Scale Test Results Research Articles

Experimental and numerical investigation on cracking mechanism of tunnel lining under bias pressure

Lining cracking is a common issue in tunnels, which severely affects the integrity and service life of the tunnel. Bias pressure is one of the most important factors leading to lining cracking. In the present study, scale tests were carried out with different acting ranges of the bias pressure, and the bearing capacity, deformation behavior and crack morphology of the lining were measured. Then, the applicability of the extended finite element method (XFEM) in simulating lining cracking was validated using the scale test results. Furthermore, the crack evolution process and cracking mechanism of the lining caused by the bias pressure were investigated in detail by XFEM. The results showed that there was one intrados crack at the center of the bias pressure acting region, whereas two extrados cracks were symmetrically distributed on both sides of the bias pressure acting region. The intrados crack was a tensile crack with ‘Λ’ shape, which initiated first followed by the two extrados cracks. The eccentricity of the lining cross section was the key factor controlling the crack evolution. As the acting range of the bias pressure increased, the eccentricity of the cross section of the intrados crack gradually decreased, which led to a decrease in the crack propagation depth and width. This work can provide some helpful guidance for addressing the tunnel lining issues.

Attaining Optimum Values of Colourfastness Properties of Sustainable Dyes on Cotton Fabrics

The aim of this research was to identify optimum values of the colorfastness properties of sustainable dyes on cotton fabrics. Sustainable dyes are ecofriendly, biodegradable, economical and easily attainable from natural sources. The findings of this research established that good colourfastness properties of cellulosic fibres could be obtained using sustainable natural dyes. Experiments were carried out on 100% cotton voile fabrics of plain weave using four types of natural dyes: strawberry dye, beetroot dye, rose dye and China rose dye. Strawberry dye reacted with the cellulose of the cotton in an alkaline condition to form a stable covalent bond amid the dye and cellulose and showed outstanding colour fastness properties. The required experiments were conducted using the standard specified by ASTM and AATCC as stated in this paper. The colour strength properties, colour intensity properties, colour absorbency properties and colorfastness properties were investigated using a reflectance spectrophotometer and “Agilent Cary 630 FTIR Instrument” as stated in this paper. A sample dyeing machine – “Pad Dye Pad Steam” was used in this research to dye the cotton fabrics with sustainable natural dyes. The colorfastness properties were investigated using grey scale test results, and the colour strength and absorbency properties were tested using the spectrophotometer and FTIR instruments. The peak values of the FTIR instrument guaranteed the existence of the colourant or chromophore present in the dyestuffs, and exposed the best colourfastness properties. The findings of this research could be beneficial to personnel involved in textile industries who are in charge of dyeing cotton fabrics with natural dyes as well as controlling their colourfastness properties and colour intensity properties.

Minimally invasive technique for suprasyndesmotic ankle fracture fixation

Objective: To evaluate the clinical and radiographic results of suprasyndesmotic ankle fracture fixation with a minimally invasive technique. Methods: Retrospective study of 11 patients with suprasyndesmotic fractures of the lateral malleolus who underwent surgery between 2016 and 2018. Retrospective analysis of medical records considered the following: radiographic assessments (preoperative, immediate postoperative, six weeks postoperative), clinical evaluation, and strength scale and movement test results. Results: Of the 18 patients qualified for inclusion, 7 failed to appear at the follow-up appointment and were excluded. The patients’ age varied from 20 to 53 years, and 72.7% were male. The trauma mechanisms included torsion (46% of the cases), automobile accidents (36.4%) and direct trauma (17.6%). The mean time between trauma and definitive surgery was 3.27 days. The mean talocrural angle in the preoperative period was 83.13º, ranging from 80.63º in the immediate postoperative period to 81.27º at 6 months postoperatively. Approximately 90% of the patients did not lose strength. Regarding the range of motion, the mean dorsiflexion and plantar flexion 6 months postoperatively were 10.72º and 34.4º, respectively. Conclusion: The minimally invasive technique had excellent technical results in patients treated surgically for ankle fractures and required smaller incisions than conventional surgery. Osteolysis or fatigue of the osteosynthesis material is a possibility with this technique, which generally occurred between three and four months postoperatively. Level of Evidence IV; Therapeutic Studies; Case series.

