Eräällä pelkkahakkurilla tuotetun selluhakkeen laatujakauman hallinta

Tämän diplomityön tarkoituksena on selvittää eräällä pelkkahakkurilla tuotetun selluhakkeen laadun vaihtelua ja laadun hallinnan mahdollisuuksia. Tutkittu laite on Veisto Oy:n suunnittelema ja valmistama HewSaw R200 - pelkkahakkuri. Tutkimuksessa selvitetään sahauksen yhteydessä pelkkahakkurilla tuotettavaan selluhakkeeseen vaikuttavien parametrien: hakkurin pyörimisnopeuden, tukin syöttönopeuden, hakkurin terien vaihtovälin, selluhakkeen palakoon, tukkiluokan, puun lämpötilan ja puulajin välisiä korrelaatioita ja edellä mainittujen tekijöiden vaikutusta tuotettavan hakkeen palakokojakaumaan. Tämä palakokojakauma määrää selluhakkeen laadunmäärityksessä käytettävän, niin sanotun hintakertoimen. Kyseinen hintakerroin määritellään SCAN – CM 40 – standardin mukaisella seulonnalla. Tämä standardi on käytössä laadunmäärityksen perusteena kaikilla pohjoismaisilla sellutehtailla.Tutkimuksen kirjallisessa osuudessa esitellään sahateollisuuden merkittävimmät sahausmenetelmät ja sivuotteiden tuotanto . Seuraavassa osassa käsitellään erikseen selluhaketta sahateollisuuden sivutuotteena ja sen taloudellista merkitystä sahateollisuudessa. Jatkossa keskitytään selluhakkeen tuottamiseen pelkkahakkurilla ja puun työstämiseen liittyviin periaatteisiin.Tutkimuksen kokeellisessa osuudessa tutkittaan, eri sahalaitoksilta otettujen hakenäytteiden perusteella, tärkeimmiksi havaittujen tuotantoparametrien vaikutusta selluhakkeen laatuun ja saantoon. Näytteitä otettiin tutkimuksen kokeellisessa osuudessa yhteensä noin 250 kappaletta. Tutkimuksen tuloksia käsittelevässä osuudessa on annettu malli tutkitulla HewSaw R200 - pelkkahakkurilla tuotetun selluhakkeen laadun ja määrän arvioimiseen.

Balancing guava nutrition with liming and fertilization

Guava response to liming and fertilization can be monitored by tissue testing. Tissue nutrient signature is often diagnosed against nutrient concentration standards. However, this approach has been criticized for not considering nutrient interactions and to generate numerical biases as a result of data redundancy, scale dependency and non-normal distribution. Techniques of compositional data analysis can control those biases by balancing groups of nutrients, such as those involved in liming and fertilization. The sequentially arranged and orthonormal isometric log ratios (ilr) or balances avoid numerical bias inherent to compositional data. The objectives were to relate tissue nutrient balances with the production of "Paluma" guava orchards differentially limed and fertilized, and to adjust the current patterns of nutrient balance with the range of more productive guava trees. It was conducted one experiment of 7-yr of liming and three experiments of 3-yr with N, P and K trials in 'Paluma' orchards on an Oxisol. Plant N, P, K, Ca and Mg were monitored yearly. It was selected the [N, P, K | Ca, Mg], [N, P | K], [N | P] and [Ca | Mg] balances to set apart the effects of liming (Ca-Mg) and fertilizers (N-K) on macronutrient balances. Liming largely influenced nutrient balances of guava in the Oxisol while fertilization was less influential. The large range of guava yields and nutrient balances allowed defining balance ranges and comparing them with the critical ranges of nutrient concentration values currently used in Brazil and combined into ilr coordinates.

