1,229 research outputs found

    Ultrasound intensification suppresses the need of methanol excess during the biodiesel production with Lipozyme TL-IM

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    The synthesis of biodiesel from sunflower oil and methanol based on transesterification using the immobilized lipase from Thermomyces lanuginosus (Lipozyme TL-IM) has been investigated under silent conditions and under an ultrasound field. Ultrasound assisted process led to reduced processing time and requirement of lower enzyme dosage. We found for the first time that ratio 1:3 (oil to methanol) was favoured for the ultrasound assisted enzymatic process which is lower as that favoured for the silent process (ratio of 1.4). Our results indicate that intensification provided by ultrasound suppresses the need of the excess of the methanol reactant during the enzymatic biodiesel production. Ultrasound assisted enzymatic biodiesel production is therefore a faster and a cleaner processes.The authors acknowledge Brenntag India Pvt. Ltd. for kindly providing gift sample of lipase enzyme Lipozyme TL IM to carry out the research work. All authors acknowledge the funding of Department of Science and Technology and Portuguese Science Foundation under the Indo-Portuguese collaborative program

    A Branch and Bound Algorithm for Exact, Upper, and Lower Bounds on Treewidth

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    In this paper, a branch and bound algorithm for computing the treewidth of a graph is presented. The method incorporates extensions of existing results, and uses new pruning and reduction rules, based upon roperties of the adopted branching strategy. We discuss how the algorithm can not only be used to obtain exact bounds for the treewidth, but also to obtain upper and/or lower bounds. Computational results of the algorithm are presented

    Enhanced gas-liquid mass transfer of an oscillatory constricted-tubular reactor

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    The mass transfer performance has been tested for gas-liquid flow in a new tubular reactor system, the oscillating mesotube (OMT), which features the oscillatory movement of fluid across a series of smooth constrictions located periodically along the vertical 4.4 mm internal diameter tube. The effect of the fluid oscillations (frequency,f, and center-to-peak amplitude, x(0), in the range of 0-20 s(-1) and 0-3 mm, respectively) on the overall volumetric mass transfer coefficient (k(L)a) has been tested by measuring the oxygen saturation levels with a fiber-optical microprobe (oxygen micro-optrode), and a mathematical model has been produced to describe the oxygen mass transport in the OMT. The oxygen mass transfer rates were about I order of magnitude higher (k(L)a values up to 0.16 s(-1)) than those values reported for gas-liquid contacting in a 50 mm internal diameter oscillatory flow reactor (OFR), for the same peak fluid oscillatory velocity, i.e., 2 pi fx(0). This represents remarkable oxygen transfer efficiencies, especially when considering the very low mean superficial gas velocity involved in this work (0.37 mm s(-1)). The narrower constrictions helped to increase the gas fraction (holdup) by reducing the rise velocity of the bubbles. However, the extent of radial mixing and the detachment of vortex rings from the surface of the periodic constrictions are actually the main causes of bubbles retention and effective gas-liquid contacting and are, thus, responsible for the enhancement of k(L)a in the OMT.N.R. thanks the Portuguese Foundation for Science and Technology (FCT) for financial support of his work (SFRH/BD/6954/2001)

    Traumatic 6th Nerve Palsy Managed with Medial Rectus Recession with Hangback Sutures and Hummelsheim Procedure

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    Traumatic paralytic esotropia due to 6th nerve palsy is not uncommon but difficult to manage. We reported a case of 38‑year‑old male who sustained head injury in road traffic accident 15 years ago and inward deviation of his left eye. His vision in right eye was 20/20 and counting fingers at one foot in the left eye. He had >70 prism diopters esotropia in the left eye with restriction of movements in all directions of gaze except adduction. His forced duction test was positive. Examinations of the anterior and posterior segments of both eyes were within normal limits. Magnetic resonance imaging suggested old traumatic insult in the left eye. Diagnosis of left eye traumatic 6th nerve palsy with medial rectus contracture was made. Left medial rectus recession with hangback sutures and Hummelsheim procedure were performed. Postoperatively, the patient’s vision in the left eye had improved to 20/80 the esotropia had reduced to 15 prism diopters (delta).Keywords: Abducent nerve, esotropia, traum

