On-line Time Domain Vibration and Current Signals Based Multi-fault Diagnosis of Centrifugal Pumps Using Support Vector Machines

With a view to gaining an in-depth assessment of the response of particleboards (PBs) to different in-service loading conditions, samples of high-density homogeneous PBs of sugarcane bagasse and castor oil polyurethane resin were manufactured and subjected to low velocity impacts using an instrumented drop weight impact tower and four different energy levels, namely 5, 10, 20 and 30 J. The prediction of the damage modes was assessed using Comsol Multiphysics\(^\circledR .\) In particular, the random distribution of the fibres and their lengths were reproduced through a robust model. The experimentally obtained dent depths due to the impactor were compared with the ones numerically simulated showing good agreement. The post-impact damage was evaluated by a simultaneous system of image acquisitions coming from two different sensors. In particular, thermograms were recorded during the heating up and cooling down phases, while the specklegrams were gathered one at room temperature (as reference) and the remaining during the cooling down phase. On one hand, the specklegrams were processed via a new software package named Ncorr v.1.2, which is an open-source subset-based 2D digital image correlation (DIC) package that combines modern DIC algorithms proposed in the literature with additional enhancements. On the other hand, the thermographic results linked to a square pulse were compared with those coming from the laser line thermography technique that heats a line-region on the surface of the sample instead of a spot. Surprisingly, both the vibrothermography and the line scanning thermography methods coupled with a robotized system show substantial advantages in the defect detection around the impacted zone.     

Advanced lifting wavelet transform and V-degree polynomial-based channel estimation in MIMO-GFDM

The future generation of wireless communications systems uses the generalized frequency division multiplexing (GFDM) due to its viable candidate waveform to perform multiple user scheduling. It is a non-orthogonal waveform susceptible to intercarrier and intersymbol interference (ISI); still, it offers flexible pulse shaping that enhances the efficiency of user scheduling. Here, to accomplish spatial diversity, the multiple-input multiple-output (MIMO) is incorporated with GFDM to enhance the performance; there is also an extra inter-antenna interference problem that limits the model's performance. The issue concerning inter-antenna interference can be resolved by adopting pilot-based information transfer. The detection of a signal at the receiver based on the minimum mean square error has the issue of computational complexity while enhancing the estimation quality of a detector. Hence, a low-complexity channel estimation technique is proposed in this research using the V-degree polynomial-based channel estimation technique, wherein the cubic order computation is reduced to square order. Also, the proposed adaptive pulse shaping technique, wherein the filter coefficient is optimized using the gazelle optimization algorithm (GOA) to provide optimal pulse shaping filter parameters by employing bit error rate (BER) as the objective function. The performance of a proposed V-degree polynomial-based channel estimation is analyzed based on various assessment measures like BER and MSE and acquired the minimal values of 5.75E-05 and 2.07E-05, respectively.     

Determination of biogenic amines in Japanese miso products

Eight miso products sold in supermarket were purchased from Japan and analyzed for the determination of biogenic amines (BAs). Quantitative determination of BAs in miso products was carried out by means of HPLC with spectrophotometric UV-VIS detector. The amines were extracted in acid aqueous solution (HClO₄) and then derivatized by dansyl chloride. The levels of pH in the tested miso samples were ranged from 4.8–5.5. The BAs (tryptamine, 2-phenyl ethylamine, putrescine, cadaverine, agmatine, tyramine, and spermidine) determined in 8 miso samples were found in their respective range of ND-0.13, ND-4.20, ND-1.29, ND-0.87, ND-0.90, ND-4.19, and ND-3.57 mg%. None of the miso samples contained histamine and spermine, the major BAs of food poisoning.     

Enhanced DSSC performance with high surface area thin anatase TiO2 nanoleaves

Thin anatase TiO₂ nanoleaves (NLs) with high surface area (∼93 m²/g) are synthesized by hydrothermal route and dye-sensitized solar cells (DSSC) made using such NLs are compared with those made with hydro-thermally synthesized TiO₂ nanoparticles and the Degussa P25 powder. The NLs-based DSSCs show increment of 16% and 24% in the total conversion efficiency over the cells made with NPs and P25 respectively. Interestingly, the highest increment in the conversion efficiency (∼35%) is achieved for cells made using a 50:50 (wt/wt) mixture of NLs and NPs. In this case the dye loading is found to be >50% higher than the case of NP films. Moreover the DC resistance of diffusion of in electrolyte (as revealed by the electrochemical impedance spectroscopy) is substantially lower than the NP film case, other cell parameters being nominally comparable.     

Understanding the thermodynamic micro-environment inside a pan coater using a data logging device

Objective: The objective of the current study was to establish the use of PyroButton data-logging device to monitor and quantify the thermodynamic environment (temperature and humidity) of a pan coating process.

