Optimisation of an integrated transport and distribution system

Imperial Users onl

Dielectric Properties and Numerical Modelling of Microwave Heating of Portland Cement/Fly Ash Blends

Due to its volumetric heating mechanism, microwave is increasingly being recognized as a potential alternative low-energy heating technique for curing cementitious products. However, its heating capacity, among other factors, heavily relies on the dielectric properties of the raw materials, which, in turn, can be affected by moisture content, temperature and the degree of hydration. Unfortunately, current understanding on these issues is still very limited. Consequently, it is difficult to predict the heating profile of the cementitious products heated in microwave, even though a good knowledge of this is essential to optimize the microwave operation condition in order to ensure the quality of cementitious products. In this paper, the dielectric properties of Portland cement/fly ash blends were investigated during a 24-hour hydration period under 25oC, 40oC and 60oC at a frequency of 2.45GHz. The Portland cement was replaced by fly ash at the levels of 0% and 55% by weight at water-to-binder ratios of 0.25 and 0.35, respectively. Setting times were also measured in order to interpret the changes of the dielectric properties at different stages of hydration. Based on the obtained dielectric properties data, heating models were developed using two different software packages, namely, ANSYS and COMSOL, which were then validated by the heating profiles obtained in a tailored microwave system using FBG sensor and thermal imaging techniques. It showed that both simulated results overestimated the real temperature within the sample. However, COMSOL can give a better prediction of the overall temperature profile, whilst ANSYS is more reliable in predicting single temperature. Further investigation is still needed in order to identify which modelling technique is the best option for predicting both the temperature profile and the temperature within cementitious materials cured under microwave

Modelling of moisture migration and spalling behaviour in non-uniformly heated concrete

Imperial Users onl

Seasonal evaluation of serumal Ca, P and ALP of slaughtered cattle in Tabriz abattoir

Increasing knowledge of metabolic disorders and prevention of any prduction decrease is beneficial in animal breeding. Problems related to calcium and phosphorus deficiency in high producing animals are among the most important metabolic disorders with disease such as osteomalacia, rickets, milk fever, pos parturition hemoglobinuria and reproductive disorders named as the metabolic complications. This study was conducted on non pregnant crossbreed dairy cattle. In the middle of each season with daily referral to the abattoir, blood samples were collected in veneject tubes and after transfer to the laboratory, the serumic levels of Ca, P and ALP were measured by spectrophotometry. One hundred samples for each season and a total of 400 samples were studied. The mean serumic levels of Ca, P and ALP were 8.83±0.02 mg/dl, 3.88±0.07 mg/dl, 163.4±0.8 Iu/lit; 9.05±0.03mg/dl, 4.19±0.01mg/dl, 240.7±1.2 Iu/lit; 9.03±0.07 mg/dl, 5.33±0.02mg/dl, 185.06±2.3 Iu/lit and 9.33±0.09 mg/dl, 5.74±0.08 mg/dl, 230.03±7.4 Iu/lit, in the spring, summer, autumn and winter respectively. Considering the normal Ca, P and ALP values in cattle, 6.3% and 83% of cases had Ca and P deficiency respectively in the spring, 80% of cases had subclinical phosphorus deficiency in the summer, 7.3% of cases had subclinical phosphorus deficiency in the autumn and 9.45% and 7.36% of cases had Ca deficiency and ALP elevation respectively in the winter. The significant decrease in Ca and P levels in the spring and P levels in the summer (

Degradation of polyamide reverse osmosis membranes in the presence of chloramine

Exposure to relatively low concentrations of chlorinated chemicals such as hypochlorite can reduce the performance and ultimately result in the failure of polyamide (PA) reverse osmosis membranes. Whereas the tolerance of PA membranes to chloramine solutions is considerably higher than that of hypochlorite, the presence of some metal ions can potentially catalyze and accelerate degradation reactions. Spectroscopic techniques are commonly used to qualitatively assess the chemical degradation of membranes by observing changes in structural peaks. This paper presents a technique to quantitatively evaluate changes in PA membranes exposed to chloramine by means of a peak ratio derived from a typical amide peak and an invariant peak in the same spectrum. The effect of some common metal ions and combinations of these on the peak ratio parameter derived from a typical amide peak is also reported

Prediction of colorectal cancer diagnosis based on circulating plasma proteins

International audienceNon-invasive detection of colorectal cancer with blood-based markers is a critical clinical need. Here we describe a phased mass spectrometry-based approach for the discovery, screening, and validation of circulating protein biomarkers with diagnostic value. Initially, we profiled human primary tumor tissue epithelia and characterized about 300 secreted and cell surface candidate glycoproteins. These candidates were then screened in patient systemic circulation to identify detectable candidates in blood plasma. An 88-plex targeting method was established to systematically monitor these proteins in two large and independent cohorts of plasma samples, which generated quantitative clinical datasets at an unprecedented scale. The data were deployed to develop and evaluate a five-protein biomarker signature for colorectal cancer detection