926 resultados para clean and large throughput differential pumping system


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The need for automated analyzers for industrial and environmental samples has triggered the research for new and cost-effective strategies of automation and control of analytical systems. The widespread availability of open-source hardware together with novel analytical methods based on pulsed flows have opened the possibility of implementing standalone automated analytical systems at low cost. Among the areas that can benefit from this approach are the analysis of industrial products and effluents and environmental analysis. In this work, a multi-pumping flow system is proposed for the determination of phosphorus in effluents and polluted water samples. The system employs photometric detection based on the formation of molybdovanadophosphoric acid, and the fluidic circuit is built using three solenoid micropumps. The detection is implemented with a low cost LED-photodiode photometric detection system and the whole system is controlled by an open-source Arduino Uno microcontroller board. The optimization of the timing to ensure the color development and the pumping cycle is discussed for the proposed implementation. Experimental results to evaluate the system behavior are presented verifying a linear relationship between the relative absorbance and the phosphorus concentrations for levels as high as 50 mg L-1.

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Nykypäivänä energiansäästötavoitteet ovat haasteena yhä useammalle energiankuluttajalle. Tavoitteisiin päästäkseen yritykset ja kunnalliset energiankuluttajat kaipaavat usein apua kannattavien energiansäätökeinojen löytämiseksi. Erilaiset energiakatselmukset vastaavat tähän tarpeeseen ja ovat esimerkki tuloksellisesta energiansäästöstä. Lappeenrannan teknillinen yliopisto on tutkinut energiatehokkuutta pitkään erilaisissa projekteissa teollisuuden kanssa yhteistyössä. Osa LUT:n energiatehokkuustutkimusta ovat energia-auditoinnit yrityksille ja kunnille, joita LUT Energian projektin puitteissa alettiin kehittää vuoden 2008 syksyllä. Energia-auditointien fokuksena on pyritty pitämään pumppausprosessien energiatehokkuuden optimointia, sillä aihetta on tutkittu yliopistolla laajasti. Pumppausprosesseissa on todettu olevan merkittävä energiansäästöpotentiaali: pumppauksen kuluttamasta energiasta voi olla mahdollista säästää jopa 50 % erilaisilla laite- ja säästötaparatkaisuilla. Pumppausprosessien energia-auditointeja on tehty teollisuuden pumppauskohteisiin kuin myös kunnallisiin vesi-huoltolaitoksiin. Lisäksi energia-auditointien puitteissa on tutkittu energiansäästömahdollisuuksia rakennuksissa. Energiansäästökohteita etsitään sekä lämpö- että sähköenergian osalta. Energia-auditoinneissa pumppausten osalta energiansäästöpotentiaalia on todettu olevan etenkin suuren kokoluokan pumpuissa, joilla on pitkä vuosittainen käyttöaika. Myös pumppujen säätötavalla on suuri merkitys energiankulutukseen. Rakennusten osalta on pyritty selvittämään, kuinka energiankulutus jakautuu eri kulutusryhmien kesken. Säästökohteita on löydetty muun muassa rakennusten tiiviydestä, ilmanvaihdosta kuin valaistuksestakin. Monia auditointien asiakkaita on kiinnostanut etenkin led-teknologian hyödyntäminen yleisvalaistuksessa sekä muut keinot säästää valaistuksen energiankulutuksessa. Pyrkimyksenä on kehittää energia-auditointeja projektin aikana saavutettujen kokemusten avulla sekä myös liiketaloudellisessa mielessä opinnäytetutkielmien avulla. Menestyksekäs palveluliiketoiminta edellyttää määriteltyjä toimintatapoja, riittävän tarkkaa palvelujen rajausta ja koko energia-auditointiprosessin kehittämistä aina asiakassuhteen luomisesta sen jatko-hoitoon saakka.

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This paper describes the cost-benefit analysis of digital long-term preservation (LTP) that was carried out in the context of the Finnish National Digital Library Project (NDL) in 2010. The analysis was based on the assumption that as many as 200 archives, libraries, and museums will share an LTP system. The term ‘system’ shall be understood as encompassing not only information technology, but also human resources, organizational structures, policies and funding mechanisms. The cost analysis shows that an LTP system will incur, over the first 12 years, cumulative costs of €42 million, i.e. an average of €3.5 million per annum. Human resources and investments in information technology are the major cost factors. After the initial stages, the analysis predicts annual costs of circa €4 million. The analysis compared scenarios with and without a shared LTP system. The results indicate that a shared system will have remarkable benefits. At the development and implementation stages, a shared system shows an advantage of €30 million against the alternative scenario consisting of five independent LTP solutions. During the later stages, the advantage is estimated at €10 million per annum. The cumulative cost benefit over the first 12 years would amount to circa €100 million.

