Cooling Methods for Railway Tunnels

1995 ◽  
Vol 209 (2) ◽  
pp. 105-112 ◽  
Author(s):  
H Barrow ◽  
C W Pope
Keyword(s):  
Energy Dissipation ◽  
Cost Effective ◽  
Point Of View ◽  
Passive Cooling ◽  
Railway Tunnel ◽  
Cooling Systems ◽  
First Law Of Thermodynamics ◽  
Air Temperatures ◽  
Cooling Methods

In this paper the cooling of a railway tunnel and its environment is investigated, with particular reference to a study of possible methods for reducing both local and overall average tunnel air temperatures. Both passive and supplementary cooling of a tunnel are considered and then various practical systems are proposed for those situations where passive cooling alone may be inadequate. In some cases, calculations for realistic conditions are made using the First Law of Thermodynamics to assess the efficacy of the system from the thermal point of view. It is concluded that with the advent of increasing energy dissipation, as a consequence of increase in tunnel usage, thermally efficient and cost-effective cooling systems must be developed if temperatures are to be maintained at acceptable levels.

The Role of Economic Evaluation in Dissemination and Implementation Research

2017 ◽  
Author(s):  
Ramesh Raghavan
Keyword(s):  
Service Providers ◽  
Implementation Strategies ◽  
Cost Effective ◽  
Point Of View ◽  
Dissemination And Implementation ◽  
Economic Point ◽  
Open Questions ◽  
Public Health Organizations ◽  
Quality Health ◽  
Dissemination And Implementation Research

This chapter presents an overview of how D&I research can be evaluated from an economic point of view. Dissemination and implementation imposes costs upon knowledge purveyors, provider organizations, public health organizations, and payers (including governments). However, whether these added costs will result in improved service delivery and, perhaps more importantly, client outcomes and improvements in population health remain as open questions. If emerging studies reveal that defined implementation strategies are more cost effective than “usual” implementation, then policymakers and service providers will need to resource these added costs of implementation in order to assure the success and sustainability of high-quality health services over the long term.

Price structures for electricity supply and potential consequences for building services systems

2021 ◽  
pp. 014362442199081
Author(s):  
Roger Hitchin
Keyword(s):  
Cost Effective ◽  
Building Design ◽  
Electricity Supply ◽  
Cooling Systems ◽  
Price Structure ◽  
Heating And Cooling ◽  
Future System ◽  
The Cost ◽  
Supply Systems ◽  
Effective Design

Policies to reduce carbon emissions are leading to substantial changes in the demand for electricity and to the structure of electricity supply systems, which will alter the cost structure of electricity supply. This can be expected to result in corresponding changes to the price structure faced by customers. This note is an initial exploration of how possible new price structures may impact on HVAC system and building design and use. Changes in the price structure of electricity supply (separately from changes in price levels) can significantly affect the cost-effective design and operation of building services systems; especially of heating and cooling systems. The nature and implications of these changes can have important implications for future system design and operation.

scholarly journals Comparison between Concentrated Solar Power and Gas-Based Generation in Terms of Economic and Flexibility-Related Aspects in Chile

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1063
Author(s):  
Catalina Hernández Moris ◽  
Maria Teresa Cerda Guevara ◽  
Alois Salmon ◽  
Alvaro Lorca
Keyword(s):  
Natural Gas ◽  
Solar Power ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Hybrid Plant ◽  
Point Of View ◽  
Concentrated Solar Power ◽  
Economic Point ◽  
Hybrid Plants ◽  
Cost Of Energy

The energy sector in Chile demands a significant increase in renewable energy sources in the near future, and concentrated solar power (CSP) technologies are becoming increasingly competitive as compared to natural gas plants. Motivated by this, this paper presents a comparison between solar technologies such as hybrid plants and natural gas-based thermal technologies, as both technologies share several characteristics that are comparable and beneficial for the power grid. This comparison is made from an economic point of view using the Levelized Cost of Energy (LCOE) metric and in terms of the systemic benefits related to flexibility, which is very much required due to the current decarbonization scenario of Chile’s energy matrix. The results show that the LCOE of the four hybrid plant models studied is lower than the LCOE of the gas plant. A solar hybrid plant configuration composed of a photovoltaic and solar tower plant (STP) with 13 h of storage and without generation restrictions has an LCOE 53 USD/MWh, while the natural gas technology evaluated with an 85% plant factor and a variable fuel cost of 2.0 USD/MMBtu has an LCOE of 86 USD/MWh. Thus, solar hybrid plants under a particular set of conditions are shown to be more cost-effective than their closest competitor for the Chilean grid while still providing significant dispatchability and flexibility.

