bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconciling Negative Soil CO2 Fluxes: Insights from a Large-Scale Experimental Hillslope
Authors: Cueva Alejandro , Volkmann Till H. M. , van Haren Joost , Troch Peter A. , Meredith Laura K.
Published: January 2019

Soil fluxes of CO2 (Fs) have long been considered unidirectional, reflecting the predominant roles of metabolic activity by microbes and roots in ecosystem carbon cycling. Nonetheless, there is a growing body of evidence that non-biological processes in soils can outcompete biological ones, pivoting soils from a net source to sink of CO2, as evident mainly in hot and cold deserts with alkaline soils. Widespread reporting of unidirectional fluxes may lead to misrepresentation of Fs in process-based models and lead to errors in estimates of local to global carbon balances. In this study, we investigate the variability and environmental controls of Fs in a large-scale, vegetation-free, and highly instrumented hillslope located within the Biosphere 2 facility, where the main carbon sink is driven by carbonate weathering. We found that the hillslope soils were persistent sinks of CO2 comparable to natural desert shrublands, with an average rate of −0.15 ± 0.06 µmol CO2 m2 s−1 and annual sink of −56.8 ± 22.7 g C m−2 y−1. Furthermore, higher uptake rates (more negative Fs) were observed at night, coinciding with strong soil–air temperature gradients and [CO2] inversions in the soil profile, consistent with carbonate weathering. Our results confirm previous studies that reported negative values of Fs in hot and cold deserts around the globe and suggest that negative Fs are more common than previously assumed. This is particularly important as negative Fs may occur widely in arid and semiarid ecosystems, which play a dominant role in the interannual variability of the terrestrial carbon cycle. This study contributes to the growing recognition of the prevalence of negative Fs as an important yet, often overlooked component of ecosystem C cycling.
County-Scale Destination Migration Attractivity Measurement and Determinants Analysis: A Case Study of Guangdong Province, China
Authors: Yang Qingsheng , Zhang Hongxian , M Mwenda Kevin
Published: January 2019

Measuring destination attractivity and finding the determinants of attractivity at the county scale can finely reveal migration flows and explain what kinds of counties have higher attractivity. Such understanding can help local governors make better policies to enhance county attractivity and attract more migrants for regional development. In this study, the county-scale relative intrinsic attractivity (RIA) of Guangdong Province is computed using the number of migrants and the corresponding distances between origins and destinations. The results show that the RIA has a higher positive correlation with the flows of migrants to destination and demonstrates an obvious phenomenon of distance decay. The RIA decreases faster when the distance between origins and destinations increases. Spatially, the RIA reveals a core-periphery belt pattern in Guangdong Province. The center of the Pearl River Delta is the highest core of RIA and the outside areas of the delta represent the low-RIA belt. The highest RIA is 6811 in Dongguan City and the lowest RIA is 1 in Yangshan County. The core area includes Dongguan, Shenzhen City and the southern regions of Guangzhou, Foshan and Zhongshan City where the RIA value is higher than 1000. The second belt is mainly composed of the periphery districts of the Pearl River Delta, which include Shunde, Nanhai, Luohu, Tianhe Huicheng, Panyu, Haizhu, Huiyang, Huadu, Yuexiu, Xiangzhou and the Yuexiu, Huangpu and Boluo, where the RIA values are higher than 100 and lower than 1000. The third belt includes the western wing, eastern wing and northern area. Most of these RIA values range from 1 to 2. In this belt, there are three areas with relatively higher RIA attractivity scattered in the ring: the downtowns of Zhanjiang City, Chaozhou and Shantou Cities and Shaoguan City. The areas farther away from the core have a lower RIA score. Determinants analysis indicates that the RIA is positively determined by destination economic development level, social service and living standard level and destination population quality. A region will be more attractive if it has higher per capital GDP, tertiary industry level, investment and number of industrial enterprises involved in economic development. A region with a high annual average wage of employees and high social service and living standards will be more attractive, while a region with low destination population quality, including aspects such as the adult illiteracy rate, will be less attractive.
Analysis of the Wider Economic Impact of a Transport Infrastructure Project Using an Integrated Land Use Transport Model
Authors: Wang Wanle , Zhong Ming , Hunt John Douglas
Published: January 2019

Major cities in developing countries are undergoing massive transportation infrastructure construction, which has significant impacts on the land use and economic activities in these cities. Standard Cost–Benefit Analysis (CBA) is applied to quantify the user benefits of transport projects, but does not provide an answer as to who will obtain the benefits and who will lose out and excludes the calculation of Wider Economic Impacts (WEIs) which can sometimes be large and hardly negligible. This paper introduces thoughts and experiences obtained through the design and development of an integrated land use transport model for the assessment of the WEI of a transport infrastructure project. The development and application of such an integrated model for WEI analysis should help decision-makers understand not only the “direct or immediate” impact of transport infrastructure on mobility, but also those “indirect or long-term” impacts on the distribution patterns of economic activities, corresponding land use, and resulting urban structure.
Tacit Collusion of Pricing Strategy Game between Regional Ports: The Case of Yangtze River Economic Belt
Authors: Dong Gang , Zhong Dandan
Published: January 2019

