Mutated hilltop inflation revisited

In this work we re-investigate pros and cons of mutated hilltop inflation. Applying Hamilton-Jacobi formalism we solve inflationary dynamics and find that inflation goes on along the ${\cal W}_{-1}$ branch of the Lambert function. Depending on the model parameter mutated hilltop model renders two types of inflationary solutions: one corresponds to small inflaton excursion during observable inflation and the other describes large field inflation. The inflationary observables from curvature perturbation are in tune with the current data for a wide range of the model parameter. The small field branch predicts negligible amount of tensor to scalar ratio $r\sim \mathcal{O}(10^{-4})$, while the large field sector is capable of generating high amplitude for tensor perturbations, $r\sim \mathcal{O}(10^{-1})$. Also, the spectral index is almost independent of the model parameter along with a very small negative amount of scalar running. Finally we find that the mutated hilltop inflation closely resembles the $\alpha$-attractor class of inflationary models in the limit of $\alpha\phi\gg 1$.Comment: 17 pages, 13 figures. Accepted for publication in EPJ

The Profitability of Paddy Cultivation and Farmers’ Perception in West Bengal with Special Reference to Purba Bardhaman District

Many economists and experts opined that agriculture is an unprofitable activity in India nowadays, mainly because of increasing cost and low prices of farm produce. However, during the field survey in Galsi-I and Galsi-II Blocks of Purba Bardhaman, it was observed that many farmers do not think so. In this context, using the secondary data on the cost of paddy cultivation for the period 1996–97 to 2015–16, this paper analyses the cost and returns from paddy cultivation in West Bengal. It is observed that the cost has increased at a very high rate. Paid out cost at current prices during the last decade has increased by 12.1 per cent per annum. However, they do not realise the right price of their produce, and consequently, the profit margin has declined. Data reveal that farmers incurred losses in paddy cultivation upto 14 times except for in 2007–08 and in 2009–10 during 2000–01 to 2015–16. They are also being deprived of getting even the minimum support prices (MSP) due to loopholes in government initiatives. Using primary data, this paper explains why many farmers think that paddy cultivation is still a profitable activity. In doing so, the research finds that they miscalculate the cost of cultivation and that is why they perceive the profit margin to be higher. The kinds of cost that they do not calculate include family labour, depreciation charge, interest on capital, the rental value of owned land, and others. Another cause for exaggerated profit is that farmers include income from paddy business as return from agriculture

Optimisation of stand-alone hybrid energy systems for power and thermal loads

Stand-alone hybrid energy systems are an attractive option for remote communities without a connection to a main power grid. However, the intermittent nature of solar and other renewable sources adversely affects the reliability with which these systems respond to load demands. Hybridisation, achieved by combining renewables with combustion-based supplementary prime movers, improves the ability to meet electric load requirements. In addition, the waste heat generated from backup Internal Combustion Engines or Micro Gas Turbines can be used to satisfy local heating and cooling loads. As a result, there is an expectation that the overall efficiency and Greenhouse Gas Emissions of stand-alone systems can be significantly improved through waste heat recovery. The aims of this PhD project are to identify how incremental increases to the hardware complexity of hybridised stand-alone energy systems affect their cost, efficiency, and CO2 footprint. The research analyses a range of systems, from those designed to meet only power requirements to others satisfying power and heating (Combined Heat and Power), or power plus both heating and cooling (Combined Cooling, Heating, and Power). The majority of methods used focus on MATLAB-based Genetic Algorithms (GAs). The modelling deployed finds the optimal selection of hardware configurations which satisfy single- or multi-objective functions (i.e. Cost of Energy, energy efficiency, and exergy efficiency). This is done in the context of highly dynamic meteorological (e.g. solar irradiation) and load data (i.e. electric, heating, and cooling). Results indicate that the type of supplementary prime movers (ICEs or MGT) and their minimum starting thresholds have insignificant effects on COE but have some effects on Renewable Penetration (RP), Life Cycle Emissions (LCE), CO2 emissions, and waste heat generation when the system is sized meeting electric load only. However, the transient start-up time of supplementary prime movers and temporal resolution have no significant effects on sizing optimisation. The type of Power Management Strategies (Following Electric Load-FEL, and Following Electric and Following Thermal Load- FEL/FTL) affect overall Combined Heating and Power (CHP) efficiency and meeting thermal demand through recovered heat for a system meeting electric and heating load with response to a specific load meeting reliability (Loss of Power Supply Probability-LPSP). However, the PMS has marginal effects on COE. The Electric to Thermal Load Ratio (ETLR) has no effects on COE for PV/Batt/ICE but strongly affects PV/Batt/MGT-based hybridised CHP systems. The higher thermal than the electric loads lead to higher efficiency and better environmental footprint. Results from this study also indicate that for a stand-alone hybridised system operating under FEL/FTL type PMS, the power only system has lower cost compared to the CHP and the Combined Cooling, Heating, and Power (CCHP) systems. This occurs at the expense of overall energy and exergy efficiencies. Additionally, the relative magnitude of heating and cooling loads have insignificant effects on COE for PV/Batt/ICE-based system configurations, however this substantially affects PV/Batt/MGT-based hybridised CCHP systems. Although there are no significant changes in the overall energy efficiency of CCHP systems in relation to variations to heating and cooling loads, systems with higher heating demand than cooling demand lead to better environmental benefits and renewable penetration at the cost of Duty Factor. Results also reveal that the choice of objective functions do not affect the system optimisation significantly

Successful Primary Angioplasty of Anomalous Coronary Artery through Radial Access and Increased Guide Support: A Case Report

One of the rare abnormalities of coronary artery anatomy is the common origin of all three coronary arteries from the right sinus of Valsalva, which, may associated with myocardial ischemia. Percutaneous coronary intervention of such patients with anomalous coronary arteries is particularly challenging. In such patients femoral route is usually chosen for coronary angioplasty, various studies have proved that the radial access provides better engagement and robust support to the guide catheter. We report a rare case diagnosed with ST-segment elevated myocardial infarction. The patient underwent successful trans-radial primary angioplasty with a buddy wire, parked in the non-culprit artery

A rare case of hepatic vein puncture during attempted pericardiocentesis mimicking right atrium perforation

Emergency pericardiocentesis done for hemodynamically significant cardiac tamponad is associated with rare but life-threatening complications including cardiac chamber perforation. Echocardiography is the usual tool to diagnose procedural complications of pericardiocentesis. We are reporting a case of attempted pericardiocentesis where apparent cardiac chamber perforation by saline contrast echo turned out to be an inconsequential hepatic vein puncture

Optimizing a diagnostic tool: coronary computed tomography angiography-guided percutaneous coronary intervention of anomalous coronary artery presenting as an acute coronary syndrome

Anomalous coronary artery presenting with acute coronary syndrome is relatively rare. Achilles heel of percutaneous coronary intervention in a such patient is difficult cannulation of the culprit artery. Coronary CT angiography provides detailed information about the origin and course of the anomalous coronary artery. A few additional information like exit angle and orifice configuration provided exclusively by CT helps in appropriate hardware selection for angiographic success