Incident Light Conditions Research Articles

Tri-channel metasurface fusion of continuously varying gray levels for nanoprinting and holographic displays.

Metasurfaces are extensively utilized in nanoprinting and hologram fusion displays due to their superior wavefront shaping capabilities. However, the creation of continuously varying grayscale images based on conventional Malus's law necessitates the use of at least one polarizer for observation, which compromises the metasurface's integration. In this study, inspired by the Jacobi-Anger expansion, we propose a tri-channel metasurface to establish three independent information channels for simultaneous grayscale nanoprinting and polarization multiplexed holography. By meticulously designing the sizes and orientation angles of the nanostructures, the multifunctional metasurface can generate a grayscale nanoprinting image observable in the near-field without any polarization control, and simultaneously reconstruct two distinct holographic images in the far-field under varying incident light conditions. With its advantages of ultra-compactness, high information capacity, flexible design, and ease of observation, the proposed multifunctional and tri-channel metasurface holds significant promise for potential applications in three-dimensional stereoscopic displays, information multiplexing storage, and beyond.

The second-order coherence analysis of number state propagation through dispersive non-Hermitian multilayered structures

To examine the second-order coherence of light propagation of quantum states in arbitrary directions through dispersive non-Hermitian optical media, we considered two sets of non-Hermitian periodic structures that consist of gain/loss unit cells. We show that each batch can satisfy the parity-time symmetry conditions at a distinct frequency. We then varied the gain/loss strength in the stable electromagnetic regime to evaluate the transmittance of N-photon number states through each structure. The results show both sets preserve their antibunching characteristics under specific incident light conditions. Furthermore, s(p)-polarized light exhibits higher (lower) second-order coherence at larger incident angles. In addition, the antibunching features of the transmitted states degrade with an increase in the number of unit cells in multilayered structures for both polarizations.

Preserving polarization maintaining photons for enhanced contrast imaging of the retina.

The purpose of this study is to demonstrate the feasibility of using polarization maintaining photons for enhanced contrast imaging of the retina. Orthogonal-polarization control has been frequently used in conventional fundus imaging systems to minimize reflection artifacts. However, the orthogonal-polarization configuration also rejects the directly reflected photons, which preserve the polarization condition of incident light, from the superficial layer of the fundus, i.e., the retina, and thus reduce the contrast of retinal imaging. We report here a portable fundus camera which can simultaneously perform orthogonal-polarization control to reject back-reflected light from the ophthalmic lens and parallel-polarization control to preserve the backscattered light from the retina which partially maintains the polarization state of the incoming light. This portable device utilizes miniaturized indirect ophthalmoscopy illumination to achieve non-mydriatic imaging, with a snapshot field of view of 101° eye-angle (67° visual-angle). Comparative analysis of retinal images acquired with a traditional orthogonal-polarization fundus camera from both normal and diseased eyes was conducted to validate the usefulness of the proposed design. The parallel-polarization control for enhanced contrast in high dynamic range imaging has also been validated.

Synthesis and Characterization of rGO/Fe3O4 Nanocomposite as Counter Electrode for Dye Sensitized Solar Cell

Abstract: In this project work deals with the synthesis and characterization of rGO/Fe3o4 nanocomposite as counter electrode for dye sensitized solar cell . The growing population in the world arouses energy concerns in all kinds of fields. It is mandatory to meet our everyday energy demands from solar, wind, geothermal, and so on. The proposed Dye-Sensitized Solar Cells (DSSC’s) belong to the group of thin-film solar cells that have been the subject of research for more than two decades due to their low cost, simple preparation methodology, low toxicity, ease of production, and simple methodology. Still, there is a lot of scope for the replacement of current DSSC’s materials due to their high cost, limited abundance, and long-term stability. These cells have the advantages of low-energy and high-throughout processing technologies, low material costs, and the ability to work even in low incident light conditions. To studied about the structural and morphological properties of synthesized rGO/Fe3O4 nanocomposite by using various characterization techniques such as XRD analysis, then the efficiency of existing DSSC’s may be upto 10-12% by using eosin yellow dyes and optimising material.

Analysis on the Influence of Incident Light Angle on the Spatial Aberrations of Acousto-Optical Tunable Filter Imaging.

