Prediction of transients and control reactions in a transonic wind tunnel

This work describes a lumped parameter mathematical model for the prediction of transients in an aerodynamic circuit of a transonic wind tunnel. Control actions to properly handle those perturbations are also assessed. The tunnel circuit technology is up to date and incorporates a novel feature: high-enthalpy air injection to extend the tunnel’s Reynolds number capability. The model solves the equations of continuity, energy and momentum and defines density, internal energy and mass flow as the basic parameters in the aerodynamic study as well as Mach number, stagnation pressure and stagnation temperature, all referred to test section conditions, as the main control variables. The tunnel circuit response to control actions and the stability of the flow are numerically investigated. Initially, for validation purposes, the code was applied to the AWT ("Altitude Wind Tunnel" of NASA-Lewis). In the sequel, the Brazilian transonic wind tunnel was investigated, with all the main control systems modeled, including injection.

Nonlinear dynamics and control of multibody systems

The dynamics of flexible systems, such as robot manipulators , mechanical chains or multibody systems in general, is becoming increasingly important in engineering. This article deals with some nonlinearities that arise in the study of dynamics and control of multibody systems in connection to large rotations. Specifically, a numerical scheme that adresses the conservation of fundamental constants is presented in order to analyse the control-structure interaction problems.

Proposal of methodology for the modeling and control of manipulators

Industrial applications demand that robots operate in agreement with the position and orientation of their end effector. It is necessary to solve the kinematics inverse problem. This allows the displacement of the joints of the manipulator to be determined, to accomplish a given objective. Complete studies of dynamical control of joint robotics are also necessary. Initially, this article focuses on the implementation of numerical algorithms for the solution of the kinematics inverse problem and the modeling and simulation of dynamic systems. This is done using real time implementation. The modeling and simulation of dynamic systems are performed emphasizing off-line programming. In sequence, a complete study of the control strategies is carried out through the study of several elements of a robotic joint, such as: DC motor, inertia, and gearbox. Finally a trajectory generator, used as input for a generic group of joints, is developed and a proposal of the controller's implementation of joints, using EPLD development system, is presented.

Long-term nutrient load management and lake restoration: Case of Säkylän Pyhäjärvi (SW Finland)

Eutrophication caused by anthropogenic nutrient pollution has become one of the most severe threats to water bodies. Nutrients enter water bodies from atmospheric precipitation, industrial and domestic wastewaters and surface runoff from agricultural and forest areas. As point pollution has been significantly reduced in developed countries in recent decades, agricultural non-point sources have been increasingly identified as the largest source of nutrient loading in water bodies. In this study, Lake Säkylän Pyhäjärvi and its catchment are studied as an example of a long-term, voluntary-based, co-operative model of lake and catchment management. Lake Pyhäjärvi is located in the centre of an intensive agricultural area in southwestern Finland. More than 20 professional fishermen operate in the lake area, and the lake is used as a drinking water source and for various recreational activities. Lake Pyhäjärvi is a good example of a large and shallow lake that suffers from eutrophication and is subject to measures to improve this undesired state under changing conditions. Climate change is one of the most important challenges faced by Lake Pyhäjärvi and other water bodies. The results show that climatic variation affects the amounts of runoff and nutrient loading and their timing during the year. The findings from the study area concerning warm winters and their influences on nutrient loading are in accordance with the IPCC scenarios of future climate change. In addition to nutrient reduction measures, the restoration of food chains (biomanipulation) is a key method in water quality management. The food-web structure in Lake Pyhäjärvi has, however, become disturbed due to mild winters, short ice cover and low fish catch. Ice cover that enables winter seining is extremely important to the water quality and ecosystem of Lake Pyhäjärvi, as the vendace stock is one of the key factors affecting the food web and the state of the lake. New methods for the reduction of nutrient loading and the treatment of runoff waters from agriculture, such as sand filters, were tested in field conditions. The results confirm that the filter technique is an applicable method for nutrient reduction, but further development is needed. The ability of sand filters to absorb nutrients can be improved with nutrient binding compounds, such as lime. Long-term hydrological, chemical and biological research and monitoring data on Lake Pyhäjärvi and its catchment provide a basis for water protection measures and improve our understanding of the complicated physical, chemical and biological interactions between the terrestrial and aquatic realms. In addition to measurements carried out in field conditions, Lake Pyhäjärvi and its catchment were studied using various modelling methods. In the calibration and validation of models, long-term and wide-ranging time series data proved to be valuable. Collaboration between researchers, modellers and local water managers further improves the reliability and usefulness of models. Lake Pyhäjärvi and its catchment can also be regarded as a good research laboratory from the point of view of the Baltic Sea. The main problem in both of them is eutrophication caused by excess nutrients, and nutrient loading has to be reduced – especially from agriculture. Mitigation measures are also similar in both cases.