The impacts of dry stirred milling application on quality and production rate of the cement grinding circuits

Cement industry has been one of the key processes within the modern life and attracted the interests of the researchers, machine manufacturers who are looking for the technological advances. As the industry itself is energy intense and contributes to CO2 emissions, such advances lead to the efficient use of the resources hence reduces the harm given to the environment. Cement process requires fine grinding of a material blend hence recent studies have been focusing on the improvements in these applications. The idea of dry stirred milling has come up with that aim and has been under investigation for many years. This study aims to show the possible applications of this technology within the cement grinding processes by discussing the quality and energy consumption aspects. In this context, sampling campaigns at a real plant were arranged initially and then simulation studies were undertaken by using the pilot scale test results obtained from a dry horizontal stirred mill. Basically, grinding of two different streams, classifier feed and coarse, were considered and necessary calculations had been performed. The results had proved that deploying the stirred media mill at these streams, provided energy saving between 7 and 18% and quality improvement by 2.8%. With its results shared, the paper is believed to contribute both the research and industry with its proposed flow sheet design for cement grinding circuits. The knowledge gained from this application can also be transferred to other applications requiring dry fine grinding.

A prediction method to evaluate thermal performance of protective clothing based on the correlation analysis of the bench scale and flame manikin tests

PurposeBench scale and flame manikin tests are two typical methods to evaluate thermal protective performance (TPP) of fire protective clothing. However, flame manikin test is limited to be widely used for its complication and high cost. The purpose of this paper is to develop a method to evaluate the thermal performance of protective clothing from the bench scale test results and garment parameters, which predicts the body burn injuries without conducting flame manikin tests.Design/methodology/approachBench scale and flame manikin tests’ data were collected from the previous research literature and then statistical analysis was performed to quantitatively investigate the correlations between the two test methods. Equations were established to predict the TPP values accounting for the effects of entrapped air gap and thermal shrinkage. Fitting analysis was conducted to analyze the relationship between the predicted TPP values and total burn injury. Finally, a method to predict total burn injury from the TPP values was proposed and validated.FindingsThe results showed that when the TPP value was predicted with the effects of air gap and thermal shrinkage considered, there was an approximate linear relationship between the predicted TPP values and total burn injury from the manikin test. Therefore, the prediction model of burn injury was developed based on the correlation analysis and verified with a generally good accuracy.Originality/valueThis paper presented a new prediction method to evaluate the thermal performance of protective clothing, which saved significant time and cost compared to the conventional methods. It can provide useful information for burn injury prediction of protective clothing.

Correlation Between Frequency of Seizure and Cognitive Development Levels in Children with Drug Resistant Epilepsy

Epilepsy, if not treated properly, can develop into refractory epilepsy or drug-resistant epilepsy. This type of epilepsy does not respond perfectly to the anti-epileptic drugs given. Drug-resistant epilepsy causes ischemia in neuron cells in the brain. Drug resistant epilepsy can cause impaired cognitive function, especially in children who are in the golden age. Epilepsy prevalence from various studies ranged from 1.5 to 31/1000 population. Epilepsy cases in Indonesia are predicted to range from 0.7 to 1% of the population in Indonesia or range from 1.5 to 2 million people. To determine correlation between the frequency of seizures with the level of cognitive development in children with drug resistant epilepsy. A cross sectional correlation study was carried out in 41 children with drug resistant epilepsy to determine cognitive values in drug resistant epileptic children. The sample was chosen from an affordable population by non-random sampling or consecutive sampling. The research hypothesis is there is a level of cognitive development in children aged 6 to 68 months with drug resistant epilepsy. Calculation of research subjects used the formula for correlative research. Data analysis was performed by Saphiro-Wilk data normality test, correlation analysis used Coefficient Lambda. Results were significant if the value of p<0.05. The results of this study found female subject 26 (63.4%). There were 16 subjects (39%) well nourished. diagnosis age of epilepsy<1 year 15 (37%). Number of seizure periods < 10 times 12 (29%). The number of anti-seizure medication were 2 drugs 27 subject (65%). Abnormal 1 EEG results were 8 subjects (19.5%). The Mullen Scale test results are below average 38 subject (97.2%). Strong correlation of seizure frequency ≥ 10 times was statistically significant to the level of cognitive development in children with epilepsy with r 0.783 with a p value was 0.00. Frequency of seizure 43.3% influenced cognitive development level. Conclusion, the frequency of seizures has a positive strong correlation to the level of cognitive development.

