840 resultados para additive technologies,


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Information gained from the human genome project and improvements in compound synthesizing have increased the number of both therapeutic targets and potential lead compounds. This has evolved a need for better screening techniques to have a capacity to screen number of compound libraries against increasing amount of targets. Radioactivity based assays have been traditionally used in drug screening but the fluorescence based assays have become more popular in high throughput screening (HTS) as they avoid safety and waste problems confronted with radioactivity. In comparison to conventional fluorescence more sensitive detection is obtained with time-resolved luminescence which has increased the popularity of time-resolved fluorescence resonance energy transfer (TR-FRET) based assays. To simplify the current TR-FRET based assay concept the luminometric homogeneous single-label utilizing assay technique, Quenching Resonance Energy Transfer (QRET), was developed. The technique utilizes soluble quencher to quench non-specifically the signal of unbound fraction of lanthanide labeled ligand. One labeling procedure and fewer manipulation steps in the assay concept are saving resources. The QRET technique is suitable for both biochemical and cell-based assays as indicated in four studies:1) ligand screening study of β2 -adrenergic receptor (cell-based), 2) activation study of Gs-/Gi-protein coupled receptors by measuring intracellular concentration of cyclic adenosine monophosphate (cell-based), 3) activation study of G-protein coupled receptors by observing the binding of guanosine-5’-triphosphate (cell membranes), and 4) activation study of small GTP binding protein Ras (biochemical). Signal-to-background ratios were between 2.4 to 10 and coefficient of variation varied from 0.5 to 17% indicating their suitability to HTS use.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The iron ore pelletizing process consumes high amounts of energy, including nonrenewable sources, such as natural gas. Due to fossil fuels scarcity and increasing concerns regarding sustainability and global warming, at least partial substitution by renewable energy seems inevitable. Gasification projects are being successfully developed in Northern Europe, and large-scale circulating fluidized bed biomass gasifiers have been commissioned in e.g. Finland. As Brazil has abundant biomass resources, biomass gasification is a promising technology in the near future. Biomasses can be converted into product gas through gasification. This work compares different technologies, e.g. air, oxygen and steam gasification, focusing on the use of the product gas in the indurating machine. The use of biosynthetic natural gas is also evaluated. Main parameters utilized to assess the suitability of product gas were adiabatic flame temperature and volumetric flow rate. It was found that low energy content product gas could be utilized in the traveling grate, but it would require burner’s to be changed. On the other hand, bio-SGN could be utilized without any adaptions. Economical assessment showed that all gasification plants are feasible for sizes greater than 60 MW. Bio-SNG production is still more expensive than natural gas in any case.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The evolution of our society is impossible without a constant progress in life-important areas such as chemical engineering and technology. Innovation, creativity and technology are three main components driving the progress of chemistry further towards a sustainable society. Biomass, being an attractive renewable feedstock for production of fine chemicals, energy-rich materials and even transportation fuels, captures progressively new positions in the area of chemical technology. Knowledge of heterogeneous catalysis and chemical technology applied to transformation of biomass-derived substances will open doors for a sustainable economy and facilitates the discovery of novel environmentally-benign processes which probably will replace existing technologies in the era of biorefinary. Aqueous-phase reforming (APR) is regarded as a promising technology for production of hydrogen and liquids fuels from biomass-derived substances such as C3-C6 polyols. In the present work, aqueous-phase reforming of glycerol, xylitol and sorbitol was investigated in the presence of supported Pt catalysts. The catalysts were deposited on different support materials, including Al2O3, TiO2 and carbons. Catalytic measurements were performed in a laboratory-scale continuous fixedbed reactor. An advanced analytical approach was developed in order to identify reaction products and reaction intermediates in the APR of polyols. The influence of the substrate structure on the product formation and selectivity in the APR reaction was also investigated, showing that the yields of the desired