Mooring designs for a combined wind and wave energy system in intermediate water depth

Over the past few decades, the renewable energy industry has expanded offshore in response to the growing demand for clean and sustainable energy. Larger structures with greater power output and less visual disturbance from shore are some of the reasons that motivate the development. Floating energy systems such as offshore wind turbines and wave energy converters (WECs) offer significant potential for producing clean, sustainable energy. The levelized cost of energy from wind and wave energy can potentially be reduced by developing combined wind and wave energy systems which allows for the co-sharing of infrastructure such as mooring systems, supporting platforms and power cables. In the present study, different mooring systems of a combined wind and wave energy system – the semi-submersible torus flap combination (STFC) concept, deployed in intermediate water depths are developed. STFC consists of a torus WEC, three flap type WECs and a 5 MW NREL reference wind turbine. Fully coupled time-domain analysis of STFC under aligned wind and wave conditions has been performed using SIMA, a software for the analysis of marine operations. The tension-stretch relationship of polyester ropes is modelled using the Syrope model. Six environmental conditions at 50 m water depth representing operational conditions of STFC have been simulated. The findings of this study have led to the production of two papers focusing on the mooring systems of STFC. The first paper compares catenary and taut mooring systems against a hybrid system consisting of chains, polyester ropes and a buoy. The results are presented in terms of system restoring forces, system natural periods, motion responses, mooring line tensions responses and the cost of mooring. Lastly, a design recommendation for the mooring system of STFC is given. The second paper focuses on a parametric study of the anchor radius of a polyester-based taut mooring system in order to reduce the mooring footprint and cost. The system restoring stiffness is kept constant while anchor spacing, mooring line length, cross-sectional area and minimum breaking load are proportionally reduced. Results are presented in terms of motion responses and mooring line tension responses. In the first paper, the deployment of a hybrid mooring system is seen to decrease the non-linearity of tension responses, mooring stiffness, and the cost of mooring when compared to catenary and taut mooring systems. No slack line, vertical load on the anchor or contact between the polyester ropes and seabed is observed. Hybrid mooring systems offer solutions with the lowest cost as the combination of polyester ropes and drag-embedment anchors significantly reduce cost. In the second paper, a reduction in anchor radius while maintaining similar surge and sway restoring stiffnesses is seen to reduce pre-tension. Consequently, the yaw stiffness reduces, and a longer yaw natural period is observed between the largest and smallest anchor radius. The maximum tension increases with decreasing anchor radius due to increased surge resonant response. No event of slack line is observed. The minimum tension decreases at an increasing rate as the anchor radius decreases, suggesting that a further proportional reduction of the anchor radius would result in a slack line

Bruk av Technology Acceptance Model 3 for å optimalisere innføring av IT-systemer i små og mellomstore bedrifter - En case-studie ved Trondheim Havn

Digitaliseringen av arbeidsplassen er i full gang, og stadig innføres det nye og mer sofistikerte IT-systemer. Slike innføringer medfører derimot ofte også en stor risiko for bedrifter siden anskaffelsen, innføringen og vedlikeholdet av dem er svært kostbar. Samtidig er det en forholdsvis stor sannsynlighet for at innføringen helt, eller delvis, mislyktes. Teknologiakseptanse er graden av akseptanse en bruker har for et gitt IT-system, og flere kilder har fastslått at de mislykkede innføringsprosjektene i stor grad skyldes brukernes manglende teknologiakseptanse ovenfor IT-systemene de introduseres for. Teknologiakseptansemodeller er en type verktøy som er utviklet for å håndtere dette problemet, og blant dem finnes modellen Technology Acceptance Model 3 (TAM3). Disse modellene, inkludert TAM3, er ofte utviklet til bruk i store bedrifter hvor man kan hente informasjon fra et stort antall informanter. Det finnes derimot langt flere små og mellomstore bedrifter enn det gjør store bedrifter. Problemstillingen valgt for denne oppgaven er derfor: «Hvordan kan teknologiakseptansemodellen TAM3 bidra til å øke teknologiakseptansen, og dermed øke gevinsten, under digitalisering i små og mellomstore bedrifter?» Dette er en casestudie gjennomført ved Trondheim Havn IKS, under perioden hvor de innførte arkivsystemet Public 360. Underveis i innføringen ble det samlet inn data via en kvantitativ spørreundersøkelse, kvalitative intervjuer og observasjon. Denne studien demonstrerer at TAM3 kan brukes under disse omstendighetene, til tross for den kraftige reduksjonen i antall informanter. Ved bruk av TAM3 bidrar studien til å forbedre innføringen av IT-systemer på følgende tre måter: 1. Den gir en detaljert kartleggelse av årsaken til brukernes akseptanse for IT-systemet, noe som gjør det mulig for prosjektledelsen å velge de mest effektive prosjektaktivitetene for innføringsprosjektet. 2. Den forenkler identifikasjon og håndtering av motstanden de ansatte utøver mot endringene påført virksomheten via innføringen av et nytt IT-system. 3. Den kan identifisere personer med flere av de karakteristiske trekkene som definerer en god superbruker. Disse funnene er basert på antakelsen om at resultatene kan bekreftes ved å gjennomføre en tilsvarende studie i en bedrift under lignende omstendigheter som ved Trondheim Havn. Hvis dette er tilfellet vil resultatene ikke kun gjelde for Trondheim Havn, da de danner et solid rammeverk for innføring av IT-systemer i små og mellomstore bedrifter

Eksperimentelt og numerisk studium av glassfiberarmert polyamid (PA)

