I detta arbete utvärderas och jämförs de i dagsläget aktuella teknikerna för automatisering av avloppspumpstationer. Utifrån undersökningen kommer en rekommendation av ett system göras som sedan ska kon-strueras och monteras ihop. Arbetet visar att trots energivinsterna som en extra investering i form av reglering ger så lönar det sig sällan om man inte byter pump samtidigt. Vid byte av pump kan man välja en pump som klarar det maximala flödet men samtidigt arbetar med högst effektivitet vid det vanligaste flödet. Då pumpar i avloppstationer ofta är överdimensionerade med avseende på det vanligaste flödet betyder en nedreglering att pumpen hamnar för långt bort från konstruktions-punkten. Pumpen får då sämre verkningsgrad och efter en viss punkt klara pumpen att inte av att överstiga det statiska motståndet och där-med inte skapa något flöde alls. Av dessa anledningar rekommenderas av/på-styrning vilket är den ledande tekniken idag / In this report the currently leading technologies for automation of sewage pump stations will be evaluated and compared. Based on this comparison a recommendation of a design will be done and the chosen control system will finally be assembled in a cabinet. The report shows that even thou there are energy savings to be done by using variable frequency drives it is rarely possible unless pumps are changed at the same time. When pumps are changed at the same time you have the opportunity to pick a pump that can handle the maximum inflow but at the same time have its best efficiency  point at lower speed. Pumps in sewage pump stations are often over dimensioned with regards to the most common inflow, lowering the speed will in this case result in lower efficiency and more losses. At one point the pump will not be able to overcome the static pressure in the system and will fail to produce any flow. Due to these reasons on/off control will be recommended which also is the most common method of today.

Volym- och sprutpumpar används inom neonatalvården tillsammans med en specialanpassad kateter. De prematurfödda barnen är mycket känsliga för feldoseringar men det finns minimalt med dokumenterade projekt som undersöker hur väl den distribuerade dosen stämmer överens med den angivna på infusionspumpen. Målet med denna studie var att kontrollera om det fettbaserade läkemedlet Clinoleic flyter tillbaka i det gemensamma blocket, avgöra tiden det tar för läkemedel att flyta fram samt mäta mängden av läkemedel som kommer till mynningen av katetern. Antalet pumpar begränsades till startuppsättningen inom intensivvården på neonatalavdelningen, vilket är fyra pumpar. Mängden av läkemedlet för fem olika flöden undersöktes endast för läkemedlet Peyona med koffeinbas. Projektet genomfördes på Karolinska Universitetssjukhuset och i samarbete med Nya Karolinska Solna förbättrades förståelse för uppsättningens användning. Samtliga sjuksköterskor och ingenjörer vi kom i kontakt med på sjukhusen ansåg att fler studier behöver göras inom distribution av läkemedlen. Tydliga kopplingar kan ses mellan resultat som presenteras i arbetet och misstankar och förväntningar efter samtal med de som jobbar med pumpar. Möjliga framtida experiment som kan ge tydligare riktlinjer inom neonatalvården diskuteras. Det är några anmärkningsvärda resultat som redovisas i studien. De är att Clinoleic flyter bakåt i blocket och att fylla backventilen tar mellan 16 och 25 minuter för de undersökta flödena. Dessutom framgår det att distributionen av Peyona avviker minst för de högre flödena. / Volume and syringe pumps are used in neonatal care together with a customized catheter. The premature born children are extremely sensitive to incorrect dosage, but there are only a short number of documented projects that investigate how well the distributed dose corresponds to that indicated on the infusion pump. The aim of this study was to check whether the fat-based drug Clinoleic flows back into the common block, determine the time it takes for drug to flow and measure the amount of drug that comes to the orifice of the catheter. The number of pumps and drugs was limited to the initial set that is used in intensive care in the neonatal department. The setup consists of four pumps and the drugs Peyona, Clinoleic, Glucos and Sodium Chloride solution. The amount of medicine distributed for five different flows was investigated only for the caffeine-based drug Peyona. The project was implemented at Karolinska Universitetssjukhuset and with help of Nya Karolinska Solna the understanding for the used setup was improved. All nurses and engineers we came into contact with at the hospitals felt that more studies should be done in the subject of the distribution of the drugs. Obvious connections are seen between results that are presented and suspicions and expectations after consultation with those who work with pumps daily. Possible future experiments that provide clearer guidelines for neonatal care are discussed. There are some notable results reported in the study. They are that Clinoleic is flowing back into the block and filling the check valve takes between 16 and 25 minutes for the investigated flows. for the investigated flows and that that the smallest distribution deviation of Peyona is observed in higher flows.

