A design procedure for the weight optimization of straight finned radiators

Design technique evaluates optimum weight of space radiator consisting of finned, right circular cylinder

Integrated Urban Water Resources Modeling In A Semi-Arid Mountainous Region Using A Cyber-Infrastructure Framework

Water resources management in cities is facing growing challenges related to increases in water demand, uncertain future climate variability, and conflicts related to water rights and access. Integrated water resource management (IWRM) is an inter-disciplinary framework which connects separated infrastructures and elements of a water resource system together which have dynamic interconnection. An IWRM process broadly involves water supply systems, stormwater management, wastewater collection, climate variables, groundwater and other water related sectors to solve the water and environmental problems. In this study, an integrated framework applying the GoldSim Monte-Carlo simulation software is presented to provide dynamic simulation of inter-related parts of an urban water system. The framework supports fast access and application of data resources, exchange of data among sub-models, and capacity to produce long-term simulations with sufficiently high spatial resolution to support urban water management research. Also parts of the framework are web-based interface, results analysis, and visualization tools. Working with local water managers the framework has been designed to provide specific and useful information for stakeholders, water managers and researchers to answer location-specific questions related to water availability, stormwater management, and other aspects. It also has the potential to provide exploratory opportunities for community and K-12 education. This paper describes the framework and presents an analysis of decentralized versus centralized urban water management solutions for the Salt Lake City metropolitan area in Utah, USA

Ratio of solid velocity to mixture velocity in slurry flow

The study consisted of two parts, a theoretical analysis of the problem and an experimental investigation under controlled conditions. The theoretical analysis resulted in an equation which expressed the velocity ratio in terms of dimensionless parameters representing the distribution of the particles in the mixture, the slip between the solid particles and the adjacent fluid, and the velocity distribution of the fluid in the conduit

Impacts of Large-Scale Stormwater Green Infrastructure Implementation and Climate Variability on Receiving Water Response in the Salt Lake City Area

This study evaluated impacts of Green Infrastructure (GI) as a stormwater management practice on return flows and the further Implications of climate variability. The goal was to create a model to explore the impacts that bioretention and Rainwater Harvesting (RWH) representing GI had using goldsim and Stormwater Management Modeling (SWMM) software. The software was used to represent impacts that climate variability individually and combined, may have on downstream stakeholders and receiving water systems in Salt Lake city, Utah, USA. Primary stakeholders included downstream water rights users, Farmington Bay waterfowl management area and the migratory birds that rely on Farmington Bay and the advocates that represent them. The steps to reach this goal were broken down incrementally to: (1) Characterize daily inflows to Farmington Bay, (2) Provide daily inflows from natural and urban runoff to the Jordan river, (3) Create a daily water balance model of Farmington Bay, (4) Demonstrate the model with and without stormwater GI and climate variability scenarios and (5) Determine trends of inflow to the Jordan River, duck clubs and Farmington Bay under various scenarios. The simulation results demonstrated that bioretention and RWH individually and combined had minimal impact on downstream water users, Jordan River flows and ultimately Farmington Bay water levels. Bioretention reduced the flow in the Jordan River minimally, with reductions primarily during peak flow. RWH actually kept more water in the natural system on average because less water was needed from the water treatment facilities when outdoor irrigation was supplemented with rainwater. The user reliability did not differ for any of the bioretention and RWH scenarios. The climate variability scenario had the greatest impact to Jordan River flows, Farmington Bay water levels and user reliability. When analyzed without GI implementation, the climate variability induced reduction in tributary flows and precipitation led to an average decrease of 11% in the Jordan River streamflow when compared to average baseline scenario over a 25 year simulation. The user reliability decreased by 5% and most importantly there was found to be an average of 36% decrease in the water levels in Farmington Bay. The resultant of the decrease in Farmington Bay water level is a loss of up to 61 square kilometers (15,000 acres) of open bay that would impact bird habitat, brine shrimp grounds, recreationalists, bird watchers, hunters and more. For this case study the implications of climate variability on the water system are much greater than implementing GI

Impacts of DEM Type and Resolution on Deep Learning-Based Flood Inundation Mapping

