Optimal PID Controller designing for voltage control of Fuel Cell

This paper is proposed a PID optimal controller in order to control of one of the most important types of fuel cell, namely proton exchange membrane fuel cell (PEMFC). At first, the introducing and implementation of PEMFC is present and next, during system load variations the proposed controller is designed. The controller should be designed against the load variations for keeping in a fixed value of Fuel cell output voltage. Here, the PID Controller is used which its coefficients are optimized based on Invasive Weed Optimization (IWO). In order to use this algorithm, at first, problem is written as an optimization problem which includes the objective function and constraints, and then to achieve the most desirable controller, IWO algorithm is applied to solve the problem. Simulation results are done for various loads in time domain, and the results show the efficiency of the proposed controller in contrast to the previous controllers

Use of multislice CT for investigation of occult geriatric hip fractures and impact on timing of surgery

Introduction: The National Institute of Health and Clinical Excellence guidelines in the United Kingdom recommend magnetic resonance imaging (MRI) as the first-line investigation for radiographically occult hip fractures, if available within 24 hours. In our department, however, multislice computerized tomography (MSCT) is instead used as a first-line investigation due to significant delays associated with obtaining MRI. Our aim was to determine the validity and practicality of MSCT for diagnosis of occult hip fractures and its impact on timing of surgery. Materials and Methods: We retrospectively analyzed medical records and imaging for consecutive patients who underwent MSCT to investigate occult hip fractures between January 2014 and October 2016. We reviewed subsequent imaging and reattendances for patients with negative MSCT to exclude initially missed fractures. Results: Two hundred six patients underwent MSCT to investigate occult hip fracture during the study period. Hip fractures were identified in 59 patients, comprising 35 (59.3%) subcapital, 12 (20.0%) intertrochanteric, 8 (13.6%) transcervical, and 4 (6.8%) basicervical fractures. One missed hip fracture was identified: a patient with a negative MSCT was further investigated with MRI that demonstrated acute subcapital hip fracture. Multislice computerized tomography was obtained within 24 hours of initial radiograph in 145 (70.4%) patients. A total of 44.5% of occult hip fractures had surgery within the nationally recommended 36 hours of admission (hospital average for all hip fractures was 76.4% over the same period). Discussion and Conclusions: Multislice computerized tomography is a pragmatic approach to investigate the majority of occult hip fractures in a timely manner and minimize associated delay to surgery. However it cannot completely exclude the diagnosis, especially in abnormal anatomy. The lack of a true gold standard comparison (ie, MRI) means a true sensitivity and specificity cannot be calculated, although can be cautiously estimated by lack of subsequent reattendance or investigation. Further prospective randomized CT versus MRI trials are required

Synthesis of high-performance aqueous fluorescent nanodispersions for textile printing — a study of influence of moles ratio on fastness properties

Aqueous fluorescent dispersions containing dyed acrylic-based copolymer nanoparticles possess significant credentials concerning green technology as compared to those prepared with the conventional vinyl-based monomers in textile and garment sectors; however, their essential textile fastness properties are yet to achieve. In the present work, a series of acrylic nanodispersions were synthesized by varying the moles ratio of benzyl methacrylate (BZMA), methyl methacrylate (MMA), and 2-hydroxypropyl methacrylate (HPMA) monomers. This was done to study their effect on dye aggregation and dyed polymer particles agglomeration. FT-IR spectral analysis showed the formation of polymer structures, while Malvern Analyzer, Transmission Electron Microscopy, and Scanning Electron Microscopy analysis suggested that the particles are spherical in shape and their size is less than 200 nm. The obtained nanodispersions were later applied on cotton fabrics for the evaluation of wash fastness and colour migration. Premier color scan spectrophotometer and zeta potential measurement studies suggested that colour migration of printed cotton fabrics increased with an increasing agglomeration of particles and it was also observed to increase with the moles ratio of MMA and zeta potentials

Essays on Advertising Spending During the Great Recession and Real Earnings Management Using Advertising Budgets

