2,273 research outputs found
Non-alloy Mg anode for Ni-MH batteries: Multiple approaches towards a stable cycling performance
No full textMg attracts much research interest as anode material for Ni-MH batteries thanks to its lightweight, cost-effectiveness and high theoretical capacity (2200 mA h g−1). However, its practical application is tremendously challenged by the poor hydrogen sorption kinetics, passivation from aggressive aqueous electrolytes, and insulating nature of MgH2. Mg-based alloys exhibit enhanced hydrogen sorption kinetics and electrical conductivity, but significant amount of costly transition metal elements are required. In this work, we have, for the first time, utilized non-alloyed but catalyzed Mg as anode for Ni-MH batteries. 5 mol.% TiF3 was added to nanosized Mg for accelerating the hydrogen sorption kinetics. Several strategies for preventing the problematic passivation of Mg have been studied, including protective encapsulation of the electrode and utilizing room-temperature/high-temperature ionic liquids and an alkaline polymer membrane as working electrolyte. Promising electrochemical performance has been achieved in this Mg–TiF3 composite anode based Ni-MH batteries with room for further improvements.</p
Assessing risk of self-harm in acute paediatric settings: A multicentre exploratory evaluation of the CYP-MH SAPhE instrument
No full textOBJECTIVE: To psychometrically assess the Children and Young People-Mental Health Self-harm Assessment in Paediatric healthcare Environments (CYP-MH SAPhE) instrument for the identification of immediate risk of self-harm in CYP, aged 10-19 years, in acute paediatric wards or emergency departments., DESIGN: The CYP-MH SAPhE Instrument was developed through a robust scoping review and Delphi consensus with 30 clinicians/topic experts. To evaluate the psychometric properties, a multicentre exploratory study was conducted., SETTING: Three acute hospitals in the UK., PARTICIPANTS: 163 CYP presenting at acute hospital settings with primary mental health (cases) or physical health (non-cases) conditions., PRIMARY AND SECONDARY OUTCOME MEASURES: Psychometric properties of the CYP-MH SAPhE instrument were evaluated through Principle Axis Factoring (PAF) with Oblimin (Kaiser normalisation) alongside measures of internal consistency (Cronbach's alpha), convergent, discriminant and face validity., RESULTS: PAF of the dichotomous items (n=9) loaded onto three factors (1) behaviours and intentions; (2) suicidality and (3) self-harm. Factors 1 (Cronbach's alpha=0.960) and 3 (Cronbach's alpha=1) had high internal consistency. There was: good level of agreement between raters (kappa=0.65); a moderately positive correlation between the CYP-MH SAPhE instrument and the Columbia-Suicide Severity Rating Scale; and discrimination between cases and non-cases across the three factors (factor 1: m=88 vs 70; factor 2: m=102 vs 70; factor 3: m=104 vs 68). Assessment of face validity resulted in six items being removed, culminating in an eight question, rapid assessment instrument., CONCLUSIONS: The results support the CYP-MH SAPhE Tool as a potentially reliable and valid instrument to identify immediate risk of self-harm in CYP presenting to acute paediatric healthcare environments, which is a burgeoning and significant global health issue. Copyright © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.https://dx.doi.org/10.1136/bmjopen-2020-04376
Vickers hardness value test via multi-task learning convolutional neural networks and image augmentation
No full text[[abstract]]Featured Application Feature Applications: This paper proposes a data-driven approach based on convolutional neural networks to measure the Vickers hardness value directly from the image of the specimen to get rid of the requirement of the manually generation of indentations for measurement. Hardness testing is an essential test in the metal manufacturing industry, and Vickers hardness is one of the most widely used hardness measurements today. The computer-assisted Vickers hardness test requires manually generating indentations for measurement, but the process is tedious and the measured results may depend on the operator's experience. In light of this, this paper proposes a data-driven approach based on convolutional neural networks to measure the Vickers hardness value directly from the image of the specimen to get rid of the aforementioned limitations. Multi-task learning is introduced in the proposed network to improve the accuracy of Vickers hardness measurement. The metal material used in this paper is medium-carbon chromium-molybdenum alloy steel (SCM 440), which is commonly utilized in automotive industries because of its corrosion resistance, high temperature, and tensile strength. However, the limited samples of SCM 440 and the tedious manual measurement procedure represent the main challenge to collect sufficient data for training and evaluation of the proposed methods. In this regard, this study introduces a new image mixing method to augment the dataset. The experimental results show that the mean absolute error between the Vickers hardness value output by the proposed network architecture can be 10.2 and the value can be further improved to 7.6 if the multi-task learning method is applied. Furthermore, the robustness of the proposed method is confirmed by evaluating the developed models with an additional 59 unseen images provided by specialists for testing, and the experimental results provide evidence to support the reliability and usability of the proposed methods
Vickers Hardness and Shrinkage Stress Evaluation of Low and High Viscosity Bulk-Fill Resin Composite