The Developing Assessment Instrument In Critical Thinking Ability For Fifth Grade Of Elementary School In Thematic Learning

The background of this study is about the availibility of the test assessment instrument to measure the critical thinking ability of fifth grade elementary school students which is limitted. Therefore, it needs to be developed. This development research used the Borg &amp; Gall development method. The purpose of this study was to develop an assessment instrument in essay. The assessment instrument was validated by 5 Experts Judgment by using the Aiken'V formula. The results of trials using the construct validity of the Confirmatory Factor Analysis (CFA), interater reliability used Two Ways Anova proved by the Ebel formula and internal consistent reliability with the Alpha Cronbach formula. The result of expert judgment validation showed that ≥0.8 which mean that 10 items were in valid category, construct validity results from large-scale test analysis by using LISREL 8.8 namely Confirmatory Factor fulfilled the testing of goodness of fit GFI value 0,93, CFI=0,97 and NFI=0,91. The three assessment criteria have value &gt; 0,90. It can be concluded that the construct validity is met. The construct validity is also evidenced by the loading factor of 10 items. All of which have a price of &gt; 0,3. The interrater reliability assessment instruments based on Expert Judgment coefficient value was 0,62. The expert agreement indicated that the rating given by each rater is reliable or consistent between one another and internal consistency of small scale test results of coefficient value of alpha 0,861, large scale 0.813. Practicality of assessment instruments based on expert judgment had mean 37.2 and included in practical category. The profile of critical thinking skills of fifth grade elementary school students category “Medium”. The Conclusions was the assessment instruments in critical thinking skills of fifth grade students on thematic learning were tested in validity, reliability and suitable to be used.

Simulations of In-Situ Upgrading Process: Interpretation of Laboratory Experiments and Study of Field-Scale Test

Summary In–situ upgrading (IU) is a promising method of improved viscous– and heavy–oil recovery. The IU process implies a reservoir heating up and exposure to a temperature higher than 300°C for a time period long enough to promote a series of chemical reactions. The pyrolysis reactions produce lighter oleic and gaseous components, while a solid residue remains underground. In this work, we developed a numerical model of IU using laboratory experience (kinetics measurements and core experiments) and validated the results by applying our model to an IU field–scale test published in the literature. Finally, we studied different operational conditions in a search for energy–efficient configurations. In this work, two types of IU experimental data are used from two vertical–tube experiments with Canadian bitumen cores (0.15 and 0.69 m). A general IU numerical model for the different experimental setups has been developed and compared with experimental data, using a commercial reservoir–simulator framework. This model is capable of representing the phase distribution of pseudocomponents, the thermal decomposition reactions of bitumen fractions, and the generation of gases and residue (solid) under thermal cracking conditions. Simulation results for the cores exposed to a temperature of 380°C and production pressure of 15 bar have shown that oil production (per pseudocomponent) and oil–sample quality were well–predicted by the model. Some differences in gas production and total solid residue were observed with respect to laboratory measurements. Computer–assisted history matching was performed using an uncertainty–analysis tool with the most–important model parameters. To better understand IU field–scale test results, the Shell Viking pilot (Peace River) was modeled and analyzed with the proposed IU model. The appropriate gridblock size was determined and the calculation time was reduced using the adaptive mesh–refinement (AMR) technique. The quality of products, the recovery efficiency, and the energy expenses obtained with our model were in good agreement with the field test results. In addition, the conversion results (upgraded oil, gas, and solid residue) from the experiments were compared with those obtained in the field test. Additional analysis was performed to identify energy–efficient configurations and to understand the role of some key variables (e.g., heating period and rate and the production pressure) in the global IU upgrading performance. We discuss these results, which illustrate and quantify the interplay between energy efficiency and productivity indicators.

