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Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 175
Author(s):  
Yong He ◽  
Jianjian Wu ◽  
Haoluan Fu ◽  
Zeyu Sun ◽  
Hui Fang ◽  
...  

Spray droplet size is the main factor affecting the deposition uniformity on a target crop. Studying the influence of multiple factors on the droplet size distribution as well as the evaluation method is of great significance for improving the utilization of pesticides. In this paper, volume median diameter (VMD) and relative span (RS) were selected to evaluate the droplet size distribution under different hollow cone nozzles, flow rates and spatial positions, and the quantitative models of VMD and RS were established based on machine learning methods. The results showed that support vector regression (SVR) had excellent results for VMD (Rc = 0.9974, Rp = 0.9929), while multi-layer perceptron (MLP) had the best effect for RS (Rc = 0.9504, Rp = 0.9537). The correlation coefficient of the prediction set is higher than 0.95, showing the excellent ability of machine learning on predicting the droplet size distribution. In addition, the visualization images of the droplet size distribution were obtained based on the optimal models, which provided intuitive guidance for realizing the uniform distribution of pesticide deposition. In conclusion, this study provides a novel and feasible method for quantitative evaluation of droplet size distribution and offers a theoretical basis for further determining appropriate operation parameters according to the optimal droplet size.


Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 430
Author(s):  
Jianhua Wu ◽  
Xiaofeng Zhang ◽  
Liang Chen

Acousto-optic modulator (AOM) and electro-optical modulator (EOM) are applied to realize the all-fiber current sensor with a pulsed light source. The pulsed light is realized by amplitude modulation with AOM. The reflected interferometer current sensor is constructed by the mirror and phase modulation with EOM to improve the anti-interference ability. A correlation demodulation algorithm is applied for data processing. The influence of the modulation frequency and duty cycle of AOM on the optical system is determined by modeling and experiment. The duty cycle is the main factor affecting the normalized scale factor of the system. The modulation frequency mainly affects the output amplitude of the correlation demodulation and the system signal-to-noise ratio. The frequency multiplication factor links AOM and EOM, primarily affecting the ratio error. When the frequency multiplication factor is equal to the duty cycle of AOM and it is an integer multiple of 0.1, the ratio error of the system is less than 1.8% and the sensitivity and the resolution of AFOCS are 0.01063 mV/mA and 3 mA, respectively. The measurement range of AFOCS is from 11 mA to 196.62 A, which is excellent enough to meet the practical requirements for microcurrent measurement.


Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 364
Author(s):  
Yanding Qin ◽  
Haoqi Zhang ◽  
Xiangyu Wang ◽  
Jianda Han

The hysteretic nonlinearity of pneumatic artificial muscle (PAM) is the main factor that degrades its tracking accuracy. This paper proposes an efficient hysteresis compensation method based on the active modeling control (AMC). Firstly, the Bouc–Wen model is adopted as the reference model to describe the hysteresis of the PAM. Secondly, the modeling errors are introduced into the reference model, and the unscented Kalman filter is used to estimate the state of the system and the modeling errors. Finally, a hysteresis compensation strategy is designed based on AMC. The compensation performances of the nominal controller with without AMC were experimentally tested on a PAM. The experimental results show that the proposed controller is more robust when tracking different types of trajectories. In the transient, both the overshoot and oscillation can be successfully attenuated, and fast convergence is achieved. In the steady-state, the proposed controller is more robust against external disturbances and measurement noise. The proposed controller is effective and robust in hysteresis compensation, thus improving the tracking performance of the PAM.


Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 166
Author(s):  
Iolanda Corrado ◽  
Rocco Di Girolamo ◽  
Carlos Regalado-González ◽  
Cinzia Pezzella

Plant-derived essential oils (EOs) represent a green alternative to conventional antimicrobial agents in food preservation. Due to their volatility and instability, their application is dependent on the development of efficient encapsulation strategies allowing their protection and release control. Encapsulation in Polyhydroxyalkanoate (PHA)-based nanoparticles (NPs) addresses this challenge, providing a biodegradable and biobased material whose delivery properties can be tuned by varying polymer composition. In this work, EO from Mexican oregano was efficiently encapsulated in Polyhydroxybutyrate (PHB) and Poly-3-hydroxybutyrate-co-hydroxyhexanoate (PHB-HHx)-based NPs by solvent evaporation technique achieving high encapsulation efficiency, (>60%) and loading capacity, (about 50%). The obtained NPs displayed a regular distribution with a size range of 150–210 nm. In vitro release studies in food simulant media were fitted with the Korsmeyer–Peppas model, indicating diffusion as the main factor controlling the release. The cumulative release was affected by the polymer composition, possibly related to the more amorphous nature of the copolymer, as confirmed by WAXS and DSC analyses. Both the EO-loaded nanosystems displayed antimicrobial activity against Micrococcus luteus, with PHB-HHx-based NPs being even more effective than the pure EO. The results open the way to the effective exploitation of the developed nanosystems in active packaging.


