Reduction of specific energy consumption of a thermomechanical pulping plant

Kuumahiertoprosessi on erittäin energiaintensiivinen prosessi, jonka energianominaiskulutus (EOK) on yleisesti 2–3.5 MWh/bdt. Noin 93 % energiasta kuluu jauhatuksessa jakautuen niin, että kaksi kolmasosaa kuluu päälinjan ja yksi kolmasosa rejektijauhatuksessa. Siksi myös tämän työn tavoite asetettiin vähentämään energian kulutusta juuri pää- ja rejektijauhatuksessa. Päälinjan jauhatuksessa tutkimuskohteiksi valittiin terityksen, tehojaon ja tuotantotason vaikutus EOK:een. Rejektijauhatuksen tehostamiseen pyrittiin yrittämällä vähentää rejektivirtaamaa painelajittelun keinoin. Koska TMP3 laitoksen jauhatuskapasiteettia on nostettu 25 %, tavoite oli nostaa päälinjan lajittelun kapasiteettia saman verran. Toisena tavoitteena oli pienentää rejektisuhdetta pää- ja rejektilajittelussa ja siten vähentää energiankulutusta rejektijauhatuksessa. Näitä tavoitteita lähestyttiin vaihtamalla päälinjan lajittimiin TamScreen-roottorit ja rejektilajittimiin Metso ProFoil-roottorit ja optimoimalla kuitufraktiot sihtirumpu- ja prosessiparametrimuutoksin. Syöttävällä terätyypillä pystyttiin vähentämään EOK:ta 100 kWh/bdt, mutta korkeampi jauhatusintensiteetti johti myös alempiin lujuusominaisuuksiin, korkeampaan ilmanläpäisyyn ja korkeampaan opasiteettiin. Myös tehojaolla voitiin vaikuttaa EOK:een. Kun ensimmäisen vaiheen jauhinta kuormitettiin enemmän, saavutettiin korkeimmillaan 70 kWh/bdt EOK-vähennys. Tuotantotason mittaamisongelmat heikensivät tuotantotasokoeajojen tuloksia siinä määrin, että näiden tulosten perusteella ei voida päätellä, onko EOK tuotantotasoriippuvainen vai ei. Päälinjan lajittelun kapasiteettia pystyttiin nostamaan TS-roottorilla vain 18 % jääden hieman tavoitetasosta. Rejektilajittelussa pystyttiin vähentämään rejektimäärää huomattavasti Metso ProFoil-roottorilla sekä sihtirumpu- ja prosessiparametrimuutoksin. Lajittamokehityksellä saavutettu EOK-vähennys arvioitiin massarejektisuhteen pienentymisen ja rejektijauhatuksessa käytetyn EOK:n avulla olevan noin 130 kWh/bdt. Yhteenvetona voidaan todeta, että tavoite 300 kWh/bdt EOK-vähennyksestä voidaan saavuttaa työssä käytetyillä tavoilla, mikäli niiden täysi potentiaali hyödynnetään tuotannossa.

Raw water use charge reduction for the rural sector in the PCJ Watershed

The deficient environmental preservation on agricultural properties has reflected in great soil losses for erosion and the high rate of sedimentation. Therefore, this work brings the application of software to demonstrate that planters can get benefits by the conservationist practices. The benefits will be obtained from the environment aspect (erosion and sedimentation control), as well as economical aspect (financial incentives). A proposal has been created by the Technical Chamber of Rural Water Use and Conservation (CT-Rural) to estimate the reduction in raw water use charge for the rural water users of the PCJ Watershed - this reduction is being possible since January 2007, at the PCJ Committee. The software develops a simple relationship, so that if the rural conservationist action goes more efficient, such as if the conserved rural area goes larger, then the reduction value will bring better benefits for the rural water users. Within the purposes of this study, there is the idealization of mechanisms that may support specific management matters related to the water users of federal rivers from the rural sector of PCJ Watershed.

Determining the concrete stiffness matrix through ultrasonic testing

The determination of the modulus tangent (Eci ) and of the modulus secant (Ecs) of the concrete can be done using compression test but, to be simpler, it is used relations with characteristic strength (f ck). Relations are also used to determine the transversal modulus (Gc) and, in the case of the Poisson's ratio (ν), a fixed value 0.20 is established. The objective of this research was to evaluate the use of the ultrasonic propagation waves to determine these properties. For the tests were used specimens with f ck varying from 10 to 35 MPa. For the ultrasonic tests were used cylindrical and cubic specimens. The modulus of deformation obtained by ultrasound was statistically equivalent to the obtained by compression tests. The results of modules obtained using the relations with f ck was far away from those obtained by ultrasound or by compression tests. The Poisson's ratio obtained by ultrasound was superior to the fixed value. We can conclude that the concrete characterization by ultrasound is consistent and, to this characterization the cylindrical specimen, normally used to determine f ck, can be used.

