MATHEMATICAL EXPERIMENTAL PLANNING AND DETERMINATION OF RATIONAL VALUES OF SKIN FAT PARAMETERS FOR TOP SHOES BASED ON ESTER

The article presents the results of research to determine the optimal parameters of the process of fattening the skin using a full-factor experiment. According to Cochran's criterion, the deviations in the case under study turned out to be uniform.

Development of a methodology for calculating and designing a single-phase asynchronous electric motor without external phase-shifting devices for ship automation systems using a mathematical model obtained using experimental planning methods

Статья посвящена разработке методики проектирования однофазного асинхронного электродвигателя без внешних фазосдвигающих устройств для систем судовой автоматики. Отмечается, что существующие на сегодняшний день известные методики расчёта микромашин не учитывает потерь в стали, что приводит к значительным погрешностям при расчёте двигателя. Авторами предлагается применять разработанную уточненную методику расчёта двигателя для дальнейшего его проектирования. Отмечается, что из выявленных в работе зависимостей важнейшей является зависимость пускового момента от электрического угла между осями обмоток 1 и 44 - α. Где выбор не оптимального электрического угла - крайне негативно сказывается на величине пускового момента однофазной микромашины. Для пояснения особенностей определения активной части двигателя авторами строится график зависимости наружной поверхности и потерь от полезной мощности. Также, в статье авторы приводят номограммы, позволяющие принимать проектировочные решения не только на основания расчёта, но и графоаналитическим методом. Результатом работы является получение новой методики расчёта и проектирования однофазной микромашины для систем судовой автоматики, используя для расчёт математическую модель, полученную с помощью методов планирования эксперимента. The article is devoted to the development of a design technique for a single-phase asynchronous electric motor without external phase-shifting devices for ship automation systems. It is noted that the currently known methods for calculating micromachines do not take into account losses in steel, which leads to significant errors in calculating the engine. The authors propose to apply the developed refined methodology for calculating the engine for its further design. It is noted that of the dependences identified in the work, the most important is the dependence of the starting torque on the electric angle between the axes of the windings 1 and 44 - α. Where the choice of a non-optimal electrical angle has an extremely negative effect on the magnitude of the starting torque of a single-phase micromachine. To clarify the features of determining the active part of the engine, the authors build a graph of the dependence of the outer surface and losses on the net power. Also, in the article, the authors provide nomograms that allow making design decisions not only on the basis of calculation, but also by the graphical analytical method. The result of the work is to obtain a new methodology for calculating and designing a single-phase micromachine for ship automation systems, using for the calculation a mathematical model obtained using experimental planning methods.

Optimization of the Possibility of Dropping Materials on the Flip-over Bridge for Cassava Roots with Lifting Capacity of 60-80 tons

The paper presents the results of a survey on the ability to vent and dropping materials of the lift-over bridge for cassava roots with a lifting capacity of 60-80 tons based on the experimental planning model. The content of the survey on the influence of technological and technical parameters on the ability of venting/dropping materials on cassava trucks when the system of lifting-flip equipment uses transmission and hydraulic control. The research results build regression equations to show the influence relationship between the three basic structural parameters as lifting load, lift angle, distance A. Optimizing multi-objective function with Box Behnken algorithm model, the optimal conditions are as follows: A 5000 mm, lift angle 39.88 degree, lifting load 60.000 kg. Under these conditions, the highest guessing performance is 86,6%, then the objective function achieves the expected value of product clearance 99.9%, specific energy consumption 6.9 kW/h. There is no much difference in the results between the regression model and the experimental results which are similar almost similar.

Deep Learning Enables Design of Multifunctional Synthetic Human Gut Microbiome Dynamics

Predicting the dynamics and functions of microbiomes constructed from the bottom-up is a key challenge in exploiting them to our benefit. Current ordinary differential equation-based models fail to capture complex behaviors that fall outside of a predetermined ecological theory and do not scale well with increasing community complexity and in considering multiple functions. We develop and apply a long short-term memory (LSTM) framework to advance our understanding of community assembly and health-relevant metabolite production using a synthetic human gut community. A mainstay of deep learning, the LSTM learns a high dimensional data-driven non-linear dynamical system model used to design communities with desired metabolite profiles. We show that the LSTM model can outperform the widely used generalized Lotka-Volterra model. We build methods decipher microbe-microbe and microbe-metabolite interactions from an otherwise black-box model. These methods highlight that Actinobacteria, Firmicutes and Proteobacteria are significant drivers of metabolite production whereas Bacteroides shape community dynamics. We use the LSTM model to navigate a large multidimensional functional landscape to identify communities with unique health-relevant metabolite profiles and temporal behaviors. In sum, the accuracy of the LSTM model can be exploited for experimental planning and to guide the design of synthetic microbiomes with target dynamic functions.

