Starting from the relationship between urban planning and mobility management, TeMA has gradually expanded the view of the covered topics, always following a rigorous scientific in-depth analysis. ...This section of the Journal, Review Notes, is the expression of a continuous updating of emerging topics concerning relationships among urban planning, mobility and environment, through a collection of short scientific papers. The Review Notes are made of four parts. Each section examines a specific aspect of the broader information storage within the main interests of TeMA Journal. In particular, the Urban Practices section aims at producing, analyzing and reporting data on recent and relevant policies in the urban domain. The present note in particular reports on the recent initiatives undertaken by two major Southern Italian cities to foster sustainable mobility: Palermo and Cagliari. To this aim, the note briefly introduces the legal background and current developments of the Sustainable Urban Mobility Plan (SUMP), a framework developed by the European Commission to support local administrations in developing holistic urban mobility strategies. This is followed by (i) an overview of the mobility situations in Palermo and Cagliari and by (ii) an analysis of the objectives, the strategies and the measures set in their respective SUMPs.
Starting from the relationship between urban planning and mobility management, TeMA has gradually expanded the view of the covered topics, always following a rigorous scientific in-depth analysis. ...This section of the Journal, Review Notes, is the expression of a continuous updating of emerging topics concerning relationships among urban planning, mobility and environment, through a collection of short scientific papers. The Review Notes are made of four parts. Each section examines a specific aspect of the broader information storage within the main interests of TeMA Journal. In particular, the Urban Practices section aims at producing, analyzing and reporting data on recent and relevant policies in the urban domain. The present note in particular reports on the recent initiatives undertaken by two major Southern European capitals to foster sustainable mobility: Rome (IT) and Madrid (ES). To this aim, the note briefly introduces the legal background and current developments of the Sustainable Urban Mobility Plan (SUMP), a framework developed by the European Commission to support local administrations in developing holistic urban mobility strategies. This is followed by (i) an overview of the mobility situations in Rome and Madrid and by (ii) an analysis of the objectives, the strategies and the measures set in their respective SUMPs. A comparative analysis of the two SUMPs is proposed in the last paragraph as summary factsheet of the contribution.
In the event of a severe nuclear accident, one major concern is the release of radioactive material into the environment causing potential exposure of the general public to radiation. Among the ...volatile radionuclides are a range of tellurium isotopes. Due to the radioactivity and the volatility of tellurium, it has to be taken into account when assessing the overall effects of an accident. The interest in tellurium is not limited only to its release but also to the fact that some tellurium isotopes decay to iodine, and thus affect the iodine release behavior. The release and transport behavior of tellurium has been investigated over the past decades, however, the aqueous chemistry of tellurium in the complex containment sump system is still unclear. This study presents the behavior of tellurium dioxide in simplified containment sump conditions in relation to dissolution, redox reactions, and interactions with water radiolysis products. The results indicate that radiolysis products have a significant effect on tellurium chemistry in both a reducing and oxidizing manner depending on the solution composition. The redox reactions also affect the solubility of tellurium. The results show that the current information used to assess tellurium source term needs to be reevaluated for both severe accident management and for code validation purposes.
Gravitational settling is crucial for treating produced water, and its efficiency affects the separation in multi-stage treatment processes. Due to complex water properties and thickening upper oil ...layer during the settling process, sump oil recovery in appropriate time is essential to avoid secondary pollution of separated water and recover oil resources. This paper constructs and analyzes the dataset of sump oil recovery for produced water separation. It is determined that the factors affecting the sump oil growth are oil content, daily processing capacity, polymer concentration, and suspended solids content. The produced water of water-flooding, polymer-flooding, and ASP-flooding, with average oil contents of 0.03893, 0.20072, and 0.05387, respectively, is carried out to train the prediction model for the sump oil growth rate. It is indicated that for actual settling tanks with cross-sectional areas ranging from 100 m2 to 900 m2 and daily processing capacity range from 5000 m3 to 30000 m3, the sump oil growth rate for produced water of water-flooding, polymer-flooding, and ASP-flooding are distributed in the ranges of 0.1094 m/day to 2.5206 m/day, 0.0309 m/day to 0.7524 m/day, and 0.0505 m/day to 1.8764 m/day, respectively. The predicted results are consistent with actual operation.
The Roof-attached Vortex (RAV), Floor-attached Vortex (FAV) and Combined Submerged Vortices (CSV) induced by the closed sump of a tidal pumping station have become an intricate problem that urgently ...needs to be clarified in expanding the stable operation range of units. This work reveals the dynamic evolution laws of various vortices and their typical forms under different flow conditions based on a combination of high-speed visualization and scale-resolving simulation methods. The results show that the RAV is a single spiral vortex structure under low flow rates and a main-secondary vortex double spiral structure under high flow rate conditions. The increase in flow rate has a positive promoting effect on the growth of the FAV. The RAV and FAV frequency values of occurrence are in the range of 0.001–0.1 Hz and 0.007–0.06 Hz, respectively. The maximum frequency of the CSV is 0.03 Hz. In the symbiotic stage of the CSV, there is an interaction between RAV and FAV. The suction of the surrounding low-pressure system affects the FAV, with vertical vorticity propagating towards the side of the RAV. In addition, the tangential velocity distribution of RAV and FAV exhibit rigid-like rotation characteristics consistent with the Burgers vortex model.