2022 ◽  
Vol 9 (1) ◽  
pp. 153-161
Author(s):  
A Azurianti ◽  
Restu Wulansari ◽  
Faris Nur Fauzi Athallah ◽  
Sugeng Prijono

Tea plantation area in recent years has decreased by 0.75% annually. With the decline in the area of tea plantations, productivity also decreases. Decreased productivity can be caused by erosion, climate, clones, and management applications. The purpose of this study was to determine the availability of soil nutrients in Pagar Alam tea plantation and the relationship with productivity. The observation was held with secondary data and analyzed statistically with the correlation method. Parameters observed were pH, organic C, total N, P2O5, exchangeable K, and exchangeable Mg. The result showed that the relationship between soil nutrients such as organic C, total N, available P, exchangeable K, and exchangeable Mg with productivity was weak with correlation coefficient values of 0.00 – 0.199. These results also showed that the correlation was negative, which means that the two variables were inversely proportional. Plant maintenance factors have a more significant role in tea plant productivity than nutrients and fertilization, such as picking, pruning, root zone improvement, and plant pest control. If these factors can be controlled properly, shoot production will increase, and plant health can be maintained. Thus, in this case, the nutrient factor is not the main factor affecting productivity at Pagar Alam Tea Plantation, indeed the plant care factor.


Author(s):  
Olga NOSOVA ◽  
Volodymyr LYPOV

The purpose of the proposed paper is to study the specific factors shaping the benefits of information platforms as an innovative institutional form and model of doing business. Active dissemination of the business model of online platforms radically transforms the competitive landscape of the market environment. The task of determining the sources and mechanisms for studying the changes that are taking place is being updated. New areas of competition include competition between hierarchical and network structures, between global «structuring» platforms, competition in dominant platform ecosystems, the interaction between platforms operating in competitive markets, competition between organizers and users, and between platform users. The impact of platforming on cross-industry, regional and international competition is determined. The sources of competitive advantages of platforms are investigated. These include reliance on data as the main factor of production, changing the cost structure of entering the market; the possibility of building large-scale networks, niche specialization, combining the effects of increasing the scale of production and demand, multihoming, multi productivity, network effects.


2021 ◽  
pp. 124-128
Author(s):  
A. B. Kostyshyn ◽  
Z. T. Kostyshyn ◽  
U. R. Lukach ◽  
O. G. Boychuk-Tovsta ◽  
O. M. Repetska ◽  
...  

One of the main tasks of modern higher education is to train specialists with a high level of competence who can constantly work on themselves. The relevance of the research topic is due to the need for continuous professional development of future dentists and the motivation of their training, and the development of an active life position in modern society. The purpose of our work is to study aspiration peculiarities of IFNMU students and interns to the successful and versatile improvement of personality. The personal qualities of the doctor provide comfortable psychological contact with the patient and maintain professional activities dedication. Communicative competence is the subject of special research in the field of future doctors' training. Professional communication is considered to be one of the components of the general culture of relations and contributes to the successful career of a specialist in any sphere of activity, especially the medical one. The problem of forming and maintaining educational interest to master the future specialty of students and interns continues to exist. Motivational components and factors that affect the professional and personal development of the future doctor increase with each year of study, and this process should not stop for life. It’s effectiveness depends on the forms of the material presentation. The presence or absence of positive motives in students and interns have a significant impact on educational activities. Insufficient motivation cannot contribute to the formation of their high professional realization. Therefore, a genuine and persistent desire to acquire knowledge and skills should be the starting point in the formation of a highly qualified healthcare professional. The main factor influencing the interest in the education of students and interns is the acquisition of knowledge, skills, and abilities, which will form the foundation of professional activity in the future. The following factors contribute to increase the motivation of learning: the method of learning the material, its content, teaching methods; usage of problem tasks at each stage of the class; application of interactive technologies. Our analysis showed that gaining knowledge among students and interns is dominated by professional motives: to become a highly qualified dentist and to find a job that meets personal desires in the occupation of their choice. Thus, learning is more effective when it is motivated, and the activities of students coincide in direction and purpose. As a result, the graduate's professional training becomes successful. The effectiveness of the educational process depends on the variety of forms and methods of presenting scientific and practical material. The directions of increasing motivation are as follows: constant improvement and updating of material, the use of interdisciplinary links to understand the importance and practical necessity of each subject in a higher educational establishment, the use of multimedia presentations during practical and lecture classes, work in simulation centers, implementation in the educational process of situational tasks "patient-doctor and doctor-patient" with further discussion and recognition of the flaws of each participants' work. The usage of the latest information technologies and simulation centers helps not only to memorize a large amount of theoretical material but also to obtain practical and communication skills which are necessary for a modern doctor.


