Determining the mineralogical properties of Gua Sagu ancient pottery using X-Ray Diffraction and portable Raman spectrometer

Several military bases and monitions facilities throughout the world are contaminated with toxic explosives like 2,4,6-trinitrotoluene (TNT). This is an energetic compound and the least mobile of the military explosives. For this reason TNT gives one of the largest soil contamination problems. To understand the adsorption mechanism between TNT explosive and soil environments, the mechanical method analysis is used in our laboratory in order to obtain the soil texture classification. In these experiments, soil samples from horizons Ap and A were obtained from Jobos Series at Isabela, Puerto Rico. Based on the USDA texture triangle, the soil from the Ap horizon is classified as sandy clay. In contrast, the soil from A horizon fall in the sandy clay loam class. The clay minerals were separated from the other soil components using the mechanical method analysis. Cation exchange capacity (CEC), surface area, percent of organic matter and pH were determined for the soil and clay samples. The CEC results for soil samples were 3.62 mequiv/100 g for Ap horizon and 2.67 mequiv/100 g for A horizon while for the clay samples the CEC was 13.12 mequiv/100 g and 12.50 mequiv/100 g, for the Ap and A horizons, respectively. The results obtained for surface area analysis were 85.32 g/m² and 51.19 g/ m² for the two soil horizons and 189.71 g/m² and 163.87 g/m² for clay samples in the Ap and A horizons, respectively. These results indicate that the major adsorption could occur in the Ap horizon, specially in the clay fraction. A complete characterization of clay mineral samples using X-ray analysis reveals the present of kaolinite and quartz as main minerals. In order to obtain adsorption coefficients (K_dvalues), soil samples and the clay obtained from the mechanical method analysis, is being used for TNT adsorption studies by means of High Performance Liquid Chromatography (HPLC).

Archaeological excavations at the Sungai Batu Archeological Complex have unearthed potsherds with monument structures. The discovery of the potsherds enables scientific studies of X-ray diffraction (XRD), X-ray fluorescence (XRF) and Scanning Electron Microscopy (SEM) analysis to be conducted and resolve related issues such as where the raw materials were obtained by the manufacturers. To solve the issue, potsherds were taken from around the ancient river, and scientific analyses was conducted for comparison purposes. Before the clay sample was subjected to the scientific analyses, the samples were cleaned and measured (for weight, thickness and width). Color sampling was also performed. Based on results of the analyses, it clearly shows that the potsherds was produced using raw materials from the ancient river in the Sungai Batu Complex itself and baked at a temperature between 550°C and 650°C.

An inorganic geochemical study of a clay and shale sediments sequence around Araromi and Irogun- akere (the Southern part of Yewa River), Eastern dahomey basin, south western Nigeria, was carried out to determine the sediment's depositional conditions, provenance and tectonics. Fifteen shale and clay sediment samples underwent mineralogical and geochemical analysis involving major, trace and rare earth element analysis at acme analytic laboratory, Ontario, Canada using an ICP mass spectrometer (Perkin-Elmer, Elan 6000). Mineralogical studies using X-ray diffraction analysis revealed prominent kaolinite, montmorillonite and illite peaks; accessory minerals included quartz and microcline. Major element abundance showed that the shale samples consist of SiO2 (44.77%), Al2O3 (15.01%) and Fe2O3 (5.75%), constituting more than 65% of bulk chemical composition. Thirty-four elements trace metals; heavy rare earth elements and light rare earth elements analysis were quantified from the geochemical analysis. The shale sediments exhibit higher Ni, Ba, CO, Zr, Rb and Th concentrations than clay sediments, whereas clay samples are Sr-, Zn,, Pb- and U-enriched .Light rare earth element (La, Ce, Nd,Sm,Pr) were enrich in shale and clay sediment samples while, heavy rare earth elements (Tb, Yb, Lu, Gd ,Dy ,Ho, TM and Eu) are depleted. High TiO2 and Rb/K2O values also indicated that the shale and clay samples were matured. Geochemical parameters such as U, U/Th, Ni/Co and Cu/Zn ratios indicated that these shales were deposited in oxic conditions; the Al2O3/TiO2 ratio suggested that intermediate igneous rocks were probable source rocks for the shale, while mafic rocks were suggested as being source rocks for the claystone. However, the La/Sc, Th/Sc, Th/Co ratios and shale and clay sediment plots revealed that they came within the range given for felsic rocks as provenance, thereby suggesting mixed provenance for the sediments. A passive-margin tectonic setting was adduced for the sedimentary sequences.

