Deformation characteristics and damage ontologies of soft and hard composite rock masses under impact loading

As one of the most common occurring geological landforms in deep rock formations, the dynamic mechanical properties of layered composite rock bodies under impact loading have been widely studied by scholars. To study the dynamic properties of soft and hard composite rocks with different thickness ratios, this paper utilizes cement, quartz sand and gypsum powder to construct soft and hard composite rock specimens and utilizes a combination of indoor tests, numerical calculations, and theoretical analyses to investigate the mechanical properties of soft and hard composite rock bodies. The test results reveal that:(1) When the proportion of hard rock increases from 20% to 50%, the strength of the combined rock body increases by 69.14 MPa and 87 MPa when the hard rock face and soft rock face are loaded, respectively;however, when the proportion of hard rock is the same, the compressive strength of the hard rock face impact is 9%-17% greater than that of the soft rock face impact;(2) When a specimen of soft and hard combined rock body is subjected to impact loading, the damage mode involves mixed tension and shear damage, and the cracks generally first appear at the ends of the specimen, then develop on the laminar surface from the impact surface, and finally end in the overall damage of the soft rock part. The development rate and the total number of cracks in the same specimen when the hard rock face is impacted are significantly greater than those when the soft rock face is impacted;(3) By introducing Weibull’s statistical strength theory to establish the damage variables of soft-hard combined rock bodies, combined with the DP strength criterion, the damage model and the Kelvin body are concatenated to obtain a statistical damage constitutive model, which can better fit the full stress-strain curve of soft-hard combined rock body specimens under a single impact load.

Determination of Ten Kinds of Alpha-2 Agonists Residues in Animal Derived Food by UHPLC-Triple Quadrupole/Composite Linear Ion Trap Mass Spectrometry

[Objectives]The paper was to establish an ultra high performance liquid chromatography-quadrupole/linear ion trap complex mass spectrometry for the determination of 10 kinds ofα2-receptor agonists in animal derived food.[Methods]The samples were extracted with sodium carbonate buffer solution and ethyl acetate,and analyzed by mass spectrometry after solid phase extraction and high performance liquid chromatography separation.[Results]Ten kinds ofα2-receptor agonists showed a good linear relationship in the range of 1-100μg/mL,with the average recovery of over 69%and the relative standard deviation less than 8.32%.The detection limit of 10 kinds of α_(2)-receptor agonists was up to 1μg/kg.[Conclusions]The method has good selectivity and strong anti-interference ability,and can meet the requirements of 10 kinds ofα2-receptor agonists residues in animal derived food.

Nylon 6-cellulose composite hosted in a hypodermic needle: Biofluid extraction and analysis by ambient mass spectrometry in a single device

This study proposes a hypodermic needle(HN)as a sorbent holder and an electrospray(ESI)emitter,thus combining extraction and analysis in a single device.A novel nylon 6-cellulose(N6-Cel)composite sorbent is proposed to extract methadone from oral fluid samples.The cellulosic substrate provides the composite with high porosity,permitting the flow-through of the sample,while the polyamide contributes to the extraction of the analyte.The low price of the devices(considering the holder and the sorbent)contributes to the affordability of the method,and their small size allows easy transportation,opening the door to on-site extractions.Under the optimum conditions,the analyte can be determined by high-resolution ambient ionization mass spectrometry at a limit of detection(LOD)as low as 0.3 mg/L and precision(expressed as relative standard deviation,RSD)better than 9.3%.The trueness,expressed as relative recovery(RR),ranged from 90%to 109%.As high-resolution mass spectrometers are not available in many laboratories,the method was also adapted to low-resolution spectrometers.In this sense,the direct infusion of the eluates in a triple quadrupole-mass spectrometry provided an LOD of 2.2 mg/L.The RSD was better than 5.3%,and the RR ranged from 96%to 121%.

Exploring overweight and obesity beyond body mass index:A body composition analysis in people with and without patellofemoral pain

