Somsak Dangtip

Effect of cross-linking on physicochemical properties of tapioca starch and its application in soup product

Physicochemical properties of cross-linked tapioca starch (CLTS) with different cross-linking levels and their application as a thickening agent in soups were studied. The CLTS was prepared by cross-linking native tapioca starch suspended in alkaline solution (41.67% (w/w), pH 11) using a mixture (99:1 (w/w) ratio) of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) at different concentrations ranged from 0.25% to 6.0% (w/w of starch) at 45°C for 3h. Starch paste clarity decreased with increasing concentration of STMP/STPP mixture. Variations of swelling power, solubility, pasting, gelatinization, and rheological properties of the CLTS were found. Thermogravimetric analysis exhibited higher thermal stability for the CLTS granules compared to the native one. Among the samples, the CLTS prepared using 1.0% STMP/STPP (1.0%-CLTS) and soup containing the 1.0%-CLTS exhibited the strongest gel characteristic and the greatest shear resistant properties. The 1.0%-CLTS improved the textural properties and sensory quality of soups.

Characterization of Modified Tapioca Starch in Atmospheric Argon Plasma under Diverse Humidity by FTIR Spectroscopy

Tapioca is economical crop grown in Thailand and continues to be one of the major sources of starch. Nowadays, tapioca starch has been widely used in industrial applications, however the native form of starch has limited the applications. Thus scientists try to modify the properties of starch for increasing the stability of the granules, pastes to low pH, heat, and shear during the food process. We modify the tapioca starch by plasma treatment under an argon atmosphere. The degree of modification is determined by following water content in the starch granules. The tablet samples of native starch are also prepared and compared with the plasma treated starch. Before plasma treatment, the starch tablets are stored under three different relative humilities (RH) including 11%, 68%, and 78%RH, respectively. The samples are characterized using FTIR spectroscopy associated with the degree of cross-linking. The results show that the water molecules are engulfed into the starch structure in two ways, a tight bond and a weak absorption of water molecules which is represented at two wave number of 1630 cm−1 and 3272 cm−1, respectively. The degree of cross-linking can be identified from the relative intensity of these two peaks with the C—O—H peak at 993 cm−1. The results show that the degree of cross-linking increase in the plasma treated starch. The degree of cross-linking of the treated starch with high relative humidity is less than that of the treated starch with low relative humidity.

Modification of tapioca starch by non-chemical route using jet atmospheric argon plasma

Non-chemical modification of tapioca starch was investigated using jet atmospheric argon plasma treatment. Two forms of starch slurry, i.e. granular starch (G) and cooked starch (C), were jet-treated by argon plasma generated by supplying input power of 50 W (denoted as G50 and C50 samples) and 100 W (denoted as G100 and C100 samples) for 5 min. Physical, rheological, and structural characteristics of the modified starch were investigated. The G50 and C100 samples had lower paste clarity but higher thermal stability and performed stronger gels (G50 only) compared to their control counterparts. On the other hand, the analyzed properties of the G100 and C50 samples showed the opposite trend. FTIR and (1)H NMR results revealed that the relative areas of COC and OH peaks were changed after the treatment. Cross-linking reaction seemed to predominantly take place for the G50 and C100 samples, whereas depolymerization predominated for the G100 and C50 samples.

Blue Flexible Transparent Organic Light-Emitting Devices

Blue transparent organic light-emitting devices (TOLEDs) and blue flexible OLEDs (FOLEDs) have been fabricated on glass and plastic films, respectively. We have also fabricated blue flexible transparent OLEDs (FTOLEDs) having both flexibility and transparency by using indium-tin-oxide:cesium (ITO:Cs) as a cathode. A Cs-incorporated ITO electrode is useful for the fabrication of not only a TOLED on a glass substrate but also a flexible TOLED on a plastic film.

Study of low power deposition of ITO for top emission OLED with facing target and RF sputtering systems

Deposition of ITO as top transparent electrode was studied using two deposition systems with and without direct contact to working plasma; namely with conventional RF-magnetron planar (RSS) and pulsed-DC facing target sputtering systems (FTS). Test devices were made on glass substrates and consisted of (from bottom up) ITO/4 Organic Layers/ITO. Depositions were performed at low deposition powers; 30 and 60 watts, to reduce damages by energetic sputtered particles to underlying organic layers. Test devices from both sputtering systems were found to function well. Leakage current density at -5 V reverse bias were relatively constant from 0.3 and 0.4 mA/cm2 at 30 W and 60 W in FTS, while the values were found to increase from 0.001 to 0.2 mA/cm2 at 30 W and 60 W in RSS.

