Physiochemical characteristics of controlled low strength materials influencing the electrochemical performance and service life of metallic materials

Controlled Low Strength Materials (CLSM) are cementitious self-compacting materials, comprised of low cement content, supplementary cementing materials, fine aggregates, and water. CLSM is typically used as an alternative to conventional compacted granular backfill in applications, such as pavement bases, erosion control, bridge abutments, retaining walls, bedding and backfilling of pipelines. This dissertation presents the findings of an extensive study carried out to determine the corrosivity of CLSM on ductile iron and galvanized steel pipelines. The study was performed in two phases and evaluated more than 40 different CLSM mixture proportions for their corrosivity. An extensive literature survey was performed on corrosion of metals in soils and corrosion of reinforcement in concrete environments to determine possible influential factors. These factors were used as explanatory variables with multiple levels to identify the statistically significant factors. Empirical models were developed for percent mass loss of metals embedded in CLSM and exposed to different environments. The first and only service life models for ductile iron and galvanized steel pipes embedded in CLSM mixtures were developed. Models indicated that properly designed CLSM mixtures can provide an equal or longer service life for completely embedded ductile iron pipes. However, the service life of galvanized pipes embedded in CLSM should not be expected to be more than the service life provided by corrosive soils

Low-Grade Endometrial Stromal Sarcoma - a Review

Like other uterine sarcomas, low-grade endometrial stromal sarcomas (LG-ESS) are a very rare tumor entity. In the past, research studies therefore discussed the various different types of the disease in combination. In addition, the classification of endometrial stromal tumors presented difficulties for quite some time so that in earlier studies it was not always possible to precisely distinguish between LG-ESS, high-grade endometrial stromal sarcoma, and undifferentiated uterine sarcoma. For LG-ESS, surgery with hysterectomy and adnexectomy is the first-line treatment. The benefits of lymphadenectomy and tumor debulking are unclear. Endocrine therapy with gestagens and aromatase inhibitors is under discussion to provide adjuvant treatment for patients with advanced stages of the disease. As radiotherapy only provides locoregional control, and in view of the usually good prognosis of patients with LG-ESS, its benefits need to be weighed against its side effects. In the case of recurrence, repeat surgery is the first choice. Further research studies viewing LG-ESS as a distinct entity are needed in order to improve treatment options for patients with LG-ESS

Low-Grade Endometrial Stromal Sarcoma - a Review

Like other uterine sarcomas, low-grade endometrial stromal sarcomas (LG-ESS) are a very rare tumor entity. In the past, research studies therefore discussed the various different types of the disease in combination. In addition, the classification of endometrial stromal tumors presented difficulties for quite some time so that in earlier studies it was not always possible to precisely distinguish between LG-ESS, high-grade endometrial stromal sarcoma, and undifferentiated uterine sarcoma. For LG-ESS, surgery with hysterectomy and adnexectomy is the first-line treatment. The benefits of lymphadenectomy and tumor debulking are unclear. Endocrine therapy with gestagens and aromatase inhibitors is under discussion to provide adjuvant treatment for patients with advanced stages of the disease. As radiotherapy only provides locoregional control, and in view of the usually good prognosis of patients with LG-ESS, its benefits need to be weighed against its side effects. In the case of recurrence, repeat surgery is the first choice. Further research studies viewing LG-ESS as a distinct entity are needed in order to improve treatment options for patients with LG-ESS

Laparoscopy training of novices with complex curved instruments using 2D- and 3D-visualization

Purpose Beside many advantages, disadvantages such as reduced degrees of freedom and poorer depth perception are still apparent in laparoscopic surgery. 3D visualization and the development of complex instruments are intended to counteract the disadvantages. We want to find out whether the use of complex instruments and 3D visualization has an influence on the performance of novices. Methods 48 medical students with no experience in laparoscopic surgery or simulator-based laparoscopy training were included. They were randomized in four groups according to a stratification assessment. During a structured training period they completed the FLS-Tasks “PEG Transfer”, “Pattern Cut” and “Intracorporeal Suture” and a transfer task based on these three. Two groups used conventional laparoscopic instruments with 3D or 2D visualization, two groups used complex curved instruments. The groups were compared in terms of their performance. Results In 2D laparoscopy there was a better performance with straight instruments vs. curved instruments in PEG Transfer and Intracorporeal Suture. In the transfer task, fewer errors were made with straight instruments. In 2D vs. 3D laparoscopy when using complex curved instruments there was an advantage in Intracorporeal Suture and PEG Transfer for 3D visualization. Regarding the transfer exercise, a better performance was observed and fewer errors were made in 3D group. Conclusion We could show that learning laparoscopic techniques with complex curved instruments is more difficult with standard 2D visualization and can be overcome using 3D optics. The use of curved instruments under 3D vision seems to be advantageous when working on more difficult tasks

Application of single-sided NMR for the non-destructive testing of the degree of cross-linking of adhesives and cross-linked plastic parts