No full textThe aim of this in vitro study was to evaluate the hardness and shrinkage stress (SS) of six bulk-fill resin composites. To evaluate microhardness (MH), ten 6 mm specimens were prepared using a metal mold for each selected bulk-fill resin composite and irradiated from the top side for 40 s using an LED light. After 24 h of storage, Vickers MH was evaluated on the upper, lower and lateral sides of the specimens. SS evaluation was then performed with a universal machine, which evaluated the contraction force generated by a bulk-fill composite specimen placed between two metal cylinders during and after light curing. The results were evaluated with a one-way ANOVA test with a post-hoc Bonferroni test and linear regression analysis (p < 0.05). All materials showed a significant MH decrease between the top and bottom surfaces. However, the bulk-fill materials tested performed differently when considering lateral depth progression. ANOVA tests for SS evaluation showed that both SDR and Venus Bulk Fill had significantly lower stress during irradiation than other tested materials. Further, MH decrease became significantly lower from the top surface at different depths in each tested group. Among the different resins, Venus Bulk Fill and SDR showed not only inferior hardness, but also a significant reduction in SS
Thrifty metabolic programming in rats is induced by both maternal undernutrition and postnatal leptin treatment, but masked in the presence of both: implications for models of developmental programming.
No full textBACKGROUND
Maternal undernutrition leads to an increased risk of metabolic disorders in offspring including obesity and insulin resistance, thought to be due to a programmed thrifty phenotype which is inappropriate for a subsequent richer nutritional environment. In a rat model, both male and female offspring of undernourished mothers are programmed to become obese, however postnatal leptin treatment gives discordant results between males and females. Leptin treatment is able to rescue the adverse programming effects in the female offspring of undernourished mothers, but not in their male offspring. Additionally, in these rats, postnatal leptin treatment of offspring from normally-nourished mothers programmes their male offspring to develop obesity in later life, while there is no comparable effect in their female offspring.
RESULTS
We show by microarray analysis of the female liver transcriptome that both maternal undernutrition and postnatal leptin treatment independently induce a similar thrifty transcriptional programme affecting carbohydrate metabolism, amino acid metabolism and oxidative stress genes. Paradoxically, however, the combination of both stimuli restores a more normal transcriptional environment. This demonstrates that "leptin reversal" is a global phenomenon affecting all genes involved in fetal programming by maternal undernourishment and leptin treatment. The thrifty transcriptional programme was associated with pro-inflammatory markers and downregulation of adaptive immune mediators, particularly MHC class I genes, suggesting a deficit in antigen presentation in these offspring.
CONCLUSIONS
We propose a revised model of developmental programming reconciling the male and female observations, in which there are two competing programmes which collectively drive liver transcription. The first element is a thrifty metabolic phenotype induced by early life growth restriction independently of leptin levels. The second is a homeostatic set point calibrated in response to postnatal leptin surge, which is able to over-ride the metabolic programme. This "calibration model" for the postnatal leptin surge, if applicable in humans, may have implications for understanding responses to catch-up growth in infants. Additionally, the identification of an antigen presentation deficit associated with metabolic thriftiness may relate to a previously observed correlation between birth season (a proxy for gestational undernutrition) and infectious disease mortality in rural African communities
Vickers hardness and shrinkage stress evaluation of low and high viscosity bulk-fill resin composite
No full textThe aim of this in vitro study was to evaluate the hardness and shrinkage stress (SS) of six bulk-fill resin composites. To evaluate microhardness (MH), ten 6 mm specimens were prepared using a metal mold for each selected bulk-fill resin composite and irradiated from the top side for 40 s using an LED light. After 24 h of storage, Vickers MH was evaluated on the upper, lower and lateral sides of the specimens. SS evaluation was then performed with a universal machine, which evaluated the contraction force generated by a bulk-fill composite specimen placed between two metal cylinders during and after light curing. The results were evaluated with a one-way ANOVA test with a post-hoc Bonferroni test and linear regression analysis (p < 0.05). All materials showed a significant MH decrease between the top and bottom surfaces. However, the bulk-fill materials tested performed differently when considering lateral depth progression. ANOVA tests for SS evaluation showed that both SDR and Venus Bulk Fill had significantly lower stress during irradiation than other tested materials. Further, MH decrease became significantly lower from the top surface at different depths in each tested group. Among the different resins, Venus Bulk Fill and SDR showed not only inferior hardness, but also a significant reduction in SS
The times; or, the age of ruin. A poem. [electronic resource] : By the author of "A poetical and complimentary epistle to R. Brothers the prophet, and N. B. Halhed, Esq;" &c.