Polyamid (PA) og glassfiberarmert polyamid med fiberandel på 15 vekt% (PA15) og 30 vekt% (PA30) produsert ved sprøytestøping har blitt studert. Det ble utført én-akset strekktester av materialene på prøvestykker med forskjellig orientering med hensyn til støperetning til platene: 0˚, 45˚ og 90˚, med tre repetisjoner. Resultatene fra materialtestene ble analysert ved bruk av Digital Image Correlation (DIC), og den mekaniske oppførselen til materialene ble evaluert. Resultatene viste en duktil oppførsel for PA og en mer stiv og sprø oppførsel for fiberarmert PA. SIMLab sin materialmodellen for sprø materialer ble brukt til å predikere den mekaniske oppførselen til PA15 og PA30. Skadeparameterene til materialmodellen ble kalibrert gjennom numeriske simuleringer av materialtester for orientering på 0˚. Responsen fra den numeriske modellen stemte godt overens med materialtestene for 0˚ og 90˚ orientering, men ga en for stiv og sprø oppførsel for orientering på 45˚. Den kalibrerte materialmodellen ble validert gjennom strekktester av plater med hull for PA15 og PA30. Komponenttestene ble utført i tre forskjellige orienteringer i forhold til støperetning: 0˚, 45˚ og 90˚, med tre repetisjoner. Resultatene som ble presentert viste en høyere maksimal kraft og stivhet for den numeriske modellen enn komponenttestene for alle orienteringene. Forskyvningen ved brudd stemte godt for PA30, men materialmodellen til PA15 ga en større forskyvning ved brudd enn forsøkene

Effects of oxygen deficit on post-smolt salmon. Trial II

The study at EWOS Innovation in Dirdal was conducted as collaboration between EWOS Innovation and Rogaland Research. Tests of the effects of dissolved oxygen (DO) deficit on salmon post-smolt are a vital part of the on-going R&D project involving EWOS Innovation – OxSeaVision (OSV) – RF. The reported study was carried out at high summer temperature (mainly ca. 15 °C) – unlike the formerly reported study conducted at 8 – 9 °C.EWO

Design and control of ROV manipulators

This thesis is about the design and production of a manipulator for a ROV for the student driven company UiS Subsea. The ROV will be used in the MATE ROV competition. The design and mechanisms were chosen based on weight optimization, lifting capacity, and how well it can execute the tasks in the MATE competition. Autodesk Inventor was used to design all the non-standard parts and the software Adams was used to simulate the movement of the arm. The manipulators from previous years varied from very large and heavy, to small and with limited movement. Some ideas and mechanisms were re-used and implemented into the final design of the manipulator, while other new types of mechanisms were tested from early on and selected based on efficiency and lifting capacity. The first prototype was 3D-printed, and any visible sign of weaknesses or potential of failure was improved. This was an iterative testing phase and the result was that the final design has two main rotational joints and one rotational joint for the end effector, in total three 3 DOF. There are 4 electrical motors in total to execute the movements of the manipulator. One motor for each main joint, one for the rotation of the end effector, and one to pull the wire for gripping. Three stepper motors are placed on the base, behind the arm. A smaller BLDC motor is placed in the arm, right behind the end effector. Compared to manipulators from previous years, the manipulator in this thesis is much lighter while only sacrificing one DOF. Comparing to the manipulator from 2015 the new manipulator is approximately 45% lighter

Design and control of ROV manipulators

This thesis is about the design and production of a manipulator for a ROV for the student driven company UiS Subsea. The ROV will be used in the MATE ROV competition. The design and mechanisms were chosen based on weight optimization, lifting capacity, and how well it can execute the tasks in the MATE competition. Autodesk Inventor was used to design all the non-standard parts and the software Adams was used to simulate the movement of the arm. The manipulators from previous years varied from very large and heavy, to small and with limited movement. Some ideas and mechanisms were re-used and implemented into the final design of the manipulator, while other new types of mechanisms were tested from early on and selected based on efficiency and lifting capacity. The first prototype was 3D-printed, and any visible sign of weaknesses or potential of failure was improved. This was an iterative testing phase and the result was that the final design has two main rotational joints and one rotational joint for the end effector, in total three 3 DOF. There are 4 electrical motors in total to execute the movements of the manipulator. One motor for each main joint, one for the rotation of the end effector, and one to pull the wire for gripping. Three stepper motors are placed on the base, behind the arm. A smaller BLDC motor is placed in the arm, right behind the end effector. Compared to manipulators from previous years, the manipulator in this thesis is much lighter while only sacrificing one DOF. Comparing to the manipulator from 2015 the new manipulator is approximately 45% lighter

Effects of oxygen deficit on post-smolt salmon. Trial II

The study at EWOS Innovation in Dirdal was conducted as collaboration between EWOS Innovation and Rogaland Research. Tests of the effects of dissolved oxygen (DO) deficit on salmon post-smolt are a vital part of the on-going R&D project involving EWOS Innovation – OxSeaVision (OSV) – RF. The reported study was carried out at high summer temperature (mainly ca. 15 °C) – unlike the formerly reported study conducted at 8 – 9 °C

Large scale functional exploration of the GH5 family

The large and functionally diverse GH5 family is one of the very first Carbohydrate-Active enZYme families classified back in 1991 [3], [4]. The number of confirmed members in CAZy has grown to a staggering 27,000 where only approximately 600 (2%) have been assigned a function experimentally. In spite of early large-scale efforts [1], [2], the eye-watering paucity of characterized GH5 enzymes constitutes a general problem observed in most CAZy families, worsened by an unequal distribution of the characterized GH5 across the sequence space. This project attempts to address this problem by implementing large scale functional screening of approximately 200 carefully chosen GH5 candidates that systematically targets low or unexplored subfamilies in the known sequence space, thereby creating an excellent and large training set for use in developing progressive machine-learning algorithms that potentially can provide reliable and stable functional predictions of enzymes based on sequence information