Temperature Coefficient of Poly-Silicon TFT and its Application on Voltage Reference Circuit With Temperature Compensation in LTPS Process

The temperature coefficient (TC) of n-type polycrystalline silicon thin-film transistors (poly-Si TFTs) is investigated in this paper. The relationship between the TC and the activation energy is observed and explained. From the experimental results, it is also found that TC is not sensitive to the deviation of the laser crystallization energy. On the contrary, channel width can effectively modulate the TC of TFTs. By using the diode-connected poly-Si TFTs with different channel widths, the first voltage reference circuit with temperature compensation for precise analog circuit design on glass substrate is proposed and realized. From the experimental results in a low-temperature poly-Si process, the output voltage of voltage reference circuit with temperature compensation exhibits a very low TC of 195 ppm/degC , between 25degC and 125degC. The proposed voltage reference circuit with temperature compensation can be applied to design precise analog circuits for system-on-panel or system-on-glass applications, which enables the analog circuits to be integrated in the active-matrix liquid crystal display panels.     

Colossal Magnetoresistance Properties of La0.83Sr0.17MnO3 Thin Films Grown by MOCVD on Lucalox Substrate

The magnetoresistance (MR) of polycrystalline La_0.83Sr_0.17MnO₃ thin films have been studied in high pulsed magnetic fields up to 38 T in the temperature range 100–300 K. The lucalox substrates were used to obtain polycrystalline structures with naturally formed grain boundaries (GBs) and crystallites whose dimensions were determined by film deposition temperature. It was found that the MR value is highest in the films having smallest crystallites. The main behaviour of high-field MR was analysed using modified Mott’s hopping model assuming that the GBs might be ferromagnetic with a Curie temperature T _C being reduced in comparison with that of the crystallites interior.     

Detection Thresholds for 2-Isopropyl-3-Methoxypyrazine in Concord and Niagara Grape Juice

ABSTRACT:  2-Isopropyl-3-methoxypyrazine (IPMP) is the compound responsible for the off-flavor known as ladybug taint, which occurs when Harmonia axyridis beetles become incorporated with the grapes during juice processing. It is also an important grape-derived component of juice flavor in some varieties. The main objective of this study was to determine the orthonasal (ON) and retronasal (RN) detection thresholds for IPMP in juice. The ASTM E679 ascending forced choice method of limits was used to determine detection thresholds for 26 individuals in Concord and Niagara juices. Group best estimate thresholds (BETs) averaged 0.93 ng/L and were 50% and 21% higher in Concord than in Niagara juices for ON and RN evaluation, respectively. Group BETs for IPMP (ng/L) for Concord were ON: 1.11; RN: 1.02 and for Niagara were ON: 0.74; RN: 0.84. Variation in individual detection thresholds was observed, although familiarity with ladybug taint was not associated with individual threshold values. We conclude that humans are very sensitive to IPMP in juice, and that detection thresholds are more strongly influenced by grape variety than evaluation mode. These results may assist juice producers in establishing tolerance levels for IPMP in juice affected by ladybug taint or derived from grapes of suboptimal ripeness.     

Hardware/firmware co-design in an 8-bits microcontroller to solve the system-level ESD issue on keyboard

A hardware/firmware co-design solution in an 8-bits microcontroller has been proposed to practically fix the system-level electrostatic discharge (ESD) issue on the keyboard products. By including the especial ESD sensors and an additional ESD flag into the chip, the fast electrical transient due to the system-level ESD zapping on the keyboard can be detected. The firmware stored in the ROM of the 8-bits microcontroller is designed to automatically check the ESD flag to monitor the abnormal conditions in system operations. If the keyboard is upset or locked up by a system-level ESD transient, the microcontroller can be quickly recovered to a known and stable state. The 8-bits microcontroller with such a hardware/firmware co-design solution has been fabricated in a 0.45-μm CMOS process. The system-level ESD susceptibility of the keyboard with this 8-bits microcontroller has been improved from the original ±2 kV (±4 kV) to become greater than ±8 kV (±15 kV) in the contact-discharge (air-discharge) ESD zapping.     

Drying of foam-formed mats from virgin pine fibers

The purpose of this work was to select an efficient drying technique for drying of highly porous thick fiber foam mats with minimum impact on their structure after forming and drainage. Thick fiber mats were produced from wood fibers using foam-forming technology and dried using several different drying methods. The mixture of pine fibers and surfactant (foaming agent) in water was blended using a high-speed blender. After fiber foam generation, a sample mold was filled with wet fiber foam, and after drainage, drying experiments were performed. For comparison, experiments were carried out in an oven, an impingement dryer assisted with a vacuum, and a combined impingement-infrared dryer. At low moisture contents, through-air drying experiments were also carried out. Drying curves, temperature profiles, and shrinkage were measured from the produced mat structures. The most promising drying technique in this study was the combined impingement-infrared drying, used until the fiber mat became permeable, followed by through-air drying until the desired final moisture content was achieved.     

