| 1. |
- Sharma, Manish Kumar, et al.
(författare)
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Comprehensive investigations of the synergistic effect of chalcone on the anti-corrosion activity of environmentally benign triazole hybrid
- 2023
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Ingår i: Inorganic Chemistry Communications. - : Elsevier B.V.. - 1387-7003 .- 1879-0259. ; 158
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Tidskriftsartikel (refereegranskat)abstract
- This research article presents a comprehensive investigation into the corrosion inhibition performance of a 1,2,3-triazole-based hybrid (TCA) with incorporated triazole, chalcone, and amide moieties. The amalgamation of these pharmacologically active moieties synergistically enhances the ability of the TCA hybrid to form protective films on metal surfaces. The study employs a combination of experimental and theoretical methods to assess the corrosion inhibition properties. Multiple sophisticated techniques like weight loss, EIS, PDP, SEM, EDX, and UV–Vis spectroscopy reveals TCA's exceptional inhibitory efficiency (∼99 % at 200 ppm) for mild steel (MS). PDP analysis suggests a mixed-type inhibition mechanism. The experimental findings are further supported by the DFT calculations by exploring the interactions between the inhibitor and mild steel (MS). The remarkable corrosion inhibition efficacy of TCA along with its eco-friendly behavior aligns the present work with the growing global emphasis on sustainability.
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| 2. |
- Ho, Anna Y. Q., et al.
(författare)
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A Search for Extragalactic Fast Blue Optical Transients in ZTF and the Rate of AT2018cow-like Transients
- 2023
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 949:2
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Tidskriftsartikel (refereegranskat)abstract
- We present a search for extragalactic fast blue optical transients (FBOTs) during Phase I of the Zwicky Transient Facility (ZTF). We identify 38 candidates with durations above half-maximum light 1 day < t (1/2) < 12 days, of which 28 have blue (g - r less than or similar to -0.2 mag) colors at peak light. Of the 38 transients (28 FBOTs), 19 (13) can be spectroscopically classified as core-collapse supernovae (SNe): 11 (8) H- or He-rich (Type II/IIb/Ib) SNe, 6 (4) interacting (Type IIn/Ibn) SNe, and 2 (1) H&He-poor (Type Ic/Ic-BL) SNe. Two FBOTs (published previously) had predominantly featureless spectra and luminous radio emission: AT2018lug (The Koala) and AT2020xnd (The Camel). Seven (five) did not have a definitive classification: AT 2020bdh showed tentative broad H alpha in emission, and AT 2020bot showed unidentified broad features and was 10 kpc offset from the center of an early-type galaxy. Ten (eight) have no spectroscopic observations or redshift measurements. We present multiwavelength (radio, millimeter, and/or X-ray) observations for five FBOTs (three Type Ibn, one Type IIn/Ibn, one Type IIb). Additionally, we search radio-survey (VLA and ASKAP) data to set limits on the presence of radio emission for 24 of the transients. All X-ray and radio observations resulted in nondetections; we rule out AT2018cow-like X-ray and radio behavior for five FBOTs and more luminous emission (such as that seen in the Camel) for four additional FBOTs. We conclude that exotic transients similar to AT2018cow, the Koala, and the Camel represent a rare subset of FBOTs and use ZTF's SN classification experiments to measure the rate to be at most 0.1% of the local core-collapse SN rate.
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| 3. |
- Panchal, Vaidik, et al.
