The Effect of the Direct Anti-Human Globulin Test on the Clinical Outcome of Patients Receiving Blood Transfusion

Objective:To study the effect of the direct anti-human globulin test on the clinical efficacy of blood transfusion patients.Methods:52 transfused patients were selected for this study,of which 26 cases with positive direct anti-human globulin tests were included in the positive group,and another 26 cases with negative direct anti-human globulin tests were included in the negative group.The apparent efficacy of the patients in the two groups after blood transfusion was compared.Results:After blood transfusion,the apparent efficacy of the negative group was significantly higher,P<0.05;in the positive group,the proportion of the predominantly multi-antibody group was the highest;after blood transfusion,the post-transfusion apparent efficacy of the simple IgG group was higher than that of the multi-antibody group,P<0.05;comparing the intensity of the different antibodies resulted in the 1+group,and the 3+to 4+groups were significantly lower after blood transfusion,P<0.05.Conclusion:The use of the direct antiglobulin test in transfused patients showed that patients with positive results would have better clinical efficacy.Direct anti-human globulin tests will have an impact on the clinical efficacy of blood transfusion in patients with positive results,so it is very important to carry out a direct anti-human globulin test on blood transfusion patients.

Tensile strength and failure behavior of rock-mortar interfaces: Direct and indirect measurements

The tensile strength at the rock-concrete interface is one of the crucial factors controlling the failure mechanisms of structures,such as concrete gravity dams.Despite the critical importance of the failure mechanism and tensile strength of rock-concrete interfaces,understanding of these factors remains very limited.This study investigated the tensile strength and fracturing processes at rock-mortar interfaces subjected to direct and indirect tensile loadings.Digital image correlation(DIC)and acoustic emission(AE)techniques were used to monitor the failure mechanisms of specimens subjected to direct tension and indirect loading(Brazilian tests).The results indicated that the direct tensile strength of the rock-mortar specimens was lower than their indirect tensile strength,with a direct/indirect tensile strength ratio of 65%.DIC strain field data and moment tensor inversions(MTI)of AE events indicated that a significant number of shear microcracks occurred in the specimens subjected to the Brazilian test.The presence of these shear microcracks,which require more energy to break,resulted in a higher tensile strength during the Brazilian tests.In contrast,microcracks were predominantly tensile in specimens subjected to direct tension,leading to a lower tensile strength.Spatiotemporal monitoring of the cracking processes in the rock-mortar interfaces revealed that they show AE precursors before failure under the Brazilian test,whereas they show a minimal number of AE events before failure under direct tension.Due to different microcracking mechanisms,specimens tested under Brazilian tests showed lower roughness with flatter fracture surfaces than those tested under direct tension with jagged and rough fracture surfaces.The results of this study shed light on better understanding the micromechanics of damage in the rock-concrete interfaces for a safer design of engineering structures.

A novel method for geometric quality assurance of rock joint replicas in direct shear testing-Part 2:Validation and mechanical replicability

Each rock joint is unique by nature which means that utilization of replicas in direct shear tests is required in experimental parameter studies.However,a method to acquire knowledge about the ability of the replicas to imitate the shear mechanical behavior of the rock joint and their dispersion in direct shear testing is lacking.In this study,a novel method is presented for geometric quality assurance of replicas.The aim is to facilitate generation of high-quality direct shear testing data as a prerequisite for reliable subsequent analyses of the results.In Part 1 of this study,two quality assurance parameters,smf and V_(Hp100),are derived and their usefulness for evaluation of geometric deviations,i.e.geometric reproducibility,is shown.In Part 2,the parameters are validated by showing a correlation between the parameters and the shear mechanical behavior,which qualifies the parameters for usage in the quality assurance method.Unique results from direct shear tests presenting comparisons between replicas and the rock joint show that replicas fulfilling proposed threshold values of σ_(mf)<0.06 mm and
|V_(Hp100)|
<0.2 mm have a narrow dispersion and imitate the shear mechanical behavior of the rock joint in all aspects apart from having a slightly lower peak shear strength.The wear in these replicas,which have similar morphology as the rock joint,is in the same areas as in the rock joint.The wear is slightly larger in the rock joint and therefore the discrepancy in peak shear strength derives from differences in material properties,possibly from differences in toughness.It is shown by application of the suggested method that the quality assured replicas manufactured following the process employed in this study phenomenologically capture the shear strength characteristics,which makes them useful in parameter studies.