TRENDS AND DETERMINANTS OF DEMOGRAPHIC PROCESSES IN RUSSIA

The article substantiates the need to identify trends in the development of processes demographic in individual countries and regions. The analysis of the determination of demographic processes is a necessary condition for the development of an effective demographic policy. The authors studied the dynamics of the population of the planet as whole, Europe, and Russia over the past 50 years. The assessment of the degree of influence of the measures taken in certain countries of the world on the demographic situation is given. The article deals with both methodological issues of studying the determination of demographic processes, and the results of research based on statistical information. Much attention is paid to the issues of determining the birth rate and mortality. An assessment of the impact of material payments on the birth rate is given. At the same time, the issues of determining migration processes and population aging are not left without attention. To analyze the causes of population migration in the region, the experimental planning method was used. The use of this method allowed us to identify the factors that affect migration processes and to assess the degree of influence of each of them on the level of the migration efficiency coefficient. The study showed the possibility of using the planning method in the study of socio-economic processes. The authors consider three variants of the population forecast of the Russian Federation until 2035, proposed by Rosstat, and assessed possible options for their implementation.

Biocompatible Sulphonated PEEK Spheres: Influence of Processing Conditions on Morphology and Swelling Behavior

This work aimed to develop and evaluate the influence of processing variables on the morphology and swelling of sulfonated poly(ether ether ketone) (SPEEK) spheres for possible applications as a biomaterial. We used the drip method to obtain spheres with the polymer starting solutions SPEEK-6 (w/v: 6%) and SPEEK-10 (w/v: 10%), drip rates (20 and 30 mL/h), and drip heights (5 and 10 cm) in experimental planning. The samples were characterized by Fourier-transform infrared spectroscopy (FTIR), optical microscopy (OM), the absorption capacity of phosphate-buffered saline (PBS) by swelling (%), and statistical analysis of data through Design of Experiments (DOE). The obtained results evidenced that the processing variables influenced the morphology and swelling. Spheres with a bigger concentration of the polymer solution presented a greater degree of sulfonation (DS). We verified that the diameter of the spheres was directly related to the variable height and the sphericity was associated with the speed and viscosity of the solution. Bigger and more pores in a greater amount were observed in the spheres with a greater DS, influencing the behavior of the swelling in PBS. The better variable combinations with a high DS, regular sphericity, a smaller diameter, and greater swelling were the samples S2-10-20-5 e S10-10-20-5. The cytotoxicity indicated that the best samples obtained in the experimental planning (S2-10-20-5 and S10-10-20-5) were not toxic. In that regard, the evaluated spheres presented cell viability and swelling capacity, suggesting their possible applications as biomaterials.

Use of Paper Microdevices in the Identification and Quantification of Cocaine in Seized Street Samples

The growing consumption of illicit drugs in Brazil is becoming increasingly problematic for society. It is therefore critical to develop technologies to combat drug trafficking that allow for rapid, non-invasive evaluation of drug samples. Microfluidics is a technology that manipulates and studies small amounts of fluids, using structures with dimensions from ten to hundreds of micrometers (microdevices). The main advantages of microfluidic approaches are its low cost, speed, and ability to provide results in loco. Here, paper microfluidics were developed to perform the modified Scott test to calculate the cocaine hydrochloride content in seized samples of cocaine (n = 30) and crack (n = 30). A smartphone with the Photometrix® app was used to construct a model for quantifying the samples. A factorial model was developed to optimize microfluidic analytical parameters such as spot size (6, 8 and 10 mm), reagent content (50, 75, and 100% cobalt thiocyanate II), cocaine hydrochloride concentration (4, 6 and 8 mg mL-1) and response time (or analyte detection; t = 0, 0.5 1, 12 and 24 h). After experimental planning, a diameter of ΜPADs = 8 mm - [Co(SCN)2] = 100% and a 1 h response time were identified as the best conditions. We observed that the cocaine hydrochloride concentration did not influence the model. A sample concentration of 15 mg mL-1 was used to quantify cocaine hydrochloride in street samples apprehended by the Forensic Police of Espírito Santo state (with n = 60). The quantification curve constructed to determine the cocaine hydrochloride concentration showed a determination coefficient, R2, of 0.98246 and RMSEC (root mean squares error calibration - mean square error of the calibration) of 0.39480, with a LOD and LOQ of 0.09 and 0.30 mg mL-1, respectively. For the crack samples, the cocaine hydrochloride concentrations ranged from 2.5 to 60.8 wt% with an average purity content of 21.3 ± 13.3 wt%. For the seized cocaine samples, variation in hydrochloride content from 1.2 to 22.6 wt% was observed with a mean percentage of 14.19 ± 6.92 wt%. Finally, chemometric tools such as principal component analysis were used to assess the similarity among the samples.