Influence of stiffness in bolted connections in wooden plane structure of truss type

Trusses are structural systems commonly used in projects, being employed mainly in roof structures, present in most rural buildings. The design of trusses, as well as other structural systems, requires the determination of displacements, strains and stresses. However, the project is developed from an ideal model of calculation, considering free rotation between the elements of a connection. This paper presents a computer program for the analysis of bidimensional wooden trusses with connections formed with two screws per node. The formulation is based on the flexibility method, taking into account the influence of the effect of semi-rigid connections formed by two screws. An example of a structure is presented and analyzed by the program developed here, highlighting the importance of behavior analysis on semi-rigid connections.

Relative reduction in annual soil loss in micro watersheds due to the relief and forest cover

With the intense debate, in Brazil, between landowners and public agencies about the amount of area with forest cover needed in different regions, there is an increase of the need for provision of technical data used as a basis for decision making. One of the criteria to evaluate the effect of forest cover in protecting water resources is the soil loss, which leads to several consequences on the environment, including the silting of the rivers. Therefore, this study aimed to evaluate the reduction in the soil loss in micro watersheds with different reliefs, size and location of forest cover, in the Corumbataí River watershed, in the state of São Paulo, using the Revised Universal Soil Loss Equation (RUSLE) in a GIS environment. For this study, 18 watersheds in three degrees of slope were selected, and 20 scenarios for land-use were established, by analyzing the influence of the PPA size, and the size and the location of the Legal Reserve. The results showed that: a) the effect of forest cover in reducing annual soil loss varies depending on the average slope of the watershed; b) the PPA width must be determined taking into account the slope of the watershed; c) the Legal Reserve must be located along the PPA. These provide better results in reducing annual soil loss.

Communicative Purposes of Press Releases Announcing Reduction in Workforce

Tämä tutkielma käsittelee kaupallisten yhtiöiden julkaisemia lehdistötiedotteita, joissa ilmoitetaan henkilöstövähennyksistä. Erityisenä tutkimuskohteena ovat lehdistötiedotteiden informatiiviset ja promotionaaliset päämäärät ja tarkoitukset sekä näiden päämäärien ja tarkoitusten ilmentyminen tekstin retorisen rakenteen, valittujen retoristen strategioiden sekä leksikaalisten ja kieliopillisten valintojen kautta. Tutkimuksen aineisto koostuu 50 englanninkielisestä lehdistötiedotteesta, jotka sisältävät ilmoituksen henkilöstövähennyksistä. Lehdistötiedotteet kerättiin yritysten verkkosivuilta. Tutkimuksen teoreettisena viitekehityksenä toimivat soveltavan kielentutkimuksen alalla erityisesti ammattikielentutkimuksessa (ESP, English for Specific Purposes) laajalti käytetty Swalesin (1990) tekstilajia (genre) koskeva määritelmää ja Bhatian (1993) kehittämä geneerisen analyysin malli. Ennen aineiston kielitieteellistä analysointia tutkimuksessa perehdyttiin Bhatian (1993) mallin mukaisesti lehdistötiedotteiden historiaan, kohdeyleisöihin, diskurssiyhteisöön ja sen tuottamiin muihin tekstilajeihin, aikaisempiin lehdistotiedotteita käsitteleviin kielitieteellisiin tutkimuksiin sekä erityisesti yritysten henkilövähennyksiin liittyvään tilannekontekstiin. Kielitieteellisessä analyysissä tutkittavista teksteistä tunnistettiin kahdeksan retorista vaihetta (move), jotka olivat tyypillisiä tutkituille teksteille. Kunkin retorisen vaiheen yksittäiset ilmentymät koottiin yhteen erillisiksi aineistoiksi, joista pyrittiin tunnistamaan kullekin vaiheelle tyypilliset retoriset strategiat sekä toistuvat leksikaaliset ja kieliopilliset valinnat. Tutkimuksessa todettiin, että vaikka tutkittujen lehdistötiedotteiden pääasiallinen tarkoitus oli yhtiön toiminnasta tiedottaminen, niillä oli myös promotionaalinen päämäärä, joka ilmeni mm. pyrkimyksenä välittää yhtiöstä mahdollisimman positiivinen kuva eri kohdeyleisöille, erityisesti sijoittajille. Tämän positiivisen kuvan välittämiseen käytettyjä keinoja olivat mm. odotettavissa olevien saavutusten korostaminen, ulkoisten tekijöiden nimeäminen nykyisen tilanteen aiheuttajaksi, passiivin käyttö sekä erilaiset yrityksen julkisen kuvan säilyttämiseen pyrkivät (face-saving) strategiat.

