Bio-inspired optimization algorithms for optical parameter extraction of dielectric materials: A comparative study

Particle swarm optimization(PSO) and invasive weed optimization(IWO) algorithms are used for extracting the modeling parameters of materials useful for optics and photonics research community. These two bio-inspired algorithms are used here for the first time in this particular field to the best of our knowledge. The algorithms are used for modeling graphene oxide and the performances of the two are compared. Two objective functions are used for different boundary values. Root mean square(RMS) deviation is determined and compared.     

Course of Uptake of Weed-Borne Nitrogen by Maize,Tested with 15N

Abstract

The course of uptake of weed-borne nitrogen by maize was tested with ¹⁵N in a pot experiment with silty loam after common growth of maize and Chenopodium album L., and mulching the weed in the 5-leaf stage of maize. Harvests 4,8 and 12 weeks after mulching show that the maize took up 35, 63 and 70% of the weed-borne nitrogen, resp., in consequence of a rapid and almost complete mineralization. The portion of weed-borne nitrogen in total N of the maize was 16% at all harvest dates. The differences in yield between weeded and unweeded maize were not significant neither at 5-leaf stage nor at corn maturity.     

消除个体条件测量差异的动态光谱及其频域提取法的研究

在近红外光谱的皮肤无创检测中,个体差异是一个相当大的技术难题。在血液成分无创检测中,个体差异包括毛发、角质层、表皮、真皮、皮下组织、肌肉、骨骼等。研究表明,个体差异随着个体不同而不同,是阻碍血液成分无创检测技术实用化的重要因素。文章提出了基于光电容积脉搏波的产生机理和傅里叶变换的检测血液成分浓度的新方法——频域提取法,这种方法可以消除测量中由于皮肤组织和肌肉组织产生的差异;提出了动态光谱的概念,从理论和实验两个方面说明了这种方法的优点,并通过实验直接提取了各波长中仅由血液成分产生的吸光度光谱图,对于近红外光谱无创检测血液成分的实际应用有着重要意义。     

Fourier Transform Infrared Spectroscopic Analysis of Breast Cancer Tissues; Identifying Differences between Normal Breast,Invasive Ductal Carcinoma,and Ductal Carcinoma In Situ of the Breast

Abstract

A nondestructive method employing Fourier transform infrared (FTIR) microspectroscopy coupled with attenuated total reflectance (ATR) objective for the analysis of histopathological specimens is described. Malignant breast tissue specimens have been analyzed to demonstrate the hypothesis that chemical changes taking place in biological tissue can be reliably and reproducibly identified. This study is the first report to elucidate clear spectral differences between different ductal carcinoma in situ (DCIS) grades. Sixty individual cases of breast carcinoma including DCIS and invasive ductal carcinoma (IDC) and seven cases of normal breast tissues were studied using the FTIR-ATR spectroscopic technique. FTIR analysis of tissue sections has provided distinct spectra that can be used to distinguish between the nuclear grades of DCIS and IDC of the breast. It was concluded that FTIR could objectively and reproducibly discriminate between DCIS and IDC grades without sample destruction. In the future, applications of FTIR approaches should become feasible in the nondestructive express classification of grades and diagnosis of breast carcinoma.     

Raman scattering features of lead pyroantimonate compounds: implication for the non‐invasive identification of yellow pigments on ancient ceramics. Part II. In situ characterisation of Renaissance plates by portable micro‐Raman and XRF studies

The effectiveness of Raman spectroscopy (using a bench‐top system on standard pigments) for the characterisation of modified lead antimonate yellows was demonstrated in the already published Part I. The knowledge gained is employed here for the study of yellow glazes on genuine Renaissance plates with the aim of identifying non‐invasively lead pyroantimonate compounds by portable micro‐Raman equipment. The investigation was carried out directly on site, at the Victoria and Albert Museum (London, UK) and at the Museo Statale d'Arte Medievale di Arezzo (Arezzo, Italy), combining Raman and X‐ray fluorescence analyses. In addition to the spectral features of both unmodified Naples yellow and Sn‐ and Zn‐modified lead antimonate compounds, the Raman patterns related to partially modified pyrochlore structures were observed. For this reason, the possible Sn‐induced modification of Naples yellow by cassiterite (SnO₂), present within the glaze as opacifier was explored on lead antimonate yellow glaze mock‐ups fired at different temperatures. Copyright © 2010 John Wiley & Sons, Ltd.     

A detachable SERS active cellulose film: a minimally invasive approach to the study of painting lakes

The design and synthesis of a tailor‐made surface‐enhanced Raman scattering (SERS) active film that is fabricated to be removable from the surface of an artwork under study following effective measurements is detailed. It is shown that silver nanoparticles prepared by green chemical reduction with glucose can be effectively doped into a methylcellulose (MC) matrix for the formation of a gel, which can be subsequently applied to a minute area (ca 1–1.5 mm) of an artwork without posing a threat to its integrity. Studies have been aimed at characterizing this film's chemical and physical properties, with regard to the stability of the nanoparticles dispersed within the MC, the ease of application of the viscous gel, its speed of drying and the transparency of the dry film for SERS measurements. Importantly, results have led to reproducible SERS enhancements of the order 10³–10⁴ for studies carried out on reference laboratory dye components and unvarnished mock‐paintings. Techniques including optical and scanning electron microscopy were used to monitor the drying of the film and its resulting morphology, as well as to map the distribution of silver nanoparticles in the film so as to account for any visual modification to the underlying surface upon film removal. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthetic disproof of the structure proposed for solanacol, the germination stimulant for seeds of root parasitic weeds

The structure proposed for solanacol, the germination stimulant for seeds of root parasitic weeds isolated from tobacco (Nicotiana tabacum L.), was synthesized. Comparison of the ¹H NMR data of the synthetic compounds with those reported for solanacol showed the previously proposed structure to be incorrect.     

Multivariate analysis of combined Raman and fibre‐optic reflectance spectra for the identification of binder materials in simulated medieval paints

The non‐invasive identification of paint materials used in works of art is essential, both for preserving and restoring them, and also for understanding and verifying the history surrounding their creation. As such, the development of suitable non‐invasive techniques has received much interest in recent years. We have investigated the use of Fourier transform (FT)‐Raman spectroscopy and fibre‐optic reflectance spectroscopy (FORS), together with multivariate principal‐component analysis (PCA) techniques, in order to identify the pigment and binding materials used in made‐up samples representative of real artwork. We demonstrate that both types of spectroscopy provide complementary information which can be used to identify the pigments and binders in paint samples. We show that PCA with FT‐Raman spectra can be used to assist in the identification of oil‐based binders, and that the additional data provided by FORS spectra enables PCA on combined spectra to identify more complex proteinaceious and polysaccharide‐based binding media. The results presented here demonstrate that multivariate analyses of lead‐based paints, using data measured by FT‐Raman and FORS in conjunction, have much potential for identifying individual pigments and binders in paint samples. This provides a path towards computer‐assisted characterisation of paint materials on artwork. Copyright © 2013 John Wiley & Sons, Ltd.