1,127 research outputs found
Cyclic Performance of Beam-Column Joints with Extended Column Fixed at Base: Part I - Experimental Investigation
http://www.icevirtuallibrary.com/content/journals āPermission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees.āThe seismic performance of a non-seismically detailed reinforced concrete (RC) beamācolumn joint with column
pinned and fixed at the base is experimentally investigated in this paper. Six half-scale RC beamācolumn specimens
were tested to study the effect of inflection point on the cyclic behaviour of beamācolumn sub-assemblages. The
specimens were separated into two groups. The shape of specimens in the first group was cruciform; the size of the
column in those specimens was varied while the size of beam was kept nearly constant. The dimensions and
reinforcing detail of specimens in the second group were identical to those in the first one except that the column
was extended to the footing and fixed at the base. The main variable in this study was the relative stiffness between
beam and column, which affects the position of the inflection point. The test results demonstrated a significant
effect of inflection point position on the load capacity, joint shear stress and failure mode
Machine Learning-Based Prediction of Compressive Performance in Circular Concrete Columns Confined with FRP
This article presents a comprehensive investigation, focusing on the prediction and formulation of the design equation of compressive strength of circular concrete columns confined with Fiber Reinforced Polymer (FRP) using advanced machine learning models. Through an extensive analysis of 170 experimental data specimens, the study examines the effects of six key parameters, including concrete cylinder diameter, concrete cylinder-FRP thickness, compressive strength of concrete without FRP, initial compressive strain of concrete without FRP, elastic modulus and tensile strength of FRP, on the compressive strength of the circular concrete columns confined with FRP. The predictive model and design equation of compressive strength is developed using a machine learning technique, specifically the artificial neural networks (ANN) model. The results demonstrates strong correlations between the compressive strength of the circular concrete columns confined with FRP and certain factors, such as the compressive strength of the concrete and compressive strain of the concrete column without FRP, elastic modulus of FRP, and tensile strength of FRP. The ANN model specifically developed using Neural Designer, exhibits superior predictive accuracy compared to other constitutive models, showcasing its potential for practical implementation. The study's findings contribute valuable insights into accurately predicting the compressive performance of circular concrete columns confined with FRP, which can aid in optimizing and designing civil engineering structures for enhanced performance and efficiency
Stillbirths among Pregnant Women Admitted to the Department of Obstetrics and Gynaecology in a Tertiary Care Centre: A Descriptive Cross-sectional Study
Introduction: Stillbirth is often defined as the death of a foetus in the uterus prior to its birth or during the process of birth. Most of the stillbirths are preventable global health problem. The aim of this study was to find out the prevalence of stillbirths among pregnant women admitted to the Department of Obstetrics and Gynaecology in a tertiary care centre. Methods: A descriptive cross-sectional study was conducted in the Department of Obstetrics and Gynaecology in a tertiary care centre among pregnant women admitted between 14 April 2021 to 13 April 2022. Ethical approval was taken from the Institutional Review Committee (Reference number: 43). Convenience sampling method was used. The data were collected from the medical record section using a proforma. Point estimate and 95% Confidence Interval were calculated. Results: Among 5,118 pregnant women, stillbirths were found in 126 (2.46%) (2.04-2.88, 95% Confidence Interval). Conclusions: The prevalence of stillbirth among pregnant women was higher than in the other studies done in similar settings
Effects of Row Spacings and Varieties on Grain Yield and Economics of Maize
Maize is the second most important crop of Nepal. The yield of the crop is low due to lack of appropriate plant density for the varieties. The field experiment was carried out to study the effect of different row spacings on different maize varieties at Deupur, Lamahi municipality of the dang district in province No. 5, Nepal during the rainy season from June to September, 2018. Four levels of spacings (boardcasting and three row spacings of 45, 60 and 75 cm) and two maize varieties (Rampur Composite and Arun-2) were evaluated using randomized complete block design with three replications. The highest grain yield was found in Rampur Composite and Arun-2 while they were planted with row spacing of 60 cm with plant to plant spacing of 25 cm. The highest grain yield, cob length, cob circumference, number of rows per cob, thousand grain weight were reported when maize was planted in the row spacing 60Ć25cm. Among the maize varieties, Rampur Composite produced the highest grain yield, cob length, cob circumference, number of rows per cob as compared to Arun-2. This study suggested that maize production can be maximized by cultivating maize varieties with row spacing of 60 cm with plant to plant spacing of 25 cm
Effect of top reinforcing on the fire performance of continuous reinforced concrete beams
This paper examines the behaviour of continuous reinforced concrete beams exposed to
fire on three sides, in order to investigate the effect of different lengths of the top
reinforcing bars over the supports. The study was performed with 2D finite element
analysis using SAFIR. The effect of continuity was investigated with rectangular crosssection
beams spanning over two and three bays subjected to the ISO 834 fire. Compared
to a single span beam, the continuous beams resisted the fire exposure for a longer period
of time. It was found that different lengths of the top reinforcing bars resulted in different
failure mechanisms, but did not greatly affect the fire resistance of the beams . The
influence of the full process of fire development was analysed using the ISO fire for 30,
60 and 90 minutes followed by a decay phase. Structural failure only occurred if the fully
developed phase of the fire continued until very close to the failure time reached with no
decay phase
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Observations on typing from 136 million keystrokes
We report on typing behaviour and performance of 168,000
volunteers in an online study. The large dataset allows detailed
statistical analyses of keystroking patterns, linking them
to typing performance. Besides reporting distributions and
confirming some earlier findings, we report two new findings.
First, letter pairs typed by different hands or fingers are more
predictive of typing speed than, for example, letter repetitions.
Second, rollover-typing, wherein the next key is pressed before
the previous one is released, is surprisingly prevalent. Notwithstanding
considerable variation in typing patterns, unsupervised
clustering using normalised inter-key intervals reveals
that most users can be divided into eight groups of typists that
differ in performance, accuracy, hand and finger usage, and
rollover. The code and dataset are released for scientific use
Low velocity impact and creep-strain behaviour of vinyl ester matrix nanocomposites based on layered silicate
The impact properties of neat vinyl ester and the nanocomposites were performed using a low velocity impact testing. The addition of layered silicate into the polymer matrix shows that an optimum range of nanoclay reinforcement in the vinyl ester matrix can produce enhanced load bearing and energy absorption capability compared to the neat matrix. In addition, the amount of microvoids in the nanocomposites structure influences the overall properties. Likewise, the influence of the clay addition into the neat polymer on the creep relaxation behaviour at 25Ā°C and 60Ā°C was studied. In both cases, the presence of the layered silicate remarkably improved the creep behaviour. The improvement of these properties can be assigned to the stiff fillers and the configurational linkage between the polymer and the layered silicate which are supported by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterisations by showing a distinct change in surface morphology associated with improved impact toughness and creep response
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