scholarly journals Performance of Flowable Concrete in Underground Structures

2021 ◽  
Author(s):  
Sandip Sonule ◽  
H.Jayarama
Keyword(s):  
Test Results ◽  
Underground Structures ◽  
Long Distance ◽  
Experimental Procedure ◽  
Slump Flow ◽  
Flow Test ◽  
Natm Tunnel ◽  
Metro Project ◽  
Successful Production

Abstract Flowable concrete gives special combinations of uniformity, performance and consistency requirements that cannot be possible by traditional normal slump concrete. It is more superior concrete than the traditional concrete with high workability without segregation, bleeding, and is also suitable for use on structures with long distance pumping i.e., more than 120-meter length, for example, in NATM tunnels and cross-passages, and the concrete structure of the station box. Flowable concrete can flow itself without vibration or little bit vibration like surface tamping outer surface of the formwork for achieving a smooth surface finish after de-shuttering. The proportion of the mix is to be used in concrete, it must ensure a balance between deformability and stability. The behavior of concrete can be influenced by the properties of the selected item in the concrete, and the aspect ratio of the mixture. There is a need for the development of a methodology for the design of the flowable concrete mix. The paper presents an experimental procedure for the mix design of flowable concrete for grade M40 and implementation of the same mix at the cast in situ Base slab, Roof slab Rcc walls for underground metro stations, NATM tunnel & cross passages in Mumbai Metro Project, package -UGC-07. The test results for acceptance characteristics of M40 grade flowable concrete such as Slump flow test, compressive strength at the ages of 7, 28, and 56 days determined, and results are included here. Successful production of temperature control flowable concrete from batching plant, transportation, placement procedures, and proper planning of handling and execution of flowable concrete at the site are presented in this article.

scholarly journals Performance of Flowable Concrete in Underground Structures

2021 ◽  
Author(s):  
Sandip Sonule ◽  
H.Jayarama ◽  
Partha Sarath Ojha ◽  
C.M Jadhav ◽  
K.C Tayade
Keyword(s):  
Fixed Ratio ◽  
Concrete Durability ◽  
Test Results ◽  
Underground Structures ◽  
Long Distance ◽  
Durability Test ◽  
Natm Tunnel ◽  
Stability Type ◽  
Passing Ability

Abstract Flowable concrete gives special combinations of uniformity, performance and consistency requirements that cannot be possible by traditional normal slump concrete. It is superior concrete than the traditional concrete with high workability, no segregation, no bleeding, and it is also suitable for use in the structures with long-distance pumping i.e., more than 120-meter length, for example, in NATM tunnels, cross-passages, and the concrete structure of the station box. Flowable concrete can flow itself without vibration or a little bit of vibration like surface tamping at outer surface of the formwork for achieving a smooth surface finish after de-shuttering. Percentages of concrete ingredients that are used in concrete to ensure a balance between deformability and stability. Type of selected materials and the fixed ratio of concrete materials can be affected on the fresh and harden properties of the concrete. The article presents experimental techniques for mix designing of flowable concrete for grade M40 and application of the same concrete mix at the cast in situ Base slab, Roof slab Rcc walls for underground metro stations, NATM tunnel & cross passages in Mumbai Metro Project, package -UGC-07. The test results for conformity requirements of M40 grade flowable concrete such as flowability, viscosity, passing ability of fresh concrete, durability test and harden concrete tests determined, and results are included here.

scholarly journals Evaluating the applicability of rheometry in steel fiber reinforced self-compacting concretes

2016 ◽  
Vol 9 (6) ◽  
pp. 969-988 ◽  
Author(s):  
R. S. Alferes Filho ◽  
◽  
F. K. Motezuki ◽  
R. C. O. Romano ◽  
R. G. Pileggi ◽  
...  
Keyword(s):  
Construction Industry ◽  
Steel Fiber ◽  
Rheological Parameters ◽  
Experimental Program ◽  
Test Results ◽  
Slump Flow ◽  
Flow Test ◽  
Conventional Tests ◽  
Fresh State ◽  
Passing Ability