With on-going developments in the field of trans-critical carbon dioxide (R-744) vapour compression cycles, a need to effectively describe the heat transfer of supercritical carbon dioxide for application in larger diameter tube-in-tube heat exchangers was identified. This study focuses on the in-tube cooling of supercritical carbon dioxide for application in the gas cooler of a trans-critical heat pump. A literature study has revealed Nusselt number correlations specifically developed for the cooling of supercritical carbon dioxide. These correlations were proven to be accurate only for certain operating conditions and tube geometries. A shortcoming identified in the reviewed literature was a generic heat transfer correlation that can be applied over a wide range of fluid conditions for supercritical carbon dioxide cooling. The objective of this study was to compare experimental data obtained from a trans-critical heat pump with different Nusselt number correlations available in literature. The experimental tube diameter used for this study (16mm), was considerably larger than the validated tube diameters used by the researchers who developed Nusselt number correlations specifically for the supercritical cooling of carbon dioxide. The experimental Reynolds number (Re) ranges (350’000 - 680’000) were very high compared to the studies found in the literature (< 300’000), due to the test section from this study forming part of a complete heat pump cycle. Experimental results showed that correlations specifically developed for supercritical carbon dioxide cooling generally over-predicts experimental Nusselt numbers (Nuexp) with an average relative error of 62% to 458% and subsequently also over-predicts the convection heat transfer coefficient. Furthermore, generic heat transfer correlations were compared to the experimental results which over-predicted the Nuexp with an average relative error between 20% and 45% over the entire Re number range. More specifically, the correlation by Dittus & Boelter (1985) correlated with an average relative error of 9% for 350’000 < Re < 550’000. From the results of this study it was concluded that cooling heat transfer of supercritical carbon dioxide in larger tube diameters at higher Re numbers is more accurately predicted by the generic Dittus & Boelter (1985) and Gnielinski (1975) correlations mainly due to the absence of thermo-physical property ratios as seen in the CO2-specific correlations. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

With on-going developments in the field of trans-critical carbon dioxide (R-744) vapour compression cycles, a need to effectively describe the heat transfer of supercritical carbon dioxide for application in larger diameter tube-in-tube heat exchangers was identified. This study focuses on the in-tube cooling of supercritical carbon dioxide for application in the gas cooler of a trans-critical heat pump. A literature study has revealed Nusselt number correlations specifically developed for the cooling of supercritical carbon dioxide. These correlations were proven to be accurate only for certain operating conditions and tube geometries. A shortcoming identified in the reviewed literature was a generic heat transfer correlation that can be applied over a wide range of fluid conditions for supercritical carbon dioxide cooling. The objective of this study was to compare experimental data obtained from a trans-critical heat pump with different Nusselt number correlations available in literature. The experimental tube diameter used for this study (16mm), was considerably larger than the validated tube diameters used by the researchers who developed Nusselt number correlations specifically for the supercritical cooling of carbon dioxide. The experimental Reynolds number (Re) ranges (350’000 - 680’000) were very high compared to the studies found in the literature (< 300’000), due to the test section from this study forming part of a complete heat pump cycle. Experimental results showed that correlations specifically developed for supercritical carbon dioxide cooling generally over-predicts experimental Nusselt numbers (Nuexp) with an average relative error of 62% to 458% and subsequently also over-predicts the convection heat transfer coefficient. Furthermore, generic heat transfer correlations were compared to the experimental results which over-predicted the Nuexp with an average relative error between 20% and 45% over the entire Re number range. More specifically, the correlation by Dittus & Boelter (1985) correlated with an average relative error of 9% for 350’000 < Re < 550’000. From the results of this study it was concluded that cooling heat transfer of supercritical carbon dioxide in larger tube diameters at higher Re numbers is more accurately predicted by the generic Dittus & Boelter (1985) and Gnielinski (1975) correlations mainly due to the absence of thermo-physical property ratios as seen in the CO2-specific correlations. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

