Akhiruddin Maddu

Biosensor H2O2 by Using Immobilized Horseradish PeroxidaseGlutaraldehyde on Carbon Polyaniline Nanofiber Composite

Mutations in the AGK gene are known to cause Sengers Syndrome, a rare recessive disorder characterized by congenital cataracts, hypertrophic cardiomyopathy, skeletal myopathy, exercise intolerance and lactic acidosis with normal mental development. Since the first report in 1975 by Sengers et al. about 50 individuals have been described as having this syndrome. Here we report two novel mutations in the AGK gene in two patients with neonatal Sengers syndrome.

SINTESIS NANOSILIKA DARI ABU KETEL INDUSTRI GULA DENGAN METODE ULTRASONIKASI DAN PENAMBAHAN SURFAKTAN

Boiler ash from sugar industry contains silica compounds which could be synthesized into nanosilica by ultrasonication method. The addition of surfactants in this synthesis method can affect the characteristics of nanosilica. This study aims to synthesize nanosilica with ultrasonication method and determine the effect of surfactants on characteristics of nanosilica generated. This research was divided into three stages: (1) boiler ash preparation to furnace ash, (2) silica extraction from furnace ash, and (3) synthesis of nanosilica using ultrasonication method with surfactant addition: PEG 6000 1:5, CMC 2.5% (b/b), CMC 5% (b/b), CMC 10% (b/b), and Tween 80 3% (b/v). Silica content in boiler ash and furnace ash was 49.69% and 78.75%, respectively. The nanosilics produced using the ultrasonication method had the uniform size (PDI) of 0.638, and with the addition of surfactant might increase the uniformity of the particle (PDI) to 0.045 and 0.047 on the usage of CMC 5 and 2.5%. The addition of surfactant also increased the crystallinity degree from 76.96% at no surfactant to 84.04% with 10% CMC surfactant added. The crystalline size of the silica nanoparticles also became smaller with the addition of 10% CMC of 37.69 nm from 41.40 nm crystal size without the addition of surfactant. The addition of an enlarged CMC concentration would increase the degree of crystallinity and decrease the crystal size of the nanosilica particles. Keywords : boiler ash, nanosilica, ultrasonication, surfactant, degree of crystallinity

A Novel Vible-Light Photodetector Based on Chlorophyll-Modified ZnO Nanoparticles

The paper presents the way that colour can serve solving the problem of calibration points indexing in a camera geometrical calibration process. We propose a technique in which indexes of calibration points in a black-and-white chessboard are represented as sets of colour regions in the neighbourhood of calibration points. We provide some general rules for designing a colour calibration chessboard and provide a method of calibration image analysis. We show that this approach leads to obtaining better results than in the case of widely used methods employing information about already indexed points to compute indexes. We also report constraints concerning the technique. Nowadays we are witnessing an increasing need for camera geometrical calibration systems. They are vital for such applications as 3D modelling, 3D reconstruction, assembly control systems, etc. Wherever possible, calibration objects placed in the scene are used in a camera geometrical calibration process. This approach significantly increases accuracy of calibration results and makes the calibration data extraction process easier and universal. There are many geometrical camera calibration techniques for a known calibration scene [1]. A great number of them use as an input calibration points which are localised and indexed in the scene. In this paper we propose the technique of calibration points indexing which uses a colour chessboard. The presented technique was developed by solving problems we encountered during experiments with our earlier methods of camera calibration scene analysis [2]-[3]. In particular, the proposed technique increases the number of indexed points points in case of local lack of calibration points detection. At the beginning of the paper we present a way of designing a chessboard pattern. Then we describe a calibration point indexing method, and finally we show experimental results. A black-and-white chessboard is widely used in order to obtain sub-pixel accuracy of calibration points localisation [1]. Calibration points are defined as corners of chessboard squares. Assuming the availability of rough localisation of these points, the points can be indexed. Noting that differences in distances between neighbouring points in calibration scene images differ slightly, one of the local searching methods can be employed (e.g. [2]). Methods of this type search for a calibration point to be indexed, using a window of a certain size. The position of the window is determined by a vector representing the distance between two previously indexed points in the same row or column. However, experiments show that this approach has its disadvantages, as described below. * E-mail: A.Nowakowski@ire.pw.edu.pl Firstly, there is a danger of omitting some points during indexing in case of local lack of calibration points detection in a neighbourhood (e.g. caused by the presence of non-homogeneous light in the calibration scene). A particularly unfavourable situation is when the local lack of detection effects in the appearance of separated regions of detected calibration points. It is worth saying that such situations are likely to happen for calibration points situated near image borders. Such points are very important for the analysis of optical nonlinearities, and a lack of them can significantly influence the accuracy of distortion modelling. Secondly, such methods may give wrong results in the case of optical distortion with strong nonlinearities when getting information about the neighbouring index is not an easy task. Beside this, the methods are very sensitive to a single false localisation of a calibration point. Such a single false localisation can even result in false indexing of a big set of calibration points. To avoid the above-mentioned problems, we propose using a black-and-white chessboard which contains the coded index of a calibration point in the form of colour squares situated in the nearest neighbourhood of each point. The index of a certain calibration point is determined by colours of four nearest neighbouring squares (Fig.1). An order of squares in such foursome is important. Because the size of a colour square is determined only by the possibility of correct colour detection, the size of a colour square can be smaller than the size of a black or white square. The larger size of a black or white square is determined by the requirements of the exact localisation step which follows the indexing of calibration points [3]. In this step, edge information is extracted from a blackand-white chessboard. This edge information needs larger Artur Nowakowski, Wladyslaw Skarbek Institute of Radioelectronics, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warszawa, A.Nowakowski@ire.pw.edu.pl Received February 10, 2009; accepted March 27, 2009; published March 31, 2009 http://www.photonics.pl/PLP

