Theoretical and numerical research on the dynamic launch response of carbon fiber composite cartridges

Understanding the dynamic response of composite material cartridges during the firing process is of great significance for improving their reliability and safety.A theoretical model describing the dynamic response of composite material cartridges is established based on the thick-walled cylinder theory and rate-dependent constitutive model of composite materials.The correctness of the theoretical model is validated through finite element simulations of cartridge deformation.The influence of chamber pressure and cartridge wall thickness on the cartridge's deformation process and stress distribution is analyzed.The results indicate that the primary deformation of composite material cartridges inside the chamber is elastic deformation.Compared to metal cartridges,composite material cartridges require higher pressure for touching-chamber and are more prone to developing gaps after unloading to ensure smooth extraction.During the deformation process,the touching-chamber behavior of the cartridge can improve the stress distribution.Under the same chamber pressure,the touching-chamber behavior can reduce the circumferential stress by approximately 30%.The inner wall surface of the cartridge is a critical area that requires attention.The touching-chamber behavior can be facilitated by appropriately reducing the cartridge wall thickness while ensuring overall strength.This study can provide guidance for the optimization design of composite material cartridges.

DYNAMIC CHARACTERISTICS OF LARGE FLOW RATING ELECTROHYDRAULIC PROPORTIONAL CARTRIDGE VALVE

A kind of cartridge servo proportional valve is discussed, which can be used for controlling large flow rate with high performance. By analyzing the structure principle of the valve, the transfer fimction of the valve is derived. With the transfer function, some structure elements that may affect its performance are investigated. Through the numerical simulation and test study, some principles of optimality and effective methods for improving the dynamic performance of the valve are proposed. The test results conform to the results of the theoretical analysis and simulation, which proves the correctness of the study and simulation works. The paper provides theoretical basis for engineering applications and series expanding design works

Fractal Dimension of Pore Structure of Combustible Cartridge Cases

A fractal pore structure model of combustible cartridge cases was established by virtue of the fractal geometry. Pore structure information, such as backbone fractal dimension and pore fractal dimension, of four kinds of combustible cartridge case were obtained by mercury intrusion porosimetry (MIP) . The formation mechanism of fractal pore structure of combustible cartridge was studied. The results show that the backbone fractal dimension consists of the component and influenced by the component number and size of components; the pore percolation fractal dimension reflects the pore structures of components; and the fractal dimension of pore structure is positively relative to the tensile strength of combustible cartridge case.

Strain concentration caused by the closed end contributes to cartridge case failure at the bottom

Ruptures at the bottom of cartridges are a common cause of failure of ammunitions,which directly threatens the safety of weapons and shooters.Based on plastic tube theory,this study analyses the radial and axial deformation of a cartridge,considering the radial constraint of the closed end at the bottom of the cartridge.Owing to the influence of the closed end,the bottom of a cartridge does not establish complete contact with the chamber.Owing to strain concentration in the non-contact area,this area is more amenable to the occurrence of cartridge rupture.This theory predicts the location of the fracture more accurately than the traditional theory.The maximum axial deformation of a cartridge comprises bending and friction deformation.The maximum strain at the bottom of the cartridge increased by 135%owing to the introduction of bending strain caused by the closed end.The strain distribution of a cartridge was measured using digital image correlation technology,and the measured result was consistent with the predicted results of the bending deformation theory and rupture case.The effects of wall thickness,radial clearance,friction coefficient,and axial clearance on the axial deformation of the cylinder were studied.Increasing the wall thickness and reducing radial clearance were found to reduce bending deformation;furthermore,lubrication and reduction in axial clearance reduce frictional deformation,which in turn reduce cartridge rupture.