Acousto-optical tunable filter (AOTF) does not conform to the pinhole model due to the acousto-optic interaction. A calculation method of AOTF aberrations under the condition of incident light with a large arbitrary angle is proposed to solve the problem of coordinate mapping between object space and image space of the AOTF system without refractive index approximation. This approach can provide accurate pointing information of the interested targets for the tracking and searching system based on AOTF. In addition, the effect of cut angle values of the paratellurite crystal on aberrations was analyzed to optimize the design of AOTF cutting according to different application requirements. Finally, distribution characteristics and quantitative calculation results of AOTF aberrations were verified by experiments with different targets, respectively. The experimental results are in good agreement with the simulations.

Method of measuring one-dimensional photonic crystal period-structure-film thickness based on Bloch surface wave enhanced Goos–Hänchen shift

This paper puts forward a novel method of measuring the thin period-structure-film thickness based on the Bloch surface wave (BSW) enhanced Goos–Hänchen (GH) shift in one-dimensional photonic crystal (1DPC). The BSW phenomenon appearing in 1DPC enhances the GH shift generated in the attenuated total internal reflection structure. The GH shift is closely related to the thickness of the film which is composed of layer-structure of 1DPC. The GH shifts under multiple different incident light conditions will be obtained by varying the wavelength and angle of the measured light, and the thickness distribution of the entire structure of 1DPC is calculated by the particle swarm optimization (PSO) algorithm. The relationship between the structure of a 1DPC film composed of TiO2 and SiO2 layers and the GH shift, is investigated. Under the specific photonic crystal structure and incident conditions, a giant GH shift, 5.1 × 103 times the wavelength of incidence, can be obtained theoretically. Simulation and calculation results show that the thickness of termination layer and periodic structure bilayer of 1DPC film with 0.1-nm resolution can be obtained by measuring the GH shifts. The exact structure of a 1DPC film is innovatively measured by the BSW-enhanced GH shift.

Local flow convergence, bed scour, and aquatic habitat formation during floods around wooden training structures placed on sand-gravel bars

Riverine ponds, which are formed and sustained through sediment erosion and deposition, are key habitats for enhancing biodiversity in river reaches. The objective of this study was to understand the roles of traditional river-training wooden structures called “seigyu” on the formation of ponds on nonvegetated bars. Here, the spatial and temporal patterns of the flow and bedform coupled with pond formations for several flood events were assessed. The surface flow patterns were monitored by an unmanned aerial vehicle (UAV) and evaluated by large-scale particle image velocimetry (LSPIV); the maximum flow velocities were 1.3 m s−1 and 1.9 m s−1 during floods when seigyu units were partially and fully submerged, respectively. Although the overall mean flow velocity was greater for the latter events, the spatial variation in flow velocity and dissipation rate of turbulent kinetic energy (TKE) around seigyu was greater for the former events. Such flow patterns affected both bed formation and ecological habitats; ponds were formed at locations beside and behind seigyu, where the flow converged and bed scouring occurred during floods. The frequency and size of ponds around seigyu increased in the early half of the season, and they decreased in the other half when floods were greater in magnitude, which suggests that the bed scouring effect of seigyu was greater in flood stages with partial than fully submergence. Although the bar ponds lack shade to temper the effects of incident light and atmospheric conditions, the ponds displayed smaller daily oscillations in temperature than did the main river, probably due to hyporheic water supply to the ponds. Because many aquatic species cannot tolerate extremely high temperatures in summer, the generation and maintenance of deeper ponds by scouring with sufficient water exchange with the hyporheic zone can be key to enhancing colonization by various aquatic species.

Organization of leaf vascular system and gas exchange in seedlings of Guazuma ulmifolia Lam. in different light conditions

