Engineering behaviors of reinforced gabion retaining wall based on laboratory test

In order to study the engineering behaviors of reinforced gabion retaining wall,laboratory model test was carried out.Cyclic load and unload of five levels(0-50,0-100,0-50,0-200 and 0-250 kPa) were imposed.Vertical earth pressure,lateral earth pressure,deformation behaviors of reinforcements,potential failure surface and deformation behaviors of wall face were studied.Results show that vertical earth pressure is less than theoretical value,the ratio of vertical earth pressure to theoretical value increases nearly linearly with increasing load,and the correlation coefficient of regression equation is 0.92 for the second layer and 0.79 for the fifth layer.The distribution of lateral earth pressure along the wall back is nonlinear and it is less than theoretical value especially when the load imposed at the top of retaining wall is large.Therefore,reinforced gabion retaining wall will be in great safety when current method is adopted.The deformation behaviors of reinforcements both in the third layer and the fifth layer are single-peak distributions,and the position of the maximum strain is behind that determined by 0.3H(Here H refers to the height of retaining wall) method or Rankine theory.Lateral deformation of wall face increases with increasing load,and the largest lateral deformation occurs in the fourth layer,which lead to a bulging in the middle of wall face.

Laboratory Test on Volumetric Characteristics of Saturated Sea Sand Under Cyclic Loading

The deformation of sea coast or sandy deposits caused by earthquakes can lead to catastrophic damages to various port structures. The volumetric deformation is mainly induced by densification of sand during the dissipation of excess pore water pressure created by cyclic loading. Based on laboratory test, the reconsolidation volumetric characteristics of saturated sea sand are investigated. The experiments are conducted with a newly developed multi functional triaxial test equipment. Two types of dynamic loads are applied to the samples to clarify different kinds of affecting factors. It is found that the reconsolidation volumetric strain is correlated not only to the excess pore water pressure and the maximum shear strain during the dynamic loading, but also to the effective confining pressure. A new formula is put forward to calculate the volumetric strain during reconssolidation.

Clinical Diagnosis and Treatment Characteristics of Acute Respiratory Infections in Children and New Developments in Laboratory Testing

Acute respiratory tract infection (ARTI) in children is the most common infectious disease in childhood, and its pathogens include viruses, bacteria and fungi, mycoplasma, chlamydia and rickettsia. In recent years, with the continuous development of pathogen detection methods, the diagnosis and treatment of acute respiratory infections has received more and more clinical attention. The clinical diagnosis and treatment characteristics of acute respiratory infections in children and the research of clinical laboratory detection methods have also been continuously developed. The author collected references to review the clinical features and new developments in laboratory testing of acute respiratory tract infection in children.

Subjective Evaluation of Clothing Comfort and Their Correlation with Laboratory Test

A series of polyester, cotton, and polyester/cotton blend fabrics were evaluated in a subjective wear. Subjective trial data were correlated with the results of in-house laboratory tests with the regression methods. Experimental results indicate that clothing-comfort assessment by human perception provides a sound basis for comparison of apparel garments under combined microclimates and human-activity levels of

The Importance of Molecular and Clinical Laboratory Tests in Diagnosis and Treatment of Coronavirus Disease

900 abusers were tested for the presence of drug abuse and coronavirus disease.In the early stage,the throat and noise samples of these patients were examined by polymerase chain reaction(PCR).The mean age of the study group is 42±23.Hematological and serological examinations were performed on 131 patients.All data were analyzed by t-test and one-way analysis of variance(ANOVA).Therefore,P<0.05 is considered as the significance of the test results.The results showed that 131 patients in the study group had positive results of PCR tests and nearby they had Covid-19.Approximately 90%of patients with coronavirus disease showed positive serological tests and lymphopenic condition.All of urine or blood samples in the 131 patients were positive for the presence of abuse drugs.C-reactive protein(CRP)is one of important serologic test that detected on these patients.This study showed the importance of molecular genetics test such as PCR and also hematology and serology tests in distinguish of coronavirus diseases.