Effect of hemoperfusion cartridge on different internal environmental indicators

BACKGROUND:This study aimed to observe the effect of hemoperfusion(HP) cartridge on different internal environment indicators at different time points in patients with acute blood poisoning and to find alternative indicators for the detection of blood poisoning.METHODS:The levels of internal environment indicators(blood pH,P_vCO_2,P_vCO_2,blood lactate,potassium,free calcium,bicarbonate,and blood glucose) before and after HP treatment were recorded for patients with acute poisoning at time points of 30 minutes and 120 minutes.After calculating the difference value 5,the statistical software was used to analyze the statistical difference of the influence caused by HP cartridge at two time points.According to the formula,adsorption rate%=(a-v)/a×100,the adsorption rate of each indicator was calculated respectively.RESULTS:The difference of indicators at different time points in inlet and outlet such as blood glucose,free-calcium,and lactate was statistically significant(P<0.05),but the difference in indicators such as pH,P_vCO_2,P_vO_2,potassium,sodium,and bicarbonate was not statistically significant(P>0.05).CONCLUSION:During HP treatment,the indicators of blood glucose,free-calcium and lactate were significantly affected by HP cartridge,and the effect varies with time.

Theoretical and numerical investigations on the headspace of cartridge cases considering axial deformation and movement

The cartridge case headspace is the axial clearance between the cartridge and bolt of an automatic weapon,and influences the reliability and security of the weapon.Accordingly,theoretical and numerical studies were conducted to analyze the dynamic response of cartridge cases during internal impact considering the initial radial clearances between the cartridge case and chamber.A theoretical model was proposed to predict the cartridge case headspace considering both the deformation and movement of the cartridge case and confirmed by the results of nonlinear finite element simulations.The differences between the results of the conventional static model and the dynamic model were then comprehensively evaluated.The effects of the angle between the cartridge and chamber,the cartridge case material,and the intermal impact pressure on the predicted headspace value were also analyzed.The dynamic response of the cartridge case predicted by the dynamic model was more accurate than that predicted by the conventional static model.The internal impact pressure,pressure change rate,and cartridge material were all found to affect the predicted headspace.

An experimental and numerical approach-characterisation of power cartridge for water-jet application

Power Cartridges are pyrotechnic devices where hot combustion gases utilized to do mechanical work for disruption of suspected Improvised Explosive Devices(IEDs). It plays a vital role either in destroying the suspicious object or making them non-functional by generating the gas pressure on burning of propellant against the water column inside the barrel, Present work is focused on characterisation,numerical solution such as deformation; strain; stress using FEM(Finite Element Method), design qualification, performance and evaluation of power cartridge for disruptor application. Experimental trials for pressure-time(P-t) measurement in closed vessel(CV), various electrical parameters like all fire current(AFC), no fire current(NFC) and ignition delay have been measured. Further, mechanical properties for brass material have been determined. An attempt has been made to characterise the power cartridge by FEM and carrying out the experiments for water-jet application.

Purification of Astaxanthin from Laminaria japonica by Ionic Liquid-based Monolithic Cartridge

An effective and accurate method was developed for the extraction of astaxanthin from Laminariajapo- nica with subsequent separation by ionic liquid-based monolithic cartridge. The optimized extraction conditions in- cluding extraction solvent（ethanol）, extraction time（90 min） and ultrasonic power（75 W） were obtained by systema- tical investigation. Chromatographic analysis was performed on a C18 column with ultraviolet（UV） detection at 476 nm, and a solution consisting of methanol/acetonitrile/H2O/dichloromethane（83：6：6：5, volume ratio） was used as the mobile phase at a flow rate of 0.7 mL/min. After ionic liquid-based monolithic solid phase extraction, 17.82 μg/g as- taxanthin was obtained from Laminaria japonica. This ionic liquid-based monolithic cartridge exhibits high affinity and selectivity for astaxanthin, and it can be potentially used as the stationary phase of high performance liquid chromatography（HPLC）.

Design of a 70 MPa Two-Way Proportional Cartridge Valve for Large-Size Hydraulic Forging Press

For an ultra-high-pressure hydraulic transmission system of a large-size hydraulic forging press(LHFP),a 70 MPa two-way proportional cartridge valve has been developed to improve the power weight ratio of the hydraulic forging press.In this study,a nominal diameter 25 mm(DN25)cartridge valve is taken as the research object.A longer concentric cylindrical annular gap is set to effectively prevent the ultra-high-pressure oil from flowing to the pilot stage and a seated valve structure is set to form the linear sealing zone in the closing state of the main valve port.Electric-displacement feedback is adopted to realize precise control of the main valve port flow and the features of this valve are investigated.In order to verify the strength and static and dynamic characteristics,the finite element model and a simulation model of the valve proposed above are built.There is a little deformation which does not affect the main valve spool movement,and the main valve port flow meets the design demands.Then,the prototype of DN2570 TPCV is manufactured and a ultra-high-pressure experimental platform is developed.The experimental results show that the DN2570 TPCV designed in this study has the advantage of fast response,high control precision,and low leakage,which can meet the requirements of LHFPs.

