Painehiomon tuotantokapasiteetin lisäyksen vaikutus painehiokkeen laatuominaisuuksiin

Diplomityön keskeisenä tavoitteena oli selvittää painehiomon tuotantokapasiteetin lisäyksen vaikutus painehiokkeen laatuominaisuuksiin. Tarkasteltavina painehiomon tuotanto-kapasiteettiin vaikuttavina tekijöinä olivat painehiomakoneen suihkuveden lämpötilan lasku sekä uuden rejektijauhimen käyttöönotto. Painehiomakoneen suihkuveden lämpötilan lasku 95 ºC:sta 70 ºC:een toteutettiin kahden viikon mittaisena koeajona. Tarkoituksena oli selvittää painehiontaprosessissa ja painehiokkeen sekä paperin laadussa tapahtuva muutos. PGW70-koeajolla saavutettiin mahdollisuus nostaa tuotantonopeutta hiomakivillä silti kuormittamatta liiaksi lajittelua ja rejektinkäsittelyä. Tarkasteltaessa painehiokkeen laatua PGW70-koeajossa kiteytyi tapahtunut laatumuutos lyhentyneestä kuidun pituudesta aiheutu-neeksi. Havaittiin, että alentamalla hiontalämpötilaa on mahdollista saavuttaa paremmat painehiokkeen pinta- ja optiset ominaisuudet lujuusominaisuuksien heiketessä hieman. Rejektijauhimen käyttöönottoon liittyvien tarkasteluiden tavoitteena oli selvittää uuden rejektijauhimen käyttöönoton myötä painehiokkeessa mahdollisesti tapahtuva laatumuutos. Lisäksi haluttiin tarkastella jauhetun rejektin laatuominaisuuksia rejektijauhimen energian ominaiskulutuksen eri tasoilla ja mahdollisuutta siirtää kuidutuksen painopistettä hiomakiviltä rejektijauhatukseen nostamalla kivenalusfreenestä. Varsinaisessa rejektijauhimen käyttöönottovaiheessa ei painehiokkeen laatumuutosta ollut havaittavissa. Rejektijauhimen kuormituskoeajossa ajettiin rejektijauhimella 2 koesarjaa, matalalla ja korkealla kivenalusfreeneksellä, kasvattaen rejektijauhimen EOK:a. Lisä-muuttujaksi koeajossa muodostui tahattomasti jauhatussakeus. Koejossa paras kuidun muokkau-tuvuus saavutettiin alhaisemmalla kivenalusfreeneksellä (130-140 ml) ja jauhatussakeudella (alle 40 %) korkeimmalla saavutetulla EOK:lla eli 0,80 MWh/t. Korkealla kivenalusfreeneksellä ja jauhatussakeudella tapahtunut jauhatus osoittautui kuituja katkovaksi. Karkeaan painehiokerejektiin tulisi kohdistaa huomattavasti enemmän jauhatusenergiaa kuin koeajossa oli mahdollista. Ongelmaksi siis muodostui rejektijauhimen heikko kuormitettavuus, jota tulee parantaa esimerkiksi terävalinnoin.