Evaluation of Abuse Drugs and Clinical Laboratory Tests Variations in Whole Blood ＆ Urine Samples of Abusers

In this study, five hundred urine samples and five hundred blood samples of abusers were examined for the presence of alkaloid substances and abuse drugs in urines and bloods. These numbers of blood and urine samples of addicts in clinics of welfare organization, during detoxification treatment or maintenance treatment were screened for abuse drugs presence. The all of samples were tested through as a view of clinical laboratory methods. Age ranges of female patients were 35 ~ 15 and age range of males patients were 45 ~ 15. All patients filled questionnaire and satisfy forms too. First, all fresh urine and blood samples were examined to confirm presence drugs abuses, depend on their addiction and treatment, so all samples were confirmed by two tests. Then they were examined to other clinical laboratory tests. All data were analyzed by t-test and were Anova one way and two ways of Anova Turkey, and p 〈 0.05 was considered significant. The p-value of this study was p = 0.0001. The results of this study were showed that 4% of abusers had mild increase in hematocrite level and 2% of narcotic drugs abusers had mild lower level of blood sugars than normal range and 4% of participants had increase liver enzymes such ALT （alanine transferase）, AST （aspartat transferase）, ALP （alkaline phosphatease） and 1% of them had renal failure. Although blood level BUN （blood urea nitrogen） and creatinin were examined to evaluation of their renal failure .The results in Tabriz/Iran undrevision of welfare organization clinics were approximately showed that positive results of addiction are in each of urine and blood samples. Because some of abusers directly consumed full long time agonist or partial agonists＇ drugs such as methadone and buprenorphine for their maintenance therapy in clinics. Also doing test on blood samples has high importance in distinguishing and confirmation of drugs abuse in samples. Also in this study we conclude that among all drug analytical methods the cheapest and easiest test to screening opioids and other abuse drugs in urine and blood samples is strip test for rapid diagnosis, also tests on blood samples have high importance as a view point of accuracy to distinguishing of drugs abuse, and serum levels of some other parameters showed all abusers patients situation such as liver and renal dysfimction through clinical laboratory tests.

From bed to bench: Which attitude towards the laboratoryliver tests should health care practitioners strike?

There is a general consensus in re-interpreting the so-called liver function tests in the light of novel discoveries. At the same time, recent evidence favours the use of different laboratory data to assess liver damage, fibrosis or regenerative process, but this point is not always shared. Actually, balancing the need for diagnosis, prognostic evaluation and therapy response of liver disease with a good cost/benefit ratio is very difficult. New tests are probably not needed but the aim should be for better utilization of existing tests to contain the increasing cost of health care.

New Progress in Clinical Diagnosis, Treatment and Laboratory Testing of Acute Respiratory Infections in Children

Acute respiratory infection in children (ARTI) is the most common childhood infectious disease, and its pathogens include bacteria, fungi, viruses, chlamydia, mycoplasma and rickettsia. In recent years, with the continuous development of pathogen detection methods, the diagnosis and treatment of acute respiratory infections has received more and more attention from clinicians. The clinical diagnosis and treatment of acute respiratory infections in children and the research of laboratory detection methods have also been continuously developed. The manuscript presents a review of progress in the clinical diagnosis, treatment and laboratory testing of acute respiratory infections in children by collecting references.

Alterations in the Results of Biochemical Laboratory Tests Due to the Administration of Antihypertensive Drugs

Objective:Perform a literary review of the interference in the results of biochemical laboratory tests caused by antihypertensive drugs.Methods:This is a review of the scientific literature with descriptive research performed according to the PRISMA model using the databases PUBMED,SCIELO,MEDLINE,LILACS,and searches of Brazilian Ministry of Health and Federal Pharmacy Council publications,reagent kits and package inserts approved by ANVISA.Literature and papers in Portuguese and English were selected,prioritizing the years 2010 to 2020.Results:The diuretic class of antihypertensive drugs causes decreases glucose tolerance,thus resulting in an increase in triglycerides.In long-term use,the drug captopril can increase serum levels of potassium,creatine kinase and decreases blood sodium.Methyldopa causes an increase in AST levels.Propranolol is associated with an increase in triglyceride levels and a decrease in HDL and glucose levels.The constant use of losartan results in an increase in HDL,a decrease in uric acid levels and a slight and transient increase in transaminases.In the Gold Analisa,Bioclin and Labtest reagent kits,most of the alterations occur due to the increase in levels of serum biomarkers according to the class of the antihypertensive drug.Conclusions:Biochemical alterations in serum can result in false-positive or false-negative reports,since it can be observed that most of the dosages caused increases due to the physiological effect of the drugs.The antihypertensive drugs that showed the highest incidence of interference were captopril,atenolol,losartan and propranolol.

