Quantifying the efficiency and quality of air void distributions in concrete

This work establishes new ways to measure and examine the air bubble distribution within concrete. This is important to provide freeze thaw durability and resistance to oxychloride formation. These bubbles decrease the fluid pressure on freezing and crystal formation. The quality of the air void distribution is important to maintain from mixing the concrete until it is hardened to ensure durability. If these bubbles are significantly modified or destroyed during construction or are lost over time, then they cannot provide the needed protection. This work studies concrete mixtures immediately after mixing, during placement, after hardening, throughout freezing and thawing cycles, and soaked in chloride solution through temperature changes. The SAM (AASHTO TP 118), Hardened Air Void Analysis (ASTM C), Freeze Thaw Durability Factor (ASTM C666), and Micro computed tomography (Micro-CT) are all utilized to verify and establish the quality of the air void system within concrete mixtures [1-3]

Estimating Individual and Household Reproduction Numbers in an Emerging Epidemic

Reproduction numbers, defined as averages of the number of people infected by a typical case, play a central role in tracking infectious disease outbreaks. The aim of this paper is to develop methods for estimating reproduction numbers which are simple enough that they could be applied with limited data or in real time during an outbreak. I present a new estimator for the individual reproduction number, which describes the state of the epidemic at a point in time rather than tracking individuals over time, and discuss some potential benefits. Then, to capture more of the detail that micro-simulations have shown is important in outbreak dynamics, I analyse a model of transmission within and between households, and develop a method to estimate the household reproduction number, defined as the number of households infected by each infected household. This method is validated by numerical simulations of the spread of influenza and measles using historical data, and estimates are obtained for would-be emerging epidemics of these viruses. I argue that the household reproduction number is useful in assessing the impact of measures that target the household for isolation, quarantine, vaccination or prophylactic treatment, and measures such as social distancing and school or workplace closures which limit between-household transmission, all of which play a key role in current thinking on future infectious disease mitigation

A Review of Current Methodologies for Regional Evapotranspiration Estimation from Remotely Sensed Data

An overview of the commonly applied evapotranspiration (ET) models using remotely sensed data is given to provide insight into the estimation of ET on a regional scale from satellite data. Generally, these models vary greatly in inputs, main assumptions and accuracy of results, etc. Besides the generally used remotely sensed multi-spectral data from visible to thermal infrared bands, most remotely sensed ET models, from simplified equations models to the more complex physically based two-source energy balance models, must rely to a certain degree on ground-based auxiliary measurements in order to derive the turbulent heat fluxes on a regional scale. We discuss the main inputs, assumptions, theories, advantages and drawbacks of each model. Moreover, approaches to the extrapolation of instantaneous ET to the daily values are also briefly presented. In the final part, both associated problems and future trends regarding these remotely sensed ET models were analyzed to objectively show the limitations and promising aspects of the estimation of regional ET based on remotely sensed data and ground-based measurements

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

A Dataset on the influence of air voids and fluid absorption on salt-induced calcium oxychloride damage

This dataset aims to display damage induced by calcium oxychloride formation with respect to concrete air void content, and boundary conditions. The purpose of this data set is to complete the data in the paper submitted to Cement and Concrete Composites Journal. The citation for this journal paper is : [1] Rita M. Ghantous, K. Zetterberg, H. H. Becker, A. Behravan, M. T. Ley, O. B. Isgor, W. J. Weiss (2022). “The influence of air voids and fluid absorption on salt-induced calcium oxychloride damage,” submitted to Cement and Concrete Composites Journal.Keywords: deicing salts, calcium chloride, calcium oxychloride, salt damage, air void content, concrete pavement