We develop a game model to analyze the tacit collusion between regional ports under three different scenarios. In the first scenario, there is simultaneous pricing game between regional ports; this intends to depict pricing strategy adopted independently. In the second, we consider two competing ports that make sequential pricing decisions. Thirdly, an infinitely repeated game model is then formulated for regional ports to test the stability of Nash equilibrium. Our main finding is that there is a certain degree of tacit collusion of pricing strategy between regional ports in the competitive environment; in particular, the tacit collusion of pricing strategy will gradually stabilize with the increasing number regional ports games. A case study of Yangtze River Economic Belt is provided to illustrate the results.
The Common Good Provision Scale (CGP): A Tool for Assessing People’s Orientation towards Economic and Social Sustainability
Authors: Castiglioni Cinzia , Lozza Edoardo , Bonanomi Andrea
Published: January 2019

Many governments and institutions are currently challenged with insecurity, economic instability, and ongoing turbulence which may undermine the quality of life of each human being and the sustainable development of civil society. As this kind of sustainable development is strictly related to the promotion of the ‘common good’, it is of paramount importance to understand the different motives that lead people to give their contribution to the common good, in order to sustainably align individual needs with the needs of the society. By adopting a psychological perspective for the promotion of the sustainable development, the aim of this study is to develop and validate a new metric, the Common Good Provision scale (CGP), to assess people’s orientation towards economic and social sustainability. Items were generated from a preliminary qualitative study investigating meaning and representations on the common good and its provision. Both exploratory and confirmatory factor analyses were undertaken to validate and improve the scale. The final scale, which consists of seven items, contains two dimensions: Accessibility (i.e., making the common good accessible to anyone and fulfilling people’s basic needs) and Personal Gain (i.e., getting a return and personal advantage in exchange for one’s contribution). In addition, we tested a model in relation to a specific form of contribution: Paying taxes and making charitable donations, that are two complementary ways to financially provide for the common good. It was found that when the Accessibility motive prevails, people are more willing to pay taxes and make donations, whereas when the Personal Gain motive prevails, people are more likely to commit tax evasion and less willing to make monetary donations. The study is novel in that it represents the first attempt to develop a metric to assess people’s motives towards the common good provision. Potentialities and further applications of the CGP scale to other contexts are discussed in relation to the promotion of people’s wellbeing and sustainable development.
Struvite Phosphorus Recovery from Aerobically Digested Municipal Wastewater
Authors: Hallas John , Mackowiak Cheryl , Wilkie Ann , Harris Willie
Published: January 2019

Small, municipal wastewater treatment plants (WWTPs) that use aerobic digestion treat approximately 40% of the discharged wastewater in the USA, and yet they are an overlooked source of recoverable P. There are no known reports of small, aerobic WWTPs recovering P through struvite (MgNH4PO4·6H2O) precipitation for repurposing as a mineral fertilizer, even though some large WWTPs with anaerobic digestion are. Four small WWTPs in north Florida, USA, with treatment capacities from 371 to 2650 m3 wastewater d−1 and incoming P loads from 2 to 14 kg d−1 were investigated for their potential to produce struvite from digester filtrates. A chemical equilibrium model was used to predict the feasibility of struvite production and the results compared with actual WWTP filtrate measurements. Filtrates from aerobic digesters were able to form struvite if solution pH was increased by ≤1 pH unit. Depending on the WWTP, P recovery in filtrates through struvite precipitation ranged from 27–57% by mass at pH 8.5, via NaOH additions or air sparging. Increasing filtrate Mg concentrations improved P recovery up to 97%. Based upon these results, small WWTPs using aerobic digestion will be able to lower their P waste output through recovery as struvite fertilizer.
The Growth Promotion of Two Salt-Tolerant Plant Groups with PGPR Inoculation: A Meta-Analysis
Authors: Pan Jing , Peng Fei , Xue Xian , You Quangang , Zhang Wenjuan , Wang Tao , Huang Cuihua
Published: January 2019

Understanding the primary mechanisms for plant promotion under salt stress with plant growth promoting rhizobacteria (PGPR) inoculation of different salt-tolerant plant groups would be conducive to using PGPR efficiently. We conducted a meta-analysis to evaluate plant growth promotion and uncover its underlying mechanisms in salt-sensitive plants (SSP) and salt-tolerant plants (STP) with PGPR inoculation under salt stress. PGPR inoculation decreased proline, sodium ion (Na+) and malondialdehyde but increased plant biomass, nutrient acquisition (nitrogen, phosphorus, potassium ion (K+), calcium ion (Ca2+), and magnesium ion (Mg2+)), ion homeostasis (K+/Na+ ratio, Ca2+/Na+ ratio, and Mg2+/Na+ ratio), osmolytes accumulation (soluble sugar and soluble protein), antioxidants (superoxide dismutase), and photosynthesis (chlorophyll, carotenoid, and photosynthetic rate) in both SSP and STP. The effect size of total biomass positively correlated with the effect sizes of nutrient acquisition and the homeostasis of K+/Na+, and negatively correlated with the effect size of malondialdehyde in both SSP and STP. The effect size of total biomass also positively correlated with the effect sizes of carotenoid and the homeostasis in Ca2+/Na+ and Mg2+/Na+ and negatively correlated with the effect size of Na+ in SSP, but it only negatively correlated with the effect size of Ca2+ in STP. Our results suggest that the plant growth improvement depends on the nutrient acquisition enhancement in both SSP and STP, while ion homeostasis plays an important role and carotenoid may promote plant growth through protecting photosynthesis, reducing oxidative damage and promoting nutrient acquisition only in SSP after PGPR inoculation under salt stress.
Practical Road-Resistance Functions for Expressway Work Zones in Occupied Lane Conditions
Authors: Zhang Chi , Qin Jihan , Zhang Min , Zhang Hong , Hou Yudi
Published: January 2019

