The performance of dye-sensitized solar cells (DSSC), made of highly ordered anodic titanium oxide (ATO) nanotube (NT) arrays produced directly on Ti foil, depends on the length of these arrays. We controlled these lengths L from 4 to 41 µm while varying the concentration (0.1, 0.25, 0.5, and 0.8 wt %) of the electrolyte (NH 4 F) in ethylene glycol in the presence of H 2 O (2 vol %) with anodization for various periods (t ) 0.5-8 h). The compact and bundle layers introduced during anodization were effectively removed upon simple ultrasonic cleaning in deionized water containing submicrometer particles of Al 2 O 3 in a small proportion. The photovoltaic performance of the NT-DSSC devices (NH 4 F at 0.5 wt %) made of ATO films, as prepared, increased from 3.0% to 5.2% as L was increased from 6 µm (t ) 0.5 h) to 30 µm (t ) 8 h). After treatment of the ATO films with TiCl 4 in a two-step annealing process, the optimized NT-DSSC device attained an overall efficiency of 7.0% power conversion.

A reported 30% of people worldwide have abnormal lung sounds, including crackles, rhonchi, and wheezes. To date, the traditional stethoscope remains the most popular tool used by physicians to diagnose such abnormal lung sounds, however, many problems arise with the use of a stethoscope, including the effects of environmental noise, the inability to record and store lung sounds for follow-up or tracking, and the physician’s subjective diagnostic experience. This study has developed a digital stethoscope to help physicians overcome these problems when diagnosing abnormal lung sounds. In this digital system, mel-frequency cepstral coefficients (MFCCs) were used to extract the features of lung sounds, and then the K-means algorithm was used for feature clustering, to reduce the amount of data for computation. Finally, the K-nearest neighbor method was used to classify the lung sounds. The proposed system can also be used for home care: if the percentage of abnormal lung sound frames is > 30% of the whole test signal, the system can automatically warn the user to visit a physician for diagnosis. We also used bend sensors together with an amplification circuit, Bluetooth, and a microcontroller to implement a respiration detector. The respiratory signal extracted by the bend sensors can be transmitted to the computer via Bluetooth to calculate the respiratory cycle, for real-time assessment. If an abnormal status is detected, the device will warn the user automatically. Experimental results indicated that the error in respiratory cycles between measured and actual values was only 6.8%, illustrating the potential of our detector for home care applications.

Watermarking is a potential method for copyright protection and authentication of multimedia data on the internet. In this paper, a novel watermarking scheme using phase shift keying (PSK) modulation with amplitude boost (AB) and low amplitude block selection (LABS) is proposed to achieve superior performance in terms of robustness and imperceptibility. AB is hired to increase the robustness while LABS is employed to improve the imperceptibility.In order to demonstrate the effectiveness of the proposed scheme, simulations under various conditions were conducted. The empirical results show that our proposed scheme can sustain most common attacks including JPEG compression, rotating, resizing, cropping, painting, noising and blurring etc.

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The NCO functional group of 3-isocyanatoproplytriethoxysilane (IPTS) and the OH functional group of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phospha-phenantbrene-10-oxide (DOPO-BQ) were used to conduct an addition reaction. Following completion of the reaction, triglycidyl isocyanurate (TGIC) was introduced to conduct a ring-opening reaction. Subsequently, a sol–gel method was used to initiate a hydrolysis–condensation reaction on TGIC–IPTS–DOPO-BQ to form a hyperbranched nitrogen–phosphorous–silicon (HBNPSi) flame retardant. This flame retardant was incorporated into a polyurethane (PU) matrix to prepare a hybrid material. Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), limiting oxygen index (LOI), UV-VIS spectrophotometry, and Raman analysis were conducted to characterize the structure and analyze the transparency, thermal stability, flame retardancy, and residual char to understand the flame retardant mechanism of the prepared hybrid material. After the flame retardant was added, the maximum degradation rate decreased from −36 to −17 wt.%/min, the integral procedural decomposition temperature (IPDT) increased from 348 to 488 °C, and the char yield increased from 0.7 to 8.1 wt.%. The aforementioned results verified that the thermal stability of PU can be improved after adding HBNPSi. The LOI analysis indicated that the pristine PU was flammable because the LOI of pristine PU was only 19. When the content of added HBNPSi was 40%, the LOI value was 26; thus the PU hybrid became nonflammable.

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Blocked polyurethane (PU)/epoxy full-interpenetrating polymer network (full-IPN) were synthesized from blocked NCO-terminated PU prepolymer, with 4,4-methylene diamine as a chain extender and epoxy prepolymer, with 4,4-methylene diamine as a curing agent, using simultaneous polymerization (SIN) method. From FTIR spectra analysis it was found that the major reactions in the blocked PU/epoxy IPN system are the self-polymerization of block PU/chain extender and the self-polymerization of epoxy/curing agent. Meanwhile, from reaction mechanisms the copolymerization of IPN may have occurred at the same time. The weight loss by thermogravimetric analysis decreased with increasing epoxy and filler content. It was confirmed from scanning electron micrography (SEM) that when the blocked PU content increased, the microstructure of IPN became rougher.