NUMERICAL MODELING OF MULTI-CYLINDER ELECTRO-HYDRAULIC SYSTEM AND CONTROLLER DESIGN FOR SHOCK TEST MACHINE

A high fidelity dynamic model of a high-energy hydraulically-actuated shock test machine for heavy weight devices is presented to satisfy the newly-built shock resistance standard and simulate the actual underwater explosion environments in laboratory as well as increase the testing capability of shock test machine. In order to produce the required negative shock pulse in the given time duration, four hydraulic actuators are utilized. The model is then used to formulate an advanced feedforward controller for the system to produce the required negative waveform and to address the motion synchronization of the four cylinders. The model provides a safe and easily controllable way to perform a ＂virtual testing＂ before starting potentially destructive tests on specimen and to predict performance of the system. Simulation results have demonstrated the effectiveness of the controller.

Research on the intelligent internet nursing model based on the child respiratory and asthma control test scale for asthma management of preschool children

BACKGROUND Childhood asthma is a common respiratory ailment that significantly affects preschool children.Effective asthma management in this population is particularly challenging due to limited communication skills in children and the necessity for consistent involvement of a caregiver.With the rise of digital healthcare and the need for innovative interventions,Internet-based models can potentially offer relatively more efficient and patient-tailored care,especially in children.AIM To explore the impact of an intelligent Internet care model based on the child respiratory and asthma control test(TRACK)on asthma management in preschool children.METHODS The study group comprised preschoolers,aged 5 years or younger,that visited the hospital's pediatric outpatient and emergency departments between January 2021 and January 2022.Total of 200 children were evenly and randomly divided into the observation and control groups.The control group received standard treatment in accordance with the 2016 Guidelines for Pediatric Bronchial Asthma and the Global Initiative on Asthma.In addition to above treatment,the observation group was introduced to an intelligent internet nursing model,emphasizing the TRACK scale.Key measures monitored over a six-month period included the frequency of asthma attack,emergency visits,pulmonary function parameters(FEV1,FEV1/FVC,and PEF),monthly TRACK scores,and the SF-12 quality of life assessment.Post-intervention asthma control rates were assessed at six-month follow-up.RESULTS The observation group had fewer asthma attacks and emergency room visits than the control group(P<0.05).After six months of treatment,the children in both groups had higher FEV1,FEV1/FVC,and PEF(P<0.05).Statistically significant differences were observed between the two groups(P<0.05).For six months,children in the observation group had a higher monthly TRACK score than those in the control group(P<0.05).The PCS and MCSSF-12 quality of life scores were relatively higher than those before the nursing period(P<0.05).Furthermore,the groups showed statistically significant differences(P<0.05).The asthma control rate was higher in the observation group than in the control group(P<0.05).CONCLUSION TRACK based Intelligent Internet nursing model may reduce asthma attacks and emergency visits in asthmatic children,improve lung function,quality of life,and the TRACK score and asthma control rate.The effect of nursing was significant,allowing for development of an asthma management model.

Nonlinear Modeling and Identification of Structural Joint by Response Control Vibration Test

Components of mechanical product are assembled by structural joints,such as bolting,riveting,welding,etc.Structural joints introduce nonlinearity to some engineering structures,and the nonlinearity need to be modeled precisely.To meet serious quality requirements,it is necessary to detect and identify nonlinearity of mechanical products for structural optimization.Modal test to acquire a dynamic response has been applied for decades,which provides reliable results for finite element(FE)model updating.Here response control vibration test for identification of nonlinearity is presented.A nonlinear system can be regarded as linearity for particular steady state response,and classical linear analysis tool is applicable to extract modal data for particular response.First,its applicability is illustrated by some numerical simulations.Subsequently,it is implemented on experimental setup with structural joints by shaking table.The stiffness and damping function dependent of relative displacement are fitted to describe its inherent nonlinearity.The spring and damping forces are identified by harmonic balance method(HBM)to predict output response.Based on the identified results,the procedure is recommended that it allows a reliable measurement of nonlinearity with a certain accuracy.

