124 research outputs found

    Preparation of flexible dielectric nanocomposites using nanocellulose and recycled alum sludge for wearable technology applications

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    With the rapid development of wearable technology, flexible dielectric materials with environmental-friendly, low-cost and high-energy efficiency characteristics are in increasing demand. In this work, a flexible dielectric nanocomposite was developed by incorporating two components: cellulose nanofibrils (CNF) and recycled alum sludge, as the reinforcement phase and for enhancing the dielectric properties, in a bio-elastomer matrix. CNF and alum sludge were processed from waste materials which would otherwise be disposed to landfills. CNF were derived from water hyacinth, an invasive aquatic weed. Dried water hyacinth was treated using a simple and less energy-intensive process to obtain CNF. The alum sludge raw material was collected from a water treatment plant of Scottish Water and heat treated and refined before being used in preparing the composites. A biodegradable elastomer polydimethylsiloxane was used as the matrix and the nanocomposites were processed by casting the materials in petri dishes. The processed composites were characterised using scanning electron microscopy (SEM), thermogravimetric (TGA/DTG) and X-ray diffraction (XRD) analysis. The SEM micrographs illustrated CNF of approximately 20nm in diameter and alum sludge particles of approximately 200um in size. The TGA/DTG analysis results showed that a total mass of 46% has been removed when the sludge sample was heated up to 900°C. The XRD result showed that both quartz SiO2 and cubic γ-Al2O3 structures can be found in the sample that was heat treated up to 800°C. Other experiments also showed that the composites exhibit comparable mechanical and dielectric performances with other works in the literature. The work depicts that it is a sustainable practice of reusing such wastes in preparing flexible, lightweight and miniature dielectric materials that can be used for wearable technology applications

    Preparation of Elastomeric Nanocomposites Using Nanocellulose and Recycled Alum Sludge for Flexible Dielectric Materials

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    Flexible dielectric materials with environmental-friendly, low-cost and high-energy density characteristics are in increasing demand as the world steps into the new Industrial 4.0 era. In this work, an elastomeric nanocomposite was developed by incorporating two components: cellulose nanofibrils (CNFs) and recycled alum sludge, as the reinforcement phase and to improve the dielectric properties, in a bio-elastomer matrix. CNF and alum sludge were produced by processing waste materials that would otherwise be disposed to landfills. A biodegradable elastomer polydimethylsiloxane was used as the matrix and the nanocomposites were processed by casting the materials in Petri dishes. Nanocellulose extraction and heat treatment of alum sludge were conducted and characterized using various techniques including scanning electron microscopy (SEM), thermogravimetric analysis/derivative thermogravimetric (TGA/DTG) and X-ray diffraction (XRD) analysis. When preparing the nanocomposite samples, various amount of alum sludge was added to examine their impact on the mechanical, thermal and electrical properties. Results have shown that it could be a sustainable practice of reusing such wastes in preparing flexible, lightweight and miniature dielectric materials that can be used for energy storage applications

    Abnormal ECG Findings in Athletes: Clinical Evaluation and Considerations.

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    PURPOSE OF REVIEW: Pre-participation cardiovascular evaluation with electrocardiography is normal practice for most sporting bodies. Awareness about sudden cardiac death in athletes and recognizing how screening can help identify vulnerable athletes have empowered different sporting disciplines to invest in the wellbeing of their athletes. RECENT FINDINGS: Discerning physiological electrical alterations due to athletic training from those representing cardiac pathology may be challenging. The mode of investigation of affected athletes is dependent on the electrical anomaly and the disease(s) in question. This review will highlight specific pathological ECG patterns that warrant assessment and surveillance, together with an in-depth review of the recommended algorithm for evaluation

    From Harm to Robustness: A Principled Approach to Vice Regulation

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    John Stuart Mill’s harm principle maintains that adult behavior cannot justifiably be subject to social coercion unless the behavior involves harm or a significant risk of harm to non-consenting others. The absence of harms to others, however, is one of the distinguishing features of many manifestations of “vices” such as the consumption of alcohol, nicotine, recreational drugs, prostitution, pornography, and gambling. It is with respect to vice policy, then, that the harm principle tends to be most constraining, and some current vice controls, such as prohibitions on drug possession and prostitution, violate Mill’s precept. In the vice arena, we seem to be willing to accept social interference with what Mill termed “self-regarding” behavior. But does that willingness then imply that any social intervention into private affairs is justifiable, that the government has just as much right to outlaw Protestantism, or shag carpets, or spicy foods, as it does to outlaw drugs? In this paper I argue that advances in neuroscience and behavioral economics offer strong evidence that vices and other potentially addictive goods or activities frequently involve less-than-rational choices, and hence are exempt from the full force of the harm principle. As an alternative guide to vice policy, and following some guidance from Mill, I propose the “robustness principle”: public policy towards addictive or vicious activities engaged in by adults should be robust with respect to departures from full rationality. That is, policies should work pretty well if everyone is completely rational, and policies should work pretty well even if many people are occasionally (or frequently) irrational in their vice-related choices. The harm and robustness principles cohere in many ways, but the robustness principle offers more scope for policies that try to direct people “for their own good,” without opening the door to tyrannical inroads upon self-regarding behavior

    Evidence for Habitual and Goal-Directed Behavior Following Devaluation of Cocaine: A Multifaceted Interpretation of Relapse

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    BACKGROUND:Cocaine addiction is characterized as a chronically relapsing disorder. It is believed that cues present during self-administration become learned and increase the probability that relapse will occur when they are confronted during abstinence. However, the way in which relapse-inducing cues are interpreted by the user has remained elusive. Recent theories of addiction posit that relapse-inducing cues cause relapse habitually or automatically, bypassing processing information related to the consequences of relapse. Alternatively, other theories hypothesize that relapse-inducing cues produce an expectation of the drug's consequences, designated as goal-directed relapse. Discrete discriminative stimuli signaling the availability of cocaine produce robust cue-induced responding after thirty days of abstinence. However, it is not known whether cue-induced responding is a goal-directed action or habit. METHODOLOGY/PRINCIPAL FINDINGS:We tested whether cue-induced responding is a goal-directed action or habit by explicitly pairing or unpairing cocaine with LiCl-induced sickness (n = 7/group), thereby decreasing or not altering the value of cocaine, respectively. Following thirty days of abstinence, no difference in responding between groups was found when animals were reintroduced to the self-administration environment alone, indicating habitual behavior. However, upon discriminative stimulus presentations, cocaine-sickness paired animals exhibited decreased cue-induced responding relative to unpaired controls, indicating goal-directed behavior. In spite of the difference between groups revealed during abstinent testing, no differences were found between groups when animals were under the influence of cocaine. CONCLUSIONS/SIGNIFICANCE:Unexpectedly, both habitual and goal-directed responding occurred during abstinent testing. Furthermore, habitual or goal-directed responding may have been induced by cues that differed in their correlation with the cocaine infusion. Non-discriminative stimulus cues were weak correlates of the infusion, which failed to evoke a representation of the value of cocaine and led to habitual behavior. However, the discriminative stimulus-nearly perfectly correlated with the infusion-likely evoked a representation of the value of the infusion and led to goal-directed behavior. These data indicate that abstinent cue-induced responding is multifaceted, dynamically engendering habitual or goal-directed behavior. Moreover, since goal-directed behavior terminated habitual behavior during testing, therapeutic approaches aimed at reducing the perceived value of cocaine in addicted individuals may reduce the capacity of cues to induce relapse

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Transcending Sovereignty: Locating Indigenous Peoples in Transboundary Water Law

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