Today's energy production is changing from scheduled to intermittent generation due to the increasing energy injection from renewable sources. This alteration requires flexibility in energy generation and demand. Electric heat pumps and thermal storages were found to have a large potential to provide demand flexibility which is analysed in this work. A three-fold method is set up to generate thermal load profiles, to simulate heat pump pools and to assess heat pump flexibility. The thermal profile generation based on a combination of physical and behavioural models is successfully validated against measurement data. A randomised system sizing procedure was implemented for the simulation of heat pump pools. The parameter randomisation yields correct seasonal performance factors, full load hours and average operation cycles per day compared to 87 monitored systems. The flexibility assessment analysis the electric load deviation of representative heat pump pool in response to 5 different on / off signals. The flexibility is induced by the capacity of thermal storages and analysed by four parameters. Generally, on signals are more powerful than off signals. A generic assessment by the ambient temperature yield that the flexibility is highest for heating days and the activated additional space heating storage: Superheating of the storage to the maximal temperature provides a flexible energy of more than 400 kWh per 100 heat pumps in a temperature range between -10 and +13 °C.

Multidrug efflux pumps are membrane proteins that actively transport foreign objects out of cells. The active efflux of these pumps is a critical self-defense mechanism that enables the survival of bacteria under hostile environments. Efflux pump AcrB is a member of the Resistance-Nodulation-Division (RND) super family. In E. coli, it associates with periplasmic protein AcrA and outer membrane channel TolC to extrude a variety of noxious compounds out of cell from both the cytoplasm and the periplasm. My dissertation research focused on two aspects of this multidrug efflux pump: the oligomerization process during the biogenesis of AcrB and its degradation. Oligomerization is an important aspect of the structure and function for many proteins and has been the subject of many studies. However, most of such studies focused on soluble proteins. The oligomerization process of membrane proteins, including AcrB, is rarely explored. In chapter 2, the co-assembly of AcrB variants co-expressed in the same cell was used as a tool to investigate the assembly of AcrB trimers during its bio-production. By monitoring the portion of pure trimers containing only one type of subunit and hybrid trimers containing a mixture of the two kinds of subunits, it was found that the oligomerization of membrane proteins is not a random process as the formation of pure trimer is favored. In chapter 3, the GALLEX system was used to monitor AcrB oligomerization in cells under the native condition. Previously GALLEX has only been used to monitor the oligomerization of small transmembrane proteins. By constructing a series of fusion proteins with different linker length between LexA and AcrB, and optimizing inducer concentration, we finally developed a system that could be used to differentiate AcrB trimers of different oligomerization affinities. While chapters 2 and 3 focus on the trimerization of AcrB, a critical step of its biogenesis, chapters 4 and 5 focus on its life time and degradation. In chapter 4, the life time of AcrB was measured by incorporating non-natural amino acid azidohomoalanine (AHA) into protein translation. Using this method, it was determined that that the half-life of both AcrA and AcrB in E. coli were six days. The surprisingly long lifetime of these detoxification proteins might represent a strategy by the bacteria to conserve energy and maximize their competition niche for survival in a hostile environment. In chapter 5, the degradation process of ssra tagged AcrB was investigated. In-vivo degradation test showed that properly inserted AcrB can be digested after addition of ssra-tag to its C-terminus. It was found that cytoplasmic unfoldase-protease complex ClpXP and chaperone SspB are involved in the degradation. In vitro assay is still being optimized to quantitatively analyze the activity of ClpXP in the degradation of AcrB.

UA Open Access Publishing Fund / Background: The use of intra-aortic balloon pump (IABP) via the trans-femoral approach has been established for hemodynamic support in patients undergoing high-risk percutaneous coronary intervention (PCI). However, there are various challenges associated with its use, especially in patients with aortoiliac occlusive arterial disease. Case presentation: We describe a case of high-risk PCI with IABP support complicated by intra-procedural detection of severe abdominal aortic stenosis that was successfully overcome with angioplasty of the stenotic lesion. Conclusions: Our report highlights distal abdominal aortic stenosis as a potential barrier to successful PCI with IABP support, and angioplasty as an effective means to overcome it.