Background:We compared body mass index(BMI),body fat,and skeletal muscle mass between(1) a mixed-sex nonathletic cohort of people with patellofemoral pain(PFP) and pain-free people,and(2) a nonathletic cohort of people with PFP and pain-free people subgrouped by sex(i.e.,men and women with PFP vs.pain-free men and women).Methods:This cross-sectional study included 114 people with PFP(71 women,43 men) and 54 pain-free controls(32 women,22 men).All participants attended a single testing session to assess body composition measures,which included BMI,percentage of body fat(%BFBioimpedance),and skeletal muscle mass(both assessed by bioelectrical impedance analysis),and percentage of body fat(%BFskinfoid)(assessed by skinfold caliper analysis).A one-way univariate analysis of covariance(age and physical activity levels as covariates) was used to compare body composition measures between groups(i.e.,PFP vs.pain-free group;women with PFP vs.pain-free women;men with PFP vs.pain-free men).Results:Women with PFP presented significantly higher BMI,%BFBiompedance,and %BFSkinfold,and lower skeletal muscle mass compared to pain-free women(p≤0.04;effect size:-0.47 to 0.85).Men with PFP and men and women combined had no differences in BMI,%BFBioimpedance,%BFSkinfold,and skeletal muscle mass compared to their respective pain-free groups(p> 0.05).Conclusion:Our findings indicate that BMI and body composition measures should be considered as part of the evaluation and management of people with PFP,especially in women,who have demonstrated higher BMI and body fat and lower skeletal muscle mass compared to pain-free controls.Future studies should not assess body composition measures in a mixed-sex population without distinguishing men participants from women participants.

Experimental determination of grain density function of AZ91/SiC composite with different mass fractions of SiC and undercoolings using heterogeneous nucleation model

The grain density,Nv,in the solid state after solidification of AZ91/SiC composite is a function of maximum undercooling,ΔT,of a liquid alloy.This type of function depends on the characteristics of heterogeneous nucleation sites and number of SiC present in the alloy.The aim of this paper was selection of parameters for the model describing the relationship between the grain density of primary phase and undercooling.This model in connection with model of crystallisation,which is based on chemical elements diffusion and grain interface kinetics,can be used to predict casting quality and its microstructure.Nucleation models have parameters,which exact values are usually not known and sometimes even their physical meaning is under discussion.Those parameters can be obtained after mathematical analysis of the experimental data.The composites with 0,1,2,3 and 4wt.% of SiC particles were prepared.The AZ91 alloy was a matrix of the composite reinforcement SiC particles.This composite was cast to prepare four different thickness plates.They were taken from the region near to the thermocouple,to analyze the undercooling for different composites and thickness plates and its influence on the grain size.The microstructure and thermal analysis gave set of values that connect mass fraction of SiC particles,and undercooling with grain size.These values were used to approximate nucleation model adjustment parameters.Obtained model can be very useful in modelling composites microstructure.

Research on inspection of stability of subsiding area in composite rock-mass roadway

The research concentrates mainly on the development of failure process in composite rock-mass through acoustic emission, convergence inspection, stress measurement, subside area measurement, level measurement in the process of stability and safety monitoring as well as inspecting of subside area in composite hard rock. In terms of the modern signal analysis technology, various aspects are discussed. The monitoring result and the stability of rock mass can be synthetically evaluated and inferred, and the location of acoustic origin according to the acoustic emission regularity can be successfully detected. Finally the key factors of the deformation can be inferred from in subside area.

Longitudinal changes in body weight of breastfeeding mothers in the first year after delivery and its relationship with human milk composition:a combined longitudinal and cross-sectional cohort study

Objective:Postpartum weight retention(PPWR)is a common problem among women after childbirth.The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition,including macronutrients,leptin,and adiponectin.Methods:The study included a longitudinal cohort(122 mothers),and a cross-sectional cohort(37 mothers).The human milk,maternal weight,and dietary surveys were collected in the longitudinal cohort at different follow-up time points(1-14 days postpartum,2-4 months postpartum,5-7 months postpartum,and 12-17 months postpartum).The maternal body weight was analyzed using the responses in the survey questionnaires.A milk analyzer based on the mid-infrared spectroscopy(MIRS)was used to determine milk composition,and nutrition analysis software evaluated dietary intakes.In the cross-sectional cohort,participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body composition.Maternal body composition was measured by bioelectrical impedance analysis(BIA),while ELISA analyzed leptin and adiponectin in milk and serum.Results:At 5-7 months postpartum,the PPWR of breastfeeding mothers was(2.46±3.59)kg.At 12-17 months postpartum,the PPWR was(0.98±4.06)kg.PPWR was found to be negatively correlated with milk fat content within 14 days postpartum and positively correlated at 2-4 months postpartum.In addition,the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in milk.Plasma leptin was positively correlated with the mother’s body weight,body mass index(BMI),FAT percentage,and body fat mass,while plasma adiponectin did not correlate with any parameter.The results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or milk.Conclusions:Breastfeeding mothers may retain considerable weight gain one year after delivery.Human milk composition may be related to changes in maternal body weight.Leptin and adiponectin in breast milk and leptin in plasma are associated with the maternal body composition.This study supports the notion that maternal nutritional status may affect offspring health through lactation,and future research should focus on exploring weight management of postpartum mothers.