Material and methods: PyroButtons were placed (fixed) at various locations in a pan coater, including exhaust plenum, spray-gun bar, baffles and were also allowed to freely move with the tablet-bed. A full factorial design of experiments (DOE) study on three process parameters, exhaust temperature, pan speed and spray rate was conducted on a 24 inch pan coater, using a coating system and a core tablet combination expected to have a narrow process operating space.

Results: It was shown that the PyroButtons can provide a detailed and useful signature of the coating process. PyroButton data showed that the tablet-bed temperature was always lower than exhaust temperature and that the difference was a function of the operating conditions such as spray rate. Similarly, the tablet-bed humidity was found to always be higher than exhaust humidity. Some of the DOE batches showed coating defects (logo-bridging). It was shown that the relative humidity (RH), as measured by the freely-moving PyroButtons in the tablet-bed, correlated well with the logo-bridging events. A critical RH value (30%) was established, above which logo-bridging was observed for the selected formulation.

Conclusions: This study showed that PyroButtons can provide very meaningful micro-environmental data that can be correlated to coating defects, and can aid in establishing a process design space for a given coating and tablet formulation.     

Effect of Novel Starter Culture on Reduction of Biogenic Amines,Quality Improvement,and Sensory Properties of Doenjang,a Traditional Korean Soybean Fermented Sauce Variety

To select appropriate microorganisms as starter cultures for the reliable and reproducible fermentation of soybean fermented products of Korean Doenjang, various ratios of fungi (Aspergillus oryzae J, Mucor racemosus 15, M. racemosus 42) combined with Bacillus subtilis TKSP 24 were selected as either single, double, or multiple Meju strains for commercial mass production of Doenjang, followed by analysis of sensory characteristics. In the sensory evaluation, Doenjang BAM15‐1 and BAM42‐1, which were fermented with multiple strains (1:1:1), showed the highest sensory scores as compared to control. Based on sensory characteristics, 6 Doenjang samples were subjected to quantitative determination of amino acids, free sugars, and organic acids (volatile and nonvolatile) contents, followed by determination of biogenic amines. Total sweet taste amino acid contents were highest in BAM15‐1 and BAM42‐1 samples (333.7 and 295.8 mg/100 g, respectively) and similar that of control (391.1 mg/100 g). Samples BAM15‐1 and BAM42‐1 showed the relatively high volatile and nonvolatile organic acid contents (154.24, 192.26, and 71.31, 82.42 mg/100 g, respectively). In addition, BAM15‐1 and BAM42‐1 showed negligible biogenic amine formation, ranging from 0.00 to 1.02 and 0.00 to 3.92 mg/100 g, respectively. These findings indicate that determination of food components along with sensory and quality attributes using multiple microbial Meju strains as a starter culture may provide substantial results on improved quality fermented Doenjang products.     

Description of integrated competency examination: tools to assess the chiropractic curriculum effectiveness and students' competency levels

Los Angeles College of Chiropractic (LACC) has developed a variety of methods to monitor the effectiveness of its competency based/problem-centered curriculum. The College introduced two Integrative Competency Examination courses (ICE I and ICE II) to assess the chiropractic program's effectiveness and students' competency levels. The ICE courses are pass/fail examinations that use a multistation, objective structured clinical examination (OSCE) format that involves standardized patients along with cognitive assessment of basic science information as methods of evaluation. ICE I requires students to perform psychomotor skills and interpret clinical data; ICE II requires students to perform at a higher level. They are directed to select, perform and interpret clinical data appropriately and correlate this data with relevant basic science information. Through these two levels of evaluation, the educational program, the individual courses and the competency level of each student are assessed. This paper describes the format, content and evaluation tools used in the ICE courses as well as the potential benefits of the courses.     

Investigation of dual ion beam sputtered transparent conductive Ga-doped ZnO films

Ga-doped ZnO (GZO) transparent conducting films were deposited on sapphire (0001) substrates using dual ion beam sputtering deposition system. The impact of growth temperature on the structural, morphological, elemental, optical, and electrical properties was thoroughly investigated and reported. X-ray diffraction measurements explicitly confirmed that all GZO films had (002) preferred crystal orientation. The film deposited at 400 °C exhibited the narrowest full-width at half-maximum value of 0.24° for (002) crystalline plane and the lowest room temperature electrical resistivity of 4.11 × 10^?3 Ω cm. The Raman spectra demonstrated the vibrational modes at 576 and 650–670 cm^?1, associated with native oxygen vacancies and elemental Ga doping in ZnO lattice, respectively. All doped films showed an overall transmittance of above 95 % in the visible spectra. A correlation between structural, optical, elemental, and electrical properties with GZO growth temperature was established.