The Use of Tailored Micro-Hydro System in Micro-Urban Scale as a Partial Presumption for Creating the Autarchic Micro-Urban Structures

2013 ◽  
Vol 724-725 ◽  
pp. 1264-1267
Author(s):  
Stefan Tkac ◽  
Zuzana Vranayova

High energy import rates (over 90% per year) make both countries (Taiwan R.O.C. and Slovak Republic), viably engaged in research on renewable resources, also green planning policy has been proposed. Population is concentrated in the major cities which are facing energy deficiency issues; the unregulated development of micro-urban areas is underestimated in both cases so are the energy issues bound with them. Centralized energy sources require long distance wires to support remote areas; hydro energy is so far the most common, stable and efficient renewable resource in use. Water turbine’s efficiency has gone up to 96%; a proposed new multi-purpose small hydro type is one of the preliminary small scale systems that could be precisely tailored to micro-urban demands. It could stand by for direct use if needed and also use various types of working mediums (e.g. compressed gas, steam, water).

2013 ◽  
Vol 740 ◽  
pp. 809-816 ◽  
Author(s):  
Štefan Tkáč ◽  
Zuzana Vranayová

Currently Taiwan and Slovakia import over 90% of energy consumables annually. High energy import rates make both countries viably engaged in research on renewable resources, also green planning policy has been proposed. Population is concentrated in the major cities which are facing energy deficiency issues. The unregulated development of micro-urban areas is underestimated in both cases so are the energy issues bound with them. Centralized energy sources require long distance wires to support remote areas. The proposed urban idea consists of energy resource decentralization by detailed focus on micro-urban development through the combination of accurate hydro distribution system for direct energy production in a place of consumption as a part of the autarchic micro-urban grids arranged in efficiency electric power grid circles calculated by loses in wiring. This urban energy model binds micro-urban structures in one solid network and at the same time creates local smart energy communities built up on each individual dwelling unit that can produce energy for itself from renewable resources locally available and support the local micro-urban public grid or even support nearest city public grid. Hydro energy is so far the most common, stable and efficient renewable resource in use. Water turbines efficiency has gone up to 96%. Proposed new multi-purpose small hydro type is one of the preliminary small scale systems that could be precisely tailored to micro-urban demands. It could stand by for direct use if needed and also use various types of working mediums (e.g. compressed gas, steam, water).


2013 ◽  
Vol 361-363 ◽  
pp. 107-110
Author(s):  
Stefan Tkac ◽  
Zuzana Vranayova

Population is concentrated in the major cities which are facing the energy deficiency issues. The unregulated development of micro-urban areas is underestimated in both cases (Slovak Republic and Taiwan R.O.C.) so are the energy issues bound with them. Centralized energy sources require long distance wires to support remote areas.


2016 ◽  
Vol 11 (1) ◽  
pp. 176-186 ◽  
Author(s):  
Andrea G. Capodaglio ◽  
Paolo Ghilardi ◽  
Joanna Boguniewicz-Zablocka

In order to achieve a sustainable degree of water resources usage, new paradigms in urbanized basins planning must be adopted. Worldwide urbanized areas total population has overcome in 2010, its rural counterpart. While urbanization can be a powerful driver of sustainable development, as the higher population density enables governments to more easily deliver essential infrastructure and services in urban areas at relatively low cost per capita, these benefits do not materialize automatically and inevitably. Water bodies are usually severely hit and impaired by poorly planned urbanization. Old water resources planning paradigms must be abandoned and new ones, which include the connection of ‘green cities’ and their infrastructure with new modes of drainage and landscape planning and improved consideration of receiving waters, ought to be adopted. These must not only be environmentally and ecologically sound, but also functionally and aesthetically attractive to the public. New eco-cities shall no longer rely on excessive water volumes withdrawn from often distant surface and groundwater sources, with a once-only use of the resource, and large water losses due to leaks and evapotranspiration. Long-distance transfer of wastewater and high energy usage and emissions for its treatment should be avoided by distributed and decentralized integrated water/wastewater management. Effluent-domination shall no longer be a characteristic of urbanized river basins. The paper examines some of the paradigms that have been proposed for improving integrated water resources management in urban basins and illustrates some recent examples whether already implemented or still at the proposal stage.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 139-144 ◽  
Author(s):  
S. Iwai ◽  
Y. Oshino ◽  
T. Tsukada

Although the ratio of sewer systems to population in Japan has been improving in recent years, the construction of sewer systems in small communities such as farming or fishing villages, etc. had lagged behind that of urban areas. However, construction of small-scale sewer systems in farming and fishing villages has been actively carried out in recent years. This report explains the history of the promotion of small-scale sewer systems, why submerged filter beds are being employed in many cases, and introduces the design, operation and maintenance of representative waste-water treatment plants in farming and fishing villages which incorporate de-nitrogen and dephosphorization.


