1,257 research outputs found
POtenzialità della tecnica EIS per il rilievo del degrado delle barriere termiche sottoposte a prove di ossidazione ciclica
reserved3Questo lavoro è dedicato allo studio dell’evoluzione dei rivestimenti tipici delle parti calde delle turbine a gas,
costituiti da uno strato metallico e da uno ceramico di zirconia parzialmente stabilizzata con ittria, con funzione di barriera termica. Vengono dapprima mostrati i risultati di una campagna sperimentale svolta su campioni invecchiati in prove di ossidazione ciclica a due diverse temperature e sottoposti ad analisi metallografiche per individuare i meccanismi di degrado indotti dall’esposizione alle elevate temperature e dall’azione di ripetuti cicli termici. Viene poi presa in esame la possibilità di applicare una tecnica di controllo non distruttivo
(la spettroscopia d’impedenza elettrochimica) per rilevare il grado crescente di danneggiamento. La variazione degli spettri d’impedenza ottenuti ha confermato la sensibilità della tecnica allo spessore dello strato ceramico, alle sue caratteristiche (porosità e microcriccatura) e alla formazione dello strato di ossido all’interfaccia metallo/ceramico. I risultati ottenuti vengono discussi alla luce delle analisi metallografiche quantitative e delle
informazioni reperibili in letteratura. Si suggeriscono infine alcune linee di ulteriore sviluppo.A. Lapina; M. Bestetti; C. RinaldiA., Lapina; Bestetti, Massimiliano; C., Rinald
Electroless and Electrochemical Deposition of Metallic Coatings on Magnesium Alloys Critical Literature Review
GENOME WIDE ANALYSIS IN A COHORT OF 46,XX PATIENTS AFFECTED BY AN EXTREME PHENOTYPE OF PRIMARY OVARIAN INSUFFICIENCY: AN EFFICIENT TOOL TO IDENTIFY NEW GENES INVOLVED IN OOCYTE MATURATION AND DIFFERENTIATION
Primary Ovarian Insufficiency (POI) is a heterogeneous group of disorders with an incidence of 1:10,000 women by age 20, 1:1,000 by age 30, 1:100 by age 40. POI describes the progression toward the cessation of ovarian function and can occur in the most serious form as primary amenorrhea (PA), with absent pubertal development and/or ovarian dysgenesis (OD), or in milder phenotype with post-pubertal onset and secondary amenorrhea (SA). Several are the etiological causes that may induce ovarian dysfunction, among which the genetic component is considered prevalent (as supported by the occurrence of families with more than one affected women and the existence of several idiopathic cases) but highly heterogeneous.
46,XX non-syndromic women showing the most severe phenotype, characterized by the absence of pubertal development with PA and OD, are very rare but the search for genetic variations in this extreme phenotype may be more effective in identifying novel pathogenic mechanisms. Hence, using high resolution array-CGH we searched for rare high-penetrant CNVs involving genes essential for ovarian function in a cohort of 67 46,XX non-syndromic patients affected by PA, namely 53 sporadic (79.1%) and 14 familial (20.9%) cases. 28 out of 67 women resulted positive to array-CGH analysis because having at least one rare \u201covarian\u201d CNV: a total number of 32 CNVs involving 37 ovarian genes was selected.
Population from Database of Genomic Variants (DGV) was used to evaluate the rarity of POI CNVs, but it does not match to the ideal set of controls for POI disease (neither age nor gender of DGV controls are known). Thus, to better understand the CNVs contribution in disease onset, the rare \u201covarian\u201d CNVs found in patients according to DGV were searched in an ad hoc control cohort, previously screened by array-CGH, consisting in 140 healthy women with normal reproductive life and physiological menopause. 28 out of 32 rare \u201covarian\u201d CNVs detected in patients were not found in the control group thus supporting their role in the POI\u2019s pathogenesis. Moreover, to evaluate the presence of a significant enrichment in ovarian genes in the POI group, array-CGH of the ad hoc control cohort were analyzed with the same approach adopted for patients cohort and 49 CNVs involving 54 ovarian genes were selected. Several statistical analyses were performed comparing patients\u2019 to controls\u2019 data and revealed no significant differences. Nevertheless, the CNVs found in the POI cohort containing ovarian genes are more harmful respect to the CNVs identified in the controls cohort.
The 37 genes perturbed or possibly perturbed by POI CNVs are implicated in several ovarian processes (e.g., regulation of cytoskeleton dynamics for oocytes asymmetric division, maintenance of oocytes genomic integrity, ovarian differentiation, follicular development, and meiotic resumption), thus supporting their involvement in POI etiology. Validation and characterization of selected CNVs, as well as the study of a possible gene perturbation at mRNA level, was also crucial in order to perform a correct genotype-phenotype correlation and to propose new candidate genes for POI disease (e.g. TP63, VLDLR).
