Aluminum-rich belite sulfoaluminate cements: clinkering and early age hydration

Belite sulfoaluminate (BSA) cements have been proposed as environmentally friendly building materials, as their production may release up to 35% less CO2 into the atmosphere when compared to ordinary Portland cements. Here, we discuss the laboratory production of three aluminum-rich BSA clinkers with nominal mineralogical compositions in the range C2S (50-60%), C4A3$(20- 30$, i.e. a value as close as possible to the nominal composition. Under these experimental conditions, three different BSA clinkers, nominally with 20, 30 and 30 wt% of C4A3$, had 19.6, 27.1 and 27.7 wt$ respectively, as determined by Rietveld analysis. We also studied the complex hydration process of BSA cements prepared by mixing BSA clinkers and gypsum. We present a methodology to establish the phase assemblage evolution of BSA cement pastes with time, including amorphous phases and free water. The methodology is based on Rietveld quantitative phase analysis of synchrotron and laboratory X-ray powder diffraction data coupled with chemical constraints. A parallel calorimetric study is also reported. It is shown that the b-C2S phase is more reactive in aluminum-rich BSA cements than in standard belite cements. On the other hand, C4A3$ reacts faster than the belite phases. The gypsum ratio in the cement is also shown to be an important factor in the phase evolution

Enthalpy of formation of ye’elimite and ternesite

Calcium sulfoaluminate clinkers containing ye’elimite (Ca4Al6O12(SO4)) and ternesite (Ca5(SiO4)2SO4) are being widely investigated as components of calcium sulfoaluminate cement clinkers. These may become low energy replacements for Portland cement. Conditional thermodynamic data for ye’elimite and ternesite (enthalpy of formation) have been determined experimentally using a combination of techniques: isothermal conduction calorimetry, X-ray powder diffraction and thermogravimetric analysis. The enthalpies of formation of ye’elimite and ternesite at 25 °C were determined to be − 8523 and − 5993 kJ mol−1, respectively

Uniform electron gases

We show that the traditional concept of the uniform electron gas (UEG) --- a homogeneous system of finite density, consisting of an infinite number of electrons in an infinite volume --- is inadequate to model the UEGs that arise in finite systems. We argue that, in general, a UEG is characterized by at least two parameters, \textit{viz.} the usual one-electron density parameter $\rho$ and a new two-electron parameter $\eta$. We outline a systematic strategy to determine a new density functional $E(\rho,\eta)$ across the spectrum of possible $\rho$ and $\eta$ values.Comment: 8 pages, 2 figures, 5 table

Alveolar Dynamics and Beyond – The Importance of Surfactant Protein C and Cholesterol in Lung Homeostasis and Fibrosis

Surfactant protein C (SP-C) is an important player in enhancing the interfacial adsorption of lung surfactant lipid films to the alveolar air-liquid interface. Doing so, surface tension drops down enough to stabilize alveoli and the lung, reducing the work of breathing. In addition, it has been shown that SP-C counteracts the deleterious effect of high amounts of cholesterol in the surfactant lipid films. On its side, cholesterol is a wellknown modulator of the biophysical properties of biological membranes and it has been proven that it activates the inflammasome pathways in the lung. Even though the molecular mechanism is not known, there are evidences suggesting that these two molecules may interplay with each other in order to keep the proper function of the lung. This review focuses in the role of SP-C and cholesterol in the development of lung fibrosis and the potential pathways in which impairment of both molecules leads to aberrant lung repair, and therefore impaired alveolar dynamics. From molecular to cellular mechanisms to evidences in animal models and human diseases. The evidences revised here highlight a potential SP-C/cholesterol axis as target for the treatment of lung fibrosis

Estimation of standard molar entropy of cement hydrates and clinker minerals

It is not straightforward to experimentally measure the standard molar entropy of cement hydrates or clinker minerals. This is further compounded by the controversies surrounding the entropy values reported in established thermodynamic datasets for cements. The purpose of this study is to assess the reliability of standard entropies compiled in those datasets. To this end, a simple but robust method is used in which the standard entropy of an inorganic solid is correlated to its formula unit volume via a linear equation. The results of this analysis show that the standard entropies and/or molar volumes (and in cases solubility products) of the following phases deserve closer scrutiny: meta-ettringite phases; magnesium/aluminium layered double hydroxide solid solutions; almost all iron-bearing monosulfate and hydrogarnet phases; and several calcium silicate hydrate solid solution end-members. In addition, this study reports the provisional estimates for the standard entropies of minerals ternesite and ye'elimite

The zCOSMOS Redshift Survey: the role of environment and stellar mass in shaping the rise of the morphology-density relation from z~1

For more than two decades we have known that galaxy morphological segregation is present in the Local Universe. It is important to see how this relation evolves with cosmic time. To investigate how galaxy assembly took place with cosmic time, we explore the evolution of the morphology-density relation up to redshift z~1 using about 10000 galaxies drawn from the zCOSMOS Galaxy Redshift Survey. Taking advantage of accurate HST/ACS morphologies from the COSMOS survey, of the well-characterised zCOSMOS 3D environment, and of a large sample of galaxies with spectroscopic redshift, we want to study here the evolution of the morphology-density relation up to z~1 and its dependence on galaxy luminosity and stellar mass. The multi-wavelength coverage of the field also allows a first study of the galaxy morphological segregation dependence on colour. We further attempt to disentangle between processes that occurred early in the history of the Universe or late in the life of galaxies. The zCOSMOS field benefits of high-resolution imaging in the F814W filter from the Advanced Camera for Survey (ACS). We use standard morphology classifiers, optimised for being robust against band-shifting and surface brightness dimming, and a new, objective, and automated method to convert morphological parameters into early, spiral, and irregular types. We use about 10000 galaxies down to I_AB=22.5 with a spectroscopic sampling rate of 33% to characterise the environment of galaxies up to z~1 from the 100 kpc scales of galaxy groups up to the 100 Mpc scales of the cosmic web. ABRIDGEDComment: 23 pages, 12 figures, accepted for publication in Astronomy and Astrophysic

