Ni-doped goethite (α-FeOOH) nanorods were synthesized from mixed Fe(III)-Ni(II) nitrate solutions with various Ni/(Ni+Fe) ratios (0, 5, 10, 20, 33 and 50 mol % Ni) by hydrothermal precipitation in a highly alkaline medium using the strong organic alkali, tetramethyl¬ammonium hydroxide (TMAH). Ni-doped hematite (α-Fe2O3) nanorods were obtained by calcination of Ni- doped goethite nanorods at 400 °C. The Ni2+- for-Fe3+ substitution in goethite and hematite was confirmed by determination of the unit cell expansion (due to the difference in the ionic radii of Fe3+ and Ni2+) using XRPD and determination of the reduction of a hyperfine magnetic field (due to the difference in magnetic moments of Fe3+ and Ni2+) using Mossbauer spectroscopy. Single- phase goethite nanorods were found in samples containing 0 or 5 mol % Ni. A higher Ni content in the precipitation system (10 mol % or more) resulted in a higher Ni2+-for-Fe3+ substitution in goethite, and larger Ni-doped goethite nanorods, though with the presence of low crystalline Ni-containing ferrihydrite and Ni ferrite (NiFe2O4) as additional phases. Significant changes in FT-IR and UV-Vis-NIR spectra of prepared samples were observed with increasing Ni content. Electrochemical measurements of samples showed a strong increase in oxygen evolution reaction (OER) electrocatalytic activity with increasing Ni content.

W referacie zaprezentowano empiryczny model do szacowania tlumienia systemowego dla radiowych sieci BAN pracujących w środowisku promu pasazerskiego przy czestotliwości 2,45 GHz dla komunikacji typu off-body. Badania pomiarowe przeprowadzono dla scenariuszy dynamicznych w pomieszczeniu dyskoteki promu pasazerskiego. Postac analityczna modelu sklada sie z trzech skladowych: tlumienia średniego, tlumienia wynikającego ze zmiennej pozycji anteny na ciele czlowieka oraz tlumienia wynikającego z wystepowania zanikow sygnalu radiowego.

Analyzing video data is a complex problem for social science researchers. This study explored the use of an analytical visualization method to support the process of narrowing a video data corpus—focusing on meaningful moments for further qualitative analysis. We used the real-time observational coding tool to examine students’ activities and engineering design practices in a STEM curriculum. The findings suggest that using this tool supports time-efficient analyses of large corpuses of video data.

Projection of high-dimensional data is usually done by reducing dimensionality of the data and transforming the data to the latent space. We created synthetic data to simulate real gene-expression datasets and we tested methods on both synthetic and real data. With this work we address the visualization of our data through implementation of regularized singular value decomposition (SVD) for biclustering using L0-norm and L1-norm. Additional knowledge is introduced to the model through regularization with the two prior adjacency matrices. We show that L0-norm SVD and L1-norm SVD give better results than standard SVD.

Many effective robot-manipulator control schemes using a disturbance observer have been reported in the literature in the past decades. Besides, the disturbance observer combined with the Kalman filter has attracted the attention of researchers in the field of motion control. The major advantage of a motion control system based on the Kalman filter and disturbance observer is the realization of high robustness against disturbance and parameter variations, effective noise suppression and wideband force sensing. This paper presents a survey of motion control based on the Kalman filter and disturbance observer, which have been previously introduced by the authors. Several control schemes, as well as formulations and applications of the Kalman filter and disturbance observer, are described in the paper. The performance and effectiveness of the control schemes are evaluated to give a useful and comprehensive design of the Kalman filter and disturbance observer in various motion control applications.

Received: 12.09.2017 Accepted: 28.10.2017 Department of Neurosurgery, Cantonal Hospital Zenica, Bosnia and Herzegovina1, Department of maxillofacial surgery, Cantonal Hospital Zenica, Bosnia and Herzegovina2, Department of infectious diseases, Cantonal Hospital Zenica, Bosnia and Herzegovina3 Yazışma adresi: Fahrudin Alić, Department of Neurosurgery, Cantonal Hospital Zenica, Bosnia and Herzegovina e-mail: alifahrudyn@gmail.com INTRODUCTION