The study aims to determine the trust and presence of police officers in schools in Serbia, as well as the perception of the principals and secretaries, teachers and staff, parents, and students on ...how successful the specific police units dedicated to schools were in fulfilling their tasks. The ex-post analysis was conducted through PEST/SWAT analysis, mapping the key actors and using batteries of online questionnaires, besides interviews with the MOI representatives, surveyed with personal interviewing, computer-aided surveying, desk analysis, and content analysis. The survey was conducted from September 2021 to June 2022. The research methods were implemented in 1140 schools in Serbia, and 8,617 people were included in surveys: police officers (308); principals and secretaries (1085); the team for protection against discrimination (982); teachers and staff (2988); parents (938) and students (2316). The relationships between the covariates and perception were investigated using the t-test, one-way ANOVA, multivariate linear regression, and binary regression. The results showed that a project of school police officers was not fully recognized as one of the strategically essential instruments for safe schools; trust is low, but presence is high. Besides that, the results suggest that the entire public believes that police are needed in schools and that it positively affects school safety. Regarding school safety policy, it is necessary to undertake three measures for the sustainable development of trust and the presence of police in school: regulatory, informative-educational, and institutional-organizational.
The shear process can significantly affect the hydro-mechanical properties of rock fractures. In the present study, a new approach is developed to predict the direct shear process of rock fractures ...under the constant normal load condition. This approach is validated by three sets of laboratory direct shear test data and it is then used to study the impact of rock mechanical properties on the shear process. The results show that the presented shear modelling approach can reliably predict the entire shear process of direct shear tests on rough rock fractures under the constant normal load condition. The shear strengths and the normal displacement are sensitive to different physical parameters, which are demonstrated through a comprehensive sensitivity analysis of the physical parameters (i.e., the mechanical properties). The presented shear modelling approach and the sensitivity analysis results are useful for further hydro-mechanical investigations of fractured rocks.
•A new approach for predicting direct shear of rough rock fractures is developed.•The new approach is validated by three sets of laboratory direct shear test data.•The sensitivity of mechanical properties to direct shear of granite fractures is analysed.
We study tracer retention in fractured rock by combing Lagrangian and time domain random walk frameworks, as well as a statistical representation of the retention process. Mass transfer is quantified ...by the retention time distribution that follows from a Lagrangian coupling between advective transport and mass exchange processes, applicable for advection‐dominated transport. A unifying parametrization is presented for generalized diffusion using two rates denoted by k1 and k2 where k1 is a forward rate and k2 a reverse rate, plus an exponent as an additional parameter. For the Fickian diffusion model, k1 and k2 are related to measurable retention properties of the fracture‐matrix by the method of moments, whereas for the non‐Fickian case dimensional analysis is used. The derived retention time distributions are exemplified for interpreting tracer tests as well as for predictive modeling of expected tracer breakthrough. We show that non‐Fickian effects can be notable when transport is upscaled based on a non‐Fickian interpretation of a tracer test for which deviations from Fickianity are relatively small. The statistical representation of retention clearly shows the significance of the forward rate k1 which depends on the active specific surface area and is the most difficult parameter to characterize in the field.
Key Points
A generalized tracer retention formulation with a retention time distribution is derived
Statistical and continuum representations of retention process presented and compared
Potential significance of non‐Fickian diffusion from generic to field case illustrated
When it comes to legitimation and institutional structure, Berger and Luckmann's work remains relevant today despite its age. This paper is an attempt to explore what seems to be an unjustly ...underutilized approach - institutional analysis through legitimation. The first part presents the concept of legitimation and the role it plays in the construction and maintenance of institutions based on the book The Social Construction of Reality. The article argues that institutional analysis through legitimation provides us with knowledge of institutional structure and position as seen by members of society, hence bridging the gap between formal and informal institutions. In the second part, the main ideas are explored as a basis for research and cluster analysis, and a coherent theoretical and methodological approach is suggested.
Recently, Hoang et al. (2021) discussed our paper Zou et al. (2020). In our paper, we made a statement that Dai and Bird (1981)'s solution for two-dimensional (2D) radial Bingham fluid flow between ...parallel plates violates mass balance. Hoang et al. pointed out that Dai and Bird (1981)'s solution does not violate the mass balance because Dai and Bird (1981)'s solution and our analysis are based on different assumptions, i.e. with consideration of the vertical velocity component in the continuity equation or not, which leads to two different approximation models. In this sense, the mass balance of Dai and Bird (1981)'s solution should not be checked using our solution as a reference. In this reply, we add remarks on the two approximation models and their implication for rock grouting analysis. The discussion by Hoang et al. and this reply are helpful to thoroughly eliminate the existing confusion regarding the two solutions in the rock grouting research community.