ABSTRACT The use of self-compacting concrete in civil construction industry presents various advantages, since the material shows adequate workability during fresh state. When fiber reinforcement is used, there are changes in its behavior that require attention. This study aimed to evaluate the applicability of rheological tests and the correlation between its results and those obtained with regular tests used to control SCCs. In that sense, different mixtures of SCC with different steel fiber contents were produced in order to be analyzed in the experimental program described. Rotational rheology tests and slump flow and L-box tests were performed. The results showed that slump flow test did not present good correlations with rheological parameters. On the other hand, this test was able to point out the risk of segregation of the mixtures with higher fiber contents. A good correlation was obtained between the L-box test results and rheological parameters. The L-box was also able to show loss in the passing ability of SCC related to the rise of plastic viscosity and yield stress. These tests also presented a good correlation with the rheological parameters when lower fiber contents were used. Although the rheometry test was unable to evaluate these problems, this kind of test gave more objective and reliable data on variations in rheological parameters related to the increase of fiber content, and proved to be a more reliable test to this kind of application, especially when applied together with the conventional tests.

scholarly journals Chromosomal painting of the sandpiper (Actitis macularius) detects several fissions for the Scolopacidae family (Charadriiformes)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Melquizedec Luiz Silva Pinheiro ◽  
Cleusa Yoshiko Nagamachi ◽  
Talita Fernanda Augusto Ribas ◽  
Cristovam Guerreiro Diniz ◽  
Patricia Caroline Mary O´Brien ◽  
...  
Keyword(s):  
Chromosome Painting ◽  
Diploid Number ◽  
Chromosomal Evolution ◽  
Long Distance ◽  
Chromosomal Painting ◽  
Cytogenetic Studies ◽  
Burhinus Oedicnemus ◽  
Clear Idea ◽  
First Time

Abstract Background The Scolopacidae family (Suborder Scolopaci, Charadriiformes) is composed of sandpipers and snipes; these birds are long-distance migrants that show great diversity in their behavior and habitat use. Cytogenetic studies in the Scolopacidae family show the highest diploid numbers for order Charadriiformes. This work analyzes for the first time the karyotype of Actitis macularius by classic cytogenetics and chromosome painting. Results The species has a diploid number of 92, composed mostly of telocentric pairs. This high 2n is greater than the proposed 80 for the avian ancestral putative karyotype (a common feature among Scolopaci), suggesting that fission rearrangements have formed smaller macrochromosomes and microchromosomes. Fluorescence in situ hybridization using Burhinus oedicnemus whole chromosome probes confirmed the fissions in pairs 1, 2, 3, 4 and 6 of macrochromosomes. Conclusion Comparative analysis with other species of Charadriiformes studied by chromosome painting together with the molecular phylogenies for the order allowed us to raise hypotheses about the chromosomal evolution in suborder Scolopaci. From this, we can establish a clear idea of how chromosomal evolution occurred in this suborder.

scholarly journals Certification tests of a protective device such as ROPS to ensure safe usage of tractors

2018 ◽  
Vol 224 ◽  
pp. 02061
Author(s):  
Irina Troyanovskaya ◽  
Anton Kalugin
Keyword(s):  
Strain Curve ◽  
Protective Device ◽  
Test Results ◽  
Experimental Procedure ◽  
Structure Deformation ◽  
Safety Requirements ◽  
Performance Check ◽  
Protective Structures ◽  
Full Scale Tests ◽  
Tractor Plant

