Strand bond performance in prestressed concrete accounting for bondslip

This paper presents the results of an experimental research program addressing the bond behavior of prestressing strands in pretensioned prestressed concrete members after anchorage failure has occurred. A test methodology based on measuring the prestressing strand force and strand end slip at the specimens free end was employed. Transmission- and anchorage-length tests were performed on several series of prestressed specimens with different embedment lengths using twelve concrete mixes. Average bond stresses along the transmission length and the anchorage length were obtained for specimens with release strengths ranging from 24 MPa to 55 MPa. For the anchorage analysis, a parameter was developed that includes strand slip to be used in determining anchorage length. Based on the test results, an analysis to experimentally substantiate the Stress Waves Theory of Janney has been proposed. Additionally, the potential bond performance of prestressing strands after anchorage failure at the end regions has been suggested.The content of the present paper is based on tests which were conducted in the Institute of Concrete Science and Technology (ICITECH), at Universitat Politecnica of Valencia (Spain), in collaboration with the companies PREVALESA and ISOCRON. Funding for this experimental research work was provided by the Spanish Ministry of Education and Science/Science and Innovation and ERDF (Project BIA2006-05521 and Project BIA2009-12722). The authors wish to thank the above companies as well as the concrete structures laboratory technicians at the Universitat Politecnica of Valencia for their cooperation. Finally, the authors also wish to pay their respects to C.A. Arbelaez.Martí Vargas, JR.; Serna Ros, P.; Hale, WM. (2013). Strand bond performance in prestressed concrete accounting for bondslip. Engineering Structures. 51:236-244. doi:10.1016/j.engstruct.2013.01.023S2362445

Application of Electrical Bio-Impedance for the Evaluation of Strawberry Ripeness

