Chemical characterization of pitch deposits produced in the manufacturing of high-quality paper pulps from hemp fibers

Instituto de Recursos Naturales y Agrobiología, CSIC, P.O. Box 1052, E-41080, Seville, Spain E-mail address: [email protected] composition of pitch deposits occurring in pulp sheets and mill circuits during soda/anthraquinone pulping and elemental chlorine-free pulp bleaching of bast fibers of industrial hemp (Cannabis sativa) has been studied. Pitch deposits were extracted with acetone, and the extracts analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Acetone extracts (15-25% of pitch deposits) were constituted by the defoamers used at the mill and by lipophilic extractives from hemp fibers. Acetone-insoluble residues (75-85% of pitch deposits) were analyzed by pyrolysis-GC/MS in the presence and absence of tetramethylammonium hydroxide. These residues were constituted by salts of fatty acids (arising from hemp fibers) with calcium, magnesium, aluminum and other cations that were identified in the deposits. It was concluded that inappropriate use of defoamer together with the presence of multivalent ions seemed to be among the causes of hemp extractives deposition in the pitch problems reported here.This study has been supported by the Spanish Ministerio de Ciencia y Tecnología (MCYT) and FEDER funds (projects 2FD97-0896-C02-02 and AGL2002-00393). A.G. acknowledges a "Ramón y Cajal" contract of the Spanish MCYT. We also thank CELESA (Tortosa, Spain) for providing the samples.Peer reviewe

Invariant local twistor calculus for quaternionic structures and related geometries

New universal invariant operators are introduced in a class of geometries which include the quaternionic structures and their generalisations as well as 4-dimensional conformal (spin) geometries. It is shown that, in a broad sense, all invariants and invariant operators arise from these universal operators and that they may be used to reduce all invariants problems to corresponding algebraic problems involving homomorphisms between modules of certain parabolic subgroups of Lie groups. Explicit application of the operators is illustrated by the construction of all non-standard operators between exterior forms on a large class of the geometries which includes the quaternionic structures.Comment: 44 page

Aspects of seasonal variation in breeding success of herring and lesser black-backed gulls (larus argentatus and l. fuscus)

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Accuracy of Cut-Mark Analysis Databases within Forensic Anthropology

When it comes to trauma analysis, there are multiple databases and criteria used to determine weapons. Therefore, the purpose of this research is to determine whether or not the accuracy of these databases are precise enough to definitively determine which type of weapon is used. Five different tools were used, split into two different sections. The first were weapons used in stabbings: scalpels, pocket knife, and kitchen knife. The next section of weapons were those used in the dismembering of remains: an axe and machete. It is apparent that the identification of murder weapons is a clear link to the arrest and prosecution of an individual. If there is an inaccuracy within these databases, it may depict a larger issue than just identifying the wrong weapon, as it could truly be a matter of life or death for a potentially wrongly accused perpetrator

Gambling problems and help-seeking in serving United Kingdom military personnel: a qualitative study

Introduction In military personnel are vulnerable to gambling problems, yet many are reluctant to seek help. The aim of the current study was to explore the lived experience of problem gambling and help-seeking among serving members of the United Kingdom Armed Forces. Methods Seventeen individuals from a larger, cross-sectional survey of gambling and wellbeing in the Royal Air Force (RAF) completed semi-structured interviews. Interview questions focused on personal experiences, the context of the RAF and its influence, knowledge and experiences of treatment and support services, and the impact of COVID-19. Results Reflexive thematic analysis revealed four themes: (1) harmful and protective occupational factors; (2) socio-cultural and personal influences; (3) organizational attitudes toward mental health and help-seeking, and (4) current support pathways and provision. Discussion Findings also indicated that gambling and alcohol use are common within the RAF, and that personnel are actively coping with mental health challenges

