A novel combined baffle-cavity micro-combustor configuration for Micro-Thermo-Photo-Voltaic applications

The major issues of Micro-Thermo-Photo-Voltaic (MTPV) micro-combustors are flame instabilities, which narrow the operational range, and non-uniform wall temperature, which lowers the overall efficiency. The purpose of the present research is to propose a novel micro-combustor with combined baffle and cavity configuration to address these issues. For this aim, a numerical modeling approach is validated and used. The performance of the improved combustor is compared with another recent baffle-bluff configuration. It is shown that the novel design improves the average wall temperature by 36.4 K and mitigates its standard deviation by 13.4 K. Moreover, using the optimal baffle thickness, these enhancements can be augmented by 4% raise of average wall temperature, 62% increase of temperature uniformity, and 20% reduction in overall emission. The baffle length of 0.6 times the combustor length and thickness of 0.0625 times the baffle spacing result in the optimal operation due to the flame lift-off in the upstream direction. According to the sensitivity analysis, the most effective geometrical parameters are the baffle length and thickness. It is expected that using this novel micro-combustor with optimized design parameters improves the overall efficiency of MTPV systems.     

PCAPooL: unsupervised feature learning for face recognition using PCA,LBP, and pyramid pooling

Pattern Analysis and Applications - Human face is a widely used biometric modality for verification and revealing the identity of a person. In spite of a great deal of research on face recognition,...     

Applying metamer sets to investigate data dependency of principal component analysis method in recovery of spectral data

Principal component analysis (PCA) has been widely studied for reconstruction of spectral reflectance of a color sample from its tristimulus values. One of the most important factors that influences the recovery performance is the characteristic of the data set used for obtaining principal vectors. In this article, we investigated the influence of color similarities or color differences between the recovered and principal component (PC) data sets on the reconstruction error. For this purpose, two metamer sets that have similar color differences with the recovered samples, are used. The results show that two metamer sets can make completely different performance in recovery of specific color samples. It was shown that the most important factor that influences the recovery of spectral reflectance by PCA method is the characteristics of the data set used for obtaining PC vectors independent of the recovered samples. Another factor that influences the performance of PCA for spectral recovery is the characteristic of the sample that would be recovered. Some spectral data cannot be recovered precisely even applying different PC data sets. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2011     

The Human Gut Microbiome as a Potential Factor in Autism Spectrum Disorder

The high prevalence of gastrointestinal (GI) disorders among autism spectrum disorder (ASD) patients has prompted scientists to look into the gut microbiota as a putative trigger in ASD pathogenesis. Thus, many studies have linked the gut microbial dysbiosis that is frequently observed in ASD patients with the modulation of brain function and social behavior, but little is known about this connection and its contribution to the etiology of ASD. This present review highlights the potential role of the microbiota–gut–brain axis in autism. In particular, it focuses on how gut microbiota dysbiosis may impact gut permeability, immune function, and the microbial metabolites in autistic people. We further discuss recent findings supporting the possible role of the gut microbiome in initiating epigenetic modifications and consider the potential role of this pathway in influencing the severity of ASD. Lastly, we summarize recent updates in microbiota-targeted therapies such as probiotics, prebiotics, dietary supplements, fecal microbiota transplantation, and microbiota transfer therapy. The findings of this paper reveal new insights into possible therapeutic interventions that may be used to reduce and cure ASD-related symptoms. However, well-designed research studies using large sample sizes are still required in this area of study.     

Three‐Dimensional Reconstruction and Microstructure Modeling of Porosity‐Graded Cathode Using Focused Ion Beam and Homogenization Techniques

In this study, microstructure of a porosity‐graded lanthanum strontium manganite (LSM) cathode of solid oxide fuel cells (SOFCs) has been characterized using focused ion beam (FIB) and scanning electron microscopy (SEM) combined with image processing. Two‐point correlation functions of the two‐dimensional (2D) images taken along the direction of porosity gradient are used to reconstruct a three‐dimensional (3D) microstructure. The effective elastic modulus of the two‐phase porosity‐graded cathode is predicted using strong contrast (SC) and composite inclusion (CI) homogenization techniques. The effectiveness of the two methods in predicting the effective elastic properties of the porosity‐graded LSM cathode is investigated in comparison with the results obtained from the finite element model (FEM).     

