FOREST COVER MOSAICS OF CONIFEROUS-DECIDUOUS FORESTS IN THE VALUEVSKY FOREST PARK

Relevance and purpose. The Russian geobotanical science has a profound tradition of studying the vegetation cover heterogeneities. However, the number of studies on the mosaics in complexly organized coniferous-deciduous forests is very limited, and there is high ambiguity in the obtained results. In addition, there has appeared a need to resolve the “terminological issue”. The aim of this study was to assess the vegetation cover mosaics of widespread forest phytocenoses in the Moskva-Oka Plain. Material and methods. We present a review of publications on the intracenotic heterogeneity of forest cover and make an attempt to systematize the existing terminology. The field studies were carried out on the territory of the Valuevsky forest park (Novomoskovsky AO, Moscow) using classical geobotanical methods. The acquired data was analyzed with various modern methods of statistical data analysis. Results and conclusions. The obtained results indicate that differences in vegetation are much more pronounced at the level of phytocenoses than at the level of microgroups. The most powerful edificatory effect of spruce has been confirmed. We identified the following reasons that determine the weak differentiation of vegetation at the level of microgroups: the co-influence of neighboring microgroups, the lack of individual trees’ impact duration for a noticeable transformation of vegetation, and legacies in the structure and species composition of previous states over a long period of time.

Measuring a small nonreciprocity of the objects.

In the paper the methods and features of measuring the small nonreciprocity of objects is considered. Several variants of nonreciprocity characteristics are proposed and the variant with most noise immunity is selected. A method of normalizing the chosen nonreciprocity characteristic is considered. It is shown that the exposure of nonreciprocity depends on the probing signals. It is noted that the main factor that limiting the bottom bound of the nonreciprocity measurement range is the difference of the impedances of input and output networks. If a calibration is absent and if the difference between the inductance of the input and output networks is of few tenths of nH, then at a test impact duration of about 50 ps the bottom bound of the nonreciprocity measurement range is of about 1%. The observation of nonreciprocity with a relative value of 3% has been performed experimentally.

ĐA DẠNG SINH KẾ VỚI KHẢ NĂNG PHỤC HỒI SAU SỰ CỐ Ô NHIỄM MÔI TRƯỜNG BIỂN FORMOSA 2016 ĐỐI VỚI NGƯ DÂN KHAI THÁC THỦY SẢN GẦN BỜ TỈNH THỪA THIÊN HUẾ

Nghiên cứu này xem xét vai trò của đa dạng sinh kế đến “năng lực chống chịu” của hộ khai thác thủy sản biển ven bờ bị ảnh hưởng bởi sự cố môi trường biển Formosa năm 2016. Năng lực chống chịu của hộ được thể hiện thông qua mức độ tác động của sự cố và sự phục hồi sau sự cố. Các hộ được chọn nghiên cứu là hộ khai thác thủy sản biển gần bờ tỉnh Thừa Thiên Huế gồm nhóm chuyên khai thác thủy sản (KTTS) không đa dạng và nhóm KTTS đa dạng sinh kế. Kết quả nghiên cứu cho thấy, thời gian ảnh hưởng của sự cố đến nhóm hộ chuyên KTTS dài hơn nhóm hộ KTTS đa dạng sinh kế. Mặc dù giá trị thiệt hại về thu nhập của nhóm hộ KTTS đa dạng sinh kế cao hơn (khoảng 307,53 triệu đồng), nhưng tỷ lệ thiệt hại so với thu nhập của nhóm hộ này thấp hơn so với nhóm hộ chuyên KTTS (107,1% so với 123,31%). Sau 30 tháng, nhóm KTTS đa dạng sinh kế có quá trình phục hồi tốt hơn với tỷ lệ giá trị thu nhập phục hồi khoảng 77,88%, cao hơn khoảng 10% so với nhóm còn lại. Đa dạng sinh kế của hộ KTTS được xem là yếu tố ảnh hưởng tích cực nâng cao năng lực chống chịu của hộ đối với sự cố môi trường và phục hồi các hoạt động sinh kế. ABSTRACT This study examined the role of livelihood diversity on the resilience capacity of coastal fishing households affected by the Formosa incident in 2016. The resilience capacity of househoulds was characterized by the impact level of the incident and post-incident recovery. The households selected in this study were nearshore fishing groups in Thua Thien Hue province, including two fishing groups of undiversified and diversified livelihood. The results showed that the impact duration of the incident on undiversified livelihood fishery group was longer than that on the diversified livelihood group. Although the value of income loss of the households group with diversification was higher (about 307.53 million VND), the rate of income loss of this group was lower than that of their counterparts (107.1% compared to 123.31%). After 30 months, the diversified livelihood group had better recovery with the proportion of income recovered at roughly 77.88%, about 10% higher than that of the other group. Diversified livelihood of fishing households was considered as the positive influence on improving their resilience to environmental incidents and restoration of livelihood activities.

