193 research outputs found

    Kerrostalokohteen itselleluovutuksen kehittäminen

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    Tämän opinnäytetyön tavoitteena oli kehittää viimeistelyvaiheen itselleluovuttamista pääurakoitsijan näkökulmasta. Itselleluovutuksella on suuri merkitys lopputuotteen laadunvarmistukseen. Kohteen onnistunut luovutus säästää kustannuksia huomattavasti sekä parantaa yrityksen imagoa. Työssä käytettiin aineistona olemassa olevaa kirjallisuutta, aiheeseen liittyviä tutkimuksia ja omia kokemuksia itselleluovutuksesta. Työtä varten käytiin myös keskusteluita kahden työmaan toimihenkilöiden kanssa ja vierailemalla itse kohteessa. Työn tuloksena todettiin, että prosessi voi olla raskas ja aikaa vievä. Joten itselleluovuttamisen täytyy olla systemaattista sekä hyvin organisoitua. Haastatteluissa kävi ilmi, että aliurakoitsijoiden itselleluovuttaminen on usein puutteellisia tai ne ajoitetaan liian myöhäiseksi, sekä niitä ei edes aina vaadita työmaalla tarpeeksi. Tablettien, eli kämmentietokoneiden tulemista työmaille pidettiin potentiaalisena helpotuksena prosessissa, kun itse kohteessa voidaan kirjata viat ja puutteet suoraan sähköiseen muotoon. Työssä avattiin prosessin eri vaiheita ja pyrittiin tuomaan esille työmaan kannalta olennaisia asioita helpottamaan tätä prosessia.The aim of this thesis was to develop the self-inspection of the finishing phase from the main contractor's perspective. Pre-handover self-inspection is of great importance to quality assurance of the final product. A successful handover saves costs significantly and improves the company's image. In this thesis, the used material was the existing literature, related studies and own experiences of pre-handover self-inspection. There were also two conversations with site employees and a visit to the site itself that provided relevant information for the study. As a result, it was concluded that the process can be cumbersome and time-consuming. So self-inspection must be systematic and well organized. The interviews revealed that the subcontractor’s self-inspection is often incomplete or scheduled too late, and they are not even always required at the site. Tablets have the potential to ease the process as defects can then be recorded directly in electronic format. The thesis discusses the various stages of the process and aims to identify the issues that ease the process from the site perspective

    Steam Oxidation of Aluminide-Coated and Uncoated TP347HFG Stainless Steel under Atmospheric and Ultra-Supercritical Steam Conditions at 700 °C

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    The efficiency of ultra-supercritical (USC) steam power plants is limited by the materials properties, in particular, the steam oxidation resistance of the currently used steels at temperatures higher than 600 °C. Under these conditions, steam oxidation results in the development of thick oxide scales which spall and can accumulate in tube bends leading to blockage, overheating and premature creep rupture, as well as erosion of downstream components such as steam valves and turbine blades. Most published work related to oxidation testing is carried out at atmospheric pressure, with significantly less testing of austenitic steels in supercritical steam, and rarely including protective coatings. Indeed, the effect of high-pressure steam in the oxidation process is not quite understood at present. This paper covers a comparison of the behaviour of TP347HFG stainless steel at 700 °C under atmospheric pressure and 25 MPa, with and without slurry-applied diffusion aluminide coatings. The results show a very protective behaviour of the aluminide coatings, which develop a very thin Al-rich protective oxide, and no significant difference between the two environments. In contrast, the uncoated steel exhibited a different behaviour. Indeed, under atmospheric pressure after 3000 h, very thin scales, rich in Cr and not surpassing 5 to 10 µm in thickness, covered the samples along with some much thicker Fe-rich oxide nodules (up to 150 µm). However, under 25 MPa, a thick multilayer scale with a non-homogeneous thickness oscillating between 10 to 120 µm was present. A microstructural investigation was undertaken on the oxidised uncoated and coated substrates. The results suggest that pressure increases the oxidation rate of the chromia former steels but that the oxidation mechanism remains the same. A mechanism is proposed, including early detachment of the outer growing scales under supercritical pressure

    Size-dependent filling effect of crystalline celluloses in structural engineering of composite oleogels

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    Oleogels are a class of solid-fat mimetics that contain a large fraction of oil. Most of these materials have low stiffness and poor oil-binding capacity at commercially viable concentrations, which limits their application in the food and cosmetic industries. To improve their mechanical behavior, we exploited the concepts of particulate-filled materials by developing oil-continuous monoglyceride composites reinforced with crystalline cellulose of various sizes. Cellulose was used as the reinforcing filler material due to its strength, biodegradability, and abundance. The composites gradually stiffened and became more brittle with a progressive increase of the cellulose weight fraction as the maximum packing fraction of fillers approached. This was manifested as an increase in the viscoelastic moduli and yield stress, consistent with the size of the filler. Based on differential scanning calorimetry, X-ray diffraction, X-ray scattering analyses, and microscopic analyses, the inert surface of crystalline celluloses provided a solid substrate for the crystallization of monoglycerides, favoring the lamellar stacking of monoglyceride molecules during the composite oleogel formation regardless of the cellulose size. The present study suggests that cellulose is a suitable bio-based filler material to obtain mechanically strong oleogels suitable for high-shear applications e.g., in food and pharmaceutical industries.Peer reviewe

    Puukerrostalon työmaavaiheen lämpö- ja kosteusolosuhteiden mittaukset

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    Puukerrostalorakentamisen kosteudenhallinta