Quantification and prediction of visually perceived specular gloss at three illumination/viewing geometries

In the present study, attempts were made to clarify the existence of a correlation between visually perceived and instrumentally measured specular gloss of a series of achromatic samples. To this end, seven achromatic physical scales of specular gloss each consisting of 10 or 11 samples were prepared using lithographically printed black, white, and five in between gray papers. The samples were visually assessed and subsequently quantified in terms of a visually uniform color constant lightness scale, by a panel of 14 observers in an especially designed unidirectional light compartment at three illumination/observation geometries, namely 20°/20°, 60°/60°, and 85°/85°. Four statistical parameters were utilized to determine the correlation between visually perceived and instrumentally measured specular gloss. The results show that the instrumental 60°/60° geometry is capable of efficiently quantifying the equivalent specular gloss as perceived by a human observer. Surprisingly, it was also possible to accurately predict the visually quantified specular gloss both at the 20° and the 85° geometries by the aid of applying special linear relationships derived from the instrumentally measured specular gloss of the 60° geometry.     

Clustering techniques in object bases: A survey

It is widely acknowledged that clustering is a cornerstone for the performance of database management systems. In particular, object-oriented databases have special properties which make clustering even more important for them than for conventional database models. In this paper, a survey is presented for the state of the art in the field of clustering in object bases. Several design dimensions are discussed and used as a basis for comparing different systems. Moreover, a set of selection guidelines and evaluation criteria are proposed and finally, open questions and future research directions are outlined.     

Investigating the effect of texture on the performance of color difference formulae

To predict the perceived color differences, the effect of the surface texture on the performance of the color difference formulae was investigated. To this end, knitted polyester fabrics with eight different textures were prepared. The fabrics were dyed by seven dyestuffs in five different depths. The selected pairs from the five samples with different depths in each hue covered small to large color differences. The assessed pair of samples had the same texture and hue, but different depths. A panel of 23 observers assessed the color differences of the pairs by gray scale method. The results showed that for the textile samples with different texture structures, the CIEDE2000 (2:1:1) performed the best followed by CMC (2:1:1), CIE94 (2:1:1), and CIELAB with approximately same performance. In addition, the magnitude of color difference influenced the ability of the formulae to predict the visual assessments and the best performance obtained for medium color differences. The comparison between eight different texture groups indicated that the texture structures of the pairs significantly affected the performance of the color difference formulae. For instance, the PF/3 measures obtained for the eight texture groups by CIEDE2000 (2:1:1) color formula could be varied between 21.98 and 33.37 PF/3 units. © 2009 Wiley Periodicals, Inc., Col Res Appl, 2010.     

Color naming for the Persian language

According to Berlin and Kay, there is a set of 11 universal basic color terms: White, Black, Red, Green, Yellow, Blue, Brown, Purple, Pink, Orange, and Gray. To approve this, a world survey (WCS) was begun to gather data on color categorization through the world, although, despite many languages, Persian language has not been studied so far. We report a study of color naming in Iran. A study was carried out in six major cities including: Tehran, Isfahan, Mashhad, Yazd, Rasht, and Shiraz to investigate the color naming for Persian language and also the effect of local culture. The main purpose of this study was to describe the basic color terms of Persian language and to verify Berlin and Kay's theory. In total, 200 subjects were studied from all the six cities. Our results showed that there were the same basic color terms (as Berlin and Kay's theory) in Persian language overall including:“ (White) ”,“ (Black) ”, “ (Red) ”, “ (Green) ”, “ (Yellow) ”, “ (Blue) ”, “ (Brown) ”, “ (Purple) ”, “ (Pink) ”, “ (Orange), ” and “ (Gray) ”. However, this was not valid for all the cities when they were investigated individually. There were 10 basic terms in Mashhad and Shiraz while the other cities had 11 basic terms. Also, the set of the used terms would differ by the city. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 352–360, 2015