bluuebunny/crossref_metadata_2025 huggingface dataset:
How do different pathways connect the stratospheric polar vortex to its tropospheric precursors?
Authors: Köhler Raphael Harry , Jaiser Ralf , Handorf Dörthe
Published: February 2023

Abstract. Processes involving troposphere-stratosphere coupling have been identified as important contributors to an improved subseasonal to seasonal prediction in mid-latitudes. However, there is only a very vague understanding of the localised coupling mechanisms and involved timescales, in particular when it comes to connecting tropospheric precursor patterns to the strength of the stratospheric polar vortex. Based on a novel approach in this study, we use ERA5 reanalysis data and ensemble simulations with the ICOsahedral Non-hydrostatic atmospheric model (ICON) to investigate tropospheric precursor patterns, localised troposphere-stratosphere coupling mechanisms and the involved timescales of these processes in Northern Hemisphere extended winter. We identify two precursor regions: Mean sea level pressure in the Ural region is negatively correlated to the strength of the stratospheric polar vortex for the following 5–55 days with a maximum at 25–45 days, and the pressure in the extended Aleutian region is positively correlated to the strength of the stratospheric polar vortex the following 10–50 days with a maximum at 20–30 days. A simple precursor index based on the mean pressure difference of these two regions is very strongly linked to the strength of the stratospheric polar vortex in the following month. The pathways connecting these two regions to the strength of the stratospheric polar vortex, however, differ from one another. Whereas a vortex weakening can be connected to prior increased vertical planetary wave forcing due to high-pressure anomalies in the Ural region, this is not the case for the extended Aleutian region. A low-pressure anomaly in this region can trigger a Pacific/North American (PNA) related pattern leading to geopotential anomalies of the opposite sign in the mid-troposphere over central North America. This positive geopotential anomaly travels upward and westward in time directly penetrating into the stratosphere and thereby strengthening the stratospheric Aleutian High, a pattern linked to the displacement towards Eurasia and subsequent weakening of the stratospheric polar vortex. Overall, this study emphasises the importance of the non-zonally-averaged picture for an in-depth understanding of troposphere-stratosphere coupling mechanisms. Additionally, this study demonstrates that these coupling mechanisms are realistically reproduced by the global atmosphere model ICON.
Strengthening gradients in the tropical west Pacific connect to European summer temperatures on sub-seasonal timescales
Authors: van Straaten Chiem , Coumou Dim , Whan Kirien , van den Hurk Bart , Schmeits Maurice
Published: February 2023

Abstract. Recent work has shown that (sub-)seasonal variability in tropical Pacific convection, closely linked to ENSO, relates to summertime circulation over the Euro-Atlantic. The teleconnection is non-stationary, probably due to long-term changes in both the tropical Pacific and extra-tropical Atlantic. It also appears imperfectly captured by numerical models. In a previous study we found that the best predictor of errors in sub-seasonal forecasts of European temperature, is a dipole in tropical west Pacific sea surface temperatures (SSTs). In this diagnostic study we use reanalysis data to further investigate the teleconnection pathway and the processes behind its non-stationarity. We show that SST gradients associated with the dipole represent a combination of ENSO variability and west Pacific warming, and have become stronger since 1980. Associated patterns of suppressed and enhanced tropical heating are followed by quasi-stationary waves that linger for multiple weeks. Situations with La Niña-like gradients are followed by high pressure centers over eastern Europe and Russia, three to six weeks later. Inverted situations are followed by high pressure over western Europe, three to six weeks later. The latter situation is however also conditional on a strong meridional tripole in north Atlantic SST and a co-located jet stream. Overall, the sub-seasonal pathway diagnosed in this study connects to patterns detected at seasonal scales, and confirms earlier findings that the summertime connectivity between the Pacific and Europe has shifted in recent decades. It also partly explains the increased occurrence of high sea level pressures and summer temperatures over the European continent.
Overview of normal behavior modeling approaches for SCADA-based wind turbine condition monitoring demonstrated ondata from operational wind farms
Authors: Chesterman Xavier , Verstraeten Timothy , Daems Pieter-Jan , Nowé Ann , Helsen Jan
Published: February 2023

Abstract. Condition monitoring and failure prediction for wind turbines is currently a hot research topic. This follows from the fact that investments in the wind energy sector have increased dramatically due to the transition to renewable energy production. This paper reviews and implements several techniques from state-of-the-art research on condition monitoring for wind turbines using SCADA data and the Normal Behavior Modelling framework. The first part of the paper consists of an in-depth overview of 5 the current state-of-the-art. In the second part, several techniques from the overview are implemented and compared using data (SCADA and failure data) from five operational wind farms. To this end, 6 demonstration experiments are designed. The first 5 experiments test different techniques for the modeling of the normal behavior. The sixth experiment compares several techniques that can be used for identifying anomalous patterns in the prediction error. The paper concludes with several directions for future work.
Aeroelastic Tailoring of Wind Turbine Rotors Using High-Fidelity Multidisciplinary Design Optimization
Authors: Mangano Marco , He Sicheng , Liao Yingqian , Caprace Denis-Gabriel , Ning Andrew , Martins Joaquim R. R. A.
Published: February 2023

