Engineering Properties of Marls

The term “marl” is used to designate soft, carbonate-rich, fine-grained soils, which pose concerns related to both settlement and stability. Despite the prevalence of marls in Indiana and the concerns associated with their behavior, very limited work has been done to study the engineering properties of these soils. This was the motivation for this research project, which involved two primary activities: a) the creation of a map and database of existing information on marl deposits in Indiana; and b) an in-depth characterization of the properties of a marl deposit in Daviess County, which was considered representative of similar deposits encountered in Indiana. The marl database was generated using ArcGIS 10.0.from information available at the INDOT, and involved mining data from over five thousand boreholes. The second part of the project involved field tests (seismic cone penetration tests, standard penetration tests, field vane shear tests), and laboratory experiments (index tests, incremental and constant rate of strain consolidation tests, and K0-consolidated undrained triaxial tests) conducted on high quality Shelby tubes samples. Additionally, the mineralogy and the microstructure of the soil were studied in detail. The laboratory tests reveal that the deposit was not homogeneous as was initially anticipated, but was, instead, formed by two types of soils that repeat in horizontal thin layers. These two soils, referred to as ‘soil M’ and ‘soil C’, are both characterized by very high calcium carbonate contents but show distinct index and engineering properties, that may be ascribed to differences in mineralogy and composition. This stratification is not detected by the field tests. The consolidation tests show that the deposit has an OCR less than 2 and compressibility parameters markedly dependent on stress level, as typical of sensitive soils. K0-consolidated undrained compression triaxial tests show that both soils exhibit normalized behavior, and that the relationship between strength and stress history is well described by the SHANSEP equation (although the SHANSEP parameters differ for the two soils). Comparison of the field data and laboratory results provides the means to validate published correlations for interpretation of the geotechnical properties of marls from field results. For the site examined, correlations to estimate shear wave velocity, stress history, and undrained strength from CPT results are identified. Implementation recommendations are provided for soil identification, sampling and specimen preparation, interpretation of filed data, and preliminary design

Development of a laboratory test procedure for the evaluation of potential gaseous emissions of asphalt rubber bituminous mixtures

The superior performance of bituminous mixtures containing crumb rubber from end-of-life tyres has been widely documented from a structural and functional point of view. However, potential impact of the use of crumb rubber on the health of workers in pavement construction sites has been the subject of a limited number of investigations, with a consequent gap in currently available technical knowledge. Following previous research work focused on the chemical analysis of fumes sampled on site, in this paper the Authors present results obtained in the development of a laboratory test procedure for the evaluation of gaseous emissions of asphalt rubber bituminous mixtures in standard, controlled conditions unaffected by site-specific factors. The investigation included monitoring of emissions at the paver's driving seat and at the screed during the laying of gap-and dense-graded wearing course mixtures in three different sites. Laboratory tests were performed by following a fume-generation protocol and by measuring the contents of volatile organic compounds and polycyclic aromatic hydrocarbons in produced emissions. Comparison of results derived from laboratory and field data was carried out in absolute terms and within a carcinogenic risk assessment model. It was found that the proposed laboratory procedure yields emissions which in most cases are similar to those recorded on site at the paver's screed and that lead to a conservative risk estimat

Verification of the Enhanced Integrated Climatic Module Soil Subgrade Input Parameters in the MEPDG

At the beginning of 2009, INDOT adopted the Mechanistic-Empirical Pavement Design Guide (MEPDG) method to study the tong-term pavement performance. The implementation of this new design approach led to difficulties for the pavement to pass the INDOT performance criteria; in particular pavement roughness (IRI) when A-6 or A-7-6 soils were considered as subgrade. This study focuses on investigating the influence of the soil input parameters in the Enhanced Integrated Climatic Model (EICM) on the prediction of the soil resilient modulus (MR) in the MEPDG. A total of four sites located around the state of Indiana are used to propose/validate the observations and conclusions made in the research. The study shows that (1) for the climatic conditions existing in Indiana, the location of the water table does not affect the value that the MEPDG uses for the subgrade MR; (2) the gravimetric water content is the most influential parameter on the EICM since it is directly related to the optimum degree of saturation of the subgrade; and (3) For A-7-6 soils, the overall deformation of the pavement structure is controlled by the subgrade (~80% of total deformation). In order to properly model the pavement structure, the MR input into the MEPDG for the subgrade should represent the optimum condition. This value will then be reduced within the EICM to reflect actual site conditions; and the MR input into the MEPDG for the treated layer should be a constant (i.e. not affected by EICM) and with PI and P200 values that are representative of the soil after treatment, given that the fines content and plasticity of a chemically-treated soil tend to decrease with treatment