In tropical forests, different physiological characteristics of leaves in tree species are evidenced by variations in different incident light conditions. We aim to evaluate gas exchange and organization of leaf vascular system in Guazuma ulmifolia Lam. seedlings under different light conditions. Seedlings were obtained from seeds germinated under greenhouse conditions with controlled environment. Ninety days after germination, seedlings in 8kg pots were transferred to the experimental site to allow acclimatization under sun and shade conditions. The experimental design was completely randomized, with two treatments: full sunlight and artificial shading, limiting the luminosity to about 5% of irradiance. Seedlings were maintained under these conditions for 120 days before measuring gas exchange parameters. We measured photosynthetic rate, stomatal conductance, sub-stomatic CO2 concentration, transpiration, and chlorophyll content. Anatomical analysis measured distance between veins, distance from veins to abaxial epidermis, distance from veins to adaxial epidermis, distance from veins to stomata, total leaf thickness, abaxial epidermis thickness, adaxial epidermis thickness, palisade parenchyma thickness, and spongy parenchyma thickness of foliar gas exchange of G. ulmifolia which presented significant differences between light environments. Photosynthetic rate and stomatal conductance were reduced by 78% and 39%, respectively, in shade, while stomatal conductance increased by 31% in full sunlight. Transpiration showed no significant difference between the two treatments, but chlorophyll content was 30% lower in full sunlight. Distance between veins and distance from veins to stomata showed no difference between treatments, but the other parameters increased in full sunlight. Thus, the results showed that the pioneer species G. ulmifolia presented leaf gas exchange acclimated to environments with high luminosity.

Size-dependent optical-electrical characteristics of blue GaN/InGaN micro-light-emitting diodes.

To derive the impact of chip size reduction on optical efficiency in micro-LED array panels, blue InGaN/GaN LEDs, which consist of 21×7 arrays (60 ppi display) with different mesa sizes on sapphire substrates, are designed and fabricated in this study. Changing the mesa area of the chip is first proposed to investigate the luminous efficiency (cd/A) of the screen. The current efficiency with a peak wavelength of 450 nm reaches up to 14.29 cd/A for the biggest pixel 50µm×60µm and to 12.25 cd/A for the 15µm×25µm chip, delivering high-level efficiencies to the current LED research field. The mechanisms of size-dependent efficiency variation trends and efficiency droops of blue LEDs are investigated experimentally, confirming that the current efficiency is more efficient at high injection current density while exhibiting poorer performance at the low current density region for smaller chips. The peak efficiency corresponds to higher current density with a decrease in chip size according to the carrier recombination ABC model. Moreover, the characteristic curve of the spectrum and the changes in the yellow light band under different incident light conditions (i.e., 355 nm and 375 nm) are analyzed by photoluminescence.

A novel machine learning algorithm for tracking remotely sensed waves in the surf zone

This paper describes a novel image processing technique that detects wave breaking and tracks waves in the surf zone using machine learning procedures. Using time-space images (timestacks), the algorithm detects white pixel intensity peaks generated by breaking waves, confirms these peaks as true wave breaking events by learning from the data's true colour representation, clusters individual waves, and obtains optimal wave paths. The method was developed and tested using data from four sandy Australian beaches under different incident wave and light conditions. Results are a representation of the position of the wave front through time, i.e., space-time data, which when shown overlaid on the original timestack shows the high degree of accuracy of the method developed here. The utility of the method is demonstrated in two ways: 1) through a comparison between the instantaneous wave speed calculated from the wave paths with the theoretical shallow water wave speed, and 2) by obtaining optical intensities that could be translated into wave roller lengths. The algorithm developed here has the potential to improve understanding numerous nearshore process such as bore propagation and capture in the surf zone, surf zone energy dissipation, surf beat and infragravity waves, and as a direct speed input for depth inversion methods.

Broadband Optical Reflection Modulator in Indium-Tin-Oxide-Filled Hybrid Plasmonic Waveguide with High Modulation Depth

A surface plasmon resonance (SPR)-based optical reflection modulator consisting of vertically stacked silica-silicon-HfO2-ITO-HfO2-Ag-prism multilayer is proposed and numerically investigated. The free carrier-concentration-dependent permittivity of indium-tin-oxide (ITO) at the HfO2/ITO interface induces an epsilon-near-zero (ENZ) effect contributing to strong field enhancement and modifies the SPR condition of incident light. With optimal geometry parameters and proper design of carrier concentration at the accumulation layer, modulation depth (MD) of ~100% and insertion loss (IL) of 3.7% can be simultaneously achieved. The IL can be further reduced by engineering silicon layer thickness. Moreover, the device offers a broadband operation wavelength from 1.5 to 1.6 μm with the variations of MD and IL smaller than 4 and 3%, respectively.