    A novel deep learning driven low-cost mobility prediction approach for 5G cellular networks: The case of the Control/Data Separation Architecture (CDSA)

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    One of the fundamental goals of mobile networks is to enable uninterrupted access to wireless services without compromising the expected quality of service (QoS). This paper proposes a novel analytical model for a holistic handover (HO) cost evaluation, that integrates signaling overhead, latency, call dropping, and radio resource wastage. The developed mathematical model is applicable to several cellular architectures, but the focus here is on the Control/ Data Separation Architecture (CDSA). Furthermore, HO prediction is proposed and evaluated as part of the holistic cost for the first time, including through the novel application of a recurrent deep learning architecture, specifically, a stacked long-short-term memory (LSTM) model. Simulation results and preliminary analysis reveal different cases where non-predictive and predictive deep neural networks can be utilized, complying with the low cost and effective HO management requirement. Both analytical and machine learning models are evaluated with real-world human behaviors and interactions modeling data set. Numerical and comparative simulation results demonstrate the potential of our proposed framework in designing an enhanced, deep-learning driven HO management

    BUDH IES V:The baryonic Tully-Fisher relation at z = 0.2 based on direct H I detections

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    We present H I-based B- and R-band Tully-Fisher relations (TFRs) and the Baryonic TFR (BTFR) at z = 0.2 using direct H I detections from the Blind Ultra-Deep H I Environmental Survey (BUDH IES). Deep photometry from the Isaac Newton Telescope was used for 36 out of 166 H I sources, matching the quality criteria required for a robust TFR analysis. Two velocity definitions at 20 and 50 per cent of the peak flux were measured from the global H I profiles and adopted as proxies for the circular velocities. We compare our results with an identically constructed z= 0 TFR from the Ursa Major association (UMa) of galaxies. To ensure an unbiased comparison of the TFR, all the samples were treated identically regarding sample selection and applied corrections. We provide catalogues and an atlas showcasing the properties of the galaxies. Our analysis is focused on the zero points of the TFR and BTFR with their slopes fixed to the z = 0 relation. Our main results are: (1) The BUDH IES galaxies show more asymmetric H I profiles with shallower wings compared to the UMa galaxies, which is likely due to the environment in which they reside, (2) The luminosity-based z= 0.2 TFRs are brighter and bluer than the z = 0 TFRs, even when cluster galaxies are excluded from the BUDH IES sample, (3) The BTFR shows no evolution in its zero point over the past 2.5 billion yr and does not significantly change on the inclusion of cluster galaxies, and (4) proper sample selection and consistent corrections are crucial for an unbiased analysis of the evolution of the TFR

    An experimental analysis of attack classification using machine learning in IoT networks

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    \ua9 2021 by the authors. Licensee MDPI, Basel, Switzerland. In recent years, there has been a massive increase in the amount of Internet of Things (IoT) devices as well as the data generated by such devices. The participating devices in IoT networks can be problematic due to their resource-constrained nature, and integrating security on these devices is often overlooked. This has resulted in attackers having an increased incentive to target IoT devices. As the number of attacks possible on a network increases, it becomes more difficult for traditional intrusion detection systems (IDS) to cope with these attacks efficiently. In this paper, we highlight several machine learning (ML) methods such as k-nearest neighbour (KNN), support vector machine (SVM), decision tree (DT), naive Bayes (NB), random forest (RF), artificial neural network (ANN), and logistic regression (LR) that can be used in IDS. In this work, ML algorithms are compared for both binary and multi-class classification on Bot-IoT dataset. Based on several parameters such as accuracy, precision, recall, F1 score, and log loss, we experimentally compared the aforementioned ML algorithms. In the case of HTTP distributed denial-of-service (DDoS) attack, the accuracy of RF is 99%. Furthermore, other simulation results-based precision, recall, F1 score, and log loss metric reveal that RF outperforms on all types of attacks in binary classification. However, in multi-class classification, KNN outperforms other ML algorithms with an accuracy of 99%, which is 4% higher than RF