Hydrodynamics and Heat Transfer in an Airlift Reactor

Työn teoriaosassa esitetään kirjallisuudessa esiintyviä teoreettisia ja kokeellisia yhtälöitä nesteen nopeuden, kaasun tilavuusosuuden, painehäviön ja lämmönsiirron laskemiseksi. Lisäksi käsitellään airlift-reaktoreiden toimintaa, rakennetta ja teollisia sovelluksia, sekä sekoitusta ja geometrian vaikutusta airlift-reaktoreiden hydrodynaamisiin ominaisuuksiin. Kokeellisessa osassa kuvataan käytetty koelaitteisto ja mittausmenetelmät sekä esitetään saadut koetulokset. Koelaitteisto on viidellä nousuputkella varustettu ulkoisen kierron airlift-reaktori. Kokeellisessa osassa pyritään ratkaisemaan tällaisessa reaktorissa mahdollisesti esiintyviä ongelmia, kuten "slug flown" muodostuminen nousuputkissa sekä fluidien epätasainen jakautuminen nousuputkiin. Lisäksi tutkitaan erilaisten muuttujien, kuten kaasun tilavuusvirran, nesteen viskositeetin, suutinkoon ja nesteen jakoputken rakenteen, vaikutusta kaasun tilavuusosuuteen ja nesteen nopeuteen nousuputkissa. Nesteen nopeudet mitataan merkkiainemenetelmällä ja kaasun tilavuusosuudet manometrimenetelmällä. Lämmönsiirtoa tutkitaan mittaamalla lämpötilaeroja nousuputkissa NiCr-Ni –termoelementeillä. Mittaustulosten perusteella muokataan korrelaatiot kaasun tilavuusosuudelle ja nesteen tyhjäputkinopeudelle. Korrelaatioista lasketut tulokset sopivat kohtuullisen hyvin yhteen mitattujen tulosten kanssa. "Slug flown" ei todettu muodostuvan ongelmaksi 2.5 mPa s pienemmillä viskositeetin arvoilla 2 metriä pitkissä ja 19 mm halkaisijaltaan olevissa putkissa. Lisäksi todettiin, että kaasu- ja nestefaasien jakautumisongelmat voidaan ratkaista rakenteellisesti.

GROWTH, YIELD AND POSTHARVEST QUALITY OF WAX APPLE AS AFFECTED BY NAPHTHALENE ACETIC ACID APPLICATION

Results of this study represent the first report of the effect of Naphthalene Acetic Acid (NAA) on the pre and post harvest quality of wax apple fruit. The wax apple trees were spray treated with 0, 5, 10 and 20 mg L-1 NAA under field conditions during 2008 to 2011. The experiments were carried out in Completely Randomized Design (CRD) with six replications. Leaf chlorophyll content, chlorophyll fluorescence, photosynthetic yield, net photosynthetic rate, drymatter content of leaves and total soluble solids and K+content of wax apple fruits were significantly increased after treatments with 10 mg L-1. Polygalacturonase activity significantly decreased with NAA treatments. The application of 5 mg L-1 NAA increased 27% more bud and reduced 42% less fruit drop compared to the control. In addition, higher protein and phosphate synthase activity of leaves, fruit set, fruit growth, larger fruit size and yield were recorded in NAA treated plants. In storage, treated fruits exhibited higher TSS and firmness and less weight loss, browning, titratable acidity, respiration and ethylene production than the control. It is concluded that spraying with 5 and 10 mg L-1 NAA once a week under field conditions produced better fruit growth and yield of the wax apple and maintained better fruit quality in postharvest storage.

PIENEN OSAKEYHTIÖN TILINPÄÄTÖKSEEN LIITTYVIEN KIRJANPITOLAIN JA –ASETUKSEN MUKAISTEN PAKOLLISTEN LIITETIETOJEN MUUTOKSET 1990-LUVULLA

Tutkimuksen tavoite oli selvittää, miten kirjanpitolainsäädännön muutokset 1990-luvulla ovat vaikuttaneet pienen osakeyhtiön tilinpäätöksen selventämiseksi annettavien liitetietojen esittämiseen, niiden määrään sekä esityspaikkaan. Tutkimus tehtiin käyttämällä pitkittäistarkastelua. Tutkimusaineisto koostui tutkimuskohteesta johtuen pääasiassa vuosien 1973 ja 1997 kirjanpitolaeista ja –asetuksista sekä niitä tulkitsevista ja täydentävistä kotimaisista teoksista. Muutoksia tutkittiin vertailemalla tutkimuskauden aikana voimassa olleita kirjanpitoon liittyviä säädöksiä keskenään siten, että tarkasteltiin mitä on tullut lisää ja mitä poistunut lainsäädännön vaatimuksista. Lakimuutoksia tarkasteltiin 23.8.2001 saakka. Pienen osakeyhtiön tilinpäätökseen liittyvien pakollisten liitetietojen määrä lisääntyi tutkimuskauden aikana merkittävästi. Muutosten seurauksena tilinpäätöksen informaatioarvo yritysten sidosryhmille kasvoi olennaisesti, mutta itse kirjanpitovelvolliselle lainsäädännön muutokset toivat huomattavasti lisävelvoitteita.