Novel computerized psychometric tests as primary screening tools for the diagnosis of minimal hepatic encephalopathy

Minimal hepatic encephalopathy(MHE)is a critical neurocognitive complication of decompensated liver cirrhosis and portosystemic shunting,which results in a wide range of cognitive deficits including impairments in working attention,psychomotor speed,and executive function.Current guidelines have recommended paper-and-pencil psychometric tests for the diagnosis of MHE.Most high-risk cirrhotic patients are required to be examined;however,paperand-pencil psychometric tests are neither convenient nor rapid to perform in the clinic.Recently,novel computerized psychometric tests,including the inhibitory control test,EncephalApp Stroop App,and critical flicker frequency,have been proven to be rapid,effective,and convenient methods for screening MHE in clinical practice and for identifying high-risk cirrhotic patients for further validation using rigid neuropsychometric examinations.However,diagnostic accuracy of these tests is influenced by educational background,age,and cultural differences.This review summarizes clinical evidence of the application of novel computerized psychometric tests for screening MHE.

Correlation between the Childhood-Asthma Control Test and the Criterion for Clinical Asthma Control

Setting: Three pediatric pneumatologist offices in Bucaramanga, Colombia. Objective: To establish the concordance between medical criteria and the Childhood-Asthma Control Test (cACT). Design: Study of the assessment of diagnostic technology using transverse sampling. 127 asthma patients aged between 4 and 11 years and their parents filled before clinical evaluation made by a pediatric pneumologist. Patients were classified as controlled or not controlled. Criteria validity was established comparing this classification using Cohen’s kappa and performance indicators according to ROC analysis. Results: 78% of the patients were controlled;patients who are not controlled have a higher score in cACT (mean difference: 3.25 points). Concordance among cACT subscales is acceptable (ρ = 0.554). cACT’s sensitivity was 53.6%, specificity 78.8%, positive likelihood ratio (LR+) 2.53, and negative likelihood ratio (LR-) 0.59. The best cut-off point is 15, with 98% sensitivity, a specificity of 14.3%, LR+ in 1.14, and LR- in 0.14. Conclusions: cACT is a valid tool to determine asthma control in children without replacing medical criteria or other clinical tests. In populations with difficult access to high complexity services, it is useful to decide whether urgent referral to the specialist is necessary.

Velocity plus displacement equivalent force control for real-time substructure testing

This paper employs a velocity plus displacement（V＋D）-based equivalent force control（EFC） method to solve the velocity/displacement difference equation in a real-time substructure test. This method uses type 2 feedback control loops to replace mathematical iteration to solve the nonlinear dynamic equation. A spectral radius analysis of the amplification matrix shows that the type 2 EFC-explicit, Newmark-β method has beneficial numerical characteristics for this method. Its stability limit of Ω = 2 remains unchanged regardless of the system damping because the velocity is achieved with very high accuracy during simulation. In contrast, the stability limits of the central difference method using direct velocity prediction and the EFC-average acceleration method with linear interpolation are shown to decrease with an increase in system damping. In fact, the EFC-average acceleration method is shown to change from unconditionally stable to conditionally stable. We also show that if an over-damped system with a damping ratio of 1.05 is considered, the stability limit is reduced to Ω =1.45. Finally, the results from an experiment with a single-degree-of-freedom structure installed with a magneto-rheological（MR） damper are presented. The results demonstrate that the proposed method is able to follow both displacement and velocity commands with moderate accuracy, resulting in improved test performance and accuracy for structures that are sensitive to both velocity and displacement inputs. Although the findings of the study are promising, additional test data and several further improvements will be required to draw general conclusions.

Research on Time-Synchronization-Based Test and Control System of Aeroengine

This paper presents a method of NTP-based time synchronization and a strategy of master-slave server structured time synchronization to ensure the test and control system of aeroengine to be time-synchronized. Based on time synchronization, the hierarchy and the integration of the measurement and control system of aeroengine are investigated. In result, our method is successfully applied for multiple front-end tests in a simulative altitude test facility of aeroengine.