Effects of Substrate Temperature and Vacuum Annealing on Properties of ITO Films Prepared by Radio-Frquency Magnetron Sputtering

Indium tin oxide (ITO) films were prepared by rf magnetron sputtering under two conditions: (i) at substrate temperature Ts from room temperature (RT) to 350° C, (ii) with additional post-annealing in vacuum at 400° C for 30 min in comparison of their crystalline structures, and electrical-optical properties of the films deposited. From the experimental results, it is found that, under the first condition, the crystalline structures and the electrical-optical properties of the films are improved with the increasing Ts. Under the other condition, i.e. with the additional post-annealing, the films exhibit higher degree of crystallinities and better electrical-optical properties. Under the two deposition conditions, inter-relation between electrical-optical properties and the crystalline structure is observed clearly. However, even under the same annealing condition, it is observed that improved properties of the films are different, depending on their deposition temperatures, which implies that an initial stage of the ITO film before annealing is an important factor for the films properties improved after annealing. The resistivity of 2.33 × 10−4 Ω·cm can be achieved at Ts of 350° C after annealing.

Experimental Double-Differential Light-Ion Production Cross Sections for Silicon at 95 MeV Neutrons

The importance of cosmic radiation effects in aircraft electronics has recently been highlighted. At commercial flight altitudes, as well as at sea level, the most important particle radiation is due to neutrons, created in the atmosphere by spallation of nitrogen and oxygen nuclei, induced by cosmic-ray protons. When, e.g., an electronic memory circuit is exposed to neutron radiation, charged particles can be produced in a nuclear reaction. The charge released by ionization can cause a flip of the memory content in a bit, which is called a single-event upset (SEU). A similar logic error in one of the storage registers of a microprocessor may trigger an unanticipated loop that cannot be escaped without turning the unit off. To get a deeper understanding of these phenomena, more detailed cross section information on neutron-induced charged-particle production at intermediate energies is needed. To this end, double-differential cross sections of inclusive light-ion production in silicon, induced by 95 MeV neutrons, have been measured. The experiment was performed using the MEDLEY setup, which consists of eight three-element particle telescopes, covering the angular range 20° – 160°. The charged particles were identified using ΔE – ΔE – E techniques. By using an active target, consisting of a 300 μm thick Si detector, the energy loss in the target itself could be measured and corrected for.

Study of Thermal Property of Glass-Ceramics Produced from Soda Lime Glass Waste by Single-Step Sintering Process

Soda lime glass (SLG) is one type of glass mainly used in beverage and food packaging industries. SLG has high potential as starting materials for glass-ceramics (GC) production as SLG consists of large proportion of silicate and has considerably low of melting temperature. In addition, large consumption of beverages and foods, SLG makes up a large bulk of the waste. Producing glass-ceramics (GC) from SLG is thus interesting. Processing of SLG to GC is strongly dependent on their thermal property. Before processing, thermal profile of SLG was analyzed by differential scanning calorimetry; crystallization temperature at 711 °C was identified at the heating rate of 5 °C/min. It was also possible to extract information about crystallization kinetic by applying the Kissinger and the Ozawa relations. It was found that crystallization activation energies were 365.06 and 381.60 kJ/mol, respectively. For the GC processing, SLG powder was mixed with precursors to the ratio of 60SLG-35SiO2-2TiO2-2ZnO-1CuO before sintering with single step method at 711, 800, 850, 900, 950, 1,000 °C. An analysis by XRD has shown that there were two phases; beta-quartz and beta-cristobalite, in the sintered samples. Different sintering temperatures have yielded different proportion of alpha-to beta-phases. SEM/EDX has also revealed uneven distribution of different oxides in the produced glass-ceramics.

Detecting DNA-DNA Hybridization at 3-Mercaptopropionic Acid Self-Assembled on Tin-Doped Indium Oxide Film with Electrochemical Measurement

Self-assembled monolayers (SAM) of 3-mercaptopropionic acid (MPA) were applied on tin-doped indium oxide (ITO) surfaces and used as a working electrode for sensing DNA hybridization. The concentration of probe single stranded DNA (ssDNA), complemented with target DNA, was optimized for the highest yield immobilization on MPA/ITO platform. The ssDNA/MPA/ITO was allowed to hybridize to target DNA prepared from PCR amplification that first tested by the synthesized complementary sequences. Both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed for investigating probe ssDNA immobilization and target DNA hybridization. For fast and low concentration detecting purposes, methylene blue (MB) coupled with differential pulse voltammetry (DPV) was used for detecting the target DNA hybridization events.

Fabrication of micropattern grating platform for sensing bio-molecule interaction

Device consisting of a micro-pattern grating structure with membrane of alternating dielectric materials such as SiO2, Si3N4 and SOG or ITO, is fabricated. Its utilization as a platform for attaching active silane layer such as APTES, further as a sensor after immobilizing of sensing molecules and hybridizing with complimentary molecules is demonstrated. Shifting in peak wavelength is observed when new layer is introduced onto the platform.