No full textPublication date from MH-H.Electronic reproduction.English Short Title Catalog,Reproduction of original from Harvard University Houghton Library
Farklı Polimerizasyon Sürelerinin Rezin Kompozitlerin Mikrosertlik ve Dönüşüm Derecesi Üzerine Etkisi
No full textAmaç: Bu çalışmanın amacı, farklı polimerizasyon sürelerinde bulk-fill ve konvansiyonel rezin kompozitlerin polimerizasyon özelliklerinin monomer dönüşüm derecesi (DC) ve mikrosertlik (MH) açısından değerlendirilmesidir. Materyal ve metod: Bu çalışmada, iki bulk-fill rezin kompozit (Filtek One Bulk Fill Restorative, X-tra Fil) ve iki geleneksel rezin kompozitten (Filtek Z550, Charisma Smart) hazırlanan disk şeklindeki örneklere (6 mm genişliğinde ve 2 mm yüksekliğinde) üç farklı polimerizasyon süresi (20 sn, 60 sn ve 100 sn) uygulandı. Polimerize edilen numunelerin DC'si bir FT-IR/ATR cihazı ile, MH değerleri ise bir Vickers sertlik cihazı ile ölçüldü. Elde edilen veriler istatistiksel yöntemlerle analiz edildi. Bulgular: FT-IR analizi ve Vickers mikrosertlik testi sonuçlarına göre 100 saniye ışık uygulanan grupların DC ve MH değerlerinin diğer gruplara göre anlamlı derecede büyük olduğu ortaya çıkmıştır (pObjective: The aim of this study was to evaluate the polymerization properties of bulk-fill and conventional resin composites in terms of the degree of conversion (DC) and microhardness (MH) at different polymerization times. Materials and Methods: In this study three different polymerization times (20 s, 60 s, and 100 s) were applied to disc shaped samples (6 mm wide; and 2 mm high) prepared from two bulk-fill resin composites (Filtek One Bulk Fill Restorative, X-tra Fil) and two traditional resin composites (Filtek Z550, Charisma Smart). The DC of the polymerized samples was measured with a FT-IR/ATR device, and the MH values were measured with a Vickers hardness device. The collected data were subjected to statistical analysis. Results: The results of the FT-IR analysis and Vickers microhardness test demonstrated that the DC and MH values of the groups exposed to 100 s of light curing were significantly higher than those of the other groups (
[The] lady's watch. [electronic resource] : By the author of The prude.
No full textVerse - "A fair one sought the silent poplar shade".'The prude, a tale.' was first published in Dublin in 1722.MH-H copy may be cropped at head, affecting first word of titleFoxon,Electronic reproduction.English Short Title Catalog,Reproduction of original from Harvard University Houghton Library
Between Mother and Son: Preparation of the assambly MH+-
No full textEl presente informe recopila los detalles y el proceso creativo de la obra de danza MH+-, donde se reunieron los saberes académicos en términos prácticos, teóricos y experienciales, apropiados por el estudiante y autor de la obra en mención y este texto, Ricardo Nieto Ortíz. En esta obra se tomó como inspiración temática la relación personal de dicho estudiante y su madre, desde el momento en que este se identificó frente a ella como un hombre homosexual. El proceso de creación se llevó a cabo a través de un laboratorio de investigación creación con seis intérpretes creadores, incluido Ricardo Nieto, durante seis meses, con cuatro etapas de desarrollo utilizando herramientas como la improvisación, la creación de personajes y la ejercitación de los imaginarios que nutren los procesos creativos de los intérpretes.This report compiles the details and the creative process of the dance work MH+-, where the academic knowledge in practical, theoretical and experiential terms was gathered, appropriated by the student and author of the work in question and this text, Ricardo Nieto Ortiz. In this work, the personal relationship of this student and his mother was taken as thematic inspiration, from the moment he identified himself in front of her as a homosexual man. The creation process was carried out through a creation research laboratory with six creative interpreters, including Ricardo Nieto, for six months, with four stages of development using tools such as improvisation, the creation of characters and the exercise of the imaginaries that nourish the creative processes of the performers
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