met the inclusion criteria. The patients were predominantly women (81.2%) aged ≥ 40 years (92.8%). The sensitization rates with confirmed allergic contact stomatitis in women (n = 444) were highest for metals (nickel 28.6%, palladium 21.4%, amalgam 10.9%), (meth)acrylates [2-hydroxyethyl methacrylate (HEMA) 4.8%] and the substances propolis (6.8%) and ‘balsam of Peru’ (11.4%). The most relevant acrylates were HEMA, 2-hydroxypropyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate and pentaerythritol triacrylate. Few men were diagnosed with allergic contact stomatitis (n = 68); sensitization rates in men were highest for propolis (14.9%) and amalgam (13.6%).

Conclusions

Allergic contact stomatitis to dental materials is rare. Patch testing should not only focus on metals such as nickel, palladium, amalgam and gold, but also (meth)acrylates and the natural substances propolis and ‘balsam of Peru’.
Variations in older people’s emergency care use by social care setting: a systematic review of international evidence
Authors: Brotherhood Kelly , Searle Ben , Spiers Gemma Frances , Caiado Camila , Hanratty Barbara
Published: December 2023

Background

Older adults’ use of social care and their healthcare utilization are closely related. Residents of care homes access emergency care more often than the wider older population; however, less is known about emergency care use across other social care settings.

Sources of data

A systematic review was conducted, searching six electronic databases between January 2012 and February 2022.

Areas of agreement

Older people access emergency care from a variety of community settings.

Areas of controversy

Differences in study design contributed to high variation observed between studies.

Growing points

Although data were limited, findings suggest that emergency hospital attendance is lowest from nursing homes and highest from assisted living facilities, whilst emergency admissions varied little by social care setting.

Areas timely for developing research

There is a paucity of published research on emergency hospital use from social care settings, particularly home care and assisted living facilities. More attention is needed on this area, with standardized definitions to enable comparisons between studies.
Hemodynamic and electrophysiological responses of the human amygdala during face imitation—a study using functional MRI and intracranial EEG
Authors: Iidaka Tetsuya , Maesawa Satoshi , Kanayama Noriaki , Miyakoshi Makoto , Ishizaki Tomotaka , Saito Ryuta
Published: December 2023

The involvement of the human amygdala in facial mimicry remains a matter of debate. We investigated neural activity in the human amygdala during a task in which an imitation task was separated in time from an observation task involving facial expressions. Neural activity in the amygdala was measured using functional magnetic resonance imaging in 18 healthy individuals and using intracranial electroencephalogram in six medically refractory patients with epilepsy. The results of functional magnetic resonance imaging experiment showed that mimicry of negative and positive expressions activated the amygdala more than mimicry of non-emotional facial movements. In intracranial electroencephalogram experiment and time-frequency analysis, emotion-related activity of the amygdala during mimicry was observed as a significant neural oscillation in the high gamma band range. Furthermore, spectral event analysis of individual trial intracranial electroencephalogram data revealed that sustained oscillation of gamma band activity originated from an increased number and longer duration of neural events in the amygdala. Based on these findings, we conclude that during facial mimicry, visual information of expressions and feedback from facial movements are combined in the amygdalar nuclei. Considering the time difference of information approaching the amygdala, responses to facial movements are likely to modulate rather than initiate affective processing in human participants.
Elucidating the relationship between breast cancer and brain cortical structure: a Mendelian randomization study
Authors: Lin Yilong , Wang Songsong , Zhang Liyi , Yang Qingmo
Published: December 2023

Cancer-associated cognitive impairment is a significant challenge for individuals who have survived breast cancer, affecting their quality of life. In this study, we conducted an inaugural comprehensive Mendelian randomization analysis discerning the causal relationship between breast cancer, including its two subtypes, and the cerebral cortical structure. Our analysis indicated that estrogen receptor-negative breast cancer significantly decreased surface area (β = −593.01 mm2, 95% CI: −1134.9 to −51.1 mm2, P = 0.032). At the regional level, estrogen receptor-negative breast cancer showed a significant association with surface area and thickness in 17 cortical regions. These regions included the insula, posterior cingulate, superior frontal, precuneus, fusiform, lateral occipital, and rostral middle frontal. Specifically, estrogen receptor-negative breast cancer had a significant impact on decreasing the surface area of the insula without considering global weight (β = −14.09 mm2, 95% CI: −22.91 to −5.27 mm2, P = 0.0017). The results from meta-analysis and LD Score Regression provide support for our findings. This investigation unveils the correlations between breast cancer, its various subcategories, and the cerebral cortical structure. Notably, breast cancer of the estrogen receptor-negative variety may elicit more widespread cerebral atrophy.
Exploring the antioxidant activity of Fe(III), Mn(III)Mn(II), and Cu(II) compounds in Saccharomyces cerevisiae and Galleria mellonella models of study
Authors: Mattos Larissa M M , Hottum Hyan M , Pires Daniele C , Segat Bruna B , Horn Adolfo , Fernandes Christiane , Pereira Marcos D
Published: December 2023