Growth of the crabgrass species Digitaria ciliaris and Digitaria nuda

The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods) with four replications. Assessments began at 15 days after sowing (DAS), and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems), leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.

The many faces of strikes : attitudes towards industrial action by labour, management and human resources

Strikes provide a current, fresh but also a seldom-addressed issue to study from economic sciences perspective. This study provides to filling this research gap by trying to identify attitudes towards strikes that can be found inside organizations. The research problem this study then sets out to answer is: “What kinds of attitudes exist inside organizations towards industrial actions and how attitudes vary between labour, management and human resources?” This study has been planned with a view to test how qualitative attitudinal research, as a method, is suited to studying a phenomenon such as strike. At the heart of this research approach lies an assumption linked to rhetoric social psychology, that attitude is a phenomenon that can be identified in argumentation. For this research 10 semi-structured interviews in 4 organizations were conducted utilizing statements and pictures as stimulants for discussion. The material was transcribed and analysed following the two levels, categorical and interpretive, demanded by the chosen method. Altogether five attitudes were discovered; three of them negative, one indifferent and one positive by nature. The negative attitudes of unfairness, failure and personification towards strikes represented the side of strikes that was perhaps the most anticipated, portraying the contradictions between employees and employer. The attitude of ordinariness, which portrayed indifference, and the positive attitude of change however, were more unanticipated findings. They reflect shared understanding and trust between conflict parties. The utilization of qualitative attitudinal approach to study strikes was deemed successful. The results of this study support prior literature on workplace conflicts for example in regards of the definition of conflict and typologies conflicts. In addition the multifaceted nature of strikes can be perceived as one statement supported by this study. It arises in the nature of the attitudes, the diversity of discussion themes during the interviews as well as in the extent of possible theories to apply.

Oxalic acid and calcium oxalate in production of wood-containing paper : formation, analysis, and control

