Changes in Reconstructed Soil Physicochemical Properties in an Opencast Mine Dump in the Loess Plateau Area of China

Soil construction and revegetation are essential for ecological restoration in mining areas. The influence of vegetation on the horizontal and vertical distribution patterns of soil properties should be fully understood. However, most studies on reconstructed soils in mining areas only concentrate on the surface soil, without exploring the vertical variations in soil properties. Overall, this study aims to explore the potential mechanisms by which surface vegetation exerts some influence on the spatial distribution of soil physicochemical properties, and to provide some insight into revegetation and soil reclamation in mining areas. Descriptive statistics and one-way analysis of variance (one-way ANOVA) were employed to evaluate the differences in the soil physicochemical properties in horizontal and vertical directions under different land-use types in the south dump of Antaibao opencast mine in Pingshuo, Shanxi Province, China. The main results of this study are as follows: (1) In the horizontal direction, except for the strong variation (variation coefficient ≥ 100%) in soil organic matter (SOM) content at some depths, the degree of variation in other soil physicochemical properties at various depths was moderate or weak (variation coefficient < 100%). The soil physicochemical properties gradually remained constant after years of reclamation. In the vertical direction, the soil bulk density (SBD), soil porosity, SOM content, soil C/N ratio, soil total nitrogen (STN) content, soil available phosphorus (SAP) content, and soil available potassium (SAK) content showed significant variations (p < 0.05) between soil depths. In contrast, no significant difference was found for other physicochemical properties. (2) The SBD, STN, SAK, soil porosity, and soil clay content were significantly different (p < 0.05) under different vegetation cover types, but the influence of vegetation on other soil physicochemical properties seemed to be limited. The results reveal that trees have a stronger ability to reduce soil grain sizes and enhance SAP contents than shrubs or herbs; however, the beneficial effects of herbs on the physicochemical properties of shallow soil are more obvious than those of trees and shrubs. (3) This study indicates that more shrubs and trees should be planted in the areas with low vegetation coverage, and more measures should be taken to improve soil physicochemical properties in order to prevent the occurrence of large-scale degradation. The reconstruction of soil structure should be preferentially considered in the process of soil reconstruction and revegetation in areas under similar conditions. Herbs should first be planted in the early reclamation stage. At the same time, shrubs or trees can be adopted in the middle and late stages of vegetation reconstruction in order to achieve comprehensive revegetation.

The study of rheological and physical dough properties of the winter wheat varieties

There have been represented the study results of flour quality of the winter bread wheat varieties of semi-intensive type of the FSBSI Agricultural Research Center “Donskoy”. The purpose of the current study was to estimate variability of the values of indicators that characterize physical and rheological dough properties, to identify the correlation between them, and to isolate genetic sources. The objects of study were 20 winter bread wheat varieties. Field trials were carried out in 2017–2019 in the fields of the department of winter wheat breeding and seed production, the forecrop was maize for grain. The variety ‘Don 107’ was used as a standard. The quality of grain and flour of the winter bread wheat varieties was assessed in the laboratory for biochemical estimation of breeding material and seed quality. There have been identified the varieties ‘Asket’ (26.9%), ‘Podarok Krymu’ (26.2%), ‘Zolotoy Kolos’ (25.5%) and ‘Izyuminka’ (25.5%) with the maximum gluten content in grain. It was determined that the trait ‘gluten deformation index’ varied from 62 u.v. to 77 u.v., all varieties corresponded to the 1st quality class. There have been identified the genotypes ‘Volny Don’, ‘Don 93’, ‘Premiera’, ‘Podarok Krymu’, ‘Ambar’, ‘Donskoy Surpriz’ and ‘Izyuminka’ with low values of the variation coefficient of the trait. There have been identified the varieties ‘Krasa Dona’ (6.7%), ‘Zhavoronok’ (6.8%) and ‘Asket’ (8.2%) with low values of the variation coefficient of the trait ‘specific work of dough deformation’. There have been identified the varieties ‘Don 93’, ‘Izyuminka’ and ‘Podarok Krymu’, which according to P/L corresponded to the class of strong wheat. It was found that the varieties ‘Zolotoy Kolos’ and ‘Volnitsa’ corresponded to the class of strong wheat according to the valorimetric assessment. Correlation analysis showed that the rheological dough properties were significantly influenced by gluten content in grain. There has been estimated the quantitative manifestation and variability of the traits, which characterize the rheological and physical dough properties. There have been identified the varieties with the smallest varietal variation of traits, which are recommended to use in the breeding process as sources of useful traits and properties. The selection according to the traits ‘delute of dough’ and ‘valorimetric assessment’ allow developing and introducing into production genotypes with good baking properties.

