Fatigue life of high strength steel for cold forming

The article presents the results of fatigue tests carried out on STRENX-type high-strength cold forming steel. For high-cycle fatigue tests carried out using low cycle loading frequencies of around 30 Hz, a ROTOFLEX machine was used. For ultra high-cycle tests, a KAUP-ZU testing machine was employed, which enables fatigue tests to be performed with symetric specimen loading (R = -1) and at a frequency of f ≈ 20 kHz. The relationships σa = f(N) were determined experimentally in the high and ultra high-cycle region for STRENX high-strength steel. To determine the fatigue crack initiation mechanism, the fractographic analysis of fatigue fractures was made

The effect of high-frequencies loading on the fatigue cracking of nodular cast iron

The article presents the results of fatigue tests using high-frequency loading of nodular cast iron. Nodular cast iron GJS-500-7, GJS-600-3 and cast iron ADI with a tensile strength of Rm = 1 125 MPa were used for the tests. The fatigue tests were conducted on a resonance testing machine. For the cast iron grades under investigation, fatigue characteristics in high and ultra-high-cycle regions were experimentally determined. After the completion of the tests, the fractographic analysis of fatigue fractures was made with the aim of determining the fatigue crack initiation location and the fracture mechanism

Sustav kontrole kvalitete u proizvodnji ljeva od sferoidnog lijevanog željeza

In work opinions of form incompatibility were executed during process of production of casting articles from spheroidal cast iron. Using the quality tools such as the Ishikawa diagram and the Pareto-Lorenz analyses one identified often-appeared defects and, were identified and qualified. Identification of critical points of productive system was executed and the range of correcting workings was qualified. On basis of data from analysis of causes of occurrence of incompatibilities and appointed critical points system of control of quality was worked out for serial and isolated production. Use of statistical method of casts in connection with active control of quality and selection of productive stages for serial production of casts from spheroid cast iron caused lower level of defects, and in economic aspect contributed to the reduction of costs of connected production with low level of quality.U pogonu su ispitivane varijante kompatibilnosti oblika tijekom procesa proizvodnje lijevanih predmeta iz sferoidnog lijevanog željeza. Uporabom kvalitetnih metoda kao što su Ishikawin dijagram i Pierto-Lorenzova analiza utvrđene su i opisane najčešće greške. Na osnovu podataka dobivenih analizom izvršena je identifikacija kritičnih točaka u proizvodnom sistemu i određene radnje za ispravljanje grešaka. Temeljem podataka dobivenih analizom uzroka pojava inkompatibilnosti i istaknutih točaka razrađen je sustav kontrole za serijsku i pojedinačnu proizvodnju. Uporaba statističke metode praćenja talina, zajedno s aktivnom kontrolom kvalitete i odabirom proizvodnih faza za serijsku i pojedinačnu proizvodnju talina iz lijevanog željeza, smanjuje broj grešaka te s ekonomskog aspekta doprinosi nižim troškovima

MicroRNA expression patterns in canine mammary cancer show significant differences between metastatic and non-metastatic tumours

Background: MicroRNAs may act as oncogenes or tumour suppressor genes, which make these small molecules potential diagnostic/prognostic factors and targets for anticancer therapies. Several common oncogenic microRNAs have been found for canine mammary cancer and human breast cancer. On account of this, large-scale profiling of microRNA expression in canine mammary cancer seems to be important for both dogs and humans. Methods: Expression profiles of 317 microRNAs in 146 canine mammary tumours of different histological type, malignancy grade and clinical history (presence/absence of metastases) and in 25 control samples were evaluated. The profiling was performed using microarrays. Significance Analysis of Microarrays test was applied in the analysis of microarray data (both unsupervised and supervised data analyses were performed). Validation of the obtained results was performed using real-time qPCR. Subsequently, predicted targets for the microRNAs were searched for in miRBase. Results: Results of the unsupervised analysis indicate that the primary factor separating the samples is the metastasis status. Predicted targets for microRNAs differentially expressed in the metastatic vs. non-metastatic group are mostly engaged in cell cycle regulation, cell differentiation and DNA-damage repair. On the other hand, the supervised analysis reveals clusters of differentially expressed microRNAs unique for the tumour type, malignancy grade and metastasis factor. Conclusions: The most significant difference in microRNA expression was observed between the metastatic and non-metastatic group, which suggests a more important role of microRNAs in the metastasis process than in the malignant transformation. Moreover, the differentially expressed microRNAs constitute potential metastasis markers. However, validation of cfa-miR-144, cfa-miR-32 and cfa-miR-374a levels in blood samples did not follow changes observed in the non-metastatic and metastatic tumours. © 2017 The Author(s)

Zastosowanie metody Servqual do oceny jakości usług edukacyjnych na uczelni wyższej

The quality of provided educational service, its perception by students as well as employers in the market is an important element in the positioning of future employee in the labour market. We can conclude that the completion of the university with an established reputation can help in a graduate career. There is therefore a necessity, not only statutory but also market, to research quality and integrity of provided educational services. The article presents research results of quality of provided services based on the level of satisfaction of students majoring in Management and Production Engineering at the Faculty of Management of the Czestochowa University of Technology. The study will be expanded in the future on the results of perception of quality of educational services from the perspective of employers who employ students of analyzed university.Jakość świadczonych usług edukacyjnych, jej postrzeganie przez studentów, jak i pracodawców na rynku jest istotnym elementem umiejscawiania przyszłego pracownika na rynku pracy. Możemy stwierdzić, że ukończenie uczelni o ugruntowanej renomie może pomóc w karierze absolwenta. Istnieje zatem konieczność, nie tylko ustawowa, ale także rynkowa, do badania jakości i integralności świadczonych usług edukacyjnych. W artykule zaprezentowano wyniki badań jakości świadczonych usług na podstawie poziomu satysfakcji studentów kierunku Zarządzanie i Inżynieria Produkcji na Wydziale Zarządzania Politechniki Częstochowskiej. Badanie zostanie w przyszłości rozbudowane o wyniki postrzegania jakości usług edukacyjnych z perspektywy pracodawców, którzy zatrudniają studentów analizowanej uczelni wyższej