Muscle Mass Is Associated with Depression in Adolescents and Young Adults

Background and Aims: The study aims to explore the association between body composition and depression in adolescents and young adults. Methods: A random cluster sampling method was used to select 41 age-matched indi-viduals (aged 11 - 30) as a non-depressive control group. The Department of Psychology at the Affiliated Hospital of Youjiang Medical University for Na-tionalities recruited 27 depressive patients within the same age range. Bioelec-trical impedance analysis measured body composition, while SCL-90, SAS, and SDS were employed for depression diagnosis. Logistic regression analysis was conducted to assess the relationship between body composition and de-pression scores. Results: The Depression Group exhibited higher levels of fat mass (p Conclusion: Depression is associated with age, gender, and muscle mass in adolescents and young people. Proper exercise and a healthy diet can increase muscle mass, thereby reducing fat mass and, as a result, reducing the prevalence of depression.

A New Interpretation of the Higgs Vacuum Potential Energy Based on a Planckion Composite Model for the Higgs

We present a new interpretation of the Higgs field as a composite particle made up of a positive, with, a negative mass Planck particle. According to the Winterberg hypothesis, space, i.e., the vacuum, consists of both positive and negative physical massive particles, which he called planckions, interacting through strong superfluid forces. In our composite model for the Higgs boson, there is an intrinsic length scale associated with the vacuum, different from the one introduced by Winterberg, where, when the vacuum is in a perfectly balanced state, the number density of positive Planck particles equals the number density of negative Planck particles. Due to the mass compensating effect, the vacuum thus appears massless, chargeless, without pressure, energy density, or entropy. However, a situation can arise where there is an effective mass density imbalance due to the two species of Planck particle not matching in terms of populations, within their respective excited energy states. This does not require the physical addition or removal of either positive or negative Planck particles, within a given region of space, as originally thought. Ordinary matter, dark matter, and dark energy can thus be given a new interpretation as residual vacuum energies within the context of a greater vacuum, where the populations of the positive and negative energy states exactly balance. In the present epoch, it is estimated that the dark energy number density imbalance amounts to, , per cubic meter, when cosmic distance scales in excess of, 100 Mpc, are considered. Compared to a strictly balanced vacuum, where we estimate that the positive, and the negative Planck number density, is of the order, 7.85E54 particles per cubic meter, the above is a very small perturbation. This slight imbalance, we argue, would dramatically alleviate, if not altogether eliminate, the long standing cosmological constant problem.

Monitoring and analysis of nonlinear dynamic damage of transport roadway supported by composite hard rock materials in Linglong Gold Mine

The study concentrates mainly on the development of failure process incomposite rock mass. By use of acoustic emission (AE), convergence inspection, pressure monitoring,level measurement techniques and the modem signal analysis technology, as well as scan electronmicroscopy (SEM) experiment, various aspects of nonlinear dynamic damage of composite rock masssurrounding the transport roadway in Linglong gold mine are discussed. According to the monitoringresults, the stability of the rock mass can be synthetically evaluated, and the intrinsic relationbetween the damage and the characteristic parameters of acoustic emission can be determined. Thelocation of the damage of rock mass can also be detected based on the acoustic emission couplemonitoring signals. Finally, the key factors which influence the stability of the transport roadwaysupported by composite hard rock materials are found out.

Corrosion Behavior of Alumina Reinforced Aluminium (6063) Metal Matrix Composites

The influence of alumina volume percent and solution heat-treatment on the corrosion behaviour of Al (6063) composites and its monolithic alloy in salt water, basic and acidic environments is investigated. Al (6063) – Al2O3 particulate composites containing 6, 9, 15, and 18 volume percent alumina were produced by adopting two step stir casting. Mass loss and corrosion rate measurements were utilized as criteria for evaluating the corrosion behaviour of the composites. It is observed that Al (6063) – Al2O3 composites exhibited excellent corrosion resistance in NaCl medium than in the NaOH and H2SO4 media. The unreinforced alloy exhibited slightly superior corrosion resistance than the composites in NaCl and NaOH media but the composites had better corrosion resistance in H2SO4 medium. Furthermore, solution heat-treatment resulted in improved corrosion resistance for both the composites and the unreinforced alloy while the effect of volume percent alumina on corrosion resistance did not follow a consistent trend.

