scholarly journals Application of Stable Water Isotopes to Improve Conceptual Model of Alluvial Aquifer in the Varaždin Area

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 379 ◽  
Author(s):  
Tamara Marković ◽  
Igor Karlović ◽  
Melita Perčec Tadić ◽  
Ozren Larva

To understand groundwater flow and geochemical processes within an aquifer, it is necessary to set up a conceptual model of the aquifer. To accomplish this, different methods are used, and one of them is an isotopic technique. The study area is located in the Varaždin area (NW Croatia). The aquifer represents the main source of potable water for the town of Varaždin and the surrounding settlements. The conceptual model of the alluvial aquifer has to be set up prior to creating a groundwater flow and transport model. Measurements of ratios δ18Ο and δ2H in ground- and surface waters and precipitation samples were carried out. The relationship between ratios δ18Ο, δ2H, and d-excess for local precipitation in the study area showed that precipitation originates from the Atlantic air masses, although during the colder periods of the year, influence of the Mediterranean air masses was not negligible. The monitored period was warmer and wetter than average. Evaporation was observed at all monitored surface waters, but the largest rate was at the location of a gravel pit in Šijanec. The isotopic composition of the precipitation and groundwater showed a good correlation due to the isotopic homogenization of groundwater along the flow path.

Author(s):  
Riccardo Armellini ◽  
Elena Baldini ◽  
Dario Del Seppia ◽  
Fabrizio Franceschini ◽  
Natacha Gori ◽  
...  

This work provides a groundwater flow and transport model of trichlorethylene and tetrachlorethylene contamination in the Cecina’s coastal aquifer. The contamination analysis, with source located in the Poggio Gagliardo area (Montescudaio, Pisa), was necessary to optimize the groundwater monitoring and remediation design. The work was carried out in two phases: • design of a conceptual model of the aquifer using GIS analysis of many stratigraphic, chemical and hydrogeological data, collected from 2004 to 2012 in six aqueduct wells; • implementation of a groundwater flow and transport numerical model using the MODFLOW 88/96 and MT3D code and the graphical user interface GroundWaterVistas 5. The conceptual model hypothesizes a multilayer aquifer in the coastal plain extended to the sandy-clay hills, recharged by rainfall and by the Cecina River. The aquifer shows important hydrodynamic features affecting both the contamination spreading, due to the presence of a perched and heavily polluted layer separate from the underlying productive aquifer, and the hydrological balance, due to a thick separation layer that limits exchanges between the river and the second groundwater aquifer. The numerical model, built using increasingly complex versions of the initial conceptual model, has been calibrated using monitoring surveys conducted by the Environmental Protection Agency of Regione Toscana (ARPAT), in order to obtain possible forecast scenarios based on the minimum and maximum flow periods, and it is currently used as a tool for decision support regarding the reclamation and/or protection of the aquifer. Future developments will regard the implementation of the multilayer transport model, based on a new survey, and the final coupling with the regional hydrological model named MOBIDIC.


2011 ◽  
Vol 11 (8) ◽  
pp. 23469-23511
Author(s):  
S. L. Capps ◽  
D. K. Henze ◽  
A. Hakami ◽  
A. G. Russell ◽  
A. Nenes

Abstract. We present the development of ANISORROPIA, the discrete adjoint of the ISORROPIA thermodynamic equilibrium model that treats the Na+-SO42−-HSO4−-NH4+-NO3−-Cl−-H2O aerosol system, and we demonstrate its sensitivity analysis capabilities. ANISORROPIA calculates sensitivities of an inorganic species in aerosol or gas phase with respect to the total concentrations of each species present with only a two-fold increase in computational time over the forward model execution. Due to the highly nonlinear and discontinuous solution surface of ISORROPIA, evaluation of the adjoint required a new, complex-variable version of the the model, which determines first-order sensitivities with machine precision and avoids cancellation errors arising from finite difference calculations. The adjoint is verified over an atmospherically relevant range of concentrations, temperature, and relative humidity. We apply ANISORROPIA to recent field campaign results from Atlanta, GA, USA, and Mexico City, Mexico, to characterize the inorganic aerosol sensitivities of these distinct urban air masses. The variability in the relationship between PM2.5 mass and precursor concentrations shown has important implications for air quality and climate. ANISORROPIA enables efficient elucidation of aerosol concentration dependence on aerosol precursor emissions in the context of atmospheric chemical transport model adjoints.


Author(s):  
T. G. Naymik

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.


2019 ◽  
Vol 16 (3) ◽  
pp. 417-428
Author(s):  
Özgün Ünver ◽  
Ides Nicaise

This article tackles the relationship between Turkish-Belgian families with the Flemish society, within the specific context of their experiences with early childhood education and care (ECEC) system in Flanders. Our findings are based on a focus group with mothers in the town of Beringen. The intercultural dimension of the relationships between these families and ECEC services is discussed using the Interactive Acculturation Model (IAM). The acculturation patterns are discussed under three main headlines: language acquisition, social interaction and maternal employment. Within the context of IAM, our findings point to some degree of separationism of Turkish-Belgian families, while they perceive the Flemish majority to have an assimilationist attitude. This combination suggests a conflictual type of interaction. However, both parties also display some traits of integrationism, which points to the domain-specificity of interactive acculturation.


