Prediction of oil and oleic acid concentrations in individual corn (Zea mays L.) kernels using near-infrared reflectance hyperspectral imaging and multivariate analysis

Due to their heterogeneous structure and variability in form, individual corn (Zea mays L.) kernels present an optical challenge for nondestructive spectroscopic determination of their chemical composition. Increasing demand in agricultural science for knowledge of specific traits in kernels is driving the need to find high-throughput methods of examination. In this study macroscopic near-infrared (NIR) reflectance hyperspectral imaging was used to measure small sets of kernels in the spectroscopic range of 950 nm to 1700 nm. Image analysis and principal component analysis (PCA) were used to determine kernel germ from endosperm regions as well as to define individual kernels as objects out of sets of kernels. Partial least squares (PLS) analysis was used to predict oil or oleic acid concentrations derived from germ or full kernel spectra. The relative precision of the minimum cross-validated root mean square error (RMSECV) and root mean square error of prediction (RMSEP) for oil and oleic acid concentration were compared for two sets of two hundred kernels. An optimal statistical prediction method was determined using a limited set of wavelengths selected by a genetic algorithm. Given these parameters, oil content was predicted with an RMSEP of 0.7% and oleic acid content with an RMSEP of 14% for a given corn kernel.     

Development and validation of a method to determine the boron isotopic composition of crop plants

We present a comprehensive chemical and mass spectrometric method to determine boron isotopic compositions of plant tissue. The method including dry ashing, a three-step ion chromatographic boron-matrix separation, and (11)B/(10)B isotope ratio determinations using the Cs(2)BO(2)(+) graphite technique has been validated using certified reference and quality control materials. The developed method is capable to determine δ(11)B values in plant tissue down to boron concentrations of 1 mg/kg with an expanded uncertainty of ≤1.7‰ (k = 2). The determined δ(11)B values reveal an enormous isotopic range of boron in plant tissues covering three-quarters of the natural terrestrial occurring variation in the boron isotopic composition. As the local environment and anthropogenic activity mainly control the boron intake of plants, the boron isotopic composition of plants can be used for food provenance studies.     

Determination of pigments in colour layers on walls of some selected historical buildings using optical and scanning electron microscopy

For successful restoration of painted walls and painted coloured finishing coats it is necessary to determine the composition of the original colour layers. Identification of the pigments used in The Cistercian Abbey of Stična and The Manor of Novo Celje was carried out using optical and scanning electron microscopy. Selected samples of wall paintings were inspected by the combined application of an optical microscope and a low-vacuum Scanning Electron Microscope to determine their colour and structural features and to identify the position of individual pigment grains. Energy dispersive spectroscopy was used to determine the elemental distribution on selected surfaces and elemental composition of individual pigments. It was found that the most abundantly used pigments were iron oxide red, cinnabar, green earth, umber, calcium carbonate white, ultramarine, yellow ochre and carbon black. These identifications have allowed us to compare the use of various pigments in buildings from different historical periods.     

Analytical study of ancient pottery from the archaeological site of Aiani,northern Greece

The present study is a multi-analytical approach on the characterization of several potsherd samples, dated from prehistoric to hellenistic times, from Aiani, ancient Upper Macedonia, northern Greece. In particular, X-ray Diffraction (XRD), X-ray Fluorescence (XRF) and Environmental Scanning Electron Microscopy, coupled with Energy Dispersive X-ray system (ESEM-EDX) were used for the determination of the morphological, chemical and mineralogical characteristics of the potsherds. The preliminary results indicated a rather local provenance of the analyzed ancient pottery samples and a finer texture and thus better ceramic manufacture as getting to hellenistic era. The use of a silicious or calcerous raw material is probably related to the specific utilization of each ceramic vessel in ancient times. The presence of gehlenite or pyroxene minerals in the ceramic matrix indicated higher firing temperatures, while lower temperatures were deduced when finding phylosilicate minerals. The preliminary results of this study do not necessarily imply that all the pottery of this area, belonging to the same chronological type, have similar physicochemical characteristics.     

A new application of fiber-optic reflection spectroscopy (FORS): characterization of low-temperature alteration of chlorite schist and implications for understanding ancient stone cooking vessels

Bulk thermal alterations to chlorite schist occurring at temperatures above 450 °C are traditionally studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, or thermogravimetric analysis (TGA), but lower temperature changes that lead to structural and chemical alteration, including changes in oxidation state that are not followed by a crystalline modification, are not detectable using these techniques. In this paper we present the results of the first study to examine the application of fiber-optic reflection spectroscopy (FORS) for the detection and quantification of low-temperature thermal alterations in chlorite schist. Such changes have been observed during research on the thermal behavior of medieval (12th-13th centuries AD) chlorite cooking pots from the archaeological site of Merv, Turkmenistan. FORS was used to investigate these changes, testing the archaeological samples against a model data set of experimental reference specimens. The results demonstrate the potential of FORS for tracking low-temperature thermal alterations and offer the opportunity to examine temperatures attained by ancient chlorite vessels during their past use in cooking activities.     