A new 3D JRC calculation method of rock joint based on laboratory-scale morphology testing and its application in shear strength analysis

In order to study the 3D joint roughness coefficient (JRC), a series of direct shear tests were carried out and the surface morphologies of joints were tested using laser scanning technology. A digital method was put forward to convert the 3D surface morphology of a joint into an average height 2D profile. JRC values of 15 joints were calculated on the basis of the statistical parameter Z2 (root mean square first derivative values). The maximum profile angles of the converted average height 2D joint profile lines were measured and inserted into the Barton’s empirical formula to calculate the peak shear strength of the rock joint. Comparison between laboratory specimen scale test results and calculation results shows that the improved shear strength calculation model based on Barton’s empirical formula can exactly calculate the peak shear strength of rock joints. The arithmetic of converting the 3D joint surface morphology into a 2D average height joint profile is reliable in the laboratory study of joint shear mechanical characteristics.

Experimental studies of seismic soil pressures on vertical flexible, underground structures and analytical comparisons

Seismic soil pressures are critical analysis components to understand and design for soil-structure interaction of sub-surface structures. A large scale experimental research program conducted at E-Defense's Shake table in Miki, Japan, included unprecedented seismic soil pressure measurements on a vertical, flexible, hollow shaft with model scale dimensions of 0.8 m square and 7.0 m in height. The densely instrumented vertical shaft was part of a larger system of underground structures, placed in an 8.0 m diameter laminar soil box. The two-layer soil stratigraphy consisted of an upper layer of medium dense sand and a lower layer of simulated bedrock. The hollow vertical shaft was constructed of aluminum and scaled to 1/20th of its prototype dimension. Two-directional, scaled ground motions of the 1995 Kobe earthquake were applied via shake table loading and seismic pressures were recorded using contact pressure sensors. Experimental results, including a dynamic system characterization, site response analyses, pressure time histories, and seismic pressure distribution profiles provide a critical benchmark for imminent numerical studies and the advancement of seismic soil pressure models for flexible structures. Following a thorough review of soil pressure analysis methodologies in literature, a detailed description of the large scale test and experimental results is presented. A comparison with limit state and elastic-based analytical approaches for retaining walls found in literature showed that, despite the unique shaft geometry, analytical methods accounting for the structural flexibility were able to closely predict the experimental soil pressures, while methodologies derived for rigid subsurface elements can only serve as rough preliminary estimate and should not be employed in performance based geotechnical analyses.

Lower stiffness of GFRP after sulfuric acid-solution aging is due to degradation of fibre-matrix interfaces?

The aging effects on composite stiffness are important when structures are monitored under long-term mechanical loads and harsh chemical environment. This work aims to reveal the role of fibre-to-matrix interfacial aging on elastic constants due to a long-term sulfuric acid immersion at a high temperature and pressure. The aging effects of glass fibre matrix interfaces are rather impossible to measure directly and they cannot be easily subtracted from macro scale test results. Here, extensive numerical simulations are automatically run to show the sensitivity of all the essential elastic constants on the experimentally observed output of mechanical tests in reality. Material models are formulated for two different length-scales to understand (1) the sensitivity of the layer’s length scale related elastic constants and (2) micro scale material properties. The well-established Halpin-Tsai parameters are used to include interfacial effects. The experimental results show that the aging significantly affects tensile and flexural behavior of glass fibre vinylester epoxy composites: tensile and flexural stiffness decreased 6–49% and ultimate strength values 13–34%. The simulations presented that the degradation of fibre matrix interfaces cannot be excluded and they verified the degradation of glass-fibres’ modulus due the conditioning.

Evaluation of getters for methane and ammonia decomposition

Getters are used in many tritium purification systems for impurity removal. One getter material, SAES® ST909, can be used to decompose various impurities (methane, carbon oxides, ammonia and others), and release the hydrogen bound in these compounds for further processing. Because, ST909 absorbs eight to nine percent of its initial weight in nitrogen, alternate materials may provide greater operational flexibility to accommodate variable operating carrier gases. The gettering capability of ST909 is related to the tri-metallic alloy (zirconium, manganese, and iron) composition. However, simply using a material with the same composition may not provide similar methane and ammonia decomposition conversion efficiency. For this testing, alternative materials to ST909 are compared to track methane and ammonia decomposition performance. Bench scale tests were performed at elevated temperature using various gas mixtures. Changes in methane and ammonia decomposition performance were tracked using RGA analysis during bench scale testing. Analytical comparisons of chemically equivalent materials to ST909 were also performed and correlated to bench scale test results. Characterization testing performed to evaluate chemically equivalent materials included: X-ray fluorescence, X-ray diffraction, and inductively coupled plasma-mass spectrometry (ICP-MS). Results are expounded upon and differences in gettering capability of alternate materials are highlighted.

