411 research outputs found
Detection and Diagnosis of Compound Faults in a Reciprocating Compressor based on Motor Current Signatures
Induction motors are the most common driver in the industry and consume
tremendous energy every year. Monitoring the status of a motor and its
downstream equipment and diagnosing faults in time not only avoids great damage
to mechanical systems but also allows the motor to run at optimal efficiency.
This paper studies the use of information from motor current signals to detect and
diagnose faults of a reciprocating compressor (RC) and its upstream three-phase
motor. The motor is applied by the RC with an oscillator torque which induces
additional components in measured current signals. Moreover, the current signatures
contain changes with the torque profiles due to different types of faults.
Based on these analytical studies, experimental studies were carried out for different
common RC faults, such as valve leakage, intercooler leakage, stator asymmetries
and the compounds of them. The envelope analysis of current signals
allows accurate demodulation of the torque profiles and thereby it can be combined
with overall current levels for implementing model based detections and
diagnosis. The results show these simulated faults can be separated under all operating
pressures
Preparation of Phase Homogeneous Mn-Zn Ferrite Powder by Spray Pyrolysis
Two kinds of aqueous precursor solutions are used to synthesize Mn-Zn ferrite powders: (i) nitrate (NO) precursor-derived from solutions of Mn(NO3)2, Zn(NO3)2, and Fe(NO3)3; and (ii) acetate (AC) precursor-derived from solutions of Mn(CH3COOO)2, Zn(CHCH3COOO)2, and Fe(NO3)3. The composition of the powders synthesized from the precursor AC is very uniform, whereas powders derived from the precursor NO have Mn and Zn segregated on the particle surfaces. In addition, the powders synthesized from precursor AC are solid spherical particles with fine porosity, whereas many hollow and fragmented particles are observed in the powder derived from precursor NO. Overall, the properties of Mn-Zn ferrite cores prepared from the precursor AC are superior to those prepared from the precursor NO. The reasons for the differences are explained and described in detail. The AC precursor powders synthesized by spray pyrolysis produced Mn-Zn ferrite cores with good magnetic properties
Proteases and Protease Inhibitors of Urinary Extracellular Vesicles in Diabetic Nephropathy
Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus (DM), leads to chronic kidney disease (CKD), and, ultimately, is the main cause for end-stage kidney disease (ESKD). Beyond urinary albumin, no reliable biomarkers are available for accurate early diagnostics. Urinary extracellular vesicles (UEVs) have recently emerged as an interesting source of diagnostic and prognostic disease biomarkers. Here we used a protease and respective protease inhibitor array to profile urines of type 1 diabetes patients at different stages of kidney involvement. Urine samples were divided into groups based on the level of albuminuria and UEVs isolated by hydrostatic dialysis and screened for relative changes of 34 different proteases and 32 protease inhibitors, respectively. Interestingly, myeloblastin and its natural inhibitor elafin showed an increase in the normo- and microalbuminuric groups. Similarly, a characteristic pattern was observed in the array of protease inhibitors, with a marked increase of cystatin B, natural inhibitor of cathepsins L, H, and B as well as of neutrophil gelatinase-associated Lipocalin (NGAL) in the normoalbuminuric group. This study shows for the first time the distinctive alterations in comprehensive protease profiles of UEVs in diabetic nephropathy and uncovers intriguing mechanistic, prognostic, and diagnostic features of kidney damage in diabetes.Peer reviewe
Mitogenome-based phylogeny of the gastropod order Neomphalida points to multiple habitat shifts and a Pacific origin
Neomphalida is an order of gastropod molluscs with highly diverse morphology and a global distribution across various chemosynthesis-based ecosystems from organic falls to hot vents. The phylogenetic relationships of taxa within this order remain contentious, due to the rarity of material leading to a low taxonomic coverage and few genetic markers used. Neomphalida includes three families—Melanodrymiidae, Neomphalidae, and Peltospiridae—and molecular sequences are especially lacking in Melanodrymiidae. Here, we assembled a total of 11 mitogenomes covering these three families and 14 genus-level groups to reconstruct the most complete phylogeny of Neomphalida to date. Our current result recovered the monophyly of three families with maximum support and a likely interfamilial relationship of (Melanodrymiidae + Neomphalidae) + Peltospiridae. These indicate the possibility of habitat shifting from non-chemosynthetic deep sea to hot vent and then to sunken wood, accompanied by elevated mitogenome rearrangements and amino acid substitution rates in Melanodrymiidae. By mapping species distribution on the phylogeny, our findings suggest a Pacific origin of Neomphalida and multiple historical dispersal events of Peltospiridae to the Indian Ocean and at least once to the Atlantic
