Databases are used in modern applications and are employed across a wide range of industries and services. Since there are hundreds of different databases to choose from, there are some critical factors to consider, with two of the most important being query speed and memory usage. Numerous studies have compared various databases and their features, employing different technologies to evaluate performance. This thesis compares the performance between two of the most popular relational databases, PostgreSQL and MySQL (InnoDB engine). It focuses on the speed of the CRUD operations (insert, select, update, remove) and memory allocation, in terms of single-column B-tree indexes, which are employed to accelerate data retrieval operations in database tables. The experiment consists of four different database sizes (104 to 107), where each CRUD operation and space allocation is evaluated both with and without the use of indexes for both databases. The results show that indexed MySQL exhibits the fastest performance for select, update, and remove operations on larger datasets, while indexed PostgreSQL is the fastest for these operations on smaller datasets. The results also indicate that using indexes requires additional memory and increases the time needed for the insertion operation in both databases.

In todays digitalised society, effective solutions to manage huge amount of data is needed. An established design pattern that are used in many systems are CRUD. To handle data in events have become more popular over the years, but CRUD is not optimised for it. A possible replacement is CQRS, it is designed with events in mind. The purpose of the report is to see if CQRS can replace CRUD. The report shows that when it comes to an event driven system using event sourcing, CQRS is recommended. Reason being CQRS is more compatible with events then CRUD. CRUD is more designed around data driven design and therefor is a better fit for other systems. / I dagens digitaliserade samhälle krävs effektiva lösningar för att behandla stora mängder data. Ett etablerat designmönster som används i många system är CRUD. Att hantera data i händelser är något som har blivit alltmer populärt, men CRUD är inte optimerad kring just det. En möjlig ersättare är CQRS, som är designad med event i åtanke. Målet med denna rapport är att se om CQRS kan ersätta CRUD i ett händelsebaserat system. Rapporten visar att när det kommer till ett händelsedrivet system som använder händelsekällor, så är rekommendationen att använda CQRS. Detta för att CQRS är mer kompatibel med händelser än CRUD. CRUD är mer designat runt data driven design och funkar därför bättre med andra typer av system.

The project involves an extensive database with SQL, developing a backend with Express.js and implementing the frontend with React. The database forms the backbone of the entire application and supports its functionality, while the frontend interface is focused on offering an administration panel for users. The backend is designed to function as a REST API, enabling simple and efficient communication between different parts of the application. Using Express.js, the system uses CRUD (Create, Read, Update, Delete) operations to efficiently manage the database and provide a smooth user experience. Important features such as authentication and registration confirmation via email have also been implemented using SendGrid, ensuring a secure and user-friendly platform. By integrating these elements, the project creates a stable foundation for further development of the application. / Projektet handlar om att skapa en omfattande databas med SQL, utveckla en backend med Express.js och implementera frontend med React. Databasen utgör ryggraden i hela applikationen och stöder dess funktionalitet, medan frontend-gränssnittet är inriktat på att erbjuda en administrationspanel för användare. Backenden är designad för att fungera som ett REST API, vilket möjliggör enkel och effektiv kommunikation mellan olika delar av applikationen. Med hjälp av Express.js använder systemet CRUD-operationer (Create, Read, Update, Delete) för att effektivt hantera databasen och tillhandahålla en smidig användarupplevelse. Viktiga funktioner såsom autentisering och registreringsbekräftelse via e-post har också implementerats med hjälp av SendGrid, vilket säkerställer en trygg och användarvänlig plattform. Genom att integrera dessa element skapar projektet en stabil grund för vidareutveckling av applikationen.

This report summarizes the procedure of the independent work in the final course DT140G. The project's task and main goal has been to help the company involved to enable a potential interruption with a time registration service called Harvest which they currently consume. The task itself has been sectioned into three clear parts with completely different orientations but towards the same end goal. The first part has involved data management from the consumed time registration service in terms of both exporting and importing data. The second part has been about developing a CRUD functionality that can be consumed in the frontend by another developer. The last part has meant that a report compilation application has been created where data from the previous parts is handled and produces various reports which could then be exported in Excel files. The result of this independent work resulted in an application with great similarities in terms of functionality as the previous time registration service. The company has taken a step closer to their vision of a break from Harvest. This has been done with access to source code from a previous developer who shared his repository via GitLab and the React Admin framework. The CRUD functionality has been checked with the help of the test tool ARC and all code development has taken place in the software development environment Visual Studio Code. / Denna rapport sammanfattar proceduren av det självständiga arbetet i slutkursen DT140G. Projektets uppgift och främsta mål har varit att hjälpa det involverade företaget att möjliggöra ett potentiellt avbrott med en tidsregistreringstjänst vid namn Harvest som de i dagsläget konsumerar. Själva uppgiften i sig har varit sektionerad i tre tydliga delar med helt olika inriktningar fast mot samma slutmål. Den fösta delen har involverat datahantering ifrån den konsumerade tidsregistreringstjänsten vad det gäller att både exportera och importera data. Den andra delen har handlat om att utveckla en CRUD-funktionalitet som skall kunna konsumeras i frontend av en annan utvecklare. Den sista delen har inneburit att en rappportsammanställningsapplikation har skapats där data ifrån de tidigare delarna hanteras och frambringar olika rapporter som sedan skulle kunna exporteras i Excel-filer. Utkomsten av detta självständiga arbete resulterade i en applikation med väldiga likheter funktionsmässigt vad det gäller den tidigare tidsregistreringstjänsten. Företaget har tagits ett steg närmare sin vision om en frislagning ifrån Harvest. Detta har genomförts med tillgång till källkod ifrån en tidigare utvecklare som delat sitt repository via GitLab samt ramverket React Admin. CRUD-funktionaliteten ha kontrollerats med hjälp av testverktyget ARC och all utveckling av kod har skett i programutvecklingsmiljön Visual Studio Code