Sellutehdasprojektin tiedonhallintamalli

Tässä työssä käsitellään globaalin toimitusprojektin tiedonhallintaa. Työn pääpaino on modernin toimintaympäristön tiedonhallinnalle asettamien vaatimuksien kuvaamisessa. Lisäksi perehdytään projektin suunnittelun ja ohjauksen tekniikoihin integroidussa projektinohjausjärjestelmässä. Tiedonhallinnalla on erityisen merkittävä rooli toimitusprojektissa, jossa toimittajalla ei ole omaa valmistusta.Työn tavoitteena oli kehittää tiedonhallintamalli toimitusprojektille, joka on hajautettu useisiin eri toimipaikkoihin. Tämä malli on kehitetty pääasiassa selkeyttämään toimintaympäristöä, havaitsemaan tiedonhallinnan puutteita ja luomaan taustaa jatkokehitystä varten.Työssä koottu materiaali perustuu pääasiassa haastatteluihin, palavereihin, erilaisiin sisäisiin raportteihin, kirjallisuuteen ja itsenäiseen selvitystyöhön. Suunnitteluprojektia käytetään esimerkkinä aikataulu- ja resurssienhallinnan työkalun laajemmasta käytöstä sekä tuloksenarvomenetelmään tutustuttamiseen.

Atk-avusteinen tilintarkastus

Tutkimuksen päätavoitteena oli atk-avusteisen tilintarkastuksen käytön tutkiminen. Tutkimus jakaantuu teoreettiseen ja empiiriseen osaan. Teoriaosuudessa käydään läpi tilintarkastusprosessia ja esitellään tietokoneavusteisen tilintarkastuksen työvälineitä sekä arvioidaan kirjallisuuden ja muun lähdeaineiston perusteella atk:n tuottamia hyötyjä ja aiheuttamia riskejä. Empiriaosuudessa tutkittiin tilintarkastajille suunnatun kyselytutkimuksen avulla miten laajaa atk:n hyväksikäyttö on tilintarkastusmaailmassa ja miten tilintarkastajat itse näkevät sen tuomat hyödyt ja haitat sekä atk-avusteisen tilintarkastuksen kehittymisen lähitulevaisuudessa. Tutkimustuloksia verrataan aikaisemmin samasta aihepiiristä tehtyjen tutkimusten tuloksiin. Tutkimustuloksia verrattaessa käy ilmi, että tietokoneen käyttö ja hyödyntäminen tilintarkastustyössä on selvästi lisääntynyt. On huomattava, että atk:n mukaantulo tilintarkastustoimintaan tuo mukanaan ongelmia, jotka tulee tiedostaa, mutta atk:n tuottamien lisäetujen määrä on niin huomattava, että tulevaisuudessa tehokas tilintarkastustyö ei onnistu ilman atk-avusteisia menetelmiä.

Una aproximación a la evolución de la ciencia regional en España a través de las contribuciones a las Reuniones de Estudios Regionales (1973-2004)

This paper presents a bibliometric analysis of the contributions that have been presented to the 30 Spanish Regional Studies Meetings which have been hold since 1973. Firstly, the paper displays rankings of the authors and institutions that have participated more actively in the Meetings. Secondly, the paper analyses the main changes in the objectives, topics and research techniques of the contributions, as well as in the scientific specialisation of their authors. This analysis allows drawing some conclusions on the evolution of Regional Science in Spain throughout the last 30 years.

Les pintures murals de la basílica paleocristiana de «Es Cap des Port» (Fornells, Menorca): materials i tècniques

