Yes / The estimation of Polycrystalline Diamond Compact (PDC) cutters wear has been an area of concern for the drilling industry for years now. The cutter's wear has been measured practically by pulling the bit out for evaluation at the surface. It is important to find the right time for tripping out as this helps to avoid the fishing job and reduces the operational cost significantly. The prediction of the drilling performance is based on the interaction of cutter and rock. Several authors focused on the cutter-rock interface but only a few researchers tried to model the wear of the PDC bit cutters. The aim of this research is to understand the relationships between the rate of penetration (ROP) and the drilling variables per each foot, and then determine the overall bit efficiency for the whole drilling operation. A new mathematical model is derived to predict the PDC bit performance by considering the factors that were already not taken into account. These factors include rock strength, bit design, and bit hydraulic. The model investigates the effect of these parameters to estimate the abrasive cutters wear on the inner and the outer bit cones by deriving modified equations to calculate the mechanical specific energy (MSE), torque, and depth of cut (DOC) as a function of effective blades (EB). The model is used to forecast the bit cutters wear conditions in four wells in the oil fields located in Libya, which were drilled with three different PDC's sizes. The model enables the results to be compared to the actual bit cutters wear measured for inner and outer cones. The results are found that are well in agreement with the actual field data obtained in bit records. / Financial support from ministry of higher education in Libya.

Yes / Predicting the PDC bit performance during drilling operation is important for the cost effectiveness of the operation. The majority of PDC bits are assessed based on their performance that are relative to offset wells. Determination of mechanical specific energy (MSE) in real time and compare it with the known MSE for a sharp bit to assess the bit life has been utilized by several operators in the past. However, MSE still cannot be used to predict the bit performance in exploration wells and also it cannot assess the bit efficiency in the inner and outer cones. A more precise approach needs to be devised and applied to improve the prediction of bit life and the decision when to pull the bit out of the hole. Effective mechanical specific energy (EMSE) developed in this work is a new wear and performance predictive model that is to measure the cutting efficiency based on number of cutters, which contact the rock as a function of weight on bit (WOB), rotary speed (RPM), torque, and depth of cut (DOC). This model modifies the previous MSE model by incorporating such parameters and including detailed design of the bit, number of blades, cutter density, cutter size, and cutting angle. Using this approach together with the analysis of rock hardness, a level of understanding of how the drilling variables influence the bit performance in the inner and outer cone is improved, and a convenient comparison of the bit condition in the frame of the standard bit record is achieved. This work presents a new simple model to predict the PDC cutters wear using actual data from three sections drilled in three oil wells in Libya. It is found that the obtained results are in well agreement with the actual dull grading shown in the bit record.

A manufacturer would love to see progress in the optimization of a production system to maximize profit while maintaining the environmental regulations enacted by a government or society. Thus, a key performance indicator is needed to indicate how the system production is performing in monetary as well as environmental aspects. However, the manufacturer and the regulating body may not be aware of the environmental impacts associated with the production system as a key performance indicator like Overall Equipment Effectiveness (OEE) only implies the monetary aspects of the process. Therefore, there is a need to quantify the carbon emissions of the process and use it as a parameter that indicates profitability and environmental sustainability at the same time. From the public and policy-making body's point of view, they need a proper scale that can be used to track the compliance of the manufacturers with the environmental regulations. In this study, this carbon-based indicator (COEE) aims to discover a way of monitoring the progress of a process with environmental considerations. This study raises key questions that are constructive to each other to build a comparison of the ordinary OEE and environmental COEE. To do so a case study about the plastic process using an injection molding machine is conducted. The data used in this study was provided by the company named Good Solutions. Based on the data provided, the ordinary OEE of the machine for each shift is used to contrast with the result of the new modeled COEE. The RMSE for the given OEE of the machine was 13.424 while for COEE is 12.695. The RMSE of both OEEs indicates that the COEE can be used as an indicator for economic as well as environmental assessments.

Yes / The successful use of Reverse Osmosis (RO) process has increased significantly in water desalination, water treatment and food processing applications. In this work, the economic feasibility of a multi-stage RO process including both retentate and permeate reprocessing for the removal of chlorophenol from wastewater is explored using simulation and optimisation studies. Firstly, a mathematical model of the process is developed based on the solution diffusion model, which was validated using experimental chlorophenol removal from the literature, is combined with several appropriate cost functions to form a full model package. Secondly, for a better understanding of the interactions between the different parameters on the economic performance of the process, a detailed process simulation is carried out. Finally, a multi-objective optimisation framework based on Non-Linear Programming (NLP) problem is developed for minimising the product unit cost, the total annualised cost, the specific energy consumption together with optimising the feed pressure and feed flow rate for an acceptable level of chlorophenol rejection and total water recovery rate. The results clearly show that the removal of chlorophenol can reach 98.8% at a cost of approximately 0.21 $/m³.