In order to create a practical road-resistance function for work zones under different lane occupation conditions, the expected speed of vehicles was calibrated in the work zone simulation model based on measured data, and simulation models were constructed for the closed half lane and the closed inside lane under different rates of trucks. Based on the statistical theory, the influence of significance of traffic volume and truck ratios for road resistance was analyzed, and a suitable truck ratio was found for the work zone. By using the optimal nonlinear fitting theory, the practical road-resistance function for work zones under different lane occupation conditions was constructed. The results showed that the road resistance is significantly affected by the traffic volume and rate of trucks. Under the same truck ratio, the road resistance linearly increases slowly when the traffic volume is less than the critical traffic volume and rapid increases irregularly when it is greater than the critical traffic volume. Under the same traffic load, the road resistance of the work zone increases with the increase in the rate of trucks, and the difference is not obvious when the traffic volume is less than the critical traffic volume, and increases gradually when it is greater than the critical traffic volume. Through the goodness of fit test and the homogeneity of variance test, the road-resistance function constructed in this paper has high goodness of fit. The practical road-resistance functions constructed in this study could be used to guide the diversion of the rebuilt/expanded highway to ensure traffic safety. Further, the study provides a theoretical basis for the construction of intelligent highway work zones.
Toward Sustainable Overseas Mobility of Vietnamese Students: Understanding Determinants of Attitudinal and Behavioral Loyalty in Students of Higher Education
Authors: Lai Sue Ling , Pham Hiep-Hung , Nguyen Hong-Kong To , Nguyen The-Cuong , Le Anh-Vinh
Published: January 2019

Research on internationalization in higher education has not shed enough light on how cross-border student mobility might contribute to the issue of sustainability. Given that a sustainable movement of loyal international students could help sustain the financial income, ranking, and prospective human resources of the host universities and countries, this study aims to investigate the mechanisms that lead to such loyalty. Specifically, this study adds to the literature by examining how switching cost interacts with disconfirmation and satisfaction in generating attitudinal and behavioral loyalty among international students. The study, surveying 410 Vietnamese students who are studying at either at the undergraduate or graduate level in 15 countries across the globe, first adopts confirmatory factor analysis (CFA) using software SAS 9.3 to evaluate if multiple fit indices, the standardized factor loading, and the average variance extracted scores are satisfactory. It then employs the Structural Equation Model (SEM) to test five hypotheses concerning the interaction between disconfirmation and satisfaction as well as among satisfaction, switching cost and behavioral/attitudinal loyalty. The results find that disconfirmation has both direct and indirect impact, while satisfaction only has a direct impact on attitudinal loyalty. Meanwhile, switching cost is found to have a direct impact on behavioral loyalty, but not on attitudinal loyalty. Based on these findings, the study proposes some theoretical and managerial implications for sustainability in general and sustainability of higher education in particular as well as direction for future studies.
An Investigation of the Feasibility of the Organic Municipal Solid Waste Processing by Coking
Authors: Paukov Alexey , Magaril Romen , Magaril Elena
Published: January 2019

In the context of transition to a circular economy, one of the strategic priorities is the development of technological innovations aimed at waste processing. In this study, the foundations have been developed for a low-temperature, environmentally safe method for efficient processing of organic municipal solid waste, which may be further applied for processing both municipal and industrial waste organics in order to obtain liquid products. The maximum yield of liquid products is ensured when conducting the coking of a mixture of organic waste with long residuum in the temperature range of 400–420 °C, with a heating rate of 5–70 °C/min, and with an optimal heating time to the coking temperature of 80 min. Recommendations on the use of the waste recycling products are given. The proposed process is consistent with the principles of circular economy and does not require external energy costs because the energy needed for the process is generated by burning the gas produced during the waste coking. The process does not produce emissions into the environment and, in combination with standard refining processes, can be used to obtain commercial petroleum products.
An Exploration of Factors Affecting Drivers’ Daily Fuel Consumption Efficiencies Considering Multi-Level Random Effects
Authors: Li Dawei , Li Cheng , Miwa Tomio , Morikawa Takayuki
Published: January 2019