"This is an Author's Accepted Manuscript of an article published in González-Araiza, José Raymundo, María Coral Ortiz-Sánchez, Francisco Miguel Vargas-Luna, and José Manuel Cabrera-Sixto. 2016. Application of Electrical Bio-Impedance for the Evaluation of Strawberry Ripeness. International Journal of Food Properties 20 (5). Informa UK Limited: 1044 50. doi:10.1080/10942912.2016.1199033, available online at: https://www.tandfonline.com/doi/full/10.1080/10942912.2016.1199033."[EN] Electrical bio-impedance measurements were conducted on local strawberry fruits. A non-destructive device was designed to obtain the impedance spectrum of the whole fruit. Four electrical variables were tested: low frequency resistor R0 (related to extracellular resistances), the high frequency resistor R∞ (related to intracellular resistances), and constant phase element (magnitude and phase, related to the membrane capacitances and heterogeneity, respectively). In parallel with the electrical bio-impedance measurement, color and firmness were correlated to the ripeness stage. The results indicated that the strawberries at the highest stage of ripeness had significantly lower constant phase element and R0 values.The authors would like to express their gratitude to Mr. and Mrs. Abraham from Irapuato, Mexico for providing the fruits, and to Mr. Juan Manuel Noriega from the University of Guanajuato for his technical support. The authors would like to thank the University of Guanajuato for the financial support.Gonzalez-Araiza, J.; Ortiz Sánchez, MC.; Vargas-Luna, F.; Cabrera-Sixto, J. (2017). Application of Electrical Bio-Impedance for the Evaluation of Strawberry Ripeness. International Journal of Food Properties. 20(5):1044-1050. https://doi.org/10.1080/10942912.2016.1199033S10441050205Cordenunsi, B. R., Nascimento, J. R. O., & Lajolo, F. M. (2003). Physico-chemical changes related to quality of five strawberry fruit cultivars during cool-storage. Food Chemistry, 83(2), 167-173. doi:10.1016/s0308-8146(03)00059-1Sacks, E. J., & Shaw, D. V. (1994). Optimum Allocation of Objective Color Measurements for Evaluating Fresh Strawberries. Journal of the American Society for Horticultural Science, 119(2), 330-334. doi:10.21273/jashs.119.2.330Harker, F. R., & Forbes, S. K. (1997). Ripening and development of chilling injury in persimmon fruit: An electrical impedance study. New Zealand Journal of Crop and Horticultural Science, 25(2), 149-157. doi:10.1080/01140671.1997.9514001Bauchot, A. D., Harker, F. R., & Arnold, W. M. (2000). The use of electrical impedance spectroscopy to assess the physiological condition of kiwifruit. Postharvest Biology and Technology, 18(1), 9-18. doi:10.1016/s0925-5214(99)00056-3Harker, F. R., & Maindonald, J. H. (1994). Ripening of Nectarine Fruit (Changes in the Cell Wall, Vacuole, and Membranes Detected Using Electrical Impedance Measurements). Plant Physiology, 106(1), 165-171. doi:10.1104/pp.106.1.165Fang, Q., Liu, X., & Cosic, I. (s. f.). Bioimpedance Study on Four Apple Varieties. 13th International Conference on Electrical Bioimpedance and the 8th Conference on Electrical Impedance Tomography, 114-117. doi:10.1007/978-3-540-73841-1_32Vozáry, E., & Benkó, P. (2010). Non-destructive determination of impedance spectrum of fruit flesh under the skin. Journal of Physics: Conference Series, 224, 012142. doi:10.1088/1742-6596/224/1/012142Harker, F. R., Elgar, H. J., Watkins, C. B., Jackson, P. J., & Hallett, I. C. (2000). Physical and mechanical changes in strawberry fruit after high carbon dioxide treatments. Postharvest Biology and Technology, 19(2), 139-146. doi:10.1016/s0925-5214(00)00090-9Juansah, J., Budiastra, I. W., Dahlan, K., & Seminar, K. B. (2014). Electrical Properties of Garut Citrus Fruits at Low Alternating Current Signal and its Correlation with Physicochemical Properties During Maturation. International Journal of Food Properties, 17(7), 1498-1517. doi:10.1080/10942912.2012.723233O’Toole, M. D., Marsh, L. A., Davidson, J. L., Tan, Y. M., Armitage, D. W., & Peyton, A. J. (2015). Non-contact multi-frequency magnetic induction spectroscopy system for industrial-scale bio-impedance measurement. Measurement Science and Technology, 26(3), 035102. doi:10.1088/0957-0233/26/3/035102Gore, C. M., White, J. O., Wachsman, E. D., & Thangadurai, V. (2014). Effect of composition and microstructure on electrical properties and CO2 stability of donor-doped, proton conducting BaCe1−(x+y)ZrxNbyO3. Journal of Materials Chemistry A, 2(7), 2363. doi:10.1039/c3ta12668

Effects of concrete composition on transmission length of prestressing strands

The bond behaviour of prestressing strands in precast pretensioned concrete members, and its transmission length, depends on several factors. However, no consensus exists on the main parameters to be considered in the expressions to predict the transmission length. Usually when the concrete properties are considered, only the concrete compressive strength is included. This study analyzes the influence of concrete composition made up of different cement contents and water/cement ratios on the bond behaviour in transmission of seven-wire prestressing strands. The bond properties and the transmission lengths have been determined. The results show that the influence of the water/cement ratio is very small for concretes with lows cement contents, but the influence of the water/cement ratio on the transmission lengths is highly significant when cement content is high. The effect of cement content in the transmission lengths can reveal different tendencies based on the level of the water/cement ratioThe content of this article forms a part of research that the Universitat Politecnica de Valencia's Institute of Concrete Science and Technology (ICITECH) is presently conducting in conjunction with PREVALESA and ISOCRON. This study was funded by the Ministry of Education and Science and ERDF (Project BIA2006-05521). The authors wish to thank the above companies as well as the concrete structures laboratory technicians at the Universitat Politecnica de Valencia for their cooperation. Also, the authors wish to pay their respects to C.A. Arbelaez.Martí Vargas, JR.; Serna Ros, P.; Navarro Gregori, J.; Bonet Senach, JL. (2012). Effects of concrete composition on transmission length of prestressing strands. Construction and Building Materials. 27(1):350-356. https://doi.org/10.1016/j.conbuildmat.2011.07.038S35035627