Managing Health Treatment by Optimizing Complex Lab-Developed Test Configurations: A Health Informatics Perspective

A complex Laboratory Developed Test(LDT)is a clinical test developed within a single laboratory.It is typically configured from many fea-ture constraints from clinical repositories,which are part of the existing Lab-oratory Information Management System(LIMS).Although these clinical repositories are automated,support for managing patient information with test results of an LDT is also integrated within the existing LIMS.Still,the support to configure LDTs design needs to be made available even in standard LIMS packages.The manual configuration of LDTs is a complex process and can generate configuration inconsistencies because many constraints between features can remain unsatisfied.It is a risky process and can lead patients to undergo unnecessary treatments.We proposed an optimized solution(opt-LDT)based on Genetic Algorithms to automate the configuration and resolve the inconsistencies in LDTs.Opt-LDT encodes LDT configuration as an optimization problem and generates a consistent configuration that satisfies the constraints of the features.We tested and validated opt-LDT for a local secondary care hospital in a real healthcare environment.Our results,averaged over ten runs,show that opt-LDT resolves 90%of inconsistencies while taking between 6 and 6.5 s for each configuration.Moreover,positive feedback based on a subjective questionnaire from clinicians regarding the performance,acceptability,and efficiency of opt-LDT motivates us to present our results for regulatory approval.

Statistical analysis of physico-mechanical parameters of sandstones occurring in orogenic settings

In northeastern Sicily(Italy),sandstone rock masses widely crop out as cover deposits over crystalline terrains belonging to the orogenic belt.Despite being part of the same geological formation,these sandstones are characterized by highly different features in terms of texture and physico-mechanical properties.This poses a scientific question on the possibility of tracing these rocks to a single statistical model,which could be representative of their main engineering geological properties.Therefore,it is worth investigating on the possible reasons of such differences,that should be searched either in the current geographical sandstone distribution or in the rock texture.For this study,sandstone samples were collected from different sites and were analyzed at both the hand and thin section scales.Three sandstone types were recognized,characterized by a different texture.Then,the laboratory characterization allowed estimating their main physico-mechanical and ultrasonic properties,such as porosity,density,mechanical strength,deformability,and ultrasonic velocities.The rock mechanical strength proved linked to the rock compactness and to the presence of lithic fragments,while pores and a pseudo-matrix between grains represent weakening features.Rock data were also statistically analyzed by grouping the specimens according to a geographical criterion,with respect to their sampling area,but no link was found between location and rock properties.Finally,with the aim of achieving mathematical laws that could be used to predict some rock properties from others,useful for practical purposes when dealing with such a high property variability,single and multiple regression analyses were carried out.Results show that the Uniaxial Compressive Strength,porosity,and P-wave velocity are the best predictors for a quick,indirect estimation of the main physico-mechanical parameters.The methodological approach developed for this research can be taken as reference to study other worldwide cases,involving rocks characterized by a wide range of physico-mechanical properties and covering large regional territories.

Discussion of“Site observations of weathered granitic soils subjected to cementation and partial drainage using SCPTU”[J Rock Mech Geotech Eng 15(2023)984e996]

Comprehensive data from in situ and laboratory tests in residual soil have been presented by Zhang et al.(2023).A number of issues addressed in the paper have been the interest of the discussers,namely the characterisation and behaviour of residual soils,limitation of piezocone testing due to the capacity of the entire system,measurement of shear wave velocity,rate effect of piezocone(CPTU)testing and piezocone testing with dual pore pressure penetrometers.Clarification and complementation of these issues are required with regard to both the execution and interpretation of the tests.