2020 ◽  
Vol 37 ◽  
pp. 63-71
Author(s):  
Yui-Chuin Shiah ◽  
Chia Hsiang Chang ◽  
Yu-Jen Chen ◽  
Ankam Vinod Kumar Reddy

ABSTRACT Generally, the environmental wind speeds in urban areas are relatively low due to clustered buildings. At low wind speeds, an aerodynamic stall occurs near the blade roots of a horizontal axis wind turbine (HAWT), leading to decay of the power coefficient. The research targets to design canards with optimal parameters for a small-scale HAWT system operated at variable rotational speeds. The design was to enhance the performance by delaying the aerodynamic stall near blade roots of the HAWT to be operated at low wind speeds. For the optimal design of canards, flow fields of the sample blades with and without canards were both simulated and compared with the experimental data. With the verification of our simulations, Taguchi analyses were performed to seek the optimum parameters of canards. This study revealed that the peak performance of the optimized canard system operated at 540 rpm might be improved by ∼35%.


Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 171
Author(s):  
Lihui Zhang ◽  
Xuezhong Wang ◽  
Hong Li ◽  
Nianliang Cheng ◽  
Yujie Zhang ◽  
...  

To better evaluate the variations in concentration characteristics and source contributions of atmospheric volatile organic compounds (VOCs) during continuous haze days and non-haze days, hourly observations of atmospheric VOCs were conducted using a continuous on-line GC-FID (Airmo VOC GC-866) monitoring system during 1–15 March 2019, in urban areas of Beijing, China. The results showed that the total VOC concentrations during haze days and non-haze days were 59.13 ± 31.08 μg/m3 and 16.91 ± 7.19 μg/m3, respectively. However, the average O3 concentrations during the two haze days were lower than those of non-haze days due to the extremely low concentrations at night instead of the reported lower photochemical reaction in daytime. The ratio of OH radical concentration during haze and non-haze days indicating that the rate of photochemical reaction during haze days was higher than those of non-haze days from 13:00–19:00. The stable air conditions and the local diesel emission at night were the main reasons for the decreased O3 concentrations during haze days. Six major sources were identified by positive matrix factorization (PMF), namely, diesel exhaust, combustion, gasoline evaporation, solvent usage, gasoline exhaust, and the petrochemical industry, contributing 9.93%, 25.29%, 3.90%, 16.88%, 35.59% and 8.41%, respectively, during the whole observation period. The contributions of diesel exhaust and the petrochemical industry emissions decreased from 26.14% and 6.43% during non-haze days to 13.70% and 2.57%, respectively, during haze days. These reductions were mainly ascribed to the emergency measures that the government implemented during haze days. In contrast, the contributions of gasoline exhaust increased from 34.92% during non-haze days to 48.77% during haze days. The ratio of specific VOC species and PMF both showed that the contributions of gasoline exhaust emission increased during haze days. The backward trajectories, potential source contribution function (PSCF) and concentration weighted trajectory (CWT) showed that the air mass of VOCs during haze days was mainly affected by the short-distance transportation from the southwestern of Hebei province. However, the air mass of VOCs during non-haze days was mainly affected by the long-distance transportation from the northwest.


Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.


2021 ◽  
Vol 13 (3) ◽  
pp. 1360
Author(s):  
Teodora M. Șoimoșan ◽  
Ligia M. Moga ◽  
Livia Anastasiu ◽  
Daniela L. Manea ◽  
Aurica Căzilă ◽  
...  