Identification of flexural stiffness parameters of beams

A three degree of freedom model of the dynamic mass at the middle of a test sample, resembling a Stockbridge neutraliser, is introduced. This model is used to identify the hereby called equivalent complex cross section flexural stiffness (ECFS) of the beam element which is part of the whole test sample. This ECFS, once identified, gives the effective cross section flexural stiffness of the beam as well as its effective damping, measured as the loss factor of an equivalent viscoelastic beam. The beam element of the test sample may be of any complexity, such as a segment of stranded cable of the ACSR type. These data are important parameters for the design of overhead power transmission lines and other cable structures. A cost function is defined and used in the identification of the ECFS. An experiment, designed to measure the dynamic masses of two test samples, is described. Experimental and identified results are presented and discussed.

Identification of Flexural Stiffness Parameters of Beams

A three degree of freedom model of the dynamic mass at the middle of a test sample, resembling a Stockbridge neutraliser, is introduced. This model is used to identify the hereby called equivalent complex cross section flexural stiffness (ECFS) of the beam element which is part of the whole test sample. This ECFS, once identified, gives the effective cross section flexural stiffness of the beam as well as its effective damping, measured as the loss factor of an equivalent viscoelastic beam. The beam element of the test sample may be of any complexity, such as a segment of stranded cable of the ACSR type. These data are important parameters for the design of overhead power transmission lines and other cable structures. A cost function is defined and used in the identification of the ECFS. An experiment, designed to measure the dynamic masses of two test samples, is described. Experimental and identified results are presented and discussed.

An Inspection System to Identify Fatigue Damage on Steel-Bridge Structures

Crack formation and growth in steel bridge structural elements may be due to loading oscillations. The welded elements are liable to internal discontinuities along welded joints and sensible to stress variations. The evaluation of the remaining life of a bridge is needed to make cost-effective decisions regarding inspection, repair, rehabilitation, and replacement. A steel beam model has been proposed to simulate crack openings due to cyclic loads. Two possible alternatives have been considered to model crack propagation, which the initial phase is based on the linear fracture mechanics. Then, the model is extended to take into account the elastoplastic fracture mechanic concepts. The natural frequency changes are directly related to moment of inertia variation and consequently to a reduction in the flexural stiffness of a steel beam. Thus, it is possible to adopt a nondestructive technique during steel bridge inspection to quantify the structure eigenvalue variation that will be used to localize the grown fracture. A damage detection algorithm is developed for the proposed model and the numerical results are compared with the solutions achieved by using another well know computer code.

Reduction of seed production of red rice escapes in clearfield rice

Roguing is a practice used to reduce the seed source of red rice escapes to control in Clearfield-rice areas. However, there is great difficulty in performing it in large and heavily infested rice fields. This objective of this work was to evaluate the effects of the use of imazamox herbicide, applied in different rates and times, on plants of Clearfield-rice and red rice. Four experiments were conducted during the 2007/08 and 2008/09 growing seasons, in completely randomized block design and treatments arranged in factorial design, using three replications per treatment. The treatments had increasing rates of imazamox, application times and rice cultivars. The rice cultivars tested were IRGA 417, IRGA 422 CL, Avaxi CL and Puitá INTA CL. The variables evaluated were the number of panicles m-2, number of grains panicle-1, spikelet sterility in rice and red rice; and, rice grain yield and its components. The imazamox reduced the seed production of red rice escapes in a simulated situation of commercial Clearfield-rice area. The greater percentage reductions were obtained when this herbicide was applied at final formation of the panicle or panicle exertion of the red rice plant escapes to control. The Puitá INTA CL cultivar has high level of resistance to imazamox, independent of rate and application times tested, becoming the only alternative to the use of this practice.