According to the safety requirements, all protective devices of tractor units are subject to obligatory certification. One of the main means of protecting the operator during overturning is ROPS system. In accordance with GOST (National State Standard), a performance check of ROPS protective structures is carried out on basis of full-scale tests. The purpose of the presented study is to develop the experimental procedure and to obtain the performance check result of ROPS protective device of the tractor unit’s cabin using B10 bulldozer manufactured by the Chelyabinsk Tractor Plant as an example. The tests were carried out at the Ural Test Center NATI. For this purpose, a special bedplate was used, allowing to test the protective cabins of tractors with the total mass of up to 110 tons. The hydraulic system of the bedplate allowed to carry out the process of lateral loading of ROPS step by step, where each step corresponded to the 10 mm structure deformation. The applied load and structure deformation were recorded at each step. The energy accumulated by the structure was calculated as the area under the stress-strain curve. The energy U = 40867 J, which was required according to GOST, was accumulated during lateral deformation Δ = 270 mm. The force constituted Fy = 243 kN. After removing the lateral load, the structure was subjected to the vertical static and longitudinal loading. During the whole experiment of ROPS protective device, repairs, deformation corrections and adjustments were not allowed. The test results of ROPS structure of B10 bulldozer cabin showed compliance with the GOST safety requirements. During ROPS deformation, penetration of the protective structure elements into the driver’s limited zone was not observed.

Correlation of Grassy Lake and Cedar Lake ambers using infrared spectroscopy, stable isotopes, and palaeoentomology

2008 ◽  
Vol 45 (9) ◽  
pp. 1061-1082 ◽  
Author(s):  
Ryan C. McKellar ◽  
Alexander P. Wolfe ◽  
Ralf Tappert ◽  
Karlis Muehlenbachs
Keyword(s):  
Stable Isotopes ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Late Cretaceous ◽  
Western Canada ◽  
Long Distance ◽  
Geochemical Fingerprinting ◽  
Long Distance Transport ◽  
Distance Transport

The Late Cretaceous Grassy Lake and Cedar Lake amber deposits of western Canada are among North America’s most famous amber-producing localities. Although it has been suggested for over a century that Cedar Lake amber from western Manitoba may be a secondary deposit having originated from strata in Alberta, this hypothesis has not been tested explicitly using geochemical fingerprinting coupled to comparative analyses of arthropod faunal content. Although there are many amber-containing horizons associated with Cretaceous coals throughout Alberta, most are thermally mature and brittle, thus lacking the resilience to survive long distance transport while preserving intact biotic inclusions. One of the few exceptions is the amber found in situ at Grassy Lake. We present a suite of new analyses from these and other Late Cretaceous ambers from western Canada, including stable isotopes (H and C), Fourier transform infrared (FTIR) spectra, and an updated faunal compendium for the Grassy and Cedar lakes arthropod assemblages. When combined with amber’s physical properties and stratigraphic constraints, the results of these analyses confirm that Cedar Lake amber is derived directly from the Grassy Lake amber deposit or an immediate correlative equivalent. This enables the palaeoenvironmental context of Grassy Lake amber to be extended to the Cedar Lake deposit, making possible a more inclusive survey of Cretaceous arthropod faunas.

scholarly journals Performance of the Innova SARS-CoV-2 antigen rapid lateral flow test in the Liverpool asymptomatic testing pilot: population based cohort study

BMJ ◽  
2021 ◽  
pp. n1637 ◽  
Author(s):  
Marta García-Fiñana ◽  
David M Hughes ◽  
Christopher P Cheyne ◽  
Girvan Burnside ◽  
Mark Stockbridge ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Load ◽  
Predictive Value ◽  
High Viral Load ◽  
Test Results ◽  
Chain Reaction ◽  
Viral Loads ◽  
Flow Test ◽  
Polymerase Chain ◽  
Lateral Flow Test