On Distributed Concurrent Multi-Port Router Test System

This paper presents a framework of the distributed concurrent multi-port-testing test system (CMPT-TS) for IP routers under development at Sichuan Network Communication Key Laboratory. Having analyzed the actuality of concurrent testing for routers, this paper develops a distributed architecture of CMPT-TS and discusses its functional components in detail. Moreover, a new test definition language, CMPT definition language, is also introduced simply.

Meta-analysis of Xiaoxianxiong Decoction in the treatment of gastroesophageal reflux disease

Objective:To evaluate the clinical efficacy of Xiaoxianxiong Decoction in the treatment of gastroesophageal reflux disease.Methods:CNKI,Wan Fang,VIP,Sino Med,Cochrane Library and Pub were searched by computer Randomized controlled trials(RCTS)of Xiaoxianxiong Decoction in the treatment of gastroesophageal reflux disease(GERD)from the establishment of Med and other Chinese and English databases to December 2021.Literatures was screened and extracted according to the exclusion criteria,Cochranev5.1.0 bias risk assessment tool and modified Jadad scale were used to evaluate the quality of the included literatures,and Rev Man5.3 software was used for Meta-analysis.Results:(1)Eleven articles were included,including 873 patients;(2)Meta-analysis showed that the total effective rate of Xiaoxiangxiong Decoction in treating GERD was higher than that of the control group[P=0.89,I2=0%,OR=3.48,95%CI(2.29,5.30),Z=5.84,P<0.00001].Compared with other conventional western medicine therapies,acid reflux symptoms were significantly improved[WMD=-0.30,95%CI[-0.59,-0.01],Z=2.06,P=0.04(subgroup 1);WMD=-0.17,95%CI[-0.44,0.11],Z=1.18,P=0.24(subgroup 2);WMD=-0.17,95%CI[-0.44,0.11],Z=1.18,P=0.24(subgroup 2).WMD=-0.14,95%CI[-0.37,0.08],Z=1.23,P=0.22(subgroup3)];The recurrence rate was lower[OR=0.13,95%CI[0.05,0.37],Z=3.89,P<0.0001];There was no significant difference in the improvement of heartburn and retrosternal pain symptoms between the experimental group and the control group(P>0.05).Conclusion:Compared with other conventional western medicine therapies,Xiaoxianxiong Decoction has a higher total effective rate and lower recurrence rate in the treatment of Gastroesophageal reflux disease,and has certain advantages in alleviating acid reflux symptoms,but has no obvious advantages in improving heartburn and retrosternal pain symptoms.

Joints in unsaturated rocks:Thermo-hydro-mechanical formulation and constitutive behaviour

A formulation for the coupled analysis of thermo-hydro-mechanical （THM） problems in joints is first presented. The work involves the establishment of equilibrium and mass and energy balance equations. Balance equations were formulated taking into account two phases： water and air. The joint element developed was implemented in a general purpose finite element computer code for THM analysis of porous media （Code_Bright）. The program was then used to study a number of cases ranging from laboratory tests to large scale in situ tests. A numerical simulation of coupled hydraulic shear tests of rough granite joints is first presented. The tests as well as the model show the coupling between permeability and the deformation of thejoints. The experimental investigation was focused on the effects of suction on the mechanical behaviour of rock joints. Laboratory tests were performed in a direct shear cell equipped with suction control. Suction was imposed using a vapour forced convection circuit connected to the cell and controlled by an air pump. Artificial joints of Lilla claystone were prepared.Joint roughness of varying intensity was created by carving the surfaces in contact in such a manner that rock ridges of different tip angles were formed. These angles ranged from 0° （smooth joint） to 45° （very rough joint profile）. The geometric profiles of the two surfaces in contact were initially positioned in a ＂matching＂ situation. Several tests were performed for different values of suctions （200, 100, and 20 MPa） and for different values of vertical stresses （30, 60, and 150 kPa）. A constitutive model including the effects of suction and joint roughness is proposed to simulate the unsaturated behaviour of rock joints. The new constitutive law was incorporated in the code and experimental results were numerically simulated.

