High SN Ratio Research Articles

Ternary-Metal Sn-Pb-Zn Perovskite to Reconstruct Top Surface for Efficient and Stable Less-Pb Perovskite Solar Cells.

Though Sn-Pb alloyed perovskite solar cells (PSCs) achieved great progress, there is a dilemma to further increase Sn for less-Pb requirement. High Sn ratio (>70%) perovskite exhibits nonstoichiometric Sn:Pb:I at film surface to aggravate Sn2+ oxidation and interface energy mismatch. Here, ternary metal alloyed (FASnI3 )0.7 (MAPb1- x Znx I3 )0.3 (x = 0-3%) is constructed for Pb% < 30% perovskite. Zn with smaller ionic size and stronger ionic interaction than Sn/Pb assists forming high-quality perovskite film with ZnI6 4- enriched at surface to balance Sn:Pb:I ratio. Differing from uniform bulk doping, surface-rich Zn with lower lying orbits pushes down the energy band of perovskite and adjusts the interface energy for efficient charge transfer. The alloyed PSC realizes efficiency of 19.4% at AM1.5 (one of the highest values reported for Pb% < 30% PSCs). Moreover, stronger bonding of Zn─I and Sn─I contributes to better durability of ternary perovskite than binary perovskite. This work highlights a novel alloy method for efficient and stable less-Pb PSCs.

An Investigation into the Mechanical and Wear Characteristics of Hybrid Composites: Influence of Different Types and Content of Biodegradable Reinforcements

ABSTRACT This research work focuses on the wear characteristics of hybrid composites prepared using Sisal fiber (SF) /Pineapple fiber (PF) and Pineapple fly ash (PA) in various wt.%. Linear reciprocating tribometer was used for determining the Specific Wear Rate (SWR) and Coefficient of Friction (CoF) of the hybrid composites. The XRF results of PA filler showed the existence of silica (64.43%) and aluminum oxide (10.03%) in a major percentage. The hybrid fiber combination of 30-50 wt.% showed improvement in Tensile Strength (TS), Flexural Strength (FS) and Impact Strength (IS) with the filler mixing up to 5 wt.%. The Taguchi optimization (SN graph) observed the combination with PA addition of 5 wt.%, hybrid fiber addition of 30 wt.%, sliding distance and load of 1500 m, 10 N having lower SWR. Similarly for lower CoF, fly ash of 1 wt.%, fiber of 30 wt.%, sliding distance and load of 500 m and 5 N, respectively, with high SN ratio is the best combination. SEM results showed a decrease in filler content, higher load conditions, higher reinforcement causing more surface deformations in the composites.

Highly sensitive microcantilever biosensors with enhanced sensitivity for detection of human papilloma virus infection

This paper demonstrates a piezoresistive microcantilever biosensor for a potential of the early detection of HPV infection. Gold was patterned on the top surface of the microcantilever to define the sensing area. Then, a self-assembled monolayer (SAM) was coated on the gold surface for the attachment of a gold binding protein (GBP) which was functionally activated with carboxyl groups and amine groups to bind probe molecules such as antibodies, oligonucleotide probes, DNA, and proteins. The surface-activated magnetic beads were introduced to the sensing area with DNA fragments of the HPV-infected cells. The magnetic force was induced to the surface-activated magnetic beads bound with probe molecules and HPV DNA fragments by placing a permanent magnet. The electrical signal output measured from the piezoresistive sensor integrated in the microcantilever was amplified 1000 times compared with non-HPV solution with a high SN ratio.

G211 顕微鏡一体型デバイス"Evanescent Wave for a Chip"を用いた固液界面極近傍の多変量分布計測(OS-12:先端計測による熱工学の学際的展開(2))

Simple and easy evanescent wave generating device "Evanescent Wave for a Chip" (EvaChip) was developed. The purpose of this study is to measure pH distribution and velocimetry vector map of flow in the vicinity of liquid-solid interface by using 3CCD camera. Nano-PIV and nano-LIF were carried out by using particles and dye with different emission wavelength, respectively. EvaChip was improved to measure with high SN ratio so as to measure in both methods. Based on the results, in order to investigate the effect of thermofluid phenomena to the chemical reaction, simultaneous measurement will be carried out by using EvaChip.

Photoresist-Free Fully Self-Patterned Transparent Amorphous Oxide Thin-Film Transistors Obtained by Sol-Gel Process

We demonstrated self-patterned solution-processed amorphous oxide semiconductor thin-film transistors (TFTs) using photosensitive sol-gels. The photosensitive sol-gels were synthesized by adding β-diketone compounds, i.e., benzoylacetone and acetylacetone, to sol-gels. The chemically modified photosensitive sol-gels showed a high optical absorption at specific wavelengths due to the formation of metal chelate bonds. Photoreactions of the modified solutions enabled a photoresist-free process. Moreover, Zn–Sn–O with a high Sn ratio, which is hard to wet-etch using conventional photolithography due to its chemical durability, was easily patterned via the self-patterning process. Finally, we fabricated a solution-processed oxide TFT that included fully self-patterned electrodes and an active layer.