2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Sunita ◽  
Urvashi Singh ◽  
Shalini Singh ◽  
Rajnee Sharma

The present study was conducted to examine the relationship between organisational stress and organisational citizenship behaviours (OCBs) in employees of call centers. The study also further explored as how stress at work set-up has negative impact on OCBs. A sample of 250 employees working in call centre of Gurgaon belonging to an age group of 25-30 years were selected on availability basis. All were working married couples living in nuclear families. Job stress survey (Spielberger & Vagg, 1999) and Organisational Citizenship Behaviour (Bateman & Organ, 1983) were administered. Data was analysed by using simple correlation and multiple regression. Results showed the negative relationship between organisational stress and OCBs. Results of regression analysis also exhibited the negative impact of stress on OCBs. The implications for the employees are discussed.


2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Ginu George ◽  
Binoy Joseph

Employee engagement is becoming an important area of focus by many HR consultancies in the recent years. Organizations having engaged employees tend to out-perform than employees who are not engaged or disengaged, also it will enable them to compete better in their industry resulting in higher performance, lower turnover, more profitability etc., Despite of all this there are still some industries who are ignorant and neglect the importance of having engaged employees. Therefore there is a necessity for more of academic research on employee engagement which helps in creating awareness to these organizations about the prominence of focusing on employee engagement and the findings will also augments the existing literature on employee engagement. The study was conducted on 433 employees working in travel organizations set up in Bangalore with the purpose of determining the relationship psychological climate (antecedent) has on employee engagement and in turn its relationship with organizational citizenship behavior (outcome). The study also determines the mediating relationship of employee engagement between PC and OCB.


Author(s):  
Donghui Zhang ◽  
Ruijie Liu

Abstract Orienteering has gradually changed from a professional sport to a civilian sport. Especially in recent years, orienteering has been widely popularized. Many colleges and universities in China have also set up this course. With the improvement of people’s living conditions, orienteering has really become a leisure sport in modern people’s life. The reduced difficulty of sports enables more people to participate, but it also exposes a series of problems. As the existing positioning technology is relatively backward, the progress in personnel tracking, emergency services, and other aspects is slow. To solve these problems, a new intelligent orienteering application system is developed based on the Internet of things. ZigBee network architecture is adopted in the system. ZigBee is the mainstream scheme in the current wireless sensor network technology, which has many advantages such as convenient carrying, low power consumption, and signal stability. Due to the complex communication environment in mobile signal, the collected information is processed by signal amplification and signal anti-interference technology. By adding anti-interference devices, video isolators and other devices, the signal is guaranteed to the maximum extent. In order to verify the actual effect of this system, through a number of experimental studies including the relationship between error and traffic radius and the relationship between coverage and the number of anchor nodes, the data shows that the scheme studied in this paper has a greater improvement in comprehensive performance than the traditional scheme, significantly improving the accuracy and coverage. Especially the coverage is close to 100% in the simulation experiment. This research has achieved good results and can be widely used in orienteering training and competition.


2021 ◽  
Vol 13 (8) ◽  
pp. 4448
Author(s):  
Alberto Dianin ◽  
Elisa Ravazzoli ◽  
Georg Hauger

Increasing accessibility and balancing its distribution across space and social groups are two fundamental goals to make transport more sustainable and equitable. In the next decades, autonomous vehicles (AVs) could significantly transform the transport system, influencing accessibility and transport equity. In particular, depending on the assumed features of AVs (e.g., private or collective) and the considered spatial, social, and regulative context (e.g., rural or urban areas), impacts may be very different. Nevertheless, research in this field is still limited, and the relationship between AV assumptions and accessibility impacts is still partially unclear. This paper aims to provide a framework of the key and emerging aspects related to the implications of AVs for accessibility and transport equity. To set this framework, we perform an analysis of the scientific literature based on a conceptual model describing the implications of AVs for the distribution of accessibility across space and social groups. We recognize four main expected impacts of AVs on accessibility: (1) accessibility polarization, (2) accessibility sprawl, (3) exacerbation of social accessibility inequities, and (4) alleviation of social accessibility inequities. These impacts are described and analyzed in relation to the main AV assumptions expected to trigger them through different mechanisms. Based on the results, some recommendations for future studies intending to focus on the relation between AVs, accessibility, and transport equity are provided.


2021 ◽  
Vol 13 (11) ◽  
pp. 6494
Author(s):  
Grzegorz Baran ◽  
Aleksandra Berkowicz

The main idea of the paper is to combine modern research methods (as living labs that enable research in a real-life setting) with the new technological opportunities for entrepreneurship and innovation development (as digital platforms) to search for innovative solutions, while addressing the sustainable development problems. Thus, the paper aims to explain how real value for society is created within digital platform ecosystems and how they employ to this end novel solutions that better address existing social problems. Consequently, it proposes a conceptual framework to research and develop sustainable entrepreneurship and innovation with the use of digital platforms. This research study takes a synthesizing conceptual approach that seeks to integrate the existing knowledge drawn on two major streams of research: living labs as a methodology and digital platform ecosystems to enrich the theory of sustainable entrepreneurship and innovation development. The paper contributes to the body of knowledge by proposing a novel conceptual model of digital platform ecosystems as living labs for sustainable entrepreneurship and innovation. The model depicts digital platform ecosystems examined as living labs and the implicit processes that include platform users in problem-solving and value-creation in real-life settings. The novelty of the model stems from framing these processes that capture the relationship between individuals and opportunities as the foundations of entrepreneurship and the relationship between the problem space and the solution space, where the opportunities occur.


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