Putting Performance and Kinematics Differ with Skill Level in Female Golfers

Background: Female professional golf tours are gaining popularity around the world; there are key performance factors that are related to high performance on the female professional tour, like “driving distance and accuracy” and “putting per round”. However, there is a lack of research on the putting kinematics of female golfers with a lack of understanding the differences between the skill levels of female golfers. Objective: This study aimed to assess the putting performance and kinematics across three skill levels of female golfers. Methods: A total of one hundred and forty-nine right-handed female golfers were divided into three groups based on their playing skill levels: 64 professional tour golfers, 46 national team level golfers, and 39 college level golfers. Each participant executed seven putts on a straight, three meter indoor artificial turf. The three-dimensional kinematic data of each putt were captured using a high-precision ultrasound system (70Hz*3) (SAM PuttLab, Science&Motion Sports). Results: Significant differences were found between the three groups of female golfers in the face angle at impact (p<0.000), putter path at impact (p<0.000), vertical impact spot (p<0.000), rise angle (p<0.000), backswing duration (p<0.000), impact duration (p<0.000) and downswing duration (p<0.000). Additionally, the female professional golfers were more efficient than amateurs golfers on putter path (g=.-645), vertical impact spot (g=.707), rise angle (g=.878), shaft angle (g=-.602), backswing duration (g=-.512), impact duration (g=-.873), and downswing duration (g=.752). There were no differences between skill groups with horizontal impact spot, velocity at impact, backswing displacement, downswing displacement and face rotation from the top of backswing to impact. Conclusion: Our findings concluded that female professional golfers have a precise face angle and putter path relative to the target, with an upward stroke through impact, and a high impact spot on the putter, a shorter duration of the backswing time and time to impact, and a longer downswing. The study did not find significant differences in velocity at impact and swing phase displacement between the skill levels, which were found in previous studies on male golfers. There were differences in putting kinematics found between female and male professional golfers. Overall, female professionals have better putting performance, more precise direction, and optimized putting distance parameter control. These findings can be used as a guideline for golf coaching of female golfers. Future studies can focus on different distances, slopes, and additional skill levels.

Development of Failure Cause–Impact–Duration (CID) Plots for Water Supply and Distribution System Management

Understanding the impact and duration (consequences) of different component failures (cause) in a water supply and distribution system (WSDS) is a critical task for water utilities to develop effective preparation and response plans. During the last three decades, few efforts have been devoted to developing a visualization tool to display the relationship between the failure cause and its consequences. This study proposes two visualization methods to effectively show the relationship between the two failure entities: A failure cause–impact–duration (CID) plot, and a bubble plot. The former is drawn for an effective snapshot on the range (extent) of failure duration and the impact of different failures, whereas the latter provides failure frequency information. A simple and practical failure classification system is also introduced for producing the two proposed plots effectively. To verify the visualization schemes, we collected records of 331 WSDS component failures that occurred in South Korea between 1980 and 2018. Results showed that (1) the proposed CID plot can serve as a useful tool for identifying most minor and major WSDS failures, and (2) the proposed bubble plot is useful for determining significant component failures with respect to their failure consequences and occurrence likelihoods.

Heat Transfer During Impact of Elastoplastic and Cohesive Particles

This paper presents a theoretical study of the heat transfer during particles colliding with a surface considering the material elastoplastic properties and adhesion forces of particles. The model divides the impact processes into three stages, the elastic stage, the elastic-plastic stage, and full plastic stage, and assumes that the recovery stage is fully elastic. The rebound velocities of particles are obtained by the comparison of initial kinetic energy and total energy losses, and the major loss mechanisms in the form of adhesion forces and plastic deformation of particles. During each stage of the collision, the impact duration of collision is predicted numerically by integrating the differential equations of contact forces and particle motion. Elastic impact duration and heat transfer of a 4.76 mm stainless steel particle with 304 stainless steel surface agrees well with a previous analytical model. The result shows that at higher impact velocity, a larger percentage of time is spent in the compression stage. Sand particles under 50 μm impacting a nickel based super alloy surface (DD3) from room temperature to 1273 K are evaluated. Time duration decreases with an increase in impact velocity and a decrease in particle size. Heat transfer at particle impact is determined primarily by the contact area and time duration, besides the temperature difference and thermal conductivity. Heat transfer of plastic impact is noticeably smaller than the Sun and Chen’s analytical model, and the difference increases with increase in impact velocity. Adhesion forces affect the time duration significantly at low impact velocity. Heat transfer for 20 μm sand particles at 1073 K, 1173 K and 1273 K is about 1.12, 1.15 and 1.25 times that at room temperature, and about 1.07, 1.08 and 1.15 times the impact duration at room temperature.

Numerical Study on Evaluating the Concrete-Bedrock Interface Condition for Hydraulic Tunnel Linings Using the SASW Method

The current methods for evaluating the contact condition between concrete and lining were the ground penetrating radar (GPR) and the coring method. The penetration of radar electromagnetic waves was greatly affected by steel reinforcement and water, which often made the detection results of GPR unsatisfactory. A spectral analysis of the surface wave (SASW) method was used to evaluate the concrete-bedrock interface condition for hydraulic tunnel linings in this paper, since the impact elastic wave is less affected by steel bars and water content. An SASW implementation program based on fast Fourier transformation (FFT) was developed to analyze data from numerical simulations and field tests. Various models were studied to investigate the feasibility of using numerical analysis. For the first time, the study was employed to find out the influences of different receiver spacings and impact duration on the efficiency of detecting the existence of a weak layer underneath the concrete using the SASW method. On this basis, in-situ tests were carried out to verify the applicability in the field and results were verified by coring. In the research, the following results were found: (1) The finite element analysis results of different uniform or layered models showed that the SASW method could accurately identify the interface contact condition between the concrete lining and bedrock, especially the existence of voids; (2) when the receiver spacing was 1.0–1.5 times the thickness of the target object to be inspected, the quality of the collected signal data was the best; (3) under a certain reasonable range, the impact duration had an insignificant effect on the phase spectra and dispersion curves of a concrete-weak layer model; (4) in-situ SASW inspection could accurately tell whether the voids exist at the concrete-bedrock interface; and (5) the data processing program of the SASW method based on the MATLAB platform was accurate, convenient, and worth promoting.