Materiaalihallinnan kehittäminen GA Telesiksellä

Opinnäytetyön aiheena oli etsiä ongelmakohtia materiaalihallinnasta GA Telesis Engine Services Oy:ssä. Huomiota tuli kiinnittää erityisesti korjauskierrolla olevien osien ja laitteiden seurantaan. Päätavoitteena opinnäytetyössä oli kehittää materiaalivirtojen seurantaa siten, ettei yllättäviä materiaalipuutteita esiintyisi kokoonpanojen alkaessa. Opinnäytetyö keskittyi CF6-80 moottorin materiaalivirtojen tutkimiseen. GA Telesis Engine Services Oy:ssä huolletaan ja korjataan käytettyjä suihkumoottoreita. Suihkumoottorikorjaamon materiaalivirtojen suuri volyymi aiheuttaa etenkin materiaalihallinnalle haasteita. Ilmailualalla noudatettavat tiukat laatustandardit vaikuttavat suuresti osien korjauskelpoisuuteen. Kaikkia moottoreista purettuja osia ei voida aina korjata takaisin lentokelpoisiksi. Opinnäytetyö aloitettiin tutustumalla tuotantolaitoksen toimintaan erityisesti materiaalihallinnan näkökulmasta sekä tutustumalla GA Telesiksen käyttämään IFS tietokantajärjestelmään. Ongelmakohtia pyrittiin löytämään seuraamalla yrityksen toimintaa noin puolen vuoden ajan. Ongelmia etsittiin myös haastattelemalla yrityksen eri työpisteiden työntekijöitä. Opinnäytetyössä materiaalien seurantaan kehitettyä Excel-pohjaista järjestelmää parannettiin niin, että riskialtteimmat osat saivat enemmän huomiota. Opinnäytetyön tuloksena korjauskierrolla olevien osien seurannasta saatiin tehokkaampaa ja aiemmin ongelmia aiheuttaneiden osien seurantaa parannettiin. Moottoreiden korjauskierrolla olevien osien seurannan on oltava jatkossa tehokkaampaa ja ongelmakohtiin tulee puuttua mahdollisimman aikaisessa vaiheessa. Kokoonpanojen materiaalien seurantaan kehitettyä Excel-pohjaista järjestelmää tulee jatkossa päivittää säännöllisesti. Etenkin pitkäkestoisiin korjauksiin kiinnitetään jatkossa suurempaa huomiota, jotta kokoonpanojen alkamista ei tarvitse lykätä. Järjestelmä toimii parhaiten silloin, kun tiedonvälitys työpisteiden välillä toimii saumattomasti. Tämän vuoksi tuotanto-palavereja korjauskierrolla olevista osista tulee jatkossa pitää entistä enemmän.The main theme of this thesis was to find potential issues in the material handling process at the GA Telesis Corporation. This work focused specially on parts which were in repair cycle. The main goal was to develop material handling so that there would not be undetected shortages at the beginning of assembly stage. The focus of investigation was on CF6-80 turbofan engine material flow. GA Telesis Corporation overhauls used turbofan engines. A big amount of materials flowing throw the production sets up a challenge especially in terms of material handling. The strict quality standard system in aviation makes part repairs more difficult. That is why parts removed from an engine must be scrapped very often because the result of repair does not measure up to aviation standards. This study was started by a review of the operations of the production facility, especially from a material handling point of view. It was also important to learn how to use IFS database. There was about half a year time to find issues from material handling. Furthermore, a number of people working in the company were interviewed to gain more information on the subject. The Excel-based system for material flow handling was develop so that problematic parts were getting more attention. The end result of this study was better follow-up data for parts in repair cycle. Moreover, parts causing problems to assemblies were also handled better. Previously turbofan engine parts in repair cycle have not been followed accurately enough. The Excel-based material handling system has to be updated regularly in future. Especially parts with long repair cycle must be followed better so that there will not be any delays in assembly starting dates. This system will work the best possible way when communication between different offices is shared without restraint. That is why it is important to have production meetings about unfinished assemblies