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Approximately a quarter of electrical power consumption in pulp and paper industry is used in different pumping systems. Therefore, improving pumping system efficiency is a considerable way to reduce energy consumption in different processes. Pumping of wood pulp in different consistencies is common in pulp and paper industry. Earlier, centrifugal pumps were used to pump pulp only at low consistencies, but development of MC technology has made it possible to pump medium consistency pulp. Pulp is a non-Newtonian fluid, which flow characteristics are significantly different than what of water. In this thesis is examined the energy efficiency of pumping medium consistency pulp with centrifugal pump. The factors effecting the pumping of MC pulp are presented and through case study is examined the energy efficiency of pumping in practice. With data obtained from the case study are evaluated the effects of pump rotational speed and pulp consistency on energy efficiency. Additionally, losses caused by control valve and validity of affinity laws in pulp pumping are evaluated. The results of this study can be used for demonstrating the energy consumption of MC pumping processes and finding ways to improve energy efficiency in these processes.

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Cyanobacteria are a diverse group of oxygenic photosynthetic bacteria that inhabit in a wide range of environments. They are versatile and multifaceted organisms with great possibilities for different biotechnological applications. For example, cyanobacteria produce molecular hydrogen (H2), which is one of the most important alternatives for clean and sustainable energy. Apart from being beneficial, cyanobacteria also possess harmful characteristics and may become a source of threat to human health and other living organisms, as they are able to form surface blooms that are producing a variety of toxic or bioactive compounds. The University of Helsinki Culture Collection (UHCC) maintains around 1,000 cyanobacterial strains representing a large number of genera and species isolated from the Baltic Sea and Finnish lakes. The culture collection covers different life forms such as unicellular and filamentous, N2-fixing and non-N2-fixing strains, and planktonic and benthic cyanobacteria. In this thesis, the UHCC has been screened to identify potential strains for sustainable biohydrogen production and also for strains that produce compounds modifying the bioenergetic pathways of other cyanobacteria or terrestrial plants. Among the 400 cyanobacterial strains screened so far, ten were identified as high H2-producing strains. The enzyme systems involved in H2 metabolism of cyanobacteria were analyzed using the Southern hybridization approach. This revealed the presence of the enzyme nitrogenase in all strains tested, while none of them are likely to have contained alternative nitrogenases. All the strains tested, except for two Calothrix strains, XSPORK 36C and XSPORK 11A, were suggested to contain both uptake and bidirectional hydrogenases. Moreover, 55 methanol extracts of various cyanobacterial strains were screened to identify potent bioactive compounds affecting the photosynthetic apparatus of the model cyanobacterium, Synechocystis PCC 6803. The extract from Nostoc XPORK 14A was the only one that modified the photosynthetic machinery and dark respiration. The compound responsible for this effect was identified, purified, and named M22. M22 demonstrated a dual-action mechanism: production of reactive oxygen species (ROS) under illumination and an unknown mechanism that also prevailed in the dark. During summer, the Baltic Sea is occupied by toxic blooms of Nodularia spumigena (hereafter referred to as N. spumigena), which produces a hepatotoxin called nodularin. Long-term exposure of the terrestrial plant spinach to nodularin was studied. Such treatment resulted in inhibition of growth and chlorosis of the leaves. Moreover, the activity and amount of mitochondrial electron transfer complexes increased in the leaves exposed to nodularin-containing extract, indicating upregulation of respiratory reactions, whereas no marked changes were detected in the structure or function of the photosynthetic machinery. Nodularin-exposed plants suffered from oxidative stress, evidenced by oxidative modifications of various proteins. Plants initiated strategies to combat the stress by increasing the levels of alpha-tocopherol, mitochondrial alternative oxidase (AOX), and mitochondrial ascorbate peroxidase (mAPX).

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In this study, it was adjusted a mathematical model to measure the effect of electric motor efficiency on pumping system costs for irrigation on the tariff structure of conventional electricity and green horo-seasonal , and also to calculate the recovery period of the invested capital in higher efficiency equipment. Then, it was applied to a center pivot irrigation system in two options of electric motor efficiency, 92,6% (standard line) and 94,3% (high efficiency line), and the acquisition cost of the first corresponded to 70% the of the second. The power of the electric motor was 100hp. The results showed that the model allowed us to evaluate if a high efficiency motor was economically viable compared to the standard motor in each tariff structure. The high efficiency motor was not viable in the two tariff structures. In the green horo-seasonal tariff, would only be viable if its efficiency was 4.46% higher than the standard motor. In the conventional tariff, it would only be viable if the efficiency overcame 2.71%.