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    The PNPLA3-I148M Variant Confers an Antiatherogenic Lipid Profile in Insulin-resistant Patients

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    Context: The I148M (rs738409-G) variant in PNPLA3 increases liver fat content but may be protective against cardiovascular disease. Insulin resistance (IR) amplifies the effect of PNPLA3-I148M on liver fat. Objective: To study whether PNPLA3-I148M confers an antihyperlipidemic effect in insulin-resistant patients. Design: Cross-sectional study comparing the impact of PNPLA3-I148M on plasma lipids and lipoproteins in 2 cohorts, both divided into groups based on rs738409-G allele carrier status and median HOMA-IR. Setting: Tertiary referral center. Patients: A total of 298 obese patients who underwent a liver biopsy during bariatric surgery (bariatric cohort: age 49 +/- 9 years, body mass index [BMI] 43.2 +/- 6.8 kg/m(2)), and 345 less obese volunteers in whom liver fat was measured by proton magnetic resonance spectroscopy (nonbariatric cohort: age 45 +/- 14 years, BMI 29.7 +/- 5.7 kg/m(2)). Main Outcome Measures: Nuclear magnetic resonance profiling of plasma lipids, lipoprotein particle subclasses and their composition. Results: In both cohorts, individuals carrying the PNPLA3-I148M variant had significantly higher liver fat content than noncarriers. In insulin-resistant and homozygous carriers, PNPLA3-I148M exerted a distinct antihyperlipidemic effect with decreased very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) particles and their constituents, and increased high-density lipoprotein particles and their constituents, compared with noncarriers. VLDL particles were smaller and LDL particles larger in PNPLA3-I148M carriers. These changes were geometrically opposite to those due to IR. PNPLA3-I148M did not have a measurable effect in patients with lower IR, and its effect was smaller albeit still significant in the less obese than in the obese cohort. Conclusions: PNPLA3-I148M confers an antiatherogenic plasma lipid profile particularly in insulin-resistant individuals.Peer reviewe

    Assessment of Lifestyle Factors Helps to Identify Liver Fibrosis Due to Non-Alcoholic Fatty Liver Disease in Obesity

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    Only some individuals with obesity develop liver fibrosis due to non-alcoholic fatty liver disease (NAFLD-fibrosis). We determined whether detailed assessment of lifestyle factors in addition to physical, biochemical and genetic factors helps in identification of these patients. A total of 100 patients with obesity (mean BMI 40.0 ± 0.6 kg/m2) referred for bariatric surgery at the Helsinki University Hospital underwent a liver biopsy to evaluate liver histology. Physical activity was determined by accelerometer recordings and by the Modifiable Activity Questionnaire, diet by the FINRISK Food Frequency Questionnaire, and other lifestyle factors, such as sleep patterns and smoking, by face-to-face interviews. Physical and biochemical parameters and genetic risk score (GRS based on variants in PNPLA3, TM6SF2, MBOAT7 and HSD17B13) were measured. Of all participants 49% had NAFLD-fibrosis. Independent predictors of NAFLD-fibrosis were low moderate-to-vigorous physical activity, high red meat intake, low carbohydrate intake, smoking, HbA1c, triglycerides and GRS. A model including these factors (areas under the receiver operating characteristics curve (AUROC) 0.90 (95% CI 0.84–0.96)) identified NAFLD-fibrosis significantly more accurately than a model including all but lifestyle factors (AUROC 0.82 (95% CI 0.73–0.91)) or models including lifestyle, physical and biochemical, or genetic factors alone. Assessment of lifestyle parameters in addition to physical, biochemical and genetic factors helps to identify obese patients with NAFLD-fibrosis

    Käypä hoito -suosituksen fibroosilaskureiden toimivuus lihavien rasvamaksatautipotilaiden edenneen fibroosin selvittelyssä

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    JOHDANTO : Rasvamaksatautipotilaiden edenneen fibroosin tunnistaminen on tärkeää vakavien maksakomplikaatioiden ehkäisyssä. Käypä hoito -suosituksessa käytetään Fibrosis-4- (FIB-4) ja NAFLD Fibrosis Score (NFS) -fibroosilaskureita kaksiportaisesti. Selvitimme, miten Käypä hoito -algoritmin kaksiportainen seulonta toimii edenneen fibroosin selvittelyssä verrattuna yleisesti suositellun pelkän FIB-4:n käyttöön. MENETELMÄT : Tutkimukseen osallistui 401 lihavaa potilasta, joille tehtiin kliinisen tutkimuksen lisäksi maksabiopsia. Potilaille laskettiin FIB-4- ja NFS-riskipisteet, ja niiden osuvuutta tunnistaa maksabiopsialla varmistettu edennyt fibroosi arvioitiin. TULOKSET : Maksabiopsiassa ilmeni rasvamaksatauti 64 %:lla ja edennyt fibroosi 5 %:lla potilaista. Käypä hoito -algoritmi ohjasi jatkotutkimuksiin 76 potilasta eli merkitsevästi vähemmän kuin pelkkä FIB-4 (129 potilasta, p < 0,001). Algoritmi ja pelkkä FIB-4 tunnistivat edenneen fibroosin yhtä hyvin (18/20 vs 15/20 potilasta, p = 0,41). PÄÄTELMÄT : Käypä hoito -algoritmin mukainen lihavien potilaiden edenneen fibroosin kaksiportainen seulonta vähentää turhia lähetteitä jatkotutkimuksiin verrattuna pelkän FIB-4:n käyttöön.Peer reviewe
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