Abstract. Reducing the cost of energy from wind power is a critical step towards decarbonizing the electric grid and mitigating climate change effects. Computational models are crucial in understanding the complex, multiphysics interactions of modern, highly flexible wind turbine rotors. When coupled with numerical optimization, such models provide an efficient way to explore the design space. We propose a high-fidelity aerostructural framework that couples computational fluid dynamics with 5 computational structural mechanics to analyze and optimize wind turbines. The framework uses a gradient-based optimization strategy with gradients efficiently computed using a coupled-adjoint approach. We optimize a benchmark utility-scale wind turbine rotor and explore its trade-offs between steady-state aerodynamic efficiency and structural weight. The optimizations account for a representative below-rated operating condition and use more than 100 structural and geometric design variables. The monolithic approach we propose is compared with a loosely-coupled optimization strategy used for the structural sizing 10 of the baseline rotor layout. We then discuss specific optimized blade features and a broader design trade space exploration between extracted torque and rotor mass. Optimized layouts increase the torque by up to 14 % and reduce the mass by up to 9 % or reduce the mass by up to 27 % with the same torque output compared to the baseline blade. The results demonstrate the benefits of optimizing a tightly-coupled aerostructural model and reveal additional insights that high-fidelity analysis provide to complement conventional design approaches.
Investigating the physical mechanisms that modify wind plant blockage in stable boundary layers
Authors: Sanchez Gomez Miguel , Lundquist Julie K. , Mirocha Jeffrey D. , Arthur Robert S.
Published: February 2023

Abstract. Wind plants slow down the approaching wind, a phenomenon known as blockage. Wind plant blockage undermines turbine performance for front-row turbines and potentially for turbines deeper into the array. We use large-eddy simulations to characterize blockage upstream of a finite-size wind plant in flat terrain for different atmospheric stability conditions, and investigate the physical mechanisms modifying the flow upstream of the turbines. To examine the influence of atmospheric stability, we compare simulations of two stably stratified boundary layers using the Weather Research and Forecasting model in large-eddy simulation mode, representing wind turbines using the generalized actuator disk approach. For a wind plant, a faster cooling rate at the surface, which produces stronger stably stratified flow in the boundary layer, amplifies blockage. As a novelty, we investigate the physical mechanisms amplifying blockage by evaluating the different terms in the momentum conservation equation within the turbine rotor layer. The velocity deceleration upstream of a wind plant is caused by an adverse pressure gradient and momentum advection out of the turbine rotor layer. The cumulative deceleration of the flow upstream of the front-row turbines sets in motion a secondary circulation. The horizontal flow is diverted vertically, reducing momentum availability in the turbine rotor layer. Although the adverse pressure gradient upstream of the wind plant remains unchanged with atmospheric stability, vertical momentum advection is amplified in the more strongly stable boundary layer, mainly by larger shear of the horizontal velocity, thus increasing the blockage effect.
Developing Methodology for Strategic Environment Assessment for Urban Transportation Policy: A Case of Ahmadabad City, India
Authors: Garg Abhinav
Published: February 2023

The last two decades have witness controversial yet rapid development of the environmental policy agenda. It is considered more important to improve environmental performance and environmental awareness in decision-making. Nowadays Strategic Environment Assessment (SEA) is the most accepted term for the environmental assessment of impacts of proposed policy or plan, for ensuring full inclusion of environmental concern. SEA appropriately addresses the environmental, social and financial consideration at the earliest and appropriate stage of decision-making. This work is an attempt to formulate SEA process which could be helpful in formulating plan/ policy for urban transportation system, thereby ensuring that economical, social and environmental considerations are taken at planning stage itself. It was found out that the proposals should consider the city’s morphology into account before arriving at any decision. More stress should be given on decreasing the total passenger-Km by innovative land-use planning; concern should be toward controlling motorization and encouraging non- motorized movement in the city. The increasing trend to travel by vehicle will put extra economical burden on the economical weaker section of society. Hence it is concluded that for long term Sustainability there is a need of integrated land-use and transportation planning.
Drastic Revolution in Supply of Renewable Energy and Astonished Energy Performance Technologies
Authors: Dua Vinay
Published: February 2023

