Biofuels production from hydrotreating of vegetable oil using supported noble metals, and transition metal carbide and nitride

The focus of this research is to prepare non-sulfided hydrotreating catalysts, supported noble metal and transition metal carbide/ nitride, and evaluate their hydrocracking activities and selectivities by using soybean oil as the feedstock. For comparison study, catalytic cracking of soybean oil over a commercialized ZSM-5 was investigated. However, steady state could not be reached because significant amounts of tar and coke were generated during the reaction though a high yield (21%) of jet fuel was obtained from the process. Compared to the catalytic cracking process, less tar and coke were formed during the hydrocracking process and stable continuous flow reaction was obtained by using the bifunctional Ru/ZSM-5 catalyst. 16% yield of jet fuel, which is comparable to yields over commercialized sulfided NiMo catalysts while at a much lower pressure of 650 psi was produced. A 20 - 29% diesel yield was also obtained during the process. But coke was the issue with this noble metal catalyst. In the following stage, novel bi-functional catalysts, NiMo carbide or nitride supported on ZSM-5, zeolite â, USY, ã-alumina oxide, and Al-SBA-15 were prepared by the temperature-programmed reaction method and the effects of process parameters on catalytic hydrocracking of soybean oil were investigated. 100% conversion of soybean oil was attained under the 650 psi and 360-450 oC reaction conditions. Among them, three zeolite supported carbide catalysts showed high selectivity to green gasoline (about 15-40%) due to the high cracking activities. ã-alumina and Al-SBA-15 supported catalysts mainly produced green diesel fuels. Especially Al-SBA-15 supported NiMo carbide catalyst gave the highest yield of organic liquid product (96%) and highest selectivity (97%) to hydrocarbons in the boiling range of the diesel fraction. The study of carbide and nitride catalysts provides a promising approach for preparing drop-in fuels from renewable resources under a lower pressure without sulfurization reagents involved in the process. NiMoC/Al-SBA-15 showed the greatest potential for producing green diesel from renewable feedstock

SNR-Based Teachers-Student Technique for Speech Enhancement

It is very challenging for speech enhancement methods to achieves robust performance under both high signal-to-noise ratio (SNR) and low SNR simultaneously. In this paper, we propose a method that integrates an SNR-based teachers-student technique and time-domain U-Net to deal with this problem. Specifically, this method consists of multiple teacher models and a student model. We first train the teacher models under multiple small-range SNRs that do not coincide with each other so that they can perform speech enhancement well within the specific SNR range. Then, we choose different teacher models to supervise the training of the student model according to the SNR of the training data. Eventually, the student model can perform speech enhancement under both high SNR and low SNR. To evaluate the proposed method, we constructed a dataset with an SNR ranging from -20dB to 20dB based on the public dataset. We experimentally analyzed the effectiveness of the SNR-based teachers-student technique and compared the proposed method with several state-of-the-art methods.Comment: Published in 2020 IEEE International Conference on Multimedia and Expo (ICME 2020

Deterministic Binary Sequences for Modulated Wideband Converter

Publication in the conference proceedings of SampTA, Bremen, Germany, 201

Prevalence of Neuropsychiatric Symptoms across the Declining Memory Continuum: An Observational Study in a Memory Clinic Setting

Aims: The study aimed to compare the frequency of neuropsychiatric symptoms (NPS) across the declining memory continuum, from normal aging, subjective cognitive impairment (SCI), and mild cognitive impairment (MCI) to Alzheimer’s disease (AD), and to explore the clinical correlates of NPS. Method: In a memory clinic, 157 subjects (46 mild AD patients, 38 MCI individuals, 24 SCI subjects, and 49 normal controls) completed the neurobehavioral assessments with the Neuropsychiatric Inventory (NPI). The clinical significance of each NPI domain was defined as an item score ≥4. Result: Clinically significant depression was more common in the SCI than in the normal control group (p Conclusion: Across the declining memory continuum, the frequency of NPS was highest among mild AD patients. Depression, apathy, and aberrant motor behavior deserve more attention. Presence of apathy might be an independent determinant for mild AD

Abnormal Spontaneous Brain Activity in Early Parkinson’s Disease With Mild Cognitive Impairment: A Resting-State fMRI Study