Tribological stability of particle reinforced aluminum matrix composites in braking

The tribological stability of particle reinforced aluminum matrix composites in braking was studied. Considering the requirements of the intention of present transportation field, high braking pressure and high initial braking rotating speed, as well as different reinforcement volume fractions were selected. The results indicate that under a systematic comparison with traditional braking material of cast iron, SiC particulate reinforced aluminum material composites (PRAMC) can retain stable friction coefficient in various braking pressures and rotating speeds. Even in a concrete course of braking, PRAMC can also maintain friction coefficient with little fluctuation. The existence of a uniform mass transfer layer adhering to the contact surface is an important prerequisite for maintaining a stable friction coefficient.

GLOBAL COMPOSITE ELEMENT ITERATION FOR ANALYSIS OF SEEPAGE FREE SURFACE

As one of the most difficult topics in rock mass hydromechanics, seepage free surface plays an important part in slope stability researches. Based on analysis of numerical methods to solve seepage free surface, global composite element iteration (GCEI) is presented in this paper. FEM program is made by using GCEI. Calculation shows that not only the program is simple using GCEI, but also the tolerance is higher after 5 iterations.

Relationship of Food Craving Behavior with Body Mass Index and Body Composition in Reproductive Age Females

Objective: To estimate the relationship of Food Craving (FC) behavior with females’ Body Mass Index (BMI), and body-composition. Design, setting and participants: A cross-sectional study of 302 reproductive-age women from middle-socioeconomic class was conducted at the Health & Occupational-Environmental Laboratory. Variable Measures: A FC behavior questionnaire (FCQ) was designed and validated in 151 female subjects. This questionnaire evaluated five dimensions: FC-leisure, FC-psychological reactance, FC-depression, FC-anxiety/stress, and FC-anger. Dependent variables were Body Mass Index (BMI, kg/m2) and the body fat mass. Interventions: A second group of 151 women completed the FCQ. Anthropometrical variables were recorded using the International Society for the Advancement of Kinanthropometry procedure. Analysis: A multiple regression-analysis using STAT- ISTICS version 7 was performed to determine the relationship of FC behavior with anthropometrical variables described. Results: We demonstrated that 98.7% of women had FC behavior. Women with higher BMI had higher scores of FC-depressions (p = 0.02) and FC-anger (p = 0.007). Food craving behavior (p < 0.0008), and food psychological-reactance (p = 0.006), were positive predictors of BMI;food psychological reactance was also a positive predictor of upper and lower-body fat mass (p = 0.005) and (p = 0.008), respectively. Conclusion and Implications: The food craving behavior is a common problem in the female population. Food psychological reactance, in addition to another affective alteration that present the population of women are predictor variables for the increase in BMI and in body-fat mass. It is important that health professionals are aware of the affective states of their patients.

Effect of Structural Parameters on the Performance of NS High-efficiency Composite TraysⅠ.The Effect of Aperture and Opening Ratio on NS High-efficiency Composite Trays

In this paper,the structure and characteristics of the NS high-efficiency composite trays based on the doublelayer aperture jet sieve plate and compositely structured packing were investigated.The effect of aperture and opening ratio of plate on the fluid dynamics of the NS high-efficiency composite trays,such as the dry tray pressure drop,the wet tray pressure drop,the entrainment,the froth height,the leakage and mass transfer characteristics,were investigated.As a result, the low pressure drop,the high efficiency and the high capacity are the main advantages of the NS high-efficiency composite trays compared to other types of trays.According to this study,small aperture is useful for reducing the pressure drop and entrainment with a high mass transfer efficiency;while large aperture can achieve high capacity and efficiency in a broader operating range at the same pressure drop and entrainment.

Elemental Compositions and Chemical Mass Closure of Fine Particulate in an Animal Feeding Operation Facility and Its Vicinity

Particulate matter (PM) emissions from animal feeding operations (AFOs) have been considered as an important contributor to ambient PM in rural areas. Investigation of the chemical compositions of PM2.5 inside and in the vicinity of AFOs can enhance our understanding of the AFO emissions impact on ambient PM characteristics. This year-long field study was conducted on a commercial egg production farm to investigate ambient PM chemical compositions as impacted by the air emissions from the production houses. The PM2.5 samples were collected from five sampling stations (one in-house station and four ambient locations in four wind directions). The trace elements, major ions, organic carbon (OC) and element carbon (EC) were analyzed by X-ray florescence (XRF), ion chromatography (IC), and thermo-optical analyzer, respectively. There were significant differences in elemental compositions between PM samples from in-house station (ST1) and ambient stations (ST2-ST5). The chemical mass balance analysis revealed that OC accounted for above 50% of PM2.5 mass at in-house and ambient stations;NH4+, SO42-, and NO3- accounted for about 40.0% of the total PM2.5 mass in ambient locations and for only 12% of the total PM2.5 mass in house. The measured PM2.5 masses agreed with the sums of the masses of chemical compositions at all stations except for the in-house station. Knowledge gained from this study, with additional consideration of NH3 concentrations and emissions, will lead to better understanding of PM2.5 source and formation, fate and transport, and their atmospheric dynamics.