products varied depending on the substrate chain length. Additionally, the influence of bioethanol additive in the APR of glycerol and sorbitol was studied. A reaction network was advanced explaining the formation of products and key intermediates. The structure sensitivity in the aqueous-phase reforming reaction was demonstrated using a series of platinum catalysts supported on carbon with different Pt cluster sizes in the continuous fixed-bed reactor. Furthermore, a correlation between texture physico-chemical properties of the catalysts and catalytic data was established. The effect of the second metal (Re, Cu) addition to Pt catalysts was investigated in the APR of xylitol showing a superior hydrocarbon formation on PtRe bimetallic catalysts compared to monometallic Pt. On the basis of the experimental data obtained, mathematical modeling of the reaction kinetics was performed. The developed model was proven to successfully describe experimental data on APR of sorbitol with good accuracy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Laser additive manufacturing (LAM), known also as 3D printing, has gained a lot of interest in past recent years within various industries, such as medical and aerospace industries. LAM enables fabrication of complex 3D geometries by melting metal powder layer by layer with laser beam. Research in laser additive manufacturing has been focused in development of new materials and new applications in past 10 years. Since this technology is on cutting edge, efficiency of manufacturing process is in center role of research of this industry. Aim of this thesis is to characterize methods for process efficiency improvements in laser additive manufacturing. The aim is also to clarify the effect of process parameters to the stability of the process and in microstructure of manufactured pieces. Experimental tests of this thesis were made with various process parameters and their effect on build pieces has been studied, when additive manufacturing was performed with a modified research machine representing EOSINT M-series and with EOS EOSINT M280. Material used was stainless steel 17-4 PH. Also, some of the methods for process efficiency improvements were tested. Literature review of this thesis presents basics of laser additive manufacturing, methods for improve the process efficiency and laser beam – material- interaction. It was observed that there are only few public studies about process efficiency of laser additive manufacturing of stainless steel. According to literature, it is possible to improve process efficiency with higher power lasers and thicker layer thicknesses. The process efficiency improvement is possible if the effect of process parameter changes in manufactured pieces is known. According to experiments carried out in this thesis, it was concluded that process parameters have major role in single track formation in laser additive manufacturing. Rough estimation equations were created to describe the effect of input parameters to output parameters. The experimental results showed that the WDA (width-depth-area of cross-sections of single track) is correlating exponentially with energy density input. The energy density input is combination of the input parameters of laser power, laser beam spot diameter and scan speed. The use of skin-core technique enables improvement of process efficiency as the core of the part is manufactured with higher laser power and thicker layer thickness and the skin with lower laser power and thinner layer thickness in order to maintain high resolution. In this technique the interface between skin and core must have overlapping in order to achieve full dense parts. It was also noticed in this thesis that keyhole can be formed in LAM process. It was noticed that the threshold intensity value of 106 W/cm2 was exceeded during the tests. This means that in these tests the keyhole formation was possible.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this work is to perform an in-depth overview on the sustainability of several major commercialized technologies for water desalination and to identify the challenges and propose suggestions for the development of water desalination technologies. The overview of those technologies mainly focuses on the sustainability from the viewpoint of total capital investment, total product cost, energy consumption and global warming index. Additionally, a systematic sustainability assessment methodology has been introduced to validate the assessment process. Conclusions are:1) Reverse osmosis desalination (RO) plants are better than multi-stage flash distillation (MSF) desalination plants and multiple-effect distillation (MED) desalination plants from the viewpoint of energy consumption, global warming index and total production cost; 2)Though energy intensive, MSF plants and MED plants secure their advantages over RO plants by lower total capital investment, wider applicability