Rheological and Processing Properties of Poly(lactic acid) Composites Filled with Ground Chestnut Shell

Mateusz Barczewski,Olga Mysiukiewicz 한국고분자학회 2018 폴리머 Vol.42 No.2

Rheological behavior of the poly(lactic acid) (PLA) composites filled with ground chestnut shell (CN) was investigated. Application of various measuring techniques: small amplitude oscillatory shearing rheometry and capillary rheometry, allowed to determine in detail changes of rheological behavior and potential processing limitations of fully biodegradable composites modified by an organic waste filler. Different influence of the ground chestnut shell filler on PLA-based composites flow behavior was observed during rotational and capillary rheometry. Incorporation of particleshaped natural filler resulted in strong increase of composites’ complex viscosity. However, due to occurrence of significant wall slip during capillary flow, materials containing ground chestnut were characterized by improved processability which result in increased melt flow index (MFI).

Nanosecond Spin Dynamics in (Cd,Mn)Te Quantum Dots and Quantum Wells

Mateusz Goryca,Piotr Kossacki,Michal Nawrocki,Piotr Wojnar,Grzegorz Karczewski 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

Results of studies of the magnetization evolution in a single (Cd,Mn)Te quantum well after a short pulse of magnetic field of a few tens of millitesla is compared with results of analogous studies performed on an ensemble of (Cd,Mn)Te quantum dots. The characteristic time of magnetization relaxation in the absence of external magnetic field is of the order of tens of nanoseconds. Upon application of a static magnetic field of the order of 1 T, the relaxation in the quantum well slows down by about three orders of magnitude, while relaxation in quantum dots remains unchanged. One possible explanation of this is a much larger mixing of Mn ion spin states in the quantum dots due to, e.g., local deformation.

Effect of Heterogeneous Nucleation on Isotactic Polypropylene-Polyoxymethylene Blends Properties and Miscibility

Mateusz Barczewski,Danuta Matykiewicz,Jacek Andrzejewski 한국고분자학회 2015 Macromolecular Research Vol.23 No.9

This paper presents a study of the effect of heterogeneous nucleation on isotactic polypropylene-polyoxymethylene (iPP-POM) blends properties and miscibility. Polyoxymethylene have been blended with polypropylene matrix in three different amounts: 25, 50, and 75 wt% with and without sorbitol based nucleating agent. Thermal and mechanical properties of blends have been investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanic thermal analysis (DMTA), static tensile test as well as rheological analysis. The structure of the blends was investigated using Scanning Electron Microscopy (SEM) and polarized optical microscopy (PM). Rheological analysis confirmed that the iPP-POM blends are partially miscible in a molten state.

Impact of PSI-KIT Nitriding model on hypothetical Spent Fuel Pool accident simulation

Mateusz Malicki,Terttaliisa Lind Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.7

In past years the Paul Scherrer Institute (PSI, Switzerland) and the Karlsruhe Institue of Technology (KIT, Germany)) collaborated to develop a model to account for the active role of nitrogen in the air oxidation of a Zircalloy cladding. The "PSI-KIT Nitriding Model for Zirconium based Fuel Cladding" model was implemented at PSI into PSI-MELCOR 1.8.6. In order to make a preliminary evaluation of the effect of the new model on the evolution of full-scale spent fuel pool accidents, one spent fuel pool event was analyzed using the PSI research version of PSI-MELCOR 1.8.6, which includes the nitriding model. To adapt an existing input deck for the calculations, a sensitivity study was conducted to find an optimal nodalization for the analyses. The nitriding model results were compared to those calculated with the MELCOR 1.8.6-PSI without the new nitriding model. The results demonstrate the effect of the nitriding reactions in spent fuel pool accident progression. Moreover, they confirm the impact of ZrN formation during cladding oxidation in air when the oxidation reactions lead to oxygen starvation inside the fuel assemblies. The nitriding reaction led to higher chemical heat generation during the accident and to an earlier failure of the cladding than when the effect of nitrogen reactions was not considered. It should be noted that the nitriding model, as implemented in the PSI version of MELCOR 1.8.6 has not yet been conclusively validated. Thereby the results presented in this paper should be treated as a preliminary demonstration of the capabilities of the model.

Targeted Bisulfite Sequencing-Based Analysis of MGMT Promoter Methylation in Meningiomas

Bujko, Mateusz,Kober, Paulina Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Opto-Electrochemical Sensing Device Based on Long-Period Grating Coated with Boron-Doped Diamond Thin Film

Robert Bogdanowicz,Mateusz Śmietana,Michał Sobaszek,Mateusz Ficek,Marcin Gnyba,Jacek Ryl,Katarzyna Siuzdak,Wojtek J. Bock 한국광학회 2015 Current Optics and Photonics Vol.19 No.6

The fabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrodes on fused silica single mode optical fiber cladding has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ºC. We have obtained homogenous, continuous and polycrystalline surface morphology with high sp 3 content in B-NCD films and mean grain size in the range of 100-250 nm. The films deposited on the glass reference samples exhibit high refractive index (n=2.05 at λ=550 nm) and low extinction coefficient. Furthermore, cyclic voltammograms (CV) were recorded to determine the electrochemical window and reaction reversibility at the B-NCD fiber-based electrode. CV measurements in aqueous media consisting of 5 mM K3[Fe(CN)6] in 0.5 M Na2SO4 demonstrated a width of the electrochemical window up to 1.03 V and relatively fast kinetics expressed by a redox peak splitting below 500 mV. Moreover, thanks to high-n B-NCD overlay, the coated fibers can be also used for enhancing the sensitivity of long-period gratings (LPGs) induced in the fiber. The LPG is capable of measuring variations in refractive index of the surrounding liquid by tracing the shift in resonance appearing in the transmitted spectrum. Possible combined CV and LPG-based measurements are discussed in this work