Standardization and Quality control parameters of Kayam Churna

Kayam Churna is proprietary ayurvedic formulation which is blend of seven ingredients which are Senna leaves(Cassia angustifolia),Black Salt,Mulethi(Glycyrrhiza glabra),Nishoth(Operculina turpethum),Ajwain(Trachyspermum ammi),Haritaki(Terminalia chebula)and Svarjikshara(Sodium bicarbonate)with Senna as a major ingredient.Standardization and stability studies play a vital role for each herbal formulation,so the research was carried out to prepare the formulation in the laboratory and to standardize the Churna,by means of its physicochemical properties,phytochemical analysis and microbiology study.The organoleptic and powdered characteristics were studied and compared with monographs.Various physicochemical analysis was carried out like bulk density,tapped density,percent compressibility,loss on drying,ash value and heavy metal determination.Phytochemical analysis was carried out to find the presence of tannins,alkaloids,glycosides,flavonoids and steroids.Microbiological analysis was evaluated using the Total Viable Count method.HPTLC Chromatographic technique was used for fingerprinting.Microscopic analysis of Formulation showed the presence of Vessels,Fibre,Calcium oxalate crystals,etc.Tannins,Alkaloids,flavonoids were found to be present in the formulation.Microbial count and all physicochemical parameters were found to be within the limits as per the WHO guidelines.Further studies can be carried out for finding out its efficacy and potency.

The relationship between controllability, optimal testing resource allocation, and incubation-latent period mismatch as revealed by COVID-19

The severe shortfall in testing supplies during the initial COVID-19 outbreak and ensuing struggle to manage the pandemic have affirmed the critical importance of optimal supplyconstrained resource allocation strategies for controlling novel disease epidemics.To address the challenge of constrained resource optimization for managing diseases with complications like pre-and asymptomatic transmission,we develop an integro partial differential equation compartmental disease model which incorporates realistic latent,incubation,and infectious period distributions along with limited testing supplies for identifying and quarantining infected individuals.Our model overcomes the limitations of typical ordinary differential equation compartmental models by decoupling symptom status from model compartments to allow a more realistic representation of symptom onset and presymptomatic transmission.To analyze the influence of these realistic features on disease controllability,we find optimal strategies for reducing total infection sizes that allocate limited testing resources between‘clinical’testing,which targets symptomatic individuals,and‘non-clinical’testing,which targets non-symptomatic individuals.We apply our model not only to the original,delta,and omicron COVID-19 variants,but also to generically parameterized disease systems with varying mismatches between latent and incubation period distributions,which permit varying degrees of presymptomatic transmission or symptom onset before infectiousness.We find that factors that decrease controllability generally call for reduced levels of non-clinical testing in optimal strategies,while the relationship between incubation-latent mismatch,controllability,and optimal strategies is complicated.In particular,though greater degrees of presymptomatic transmission reduce disease controllability,they may increase or decrease the role of nonclinical testing in optimal strategies depending on other disease factors like transmissibility and latent period length.Importantly,our model allows a spectrum of diseases to be compared within a consistent framework such that lessons learned from COVID-19 can be transferred to resource constrained scenarios in future emerging epidemics and analyzed for optimality.

Study on the Method of Antibiotic Ointment to Control Bacterial Contamination

Aim:To analyze the effective methods of antibiotic ointment to control bacterial growth,and to provide references for the research work of related personnel.Method:In this experiment,membrane filtration method combined with centrifugal precipitation method was used to complete the inspection of antibiotic ointment,and the final result was analyzed.Results:The application of membrane filtration method combined with centrifugal precipitation method to complete the test of antibiotic ointment has a significant effect.The test solution is milky white.The possibility if it can exert the effect of eliminating antibacterial components,so that Pseudomonas aeruginosa and Staphylococcus caureus can show an affecting state in the positive test tube,and colonies can be found after observation.Conclusion:The application of membrane filtration method combined with centrifugal precipitation method to complete the inspection of antibiotic ointment can achieve satisfactory results.The method is simple to operate and has high feasibility.It is worthy of further promotion and application.