Clinical Profile and Prediction of Response to Treatment in Childhood Epilepsy - A Single-Centre Experience from Eastern India

2021 ◽  
Vol 8 (15) ◽  
pp. 977-981
Author(s):  
Prakash Chandra Ghosh ◽  
Mitali Bera ◽  
Punyabrata Barma ◽  
Arijit Roy ◽  
Sananda Majumder ◽  
...  
Keyword(s):  
Management Strategies ◽  
Poor Response ◽  
Cost Effective ◽  
Point Of View ◽  
Clinical Profile ◽  
Response To Treatment ◽  
Childhood Epilepsy ◽  
Primary Health Centres ◽  
Single Centre Experience ◽  
Active Epilepsy

BACKGROUND Though epilepsy remains a significant problem for children and adolescents in our country, studies delineating the clinical profile and response to treatment in childhood epilepsy are lacking. The current study was carried out for obtaining a baseline profile and to predict the response to treatment in childhood epilepsy in India that may be helpful in planning management strategies from a public health point of view. METHODS Patients with clinical suggestion of active epilepsy (N = 141) from one month to 12 years, were enrolled into the study over a period of 1 year (February 2010 to January 2011) from the out-patient department and epilepsy clinic of Bangur Institute of Neurology. Detailed history was taken along with neurological examination. Electroencephalography (EEG) and neuroimaging (MRI / CT scan) were done on all patients. Each patient included in the study was kept in followup for a period of 6 months and their response to the treatment was recorded. RESULTS About 48.9 % (N = 69) patients had localisation related epilepsy while the rest had generalised epilepsy. Of those with generalised epilepsy, generalised tonicclonic seizures (GTCS) was by far the most common type. Of those with focal EEG activity, the highest proportion (50 %), were localised to the temporal lobe. Symptomatic aetiology accounted for 59.6 % (N = 84) of the patients. 20.6 % (N = 29) had poor response to treatment at 6 months follow-up. Abnormal neuroimaging (OR = 6.708) and abnormal EEG (OR = 6.357) were effective factors in predicting poor response to treatment. CONCLUSIONS Our study highlights the need to link specialised epilepsy services with primary health centres for early detection and treatment. EEG is an essential cost-effective modality in determining seizure localisation and response to treatment. KEYWORDS Paediatric, Epilepsy, Clinical Profile, Response to Treatment

Geophysical measurements in an abandoned old railway tunnel located in a karst area

2021 ◽  
Author(s):  
Enzo Rizzo ◽  
Luigi Capozzoli ◽  
Gregory De Martino ◽  
Giacomo Fornasari ◽  
Valeria Giampaolo
Keyword(s):  
Karst Aquifer ◽  
Geophysical Methods ◽  
Water Reservoir ◽  
Test Site ◽  
Point Of View ◽  
Karst Area ◽  
Fluid Circulation ◽  
Railway Tunnel ◽  
Interdisciplinary Field ◽  
Karst Systems

<p>Carbonate aquifers in karst systems are very important water reservoir and are recognized as the most difficult to characterize. The purpose of this article is to present a project aimed to understand the circulation of fluids in carbonate reservoirs through innovative hydrogeophysical methodologies both in the laboratory and in the field. The test site is located in the Castel di Lepre karst system, which is disposed in the Mezo-Cenozoic carbonate substratum of the Monti della Maddalena ridge (Southern Appenines). In the karst area are located several caves, but the presence of an artificial tunnel (disused railway tunnel) could give the opportunity to characterize the whole area and the fluid circulation by multisensors geophysical sensors installed inside the karst aquifer. This natural laboratory permits to define an Applied Geophysics strategy developing several main topics from an engineering to hydrogeological point of view. Firstly, the geophysical investigations conducted, without altering the structure and in a fast manner, obtains important information concerning the construction of the tunnel, and the interaction between the infrastructure and surrounding rock, in that area that we define infrastructural critical zone. The study conducted aims to highlight the potential and any limitations of the use of geophysical techniques applied to infrastructures, emphasizing the emerging role of urban geophysics for the importance and topicality of its contents as well as the important innovations that the use of these techniques they can contribute to the hazardous processes. Secondly, the geophysical methods are used as a tool to characterize the fluid circulation by hydrogeophysal sensors installed inside the karst aquifer. The hydrogeophysics arose as an interdisciplinary field that focuses on the improved understanding of hydrological processes through geophysical observation. These approaches aimed at mitigating the detrimental effects of environmental problems.</p>

scholarly journals Applying Biomimetic Principles to Thermoelectric Cooling Devices for Water Collection

2017 ◽  
Vol 7 (3) ◽  
pp. 27
Author(s):  
Kyle B Davidson ◽  
Bahram Asiabanpour ◽  
Zaid Almusaied
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Thermoelectric Cooling ◽  
Device Structure ◽  
Cooling Systems ◽  
Cooling Devices ◽  
Water Collection ◽  
Maximum Water ◽  
The Ideal

The shortage of freshwater resources in the world has developed the need for sustainable, cost-effective technologies that can produce freshwater on a large scale. Current solutions often have extensive manufacturing requirements, or involve the use of large quantities of energy or toxic chemicals. Atmospheric water generating solutions that minimize the depletion of natural resources can be achieved by incorporating biomimetics, a classification of design inspired by nature. This research seeks to optimize thermoelectric cooling systems for use in water harvesting applications by analyzing the different factors that affect surface temperature and water condensation in TEC devices. Further experiments will be directed towards developing a robust, repeatable system, as well as an accurate measurement system. Surface modifications, device structure and orientation, and power generation will also be studied to better understand the ideal conditions for maximum water collection in thermoelectric cooling systems.