Detonation cell size model based on deep neural network for hydrogen, methane and propane mixtures with air and oxygen

Konrad Malik,Mateusz Zbikowski,Andrzej Teodorczyk 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2

The aim of the present study was to develop model for detonation cell sizes prediction based on a deepartificial neural network of hydrogen, methane and propane mixtures with air and oxygen. The discussionabout the currently available algorithms compared existing solutions and resulted in a conclusionthat there is a need for a new model, free from uncertainty of the effective activation energy and thereaction length definitions. The model offers a better and more feasible alternative to the existing ones. Resulting predictions were validated against experimental data obtained during the investigation ofdetonation parameters, as well as with data collected from the literature. Additionally, separate modelsfor individual mixtures were created and compared with the main model. The comparison showed nodrawbacks caused by fitting one model to many mixtures. Moreover, it was demonstrated that the modelmay be easily extended by including more independent variables. As an example, dependency onpressure was examined. The preparation of experimental data for deep neural network training wasdescribed in detail to allow reproducing the results obtained and extending the model to differentmixtures and initial conditions. The source code of ready to use models is also provided

Nanofiltration separation of succinic acid from post-fermentation broth: Impact of process conditions and fouling analysis

Jerzy Antczak,Mateusz Szczygiełda,Krystyna Prochaska 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.77 No.-

In this study a pilot-scale setup was used in the nanofiltration (NF) process for recovery of succinic acidfrom model solutions and the actual post-fermentation broth left after the bioconversion of glycerol. Theeffects of composition and pH of feed solutions, initial concentration of components and the magnitudeof applied transmembrane pressure (TMP) on the separation efficiency, the value of the permeatefluxand retention ratio of individual components present in the feed solutions, were investigated. In order toestimate the mechanism of membrane layer fouling formation, the experimental data obtained werecompared to the Hermia model.

Diagnosis of early-stage damage to polymer - glass fibre composites using non-contact measurement of vibration signals

Tomasz Figlus,Mateusz Koziol 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.8

Ensuring reliable operation of the means of transport requires the development of methods for early detection of damage to its components made of composite materials. For diagnostic testing of composite materials during normal operation of the means of transport, the authors propose to use non-contact vibration measurement methods and their subsequent processing and analysis. The paper presents the results of laboratory tests whose aim was to assess the ability to detect early symptoms of damage to composite materials using noncontact vibration measurement methods. The measurements included mechanical curves of the glass composite samples made in a conventional manner and simultaneously their vibrations were measured in a non-contact manner using a laser vibrometer. Continuous wavelet transform was used for processing vibration signals. Calculated time-frequency scale distributions of vibration signals enabled the designation of frequency scale bands in which early, low-energy symptoms of damage to glass composites are observed. The analysis results allow to draw conclusions that the use of non-contact measurements and processing of vibration signals extends the existing range of composites research and enables detection of early, low-energy symptoms of damage to glass fibre reinforced composites.

Promoter methylation and expression levels of selected hematopoietic genes in pediatric B-cell acute lymphoblastic leukemia

Ewa Musialik,Mateusz Bujko,Paulina Kober,Agnieszka Wypych,Karolina Gawle-Krawczyk,Michal Matysiak,Janusz Aleksander Siedlecki 대한혈액학회 2015 Blood Research Vol.50 No.1

BackgroundPrecursor B-cell acute lymphoblastic leukemia (B-cell ALL) is the most common neoplasmin children and is characterized by genetic and epigenetic aberrations in hematopoietictranscription factor (TF) genes. This study evaluated promoter DNA methylation and aberrantexpression levels of early- and late-acting hematopoietic TF genes homeobox A4 andA5 (HOXA4 and HOXA5), Meis homeobox 1 (MEIS1), T-cell acute lymphocytic leukemia1 (TAL1), and interferon regulatory factors 4 and 8 (IRF4 and IRF8) in pediatric B-cell ALL. MethodsBlood samples of 38 ALL patients and 20 controls were obtained. DNA was treated withsodium bisulfite and DNA methylation level of HOXA4, HOXA5, MEIS1, TAL1, IRF4, and IRF8was assessed using quantitative methylation-specific polymerase chain reaction (PCR). Relative gene expression was measured using quantitative reverse transcription-PCR. ResultsAberrant methylation of TAL1, IRF8, MEIS1, and IRF4 was observed in 26.3%, 7.9%, 5.3%,and 2.6% patients, respectively, but not in controls. HOXA4 and HOXA5 were methylatedin some controls and hypermethylated in 16% and 5% patients, respectively. IRF8, MEIS1,and TAL1 expression was lower in patients than in controls. MEIS1 expression was inverselycorrelated with white blood cell (WBC) count. HOXA4 expression was downregulatedin patients with high risk according to the National Cancer Institute (NCI)classification. TAL1 methylation was slightly elevated in patients aged >9 years and inpatients showing relapse, suggesting its potential prognostic value. ConclusionAberrant methylation and expression of the selected hematopoietic genes were correlatedwith demographic/clinical prognostic factors of pediatric ALL, such as age, WBCcount, and NCI risk classification.