39 out of 67 women resulted negative for rare \u201covarian\u201d CNVs (58.2%) suggesting to combine different genomic approaches in order to increase the detection rate of the disorder. Hence, 17 out of 67 collected patients, were submitted to a preliminary WES analysis searching for rare SNVs in a total of 191 genes selected from array-CGH data, and literature regarding POI and ovary. The WES preliminary analysis allowed to confirm the importance of some array CGH new candidate genes in POI onset (e.g. VLDLR) and the complex heterogeneity of POI.
The combination of these molecular evidences, with major or minor contribution, might have been at the basis of POI supporting the existence of a disease genetic model characterized by oligogenic heterozygosity (i.e., the simultaneous presence in a single patient of multiple heterozygous quantitative variants/rare mutations, both de novo and/or inherited, affecting multiple genes).
The present approach using both array-CGH and WES techniques, resulted an efficient tool to identify rare variants (CNVs and SNVs) involving both genes already reported in POI, and new candidate genes with a role in oocyte maturation and differentiation. The results of this study are promising to expand the knowledge about the molecular pathways involved in POI pathogenesis and probably provide the basis for a more accurate genetic diagnosis of POI patients
Assessment of Investment Possibilities of Czech Households` Free Funds
Import 02/11/2016Tématem bakalářské práce je nalezení vhodného investičního produktu, který je nabízen investorům investičními poskytovateli na Českém finančním trhu a správně ho zařadit do investičního portfolia. Správně zvolený investiční produkt pomůže k dosažení cíle, který byl je stanoven investorem v investičním plánu.
Práce je rozdělena do tři hlavních kapitol. V první kapitole se popisuji základní investiční procesy. Je v ni popsán investiční plán, který investor před tím než se rozhodne investovat sestavuje a další témata jako je výběr investiční strategie a faktory, které dokážou ovlivnit reálnou výnosnost. Ve třetí kapitole jsou popsaný a charakterizovány produkty, se kterými se investor setkává na finančním trhu. V poslední hlavní kapitole je výběr investičních produktu, které jsou rozděleny dle investičních horizontu a srovnávaný mezi sebou.
Cílem bakalářské práce bylo zjistit možnosti investování na Českém finančním trhu a vybrat vhodný investiční produkt do investičního portfolia investora dle kritéria časových investičních horizontu, ze kterých investor při svém investičním rozhodováním může vybírat a následně je porovnat i mezi sebou.The theme of the bachelor thesis is a determination of suitable investment product, which is offered to investors by investment providers on Czech financial market. The thesis also aims to correctly classify the product in the investment portfolio. Appropriately chosen investment product helps to reach the objective, which is set by the investor in an investment plan.
The thesis is divided into three main parts. In the first part, the basic investment processes are described. The first part also contains a description of an investment plan that the investor sets before he decides to invest. Moreover, it also looks at other topics such as selection of investment strategy or aspects that can influence the real profit. In the second part the products that the investor encounters on financial market are described. The last part contains selection of investment products, which are divided by investment horizons and compared with each other.
The aim of the bachelor thesis is to determine the possibilities for investment on Czech financial market and to choose the appropriate investment product in the investor’s investment portfolio by the means of time investment horizons, from which can an investor choose and then also compare them with each other.154 - Katedra financívelmi dobř
Synthesis of a Cr-Cu surface alloy using a low-energy high-current electron beam
A Cr-Cu surface alloy is synthesized using successive operations of Cr film deposition followed by mixing in a melted phase with the Cu substrate by a low-energy, high-current electron beam (LEHCEB). The parameters of LEHCEB are as follows: electron energy 20–30 keV and pulse duration 2–4 μs. Depending on the LEHCEB energy density, the concentration of Cr in the alloy is in the range from 60 to 20 at.%. The alloy microstructure has been analyzed, and its morphology is shown to represent nanosized chromium particles measuring 10–30 nm uniformly distributed in the copper matrix. The synthesized Cr-Cu surface alloys demonstrate a more than a factor of 3 a decrease in wear coefficient, which is nearly as low as the wear coefficient of Cr coatings. Some defects such as networks of cracks and pores, are observed in the lengthy regions of chromium. They are attributed to the tensile thermal stresses taking place during solidified melt cooling due to a large difference between the thermal expansion coefficients of copper and chromium. Keywords: Surface alloy, Cr-Cu alloy, Pulsed electron beam, Wear resistance, Nanostructurin
Le metodologie di stima dell\u2019et\ue0 in ambito forense: il contributo dell\u2019AgEstimation Project
La stima dell\u2019et\ue0 \ue8 un elemento importante in ambito medico-legale, connesso sia a questioni legali che sociali.