Yes / Brackish water can be considered an important source of fresh water, via desalination, especially for arid districts. Reverse Osmosis (RO) process has been successfully used to produce fresh water from brackish water sources. However, there is still the challenge of improving the performance of multistage RO desalination plants. From the selection of the RO configurations to the selection of the appropriate type of membranes and the operating conditions at the end determines the performance of RO process in terms of recovery, salt rejection, energy consumptions and ultimately the cost of production of freshwater. Using model-based simulation, this work attempts to investigate the most suitable types of membranes for an industrial scale RO plant from a set of different membrane brands that would attain the highest-performance at lowest specific energy consumption (SEC). As a case study, we considered a multistage multi-pass medium-scale RO plant (1200 m3/day) of Arab Potash Company (APC, Jordan) which produces high quality water for the boilers after pre-treatment stage. The simulation results confirmed that employment of the Filmtec BW30LE-440 would increase water recovery by about 22% besides reducing the product salinity and SEC by about 15% and 10%, respectively compared to the existing membrane.

The laboratory cutting specific energy is widely used to estimate the cuttability of rocks by a roadheader fitted with sharp picks. Sharp picks on the other hand become blunt due to wear in time and require replacement. Although it is known that the pick blunting affects adversely the rock cuttability, no study exists to show the relationships between the degree of pick wear and the cutting specific energy obtained by standard cutting tests. In this study, standard cutting tests were carried out on different rock types, with picks having varying degrees of blunting. The relationships between wear flats and the cutting forces, specific energies and size distribution for various rock properties such as uniaxial compressive strength, tensile strength, cone indenter number, shore hardness, schmidth hammer hardness, density and grain size were established. The mean cutting force and the cutting specific energy have been found to increase 2-3 times and 4-5 times respectively with 4 mm wear flat as compared to sharp picks as the strength and density of rocks increase. No relation exists between mineral grain size and the cutting performance. A definite relation could not be established between the wear land and the size distribution of the product. Charts have been produced to predict critical wear flats for different rock property values considering 25 MJ/m&sup3 / as the limiting specific energy above which poor cutting performance occurs. Nine prediction models have been developed by statistical analysis to estimate the laboratory cutting specific energy from various rock properties and wear rates.

In this thesis, in-situ instantaneous cutting rates of boom type, medium-weight milling type roadheaders (Mk-2B) at &Ccedil / ayirhan Coal Mine are determined by studying previous performance tests and carrying out additional underground cutting tests. Some rock properties such as uniaxial compressive strength, tensile strength, Cone Indenter hardness, Shore hardness, Schmidt hammer rebound hardness and laboratory cutting specific energies are determined by laboratory tests for the rock and coal types encountered in the drivage of roadways. The relations between the instantaneous cutting rates and the above rock characteristics and the laboratory cutting specific energies are established. The results show that instantaneous cutting rates can be best predicted using laboratory cutting specific energy which provides the highest correlation (R2 = 0.8411) as compared to other rock properties. The model developed for the medium-weight machine to predict instantaneous cutting rate is compared with those developed earlier for the light-weight and heavy-weight machines. It is determined that improvements in cutting performance with the medium-weight machines as compared to light-weight machines is achieved for the rocks requiring laboratory cutting specific energy greater than 5 MJ/m3.

Philosophiae Doctor - PhD / To meet a fast-growing market demand for next generation portable electronic devices with higher performance and increased device functionalities, efficient electrical energy devices with substantially higher energy, power densities and faster recharge times such as supercapacitors are needed. The overall aim of this thesis was to synthesize nanostructured sulphonated polyaniline and transition metal single, binary and ternary mixed oxide doped nanocomposites with electro-conductive properties. These nanocomposites were anchored on activated graphitic carbon and used in design of asymmetric supercapacitors. Tantalum(IV)oxide, tantalum(IV)oxide-nickel(II)oxide, tantalum(II)oxide-manganese(III)oxide, tantalum(II)oxide-nickel(II)oxide-manganese(II,III)oxide nanoparticles were synthesised using modified sol-gel methods. These were then dispersed, individually, in acidic media through sonication and incorporated in-situ into the polymeric matrix during the oxidative chemical polymerization of aniline doped with poly(4-styrene sulphonic acid). These novel polymeric nanocomposites were characterised with FTIR, UV-visible, TEM, SEM, EDS, XRD to ascertain successful polymerization, doping, morphology and entrapment of the metal oxide nanoparticles. SECM approach curves and interrogation of CV revealed that these nanocomposites are conductive and electro-active. The cells showed good supercapacitor characteristics with high specific capacitances of 170.5 Fg⁻¹ in TaO₂- PANi-PSSA, 166.1 Fg⁻¹ in TaO₂-NiO-PANi-PSSA, 248.4 Fg-1 in TaO-Mn₂O₃-PANi- PSSA and 119.6 Fg⁻¹ in TaO-NiO-Mn₃O₄-PANi-PSSA. Their corresponding energy densities were calculated as 245.5 Whg⁻¹, 179.4 Whg⁻¹, 357.7 Whg⁻¹ and 172.3 Whg⁻¹ respectively. They also gave respective power densities of 0.50 Whg⁻¹, 0.61 Whg⁻¹, 0.57 Whg⁻¹ and 0.65 Whg⁻¹ and showed good coulombic efficiencies ranging between 77.97% and 83.19%. These materials are found to have a long cycle life and therefore good electrode materials for constructing supercapacitor cells. / National Research Foundation (NRF)