This paper investigates the factors affecting drivers’ vehicle fuel consumption efficiency, which was defined as the daily average fuel consumption for a unit of driving mileage. Based on the long-term Controller Area Network (CAN) data collected from private cars during 10 months in Toyota City, Japan, we explored the relationships between drivers’ fuel consumption efficiencies, and factors including drivers’ characteristics, car attributes, date-specific environmental attributes, and travel behavior. Furthermore, a multi-level model was applied to explicitly incorporate the effects of individual-specific, date-specific, and observation-specific unobserved factors. According to the estimation results, it was found that, on working days, model fit was significantly enhanced by incorporating all three error terms. Several findings regarding the relationships between observed factors and drivers’ fuel consumption efficiencies were also obtained.
The Method of Planning Green Infrastructure System with the Use of Landscape-Functional Units (Method LaFU) and its Implementation in the Wrocław Functional Area (Poland)
Authors: Niedźwiecka-Filipiak Irena , Rubaszek Justyna , Potyrała Jerzy , Filipiak Paweł
Published: January 2019

Green infrastructure (GI) is planned at various scales, including a regional one: city-regions. Strategic GI planning included in the city-regions spatial development policy can contribute to their sustainable development through, among others, providing a range of ecosystem services. In order to meet the challenge of planning GI on a regional scale, the authors present the Method of Landscape-Functional Units (Method LaFU), which is used for the planning and evaluation of such systems. This method was tested in the Wrocław Functional Area (WFA), which is characterized by many negative processes, primarily uncontrolled development of built-up areas, fragmentation of landscape, and declining natural and semi-natural areas. The presented results show the effectiveness of the Method LaFU in GI planning and, above all, in its assessment, which makes it possible to identify problem areas that are at risk but still important for the functioning of the GI system. This allows for quick decision making by entities responsible for spatial planning in the region. The proposed method can also be used in other city-regions.
Effects of Vegetation Pattern and Spontaneous Succession on Remediation of Potential Toxic Metal-Polluted Soil in Mine Dumps
Authors: Chen Fuyao , Yang Yongjun , Mi Jiaxin , Liu Run , Hou Huping , Zhang Shaoliang
Published: January 2019

The ecological rehabilitation of potential toxic metal-contaminated soils in sites disturbed by mining has been a great challenge in recent decades. Phytoremediation is one of the most widely promoted renovation methods due to its environmental friendliness and low cost. However, there is a lack of in situ investigation on the influence of vegetation pattern and spontaneous succession on the rehabilitation of potential toxic metal-polluted soil. To clarify how the vegetation pattern in the early stage of restoration and the spontaneous succession influence the remediation of the soil, we investigated a metal mining dump in Sichuan, China, by field investigation and laboratory analysis. We determined the plant growth, soil fertility, and the capacity of potential toxic metals (PTMs) in metal mining soil under different initial vegetation patterns for different years to understand the role of vegetation pattern and spontaneous succession in PTM pollution phytoremediation projects. The results show that: (1) Phytoremediation with a simple initial vegetation pattern (RP rehabilitative plant pattern) which involves two rehabilitation plants, Agave sisalana and Neyraudia reynaudiana, achieves a PTM pollution index that is 9.28% lower than that obtained with the complex vegetation pattern (RP&LP rehabilitation plants mixed with local plants pattern), 21.86% lower in the soil fertility index, and 73.69% lower in the biodiversity index; (2) The phytoremediation with the 10-year RP&LP pattern was associated with a PTM pollution index that was 4.04% higher than that for the 17-year RP&LP pattern, a soil fertility index that was 4.48% lower, and a biodiversity index that was 12.49% lower. During the process of vegetation succession, if accumulator plants face inhibition of growth or retreat, the reclamation rate will decrease. The vegetation patterns influence the effect of phytoremediation. Spontaneous vegetation succession will cause the phytoremediation process to deviate from the intended target. Therefore, according to the goal of vegetation restoration, choosing a suitable vegetation pattern is the main premise to ensure the effect of phytoremediation. The indispensable manipulation of succession is significant during the succession series, and more attention should be paid to the rehabilitative plants to ensure the stable effect of reclamation. The results obtained in this study could provide a guideline for the in situ remediation of PTM-polluted soil in China.
Vacuum Condensate Picture of Quantum Gravity
Authors: Hamber Herbert
Published: January 2019

In quantum gravity perturbation theory in Newton’s constant G is known to be badly divergent, and as a result not very useful. Nevertheless, some of the most interesting phenomena in physics are often associated with non-analytic behavior in the coupling constant and the existence of nontrivial quantum condensates. It is therefore possible that pathologies encountered in the case of gravity are more likely the result of inadequate analytical treatment, and not necessarily a reflection of some intrinsic insurmountable problem. The nonperturbative treatment of quantum gravity via the Regge–Wheeler lattice path integral formulation reveals the existence of a new phase involving a nontrivial gravitational vacuum condensate, and a new set of scaling exponents characterizing both the running of G and the long-distance behavior of invariant correlation functions. The appearance of such a gravitational condensate is viewed as analogous to the (equally nonperturbative) gluon and chiral condensates known to describe the physical vacuum of QCD. The resulting quantum theory of gravity is highly constrained, and its physical predictions are found to depend only on one adjustable parameter, a genuinely nonperturbative scale ξ in many ways analogous to the scaling violation parameter Λ M ¯ S of QCD. Recent results point to significant deviations from classical gravity on distance scales approaching the effective infrared cutoff set by the observed cosmological constant. Such subtle quantum effects are expected to be initially small on current cosmological scales, but could become detectable in future high precision satellite experiments.
Osmotic-Adaptation Response of sakA/hogA Gene to Aflatoxin Biosynthesis, Morphology Development and Pathogenicity in Aspergillus flavus
Authors: Tumukunde Elisabeth , Li Ding , Qin Ling , Li Yu , Shen Jiaojiao , Wang Shihua , Yuan Jun
Published: January 2019

