The objective of this thesis is to study two Basins of the Gulf of Guinea (GoG), namely the Dahomey and the Liberian Basins. These Basins are located in the northern part of the GoG, where oil and gas exploration has significantly increased in the last 10 years or so. We proposed geological descriptions of these two Basins. The key characteristics of the two models are the presence of channels and pinch-outs for depths of between 1 km and 2 km (these values are rescaled for our numerical purposes to 600- m and 700-m depths) and normal faults below 3 km (for our numerical purposes we use 1 km instead of 3 km). We showed that these models are consistent with the plate tectonics of the region, and the types of rocks and ages of rocks in these areas. Furthermore, we numerically generated seismic data for these two models and depth-migrated them. We then interpreted the migrated images under the assumption that the geologies are unknown. The conclusions of our interpretations are that we can see clearly the fault systems in both models. However, our results suggest that seismic interpretations of the channels and pinch-outs associated with the geology of the Dahomey and Liberian Basins will generally be difficult to identify. In these particular cases, we missed a number of channels and pinch-outs in our interpretations. The limited resolution of seismic images is the key reason for this misinterpretation.

Femoral neck fracture (FNF) is a great challenge for today´s health care and is associated with high mortality and morbidity in the elderly.  In the short term several studies in the literature have demonstrated improved hip function, quality of life and fewer re-operations in elderly patients treated with total hip arthroplasty (THA) instead of internal fixation (IF). There are few reports on the long-term outcome comparing IF and THA. The vast majority of orthopaedic departments in Sweden use the direct lateral (DL) or posteriolateral (PL) approaches for hip arthroplasty. The PL approach has been linked to an increased risk of dislocation of the prosthesis and a higher rate of revision surgery in comparison to the DL approach. There are few reports focusing on radiological risk factors for prosthetic dislocation and patient reported hip function comparing the two surgical approaches for hip arthroplasty in FNF. The randomized controlled trial (RCT) is the gold standard for evaluating medical or surgical interventions. An RCT of high quality has to be internally and externally valid. Internal validity refers to a correct study design to avoid bias skewing the results. External validity (EV) refers to whether the results will be clinically relevant to a definable group of patients and can be extrapolated to the general health care situation. There are only a few reports in the orthopaedic literature focusing on the EV of published studies and none in the field of hip fractures. Study I: This is a RCT of 100 patients with a displaced FNF comparing THA and IF. Follow-up evaluations were performed at three months and 1, 2, 4, 11 and 17 years. It was found that the Harris hip score (HHS) was higher and the rate of reoperations lower for patients treated with THA. Study II: This is a prospective cohort study of 185 hips, comparing the DL and the PL approaches in patients treated with a hemiarthroplasty (HA) for a displaced FNF. Follow-up was after 1 year. There was no difference in patient reported outcome between the groups measured with the HHS and WOMAC index. The PL approach resulted in a higher re-operation rate while the DL approach in a higher incidence of limping. Study III: This is a retrospective cohort study of 373 patients with a cemented bipolar HA using a PL approach for a FNF with a follow-up ranging from 6 months to 7 years. Radiographs and all surgical records were reviewed regarding femoral offset (FO), leg length discrepancy (LLD) and Wiberg angle. Patients with recurrent dislocations had a decreased postoperative FO, LLD and shallower acetabulum on the operated side compared with their controls. Study IV: This is a prospective cohort study of 840 hips comparing patients included in a RCT with those that did not give their informed consent (NC) or did not fulfill the criteria for participating in the trial (MS). Patients in the NC and MS groups had an increased mortality rate in comparison to those included in the study. We did not find any differences in hip function between these groups. The main conclusions of this thesis are: Healthy and lucid elderly patients with good hip function preoperatively, should