Protective benefits of HDPE board sand fences in an environment with variable wind directions on Gobi surfaces:wind tunnel study

The Golmud-Korla Railway in the Gobi area faces operational challenges due to sand hazards,caused by strong and variable winds.This study addresses these challenges by conducting wind tunnel tests to evaluate the protective benefits of High Density Polyethylene(HDPE)board sand fences,focusing on their orientation relative to various wind directions(referred to as'wind angle').This study found that the size of the low-velocity zone on the leeward side of the sand fences(LSF)expanded with an increase in the wind angle(WA).At 1H(the height of the sand fence)and 2H positions on the LSF,the wind speed profiles(WSP)exhibited a segmented logarithmic growth,constrained by Z=H at varying WAs.The efficacy of the sand fence in obstructing airflow escalated as WA increased.The size of the WA has a significant impact on the protective efficiency of HDPE board sand fences.Furthermore,compared to typical sandy surfaces,the rate of sand transport across the Gobi surface diminishes more slowly with height,attributed to the gravel's rebound effect.This phenomenon allows some sand particles to bypass the fences,rendering them less effective at blocking wind and trapping sand than in sandy environments.This paper offers scientific evidence supporting the practical use and enhancement of HDPE board sand fences in varied wind conditions.

Two stages power generation test of the hot dry rock exploration and production demonstration project in the Gonghe Basin,northeastern Qinghai-Tibet plateau,China

The Hot Dry Rock(HDR)is considered as a clean and renewable energy,poised to significantly contribute to the global energy decarbonization agenda.Many HDR projects worldwide have accumulated valuable experience in efficient drilling and completion,reservoir construction,and fracture simulation.In 2019,China Geological Survey(CGS)initiated a demonstration project of HDR exploration and production in the Gonghe Basin,aiming to overcome the setbacks faced by HDR projects.Over the ensuing four years,the Gonghe HDR project achieved the first power generation in 2021,followed by the second power generation test in 2022.After establishing the primary well group in the initial phase,two directional wells and one branch well were drilled.Noteworthy progress was made in successfully constructing the targeted reservoir,realizing inter-well connectivity,power generation and grid connection,implementing of the real-time micro-seismic monitoring.A closed-loop technical validation of the HDR exploration and production was completed.However,many technical challenges remain in the process of HDR industrialization,such as reservoir fracture network characterization,efficient drilling and completion,multiple fracturing treatment,continuous injection and production,as well as mitigation of induced seismicity and numerical simulation technology.

test252 kV三相机械联动GIS用断路器的T100s合并试验

交流高压断路器标准GB/T 1984—2014中规定了中性点有效和非有效接地系统的合并试验,但是不涉及60Hz的工况,对应STL导则中针对IEC 62271-100有50/60Hz合并试验的描述,但是国内厂家50/60Hz通常是分开试验的。文章通过介绍252kV断路器T100s的多参数的合并试验,提供了一种可以多参数试验的试验方法,指出了多参数合并试验的利弊,对后续其他类似多参数合并试验提供了有效参考。

Robot driver for vehicle durability emission test on chassis dynamometer

A method for a vehicle durability emission test using a robot driver insteadof human drivers on the chassis dynamometer is presented. The system architecture of vehicledurability emission test cell, the road load simulation strategy and the tele-monitoring systembased on Browser/Client structure are described. Furthermore, the construction of the robot driver,vehicle performance self-learning algorithm, multi-mode vehicle control model and vehicle speedtracking strategy based on fuzzy logic arealso discussed. Besides, the capability of controlparameters self-compensation on-line makes it possible to compensate the wear of vehicle componentsand the variety of clutch true bite point during the long term test. Experimental results show thattherobot driver can be applicable to a wide variety of vehicles and the obtained results stay withina tolerance band of ± 2 km/h. Moreover the robot driver is able to control tested vehicles withgood repeatability and consistency; therefore, this methodpresents a solution to eliminate theuncertainty of emission test results by human drivers and to ensure the accuracy and reliability ofemission test results.

