Estudo Comparativo de Tecnologias de Desenvolvimento front-end paraWeb

There are several JavaScript technologies intended to assist in theconstruction of web systems user interfaces. Choose the most suitablefor a new project can be a difficult task. Three of these technologieshave gained prominence: Angular, Vue and React. All focusedon the front-end development of web applications. In order to facilitatethe process of decision making about which technology is themost suitable in a new project, this work establishes a comparativestudy of the three most used JavaScript technologies currently andto highlight the advantages and disadvantages of each one. Thiswork adopted performance, size and support for different browsersto carry out an experimental comparative study. An applicationwas developed as a use case and replicated in each of the technologies,in order to analyze the development process and the resultsunder the same set of tests. A software to perform the tests in anautomated way was implemented to collect the performance resultsusing the Google Chrome browser. It was possible to identify whichtechnology is most suitable in each test scenario. For example, theAngular framework performed better in 8 out of 10 scenarios evaluated,despite having a longer startup time and build size of theapplication compared to React and Vue. It is estimated that Angularloads more information in the initialization process to make thestate of the application “more prepared” for user interactions

Model-Based Design of a Pseudo-Cogenerative Heating System for e-Boat Battery Cold Start

Full-electric boats are an expression of recent advancements in the area of vessel electrification. The installed batteries can suffer from poor cold-start performance, especially in the frigid season and at higher latitudes, leading to driving power limitations immediately after startup. At state, the leading solution is to adopt a dedicated heater placed on the common cooling/heating circuit; this implies poor volume, weight, and cost figures, given the very limited duty cycle of such a part. The Heater-in-Converter (HiC) technology allows removing this specialized component, exploiting the power electronics converters already available on board: HiC modulates their efficiency to produce valuable heat (pseudo-cogeneration). In this work, we use the model-based approach to design this system, which requires heating power minimization to fulfill power electronics limitations, while guaranteeing the user-expected startup time to full power. A multistage model is used to get the yearly vessel temperature distribution from latitude information and some additional data. Then, a lumped parameter for the cooling/heating circuit is used to determine the minimum required power as a function of the properties of the thermal interface material used for the battery coupling. The design is validated on a 1:5 test bench (battery power and energy), which demonstrates how the technology can be to scaled up to also fit different boats and battery sizes.

Systematic Model-Based Steady State and Dynamic Optimization of Combined Cooling and Antisolvent Multistage Continuous Crystallization Processes

Currently, one of the key challenges in the pharmaceutical industry is the transformation of traditional batch production methods into robust continuous processes with the intention of reducing manufacturing costs and time and improving product quality. Crystallization is by far the most important purification technology in Pharma, as more than 80% of the active pharmaceutical ingredients (API) require at least one crystallization step. A successful crystallization process requires tight control over crystal size, shape and polymorphic purity. A rigorous and systematic methodology is presented to design and optimize multistage combined cooling and antisolvent continuous (mixed-suspension, mixed-product removal- MSMPR) crystallizers. The crystallization of acetylsalicylic acid (API) in ethanol (solvent) and water (anti-solvent) is used as a case study. A predictable and validated mathematical model of the system, which consists of a one-dimensional population balance model, was used to develop several optimizations strategies. Firstly, the attainable region of the mean particle size was determined for both minimum and maximum attainable crystal size. The method helped identify the most suitable number of stages and total residence time or volume for a cascade of continuous crystallizers. This was followed by a steady state optimization which helped determine the optimal operating temperatures and antisolvent flowrates. To minimize the startup time, a series of dynamic optimization strategies were implemented, assuming starting from empty vessels. The optimal dynamic profiles of the temperature and antisolvent flow rate, at different crystallization steps, were identified using a systematic and rigorous approach allowing a reduction in the startup time by 31%.

Experimental Investigation of the Starting Procedure of a Helicopter Gas Turbine Featuring an Impingement Quick-Start System

Intended Single Engine Operation (ISEO) offers fuel saving potential for twin engine helicopters but the shut-off of one engine implies safety concerns. Due to the restart time of the gas turbine the helicopter will experience a significant loss of altitude which limits the safe envelope where ISEO is applicable. In this paper, an air impingement system, which is capable of reducing the startup time of the engine by about 60 % to 80 %, is investigated experimentally. Different parameter variations are carried out to minimize the amount of air which is necessary to accelerate the engine in order to reduce the overall weight and size of the system. The modifications to the process are elaborated for startup of the engine to ground idle and to flight operation mode. For startup to ground idle the impinged air mass could be reduced by 25 % without having drawbacks in startup time.

Design of Fast and Reliable Steam Surface Condensers

Power plants operating in cyclic mode, standby mode or as back up to solar and wind generating assets are required to come on line on short notice. Simple cycle power plants employing gas turbines are being designed to come on line within 10–15 minutes. Combined cycle plants with heat recovery steam generators and steam turbines take longer to come on line. The components of a combined cycle plant, such as the HRSG, steam turbine, steam surface condenser, cooling tower, circulating water pumps and condensate pumps, are being designed to operate in unison and come on line expeditiously. Major components, such as the HRSG, steam turbine and associated steam piping, dictate how fast the combined cycle plant can come on line. The temperature ramp rates are the prime drivers that govern the startup time. Steam surface condenser and associated auxiliaries impact the startup time to a lesser extent. This paper discusses the design features that could be included in the steam surface condenser and associated auxiliaries to permit quick startup and reliable operation. Additional design features that could be implemented to withstand the demanding needs of cyclic operation are highlighted.