be treated with THA for a displaced FNF. The DL approach is favourable in treating displaced FNF with HA due to its decreased risk of reoperation but with an identical hip function outcome as the PL approach. Care should be taken to restore the LLD and FO otherwise this may increase the risk of recurrent dislocation of a HA. Our findings suggest that trial participants had a lower mortality rate than non-participants but the functional outcome of non-participants appeared to be satisfactory. This is important to take into consideration when extrapolating study results to a health care system. / Lårbenshalsfrakturer (FNF) är en utmaning för dagens sjukvård och förknippad med hög mortalitet i den äldre befolkningen. FNF orsakas främst av lågenergitrauma efter fall i samma plan hos patienter med benskörhet. Total höftledsprotes (THA) har visat sig ge en bättre höftfunktion, livskvalitet med färre omoperationer hos äldre patienter än sluten reposition samt fixering med skruvar (IF) under de första två-fyra åren efter operation. Få studier har publicerats med långtidsuppföljning av THA jämfört med IF. Vid behandling av felställd FNF med halv höftledsplastik (HA) eller THA finns olika kirurgiska metoder (snittföring) för implantation av protesen. Majoriteten av ortopedkliniker i Sverige använder direkt lateral (DL) eller posteriolateral (PL) snittföring. PL har kopplats till en ökad risk för luxation av protesen (urledsvridning), vilket i sin tur genererat en högre risk för omoperation jämfört med DL. Få studier har utvärderat höftfunktion med avseende på snittföring. Detsamma gäller vilka radiologiska faktorer som påverkar risken förprotesluxation. Det finns olika typer av studiedesigner för utvärdering av medicinska och kirurgiska behandlingsmetoder. Studiedesignen med högst bevisvärde anses vara den randomiserade kontrollerade studien (RCT). För att en RCT skall hålla hög kvalitet krävs intern och extern validitet. Intern validitet syftar på ett korrekt studieupplägg som mäter det som avses och undviker påverkan av icke önskvärda faktorer. Extern validitet (EV) innebär att erhållna resultat från studien är generaliserbara och kan extrapoleras till andra grupper än den studerade. Det inga rapporter i ortopediska litteraturen med fokus på EV med patienter som drabbats av FNF. Studie I: Prospektiv randomiserad studie av 100 patienter med en felställd FNF jämförs THA med IF med avseende på höftfunktion och reoperationer. Uppföljning gjordes efter tre månader samt 1, 2, 4, 11 och 17 år. HHS som mått på höftfunktion var högre och andelen reoperationer lägre för patienter som behandlades med THA. Studie II: Prospektiv kohortstudie med 183 patienter med felställd FNF behandlade med HA och antingen DL eller PL. Vi fann ingen skillnad i patientrapporterad höftfunktion utvärderat med HHS och WOMAC efter 1 år men en ökad förekomst av hälta vid DL. Studie III: Retrospektiv kohortstudie av 373 patienter opererade med en cementerad bipolär HA och PL. Postoperativa röntgenbilder granskades avseende femoral offset (FO), postoperativ benlägdsskillnad (LLD) samt acetabulär Wibergvinkel och relaterades till återkommande protesluxationer. Detta relaterades till återkommande luxationer. Uppföljningstiden varierade mellan 6 månader och 7 år. Patienter med återkommande luxationer hade en minskad postoperativ global FO, förkortad LLD och grundare acetabulum på den opererade sidan jämfört med kontroller. Studie IV: Prospektiv kohortstudie av 840 patienter med felställd FNF där patienter som ingick i en RCT jämförs med de som inte gav sitt samtycke för deltagande eller ej inkluderats i screeningprocessen. De patienterna som inte gav sitt samtycke hade ökad dödlighet, men ingen skillnad i höftfunktion jämfört med deltagare. Slutsatser • Friska och kognitivt vitala äldre patienter med god höftfunktion innan en felställd lårbenshalsfraktur bör behandlas med total höftledsprotes. • DLsnittföring ger ett lika bra patientrapporterad höftfunktion men en ökad förekomst av hälta jämfört med PL snitt vid behandling med halvprotes på grund av en felställd lårbenshalsfraktur. • Ansträngning bör göras för att återställa benlängdsskillnad samtfemoral offset och därigenom minska risken för återkommande luxation. • Våra resultat tyder på att patienter som deltar i en randomiserad studie har lägre dödlighet än patienter som avböjt att delta samt de som missats i screeningprocessen. Det är viktigt att ta hänsyn till när extrapolerar studieresultat till ett hälso-och sjukvårdssystem. Detta bör vägas in i värderingen av studieresultatens externa validitet.

