17 research outputs found
Application of physical properties measurements to lithological prediction and constrained inversion of potential field data, Victoria Property, Sudbury, Canada.
In recent years the number of near-surface deposits has decreased significantly; consequently, exploration companies are transitioning from surface-based exploration to subsurface exploration. Geophysical methods are an important tool to explore below the surface. The physical property data are numerical data derived from geophysical measurements that can be analyzed to extract patterns to illustrate how these measurements vary in different geological units. Having knowledge of links between physical properties and geology is potentially useful to obtain more precise understanding of subsurface geology.
Firstly, down-hole density, gamma radioactivity, and magnetic susceptibility measurements in five drillholes at the Victoria property, Sudbury, Ontario were analyzed to identify a meaningful pattern of variations in physical property measurements. The measurements grouped into distinct clusters identified by the fuzzy k-means algorithm, which are termed ‘physical log units’. There was a meaningful spatial and statistical correlation between these physical log units and lithological units (or groups of lithological units), as classified by the geologist. The existence of these relationships suggests that it might be possible to train a classifier to produce an inferred function quantifying this link, which can be used to predict lithological units and physical units based on physical property data. A neural network was trained from the lithological information from one hole, and was applied on a new hole with 64% of the rock types being correctly classified when compared with those logged by geologists. This misclassification can occur as a result of overlap between physical properties of rock types. However, the predictive accuracy in the training process rose to 95% when the network was trained to classify the physical log units (which group together the units with overlapping properties). Secondly, lithological prediction based on down-hole physical property measurements was extended from the borehole to three-dimensional space at the Victoria property. Density and magnetic susceptibility models were produced by geologically constrained inversion of gravity and magnetic field data, and a neural network was trained to predict lithological units from the two physical properties measured in seven holes. Then, the trained network was applied on the 3D distribution of the two physical properties derived from the inversion models to produce a 3D litho-prediction model. The lithologies used were simplified to remove potential ambiguities due to overlap of physical properties. The 3D model obtained was consistent with the geophysical data and resulted in a more holistic understanding of the subsurface lithology. Finally, to extract more information from geophysical logs, the density and gamma-ray response logs were analyzed to detect boundaries between lithological units. A derivative method was successfully applied on the down-hole logs, and picked the boundaries between rock types identified by geologists as well as additional information describing variation of physical properties within and between layers not identified by the geologist.Doctor of Philosophy (PhD) in Mineral Deposits and Precambrian Geolog
A sustainable approach to the low-cost recycling of waste glass fibres composites towards circular economy
For practical applications, both environmental and economic aspects are highly required to consider in the development of recycling of fibre reinforced polymers (FRPs) encountering their end-of-life. Here, a sustainable, low cost, and efficient approach for the recycling of the glass fibre (GF) from GF reinforced epoxy polymer (GFRP) waste is introduced, based on a microwave-assisted chemical oxidation method. It was found that in a one-step process using microwave irradiation, a mixture of hydrogen peroxide (H2O2) as a green oxidiser and tartaric acid (TA) as a natural organic acid could be used to decompose the epoxy matrix of a waste GFRP up to 90% yield. The recycled GFs with ~92.7% tensile strength, ~99.0% Young\u27s modulus, and ~96.2% strain-to-failure retentions were obtained when compared to virgin GFs (VGFs). This short microwave irradiation time using these green and sustainable recycling solvents makes this a significantly low energy consumption approach for the recycling of end-of-life GFRPs
A Review of Dye Removal Using Polymeric Nanofibers by Electrospinning as Promising Adsorbents
Water is the most important material that humans and creatures need, and water contamination caused by chemicals such as dyes has brought many problems. Various methods have been used to remove dyes as organic contaminants. Polymeric nanofibers prepared by electrospinning have a nanostructure with a high adsorption capacity for removing water contaminants. To solve this problem, the adsorption process is used, which is very effective for removing water pollutants. The adsorption process is very important in terms of expense and reuse. The use of natural polymers is being promoted as a suitable alternative to synthetic polymers and to reduce environmental pollution. The results indicate that preparing nanofibers by electrospinning and using them as adsorbents is a suitable method to remove contaminants. The effect of operational parameters on the adsorption removal ability of polymeric nanofibers, the optimal adsorption conditions, and the mechanism of dye adsorption have been investigated in detail. The data indicated that polymeric electrospinning nanofibers can be used as environmentally friendly and effective adsorbents for removing water contaminants. Also, the treated dye wastewater is reused in the dyeing process and is not discharged into the environment to conquer the water shortage
Clustering of downhole physical property measurements at the Victoria property, Sudbury for the purpose of extracting lithological information
Downhole density, gamma radioactivity, and magnetic susceptibility measurements in five drillholes at the Victoria property (located in the south range of the Sudbury basin) were analyzed to identify homogenous physical units. The fuzzy k-means clustering algorithm was used for unsupervised classification of the data. Four main physical units were identified in boreholes with distinct physical characteristics. Three of them were differentiated mainly based on different gamma ray and density values, and the fourth one was characterized by high magnetic susceptibility. Physical units were compared with rock types logged by geologists to determine which rock types corresponded to physical units. We found that there was a meaningful spatial and statistical correlation between physical units (characterized based on their physical property measurements) and lithological units as indicated by rock types at the Victoria property. However, not all rock types could be uniquely identified by the statistical classification, but a set of similar groups could be identified. Hence, identifying a group of rock types described by each physical unit can be used to translate physical data to/from lithological data. Alternatively, the physical log units could be used as a quality control procedure to check the geological logs, or to highlight areas where more careful logging or other investigation would be warranted
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Functional and Histological Effects of Chronic Neural Electrode Implantation.