Response of Different Varieties of Red Cartridge Kiwifruit to Temperature and Precipitation in Growth Stages

The responses of Hongyang,Donghong and Jinhong varieties to temperature and precipitation were analyzed by observing the growth stages of different kiwifruit varieties in Longhe red cartridge kiwifruit base of Liuzhi Special Zone of Guizhou Province in 2021 and combining with the meteorological data of temperature and precipitation in the base in the same period.The results showed that Hongyang,Donghong and Jinhong all sprouted on February 1,and had the same response to temperature and precipitation.From germination to leaf spreading stage,Hongyang and Donghong had the same response to precipitation,while Donghong and Jinhong had the same response to temperature,but Jinhong needed 32.5 mm precipitation to meet its growth and development.From leaf spreading stage to budding stage,Hongyang and Donghong had similar responses to temperature and precipitation,while Jinhong needed average daily temperature of 16.5℃and precipitation of 2.1 mm.The responses of the three varieties from budding to flowering to temperature and precipitation were consistent.From flowering to fruiting,Hongyang needed 19.9℃temperature and the least precipitation,while Jinhong needed the lowest temperature and the maximum precipitation.Donghong's response to temperature and precipitation was between Hongyang and Jinhong.During the period from fruit setting to fruit ripening and picking,Hongyang needed the least temperature and precipitation,while Donghong and Jinhong had the same response to temperature and precipitation.In the key period of fruit expansion of the three kiwifruit varieties in 2021,temperature and precipitation were the most suitable for fruit expansion.In short,red cartridge kiwifruit has a good response to temperature and precipitation in different growth stages,and it requires 201 d for Hongyang variety from germination to maturity and picking,211 d for Donghong variety and 218 d for Jinhong variety.

Effect of Methanol in the Wash-Solvent Bottle and the OnGuard Cartridges on the Determination of Different Anions Using Ion Chromatography

The effect of using methanol in the flush-solvent bottle of the auto-sampler of Ion Chromatograph on the determination of sulfate ions was studied using AS11-HC 2 mm analytical column. The use of 50% methanol in the flush solvent bottle results in overestimation of sulfate concentration by 18%. However, the use of 10% methanol instead of 50% did not show such error in the determination of sulfate using the same column. Furthermore, the effect of using OnGuard-RP and OnGuard-P cartridges for sample pretreatment on the determination of different anions was also studies using AS14-HC 2 mm analytical column. The results indicate that using OnGuard-RP cartridge caused the concentration of fluoride, bromide, nitrate, phosphate and sulfate ions to be underestimated, whereas the concentration of chloride ions to be overestimated. The error in the determination of fluoride, bromide, nitrate, phosphate sulfate, and chloride was found to be 40.0%, 26.0%, 22.8%, 26.8%, 18.0%, and 25.0% of the certified standard concentration, respectively. It was also found that the use of OnGuard-P cartridge resulted in underestimation of fluoride, chloride, bromide, nitrate, phosphate, and sulfate by 60.0%, 40.0%, 82.0%, 87.2%, 45.2%, and 39.0% of the certified standard concentration, respectively. These findings point out to careful corrections that should be considered in any application of ion chromatography utilizing such sample pretreatment.