Clinical study of the high frequency transcranial magnetic stimulation in the treatment of non motor symptoms of Parkinson's disease

Objective To explore the clinical effect of the high frequency transcranial magnetic stimulation in the treatment of Parkinson's non motor symptoms. Methods 80 patients with Parkinson's disease were randomly divided into observation group and control group by using random number table, 40 cases in each group.The patients in the observation group received high-frequency repetitive transcranial magnetic stimulation treatment based on the conventional anti-Parkinson's disease drugs.The patients of the control group were treated with conventional anti-Parkinson's disease drugs.The therapeutic effect of the two groups was compared, The test results of the unified Parkinson's disease, Hamilton depression scale, scores of Pittsburgh sleep quality index before and after treatment were analyzed in the two groups. Results After treatment for 7 days and 1 month, the unified Parkinson's disease rating scale test results of the observation group were (29.1±7.3)points, (29.5±6.9)points, respectively, which were significantly lower than (38.6±9.8)points before treatment, the difference was statistically significant(F=4.881, P<0.05). After treatment for 7 days, the Hamilton depression scale score of the observation group was (8.33±4.01)points, which was significantly lower than (13.55±8.27)points of the control group (t=2.356, P<0.05). After treatment for 1 month, the Hamilton depression scale score of the observation group was (8.01±3.87)points, which was significantly lower than (12.98±8.34)points of the control group , the difference was statistically significant(t=3.018, P<0.05). After treatment for 7 days, the Pittsburgh sleep quality index between the two groups had statistically significant difference [(19.7±2.2)points in the observation group, (16.1±1.1)points in the control group, t=2.371, P<0.05]. After treatment for 1 month, the Pittsburgh sleep quality index of the observation group was (26.5±1.3)points, which was significantly higher than (17.2±1.2)points of the control group , the difference was statistically significant(t=3.004, P<0.05). Conclusion The high frequency transcranial magnetic stimulation in the treatment of non motor symptoms of Parkinson's disease can significantly improve the patients' movement, speech, consciousness, emotion, sleep quality, and the effect is good. Key words: Parkinson disease; Transcranial magnetic stimulation; Comparative effectiveness research

IMPACT OF LOWER‐LIMB ENDURANCE TRAINING ON DYSPNEA SCALE AND PULMONARY FUNCTION TEST RESULTS IN COPD PATIENTS

RespirologyVolume 22, Issue S3 p. 104-105 APSR Poster Abstracts IMPACT OF LOWER-LIMB ENDURANCE TRAINING ON DYSPNEA SCALE AND PULMONARY FUNCTION TEST RESULTS IN COPD PATIENTS First published: 23 November 2017 https://doi.org/10.1111/resp.13207_51Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume22, IssueS3Supplement: 22nd Congress of the Asian Pacific Society of Respirology, International Convention Centre, Sydney, Australia, 23–26 November 2017November 2017Pages 104-105 RelatedInformation

09.10: Shear damage evaluation of bolted steel joints

ABSTRACTThe purpose of this study is to address a way of predicting the ductility capacity of steel joints. Recent research studies show that a joints’ ability to perform under elevated deformations, without fracturing, is a key factor in enabling mechanisms preventing collapse to be developed, and thus, improve the overall robustness of steel framed structures. This theme is becoming rather timely as building owners and insurers try to assess the collapse risk of their buildings, and the probability of a wide spread collapse if subjected to extreme events, either due to natural or terrorist causes. However, regarding this matter, current design code guidelines are limited to a prescriptive approach, by recommending a nominal tying force to be met, or quantifying a force that reproduces accidental scenarios, such as an impact of a vehicle, ships or helicopters, which do not address the overall behavior and performance of the structure.This paper presents an evaluation of the shear damage state of a bolted steel joint. For that, it is necessary to establish the shear damage parameters that are required to numerically obtain the rupture of steel elements, allowing the prediction of the ductility of steel joints. Previous authors’ research has showed that a ductile damage model may be insufficient to capture its end‐plate fracture and to establish a joints’ rupture. Hence, this study looks forward to improve the damage threshold for smaller triaxial stress states, within the shear and compression zones.In order to achieve this objective, a finite element model is developed and compared with real scale test results of a bolted steel joint under bending. The numerical model takes into account the strain softening of the material by means of a continuum damage mechanics approach and making use of the “element deletion” technique to approximate the fracture pattern of the studied joint. The analyses are carried out using the finite element software ABAQUS.