Der Vernetzungsgrad von Klebstoffen und strahlenvernetzter Kunststoffformteile beeinflusst zahlreiche Materialeigenschaften und ist von essenzieller Bedeutung für die Funktionalität von Klebeverbindungen und die Beständigkeit medizinischer Implantate. Die zerstörungsfreie Prüfung dieser Qualitätsgröße ist von großem industriellem Interesse, aber noch nicht Stand der Technik. Die unilaterale Kernspinresonanz (uNMR) ist ein vielversprechendes Verfahren zur Lösung dieser Problematik. In diesem Buch wird die nicht-invasive Vernetzungsgradprüfung von strahlenvernetztem UHMWPE und verschiedenen Klebstoffen mittels uNMR demonstriert. Auf Basis der guten Korrelation mit praxisrelevanten Referenzmethoden (thermisch, rheologisch, dielektrisch) wurden Vergleichsmodelle entwickelt, welche Anwendern von Klebstoffen und vernetzten Kunststoffformteilen den Einsatz der uNMR zur zerstörungsfreien Qualitätssicherung ermöglichen.The degree of curing is a central quality feature of adhesives, which influences numerous material properties and is therefore of crucial importance for adhesive bonds. The same applies to the degree of cross-linking of radiation-cross-linked plastic components as used in the field of medical implants. The non-destructive testing of this property is still of great interest, both from the industrial and research perspective, but not possible yet. With unilateral or single-sided nuclear magnetic resonance (uNMR) a method that has the potential to solve this problem has been available for several years. However, this method has not been implemented on an industrial scale up to now. Reasons for this may be the lack of application-specific knowledge or the reluctance to use an allegedly complicated technology. Within the scope of this work the application of this measuring technique for non-destructive testing of the degree of cross-linking and curing on different material systems was evaluated. Besides radiation-cross-linked polyethylene with ultra-high molecular weight (UHMWPE-Xc) a selection of different adhesives with various reaction mechanisms and their adhesive bonds were investigated. The results of the uNMR measurements were compared to a variety of reference methods commonly used in practice to characterize cross-linked plastics, adhesives and bonded joints and evaluated with regard to their informative value. Temperature monitoring for the magnets and the test specimens was integrated into the uNMR system in order to monitor the temperature effects of various standard measuring sequences and the employed reactive materials as well as the influence of the ambient temperature. For the evaluation of the uNMR measurements, different methods were compared to one another. On the one hand, multi-component fits were employed to determine the characteristic relaxation times, taking into account different material phases. On the other hand, echo-based methods (binning, echo sums, weighting) were used. It could be demonstrated that normalized echo sums are very well suited for quantifying the curing of adhesives – directly in the bond – and for characterizing the degree of cross-linking of UHMWPE-Xc. Material components with specific T2eff relaxation times can also be described in a targeted manner, by also considering the echo sum ratios. The uNMR results showed a good correlation with the applied reference methods (differential scanning calorimetry, dielectric analysis, rheological investigations in plate/plate rheometer). On this basis corresponding comparison models could be developed. These illustrate the potential applications of uNMR for non-destructive quality assurance to users of adhesives and cross-linked plastic components.Der Aushärtegrad von Klebstoffen ist ein zentrales Qualitätsmerkmal, welches zahlreiche Materialeigenschaften beeinflusst und daher auch für die Klebeverbindungen von entscheidender Bedeutung ist. Gleiches gilt für den Vernetzungsgrad von strahlenvernetzten Kunststoffformteilen, wie sie im Implantatbereich eingesetzt werden. Die zerstörungsfreie Prüfung (ZfP) dieser Kenngrößen ist nach wie vor von großem Interesse, sowohl von industrieller als auch Forschungsseite, allerdings bisher nicht Stand der Technik. Mit der unilateralen oder einseitigen Kernspinresonanz (uNMR, engl. unilateral nuclear magnetic resonance oder oft auch single-sided NMR genannt) steht seit einigen Jahren ein Verfahren zur Verfügung, welches das Potenzial hat, die genannte Problematik zu lösen. Eine industrielle Umsetzung erfolgte bis dato jedoch nicht. Gründe hierfür können das Fehlen von anwendungsspezifischem Basiswissen oder die Scheu vor dem Einsatz einer vermeintlich komplizierten Technik sein. Im Rahmen dieser Arbeit wurde der Einsatz dieses Messverfahrens zur ZfP des Vernetzungs- und Aushärtegrades an verschiedenen Materialsystemen evaluiert. Neben strahlenvernetztem Polyethylen mit ultrahohem Molekulargewicht (UHMWPE-Xc) wurden eine Auswahl an verschiedenen Klebstoffen mit unterschiedlichen Reaktionsmechanismen und deren Klebeverbindungen untersucht. Die Ergebnisse der uNMR-Messungen wurden mit verschiedenen praxisrelevanten Referenzmethoden zur Charakterisierung vernetzter Kunststoffe, Klebstoffe und Klebeverbindungen verglichen und hinsichtlich ihrer Aussagekraft bewertet. In das verwendete uNMR-System wurde eine Temperaturüberwachung für die Magnete und die untersuchten Probekörper integriert. Damit wurden die Temperatureffekte verschiedener Standard-Messsequenzen und der eingesetzten reaktiven Materialien sowie der Einfluss der Umgebungstemperatur betrachtet. Für die Auswertung der uNMR-Messungen wurden unterschiedliche Auswerteverfahren verglichen. Einerseits wurden Multiparameter-Fits zur Bestimmung der charakteristischen Relaxationszeiten unter Berücksichtigung verschiedener Materialphasen verwendet. Andererseits kamen echobasierte Methoden (Gruppierung, Echosummen, Gewichtung) zum Einsatz. Anhand der Resultate konnte demonstriert werden, dass sich normierte Echosummen sehr gut zur Quantifizierung der Aushärtung von Klebstoffen – direkt in der Klebeverbindung – und zur Charakterisierung des Vernetzungszustands von UHMWPEXc eignen. Durch die zusätzliche Betrachtung der Echosummenverhältnisse konnten auch gezielt Materialkomponenten mit bestimmten T2eff -Relaxationszeiten beschrieben werden. Die uNMR-Ergebnisse zeigten gute Korrelationen mit den verwendeten Referenzverfahren (Dynamische Differenzkalorimetrie, Dielektrische Analyse, rheologische Untersuchungen im Platte/Platte-Rheometer). Darauf basierend konnten entsprechende Vergleichsmodelle entwickelt werden. Die Resultate verdeutlichen Anwendern von Klebstoffen und vernetzten Kunststoffformteilen die Einsatzmöglichkeiten der uNMR zur zerstörungsfreien Qualitätssicherung