Modeling and Analysis of A Rotary Direct Drive Servovalve

Direct drive servovalves are mostly restricted to low flow rate and low bandwidth applications due to the considerable flow forces.Current studies mainly focus on enhancing the driving force,which in turn is limited to the development of the magnetic material.Aiming at reducing the flow forces,a novel rotary direct drive servovalve（RDDV）is introduced in this paper.This RDDV servovalve is designed in a rotating structure and its axially symmetric spool rotates within a certain angle range in the valve chamber.The servovalve orifices are formed by the matching between the square wave shaped land on the spool and the rectangular ports on the sleeve.In order to study the RDDV servovalve performance,flow rate model and mechanical model are established,wherein flow rates and flow induced torques at different spool rotation angles or spool radiuses are obtained.The model analysis shows that the driving torque can be alleviated due to the proposed valve structure.Computational fluid dynamics（CFD）analysis using ANSYS/FLUENT is applied to evaluate and validate the theoretical analysis.In addition,experiments on the flow rate and the mechanical characteristic of the RDDV servovalve are carried out.Both simulation and experimental results conform to the results of the theoretical model analysis,which proves that this novel and innovative structure for direct drive servovalves can reduce the flow force on the spool and improve valve frequency response characteristics.This research proposes a novel rotary direct drive servovalve,which can reduce the flow forces effectively.

Inertia Matching During Dynamic Simulation of Vehicle Drive System on Test Bench

Framework and basic parameters of a test bench for motor drive system of electric vehicle (EV) are illuminated. Two kinds of electric drive models, one was for the electric vehicle drived on real road, the other was for that on test bench, are put forward. Then, dynamic analysis of these models is made in detail. Inertia matching method of the test bench is researched and some useful formulas and graphs are brought forward. The experiment of an electric bus is introduced in order to explain the usage of this inertia matching method.

Laser-direct-drive program: Promise, challenge, and path forward

Along with laser-indirect(X-ray)-drive and magnetic-drive target concepts,laser direct drive is a viable approach to achieving ignition and gain with inertial confinement fusion.In the United States,a national program has been established to demonstrate and understand the physics of laser direct drive.The program utilizes the Omega Laser Facility to conduct implosion and coupling physics at the nominally 30-kJ scale and lasereplasma interaction and coupling physics at the MJ scale at the National Ignition Facility.This article will discuss the motivation and challenges for laser direct drive and the broad-based program presently underway in the United States.

Direct Yaw Moment Control for Distributed Drive Electric Vehicle Handling Performance Improvement

For a distributed drive electric vehicle（DDEV） driven by four in-wheel motors, advanced vehicle dynamic control methods can be realized easily because motors can be controlled independently, quickly and precisely. And direct yaw-moment control（DYC） has been widely studied and applied to vehicle stability control. Good vehicle handling performance： quick yaw rate transient response, small overshoot, high steady yaw rate gain, etc, is required by drivers under normal conditions, which is less concerned, however. Based on the hierarchical control methodology, a novel control system using direct yaw moment control for improving handling performance of a distributed drive electric vehicle especially under normal driving conditions has been proposed. The upper-loop control system consists of two parts： a state feedback controller, which aims to realize the ideal transient response of yaw rate, with a vehicle sideslip angle observer; and a steering wheel angle feedforward controller designed to achieve a desired yaw rate steady gain. Under the restriction of the effect of poles and zeros in the closed-loop transfer function on the system response and the capacity of in-wheel motors, the integrated time and absolute error（ITAE） function is utilized as the cost function in the optimal control to calculate the ideal eigen frequency and damper coefficient of the system and obtain optimal feedback matrix and feedforward matrix. Simulations and experiments with a DDEV under multiple maneuvers are carried out and show the effectiveness of the proposed method： yaw rate rising time is reduced, steady yaw rate gain is increased, vehicle steering characteristic is close to neutral steer and drivers burdens are also reduced. The control system improves vehicle handling performance under normal conditions in both transient and steady response. State feedback control instead of model following control is introduced in the control system so that the sense of control intervention to drivers is relieved.

Acoustic emission activity in directly tensile test on marble specimens and its tensile damage constitutive model

For understanding acoustic emission （AE） activity and accumulation of micro-damage inside rock under pure tensile state, the AE signals has been monitored on the test of directly tension on two kinds of marble specimens. A tensile constitutive model was proposed with the damage factor calculated by AE energy rate. The tensile strength of marble was discrete obviously and was sensitive to the inside microdefects and grain composition. With increasing of loading, the tensile stress-strain curve obviously showed nonlinear with the tensile tangent modulus decreasing. In repeated loading cycle, the tensile elastic modulus was less than that in the previous loading cycle because of the generation of micro damage during the prior loading. It means the linear weakening occurring in the specimens. The AE activity was corresponding with occurrence of nonlinear deformation. In the initial loading stage which only elastic deformation happened on the specimens, there were few AE events occurred; while when the nonlinear deformation happened with increasing of loading, lots of AE events were generated. The quantity and energy of AE events were proportionally related to the variation of tensile tangent modulus. The Kaiser effect of AE activity could be clearly observed in tensile cycle loading. Based on the theory of damage mechanics, the damage factor was defined by AE energy rate and the tensile damage constitutive model was proposed which only needed two property constants. The theoretical stress-strain curve was well fitted with the curve plotted with tested datum and the two property constants were easily gotten by the laboratory testing.