Microscopic-macroscopic approach for binding energies with the Wigner-Kirkwood method

The semiclassical Wigner-Kirkwood ̄h expansion method is used to calculate shell corrections for spherical and deformed nuclei. The expansion is carried out up to fourth order in ̄h. A systematic study of Wigner-Kirkwood averaged energies is presented as a function of the deformation degrees of freedom. The shell corrections, along with the pairing energies obtained by using the Lipkin-Nogami scheme, are used in the microscopic-macroscopic approach to calculate binding energies. The macroscopic part is obtained from a liquid drop formula with six adjustable parameters. Considering a set of 367 spherical nuclei, the liquid drop parameters are adjusted to reproduce the experimental binding energies, which yields a root mean square (rms) deviation of 630 keV. It is shown that the proposed approach is indeed promising for the prediction of nuclear masses.

Prevalence of Acute Coronary Syndrome in Patients Suspected for Pulmonary Embolism or Acute Aortic Syndrome: Rationale for the Triple Rule-out Concept.

BACKGROUND: The aims of the study were to evaluate the prevalence of acute coronary syndrome (ACS) among patients presenting with atypical chest pain who are evaluated for acute aortic syndrome (AAS) or pulmonary embolism (PE) with computed tomoangiography (CTA) and discuss the rationale for the use of triple rule-out (TRO) protocol for triaging these patients. METHODS: This study is a retrospective analysis of patients presenting with atypical chest pain and evaluated with thoracic (CTA), for suspicion of AAS/PE. Two physicians reviewed patient files for demographic characteristics, initial CT and final clinical diagnosis. Patients were classified according to CTA finding into AAS, PE and other diagnoses and according to final clinical diagnosis into AAS, PE, ACS and other diagnoses. RESULTS: Four hundred and sixty-seven patients were evaluated: 396 (84.8%) patients for clinical suspicion of PE and 71 (15.2%) patients for suspicion of AAS. The prevalence of ACS and AAS was low among the PE patients: 5.5% and 0.5% respectively (P = 0.0001), while the prevalence of ACS and PE was 18.3% and 5.6% among AAS patients (P = 0.14 and P = 0.34 respectively). CONCLUSION: The prevalence of ACS and AAS among patients suspected clinically of having PE is limited while the prevalence of ACS and PE among patients suspected clinically of having AAS is significant. Accordingly patients suspected for PE could be evaluated with dedicated PE CTA while those suspected for AAS should still be triaged using TRO protocol.

Singling out individual inventors from patent data

An increasing number of studies in recent years have sought to identify individual inventors from patent data. A variety of heuristics have been proposed for using the names and other information disclosed in patent documents to establish who is who in patents. This paper contributes to this literature by describing a methodology for identifying inventors using patents applied to the European Patent Office, EPO hereafter. As in much of this literature, we basically follow a threestep procedure : 1- the parsing stage, aimed at reducing the noise in the inventor’s name and other fields of the patent; 2- the matching stage, where name matching algorithms are used to group similar names; and 3- the filtering stage, where additional information and various scoring schemes are used to filter out these similarlynamed inventors. The paper presents the results obtained by using the algorithms with the set of European inventors applying to the EPO over a long period of time.

Bernoulli correction to viscous losses: Radial flow between two parallel discs

For a massless fluid (density = 0), the steady flow along a duct is governed exclusively by viscous losses. In this paper, we show that the velocity profile obtained in this limit can be used to calculate the pressure drop up to the first order in density. This method has been applied to the particular case of a duct, defined by two plane-parallel discs. For this case, the first-order approximation results in a simple analytical solution which has been favorably checked against numerical simulations. Finally, an experiment has been carried out with water flowing between the discs. The experimental results show good agreement with the approximate solution

Effects of medium on nuclear properties in multifragmentation

In multifragmentation of hot nuclear matter, properties of fragments embedded in a soup of nucleonic gas and other fragments should be modified as compared with isolated nuclei. Such modifications are studied within a simple model where only nucleons and one kind of heavy nuclei are considered. The interaction between different species is described with a momentum-dependent two-body potential whose parameters are fitted to reproduce properties of cold isolated nuclei. The internal energy of heavy fragments is parametrized according to a liquid-drop model with density- and temperature-dependent parameters. Calculations are carried out for several subnuclear densities and moderate temperatures, for isospin-symmetric and asymmetric systems. We find that the fragments get stretched due to interactions with the medium and their binding energies decrease with increasing temperature and density of nuclear matter.