and purer water desalted and they are still likely to flourish in energy-rich area;3) Water production stage and wastewater disposal stage are the two stages during which most pollutant gases are emitted. The water production stage alone contributes approximately 80~90% of the total pollutant gases emission during its life cycle; 4)The total capital cost per m3 desalted water decreases remarkably with the increasing of plant capacity. The differences between the capital cost per m3 desalted water of RO and other desalination plants will decrease as the capacity increases; 5) It is found that utilities costs serve as the major part of the total product cost, and they account for 91.16%, 85.55% and 71.26% of the total product cost for MSF, MED and RO plants, respectively; 6) The absolute superiority of given technology depends on the actual social-economic situation (energy prices, social policies, technology advancements).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this report, information is published concerning Russian water and wastewater treatment plants. The information is based on a questionnaire sent to 70 water and wastewater treatment plants in 2012-2013. The questionnaire was prepared by the International Advanced Water Technologies Centre (IAWTC) and Lahti Development Company (LADEC). The questions dealt with an assessment of the present state, the need for changes, renovation, investments, and how to improve the efficiency of the operation by training and investments. A significant need to renew the old pipelines, constructions, and processes was clearly evident. The aggregated answers can be utilized in Russia as internal benchmarking in order to arrange training and plant visits, which were requested in many of the answers. Sharing this open report with the respondents can aid networking and awareness of HELCOM requirements which relate to waste water treatment plants discharging their waste water directly or indirectly into the Baltic Sea. The aim of this report is to provide information for Finnish small and medium size companies (SMEs) as regards possible water related exportation to different parts of Russia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The present study introduce two pretreatment technologies which are torrefaction and steam explosion, and compare energy balance for both technologies to investigate and compare the use of these technologies to improve pelletization. In this research, torrefaction and steam explosion pretreatments were accomplished on the mixed small diameter wood (70%) with moisture content of 40 %, and logging residues (30%) with moisture content of 45 % at temperature 230 ̊C, and treatment duration 10 min. Competing methods were evaluated, and the results showed higher volumetric energy for steam explosion pellet than torrefied pellet.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Suurelle yleisölle lisäävä valmistustekniikka eli ns. 3D-tulostustekniikka näyttäytyy lehtien otsikoissa ja artikkeleissa esiin pulpahtavana ”muotiaiheena”, mutta sekä muovien 3D-tulostustekniikka että metallienkin vastaava valmistustekniikka on ollut olemassa maailmalla ja Suomessa 80-luvun puolivälistä alkaen. Yhdysvalloissa ja Saksassa tekniikkaa käytetään valmistavassa teollisuudessa toiminnallisten osien tuotannossa. Esimerkiksi lentokoneen suihkumoottorien osia ja lääketieteellisiä välineitä tehdään metallijauheesta lisäävän valmistuksen avulla. Itse asiassa eräs menetelmä metalliesineiden valmistamiseksi lasersäteen avulla keksittiin Suomessa ja sitä myös kehiteltiin täällä, mutta teollisuudenala lähti aikanaan nousuun Saksassa. Lisäävä valmistus on tällä hetkellä maailmanlaajuisesti eräs kiinnostavista tuotantotekniikoista, jonka uskotaan muuttavan monia asioita tuotteiden suunnittelussa, toiminnoissa ja valmistuksessa. Tämä tekniikka ei kiinnosta pelkästään valmistavaa teollisuutta, vaan tietotekniikan, lääketieteen, koruvalmistuksen ja muotoilun osaajat sekä uusien liiketoimintamallien kehittäjät ja logistiikka operaattorit ovat teknologiasta kiinnostuneita. Suomelle 3D-tulostustekniikka on suuri mahdollisuus, sillä maassamme on vahva teollinen tieto- ja viestintätekniikkaosaaminen sekä lisäksi olemme maassamme erikoistuneet varsin vaativien teollisiin laitteiden valmistukseen. Eräät suurimmista mahdollisuuksista tällä tekniikalla ovat toimitusketjuihin liittyvät muutokset. Uutta on, että pienetkin yritykset ja organisaatiot voivat soveltaa tätä tekniikkaa valmistuksessa ja jopa kehitellä täysin uusia tuotteita. On myös arvioitu, että lisäävän valmistuksen merkitys valmistustapoihin ja toimitusketjuihin voi olla suurempi kuin koskaan aikaisemmin minkään teknologisen uudistuksen kohdalla. Lisäävästä valmistuksesta usein puhutaankin kolmantena teollisena vallankumouksena juuri tämän takia. 