Protective effect of retaining wall on rock avalanche:A case study of Nayong rock avalanche in China

Rock avalanches are generally difficult to prevent and control due to their high velocities and the extensive destruction they cause.However,barrier structures constructed along the path of a rock avalanche can partially mitigate the magnitudes and consequences of such catastrophic events.We selected a rock avalanche in Nayong County,Guizhou Province,China as a case to study the effect of the location and height of a retaining wall on the dynamic characteristics of rock avalanche by using both actual terrain-based laboratory-model tests and coupled PFC3D-FLAC3D numerical simulations.Our findings demonstrate that a retaining wall can largely block a rock avalanche and its protective efficacy is significantly influenced by the integrity of the retaining wall.Coupled numerical simulation can serve as a powerful tool for analyzing the interaction between a rock avalanche and a retaining wall,facilitating precise observations of its deformation and destruction.The impact-curve characteristics of the retaining wall depend upon whether or not the rock avalanche-induced destruction is taken into account.The location of the retaining wall exerts a greater influence on the outcome compared to the height and materials of the retaining wall,while implementing a stepped retaining-wall pattern in accordance with the terrain demonstrates optimal efficacy in controlling rock avalanche.

Compaction and seepage characteristics of broken coal and rock masses in coal mining:A review in laboratory tests

Broken coal and rock(BCR)are an important component medium of the caving zone in the goaf(or gob),as well as the main filling material of fault fracture zone and collapse column.The compaction seepage characteristics of BCR directly affect the safe and efficient mining of coal mines.Thus,numerous laboratory studies have focused on the compaction seepage characteristics of BCR.This paper first outlines the engineering problems involved in the BCR during coal mining including the air leakage,the spontaneous combustion,the gas drainage,and the un-derground reservoirs in the goaf.Water inrush related to tectonics such as faults and collapse columns and surface subsidence related to coal gangue filling and mining also involve the compaction seepage characteristics of BCR.Based on the field problems of BCR,many attempts have been made to mimic field environments in laboratory tests.The experimental equipment(cavity size and shape,acoustic emission,CT,etc.)and experimental design for the BCR were firstly reviewed.The main objects of laboratory analysis can be divided into compression tests and seepage test.During the compaction test,the main research focuses on the bearing deformation characteristics(stress-strain curve),pore evolution characteristics,and re-crushing characteristics of BCR.The seepage test mainly uses gas or water as the main medium to study the evolution characteristics of permeability under different compaction stress conditions.In the laboratory tests,factors such as the type of coal and rock mass,particle size,particle shape,water pressure,temperature,and stress path are usually considered.The lateral compression test of BCR can be divided into three stages,including the self-adjustment stage,the broken stage,and the elastic stage or stable stage.At each stage,stress,deformation,porosity,energy,particle size and breakage rate all have their own characteristics.Seepage test regarding the water permeability experiment of BCR is actually belong to variable mass seepage.While the experimental test still focuses on the influence of stress on the pore structure of BCR in terms of gas permeability.Finally,future laboratory tests focus on the BCR related coal mining including scaling up,long term loading and water immersion,mining stress path matching were discussed.