Aspergillus flavus is one of the fungi from the big family of Aspergillus genus and it is capable of colonizing a large number of seed/crops and living organisms such as animals and human beings. SakA (also called hogA/hog1) is an integral part of the mitogen activated protein kinase signal of the high osmolarity glycerol pathway. In this study, the AfsakA gene was deleted (∆AfsakA) then complemented (∆AfsakA::AfsakA) using homologous recombination and the osmotic stress was induced by 1.2 mol/L D-sorbital and 1.2 mol/L sodium chloride. The result showed that ∆AfsakA mutant caused a significant influence on conidial formation compared to wild-type and ∆AfsakA::AfsakA strains. It was also found that AfsakA responds to both the osmotic stress and the cell wall stress. In the absence of osmotic stress, ∆AfsakA mutant produced more sclerotia in contrast to other strains, whereas all strains failed to generate sclerotia under osmotic stress. Furthermore, the deletion of AfsakA resulted in the increase of Aflatoxin B1 production compared to other strains. The virulence assay on both maize kernel and peanut seeds showed that ∆AfsakA strain drastically produced more conidia and Aflatoxin B1 than wild-type and complementary strains. AfSakA-mCherry was located to the cytoplasm in the absence of osmotic stress, while it translocated to the nucleus upon exposure to the osmotic stimuli. This study provides new insights on the development and evaluation of aflatoxin biosynthesis and also provides better understanding on how to prevent Aspergillus infections which would be considered the first step towards the prevention of the seeds damages caused by A. flavus.
Cross-Generational Effects of Heat Stress on Fitness and Wolbachia Density in Aedes aegypti Mosquitoes
Authors: Foo Isabelle Jia-Hui , Hoffmann Ary A. , Ross Perran A.
Published: January 2019

Aedes aegypti mosquitoes infected with Wolbachia symbionts are now being released into the field to control the spread of pathogenic human arboviruses. Wolbachia can spread throughout vector populations by inducing cytoplasmic incompatibility and can reduce disease transmission by interfering with virus replication. The success of this strategy depends on the effects of Wolbachia on mosquito fitness and the stability of Wolbachia infections across generations. Wolbachia infections are vulnerable to heat stress, and sustained periods of hot weather in the field may influence their utility as disease control agents, particularly if temperature effects persist across generations. To investigate the cross-generational effects of heat stress on Wolbachia density and mosquito fitness, we subjected Ae. aegypti with two different Wolbachia infection types (wMel, wAlbB) and uninfected controls to cyclical heat stress during larval development over two generations. We then tested adult starvation tolerance and wing length as measures of fitness and measured the density of wMel in adults. Both heat stress and Wolbachia infection reduced adult starvation tolerance. wMel Wolbachia density in female offspring was lower when mothers experienced heat stress, but male Wolbachia density did not depend on the rearing temperature of the previous generation. We also found cross-generational effects of heat stress on female starvation tolerance, but there was no cross-generational effect on wing length. Fitness costs of Wolbachia infections and cross-generational effects of heat stress on Wolbachia density may reduce the ability of Wolbachia to invade populations and control arbovirus transmission under specific environmental conditions.
Characterization and Genome Analysis of Staphylococcus aureus Podovirus CSA13 and Its Anti-Biofilm Capacity
Authors: Cha Yoyeon , Chun Jihwan , Son Bokyung , Ryu Sangryeol
Published: January 2019

Staphylococcus aureus is one of the notable human pathogens that can be easily encountered in both dietary and clinical surroundings. Among various countermeasures, bacteriophage therapy is recognized as an alternative method for resolving the issue of antibiotic resistance. In the current study, bacteriophage CSA13 was isolated from a chicken, and subsequently, its morphology, physiology, and genomics were characterized. This Podoviridae phage displayed an extended host inhibition effect of up to 23 h of persistence. Its broad host spectrum included methicillin susceptible S. aureus (MSSA), methicillin resistant S. aureus (MRSA), local S. aureus isolates, as well as non-aureus staphylococci strains. Moreover, phage CSA13 could successfully remove over 78% and 93% of MSSA and MRSA biofilms in an experimental setting, respectively. Genomic analysis revealed a 17,034 bp chromosome containing 18 predicted open reading frames (ORFs) without tRNAs, representing a typical chromosomal structure of the staphylococcal Podoviridae family. The results presented here suggest that phage CSA13 can be applicable as an effective biocontrol agent against S. aureus.
White Teeth and Healthy Skeletons for All: The Path to Universal Fluoride-Free Drinking Water in Tanzania
Authors: Ndé-Tchoupé Arnaud Igor , Tepong-Tsindé Raoul , Lufingo Mesia , Pembe-Ali Zuleikha , Lugodisha Innocent , Mureth Risala Iddi , Nkinda Mihayo , Marwa Janeth , Gwenzi Willis , Mwamila Tulinave Burton , Rahman Mohammad Azizur , Noubactep Chicgoua , Njau Karoli N.
Published: January 2019