Passive Human Sensing Enhanced by Reconfigurable Intelligent Surface: Opportunities and Challenges
Reconfigurable intelligent surfaces (RISs) have flexible and exceptional
performance in manipulating electromagnetic waves and customizing wireless
channels. These capabilities enable them to provide a plethora of valuable
activity-related information for promoting wireless human sensing. In this
article, we present a comprehensive review of passive human sensing using radio
frequency signals with the assistance of RISs. Specifically, we first introduce
fundamental principles and physical platform of RISs. Subsequently, based on
the specific applications, we categorize the state-of-the-art human sensing
techniques into three types, including human imaging,localization, and activity
recognition. Meanwhile, we would also investigate the benefits that RISs bring
to these applications. Furthermore, we explore the application of RISs in human
micro-motion sensing, and propose a vital signs monitoring system enhanced by
RISs. Experimental results are presented to demonstrate the promising potential
of RISs in sensing vital signs for manipulating individuals. Finally, we
discuss the technical challenges and opportunities in this field
Heterogeneity characterization of hepatocellular carcinoma based on the sensitivity to 5-fluorouracil and development of a prognostic regression model
Background: 5-Fluorouracil (5-FU) is a widely used chemotherapeutic drug in clinical cancer treatment, including hepatocellular carcinoma (HCC). A correct understanding of the mechanisms leading to a low or lack of sensitivity of HCC to 5-FU-based treatment is a key element in the current personalized medical treatment.Methods: Weighted gene co-expression network analysis (WGCNA) was used to analyze the expression profiles of the cancer cell line from GDSC2 to identify 5-FU-related modules and hub genes. According to hub genes, HCC was classified and the machine learning model was developed by ConsensusClusterPlus and five different machine learning algorithms. Furthermore, we performed quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis on the genes in our model.Results: A total of 19 modules of the cancer cell line were divided by WGCNA, and the most negative correlation with 5-FU was the midnight blue module, from which 45 hub genes were identified. HCC was divided into three subgroups (C1, C2, and C3) with significant overall survival (OS) differences. OS of C1 was the shortest, which was characterized by a high clinical grade and later T stage and stage. OS of C3 was the longest. OS of C2 was between the two subtypes, and its immune infiltration was the lowest. Five out of 45 hub genes, namely, TOMM40L, SNRPA, ILF3, CPSF6, and NUP205, were filtered to develop a risk regression model as an independent prognostic indicator for HCC. The qRT-PCR results showed that TOMM40L, SNRPA, ILF3, CPSF6, and NUP205 were remarkably highly expressed in hepatocellular carcinoma.Conclusion: The HCC classification based on the sensitivity to 5-FU was in line with the prognostic differences observed in HCC and most of the genomic variation, immune infiltration, and heterogeneity of pathological pathways. The regression model related to 5-FU sensitivity may be of significance in individualized prognostic monitoring of HCC
Capacity Analysis and Optimization in Heterogeneous Network with Adaptive Cell Range Control
As an attractive means of expanding mobile network capacity, heterogeneous network is regarded as an important direction of mobile network evolution. To increase the capacity of, for example, hot spots, a typical scenario in heterogeneous network is that the coverage areas of low power nodes (LPNs) are overlapped with macrocell. To increase the utilization of small cells generated by LPNs, cell range extension (CRE) is used to extend the coverage of the small cells by adding cell specific offset (CSO) to small cells during cell selection procedure. The value of CSO, however, needs to be set carefully. In this paper, the capacity of users in macrocells, users in small cells, and users in range extension areas is analyzed thoroughly in conditions with and without CRE. Based on the analysis, an adaptive CSO updating algorithm is proposed. The proposed algorithm updates the CSO value periodically by predicting the overall capacity and a new CSO value is selected which can give the optimal overall capacity. The proposed algorithm is evaluated by system-level simulations. Simulation results indicate that the proposed algorithm can ensure a nearly optimal performance in all tested traffic load situations
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