This article proposes a novel collaborative-flip synchronized switch harvesting on capacitors (CF-SSHCs) rectifier and multioutput synchronous dc-dc converters with shared capacitors. Compared to the traditional SSHC, our CF-SSHC rectifier can increase the number of flipping phases, potentially enhancing the flipping efficiency and output power under specific conditions where C FLY is close to C_P. The synchronous dc-dc converters reuse the flying capacitors to achieve a high maximum output power improving rate (MOPIR) over a limited input power range and provide multiple outputs. This work achieves an advanced number of flipping phases in capacitor-based rectifier interface technology and explores multiple-input multiple-output configurations, evaluating the system's performance under periodic and shock conditions for the first time. The system's adaptability to various piezoelectric transducer (PT) array configurations is validated, highlighting its potential for Internet of Things (IoT) networks. The design is fabricated in standard 0.18- μ m CMOS. Measurement results demonstrate that the voltage flipping efficiency of up to 83% is achieved. Compared with full-bridge rectifier (FBR), the MOPIR can be increased to 5.06 × and 4.78 × under off-resonance and on-resonance excitation, respectively. It can also achieve a 2.14 × power enhancement under shock excitation. Additionally, when the input power P INFBR is in the range of 1.42-28.4 μ W, the MOPIR of the proposed system is always greater than 4.

This article proposes a novel eight-phase self-bias-flip piezoelectric energy harvesting interface with charge recycling and reusing (SBFRR) and a switched-piezoelectric energy harvester (PEH) dc–dc (SPDC) converter. The proposed scheme innovatively utilizes the inherent capacitors ( CP ) of four PEHs as energy sources, flying capacitors, and flipping capacitors for time-sharing reuse to achieve both a high-voltage flipping and dc–dc conversion efficiency, while avoiding the use of extra energy reservoirs. The design is fully integrated and fabricated in standard 0.18- μ m CMOS. Measurement result demonstrates that the voltage flipping efficiency of up to 80% is achieved. Compared with the ideal full-bridge rectifier (FBR), the measured maximum output power improving rate (MOPIR) can be increased to 4.88 × . In addition, with the four CP serving as flying capacitors to achieve SPDC conversion for maximum power point track (MPPT), an MOPIR of > 3.5 × can be maintained with a PEH input voltage from 0.78 to 4.9 V.

This article presents a piezoelectric energy harvesting (PEH) interface circuit using a new self-bias-flip with the charge recycle (SBFR) technique without employing any additional energy reservoir. Traditional designs, including synchronous-switch harvesting on inductor (SSHI), synchronous-switch harvesting on capacitor (SSHC), synchronous electric charge extraction (SECE), etc., require additional capacitors or inductors to reverse the voltage on the PEH at the zero-crossing point. This design innovatively uses the inherent capacitors of the piezoelectric harvesters as the flipping capacitors. In order to improve the extract efficiency of the interface, the zero-crossing state is split into a charge recycle stage and a voltage-flip stage. For a piezoelectric array with 2^n PEHs, a configuration with (n-1) phases in the charge recycle stage is adopted to reduce the loss caused by direct charge neutralization. The charge redistribution loss is reduced by employing (2n+1) phases in the voltage-flip stage. The proposed principle has been implemented with discrete components and is verified by three different prototypes. The measurement results show that a flipping efficiency of 67% is achieved by utilizing SBFR with four PEHs. And the proposed interface can provide up to 5.2x improvement when compared with the full-bridge rectifier (FBR).

After the spread of COVID-19, surgical masks became highly recommended to the public. They tend to be handled and used multiple times, which may impact their performance. To evaluate this risk, surgical masks of Type IIR were submitted to four simulated treatments: folding, ageing with artificial saliva or sweat and washing cycles. The air permeability, mechanical integrity, electrostatic potential, and filtration efficiency (FE) of the masks were measured to quantify possible degradation. Overall, air permeability and mechanical integrity were not affected, except after washing, which slightly degraded the filtering layers. Electrostatic potential and FE showed a strong correlation, highlighting the role of electrostatic charges on small particle filtration. A slight decrease in FE for 100 nm particles was found, from 74.4% for the reference masks to 70.6% for the mask treated in saliva for 8 h. A strong effect was observed for washed masks, resulting in FE of 46.9% (± 9.5%), comparable to that of a control group with no electrostatic charges. A dry store and reuse strategy could thus be envisaged for the public if safety in terms of viral and bacterial charge is ensured, whereas washing strongly impacts FE and is not recommended.

