23 research outputs found

    Comparison of the force deterioration of different orthodontic elastomeric materials in artificial saliva: An in vitro study

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    The orthodontist must be able to choose an elastic band with force-extension characteristics that are most suitable for the particular tooth movement required. From a clinician view it would be mandatory not only to know the clinical aspect of these elastics but also their basic properties, in order to extract the most out of these polymers. Stretching of elastics are thought to be the primary cause of force degradation of orthodontic elastics but there is evidence of increased force degradation of elastics when exposed to various types of substances like artificial saliva, phosphoric acid and citric acid. Orthodontic elastics have received mixed reactions of practitioners as reported by the vendors of orthodontic supplies. The present study is designed to compare the force deterioration of different orthodontic elastomeric materials in artificial saliva medium. There was a force deterioration over time in all materials, being greatest on the seventh day of the experiment, especially more in the chains; From the third to the fourth week there was no noticeable force degradation in either group; By the end of the experiment, modules showed less deterioration of the force compared to the chains and threads

    Comparison of the force deterioration of different orthodontic elastomeric materials in artificial saliva: An in vitro study

    Get PDF
    The orthodontist must be able to choose an elastic band with force-extension characteristics that are most suitable for the particular tooth movement required. From a clinician view it would be mandatory not only to know the clinical aspect of these elastics but also their basic properties, in order to extract the most out of these polymers. Stretching of elastics are thought to be the primary cause of force degradation of orthodontic elastics but there is evidence of increased force degradation of elastics when exposed to various types of substances like artificial saliva, phosphoric acid and citric acid. Orthodontic elastics have received mixed reactions of practitioners as reported by the vendors of orthodontic supplies. The present study is designed to compare the force deterioration of different orthodontic elastomeric materials in artificial saliva medium. There was a force deterioration over time in all materials, being greatest on the seventh day of the experiment, especially more in the chains; From the third to the fourth week there was no noticeable force degradation in either group; By the end of the experiment, modules showed less deterioration of the force compared to the chains and threads

    Noise analysis of the Indian Pulsar Timing Array data release I

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    The Indian Pulsar Timing Array (InPTA) collaboration has recently made its first official data release (DR1) for a sample of 14 pulsars using 3.5 years of uGMRT observations. We present the results of single-pulsar noise analysis for each of these 14 pulsars using the InPTA DR1. For this purpose, we consider white noise, achromatic red noise, dispersion measure (DM) variations, and scattering variations in our analysis. We apply Bayesian model selection to obtain the preferred noise models among these for each pulsar. For PSR J1600-3053, we find no evidence of DM and scattering variations, while for PSR J1909-3744, we find no significant scattering variations. Properties vary dramatically among pulsars. For example, we find a strong chromatic noise with chromatic index \sim 2.9 for PSR J1939+2134, indicating the possibility of a scattering index that doesn't agree with that expected for a Kolmogorov scattering medium consistent with similar results for millisecond pulsars in past studies. Despite the relatively short time baseline, the noise models broadly agree with the other PTAs and provide, at the same time, well-constrained DM and scattering variations.Comment: Accepted for publication in PRD, 30 pages, 17 figures, 4 table

    Multi-band Extension of the Wideband Timing Technique

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    The wideband timing technique enables the high-precision simultaneous estimation of Times of Arrival (ToAs) and Dispersion Measures (DMs) while effectively modeling frequency-dependent profile evolution. We present two novel independent methods that extend the standard wideband technique to handle simultaneous multi-band pulsar data incorporating profile evolution over a larger frequency span to estimate DMs and ToAs with enhanced precision. We implement the wideband likelihood using the libstempo python interface to perform wideband timing in the tempo2 framework. We present the application of these techniques to the dataset of fourteen millisecond pulsars observed simultaneously in Band 3 (300 - 500 MHz) and Band 5 (1260 - 1460 MHz) of the upgraded Giant Metrewave Radio Telescope (uGMRT) as a part of the Indian Pulsar Timing Array (InPTA) campaign. We achieve increased ToA and DM precision and sub-microsecond root mean square post-fit timing residuals by combining simultaneous multi-band pulsar observations done in non-contiguous bands for the first time using our novel techniques.Comment: Submitted to MNRA

    Software-Hardware Co-design for Fast and Scalable Training of Deep Learning Recommendation Models

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    Deep learning recommendation models (DLRMs) are used across many business-critical services at Facebook and are the single largest AI application in terms of infrastructure demand in its data-centers. In this paper we discuss the SW/HW co-designed solution for high-performance distributed training of large-scale DLRMs. We introduce a high-performance scalable software stack based on PyTorch and pair it with the new evolution of Zion platform, namely ZionEX. We demonstrate the capability to train very large DLRMs with up to 12 Trillion parameters and show that we can attain 40X speedup in terms of time to solution over previous systems. We achieve this by (i) designing the ZionEX platform with dedicated scale-out network, provisioned with high bandwidth, optimal topology and efficient transport (ii) implementing an optimized PyTorch-based training stack supporting both model and data parallelism (iii) developing sharding algorithms capable of hierarchical partitioning of the embedding tables along row, column dimensions and load balancing them across multiple workers; (iv) adding high-performance core operators while retaining flexibility to support optimizers with fully deterministic updates (v) leveraging reduced precision communications, multi-level memory hierarchy (HBM+DDR+SSD) and pipelining. Furthermore, we develop and briefly comment on distributed data ingestion and other supporting services that are required for the robust and efficient end-to-end training in production environments

    Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms.

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    Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings

    Optimization of Rice Bran Oil Encapsulation Using Jackfruit Seed Starch – Whey Protein Isolate Blend as Wall Material and Its characterization

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    Abstract Response surface methodology (RSM) was used to optimize rice bran oil encapsulation using jackfruit seed starch – whey protein isolate blend as wall material by spray drying technique. Oil concentration (20, 25 and 30 %), wall material (Jackfruit seed starch &amp; whey protein isolate) starch-protein ratio (1:1, 3:1 and 5:1) and spray drying inlet air temperature (140, 150 and 160 °C) were considered as process variables for optimization. A three-factor, three-level Box-Behnken design of RSM was used to conduct the experiments with the aim of maximizing encapsulation efficiency and minimizing peroxide value in the encapsulated powder. A polynomial regression model was fitted using design expert software, and the optimum conditions obtained were 20 % oil concentration, 3:1 starch-protein ratio and 140 °C spray drying inlet air temperature. The encapsulated rice bran oil powers obtained at optimized conditions offered 85.90 % of encapsulation efficiency and 1.18 meq/kg oil of peroxide value. The characterization study revealed that powder particles size (diameter) varied from 3.40 to 300.51 µm and most of the particles were smooth spheres with little appendages.</jats:p
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