Sacha inchi oil (Plukenetia volubilis) stabilized with antioxidants for addition in fresh cheese

Sacha Inchi (Plukenetia volubilis) is a nut that has been grown in the Amazon Rainforest and the high Andes Mountains of Peru for countless centuries. The oil of this nut, natural source of omega 3, 6 and 9, has been recognized by its high antioxidant capacity in humans. In this work, oil from Sacha Inchi was fortified with two commercial antioxidants (Ecoprol 2020 and tocopherol) in order to prepare a fresh cheese from cow's milk. The antioxidant capacities of Sacha Inchi and commercial antioxidants were used as preservatives with the purpose to increase the shelf-life of fresh cheese besides nutritional content. The factorial method was necessary to prepare seven formulations in order to find the optimal concentration of the antioxidants added to Sacha Inchi oil andthe addition of this oil to the fresh cheese. A sensory analysis was performed to choose the best formulation. The results showed that an oil formulation (F4) with tocopherol (150 mg/kg of oil) and Ecoprol 2020 (1000 mg/kg of oil) displayed the lowest peroxide values (PI: 2.6 ± 0.1 meq O2/kg of oil, p < 0.001) and it was able to reduce approximately 50% of fatty acid oxidation in Sacha Inchi oil in relation to the PI control. Then, F4 was used to elaborate further nine formulations (F’1 – F’9), enriched with Sacha Inchi oil (1 to 4%) to prepare the fresh cheese. Microbiological analysis for all formulations were performed (limits of mold, yeasts, coliforms, salmonella, and  bacteria) in order to meet the legal requirements of health and safety in Peru. The cheese taste acceptability was determined through the sensorial evaluation, which reached 7.2 according to the 9- hedonic scale for F'5. Thus, an optimum fresh cheese was obtained from the formulation (F’5) with 22.5g/L of salt and 2.5% of Sacha Inchi oil enriched with 150 mg/kg of tocopherol and 1000 mg/kg of Ecoprol 2020. The cheese shelf-life was also evaluated, increasing it up from 7 days to 16 days in refrigeration. Key words: cheese, antioxidant, Sacha Inchi, shelf-life, Ecoprol 2020, tocophero

Simple gold recovery from e-waste leachate by selective precipitation using a quaternary ammonium salt

Precipitation processes, if selective, present a simple and economical alternative for the recovery of critical metals from primary and secondary ores including electronic wastes. In this work, the recovery of gold by precipitation from both mono-elemental solutions and real CPU leach solution was demonstrated using hydrophilic quaternary ammonium salts. The gold precipitation yield is shown to be dependent on the apolar volume of the precipitant, with the addition of tetrabutylammonium-based salts resulting in the recovery of over 90 % of gold from synthetic solutions. The origin of gold precipitation selectivity relative to common metal ions upon addition of tetrabutylammonium nitrate ([N4444][NO3]) was assigned by X-ray crystal structure to the formation of size selective apolar cavity between neighbouring [N4444]+ cation and the [AuCl4]- anion. Following optimisation as a function of the gold to precipitant molar ratio, aqua regia concentration and time, approximately 70 % of gold could be recovered from waste CPU leach solution with a final purity of 91.4 % (mol/mol). [N4444][NO3] proved to be a versatile gold extractant and could be further applied as part of an acidic aqueous biphasic system at higher aqua regia concentrations were precipitation yields decreased, ensuring a selective gold recovery across a range of leachate conditions. The disclosed results improve the circularity of gold by providing a new avenue for its simple recycling.publishe

