Vol. 12, No. 2 (2024): Regular Issue

As the problems of declining shallow groundwater levels becomes more prominent, depletion of water resources and deterioration of water quality are becoming increasingly prominent. To study the dynamic trend of shallow groundwater and its influencing factors, this study used Hilbert-Huang Transform analysis and Wavelet analysis to analyze the multiscale cycle and trend of the burial depth of shallow groundwater in the Jizhou area of Tianjin and evaluated three factors (annual precipitation, exploitation and evaporation) affecting the burial depth of shallow groundwater by multiple regression and gray correlation analysis. The results showed that there were obvious interannual variation cycles in the burial depth series of shallow groundwater in Jizhou; the correlation between the burial depth of shallow groundwater and the amount of extraction is the greatest; the Wavelet transform and HHT methods had good applicability to the analysis of groundwater hydrological time series, which helped to comprehensively understand the dynamic change characteristics of shallow groundwater.

We examine the relationship between property losses caused by tornadoes and their physical parameters, namely the tornado path length and width, using data reported by the National Oceanic and Atmospheric Administration in the United States. We observe that the statistics of property losses cannot be described by a single distribution but rather by a two-dimensional statistical manifold of distributions that may reflect two different mechanisms of property loss compensations. Assessing the difference between distributions of losses caused by tornadoes using Kolmogorov-Smirnov's distance, we construct the 2-D manifold using the method of multi-dimensional scaling. Then we define a ``curvature coefficient'' that characterizes the contraction and expansion of the derived manifold to explain the complex dynamics of the probability distributions of losses. The regions with expansions identify the ranges of physical parameters for which the extreme tornado events may occur, which helps in assessing compensation strategies.

Finite-time Lyapunov exponent (FTLE) is introduced to study the evolution of streamwise vortices in a cavity flow, which is crucial in the mass exchange and pollutant emission around aircrafts. First, the structures of streamwise vortices are captured using ridges of FTLE, and the evolution of streamwise vortex structures is illustrated in detail. The results show that there exists asymmetry featured by differences in structure and scale between streamwise vortices. Then, the evolution of vortex structures is analyzed and compared. It is found that several critical flow structures inside the cavity could block the forming of certain vortex, causing differences in evolution of vortex structures. Such flow structures are then briefly introduced and studied. Finally, the influences of asymmetry of the flow on streamwise vortex formation are summarized. In conclusion, the differences in flow structures imply that critical flow structures have strong influences on the formation of streamwise vortices, which could serve as a main mean of mass transport across the shear layer. The results provide theoretical support for controlling mass transport and thus reduce pollutant emission through cavity structures.

As a new passive flow control technology, bionic airfoil leading edge can be used for drag reduction control of aircraft, to achieve low carbon dioxide emission in aircraft in the future. Studies have shown that the wave leading edge can delay the flow separation, and improve the aerodynamic performance of the airfoil at a high angle of attack (AOA). However, due to the difficulty of detailed measurement of the complex flow structure on the wave leading edge airfoil surface, its main flow characteristics and formation mechanism have not been fully understood. Therefore, it is necessary to thoroughly explore the measurement method of complex separation flow structure and the control mechanism of wave leading edge on surface topology. In this paper, the Global Luminescent Oil Film (GLOF) surface friction technique based on optical flow is used to obtain the surface flow structure of wave leading edge airfoil and baseline airfoil (NACA0012). Firstly, the principle of GLOF and the wind tunnel experiment setup are introduced. Then, the skin friction lines are drawn from the global skin friction vector information obtained from the experiment to obtain the skin friction topology. The influence of wave leading edge on surface flow structure is also discussed. The isolated singularities and boundary switching points in the topological structure are identified to verify whether they satisfy the conservation law given by Poincare-Bendixson (P-B) index formula. The results show that, compared with baseline airfoils, the topological structure of the airfoil does not change significantly when the AOA of the airfoil is low. At the large AOA, the wave leading edge airfoil increases the vortex structure of the airfoil surface and inhibits the generation of separation flow, thus delaying the stall. In addition, the surface topology can be drastically changed, and the area of the separation zone can be greatly reduced, thus improving the aerodynamic performance.

The evaluation of cultural information is a great challenge for any form of environmental accounting, including the emergy methodology advocated in this paper. What has been needed for some time are better tools to understand and represent culture in quantitative analyses. This paper accomplishes that objective with several innovations. Its focus is one 'scale' in the multiple scales of cultural production and maintenance, as developed in my earlier papers conceiving of culture as a nested hierarchy of information cycles. It is an 'area' analysis, which evaluates the total emergy contributions from the total area of information production, in this case the island of Taiwan. And it is a 'parallel cycles' evaluation that accounts for both the information objects (academic paper, books), but also the information required to manage the systems of information production, specifically the research centers and publication houses. The analysis produces several transformities for information, influenced by the multiple methods proposed by Odum for evaluating information. It concludes that a modified `recipient interaction time' method is the most versatile methodology.

Water is an important natural resource for living things, which needs a proper management system to avoid water scarcity. This study aims to analyze the application of Blue Management Accounting (BMA) at WKP Corporation Headquarters in Indonesia. A qualitative as well as quantitative research approach has been utilized to assess the water footprint, cost, efficiency, savings, and internal controls. The results showed that the water footprint is in accordance with the standard of healthy living. The water cost is still reasonable, and water efficiency is almost achievable and maintained by the company. However, water savings have not been running well, and internal water control has not worked well. This further reflects that, although overall, the implementation of BMA at WKP Corporation Headquarters has not been completely fulfilled, however, efforts made to improve water efficiency. The results also showed that there had been a change in water use that has increased since the COVID-19 pandemic entered Riau Province. Recommendations for the company are to maintain efficient use of water because it is directly related to costs, apply tighter internal controls, especially on the monitoring element, because any risk can occur.

This study examines how board attributes influence quality and quantity disclosure of energy consumed by the listed non-financial firms for the period of 5 years (2016 -- 2020). The study aims at providing empirical evidence on how institutional strength influences the relationship between board attributes and firms' energy in reducing emission discharges and achieving sustainable development goals on world climate policy. The study obtained data from a sample of 78 listed non-financial firms, content analysis technique was employed to compute energy disclosure indexes using Global Reporting Initiatives standards. The study runs a generalized method of movement (GMM) to regulate the impending endogeneity of the selected listed companies in Nigeria. The study also conducted several to robust the findings. The overall results found that board independence has a significant but negative relationship with energy disclosure. Conversely, board ownership and institutional strength have a positive and significant relationship with the energy disclosure. The study documents a significant positive relationship between board independence moderated by institutional strength and energy disclosure. This indicates that institutional strength strengthens the relationship between board independence and energy disclosure. Thus, the United Nation should work hand in hand with governance regulator to poster board independence which will help in embracing the Global Reporting Initiatives standards as the most widely used Environmental, Social and Governance globally. This will expose the peculiarities of most developing nations like Nigeria in adopting the standards and way forwards to attain Sustainable Development Goals 13.