Mesomechanical simulation of direct shear test on outwash deposits with granular discrete element method

The mechanical properties of outwash deposits which are taken as unconsolidated geo-materials with the characteristics of non-uniformity, heterogeneity and multiphase have attracted much attention in engineering. According to the results of laboratory direct shear test on the remolded samples, the soil particle parameters of numerical model based on in-situ particle size cumulative curves and 3D granular discrete element method were determined. Then, numerical experiments on different lithology, stone content and gradation composition were conducted. The results show that it is not a flat surface but a shear band that yields in the sample. The curve of particle velocity vs distance from the designed shear surface of test model that is taken as a datum plane in the vertical section of sample shows in "S" shape. The shear disturbance area is about twice the maximum diameter of stone blocks. The greater the stiffness of stone is, the rougher the shear surface is. The shear strength of outwash deposits is largely controlled by lithology and stone content, and the bite force between stone blocks is the root reason of larger friction angle. It is also shown that strain hardening and low shear dilatancy occur under high confining pressure as well as possibility of shear shrinkage. But it is easy to behave shear dilatation and strain softening under low confining pressure. The relationship between particle frictional coefficient and stone content presents an approximately quadratic parabola increase. The strain energy first increases and then drops with the increase of frictional energy. The cohesion increases with soil stiffness increasing but decreases with stone stiffness increasing. Numerical results are consistent with the laboratory test results of remolded samples, which indicate that this method can be a beneficial supplement to determine the parameters of engineering deposit bodies.

DIRECT DIGITAL DESIGN AND SIMULATION OF MESHING IN WORM-GEAR DRIVE

A direct digital design method （DDDM） of worm-gear drive is proposed. It is directly based on the simulation of manufacturing process and completely different from the conventional modeling method. The loaded tooth contact analysis （LTCA） method is analyzed, in which the advanced surface to surface searching technique is included. The influence of misalignment errors and contact deformations on contact zone and transmission error （TE） is discussed. Combined modification approach on worm tooth surface is presented. By means of DDDM and LTCA, it is very conven- ient to verify the effect of worm-gear drive＇s modification approach. The analysis results show that, the modification in profile direction reduces the sensitivity of worm-gear drive to misalignment errors and the modification in longitudinal direction decreases the TE. Thus the optimization design of worm-gear drive can be achieved prior to the actual manufacturing process.

Extended research on software hybrid testing combining reliability and directed testing

The software reliability testing has many disadvantages in practice, such as high complexity of constructing operational profiles and poor fault detection efficiency. Oppositely, the directed testing with a high fault detection rate is incapable of estimating reliability quantificationally. To solve this problem, a hybrid testing combining reliability and directed testing as well as a reliability model based on the order statistic （OS） model were presented by Mitchell. An extended research on Mitchell＇s work is proposed. Firstly, the most proper distribution of the fault＇s failure rate which tends to be Iognormal is suggested, and a detailed form of the OS model based on Iognormal and the corresponding parameter estimation method are proposed, respectively. Secondly, an im- plementing framework for the hybrid testing is proposed. Finally, the hybrid testing and the OS model are applied on a real website system. The experimental results indicate： the hybrid testing has more efficient fault detection power and lower testing cost than the reliability testing; compared with three traditional software reliabil ity growth models, the OS model has a best or pretty estimation or prediction power for each data set; and for the failure data set collected from hybrid testing, the OS model also achieves an ac- ceptable estimation result.

Large-scale direct shear testing of geocell reinforced soil

The tests on the shear property of geocell reinforced soils were carried out by using large-scale direct shear equipment with shear-box-dimensions of 500 mm×500 mm×400 mm (length×width×height). Three types of specimens, silty gravel soil, geocell reinforced silty gravel soil and geocell reinforced cement stabilizing silty gravel soil were used to investigate the shear stress-displacement behavior, the shear strength and the strengthening mechanism of geocell reinforced soils. The comparisons of large-scale shear test with triaxial compression test for the same type of soil were conducted to evaluate the influences of testing method on the shear strength as well. The test results show that the unreinforced soil and geocell reinforced soil give similar nonlinear features on the behavior of shear stress and displacement. The geocell reinforced cement stabilizing soil has a quasi-elastic characteristic in the case of normal stress coming up to 1.0 GPa. The tests with the reinforcement of geocell result in an increase of 244% in cohesion, and the tests with the geocell and the cement stabilization result in an increase of 10 times in cohesion compared with the unreinforced soil. The friction angle does not change markedly. The geocell reinforcement develops a large amount of cohesion on the shear strength of soils.