Evaluation of the Magnet Breakaway Force Measurement Accuracy of the NT-800 Sensors for Early Detection of Defects of Their Manufacturing

Сontrol of mechanical stresses formed with the deposition of nickel coatings plays an important role in the diagnosis of coatings’ technical condition. Large internal stresses can lead to cracking or flaking of coatings which is completely unacceptable for critical parts and assembly units used, for example, in space technology for which reliability is of paramount importance. An important aspect of internal stresses monitoring is the measurement error of the instruments used. The purpose of this work was to determine the characteristics of the device sensors, which make the assessment of their manufacturing possible at the preliminary stage of the measuring equipment assembling in order to maintain the required accuracy of subsequent measurements.In most cases the measurement error assessment is possible only after the equipment manufacture and calibration. In this paper it is proposed to evaluate the accuracy characteristics of device sensors based on the precision (repeatability and reproducibility) of the primary informative parameter recording. In the case of the NT-800 device that was developed at the Institute of Applied Physics of the National Academy of Sciences of Belarus the effect of precision characteristics deterioration on the eventual measurement error is demonstrated. Determining the precision parameters before establishing correlation dependences between the primary informative parameter and the measured characteristic is proposed in order to reject poorly manufactured sensors and reduce labor costs.In particular, measurements of the magnitude proportional to the magnetic breakaway force were carried out using the NT-800 device with nickel specimens simulating coatings with a thickness of 200 to 700 μm and a rolling value from 0 to 40 %. It was established that in the case of well-made sensors the variation coefficient calculated from the dispersion of repeatability is in the range 0.2–0.6 %, and the variation coefficient calculated from the dispersion of reproducibility does not exceed 0.9 %. In the case of a sensor with the sensitive element parameters worsened, the variation coefficient of repeatability and reproducibility were up by one and a half times. Deterioration of the precision characteristics resulted in significant changes in the readings of the calibrated instrument. Thus the absolute measurement error for a sensor with a poorly made sensitive element turned out to be approximately 3 times higher in the range of 200– 300 MPa than that for a sensor with good precision parameters.

Correlations between the Parameters of the Light Volume Scattering Functions in the Mediterranean Sea Surface Waters

Purpose. The aim of the work is to study relationships between the parameters of the light volume scattering functions based on the data of their measurements in the Mediterranean Sea surface waters. Methods and Results. The data of measurements of the light volume scattering functions in the water samples taken in a few regions of the southern Mediterranean Sea, namely from the Strait of Gibraltar to the Levant Sea, as well as in the central part of the Aegean Sea and near the Dardanelles Strait (May, 1998) were used. The following parameters of the volume scattering functions were calculated: total scattering coefficient, and asymmetry and variation coefficients. The maximum and minimum values of the scattering coefficient were 0.21 and 0.09 m–1, respectively; and those for the asymmetry coefficient – 77.8 and 33.9. The variation coefficient of the angle scattering coefficients changed within 35–79%, its maximum and minimum values fell on the angles 7.5° and 162.5°, respectively. Obtained were the relations between the variation coefficient and the scattering angle, the asymmetry coefficient and the scattering coefficient, and the angle scattering coefficients and the total scattering coefficient. All of them possess high (more than 0.9) correlation coefficients. The coefficient value (51.7%) at the angle 2° does not correspond to general relation of the variation coefficient to the scattering angle. This fact is explained by different contributions of coarse and fine suspended matter to the light volume scattering function. At the angle 2°, the main contribution is made by a coarse (organic) suspended matter, whereas at the angles exceeding 7.5° – by a fine (mineral) suspension. Conclusions. The values of the variation coefficient of the angle scattering coefficient at the angles equal to 2° and exceeding 7.5° demonstrate variability of the coarse and fine suspended matter in the Mediterranean Sea, respectively. The equation for the relation between the asymmetry coefficient of the light volume scattering functions and the total scattering coefficient obtained for the Mediterranean Sea waters is close to the analogous one obtained for the Atlantic Ocean tropical waters. The angle 3.5° is optimal for determining the total scattering coefficient using the angle scattering coefficient for the Mediterranean Sea functions.

