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2021 ◽  
Author(s):  
Bharat Tandon ◽  
Sofia A. Shubert-Zuleta ◽  
Delia J. Milliron

Doped metal oxide nanocrystals (NCs) attract immense attention because of their ability to exhibit a localized surface plasmon resonance (LSPR) that can be tuned extensively across the infrared region of the electromagnetic spectrum. LSPR tunability triggered through compositional and morphological changes during the synthesis (size, shape and doping percentage) is becoming well-established while the principles underlying dynamic, post-synthetic modulation of LSPR are not as well understood. Recent reports have suggested that the presence of a depletion layer on the NC surface may be instrumental in governing the LSPR modulation of doped metal oxide NCs. Here, we employ post-synthetic electron transfer to colloidal Sn-doped In2O3 NCs with varying size and Sn doping concentration to investigate the role of the depletion layer in LSPR modulation. By measuring the maximum change in LSPR frequency after NC reduction, we determine that a large initial volume fraction of the depletion layer in NCs results in a broad modulation of the LSPR energy and intensity. Utilizing a mathematical Drude fitting model, we track the changes in the electron density and the depletion layer volume fraction throughout the chemical doping process, offering fundamental insight into the intrinsic NC response resulting from such electron transfer events. We observe that the maximum change in electron density that can be induced through chemical doping is independent of Sn concentration, and subsequently, the maximum total electron density in the presence of excess reductant is independent of the NC diameter and is dependent only on the as-synthesized Sn doping concentration. This study establishes the central role that surface depletion plays in the electronic changes occurring in the NCs during post-synthetic doping and the results will be instrumental in advancing the understanding of optical and electrical properties of different colloidal plasmonic NCs.


Author(s):  
Kaifeng Huang ◽  
Juqiang Feng ◽  
Zegong Liu ◽  
Long Wu ◽  
Xing Zhang

Power battery SOC (state of charge, SOC) is one of the important decision-making factors of energy management. Accurate estimation plays an important role in optimizing vehicle energy management and improving the utilization of power battery energy. The key to accurate estimation of SOC is to determine circuit model parameters and estimation methods. The research object of this article is lithium manganese oxide battery for mining (LiMn2O4). The experiments of multiplying power, temperature and HPPC (hybrid pulse power characteristic, HPPC) are carried out. A self-tuning calculation method of dynamic system is proposed, and the dynamic self-tuning model based on second-order RC is established. At the same time, in view of the shortcoming that the UKF (Unscented Kalman Filter, UKF) algorithm cannot estimate the noise in real time, In order to improve the accuracy of battery SOC estimation, an adaptive square root unscented Kalman filter (ASR-UKF) algorithm is proposed, which can make the noise statistical characteristics follow the estimation results for adaptive adjustment. Finally, the constant current and dynamic conditions are tested. The results show that the maximum change rate of model parameters with magnification is 76%, and the maximum change rate with temperature is 73.7%. The analysis of dynamic characteristics is a key factor to improve the accuracy of SOC estimation; ASR-UKF Compared with the UKF algorithm, the error is reduced by 78% under constant current conditions and 85.7% under dynamic conditions. The reliability and real-time performance of the algorithm can be obtained by comparing the simulation data with the actual data. The conclusions of this paper can be used as a theoretical basis, which can be used for model analysis of lithium batteries for mining and estimation of internal state variables.


Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4433
Author(s):  
Lisa Patzelt ◽  
Daniela Junker ◽  
Jan Syväri ◽  
Egon Burian ◽  
Mingming Wu ◽  
...  

Purpose: To evaluate the suitability of psoas and erector spinae muscle proton density fat fraction (PDFF) and fat volume as biomarkers for monitoring cachexia severity in an oncological cohort, and to evaluate regional variances in muscle parameters over time. Methods: In this prospective study, 58 oncological patients were examined by a 3 T MRI receiving between one and five scans. Muscle volume and PDFF were measured, segmentation masks were divided into proximal, middle and distal muscle section. Results: A regional variation of fat distribution in erector spinae muscle at baseline was found (p < 0.01). During follow-ups significant relative change of muscle parameters was observed. Relative maximum change of erector spinae muscle showed a significant regional variation. Correlation testing with age as a covariate revealed significant correlations for baseline psoas fat volume (r = −0.55, p < 0.01) and baseline psoas PDFF (r = −0.52, p = 0.02) with maximum BMI change during the course of the disease. Conclusion: In erector spinae muscles, a regional variation of fat distribution at baseline and relative maximum change of muscle parameters was observed. Our results indicate that psoas muscle PDFF and fat volume could serve as MRI-determined biomarkers for early risk stratification and disease monitoring regarding progression and severity of weight loss in cancer cachexia.