Electricity consumption will comprise an increasing share of global energy demand during the next two decades. In recent years, the increasing prices of fossil fuels and concerns about the environmental consequences of greenhouse gas emissions have renewed the interest in the development of alternative energy resources. In particular, the Fukushima Daiichi accident was a turning point in the call for alternative energy sources. Renewable energy is now considered a more desirable source of fuel than nuclear power due to the absence o frisk and disasters. Considering that the major component of greenhouse gases is carbon dioxide, there is a global concern about reducing carbon emissions. In this regard, different policies could be applied to reducing carbon emissions, such as enhancing renewable energy deployment and encouraging technological innovations. Two main solutions may be implemented to reduce CO2 emissions and overcome the problem of climate change: replacing fossil fuels with renewable energy sources as much as possible and enhancing energy efficiency. In this paper, we discuss alternative technologies for enhancing renewable energy deployment and energy use efficiency. JEL Classification: D61, D62, H23, N50, O13, Q52, Q55
Unconstraint Optimal Power Flow using Improved Cuckoo Search Algorithm
Authors: Solaimani S. , Arul P.
Published: February 2023

This paper presents an efficient and reliable a swarm-Intelligence based algorithm and bio-Inspired algorithm approach to unconstraint obtain optimal power flow (OPF) problem solution. This approach employs a nature inspired meta-heuristics optimization algorithm such as improved cuckoo search algorithm to determine the optimal setting of control variable. The performance of the improved cuckoo search algorithm (ICS) is examined and tested on IEEE 30 bus test system with objective function is minimization of fuel cost. The solution is done using MATLAB software.
An Experimental Study to Achieve Minimum Surface Roughness While Machining P20 Tool Steel Using Wire EDM
Authors: Bhatia Anmol , Singh Gagan Vijay , Madaan Anmol , Bhatia Akansha
Published: February 2023

There is a rapid increase in the usage of hard materials. The conventional machining process has been left behind by complex and intricate part machining. Such complex machining of hard materials via conventional machining methods does often lead to poor quality characteristics such as low surface roughness. Thus, to achieve the goal of better quality characteristics while machining hard materials, non-conventional machining processes come into play. Wire Electric Discharge Machining (Wire-EDM), is an example of such non-conventional machining processes. This paper highlights a research analysis on parametric optimization of Wire EDM process while machining P20 tool steel. It deals with the optimization of parameters namely Pulse on time, Pulse off time, Peak current and Wire Tension so as to obtain low surface roughness. Taguchi’s design of experiments and Analysis of Variance (ANOVA) has been used for the optimization purpose and L9 orthogonal array has been used for the same. Furthermore, it was found that Pulse off time and Peak Current were the most significant factors, followed by Pulse on time and Wire Tension.
Performance Comparison of Cuboical Box Type Solar Still Deployed with Different Basin Profiles
Authors: Malaiya Abhinav , Arora Akhilesh , Arora B. B.
Published: February 2023

The need for pure drinking water in dry and remote areas is very acute particularly in Rajasthan, Kuchchh etc. The dry areas however have no shortage of solar energy which is available in plenty. Solar desalination is a technique to curb this problem in dry areas. The work presented in this paper relates to a cuboidal type solar still. The solar still is designed and a sheet of porous material (jute sack) is deployed on different basin profiles placed inside the still and saline water is externally fed. On this vary design, experimentation has been performed to compare the performance of cuboidal box type solar still with different basin profiles and different parameters are measured in this process. The results are obtained at an inclination angle of 24˚ which is best suited for Rewa Madhya Pradesh (coordinates 24.53˚ N,81.3˚E ). The process of performance comparison comprises the measurement of productivity and temperatures at different points on solar still.
Impact of Academics and Experience on the Motivation and Satisfaction Level of Management Faculties: A Case Study
Authors: Agrawal Manish Kumar , Tanwar Pranay , Kumar Kewal
Published: February 2023

In the present milieu, organization thrives and survives on human resources. The behavior, attitude, perception and values of employees very much influence their performance so that they become able to realize individual as well as organizational goals, which are almost depends on self motivation , self discipline and self satisfaction implies the level of satisfaction agreement between job expectation of a worker and the reward that the job provides. The different demographics traits such as age, education, working hours, position at work place and years in service have significant impact on job satisfaction. The aim of this study is to measure the level of satisfaction among employee and the impact of different parameters on the job satisfaction of employees. The different parameters include the general working conditions pay, promotion, Boss-subordinate relationship, Age, Education, Skills and abilities.
In Container Integration Testing Frame Work
Authors: Kumar H. S. Vijaya , S. M. Vikas
Published: February 2023

In Container Integration testing framework is a combination of four open source technologies. Arquillian, Test NG, JaCoCo, and Maven. The aim of this work is to deals with automating the code using JaCoCo. JaCoCo is a Java framework calculates code coverage. It find’s the amount of code coverage in each lines of module that has been executed or missed and finally it will be deploy to wild fly server in the user matrix project source container.The main idea behind developing in this automation testing framework is able to test server side components developed using Java. The tests will be such that they will run in the container/application server (e.g. Wild Fly) where the server side component (e.g. test1) is deployed and because of that the tests will be able to use all the real resources (e.g. EJB etc.) provided by the container instead of mocking them.[1]Web Service Description Language (WSDL) speciﬁcation, we ﬁrst automatically generate necessary Java code to implement a client. We then leverage automated unit test generation tools for Java to generate unit tests, and execute the generated unit tests, which in turn invoke the service under test. The next important objective is to calculate amount of code covered by the test cases.
Thermodynamic Performance Evaluation of Heat Pipe
Authors: Jain Vaibhav , Joshi Harsh , Malik Lakshay
Published: February 2023