Application of multivariate curve resolution for analysis of FT-IR microspectroscopic images of in situ plant tissue

The chemometric techniques of multivariate curve resolution (MCR) are aimed at extracting the spectra and concentrations of individual components present in mixtures using a minimum set of initial assumptions. We present results from the application of alternating least squares (ALS) based MCR to the analysis of hyperspectral images of in situ biological material. The spectra of individual pure components were mathematically extracted and then identified by searching the spectra against a commercial library. No prior information about the chemical composition of the material was used in the data analysis. The spectra recovered by ALS-MCR analysis of an FT-IR microspectroscopic image of an 8-micron-cornkernel section matched very well the spectra of the corn storage protein, zein, and starch. Through the application of MCR, we were able to show the presence of a second spectrally different protein, which could not be easily seen using univariate analysis. These results demonstrate the value of multivariate curve resolution techniques for the analysis of biological tissue. The value of principal components analysis (PCA) for hyperspectral image analysis is also discussed.     

木素含量对保鲜纸中亚氯酸钠留着率的影响

目的 探究不同木素含量的纸基对保鲜纸中亚氯酸钠留着率的影响规律。方法 采用化学浆和化学机械浆配抄不同木素含量的纸基, 采用涂布法制得保鲜纸, 利用 《纸浆 酸不溶木素的测定》 中的方法测定纸基中木素的含量, 用碘量法测定亚氯酸钠的留着率。结果 随着时间的延长, 纸基中亚氯酸钠的留着率均出现下降趋势, 但下降程度和速率不同。结论 纸基中木素含量与化学机械浆的比例呈正相关性, 木素会导致亚氯酸钠留着率的降低, 木素含量与亚氯酸钠留着率的降低程度呈正相关。     

云母钛珠光颜料的制备研究

采用尿素作为中和剂,用液相沉积法制备了云母钛珠光颜料.采用扫描电镜和X射线衍射仪对珠光颜料进行表征,系统考察了pH值、温度、TiCl4浓度、加料速度、尿素加入量、搅拌速度、晶型促进剂、煅烧温度等制备参数对珠光颜料质量的影响规律,确定了珠光颜料的生产工艺参数,提出了将TiCl4部分转化成TiOSO4,分步加入尿素制备云母钛珠光颜料的新方法.     

Natural radionuclide concentrations in granite rocks in Aswan and Central-Southern Eastern Desert, Egypt and their radiological implications

Different types of granites, used extensively in local construction, were collected from five localities in Egypt, namely: Abu Ziran (Central Eastern Desert), Gabal El Maesala (Aswan) and three areas from Wadi Allaqi, (Gabal Abu Marw, Gabal Haumor and Gabal um Shalman), in the South Eastern Desert. Granite samples were studied radiologically, petrographically and geochemically. The contents of natural radionuclides ((226)Ra, (232)Th and (40)K) were measured in investigated samples by using gamma spectrometry [NaI (Tl) 3'×3']. The activity concentrations of (226)Ra, (232)Th and (40)K in the selected granite samples ranged from 9±0.5 to 111±7, 8±1 to 75±4 and 100±6 to 790±40 Bq kg(-1), respectively. The external hazard index (H(ex)), absorbed dose and annual effective dose rate were evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. The calculated radium equivalents were lower than the values recommended for construction materials (370 Bq kg(-1)). The excess lifetime cancer risks were also calculated. Petrographically, the granites studied are varied in the form of potash-feldspar, quartz, plagioclase, mica and hornblende. The accessory minerals are zircon, apatite and allanite. Geochemically, the chemical composition of the granite is studied especially for major oxides. They are characterized to have SiO(2), K(2)O, Na(2)O and Al(2)O(3) with depletion in CaO, MgO, TiO(2) and P(2)O(5).     

State-of-the-art report

In-situ distortion of fibrous-cement slates is brought about by exposure to different temperature and hygrometric gradient across the material. The aim of the research was to understand in detail the effect of each composition change on the physical properties, and to use this knowledge for the manufacture of slates which would exhibit better mechanical properties. The present research has concentrated on measuring the physical parameters controlling moisture transfer. A second paper (in preparation) shall use these experimental results in a numerical model to simulate moisture movements. The key physical parameters measured include: porosity, saturated permeability, vapour diffusivity and the suction-moisture content relationship. The experimental results show clearly the effects of various treatments (painting the slate, adding additional layers, replacing the fibres, slate compaction) on the physical properties.

