Interpretation of comprehensive two-dimensional gas chromatography data using advanced chemometrics

The power of comprehensive two-dimensional gas chromatography (GC × GC) for the study of complex mixtures has been indisputably proved in the past several decades. This review encompasses the whole of GC × GC-related data processing and summarizes relevant applications. We include theoretical introduction to some specific methods and studies to aid readers' understanding of chemometrics strategies for advanced data interpretation

Application of Infrared Spectroscopy and Chemometrics to the Cocoa Industry for Fast Composition Analysis and Fraud Detection

Tesis por compendio[ES] El cacao es un producto de alto valor, no únicamente por sus características sensoriales, sino porque también presenta un alto contenido en antioxidantes y alcaloides estimulantes con efectos saludables. Debido a la alta demanda, la industria del cacao en polvo tiene el desafío de asegurar la calidad de grandes volúmenes de producción de una manera rápida y precisa, evitando la presencia de contaminantes o adulterantes en la materia prima, ofreciendo productos donde se preserven las propiedades saludables. La espectroscopia del infrarrojo cercano (NIR) es una tecnología rápida y no destructiva útil en el análisis de productos alimentarios. La presente tesis doctoral se centra en evaluar el potencial uso del NIR como una herramienta de control de calidad con el fin de poder resolver problemas que se presentan en la industria del cacao en polvo. Los problemas a resolver incluyen la detección de materiales no deseados o adulterantes en el cacao en polvo, y la monitorización rápida y precisa del contenido de flavanoles y metilxantinas del cacao en polvo durante el proceso de alcalinización. El primer capítulo evalúa la viabilidad del NIR, en combinación con análisis quimiométricos, en la detección de la presencia de materiales no deseados o adulterantes como son cascarilla de cacao o harina de algarroba. Para ello, diferentes muestras de cacao en polvo natural y con diferentes niveles de alcalinización (suave, medio y fuerte) fueron mezcladas con distintas proporciones de cascarilla de cacao (con cacao natural) o harina de algarroba (con cacao natural y alcalinizado). Los resultados obtenidos indican que el NIR, combinado con modelos estadísticos tales como el análisis discriminante por mínimos cuadrados parciales (PLS-DA) y la regresión parcial de mínimos cuadrados (PLS), es un método rápido y eficaz para identificar cualitativa y cuantitativamente materiales no deseados o adulterantes como la cascarilla y la algarroba en cacao en polvo, independientemente del grado de alcalinización o el nivel de tostado de la harina de algarroba. En el segundo capítulo, el análisis composicional del cacao en polvo se orientó al control de los cambios producidos en el contenido de flavanoles y metilxantinas debidos al proceso de alcalinización al que se somete el caco en polvo. Se determinó el contenido de catequina, epicatequina, cafeína y teobromina mediante cromatografía líquida de alta resolución (HPLC), correlacionándose los contenidos obtenidos para cada uno de estos compuestos con las determinaciones NIR. Se obtuvieron buenos modelos para la predicción de los compuestos mediante regresión PLS con valores superiores a 3 para la relación entre el rendimiento y la desviación (RDP), lo cual demuestra que los modelos obtenidos pueden ser utilizados para la rápida y fiable predicción del contenido de flavanoles y metilxantinas en cacaos naturales y con diferentes niveles de alcalinización.[CA] El cacau és un producte d'alt valor, no sols per les seues característiques sensorials, sinó perquè també presenta un elevat contingut en antioxidants i alcaloids estimulants amb efectes saludables. A conseqüència a l'alta demanda, l'industria del cacau en pols té el desafiament d'assegurar la qualitat de grans volums de producció d'una manera ràpida i precisa, evitant la presència de contaminants o adulterants en la matèria cosina, oferint productes a on se preserven les propietats saludables. L'espectroscòpia de l'infrarroig proper (NIR) és una tecnologia ràpida i no destructiva útil en l'anàlisi de productes alimentaris. La present tesis doctoral se centra en avaluar el potencial ús del NIR com una eina de control de qualitat amb l'objectiu de poder resoldre problemes que es presenten en l'industria del cacau en pols. Els problemes a resoldre inclouen la detecció de materials no desitjats o adulterants en el cacau en pols, i la monitorització ràpida i precisa del contingut de flavanols i metilxantines del cacau en pols durant el procés d'alcalinització. El primer capítol avalua la viabilitat del NIR, en