Load Shedding Algorithm Using Voltage and Frequency Data

Under frequency load shedding schemes have been widely used, to restore power system stability post major disturbances. However, the analysis of recent blackouts suggests that voltage collapse and voltage-related problems are also important concerns in maintaining system stability. For this reason, both frequency and voltage need to be taken into account in load shedding schemes. The research undertaken here considers both parameters in designing a load shedding scheme to determine the amount of load to be shed and its appropriate location. An introduction about the need for a load shedding scheme and the purpose of doing research on this particular topic is given. This is followed by a discussion on the literature review of some of these schemes. The discussion is divided into two parts. The first part is about the actual load shedding schemes used in the power industry world wide. The second part gives a detailed overview about the two types of load shedding schemes, namely the under frequency and under voltage load shedding schemes. The methodology used for the proposed load shedding algorithm includes frequency and voltage as the inputs. The disturbance magnitude is estimated using the rate of change of frequency and the location and the amount of load to be shed from each bus is decided using the voltage sensitivities. The methodology describes the algorithm in a stepwise manner and gives brief information about the test system and the PSS/E software used to model the disturbance. The test systems used are the IEEE 39 bus system and IEEE 50 bus system. The disturbances modelled are the loss of a generator for various buses and the loss of transmission lines for various cases. The observations and results obtained from the simulations comprise of the frequency and voltage plots before and after applying the proposed load shedding scheme. The load shedding scheme is implemented on an equivalent system provided by Duke Energy. The data has been collected from a Duke simulator. The calculations for determining the magnitude of the disturbance and the amount of load shed from each bus are also presented here. The conclusion chapter includes the summary of the observations and suggestions for future work

Gaps in Knowledge and Awareness Related to Equipment Safety Among Nursing Personnel Working in Pediatric and Neonatal Medical- Surgical Icus at Tertiary Care Hospital

Equipments are the essential part of any pediatric or neonatal ICU required for monitoring and care to children and neonates during the ICU stay. The present study was conducted to identify gaps in knowledge and awareness related to equipment safety among nursing personnel working in pediatric and neonatal medical-surgical ICUs in a tertiary care hospital. Sixty one nursing personnel working in pediatric and neonatal ICUs were enrolled using universal sampling technique. A structured pretested and validated tool containing knowledge and awareness questionnaire was used to collect the data ( α = 0.82). More than half of the nursing personnel were between the age group of 26-35 years with the mean age of 30.24 ± 6.56 (22–46). Majority nursing personnel were female (93.4%), working as sister grade II (77%, working as bedside nurses) in PICU ((42.6%), with most having BSc Nursing as their professional qualification, Majority of nursing personnel (83.6%) had not attended in-service education programme and half of them did not have any bedside demonstration of the equipments prior to its installation in the unit. Majority nursing personnel were having medium knowledge (68.9%) and awareness scores (65.6%) related to equipment safety with mean knowledge and awareness scores of 11.5 ± 1.7 (6-16) and 32.9 ± 3.4 (20–40) respectively. No correlation was observed between knowledge and awareness scores of the nursing personnel (p> 0.05)

P3_5 Balloon Mayhem in Gotham

The article investigates how high weather balloons made of helium rise before they burst and drop down to the Earth. Considering the pressure at higher altitudes, the radius of the balloon and the mass of the package we find that the balloon rises to an altitude of 37800m

A Novel Technique - Pterygium excision followed by sutureless and gluefree conjunctival autografting

Purpose: To study the efficacy and safety of sutureless and gluefree conjunctival autograft as an adjunctive therapy after removal of primary pterygium and to determine the post operative recurrence.Methods: A prospective, non-comparative, interventional case series. Pterygium excision and supero-temporal bulbar conjunctival autografting without sutures and glue was performed on 52 eyes of 50 patients with primary pterygium. patients were followed upto 1 year.Results: The mean age of the patients was 40.9 +/- 12.09 years. Of the 50 patients recurrence was observed in 1 patient (1.92%).Graft displacement was seen in 4 (7.69%) on 1st post operative day which were successfully repositioned .Graft edema was seen in 4 (7.69%) cases while graft haematoma occurred in 3(5.76%) cases. No granuloma, retention cyst or corneal dellen noted. After 4 weeks,all grafts were taken up well and there was stastically significant reduction in astigmatism(P<0.01).Conclusion: This study suggests that a sutureless and gluefree conjunctival autografting in the management of primary pterygium is a useful procedure resulting in low recurrence rate and also avoids the potential risks and complications of sutures, glue and amniotic membrane

P3_2 Don’t smoke and drive!

This paper investigates the consequences of smoking tobacco cigarettes in a car. With an average smoking rate of 5 minutes per cigarette and with no air entering or released from the car, we find that if the carbon monoxide (CO) content in the air is over 1000ppm, you would have to smoke approximately 32 cigarettes within the hour to fall unconscious from CO poisoning. Furthermore we consider whether opening a window would make it safe to smoke in a car as the air flow rate through the window would remove the CO content from the car

P3_7 Meltdown!

This paper investigates the change in the albedo of the Earth due to the presence of sea ice and its impact on Earth's surface temperature. If all the sea ice melted, the albedo of the earth will increase by approximately 7.4%. This would result in an increase of surface temperature by approximately 6˚C

P3_4 Reducing blood loss through injury

On event of sustaining an injury which results in bleeding, it is advised to apply pressure on the wound and also elevate the injury above the height of the heart [1]. This paper investigates the physics behind the two actions, and shows that both cases result in the decreasing of the volumetric flow rate, and hence reduce the rate at which blood is lost.