Alternative evaluation methods are assessed by numerical modeling of pumping tests in three‐dimensional fracture networks. Network scale heterogeneity, fracture‐to‐fracture scale heterogeneity, and ...individual fracture scale heterogeneity (fracture roughness) are considered as representative of multi‐scale hydraulic and structural heterogeneity of crystalline rocks. The results show that ambient hydraulic gradient has a negligible effect on transmissivity inference of sparsely fractured rocks using flow logs. Consequently, the common dual pumping method used to account for the ambient flow can be simplified to a single pumping. This could potentially reduce the site characterization effort in typical applications such as nuclear waste disposal. The transmissivity inference method based on the Thiem solution provides representative median transmissivity. It, however, underestimates relatively high transmissivities due to its inability to account for the impact of fracture roughness. These findings have important implications regarding pumping test schemes and data interpretation methods in the hydrogeological characterization of sparsely fractured rocks using flow‐log data.
Plain Language Summary
In this work, we study the influence of ambient hydraulic gradient on pumping tests in fractured rocks by numerical simulations of groundwater flow in three‐dimensional fracture networks. To represent the more realistic multi‐scale heterogeneity of the hydraulic property in natural rock fracture networks, we considered the aperture variability of individual fractures in addition to the network scale and the fracture‐to‐fracture scale variability regarding the fracture transmissivity. We find that the ambient hydraulic gradient has a negligible effect on inferred transmissivity. Consequently, the common dual pumping method in the field can be replaced by single pumping, which could potentially reduce the field work in the hydrogeological characterization of sparsely fractured rocks. We also find that the Thiem solution appears to be sufficiently accurate for inferencing the median value of transmissivity and fracture‐to‐fracture scale transmissivity. However, inferred transmissivity underestimates the relatively high transmissivity values once the aperture variability of individual fractures is considered because the Thiem solution does not account for transmissivity variations at the individual fracture scale. The result presented in this work can be used as a basis for improving pumping test practice and data interpretation in the hydrogeological characterization of sparsely fractured rocks.
Key Points
Ambient flow has negligible impact on transmissivity inference in sparsely fractured rocks using flow logs
Dual pumping method that accounts for ambient flow can be potentially simplified as single pumping for transmissivity inference
The transmissivity inference method based on the Thiem solution provides representative median values but underestimates high values
The significance of fracture roughness for hydraulic characterization of sparsely fractured (crystalline) rock using flow logs under steady‐state pumping conditions is investigated by numerical ...simulations in three‐dimensional fracture networks. A new solver for simulating flow in three‐dimensional discrete fracture networks is implemented using a hybrid finite volume and finite element method. The analysis is focused on different scales of heterogeneity in three‐dimensions: the network scale heterogeneity, the fracture‐to‐fracture scale heterogeneity, and the individual fracture scale heterogeneity (fracture roughness). The results show that the individual fracture scale heterogeneity due to fracture roughness is potentially an additional source of uncertainty for hydraulic tests in fractured rocks using flow logs. Specifically, it enhances the variation in measured flowrates and inferred transmissivity in addition to the network scale heterogeneity and the fracture‐to‐fracture scale heterogeneity. However, the individual fracture scale heterogeneity has relatively small impact on the inferred transmissivity distributions compared to the fracture‐to‐fracture scale heterogeneity. Moreover, fracture roughness and fracture‐to‐fracture heterogeneity have limited influence on the median values of the inferred transmissivity such that the median transmissivity is mostly reliable when inferred from flow logs. Comparison between the inferred and underlying input transmissivity distributions shows that interpreting hydraulic tests in crystalline rock using flow logs and the Thiem equation may underestimate the variation range of the underlying transmissivity. The results are helpful for understanding the uncertainty in hydraulic characterization of sparsely fractured rocks using flow logs that are relevant for various geo‐engineering and water resources applications.