Fluorosis has been prevalent in the great East African Rift Valley (EARV) since before this region was given a name. In the Tanganyika days, Germans reported elevated fluoride concentrations in natural waters. In the 1930s, the clear relationship between high fluoride level and mottling of teeth was established. Since then, the global research community has engaged in the battle to provide fluoride-free drinking water, and the battle is not yet won for low-income communities. An applicable concept for fluoride-free drinking water in the EARV was recently presented, using the Kilimanjaro as a rainwater harvesting park. The Kilimanjaro concept implies that rainwater is harvested, stored on the Kilimanjaro mountains, gravity-transported to the point of use, eventually blended with natural water and treated for distribution. This article provides a roadmap for the implementation of the Kilimanjaro concept in Tanzania. Specifically, the current paper addresses the following: (i) presents updated nationwide information on fluoride contaminated areas, (ii) discusses the quality and quantity of rainwater, and current rainwater harvesting practices in Tanzania, (iii) highlights how low-cost water filters based on Fe0/biochar can be integrating into rainwater harvesting (RWH) systems to provide clean drinking water, and (iv) discusses the need for strict regulation of RWH practices to optimize water collection and storage, while simplifying the water treatment chain, and recommends strict analytical monitoring of water quality and public education to sustain public health in the EARV. In summary, it is demonstrated that, by combining rainwater harvesting and low-cots water treatment methods, the Kilimanjaro concept has the potential to provide clean drinking water, and overcome fluorosis on a long-term basis. However, a detailed design process is required to determine: (i) institutional roles, and community contributions and participation, (ii) optimal location and sizing of conveyance and storage facilities to avoid excessive pumping costs, and (iii) project funding mechanisms, including prospects for government subsidy. By drawing attention to the Kilimanjaro concept, the article calls for African engineers and scientists to take the lead in translating this concept into reality for the benefit of public health, while simultaneously increasing their self-confidence to address other developmental challenges pervasive in Africa.
Assessment of Water Quality and Thermal Stress for an Artificial Fish Shelter in an Urban Small Pond during Early Summer
Authors: Ahn Chang Hyuk , Lee Saeromi , Song Ho Myeon , Park Jae Roh , Joo Jin Chul
Published: January 2019

This study evaluated water quality variations in an artificial deep pool (ADP), which is an underground artificial structure built in a shallow pond as a fish shelter. The water temperature, pH, dissolved oxygen (DO), and electrical conductivity (EC) were measured on an hourly basis in the open space and inside the ADP, and a phenomenological study was performed, dividing seasons into normal and rainy seasons and environments into stagnant and circulating conditions. The results showed that the water quality parameters inside the ADP exhibit lower fluctuations and diurnal variations compared with the open space. On average, the water temperature inside the ADP is lower than outside it by 1.7–3.7 °C in stagnant conditions, and by 0.6–0.7 °C in circulating conditions during early summer. Thermal stratification occurs inside the ADP but is temporarily disturbed due to the mixing from the forced circulation and the rainwater input through rainfall events. The ADP provided a constant and optimal water temperature for living and spawning for bitterling (i.e., 15.0–21.0 °C), which dominated in experimental pond during spring to summer. Most importantly, the ADP was able to significantly reduce the thermal stress of the fish in the study site, and as a result, the bitterling, a cool water fish species, could successfully become dominant. Finally, the deployment of the ADP appears to provide a practical alternative for effective fishery resources management to improve species diversity and fish communities in an artificial freshwater ecosystem (garden pond, park pond, other artificial wetlands, etc.).
HYDROLOGICAL RESPONSE TO LAND USE CHANGES IN CENTRAL EUROPEAN LOWLAND FOREST CATCHMENTS
Authors: Okoński Bernard
Published: January 2019

The influence of forest environment characteristics especially forest vegetation and soil are the main causative, non‐climatic agents shaping water processes in forest ecosystems. The impact of land cover changes on direct runoff from a forest catchment was examined. Hydrological modeling was employed. The runoff module of the model was cascade of linear reservoir solution. The rainfall separation module is based on the SCS‐CN method altered by means of a unique methodology. Thus, the main investigation effort was applied to work out a methodological solution. The model was tested in a lowland forest catchment located in the Polish part of Central European Plain. Calibration was performed for the current cover state along with simulation for 9 hypothetical cases and a case based on reconstruction of the historic state of land cover. The cases of land cover state were developed on the basis of qualitative and/or quantitative vegetation property changes.
COMPARISON AND ANALYSIS OF INVESTIGATION RESULTS ON VOLUMETRIC ACTIVITY OF 137CS AT THE BALTIC SEA COAST IN 2003–2005
Authors: Styrо Dmitrijus , Morkūnienė Rasa , Astrauskienė Nijolė , Daunaravičienė Asta
Published: January 2019

