Coupling vibration analysis of auger drilling system

In the process of drilling coal, the kinematics of drill-rod is quite complicated. The drill-rod not only vibrates in longitudinal, transverse and torsional direction, but also random impacts and contacts coal wall. Considering the drilling load of drill-bit and coal, contact impact of the drill-rod and coal wall, the drill-rods are dispersed into a number of finite elements. At the same time, the nonlinear dynamic model of drill-rod system coupling longitudinal, transverse and torsional vibration is set up. The simulations of the dynamic model are researched under the conditions of different hardness coal (2.7, 3.7, 4.65). In order to decrease the vibration of auger drill, the stabilizer is added onto the drilling mechanism. And the underground experiments are done at 2404 working face of Xie-Zhang Coal Mine in Shan-Dong Province of China. The results indicate that the transverse vibration radius, the longitudinal vibration frequency and amplitude all decrease with the rock hardness. The maximum transverse vibration radius shows an exponential relation with the drilling depth under the condition of the same rock. Under the same condition, the drilling depth of auger drill with stabilizer is 1.39 times that with no stabilizer, and the drilling pressure decreases about 2/3

Fault diagnosis of pump valve spring based on improved singularity analysis

The fracture of pump valve springs is another typical fault of emulsion pump with high pressure and large discharge, which greatly influences the volumetric efficiency of emulsion pump. The fault diagnosis on pump valve springs of emulsion pump was analyzed based on the singularity analysis of continuous wavelet transform. The improved method for Lipschitz index was presented with better robustness and efficiency based on the Least Square Method. The criterion for the fracture of pump valve was confirmed. Diagnostic results indicate that it is accurate and effective of the improved method to locate the singularity of signals, identify the moment when the valve disc impacts on base or lift limiter and judge the fault diagnosis of pump valve

Interference model of conical pick in cutting process

The load on conical pick is affected by many factors such as pick geometry and installation angle. In order to decrease the wear and vibration of pick in the cutting process by choosing proper impact angle, the interference mathematical models of straight and revolving cutting were established according to coal cutting theory. Based on this, coal cutting experiment was carried out with different impact angles β, different head face radii of pick body R and different cutting depths d to verify the mathematical model. The results indicate that the picks cutting into coal with a certain installed angle are prone to interfere with coal in the cutting progress. There is a crsitical impact angle, and it is different under different cutting conditions. The critical impact angle decreases with the head face radius of pick body R and cutting depth d. On the condition of given pick geometry and movement parameters, the cutting force of picks or cutting torque of cutting header decreases with the impact angle. When the impact angle of the pick is larger than the critical angle, the load on pick will increase prominently

Fault diagnosis of pump valve spring based on improved singularity analysis

The fracture of pump valve springs is another typical fault of emulsion pump with high pressure and large discharge, which greatly influences the volumetric efficiency of emulsion pump. The fault diagnosis on pump valve springs of emulsion pump was analyzed based on the singularity analysis of continuous wavelet transform. The improved method for Lipschitz index was presented with better robustness and efficiency based on the Least Square Method. The criterion for the fracture of pump valve was confirmed. Diagnostic results indicate that it is accurate and effective of the improved method to locate the singularity of signals, identify the moment when the valve disc impacts on base or lift limiter and judge the fault diagnosis of pump valve

Individual Differences in the Speed of Facial Emotion Recognition Show Little Specificity but Are Strongly Related with General Mental Speed: Psychometric, Neural and Genetic Evidence

Facial identity and facial expression processing are crucial socio-emotional abilities but seem to show only limited psychometric uniqueness when the processing speed is considered in easy tasks. We applied a comprehensive measurement of processing speed and contrasted performance specificity in socio-emotional, social and non-social stimuli from an individual differences perspective. Performance in a multivariate task battery could be best modeled by a general speed factor and a first-order factor capturing some specific variance due to processing emotional facial expressions. We further tested equivalence of the relationships between speed factors and polymorphisms of dopamine and serotonin transporter genes. Results show that the speed factors are not only psychometrically equivalent but invariant in their relation with the Catechol-O Methyl-Transferase (COMT) Val158Met polymorphism. However, the 5-HTTLPR/rs25531 serotonin polymorphism was related with the first-order factor of emotion perception speed, suggesting a specific genetic correlate of processing emotions. We further investigated the relationship between several components of event-related brain potentials with psychometric abilities, and tested emotion specific individual differences at the neurophysiological level. Results revealed swifter emotion perception abilities to go along with larger amplitudes of the P100 and the Early Posterior Negativity (EPN), when emotion processing was modeled on its own. However, after partialling out the shared variance of emotion perception speed with general processing speed-related abilities, brain-behavior relationships did not remain specific for emotion. Together, the present results suggest that speed abilities are strongly interrelated but show some specificity for emotion processing speed at the psychometric level. At both genetic and neurophysiological levels, emotion specificity depended on whether general cognition is taken into account or not. These findings keenly suggest that general speed abilities should be taken into account when the study of emotion recognition abilities is targeted in its specificity