STUDY ON FILLING PERFORMANCE OF HOLE FERTILIZATION DEVICE AND OPTIMIZATION OF CAVITY

Hole fertilization is an effective method to improve the utilization rate of chemical fertilizer. In order to improve the accuracy and stability of the amount of fertilizer discharging for the hole fertilization device, this paper proposed the method of rotary filling by notched disk, designed a hole fertilization device with notched disk, and completed the structure design of the device and cavity. Through the dynamic analysis of fertilizer particles in the process of fertilizer filling, this study found that the interface span of fertilizer cavity, the rotational speed of fertilizer disk, and the amount of fertilizer applied in each hole are the main factors affecting the performance of filling. Then, this study carried out the three-factor quadratic orthogonal rotation combination simulation test to optimize the structure of the cavity. The test used the discrete element method with interface span of fertilizer cavity, the rotational speed of fertilizer disk, and the amount of fertilizer applied in each hole as test factors and the accuracy and variation coefficient of filling amount as evaluation indexes. Results showed that the optimal performance was obtained when the cross section span of the cavity was 13.58°, the opening width was 29.56 mm, and the depth was 22.08 mm. The field validation showed that the average accuracy of filling amount per hole was 97.67%, and the average variation coefficient was 1.90%. The performance of fertilizer discharge satisfied the design requirements, and agreed with the law of the simulation results. The research results could provide a theoretical basis for the design of hole fertilization device and the improvement of filling performance.

Psychological Stress in the Era of Covid-19 Pandemic in Diabetic Population of Nagpur, India - A Cross Sectional Study

BACKGROUND The global health care system has been impacted by the Covid-19 pandemic and lockdowns have been imposed to stop the virus from spreading. Due to rapid spread of corona virus, citizens are facing fear, anxiety, and depression directly affecting their mental health. Adults having poor health are at a higher risk of being infected. This situation has created a stressful atmosphere and resulted in the development of many psychological problems in individuals. Those having pre-existing conditions or co-morbidities have higher mortality risk as compared to healthy individuals. Hence, the issue is more common in people having co-morbidities, with diabetes mellitus being one common among them. We wanted to study the psychological impact mainly stress in diabetic population residing in rural setup in this era of Covid-19 outbreak. METHODS A cross-sectional study was conducted among 381 diagnosed diabetic patients attending outpatient department of Rural Health Training Centre affiliated to the tertiary care hospital. The collected data was entered and also analyzed for percentage, mean, standard deviation and variation coefficient. RESULTS Approximately half (51.96 %) of the participants reported a stress of moderate level during Covid-19 with mean ± SD (20.07 ± 3.83), overall mean was (21.55 ± 8.67) and the variation coefficient was 40.22%. The variance in stress level in diabetics with HbA1c levels of less than 6 %, 6 – 8 % and > 8 % depicting the various levels of control of diabetes was 39.36, 40.84 and 40.50 respectively. Similarly the variance coefficient among stress was 42.39, 41.34, 34.65 and 32.12 % when the duration of diabetes was compared in the respondents indicating that the stress level was widely distributed amongst all the participants. CONCLUSIONS Strategies need to be implemented to take care of mental health in diabetic patients especially in this Covid pandemic era. KEY WORDS Stress, COVID-19 Pandemic, Diabetes Mellitus, Rural Population

Growth and genetic parameters of progenies of Cordia trichotoma in the juvenile phase