Internet press releases : informative or manipulative?

Una anàlisi de la difusió voluntària de dades o la seva gestió discreta en els Comunicats de Premsa i la importància de la presentació de resultats anuals. L¿exemple del context espanyol: cost de regulació i litigi.

Aetiologies of pulseless electrical activity in out-of-hospital cardiac arrests:A retrospective study and analysis of specific causes

Background: Pulseless electrical activity (PEA) cardiac arrest is defined as a cardiac arrest (CA) presenting with a residual organized electrical activity on the electrocardiogram. In the last decades, the incidence of PEA has regularly increased, compared to other types of CA like ventricular fibrillation or pulseless ventricular tachycardia. PEA is frequently induced by reversible conditions. The "4 (or 5) H" & "4 (or 5) T" are proposed as a mnemonic to asses for Hypoxia, Hypovolemia, Hypo- /Hyperkalaemia, Hypothermia, Thrombosis (cardiac or pulmonary), cardiac Tamponade, Toxins, and Tension pneumothorax. Other pathologies (intracranial haemorrhage, severe sepsis, myocardial contraction dysfunction) have been identified as potential causes for PEA, but their respective probability and frequencies are unclear and they are not yet included into the resuscitation guidelines. The aim of this study was to analyse the aetiologies of PEA out-of-hospital CA, in order to evaluate the relative frequencies of each cause and therefore to improve the management of patients suffering a PEA cardiac arrest. Method: This retrospective study was based on data routinely and prospectively collected for each PEMS intervention. All adult patients treated from January 1st 2002 to December 2012 31st by the PEMS for out-of-hospital cardiac arrest, with PEA as the first recorded rhythm, and admitted to the emergency department (ED) of the Lausanne University Hospital were included. The aetiologies of PEA cardiac arrest were classified into subgroups, based on the classical H&T's classification, supplemented by four other subgroups analysis: trauma, intra-cranial haemorrhage (ICH), non-ischemic cardiomyopathy (NIC) and undetermined cause. Results: 1866 OHCA were treated by the PEMS. PEA was the first recorded rhythm in 240 adult patients (13.8 %). After exclusion of 96 patients, 144 patients with a PEA cardiac arrest admitted to the ED were included in the analysis. The mean age was 63.8 ± 20.0 years, 58.3% were men and the survival rate at 48 hours was 29%. 32 different causes of OHCA PEA were established for 119 patients. For 25 patients (17.4 %), we were unable to attribute a specific cause for the PEA cardiac arrest. Hypoxia (23.6 %), acute coronary syndrome (12.5%) and trauma (12.5 %) were the three most frequent causes. Pulmonary embolism, Hypovolemia, Intoxication and Hyperkaliemia occurs in less than 10% of the cases (7.6 %, 5.6 %, 3.5%, respectively 2.1 %). Non ischemic cardiomyopathy and intra-cranial haemorrhage occur in 8.3 % and 6.9 %, respectively. Conclusions: According to our results, intra-cranial haemorrhage and non-ischemic cardiomyopathy represent noticeable causes of PEA in OHCA, with a prevalence equalling or exceeding the frequency of classical 4 H's and 4 T's aetiologies. These two pathologies are potentially accessible to simple diagnostic procedures (native CT-scan or echocardiography) and should be included into the 4 H's and 4 T's mnemonic.

Effect of tow-drop gaps on the damage resistance and tolerance of Variable-Stiffness Panels

This paper presents an experimental study of the effects of tow-drop gaps in Variable Stiffness Panels under drop-weight impact events. Two different configurations, with and without ply-staggering, have been manufactured by Automated Fibre Placement and compared with their baseline counterpart without defects. For the study of damage resistance, three levels of low velocity impact energy are generated with a drop-weight tower. The damage area is analysed by means of ultrasonic inspection. Results of the analysed defect configurations indicate that the influence of gap defects is only relevant under small impact energy values. However, in the case of damage tolerance, the residual compressive strength after impact does not present significant differences to that of conventional straight fibre laminates. This indicates that the strength reduction is driven mainly by the damage caused by the impact event rather than by the influence of manufacturing-induced defects