Bond of 13 mm prestressing steel strands in pretensioned concrete members

This paper presents an experimental research work to determine both the transmission and the anchorage lengths of seven-wire prestressing steel strands in different concrete mixes. A testing technique based on a bond behavior analysis by measuring the force supported by the prestressing strand on a series of specimens with different embedment lengths has been used. Relationships between the average bond stress for both the transmission length and anchorage length as a function of the concrete compressive strength have been found. Equations to compute transmission and anchorage lengths of 13 mm prestressing strands have been obtained. The experimental results have been compared with the theoretical prediction from proposed equations in the literature and with experimental results from other authors. 2012 Elsevier Ltd. All rights reserved.The content of this article forms part of the research work that the Institute of Concrete Science and Technology (ICITECH) is presently conducting in conjunction with PREVALESA and ISOCRON. This study has been funded by the Spanish Ministry of Education and Science and ERDF (Project BIA2006-05521). The authors wish to thank the above companies as well as the concrete structures laboratory technicians at the Universitat Politecnica de Valencia for their cooperation. Finally, the authors also wish to pay their respects to C.A. Arbelaez.Martí Vargas, JR.; Serna Ros, P.; Navarro Gregori, J.; Pallarés Rubio, L. (2012). Bond of 13 mm prestressing steel strands in pretensioned concrete members. Engineering Structures. 41:403-412. https://doi.org/10.1016/j.engstruct.2012.03.056S4034124

Ultra-processed food consumption is associated with renal function decline in older adults: A prospective cohort study

Ultra-processed food (UPF) consumption has been associated with increased risk of cardiovascular risk factors and mortality. However, little is known on the UPF effect on renal function. The aim of this study is to assess prospectively the association between consumption of UPF and renal function decline. This is a prospective cohort study of 1312 community-dwelling individuals aged 60 and older recruited during 2008–2010 and followed up to December 2015. At baseline, a validated dietary history was obtained. UPF was identified according to NOVA classification. At baseline and at follow-up, serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) levels were ascertained and changes were calculated. A combined end-point of renal decline was considered: SCr increase or eGFR decreased beyond that expected for age. Logistic regression with adjustment for potential confounders was performed. During follow-up, 183 cases of renal function decline occurred. The fully adjusted odds ratios (95% CI) of renal function decline across terciles of percentage of total energy intake from UPF were 1.56 (1.02–2.38) for the second tercile, and 1.74 (1.14–2.66) for the highest tercile; p-trend was 0.026. High UPF consumption is independently associated with an increase higher than 50% in the risk of renal function decline in Spanish older adults

Association of cooking patterns with inflammatory and cardio-metabolic risk biomarkers

Diet has been clearly associated with cardiovascular disease, but few studies focus on the influence of cooking and food preservation methods on health. The aim of this study was to describe cooking and food preservation patterns, as well as to examine their association with inflammatory and cardio-metabolic biomarkers in the Spanish adult population. A cross-sectional study of 10, 010 individuals, representative of the Spanish population, aged 18 years or over was performed using data from the ENRICA study. Food consumption data were collected through a face-to-face dietary history. Cooking and food preservation patterns were identified by factor analysis with varimax rotation. Linear regression models adjusted for main confounders were built. Four cooking and food preservation patterns were identified. The Spanish traditional pattern (positively correlated with boiling and sautéing, brining, and light frying) tends to be cardio-metabolically beneficial (with a reduction in C-reactive protein (-7.69%)), except for high density lipoprotein cholesterol (HDL-c), insulin levels, and anthropometrics. The health-conscious pattern (negatively correlated with battering, frying, and stewing) tends to improve renal function (with a reduction in urine albumin (-9.60%) and the urine albumin/creatinine ratio (-4.82%)). The youth-style pattern (positively correlated with soft drinks and distilled alcoholic drinks and negatively with raw food consumption) tends to be associated with good cardio-metabolic health except, for lower HDL-c (-6.12%), higher insulin (+6.35%), and higher urine albumin (+27.8%) levels. The social business pattern (positively correlated with the consumption of fermented alcoholic drinks, food cured with salt or smoke, and cured cheese) tends to be detrimental for the lipid profile (except HDL-c), renal function (urine albumin +8.04%), diastolic blood pressure (+2.48%), and anthropometrics. Cooking and food preservation patterns showed a relationship with inflammatory and cardio-metabolic health biomarkers. The Spanish traditional pattern and the health-conscious pattern were associated with beneficial effects on health and should be promoted. The youth-style pattern calls attention to some concerns, and the social business pattern was the most detrimental one. These findings support the influence of cooking and preservation patterns on health