Measurements of 137Cs volumetric activity (VA) in coastal waters of the Baltic Sea (near Juodkrante) were carried out in 2005. The highest values occurred in springtime; later they decreased, and in the summer‐autumn period approximate homogeneous values of 137Cs varied in the range of 41–57 Bq/m3, and the lowest values were observed in autumn. Comparison of these values with analogous data obtained in 2003 and 2004 was carried out. The highest average annual value of 63 Bq/m3 is proved to be in 2004. Furthermore, that year the greatest 137Cs volumetric activity variations in the range of 49–91 Bq/m3 were observed. These variations are related to possible appearance of additional sources of radioactive contamination in the sea. Evidently, such sources did not exist in 2005, when a satisfactory coincidence of measured and calculated results was obtained.
SOIL WATER MOVEMENT MODELLING IN HAPLLICC LUVISOLS (HMM) AND ALBI HAPLLIC LUVISOLS (HML) UNDER SLOVAK CLIMATIC CONDITIONS
Authors: Tóthová Iveta , Igaz Dušan , Antal Jaroslav
Published: January 2019

The aim of the research paper is simulation by the Global Model on the basis of investigation of Slovak Agricultural University (SAU) on two localities (Kolínany and Malanta). The soil moisture was measured by a time domain transmissometry instrument and compared with simulated outputs of the Global Model on Kolínany locality. Measurement of the soil moisture using the gravimetric method was applied on Malanta locality. Sugar beet was grown in Kolínany and, on the other hand, there was no plant on Malanta soil during the experiment. The experiment took three years (2002–2004). Measured and simulated courses of water content were consequently tested by correlation analysis in MS Excel. Result differences between simulated and measured values should reach according to 15 % difference at least 80 % of equality. Correlation between measured and simulated values had a high significance on Kolínany locality (in the range of 0,62–0,90) Equality between measured and simulated values was from 33 % to 75 % according to difference of 15 %.
CALIBRATION OF WATER‐QUALITY MODEL “WODA” – CASE STUDY OF THE WARTA RIVER
Authors: Sowinski Marek , Neugebauer Anna
Published: January 2019

The main feature of the proposed model implemented by a computer package WODA, that distinguishes it from other commonly used models like QUALE 2E or WASP5, is a possibility of its automatic calibration i e parameter estimation taking into account simultaneously several sets of measured concentration data. Model WODA, developed by A. Kraszewski and R. Soncini‐Sessa, enables fitting simulated values to measured concentrations of BOD and DO based on the least‐square criterion. This model was applied for parameter estimation of the Warta River in Poland. Measured concentration data used for parameter estimation were obtained from monthly monitoring. The results are presented in the form of BOD and DO lines against measured concentrations along the analysed stretch of the Warta River. Adaptation of the model simulation results to measured data is described by quantifying characteristics. They indicate relatively good adjustment. The reasons of some differences are discussed and explained.
EFFICIENCY EVALUATION OF A NOISE BARRIER
Authors: Baltrėnas Pranas , Butkus Donatas , Nainys Vytautas , Grubliauskas Raimondas , Gudaitytė Jurgita
Published: January 2019

Mechanization of industrial and agricultural production, increase of urban and rural traffic flows, modernization of domestic facilities cause a rapid expansion of acoustic discomfort zones. Since the noise level in any environment is one of the basic factors determining the human comfort indicator, investigation into noise processes is given special attention by researchers.

Seaport freight discharge terminals are also connected with noise problems. Noise from AB KLASCO fertilizer discharge terminal of Klaipeda seaport cause great concern to local people. There is a noise barrier installed near the terminal. The present paper describes the efficiency evaluation of the noise barrier according to the noise level measurements performed, modelling of noise spread and mathematical calculations.

The investigation was performed with noise measuring equipment Bruel&Kjaer mediator 2260. According to measurements, it is obvious that the noise level in the residential zone is 3–4 dBA above the limits (limits are given in HN 33–1:2003) in the daytime, and by 7 dBA at night. The modelling of noise spread was performed by CadnaA program which allowed to make different models according to variations of the noise level caused by changing conditions.
INFLUENCE OF METEOROLOGICAL CONDITIONS ON VOLATILE ORGANIC COMPOUND SPREAD IN THE ATMOSPHERIC BOUNDARY LAYER
Authors: Laškova Tatjana , Zabukas Vytenis , Vaitiekūnas Petras
Published: January 2019

The problem of volatile organic compound (VOC) emission from oil terminals is discussed in the paper. Short‐term analyses were performed to determine dependence of VOC on wind speed, environmental humidity and atmospheric pressure at minimal ambient air temperature variations (1–3 °C). 10‐day VOC concentration analyses were performed using gas chro‐matography. Complex analysis of experimental investigation and meteorological conditions (air temperature, environmental humidity, atmospheric pressure, wind speed and direction) was carried out considering the types of loading operations and oil products at the oil terminal. Dependencies between VOC concentration and separate meteorological parameters were determined.
PREVENTIVE MAINTENANCE OF FLEXIBLE PAVEMENT AND MECHANICAL PROPERTIES OF STEEL SLAG ASPHALT
Authors: Ziari Hassan , Khabiri Mohammad M.
Published: January 2019