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Résumé Les déformations locales dans les ardoises de fibro-ciment peuvent être engendrées par l’existence de gradients de température et d’hygrométrie au sein du matériau. Le but de ce travail est de comprendre en détail l’effet des modifications de composition des ardoises sur leurs propriétés physiques et d’utiliser ces connaissances dans la fabrication d’ardoises présentant de meilleures propriétés mécaniques. Le travail présenté dans cet article est axé sur létude et la mesure des paramètres physiques influant sur les transferts d’humidité. Dans un second article (en préparation) nous présenterons l’élaboration et l’exploitation d’un modèle numérique apte à décrire les phénomènes étudiés. Les paramètres pertinents sont: porosité, perméabilité saturée, succion et perméabilité en fonction de l’humidité relative. Les résultats expérimentaux montrent clairement l’effet des traitements subis par les ardoises (peinture de la surface, ajout d’une couche minérale supplémentaire, remplacement de l’amiante par d’autres fibres, compactage des ardoises) sur leurs propriétés physiques.

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Editorial note A. Raoof is working at the Laboratoire des Matériaux et des Structures (LCPC) France, which is a RILEM Titular Member. A. Sabouraud is working at Pont-⦏-Mousson SA, France, which is a RILEM Titular Member.     

Characterization of stripping properties of stone material in asphalt

Aggregates and bitumen together form a composite called asphalt concrete pavement. Moisture damage to asphalt concrete pavement can occur as stripping, and is a common problem that can lead to costly repairs. There is therefore a need to understand which stone aggregates adhere best to bituminous binder and result in a minimum of stripping. Lifshitz used the refractive index to estimate the dispersive non-polar van der Waal’s interaction component of adhesion, the predominant component in adhesion between minerals and bituminous binder. The impact of an intervening thin medium such as air or water on the adhesion can be estimated using Hamaker’s coefficient, which in turn can be related to stripping potential. Aggregates consist of minerals and minerals consist of different elements. The objective of this study was to investigate variation in the dispersive component of minerals via their refractive indices using data from mineral data sheets. The influence of the position of elements in the periodic table and chemical composition on refractive index of minerals was examined in order to classify mineral aggregates for asphalt road building with regard to dispersive adhesive properties and expected resistance to stripping. It is clear from this study that the elemental composition of a mineral will affect its refractive index and hence its dispersive adhesion to bitumen. Aggregates and minerals have been classified according to degree of stripping in the literature. In this study it was shown that aggregates and minerals that have a refractive index higher than approximately 1.6 are expected to be less susceptible to stripping. Also, minerals containing alkali metals are sensitive to stripping since they are partially soluble in water.     

Measurement of Cu and Zn adsorption onto surficial sediment components: new evidence for less importance of clay minerals

Clay minerals in surficial sediment samples, collected from the Songhua River in China, were separated via sedimentation after removal of Fe/Mn oxides and organic materials; Cu and Zn adsorption onto the sediment components was then evaluated. Clay minerals were examined via X-ray diffraction and scanning electron microscopy. Clay minerals were found to consist mainly of illite, kaolinite, chlorite and an illite/smectite mixed layer. Non-clay minerals were dominated by quartz and orthoclase. The retention of Cu and Zn by clay minerals was 1.6 and 2.5 times, respectively, greater than that of the whole, untreated surficial sediment. Compared to the other critical components in sediments related to metal sorption (Mn oxides, Fe oxides and organic materials), the adsorption capacity of clay minerals was found to be relatively lower on a unit mass basis. These data suggest that, although clay minerals may be important in the adsorption of heavy metals to aquatic sediments, their role is less significant than Fe/Mn oxides and organic materials.     

Catalyst-free growth of oriented single-walled carbon nanotubes on mica by ethanol chemical vapor deposition

In this letter, it is reported for the first time that single-walled carbon nanotubes (SWNTs) can grow on mica substrate without additional catalyst by chemical vapor deposition (CVD) using ethanol as carbon source. The single-wall structure was characterized by Raman spectra and AFM (Atomic Force Microscopy) measurements. The growth of carbon nanotubes on mica surface contributes to the small amount of iron oxide in bare mica. The uniform dispersion and nanosized Fe particles formed from the reduction of iron oxide favor for the growth of SWNTs. Horizontally aligned superlong SWNTs arrays can be successfully generated on the mica surface, which is proved to be guided by the gas flow and under “kite growth mechanism”. The mica is a machinable material which can be easily cut and made a narrow slit on, thus the nanotubes can traverse the slit which can be in millimeter scale and long suspended SWNTs can be generated. This will provide an opportunity to manipulate individual SWNT for various purposes.     