Ekonomia ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 43-61
Author(s):  
Mahmut Zeki Akarsu

Policymakers and economists consistently implement monetary and fiscal policy to control economic growth, inflation, and unemployment due to the fact that these three factors directly influence people’s living standards. Every country has a different economic characteristic structure. Economic growth and inflation have a strong correlation in some countries, while other countries have a strong correlation between economic growth and unemployment. Therefore, investigating the causal relationship among economic factors can provide us with a better understanding of how economic phenomena affect each other. In South Korea, economic growth, inflation, unemployment have been in balance since the 1998 Korean economic crisis. Hence, investigating the economic growth, inflation, and unemployment of South Korea will enlighten how these three economic indicators affect each other in a country that developed rapidly and had several economic crises. To investigate such a model, the Vector Autoregressive Model (VAR) is used with the data between the years 1980 and 2019 in order to verify whether Okun’s law or/and the Philips curve hold in South Korea. The research also determines if there is either a bi-directional or uni-directional relationship if economic growth, inflation, and unemployment have a causal relationship. The research demonstrates that GDP is the main factor in South Korea that influences the other economic factors. This research paper can contribute to academia, since it has a vital outcome which shows that the mobility of the unemployment rate in South Korea is directly correlated to the movement of GDP.


Author(s):  
L. Krichkovskaya ◽  
Essam Elnaggar ◽  
V. Dubonosov

In the present article importance of adsorptive purification of vegetable oils is shown as the most responsible technological stage. Insufficiency of scientific developments in the scope of domestic sorbents in Ukraine is pointed out. The phytosorbent with nanotubes from sunflower peel improving some quality parameters of non-refined sunflower and soybean oils to standard values for refined oils has been offered. Some literature data on the main characteristics of a number of sorption materials (carbonaceous, natural, fibrous, and sorbents obtained from agricultural waste - Corylus avellana Lambert nuts) as a result of heat treatment are analyzed. The main sorption properties are considered; dignity; limitations. The effect of temperature on the productivity of pyrolysis of plant raw materials and the properties of the resulting carbonizates in the temperature range 150-600 °C was investigated. The duration of exposure of materials at the final temperature of the process in all experiments was the same and amounted to 1 h. Analysis of the experimental data allows us to conclude that temperature is the main factor affecting the process of carbonization of the initial plant material. Regardless of the pyrolysis atmosphere, the yield of the product from plant raw materials decreases with a significant increase in temperature. At present, the main raw material for the industrial production of adsorbents is in many studies organic substances - wood, fossil coal, peat, remnants of the processing of agricultural raw materials due to their low cost and large amount. Solving the problem of creating sorbents based on plant raw materials with the inclusion of hydrated fullerenes in their composition solved the problem of creating sorbents and environmental problems, since the waste did not always find a useful application. Concentration of water solution of hydrated C60, fast C60FWS, є molecular-coloidal systems and spherical fractal clusters, structural unit of which is micro-hydrophilic, high-hydrophilic supramolecular complex, molecules can be folded to fit into ) 24-hydration of fullerene C60 (C60HyFn). The hydrated cultivation is set in its own well-ordered, structurally heterogeneous watery middle, in which the directness and kinetics of chemical processes are seen in such, that it is necessary to be washed in order to clean.


Insects ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 35
Author(s):  
Xueqin Liu ◽  
Xinpu Wang ◽  
Ming Bai ◽  
Josh Jenkins Shaw

Ground-dwelling beetles are important functional components in nutrient-poor grasslands of middle temperate steppe ecosystems in China. Here, we assessed the changes in ground beetle (Coleoptera: Carabidae) communities in the grasslands of northwestern China over 12 years to improve the management and conservation of beetles all over the world. The Generalized Additive Model (GAM) was applied to estimate the changes in carabid beetle communities in two regions: a desert steppe (Yanchi region), and a typical steppe and meadow steppe (Guyuan region). During the 12-year investigation, a total of 34 species were captured. We found that species abundance and richness per survey declined by 0.2 and 11.2%, respectively. Precipitation was the main factor affecting the distribution of carabid beetles. A distinct decline in carabid beetle species in the Yanchi region indicated that they may be threatened by less precipitation and loss of habitat, which could be due to climate change. Overall, species richness was stable in the Guyuan region. It is necessary to estimate and monitor the changes in carabid beetle communities in a temperate steppe of northern China and to protect them. Extensive desertification seriously threatens the distribution of carabid beetles. Future research should develop methods to protect carabid beetle communities in temperate steppes in China.


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