412 research outputs found
Polymer-polymer Microfibrillar Composites: Effect of Nanofillers on Structure and Properties
Microfibrillar composites (MFCs) are advantageous polymer-polymer composites with in situ formed reinforcing fibrils. The range of applications of MFCs is limited by their low thermal resistance and me-chanical parameters of polymeric microfibres, which are formed by melt or cold drawing of the polymer blend. This study addresses improving MFCs based on HDPE matrix with 20% polyamide 6 microfibrils using organophilized montmorillonite. The complex effect of the nanofiller on the structure and parameters of the MFCs is investigated.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545
Use of IR Thermodiagnostic Measuring for Diagnostics of Limestone Treatment and Processing Equipment
Tato bakalářská práce se věnuje možnosti využití termodiagnostického měření ke stanovení technického stavu pásových dopravníků ve vápencovém lomu. Teoretická část se zabývá stručným popisem těžby vápence, využití dopravníků při této činnosti, popisem hlavních částí pásových dopravníků a termodiagnostikou se zaměřením na termografii. Praktická část je zaměřena na provedení a vyhodnocení termografického měření pásového dopravníku, jsou zde uvedena i doporučení pro nápravu zjištěných závad.This bachelor's thesis deals with the possibility of using thermodiagnostic measurement to determine the technical condition of belt conveyors in a limestone quarry. The theoretical part deals with a brief description of limestone mining, the use of conveyors in this activity, a description of the main parts of belt conveyors and thermodiagnostics with a focus on thermography. The practical part is focused on the implementation and evaluation of thermographic measurement of the belt conveyors, there are also recommendations for the correction of detected defects.340 - Katedra výrobních strojů a konstruovánídobř
Assessment of the Possibilities to Reduce the Building Energy Demands
Cílem této bakalářské práce je stanovit energetickou náročnost budovy, popsat metodiku výpočtu, navrhnout možné zdroje vytápění s ohledem na konstrukční možnosti budovy a srovnat ekonomiku vytápění různými tepelnými zdroji. Výsledkem vyhodnocení bude definice ekonomicky vhodného zdroje tepelné energie z pohledu ceny paliva a investičních nákladů.The aim of this bachelor's thesis is to determine the energy performance of the building, describe the calculation methodology, design possible heating sources with respect to the design of the building and compare the economics of heating with different heat sources. The result of the evaluation will be the definition of an economically suitable source of thermal energy in terms of fuel prices and investment costs.361 - Katedra energetikyvelmi dobř
Analysis of transmission system recovery paths regarding Ferranti effect
Tato diplomová práce se zabývá podpůrnou funkcí startu ze tmy vodní elektrárny Orlík a přečerpávací elektrárny Dlouhé Stráně pro tepelnou elektrárnu Chvaletice. Vodní elektrárna Orlík již certifikace pro start ze tmy má, a tak slouží jako referenční. Poskytování služby startu ze tmy přečerpávací vodní elektrárnou Dlouhé Stráně se uvažovalo již mnohem dříve, v letech 2001 až 2004 vznikly studie a byla provedena také zkouška, která ovšem neměla požadované výsledky. V programu MODES jsou obě trasy namodelovány a při simulaci se sledují dynamické vlastnosti sítě, při najíždění jednotlivých zdrojů vlastní spotřeby tepelné elektrárny Chvaletice. Taktéž v programu ATP-EMTP jsou obě trasy namodelovány, simulovány a sledují se elektromagnetické přechodové děje.This diploma thesis deals with the blackstart of Orlík hydroelectric power plant and Dlouhé Stráně pumped-storage hydroelectricity for Chvaletice Power Station. The Orlík hydroelectric power plant already has black start certification so it serves as a reference. There was some thought about black start of Dlouhé Stráně pumped-storage hydroelectricity before. In the years 2001 to 2004 were created studies and also was performed black start test but the results was not good. Both paths have been created as models in MODES program for monitoring dynamic properties and also in the ATP-EMTP program for monitoring electromagnetic transients.410 - Katedra elektroenergetikyvelmi dobř
A robust approach for acoustic noise suppression in speech using ANFIS
The authors of this article deals with the implementation of a combination of techniques of the fuzzy system and artificial intelligence in the application area of non-linear noise and interference suppression. This structure used is called an Adaptive Neuro Fuzzy Inference System (ANFIS). This system finds practical use mainly in audio telephone (mobile) communication in a noisy environment (transport, production halls, sports matches, etc). Experimental methods based on the two-input adaptive noise cancellation concept was clearly outlined. Within the experiments carried out, the authors created, based on the ANFIS structure, a comprehensive system for adaptive suppression of unwanted background interference that occurs in audio communication and degrades the audio signal. The system designed has been tested on real voice signals. This article presents the investigation and comparison amongst three distinct approaches to noise cancellation in speech; they are LMS (least mean squares) and RLS (recursive least squares) adaptive filtering and ANFIS. A careful review of literatures indicated the importance of non-linear adaptive algorithms over linear ones in noise cancellation. It was concluded that the ANFIS approach had the overall best performance as it efficiently cancelled noise even in highly noise-degraded speech. Results were drawn from the successful experimentation, subjective-based tests were used to analyse their comparative performance while objective tests were used to validate them. Implementation of algorithms was experimentally carried out in Matlab to justify the claims and determine their relative performances.Web of Science66631030
Regression of murine lung tumors by the let-7 microRNA.