3D-tulostuksen kustannuksia tarkasteltaessa on tärkeätä huomata että vain sulatetun jauheen määrä ratkaisee, ei käytettävän geometrian monimutkaisuus. Tämä erottaa perinteisen ja lisäävän valmistuksen toisistaan. Perinteisesti kappaleen keventäminen on maksanut ”ylimääräistä”, kun taas lisäävässä valmistuksessa kappaleen keveys on jopa kustannusta alentava tekijä. Valmistettavan kappaleen korkeus on yksi kriittisimpiä kustannuksiin vaikuttavia tekijöitä. Tämän vuoksi useamman kappaleen valmistus yhdellä kertaa parantaa kannattavuutta huomattavasti. Samalla kertaa voi ja itse asiassa kannattaakin valmistaa keskenään erilaisia kappaleita. Perinteiset valmistustavat sen sijaan ovat nykyajan vaatimuksille liian hitaita; ne joustavat huonosti, kun kyseessä on pienet, asiakaslähtöiset erät. Trendi on globaalisti kohden yksilöllisiä asiakaslähtöisiä tuotteita, jolloin myös valmistustekniikoiden on oltava joustavia pysyäkseen näiden vaatimusten perässä. Lisäävä valmistus sopii erityisesti hyvin piensarjatuotantoon. Suuremmissa valmistuserissä kuitenkin perinteiset tekniikat ovat kustannustehokkaampia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Materiaalia lisäävä valmistus eli 3D-tulostus on valmistusmenetelmä, jossa kappale tehdään 3D-mallin pohjalta materiaalikerroksia lisäämällä, käyttäen useita tekniikoita ja materiaaleja. Menetelmää sovelletaan useilla teollisuuden aloilla. Lisääviä valmistustekniikoita on kehitetty 1990-luvun alkupuolelta lähtien, ja ne monipuolistuvat jatkuvasti. Tässä pro gradu -tutkielmassa tutkitaan sovellusalan terminologian kehitystä vertailevilla menetelmillä ja luodaan kolmikielinen sanasto alan asiantuntijoille, joita edustaa Suomessa FIRPA ry. Sanaston kielet ovat englanti, ranska ja suomi. Terminologian tutkimus on perinteisesti keskittynyt sanastotyöhön ja käsiteanalyysiin, sen sijaan termihistorian tutkimus on ollut vähäisempää. Tässä työssä on tehty vertailevaa termitutkimusta sekä sanastotyön että termihistorian näkökulmista. Vertailutasoja ovat termien merkityksen muuttuminen, vertailu pivot-kielen suhteen ja kielikohtaisten ominaisuuksien tarkastelu termien muotoutumisessa. Tutkittavia asioita ovat sanastokäsitteiden väliset suhteet, synonyymien, varianttien ja uudissanojen moninaisuus, ja termien yleiskielistyminen. Samalla pohditaan muita termien muuttumiseen vaikuttavia syita. Tärkeimpänä lähteenä käytetään Wohlersin vuosiraportteja, jotka kuvaavat kattavasti koko teollisuudenalaa. Koska englannin pivot-vaikutus on voimakasta teknisillä aloilla, omankielisen terminologian kehittyminen vaatii tietoista terminologiatyötä ja aktiivista omankielisten termien käyttöä. Terminologian vakiintumista voidaan arvioida termivarianttien ja uudissanojen määristä, sekä termien yleiskielistymisestä. Terminologia muuttuu jatkuvasti toimialan kehittyessä ja vaatii säännöllistä päivittämistä. Termihistorian tunteminen tukee sanastotyön termivalintoja. Alan asiantuntijat ovat vastuussa omasta terminologiastaan, ja heidän aktiivisuutensa on tärkeää sen kehittämisessä. Toteutettu sanasto on tämän pro gradu -tutkielman liitteenä ja se julkaistaan myös FIRPA ry:n Internet-sivustolla. Suomenkielinen osio sanastosta on ensimmäinen laaja suomeksi julkaistu materiaalia lisäävän valmistuksen sanasto.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Laser additive manufacturing (LAM), known also as 3D printing, is a powder bed fusion (PBF) type of additive manufacturing (AM) technology used to manufacture metal parts layer by layer by assist of laser beam. The development of the technology from building just prototype parts to functional parts is due to design flexibility. And also possibility to manufacture tailored and optimised components in terms of performance and strength to weight ratio of final parts. The study of energy and raw material consumption in LAM is essential as it might facilitate the adoption and usage of the technique in manufacturing industries. The objective this thesis was find the impact of LAM on environmental and economic aspects and to conduct life cycle inventory of CNC machining and LAM in terms of energy and raw material consumption at production phases. Literature overview in this thesis include sustainability issues in manufacturing industries with focus on environmental and economic aspects. Also life cycle assessment and its applicability in manufacturing industry were studied. UPLCI-CO2PE! Initiative was identified as mostly applied exiting methodology to conduct LCI analysis in discrete manufacturing process like LAM. Many of the reviewed literature had focused to PBF of polymeric material and only few had considered metallic materials. The studies that had included metallic materials had only measured input and output energy or materials of the process and compared to different AM systems without comparing to any competitive process. Neither did any include effect of process variation when building metallic parts with LAM. Experimental testing were carried out to make dissimilar samples with CNC machining and LAM in this thesis. Test samples were designed to include part