PID techniques: Alternatives to RICH methods

In this review article we discuss new updates on PID techniques, other than the Cherenkov method. In particular, we discuss recent efforts to develop high resolution timing, placing an emphasis on small scale test results.

Bond line models of glued wood-to-steel plate joints

The competitiveness of timber as structural material in large structures is often governed by the cost of structural joints. Tests indicate that the new joint concept presented herein using glued wood-to-steel plate joints can possibly reduce the cost by matching joint strength to member strength. The design is inspired by two previously proposed designs using a single large dowel and using a rubber foil interlayer in adhesive joints. Analytical 1D and numerical 3D models of the bond line are proposed in order to further develop the concept, both in the case of a traditional adhesive joint and for the innovative rubber foil adhesive joint.The glued wood-to-steel plate joints studied are lap joints with a load bearing capacity assumed to be governed by failure within or along the bond line. In the 1D and 3D structural models both linear elastic and non-linear fracture mechanics were applied, with the non-linear fracture mechanics model taking into account the gradual damage fracture softening in a fracture zone. For the conventional type of bond line it was found that bond line softening needs to be considered for adequate strength analysis while it was not needed for a bond line with a rubber foil.The computational results are compared to previous full scale test results. The numerical results show good agreement and the analytical results reasonable agreement. When using a high strength adhesive, the strength of the wood along the bond line is governing joint failure. For this case, the analyses predict a 150% load bearing capacity increase by the introduction of a rubber foil as compared to a traditional design. The test results indicated an even higher increase.

Numerical and experimental investigation into the accuracy of the fan scaling laws applied to large diameter axial flow fans

The cooling effectiveness of air-cooled steam condenser units is impacted by the performance of the large diameter axial flow cooling fans, which ultimately affects the overall efficiency of the power plant. Because of the large diameters of these fans, performance tests are carried out at test facilities with smaller, standardized diameters and measuring equipment. The performance of the large scale fans can be predicted based on the small scale test results using the similarity laws and scale-up formulae. This article details the results of small scale experimental tests and numerical simulations that were performed on a pair of 1.25 m diameter axial flow fans. Full scale, 10.360 m, diameter simulations of the same axial flow fans were subsequently performed and compared with the experimental results that were scaled up using the fan scaling laws.

Acupuncture for symptomatic lumbar spinal stenosis: a pilot randomized trial

lifestyle, diet, and exercise regimen. The measured outcomes will be a change in BP, hypertension incidence, and factors related to hypertension such as demographic characteristics, lifestyle, health data, SF-36v2, Beck Depression Inventory, Pittsburgh Sleep Quality Index, Fatigue Severity Scale, brain MRI, blood test, and urine test Results: NA Conclusion: Discussion: The results of this study will help establish the optimal acupuncture treatment for BP control in postmenopausal women with prehypertension or stage 1 hypertension. Contact: Kyung-Won Kang, kwkang@kiom.re.kr

Before defining performance criteria we must agree on what a "qualitative test procedure" is.

The term "qualitative test" is ambiguous and should not be used for nominal (classification) or ordinal (grading) tests. Characteristics for nominal and ordinal scale test results, such as traceability and uncertainty, remains to be established before general performance criteria can be agreed upon. For ordinal binary test with a quantitative back ground scale an assay could be characterized with the three quantities "C5", "C50", and "C95". The C50-value, or the equivalence point, ought to be declared by the manufacturers of diagnostic products. For the correct understanding and communication of results from ordinal and nominal tests the way of expressing the results also need to be harmonized.