    BUDHIES IV:Deep 21-cm neutral Hydrogen, optical, and UV imaging data of Abell 963 and Abell 2192 at z ≃ 0.2

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    In this paper, we present data from the Blind Ultra-Deep H I Environmental Survey (BUDHIES), which is a blind 21-cm H I spectral line imaging survey undertaken with the Westerbork Synthesis Radio Telescope. Two volumes were surveyed, each with a single pointing and covering a redshift range of 0.164 < z < 0.224. Within these two volumes, this survey targeted the clusters Abell 963 and Abell 2192, which are dynamically different and offer unique environments to study the process of galaxy evolution within clusters. With an integration time of 117 × 12 h on Abell 963 and 72 × 12 h on Abell 2192, a total of 166 galaxies were detected and imaged in H I. While the clusters themselves occupy only 4 per cent of the 73 400 Mpc3 surveyed by BUDHIES, most of the volume consists of large-scale structures in which the clusters are embedded, including foreground and background overdensities and voids. We present the data processing and source detection techniques and counterpart identification based on a wide-field optical imaging survey using the Isaac Newton Telescope and deep ultraviolet (UV) Galaxy Evolution Explorer (GALEX) imaging. Finally, we present H I and optical catalogues of the detected sources as well as atlases of their global H I properties, which include integrated column density maps, position-velocity diagrams, global H I profiles, and optical and UV images of the H I sources

    Cardiovascular Effects of Canagliflozin in Relation to Renal Function and Albuminuria

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    Background: People with type 2 diabetes mellitus (T2DM) have elevated cardiovascular (CV) risk, including for hospitalization for heart failure (HHF). Canagliflozin reduced CV and kidney events in patients with T2DM and high CV risk or nephropathy in the CANVAS (CANagliflozin cardioVascular Assessment Study) Program and the CREDENCE (Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation) trial. Objectives: The aim of this study was to assess the effects of canagliflozin on CV outcomes according to baseline estimated glomerular filtration rate (eGFR) and urine albumin:creatinine ratio (UACR) in pooled patient-level data from the CANVAS Program and CREDENCE trial. Methods: Canagliflozin effects on CV death or HHF were assessed by baseline eGFR (60 mL/min/1.73 m2) and UACR (300 mg/g). HRs and 95% CIs were estimated by using Cox regression models overall and according to subgroups. Results: A total of 14,543 participants from the CANVAS Program (N = 10,142) and the CREDENCE (N = 4,401) trial were included, with a mean age of 63 years, 35% female, 75% White, 13.2% with baseline eGFR 300 mg/g. Rates of CV death or HHF increased as eGFR declined and/or UACR increased. Canagliflozin significantly reduced CV death or HHF compared with placebo (19.4 vs 28.0 events per 1,000 patient-years; HR: 0.70; 95% CI: 0.62-0.79), with consistent results across eGFR and UACR categories (all P interaction >0.40). Conclusions: Risk of CV death or HHF was higher in those with lower baseline eGFR and/or higher UACR. Canagliflozin consistently reduced CV death or HHF in participants with T2DM and high CV risk or nephropathy regardless of baseline renal function or level of albuminuria. (Canagliflozin Cardiovascular Assessment Study [CANVAS], NCT01032629; A Study of the Effects of Canagliflozin [JNJ-24831754] on Renal Endpoints in Adult Participants With Type 2 Diabetes Mellitus [CANVAS-R], NCT01989754; and Evaluation of the Effects of Canagliflozin on Renal and Cardiovascular Outcomes in Participants With Diabetic Nephropathy [CREDENCE], NCT02065791
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