Shippers’ choice behaviour on choosing transport mode: a case of ASEAN region

Using South East Asia as a case study, shippers’ choice of transport modes taking into consideration their economic and environmental impacts was examined in this research. A triangulation of both quantitative and qualitative methods was deployed. First, a quantitative analysis using secondary data was conducted to establish the index score, which includes four quantitative factors (transport distance, cost, time, and CO2 emission), for each transport mode. In addition, in order to examine at what level of the importance weight shippers would change their decision on transport mode, a sensitivity analysis involving the four aforesaid factors was also conducted. Next, an in-depth interview with a major shipper in Singapore was also carried out to qualitatively validate the aforesaid four quantitative factors as well as two additional qualitative factors, namely, customer service and shipper-forwarder relationship in relation to shipper’s choice. The results from this study indicate that shippers might change to the short-sea shipping (SSS) mode when the importance weights of cost and CO2 emission increase, and to trucking mode when the weight of time decreases. It was also found that cost is the most important factor when shippers choose carriers/forwarders, whereas CO2 emission is not an important factor at the current stage. However, if the government imposes financial measures such as fine and/or tax for CO2 emission, shippers would choose eco-friendlier transport modes. This research is the first study considering the environmental issue as one of important factors that influence shippers’ choice behaviour. This research also facilitates managers’ understanding on how shippers may select LSPs taking into account important factors including the environmental consideration

IFSS, TG, FT-IR spectra of impregnated sugar palm (Arenga pinnata) fibres and mechanical properties of their composites.

This study aimed to investigate the effect of resin impregnation on the interfacial shear strength (IFSS), thermogravimetric (TG) and fourier transform infrared (FT-IR) of sugar palm (Arenga pinnata) fibres. In addition, the effect of resin impregnation on the mechanical properties of sugar palm fibre reinforced unsaturated polyester (UP) composites was also studied. The fibres were impregnated with UP via vacuum resin impregnation process at a pressure of 600 mmHg for 5 min. Composites of 10, 20, 30, 40 and 50 % fibre loadings were fabricated and tested for tensile and flexural properties. It was observed that the impregnation process caused the fibres to be enclosed by UP resin and this gave a strong influence to the increase of its interfacial bonding by the increase of its IFSS from single fibre pull-out test. It was also observed with TG and FT-IR spectra that the impregnated fibre had lower moisture uptake than the control and there was no significant increase in thermal stability of the impregnated fibre. The sequence of fibre decomposition started from the evaporation of moisture, hemicelluloses, cellulose, lignin and finally ash content and the presence of these components were proven by FT-IR spectra. For the composite specimens, due to the high interfacial bonding of the impregnated fibre and the matrix, the impregnated composites showed consistently higher tensile strength, tensile modulus, elongation at break, flexural strength, flexural modulus and toughness than the control samples. It was also observed that 30 % fibre loading gave optimum properties

Interstitial lung disease in children - genetic background and associated phenotypes

Interstitial lung disease in children represents a group of rare chronic respiratory disorders. There is growing evidence that mutations in the surfactant protein C gene play a role in the pathogenesis of certain forms of pediatric interstitial lung disease. Recently, mutations in the ABCA3 transporter were found as an underlying cause of fatal respiratory failure in neonates without surfactant protein B deficiency. Especially in familiar cases or in children of consanguineous parents, genetic diagnosis provides an useful tool to identify the underlying etiology of interstitial lung disease. The aim of this review is to summarize and to describe in detail the clinical features of hereditary interstitial lung disease in children. The knowledge of gene variants and associated phenotypes is crucial to identify relevant patients in clinical practice

The Multifunctional Host Defense Peptide SPLUNC1 Is Critical for Homeostasis of the Mammalian Upper Airway

Otitis media (OM) is a highly prevalent pediatric disease caused by normal flora of the nasopharynx that ascend the Eustachian tube and enter the middle ear. As OM is a disease of opportunity, it is critical to gain an increased understanding of immune system components that are operational in the upper airway and aid in prevention of this disease. SPLUNC1 is an antimicrobial host defense peptide that is hypothesized to contribute to the health of the airway both through bactericidal and non-bactericidal mechanisms. We used small interfering RNA (siRNA) technology to knock down expression of the chinchilla ortholog of human SPLUNC1 (cSPLUNC1) to begin to determine the role that this protein played in prevention of OM. We showed that knock down of cSPLUNC1 expression did not impact survival of nontypeable Haemophilus influenzae, a predominant causative agent of OM, in the chinchilla middle ear under the conditions tested. In contrast, expression of cSPLUNC1 was essential for maintenance of middle ear pressure and efficient mucociliary clearance, key defense mechanisms of the tubotympanum. Collectively, our data have provided the first in vivo evidence that cSPLUNC1 functions to maintain homeostasis of the upper airway and, thereby, is critical for protection of the middle ear