Abstract Objective To assess the performance of the SARS-CoV-2 antigen rapid lateral flow test (LFT) versus polymerase chain reaction testing in the asymptomatic general population attending testing centres. Design Observational cohort study. Setting Community LFT pilot at covid-19 testing sites in Liverpool, UK. Participants 5869 asymptomatic adults (≥18 years) voluntarily attending one of 48 testing sites during 6-29 November 2020. Interventions Participants were tested using both an Innova LFT and a quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) test based on supervised self-administered swabbing at testing sites. Main outcome measures Sensitivity, specificity, and predictive values of LFT compared with RT-qPCR in an epidemic steady state of covid-19 among adults with no classic symptoms of the disease. Results Of 5869 test results, 22 (0.4%) LFT results and 343 (5.8%) RT-qPCR results were void (that is, when the control line fails to appear within 30 minutes). Excluding the void results, the LFT versus RT-qPCR showed a sensitivity of 40.0% (95% confidence interval 28.5% to 52.4%; 28/70), specificity of 99.9% (99.8% to 99.99%; 5431/5434), positive predictive value of 90.3% (74.2% to 98.0%; 28/31), and negative predictive value of 99.2% (99.0% to 99.4%; 5431/5473). When the void samples were assumed to be negative, a sensitivity was observed for LFT of 37.8% (26.8% to 49.9%; 28/74), specificity of 99.6% (99.4% to 99.8%; 5431/5452), positive predictive value of 84.8% (68.1% to 94.9%; 28/33), and negative predictive value of 93.4% (92.7% to 94.0%; 5431/5814). The sensitivity in participants with an RT-qPCR cycle threshold (Ct) of <18.3 (approximate viral loads >10 6 RNA copies/mL) was 90.9% (58.7% to 99.8%; 10/11), a Ct of <24.4 (>10 4 RNA copies/mL) was 69.4% (51.9% to 83.7%; 25/36), and a Ct of >24.4 (<10 4 RNA copies/mL) was 9.7% (1.9% to 23.7%; 3/34). LFT is likely to detect at least three fifths and at most 998 in every 1000 people with a positive RT-qPCR test result with high viral load. Conclusions The Innova LFT can be useful for identifying infections among adults who report no symptoms of covid-19, particularly those with high viral load who are more likely to infect others. The number of asymptomatic adults with lower Ct (indicating higher viral load) missed by LFT, although small, should be considered when using single LFT in high consequence settings. Clear and accurate communication with the public about how to interpret test results is important, given the chance of missing some cases, even at high viral loads. Further research is needed to understand how infectiousness is reflected in the viral antigen shedding detected by LFT versus the viral loads approximated by RT-qPCR.

Documenting the Ikpana interrogative system

2021 ◽  
Vol 42 (1) ◽  
pp. 63-100
Author(s):  
Jason Kandybowicz ◽  
Bertille Baron Obi ◽  
Philip T. Duncan ◽  
Hironori Katsuda
Keyword(s):  
Comprehensive Treatment ◽  
Left Periphery ◽  
Long Distance ◽  
Southeastern Part ◽  
Endangered Language ◽  
Research Questions ◽  
Volta Region ◽  
Movement Asymmetry ◽  
Syntactic Properties

Abstract This article provides a comprehensive treatment of the interrogative system of Ikpana (ISO 639-3: lgq), an endangered language spoken in the southeastern part of Ghana’s Volta region. The article features a description and analysis of both the morphosyntax and intonation of questions in the language. Polar questions in Ikpana are associated with dedicated prosodic patterns and may be segmentally marked. As for wh- interrogatives, Ikpana allows for optional wh- movement. Interrogative expressions may appear clause-internally in their base-generated positions or in the left periphery followed by one of two optionally droppable particles with distinct syntactic properties. In this way, wh- movement structures are either focus-marked constructions or cleft structures depending on the accompanying particle. We identify an interesting wh- movement asymmetry – unlike all other wh- movement structures, ‘how’ questions may not be formed via the focus-marked or cleft strategy. We document a number of other attested wh- structures in the language, including long-distance wh- movement, partial wh- movement, long-distance wh- in-situ, and multiple wh- questions. We argue that by allowing our documentation efforts to be shaped and guided by theoretically driven research questions, we reach deeper levels of description than would have been possible if approached from a purely descriptive-documentary perspective.