Forests represent both, one of the strongest drivers of, and solutions to, the rapid shift in the earth’s climate. Integrating the use of forests as a cost effective solution into emerging global carbon markets however has proven extremely difficult. The incentive for companies to utilize carbon credits as a means to offset emissions is heavily dependent upon the credibility of the project that created it. The difficulty proving the credibility of forest projects is largely due to the inherent variation associated with forest environments. British Columbia’s pine beetle epidemic provides an extreme example of just how quickly vast carbon sinks can suddenly become sources. As such, the creation of standards to ensure the security of carbon sequestered by forest projects has proven to be instrumental in encouraging their acceptance into the market. British Columbia has recognized that its forests play an integral role in its contribution to the global carbon cycle. As a result, heavy consideration is being made as to how this resource may be integrated as a source of carbon offsets for its own Cap-and-Trade market. This will mean establishing specific standards for forest projects in a BC context. This report reviews two regional standards from the states of Georgia and California, which could be applied as templates for a set of BC specific protocols for forest carbon sequestration projects. It is intended that through a comparison and analysis of these standards that potential problems faced in applying similar standards here will be identified.

Once a source of environmental concern, mine tailings could now contribute to the fight against climate change. Greg Dipple and team are discovering how mines can potentially ofset their own emissions.

It was investigated characteristics of surfaces of offset printing plates. A method of measurement of wetting angle was improved and there were investigated the wetting characteristics of hydrophilic surfaces of offset printing plates and their dependence on dampening solution and on printed run. Experimentally investigated 16 offset printing plates. Wetting angle increases with the run. Surface roughness was investigated using profilograph. Changes of surface roughness during printing were determined and it was found that during printing quantity of bigger over 1 µm irregularities increases.

<p><font size="3" face="Arial"><font size="3" face="Arial"> <p align="left">In this study, I will look at the common law principle of offset to see whether it can be applied to employers making deductions against employees for loss or damage. Notice is a quantifiable amount and is a legal debt / therefore. it should be able to be applied as an offset. Two subsections deal with deductions / after looking carefully at the wording of theses subsections I will try to determine whether the one is alternate to the other, or whether the narrow interpretation that the Department of Labour gives to the statute is accurate. A narrow interpretation of the law states that the employee must sign an acknowledgement of debt. However, employees often refuse to sign an acknowledgement of debt, thereby frustrating the law. Could this possibly have been the intentions of the drafters? Surely not, yet the Department of Labour, by having a narrow interpretation of the law, see it as such and as a result the employer is left out of pocket. In this mini-thesis, I will look at the way the law should be interpreted and the way it should be applied in practice.</p> <p>&nbsp / </p> </font></font></p>

Orthogonal Frequency Division Multiplexing (OFDM) and Single Carrier Block Transmissions (SCBT) are located at the two opposite edges of block transmission concept. In this thesis a system which lies between OFDM and SCBT is proposed. The new system, namely Block Transmissions on Orthogonal Carriers (BTOC), can be considered as a hybrid form of OFDM and SCBT. BTOC system is investigated under the redundant filterbank precoders and equalizers framework. Peak to average power ratio (PAPR) of BTOC is formulated and compared with the PAPRs of OFDM and SCBT. Effect of frequency offset for BTOC is investigated and comparison between OFDM, SCBT, and BTOC is presented. Simulation results of Zero Padded OFDM (ZP-OFDM), SCBT, and BTOC are included.

