Work function change on O-plasma treated indium–tin-oxide

The change in work function was studied on Indium–tin-oxide (ITO) surface after O-plasma treatment using γ-focused ion beam (γ-FIB). As the surface of ITO experienced more O-plasma treatment, both the surface resistivity and the work function got higher. Auger electron spectroscopy identified the increase of oxygen as well as the decrease of Sn. The rise of work function and surface resistivity is considered to be due to the change in oxygen and Sn on the surface of ITO.     

Virtual fine delay line using one-stage inverter delay

A virtual fine delay line (VFDL) using only two ring oscillators and counters can cover a wide frequency operation range clock without adding any additional delay line stage. The proposed ring oscillator can easily make a unit delay as a one-stage inverter. The VFDL achieves fine resolution of less than 60 ps and small circuit area with two clock cycles lock-in time.     

Approximating the Outage Probability of the Pilot Channel for IS‐95‐Based Cellular CDMA Systems in the Soft Handover Region

This letter presents an approximation of the outage probability of the pilot channel that can be used for CDMA cell planning. The approximation can determine system parameters for soft handover in IS‐95‐based cellular CDMA downlink design. Computer simulations show that our analytical results agree with empirical results.     

Poly(lactic acid) nanocomposites: comparison of their properties with montmorillonite and synthetic mica (II)

Our study was to clarify the intercalation of polymer chains to organoclays and to improve the thermo-mechanical properties. Two organoclays were synthesized. One was a montmorillonite modified with hexadecylamine (C₁₆-MMT); the other was a fluorinated-mica modified with hexadecylamine (C₁₆-Mica). Dispersions of organoclays with poly(lactic acid) (PLA) were by using the solution intercalation method at different organoclay contents to produce nano-scale composites. The maximum ultimate tensile strength was observed for blends containing 4 wt% of either of the two organoclays and decreased with further increases in the organoclay content. The initial modulus increased with increasing organoclay content up to 4 wt% for C₁₆-MMT. When the C₁₆-MMT content was greater than this critical wt%, the modulus of the hybrids started to decrease. In contrast, the initial modulus of the hybrids using C₁₆-Mica increased continually with increasing clay content from 2 to 8 wt%. The tensile properties of the C₁₆-Mica hybrids were higher than those of the hybrids containing C₁₆-MMT. The optical translucency was not affected by the organoclay content up to 6 wt%; however, the films containing 8 wt% organoclays were slightly more cloudy.     

Antimicrobial activity of 4-hydroxybenzoic acid and trans 4-hydroxycinnamic acid isolated and identified from rice hull

Two antimicrobial substances in rice hull were isolated and identified as 4-hydroxybenzoic acid and trans 4-hydroxycinnamic acid by LC-MS, and 1H- and 13C-NMR. An evaluation of 50% inhibition of growth (IC50) revealed that the two substances had different inhibition profiles against various microorganisms. Most of the gram-positive and some gram-negative bacteria were sensitive to trans 4-hydroxycinnamic acid and 4-hydroxybenzoic acid at IC50 concentrations of 100-170 and 160 micrograms/ml, respectively.     

Variable VCC design techniques forbattery-operated DRAMs

Wide-voltage-range DRAMs with extended data retention are desirable for battery-operated or portable computers and consumer devices. The techniques required to obtain wide operation, functionality, and performance of standard DRAMs from 1.8 V (two NiCd or alkaline batteries) to 3.6 V (upper end of LVTTL standard) are described. Specific techniques shown are: (1) a low-power and low-voltage reference generator for detecting V_CC level; (2) compensation of DC generators, V_BB and V_PP, for obtaining high speed at reduced voltages; (3) a static word-line driver and latch-isolation sense amplifier for reducing operating current; and (4) a programmable V_CC variable self-refresh scheme for obtaining maximum data retention time over a full operating range. A sub-50-ns access time is obtained for a 16 M DRAM (2 M×8) by simulation     

Comparison of two methods of assisted fertilization in cynomolgus monkeys (Macaca fascicularis): intracytoplasmic sperm injection and partial zona dissection followed by insemination