Design of high-voltage-tolerant stimulus driver with adaptive loading consideration to suppress epileptic seizure in a 0.18-μm CMOS process

A novel design of high-voltage-tolerant stimulus driver for epileptic seizure suppression with low power design and adaptive loading consideration is proposed in this work. The proposed design can deliver the required stimulus current within a specific range of loading impedance. Besides, this design in 0.18-μm low-voltage CMOS process can be operated with high supply voltage (V_CC) of 5–10 V without using the high-voltage transistors, and the process steps of high-voltage transistors can be reduced. The proposed design can be further integrated for an electronic epilepsy prosthetic system-on-chip.     

Interactive effects of carbon nanotube and montmorrilonite reinforcement polyvinyl alcohol composite system

This work was conducted to investigate the interactive effect of carbon nanotubes (CNTs) and montmorillonite (MMT) on the mechanical–physical properties of the polyvinyl alcohol (PVOH) nanocomposites. The increasing of CNTs amounts from 0.5 phr to 1 phr has gradually increased tensile strength and Young's modulus of all PVOH/MMT blends due to good interaction effect between MMT and CNTs with PVOH matrix especially for 2 phr MMT added PVOH blends. Besides, the addition of low CNTs amounts (≤1 phr) in PVOH matrix has significantly weakened the hydrogen bonding polymer matrix of all PVOH/MMT blends as evaluated in FTIR analysis. This is attributed to the good of dispersion of low amounts of CNTs could disturb the hydrogen bonding between PVOH molecules and thus induced the strength of O? H stretching in PVOH matrix. However, higher amounts of CNTs (≥1.5 phr) have significantly increased hydrogen bonding in PVOH matrix due to the agglomeration of higher amounts of CNTs particles in PVOH matrix as observed in Fourier transform infrared spectroscopy and scanning electron microscopy analysis. From X‐ray diffraction and transmission electron microscopy observation, the MMT particles were found to effectively exfoliate in PVOH matrix of 2 phr MMT (low amounts) added PVOH/MMT/MCNTs composites, indicates that low MMT amounts could improve the interaction effect between PVOH matrix and CNTs particles. In conclusion, the incorporation of lower amounts of CNTs has effectively improved on the mechanical and physical properties of all PVOH and PVOH/MMT blends. J. VINYL ADDIT. TECHNOL., 26:77–89, 2020. © 2019 Society of Plastics Engineers     

Long-term prediction of creep strains of mineral wool slabs under constant compressive stress

The results obtained in determining the creep strain of mineral wool slabs under compressive stress, used for insulating flat roofs and facades, cast-in-place floors, curtain and external basement walls, as well as for sound insulation of floors, are presented. The creep strain tests were conducted under a compressive stress of σ _c =0.35σ _10%. Interval forecasting of creep strain was made by extrapolating the creep behaviour and approximated in accordance with EN 1606 by a power equation and reduced to a linear form using logarithms. This was performed for a lead time of 10 years. The extension of the range of the confidence interval due to discount of the prediction data, i.e. a decrease in their informativity was allowed for by an additional coefficient. Analysis of the experimental data obtained from the tests having 65 and 122 days duration showed that the prediction of creep strains for 10 years can be made based on data obtained in experiments with durations shorter than the 122 days as specified by EN 13162. Interval prediction of creep strains (with a confidence probability of 90%) was based on using the mean square deviation of the actual direct observations of creep strains in logarithmic form to have the linear trend in a retrospective area.     

Hypoglycemic effect of extract of Hericium erinaceus

Recent studies have determined that many types of mushroom (eg Hericium spp), may have important physiological functions in humans, including antioxidant activities, the regulation of blood lipid levels and reduction of blood glucose levels. In this study, a methanol extract of the fruiting bodies of Hericium erinaceus was adsorbed on silica gel columns and eluted using polarity gradients of chloroform/ethyl acetate/acetone/methanol. The major components of the extract were D ‐threitol, D ‐arabinitol and palmitic acid identified by their chromatographic profiles and spectroscopic characteristics. The methanol extract of H erinaceus was concentrated to remove solvent yielding a residue (referred to as HEM) which was added to the diet. The hypoglycemic effects of feeding HEM to streptozotocin‐induced diabetic rats were studied. Polydipsia was stronger in induced diabetic rats not fed HEM than in those receiving HEM. Rats fed with HEM had significantly lower elevation rates of blood glucose level than those not fed with HEM. The effects on blood glucose, serum triglyceride and total cholesterol levels were more significant in the rats fed daily with HEM at doses of 100 mg kg^?1 body weight (bw) rather than 20 mg kg^?1 bw (p < 0.05). Copyright © 2004 Society of Chemical Industry