Generalized liquid crystals: giant fluctuations and the vestigial chiral order of II, OO and TT matter

The physics of nematic liquid crystals has been subject of intensive research since the late 19th century. However, because of the limitations of chemistry the focus has been centered around uni- and biaxial nematics associated with constituents bearing a $D_{\infty h}$ or $D_{2h}$ symmetry respectively. In view of general symmetries, however, these are singularly special since nematic order can in principle involve any point group symmetry. Given the progress in tailoring nano particles with particular shapes and interactions, this vast family of "generalized nematics" might become accessible in the laboratory. Little is known since the order parameter theories associated with the highly symmetric point groups are remarkably complicated, involving tensor order parameters of high rank. Here we show that the generic features of the statistical physics of such systems can be studied in a highly flexible and efficient fashion using a mathematical tool borrowed from high energy physics: discrete non-Abelian gauge theory. Explicitly, we construct a family of lattice gauge models encapsulating nematic ordering of general three dimensional point group symmetries. We find that the most symmetrical "generalized nematics" are subjected to thermal fluctuations of unprecedented severity. As a result, novel forms of fluctuation phenomena become possible. In particular, we demonstrate that a vestigial phase carrying no more than chiral order becomes ubiquitous departing from high point group symmetry chiral building blocks, such as $I$, $O$ and $T$ symmetric matter.Comment: 14 pages, 5 figures; published versio

Dual gauge field theory of quantum liquid crystals in two dimensions

We present a self-contained review of the theory of dislocation-mediated quantum melting at zero temperature in two spatial dimensions. The theory describes the liquid-crystalline phases with spatial symmetries in between a quantum crystalline solid and an isotropic superfluid: quantum nematics and smectics. It is based on an Abelian-Higgs-type duality mapping of phonons onto gauge bosons ("stress photons"), which encode for the capacity of the crystal to propagate stresses. Dislocations and disclinations, the topological defects of the crystal, are sources for the gauge fields and the melting of the crystal can be understood as the proliferation (condensation) of these defects, giving rise to the Anderson-Higgs mechanism on the dual side. For the liquid crystal phases, the shear sector of the gauge bosons becomes massive signaling that shear rigidity is lost. Resting on symmetry principles, we derive the phenomenological imaginary time actions of quantum nematics and smectics and analyze the full spectrum of collective modes. The quantum nematic is a superfluid having a true rotational Goldstone mode due to rotational symmetry breaking, and the origin of this 'deconfined' mode is traced back to the crystalline phase. The two-dimensional quantum smectic turns out to be a dizzyingly anisotropic phase with the collective modes interpolating between the solid and nematic in a non-trivial way. We also consider electrically charged bosonic crystals and liquid crystals, and carefully analyze the electromagnetic response of the quantum liquid crystal phases. In particular, the quantum nematic is a real superconductor and shows the Meissner effect. Their special properties inherited from spatial symmetry breaking show up mostly at finite momentum, and should be accessible by momentum-sensitive spectroscopy.Comment: Review article, 137 pages, 32 figures. Accepted versio

Risk Factors and Prognosis for Metastatic Cutaneous Squamous Cell Carcinoma: A Cohort Study

Cutaneous squamous cell carcinoma (cSCC) has me-tastatic potential. The aims of this study were to identify the risk factors for metastasis of primary cSCC and for poor prognosis in metastatic cSCC. Retrospective primary tumour cohorts of metastatic cSCCs (n = 85) and non-metastatic cSCCs (n = 218) were analysed. The mean annual rate of metastasis for primary cSCCs was 2.28%. In 49.4% of patients with metastatic cSCC, metastasis was detected within 6 months of diagnosis of the primary cSCC. There was no prior history of cSCC in 84.7% of metastatic cSCCs. Risk factors for metastasis included Clark's level 5, tumour diameter 20-29.9 mm, age at diagnosis = 3 nodal metastases and extranodal extension of metastasis. These results characterise new risk factors for metastatic cSCC