Preventive maintenance is beneficial if pavement life is increased while maintaining its service ability, and it is an environmental problem. Steel slag material is inorganic, it can neither be incinerated nor decomposed, so it may be difficult to reclaim. This work aims to study the performance of asphalt concrete where some of the fractional fine aggregate is replaced with crushed steel slag material. Steel slag materials are brittle and rich in carbon and silicon, so the key technical indexes of steel slag‐asphalt concrete are strength. Materials used in the tests included AC 60–70 bitumen, limestone aggregate and crushed recycled steel slag. The Marshall test was used to examine the influence of optimal asphalt content, volume properties and strength of asphalt concrete when different percentages of crushed steel slag were added. The high‐temperature stability and creep stiffness performance of steel slag asphalt concrete was also tested, and the results are satisfactory.
MODELLING OF CU, NI, ZN, MN AND PB TRANSPORT FROM SOIL TO SEEDLINGS OF CONIFEROUS AND LEAFY TREES
Authors: Baltrėnaitė Edita , Butkus Donatas
Published: January 2019

Transport of trace metals (TMs) from the soil to a plant involves chemical, physical and biological processes (such as diffusion, adsorption, absorption, growth of a plant, transpiration rate, etc.) in the soil, the soil rhizosphere and in the plant itself. Because of the complexity of these processes and external factors (e.g. weather conditions, biotic factors, type of substrate, etc.) the processes are difficult to describe by mathematical formulas. Modelling of TMs transport to plants is even more complex than that of organic contaminants because, contrary to organic contaminants, TMs are essential for plant growth, metabolism, enzyme activity, etc. The octanol‐water partitioning coefficient for TMs in plants gives only limited information about their accumulation, therefore, other coefficients, such as bioconcentration and translocation coefficients, must be incorporated. The aim of this work was to simulate transport of TMs (Zn, Pb, Cu, Ni and Mn) from the soil to tree seedlings by adapting a generalized model of contaminant uptake by plants. The model applied for transport of TMs from the soil to trees was created by Hung and Muckay. When employing this model for modelling transport of TMs from the soil, amended with industrial sewage sludge, to seedlings of coniferous and leafy trees, some adjustments were made by evaluating the equilibrium partitioning coefficient of TMs between octanol and water (Kow); by introducing the equilibrium partitioning coefficient of TMs in the soil and water (K d ), which depends on the soil pH and the amount of organic matter; by introducing the coefficient (KT) of TMs solubility in water as well as by introducing corrective coefficients. When using the Hung and Muckay's model of the transport of trace metals from the soil to tree seedlings, the results of modelling differed approximately by 6 % in leaves, 5 % in the stem and 8 % in roots as compared with those of measurements.
EFFECT OF EASILY BIODEGRADABLE AMENDMENTS ON HEAVY METAL SOLUBILIZATION AND ACCUMULATION IN TECHNICAL CROPS ‐ A FIELD TRIAL
Authors: Shilev Stefan , Naydenov Mladen , Tahsin Nurettin , Sancho Enrique D. , Benlloch Manuel , Vancheva Ventsislava , Sapundjieva Krasimira , Kuzmanova Jordanka
Published: January 2019

Heavy‐metal soil pollution is a common environmental problem all over the world. In the induced phytoextraction process plants can transport and translocate to their above‐ground tissues significant concentration of contaminants. Since some heavy metals are mostly presented in non‐soluble state, the application of chelating agents is needed. In this study we introduced into the rhizosphere of maize (var. Kneja 530) and sunflower (var. Favorit) plants 1 and 5 mmol l−1 of EDDS and NTA, and 5 g kg−1 of nutrients to enhance the accumulated concentrations of cadmium, lead and zinc. The fraction of CaCl2‐extractable metals increased incrementing the concentration of chelates. This was clearly pronounced for all the metals in the treatments with NTA and for Pb in those with EDDS. Generally, under all the experimental conditions the accumulated heavy‐metal concentrations were found to be significantly higher than in the control. Thus, in the case of higher concentration of NTA and EDDS, the accumulated Cd in the leaves of sunflower was found to be threefold higher. The highest accumulation of Pb in the leaves of maize was observed when nutrients were added (62 mg kg−1). On the other hand, negative effects of the used chelating agents on soil bacteria and fungi at plant harvest were not observed. Moreover, when nutrients were added, the number of studied microorganisms significantly increased.
DEVELOPMENT OF A GFP‐BASED BIOSENSOR FOR DETECTING THE BIOAVAILABILITY AND BIODEGRADATION OF POLYCHLORINATED BIPHENYLS (PCBS)
Authors: Liu Xuemei , Germaine Kieran J. , Ryan David , Dowling David N.
Published: January 2019

Two whole-cell biosensors were constructed to detect the in situ biodegradation of polychlorinated biphenyl by chromosomal insertion of a mini‐Tn5‐Kmr‐Pm::gfp[mut3]‐T0‐T1 construct into P. fluorescens. In vitro tests showed that the expression of the Pm promoter depended on the growth phase of the biosensors and the concentration of chemical inducers; chlorinated benzoic acid derivatives. A linear relationship between the fluorescent intensity and the log10 concentration of the inducer was observed. One biosensor (F113L::1180gfp) had the ability to degrade PCBs to relevant chlorobenzoic acid derivatives and to induce expression of Gfp. The second biosensor (F113gfp), which cannot degrade PCBs, shows fluorescence after induction by chloro‐benzoic acid derivatives. By using these two biosensors, PCB degradation could be detected in vitro and in soil.