Construction projects involving the installation or repair of subsurface structures or utilities often require dewatering to induce a temporary lowering of the local groundwater elevation to facilitate construction. In the event that a known contaminant plume is present in an adjacent area, this dewatering may inadvertently draw the contaminant into the previously uncontaminated work area. Uretek Holdings, Inc. has developed its Injectable BarrierSM to be installed prior to dewatering exercises to provide a groundwater cut-off by reducing the potential movement of groundwater due to the hydraulic gradient induced by dewatering. A benefit of Injectable BarrierSM as compared to conventional methods of hydraulic control is that excavation is not required prior to its installation and no excess soils are generated through its installation. Injectable BarrierSM is a proprietary process registered with the United States Patent and Trademark Office by Uretek Holdings, Inc. Since methodical in-situ testing of the effectiveness of the Injectable BarrierSM has not been performed to date, it was the focus of this research to test the performance of the barrier under in-situ conditions utilizing a subsurface environment indicative of a West-Central Florida location. A testing plot to perform this research was selected on Hillsborough County property in Tampa, Florida which provided both a relatively shallow groundwater elevation in addition to a clay confining layer at a relatively shallow depth, making this an ideal location for testing the performance of the Injectable BarrierSM. After establishing the native conditions through baseline pump testing and repeating the testing procedure following the installation of the Injectable BarrierSM, a quantification of the reduction in hydraulic conductivity was achieved. Pumping tests were performed on the Injectable BarrierSM at its standard spacing as well as modified versions of the barrier with variation in the lateral spacing to include 6 foot, 4 foot, 3 foot, and 2 foot injection patterns to determine if a modified injection process could improve its performance. The 3 foot lateral spacing corresponding to the standard Injectable BarrierSM process indicated a 20% reduction in the hydraulic conductivity following its installation. By performing a small scale excavation following the completion of all pumping tests, it was discovered that the dispersion of the material in the subsurface appeared insufficient to provide the coverage needed to establish a barrier capable of further reducing the local hydraulic conductivity, especially at the shallowest injection depth of 3 feet below land surface (ft bls). It is concluded that modified amounts of injected material, closer lateral injection spacing, and potentially modified injection temperatures and component ratios could increase the effectiveness of the Injectable BarrierSM.

For delivery, dosing and pressure control of fluids in mobile and stationary applications electromagnetically operated piston pumps are an established solution. The volume per stroke is exactly defined by the geometry. Nevertheless cavitation, more likely with the new fuel blends containing a high proportion of ethanol /1/, deteriorates the dosing precision of the liquid portion. One important criterion of precise metering is the transport of the liquids through the reciprocating piston pump without transferring bubbles. Especially, pumping in the range of vapour pressure of gasoline fuels implies challenges for precision. The objective of this work is revealing potential sources of reduced cavitation by optimising the design. For doing so, optical investigations have been applied. In addition to this, cavitation can be diminished controlling the piston’s travel externally. The second important item covers pumping of degenerated fluids even without negative effects on the pump’s performance. Up to now, wide, inefficient gaps or high force surplus are necessary. A new helix-design /2/ has been investigated and built up in order to reduce the described effort. The effects coming with the helix allow a permanent rinsing of the stressed surfaces, leading to lubrication and lower temperature loads. The results are shown in simulation, fundamental tests and is validated in practical pump operation.

Multiple drug resistance (MDR) has been a severe issue in treatment and recovery from infection.Gram-negative bacteria intrinsically exhibit higher drug tolerance than Gram-positive microbes. In this thesis, two proteins involved in Gram-negative bacterial MDR were studied, AcrB and SurA. Resistance-nodulation-cell division pump AcrAB-TolC is the major MDR efflux system in Gram-negative bacteria and efficiently extrudes a broad range of substances from the cells. To study subtle conformational changes of AcrB in vivo, a reporter platform was designed. Cysteine pairs were introduced into different regions in the periplasmic domain of the protein, and the extents of disulfide bond formation were examined. Using this platform, an inactive mutant, AcrB∆loop, was created that existed as a well-folded monomer in vivo. Next, random mutageneses were performed on a functionally compromised mutant, AcrBP223G, to identify residues that restored the function loss. The mechanism of function restoration was examined. SurA is a periplasmic molecular chaperone for outer membrane biogenesis. Deletion of SurA decreased outer membrane density and bacterial drug resistance. The dependence of SurA function on structural flexibility and stability was examined. In addition, the effect of molecular crowding on SurA interaction with its outer membrane protein substrates was examined.