Heat pipe is known as one of the most energy efficient passive heat transfer device with high thermal conductivity. In the present paper, the thermodynamic performance of heat pipe is experimentally evaluated at different operational angles with different mass flow rates of external cooling water at condensing section. It is found that the heat transfer rate is maximum (i.e. 754 W) at the heat pipe orientation of 30°.
Impact of External Debt on Human Capital Development in Nigeria
Authors: Egungwu Ikenna C.
Published: February 2023

The need to finance budget gaps often compel nations to seek external sources of fund with the intention that such funds would be applied on projects that will enable her deepen the economy. Thus, the issue of external debt and economic development has attracted a wide discourse among researchers, analysts, practitioners etc, with the main intension to ascertain how the nation has indeed applied such funds and the effect. Extant studies have revealed conflicting results on the interaction between economic development dynamics and external debt fundamentals. Also, few of these studies have attempted to consider the linkage between the human factor matrix and external debt financing. It is against this backdrop that this study sought to examine the impact of increase in external debt stock and its servicing on human capital development. Four hypotheses were formulated and tested at 5% level of significance. Ex-post facto research design was adopted and time series data spanning 30 years (1986-2015) were processed using the models earlier formulated. Ordinary Least Square (OLS) regression technique was used to test the hypotheses. The study found that both external debt stock and external debt servicing had significant negative effect on human capital development; external debt stock borrowed from Paris club and multilateral creditors had insignificant negative effect; those borrowed from London club had insignificant positive effect while those borrowed from bilateral creditors had significant positive effect. On debt servicing, all the creditors showed insignificant positive effect except London club that had significant positive effect. The study concluded that nations could finance their budget deficits with external funds but should ensure that such funds are applied on priority projects that have the capacity to deepen the economy and improve the well fair of her citizens. Among other recommendations is the fact that both the state and federal government should create investment window that will significantly reduce the level of unemployment prevalent in the country and also embark on industrial revolution that will greatly widen the nation’s revenue base and reduce her reliance on oil and gas as the main source of revenue.
Implementation of Parity Checker Using CMOS Logic Techniques
Authors: Yasasvi Bhargava , Rana Charu , Rakheja Pankaj
Published: February 2023

The technology is growing rapidly where the sizes of the components are getting reduced as the size gets decreased the, possibility of errors gets increased. These errors can’t be prevented as they are generated in the running phase. To handle such problems, we need a circuit which will be monitoring continuously and correcting the errors generated. This paper proposes different ways to implement a parity checker in the previous self-checking register. When compared with previous techniques. The circuits are stimulated in spice using 90nm CMOS technology.
Optimization of Multiple Performance Characteristics of Cold rolling Processes Using Taguchi’s Quality Loss Function
Authors: Vaidya Vivek Anil , Waghmare Atul C.
Published: February 2023

The single stand cold rolling mills are generally called as reversing mills, whereby the metal strip is successively wound and unwound in the form of coil as it is repeatedly passed back and forth through the one mill stand. Rolling Pass schedule consists of setting of control parameters at each pass depending on various factor like input and output thickness, width of the coil, material to be rolled, mill capability etc. Majority Quality related problem faced by cold rolled producers using single stand cold rolling are strip thickness variation and strip flatness, also they are concerned about power consumption and production rate. This happens because there is no standard pass schedule available which can predict these Performance parameters. The operator uses thumb rule to make pass schedule. There is no Theoretical model available for such complex cold rolling process. Experimental Model using Taguchi based Single Optimization Method can improve the quality and process performance of the Mill. The main objective of this paper is to show the capability of the Taguchi Quality loss function based multi response optimization methods in increasing productivity of cold rolling process while controlling the Quality and cost of Production. The proposed methodology is used to optimize Multi process performance namely thickness variation, strip flatness, production rate and Power consumption by obtaining optimal solution for control factors exit tension, entry tension, Mill speed and Roll bending pressure for cold rolling of low carbon steel in single stand reversible cold rolling mill. A L_27 orthogonal array was selected and total 27 experiments were conducted after selecting control factors and its levels. Interaction plot shows no interaction among the control parameters. The ANOVA carried out which shows the mill speed is most significant control factor. The optimal values obtained using the multi characteristics optimization Model using Taguchi loss function has been validated by confirmation experiment.
Heat Transfer Enhancement of Radiators Using Various Approaches: Review
Authors: Ahmed Zakariya , Mishra Akanksha
Published: February 2023