Experiment on Conical Pick Cutting Rock Material Assisted with Front and Rear Water Jet

Conical picks are one kind of cutting tools widely used in engineering machinery. In the process of rock breaking, the conical pick bears great cutting force and wear. To solve the problem, a new method, conical pick assisted with high pressure water jet, could break rock effectively, and four different configuration modes of water jet were presented. In this paper, based on the analysis of the different water jet configuration’s advantages and disadvantages, experiments on front water jet, new typed rear water jet, and the combination of those two water jet configuration modes were conducted to study the assisting cutting performance and obtain the quantitative results

Characteristics of gas-solid two-phase flow in axial and swirling flow pneumatic conveying

U svrhu povećanja kapaciteta i učinkovitosti pneumatskih sustava prenošenja razvijen je generator vrtložnog protoka za postizanje pneumatskog prenošenja čestica vrtložnim protokom (SFPC). Provedena je numerička simulacija pneumatskog prenošenja čestica aksijalnim protokom (AFPC) i pneumatskog prenošenja čestica vrtložnim protokom (SFPC) primjenom Lagrange metode praćenja čestica (LPTM) u kojoj su uzete u obzir interakcije plinske faze i čvrste faze. Analizirane su raspodjele koncentracije čestica i brzine čestica. Rezultati pokazuju da se vrtložnim protokom poboljšala raspodjela koncentracije čestica i da je najprije porasla a zatim se smanjila brzina čestica kod pojačanog vrtložnog protoka; ipak se brzina čestica povećala za više od 40 % u odnosu na brzinu u AFPC. Vrtložni je protok pokazao optimalno ponašanje kod intenziteta vrtloženja od približno 0,3. Intenzitet vrtloženja brže se smanjivao s eksponencijalno većom aksijalnom brzinom plina. Rezultati eksperimenata o gubitku tlaka u AFPC i SFPC pokazali su da postoji optimalna brzina plina u AFPC koja je minimalizirala gubitak tlaka. Optimalna se brzina plina povećavala s količinom protoka mase; gubitak tlaka u SFPC najprije je porastao a zatim se smanjio s pojačanjem vrtloženja. Maksimalni gubitak tlaka u SFPC bio je veći od onoga u AFPC dok je vrtložni intenzitet bio 0,35; 0,376; 0,38, a količina protoka mase 1,5 kg/s; 1,9 kg/s; 2,5 kg/s. Gubitak tlaka u SFPC bio je manji nego u AFPC dok je intenzitet vrtloženja bio veći od određene vrijednosti.To improve the capacity and efficiency of pneumatic conveying systems, a swirling flow generator was developed to achieve swirling flow pneumatic conveying (SFPC) for particles. A numerical simulation of axial flow pneumatic conveying (AFPC) and swirling flow pneumatic conveying (SFPC) for particles was carried out using the Lagrange particle tracking method (LPTM), in which the interactions of the gas phase and solid phase were taken into account. The distributions of particle concentration and particle velocity were analysed. The results indicate that the distribution of particle concentration was improved by swirling flow and that of the particle velocity increased first and then decreased with swirling flow intensity; however, the particle velocity still increased by more than 40 % relative to the velocity observed in AFPC. Swirling flow exhibited the optimal behaviour when the swirling intensity was approximately 0,3. The swirling intensity decayed faster with greater axial gas velocity exponentially. The results of pressure loss experiments in AFPC and SFPC showed that there was an optimal gas velocity in AFPC that minimised the pressure loss. The optimal gas velocity increased with mass flow rate; the pressure loss in SFPC first increased and then decreased with swirling intensity. The maximum pressure loss in SFPC was larger than that in AFPC while the swirling intensity was 0,35; 0,376; 0,38 and the mass flow rate was 1,5 kg/s; 1,9 kg/s; 2,5 kg/s. The pressure loss in SFPC was lower than that in AFPC while swirling intensity was higher than a certain value