Planning an Experiment for Low-Cycle Fatigue under Conditions Deep Cooling

In the elements of structures with a limited resource during operation, significant cyclic stresses can occur, reaching and exceeding the yield strength; the results of an experimental study of the effect of the magnitude of preliminary plastic deformations on the strength and durability of structural alloys under low-cycle loading can be of undoubted interest for practice. The use of experimental planning methods in the study of the influence of the maximum cycle stresses and the magnitude of the preliminary permanent deformation on the low-cycle fatigue of 03Kh13AG19 chromium-manganese steel at T = 4.2 K under pulsating tension showed that these methods can be successfully used.

Body Temperature and Activity Adaptation of Short Photoperiod-Exposed Djungarian Hamsters (Phodopus sungorus): Timing, Traits, and Torpor

To survive the Siberian winter, Djungarian hamsters (Phodopus sungorus) adjust their behavior, morphology, and physiology to maintain energy balance. The reduction of body mass and the improvement of fur insulation are followed by the expression of spontaneous daily torpor, a state of reduced metabolism during the resting phase to save additional energy. Since these complex changes require time, the upcoming winter is anticipated via decreasing photoperiod. Yet, the extent of adaptation and torpor use is highly individual. In this study, adaptation was triggered by an artificially changed light regime under laboratory conditions with 20°C ambient temperature and food and water ad libitum. Two approaches analyzed data on weekly measured body mass and fur index as well as continuously recorded core body temperature and activity during: (1) the torpor period of 60 hamsters and (2) the entire adaptation period of 11 hamsters, aiming to identify parameters allowing (1) a better prediction of torpor expression in individuals during the torpor period as well as (2) an early estimation of the adaptation extent and torpor proneness. In approach 1, 46 torpor-expressing hamsters had a median torpor incidence of 0.3, covering the spectrum from no torpor to torpor every day within one representative week. Torpor use reduced the body temperature during both photo- and scotophase. Torpor was never expressed by 14 hamsters. They could be identified by a high, constant body temperature during the torpor period and a low body mass loss during adaptation to a short photoperiod. Already in the first week of short photoperiod, approach 2 revealed that the hamsters extended their activity over the prolonged scotophase, yet with reduced scotophase activity and body temperature. Over the entire adaptation period, scotophase activity and body temperature of the scoto- and photophases were further reduced, later accompanied by a body mass decline and winter fur development. Torpor was expressed by those hamsters with the most pronounced adaptations. These results provide insights into the preconditions and proximate stimuli of torpor expression. This knowledge will improve experimental planning and sampling for neuroendocrine and molecular research on torpor regulation and has the potential to facilitate acute torpor forecasting to eventually unravel torpor regulation processes.

ESTIMATION OF THE OPTIMUM SIZE OF PLOTS FOR SOYBEAN RADIOMETER EXPERIMENTS

The lack of error of experimental planning in agricultural field studies can result in rework, causing the waste of financial resources. The determination of the optimal size of the experimental plot for carrying out the treatments can minimize these problems. The objective of this paper was to estimate the optimal plot size for measuring reflectance in soybeans, without treatment, using the modified maximum curvature method and the maximum distance method. Reflectance readings were taken in the soybean crop with the aid of the GreenSeeker® equipment, in basic experimental units of 0.45 m², in an area of 7 lines and 8 meters in length. The data were collected in three phenological stages of soy (R4, R5.5 and R6), obtaining 63 simulations of experimental area in each stage. Based on the results, it is recommended to use plots of 7.20 m², with grouping of 4 lines of 4 m in length.