MATERIAL BIOKERAMIK BERBASIS HIDROKSIAPATIT TULANG IKAN TUNA

Material biokeramik berbasis hidroksiapatit memiliki prospek baru dalam industri elektronika dan mikroteknologi masa depan. Hidroksiapatit dengan sumber bahan baku alami merupakan potensi besar, terlebih pemanfaatan limbah tulang ikan tuna yang masih belum dilakukan dengan baik. Teknologi sintesis yang ada juga belum efektif serta karakterisasi materialnya belum banyak dikembangkan. Penelitian ini bertujuan mensintesis dan mengetahui karakteristik material biokeramik berbasis hidroksiapatit tulang ikan tuna. Metode yang digunakan dalam pengekstraksian hidroksiapatit tulang ikan tuna adalah dengan pemanasan suhu tinggi (sintering). Melalui suhu sintering 700oC telah dapat dihasilkan material biokeramik berbasis hidroksiapatit dari tulang ikan tuna dengan rendemen tertinggi (65,61±2,21)% dan berwarna putih. Semakin tinggi suhu sintering, semakin tinggi derajat kristalinitasnya, sedangkan dengan SEM memperlihatkan partikel penyusunnya berukuran 0,050 μm sampai 0,803 μm dan menyerupai bentuk kristal heksagonal. Nilai kapasitansi mengalami penurunan dengan bertambahnya frekuensi yang diberikan, dengan nilai tertinggi 0,0061 nF, sedangkan nilai konduktivitas mengalami kenaikan seiring dengan bertambahnya frekuensi dengan nilai terendah 7,73 x 10-5 S/m. Kata kunci: biokeramik, hidroksiapatit, sintering, tulang ikan tuna

PENDETEKSIAN TINGKAT KESEGARAN FILET IKAN NILA MENGGUNAKAN PENGUKURAN SIFAT BIOLISTRIK

The development of modern rapid detection techniques of fish freshness requires a new perspective of the importance of physical chemical characteristics during deterioration process of quality fishery products. Positive correlation between the changes of fish body and the electrical properties is a basic information for support the development of the detection modern techniques of fish freshness. Studies of the electrical properties become more relevant along with the increasing demand of fish fast food consumption and fish product from freshwater aquaculture, which have been less done until now. The objective of this study was to detect freshness of tilapia fillets using bioelectrical properties. The result showed that level of freshness of tilapia fillet can be detected by using bioelectrical which has correlation with TVB, TPC and pH. The level of freshness of tilapia fillet during 16 hours observation showed that impedance tend to decrease with the range of 44.34-6.30 Ω, while dielectric constant and the electrical conductivity tend to increase with range of 178,208 to 2,812,764 and 0.065 to 0.487 S/m. Key words: bioelectrical, fish freshness, tilapia fillet, quality deterioration