In my main dissertation essay, I investigate advertising spending during a recession. Advertising plays an important role in creating awareness, preference and purchase intent for many products and services. However, advertising is often cut when a firm needs to control costs. This empirical study examines a unique set of factors which motivated 553 firms to change their advertising spending during the Great Recession. The first half of the Great Recession had a moderate 2% decline in GDP and 1% to 2% cuts in advertising spending. The seasonality effect was weaker, which indicates that firms were not as likely to carryover spending from the prior year. The peak of the Great Recession had a GDP decline as high as 7%, which is considered severe. Average advertising spending declined by 13%. In addition to the seasonality effect, decreasing sales decreased advertising spending. Increasing firm risk tends to decrease advertising spending during the peak of the Great Recession, but not before. Finally, firms in high advertising intensity industries, where advertising is strategically important, had modest budget cuts. In contrast, firms in low-intensity industries had much larger percentage cuts. The second essay examines real earnings management using advertising budgets” examines. Real earnings management occurs when managers change real activities to meet or beat important earnings benchmarks. Advertising has a limited short-term impact on firm sales for many products. Therefore, when a firm’s earnings are below key benchmarks for a fiscal quarter (year), managers are compelled to reduce advertising expenditures to boost earnings. This study examines factors which persuade firms to manage earnings using advertising budgets. Similar to earlier studies, we find firms suspect of managing earnings upwards reducing advertising expenses. The findings indicate that B2C firms are more likely to manage earnings by reducing advertising expenses than B2B firms. The findings also reveal that suspect firms which spend more in high advertising elasticity mediums such as TV do not reduce advertising spending as much as firms which spend more in low advertising elasticity mediums such as newspapers and magazines. The study also find evidence to suggest that suspect firms which report advertising expenditure in their income statement make smaller advertising spending cuts than firms which don’t report advertising expenditure. Finally, earnings management activity is much stronger during the last quarter of the fiscal year

Gingival mask: A case report on enhancing smiles

Periodontal attachment loss in the maxillary anterior region can often lead to esthetic and functional clinical problems including disproportional and elongated clinical crowns and visible interdental embrasures. Gingival replacement prosthesis has historically been used to replace lost tissue. A gingival mask is an easily constructed and practical device to optimize the esthetic and functional outcome in these special situations while permitting cleansibility of the prosthesis and supporting tissues. This is a case report of a young female patient treated using silicon gingival veneer with a 2-year follow-up. The silicon gingival mask has enabled the patient to regain her lost smile and face people with newly found confidence also enhancing the esthetic appearance. Virtually, no problem was encountered during the 2 years of usage of the veneer and the patient continues to use it comfortably

Synthesis of High-Performance Aqueous Fluorescent Nanodispersions for Textile Printing—A Study of Influence of Moles Ratio on Fastness Properties

Aqueous fluorescent dispersions containing dyed acrylic-based copolymer nanoparticles possess significant credentials concerning green technology as compared to those prepared with the conventional vinyl-based monomers in textile and garment sectors; however, their essential textile fastness properties are yet to achieve. In the present work, a series of acrylic nanodispersions were synthesized by varying the moles ratio of benzyl methacrylate (BZMA), methyl methacrylate (MMA), and 2-hydroxypropyl methacrylate (HPMA) monomers. This was done to study their effect on dye aggregation and dyed polymer particles agglomeration. FT-IR spectral analysis showed the formation of polymer structures, while Malvern Analyzer, Transmission Electron Microscopy, and Scanning Electron Microscopy analysis suggested that the particles are spherical in shape and their size is less than 200 nm. The obtained nanodispersions were later applied on cotton fabrics for the evaluation of wash fastness and colour migration. Premier color scan spectrophotometer and zeta potential measurement studies suggested that colour migration of printed cotton fabrics increased with an increasing agglomeration of particles and it was also observed to increase with the moles ratio of MMA and zeta potentials

Dynamic stability enhancement of power system based on a typical unified power flow controllers using imperialist competitive algorithm

This paper presents dynamic model of power system installed with a novel UPFC that consist of two shunt converters and a series capacitor. In this configuration, a series capacitor is used between two shunt converters to inject desired series voltage. As a result, it is possible to control the active and reactive power flow. The main advantage of the proposed UPFC in comparison with the conventional configuration is injection of a series voltage waveform with a very low total harmonic distortion (THD). In addition, a linearized Phillips–Heffron model is obtained and a supplementary controller for the modeling of proposed UPFC to damp low frequency oscillations with considering four alternative damping controllers is recommended. The problem of robustly novel UPFC based damping controller is formulated as an optimization problem according to the time domain-based objective function, which are solved using particle swarm optimization (PSO) and Imperialist Competitive Algorithm (ICA) techniques

Silver nanoparticles: A boon in clinical medicine

Silver nanoparticles (AgNP) have unique properties which help in molecular diagnostics, in therapies, as well as in devices that are used in several medical procedures. AgNP are nanoparticles of silver which are in the range of 1 and 100 nm in size. The major methods used for AgNP synthesis are the physical and chemical methods. The major applications of AgNP in the medical field include diagnostic applications and therapeutic applications. In most of the therapeutic applications, it is the antimicrobial property that is being majorly explored though the anti-viral property has its fair share of applications. This review provides a comprehensive view on the synthesis and applications of nanoparticles in the medical field. The focus is on exploring their various prospective applications besides trying to understand the current scenario