Is the Mandibular Condyle Involved in Medication-Related Osteonecrosis of the Jaw? Audit of a Single Tertiary Referral Center and Literature Review

Background: Medication-related osteonecrosis of the jaw (MRONJ) may manifest as exposed mandible bone. Recent reviews of the incidence of MRONJ report primarily as exposed cortical bone of the mandibular body, ramus, and symphysis with no reports of condylar involvement. Objective: The aim of this study is to analyze the topographical incidence of MRONJ, comorbidities, demographics data, and clinical characteristics of patients diagnosed with MRONJ between 2014 and 2019 in the Maxillo-Facial Surgery Department University of Campania "Luigi Vanvitelli", and compare these results with published reports. Methods: Data on 179 patients were collected for the study, including gender, age, underlying malignancy, medical history, and specific lesion location-identifying premaxilla and posterior sectors area involvement for the maxilla and symphysis, body, ramus, and condyle area for the mandible. A literature review was performed in order to compare our results with similar or higher sample sizes and find if any condylar involvement was ever reported. The research was carried out on PubMed database identifying articles from January 2003 to November 2020, where MRONJ site distribution was discussed, and data were examined to scan for condylar localization reports. Results: 30 patients had maxillary MRONJ, 136 patients had mandibular MRONJ, and 13 patients had lesions located in both maxilla and mandible. None of the patients reported condylar involvement, neither as a single site nor as an additional localization. Literature review results were coherent to our findings showing no mention of condylar MRONJ. Conclusion: Results do not show reports of condylar involvement in MRONJ. Although the pathophysiology of the disease has not been fully elucidated, two possible explanations were developed: the first one based on the condyle embryogenetic origin; the second one based on the bisphosphonate and anti-resorptive medications effects on the different vascular patterns of the mandible areas

Production of clusters and thin films of nitrides, oxides and carbides by pulsed laser ablation and deposition

A short introduction on the principles of laser-matter interaction, material evaporation, plume formation, its reactivity with suitable gases and finally deposition are here illustrated. Experiments by mass spectrometry of formation of clusters, precursors of thin films and nanoparticles of oxides, nitrides and carbides by pulsed laser ablation (PLA) are reported. Pulsed laser ablation of targets combined with an intense atomic source produced by radiofrequency (RF), are discussed in terms of generating chemical reactions or supplying the loss of volatile components

Comparison of silver nanoparticles confined in nanoporous silica prepared by chemical synthesis and by ultra-short pulsed laser ablation in liquid

Hexagonally ordered mesoporous silica materials MCM-41 and SBA-15 have been synthesized and loaded with Ag nanoparticles, utilizing both chemical synthesis and ultra-short pulsed laser ablation in liquid. In laser ablation, a silver target, immersed in aqueous suspension of ordered mesoporous silica SBA-15, was irradiated by ultra-short laser pulses to generate silver nanoparticles. For comparison samples of similar silver contents were prepared either by incorporating silver into the SBA-15 during a hydrothermal synthesis or by introducing silver in MCM-41 by template ion-exchange. Samples were characterized by XRD, N2 physisorption, TEM and UV-vis spectroscopy. All preparations contained significant amount of 5-50 nm size silver agglomerates on the outer surface of the silica particles. The laser ablation process did not cause significant destruction of the SBA-15 structure and metallic silver (Ag0) nanoparticles were mainly generated. It is demonstrated that by laser ablation in aqueous silica suspension smaller and more uniform metallic silver particles can be produced and loaded on the surface of the silica support than by synthesis procedures. Catalytic properties of the samples have been tested in the total oxidation of toluene. Because of its favorable Ag dispersity the Ag/SBA-15 catalyst, generated by the laser ablation method, had better catalytic stability and, relative to its Ag load, higher activity than the conventional Ag/SBA-15 preparations