scholarly journals A New Tool for Airborne Gravimetry Survey Simulation

Geosciences ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 292 ◽  
Author(s):  
Daniele Sampietro ◽  
Ahmed Mansi ◽  
Martina Capponi
Keyword(s):  
Oil And Gas ◽  
Survey Design ◽  
Cost Effective ◽  
Point Of View ◽  
Global Navigation Satellite Systems ◽  
Polar Regions ◽  
Airborne Gravimetry ◽  
Satellite Systems ◽  
Observation Noise ◽  
Airborne Survey

Airborne gravimetry represents nowadays probably the most efficient technique to collect gravity observations close to the Earth’s surface. In the 1990s, thanks to the development of the Global Navigation Satellite Systems (GNSS), which has made accurate navigational data available, this technique started to spread worldwide because of its capability to provide measurements in a fast and cost-effective way. Differently from other techniques such as shipborne gravimetry, it has the advantage to provide gravity measurements also in challenging environments which can be difficult to access otherwise, like mountainous areas, rain forests and polar regions. For such reasons, airborne gravimetry is used for various applications related to the regional gravity field modelling: from the computation of high accurate local geoid for geodetic applications to geophysical ones, specifically related to oil and gas exploration activities or more in general for regional geological studies. Depending on the different kinds of application and the final required accuracy, the definition of the main characteristics of the airborne survey, e.g., the planar distance between consecutive flight tracks, the aircraft velocity, etc., can be a difficult task. In this work, we present a new software package, which would help in properly accomplishing the survey design task. Basically, the developed software solution allows for generating a realistic (from the observation noise point of view) gravimetric signal, and, after that, to predict the accuracy and spatial resolution of the final retrievable gravimetric field, in terms of gravity disturbances, given the flight main characteristics. The proposed procedure is suited for airborne survey planning in order to be able to optimize the design of the survey according to the required final accuracy. With the aim to evaluate the influence of the various survey parameters on the expected accuracy of the airborne survey, different numerical tests have been performed on simulated and real datasets. For instance, it has been shown that if the observation noise is not properly modeled in the data filtering step, the survey results degrade about 25%, while not acquiring control lines during the survey will basically reduce the final accuracy by a factor of two.

scholarly journals Cooling Performance of Heat Sinks Used in Electronic Devices

2018 ◽  
Vol 171 ◽  
pp. 02003
Author(s):  
Ibrahim Mjallal ◽  
Hussein Farhat ◽  
Mohammad Hammoud ◽  
Samer Ali ◽  
Ali AL Shaer ◽  
...  
Keyword(s):  
Heat Sink ◽  
Electronic Devices ◽  
Heat Fluxes ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Passive Cooling ◽  
Short Term ◽  
Cooling Systems ◽  
Thermal Output ◽  
Electrical Devices

Existing passive cooling solutions limit the short-term thermal output of systems, thereby either limiting instantaneous performance or requiring active cooling solutions. As the temperature of the electronic devices increases, their failure rate increases. That’s why electrical devices should be cooled. Conventional electronic cooling systems usually consist of a metal heat sink coupled to a fan. This paper compares the heat distribution on a heat sink relative to different heat fluxes produced by electronic chips. The benefit of adding a fan is also investigated when high levels of heat generation are expected.

scholarly journals A Feasibility Study of Fabrication of Piezoelectric Energy Harvesters on Commercially Available Aluminum Foil

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2797 ◽  
Author(s):  
Chongsei Yoon ◽  
Buil Jeon ◽  
Giwan Yoon
Keyword(s):  
Energy Harvesting ◽  
Elevated Temperatures ◽  
Aluminum Foil ◽  
Cost Effective ◽  
Device Fabrication ◽  
Point Of View ◽  
Plastic Substrate ◽  
Device Performance ◽  
Piezoelectric Energy ◽  
Energy Harvesting Devices

In this paper, we present zinc oxide (ZnO)-based flexible harvesting devices employing commercially available, cost-effective thin aluminum (Al) foils as substrates and conductive bottom electrodes. From the device fabrication point of view, Al-foils have a relatively high melting point, allowing for device processing and annealing treatments at elevated temperatures, which flexible plastic substrate materials cannot sustain because of their relatively low melting temperatures. Moreover, Al-foil is a highly cost-effective, commercially available material. In this work, we fabricated and characterized various kinds of multilayered thin-film energy harvesting devices, employing Al-foils in order to verify their device performance. The fabricated devices exhibited peak-to-peak output voltages ranging from 0.025 V to 0.140 V. These results suggest that it is feasible to employ Al-foils to fabricate energy-efficient energy harvesting devices at relatively high temperatures. It is anticipated that with further process optimization and device integration, device performance can be further improved.

Sign in / Sign up

Export Citation Format

Share Document