Experimental prototyping of the adhesion braking control system design concept for a mechatronic bogie

The dynamic parameters of a roller rig vary as the adhesion level changes.The change in dynamics parameters needs to be analysed to estimate the adhesion level.One of these parameters is noise emanating from wheel–rail interaction.Most previous wheel–rail noise analysis has been conducted to mitigate those noises.However,in this paper,the noise is analysed to estimate the adhesion condition at the wheel–rail contact interface in combination with the other methodologies applied for this purpose.The adhesion level changes with changes in operational and environmental factors.To accurately estimate the adhesion level,the influence of those factors is included in this study.The testing and verification of the methodology required an accurate test prototype of the roller rig.In general,such testing and verification involve complex experimental works required by the intricate nature of the adhesion process and the integration of the different subsystems(i.e.controller,traction,braking).To this end,a new reduced-scale roller rig is developed to study the adhesion between wheel and rail roller contact.The various stages involved in the development of such a complex mechatronics system are described in this paper.Furthermore,the proposed brake control system was validated using the test rig under various adhesion conditions.The results indicate that the proposed brake controller has achieved a shorter stopping distance as compared to the conventional brake controller,and the brake control algorithm was able to maintain the operational condition even at the abrupt changes in adhesion condition.

Timetabling optimization of classrooms and self-study rooms in university teaching buildings based on the building controls virtual test bed platform considering energy efficiency

The energy consumption of a teaching building can be effectively reduced by timetable optimization.However,in most studies that explore methods to reduce building energy consumption by course timetable optimization,self-study activities are not considered.In this study,an MATLAB-EnergyPlus joint simulation model was constructed based on the Building Controls Virtual Test Bed platform to reduce building energy consumption by optimizing the course schedule and opening strategy of self-study rooms in a holistic way.The following results were obtained by taking a university in Xi’an as an example:(1)The energy saving percentages obtained by timetabling optimization during the heating season examination week,heating season non-examination week,cooling season examination week,and cooling season non-examination week are 35%,29.4%,13.4%,and 13.4%,respectively.(2)Regarding the temporal arrangement,most courses are scheduled in the morning during the cooling season and afternoon during the heating season.Regarding the spatial arrangement,most courses are arranged in the central section of the middle floors of the building.(3)During the heating season,the additional building energy consumption incurred by the opening of self-study rooms decreases when duty heating temperature increases.

Test results judgment method based on BIT faults

Built-in-test （BIT） is responsible for equipment fault detection, so the test data correct- ness directly influences diagnosis results. Equipment suffers all kinds of environment stresses, such as temperature, vibration, and electromagnetic stress. As embedded testing facility, BIT also suffers from these stresses and the interferences/faults are caused, so that the test course is influenced, resulting in incredible results. Therefore it is necessary to monitor test data and judge test failures. Stress monitor and BIT self-diagnosis would redound to BIT reliability, but the existing anti- jamming researches are mainly safeguard design and signal process. This paper focuses on test results monitor and BIT equipment （BITE） failure judge, and a series of improved approaches is proposed. Firstly the stress influences on components are illustrated and the effects on the diagnosis results are summarized. Secondly a composite BIT program is proposed with information integra- tion, and a stress monitor program is given. Thirdly, based on the detailed analysis of system faults and forms of BIT results, the test sequence control method is proposed. It assists BITE failure judge and reduces error probability. Finally the validation cases prove that these approaches enhance credibility.