•Typical morphology and evolution characteristics of various vortices in a closed sump have been revealed.•The frequency of multiple vortices occurring is statistically analyzed.•The instantaneous characteristics of dynamic parameters of the combined submerged vortices are explored.•The roof-attached and floor-attached vortex exhibit tangential velocity distribution characteristics like rigid-body rotation.
Whilst there is research on how Covid-19 impacted travel demand and transport business, little attention has been paid on how Covid-19 has affected authorities' transport planning priorities and the ...actions taken to protect the public while travelling. This paper attempts to shed light on: a) how the transport planning priorities changed during the Covid-19 lockdowns in 2020/2021, and b) how the planning phases of the Sustainable Urban Mobility Plan (SUMP) framework can be strengthened to support a more resilient emergency planning environment. To address these questions, an online questionnaire was designed followed up by personal interviews from selected European cities. Data collection took place in November and December 2020, when most European countries were in lockdowns. Thirteen public authorities participated in the online questionnaire, while nine out of them were further interviewed. A mixed methods approach is used to analyse the quantitative and qualitative data and bring the results together to assess how SUMP priorities have changed. The results showed that the priority planning objectives were different in the period during the 2020/2021 lockdowns compared to the period before that. Public transport system planning was a priority in both periods, while planning for shared mobility and Mobility as a Service was further prioritised in the 2020/21 lockdowns. The main reasons for prioritising specific planning objectives were to secure public health, minimise environmental impact, support economic recovery and address social equity. The changes in the priority of planning objectives were also diverse between smaller and larger urban areas. Most of the actions adopted to accommodate the prioritised planning objectives were already defined before Covid-19, indicating that the lockdowns have acted as an accelerator of specific existing planning objectives.
•Covid-19 had an apparent impact on the prioritisation of planning objectives.•The response to the pandemic involved mostly actions that were readily available.•The pandemic has acted as an accelerator of specific existing planning objectives.•Active travel measures were preferred over more advanced mobility solutions.•Response to the pandemic revealed lack of emergency planning and preparedness.
•The reflection wave is the predominant factor that leads to air-entrainment in pump sump.•The vertical pressure gradient plays a negative role, while the streamwise and spanwise pressure gradients ...reinforce the dimples and waves.•The air-entrainment formation process for steady and unsteady cases are revealed from the perspective of wave and dimple motions.
Air-entrainment is a negative phenomenon in pump stations. The process and the underlying mechanism are far from being fully understood. Based on the previous research, the present paper numerically studies the air-entrained vortex formation in a benchmark pump sump. The bifurcation model (BM) for capturing the rotating characteristics of the vortex and the simple coupled level set and volume of fluid method (S-CLSVOF) for tracking the free surface are adopted in this study. During both steady (case 1) and unsteady (case 2) air-entrained vortex formations, it is found that the wave is the predominant aspect. Exploration on the pressure signals reveals that the wave is generated by the reflection effect of the back wall and propagates from downstream to upstream. The vertical pressure gradient plays a negative role, rather than a positive one as expected. The streamwise and spanwise pressure gradients are found to drive the dimples and waves. The processes of the air-entrained vortex formations in two cases are analyzed in detail. For case 1, the formation process is wavy – inception – propagation – steady – fully developed. For case 2, there are some differences including the collision and reformation stages. Two waves will collide with each other after the inception and reform near the pipe. The process is wavy/inception – collision – reformation – propagation – fully developed. The study offers a new perspective on the air-entrainment mechanism. Accounting for the wavy characteristics, it is expected to eliminate the air-entrained vortex by suppressing the reflection wave.
The vortex generated around the suction region of the pump sump causes problems such as damage to the pump, increased maintenance costs, and failure to supply coolant smoothly. Therefore, analyzing ...vortices is essential in pump sump design. However, the CFD analysis alone is insufficient in pump sumps vortex analysis since the reliability of the results is doubtful in scaled model tests. This study conducted the model test to validate a suitable CFD simulation method by identifying the Type 2 vortex among the three types of subsurface vortices. The dye test and PIV technology were used to visualize the Type 2 subsurface vortices, whereas the PIV vorticity results were then compared to the CFD results. The average vorticity of 60.2 (1/s) was identified as the reference level of Type 2 subsurface vortices formation by mapping the dye test results with the PIV vorticity results. Furthermore, the average vorticities of 84.63 (1/s) and 85.15 (1/s) were recorded in the presence of Type 2 subsurface vortices in PIV and CFD, respectively, and these values can be applied to the designing of pump sumps.
Background:
Technical advances in microneurosurgery facilitated the continuous evolution of surgery. In many developing countries surgeons face difficulties rendering high quality services due to ...resource constraints. The continuous dry surgical field is essential for performing microvascular anastomosis. Commercially available sump suctions are costly and beyond the reach of most surgeons in resource-constrained countries.
Methods:
We designed a suction system which functions on the principles of capillary action and sump effect.
Results:
The improvised sump suction was used successfully in our patients for micro vascular surgery, giving us a continuous dry field and removing the chance of error by an assistant.
Conclusion:
The suction system was made with the use of easily available low-cost components, and worked well to the satisfaction of the surgeon.
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