2021 ◽  
Author(s):  
Yazan Al-Hayek ◽  
Kelly Spuur ◽  
Rob Davidson ◽  
Christopher Hayre ◽  
Xiaoming Zheng

Abstract Objectives: This pilot experimental study explores the effect of vertical off-centring on CT numbers in combination with various tube voltages and phantom sizes.Methods: A CIRS Model 062 Electron Density and Combined Head and Body phantom underwent imaging using a Siemens Emotion 16-slice CT and GEMINI GXL scanners. Uniformity was evaluated as a function of vertical off-centring (20, 40, 60, and 80 mm above the gantry iso-centre) using different phantom sizes and tube voltage for ROI positions across the X and Y axis of each phantom. CT number change was assessed by comparing the measured values between anterior (upper) versus posterior (lower) ROIs.Results: The results showed that vertical off-centring and phantom size could account for 92% of the recorded variance and resultant CT number change. The uniformity test recorded a maximum change of 27.2 and 14 HU for peripheral ROIs at 80 mm phantom shift above the gantry iso-centre using the GEMINI GXL and Siemens scanners, respectively. The absolute CT number differences between anterior and posterior ROIs were 13.7 for the 30 cm phantom and 4.8 for the 20 cm phantom at 80 mm vertical off-centring. The most remarkable differences were observed at lower tube voltages.Conclusions: It is essential to highlight the significance of optimal patient centring for CT examinations and the consequences of CT numbers variation on clinical decision making. Phantom off-centring and ROI location have been demonstrated to affect CT number uniformity in this pilot experimental study. This was more evident at peripheral phantom areas, lower tube voltages and larger phantom size.


2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaoting Mai ◽  
Fangyi Ling ◽  
Yuting Gong ◽  
Jialin Chen ◽  
Hongjie Lin ◽  
...  

Purpose: This study aims to investigate the correlation between electroretinogram (ERG) and visual outcome in eyes with metallic intraocular foreign body (IOFB) injury.Methods: Cases with metallic IOFB injuries with preoperative ERG from January 2008 to May 2020 were reviewed retrospectively. Five ERG responses were recorded, including rod response, maximal response, oscillatory potentials, cone response, and 30-Hz flicker. The results were compared between the affected and the contralateral eyes. All patients received surgery to remove IOFBs. The correlation between amplitudes, implicit times, and grades of ERG with final best-corrected visual acuity (BCVA) was analyzed.Results: A total of 33 eyes of 33 patients were included. The eyes with IOFB had generally delayed implicit time and reduced amplitude in all waves. The maximum change was found in oscillatory potentials S3 and N1 (0.42 ± 0.42 and 1.95 ± 1.97 of the fellow eyes, respectively, p &lt; 0.05). All amplitudes were negatively correlated with the final BCVA (rs: −0.676 to −0.459, all p &lt; 0.05). In contrast, all implicit times were positively correlated with final BCVA, although, some of them were not statistically significant (rs: 0.035 to 0.687). Among them, oscillatory potential P3 has the highest correlation coefficient (rs = 0.687, p &lt; 0.001). All grades of ERG waves were statistically correlated with the final BCVA (rs: −0.596 to −0.664, all p &lt; 0.001).Conclusions: ERG can be used to assess visual outcome in metallic IOFB injury after surgery. Oscillatory potentials provided the most significant responses.