The Roman Toga: The Social Effects of Materiality

The social meanings of the Roman toga, in all their nuances and varieties, arise not arbitrarily from culture and custom, but, as shown in this dissertation, are shaped by the materiality of the toga and its components. Inspired by current approaches in material culture studies which center on the materiality of objects and their interactions with human bodies and behaviors, this project brings together a wide variety of literary and artistic sources, from the first century B.C.E. to the late-second century C.E. and beyond, in an examination of how togas are represented in the performance of their function as signs of identity. This analysis explains the material bases for the toga’s many uses as a marker of social identity, adding a wealth of complexity and nuance to the current image of the toga as a symbol of citizenship, masculinity, and Roman-ness. An important contribution of this study is its insight into how the toga functioned as a unifying sign of citizenship, one which identified gradations of social status only by subtleties in materiality. The all-white toga pura marked a ‘Roman citizen’ as someone integrated within a homogeneous group, with the fabric ostensibly concealing his individuality and his particular origin or status beneath a visual quality of sameness. High rank was indicated only by the addition of prestigious purple dye, making a toga no longer pura but praetexta, and by small variations in other garments such as the tunic and shoes. Nevertheless, slight physical differences in the toga’s fabric, such as its whiteness or comfort level, were used in nuanced ways to indicate other markers of identity, especially wealth, to a discerning Roman audience. As a result, the toga could mark its wearer as ‘elite’ in artistic and literary sources, but just as often, it could also reveal him to be impoverished, servile in origin, or rustic. The toga signified more than simply citizenship in Roman society. The garment was also a sign of ‘masculinity’: this study explains how its drape accentuated bodily characteristics that were gendered male, and also why transparent togas signified promiscuity and effeminacy instead. The fabric of the toga both indicated and materially enforced ‘peace’—except when it was adjusted for fighting, perhaps to imply that the upcoming violence was a civic duty. Changes in fashion served to differentiate the elite from non-elites or ‘dandies’ from more conservative dressers, as several scholars have pointed out, but in addition, this study shows how style changes also reflected shifting ideas about ideal bodily movement. In addition, many researchers have noted that various types of toga were important components of several rituals that marked social transitions, but the materiality which lies beneath their different meanings is explained here. From the brilliance of the purple-and-gold toga picta to the dark wool and filth of mourning dress, very specific changes in the toga’s materials signaled a shift in status, a new phase of life, or a civic crisis. Any variation in the toga—its fiber, fabric, drape, dyes, and surface treatments—resulted in new social meanings which were largely shaped by the physical characteristics of these substances, particularly by the effects such qualities had upon the wearer’s body

Denitrification and nitrous oxide emissions from riparian forests soils exposed to prolonged nitrogen runoff

Compared to upland forests, riparian forest soils have greater potential to remove nitrate (NO3) from agricultural run-off through denitrification. It is unclear, however, whether prolonged exposure of riparian soils to nitrogen (N) loading will affect the rate of denitrification and its end products. This research assesses the rate of denitrification and nitrous oxide (N2O) emissions from riparian forest soils exposed to prolonged nutrient run-off from plant nurseries and compares these to similar forest soils not exposed to nutrient run-off. Nursery run-off also contains high levels of phosphate (PO4). Since there are conflicting reports on the impact of PO4 on the activity of denitrifying microbes, the impact of PO4 on such activity was also investigated. Bulk and intact soil cores were collected from N-exposed and non-exposed forests to determine denitrification and N2O emission rates, whereas denitrification potential was determined using soil slurries. Compared to the non-amended treatment, denitrification rate increased 2.7- and 3.4-fold when soil cores collected from both N-exposed and non-exposed sites were amended with 30 and 60 μg NO3-N g-1 soil, respectively. Net N2O emissions were 1.5 and 1.7 times higher from the N-exposed sites compared to the non-exposed sites at 30 and 60 μg NO3-N g-1 soil amendment rates, respectively. Similarly, denitrification potential increased 17 times in response to addition of 15 μg NO3-N g-1 in soil slurries. The addition of PO4 (5 μg PO4–P g-1) to soil slurries and intact cores did not affect denitrification rates. These observations suggest that prolonged N loading did not affect the denitrification potential of the riparian forest soils; however, it did result in higher N2O emissions compared to emission rates from non-exposed forests