Plain Language Summary
We study the impact of fracture roughness on inferred transmissivity from flow log information, in three‐dimensional discrete fracture networks of crystalline rocks. For simulation of water flow, a new solver for three‐dimensional discrete fracture networks using a hybrid finite volume and finite element method is implemented in this work to include borehole hydraulics. We consider three scales of heterogeneity in discrete fracture networks: the network scale heterogeneity, the fracture‐to‐fracture heterogeneity, and the individual fracture roughness. We find that the fracture roughness slightly increases the variability of measured flowrates and inferred transmissivity. The median values of the inferred transmissivity are close to that of the actual underlying input transmissivity, indicating that the fracture roughness has limited impact on the median values. In other words, median values of transmissivity inferred from flow logs under steady‐state pumping are generally representative for the median values of the underlying transmissivity distributions. The method presented in this study is useful for modeling flow in sparsely fractured crystalline rock with conducting boreholes and rough fractures, while the presented results are helpful for understanding and quantifying uncertainty in transmissivity distributions inferred from flow log measurements.
Key Points
Three scales of hydraulic heterogeneity affect variability of measured flowrate and inferred transmissivity
Fracture roughness has relatively small impact on inferred transmissivity compared to the fracture‐to‐fracture scale heterogeneity
The median value of inferred transmissivity from flow logs is representative of the underlying transmissivity distribution
This study uses controlled numerical experimentation to comparatively simulate and investigate solute transport and concentration responses and patterns in the Baltic Sea for various solute releases ...from the land through two different coastal cases. These cases are the Swedish Kalmar County coast and the Polish coast of the Vistula River outlet. For equivalent solute releases, the coastal flow conditions and their interactions with main marine currents determine the local coastal solute spreading, while the overall spreading over the Baltic Sea is similar for the two coastal cases, despite their large local differences. For nutrient-proportional solute release scenarios, the highly-populated Vistula catchment yields much greater total, but smaller per-capita nutrient impacts, in the Baltic Sea than the Kalmar County catchment. To be as low as from the Vistula catchment, the per-capita nutrient contribution from Kalmar County would have to be reduced much more than required on average per Swedish inhabitant by the Baltic Sea Action Plan. This highlights an unfairness issue in the per-capita distribution of nutrient load allowance among the Baltic countries, which needs to be considered and handled in further research and international efforts aimed to combat the Baltic Sea eutrophication.
In the context of accelerated urbanization, socioeconomic development, and population growth, as well as the rapid advancement of information and communication technology (ICT), urban land is rapidly ...expanding worldwide. Unplanned urban growth has led to the low utilization efficiency of land resources. Also, ecological and agricultural lands are continuously sacrificed for urban construction, which in the long-term may severely impact the health of citizens in cities. A thorough understanding of the mechanisms and driving forces of a city’s urban land use changes, including the influence of ICT development, is therefore crucial to the formation of optimal and feasible urban planning in the new era. Taking Nanjing as a study case, this article attempts to explore the measurable “smart” driving indicators of urban land use change and analyze the tapestry of the relationship between these and urban land use change. Different from the traditional linear regression analysis method of driving force of urban land use change, this study focuses on the interaction relationship and the underlying causal relationship among various “smart” driving factors, so it adopts a fuzzy statistical method, namely the grey relational analysis (GRA). Through the integration of literature research and known effective data, five categories of “smart” indicators have been taken as the primary driving factors: industry and economy, transportation, humanities and science, ICT systems, and environmental management. The results show that these indicators have different impacts on driving urban built-up land growth. Accordingly, optimization possibilities and recommendations for development strategies are proposed to realize a “smarter” development direction in Nanjing. This article confirms the effectiveness of GRA for studies on the driving mechanisms of urban land use change and provides a theoretical basis for the development goals of a smart city.
Adverse outcomes from 2014 flooding in Serbia indicated problematic response phase management accentuated by a gender imbalance. For this reason, we investigated the risk perceptions and preparedness ...of women and men regarding these types of events in Serbia. Face-to-face interviews, administered to 2500 participants, were conducted across 19 of 191 municipalities. In light of the current findings, men seemed to be more confident in their abilities to cope with flooding, perceiving greater individual and household preparedness. By contrast, women displayed a deeper understanding of these events. Perhaps owing to a deeper level of understanding, women demonstrated more household-caring attitudes and behaviors and were more prone to report a willingness to help flood victims at reception centers. Emergency management agencies and land planners should account for these differences in gender awareness and preparedness. Based on these findings, doing so may increase citizen participation and shared responsibility under flood hazard scenarios.
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