Sludge morphology considerably affects the mechanism underlying microbial anaerobic degradation of phenol. Here, we assessed the phenol degradation rate, specific methanogenic activity, electron transport activity, coenzyme F₄₂₀ concentration, and microbial community structure of five phenol-degrading sludge of varying particle sizes (i.e., < 20, 20–50, 50–100, 100–200, and > 200 μm). The results indicated an increase in phenol degradation rate and microbial community structure that distinctly correlated with an increase in sludge particle size. Although the sludge with the smallest particle size (< 20 μm) showed the lowest phenol degradation rate (9.3 mg COD·gVSS⁻¹ day⁻¹), its methanogenic activity with propionic acid, butyric acid, and H₂/CO₂ as substrates was the best, and the concentration of coenzyme F₄₂₀ was the highest. The small particle size sludge did not contain abundant syntrophic bacteria or hydrogenotrophic methanogens, but contained abundant acetoclastic methanogens. Moreover, the floc sizes of the different sludge varied in important phenol-degrading bacteria and archaea, which may dominate the synergistic mechanism. This study provides a new perspective on the role of sludge floc size on the anaerobic digestion of phenol.

The authors explore the influence of the structure of a texture image on the perception of its color composition through a series of psychophysical studies. They estimate the color composition of a texture by extracting its dominant colors and the associated percentages. They then synthesize new textures with the same color composition but different geometric structural patterns. They conduct empirical studies in the form of two-alternative forced choice tests to determine the influence of two structural factors, pattern scale and shape, on the perceived amount of target color. The results of their studies indicate that (a) participants are able to consistently assess differences in color composition for textures of similar shape and scale, and (b) the perception of color composition is nonveridical. Pattern scale and shape have a strong influence on perceived color composition: the larger the scale, the higher the perceived amount of the target color, and the more elongated the shape, the lower the perceived amount of the target color. The authors also present a simple model that is consistent with the results of their empirical studies by accounting for the reduced visibility of the pixels near the color boundaries. In addition to a better understanding of human perception of color composition, their findings will contribute to the development of color texture similarity metrics.

Phosphors with high quantum efficiency and thermal stability are greatly desired for lighting industries. Based on the design strategy of solid solution, a series of deep-blue-emitting phosphors (Sr_0.99-xBa_x)₂P₂O₇:0.02Eu²⁺ (SB_xPE x = 0–0.5) are developed. Upon excitation at 350 nm, the optimized SB_0.3PE phosphor shows a relatively narrow full width at half maximum (FWHM = 32.7 nm) peaking at 420 nm, which matches well with the plant absorption in blue region. Moreover, this phosphor exhibits obvious enhancement of internal quantum efficiency (IQE) (from 74% to 100%) and thermal stability (from 88% to 108% of peak intensity and from 99% to 124% of integrated area intensity at 150°C) compared with the pristine one. The white LED devices using SB_0.3PE as deep-blue-emitting component show good electronic properties, indicating that SB_0.3PE is promising to be used in plant growth lighting, white LEDs, and other photoelectric applications. Inorganic Materials; Materials Application; Optical Materials

Terbium and europium co-doped Sr ₈ ZnY(PO ₄ ) ₇ phosphors are successfully prepared through a high temperature solid-state reaction (SSR). The crystal structure of the as-prepared samples was identified to be Sr ₈ ZnY(PO ₄ ) ₇ (SZYP) pure phase by an X-ray powder diffraction technique. Under near-ultraviolet light excitation (378 nm), the SZYP:Tb ³⁺ and SZYP:Eu ³⁺ phosphors show green and red emission peaking at 545 and 618 nm, respectively. Moreover, an effective energy transfer process from Tb ³⁺ to Eu ³⁺ could be verified by the concentration dependence of emission intensity and lifetime. The energy transfer mechanism between Tb ³⁺ and Eu ³⁺ is determined to be governed by dipole-dipole interactions. The internal quantum efficiency (IQE) is evaluated to be as high as about 91%. The temperature-dependent spectra indicate that the SZYP:Tb ³⁺ ,Eu ³⁺ phosphor shows a high thermal stability. Furthermore, the as-fabricated white LED devices exhibit an excellent correlated color temperature (CCT) of 3223 K, a color rendering index (R _a ) of 85.8 and a luminance efficiency of 37.4 lm W ^-1 . All results imply that the SZYP:Tb ³⁺ ,Eu ³⁺ phosphors have a great potential for application in white LEDs.

High permeable and selective membranes are expected to be a promising alternative for low cost and energy efficient CO₂ separation. However, the preparation and development of highly permeable and selective membranes are limited by the trade-off effect. Here, we prepared a stabilized high permeable and selective mixed matrix membrane based on the structural regulation of the NH₂-functionalized Co/ZIF-8 heterometallic nanoparticles (NH₂-Co/ZIF-8). The NH₂-Co/ZIF-8 can be homogeneously dispersed in the polymer via chelation of the ester group and the metal node in the methacrylate-terminated PEO and the acrylate-terminated PEO. The amphiphilic interaction between the polymer and NH₂-Co/ZIF-8 significantly increased the CO₂ solubility resulting in the boost of both CO₂ permeability and CO₂/N₂ selectivity. The best performance membrane exhibits a CO₂ permeability of 2916 Barrer and a CO₂/N₂ selectivity of 47, surpassing the Robeson's upper bond (2008) by a wide margin.