combinació amb anàlisis quimiométrics, en la detecció de la presència de materials no desitjats o adulterants com són pellofa de cacau o farina de garrofa. Per a això, diferents mostres de cacau en pols natural i amb diferents nivells d'alcalinització (suau, mig i fort) foren barrejades en distintes proporcions de pellofa de cacau (en cacau natural) o farina de garrofa (en cacau natural i alcalinisat). Els resultats obtinguts per a NIR, combinats amb models estadístics com l'anàlisi discriminant per mínims quadrats parcials (PLS-DA) i la regressió parcial de mínims quadrats (PLS), és un mètode ràpid i eficaç per identificar materials no desitjats o adulterants com la pellofa de cacau o la farina de garrofa, amb independència del grau d'alcalinització del cacau o de torrat de la farina de garrofa. En el segon capítol, l'anàlisi composicional del cacau en pols s'orientà al control dels canvis produïts en el contingut de flavanols i metilxantines a causa del procés d'alcalinització al que se sotmet el cacau en pols. Es va determinar el contingut de catequina, epicatequina, cafeïna i teobromina mitjançant cromatografia líquida d'alta resolució (HPLC), i es van correlacionar els continguts obtinguts per a cadascun d'estos composts amb les determinacions NIR. Es van obtindré bons models per a la predicció dels composts mitjançant regressió PLS amb valors superiors a 3 per a la relació entre el rendiment i la desviació (RDP), la qual cosa demostra que els models obtinguts poden ser emprats per a la ràpida i fiable predicció del contingut de flavanols i metilxantines en cacaus naturals o amb diferents nivells d'alcalinització.[EN] Cocoa is a product of high value, not only because of its sensory characteristics, but also because it has a high content of antioxidants and stimulating alkaloids with health effects. Due to the high demand, the cocoa powder industry has the challenge of ensuring the quality of large volumes of production in a fast and accurate way, avoiding the presence of contaminants or adulterants in the raw material, offering products where the healthy properties are preserved. The near infrared spectroscopy (NIR) is a rapid and non-destructive technology useful in the analysis of food products. The present doctoral thesis focuses on evaluating the potential use of NIR as a quality control tool in order to solve problems that arise in the cocoa industry powdered. The problems to solve include the detection of unwanted materials or adulterants in the cocoa powder, and the rapid and accurate monitorization of the flavanols and methylxanthines content in the cocoa powder during the alkalization process. The first chapter evaluates the viability of the NIR, in combination with chemometric analysis, in the detection of presence of unwanted materials or adulterants such as cocoa shell or carob flour. For this, different samples of natural cocoa powder and with different levels of alkalization (light, medium and strong) were mixed with different proportions of cocoa shell (with natural cocoa) or carob flour (with natural and alkalized cocoa). The results obtained indicate that the NIR combined with statistical models such as the partial least squares discriminant analysis (PLS-DA) and the partial least squares regression (PLS), is a fast and efficient method to identify qualitative and quantitative unwanted materials or adulterants such as shell and carob in cocoa powder, regardless of the degree of alkalization or level of roasting of carob flour. In the second chapter, the compositional analysis of cocoa powder was oriented to the control of the changes produced in the content of flavanols and methylxanthines due to the process of alkalization to which the cocoa powder is subjected. The content of catechin, epicatechin, caffeine and theobromine were determined by high performance liquid chromatography (HPLC), correlating the contents obtained for each of these compounds with the NIR determinations. Good models were obtained for the prediction of compounds by regression PLS with values above 3 for the ratio of performance to deviation (RDP), which shows that the obtained models can be used for the quick and reliable prediction of flavanol content and methylxanthines in natural cocoas and with different alkalization levels.This Doctoral Thesis has been carried out thanks to a doctoral studies scholarship granted by the Ministry of Higher Education, Science, Technology and Innovation (SENESCYT) of the Republic of EcuadorQuelal Vásconez, MA. (2019). Application of Infrared Spectroscopy and Chemometrics to the Cocoa Industry for Fast Composition Analysis and Fraud Detection [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/135258TESISCompendi