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Mitochondria are present in all eukaryotic cells. They enable these cells utilize oxygen in the production of adenosine triphosphate in the oxidative phosphorylation system, the mitochondrial respiratory chain. The concept ‘mitochondrial disease’ conventionally refers to disorders of the respiratory chain that lead to oxidative phosphorylation defect. Mitochondrial disease in humans can present at any age, and practically in any organ system. Mitochondrial disease can be inherited in maternal, autosomal dominant, autosomal recessive, or X-chromosomal fashion. One of the most common molecular etiologies of mitochondrial disease in population is the m.3243A>G mutation in the MT-TL1 gene, encoding mitochondrial tRNALeu(UUR). Clinical evaluation of patients with m.3243A>G has revealed various typical clinical features, such as stroke-like episodes, diabetes mellitus and sensorineural hearing loss. The prevalence and clinical characteristics of mitochondrial disease in population are not well known. This thesis consists of a series of studies, in which the prevalence and characteristics of mitochondrial disease in the adult population of Southwestern Finland were assessed. Mitochondrial haplogroup Uk was associated with increased risk of occipital ischemic stroke among young women. Large-scale mitochondrial DNA deletions and mutations of the POLG1 gene were the most common molecular etiologies of progressive external ophthalmoplegia. Around 1% of diabetes mellitus emerging between the ages 18 – 45 years was associated with the m.3243A>G mutation. Moreover, among these young diabetic patients, mitochondrial haplogroup U was associated with maternal family history of diabetes. These studies demonstrate the usefulness of carefully planned molecular epidemiological investigations in the study of mitochondrial disorders.

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Cells of epithelial origin, e.g. from breast and prostate cancers, effectively differentiate into complex multicellular structures when cultured in three-dimensions (3D) instead of conventional two-dimensional (2D) adherent surfaces. The spectrum of different organotypic morphologies is highly dependent on the culture environment that can be either non-adherent or scaffold-based. When embedded in physiological extracellular matrices (ECMs), such as laminin-rich basement membrane extracts, normal epithelial cells differentiate into acinar spheroids reminiscent of glandular ductal structures. Transformed cancer cells, in contrast, typically fail to undergo acinar morphogenic patterns, forming poorly differentiated or invasive multicellular structures. The 3D cancer spheroids are widely accepted to better recapitulate various tumorigenic processes and drug responses. So far, however, 3D models have been employed predominantly in the Academia, whereas the pharmaceutical industry has yet to adopt a more widely and routine use. This is mainly due to poor characterisation of cell models, lack of standardised workflows and high throughput cell culture platforms, and the availability of proper readout and quantification tools. In this thesis, a complete workflow has been established entailing well-characterised 3D cell culture models for prostate cancer, a standardised 3D cell culture routine based on high-throughput-ready platform, automated image acquisition with concomitant morphometric image analysis, and data visualisation, in order to enable large-scale high-content screens. Our integrated suite of software and statistical analysis tools were optimised and validated using a comprehensive panel of prostate cancer cell lines and 3D models. The tools quantify multiple key cancer-relevant morphological features, ranging from cancer cell invasion through multicellular differentiation to growth, and detect dynamic changes both in morphology and function, such as cell death and apoptosis, in response to experimental perturbations including RNA interference and small molecule inhibitors. Our panel of cell lines included many non-transformed and most currently available classic prostate cancer cell lines, which were characterised for their morphogenetic properties in 3D laminin-rich ECM. The phenotypes and gene expression profiles were evaluated concerning their relevance for pre-clinical drug discovery, disease modelling and basic research. In addition, a spontaneous model for invasive transformation was discovered, displaying a highdegree of epithelial plasticity. This plasticity is mediated by an abundant bioactive serum lipid, lysophosphatidic acid (LPA), and its receptor LPAR1. The invasive transformation was caused by abrupt cytoskeletal rearrangement through impaired G protein alpha 12/13 and RhoA/ROCK, and mediated by upregulated adenylyl cyclase/cyclic AMP (cAMP)/protein kinase A, and Rac/ PAK pathways. The spontaneous invasion model tangibly exemplifies the biological relevance of organotypic cell culture models. Overall, this thesis work underlines the power of novel morphometric screening tools in drug discovery.

