Pitchstone Fines: A New Inorganic Binder For Portland Cement-Based Construction Products

The findings of this investigation into the performance pitchstone fines (PF) sourced from a naturally occurring pitchstone deposit in Queensland Australia as a potential pozzolanic supplementary cementitious material (SCM) are reported. 50 mm mortar cubes were prepared by replacement of 20% of the Portland cement (PC) with PF and PF blended with silica fume (SF) in a 1:1 ratio. Mortar cubes were also prepared with a 20% PC substitution level using fly ash (FA) and FA blended with SF also in a 1:1 ratio for comparison as the SCM. Control mortar cubes without PC substitution were also prepared. The compressive strength results for PF blended mortars were comparable to FA mortars, were within 75% of the control mortar at 7 and 28 days and approached the strength of the control mortar at 91 days curing. PF and FA blends containing SF produced compressive strength which surpassed the control mortar. Drying shrinkage measurements are also reported for up to 28 days storage in air. The PF mortar was found to have comparable shrinkage to the control mortar; the shrinkage of the FA mortar was found to be significantly greater. The differences were attributed to the particle shape, angularity and size resulting in greater capillary forces in the FA mortars resulting in greater shrinkage

Characterisation of Portland cement blended with pitchstone fines aiding carbon dioxide emission reduction

Climate change and global wanning present a significant challenge as unsustainable levels of greenhouse gas emissions arising from human activities continue to be emitted. The cement industry is responsible for between five and ten per cent of annual world carbon dioxide emissions; most arising from the manufacture of Portland cement (PC). An effective way of reducing emissions is by incorporating supplementary cementitious materials (SCMs) as partial PC replacements. SCMs are silicate or aluminosilicate based pozzolanic materials which, in finely divided form, combine with water and calcium hydroxide (lime), liberated by cement hydration, to form compounds exhibiting cementitious properties. Pitchstone is such an aluminosilicate and has the potential to act as an effective pozzolan for partial replacement of PC. In North Queensland, Australia, a vast deposit of pitchstone is mined and processed for expandable perlite aggregate. During the classification stage of the excavated natural material, waste pitchstone fines (PF) less than 0.5 mm in size are generated. This study evaluates the waste PF as a viable, eco-friendly pozzolan for the partial replacement of PC. The reactivity of the PF is compared to fly ash (FA), using the pozzolanic compressive strength activity index (SAI) after seven, 28, and 91 days ageing at 20 per cent and 40 per cent PC substitutions. PF was found to be comparable to FA as a pozzolan at 20 per cent PC substitution at all ages tested. However, for the 40 per cent substitution blends significant strength was only achieved at 91 days ageing for the FA blend. The pozzolanic reactivity was also investigated using thermogravimetric analysis to determine the degree of free lime present after 91 days. In all cases where an SCM was added, the free lime was observed to be consumed with increasing age

Genetic parameters for endocrine and traditional fertility traits, hyperketonemia and milk yield in dairy cattle

High-yielding cows may suffer from negative energy balance during early lactation, which can lead to ketosis and delayed ability of returning to cyclicity after calving. Fast recovery after calving is essential when breeding for improved fertility. Traditionally used fertility traits, such as the interval from calving to first insemination (CFI), have low heritabilities and are highly influenced by management decisions. Herd Navigator (TM) management program samples and analyses milk progesterone and beta-hydroxybutyrate (BHB) automatically during milking. In this study, the genetic parameters of endocrine fertility traits (measured from milk progesterone) and hyperketonemia (measured from milk BHB) in early lactation were evaluated and compared with traditional fertility traits (CFI, interval from calving to the last insemination and interval from first to last insemination) and the milk yield in red dairy cattle herds in Finland. Data included observations from 14 farms from 2014 to 2017. Data were analyzed with linear animal models using DMU software and analyses were done for first parity cows. Heritability estimates for traditional fertility traits were low and varied between 0.03 and 0.07. Estimated heritabilities for endocrine fertility traits (interval from calving to the first heat (CFH) and commencement of luteal activity (C-LA)) were higher than for traditional fertility traits (0.19 to 0.33). Five slightly different hyperketonemia traits divided into two or three classes were studied. Linear model heritability estimates for hyperketonemia traits were low, however, when the threshold model was used for binary traits the estimates became slightly higher (0.07 to 0.15). Genetic correlation between CFH and C-LA for first parity cows was high (0.97) as expected since traits are quite similar. Moderate genetic correlations (0.47 to 0.52) were found between the endocrine fertility traits and early lactation milk yield. Results suggest that the data on endocrine fertility traits measured by automatic systems is a promising tool for improving fertility, specifically when more data is available. For hyperketonemia traits, dividing values into three classes instead of two seemed to work better. Based on the current study and previous studies, where higher heritabilities have been found for milk BHB traits than for clinical ketosis, milk BHB traits are a promising indicator trait for resistance to ketosis and should be studied more. It is important that this kind of data from automatic devices is made available to recording and breeding organizations in the future.Peer reviewe