Outsourcing – controlled shipping procedures in the automotive industry

The article presents the results of own research of assessing the impact of external visual control on the efficiency of realized processes in the automotive industry. Increasingly, companies from the automotive industry opt for the solutions offered by external companies, which are specialized in quality control. Companies providing this kind of service become strategic business partners of manufacturing companies, guaranteeing security, flexibility and cost reduction. Demand for outsourcing of complex solutions in the field of quality control grows each year. Most of the companies operating on the automotive market tend to loosen up their business in order to more quickly and easily respond to internal factors and above all external factors. Presented at work results relate to the situation of the imposition by the customer on the supplier the Controlled Shipping Level 2 procedure.W artykule przedstawiono wyniki badań własnych oceny wpływu stosowania zewnętrznej kontroli wizualnej na efektywność realizo-wanych procesów w branży motoryzacyjnej. Coraz częściej firmy z branży motoryzacyjnej wybierają rozwiązania proponowane przez podmioty zewnętrzne, które są wyspecjalizowane w kontroli jakości. Firmy świadczące tego typu usługi stają się strategicznymi partnerami biznesowymi firm produkcyjnych, gwarantującymi bezpieczeństwo, elastyczność i redukcję kosztów. Popyt na outsourcing kompleksowych rozwiązań w zakresie kontroli jakości rokrocznie rośnie. Większość firm działających na rynku motoryzacyjnym dąży do uelastycznienia swojego biznesu tak, aby szybciej i łatwiej reagować na czynniki wewnętrzne i przede wszystkim zewnętrzne. Przedstawione w pracy wyniki badań dotyczą sytuacji nałożenia przez klienta na dostawcę procedury Controlled Shipping Level 2

Effectiveness assessment of functioning of quality assurance system

This paper presents the results of six-year studies that were conducted in an iron foundry. The research consisted in effectiveness assessment of the quality assurance system. Determinants of three groups of estimation criteria were characterized. In technological criterion the required values of dimensional tolerance, the value of required hardness, raggedness, the required values of coefficients of the scattering process and also acceptable fractions of the products were taken into consideration. The economic criteria included the assumed values of internal and external costs of product defects. The exploitation criteria comprised the required level of reliability or durability and the required value of products repairability. The obtained results point to too high costs of lacks in technological criteria. The undertakings were proposed in order to decrease them

Podejście systemowe w zapewnieniu jakości kształcenia na Wydziale Zarządzania Politechniki Częstochowskiej

The article presents experiences of implementing the internal quality assurance system at the Faculty of Management of the Czestochowa University of Technology. In the literature, there is no ready-made solution connected with the functioning of internal quality assurance system, there are just defined good practices. One of the solutions used by universities is to use the model based on the ISO 9001 standard or EFQM model. Faculty of Management has chosen model based on ISO 9001 standards, the modification of this system gives great implementing potential in higher education regardless of the educational profile.Artykuł prezentuje doświadczenia związane z wdrożeniem wewnętrznego systemu zapewnienia jakości na Wydziale Zarządzania Politechniki Częstochowskiej. W literaturze nie występuje gotowe rozwiązanie dotyczące funkcjonowania wewnętrznego systemu zapewnienia jakości, znajdują się tylko opisy dobrych praktyk. Jednym z rozwiązań stosowanych przez uniwersytety jest model oparty na standardach ISO 9001 czy modelu EFQM. Wydział Zarządzania wybrał model oparty na standardach ISO 9001, a modyfikacja tego modelu daje wielkie możliwości wdrożeń w obszarze wyższej edukacji, niezależnie od jej profilu

Wykorzystanie modelu Kano do klasyfikacji elementów jakości produktu

The article presents a case study of the use of the Noriaki Kano model, which allows the identification of the characteristics of the perfect product from the perspective of a potential customer. One of the basic assumptions of the Kano model is the variability of customer requirements, which with the passage of time and copying attributes of a product by competing companies, socalled "stunning" factors become common and become expected attributes, then the desired factors, and in the final phase the discouraging factors. The studies of features, of the perfect product were carried out in the company of processing meat and vegetable. There were identified four groups of features: attracting, standard, one-dimensional and neutral. Based on obtained data there were modified packaging and changed areas of allocating given type of assortment on the market.W artykule przedstawiono studium przypadku wykorzystania modelu Noriakiego Kano, który pozwala na wyodrębnienie cech idealnego produktu z perspektywy potencjalnego klienta. Jednym z podstawowych założeń modelu Kano jest zmienność wymagań klienta, które wraz z upływem czasu i kopiowaniem atrybutów produktu przez konkurencyjne firmy, tzw. czynniki „zachwycające” powszednieją i stają się atrybutami oczekiwanymi, następnie zaś czynnikami pożądanymi, a w końcowej fazie czynnikami zniechęcającymi. Badania cech idealnego produktu przeprowadzono w przedsiębiorstwie przetwórstwa mięsno-warzywnego. Wyodrębniono cztery grupy cech: wabiące, standardowe, jednowymiarowe i obojętne. W oparciu o uzyskane dane zmodyfikowano opakowania oraz zmieniono obszary alokowania danego typu asortymentu na rynku