Varaosalogistiikan toiminta ja kehittäminen

Tässä opinnäytetyössä tehtiin selvitys Inchcape Motors Finland Oy:n varaosalogistiikan toiminnasta. Tavoitteena oli selventää, mitä kaikkea yrityksen varaosalogistiikka sisältää, ja lyhyesti analysoida sen nykytilaa. Lisäksi tavoitteena oli selvityksen pohjalta tuoda esiin joitakin ideoita toiminnan kehittämiseksi. Opinnäytetyön tiedot perustuvat yrityksen työntekijöiden haastatteluihin ja keskusteluihin, sekä yritykseltä saatuihin materiaaleihin ja raportteihin. Työn alussa käsitellään aiheeseen liittyvää teoriaa. Varaosalogistiikka sisältää paljon erilaisia varastonohjaukseen ja varastointiin liittyviä käsitteitä. Palveluaste, varaston kiertonopeus ja tilaus-toimitusprosessi ovat hyvin keskeisiä asioita varaosalogistiikassa. Tutkimusosuuden alussa esitellään yritys, jolle opinnäytetyö tehdään ja kuvataan sen toimialaa. Tämän jälkeen visualisoidaan Inchcape Motors Finland Oy:n varaosalogistiikka kokonaisuutena prosessikaavion avulla. Varaosalogistiikka koostuu useasta eri osapuolesta, joita ovat asiakas, jälleenmyyjä, keskusvarasto, maahantuoja sekä varaosatoimittajat. Seuraavaksi tarkastellaan eri osapuolten roolia varaosalogistiikassa. Lisäksi yhteys eri osapuolten välillä havainnollistetaan tilaus-toimitusprosessin avulla. Asiakkaan roolia varaosalogistiikassa ei erikseen käsitellä, vaan ainoastaan todetaan sen tärkeys koko toiminnan olemassaololle. Selvityksen jälkeen esitetään lyhyt analyysi varaosalogistiikan nykytilasta sekä tarkastellaan selvityksen myötä esiin tulleita ideoita toiminnan kehittämiseksi. Havainnot nykytilasta osoittivat toiminnan olevan suurelta osin looginen ja selkeä. Kehittämisideat eivät kaikki ole nykytilanteessa toteuttamiskelpoisia, mutta varaosaluokituksen toteuttaminen ja hyödyntäminen voisi nykytilanteessa olla mahdollista.This Bachelor´s thesis examines the spare parts logistics operations of Inchcape Motors Finland Oy. The aim was to investigate how the spare parts logistics of the company operates and analyse its current status. The aim was also to bring up some ideas to improve its operations. The data in this thesis are based on interviews and conversations with the employees and on the material and reports received from the company. The thesis was started by getting acquainted with the theory. Spare parts logistics contains several different terms referring to storage and storing management. Service rate, warehouse speed and order-delivery-process are important terms in spare parts logistics. In the beginning of the investigation phase the company that assigned the thesis is introduced. After this the spare parts logistics of Inchcape Motors Finland Oy is illustrated with the help of a process diagram. Spare parts logistics consists of several different participants, which are customer, car dealer, central warehouse, importer and spare parts dealers. After this, the role of these participants is examined. The connection between the participants is also clarified with the help of the order-delivery-process. The role of the customer is not examined, although its importance for the business is acknowledged. After the investigation a short analysis of the current state of the spare parts logistics is given. Also new ideas for improving the operations are discussed. The analysis showed that the operations are logical and efficient. All the ideas for improvement cannot be implemented in the current state, but the spare parts categorization could be possible to execute even in the current state