Stabilization of clayey soil has been studied by mixing different additives to the soil to increase its strength and durability. Recently, there has been an increasing interest in the stabilization of soils with natural pozzolans. Nevertheless, very few articles have investigated the impact of basic oxygen furnace (BOF) slag additives under freeze–thaw cycling. This study presents the results of an experimental research study on the durability behavior of clayey soils treated with BOF slag. In this study, the effects of clay soils on the bearing value were investigated by adding 3%, 6%, 9%, 12%, 15%, and 20% BOF slag to the clay mineral sample within the scope of ASTM D-5918 tests. California bearing ratio (CBR) tests were then applied before and after freezing–thawing processes to the samples prepared at these optimum conditions. The relationship between the determined freezing and swelling speeds and the strength losses of the soil samples after freeze–thawing processes were investigated. For this purpose, eight mixtures with different geotechnical properties were subjected to freeze–thaw experiments on a total of 24 soil samples, each of which was repeated three times. Results show that the addition of steel-making slag to clay soils lead to favorable effects on freezing–thawing behavior. The effects of BOF slag on the clay sample after the freezing and thawing cycle were investigated and interpreted by considering their macro and micro phase structure. The findings indicate that using BOF slag has positive effects on strength and durability of clayey soil.

A chemical study of clays and Roman pottery from the Lower Nene Valley, Eastern England

Portable Raman spectrometer - design rules and applications Raman spectroscopy has become more popular due to its new prospective field applications in forensic sciences, war against terrorism, environment protection and other field chemical analysis. Raman spectrometers can be miniaturised to portable devices and their price is decreasing due to development of optoelectronics components. Unfortunately, this technology has still numerous limitations that influence their design and limit the scope of possible applications. The conception and design of the portable Raman spectrometer is described, including discussion of performance and limitations of representative components of such device available on the market. An enhanced portable Raman spectrometer using two lasers, one emitting at 355 nm and the other at 785 nm, and employing advanced signal acquisition and data processing methods is presenented. Advantages of such system are outlined and example measurement results acquired using equivalent hardware are presented. Data processing flow for identification of chemicals is also described.

IntroductionThis study assessed the microbial quality of clay samples sold on two of the major Ghanaian markets.MethodsThe study was a cross-sectional assessing the evaluation of processed clay and effects it has on the nutrition of the consumers in the political capital town of Ghana. The items for the examination was processed clay soil samples.ResultsStaphylococcus spp and fecal coliforms including Klebsiella, Escherichia, and Shigella and Enterobacterspp were isolated from the clay samples. Samples from the Kaneshie market in Accra recorded the highest total viable counts 6.5 Log cfu/g and Staphylococcal count 5.8 Log cfu/g. For fecal coliforms, Madina market samples had the highest count 6.5 Log cfu/g and also recorded the highest levels of yeast and mould. For Koforidua, total viable count was highest in the samples from the Zongo market 6.3 Log cfu/g. Central market samples had the highest count of fecal coliforms 4.6 Log cfu/g and yeasts and moulds 6.5 Log cfu/g. “Small” market recorded the highest staphylococcal count 6.2 Log cfu/g. The water activity of the clay samples were low, and ranged between 0.65±0.01 and 0.66±0.00 for samples collected from Koforidua and Accra respectively.ConclusionThe clay samples were found to contain Klebsiella spp. Escherichia, Enterobacter, Shigella spp. staphylococcus spp., yeast and mould. These have health implications when consumed.

<p>A busca por materiais que sejam empregados na construção civil de forma sustentável, tanto do ponto de vista ambiental como em relação a durabilidade e resistência, tem sido motivo de muitas pesquisas. As argilas termicamente ativadas ganharam importância como uma fonte de material cimentício suplementar, uma vez que apresentam vantagens ambientais, como redução da emissão de CO<sub>2</sub>, econômicas, devido à redução do consumo de energia para produção de cimentos, e técnicas, uma vez que melhoram a resistência e a durabilidade dos concretos e argamassas, além da abundância na natureza. Neste trabalho, é avaliado o comportamento térmico de três argilas do litoral sul da Paraíba. As amostras das argilas foram submetidas a um tratamento térmico para as temperaturas de 600 ºC, 700 ºC e 800 ºC e analisadas pelas técnicas termoanalíticas (TGA/DTA). As argilas foram caracterizadas físico-química e mineralogicamente, antes e após o tratamento térmico, e foram classificadas como material pozolânico tipo N, de acordo com as exigências químicas da Norma NBR 12653/2015. Os estudos térmicos das amostras de argila indicam que, nas temperaturas de calcinação de 600 °C e 800 °C, as perdas de massa observadas foram muito pequenas, da ordem de 2%, enquanto que, na temperatura de calcinação de 700 °C, grandes perdas de massa foram verificadas, principalmente para as amostras JPS2 e JPS3, com valores de 7,41% e 11,02%, respectivamente.</p>