complexity and weight reductions. PUMA 2500Y lathe machine was used in the CNC machining whereas a modified research machine representing EOSINT M-series was used for the LAM. The raw material used for making the test pieces were stainless steel 316L bar (CNC machined parts) and stainless steel 316L powder (LAM built parts). An analysis of power, time, and the energy consumed in each of the manufacturing processes on production phase showed that LAM utilises more energy than CNC machining. The high energy consumption was as result of duration of production. Energy consumption profiles in CNC machining showed fluctuations with high and low power ranges. LAM energy usage within specific mode (standby, heating, process, sawing) remained relatively constant through the production. CNC machining was limited in terms of manufacturing freedom as it was not possible to manufacture all the designed sample by machining. And the one which was possible was aided with large amount of material removed as waste. Planning phase in LAM was shorter than in CNC machining as the latter required many preparation steps. Specific energy consumption (SEC) were estimated in LAM based on the practical results and assumed platform utilisation. The estimated platform utilisation showed SEC could reduce when more parts were placed in one build than it was in with the empirical results in this thesis (six parts).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis studies the advantages, disadvantages and possibilities of additive manufacturing in making components with internal flow channels. These include hydraulic components, components with cooling channels and heat exchangers. Processes studied in this work are selective laser sintering and selective laser melting of metallic materials. The basic principles of processes and parameters involved in the process are presented and different possibilities of internal channel manufacturing and flow improvement are introduced

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An electric system based on renewable energy faces challenges concerning the storage and utilization of energy due to the intermittent and seasonal nature of renewable energy sources. Wind and solar photovoltaic power productions are variable and difficult to predict, and thus electricity storage will be needed in the case of basic power production. Hydrogen’s energetic potential lies in its ability and versatility to store chemical energy, to serve as an energy carrier and as feedstock for various industries. Hydrogen is also used e.g. in the production of biofuels. The amount of energy produced during hydrogen combustion is higher than any other fuel’s on a mass basis with a higher-heating-value of 39.4 kWh/kg. However, even though hydrogen is the most abundant element in the universe, on Earth most hydrogen exists in molecular forms such as water. Therefore, hydrogen must be produced and there are various methods to do so. Today, the majority hydrogen comes from fossil fuels, mainly from steam methane reforming, and only about 4 % of global hydrogen comes from water electrolysis. Combination of electrolytic production of hydrogen from water and supply of renewable energy is attracting more interest due to the sustainability and the increased flexibility of the resulting energy system. The preferred option for intermittent hydrogen storage is pressurization in tanks since at ambient conditions the volumetric energy density of hydrogen is low, and pressurized tanks are efficient and affordable when the cycling rate is high. Pressurized hydrogen enables energy storage in larger capacities compared to battery technologies and additionally the energy can be stored for longer periods of time, on a time scale of months. In this thesis, the thermodynamics and electrochemistry associated with water electrolysis are described. The main water electrolysis technologies are presented with state-of-the-art specifications. Finally, a Power-to-Hydrogen infrastructure design for Lappeenranta University of Technology is presented. Laboratory setup for water electrolysis is specified and factors affecting its commissioning in Finland are presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The experiences of several healthcare organizations were considered to distinguish the most frequently used lean tools, the success and failure factors, and the obstacles that may appear while implementing lean. As a result, two approaches to “go lean” were defined, and analyzed from the prospective of the applicability to healthcare processes. Industrialization of healthcare was studied, and the most promising digital technology tools to improve healthcare process were highlighted. Finally, the analysis of healthcare challenges and feasible ways to address them was conducted and presented as the main result of this work. The possible ways of implementation of the findings and limitations were described in the conclusion.