Papperstillverkningen störs ofta av oönskade föreningar som kan bilda avsättningar på processytor, vilket i sin tur kan ge upphov till störningar i pappersproduktionen samt försämring av papperskvaliteten. Förutom avsättningar av vedharts är stenliknande avlagringar av svårlösliga salter vanliga. I vårt dagliga liv är kalkavlagringar i kaffe- och vattenkokare exempel på liknande problem. I massa- och pappersindustrin är en av de mest problematiska föreningarna kalciumoxalat; detta salt är nästan olösligt i vatten och avlagringarna är mycket svåra att avlägsna. Kalciumoxalat är också känt som en av orsakerna till njurstenar hos människor. Veden och speciellt barken innehåller alltid en viss mängd oxalat men en större källa är oxalsyra som bildas när massan bleks med oxiderande kemikalier, t.ex. väteperoxid. Kalciumoxalat bildas när oxalsyran reagerar med kalcium som kommer in i processen med råvattnet, veden eller olika tillsatsmedel. I denna avhandling undersöktes faktorer som påverkar bildningen av oxalsyra och utfällningen av kalciumoxalat, med hjälp av bleknings- och utfällningsexperiment. Forskningens fokus låg speciellt på olika sätt att förebygga uppkomsten av avlagringar vid tillverkning av trähaltigt papper. Resultaten i denna avhandling visar att bildningen av oxalsyra samt utfällning av kalciumoxalat kan påverkas genom processtekniska och våtändskemiska metoder. Noggrann avbarkning av veden, kontrollerade förhållanden under den alkaliska peroxidblekningen, noggrann hantering och kontroll av andra lösta och kolloidala substanser, samt utnyttjande av skräddarsydd kemi för kontroll av avlagringar är nyckelfaktorer. Resultaten kan utnyttjas då man planerar blekningssekvenser för olika massor samt för att lösa problem orsakade av kalciumoxalat. Forskningsmetoderna som användes i utfällningsstudierna samt för utvärdering av tillsatsmedel kan också utnyttjas inom andra områden, t.ex. bryggeri- och sockerindustrin, där kalciumoxalatproblem är vanligt förekommande. -------------------------------------------- Paperinvalmistusta häiritsevät usein erilaiset epäpuhtaudet, jotka kiinnittyvät prosessipinnoille ja haittaavat tuotantoa sekä paperin laatua. Puun pihkan lisäksi eräs yleinen ongelma on niukkaliukoisten suolojen aiheuttamat kivettymät. Kalkkisaostuma kahvinkeittimessä on esimerkki vastaavasta ongelmasta arkielämässä. Massa- ja paperiteollisuudessa yksi hankalimmista kivettymien muodostajista on kalsiumoksalaatti, koska se on lähes liukenematonta ja sen aiheuttamat saostumat ovat erittäin vaikeasti poistettavia. Kalsiumoksalaatti on yleisesti tunnettu myös munuaiskivien aiheuttajana ihmisillä. Puu ja varsinkin sen kuori sisältää aina jonkin verran oksalaattia, mutta suurempi lähde on kuitenkin oksaalihappo jota muodostuu valkaistaessa massaa hapettavilla kemikaaleilla, kuten vetyperoksidilla. Kalsiumoksalaattia syntyy kun veden, puun ja lisäaineiden mukana prosessiin tuleva kalsium reagoi oksalaatin kanssa. Tässä väitöskirjatyössä tutkittiin oksaalihapon muodostumiseen ja kalsiumoksalaatin saostumiseen vaikuttavia tekijöitä valkaisu- ja saostumiskokeiden avulla. Tutkimuksen painopiste oli saostumien ehkäisemisessä puupitoisten painopaperien valmistuksessa. Työssä saadut tulokset osoittavat että oksaalihapon muodostumiseen ja kalsiumoksalaatin saostumiseen voidaan vaikuttaa sekä prosessiteknisten että märänpään kemian keinojen avulla. Tehokas puun kuorinta, optimoidut olosuhteet peroksidivalkaisussa, muiden liuenneiden ja kolloidisten aineiden hallinta sekä räätälöidyn kemian hyödyntäminen kalsiumoksalaattisaostumien torjunnassa ovat keskeisissä rooleissa ongelmien välttämiseksi. Väitöskirjatyön tuloksia voidaan hyödyntää massan valkaisulinjoja suunniteltaessa sekä kalsiumoksalaatin aiheuttamien ongelmien ratkaisemisessa. Tutkimusmenetelmiä, joita käytettiin saostumiskokeissa ja eri lisäaineiden vaikutusten arvioinnissa, voidaan hyödyntää massa- ja paperiteollisuuden lisäksi myös muilla alueilla, kuten sokeri- ja panimoteollisuudessa, joissa ongelma on myös yleinen.

Supporting the creation, management, and long-term preservation of social science research data

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

In For a Penny, In For a Pound: The Management and Preservation of E-Theses in EPrints

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Germination of seeds of tropical pioneer species under controlled and natural conditions

Seed germination of eight tropical pioneer species (Cecropia hololeuca, C. pachystachya, C. glazioui, Solanum gracillimum, S. granuloso-leprosum, S. tabacifolium, Croton floribundus and Miconia chamissois) was studied. In controlled conditions, alternating temperatures were tested from 5 to 25 °C. Low Red:Far Red ratios (R:FR) were also examined. In the field, germination was evaluated in gaps and under the canopy. With the exception of Croton floribundus, all other species were photoblastic in that higher germination percentages were found under light conditions (S. tabacifolium behaved as a negative photoblastic species at some temperatures). No relationship was found between germination percentage and alternating temperature. Germination was markedly reduced under low R:FR ratios. Alternating temperature is not the main factor affecting field germination. The low R:FR ratio under the canopy seems to be the crucial factor affecting germination.