Label-free microfluidic paper-based electrochemical aptasensor for ultrasensitive and simultaneous multiplexed detection of cancer biomarkers

Simultaneous detection of multiple tumor biomarkers in body fluids could facilitate early diagnosis of lung cancer, so as to provide scientific reference for clinical treatment. This paper depicted a multi-parameter paper-based electrochemical aptasensor for simultaneous detection of carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) in a clinical sample with high sensitivity and specificity. The paper-based device was fabricated through wax printing and screen-printing, which enabled functions of sample filtration and sample auto injection. Amino functional graphene (NG)-Thionin (THI)- gold nanoparticles (AuNPs) and Prussian blue (PB)- poly (3,4- ethylenedioxythiophene) (PEDOT)- AuNPs nanocomposites were synthesized respectively. They were used to modify the working electrodes not only for promoting the electron transfer rate, but also for immobilization of the CEA and NSE aptamers. A label-free electrochemical method was adopted, enabling a rapid simple point-of-care testing. Experimental results showed that the proposed multi-parameter aptasensor exhibited good linearity in ranges of 0.01-500 ng mL for CEA (R  = 0.989) and 0.05-500 ng mL for NSE (R  = 0.944), respectively. The limit of detection (LOD) was 2 pg mL for CEA and 10 pg mL for NSE. In addition, the device was evaluated using clinical serum samples and received a good correlation with large electrochemical luminescence (ECL) equipment, which would offer a new platform for early cancer diagnostics, especially in those resource-limit areas

Adverse drug events in Chinese elder inpatients: a retrospective review for evaluating the efficiency of the Global Trigger Tool

BackgroundElderly patients frequently experience a high incidence of adverse drug events (ADEs) due to the coexistence of multiple diseases, the combination of various medications, poor medication compliance, and other factors. Global Trigger Tool (GTT) is a new method for identifying ADEs, introducing the concept of a trigger, that is, clues including abnormal laboratory values, reversal drugs, and clinical symptoms that may suggest ADEs, and specifically locating information related to ADEs in the medical record to identify ADEs. The aim of this study was to establish a GTT-based trigger tool for adverse medication events in elderly patients and to investigate the risk variables associated with such events.MethodsThe triggers were identified by reviewing the frequency of ADEs in elderly patients in Sichuan, China, retrieving relevant literature, and consulting experts. A retrospective analysis was carried out to identify adverse medication occurrences among 480 elderly inpatients in Sichuan People’s Hospital.ResultsA total of 56 ADEs were detected in 51 patients (10.62%), 13.04 per 1,000 patient days, and 11.67 per 100 admissions. The overall positive predictive value (PPV) of the triggers was 23.84, and 94.64% of ADEs caused temporary injury. Gastrointestinal system injury (27.87%) and metabolic and nutritional disorders (24.53%) were the primary organ-systems affected by ADEs. The majority of ADEs were caused by drugs used to treat cardiovascular diseases. 71.43% of ADE occurred within 2 days of administration and the risk factor analysis of ADE revealed that the number of medicines had a significant correlation.ConclusionThis study demonstrated GTT’s value as a tool for ADEs detection in elderly inpatients in China. It enhances the level of medication management and comprehensively reflects the situation of ADE of the elderly

Analysis of Aroma Components of Red Jujube from Different Origins Based on HS-SPME-GC-MS and Chemometrics

To compare the volatile flavor characteristics of red jujube from different origins, volatile aroma components of jujube fruit from five origins (Xinzheng, Lingbao, Yulin, Hotan and Dezhou) were analyzed by headspace solid-phase microextraction combined with gas chromatography mass spectrometry. The results showed that a total of 51 compounds were identified, among which the most volatile compounds were contained in Xinjiang Hotan jujube. Combined with multivariate statistical analysis, the differences in the overall volatile flavor substances of red jujube from different origins could be well distinguished. Under the conditions of satisfying the variable importance in projection>1 and P<0.05, 13 differential characteristic aroma substances, including methyl caproate, methyl decanoate, hexanal, and benzaldehyde, were screened out from red jujube samples, which imparted unique almond, sweet, and fruity flavors to red jujube. The results of this study clarify the chemical substance basis of the aroma quality of red jujube from different origins, provide a new idea for the origin tracing study of red jujube, and further provide a scientific basis for the rational processing and utilization of jujube fruit resources