Complement Factor D Is a Novel Biomarker and Putative Therapeutic Target in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the most prevalent metastatic skin cancer. Previous studies have demonstrated the autocrine role of complement components in cSCC progression. We have investigated factor D (FD), the key enzyme of the alternative complement pathway, in the development of cSCC. RT-qPCR analysis of cSCC cell lines and normal human epidermal keratinocytes (NHEKs) demonstrated significant up-regulation of FD mRNA in cSCC cells compared to NHEKs. Western blot analysis also showed more abundant FD production by cSCC cell lines. Significantly higher FD mRNA levels were noted in cSCC tumors than in normal skin. Strong tumor cell-associated FD immunolabeling was detected in the invasive margin of human cSCC xenografts. More intense tumor cell-specific immunostaining for FD was seen in the tumor edge in primary and metastatic cSCCs, in metastases, and in recessive dystrophic epidermolysis bullosa-associated cSCCs, compared with cSCC in situ, actinic keratosis and normal skin. FD production by cSCC cells was dependent on p38 mitogen-activated protein kinase activity, and it was induced by interferon-γ and interleukin-1β. Blocking FD activity by Danicopan inhibited activation of extracellular signal-regulated kinase 1/2 and attenuated proliferation of cSCC cells. These results identify FD as a novel putative biomarker and therapeutic target for cSCC progression

Local height probabilities in a composite Andrews-Baxter-Forrester model

We study the local height probabilities in a composite height model, derived from the restricted solid-on-solid model introduced by Andrews, Baxter and Forrester, and their connection with conformal field theory characters. The obtained conformal field theories also describe the critical behavior of the model at two different critical points. In addition, at criticality, the model is equivalent to a one-dimensional chain of anyons, subject to competing two- and three-body interactions. The anyonic-chain interpretation provided the original motivation to introduce the composite height model, and by obtaining the critical behaviour of the composite height model, the critical behaviour of the anyonic chains is established as well. Depending on the overall sign of the hamiltonian, this critical behaviour is described by a diagonal coset-model, generalizing the minimal models for one sign, and by Fateev-Zamolodchikov parafermions for the other.Comment: 34 pages, 5 figures; v2: expanded introduction, references added and other minor change

Sustainability analysis of Finnish pre-schoolers' diet based on targets of the EAT-Lancet reference diet

Purpose The EAT-Lancet reference diet is a healthy plant-based diet produced within planetary boundaries. To inform the food system transformation, we compared Finnish pre-schoolers' food consumption with the reference diet's food group targets. Methods Food record data for 3- to 6-year-old pre-schoolers were collected in the cross-sectional DAGIS survey. Ingredients of composite dishes were available in the data. In addition, we manually decomposed industrial products such as sausages and biscuits by estimating the shares of ingredients. We also estimated the consumption of added sugars and converted the consumption of dairy products into milk equivalents. We used usual intake modelling to estimate the mean consumption and the proportion of children who met the reference diet's targets. We set the target amounts separately for 3- to 4-year-olds and 5- to 6-year-olds in grams by proportioning the published target amounts (assuming a 2500 kcal diet) to the children's mean reported energy intake. Results For both age groups (3- to 4-year-olds, n = 460; 5- to 6-year-olds, n = 402), the daily mean consumption of whole grains, vegetables, legumes, nuts, and unsaturated oils was below targets, whereas the consumption of red meat, dairy foods, tubers, and added sugars was above targets. The consumption of fruit and fish was in line with targets. Conclusion To comply with the reference diet's targets, major changes in the diets of Finnish children are needed. The key food groups targeted for higher consumption are whole grains and legumes and targeted for lower consumption red meat and dairy products.Peer reviewe