The utilization of Application Programming Interfaces (APIs) has experiencedsignificant growth due to the increasing number of applications being devel-oped. APIs serve as a means to transfer data between different applications.While RESTful has been the standard API since its emergence around 2000,it is now being challenged by Facebook’s GraphQL, which was introducedin 2015. This study aims to fill a knowledge gap in the existing literatureon API performance evaluation by extending the focus beyond read opera-tions to include CREATE, UPDATE, and DELETE operations in both REST-ful APIs and GraphQL. Previous studies have predominantly examined theperformance of read operations, but there is a need to comprehensively un-derstand the behavior and effectiveness of additional CRUD operations. Toaddress this gap, we conducted a series of controlled experiments and anal-yses to evaluate the response time and RAM utilization of RESTful APIsand GraphQL when executing CREATE, UPDATE, and DELETE operations.We tested various scenarios and performance metrics to gain insights into thestrengths and weaknesses of each approach. Our findings indicate that con-trary to our initial beliefs, there are no significant differences between the twoAPI technologies in terms of CREATE, UPDATE, and DELETE operations.However, RESTful did slightly outperform GraphQL in the majority of tests.We also observed that GraphQL’s inherent batching functionality resulted infaster response times and lower RAM usage throughout the tests. On the otherhand, RESTful, despite its simpler queries, exhibited faster response times inGET operations, consistent with related work. Lastly, our findings suggestthat RESTful uses slightly less RAM compared to GraphQL in the context ofCREATE, UPDATE, and DELETE operations.

The goal of the project is to develop a news widget for the company Atega In-sight. This news widget will be integrated into their Priceagent application and improve the ability of customers to set prices for their products. Daily meetings with the company as well as communication via chat and other spontaneous meetings. The project includes adjustments to previous sketches to meet current requirements as well as planning the functionality of the widget in the design tool Figma. The project's code will primarily be written in Visual Studio Code. The back-end is developed with NodeJS and the Serverless Framework as the basis for the API, while MongoDB is used as the database manager. Testing of the back-end takes place using the Postman API platform. On the front-end side, reusable components are created with React, mainly written in TypeScript. Ready-made components from Ant Design and styling are done with Styled-Components. The front-end structure follows the Atomic Design Pattern. The result of the project has given the company a functional widget where users can add, remove, edit and view their news feeds. Users can also switch between different tabs and paginate the news articles. Testing of the widget has mainly been performed with various browser add-ons, including VisBug to see if the size of the various components matches the sketches and responsiveness. Wave for testing availability and Lighthouse for performance. However, there is room for more superficial development, such as a better implementation of the NewsAPI in the back-end and small adjustments to improve the user experience, as the widget can sometimes be perceived as slow. / Målet med projektet är att utveckla en nyhetswidget åt företaget Atega Insight. Denna nyhetswidget ska integreras i deras Priceagent -applikation och förbättra kundernas förmåga att satta priser på sina produkter. Dagliga möten med företaget samt kommunikation via chatt och andra spontana möten. Projektet innefattar justeringar av tidigare skisser för att möta aktuella krav samt planering av widgetens funktionalitet i designverktyget Figma. Projektets kod kommer främst att skrivas i Visual Studio Code. Back-end utvecklas med NodeJS och Serverless Framework som grund för API: et, medan MongoDB används som databashanterare. Testning av back-end sker med hjälp av API-plattformen Postman. På front-end-sidan skapas återanvändbara komponenter med React, huvudsakligen skrivet i TypeScript. Färdiga komponenter från Ant Design och styling sker med Styled Components. Front-end-strukturen följer designmönstret Atomic Design Pattern. Resultatet av projektet har gett företaget en funktionell widget där man kan lagga till, ta bort, redigera och se sina nyhetsflöden. Användarna kan ocksa byta mellan olika flikar och paginera nyhetsartiklarna. Testning av widgeten har främst utförts med olika webbläsartillägg, bland annat VisBug för att se om storleken på de olika komponenterna stämmer överens med skisserna och responsivitet. Wave för att testa tillgängligheten och Lighthöuse för prestanda. Det finns dock utrymme för ytterligare utveckling, såsom en bättre implementering av NewsAPI i back-end öch sma justeringar för att förbättra användarupplevelsen, då widgeten ibland kan upplevas som långsam.