Topological censorship for Kaluza-Klein space-times

The standard topological censorship theorems require asymptotic hypotheses which are too restrictive for several situations of interest. In this paper we prove a version of topological censorship under significantly weaker conditions, compatible e.g. with solutions with Kaluza-Klein asymptotic behavior. In particular we prove simple connectedness of the quotient of the domain of outer communications by the group of symmetries for models which are asymptotically flat, or asymptotically anti-de Sitter, in a Kaluza-Klein sense. This allows one, e.g., to define the twist potentials needed for the reduction of the field equations in uniqueness theorems. Finally, the methods used to prove the above are used to show that weakly trapped compact surfaces cannot be seen from Scri.Comment: minor correction

Short communication : Lameness impairs feeding behavior of dairy cows

Peer reviewe

The classification of static vacuum space-times containing an asymptotically flat spacelike hypersurface with compact interior

We prove non-existence of static, vacuum, appropriately regular, asymptotically flat black hole space-times with degenerate (not necessarily connected) components of the event horizon. This finishes the classification of static, vacuum, asymptotically flat domains of outer communication in an appropriate class of space-times, showing that the domains of outer communication of the Schwarzschild black holes exhaust the space of appropriately regular black hole exteriors.Comment: This version includes an addendum with a corrected proof of non-existence of zeros of the Killing vector at degenerate horizons. A problem with yet another Lemma is pointed out; this problem does not arise if one assumes analyticity of the metric. An alternative solution, that does not require analyticity, has been given in arXiv:1004.0513 [gr-qc] under appropriate global condition

NEFL mRNA Expression Level Is a Prognostic Factor for Early-Stage Breast Cancer Patients

Neurofilament, light polypeptide (NEFL) was demonstrated to be ectopically expressed in breast cancer tissues and decreased in lymph node metastases compared to the paired primary breast cancers in our previous study. Moreover, in several studies, NEFL was regarded as a tumor suppressor gene, and its loss of heterozygosity (LOH) was related to carcinogenesis and metastasis in several types of cancer. To explore the role of NEFL in the progression of breast cancer and to evaluate its clinical significance, we detected the NEFL mRNA level in normal breast tissues, primary breast cancer samples and lymph node metastases, and then analyzed the association between the NEFL expression level and several clinicopathological parameters and disease-free survival (DFS). NEFL mRNA was found to be expressed in 92.3% of breast malignancies and down-regulated in lymph node metastases compared to the paired primary tumors. NEFL mRNA level was lower in primary breast cancers with positive lymph nodes than in cancers with negative lymph nodes. Moreover, a low expression level of NEFL mRNA indicated a poor five-year DFS for early-stage breast cancer patients. Thus, NEFL mRNA is ectopically expressed in breast malignancies and could be a potential prognostic factor for early-stage breast cancer patients

Pozzolanic reactivity of the supplementary cementitious material pitchstone fines by thermogravimetric analysis

Thermogravimetric (TG) analysis was applied to the characterisation of the pozzolanic reaction in mortars containing the supplementary cementitious materials (SCMs) pitchstone fines (PF) and fly ash (FA) as partial replacements for Portland cement (PC). TG analysis was used to determine the proportion of calcium hydroxide (CH) present from the hydration of the PC based on the dehydroxylation of the CH present in the blended PC-SCM mortars. The consumption of CH indicated that both SCMs underwent the pozzolanic reaction and that PF was found to compare favourably in its pozzolanic reactivity of FA, the industry and globally accepted standard artificial pozzolan. © 2009 Akadémiai Kiadó, Budapest, Hungary

Development of hybrid organic-inorganic materials for efficient charging/discharging in electrochemical and photoelectrochemical capacitors

A composite system of poly (3,4-ethylenedioxythiophene)/multi-walled carbon nanotubes has been investigated and characterized as a potential charge storage material for coupled dye-sensitized solar cell/electrochem. capacitor systems. The selected material can easily operate in org. media (lithium triflate/propylene carbonate) giving a specific capacitance of 95 F g-1 and energy d. of 3.1 Wh kg-1. The combination of the composite material with dye-sensitized solar cell allows to obtain a photo-rechargeable supercapacitor (photocapacitor), destined to work with dies required org. media (here with N 719 dye). The photocapacitor system was built from mesoporous TiO2 electrode, typical charge relay consisting of iodine/iodide redox couple and two charge storage electrodes sepd. by a liq. electrolyte. The system was tested under light illumination of 100 mW cm-2 with xenon lamp equipped with cut-off filters eliminating the UV and IR part of the spectra

Pitchstone fines pozzolanic activity assessment as partial Portland cement (PC) replacements

Mined pitchstone fines (PF), derived as a waste by-product from expandable perlite production in Australia, are a viable, environmentally friendly aluminosilicate supplementary cementitious material (SCM) suitable for partial Portland cement (PC) replacement, thus reducing greenhouse gas emissions resulting from PC manufacture. This paper reports on the findings of pozzolanic activity exhibited at 10%, 20% and 40% replacement levels of PC, through compressive strength determinations of mortar after 1, 7 and 28 days ageing, using strength activity index (SAI) criteria. Additionally, flows and wet densities have been examined using a polycarboxylic based high-range water-reducing admixture (HRWRA) superplasticiser and fixed water content relative to cementitious material present for all PF substitution levels