In situ measurement of Scots pine needle PRI

BackgroundThe Photochemical Reflectance Index (PRI) calculated from narrow-band spectral reflectance data is a vegetation index which is increasingly used as an indicator of photosynthetic activity. The leaf-level link between the status of photosynthetic apparatus and PRI has been robustly established under controlled light conditions. However, when a whole canopy is measured instantaneously, the PRI signal is heavily modified by vegetation structure and local variations in incident light conditions. To apply PRI for monitoring the photosynthesis of whole canopies under natural conditions, these large-scale measurements need to be validated against simultaneous leaf PRI. Unfortunately, PRI changes dynamically with incident light and has a large natural variation. No generally accepted procedure exists today for determining the PRI of canopy elements in situ.ResultsWe present a successful procedure for in situ measurements of needle PRI. We describe, characterize and test an optical measurement protocol and demonstrate its applicability in field conditions. The measurement apparatus consisted of a light source, needle clip, spectroradiometer and a controlling computer. The light level inside the clip was approximately two-thirds of that on sunlit needle surfaces at midday. During each measurement the needle was inserted into the clip for approximately 5 s. We found no near-instantaneous changes (sub-second scale jumps) in PRI during the measurements. The time constants for PRI variation in light to full shade acclimations were approximately 10 s. The procedure was successfully applied to monitor the greening-up of Scots pine trees. We detected both facultative (diurnal) PRI changes of 0.02 (unitless) and constitutive (seasonal) variations of 0.1. In order to reliably detect the facultative PRI change of 0.02, 20 needles need to be sampled from both sunlit and shaded locations.ConclusionsWe established a robust procedure for irradiance-dependent leaf (needle) PRI measurements, facilitating empirical scaling of PRI from leaf (needle) to full canopy level and the application of PRI to monitoring the changes in highly structured vegetation. The measured time constants, and facultative and constitutive PRI variations support the use of an artificial light for in situ PRI measurements at leaf (needle) level.

Synthesis of a nano-sized hybrid C3N4/TiO2 sample for enhanced and steady solar energy absorption and utilization

A sub-15 nm C3N4/TiO2 heterojunction is reported for the steady and constant photocatalytic hydrogen evolution under weak and strong incident light conditions.

A simple method to simulate diurnal courses of PAR absorbed by grassy canopy

The fraction of photosynthetically active radiation absorbed by vegetation (FAPAR) quantifies the efficiency of absorbing PAR by plants. Accurate estimation of diurnal variation of FAPAR however remains a challenge because of the dynamic changes of incident light conditions and its interaction with canopy structure. Based on a field experiment, we characterized the effects of solar zenith angle (SZA) and fraction of diffuse light (fdPAR) on diurnal FAPAR in an alpine wetland on the Tibetan plateau. We found an obvious nonlinear change pattern of FAPAR against SZA with a maximum value of FAPAR at the SZA of about 30°, and opposite responses of FAPAR to fdPAR outside of a SZA range between 21° and 30°. A curve fitting (CF) method was proposed to estimate diurnal FAPAR in a rapid and accurate way. The CF method accounting for the interactions of SZA and fdPAR on FAPAR can successfully describe the diurnal dynamics of FAPAR under clear and cloudy sky conditions. The estimation deviation of daily FAPAR was only −0.28% for a period of about eight days with various sky conditions. The new method requires only very simple field measurements, but has higher accuracy than the widely-used light penetration model, which is expected to be widely used in grassy vegetations.

