Ecology of technology: Survival and compatibility

Conclusion Continuous and patient inflow of new human and financial resources by the government or by private industry based on the strong will of top management backed by the concensus of constituents of the organisation is the main factor which contributes to the prosperity of any technology.     

Electromagnetic field analysis by boundary element method using spatial eigenmodes

This paper proposes a boundary-element method using spatial eigenmodes for electromgnetic field analysis. Mapping the computation model with rotational symmetries, reflective symmetries or rotational symmetries including reflective symmetries to a group of spatial eigenmodes, the equivalent reduced models are obtained. In the method, the applicability becomes wide because arbitrary external source terms can be chosen. Furthermore, in a model including asymmetry regions, a new method which can save the merit of the symmetries is proposed. Finally, the validity of the proposed method is proved by numerical simulations.     

A [meso-tetrakis(4-sulfonatophenyl)porphyrinato]zinc(ii) complex as an oral therapeutic for the treatment of type 2 diabetic KKA(y) mice

We prepared and characterized [meso-tetrakis(4-sulfonatophenyl)porphyrinato]zinc(II) ([Zn(tpps)]), and investigated its in vitro insulin-mimetic activity and in vivo hypoglycemic effect in type 2 diabetic KKA(y) mice. The results were compared with those of previously proposed insulin-mimetic zinc(II) complexes and zinc sulfate (ZnSO(4)). The in vitro insulin-mimetic activity of [Zn(tpps)] was considerably better than that of bis(allixinato)zinc(II) ([Zn(alx)(2)]), bis(maltolato)zinc(II) ([Zn(mal)(2)]), bis(2-aminomethylpyridinato)zinc(II) ([Zn(2-ampy)(2)](2+)), and ZnSO(4). In particular, the order of in vitro insulin-mimetic activity of the complexes was determined to be: [Zn(tpps)]>[Zn(alx)(2)]>[Zn(mal)(2)]>[Zn(2-ampy)](2+)>ZnSO(4). [Zn(tpps)] normalized the hyperglycemia of KKA(y) mice within 21 days when administered orally at doses of 10-20 mg (0.15-0.31 mmol) Zn per kg body mass for 28 days. In addition, metabolic syndromes such as insulin resistance, the degree of renal disturbance, and the degree of liver disturbance were significantly improved in [Zn(tpps)]-treated KKA(y) mice relative to those administered with saline and ZnSO(4). The improvement in diabetes was validated by the results of oral glucose-tolerance tests and the decrease in the HbA(1c) level observed. In contrast, ZnSO(4) and the ligand H(2)tpps did not lower the elevated blood glucose level under the same experimental conditions. Based on these observations, [Zn(tpps)] is proposed to be the first orally active zinc(II)-porphyrin complex for the efficacious treatment of not only type 2 diabetes but also metabolic syndromes in animals.     

$V_rm DD$-Hopping Accelerators for On-Chip Power Supply Circuit to Achieve Nanosecond-Order Transient Time

A V_DD-hopping accelerator for on-chip power supply circuits is proposed and the effectiveness of the accelerator circuit is experimentally verified. The quick dropper with the linear regulator enables nanosecond-order transient time in on-chip distributed power supply systems. The measured transition time is less than 5 ns with a load circuit equivalent to 25-k logic gates in 0.18-mum CMOS. This is to be compared with the case without the accelerator of the order of mus and thus the acceleration by two orders of magnitude is achieved. Extensions of the basic approach are also discussed including implementation of the quick dropper for a switching DC-DC converter, the control stability improvement, automatic timing generation, and the parasitic element effects of the power lines     

Design impact of positive temperature dependence on drain currentin sub-1-V CMOS VLSIs

In sub-1-V CMOS designs, especially around 0.5-V CMOS designs, on-state drain current of MOSFETs shows positive temperature dependence, being different from the negative temperature dependence in the conventional voltage designs. Combined with low threshold voltage less than 0.2 V, the possibility of temperature instability increases. This paper describes possible temperature instabilities in the low-voltage regime by using circuit simulation environments incorporating temperature change in time and experiments using MOSFETs and the 32-bit adder circuit in quarter-micrometer CMOS technology with a low threshold voltage of 0.25 V     

Scattering of a Gaussian Beam by Stepped Index Luneberg Lens

The scattering and focusing characteristics of a Gaussian beam with phase distribution is studied by a stepped index Luneberg lens. A model experiment was performed using a six-layer spherical lens. Two kinds of beams, that is, broad and narrow beam are examined for the incident Gaussian beam. We find that focusing effect of a narrow beam is wholly lower than that of a broad beam. The focal point is also shifted toward outer of sphere because of phase lag for the beam source. The spot size equals almost the wavelength for the various beam parameters.     

Propagation characteristics in open-groove waveguides surrounded by rough sidewalls

The radio propagation characteristics in groove-shaped roads surrounded by rough surface sidewalls are presented. Typical sidewalls are snowpack in heavy snow regions or buildings in urban areas. In this analysis, such roads are modeled by a straight groove waveguide with statistically rough sidewalls. A simple geometrical optical approach is applied to calculate the field strength along the longitudinal direction of the road as well as transversely across the road. The theoretical results are compared with previously presented experimental results. The theoretical results show that the surface roughness causes an additional propagation loss in regions far from the transmitting point and that the field strength in the cross section exhibits a cosine distribution with a slightly changing magnitude. These theoretical characteristics agree with the experimental results.<>