This paper reviews heat transfer enhancement of radiators using different approaches. It has been found that different method of heat transfer augmentation has been employed in different radiator design. These methods ranging from fin design modification, increasing core depth of radiator, change of tubes type, increasing surface area of radiator core, change of fin material, change of flow arrangement and changing the different types of fluid and mixture concentration. The performance of a radiator depends on its thermal and hydrodynamic performance. Certain parameters are of importance to the radiator performance such as; convective heat transfer co-efficient, pressure drop, inlet and outlet coolant temperature, air and coolant mass flow-rates, fin type, fin dimension and material. The various approaches are considered, depending on the application requirement and utilizing range. Radiator design modification such as increase in number of fins and tubes, material substitution have their limitations with certain negative consequences like added cost and weight with low efficient thermal performance compare to utilization of Nano-fluid approach. The engine life and its performance depend on coolant temperature. The application of nano-fluid in automobile radiator as coolant greatly affects the performance of the engine which in turn enhances its life span and fuel consumption. This paper attempts to review literature related to various heat transfer enhancement methods in vehicle radiator with different design, and compares the most effective approach amongst the methods taking into consideration cost, weight and thermal efficiency.
Risk Level of Viet Nam Medicine Industry under Financial Leverage During and After the Global Crisis 2009-2011
Authors: Huy Dinh Tran Ngoc
Published: February 2023

This paperwork evaluates the impacts of external financing on market risk for the listed firms in the Viet nam medicine industry, esp. during and after the financial crisis 2009-2011. First of all, by using quantitative and analytical methods to estimate asset and equity beta of total 6 listed companies in Viet Nam medicine industry with a proper traditional model, we found out that the beta values, in general, for many institutions are acceptable. Second, under 3 different scenarios of changing leverage (in 2011 financial reports, 30% up and 20% down), we recognized that the risk level, measured by equity and asset beta mean, decreases when leverage increases to 30% but increases more if leverage decreases down to 20%. Third, by changing leverage in 3 scenarios, we recognized the dispersion of risk level, measured by equity beta var, keeping the same value of 0,711 if the leverage increases to 30% or if leverage decreases to 20%. But the dispersion measured by asset beta var increases to 0,200 (leverage down 20%), showing leverage impact. Finally, this paper provides some outcomes that could provide companies and government more evidence in establishing their policies in governance.
Green IOT: Principles, Current Trends, Future Directions
Authors: Yogi Manas Kumar , Ganga K. , Bhavani Devi
Published: February 2023

The two trending and popular technologies are Cloud Computing (CC) and the Internet of Things (IoT) are current hot discussions in the field of agriculture and healthcare applications. Motivated by achieving a sustainable world, this paper discusses various technologies and issues regarding green cloud computing and green Internet of Things, further improves the discussion with the reduction in energy consumption of the two techniques (CC and IoT) combination in agriculture and healthcare systems. The history and concept of the hot green information and communications technologies (ICT’s) which are enabling green IoT will be discussed. Green computing introduction first and later focuses on the recent works done regarding the emerging technologies. Finally, lists out the advantages, challenges, and future research directions related to green application design. Our research aims to make green area broad and contribution to sustainable application world.
Performance Analysis of a Three Phase Induction Motor Fed by Three Phase PWM VSI Using Variable Modulation Index
Authors: Agarwal Mayur , Joshi Deepak Kumar
Published: February 2023

Today, pulse width modulation technique is one in all the foremost wonderful management methods of speed control of the induction motor. The aim is to regulate effectively the speed and torque. This paper deals with the comprehensive performance analysis of an induction motor (IM) supported by sinusoidal PWM strategy. The PWM method, which involves the modulation of conventional sinusoidal reference signal and a triangular carrier, is used to produce pulse width modulated output only for under modulation index which is fed by voltage source inverter (VSI). For the implementation of the proposed drive the MATLAB/SIMULINK environment has been used. In this paper the impact of the modulation index on the performance of the inverter has been viewed. The whole analysis is done for under modulation (i.e. ma‹1).
Design of Walkable Bike
Authors: Bhatia Anmol , Kak Mayank , Arora Kunal , Jatwani Karan
Published: February 2023

Walkable bike is a conversion of a conventional bicycle into a treadmill cycle. It is a collaboration of two different things i.e. treadmill and electric bike. This is designed to save our environment from the harmful emissions of the vehicles which is causing a very hazardous impact on the humankind. This is designed keeping in mind that we can commute easily to different places speedily and without getting exhausted by doing some brisk walk or jogging which will eventually help us in burning some calories without leaving any carbon footprints behind , without emitting any other harmful gases , without burning any of the available fossil fuels. It does not take not more than a effort to walk in a park. This paper presents the design of Walkable bike. The idea behind this is making an affordable, eco-friendly, easy to use vehicle and using the treadmill outside the gym making the lives of people healthier and happier.
Multiresolution Analysis of Rainfall Variability Using Discrete Wavelet Transforms
Authors: Kumar Anil , Rawat Uttam Kumar
Published: February 2023