2021 ◽  
Author(s):  
Subhamoy Chatterjee ◽  
Andres Munoz-Jaramillo ◽  
Derek Lamb

Abstract Machine learning is becoming a critical tool for interrogation of large complex data. However, labeling large datasets is time-consuming. Here we show that convolutional neural networks (CNNs), trained on crudely labeled astronomical videos, can be leveraged to improve the quality of data labeling and reduce the need for human intervention. We use videos of the solar photospheric magnetic field, crudely labeled into two classes: emergence or non-emergence of large bipolar magnetic regions (BMRs). We train the CNN using crude labeling, manually verify, correct labeling vs. CNN disagreements, and repeat this process until convergence. This results in a high-quality labeled dataset requiring the manual verification of only ~50% of all videos. Furthermore, by gradually masking the videos and looking for maximum change in CNN inference, we locate BMR emergence time without retraining the CNN. This demonstrates the versatility of CNNs for simplifying the challenging task of labeling complex dynamic events.


2021 ◽  
Vol 23 (04) ◽  
pp. 393-405
Author(s):  
Kunwar Faisal Ali Khan ◽  
◽  
Zafar Alam ◽  
Syed Mohd Yahya ◽  
◽  
...  

The power from sun caught by earth is nearby 1.8 × 1011MW which is obtained by utilizing sun’s energy by photovoltaic cells appears to be a good substitute then the conventional fuels. The efficiency of the system declines due to the heat confined in photovoltaic cells throughout the operation [1]. Enhancing the efficiency of Sun power generation by engaging nanofluids in PV/T systems is achieved by recent improvement in the nanotechnology field. In our work Nano fluids are employed as coolants to lower the PV panel temperatures and thus the system efficiency increases. This study comprehensively analyses the effectiveness of Zinc nanoparticles in different base fluids i.e. water, water (75%) & ethylene glycol (25%) and water (75%) & propylene glycol (25%) to enhance the electrical and thermal efficiency of the PV/T system. Other parameters like flow rate, concentration of nanoparticles by volume and sonication time are kept constant throughout the experiment. The experiments were performed on an indoor setup and to replicate the solar irradiance a solar simulator was engaged as per previous year’s metrological data. It is perceived that the extreme change in electrical efficiency is 2.6% and maximum change in thermal efficiency observed is 31% as compared to conventional system.


2021 ◽  
Vol 004 (01) ◽  
pp. 043-061
Author(s):  
Wahyu Prasetyo ◽  
Pitojo Juwono ◽  
Dian Sisinggih

Sedimentation and erosion caused by differences in discharge is a problem that often occurs at river bends. One of the functions of placing the groyne is to reduce the river flow velocity along the riverbank, accelerate sedimentation, and ensure the embankment or river bank's safety against scouring. This study aimed to determine the distribution of current velocity, distribution of riverbed shear stress, and sediment distribution to the effect of groyne placement. There are 7 (seven) simulation models used to get the most effective groyne placement. From the model simulation results by adding a groyne building on the river's outer bend for the simulation model scenario 2 to scenario 7, the largest sedimentation production is in scenario 3, namely the height of riverbed sediment deposits 230 hours of 1.094 m. Furthermore, the groyne building's effective placement is determined based on a maximum change in the riverbed scenario. In scenario 3, the placement and dimensions of the groyne length of 17.5 m; distance between groyne 24.4 m; the groyne is inclined upstream in the direction of flow 10°


Author(s):  
R. Barathiraja ◽  
P. Thirumal ◽  
G. Saraswathy ◽  
I. Rahamathullah

The influence of pre-treatment methods like physical, chemical, combined physical, and hybrid treatments on the Turkey berry fruits to enhance the water diffusion during drying was assessed due to the removal of a waxy layer on the peel. Pre-treated and untreated samples were dried at 70?C and 4 m/s of air flow in a fluidized bed dryer. Fruits pre-treated with combined abrasion and blanching have the lowest drying time, and favorable Vitamin-C content retention of 36%. The highest drying rate of 0.396 kg water/kg db min?1, maximum effective moisture diffusivity of 6.002 x 10-10 m2/s, and volumetric shrinkage ratio of 0.68 were obtained for fruits which undergone combined physical pre-treatment along with drying. The maximum change in color ?E = 14.75 and Chroma ?C = - 10.53 were obtained for the un-treated samples.


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