Testing and modeling of cyclically loaded rock anchors

The Norwegian Public Roads Administration(NPRA) is planning for an upgrade of the E39 highway route at the westcoast of Norway. Fixed links shall replace ferries at seven fjord crossings. Wide spans and large depths at the crossings combined with challenging subsea topography and environmental loads call for an extension of existing practice. A variety of bridge concepts are evaluated in the feasibility study. The structures will experience significant loads from deadweight, traffic and environment. Anchoring of these forces is thus one of the challenges met in the project. Large-size subsea rock anchors are considered a viable alternative. These can be used for anchoring of floating structures but also with the purpose of increasing capacity of fixed structures. This paper presents first a thorough study of factors affecting rock anchor bond capacity. Laboratory testing of rock anchors subjected to cyclic loading is thereafter presented. Finally, the paper presents a model predicting the capacity of a rock anchor segment, in terms of a ribbed bar, subjected to a cyclic load history. The research assumes a failure mode occurring in the interface between the rock anchor and the surrounding grout. The constitutive behavior of the bonding interface is investigated for anchors subjected to cyclic one-way tensile loads. The model utilizes the static bond capacity curve as a basis, defining the ultimate bond sbuand the slip s1 at τ. A limited number of input parameters are required to apply the model. The model defines the bond-slip behavior with the belonging rock anchor capacity depending on the cyclic load level(τcy/τ), the cyclic load ratio(R= τcy/τcy), and the number of load cycles(N). The constitutive model is intended to model short anchor lengths representing an incremental length of a complete rock anchor.

Field load testing of copper extraction aeration pipes under simulated high heap pile

Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from the mine was used in recreating the in situ conditions.Electric heaters were utilized to raise the temperature inside each pipe to simulate the essential element of the copper extraction process.The maximum vertical deflection reached by the test pipes was close to 20%,when the simulated heap pile height was 80 m.The plastic pipes and the overliner material were also tested in the laboratory.Based on the results,the maximum heap pile fll depth was recommended for the aeration system.The results indicated that the vertical deflection was the primary performance index for the aeration pipes installed in heap piles at mines.Lastly,the pipe made of polypropylene resin was super.

A laboratory study of stress arching around an inclusion due to pore pressure changes

When the pore pressure in a porous rock changes, stress arching will occur within the rock and the surrounding region. Stress arching ratio is defined as the total stress changes in the porous rock to the pore pressure change in the region. The region may have the same or different elastic moduli with the surrounding rock, which is usually referred to as inclusion or inhomogeneity. Stress arching is responsible for many geomechanical problems encountered during production or injection; in addition, it is a crucial parameter in stress estimation during field development. This paper aims to present laboratory measurements of vertical stress arching ratio in a material surrounding the inclusion(inhomogeneity).To the authors’ knowledge, few laboratory experiments have been reported on direct measurement of stress arching. The inclusion is a cylindrical sandstone(44 mm in diameter and 50 mm in height)embedded in a larger cylindrical sandstone(150 mm in diameter and 154 mm in height), both of which are made synthetically. These two parts are separated and sealed by a internal polyurethane sleeve.Vertical stress changes are recorded by a mini hydraulic sensor embedded in surrounding rock. Laboratory results are compared to those obtained by numerical models. These models are checked with analytical formulations. The results of numerical models show a good agreement with laboratory data.The numerical results also indicate that the sensor response is affected by elastic properties of the internal sleeve. According to the sensitivity analysis performed, in the absence of the internal sleeve,properties of the inclusion have significant effects on the surrounding stress arching induced.

Analysis of laboratory and imaging examination results of patients with COVID-192 years after discharge in Chengdu

Objective:To summarize the follow-up results of laboratory examination,echocardiographic and chest CT of patients with COVID-19 at the time of 2 years after discharge in Chengdu.Methods:A total of 29 COVID-19 survivors who have participated in the 1-year follow-up and 2-year follow-up at Public Health Clinical Center of Chengdu were included in our study.Their blood laboratory tests,echocardiography and chest CT results were analyzed in order to evaluate the long-term recovery of COVID-19 survivors.Results:The most common abnormal laboratory test results at the 2-year follow-up were increased serum fibronectin(21 cases,72.4%)and decreased NK cell counts(19 cases,65.5%).Compared with laboratory test results at the 1-year follow-up,platelet count,hydroxybutyrate dehydrogenase and creatine kinase isoenzyme were decreased(all P<0.05),while serum fibrinogen,triglyceride,insulin and non-specific immunoglobulin A were increased(all P<0.05).Serum specific total SARS-CoV-2 antibody amount in COVID-19 survivors at half a year after COVID-19 vaccine was significantly higher than that before vaccination.More than half of patients(55.2%)had normal echocardiography results at the 2-year follow-up,the main abnormal results of them were valve regurgitation(7 cases,24.1%)and reduced left ventricular diastolic function(9 cases,31.0%).Compared with 1-year follow-up,7 patients had fewer abnormal cardiac ultrasound results.28 cases underwent chest CT at the 2-year follow-up,the mainly abnormal results were ground glass shadow(17.9%),pulmonary nodules(diameter<6mm)(32.1%)and scattered cable shadow(39.3%).71.4%(20/28)of them had no significant change between the two chest CT results.Conclusion:The mainly abnormal blood laboratory indicators in COVID-19 survivors at 2-year follow-up after discharge were increased serum fibronectin and decreased NK cell counts.Although echocardiography and chest CT results were no significant change between 1-year follow-up and 2-year follow-up among COVID-19 survivors,there were still some patients whose abnormal results were decreasing.Serum specific total SARS-CoV-2 antibody amount in COVID-19 survivors at half a year after COVID-19 vaccine was still significantly higher than that before vaccination,but the amount of specific antibody had a downward trend with time.