Senast år 2045 ska utsläpp av växthusgaser reduceras till en nollnivå enligt Sveriges riksdag. I Sverige står bostads- och servicesektorn för 40 % av den sammanlagda energiförbrukningen. Studien baseras på en energianalys av ett flerbostadshus beläget i Ronneby, av typen trygghetsboende vilket leder till en unik boendesituation i byggnaden. Byggnaden förbrukar cirka 25 % mer energi än den beräknade samt avtalade energiförbrukningen. Syftet är att i framtida projekt kunna få energiberäkningar att stämma bättre överens med verklig specifik energiförbrukning. Studien bygger på energisimuleringar, termografering samt undersökningar av vädringsvanor. Simuleringarna som är baserade på den verkliga datan, visar en förväntad energiförbrukning i liknande storleksordning som den uppmätta förbrukningen. Skillnaden mellan resultaten i studiens olika beräkningar beror på den unika boendesituationen i byggnaden, indatan för installationer samt byggnadens klimatskal. Studien påvisar att aktuella boendesituationer i byggnader och hur byggnader nyttjas påverkar den specifika energiförbrukningen i stor grad. / After 2045, greenhouse gases should be reduced to a zero level according to the Swedish parliament. Energy use in Sweden from residential and service sector is 40 % of the country´s total energy use. The study is based on an energy analysis of a multi-family building in Ronneby. The building is a trygghetsboende, which means unique living conditions for the residens. Actual energy use in the building is about 25 % higher than projected energy use. The main purpose of the study is to make energy calculations to match better with real specific energy use. The study is based on energy simulations, thermography and interviews of residents´ airing habits. Results from the simulations based on actual data, show an expected energy use similar to the measured values. Differences between the simulations depend on the unique conditions in the building, input data for ventilation and the building envelope elements. The conclusion is that living habits of residents in buildings have a decisive role in the buildings energy use.

This report is an exploratory and comparative study of Boverkets constitution BEN1. In this study the constitution BEN1 is examined, why the constitution was established, when is it applicable and what advantages and disadvantages will come with it. Today the housing and service sector is using a major part of Europe’s final energy use, in addition to this, these sectors also represents a major part of the total carbon dioxide emissions. The EU-commission aims to reduce the housing and service sectors energy use and emissions. In 2002 the European parliament established directives and demands for buildings energy performance. These directives were changed in 2009-2010, which led to an inspection of the already existing Swedish constitution, this was found to be inadequate by the EU-commission. Sweden decided to create a new constitution in order to satisfy EU’s new directives and demands. The focus is on a normal usage of the building in a normal year in the new constitution, BEN1.  The reader should receive an idea and understanding about BEN1 and why it was established in this report. Beyond this, the study will show the changes that happen to a buildings energy performance after the constitution is applied and what advantages and disadvantages this could bring.  This study was performed by simulating the buildings energy use with the input from BEN1 in a simulation tool, IDA Indoor Climate and Energy.  The study shows that the energy performance will change but it also shows that further studies should be made in order to obtain a more carefully drawn and common conclusion. / Detta är ett examensarbete på grundnivå (kandidatexamen), 15 högskolepoäng. Examensarbetet är en utredande och jämförande studie av Boverkets senaste författningssamling BEN1. I denna studie utreds BEN1, varför det upprättades, när det ska tillämpas och vad det medför i fråga om för- och nackdelar.   Idag utgör tjänste- och bostadssektorn en stor del av Europas slutliga energianvändning och totala koldioxidutsläpp, något som EU-kommissionen har som mål att minska. Minskningen skulle ske med tillämpning av Europaparlamentets direktiv och krav gällande energideklarationer som kom år 2002. Direktivet omarbetades under 2009-2010 vilket ledde till en granskning av det befintliga svenska regelverket, EU-kommissionen fann detta bristfälligt och beslutade därför om ett överträdelseförfarande. Sverige svarade på överträdelseförfarandet med den nya författningssamlingen BEN1 som handlar om fastställande av byggnaders energianvändning vid normalt brukande och ett normalår.  I denna rapport ska läsaren få en uppfattning om och förståelse kring Boverkets författningssamling BEN1 och varför den upprättats. Utöver det ska studien påvisa förändringarna som sker hos en byggnads energiprestanda vid tillämpning av BEN1 samt upplysa läsaren om vilka för- och nackdelar tillämpningen av BEN1 kan ge. Studien har utförts genom att simulera byggnadernas energianvändning, enligt BEN1s föreskrifter och allmänna råd, i IDA Indoor Climate and Energy, ett simuleringsverktyg. Studien visar att en byggnads energiprestanda kommer att förändras men att vidare studier bör göras för att en mer noggrann och allmän slutsats ska kunna erhållas. De största förändringarna gällande energiprestandan har skett i byggnadens behov av värme och varmvattenberedning, detta efter tillämpande av de schablonvärden BEN1 erhåller. Resultaten som erhålls i denna studie är enligt BEN1 validerade värden för byggnadernas energiprestanda.