Theoretical Research of Color Reproduction on Concentric Dot

Concentric dot is a new shape of ink dot, which subdivides dot of AM screening into ring and space. Concentric dot has morphological characteristics and reproduction characteristics of AM dots and FM dots, also has excellent color reproduction characteristics. Compared with traditional solid dot, high saturation of concentric dot has been proven. However, the mechanism of this phenomenon is rarely reported. Taking AM dots as reference, this paper try to explain the high saturation of concentric dot theoretically from several aspects, and aims to reveal the mechanism of the color reproduction characteristics of concentric dots. Due to the low amount of ink, the surface of concentric dots is smoother, and achieves better reproduction of color. The distribution characteristics of ring and space result in dot gain both inside and outside of concentric dots, which have a positive impact on the color reproduction. Establishing the relationship of optical dot area and saturation, the difference of color reproduction characteristics between concentric dots and AM dots can be analyzed as the result of the different microstructure of two dots. Using the improved Clapper-Yule model and the law of Lambert-Beer, the conclusion above can be analyzed theoretically. On this basis, experiments are designed and carried out to prove the correctness of theoretical analysis. According to the research, several conclusions are made. The conclusions can be list as follow: different saturations of concentric dots and AM dots lead to different color reproduction, when optical dot area stays the same; different saturations of concentric dots and AM dots is mainly caused by the microstructures of the tow dots; Under the same condition of incident light, concentric dots of monochrome ink reflect more of the visible spectrum than AM dots after absorption, which reasonably explains the high saturation of concentric dots. The study is to reveal the principle of color reproduction of concentric dots with high saturation, providing a theoretical basis for the application of concentric screening technology.

The Research of Mica Pulp Concentration Detecting which Is Based on Laser with 650nm Wavelength

In order to solve the in-line inspection concerning mica-pulp which is in the state of lower concentration (0-6‰)& general concentration (1%-5%).And according to the photometric characteristics of absorption and scattering about mica-particles, we propose that the laser of wavelength (650nm) can be implemented the in-line inspection of concentration. Meanwhile, we gained the good effects regardless of whether adopted the theory of single scattering in the limit of lower concentration or use the theory of multiple scattering with respect to particle systems in the limit of general concentration. Thus, we can divide the inspection areas of concentration into linear zone (single scattering) & exponential region (multiple scattering) through the experiments data.Whereas, the precision of inspection can be up to 0.1‰ among the limit of lower concentration. Due to some phenomena anomalous scattering which its concentration only can be up to 6% in the certain condition of incident light. If adding intensity of light source which can increase the width of linear zone & exponential region, the valid region of inspection will be improved naturally. Thus, as for mica, the method of laser is extremely nice; its precision of inspection is high either.

Photosynthetic acclimation to different light levels in the brown marine macroalga, Hizikia fusiformis (Sargassaceae, Phaeophyta)

Hizikia fusiformis thalli experience dynamic incident light conditions during the period of growth. The present study was designed to examine how changing photon irradiance affects the photosynthesis both in the short and long terms by culturing H. fusiformis under three different light levels: 35 μmol photons m-2 s-1 (low light, LL), 85 μmol photons m-2 s-1 (intermediate light, IL), and 165 μmol photons m-2 s-1 (high light, HL). A similar relative growth rate was observed between IL- and HL-grown algae, but the growth rate was significantly reduced in LL-grown algae. The photosynthetic rates (Pn) measured at their respective growth light levels were found to be lowest in the thalli grown at LL and highest at HL. However, LL-grown algae exhibited much higher Pn in comparison with IL- and the HL-grown thalli at the same measuring photosynthetic photon flux density, indicating the photosynthetic acclimation to low growth light in H. fusiformis. The photosynthesis–light curves showed that LL-grown algae had a highest light-saturating maximum Pn (Pmax) in comparison with IL- or HL-grown algae when the photosynthetic rates were expressed on the biomass basis. However, Pmax was highest in HL-grown algae compared to IL- or LL-grown algae when the rates were normalized to chlorophyll a. The photosynthesis–inorganic carbon (Ci) response curves were also significantly affected by the growth light conditions. The highest value of apparent photosynthetic conductance occurred in LL-grown algae while the lowest value in HL-grown algae. Additionally, the activity of external carbonic anhydrase (CA) tended to increase while the total CA activity inclined to decrease in H. fusiformis thalli when the growth light level altered from 35 to 165 μmol photons per square meter per second. The external CA inhibitors showed a higher inhibition in HL-grown algae compared with LL-grown algae. It was proposed that photosynthetic acclimation to low light condition in H. fusiformis was achieved through an increase in the number of reaction centers and increased capacities of electron transport and of Ci transport within cells. The ability of photosynthetic acclimation to low light confers H. fusiformis thalli to overcome the environmental low light condition as a result of the attenuation of seawater or self-shading through enhancing its photosynthetic performance and carbon assimilation necessary for growth.