Characteristics of Body Composition and Relationship between Muscle Mass and Muscle Strength among Elderly Women in Different Age Groups

Age-related changes in the body composition of older adults differ among age groups. The purpose of the present study was to clarify the characteristics of body compositions in young (age, 65 - 74 years;yE group) and old (age, ≥75 years;oE group) elderly women, and compare the relationship between muscle mass and strength in elderly women with that in young women for preventing motor function loss in older adults. A total of 30 elderly and 45 young women aged ≥ 65 and 19 - 22 years, respectively, participated in this study. The participants underwent body composition measurement via bioelectrical impedance analysis and examinations of handgrip and leg muscle strength. The age-related body composition changes varied among age groups. Compared with young women, fat-free mass (FFM) in the yE group did not decrease significantly;however, fat mass (FM) and waist-hip ratio (WHR) were significantly greater. Compared with the yE group, decreases in FFM, FM, and WHR in the oE group were significant;furthermore, the decrease in FM measurements was attributed to the loss of FM in the trunk and limbs (upper and lower). The measurement results suggested that the greater FM decrease in the oE group was characterized by decreases in both visceral and subcutaneous fat. In the yE group, the muscle mass was comparable to that in young women;however, there was a remarkable reduction in the lower-limb muscle mass (9% - 10%). In the oE group, muscle mass was reduced in all body parts, including upper and lower limbs and trunk. In young women, significant positive correlations between muscle mass and muscle strength in the upper and lower limbs were observed. No such correlations in the lower limbs were found in elderly women, indicating that muscle mass is not proportionally reflected in muscle strength. In conclusion, for improving and maintaining the health of elderly women, especially those above the age of 75 years, it is important to maintain muscle mass, including muscle strength, and prevent the loss of muscle quality.

Sweat Rate and Electrolyte Composition in Young Women of Varying Body Mass Indices during Moderate Exercise

Sweat is a hypotonic fluid excreted by sweat glands to cool the body. There are conflicting reports on whether or not body composition has an effect on thermoregulatory responses especially during exercise. This study was aimed at determining and comparing sweat rate and electrolyte composition in underweight (BMI BMI 30 kg/m2) during moderate exercise. Forty women (19 - 25 years) were used during this study after assessing their health status. They were stratified for BMI with each group having a total of ten women. It was ensured that all the women used in the study were euhydrated before commencing the research. Before sweat collection, the treadmill was calibrated according to the Bruce Treadmill Protocol. Sweat samples were obtained with a sweat suction apparatus from a 120 cm2 circular area marked on the skin of the face and neck, after a 15 minute fast walk on a treadmill at an inclination of 15° and at a speed of 4.2 km/h at 27°C room temperature. The time at which sweating commenced in the subjects was recorded. Sweat rate (L/hour) was calculated using the formula: sweat rate (L/hr) = (pre-exercise body weight - Post-exercise body weight)/exercise duration. Each sweat sample was collected and analysed immediately. The results showed that obese women had a significantly (P < 0.05) higher sweat rate and underweight women had a significantly (P < 0.05) lower sweat rate than all the other groups. Furthermore, subjects with a high body surface area showed significantly higher sweat rates compared to subjects with lower body surface area. Sweat electrolyte composition did not change in all BMI groups. In conclusion, obese subjects are more likely to develop fluid imbalances than underweight and normal weight subjects during moderate exercise. Also, underweight women might be at a thermoregulatory disadvantage because of their reduced body fat and body surface area.

Composite Higgs Boson in the Unified Subquark Model of All Fundamental Particles and Forces

In the unified subquark model of all fundamental particles and forces, the mass of the Higgs boson in the standard model of electroweak interactions (mH) is predicted to be about (where mw is the mass of the charged weak boson), which agrees well with the experimental values of 125 - 126 GeV recently found by the ATLAS and CMS Collaborations at the LHC. It seems to indicate that the Higgs boson is a composite of the iso-doublet subquark-antisubquark pairs well described by the unified subquark model with either one of subquark masses vanishing or being very small compared to the other.