Harnessing renewable energy sources (RES) using hybrid systems for buildings is almost a deontological obligation for engineers and researchers in the energy field, and increasing the percentage of renewables within the energy mix represents an important target. In crowded urban areas, on-site energy production and storage from renewables can be a real challenge from a technical point of view. The main objectives of this paper are quantification of the impact of the consumer’s profile on overall energy efficiency for on-site storage and final use of solar thermal energy, as well as developing a multicriteria assessment in order to provide a methodology for selection in prioritizing investments. Buildings with various consumption profiles lead to achieving different values of performance indicators in similar configurations of storage and energy supply. In this regard, an analysis of the consumption profile’s impact on overall energy efficiency, achieved in the case of on-site generation and storage of solar thermal energy, was performed. The obtained results validate the following conclusion: On-site integration of solar systems allowed the consumers to use RES at the desired coverage rates, while restricted by on-site available mounting areas for solar fields and thermal storage, under conditions of high energy efficiencies. In order to segregate the results and support optimal selection, a multicriteria analysis was carried out, having as the main criteria the energy efficiency indicators achieved by hybrid heating systems.


2021 ◽  
Vol 10 (6) ◽  
pp. 233
Author(s):  
Rasmus Karlsson

While the precautionary principle may have offered a sound basis for managing environmental risk in the Holocene, the depth and width of the Anthropocene have made precaution increasingly untenable. Not only have many ecosystems already been damaged beyond natural recovery, achieving a sustainable long-term global trajectory now seem to require ever greater measures of proactionary risk-taking, in particular in relation to the growing need for climate engineering. At the same time, different optical illusions, arising from temporary emissions reductions due to the COVID-19 epidemic and the local deployment of seemingly “green” small-scale renewable energy sources, tend to obscure worsening global trends and reinforce political disinterest in developing high-energy technologies that would be more compatible with universal human development and worldwide ecological restoration. Yet, given the lack of feedback between the global and the local level, not to mention the role of culture and values in shaping perceptions of “sustainability”, the necessary learning may end up being both epistemologically and politically difficult. This paper explores the problem of finding indicators suitable for measuring progress towards meaningful climate action and the restoration of an ecologically vibrant planet. It is suggested that such indicators are essentially political as they reflect, not only different assessments of technological feasibility, but orientations towards the Enlightenment project.


2019 ◽  
Vol 19 (10) ◽  
pp. 2183-2205 ◽  
Author(s):  
Bruno Castelle ◽  
Tim Scott ◽  
Rob Brander ◽  
Jak McCarroll ◽  
Arthur Robinet ◽  
...  

Abstract. The two primary causes of surf zone injuries (SZIs) worldwide, including fatal drowning and severe spinal injuries, are rip currents (rips) and shore-break waves. SZIs also result from surfing and bodyboarding activity. In this paper we address the primary environmental controls on SZIs along the high-energy meso–macro-tidal surf beach coast of southwestern France. A total of 2523 SZIs recorded by lifeguards over 186 sample days during the summers of 2007, 2009 and 2015 were combined with measured and/or hindcast weather, wave, tide, and beach morphology data. All SZIs occurred disproportionately on warm sunny days with low wind, likely because of increased beachgoer numbers and hazard exposure. Relationships were strongest for shore-break- and rip-related SZIs and weakest for surfing-related SZIs, the latter being also unaffected by tidal stage or range. Therefore, the analysis focused on bathers. More shore-break-related SZIs occur during shore-normal incident waves with average to below-average wave height (significant wave height, Hs = 0.75–1.5 m) and around higher water levels and large tide ranges when waves break on the steepest section of the beach. In contrast, more rip-related drownings occur near neap low tide, coinciding with maximised channel rip flow activity, under shore-normal incident waves with Hs >1.25 m and mean wave periods longer than 5 s. Additional drowning incidents occurred at spring high tide, presumably due to small-scale swash rips. The composite wave and tide parameters proposed by Scott et al. (2014) are key controlling factors determining SZI occurrence, although the risk ranges are not necessarily transferable to all sites. Summer beach and surf zone morphology is interannually highly variable, which is critical to SZI patterns. The upper beach slope can vary from 0.06 to 0.18 between summers, resulting in low and high shore-break-related SZIs, respectively. Summers with coast-wide highly (weakly) developed rip channels also result in widespread (scarce) rip-related drowning incidents. With life risk defined in terms of the number of people exposed to life threatening hazards at a beach, the ability of morphodynamic models to simulate primary beach morphology characteristics a few weeks or months in advance is therefore of paramount importance for predicting the primary surf zone life risks along this coast.


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