Permanent injury to the cranial nerves can often result in a substantial reduction in quality of life. Novel and innovative interventions can help restore form and function in nerve paralysis, with bioelectric interfaces among the more promising of these approaches. The foreign body response is an important consideration for any bioelectric device as it influences the function and effectiveness of the implant. The purpose of this review is to describe tissue and functional effects of chronic neural implantation among the different categories of neural implants and highlight advances in peripheral and cranial nerve stimulation.Data Sources: PubMed, IEEE, and Web of Science literature search.Review Methods: A review of the current literature was conducted to examine functional and histologic effects of bioelectric interfaces for neural implants.Bioelectric devices can be characterized as intraneural, epineural, perineural, intranuclear, or cortical depending on their placement relative to nerves and neuronal cell bodies. Such devices include nerve-specific stimulators, neuroprosthetics, brainstem implants, and deep brain stimulators. Regardless of electrode location and interface type, acute and chronic histological, macroscopic and functional changes can occur as a result of both passive and active tissue responses to the bioelectric implant.A variety of chronically implantable electrodes have been developed to treat disorders of the peripheral and cranial nerves, to varying degrees of efficacy. Consideration and mitigation of detrimental effects at the neural interface with further optimization of functional nerve stimulation will facilitate the development of these technologies and translation to the clinic.3
The current and future potential geographical distribution of Nepeta crispa Willd., an endemic, rare and threatened aromatic plant of Iran: Implications for ecological conservation and restoration
International audienceNepeta crispa Willd. is a very rare medicinal plant that grows in a very limited habitat in western Iran. In recent years, due to climate change, many plants have become endangered, which poses a very serious threat to very rare species such as N. crispa Willd. In the present study, we aimed to model the current and future potential geographical distributions and identify the most relevant environmental factors influencing the distribution of N. crispa Willd. an endemic plant species in west of Iran. The species distribution was modeled with the maximum entropy model by using presence data (160 sampling points) and a total of 15 climatic and environmental variables. To predict possible shifts in the geographical distribution due to climate change, we used the Representative Concentration Pathway (RCP) 2.6 and RCP 8.5 for 2050 and 2070 for two Global Climate Models (GCMs). The jackknifing method was used to evaluate the contribution of the environmental variables to the model. We found that elevation, annual mean temperature, geology and precipitation of the driest quarter were the most important variables in determining the habitat of N. crispa. The species habitat suitability maps and models were efficient in predicting the habitat suitability distribution for N. crispa in the current conditions with an Area Under the ROC Curve (AUC) of 0.983. Our modeling approach also demonstrated that climate change would expand the habitat range of N. crispa in the Alvand mountain areas in Iran towards higher elevation (above 2000 m.a.s.l). Conservation measures should therefore predominantly concentrate on the elevation range between 2000 and 3500 m.a.s.l. Knowledge of current distribution of the N. crispa and predicting its potential future geographical distribution under different climate change scenarios provide useful information for conservation actions in Iran
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Interfacing with the nervous system: a review of current bioelectric technologies.
The aim of this study is to discuss the state of the art with regard to established or promising bioelectric therapies meant to alter or control neurologic function. We present recent reports on bioelectric technologies that interface with the nervous system at three potential sites-(1) the end organ, (2) the peripheral nervous system, and (3) the central nervous system-while exploring practical and clinical considerations. A literature search was executed on PubMed, IEEE, and Web of Science databases. A review of the current literature was conducted to examine functional and histomorphological effects of neuroprosthetic interfaces with a focus on end-organ, peripheral, and central nervous system interfaces. Innovations in bioelectric technologies are providing increasing selectivity in stimulating distinct nerve fiber populations in order to activate discrete muscles. Significant advances in electrode array design focus on increasing selectivity, stability, and functionality of implantable neuroprosthetics. The application of neuroprosthetics to paretic nerves or even directly stimulating or recording from the central nervous system holds great potential in advancing the field of nerve and tissue bioelectric engineering and contributing to clinical care. Although current physiotherapeutic and surgical treatments seek to restore function, structure, or comfort, they bear significant limitations in enabling cosmetic or functional recovery. Instead, the introduction of bioelectric technology may play a role in the restoration of function in patients with neurologic deficits
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Use of interactive iBooks for patient education in otology
IntroductionPhysicians in the ambulatory setting face challenges in adequately educating patients in a brief office encounter.ObjectiveTo evaluate the efficacy of an iPad-based interactive educational module (iBook) in various otologic pathologies.MethodsPatients presenting with symptoms of tinnitus, dizziness, hearing loss, or cochlear implant evaluation were included. In total, 44 patients received the iBook and 22 patients served as controls. Prior to viewing the iBook, patients completed a pre-survey to assess baseline knowledge. After viewing the iBook, patients completed a post-survey to assess changes in perception and knowledge of their disease. Results were compared to that of the control group who did not receive iBook supplementation prior to being seen by the physician.ResultsPaired t-test analysis showed significant improvements (p<0.01) in both self-reported perception and concrete understanding in various concepts when compared to pre-iBook results. This was further compared to the control group, which showed a significant gain in factual knowledge (p=0.02).ConclusionPatients who viewed the iBook, personalized to their diagnosis, displayed significantly improved understanding of their condition. Increased use of interactive educational modalities, such as the iBook, can be of benefit to an otologic practice in improving patient education and satisfaction