Prospective evaluation of gastric emptying using ^(13)C-octanoic breath test in relationship with the metabolic control in patients with type 1and type 2 diabetes

The aims were to prospectively evaluate the association of glycemic control (HbAlc) with gastric emptying in newly diagnosed Type 1 diabetic patients and subjects with longterm diabetes mellitus. Furthermore, the day to day variability of gastric emptying for solids should be assessed. Methods 13 C octanoic breath tests were performed in 15 type 1 diabetic subjects on two separate days within one week. The influence of metabolic control on gastric emptying was prospectively examined over a mean of 8 months in 14 patients with newly diagnosed type 1 diabetes and 44 long term diabetic patients (type 1: n=31; type 2: n=13).Patients with longterm diabetes were stratified according to their HbA 1c at follow up (group 1: HbA 1c U7.5%, n=17; group 2 HbA 1c >7.5%, n=27). 13 C octanoic breath tests were sampled with an isotope selective non dispersive infrared spectrometer. The gastric emptying parameters were calculated using nonlinear regression analysis of the time course of 13 CO 2 exhalation:half emptying time (t 1/2 ) and lag phase (t lag ). Results The intraindividuell coefficient of variation was 17.8% for t 1/2 , and 28.2% for t lag . Mean t 1/2 and t lag in newly diagnosed type 1 diabetics were normal at baseline and were significantly increased at follow up. In patients with longterm diabetes, gastric emptying was unchanged during follow up. Gastric emptying was significant delayed in group 2 compared with group 1 at baseline and follow up respectively. There was a significant correlation between HbA 1c and t 1/2 , t lag at follow up. Conclusions 13 C octanoic breath test has a relatively good reproducibility in patients with type 1 diabetes. Gastric emptying times are already significantly increased after few months in newly diagnosed type 1 diabetes. There is a more pronounced delay of gastric emptying in longterm diabetic subjects with poor compared to patients with good metabolic control.

Current asthma control predicts future risk of asthma exacerbation： a 12-month prospective cohort study

Background The performance of asthma control test （ACT） at baseline for predicting future risk of asthma exacerbation has not been previously demonstrated. This study was designed to explore the ability of the baseline ACT score to predict future risk of asthma exacerbation during a 12-month follow-up. Methods This post hoc analysis included data from a 12-month prospective cohort study in patients with asthma （n=290）. The time to the first asthma exacerbation was analyzed and the association between baseline ACT scores and future risk of asthma exacerbation was calculated as adjusted odds ratio （OR） using Logistic regression models. Further, sensitivity and specificity were estimated at each cut-point of ACT scores for predicting asthma exacerbations. Results The subjects were divided into three groups, which were uncontrolled （U, n=128）, partly-controlled （PC, n=111）, and well controlled （C, n=51） asthma. After adjustment, the decreased ACT scores at baseline in the U and PC groups were associated with an increased probability of asthma exacerbations （OR 3.65 and OR 5.75, respectively）, unplanned visits （OR 8.03 and OR 8.21, respectively） and emergency visits （OR 20.00 and OR 22.60, respectively） over a 12-month follow-up period. The time to the first asthma exacerbation was shorter in the groups with U and PC asthma （all P 〈0.05）. The baseline ACT of 20 identified as the cut-point for screening the patients at high risk of asthma exacerbations had an increased sensitivity of over 90.0% but a lower specificity of about 30.0%. Conclusion Our findings indicate that the baseline ACT score with a high sensitivity could rule out patients at low risk of asthma exacerbations and predict future risk of asthma exacerbations in clinical practice.

Effect of solid contents on the controlled shear stress rheological properties of different types of sludge

Controlled shear stress （CSS） test was used to study the effect of solid contents on the corresponding rheological parameters for sludge. Three types of sludge with or without conditioning, including activated sludge （AS）, anaerobic digested sludge （ADS）, and water treatment residuals （WTRs）, were collected for the CSS test. Results showed that the yield stress and the cohesion energy of the sludge networks were improved with increased total suspending solid （TSS） contents in most cases. For the conditioned AS/ADS and the raw WTRs, exponential law was observed in the relationships between cohesion energy of material networks or yield stress and the TSS contents, whereas for the conditioned WTRs, only exponential law dependence was found between the parameters of shear modulus or critical strain and the TSS contents.