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 367)

This bibliography lists 205 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System during Aug. 1992. Subject coverage includes the following: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance

Risky Businesses: A Micro-Level Spatiotemporal Analysis of Crime, Place, & Business Establishment Type

Continuing advances in the fields of environmental criminology and geographical information sciences are facilitating place-based research. One of the current trends in environmental criminology is the focus on micro-level `places\u27 including street segments, property lots, and specific kinds of buildings and facilities in understanding crime patterns and the opportunity structure that permits crime. Despite important findings on the concentration of crime in urban areas, there continues to be substantial gaps in our knowledge about micro-level spatiotemporal patterns of crime. These gaps in micro-level environmental criminology research have primarily been a result of the lack of access to data, availability of ancillary data (land-use & business establishment data), accuracy of geocoded crime data, and availability of existing theory and methods to study crime at micro-levels. Interestingly, many studies indicate that crimes are clustered at neighborhood level, but the entire neighborhood is rarely (if ever) criminogenic and only specific parts of neighborhoods contain high concentrations of crime. Prior studies incorrectly assume that the relationships between crime, population, land-use, and business establishment types are both homogenous and spatially stationary. Environmental criminologists using Pareto\u27s 80/20 concept pointed out that not all parks are full of drug users/dealers, not all high schools have high rates of delinquency, not all bars contain high rates of assault, and not all parking lots have high rates of auto theft. In fact neighborhoods contain hot spots (high density crime areas) and cold spots (low density crime areas), bad streets and good streets, and good and bad businesses. By undertaking a micro-level spatiotemporal framework, this dissertation research is intended to promote understanding of the patterns of violent crimes and the opportunity factors that contribute to these crimes in neighborhoods, street segments, property lots and business establishment types. The integration of environmental criminological theory and novel spatial analyses at the street segment and property lot level should help criminology/criminal justice scholars and practitioners to better understand the spatial and temporal processes in the `magma\u27 that fuels today\u27s hot spots

Leaching of Rare Earth Elements from Various Sources

The proposed book is a compilation of a Special Issue on “Leaching of Rare Earth Elements from Various Sources”, published in the journal Minerals in 2020. There are 10 papers contributed by experts in the area, and these can be grouped into four categories: leaching from low-grade ores including coal, clay, soil, and red mud; pre-treatment and leaching; recycling; and precipitation and nano-hydrometallurgy. Although these articles are available in the journal Minerals, it is convenient to compile the most valuable information into a book form so that scholars and industrial practitioners can have easy access to it when they need it where the Internet is not easily available. I strongly believe that the book on a very specialized topic matter such as modern extraction technologies of rare earth elements will contribute greatly to the fast-growing industry that needs rare earth elements

Greenhouse Management for Better Vegetable Quality, Higher Nutrient Use Efficiency and Healthier Soil

Greenhouse cultivation provides an artificially controlled environment for the year-round production of vegetables, and has played an increasingly important role in agriculture production systems in recent decades. Recent works have shown that improving greenhouse conditions can promote the growth of vegetables and enhance the uptake of nutrients, leading to better vegetable quality. Meanwhile, greenhouse conditions not only directly influence soil nutrient cycling processes and properties, but also indirectly affect them by regulating vegetable root growth and plant–soil interactions. This Special Issue features twelve original research articles that deal with the effects of novel greenhouse practices and strategies on the yield and quality of horticulture crops, as well as greenhouse soil properties. Among these publications, three studied the effects of fertilizers, including organic and macro- and micro-nutrient fertilizers, on the growth and nutrient uptake of vegetables. Two articles described the effects of water and nutrient supply using irrigation or hydroponic supplying systems on the yield and quality of vegetables. Four articles investigated the effects of environmental conditions (mainly light and temperature) on the growth and quality of vegetables. In terms of degenerated greenhouse soil, three articles showed how reductive soil disinfestation decreased soil salinity, improved soil quality, and inactivated soil-borne pathogens

