An enhanced channel-quality indication (CQI) reporting scheme for HSDPA systems

A major evolution of UMTS standard is the high speed downlink packet access (HSDPA). One of key techniques supporting HSDPA is the adaptive modulation and coding (AMC) in which the modulation scheme and the coding rate are adaptively changed according to the downlink channel quality reported by the user equipment (UE). Therefore, the channel quality indication (CQI) reporting scheme is directly related to the accuracy of AMC and the performance of HSDPA. This letter proposes an enhanced CQI reporting scheme that can be used when a proportional fair scheduling algorithm (PFA) is used as a packet scheduling algorithm. The proposed scheme uses a dynamic threshold to filter off redundant CQI reports. With the proposed scheme, the battery capacity of UK can be conserved, maintaining the performance of traditional CQI reporting scheme.     

Electrochemical behavior of dopamine and ascorbic acid at osmium(II) complex cationic monolayer modified gold electrodes.

The electrooxidation of dopamine (DA) and ascorbic acid (AA) was studied using gold electrodes modified by a cationic self-assembled monolayer of [Os(bpy)2(bpy-(CH2),3SH)]2+ by cyclic voltammetry. At an [Os(bpy)2(bpy-(CH2)13SH)]2+/Au electrode, the oxidation peak of DA shifted to a much more positive potential as compared with that of a bare gold electrode, while the oxidation peak potential of AA showed a slightly negative shift due to their different electrostatic interactions with the cationic monolayer. Thus, a sufficient potential difference was achieved for distinguishing the electrochemical responses of DA and AA. However, when CH3(CH2)11SH was mixed into the cationic monolayer, the enhanced packing of the mixed monolayer blocked the access of DA or AA to the electrode, resulting in further positive shifts for both oxidation-peak potentials.     

Channel width dependence of hot electron injection program/hot hole erase cycling behavior in silicon-oxide-nitride-oxide-silicon (SONOS) memories

The channel width dependence of hot electron injection program/hot hole erase cycling behavior in silicon-oxide-nitride-oxide-silicon (SONOS) memories is investigated. While the trapped charge profile-dependent overerasure is observed in 10-μm-wide device, it is suppressed in 0.22-μm-wide device. Both the overerasure suppression and gradual positive threshold voltage shift in narrow device are explained as an elevated hot hole injection efficiency followed by more pronounced redistribution of the hole profile in the channel-center and the suppression of the lateral migration of injected holes in the channel-edge, by combining the measured endurance characteristics and TCAD simulation results. Main physical mechanisms are three-dimensional distribution of the electric field by gate/drain voltage, increasing interface states, and their trapped charge with cycling in the channel-edge.     

Analysis of the reservoir effect on electromigration reliability

The reservoir effect on electromigration reliability is analyzed using the normalized vacancy concentration distribution in the reservoir region of multi-level Al–0.5%Cu interconnect structure. With the assumption of steady state for the vacancy concentration and the fact that no current flow conducts in the reservoir region during electromigration test, a simple equation for calculation of the vacancy concentration is induced. Then direct calculation of the equation is carried out utilizing the hydrostatic stress distribution computed from finite element method to estimate the probability of initial void formation in the reservoir region. Finally, three multi-level Al–0.5%Cu interconnect structures with different reservoir lengths are constructed and electromigration lifetime for the structures is measured to clarify these computational results. From the results of this study, we conclude that the normalized vacancy concentration under the assumption of steady state can be regarded as a quantitative parameter to analyze the reservoir effect on electromigration reliability.     

Influence of interfacial reaction layer on reliability of chip-scale package joint from using Sn-37Pb and Sn-8Zn-3Bi solder

The microstructure of Sn-37Pb and Sn-8Zn-3Bi solders and the full strength of these solders with an Au/Ni/Cu pad under isothermal aging conditions were investigated. The full strengths tended to decrease as the aging temperature and time increased, regardless of the properties of the solders. The Sn-8Zn-3Bi had higher full strength than Sn-37Pb. In the Sn-37Pb solder, Ni₃Sn₄ compounds and irregular-shaped Pb-rich phase were embedded in a β-Sn matrix. The Ni₃Sn₄ compounds were observed at the interface between the solder and pad. The microstructure of the as-reflowed Sn-8Zn-3Bi solder mainly consists of the β-Sn matrix scattered with Zn-rich phase. Zinc first reacted with Au and then was transformed to the AuZn compound. With aging, Ni₅Zn₂₁ compounds were formed at the Ni layer. Finally, a Ni₅Zn₂₁ phase, divided into three layers, was formed with column-shaped grains, and the thicknesses of the layers were changed.     