IoT Based Bus Tracking System

2021 ◽  
Vol 9 (VI) ◽  
pp. 2889-2893
Author(s):  
Miss Payal W. Paratpure
Keyword(s):  
Tracking System ◽  
Cost Effective ◽  
Raspberry Pi ◽  
Accurate Estimation ◽  
Time Of Arrival ◽  
Test Results ◽  
Cloud Server ◽  
Bus Operator ◽  
Gps Device

Tracking of public bus location requires a GPS device to be installed, and lots of bus operators in developing countries don't have such an answer in situ to supply an accurate estimation of bus time of arrival (ETA). Without ETA information, it's very difficult for the overall public to plan their journey effectively. In this paper, implementation of an innovative IOT solution to trace the real time location of buses without requiring the deployment of a GPS device is discussed. It uses Bluetooth Low Energy (BLE) proximity beacon to trace the journey of a bus by deploying an Estimate location beacon on the bus. BLE detection devices (Raspberry Pi 4) are installed at selected bus stops along the path to detect the arrival of buses. Once detected, the situation of the bus is submitted to a cloud server to compute the bus ETAs. A field trial is currently being conducted in Johor, Malaysia together with an area bus operator on one single path. Our test results showed that the detection of BLE beacons is extremely accurate and it's feasible to trace the situation of buses without employing a GPS device during a cost-effective way.

The Pittsburgh Cervical Cancer Screening Model: A Risk Assessment Tool

2010 ◽  
Vol 134 (5) ◽  
pp. 744-750
Author(s):  
R. Marshall Austin ◽  
Agnieszka Onisko ◽  
Marek J. Druzdzel
Keyword(s):  
Cervical Cancer ◽  
Cancer Screening ◽  
Cervical Cancer Screening ◽  
Disease Risk ◽  
Hpv Vaccination ◽  
Dynamic Bayesian Network ◽  
Adenocarcinoma In Situ ◽  
Test Results ◽  
Hpv Test

Abstract Context.—Evaluation of cervical cancer screening has grown increasingly complex with the introduction of human papillomavirus (HPV) vaccination and newer screening technologies approved by the US Food and Drug Administration. Objective.—To create a unique Pittsburgh Cervical Cancer Screening Model (PCCSM) that quantifies risk for histopathologic cervical precancer (cervical intraepithelial neoplasia [CIN] 2, CIN3, and adenocarcinoma in situ) and cervical cancer in an environment predominantly using newer screening technologies. Design.—The PCCSM is a dynamic Bayesian network consisting of 19 variables available in the laboratory information system, including patient history data (most recent HPV vaccination data), Papanicolaou test results, high-risk HPV results, procedure data, and histopathologic results. The model's graphic structure was based on the published literature. Results from 375 441 patient records from 2005 through 2008 were used to build and train the model. Additional data from 45 930 patients were used to test the model. Results.—The PCCSM compares risk quantitatively over time for histopathologically verifiable CIN2, CIN3, adenocarcinoma in situ, and cervical cancer in screened patients for each current cytology result category and for each HPV result. For each current cytology result, HPV test results affect risk; however, the degree of cytologic abnormality remains the largest positive predictor of risk. Prior history also alters the CIN2, CIN3, adenocarcinoma in situ, and cervical cancer risk for patients with common current cytology and HPV test results. The PCCSM can also generate negative risk projections, estimating the likelihood of the absence of histopathologic CIN2, CIN3, adenocarcinoma in situ, and cervical cancer in screened patients. Conclusions.—The PCCSM is a dynamic Bayesian network that computes quantitative cervical disease risk estimates for patients undergoing cervical screening. Continuously updatable with current system data, the PCCSM provides a new tool to monitor cervical disease risk in the evolving postvaccination era.

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