159 research outputs found
Congenital pouch colon with rectal atresia revisited
No full textWe are adding two cases of congenital pouch colon with rectal atresia (RA) to the already published five cases. The presentation of RA is often delayed owing to the presence of normal anus, however, clinical evaluation, plain abdominal radiograph, and urine examination for meconuria, may help in detecting this rare association early
Scheduling of EV Charging in Grid-Connected Parking Lots with Renewable Sources
No full textThe growing concern about environmental issues is leading many countries to take measures that
allow a more rational energy usage and for a more sustainable future. The improvement of systems
e�ciency and the use of renewable sources are some points to work on to reduce greenhouse gas
emissions. That is why electric mobility is drawing the attention of companies, countries and research
groups, as an important measure to face the negative consequences derived from the current energy
usage. It is clear that the inclusion of electric vehicles will strongly a�ect the operation, management,
and planning of current electric power systems. Firstly, an additional load will have to be considered,
the electric vehicles charging. In an initial stage, when the deployment of electric vehicles is not
signi�cant, special measures will not be required. However, in the future with thousands of vehicles
in operation, ad-hoc electric vehicle charging can lead to line congestion or voltage limits violation.
Moreover, an update of the current electric power systems regarding more advanced information
and communication technologies, better metering devices, as well as the presence of more renewable
sources are required for the suitable integration of electric vehicles.
The increasing number of electric vehicles (EV) means there is a growing need for charging
stations as well. A potential solution to address the need for charging stations is to transform traditional
parking lots into smart parking lots. Due to the inherently complex and dynamic environment,
a potential obstacle, from a business perspective to the process of transforming parking lots into
smart parking lots is the complexity of estimating the pro�t of the smart parking lots owner and,
consequently, the length of time required to recover the cost of the initial investment. We propose a
simulation approach to estimate the smart parking lot owners pro�t during a certain period of time.
Thus, this thesis is intended to cover the problem of signi�cant increase in electric vehicles arriving
at the parking lot leading to a challenge for scheduling of vehicles for charging. The primary objective
of parking lot owner is to charge more vehicles and increase pro�t. But due to stringent rules from
regulators for network upgrades, increase in the number of charging slots is challenging. Installing
a distributed generation like solar microgrid will bene�t from allowing many vehicles to charge at
the parking lot. This thesis aims in proposing an algorithm called parking lot management system
(PLMS) and charging management system (CMS) for scheduling of electric vehicles with the support
of solar generation with the objective of minimizing the power drawl from the grid during high peak
pricing period. Power drawl from the grid is reduced by using the solar power available. Since
the power drawl from the grid is reduced, it is obvious that the pro�t of the parking lot owner is
increased. scheduling is done by shifting the cars to the abundant solar power period and reducing
the peaks on the grid which helps the utility operator. The proposed algorithm is simulated using
MATLAB programming, and the results are presented
Cranial migration of ventriculoperitoneal shunt
No full textWe report a rare case of an 11-month male infant with cranial migration of ventriculoperitoneal (VP) shunt assembly. The shunt chamber was lying inside the ventricles. At the time of shunt revision, outsized burr hole and wide dural opening were observed. The ventricular migrated chamber of VP shunt was first retrieved from the ventricle followed by the removal of whole shunt assembly. A new VP shunt was placed on the other side with the chamber firmly anchored to the pericranium. The diagnosis was timely done and prevented complete shunt migration into the ventricles. We attribute factors such as outsized burr hole, wide dural opening, and poor anchoring of the straight connector of shunt chamber to periosteum because of poor tissue preservation (redo operation). Repeated flushing of the shunt chamber by cranial direction pressing on it by the mother might be a contributing factor for loosening of anchor sutures and cranial migration. Patients undergoing VP shunt procedure must be under regular follow-up for early recognition of this potential complication. Cranial migration of VP shunt is usually not a fatal complication
Optimal Charging Schedule for Electric Vehicles in Parking Lot with Solar Power Generation
No full textIn order to reduce the carbon emission from vehicles, the world transportation system is transforming from conventional gasoline vehicles to electric vehicles. This transformation introduced high penetration of electric vehicles into the utility grid. This lead to a new scope of research in the area of scheduling the charging of electric vehicles. In this context the electric vehicles arriving at the parking lot is increasing which leads a challenge to parking lot owner for scheduling of vehicles for charging. The primary objective of parking lot owner is to charge more vehicles and increase his profit. But due to stringent rules from regulators for network upgrades, increase in the number of charging slots is challenging. Installing a distributed generation like solar microgrid will benefit from allowing many vehicles to charge at the parking lot. This paper aims in proposing an algorithm called parking lot management system (PLMS) for optimal scheduling of electric vehicles with the support of solar generation with the objective of minimizinz the power drawl from the grid during high peak pricing period. Power drawl from the grid is reduced by using the solar power available. Since the power drawl from the grid is reduced, it is obvious that the profit of the parking lot owner is increased. Optimal scheduling is done by shifting the cars to the abundant solar power period and reducing the peaks on the grid which helps the utility operator. The proposed algorithm is simulated using MATLAB programming, and the results are presented. Here in the simulation, it is considered two cases one is the uncoordinated case, and the other is coordinated case. In uncoordinated case charging strategy is first come first served (FCFS) basis and in coordinated case scheduling is done by shifting of cars to abundant solar periods for reducing the cost. It is observed from the results that the savings with solar installation and the uncoordinated case is 2729.59 and whereas with the coordinated case the savings are 2891.19 for one day. Since the savings are more in coordinated case, it is suggested that coordinated scheduling of vehicles will increase the profit of the parking lot owner