The understanding of the percentage departure in rainfall from average with respect to time is very important for agriculture, environment and economy of any region. The rainfall variability on basis of its average monthly record during the period from Jan. 2013 to Dec. 2017 (05 years) in Moradabad, Uttar Pradesh, India, is discussed. Approximations are low frequency and details are high frequency content of the signal and hence play important role in signal or data analysis. Approximations provide information about the trend of signal. The trend is its slowest part of the signal and represents the behavior of signal corresponding to greatest scale value. A peak in the details shows rapid change or fluctuation in the quantity of rainfall in that time period. Skewness is a measure of symmetry and more precisely, the lack of symmetry while Kurtosis is a measure of whether the data are peakedness or flatness relative to a normal distribution. There is slight significant decreasing trend for long term northeast monsoon rainfall over Moradabad region.
Synthetic Inflow GeneratorhavingVarious Oscillations
Authors: Wooyi Young , Lim Hee-Chang
Published: February 2023

Large Eddy Simulation (LES), which has recently been developed and used for the climate local environment and turbulent boundary layer flow, can be applied for a variety of area. In particular, in order to achieve a faster performance, an artificial generation of inflow turbulent flowwould be necessary to make the faster convergence as well as to maintain the real turbulent flow in the calculation domain.In this study, the synthetic inflow generator has been developed based on spatial and temporal correlation functions, which have a form similar to an exponential function. This inflow data having various oscillationobtained by the synthetic inflow generator imposed into the inlet condition of LES simulation on a channel with smooth wall. In the result, fully developed turbulent boundary layer was successfully generated in the computational domain. In addition, the variation of oscillating inflow was taken into account to observe the effect of the fully developed turbulent boundary layer.
Generation Scheduling With Renewable Energy Sources an Improved Firefly Optimization Algorithm
Authors: Saravanan R. , Prabha S Sooriya
Published: February 2023

Many optimization methods are employed in power system scheduling of generating units. Here in this paper firefly algorithm is proposed for solving the generation scheduling (GS) problem to obtain optimal solution in power systems by considering the reserve requirement, wind power availability constraints, load balance, equality and inequality constraints in wind thermal coordination. The firefly algorithm is a new meta-heuristic and swarm intelligence based on the swarming behavior of fish and bird in nature. The proposed firefly algorithm method is applied to a different test system holds 30 conventional units and 4 wind farms. The performance of proposed FFO is found for the test system by comparing the results of it with different trails and various iterations among five different populations say 10, 20, 30, 40 and 50.Computation of the solution for different populations in the system reveal that the best schedules attained by applying the firefly algorithm method. It also shows that as population size decreases the total cost value is also decreasing. The performance of FFO algorithm is efficiently proved by comparing the result obtained by FFO with the particle swarm optimization method (PSO).
A Systematic Survey on Different Modelling Methods to Manage Waiting Time in Ambulatory Patient Services
Authors: Chandra Disha , Tiwari Akhilesh
Published: February 2023

Hospitals experience frequent system block whenever or wherever there is more footfall than the expected number of patients. In order to manage this patient number, the hospitals have opted for numerous methods to cope up with these operational and structural problems in the hospital or any health care centre and improve patient’s overall experience. The first step towards betterment in health services is to reduce the Outdoor patients’ waiting time. This will improve the level of Patient satisfaction as well as overall efficiency of the system. For this purpose, several types of Operations Research Models have been developed in Health Care field. These models help in overcoming the waiting time issues faced by Outpatient in Hospitals that have been further discussed in the paper. Also, the use of electronic health records and practice management tools by Medical practitioners has enabled faster care and effective patient management. The goal is to provide relevant information to the Healthcare analysts engaged in enhancement of hospital efficiency through an appropriate OR model However, there is scope of further research in hospital system optimization for improved co-ordination between hospital departments, waiting time of patients queuing for special treatments.
Live Monitoring For Forensic Artifacts from IM Messenger Packets Using Freeware
Authors: Kadambari Sankarshana , Chauhan Bhupendra Singh , Soni Mohit
Published: February 2023

Numerous smartphone applications such as snapchat pose a major problem for a network administrator, as the chat gets deleted automatically removing every evidence of a conversation. It becomes difficult for an administrator to confirm whereabouts of a captured packet belonging to an IM application. However, if the same is captured in real time using Wireshark-a detailed analysis of the protocols would reveal information regarding the source of packet generation. This paper emulates a closed environment and uses freeware to capture encrypted packets from instant messengers and attempts to produce sufficient artifacts, so as to pin point the sender.
Image Multiplier Based on Low Power Approximate Unsigned Multiplier
Authors: Loganayaki J. , Vasanthi M.
Published: February 2023