[cat]El present treball ofereix una revisió de les pintures murals de la basílica de «Es Cap des Port» (Fornells, Menorca), així com un estudi de caracterització arqueomètrica deIs materials i tècniques per microscòpia òptica, tant amb lupa binocular com amb microscopi petrogràfic mitjançant làmina prima, difracció de raigs X i microscòpia electrònica de rastreig. Els resultats han permès identificar els pigments emprats, així com la seva tècnica d'aplicació. Igualment, han permès caracteritzar els morters i han desvelat l' existència de dos tipus diferents de suport. Malgrat aquestes diferències en els morters, els pigments són sempre els mateixos per a tots els conjunts pictòrics caracteritzats [eng] The present paper offers a revision of the wall paintings found at the early Christian church of 'Es Cap des Port' (Fornells, Menorca). Moreover, the materials and techniques employed have been archaeometrically studied by means of optical microscopy, both with steromicroscope and petrographic microscope by thin section, X-ray diffraction and scanning electron microscopy. The results enable to identify the pigments used, as well as the techniques of application. It has also been possible to characterize the mortars, revealing the existence of two different types of support. In spite of these differences in the mortars, the pigments used are the same ones for all the studied wall paintings

Prediction in transformed images

The study is related to lossless compression of greyscale images. The goal of the study was to combine two techniques of lossless image compression, i.e. Integer Wavelet Transform and Differential Pulse Code Modulation to attain better compression ratio. This is an experimental study, where we implemented Integer Wavelet Transform, Differential Pulse Code Modulation and an optimized predictor model using Genetic Algorithm. This study gives encouraging results for greyscale images. We achieved a better compression ration in term of entropy for experiments involving quadrant of transformed image and using optimized predictor coefficients from Genetic Algorithm. In an other set of experiments involving whole image, results are encouraging and opens up many areas for further research work like implementing Integer Wavelet Transform on multiple levels and finding optimized predictor at local levels.

Debating as a classroom tool for adapting learning outcomes to the European higher education area

The creation of the European Higher Education Area has meant a number of significant changes to the educational structures of the university community. In particular, the new system of European credits has generated the need for innovation in the design of curricula and teaching methods. In this paper, we propose debating as a classroom tool that can help fulfill these objectives by promoting an active student role in learning. To demonstrate the potential of this tool, a classroom experiment was conducted in a bachelor’s degree course in Industrial Economics -Regulation and Competition-, involving a case study in competition policy and incorporating the techniques of a conventional debate -presentation of standpoints, turns, right to reply and summing up-. The experiment yielded gains in student attainment and positive assessments of the subject. In conclusion, the incorporation of debating activities helps students to acquire the skills, be they general or specific, required to graduate successfully in Economics.

Ultramicroeletrodos. Parte II: construção e aplicações

This work describes the techniques of construction and several applications of ultramicroelectrodes in electrochemistry and electroanalytical chemistry. Disc shaped UME are produced by embedding metal wires on insulating materials such as glass or epoxy resin. In the field of electrochemistry, UME have been applied in studies of the hydrogen evolution reaction and the electrocrystallization of metals. The negligible values of sensibility for ohmic drop and the enhanced mass transport rate by spherical diffusion are the main advantages of UME in these applications. New important conclusions regarding the phenomena under study were drawn from the experimental results. The applications in electroanalytical chemistry involved the determination of contaminants such as heavy metals and nitrites in natural waters and food products. The use of UME requires little sample manipulation and, in general, no need for oxygen removal or the addition of supporting electrolytes.

Determinação simultânea de cobalto e níquel

The simultaneous determination of cobalt and nickel is a classical analytical problem. A great number of reagents associated with several techniques of analysis have been applied to achieve this determination. In this review 117 references, which appeared between 1996-1980, are described and classified according to the technique applied.