New species of Aulonemia and Chusquea (Poaceae: Bambusoideae: Bambuseae) from southeastern Brazil

Aulonemia fimbriatifolia and Chusquea longispiculata, two woody bamboo species from the Atlantic forest of southeastern Brazil, are described as new and key characters are illustrated. Aulonemia fimbriatifolia is compared and contrasted with four other similar species, but it is considered unique within the genus and possibly among Neotropical woody bamboos due to its basally fimbriate foliage leaf blades. Chusquea longispiculata shares extremely reduced glumes I and II and reflexed lower inflorescence branches with a number of other Brazilian species of the genus, but is distinguished based on its spikelets that reach nearly 2 cm in length, as well as several vegetative features.

Chromosome study in two Aratinga species (A. guarouba and A. acuticaudata) (Psittaciformes)

The karyotypes of two species of Psittacidae of the genus Aratinga, Aratinga guarouba and A. acuticaudata were studied for the first time. The metaphases were obtained using a short term culture of feather pulp. These karyotypes are compared with others of the genus and their karyological relationships in the Psittaciformes are discussed

Heparan sulfate and control of cell division: adhesion and proliferation of mutant CHO-745 cells lacking xylosyl transferase

We have examined the role of cell surface glycosaminoglycans in cell division: adhesion and proliferation of Chinese hamster ovary (CHO) cells. We used both wild-type (CHO-K1) cells and a mutant (CHO-745) which is deficient in the synthesis of proteoglycans due to lack of activity of xylosyl transferase. Using different amounts of wild-type and mutant cells, little adhesion was observed in the presence of laminin and type I collagen. However, when fibronectin or vitronectin was used as substrate, there was an enhancement in the adhesion of wild-type and mutant cells. Only CHO-K1 cells showed a time-dependent adhesion on type IV collagen. These results suggest that the two cell lines present different adhesive profiles. Several lines of experimental evidence suggest that heparan sulfate proteoglycans play a role in cell adhesion as positive modulators of cell proliferation and as key participants in the process of cell division. Proliferation and cell cycle assays clearly demonstrate that a decrease in the amount of glycosaminoglycans does not inhibit the proliferation of mutant CHO-745 cells when compared to the wild type CHO-K1, in agreement with the findings that both CHO-K1 and CHO-745 cells take 8 h to enter the S phase.

Reporting of Green Supply Chain Management and Industrial Symbiosis

The purpose of this thesis is to examine how the reporting of operations related to green supply chain management and industrial symbiosis has evolved in UPM, Fortum and Kemira within the last ten years. The focus is on the improved operations, which are studied based on annual reports of these companies. The study provides a deeper understanding of the nature of green supply chain management and industrial symbiosis as well as the possibilites that their combination offers. The research is part of the DemaNET research project The study indicates that the environmental regulations and reporting standards have forced the studied companies to report their operations related to green supply chain management and industrial symbiosis more in detail during the last ten years. The operations related to green supply chain management in the studied companies are more common compared to operations related to industrial symbiosis. Often these two operations were also partially integrated, indicating a hybrid model. Even though firms often used hybrid models they still focused mainly on greening the internal operations rather than finding alternative ways for symbiosis outside the organization. The integration of green supply chain management and industrial symbiosis is most likely to occur when mutually beneficial relationships align the interests of all parties, thus resulting in the co-creation of value. The findings suggest that identifying mutual benefits and the flow of by-products are the ones that companies should give more attention to.

Ellagitannins in Finnish plant species – Characterization, distribution and oxidative activity

Ellagitannins are secondary metabolites that are produced by plants. Among other features, they are assumed to function as plants’ defensive compounds against plant-eating herbivores. This thesis focuses on a theory, which suggests that the biological activity of ellagitannins is based on their tendency to oxidize at the highly alkaline gut conditions of insect herbivores (oxidative activity). To study the biological activities of ellagitannins, a wide variety of structurally different ellagitannins were purified from different plant species by using liquid chromatographic techniques. The structures were characterized with the aid of spectrometric methods. Based on the acquired data, it was also possible to create a scheme, which enables the classification and even identification of ellagitannins from plant extracts without the need to isolate each compound for individual characterization. The biological activities of ellagitannins were determined with methods that are based on the abilities of the compounds to scavenge radicals, chelate iron ions, and on their rate of oxidation at high pH. The results showed that ellagitannins possess oxidative activities both at high and neutral pH, and that their activities depend on structure. The occurrence, distribution and content of ellagitannins in Finnish plant species were also studied. The specific ellagitannin profiles of the studied plant species were found to correlate well with their taxonomic classification.