Master of Science / Department of Mechanical and Nuclear Engineering / Donald L. Fenton / Increase in demand for energy necessitates nuclear power units to increase their peak power limits. This increase implies significant changes in the design of the nuclear power unit core in order to provide better economy and safety in operations. A major hindrance to the increase of nuclear reactor performance especially in Pressurized Water Reactors (PWR) is the so called ‘Axial Offset Anomaly (AOA)’. An Axial Offset Anomaly (AOA) is the unexpected change in the core axial power distribution during the operation of a PWR from the predicted distribution. This problem is thought to be occurring because of precipitation and deposition of lithiated compounds such as lithium metaborate (LiBO[subscript]2) on the fuel rod. Due to its intrinsic property, the deposited boron absorbs neutrons thereby affecting the total power distribution in the reactor. AOA is thought to occur when there is sufficient build up of crud deposits on the cladding during subcooled nucleate boiling. Predicting AOA is difficult because there is little information regarding the heat and mass transfer during subcooled nucleate boiling. This thesis describes the experimental investigation that was conducted to study the heat transfer characteristics during subcooled nucleate boiling at prototypical PWR conditions. Pool boiling tests were conducted with varying concentrations of LiBO[subscript]2 and boric acid (H[subscript]2BO[subscript]3) solutions along with deionized water. The experimental data collected includes the effect of coolant concentration, degree of subcooling, system pressure and heat flux on pool boiling heat transfer coefficients. An analysis of deposits formed on the fuel rod during subcooled nucleate boiling is also included in the thesis. The experimental results reveal that the pool boiling heat transfer coefficient is degraded by the presence of boric acid and lithium metaborate in water. At concentration of 5000 ppm in water, the boric acid solution reduced the heat transfer coefficient by 23% and lithium metaborate solution reduced the heat transfer coefficient by 26%.

Axial offset anomaly (AOA) in pressurized water reactors (PWR) refers to deviation of the measured neutron flux in the top half of the core from the predicted values. Among other difficulties, AOA reduces the shutdown margin, and may force the plant to reduce power output. AOA is believed to be caused by three related phenomena occurring in the core while operating at full power: sub-cooled nucleate boiling concentrated mainly in the upper half of the core, corrosion product deposition on the cladding surface (crud), and the deposition of boron within the porous crud layer in regions of vigorous sub-cooled boiling. This study replicates the conditions within the PWR primary coolant; specifically, the temperature, pressure, peak surface heat flux, coolant velocity and water chemistry are simulated in order to produce prototypical crud on an electrically heated Zircaloy-4 test element. At the conclusion of each test run, the heated Zircaloy-4 test element is rapidly isolated from the coolant in order to trap any soluble boron species that may be present in the crud layer. The results of this investigation indicate that prototypical crud with significant boron deposition can be produced. The deposited boron compound has been determined to be lithium tetraborate (Li2B4O7). Comparative experiments have been run to determine the effect of coolant pH, concentration and type of additives, and duration of exposure on the thickness of the crud deposit. The data obtained in this investigation can be used to validate mechanistic models for crud deposition and AOA in pressurized water reactors.

Active Particles at the Temelin NPP, Radiobiological Risks and Protective Precautions The term active particle (AC) was applied on Temelín NPP (ETE) in order to denominate small fragments of high radioactive matters, sized up to 1 millimeter, forming into primary circuit. In accordance with latest available know-how, the ACs major contains corrosion products, that were activated during passing through reactor core. After primary circuit opening, due to carry out outage works, the ACs will spread into ETE radiation controlled area. In proportion to their size, the ACs activity is relative high, so that the ACs can jeopard workers, who will contact them. This jeopardy is namely associated with AC penetration into organism - ingestion or inhalation. The main goal of this dissertation is to determine grounds of ACs occurence in Temelín NPP, to review ACs radiobiological risks and to evaluate procedures and protective aids, used for assurance of workers radiation protection. This dissertation is resuming actual know-how about ACs occured and occuring in Temelín NPP, including suggestions for radiation protection procedures and for protective aids utilization, that are to be used for reduction of above mentioned jeopardy. Next areas are concerned: - analysis of ACs forming and matters composition - description of ACs physical-radiation parameters - identification of main ACs sources in primary circuit - assesment and evaluation of radiobiological jeopardies, associated with ACs occurence in Temelín NPP radiation controlled area - assesment of procedures and protective aids used for protection of workers, who can be endangered by ACs