Evaluation of a Direct Rapid Immunohistochemical Test (dRIT) for Rapid Diagnosis of Rabies in Animals and Humans

Presently the gold standard diagnostic technique for rabies is the direct immunofluorescence assay （dFA） which is very expensive and requires a high level of expertise. There is a need for more economical and user friendly tests, particularly for use in developing countries. We have established one such test called the direct rapid immunohistochemical test （dRIT） for diagnosis of rabies using brain tissue. The test is based on capture of rabies nucleoprotein （N） antigen in brain smears using a cocktail of biotinylated monoclonal antibodies specific for the N protein and color development by streptavidin peroxidase-amino ethyl carbazole and counter staining with haematoxollin. The test was done in parallel with standard FAT dFA using 400 brain samples from different animals and humans. The rabies virus N protein appears under fight microscope as reddish brown particles against a light blue background. There was 100 % correlation between the results obtained by the two tests. Also, interpretation of results by dRIT was easier and only required a light microscope. To conclude, this newly developed dRIT technique promises to be a simple, cost effective diagnostic tool for rabies and will have applicability in field conditions prevalent in developing countries.

Numerical simulation of direct shear tests on mechanical properties of talus deposits based on self-adaptive PCNN digital image processing

The macro mechanical properties of materials with characteristics of large scale and complicated structural composition can be analyzed through its reconstructed meso-structures.In this work,the meso-structures of talus deposits that widely exist in the hydro-power engineering in the southwest of China were first reconstructed by small particles according to the in-situ photographs based on the self-adaptive PCNN digital image processing,and then numerical direct shear tests were carried out for studying the mechanical properties of talus deposits.Results indicate that the reconstructed meso-structures of talus deposits are more consistent with the actual situation because the self-adaptive PCNN digital image processing has a higher discrimination in the details of soil-rock segmentation.The existence and random distribution of rock blocks make the initial shear stiffness,the peak strength and the residual strength higher than those of the "pure soil" with particle size less than 1.25 cm apparently,but reduce the displacements required for the talus deposits reaching its peak shear strength.The increase of rock proportion causes a significant improvement in the internal friction angle of talus deposit,which to a certain degree leads to the characteristics of shear stress-displacement curves having a changing trend from the plastic strain softening deformation to the nonlinear strain hardening deformation,while an unconspicuous increase in cohesion.The uncertainty and heterogeneity of rock distributions cause the differences of rock proportion within shear zone,leading to a relatively strong fluctuation in peak strengths during the shear process,while movement features of rock blocks,such as translation,rotation and crossing,expand the scope of shear zone,increase the required shear force,and also directly lead to the misjudgment that the lower shear strength is obtained from the samples with high rock proportion.That,however,just explains the reason why the shear strength gained from a small amount of indoor test data is not consistent with engineering practice.

Analysis of nonlinearities and effects in direct drive electro-hydraulic position servo system

The direct drive electro-hydraulic servo system is a new approach hydraulic system. It is much smaller and easier controlled than traditional systems and is a perfect energy saver. This paper will briefly introduce the popular nonlinearities in the electro-hydraulic system and analyse the effect of nonlinearities in direct drive electro-hydraulic position servo system by means of simulation research. Some valuable conclusions are given.

Effects of water saturation and loading rate on direct shear tests of andesite

For estimating the long-term stability of underground framework,it is vital to learn the mechanical and rheological characteristics of rock in multiple water saturation conditions.However,the majority of previous studies explored the rheological properties of rock in air-dried and water saturated conditions,as well as the water effects on compressive and tensile strengths.In this study,andesite was subjected to direct shear tests under five water saturation conditions,which were controlled by varying the wetting and drying time.The tests were conducted at alternating displacement rates under three vertical stresses.The results reveal that the shear strength decreases exponentially as water saturation increases,and that the increase in shear strength with a tenfold increase in displacement rate is nearly constant for each of the vertical stresses.Based on the findings of the shear tests in this study and the compression and tension tests in previous studies,the influences of both water saturation and loading rate on the Hoek-Brown failure criterion for the andesite was examined.These results indicate that the brittleness index of the andesite,which is defined as the ratio of uniaxial compressive strength to tensile strength,is independent of both water saturation and loading rate and that the influences of the water saturation dependence and the loading rate dependence of the failure criterion can be converted between each other.