(författare)
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FPGA implementation of proposed number plate localization algorithm based on YOLOv2 (You Only Look Once)
- 2023
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Ingår i: Microsystem Technologies. - : Springer Nature. - 0946-7076 .- 1432-1858. ; 29:10, s. 1501-1513
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Tidskriftsartikel (refereegranskat)abstract
- Many algorithms used in machine learning and artificial intelligence rely on exact object identification and recognition as their foundation for efficiency and accuracy. Hardware implementation of such methods, when implemented, serves to boost the reliability and productivity of object detection in a wide range of contexts. Hardware implementation of such an algorithm takes a lot of resources and a huge amount of calculation time. The object detection and recognition process require a collection of complex algorithms and a series of filtering approaches to work beyond the boundary conditions. The YOLOv2 network is superior to filters and complicated algorithms for this problem. The authors of this study propose an enhanced YOLOv2 Network for object recognition and a novel approach for optimising the existing YOLOv2 Network for localization to pinpoint the ROI that can be used to scale down and contain the object's original area. The network is proposed by configuring the existing YOLOv2 with additional convolution layers and dropout layers. The dropout layers are added to reduce the dependency on a single neuron and is an effective way of preventing overfitting of the network. Also, instead of ReLU as the activation function, we are using the Swish activation function which tends to provide better results. By isolating and producing the region of interest (ROI) from the original image, the algorithm was able to significantly cut down on both the number of resources needed and the time needed to complete the task. The proposed work is implemented on an FPGA board (Xilinx Zynq-Z7010 FPGA board), and the dataset is collected and prepared by the authors. Data augmentation is done to enhance the training data to enhance the training data, which results in better trained network. MATLAB is used to demonstrate the feasibility of the work and provide a thorough evaluation of its merits. The results show that the accuracy of the conventional algorithm approach drops to 20–30% once you move outside the boundaries, whereas the accuracy of the proposed work increases to 60–70% and a 15–20% increase in efficiency with proposed network based on YOLOv2. The proposed algorithm is three times as fast as the standard method while using only 35 percent as much technology.
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| 4. |
- Stein, Robert, et al.
(författare)
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Neutrino follow-up with the Zwicky transient facility : results from the first 24 campaigns
- 2023
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 521:4, s. 5046-5063
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Tidskriftsartikel (refereegranskat)abstract
- The Zwicky Transient Facility (ZTF) performs a systematic neutrino follow-up programme, searching for optical counterparts to high-energy neutrinos with dedicated Target-of-Opportunity (ToO) observations. Since first light in March 2018, ZTF has taken prompt observations for 24 high-quality neutrino alerts from the IceCube Neutrino Observatory, with a median latency of 12.2 h from initial neutrino detection. From two of these campaigns, we have already reported tidal disruption event (TDE) AT 2019dsg and likely TDE AT 2019fdr as probable counterparts, suggesting that TDEs contribute >7.8 per cent of the astrophysical neutrino flux. We here present the full results of our programme through to December 2021. No additional candidate neutrino sources were identified by our programme, allowing us to place the first constraints on the underlying optical luminosity function of astrophysical neutrino sources. Transients with optical absolutes magnitudes brighter that -21 can contribute no more than 87 per cent of the total, while transients brighter than -22 can contribute no more than 58 per cent of the total, neglecting the effect of extinction and assuming they follow the star formation rate. These are the first observational constraints on the neutrino emission of bright populations such as superluminous supernovae. None of the neutrinos were coincident with bright optical AGN flares comparable to that observed for TXS 0506+056/IC170922A, with such optical blazar flares producing no more than 26 per cent of the total neutrino flux. We highlight the outlook for electromagnetic neutrino follow-up programmes, including the expected potential for the Rubin Observatory.
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| 5. |
- Yao, Yuhan, et al.
(författare)
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Tidal Disruption Event Demographics with the Zwicky Transient Facility : Volumetric Rates, Luminosity Function, and Implications for the Local Black Hole Mass Function
- 2023
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Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 955:1
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Tidskriftsartikel (refereegranskat)abstract
- We conduct a systematic tidal disruption event (TDE) demographics analysis using the largest sample of optically selected TDEs. A flux-limited, spectroscopically complete sample of 33 TDEs is constructed using the Zwicky Transient Facility over 3 yr (from 2018 October to 2021 September). We infer the black hole (BH) mass (MBH) with host galaxy scaling relations, showing that the sample MBH ranges from 105.1M⊙ to 108.2M⊙. We developed a survey efficiency corrected maximum volume method to infer the rates. The rest-frame g-band luminosity function can be well described by a broken power law of , with Lbk = 1043.1 erg s−1. In the BH mass regime of 105.3 ≲ (MBH/M⊙) ≲ 107.3, the TDE mass function follows , which favors a flat local BH mass function (). We confirm the significant rate suppression at the high-mass end (MBH ≳ 107.5M⊙), which is consistent with theoretical predictions considering direct capture of hydrogen-burning stars by the event horizon. At a host galaxy mass of Mgal ∼ 1010M⊙, the average optical TDE rate is ≈3.2 × 10−5 galaxy−1 yr−1. We constrain the optical TDE rate to be [3.7, 7.4, and 1.6] × 10−5 galaxy−1 yr−1 in galaxies with red, green, and blue colors.
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