This paper presents a comprehensive study focusing on the influence of DEM type and spatial resolution on the accuracy of flood inundation prediction. The research employs a state-of-the-art deep learning method using a 1D convolutional neural network (CNN). The CNN-based method employs training input data in the form of synthetic hydrographs, along with target data represented by water depth obtained utilizing a 2D hydrodynamic model, LISFLOOD-FP. The performance of the trained CNN models is then evaluated and compared with the observed flood event. This study examines the use of digital surface models (DSMs) and digital terrain models (DTMs) derived from a LIDAR-based 1m DTM, with resolutions ranging from 15 to 30 meters. The proposed methodology is implemented and evaluated in a well-established benchmark location in Carlisle, UK. The paper also discusses the applicability of the methodology to address the challenges encountered in a data-scarce flood-prone region, exemplified by Pakistan. The study found that DTM performs better than DSM at lower resolutions. Using a 30m DTM improved flood depth prediction accuracy by about 21% during the peak stage. Increasing the resolution to 15m increased RMSE and overlap index by at least 50% and 20% across all flood phases. The study demonstrates that while coarser resolution may impact the accuracy of the CNN model, it remains a viable option for rapid flood prediction compared to hydrodynamic modeling approaches

Properties of Erbium and Ytterbium Doped Gallium Nitride Layers Fabricated by Magnetron Sputtering

We report about some properties of erbium and erbium/ytterbium doped gallium nitride (GaN) layers fabricated by magnetron sputtering onsilicon, quartz and Corning glass substrates. For fabricating GaN layers two types of targets were used - gallium in a stainless steel cup anda Ga2O3 target. Deposition was carried out in the Ar+N2 gas mixture. For erbium and ytterbium doping into GaN layers, erbium metallicpowder and ytterbium powder or Er2O3 and Yb2O3 pellets were laid on the top of the target. The samples were characterized by X-raydiffraction (XRD), photoluminescence spectra and nuclear analytical methods. While the use of a metallic gallium target ensured thedeposition of well-developed polycrystalline layers, the use of gallium oxide target provided GaN films with poorly developed crystals. Bothapproaches enabled doping with erbium and ytterbium ions during deposition, and typical emission at 1 530 nm due to the Er3+ intra-4f 4I13/2 → 4I15/2 transition was observed

Properties of Erbium Doped Hydrogenated Amorphous Carbon Layers Fabricated by Sputtering and Plasma Assisted Chemical Vapor Deposition

We report about properties of carbon layers doped with Er3+ ions fabricated by Plasma Assisted Chemical Vapor Deposition (PACVD) and by sputtering on silicon or glass substrates. The structure of the samples was characterized by X-ray diffraction and their composition was determined by Rutherford Backscattering Spectroscopy and Elastic Recoil Detection Analysis. The Absorbance spectrum was taken in the spectral range from 400 nm to 600 nm. Photoluminescence spectra were obtained using two types of Ar laser (λex=514.5 nm, lex=488 nm) and also using a semiconductor laser (λex=980 nm). Samples fabricated by magnetron sputtering exhibited typical emission at 1530 nm when pumped at 514.5 nm.&nbsp

Short Time-Interval Rainfall Disaggregation for Continuous Hydrologic Simulation

Traditionally design storms have been used to design and analyze urban drainage systems and hydraulic structures. Design storms can be developed with the desired temporal resolution to accommodate urban hydrology needs, but because the temporal distribution is generally arbitrary the application of complex disaggregation techniques is unwarranted. Continuous hydrologic simulation is recommended as an alternative to the traditional design storm approach for the design and analysis ofhydrologic and hydraulic structures for reasons discussed in James (1994) and Accurate hydrologic simulation of small urban catchments requires the use of a rainfall time series with a fine temporal resolution. Studies have shown that when the response time of a watershed is shorter than the total duration of rainfall excess, the runoff rate is observed to depend on the depth of rainfall and the intensity distribution (Ball1994

A Systematic Review of Quantitative Resilience Measures for Water Infrastructure Systems

Over the past few decades, the concept of resilience has emerged as an important consideration in the planning and management of water infrastructure systems. Accordingly, various resilience measures have been developed for the quantitative evaluation and decision-making of systems. There are, however, numerous considerations and no clear choice of which measure, if any, provides the most appropriate representation of resilience for a given application. This study provides a critical review of quantitative approaches to measure the resilience of water infrastructure systems, with a focus on water resources and distribution systems. A compilation of 11 criteria evaluating 21 selected resilience measures addressing major features of resilience is developed using the Axiomatic Design process. Existing gaps of resilience measures are identified based on the review criteria. The results show that resilience measures have generally paid less attention to cascading damage to interrelated systems, rapid identification of failure, physical damage of system components, and time variation of resilience. Concluding the paper, improvements to resilience measures are recommended. The findings contribute to our understanding of gaps and provide information to help further improve resilience measures of water infrastructure systems