Development of a Pork Fat Evaluation System by NIR Spectroscopy

The performance of a near-infrared(NIR) spectrometer that evaluates fatty acid composition in samples depends on the NIR spectroscopic features of the samples. When you develop a NIR instrument, you have to be aware how the NIR spectra of the samples behave. In some cases, you don't need a high SN ratio or high stability. In other cases, no matter how stable the system is, you can't get meaningful data. It is wasteful to develop a highly stable instrument in this case. You should research the NIR characteristics of the samples before starting designing to avoid waste and to get a proper design. We examined the pork fat spectra before starting designing and were able to get satisfactory result. The process and aspects of measuring fatty acid composition by NIR spectroscopy are described.

Sensitivity to red/green/blue illumination of amorphous selenium based photodetector driven by nitrogen (N)-Doped CVD diamond

An imaging device that could detect weak light of approximately 0.001 lx with high SN ratio is capable of opening up the possibility of creating artificial visions as a substitute for a human eye. In terms of sensitivity and SN ratio, amorphous selenium (a-Se) is known to be one of the best candidates among other photoconductive target. Combined with a-Se, a diamond cold cathode would be one of the best options in order to steadily emit electrons under low vacuum. The a-Se film is modified with Arsenic (As) and Tellurium (Te) to prevent crystallization and narrow the optical gap for red light detection. An RGB filtered light from a halogen light source was illuminated onto this modified a-Se film and the photo-response was measured for each color. The device could detect extremely weak illumination of under 0.39 lx, which is approximately the darkness under moonlight. Results of the photo-response compared between films with and without Te clarified that Te dopants enhances red light detection significantly. The illuminated light was then pulsed at 10 mHz and the current to time stability was observed. It showed clear correspondence between the intensity of the luminance and current, which the Te modified samples showed good response to other colored light as well.

ニッケル基合金の溶接金属組織と超音波探傷による欠陥検出性の関係

Ultrasonic Test (UT) method is the most appropriate method in many kinds of non-destructive test methods because of capabilities for detection and depth sizing of flaw. But it is generally said that the flaw detection in nickel base alloy welds is more difficult than that in ferritic steel welds because of dispersion and attenuation of the ultrasonic wave. Therefore, influences of welding conditions on flaw detectability and signal to noise ratio (SN ratio) of UT in nickel base alloy welds were investigated. Tested weld joints were prepared with multi-pass gas tungsten arc method. Partial weld joints were applied to weaving or magnetic stirring when that welded. Specimens having an electrical discharge machining slit in weld metal or in heat affected zone were tested by a longitudinal wave of 5 MHz in frequency and 45 degree in incident angle. Obtained results are as follows. Welded joints having columnar structures with the same growth direction showed high SN ratio that means good flaw detectability. Effective welding conditions, which make the columnar structure to be the same growth direction, were found to be the application of weaving or magnetic stirring. Same growth direction in columnar structures means same angle between the columnar structure growth direction and the ultrasonic wave propagating direction. Then, ultrasonic wave has almost same velocity in the weld metal, and the acoustic impedance will be almost same. High SN ratio may be caused by above phenomena. The SN ratio of weld joints by different base metal can be well explained by the difference of acoustic impedance at the boundary columnar structure and base metal.

A New Approach in Offline-Optimization of the Injection Molding Process

Abstract For the purpose of process optimization of the injection-molding process a robust processing point is determined, at which specified characteristics of the parts are met and the process is insensitive to disturbances. The idea of the new optimization concept is to ensure that also around the robust processing point, within the so-called robust processing window, the part geometry is in tolerance and a low standard deviation respectively a high SN-ratio is achieved. Instead of reducing the optimization task to a one-dimensional problem by combining the target functions, in this approach one defines lower and upper bounds for the characteristics to be optimized. These bounds must be fulfilled in the range of the robust processing window and, if necessary, might be sharpened or relaxed during the optimization procedure. The corresponding response surfaces are generated by means of new Scattered Data Interpolation-methods.

A Semiconductor Pressure Sensing System for Monitoring of GIS

The authors describe in this paper the application of a semiconductor pressure device for a pressure monitoring sensor, applicable to both continuous monitoring and fault locating of a gas insulated switchgear (GIS). Improvements required for these purposes are long term stability against temperature and supersensitivity for detecting a minute pressure variation caused by the fault. To get high sensitivity over a wide range, the amplifier having changeable ranges are presented. To compensate the output fluctuation due to temperature, we introduce a current driven circuit, a current source designed to have opposite characteristics to the piezzo resistance of the semiconductor and a digital compensation method. Offset drift by temperature is solved by use of AC drive. The temperature stability of the sensor consequently come at 0.01%. For high SN ratio required for the fault locating, we adopt digital filters, and pattern matching. The sensor is achieved 10Pa sensitivity with 700kPa dynamic range.

Triple-layer perpendicular recording media for high SN ratio and signal stability

Media noise, SN ratio, and signal stability of triple-layer (TL) perpendicular recording media are studied. The TL medium is composed of a CoCrTa perpendicular layer, an amorphous CoZrNb soft magnetic layer, and a CoSm in-plane hard magnetic pinning layer. A high SN ratio is obtained due to the pinning effect of the CoSm layer and with an optimum CoCrTa perpendicular layer of a 50-nm-thick Co-Cr20-Ta3.5at% (Ms=400 emu/cm/sup 3/) film. High signal stability against stray magnetic fields is obtained in TL media with a 600-nm-thick CoZrNb layer. Moreover, no thermal magnetic relaxations occurs in TL media at 60/spl deg/C for 5 hours and at room temperature for 15 hours. The TL media are promising as practical ultrahigh-density recording media having high read-write reliability.

7-4 高SN比前置増幅器

7-4 高SN比前置増幅器