Enhancement of CO2 sorption uptake on hydrotalcite by impregnation with K2CO3

The awareness of symptoms of global warming and its seriousness urges the development of technologies to reduce greenhouse gas emissions. Carbon dioxide (CO(2)) is a representative greenhouse gas, and numerous methods to capture and storage CO(2) have been considered. Recently, the technology to remove high-temperature CO(2) by sorption has received lots of attention. In this study, hydrotalcite, which has been known to have CO(2) sorption capability at high temperature, was impregnated with K(2)CO(3) to enhance CO(2) sorption uptake, and the mechanism of CO(2) sorption enhancement on K(2)CO(3)-promoted hydrotalcite was investigated. Thermogravimetric analysis was used to measure equilibrium CO(2) sorption uptake and to estimate CO(2) sorption kinetics. The analyses based on N(2) gas physisorption, X-ray diffractometry, Fourier transform infrared spectrometry, Raman spectrometry, transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy were carried out to elucidate the characteristics of sorbents and the mechanism of enhanced CO(2) sorption. The equilibrium CO(2) sorption uptake on hydrotalcite could be increased up to 10 times by impregnation with K(2)CO(3), and there was an optimal amount of K(2)CO(3) for a maximum equilibrium CO(2) sorption uptake. In the K(2)CO(3)-promoted hydrotalcite, K(2)CO(3) was incorporated without changing the structure of hydrotalcite and it was thermally stabilized, resulting in the enhanced equilibrium CO(2) sorption uptake and fast CO(2) sorption kinetics.     

Two-dimensional assembly of [Mn(III)₂Mn(II)₂] single-molecule magnets and [Cu(pic)₂] linking units (Hpic = picolinic acid)

In an attempt to develop novel coordination networks of SMMs, a Cu(II) picolinate complex has been used to coordinate S(T) = 9 tetranuclear Mn-based SMMs resulting in an intriguing 2D framework exhibiting a magnet-like behavior at low temperature.     

Aspirin attenuates the anti-inflammatory effects of theophylline via inhibition of cAMP production in mice with non-eosinophilic asthma

Theophylline is commonly used to treat severe asthma and chronic obstructive pulmonary disease (COPD) characterized by non-eosinophilic inflammation. Acetyl salicylic acid (ASA) is one of the most widely used medications worldwide, but up to 20% of patients with asthma experience aggravated respiratory symptoms after taking ASA. Here we evaluated the adverse effect of ASA on the therapeutic effect of theophylline in mice with non-eosinophilic asthma. A non-eosinophilic asthma mouse model was induced by airway sensitization with lipopolysaccharide-containing allergen and then challenged with allergen alone. Therapeutic intervention was performed during allergen challenge. Theophylline inhibited lung inflammation partly induced by T_h1 immune response. ASA attenuated the beneficial effects of theophylline. However, co-administration of the ASA metabolite salicylic acid (SA) showed no attenuating effect on theophylline treatment. The therapeutic effect of theophylline was associated with increase in cAMP levels, which was blocked by co-treatment of theophylline and ASA. ASA co-treatment also attenuated the anti-inflammatory effects of a specific phosphodiesterase 4 inhibitor. These results demonstrate that ASA reverses anti-inflammatory effects of theophylline, and that ASA exerts its adverse effects through the inhibition of cAMP production. Our data suggest that ASA reverses lung inflammation in patients taking theophylline, although clinical evidence will be needed.     

Stretchable,Transparent Zinc Oxide Thin Film Transistors

Stretchable and transparent thin film transistors (TFTs) with intrisically brittle oxide semiconductors are built using a wavy structural configuration that can provide high flexibility and stretchability. After device fabrication procedures including high temperature annealing, the oxide semiconductor‐based TFT arrays can be transferred directly to plastic or rubber substrates, without an additional device process, using transfer printing methods. This procedure can avoid some of the thermal degradation problems associated with plastic or rubber substrates by separating them from the annealing procedure needed to improve the device performance. These design and fabrication methods offer the possibility of developing a new format of stretchable electronics.