Experimental characterization and performance evaluation of geothermal grouting materials subjected to heating–cooling cycles

In recent years, the increasing rise in environmental awareness among energy consumers has led to an increasing use of renewable energies such as the geothermal energy. An important role in the efficient exploitation of the geothermal resource is played by the grouting material placed in the borehole between the pipes and the ground. Actually, the use of proper grouts is essential to provide an effective heat transfer between the ground and the heat carrier fluid in the pipes, and also to comply with the mechanical and environmental demands. However, when it comes to the construction of the GHP installations, the grout is especially required to be easy to work with (workable) and for this reason more water than required is sometimes added. In order to assess the suitability of grouting materials with significant water/solid ratios, the thermal conductivity, mechanical strength and permeability of five different grouts and grout–pipe specimens were measured for their laboratory characterization. In addition, the grouts were subjected to heating and cooling cycles to evaluate their durability with time in terms of the potential degradation of the materials and the loss of quality of the grout–pipe interface. According to the results obtained, the grouts here tested are appropriate for most of the geothermal heat pump installations, especially for those with low to medium ground thermal properties.The authors wish to express their gratitude to the Ministerio de Economía y Competitividad which funded this study within the Spanish National Plan for Scientific and Technical Research and Innovation (INNPACTO program) through the research project IPT-2011-0877-920000

DD04107-Derived neuronal exocytosis inhibitor peptides: Evidences for synaptotagmin-1 as a putative target

The analgesic peptide DD04107 (Pal-EEMQRR-NH2) and its acetylated analogue inhibit a-calcitonin gene-related peptide (a-CGRP) exocytotic release from primary sensory neurons. Examining the crystal structure of the SNARE-Synaptotagmin-1(Syt1) complex, we hypothesized that these peptides could inhibit neuronal exocytosis by binding to Syt1, hampering at least partially its interaction with the SNARE complex. To address this hypothesis, we first interrogate the role of individual side-chains on the inhibition of a-CGRP release, finding that E1, M3, Q4 and R6 residues were crucial for activity. CD and NMR conformational analysis showed that linear peptides have tendency to adopt a-helical conformations, but the results with cyclic analogues indicated that this secondary structure is not needed for activity. Isothermal titration calorimetry (ITC) measurements demonstrate a direct interaction of some of these peptides with Syt1-C2B domain, but not with Syt7-C2B region, indicating selectivity. As expected for a compound able to inhibit a-CGRP release, cyclic peptide derivative Pal-E-cyclo[EMQK]R-NH2 showed potent in vivo analgesic activity, in a model of inflammatory pain. Molecular dynamics simulations provided a model consistent with KD values for the interaction of peptides with Syt1-C2B domain, and with their biological activity. Altogether, these results identify Syt1 as a potential new analgesic target. © 202

CO₂ utilization with a novel dual function material (DFM) for capture and catalytic conversion to synthetic natural gas: An update

Dual function materials (DFMs) for CO₂ capture and conversion couple the endothermic CO₂ desorption step of a traditional adsorbent with the exothermic hydrogenation of CO₂ over a catalyst in a unique way; a single reactor operating at an isothermal temperature (320 °C) and pressure (1atm) can capture CO₂ from flue gas, and release it as methane upon exposure to renewable hydrogen. This combined CO₂ capture and utilization eliminates the energy intensive CO₂ desorption step associated with conventional CO₂ capture systems as well as avoiding the problem of transporting concentrated CO₂ to another site for storage or utilization. Here DFMs containing Rh and dispersed CaO have been developed (˃1% Rh 10% CaO/γ-Al₂O₃) which have improved performance compared to the 5% Ru 10% CaO/γ-Al₂O₃ DFM (0.50 g-mol CH₄/kg DFM) developed previously. Ruthenium remains the catalyst of choice due to its lower price and excellent low temperature performance. The role of CO₂ adsorption capacity on the final methanation capacity of the DFM has also been investigated by testing several new sorbents. Two novel DFM compositions are reported here (5% Ru 10% K₂CO₃/Al₂O₃ and 5% Ru 10% Na₂CO₃/Al₂O₃) both of which have much greater methanation capacities (0.91 and 1.05 g-mol CH₄/kg DFM) compared to the previous 5% Ru 10% CaO/γ-Al₂O₃ DFM

The leaf-tying moth Hypocosmia pyrochroma (Lep., Pyralidae), a host-specific biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia

Cat's claw creeper, Macfadyena unguis-cati, a major environmental weed in coastal and sub-coastal areas of Queensland and New South Wales, Australia is a target for classical biological control. Host specificity of Hypocosmia pyrochroma Jones (Lep., Pyralidae), as a potential biological control agent was evaluated on the basis of no-choice and choice larval feeding and survival, and adult oviposition preference tests, involving 38 plant species in 10 families. In no-choice tests, larval feeding and development occurred only on cat's claw creeper. In choice tests, oviposition and larval development was evident only on cat's claw creeper. The results support the host-specificity tests conducted in South Africa, and suggest that H. pyrochroma is a highly specific biological control agent that does not pose any risk to non-target plants tested in Australia. This agent has been approved for field release by relevant regulatory authorities in Australia

Factores de riesgo asociados a íleo posquirúrgico prolongado en pacientes sometidos a resección electiva de colon

Antecedentes: Posterior a la manipulación quirúrgica del colon, existe una inhibición de su motilidad coordinada; esto contribuye al acúmulo de secreciones y gas que, a su vez, provocan nauseas, vómito, dolor, distensión abdominal y estreñimiento. La mayoría de los pacientes recupera la motilidad dentro de las primeras 72 h; el retraso en su aparición se denomina íleo posquirúrgico prolongado. Objetivos: Investigar los factores de riesgo pre, intra y postoperatorios para el desarrollo de íleo prolongado en pacientes sometidos a resección electiva de colon. Materiales y métodos: Se analizarán 25 variables perioperatorias de 85 pacientes sometidos resección colónica entre los años 2011 y 2014 en el Hospital Christus Muguerza Alta Especialidad y su relación con la aparición de íleo prolongado. Resultados: El íleo posquirúrgico se presentó en 22.3% de los pacientes. Se encontró significación estadística como predictor de íleo: la presencia de obesidad (OR 1.119, p = 0.048) y el ingreso a terapia intensiva (OR 3.571, p = 0.050). Como factor protector se encontró el uso de anestesia peridural durante el acto quirúrgico (OR 0.363, p 0.050). Conclusiones: La presencia de estos factores de riesgo pueden servir como alertas para un seguimiento más cercano en pacientes de alto riesgo de íleo postoperatorio. El uso de anestesia peridural pudiera disminuir la incidencia de íleo

Effect of sodium stearoyl-2-lactylate, carboxymethyl cellulose and guar–xanthan gums on muffins enriched with soybean milk powder and amaranth flour

Soybean milk powder (SMP) and amaranth flour (AF) can improve the nutritional profile of bakery products. Nonetheless, these ingredients can impart undesirable effects on batter rheology and product texture. In this study, the effect of three additives (carboxymethyl cellulose(CMC), sodium stearoyl-2-lactylate (SSL), guar–xanthan gum mix (GX)) was evaluated on batter rheology and the physical, chemical and textural parameters of muffins baked with SMP and AF. Protein content was increased in all muffins made with SMP–AF. SMP–AF also increased muffins’ hardness and chewiness, but additives distinctively counteracted this effect on texture, crumb total color difference and specific volume. Of all additives, SSL ameliorated the effect of SMP–AF on the batter’s rheology. Overall results indicate that muffins’ nutritional value can be improved by using ingredients such as SMP and AF. Moreover, SSL can be added to muffins’ formulations to compensate the effect of SMP and AF on textural and rheological characteristics.La leche de soya en polvo (SMP) y la harina de amaranto (AF) pueden mejorar el perfil nutrimental de productos panaderos. Sin embargo, estos ingredientes imparten efectos no deseables en la reología de masa y textura de productos. En este estudio, el efecto de tres aditivos (carboximetilcelulosa celulosa-(CMC), estearoil-2-lactilato de sodio-(SSL), mezcla de gomas guar-xantana-(GX)) se evaluó en la reología de masa y parámetros físicos, químicos y textura en muffins con SMP-AF. Los muffins con SMP-AF tuvieron mayor proteína. La dureza y chiclosidad también se incrementaron, pero los aditivos contrarrestaron este efecto en la textura, diferencia total de color de la miga y volumen-específico. El SSL mejoró el efecto de SMP-AF en la reología de la masa. Esto indica que el valor nutrimental de muffins puede ser mejorado con SMP-AF. Además, SSL puede ser añadido a formulaciones de muffins para contrarrestar el efecto de SMP-AF en características texturiales y reológicas