Reactive oxygen species (ROS) are closely related to oxidative stress, aging, and the onset of human diseases. To mitigate ROS-induced damages, extensive research has focused on examining the antioxidative attributes of various synthetic/natural substances. Coordination compounds serving as synthetic antioxidants have emerged as a promising approach to attenuate ROS toxicity. Herein, we investigated the antioxidant potential of a series of Fe(III) (1), Mn(III)Mn(II) (2) and Cu(II) (3) coordination compounds synthesized with the ligand N-(2-hydroxybenzyl)-N-(2-pyridylmethyl)[(3-chloro)(2-hydroxy)]-propylamine in Saccharomyces cerevisiae exposed to oxidative stress. We also assessed the antioxidant potential of these complexes in the alternative model of study, Galleria mellonella. DPPH analysis indicated that these complexes presented moderate antioxidant activity. However, treating Saccharomyces cerevisiae with 1, 2 and 3 increased the tolerance against oxidative stress and extended yeast lifespan. The treatment of yeast cells with these complexes decreased lipid peroxidation and catalase activity in stressed cells, whilst no change in SOD activity was observed. Moreover, these complexes induced the Hsp104 expression. In G. mellonella, complex administration extended larval survival under H2O2 stress and did not affect the insect's life cycle. Our results suggest that the antioxidant potential exhibited by these complexes could be further explored to mitigate various oxidative stress-related disorders.
Understanding the impact of non-shared unmeasured confounding on the sibling comparison analysis
Authors: Esen Buket Öztürk , Ehrenstein Vera , Petersen Irene , Sørensen Henrik Toft , Pedersen Lars
Published: December 2023

Background

The sibling comparison analysis is used to deal with unmeasured confounding. It has previously been shown that in the presence of non-shared unmeasured confounding, the sibling comparison analysis may introduce substantial bias depending on the sharedness of the unmeasured confounder and the sharedness of the exposure. We aimed to improve the awareness of this challenge of the sibling comparison analysis.

Methods

First, we simulated sibling pairs with an exposure, a confounder and an outcome. We simulated sibling pairs with no effect of the exposure on the outcome and with positive confounding. For varying degrees of sharedness of the confounder and the exposure and for varying prevalence of the exposure, we calculated the sibling comparison odds ratio (OR). Second, we provided measures for sharedness of selected treatments based on Danish health data.

Results

The confounded sibling comparison OR was visualized for varying degrees of sharedness of the confounder and the exposure and for varying prevalence of the exposure. The confounded sibling comparison OR was seen to increase with increasing sharedness of the exposure and the confounded sibling comparison OR decreased with an increasing prevalence of exposure. Measures for sharedness of treatments based on Danish health data showed that treatments of chronic diseases have the highest sharedness and treatments of non-chronic diseases have the lowest sharedness.

Conclusions

Researchers should be aware of the challenge regarding non-shared unmeasured confounding in the sibling comparison analysis, before applying the analysis in non-randomized studies. Otherwise, the sibling comparison analysis may lead to substantial bias.
Perfect t-Embeddings of Uniformly Weighted Aztec Diamonds and Tower Graphs
Authors: Berggren Tomas , Nicoletti Matthew , Russkikh Marianna
Published: December 2023

In this work we study a sequence of perfect t-embeddings of uniformly weighted Aztec diamonds. We show that these perfect t-embeddings can be used to prove convergence of gradients of height fluctuations to those of the Gaussian free field. In particular, we provide a first proof of the existence of a model satisfying all conditions of the main theorem of [9]. This confirms the prediction of [10]. An important part of our proof is to exhibit exact integral formulas for perfect t-embeddings of uniformly weighted Aztec diamonds. In addition, we construct and analyze perfect t-embeddings of another sequence of uniformly weighted finite graphs called tower graphs. Although we do not check all technical assumptions of the mentioned theorem for these graphs, we use perfect t-embeddings to derive a simple transformation, which identifies height fluctuations on the tower graph with those of the Aztec diamond.