Opinion Mining

In this thesis we study the field of opinion mining by giving a comprehensive review of the available research that has been done in this topic. Also using this available knowledge we present a case study of a multilevel opinion mining system for a student organization's sales management system. We describe the field of opinion mining by discussing its historical roots, its motivations and applications as well as the different scientific approaches that have been used to solve this challenging problem of mining opinions. To deal with this huge subfield of natural language processing, we first give an abstraction of the problem of opinion mining and describe the theoretical frameworks that are available for dealing with appraisal language. Then we discuss the relation between opinion mining and computational linguistics which is a crucial pre-processing step for the accuracy of the subsequent steps of opinion mining. The second part of our thesis deals with the semantics of opinions where we describe the different ways used to collect lists of opinion words as well as the methods and techniques available for extracting knowledge from opinions present in unstructured textual data. In the part about collecting lists of opinion words we describe manual, semi manual and automatic ways to do so and give a review of the available lists that are used as gold standards in opinion mining research. For the methods and techniques of opinion mining we divide the task into three levels that are the document, sentence and feature level. The techniques that are presented in the document and sentence level are divided into supervised and unsupervised approaches that are used to determine the subjectivity and polarity of texts and sentences at these levels of analysis. At the feature level we give a description of the techniques available for finding the opinion targets, the polarity of the opinions about these opinion targets and the opinion holders. Also at the feature level we discuss the various ways to summarize and visualize the results of this level of analysis. In the third part of our thesis we present a case study of a sales management system that uses free form text and that can benefit from an opinion mining system. Using the knowledge gathered in the review of this field we provide a theoretical multi level opinion mining system (MLOM) that can perform most of the tasks needed from an opinion mining system. Based on the previous research we give some hints that many of the laborious market research tasks that are done by the sales force, which uses this sales management system, can improve their insight about their partners and by that increase the quality of their sales services and their overall results.

Active regions for colour texture segmentation integrating region and boundary information

In this paper a colour texture segmentation method, which unifies region and boundary information, is proposed. The algorithm uses a coarse detection of the perceptual (colour and texture) edges of the image to adequately place and initialise a set of active regions. Colour texture of regions is modelled by the conjunction of non-parametric techniques of kernel density estimation (which allow to estimate the colour behaviour) and classical co-occurrence matrix based texture features. Therefore, region information is defined and accurate boundary information can be extracted to guide the segmentation process. Regions concurrently compete for the image pixels in order to segment the whole image taking both information sources into account. Furthermore, experimental results are shown which prove the performance of the proposed method

Alternativas analíticas para determinação de ferro e titânio em cimento Portland

In the present work four different analytical methodologies were studied for the determination of iron and titanium in Portland cement. The cement samples were dissolved with hot HCl and HF, being compared Fe and Ti concentrations through four analytical methods: molecular absorption spectrophotometry using the reagents 1,2-hydroxybenzene-3,5-disulfonic acid (Tiron) and the 5-chloro-salicylic acid (CSA), inductively coupled plasma atomic emission spectrometry (ICP-AES) and flame atomic absorption spectrophotometry (FAAS). In the spectrophotometric determinations were studied pH conditions, reagents addition order, interferences, amount of reagents, linear range and stability of the system. In the techniques of ICP-AES and FAAS were studied the best lines, interferences, sensibility and linear range. The obtained results were compared and the agreement was evaluated among the methods for the determination of the metals of interest.

Técnicas de análise do perfil de execução e otimização de programas em química computacional

In this paper we review the basic techniques of performance analysis within the UNIX environment that are relevant in computational chemistry, with particular emphasis on the execution profile using the gprof tool. Two case studies (in ab initio and molecular dynamics calculations) are presented in order to illustrate how execution profiling can be used to effectively identify bottlenecks and to guide source code optimization. Using these profiling and optimization techniques it was possible to obtain significant speedups (of up to 30%) in both cases.

Determinação da massa molar por crioscopia: terc-butanol, um solvente extremamente adequado

We intend to divulge an easy experiment that permits the determination of molar masses of various compounds by cryoscopy. The major advantage of this is the use of the tert-butyl alcohol as a solvent, which requires simple apparatus and easy procedures. The melting point of this alcohol is around 25 ºC, which makes it easy to freeze and then melt the solutions. This solvent has a high cryoscopic constant and is miscible with both polar and non-polar compounds. The molar masses of acetone, water, chloroform, dichloro-methane, ethanol, hexane, carbon tetrachloride and toluene were determined. The results were good except for water. Even though there are reliable techniques of molar mass determination nowadays, this method is still frequently taught in undergraduate courses.