Mild cognitive impairment (MCI) is a common symptom at the baseline of early Parkinson’s disease (PD) diagnosis, but the neural mechanism is unclear. To address the issue, the present study employed resting-state functional magnetic resonance imaging data of 19 drug-naïve PD patients with normal cognition (PD-NC), 10 PD patients with MCI (PD-MCI) and 13 age- and gender-matched healthy controls (HC) from the Parkinson’s progression markers initiative (PPMI) (http://www.ppmi-info.org/), and examined abnormal spontaneous brain activities in the PD-MCI. The pattern of spontaneous brain activity was measured by examining the amplitude of low-frequency fluctuations (ALFF) of blood oxygen level dependent signal. Voxel-wise one-way analysis of covariance and post hoc analyses of ALFF were performed under non-parametric permutation tests in a general linear model among the three groups, with age, gender and data center as additional covariates. Statistical significances in the post hoc analysis were corrected by a small volume correction with a cluster-level threshold of p < 0.05 (n = 10000 permutations, FWE-corrected). Correlations of clinical and neuropsychological assessments [i.e., Unified Parkinson’s Disease Rating Scale (UPDRS) total score, Montreal Cognitive Assessment (MoCA) and cognitive domains] with the regional ALFF were performed in the PD-MCI group. Compared with the HC, both PD groups exhibited reduced ALFF in the occipital area (Calcarine_R/Cuneus_R). Specially, the PD-MCI group additionally exhibited increased ALFF in the opercular part of right inferior frontal gyrus (Frontal_Inf_Oper_R). Comparing with the PD-NC, the PD-MCI group exhibited significantly higher ALFF in the Frontal_Inf_Oper_R and left fusiform gyus (ps < 0.05). The correlation analysis revealed that the ALFF in the Frontal_Inf_Oper_R was positively correlated with the UPDRS total score (p < 0.05), but marginally negatively correlated with the MoCA score. For cognitive domains, the ALFF in the region also showed a significantly negative correlation with the score of SF test (p < 0.01) and a marginally negative correlation with the score of Symbol-Digit Modalities Test. Together, we concluded hyperactivity in the right inferior frontal gyrus in early PD with MCI, suggesting a compensatory recruitment in response to cognitive decline, which may shed light on thought of dementia progression and potentially comprehensive treatment in PD

Peeling Decoding of LDPC Codes with Applications in Compressed Sensing

We present a new approach for the analysis of iterative peeling decoding recovery algorithms in the context of Low-Density Parity-Check (LDPC) codes and compressed sensing. The iterative recovery algorithm is particularly interesting for its low measurement cost and low computational complexity. The asymptotic analysis can track the evolution of the fraction of unrecovered signal elements in each iteration, which is similar to the well-known density evolution analysis in the context of LDPC decoding algorithm. Our analysis shows that there exists a threshold on the density factor; if under this threshold, the recovery algorithm is successful; otherwise it will fail. Simulation results are also provided for verifying the agreement between the proposed asymptotic analysis and recovery algorithm. Compared with existing works of peeling decoding algorithm, focusing on the failure probability of the recovery algorithm, our proposed approach gives accurate evolution of performance with different parameters of measurement matrices and is easy to implement. We also show that the peeling decoding algorithm performs better than other schemes based on LDPC codes

Exposure risk assessment of 3-chloropropanol esters in 0-3 aged infants

Objective To analyze the chloropropanol monoesters (MCPD esters) levels in the infant formulas available in Hangzhou market from 2017 to 2019, and to assess the exposure risk of MCPD esters for 0-3 years infants. Methods Concentrations of 3-MCPD esters and 2-MCPD esters in the infant formulas were determined with gas chromatography-mass spectrometry (GC-MS). 3-MCPD esters exposure risk in target population was assessed by the level of 3-MCPD esters in infant formulas and the consumption recommendation from diatery guideline. Results The 3-MCPD esters and 2-MCPD esters contamination existed in all infant formulas samples; the median and P97.5 daily dietary exposure of 3-MCPD esters were 0.46-2.50 and 0.87-4.30 μg/kg BW, account for 23.0%-125.0% and 43.5%-215.0% of the tolerable daily intake (TDI, 2 μg/kg BW per day) respectively. For infants aged 0-6 months, the high intake levels (P97.5) of 3-MCPD esters were above TDI. Conclusion The levels of 3-MCPD esters in infant formulas sold in Hangzhou may pose a potential risk. Infants aged 0-6 months had higher exposure level than other age groups

Multi-Fields Modulation of Physical Properties of Oxide Thin Films

Oxide thin films exhibit versatile physical properties such as magnetism, ferroelectricity, piezoelectricity, metal-insulator transition (MIT), multiferroicity, colossal magnetoresistivity, switchable resistivity, etc. More importantly, the exhibited multifunctionality could be tuned by various external fields, which has enabled demonstration of novel electronic devices. In this article, recent studies of the multi-fields modulation of physical properties in oxide thin films have been reviewed. Some of the key issues and prospects about this field are also addressed.Comment: review article, 56 pages, 18 figure