L\u2019et\ue0 \ue8 un fattore determinante per l\u2019identificazione di un corpo: costituisce un elemento per la ricostruzione del profilo biologico, che verr\ue0 poi confrontato con i dati disponibili per le persone scomparse.
Nella nostra societ\ue0 alcuni diritti e alcune tutele sono direttamente correlate con l\u2019et\ue0 anagrafica della persona; serve una specifica et\ue0 per votare, per sposarsi, per lavorare, per ottenere la patente di guida, e soprattutto per essere considerati legalmente degli adulti.
Nei soggetti in vita, l\u2019et\ue0 \ue8 determinante anche nei casi di imputabilit\ue0 o responsabilit\ue0 criminale, di pedopornografia e di adozione, ma \ue8 anche relazionata al fenomeno dell\u2019immigrazione.
Negli ultimi anni infatti, c\u2019\ue8 stato un incremento proprio delle richieste di accertamento dell\u2019et\ue0 sulle persone in vita, dovuto all\u2019aumento degli immigrati giunti nei nostri paesi privi di documenti.
L\u2019accertamento dell\u2019et\ue0 pu\uf2 essere richiesto dalle autorit\ue0 proprio in riferimento alle domande di asilo.
La legislazione europea assicura protezione ai \u201cminori non accompagnati\u201d, cio\ue8 a quei minori che arrivano sul suolo europeo soli, senza la figura di riferimento di un adulto.
La corretta determinazione dell\u2019et\ue0 \ue8 quindi un elemento centrale per la protezione: solo se identificati, i minori possono essere protetti.
In questo specifico ambito d\u2019applicazione, l\u2019accertamento dell\u2019et\ue0 pu\uf2 avere ripercussioni notevoli sulla vita di un migrante: se riconosciuto come minore il soggetto ha il diritto di restare, diversamente, la procedura prevede il respingimento alla frontiera ed il rimpatrio.
In Italia, cos\uec come in Europa, la soglia d\u2019et\ue0 che separa i minorenni dagli adulti \ue8 quella dei diciotto anni; ma oltre a questa possono esistere altre soglie d\u2019et\ue0, come ad esempio la Minimal Age of Criminal Responsability (MACR). Questa particolare soglia d\u2019et\ue0 riconosce ai soggetti minorenni, anche se ritenuti responsabili di un crimine, il diritto di essere giudicati da una corte per i minori.
Una delle sfide della pratica forense dell\u2019accertamento riguarda la necessit\ue0 di assicurare nuovi e validi standard di riferimento, basati sullo studio di popolazioni attuali. Infatti gli studi che vengono utilizzati come riferimento sono basati sull\u2019analisi di popolazioni europee o nord americane e i dati raccolti sono riferiti a studi di pi\uf9 di cinquant\u2019anni fa. Per questo motivo attualmente le metodologie sviluppate in passato vengono applicate allo studio di popolazioni attuali, proprio al fine di ottenere dati aggiornati utili al confronto: una metodologia si applica ad una determinata popolazione per valutare quanto precisi ed accurati possano essere i risultati.
Nell\u2019ambito dell\u2019AgEstimation Project, supportato dall\u2019Istituto di Medicina Legale dell\u2019Universit\ue0 di Macerata, a partire dal 204, l\u2019equipe coordinata dal Dott. Roberto Cameriere ha presentato nuove metodologie per la stima dell\u2019et\ue0, sviluppando formule specifiche e testando queste formule in diverse popolazioni.
Le metodologie sviluppate prevedono l\u2019analisi e la misurazione delle ossa carpali e dell\u2019area del carpo nelle radiografie della mano di soggetti infantili e la misurazione dello sviluppo del terzo molare per la valutazione dell\u2019et\ue0 dei soggetti giovanili. Questa seconda tecnica prevede il calcolo dell\u2019indice del terzo molare: se tale indice risulta minore del valore 0.08, preso come valore di riferimento, il soggetto viene considerato un adulto.
L\u2019ultima tecnica analizzata in questa ricerca permette di stimare l\u2019et\ue0 nei soggetti adulti, sfruttando il fenomeno dell\u2019apposizione della dentina secondaria. Si tratta di un fenomeno continuo, che determina la riduzione della cavit\ue0 pulpare dei denti, dove questa dentina si deposita. In pratica i giovani adulti hanno una camera pulpare larga, mentre i soggetti senili presentano una cavit\ue0 pulpare molto pi\uf9 stretta. La tecnica prevede la rilevazione di misure specifiche del dente utilizzando una radiografia panoramica, utilizzate anche per la tecnica che valuta lo sviluppo del terzo molare.