MicroRNAs (miRNAs) have recently emerged as an important new class of cellular regulators that control various cellular processes and are implicated in human diseases, including cancer. Here, we show that loss of let-7 function enhances lung tumor formation in vivo, strongly supporting the hypothesis that let-7 is a tumor suppressor. Moreover, we report that exogenous delivery of let-7 to established tumors in mouse models of non-small-cell lung cancer (NSCLC) significantly reduces the tumor burden. These results demonstrate the therapeutic potential of let-7 in NSCLC and point to miRNA replacement therapy as a promising approach in cancer treatment
Effect of an organoclay on the reaction-induced phase-separation in a dynamically asymmetric epoxy/PCL system
The addition of layered silicates can significantly affect the phase behaviour of both immiscible thermoplastic blends and partially miscible thermoset systems that undergo reaction-induced phase separation (RIPS) during curing. This study focuses on the phase behaviour of polycaprolactone (PCL)/epoxy in the presence of organically modified montmorillonite (oMMT). Due to the high dynamic asymmetry caused by the differences in the molecular weights and viscosities of the PCL and the uncured epoxy, the critical point is localised at low PCL concentrations, as indicated by the pseudophase diagram. The addition of oMMT to the system led to the marked shift of the critical point towards higher concentrations of PCL, with an increase in the oMMT content occurring as a consequence of the preferential localisation of the clay in the epoxy phase, making this phase more dynamically slow. Significant changes in morphology, including phase inversion of the PCL/epoxy systems caused by the presence of oMMT, were recorded for PCL concentrations ranging from 10 to 30%
Monitoring of Morphology and Properties During Preparation of PCL/PLA Microfibrillar Composites With Organophilic Montmorillonite
Biodegradable microfibrillar composites PCL/PLA/C15, where PCL is poly(ε-caprolactone), PLA is poly(lactic acid), and C15 is organophilic montmorillonite, have been prepared. Microindentation hardness testing was employed in monitoring the gradual improvement of PCL stiffness due to PLA addition, C15 addition, flow-induced orientation, and changing crystallinity throughout the whole preparation process. Neat PCL after extrusion and injection molding was quite soft, but the stiffness of the material increased after melt-blending with 20 wt.% of PLA, after the addition of 2 wt.% of C15, and after the preparation of the final microfibrillar composite. The indentation modulus and indentation hardness of all intermediate products and the final PCL/PLA/C15 microfibrillar composite were associated not only with the composition and morphology but also with the crystallinity of both components. The modulus of the final PCL/PLA/C15 composite was almost two times higher in comparison with the original PCL matrix
A novel LabVIEW-based multi-channel non-invasive abdominal maternal-fetal electrocardiogram signal generator
PubMed ID: 26799770Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.Web of Science37225623
Perinatal germ cell development and differentiation in the male marmoset (Callithrix jacchus):similarities with the human and differences from the rat
STUDY QUESTION: Is perinatal germ cell (GC) differentiation in the marmoset similar to that in the human? SUMMARY ANSWER: In a process comparable with the human, marmoset GC differentiate rapidly after birth, losing OCT4 expression after 5–7 weeks of age during mini-puberty. WHAT IS KNOWN ALREADY: Most of our understanding about perinatal GC development derives from rodents, in which all gonocytes (undifferentiated GC) co-ordinately lose expression of the pluripotency factor OCT4 and stop proliferating in late gestation. Then after birth these differentiated GC migrate to the basal lamina and resume proliferation prior to the onset of spermatogenesis. In humans, fetal GC differentiation occurs gradually and asynchronously and OCT4(+) GC persist into perinatal life. Failure to switch off OCT4 in GC perinatally can lead to development of carcinoma in situ (CIS), the precursor of testicular germ cell cancer (TGCC), for which there is no animal model. Marmosets show similarities to the human, but systematic evaluation of perinatal GC development in this species is lacking. Similarity, especially for loss of OCT4 expression, would support use of the marmoset as a model for the human and for studying CIS origins. STUDY DESIGN, SIZE AND DURATION: Testis tissues were obtained from marmosets (n = 4–10 per age) at 12–17 weeks' gestation and post-natal weeks 0.5, 2.5, 5–7, 14 and 22 weeks, humans at 15–18 weeks' gestation (n = 5) and 4–5 weeks of age (n = 4) and rats at embryonic day 21.5 (e21.5) (n = 3) and post-natal days 4, 6 and 8 (n = 4 each). PARTICIPANTS/MATERIALS, SETTING AND METHODS: Testis sections from fetal and post-natal marmosets, humans and rats were collected and immunostained for OCT4 and VASA to identify undifferentiated and differentiated GC, respectively, and for Ki67, to identify proliferating GC. Stereological quantification of GC numbers, differentiation (% OCT4(+) GC) and proliferation were performed in perinatal marmosets and humans. Quantification of GC position within seminiferous cords was performed in marmosets, humans and rats. MAIN RESULTS AND ROLE OF CHANCE: The total GC number increased 17-fold from birth to 22 post-natal weeks in marmosets; OCT4(+) and VASA(+) GC proliferated equally in late gestation and early post-natal life. The percentage of OCT4(+) GC fell from 54% in late fetal life to <0.5% at 2.5 weeks of age and none were detected after 5–7 weeks in marmosets. In humans, the percentage of OCT4(+) GC also declined markedly during the equivalent period. In marmosets, GC had begun migrating to the base of seminiferous cords at ∼22 weeks of age, after the loss of GC OCT4 expression. LIMITATIONS, REASONS FOR CAUTION: There is considerable individual variation between marmosets. Although GC development in marmosets and humans was similar, there are differences with respect to proliferation during fetal life. The number of human samples was limited. WIDER IMPLICATIONS OF THE FINDINGS: The similarities in testicular GC differentiation between marmosets and humans during the perinatal period, and their differences from rodents, suggest that the marmoset may be a useful model for studying the origins of CIS, with relevance for the study of TGCC. STUDY FUNDING/COMPETING INTERESTS: This work was supported by Grant G33253 from the Medical Research Council, UK. No external funding was sought and there are no competing interests
- …