Analysis of Structural State of 60/40 Brass Cartridge Case (BCC) after Being Exposed to High Pressure and Temperature of Firing

This research presents an experimental and analytical study of the structural state of the 60/40 brass cartridge case, (BCC) after being fired. The oral section of the BCC has the function of confining the gases of firing by expanding against the chamber and sealing the gases. Firing conditions, namely, high pressure and temperature, 3000 bar and 2727&#176;C, respectively, affect performance properties of the (BCC). These are confining and crack strengths. Experimental study was done on the oral section to address these effects on the structural and mechanical properties of this brass. This alloy is a 60% copper (Cu) and 40% zinc (Zn) alloy and has a two-phase structure, alpha, (α) and beta, (β). Using “before and after” comparison approach;performance properties were tested in cartridge cases prepared before and after firing. These properties are hardness, tensile strength, micro-structural and chemical composition. Comparing the tests’ results, after firing demonstrated considerable degrading in performance properties, micro-structural disorder and a remarkable deficiency in the zinc element in the brass structure. This deficiency affects the percentage of beta phase in the alloy which governs the strength of the brass. According to the required properties before firing, it was found that after firing, the brass cartridge case is not qualified for reloading.

A novel cartridge for nucleic acid extraction,amplification and detection of infectious disease pathogens with the help of magnetic nanoparticles

Nucleic acid detection(NAD)based on real-time polymerase chain reaction(real-time PCR)is gold standard for infectious disease detection.Magnetic nanoparticles(MNPs)are widely used for nucleic acid extraction(NAE)because of their excellent properties.Microfluidic technology makes automated NAD possible.However,most of the NAD microfluidic chips are too complex to be applied to point-of-care(POC)testing.In this paper,a simple-structure cartridge was developed for POC detection of infectious diseases.This self-contained cartridge can be divided into a magnetic-controlled NAE part,a valve-piston combined fluidic control part and a PCR chip,which is able to extract nucleic acid from up to 500μL of liquid samples by MNPs and finish the detection process from“sample in”to“answer out”automatically.Performance tests of the cartridges show that it met the demands of automated NAD.Results of on-cartridge detection of hepatitis B virus(HBV)demonstrated that this system has good uniformity and no cross-contamination between different cartridges,and the limit of detection(LOD)of this system for HBV in serum is 50 IU/mL.Multiplex detections of severe acute respiratory syndrome coronaviruses 2(SARS-CoV-2)with a concentration of 500 copies/mL were carried out on the system and 100%positive detection rate was achieved.

Lateral Force Characteristics of Cartridge Valve Core

The flow field of eccentric conical crevices is formed into the working process of hydraulic valves.Therefore, the valve core is readily subjected to a large lateral force which affects the dynamic response speed.Here, a new type of cartridge valve core structure is proposed to solve this problem. The numerical simulationmethod is applied to analyze the flow characteristics of clearance flow field on velocity distribution, pressuredistribution, valve core motion speed, and leakage. The results using computational fluid dynamics (CFD) showthat the guide groove is set on the surface of the cartridge valve core, increasing the connecting length of thevalve core, forming a uniform radial pressure distribution and velocity distribution, effectively reducing the lateralforce, and at the same time ensuring that the leak is not too big. These findings provide theoretical guidance anda basis for optimizing cartridge valve to reduce the occurrence of jamming and improve the response frequency.

Simulation and Experimental Study of Staple Line Reinforcement Surgery

The aim of this study was to evaluate the effectiveness of BM (basement membrane) and SIS (small intestine submucosa) composite extracellular matrix staple line reinforcement in surgical procedures through finite element modelling simulations and leak-proof performance experiments. The mechanical analyses of soft tissues with and without staple line reinforcement were performed by establishing finite element models of three tissues, namely, stomach, intestine and lungs, under the use scenarios of different anastomosis staple models;and the leak-proof performance of the staple line reinforcement was evaluated by simulating leak-proof experiments of gastric incision margins, intestinal sections, and lung incision margins in vitro. The results showed that the equivalent average stresses of the staple line reinforcement were increased by 20 kPa-68 kPa in gastric and intestinal tissues, and 8 kPa-22 kPa in lung tissues. and that the BM and SIS composite extracellular matrix staple line reinforcement could strengthen the anastomotic structure, and at the same time disperse the high stresses of the anastomosed tissues, which could effectively reduce the postoperative complications such as anastomotic bleeding and anastomotic leakage, and provide a safer and more effective optimized design for surgical mechanical anastomosis. It can effectively reduce postoperative complications such as anastomotic bleeding and anastomotic leakage, and provide a safer and more effective optimized design for surgical mechanical anastomosis.