The UK Government has set an ambitious target to achieve 15% of final energy consumption from renewable sources by 2020. High Voltage Direct Current (HVDC) technology is an attractive solution for integrating offshore wind power farms farther from the coast. In the near future, more windfarms are likely to be connected to the UK grid using HVDC links. With the onset of this fairly new technology, new challenges are inevitable. This research is undertaken to help assist with these challenges by looking at possibilities of problems with respect to faster AC/DC interaction modes, especially, on the impact of inrush currents which occur during fault-recovery transients. In addition to that, possible mitigation strategies are also investigated. Initially, the relative merits of different transformer models are analysed with respect to inrush current transient studies. The most appropriate transformer model is selected and further validated using field measurement data. A detailed electro-magnetic-transient (EMT) model of a grid-connected MMC-HVDC system is prepared in PSCAD/EMTDC to capture the key dynamics of fault-recovery transformer inrush currents. It is shown that the transformer in an MMC system can evoke inrush currents during fault recovery, and cause transient interactions with the converter and the rest of the system, which should not be neglected. It is shown for the first time through a detailed dynamic analysis that if the current sensors of the inner-current control loops are placed at the converter-side of the transformer instead of the grid-side, the inrush currents will mainly flow from the grid and decay faster. This is suggested as a basic remedial action to protect the converter from inrush currents. Afterwards, analytical calculations of peak flux-linkage magnitude in each phase, following a voltage-sag recovery transient, are derived and verified. The effects of zero-sequence currents and fault resistance on the peak flux linkage magnitude are systematically explained. A zero-sequence-current suppression controller is also proposed. A detailed study is carried out to assess the key factors that affect the maximum peak flux-linkage and magnetisation-current magnitudes, especially with regard to fault specific factors such as fault inception angle, duration and fault-current attenuation. Subsequently, the relative merits of a prior-art inrush current mitigation strategy and its implementation challenges in a grid-connected MMC converter are analysed. It is shown that the feedforward based auxiliary flux-offset compensation scheme, as incorporated in the particular strategy, need to be modified with a feedback control technique, to alleviate the major drawbacks identified. Following that, eight different feedback based control schemes are devised, and a detailed dynamic and transient analysis is carried out to find the best control scheme. The relative merits of the identified control scheme and its implementation challenges in a MMC converter are also analysed. Finally, a detailed EMT model of an islanded MMC-HVDC system is implemented in PSCAD/EMTDC and the impacts of fault-recovery inrush currents are analysed. For that, initially, a MMC control scheme is devised in the synchronous reference frame and its controllers are systematically tuned. To obtain an improved performance, an equivalent control scheme is derived in the stationary reference frame with Proportional-Resonant controllers, and incorporated in the EMT model. Following that, two novel inrush current mitigation strategies are proposed, with the support of analytical equations, and verified.

BACKGROUND When a customer delivers a colour proof to a printer, they expect the final print to look similar to that proof. Today it is impossible to control if a match between proof and print is technically possible to reach at all. This is mainly due to the fact that no information regarding the production circumstances of the proof is provided, for instance the printer does not know which proofer, RIP or ICC-profile that was used. Situations where similarity between proof and print cannot be reached and the press has to be stopped are both costly and time consuming and are therefore wished to be avoided. PURPOSE The purpose of this thesis was to investigate the possibility to form a method with the ability control if a proof is of such good quality that it is likely to produce a print that is similar to it. METHOD The basic assumption was that the quality of a proof could be decided by spectrally measuring known colour patches and compare those values to reference values representing the same patches printed at optimal press conditions. To decide which and how many patches that are required, literature and reports were studied, then a test printing and a comparison between proofing systems were performed. To be able to analyse the measurement data in an effective way a tool that analyses the difference between reference and measurement data was developed using MATLAB. RESULT The result was a suggestion for a colour proof quality verification method that consists two parts that are supposed to complement each other.The first one was called Colour proofing system evaluation and is supposed to evaluate entire proofing systems. It consists of a test page containing colour patches, grey balance fields, gradations and photographs. The second part is called Colour proof control and consists of a smaller set of colour patches that is supposed to be attached to each proof. CONCLUSIONS The method is not complete since more research regarding the difference between measurement results and visual impression is needed. To be able to obtain realistic tolerance levels for differences between measurement- and reference data, the method must be tested in every-day production. If this is done the method is thought to provide a good way of controlling the quality of colour proofs.

We investigate how tax loss offset restrictions affect an investor's evaluation of risky investments under bounded rationality. We analytically identify behavioral tax effects for different levels of loss offset restrictions, tax rate and prospect theoretical biases (loss aversion, probability weighting and reference dependence) and find tax loss offset restrictions significantly bias investor perception, even more heavily than the tax rate. If loss offset restrictions are rather generous, investors are very loss averse or assign a huge weight to loss probabilities, taxation is likely to increase the preference value of risky investments (behavioral tax paradox). Surprisingly, the identified significant perception biases of tax loss offset restrictions occur under both high and low tax rates and thus are relatively insensitive to tax rate changes. Finally, we identify huge differences in behavioral tax effects across countries indicating that tax loss offset restrictions crucially determine the perceived tax quality of a country for risky investments. Our analysis is relevant for policy makers discussing future tax reforms as well as for investors assessing risky investment opportunities. / Series: WU International Taxation Research Paper Series