Inflammatory biomarkers are closely related to infectious diseases. However, traditional clinical tests of laboratory inspection are unable to achieve rapid and accurate detection of these biomarkers on-site due to shortcomings such as complex experimental operation, expensive equipment, and long test time. Herein, we proposed a lateral flow assay (LFA) strip based on surface-enhanced Raman scattering (SERS) nanotags (SERS-LFA strips) for the simultaneous and quantitative detection of dual infection biomarkers, serum amyloid A (SAA) and C-reactive protein (CRP), respectively. In practice, mesoporous silica (mSiO2)-coated Au nanoparticles (Au NPs) were used as the SERS substrate. Mercaptobenzoic acid (MBA) was embedded in the internal gap between Au NPs and the mSiO2 shell to prepare AuMBA@mSiO2 NPs, onto which SAA and CRP antibodies were modified to prepare two AuMBA@mSiO2 SERS nanotags. The Raman intensities of the test and control lines were simultaneously identified for the qualitative detection of SAA and CRP, with limits of detection (LODs) as low as 0.1 and 0.05 ng/mL for SAA and CRP, respectively. Finally, aiming at point-of-care testing (POCT) applications, we used a smartphone-based portable Raman spectrometer to quantitatively analyze the SERS-LFA strips. The Raman signal could still be accurately detected when the concentration of SAA and CRP was 10 ng/mL, which is lower than the LOD required in clinical practice for most diseases. Therefore, taking into account its simple operation and short analysis time, by using a portable Raman spectrometer which can be equipped with a 5G cloud-based healthcare management system, the current strategy based on SERS-LFA provides the potential for the quick and on-site diagnosis of infectious diseases such as sepsis, which is of great significance for medical guidance on the treatment of widely spread infection-related diseases in remote areas that lack well-developed medical resources.

Raman spectroscopy is commonly used in chemistry to identify molecular structure. This technique is a nondestructive analysis and needs no sample preparation. Recently, Raman spectroscopy has been shown to be effective as a multipurpose analytical method for forensic applications. In the present study, blood identification and discrimination between human and nonhuman blood were performed by a portable Raman spectrometer, which can be used at a crime scene. To identify the blood and to discriminate between human and nonhuman blood, Raman spectra of bloodstains from 11 species (human, rat, mouse, cow, horse, sheep, pig, rabbit, cat, dog, and chicken) were taken using a portable Raman spectrometer. Raman peaks for blood (742, 1001, 1123, 1247, 1341, 1368, 1446, 1576, and 1619cm-1) could be observed by the portable Raman spectrometer in all 11 species, and the human bloodstain could be distinguished from the nonhuman ones by using a principal component analysis. This analysis can be performed on a bloodstain sample of at least 3months old. The portable Raman spectrometer can be used at a crime scene, and this analysis is useful for forensic examination.

Evaluation of portable Raman spectrometer with 1064 nm excitation for geological and forensic applications

We investigated the suitability of the graphitic carbon (GC) content of diesel particulate matter (DPM), measured using Raman spectroscopy, as a surrogate measure of elemental carbon (EC) determined by thermal optical analysis. The Raman spectra in the range of 800-1800 cm-1 (including the D mode at ∼1322 cm-1 and the G mode at ∼1595 cm-1) were used for GC identification and quantification. Comparison of the Raman spectra for two certified DPM standards (NIST SRM 1650 and SRM 2975), two types of diesel engine exhaust soot, and three types of DPM-enriched workplace aerosols show that the uncertainty of GC quantification based on the D peak height, G peak height, and the total peak area below D and G peaks was about 6.0, 6.7, and 6.9%, respectively. The low uncertainty for different aerosol types suggested possible use of GC as a surrogate measure of EC in workplace atmospheres. A calibration curve was constructed using two laboratory-aerosolized DPM standards to describe the relationship between GC measured by a portable Raman spectrometer and the EC concentration determined by NIOSH Method 5040. The calibration curve was then applied to determine GC-based estimates of the EC contents of diesel engine exhaust samples from two vehicles and seven air samples collected at a hydraulic fracturing worksite. The GC-EC estimates obtained through Raman measurements agreed well with those found by NIOSH Method 5040 for the same samples at EC filter loadings below 2.86 μg/cm2. The study shows that using an appropriate sample collection method that avoids high filter mass loadings, onsite measurement of GC by a portable or hand-held Raman spectrometer can provide a useful indicator of EC in workplace aerosol.

Quality assessment of medicinal, aromatic plants and plant parts, and spices are to large extent based on estimation of active molecules. Such estimations require high cost, time consuming and laboratory bound methods like High Performance Liquid Chromatography. These methods can handle very few samples at a time and have no portability. Raman spectrometer has been demonstrated to be useful in rapid detection and estimation of biological molecules that demonstrate Raman shifts. Hence, a relatively low cost and portable Raman spectrometer was designed with the commercially available components. The compatible software for its use like the graphical user interface and the calibration program were developed. With this spectrometer the Raman shifts obtained with the standard compounds—benzene, chloroform and glacial acetic acid, were quite compatible with the available standard reports. Then, piperine was estimated in black pepper (Piper nigrum) seed extracts and the coefficient of determination (R 2) of 0.98 was obtained for the regression between the high performance liquidchromatography estimates and those based on the Raman spectrometer. The spectrometer can be used for other marker molecules in plants and their products by suitable modifications in the software.

Use of the product of mean intensity ratio (PMIR) technique for discriminant analysis of lycopene-rich vegetable juice using a portable NIR-excited Raman spectrometer

Detection of illicit chemicals by portable Raman spectrometer The Raman spectrometers can be built as the portable devices and can be used in various places to detect illicit chemicals. This method has become popular due to deficiency of other fast methods that could be applied against terrorist attacks or could help police at their work. The Conception of a portable Raman spectrometer has been presented. The Description enclosures the presentation of the prepared device and its possible applications by presenting exemplary detection results.