Wind Turbine Direct-Drive Permanent-Magnet Generator with Direct Liquid Cooling for Mass Reduction

Today’s electrical machine technology allows increasing the wind turbine output power by an order of magnitude from the technology that existed only ten years ago. However, it is sometimes argued that high-power direct-drive wind turbine generators will prove to be of limited practical importance because of their relatively large size and weight. The limited space for the generator in a wind turbine application together with the growing use of wind energy pose a challenge for the design engineers who are trying to increase torque without making the generator larger. When it comes to high torque density, the limiting factor in every electrical machine is heat, and if the electrical machine parts exceed their maximum allowable continuous operating temperature, even for a short time, they can suffer permanent damage. Therefore, highly efficient thermal design or cooling methods is needed. One of the promising solutions to enhance heat transfer performances of high-power, low-speed electrical machines is the direct cooling of the windings. This doctoral dissertation proposes a rotor-surface-magnet synchronous generator with a fractional slot nonoverlapping stator winding made of hollow conductors, through which liquid coolant can be passed directly during the application of current in order to increase the convective heat transfer capabilities and reduce the generator mass. This doctoral dissertation focuses on the electromagnetic design of a liquid-cooled direct-drive permanent-magnet synchronous generator (LC DD-PMSG) for a directdrive wind turbine application. The analytical calculation of the magnetic field distribution is carried out with the ambition of fast and accurate predicting of the main dimensions of the machine and especially the thickness of the permanent magnets; the generator electromagnetic parameters as well as the design optimization. The focus is on the generator design with a fractional slot non-overlapping winding placed into open stator slots. This is an a priori selection to guarantee easy manufacturing of the LC winding. A thermal analysis of the LC DD-PMSG based on a lumped parameter thermal model takes place with the ambition of evaluating the generator thermal performance. The thermal model was adapted to take into account the uneven copper loss distribution resulting from the skin effect as well as the effect of temperature on the copper winding resistance and the thermophysical properties of the coolant. The developed lumpedparameter thermal model and the analytical calculation of the magnetic field distribution can both be integrated with the presented algorithm to optimize an LC DD-PMSG design. Based on an instrumented small prototype with liquid-cooled tooth-coils, the following targets have been achieved: experimental determination of the performance of the direct liquid cooling of the stator winding and validating the temperatures predicted by an analytical thermal model; proving the feasibility of manufacturing the liquid-cooled tooth-coil winding; moreover, demonstration of the objectives of the project to potential customers.

Plant height reduction in populations of triticale (X triticosecale Wittmack) by induced mutations and artificial crosses

Induced mutations by gamma radiation (0, 5, 10, 20 and 40 kR doses) and reciprocal crosses were tested as mechanisms of enhancing genetic variability for plant height in two triticale cultivars, BR4 and EMBRAPA18. The reciprocal crosses and all doses of radiation showed similar increase in genetic amplitude for this trait, being suitable for increasing variability in breeding programs. Genotypes showed different responses as the gamma ray doses were increased, expressing shorter plant height. The decision of using induced mutations or artificial crosses depends on the resources available and the selection method to be used

Pre- and postnatal nutrition – target for allergy risk reduction

A rapid increase in allergic diseases in Western societies has led to the conclusion that our modern lifestyle is a risk factor for immune dysregulation. Potential culprits and benefactors are searched among early dietary and microbial exposures, which may act to program later allergic disease. The aim of this thesis was to investigate the role of early maternal and child nutrition in reducing the risk of child allergy. The study population comprised of 256 mother – child pairs from families with a history of allergy participating in a randomized controlled dietary counseling and probiotic intervention (Lactobacillus rhamnosus GG and Bifidobacterium lactis Bb12) study from early pregnancy onwards. The dietary counseling aimed for a diet complying with dietary recommendations for pregnant and lactating women, with special attention to fat quality. Maternal dietary counseling was reflected in cord blood fatty acids suggesting better essential fatty acid status in infants in the counseling group. Dietary counseling with probiotics or placebo had no effect on child allergy risk, but associations between maternal diet during pregnancy and breastfeeding and child allergic outcomes were found in secondary analyses. During pregnancy, milk intake was related to decreased and cheese intake to increased risk of child atopic eczema. During breastfeeding, intake of vitamin C was related to increased risk of asthma and intake of egg was related to decreased risk of atopic eczema. The timing of introduction of complementary foods to infant’s diet was not associated with risk of atopic eczema, when adjusted with parental opinion of child allergic symptoms (i.e., potential reverse causality). In conclusion, the results demonstrate that infant fatty acid supply can be modified via maternal dietary changes. In addition, interesting associations of maternal diet with child allergy risk were discovered. However, no difference in the incidence of allergic diseases with dietary counseling was observed. This suggests that more potent dietary interventions might be necessitated to induce clinical risk reduction of allergy. Highrisk families can safely adhere to dietary recommendations for pregnant and lactating women, and the results support the current conception that no additional benefit is gained with delaying introduction of complementary feeding.