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The growing spread of small but powerful mobile devices (such as PDAs, mobile phone, Internet Tablet, etc.) opens up new scenarios in which users can interact with such devices in many environments in order to access the information at different locations. In this thesis, a ubiquitous computing based system called Secure Bluetooth Audio Transmission System is introduced. This system is situated in a large public place (like airport, festival venues, etc.), where voice messages are conveyed from the system to users' Bluetooth headsets in order to inform users the latest flight schedule and other public information. The reliability of the message is secured by adopting an authorization strategy and ECDSA. In order to assess and evaluate the risks and potential weaknesses of the system, an easy-to-use prototype implementation was written and tested. Other possible uses and further research were also considered.

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Fuel cells are a promising alternative for clean and efficient energy production. A fuel cell is probably the most demanding of all distributed generation power sources. It resembles a solar cell in many ways, but sets strict limits to current ripple, common mode voltages and load variations. The typically low output voltage from the fuel cell stack needs to be boosted to a higher voltage level for grid interfacing. Due to the high electrical efficiency of the fuel cell, there is a need for high efficiency power converters, and in the case of low voltage, high current and galvanic isolation, the implementation of such converters is not a trivial task. This thesis presents galvanically isolated DC-DC converter topologies that have favorable characteristics for fuel cell usage and reviews the topologies from the viewpoint of electrical efficiency and cost efficiency. The focus is on evaluating the design issues when considering a single converter module having large current stresses. The dominating loss mechanism in low voltage, high current applications is conduction losses. In the case of MOSFETs, the conduction losses can be efficiently reduced by paralleling, but in the case of diodes, the effectiveness of paralleling depends strongly on the semiconductor material, diode parameters and output configuration. The transformer winding losses can be a major source of losses if the windings are not optimized according to the topology and the operating conditions. Transformer prototyping can be expensive and time consuming, and thus it is preferable to utilize various calculation methods during the design process in order to evaluate the performance of the transformer. This thesis reviews calculation methods for solid wire, litz wire and copper foil winding losses, and in order to evaluate the applicability of the methods, the calculations are compared against measurements and FEM simulations. By selecting a proper calculation method for each winding type, the winding losses can be predicted quite accurately before actually constructing the transformer. The transformer leakage inductance, the amount of which can also be calculated with reasonable accuracy, has a significant impact on the semiconductor switching losses. Therefore, the leakage inductance effects should also be taken into account when considering the overall efficiency of the converter. It is demonstrated in this thesis that although there are some distinctive differences in the loss distributions between the converter topologies, the differences in the overall efficiency can remain within a range of a few percentage points. However, the optimization effort required in order to achieve the high efficiencies is quite different in each topology. In the presence of practical constraints such as manufacturing complexity or cost, the question of topology selection can become crucial.

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Fan systems are responsible for approximately 10% of the electricity consumption in industrial and municipal sectors, and it has been found that there is energy-saving potential in these systems. To this end, variable speed drives (VSDs) are used to enhance the efficiency of fan systems. Usually, fan system operation is optimized based on measurements of the system, but there are seldom readily installed meters in the system that can be used for the purpose. Thus, sensorless methods are needed for the optimization of fan system operation. In this thesis, methods for the fan operating point estimation with a variable speed drive are studied and discussed. These methods can be used for the energy efficient control of the fan system without additional measurements. The operation of these methods is validated by laboratory measurements and data from an industrial fan system. In addition to their energy consumption, condition monitoring of fan systems is a key issue as fans are an integral part of various production processes. Fan system condition monitoring is usually carried out with vibration measurements, which again increase the system complexity. However, variable speed drives can already be used for pumping system condition monitoring. Therefore, it would add to the usability of a variablespeed- driven fan system if the variable speed drive could be used as a condition monitoring device. In this thesis, sensorless detection methods for three lifetime-reducing phenomena are suggested: these are detection of the fan contamination build-up, the correct rotational direction, and the fan surge. The methods use the variable speed drive monitoring and control options for the detection along with simple signal processing methods, such as power spectrum density estimates. The methods have been validated by laboratory measurements. The key finding of this doctoral thesis is that a variable speed drive can be used on its own as a monitoring and control device for the fan system energy efficiency, and it can also be used in the detection of certain lifetime-reducing phenomena.