The point-of-care-testing of nucleic acids by chip, cartridge and paper sensors

Point-of-care nucleic acid testing(POCNAT) has played an important role in the outbreak of infectious diseases(e.g., COVID-19) over recent years. POCNAT aims to realize the rapid, simple and automatic detection of nucleic acid. Thanks to the development of manufacturing technology, electronic information technology, artificial intelligence technology, and biological information technology in recent years, the development of the POCNAT device has led to significant advancement. Instead of the normal nucleic acid detection methods used in the laboratory, some novel experimental carriers have been applied, such as chips, cartridges and papers. The application of these experimental carriers has realized the automation and integration of nucleic acid detection. The entire process of nucleic acid detection is normally divided into three steps(nucleic acid extraction, target amplification and signal detection). All of the reagents required by the process can be pre-stored on these experimental carriers, without unnecessary manual operation. Furthermore, all of the processes are carried out in this experimental carrier, with the assistance of a specific control device. Although they are complicated to manufacture and precise in design,their application provides a significant step forwards in nucleic acid detection and realizes the integration of nucleic acid detection. This technology has great potential in the field of point-of-care molecular diagnostics in the future. This paper focuses on the relevant content of these experimental carriers.

Optimization of enrichment and pretreatment of low-activity radium isotopes in the open ocean

In the open ocean,radium isotopes are useful tracers of residence time and water-mass mixing.However,limited by the measurement resolution of commonly used gamma counters,the low activity of radium in the open ocean makes it necessary to enrich radium from large volumes of seawater and pretreat radium-enriched carriers prior to measurements.The commonly applied method of radium enrichment and pretreatment,however,has limitations of uneven coating of MnO_(2)on cartridges,relatively expensive cartridges,time-consuming issues during cartridge-ashing,ash loss during transfer,and changes of gamma counters efficiency caused by different ash weights.To address these issues,in this study we optimized the enrichment and pretreatment of low-activity radium prior to measurements.Firstly,we replaced commonly used acrylic cartridges with cheaper polypropylene cartridges,which took 6 h to be ashed,42 h shorter than for acrylic cartridges.Secondly,MnO_(2)-coated cartridges were prepared with a circulating hot acidic KMnO_(4)solution to ensure homogeneous coating.The radium extraction efficiency of this MnO_(2)-coated cartridge was 20%-61%higher than that prepared by directly immersing cartridges in the solution.The radium delayed coincidence counter efficiency for MnO_(2)-coated cartridge was stable with a moisture content of 0.05-1.Lastly,after ashing cartridges,instead of directly transferring the ash to a measurement vial,a mixture of hydroxylamine hydrochloride and hydrochloric acid was used to completely leach the ash for long-lived radium,followed by coprecipitation by BaSO_(4),to avoid potential loss of ash during transfer and variations in measurement geometry due to different ash weights.And the recovery of long-lived radium pretreatment was 94%-102%,which improved by 11%compared with the common method.In addition,the radium extraction efficiency of the MnO_(2)-coated cartridge varied from 3%to 4%within the in situ pump working flow rate of 4-7 L/min,which fell within the measurement errors.

学习资源标准的新发展与学习资源的发展趋势

学习资源的质量和数量直接影响着数字化学习的效果,而学习资源标准的发展又引领着资源建设和共享的实践活动的发展,是学习资源研究和应用的"制高点"。本文详细的介绍了IMS Common Cartridge和SCORM 2.0两个最新的学习资源规范的研究进展,并结合泛在学习的需求,分析和评述了它们各自的特色和不足。在此基础上,本文进一步对未来学习资源形态的可进化性、分布式、社会性、情境性、开放性、复合性等发展趋势做了简要的展望。

基于插装阀的液压缸试验台设计（英文）

根据液压缸的试验标准和现有液压缸试验台的不足,针对大型液压缸试验台要求高压、大流量的特点,设计出基于插装阀的液压缸试验台,并考虑到设计方便及经济型要求,提出加载液压缸和被测液压缸采用同一个液压源、高压系统和大流量系统并联的方案,减少了电机以及液压泵的使用数量,减小了系统功率,设计出一套自动化程度高,制造成本低,节能的液压缸试验台系统。