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•Coal and biomass samples have been experimentally characterized by TGA and DSC.•Combustion and oxy-combustion behaviours are assessed and kinetically analysed.•Kinetic analysis is ...based on both FWO and KAS methods and results are compared.•Oxy-combustion can improve the burning rate of fuels, shortening the burning time.•Both FWO and KAS are reliable for combustion, but only for coal for oxy-combustion.
This paper reports on the results of air-blown combustion and oxy-combustion kinetic characterization (comparing two different isoconversional methods: Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose) of different kinds of coal (from Italy, South Africa and Hungary) and biomass (pine and eucalyptus chips) by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) together with the assessment of different characteristic combustion parameters. It can be observed that the burning rate of fuels can be improved by the oxy-combustion process, shortening the burning time (a mean reduction of the burnout time of 14% and 22% can be observed for coal and biomass samples, respectively). Moreover, biomass shows better ignition performance than coal and enhances combustibility indexes (S and Hf), especially in oxy-combustion conditions. For example, the S index, which reflects combustion properties, increases by an order of magnitude for biomass combustion and oxy-combustion with respect to coal values, thus indicating a higher combustion activity for biomass; an opposite trend can be observed for the Hf index, which describes the rate and intensity of the process and is lower for biomass than for coal, thus indicating better performance for wood chips combustion. Kinetic analysis shows that the activation energy Ea varies with conversion values, reflecting the kinetic complexity in both the processes. Moreover, with the same range of heating rates (10 ≤ β ≤ 50 °C/min) and for the overall range of conversion (0.1 ≤ α ≤ 0.9), both of the models used fit the experimental data in combustion regime, whereas the increase of the oxygen concentration makes the results reliable for coal samples and more sensitive to weight loss for biomass samples.
ABSTRACT This is the first of a series of papers presenting the Modules for Experiments in Stellar Astrophysics (MESA) Isochrones and Stellar Tracks (MIST) project, a new comprehensive set of stellar ...evolutionary tracks and isochrones computed using MESA, a state-of-the-art open-source 1D stellar evolution package. In this work, we present models with solar-scaled abundance ratios covering a wide range of ages ( ), masses ( ), and metallicities ( ). The models are self-consistently and continuously evolved from the pre-main sequence (PMS) to the end of hydrogen burning, the white dwarf cooling sequence, or the end of carbon burning, depending on the initial mass. We also provide a grid of models evolved from the PMS to the end of core helium burning for . We showcase extensive comparisons with observational constraints as well as with some of the most widely used existing models in the literature. The evolutionary tracks and isochrones can be downloaded from the project website at http://waps.cfa.harvard.edu/MIST/.
Burning mouth syndrome is a debilitating medical condition affecting nearly 1.3 million of Americans. Its common features include a burning painful sensation in the mouth, often associated with ...dysgeusia and xerostomia, despite normal salivation. Classically, symptoms are better in the morning, worsen during the day and typically subside at night. Its etiology is largely multifactorial, and associated medical conditions may include gastrointestinal, urogenital, psychiatric, neurologic and metabolic disorders, as well as drug reactions. BMS has clear predisposition to peri-/post menopausal females. Its pathophysiology has not been fully elucidated and involves peripheral and central neuropathic pathways. Clinical diagnosis relies on careful history taking, physical examination and laboratory analysis. Treatment is often tedious and is aimed at correction of underlying medical conditions, supportive therapy, and behavioral feedback. Drug therapy with alpha lipoic acid, clonazepam, capsaicin, and antidepressants may provide symptom relief. Psychotherapy may be helpful. Short term follow up data is promising, however, long term prognosis with treatment is lacking. BMS remains an important medical condition which often places a recognizable burden on the patient and health care system and requires appropriate recognition and treatment.
Burning Mouth Syndrome Bender, Steven D., DDS
The Dental clinics of North America,
10/2018, Volume:
62, Issue:
4
Journal Article
Peer reviewed
Burning mouth syndrome (BMS) is a chronic disorder for which a definitive etiopathology is not known. The BMS patient often experiences a continuous burning pain in the mouth without any clinical ...signs. This confusing condition can create frustration for both patient and practitioner. Ultimately, it is important for the practitioner who treats head and face pain to become knowledgeable in the recognition of the many complexities and various presentations associated with BMS. In doing so, the practitioner can be better prepared to help patients cope with this confounding disorder and gain a better quality of life.
While a white dwarf (WD) is, from a theoretical perspective, the most plausible primary star of a Type Ia supernova (SN Ia), many other candidates have not been formally ruled out. Shock energy ...deposited in the envelope of any exploding primary contributes to the early SN brightness and, since this radiation energy is degraded by expansion after the explosion, the diffusive luminosity depends on the initial primary radius. We present a new non-detection limit of the nearby SN Ia 2011fe, obtained at a time that appears to be just 4 hr after explosion, allowing us to directly constrain the initial primary radius (R{sub p} ). Coupled with the non-detection of a quiescent X-ray counterpart and the inferred synthesized {sup 56}Ni mass, we show that R{sub p} {approx}< 0.02 R{sub Sun} (a factor of five smaller than previously inferred), that the average density of the primary must be {rho}{sub p} > 10{sup 4} g cm{sup -3}, and that the effective temperature must be less than a few Multiplication-Sign 10{sup 5} K. This rules out hydrogen-burning main-sequence stars and giants. Constructing the helium-burning and carbon-burning main sequences, we find that such objects are also excluded. By process of elimination, we find that only degeneracy-supported compact objects-WDs and neutron stars-are viable as the primary star of SN 2011fe. With few caveats, we also restrict the companion (secondary) star radius to R{sub c} {approx}< 0.1 R{sub Sun }, excluding Roche-lobe overflowing red giant and main-sequence companions to high significance.
Burning mouth syndrome (BMS) is a chronic oral pain disorder characterized by a generalized burning sensation in the oral mucosa without apparent medical or dental causes. Despite various hypotheses ...proposed to explain BMS pathogenesis, a clear understanding of the cellular-level events and associated histologic and molecular findings is lacking. Advancing our understanding of BMS pathogenesis could facilitate the development of more targeted therapeutic interventions.
The authors conducted an extensive literature search and review of cellular mechanisms, focusing on evidence-based data that support a comprehensive hypothesis for BMS pathogenesis. The authors explored novel and detailed mechanisms that may account for the characteristic features of BMS.
The authors proposed that BMS symptoms arise from the uncontrolled activation of proapoptotic transmembrane calcium permeable channels expressed in intraoral mucosal nerve fibers. Elevated levels of reactive oxygen species or dysfunctional antiapoptosis pathways may lead to uncontrolled oxidative stress-mediated apoptosis signaling, resulting in upregulation of transmembrane transient receptor potential vanilloid type 1 and P2X 3 calcium channels in nociceptive fibers. Activation of these channels can cause nerve terminal depolarization, leading to generation of action potentials that are centrally interpreted as pain.
The authors present a novel hypothesis for BMS pathogenesis, highlighting the role of proapoptotic transmembrane calcium permeable channels and oxidative stress-mediated apoptosis signaling in the development of BMS symptoms. Understanding these underlying mechanisms could provide new insights into the development of targeted therapeutic interventions for BMS. Additional research is warranted to validate this hypothesis and explore potential avenues for effective management of BMS.
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