Intracytoplasmic sperm injection (ICSI) and partial zona dissection followed by insemination (PZD-I) were used to establish a microinjection system in cynomolgus monkeys (Macaca fascicularis), which are potential models for human reproduction. Two experimental systems were studied, in which either hamster oocytes or cynomolgus monkey oocytes were used as the vehicle. When hamster oocytes were used, 66 out of 81 ICSI-treated oocytes (82%) showed sperm head swelling or pronucleus formation. Following PZD-I of hamster oocytes the rates of spermatozoa penetration (85/114; 75%) and fertilization (71/114; 62%) were relatively high. When cynomolgus monkey oocytes were used, 19 out of 31 (61%) were fertilized by ICSI with cynomolgus monkey spermatozoa and, subsequently, two embryos (7%) developed to the morula stage. In total, 94% (15/16) of the PZD-I treated oocytes were penetrated by spermatozoa and 63% (10/16) were fertilized. These results demonstrate that both micromanipulation techniques can be used in assisted fertilization with cynomolgus monkeys.     

Pattern classification of solder joint images using a correlation neural network

This paper presents a method of classifying solder joints on printed-circuit boards (PCB), using a neural-network approach. Inherently, the surface of the solder joints is curved, tiny and specularly reflective; it induces a difficulty of taking good images of the solder joints. The shapes of the solder joints tend to vary greatly with soldering conditions; solder joints, even when classified into the same soldering quality, have very different shapes. Furthermore, the position of the joints is not consistent within a registered solder pad on the PCB. Due to these aspects, it has been difficult to determine the visual features and classification criteria for automatic solder-joint inspection. In this research, the solder joints, imaged by using a circular, tiered illumination system of three colored lamps, are represented as red, green and blue colored patterns, showing their surface-slopes. Cross-correlation and auto-correlation of the colored patterns are used to classify the 3D shapes of the solder joints by their soldering qualities. To achieve this, a neural network is proposed, based on a functional link net, with two processing modules. The first preprocessing module is designed to implement the calculation of the correlations in functional terms. The subsequent, trainable module classifies the solder joints, based upon the capability learned from a human supervisor. The practical feasibility of the proposed method is demonstrated by testing numerous commercially manufactured PCBs.     

Manufacturing technology in Korea

This article describes a general overview of industry development, present status and future perspectives of manufacturing technology in Korea. The Advanced Manufacturing System project, which is one of the national R&D projects in manufacturing technology, is introduced. The problems for the future development of manufacturing technology in Korea is discussed.     

Identification of a peptide of the guanosine triphosphate binding site within brain glutamate dehydrogenase isoproteins using 8-azidoguanosine triphosphate

Photoaffinity labeling with [gamma-32P]8N3GTP (8-azidoguanosine triphosphate) was used to identify the guanine binding peptides of the GTT binding site within two types of glutamate dehydrogenase isoproteins (GDH I and GDH II) isolated from bovine brain. 8N3GTP, without photolysis, mimicked the inhibitory properties of GTP on GDH I and GDH II activities. Saturation of photoinsertion of GDH isoproteins revealed an apparent Kd of 8 microM (GDH I) and 24 microM (GDH II) for [gamma-32P]8N3GTP. Ion exchange and reversed-phase high-performance liquid chromatography (HPLC) were used to isolate photolabel-containing peptides generated with trypsin. This identified a portion of the guanine binding domain within the GTP binding site is the region containing the sequence I-S-G-A-S-E-X-D-I-V-H-S-A-L-A-Y-T-M E-R (GDH I) and I-S-G-A-S-E-X-D-I-V-H-S-G-L-A-Y-T-M-E-R (GDH II). The symbol X indicates a position for which no phenylthiohydantoin-amino acid could be assigned. The missing residue, however, can be designated as a photolabeled lysine since the sequences including the lysine residue in question have a complete identity with those of the other GDH species known. Also, trypsin was unable to cleave the photolabeled peptide at this site. Photolabeling of these peptides was prevented by the presence of GTP during photolysis, while other nucleotides could not reduce the amount of photoinsertion as effectively as GTP. These results demonstrate selectivity of the photoprobe for the GTP binding site and suggest that the peptide identified using the photoprobe is located in the GTP binding domain of the brain GDH isoproteins.