Increasing the productive potential of native species is a challenge for forest genetic improvement. Progeny tests are efficient tools to determine the reproductive capacity of individuals and to assist with the selection of superior genotypes. Cordia trichotoma (Vell.) Arrab. ex Steud, is a native species of commercial interest due to its high potential for sawn wood. The performance of seedling production from different progenies was the objective of this work. Seeds were collected from 34 matrices selected phenotypically and georeferenced in the region of Lavras - MG. The experiment was conducted in a completely randomized design with 4 replications of 12 plants. Germination after 70 days of sowing, survival and height at 170 days after germination were evaluated. Height and genetic parameters were estimated according to mixed REML / BLUP models using the Selegen software model 82. Progeny 104 (70.8%) was superior in germination and progenies 86 (35.42%), 92 (35.42%) and 111 (43.75%) had the highest survival rates. Height shows high values for the individual additive genetic variation coefficient (49.18%) and genotypic variation coefficient between progenies (24.59%) and moderate values of heritability in the restricted individual sense (0.45) and heritability within progenies (0.38). Due to high values for the coefficient of genotypic variation and moderate values of heritability, there is a potential for height improvements. Progenies 104 stand out in the germination and the progenies 86, 92 and 111 in the seedlings survival). Regarding height, progeny 95 is the only one that stands out negatively.

Allelopathy of vegetable residues on the sowing properties of soft winter wheat grain

Aim. To study the allelopathy of vegetable residues on sowing properties of soft wheat grain. Methods. Laboratory, mathematical and statistical, physical. Results. The highest germination energy was obtained in the variant with water, corn and wheat stalks – 100%, percentage germination was 95%. Under conditions of germination in rye, rape and oat stalks, percentage germination was 15–30 % points lower compared to the control. Germination of soft wheat grain in the stalks of other crops provided percentage germination of 15–50 %. Obviously, soybeans, sunflowers, mustard, peas, barley, flax, safflower, buckwheat and sorghum show high allelopathy during the germination of soft wheat grain. The highest seedling vigor was obtained during germination in water and in corn stalks – 50 %. This figure in wheat and rye stalks was 33 and 28 %, respectively, or 17–22 points lower than the control. During the germination of soft wheat grain in the stalks of other crops, the seedling vigor was the lowest – 8–22 %. The average germination rate varied inversely proportional to seedling vigor. On average, wheat grain in corn stalks germinated for 29 minutes which was at the control level. During germination in wheat and rye stalks, it grew for up to 43–58 minutes. During germination in the stalks of other crops, the average speed increased to 72–288 minutes. Different germination substrates changed the parameters of soft wheat stalks. This indicator was at the level of control over grain germination in rye and corn stalks – 9.2–9.3 cm with fluctuations from 8.1 to 10.3–10.4 cm, and the variation coefficient was small (V = 12.0–12.5 %). The stalk length was significantly shorter during germination in wheat stalks, but the variation coefficient was insignificant (V = 5.2 %). During germination in the stalks of other crops, the stalk length decreased from 7.3 to 0.6 cm. Coclusions. Germination of wheat grain in corn and wheat stalks did not affect the deterioration of germination. The lowest allelopathy was shown by grain germination in rye stalks. The highest allelopathy was shown by germination in soybean and sunflower stalks. Crops, according to the influence on the length of soft wheat stalk, are arranged in the following order: sunflower, buckwheat, sorghum, safflower, soybean, mustard, flax, oats, rape, barley, peas, wheat. Grain germination in corn and rye stalks did not affect the length of soft wheat stalks

INFLUENCE OF THE VARIATION COEFFICIENT ON THE BRICK STRUCTURES RELIABILITY

The goal of research was studying the influence of the variation coefficient values during statistical tests of building structures on the destruction probability and reliability of brick building structures. The article focuses on comparing the theoretical values of the probability theory problems with their practical application in building structures behavior calculation. The scientific novelty lies in the comparison of the calculated data according to the normal distribution with the practical values of the experiment carried out on brick structures. As a result, a dependence graph dependence of the reliability coefficient k on the brick grade was, taking into account various coefficients of variation.