A REAPPRAISAL OF LOWER TO MIDDLE PALAEOLITHIC BONE RETOUCHERS FROM SOUTHEASTERN FRANCE (MIS 11 TO 3)

International audienceIn southeastern France, many Final Acheulean/Early Middle Palaeolithic and Middle Palaeolithic assemblages have yielded bone retouchers. The oldest are dated to the Middle Pleistocene: from MIS 11 at Terra Amata; MIS 9 at Orgnac 3; and MIS 6-7 at Payre F, Sainte-Anne I and Le Lazaret. However, this early evidence of bone tool use only concerns a few dozen pieces among thousands of faunal and lithic remains. These re-touchers indicate behavioural changes from MIS 11-9 onwards in southeastern France, associated with a mosaic of technological and subsistence changes that became more common during the Middle Palaeolithic. The frequency of these bone artefacts increases during MIS 7, becoming much more numerous after MIS 5, sometimes totaling more than a hundred items at one site, such as Saint-Marcel Cave. Bone retoucher frequency is still highly variable throughout the Middle Palaeolithic and seems to be determined by the type of occupation and activities rather than the associated lithic technologies. This broad, regional comparative analysis contributes to a better understanding of the technical behaviour developed by Neanderthals, as well as their Middle Pleistocene ancestors, and their ability to recover and use bones

Biodegradable mulching spray for weed control in the cultivation of containerized ornamental shrubs

Abstract Background Weed control represents a major issue in plant cultivation in containers. Manual weed control is very expensive and the use of chemical herbicide or plastic mulch films has a large environmental impact. The aim of this study was to test the efficacy of an experimental biodegradable chitosan-based mulching spray in controlling weed growth in containers. This research also studied the effect of this mulch on the growth of Viburnum lucidum Mill. plants to test for possible phytotoxic effects. Results The study compared a total of six treatments derived from three types of weed control (no weed control; herbicide, oxadiazon; mulching spray) applied in containers either filled only with the sterile substrate or filled with the sterile substrate and then artificially inoculated with seeds of the weed species [Sonchus asper (L.) Hill subsp. asper and Epilobium montanum L.]. The mulch controlled the weeds effectively for more than 2 months after its application even under severe weed infestation. The mulching spray controlled the emergence of S. asper more efficiently than E. montanum plants, probably because the latter has a stronger capacity to penetrate the mulch film during emergence. Conclusions Three months after its application, the mulch started to degrade and this allowed some weeds to emerge in the containers, but, in general, the mulch performed better than the herbicide. The chitosan-based mulch did not have any negative effective on the growth of V. lucidum plants

LIPSS Applied to Wide Bandgap Semiconductors and Dielectrics: Assessment and Future Perspectives

With the aim of presenting the processes governing the Laser-Induced Periodic Surface Structures (LIPSS), its main theoretical models have been reported. More emphasis is given to those suitable for clarifying the experimental structures observed on the surface of wide bandgap semiconductors (WBS) and dielectric materials. The role played by radiation surface electromagnetic waves as well as Surface Plasmon Polaritons in determining both Low and High Spatial Frequency LIPSS is briefly discussed, together with some experimental evidence. Non-conventional techniques for LIPSS formation are concisely introduced to point out the high technical possibility of enhancing the homogeneity of surface structures as well as tuning the electronic properties driven by point defects induced in WBS. Among these, double- or multiple-fs-pulse irradiations are shown to be suitable for providing further insight into the LIPSS process together with fine control on the formed surface structures. Modifications occurring by LIPSS on surfaces of WBS and dielectrics display high potentialities for their cross-cutting technological features and wide applications in which the main surface and electronic properties can be engineered. By these assessments, the employment of such nanostructured materials in innovative devices could be envisaged