Following cocoa beans to chocolate : The search for intrinsic characteristics

The assessment of cocoa’s natural characteristics can be used to link cocoa beans and chocolate. Establishing a link between the raw material and the finished product is complicated not only because of complex characteristics of the supply chain but also because of the technology involved in the production and the composition of the ingredients. One may wonder why a link between raw material and the finished product is relevant. Nowadays, more and more attention is given to sustainability, pushing the cocoa manufacturers to take into account social, economic and environmental issues while producing. As a consequence, the demand in cocoa-importing countries for certified sustainable cocoa has increased considerably and is expected to show continuous growth over the next years. Moreover, more consumers have become increasingly aware of the existence of different cocoa varieties and their origins, and the market of specialty chocolates such as chocolates with single-origin bean, organic and fair-trade chocolate has largely grown in the last decades. The aforementioned trends in the chocolate sector and the growing concerns regarding food quality and safety led to a growing effort in the implementation of traceability systems. This trend has facilitated the need to verify and guarantee the origin of the cocoa beans along with the cocoa-chocolate supply chain and to establish a link between raw material and the finished product. For these reasons, the main objective of this thesis is to discover cocoa beans’ traits in terms of the botanical and geographical origin carried along the cocoa–chocolate supply chain. Compositional characteristics of botanical and geographical origin of cocoa beans after fermentation and drying, after manufacturing chocolate and during chocolate consumption were analysed. This information can be used to derive a link between raw material and the finished product, which in turn can be used to support traceability systems. To investigate the cocoa-chocolate botanical and geographical origin information, markers related to intrinsic properties were used: volatile and non-volatile characteristics. The latter include small non-volatile compounds, elemental composition, isotope ratios and hyperspectral profiles. The reflectance of the cocoa beans origin along the supply chain is investigated starting from the consumer perspective with the analysis of the nosespace (NS) profile of consumers eating chocolates manufactured from beans of different origins. Moving back along the supply chain, the possibility to extract botanical and geographical traits from both volatile and non-volatile profiles is further tested in chocolates available in the supermarket. To extract more information cocoa beans and corresponding chocolates to extract raw material markers in a finished product analysing their volatile, elemental and isotopic compositional traits. Finally, the raw material analysis completes the assessment of cocoa beans origin traits along the supply chain. Regarding the botanical traits carried along the supply chain, the volatile intrinsic characteristic showed the potential to track and trace raw material origin along the entire supply chain. It was possible to identify typical volatile compounds of the raw material in chocolate bar and chocolate during chocolate consumption. VOCs were found to be the most robust markers that were carried from cocoa beans to consumer products, revealing a constant shift/change between the raw materials and the finished products. Potential markers (i.e. acetic acid) were detected to reveal botanical traits from raw material to chocolate to chocolate consumption. However, in general, it was difficult to identify specific individual markers carried along the supply chain highlighting the fact that the botanical traits are more related to a general volatile pattern. The same is valid for the small non-volatile compounds analysed in chocolate. Interestingly, when analysing the non-volatile compositional traits, the botanical trend explained the samples overlapping according to the geographical origin. This occurred despite the impact of the processing step or the ingredient added on the origin expression. The brand influence was confirmed also when the elemental and stable isotope fingerprints of cocoa beans and chocolates were compared. Stable isotope signatures appear less sufficient for tracing the characteristics of cocoa in chocolate products without previously estimating the isotope signature of all the ingredients reducing the possibility to use them as origin markers. Our results support the botanical traits’ influence as highlighted for the volatile and non-volatile profiles of chocolate and the volatile NS profile of chocolate during consumption and it indicates that intrinsic features of the beans are retained after processing and even during consumption. Regarding the geographical origin traits carried along the supply chain, volatile compounds reflected the geographical trait from cocoa beans to consumers. Within the non-volatile compositional traits Cr, Fe and Cd appeared to be distinct geographical markers although they are susceptible to environmental contamination. However, along the supply chain, the geographical traits were hidden by other factors. During chocolate consumption, geographical discrimination was possible only within each botanical group. In chocolate, the geographical information was evidently contained by the volatile compounds. However, we highlighted an interference with botanical and brand traits. This was particularly clear when analysing the small non-volatile compounds. Only when reducing the influence of the brands, it becomes clear that the samples are spread according to the three origins. Regarding the raw material, the impact of the geographical origin on the volatile and hyperspectral profile of cocoa beans is influenced by the variability related to differences in fermentation and drying within a country and between countries. Despite these interferences, a similar trend both in cocoa beans and in chocolates is visible for certain compounds, making them usable as cocoa-chocolate linking markers. The evidence from this study suggests that volatile and non-volatile compositional traits of cocoa and cocoa products can be used to verify and/or follow origin traits along the supply chain and link raw material and the finished product. However, more research is needed on how to reduce botanical and geographical interaction and improve the product characterisation along the supply chain. Within the compositional traits that were measured, the volatile profile is the most suitable for gathering information at the beginning of the production and at different stages in the supply chain

エコ産業団地と循環経済型産業の評価指標システムの開発と総合評価

Circulation economy is the inevitable choice of industrialization because of improving the economic efficiency and reducing resource consumption, can fundamentally solve the contradiction between economic growth and environmental protection. The general evaluation of circular economy can be conducted from city level, industrial-park level, and enterprise level. However, the researches on the enterprise level and industrial park level are relatively few, and a unified standard system framework is not yet to be formed. In this study, the circular economy was evaluated for enterprises and eco-industrial parks. The AHP method and the expert consultation questionnaire method are used to establish their respective evaluation index systems and the weights of each index. An eco-industrial park (TEDA) and an enterprise (Tianjin SDIC power plant) as the example, their circular economy levels were conducted the comprehensive evaluation respectively according to established evaluation index systems. The results show that the established evaluation index systems have a good performance.北九州市立大