Optical Sensing Circuit Using Low-Temperature Polycrystalline Silicon p-Type Thin-Film Transistors and p–Intrinsic–Metal Diode for Active Matrix Displays with Optical Input Functions

An optical sensing circuit composed of low-temperature polycrystalline silicon (LTPS) p-type thin-film transistors (TFTs) and a p–intrinsic–metal (p–i–m) diode is proposed for image scanning and touch sensing functions. Because it is a very difficult challenge to integrate both display pixels and optical sensing circuits into the restricted pixel area, the number of additional devices and control signal lines must be minimized. Therefore, two p-type TFTs, one p–i–m diode, one capacitor, and one signal line are added to display pixel for the proposed optical sensing circuit. Active matrix liquid crystal display (AMLCD) and active matrix organic light-emitting diode (AMOLED) pixels with the proposed optical sensing circuit have image scanning and touch sensing functions, respectively. Through the measurement of the proposed circuit under the condition of incident light varying from 0 to 10,000 lx, we verified that the dynamic and output ranges of the proposed circuit are 30 dB and 1.5 V, respectively.

Effect of the transverse electric field on the pitch and reflective characteristics of the planar texture cholesteric liquid crystals

The reflective spectrums of the cholesteric liquid crystals under the condition of normal incident light are computed by using Jones matrix method. A theoretical model for discussing the influence of the transverse electric field on the twist angle and the pitch of the planar texture cholesteric liquid crystals under the in-plane switching mode is established. Based on the model, the relation between the electric field and the reflective peak for the cholesteric liquid crystals, and the relation between the electric field and the reflective spectral width for the cholesteric liquid crystals are calculated. The effects of the transverse electric field on the pitch and the reflective characteristics of the planar texture cholesteric liquid crystals are studied under different anchoring conditions. The results show that, under the in-plane switching mode, the color of the light reflected from the cholesteric liquid crystals can be changed by the applied transverse electric field, which supplies a theoretical support for the planar texture cholesteric LC color display based on the electrically-controlled pitch.

Photosynthetic efficiency and rapid light curves of sediment-biofilms along a water quality gradient in the Great Barrier Reef, Australia

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 322:61-73 (2006) - doi:10.3354/meps322061 Photosynthetic efficiency and rapid light curves of sediment-biofilms along a water quality gradient in the Great Barrier Reef, Australia Sven Uthicke* Australian Institute of Marine Science, PMB No. 3, Townsville, Queensland 4810, Australia *Email: s.uthicke@aims.gov.au ABSTRACT: The use of pulse-amplitude modulated (PAM) fluorometry in situ and in vivo as an indicator for nutrient and light status of microphytobenthos communities was investigated on the Great Barrier Reef. The 10 reefs investigated were located along a previously described water quality gradient, confirmed by sediment chemistry parameters (Corg, N) and incident light measurements. Estimates of the efficiency of Photosystem II (PSII) were biased when not corrected for background fluorescence that increased with increasing inorganic C content of the sediments. Uncorrected values mimicked a decline in quantum efficiency towards areas with presumed lower nutrient levels. Upon correction, maximum and effective quantum efficiency (ca. 0.59) did not vary significantly along the gradient. The maximum quantum efficiency (Fv/Fm,corr) measured after dark-adaptation did not differ statistically from effective quantum efficiency in the field (φPSII,corr). F0 values measured in the laboratory were much lower than in situ F readings, indicating a higher concentration of biomass on the surface of the sediment in the field. Rapid light curve parameters (initial slope α, relative electron transport rate at light saturation rETRmax, irradiance at onset of light saturation Ek) were lower during in vitro readings than in situ. rETRmax and α values exhibited no statistical differences along the gradient. In contrast, Ek increased towards midshelf reefs and correlated with incident PAR, indicating that microphytobenthos communities were highly adapted to incident light conditions. Because coral reef microphytobenthos was previously shown to be nitrogen limited, it was unexpected that efficiency measurements would not vary. It is hypothesised that, due to potential for differential vertical migration, the actual species involved in photosynthesis at a given time are nutrient sufficient. Higher nutrient supply may change the community composition on the surface to dominance by species with higher productivity. KEY WORDS: PAM · WQ gradient · Benthic microalgae (BMA) · Nutrient limitation · Light limitation Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 322. Online publication date: September 20, 2006 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2006 Inter-Research.