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The pumping processes requiring wide range of flow are often equipped with parallelconnected centrifugal pumps. In parallel pumping systems, the use of variable speed control allows that the required output for the process can be delivered with a varying number of operated pump units and selected rotational speed references. However, the optimization of the parallel-connected rotational speed controlled pump units often requires adaptive modelling of both parallel pump characteristics and the surrounding system in varying operation conditions. The available information required for the system modelling in typical parallel pumping applications such as waste water treatment and various cooling and water delivery pumping tasks can be limited, and the lack of real-time operation point monitoring often sets limits for accurate energy efficiency optimization. Hence, alternatives for easily implementable control strategies which can be adopted with minimum system data are necessary. This doctoral thesis concentrates on the methods that allow the energy efficient use of variable speed controlled parallel pumps in system scenarios in which the parallel pump units consist of a centrifugal pump, an electric motor, and a frequency converter. Firstly, the suitable operation conditions for variable speed controlled parallel pumps are studied. Secondly, methods for determining the output of each parallel pump unit using characteristic curve-based operation point estimation with frequency converter are discussed. Thirdly, the implementation of the control strategy based on real-time pump operation point estimation and sub-optimization of each parallel pump unit is studied. The findings of the thesis support the idea that the energy efficiency of the pumping can be increased without the installation of new, more efficient components in the systems by simply adopting suitable control strategies. An easily implementable and adaptive control strategy for variable speed controlled parallel pumping systems can be created by utilizing the pump operation point estimation available in modern frequency converters. Hence, additional real-time flow metering, start-up measurements, and detailed system model are unnecessary, and the pumping task can be fulfilled by determining a speed reference for each parallel-pump unit which suggests the energy efficient operation of the pumping system.

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This study will concentrate on Product Data Management (PDM) systems, and sheet metal design features and classification. In this thesis, PDM is seen as an individual system which handles all product-related data and information. The meaning of relevant data is to take the manufacturing process further with fewer errors. The features of sheet metals are giving more information and value to the designed models. The possibility of implementing PDM and sheet metal features recognition are the core of this study. Their integration should make the design process faster and manufacturing-friendly products easier to design. The triangulation method is the basis for this research. The sections of this triangle are: scientific literature review, interview using the Delphi method and the author’s experience and observations. The main key findings of this study are: (1) the area of focus in triangle (the triangle of three different point of views: business, information exchange and technical) depends on the person’s background and their role in the company, (2) the classification in the PDM system (and also in the CAD system) should be done using the materials, tools and machines that are in use in the company and (3) the design process has to be more effective because of the increase of industrial production, sheet metal blank production and the designer’s time spent on actual design and (4) because Design For Manufacture (DFM) integration can be done with CAD-programs, DFM integration with the PDM system should also be possible.

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Pumping systems account for up to 22 % of the energy consumed by electrical motors in European industry. Many studies have shown that there is also a lot of potential for energy savings in these systems with the improvement of devices, flow control or surrounding sys-tem. The best method for more energy efficient pumping has to be found for each system separately. This thesis studies how energy saving potential in reservoir pumping system is affected by surrounding variables, such as the static head variation and friction factor. The objective is to create generally applicable graphs to quickly compare methods for reducing pumping system’s energy costs. The gained results are several graphs showcasing how the chosen variables affect energy saving potential of the pumping system in one specific case. To judge if these graphs are generally applicable, more testing with different pumps and environments are required.

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The aim of the present study was to evaluate renal and liver distribution of two monoclonal immunoglobulin light chains. The chains were purified individually from the urine of patients with multiple myeloma and characterized as lambda light chains with a molecular mass of 28 kDa. They were named BJg (high amount of galactose residues exposed) and BJs (sialic acid residues exposed) on the basis of carbohydrate content. A scintigraphic study was performed on male Wistar rats weighing 250 g for 60 min after iv administration of 1 mg of each protein (7.4 MBq), as the intact proteins and also after carbohydrate oxidation. Images were obtained with a Siemens gamma camera with a high-resolution collimator and processed with a MicroDelta system. Hepatic and renal distribution were established and are reported as percent of injected dose. Liver uptake of BJg was significantly higher than liver uptake of BJs (94.3 vs 81.4%) (P<0.05). This contributed to its greater removal from the intravascular compartment, and consequently lower kidney accumulation of BJg in comparison to BJs (5.7 vs 18.6%) (P<0.05). After carbohydrate oxidation, there was a decrease in hepatic accumulation of both proteins and consequently a higher renal overload. The tissue distribution of periodate-treated BJg was similar to that of native BJs: 82.7 vs 81.4% in the liver and 17.3 vs 18.6% in the kidneys. These observations indicate the important role of sugar residues of Bence Jones proteins for their recognition by specific membrane receptors, which leads to differential tissue accumulation and possible toxicity