Vol. 12, No. 4 (2024): Regular Issue

Based on game theory, this study established game models composed of recyclers and manufacturers under the government's static and dynamic premium and penalty mechanisms, and then explored the interaction mechanisms of the behavioral strategies for both players. This study analyzed the influence of reward-penalty intensity and the government's recovery and utilization on the recyclers' and manufacturers' recovery strategies. Furthermore, the study analyzed numerical and simulation samples. Results indicated that government regulation and recyclers' and manufacturers' recycling strategies under the dynamic premium and penalty mechanism effectively resolved the instability of the behavioral strategy generated by the static premium and penalty mechanism and achieved evolutionary stability among the three players. The possibility of manufacturers choosing to actively recycle was directly proportional to the government's premium and penalty intensity and inversely proportional to the difficulty coefficient of recovery. The premium and penalty intensity of the government was proportional to the target recovery and recycling rates of waste products.The research in this paper provides a strong basis for government decision making.

This manuscript sets its sight on catering to a consistent picture of how Digitalization Capabilities (DC) demonstrates an impact on Sustainable Auditing Ecosystem (SAE) in public sector organizations (PSOs) of developing countries with a concentration on Vietnam, and gives insights regarding to impacts of Accountants' Digital Intelligence (ADI) in the interconnection between DC and SAE. The structural equation modelling was employed to mathematically analyze the survey data captured from self-administered questionnaire circulated to a convenient and snowball sample of 512 respondents. The acquired outcomes provided statistical evidences to undergird all the proposed hypotheses in the conceptual model. Beyond acting as a fruitful springboard for follow-up studies, the value of more fine-grained insights in this work could guide the practitioners to sense and seize the value of digitalization through formulating strategies and devising interventions pertaining to digitalization issues in PSOs. At the policy degree, the current research also generated a systemic model to formulate and cultivate measures addressing challenges in term of digitalization which thus enabled the design of policies and initiatives for a more inclusive and sustainable collaboration.

The olive tree is a major fruit crop in the Mediterranean Sea area and is responsible for 95% of the world's olive oil production. However, the disposal of the waste generated during olive oil production, known as mill effluent (ME), into rivers leads to surface water pollution. To address this issue, coagulation-flocculation with aluminium sulphate and ferric chloride were tested to reduce the organic matter in ME-contaminated water. The study found that for the same dose of 70 mg.L-1, ferric chloride and aluminium sulphate reduced the organic matter expressed in terms of oxidability by 69.85% and 52.94%, respectively. Prechloration improved the reduction rate of organic matter expressed in terms of oxidability by 12% for aluminium sulphate and around 9% for ferric chloride. Combining coagulants (aluminium sulfate, ferric chloride) with lime further improved the removal rate of organic matter. The organic material removal rate was 50% for 8 mg.L-1 of chlorine, 70 mg.L-1 of aluminum sulfate, and 23.3 mg.L-1 of lime at pH 7.42, while ferric chloride and lime resulted in a 52.38% organic matter removal rate for 8 mg.L-1 of chlorine, 50 mg.L-1 of ferric chloride, and 33.5 mg.L-1 of lime at pH 7.02. These results indicate that coagulation-flocculation with aluminium sulphate and ferric chloride could provide a sustainable approach for reducing water pollution and ensuring efficient use of resources.

The availability of clean water and adequate sanitation facilities are of prime importance for limiting diseases. This study was conducted in the Yaoundé city (equatorial region), Cameroon which, experiences water supply limitations. The populations there in rely on domestic wells for drinking water. The objective was to define the sanitary limit for domestic drinking water wells using multiple linear regression and geographic information system techniques. Firstly, the water quality index (WQI) is calculated for 73 wells analyzed by the relative weight method knowing the measured values of groundwater chemical parameters. Secondly, the WQI values were then estimated and the validation step between the calculated and estimated value gives the coefficient of determination $R{}^{2}=0.83$. The Pearson's correlation shows that hydraulic conductivity, groundwater depth and distance between water wells and latrines were significant parameters for assessing groundwater quality. Finally, multiple linear regression analysis is used to construct the map of the sanitary limit with the independent variables (hydraulic conductivity, groundwater depth and WQI = 25, the average value for excellent water quality) as input parameters. The map of sanitary limit shows that the values vary between 86 m and 170 m and can be used by practitioners for sustainable management of the water resources in this study area.

In this article, we investigate a modified Leslie-Gower predator-prey system with generalised Holling Type-II functional response together with fear effect in prey. The model is extended by incorporating two constant time delays, where the first delay is for density dependent feedback mechanism in the logistic growth of the prey and the second one is for gestation delay of the predator population. The dynamical behaviours such as boundedness, extinction criteria and existence, stability and bifurcations of the equilibria of the non-delay model are qualitatively discussed. The existence of periodic solutions via Hopf-bifurcation with respect to both delays is set up. Finally, numerical simulations have been carried out to confirm our numerical findings.

In the present study, the quantification of criteria gas emissions was analysed according to the economic-environmental account of Ecuador from stationary sources during the period 2008-2017. The stationary sources considered were those involved in industrial, commercial, or service processes, as well as thermoelectric generation and oil refining. The criteria gases analysed were SO$_2$, NO$_X$, CO, NH$_3$, VOC, TOC, PM$_{10}$ and PM$_{2.5}$. The environmental economic account allows determining the reciprocal relationship of the environment (physical units) with the economy (monetary units), through stationary sources, as well as by economic sector (households, industries, and government). The different economic activities belonging to the different sectors were classified according to the International Standard Industrial Classification (ISIC). Emission factors (kg/m$^{3}$) approved by the environmental authority were used. In this way, results were obtained both in a disaggregated manner (by type of industry, type of pollutant and fuel used) as well as in an aggregated manner to obtain the total tons emitted by stationary sources. The criteria air pollutant, with the greatest contribution, from stationary sources was sulphur dioxide (SO$_2$), with a total of 1,088,462.35 tons emitted during the 2008-2017 period. Being the Industrial sector the main contributor to pollution, emitting 707,530.1 tons, specifically the economic activity related to Power Plants, its discharges represented 65 % of the total emissions of SO$_2$.

This paper is devoted to the mathematical modeling and analysing of the distribution of Pb${}^{2+}$ ion concentrations along the Lom River (Adamawa-Cameroon) from the gold mining sites of Wakaso to Djouzami. The one-dimensional advection-dispersion-sorption equation is used to describe the transport of this ion. The Laplace transform technique is applied to obtain the analytical solution of transport equation. The numerical results are obtained by using the finite difference method in space and the algorithm of Runge-Kutta in time. The influence of the dispersion coefficient and flow velocity on the spatial distribution of the concentrations of Pb${}^{2+\ }$ion is illustrated. The experimental results show that this surface water is neutral (pH 6.37-8.12) and has high concentrations in Total Suspended Solids (TSS 46-562 mg L${}^{-1}$). The concentrations of Pb${}^{2+}$ ion range from 0.1 to 0.97 mg L${}^{-1}$. These concentrations exceed the limits of 0.01 mg L${}^{-1}$ set by the World Health Organization (WHO) standard. The results of analytical and numerical studies show that the distribution of Pb${}^{2+\ }$ion concentrations decrease along the section of the Lom River. These results are compared to the experimental data.