Approximate circuits have been considered for applications that can tolerate some loss of accuracy with improved performance and/or energy efficiency. Multipliers are key arithmetic circuits in many of these applications including digital signal processing (DSP). This multiplier leverages a newly designed approximate adder that limits its carry propagation to the nearest neighbours for fast partial product accumulation. Different levels of accuracy can be achieved by using either OR gates or the proposed approximate adder in a configurable error recovery circuit. The approximate multipliers using these two error reduction strategies are referred to as AM1 and AM2, respectively. Both AM1 and AM2 have a low mean error distance, i.e., most of the errors are not significant in magnitude. Compared with a Wallace multiplier optimized for speed, an 8×8 AM1 using four most significant bits for error reduction shows a 60% reduction in delay (when optimized for delay) and a 42% reduction in power dissipation (when optimized for area). In a 16×16 design, half of the least significant partial products are truncated for AM1 and AM2, which are thus denoted as TAM1 and TAM2, respectively. Compared with the Wallace multiplier, TAM1 and TAM2 save from 50% to 66% in power, when optimized for area. Compared with existing approximate multipliers, AM1, AM2, TAM1, and TAM2 show significant advantages in accuracy with a low power-delay product. AM2 has a better accuracy compared with AM1 but with a longer delay and higher power consumption. Image processing applications, including image sharpening and smoothing, are considered to show the quality of the approximate multipliers in error-tolerant applications. By utilizing an appropriate error recovery scheme, the proposed approximate multipliers achieve similar processing accuracy as exact multipliers, but with significant improvements in power.
Implementation of an Efficient Design of Multi ported Memory on FPGA
Authors: Priya A. , Thenmozhi P.
Published: February 2023

The utilization of block RAMs (BRAMs) is a critical performance factor for multi ported memory designs on field programmable gate arrays (FPGAs). Not only does the excessive demand on BRAMs block the usage of BRAMs from other parts of a design, but the complex routing between BRAMs and logic also limits the operating frequency. This paper first introduces a brand new perspective and a more efficient way of using a conventional two reads one write (2R1W) memory as a 2R1W/4Rmemory. By exploiting the 2R1W/4R as the building block, this introduces a hierarchical design of 4R1W memory that25% fewer BRAMs than the previous approach of duplicating the 2R1W module. Memories with more read/write ports can be extended from the proposed 2R1W/4R memory and the hierarchical 4R1W memory. Compared with previous xor-based and live value table-based approaches, the proposed designs can, respectively, reduce BRAM usage for 4R2W memory designs with 8K-depth. For complex multiport designs, the proposed BRAM-efficient approaches can achieve higher clock frequencies by alleviating the complex routing in an FPGA.
Improvement of test data compression using Huffman and Golomb coding techniques
Authors: . Thilagavathi , . Karthick
Published: February 2023

Test vector compression is an emerging trend in the field of VLSI testing. According to these trends, increasing test data volume is one of the biggest challenges in the testing industry. The overall throughput of automatic test equipment (ATE) is sensitive to the download time of test data. An effective approach to the reduction of the download time is to compress test data before the download. But this tester has limited speed, memory and I/O channels. The test data bandwidth between the tester and the chip is small which is the bottleneck in determining how fast the testing process. To overcome these limitations of the Automatic Test Equipment (ATE), a new hybrid test vector compression technique is proposed. the large volume of test data input is compressed in a hybrid fashion before being downloaded into the processor and the test compression ratio is increased and is experimentally verified with the benchmark circuits.
Renewable Energy Fed DC Microgrid: An Overview
Authors: Mishra Apoorva , Rai J. N.
Published: February 2023

This paper lays emphasis on need of renewable energy sources for power due to increase in the demand for energy and depletion of conventional sources of energy. We propose to integrate the renewable energy with our DC Micro grid. In this paper we study the interfacing of the Solar P-V , Wind Turbine with the DC Micro grid through the rectifier, Buck Boost and Fly back converter respectively. We present a model of a wind turbine using a Fly back converter as it can provide isolation due to the use of high frequency transformer in its design. This isolation provides the advantage of protection of the DC link from any fault on the wind turbine or synchronous generator side. The emphasis is to investigate performance of P-V with Buck Boost converter. We also apply the Perturb and Observe MPPT tracking technique on the respective converters at varying operating points to extract the maximum power and keep the DC-link voltage constant. Further the model of wind generator and solar energy performance on the MATLAB/SIMULINK environment is investigated..
Performance Analysis and Enhancement of Solar Flat Plate Collector: A Review
Authors: Singh Yashwant Kumar , Kumar Sumit
Published: February 2023

Solar ﬂat plate collectors are devices used to entraped solar thermal energy and use it for heating applications like water heating, room heating and other industrial applications. Flat plate collectors are popular for low and medium heating applications and there are undergoing constant development in terms of size reduction and enhanced efﬁciency. This paper presents an overview on the different techniques that are employed to enhance the efﬁciency of ﬂat late collectors. Effect of using nanoﬂuids as heat transfer ﬂuid, effect of altering absorber plate design for better capture of radiation, methods of heat loss reduction, use of polymer, employing mini channels for ﬂuid ﬂow, using PCM (phase changing materials) to provide heat during night without tank and effect of use of enhancement devices like inserts and reﬂector have been discussed in this paper. A brief insight on various techniques used to analyse the effects and various designs has also been presented with the development methodology. Some analytical studies and CFD models have also been mentioned. This review paper also deals with the suggestions for the research work which can be carried out in the direction of heat transfer from solar ﬂat plate collectors.
Performance Evaluation of Solar Assisted Half Effect Li/Br Vapour Absorption Refrigeration System Cascaded with Vapour Compression Refrigeration System Using Eco-friendly Refrigerants
Authors: Mishra R. S.
Published: February 2023