Evaluation of soil fabric using elastic waves during load-unload

It is essential to assess the evolution of soil fabric as it has an important role in the mechanical responses of soils during complex loading conditions.This contribution carries out the physical experiments using three granular materials in the laboratory.The variations of compression and shear wave velocities(Vp and Vs)are investigated during load-unload cycles under dry and drained conditions.Supplementary discrete element method(DEM)simulations are performed to understand the evolution of soil fabric during the equivalent load-unload cycles using spherical particles.Vp and Vs are not always reversible even though the stress state regains its isotropic condition after unload,indicating that Vp and Vs are governed by not only the stress state but also the fabric change.The variations of Vp/Vs are density-and stress-dependent;a higher level of stress ratio(s01/s03)threshold is observed for denser packings to trigger a significant change in wave velocity ratio(Vp/Vs)for experimental results using spherical glass beads and simulation data using spherical particles.Considering the particle shape,a higher s01/s03 threshold is found for more angular particles than rounded particles.The DEM result reveals that Vp/Vs of spherical particles can be correlated linearly with the evolution of fabric ratio(Fver/Fhor)during loadunload in a pre-peak range under dry and drained conditions.

Experimental evaluation of asphalt mixtures with emerging additives against cracking and moisture damage

The objective of this study was to evaluate and recommend an asphalt mixture design with emerging additive technologies that would provide superior performance against asphalt concrete(AC)stripping and cracking.To achieve this objective,a laboratory test program was developed to evaluate the use of nanomaterials(nanoclay and graphene nanoplatelet),an emerging anti-stripping agent(adhere),and warm-mix asphalt technologies(ZycoTherm,Sasobit,and EvoTherm).Two mix types were evaluated,which were a stone-matrix asphalt(SMA)and a dense-graded binder mix.In addition,the modified Lottman test(AASHTO T 283)and the indirect tensile asphalt cracking test(IDEAL-CT)test were used as performance indicators of moisture damage resistance and cracking susceptibility.Results were analyzed statistically to identify and quantify the effects of the design variables and selected additives on the performance,moisture damage resistance,and durability of asphalt mixes.Based on the cracking test results,a superior cracking resistance performance was observed with ZycoTherm,irrespective of the mix type.Adhere had the lowest average cracking indices for both mix types,which suggest that it would not perform as well as the other additives in terms of cracking resistance.Overall,SMA mixes displayed greater cracking resistance than the dense-graded mixtures,which may have been the result of the reclaimed asphalt pavement(RAP)material used in the dense-graded mix and its lower asphalt binder content.In terms of moisture resistance,both nanomaterials(graphene nanoplatelet and nanoclay)did not perform well as they did not meet the minimum required tensile strength ratio(TSR)criterion(>0.80).In addition,nanomaterials showed the lowest TSR values in both mix types suggesting that their effectiveness against moisture-induced damage may not be as good as warm-mix additives.On the other hand,warm-mix additives were expected to show enhanced performance in terms of moisture resistance as compared to the other additives evaluated in this study.