Design of a Direct Numerical Simulation of Flow and Heat Transfer in a T-junction
No full textSeveral investigations have been undertaken to study the velocity and temperature fields associated with the thermal mixing of fluids, and resulting thermal striping in a T-junction. The T-junction thermal mixing and fatigue phenomenon is a major area of study for the purposes of safety, maintenance and operational life in the nuclear industry, in which fluid mixing occurs in cooling circuits for the nuclear reactor. The existing body of work on T-junctions mainly comprises of experimental references performed at high values of Reynolds numbers. However, these available experimental databases are not sufficient to describe the involved physics in adequate detail, and, due to experimental limitations, accurate data on velocity and temperature fluctuations in regions close to the wall are not accessible. Computational Fluid Dynamics (CFD) can play an important role in predicting such complex flow features. However, predicting complex thermal fatigue phenomena is a challenge for the available momentum and heat flux turbulence models, which also require extensive validation.It was realised that a comprehensive Direct Numerical Simulation (DNS) of a T-junction was required as a benchmark for validation purposes, but also to better understand the underlying physical phenomena of thermal mixing in the fluid and thermal fatigue in the solid walls. The aim of the thesis is to thus design such a reference DNS experiment of a thermal fatigue scenario calibrated using Reynolds-Averaged Navier-Stokes (RANS) simulations. The feasibility of scaling down the Reynolds number from experimental cases to a computationally-feasible range is investigated. The junction corner shape is also modified to a slightly rounded corner, ensuring that the underlying fundamental physical phenomena of turbulence and thermal mixing flow features were preserved. The pipe lengths of the model were calibrated to ensure there would be no interference of the upstream developing region on the thermal mixing at the junction, and the outlet boundary conditions. A sample proof-of-concept under-resolved DNS (UDNS) case, with high- and low-Prandtl number passive temperature scalars, with iso-temperature, iso-flux and mixed (Robin) wall boundary conditions, is simulated and presented. This proof-of-concept simulation contributes to the finalization of the fully-resolved DNS in computational grid size selection, transient characteristics, computational costs, and additionally, the implementation of the Robin boundary condition in the fully-resolved DNS.Aerospace Engineerin
Design of a Direct numerical Simulation of flow and heat transfer in a T-junction
No full textSeveral investigations have been undertaken to study the velocity and temperature fields associated with the thermal mixing between fluids, and resulting thermal striping in a T-junction. However, the available experimental databases are not sufficient to describe the involved physics in adequate detail, and, due to experimental limitations, accurate data on velocity and temperature fluctuations in regions close to the wall are not available. Computational Fluid Dynamics (CFD) can play an important role in predicting such complex flow features. However, predicting complex thermal fatigue phenomena is a challenge for the available momentum and heat flux turbulence models. Furthermore, such models need to be extensively validated. The aim of the present work is to design a reference numerical experiment for Direct Numerical Simulation (DNS) of a thermal fatigue scenario using Reynolds-Averaged Navier-Stokes (RANS) simulations. First, the feasibility of scaling down the Reynolds number from experimental cases to a computationally-feasible range is investigated. The junction corner shape is also modified to a slightly rounded corner, ensuring that the underlying fundamental physical phenomena of turbulence and thermal mixing flow features are preserved. Finally, the pipe lengths of the model were calibrated to ensure there would be no interference of the upstream developing region and the outlet boundary conditions on the thermal mixing at the junction. A sample under-resolved DNS case, with unity and low-Prandtl number passive temperature scalars, with iso-temperature, iso-flux and mixed (Robin) wall boundary conditions, are presented. This proof-of-concept simulation contributes to the finalization of the set-up for fully-resolved DNS with respect to the computational grid size selection and transient characteristics.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Aerodynamic
An analysis on the potentials of Vertical Greenery System (VGS) in context to the application viewpoint
No full text
Non-linear optical properties of the inorganic cluster[(η-C<SUB>5</SUB>H<SUB>5</SUB>)CoFe<SUB>2</SUB>SSe(CO)<SUB>6</SUB>]
No full textNon-linear refraction and absorption have been studied in a mixed-metal, mixed chalcogenide cluster. The cluster displays optical limiting significantly superior to that displayed by C60
Intercostal Nerve Block in Patient with Chronic Obstructive Pulmonary Disease: Lessons Learned
No full textPneumothorax is a rare but potentially serious iatrogenic complication of intercostal nerve block. This case report emphasizes the importance of imaging guidance and careful patient assessment to mitigate complications in high-risk individuals undergoing intercostal nerve block. An elderly male with chronic obstructive pulmonary disease and undergoing chemotherapy for mediastinal metastasis of small-cell liver carcinoma developed severe postherpetic neuralgia resistant to pharmacological therapy. An ultrasound-guided intercostal nerve block was performed which resulted in a pneumothorax, subsequently managed with an intercostal drain
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