In the most of industrial process the waste heat energy increases the production cost. Using this waste heat to produce power or cooling can decrease the costs and increases the thermal efficiency of the systems. A growing need for refrigeration in industry and for building cooling is well known due to the main cause of growing the demands of higher living standards , by the increasing requirements for comfort, by increasing thermal load of buildings. Using LiBr-H2O solution in the vapour absorption refrigeration systems offers very good thermodynamic efficiency for cooling at over 0 0C temperature than the other solutions. In this paper, we analyzed solar assisted half effect vapour absorption refrigeration system cascaded by vapour compression refrigeration system using ecofriendly refrigerants and developed thermodynamic model to predict the variation of generator , absorber , condenser temperatures on first and second law efficiencies and to predict the solar collector area required.
Study and First Law Analysis of Gas Turbine-HRSG-ORC Co-generation System with Change in Atmospheric Temperature
Authors: Thakur Priyanshu , Kumar P. V. Ram
Published: February 2023

Gas turbine cogeneration system integrated with heat recovery steam generator and organic Rankine cycle provides an effective measure of waste heat recovery from exhaust gasses of gas turbine. The numerous study conducted to understand the variation in the performance of the integrated system has been done and the variation of performance with parameters such as turbine inlet temperature, compression ratio mass flow rate etc., has been carried out. The present paper investigates the variation in the performance of the system with change in the surrounding temperature. The paper provides the detailed first law analysis of the system and compares the first law efficiency obtained at different surrounding temperature to justify the location of use of the integrated system.
Suitable Selection of Napkins in Hotel Industry for Sustainable Development
Authors: Jaisar Sachin , Agrawal Saurabh
Published: February 2023

This paper deals with the greenhouse gases (GHG) estimated emission from the napkins used in a hotel industry along with the selection of transportation mode vehicle (diesel or petrol vehicle). This study helps us to find whether a reusable or disposable napkin should be used to make a lesser GHG impact on environment. In the present scenario, most hotels are using paper napkins because they are light weighted, cheap and hygienic. The fact, that the relevant data is scattered, and is not available in literature and databases, compelled the data, to be acquired from various sources like journal articles and online blogs with few assumptions. Some critical data that has been collected is mainly from U.S and may vary when applied in India. A hypothetical assumption is used to derive the final conclusion. Cost is calculated for both the napkins associated with their mode of transportation per year. Finally, this paper suggests that reusable napkins should be used to deplete the rate of GHG emission.
Performance and Emission Studies of a Variable Compression Ratio CI Engine using Bio Diesel Made from Waste Cooking Oil
Authors: Kataria Jatinder , Mohapatra S. K. , Kundu K. , Singh R.
Published: February 2023

Compression ignition (CI) engine is the un-debated choice for power applications, stationary or mobile. There is an urgent need of alternative high potential fuel for CI engines in order to fulfill energy needs without hampering the thermal performance and stringent emission standards. Here waste cooking oil is chosen as an alternative fuel, which is upgraded into biodiesel in the laboratory using mechanical stirring and ultrasonic cavitation technique of biodiesel production. Four blends of cooking oil are made by increasing 20% its amount in conventional diesel fuel. Performance is analyzed for two compression ratios, 15 and 17.5, on the existing VCR diesel engine set up interfaced with “Engine Soft” software. The results show that as bio-diesel concentration in a blend increases, the thermal performance (i.e., brake thermal efficiency) and emissions (i.e., CO, HC and NOx, and smoke intensity) are observed to be marginally higher; on the other hand, as compression ratio increases, the thermal performance improves; CO and smoke opacity decreases.
Exploratory Study of Thermodynamics Performance of R 134a, R 152a and R 1234yf in Vapour Compression Refrigeration Cycle
Authors: Sharma Rawinder , Singh Harpreet , Singh Harpuneet
Published: February 2023

The Study present in this article focuses on the research of alternate eco friendly refrigerants with remarkable coefficient of performance and reduced global warning potential and zero ozone depletion potential. Objective of this experimental investigation is to study the performance of R134a and R152a and R1234 yf refrigerant in vapor compression cycle and their comparison with various parameter. The result showed the alternative refrigerant R1234 yf investigated in the analysis have higher coefficient of performance than R152 a and lower than R134a. This experimental investigation is conducted on vapor compression refrigeration Test Rig in applied thermodynamic lab of Khalsa College of Engg. and Technology.