In questo progetto di ricerca, queste tre metodologie sono state applicate a tre diversi campioni
Test Conditions for Pipeline Materials Selection with High Pressure Sour Gas
Acid gases, such as CO2, H2S, and/or sulfur in oil industry's production fluids, can be responsible for both general and localized corrosion, acting with different mechanisms, which depend on chemical and physical properties of the produced fluids. Materials selection for handling such fluids is performed by combining experience with suggestions from standards and regulations. A good deal of knowledge is available to predict corrosion rates for CO2-containing hydrocarbons, but the effect of high H2S pressure is less understood, mainly due to the difficulty of performing laboratory tests in such challenging conditions. For instance, the so-called NACE solution to assess SSC (Sulfide Stress Cracking) susceptibility of steels is a water-based solution simulating production fluids in equilibrium with one bar bubbling H2S gas. This solution does not represent environments where high gas pressure is present. Moreover, it does not take into account the corrosive properties of sulfur and its compounds that may deposit in such conditions. Besides, properties of high pressure gases are intermediate between those of a gas and those of a liquid: high pressure gases have superior wetting properties and better penetration in small pores, with respect to liquids. These features could enhance and accelerate damage, and nowadays such conditions are likely to be present in many production fields. This paper is aimed to point out a few challenges in dealing with high pressure gases and to suggest that, for materials selection in sour service, a better correspondence of test conditions with the actual field conditions shall be pursued
Portfolio Performance Evaluation of Selected Collective Investment Funds
Tématem diplomové práce je zhodnocení výkonnosti portfolia vybraných fondů kolektivního investování. Popularita kolektivního investování neustále roste. Důkazem tohoto tvrzení je rostoucí podíl aktiv, která jsou spravována správci ve veřejných podílových fondech. Zásadní otázkou je zjistit, jaká je skutečná výkonnost podílových fondů. Cílem této diplomové práce je zhodnotit výkonnost sedmi vybraných podílových fondů, z nichž čtyři jsou akciovými podílovými fondy a tři dluhopisovými fondy. Vybranými podílovými fondy jsou produkty investičních společností ČSOB, Conseq a Amundi. Posouzení výkonnosti portfolia podílových fondů bude zpracováno na základě použití rizikově upravených metod měření výkonnosti portfolií za období dlouhé pět let.
Diplomová práce obsahuje celkem pět hlavních kapitol. Počínaje úvodem, na ten navazuje druhá kapitola, která se zabývá charakteristikou možnosti kolektivního investování a faktory, které dokážou ovlivnit výkonnost vybraného portfolia. Druhá část práce je rozšířena ve třetí kapitole, ve které jsou detailně popsány rizikově upravené metody měření výkonnosti portfolia, model CAPM a statistická verifikace. Čtvrtá kapitola je nejdůležitější částí této diplomové práce, protože se jedná o aplikační kapitolu, která aplikuje teoreticko-metodologická východiska na vybrané podílové fondy. V této kapitole jsou charakterizovány vybrané podílové fondy, dále jsou vymezena dvě tržní portfolia a bezrizikové aktivum. V úplném závěru této kapitoly je zpracované přehledné shrnutí zhodnocení výkonnosti vybraných podílových fondů.The theme of this diploma thesis is to evaluate the performance of the portfolio of selected collective investment funds. The popularity of collective investment is growing constantly. This is evidenced by the growing share of assets managed by trustees in public mutual funds. The key question is to find out what the real performance of mutual funds is. The aim of this diploma thesis is to evaluate the performance of seven selected mutual funds, four of which are equity mutual funds and three bond funds. The selected mutual funds are the products of the investment companies ČSOB, Conseq and Amundi. The assessment of the performance of the Mutual Fund Portfolio will be based on the use of risk-adjusted portfolio performance measurement methods over a five-year period.
The diploma thesis contains five main chapters in total. Begining with the introduction, this is followed by the second chapter, which deals with the characteristics of the collective investment opportunity and the factors that can influence the performance of the selected portfolio. The second part of the thesis is extended in the third chapter, which describes in detail risk-adjusted methods of portfolio performance measurement, CAPM model and statistical verification. The fourth chapter is the most important part of this diploma thesis because it is an application chapter that applies the theoretical and methodological basis to selected mutual funds. In this chapter are selected selected mutual funds, two market portfolios and a risk-free asset are further defined. The final section of this chapter is treated comprehensive summary evaluation of the performance of selected mutual funds.154 - Katedra financívelmi dobř
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