Thirty-Second Sit-To-Stand Test as an Alternative for Estimating Peak Oxygen Uptake and 6-Min Walking Distance in Women With Breast Cancer: A Cross-Sectional Study

[Abstract] Purpose: To determine whether the 30-s sit-to-stand (30STS) test can be a valid tool for estimating and stratifying peak oxygen uptake (VO2peak) and 6-min walking distance (6MWD) in women with breast cancer. Methods: This cross-sectional study uses data from the ONCORE randomized controlled trial, including 120 women aged 18-70 years with early-stage breast cancer under treatment with anthracycline and/or anti-HER2 antibodies. Participant characteristics were collected at baseline and pooled data from functional assessment (30STS test, relative and absolute VO2peak, and 6MWD) were collected at baseline and post-intervention (comprehensive cardio-oncology rehabilitation program vs. usual care). Bivariate correlations and multivariate linear regression analyses were performed to study the relationship between functional test variables. Results: The number of repetitions in the 30STS test showed (i) a moderate correlation with relative VO2peak (ml/kg/min) (r = 0.419; p < 0.001; n = 126), (ii) a weak correlation with absolute VO2peak (ml/min) (r = 0.241; p = 0.008; n = 120), and (iii) a moderate correlation with the 6MWD (r = 0.440; p < 0.001; n = 85). The ONCORE equations obtained from the multivariate regression models allowed the estimation of VO2peak and 6MWD (r2 = 0.390; r2 = 0.261, respectively) based on the 30STS test, and its stratification into tertiles (low, moderate, and high). Conclusion: The 30STS test was found to be a useful tool to estimate VO2peak and/or 6MWD in women with early-stage breast cancer. Its use may facilitate the assessment and stratification of functional capacity in this population for the implementation of therapeutic exercise programs if cardiopulmonary exercise testing (CPET) or 6MWT are not available.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by a competitive grant from the Asociación Española Contra el Cáncer (AECC) Scientific Foundation — PRDLC21480DÍAZ — and by a competitive grant of the Spanish Health Research Fund of the Carlos III Health Institute (ISCIII) — PI17/01687, co-funded FEDER, through Strategic Action in Healthcare, 2017. The ISCIII is the national and international reference in biomedical research and public health in Spain. The AECC Scientific Foundation and the ISCIII had no role in study design, data collection, data analysis, data interpretation, or writing of the report. Funding for open access charge will be supported by Universidade da Coruña/CISUGFundación Científica Asociación Española Contra el Cáncer; PRDLC21480DÍA

Evidencias arqueológicas de desplomes paramentales traumáticos en las Termas Marítimas de Baelo Claudia. Reflexiones arqueosismológicas

Durante los años 2011 a 2013 se han localizado, identificado y excavado parcialmente los restos de un nuevo complejo termal en la ciudad hispanorromana de Baelo Claudia (Tarifa, Cádiz), situado en el suburbium occidental de la ciudad, junto a la línea de costa. Denominadas Termas Marítimas, construidas en la primera mitad del s. II d.C. y abandonadas en época de Diocleciano/Constantino han sido excavadas estratigráficamente con detalle, habiéndose detectado la existencia de fases anteriores (que se remontan al s. II a.C.) y una continuidad de uso del ambiente en época tardorromana y moderna, vinculada con la explotación de los recursos marinos. Especialmente singular ha sido la constatación del desplome traumático de parte de los paramentos de las habitaciones del edificio en dos momentos concretos: por un lado en la Antigüedad Tardía (500 d.C. circa), ya que una unidad muraria de una de las habitaciones (H-3), anexa a la natatio, se localizó completamente derrumbada sobre el suelo, conexionada; y por otro, el desplome del muro oeste de la natatio y el oriental de la cisterna, estructuras de más de seis metros de longitud y cuatro de altura mínima conservada, desplomadas sobre los niveles de abandono del asentamiento en época bajomedieval o moderna (ss. XIV-XV d.C.). Se trata en ambas ocasiones de colapsos estructurales no habituales en circunstancias normales en los procesos de sedimentación arqueológica, por lo que es muy probable que su desplome se pueda vincular con eventos sísmicos u otras causas naturales similare