粘土矿物负载型复合催化剂的研究进展

利用粘土矿物的结构和物理化学特性负载纳米颗粒以制备高性能的功能矿物材料,是目前材料科学、矿物加工、化学工程等多学科交叉的研究前沿。粘土矿物大的比表面积、丰富的孔道结构和优越的离子交换性能为其用于矿物型复合催化材料提供了充分的保证。综述了国内外粘土矿物负载型复合催化剂的最新进展,整理分析了凹凸棒石、高岭土、蒙脱石、海泡石、硅藻土、沸石等多种复合催化剂的制备方法、应用方向及性能评价,并结合目前存在的一些问题提出见解,为深入研究提供了一定的思路。     

Equilibrium composition of products of melting of main minerals involved in the composition of basalt

Using the method of thermodynamic simulation, the equilibrium composition of products of heating of plagioclases, pyroxenes, peridots, and magnetite is determined in a temperature range of 1000–1400°C in inert, oxidizing, and reducing atmospheres. The possibility of controlling the products of melting and crystallization of the above minerals is shown, and the behavior of a series of accessory metals (Ti, Mn, Cr, V) in these processes is evaluated.     

Surface modifications of talcs. Effects of inorganic and organic acid treatments

A multipurpose acid treatment, which comprises purification, delamination, particle size reduction, and surface modification on milled talc samples, is proposed. Talcs of different origins and composition were studied in order to assess and compare the effects of different acid treatments. Associated minerals were dissolved away by both inorganic and monocarboxylic organic acids, rendering more pure and lower particle size talcs. The main results obtained from hydrochloric acid treatment were purified talcs, having silanol groups onto their surfaces. This treatment allowed the complete removal of carbonates and chlorite from initial talcs, allowing for a length and thickness reduction of talc particles and the change to hydrophilic character by breakage of siloxane bonds. The so-treated talc achieved a purity level enough to be used in plastic and paper industry, paints among other upgraded talc applications. On the other hand, organic acid attacks were able to graft carboxylic groups onto the talc surface. The occurrence of this reaction was verified by independent characterization techniques both direct (Fourier Transform Infrared Spectroscopy, Energy Dispersive X-ray) and indirect (X-ray Diffraction, Scanning Electronic Microscopy, hydrophobicity/hydrophilicity test).     

Decoupling the effects of chemical composition and fineness of fly ash in mitigating alkali-silica reaction

A comprehensive investigation was conducted to determine the individual effects of the chemical composition and particle size of fly ash on alkali-silica reaction (ASR). Test results indicated that the combined oxides content of fly ash showed a better correlation with the ASR expansions than its individual oxides. Mixtures containing finer fly ash fractions registered lower expansions than those containing the corresponding virgin fly ashes or its coarser fractions.Within the usual range of average particle size of 10 to 30 microns, of fly ash, the chemical composition had a more dominant influence on ASR mitigation than the particle size. However, when the average particle size of fly ash decreases below 10 microns, the fineness of fly ash becomes significant in mitigating ASR. In addition, the fineness of fly ash had a more significant influence in mitigating ASR in mixtures containing high-lime fly ashes than those containing low-lime fly ashes. Hence, reducing the particle size of fly ash to finer fractions is an effective strategy to mitigate ASR. The decoupling of the chemical composition of fly ash from its particle size indicated that ASR mitigation can be achieved with any fly ash having a D₅₀ below 5 μm. However, low-lime fly ashes were effective in mitigating ASR even without reducing their particle size.     

Depleted brittle mica structure determination in Ba-phlogopite glass–ceramics

This study concerns the bulk mica phase of a barium phlogopite glass–ceramic, with potential applications in Computer Aided Design and Computer Aided Manufacturing in dentistry, which has been studied in detail and characterized for the first time. A number of analytical techniques including powder X-ray diffraction (XRD), scanning electron microscopy, energy dispersive spectroscopy, electron micro-probe analysis (EMPA), single crystal XRD and Monte-Carlo methods have been used to determine the mica phase composition and crystallographic structure. This has led to the identification of a new species of trioctahedral interlayer deficient brittle mica with an ideal formula of Ba_2/3Mg₃(Si_8/3Al_4/3)O₁₀F₂. Monte-Carlo simulations of Si/Al cation ordering indicate that the (Si_8/3Al_4/3) tetrahedral composition is unique and energetically favoured over that of the original assumed mica phase of Ba_0.5Mg₃(Si₃AlO₁₀)F₂. The general mica composition X_0.5Mg₃(Si₃Al)O₁₀F₂ where X is a divalent interlayer cation; therefore, does not precipitate in brittle mica glass–ceramics.     

Infra-red spectra of some selected minerals,rocks and products

Forty-nine infra-red spectra (1600 to 400cm^–1) of rocks, minerals and products of industrial importance have been determined. These include mica, asbestos, apatite, calcite, feldspar, kyanite, slags, fly ash, etc. They have been classified into several groups based on structural parameters and chemical groups with pertinent discussions relating to the spectral characteristics of these materials for rapid identification and characterization.