Salicylic Acid Manipulates Ion Accumulation and Distribution in Favor of Salinity Tolerance in Chenopodium quinoa

Although the effects of salicylic acid (SA) on increasing plant growth in saline conditions have been well known, the mechanisms of induction of salinity tolerance, especially in quinoa (Chenopodium quinoa Willd.), are not fully understood. In the present work, two quinoa genotypes (Titicaca and Giza1) were treated with different SA concentrations (0, 0.75, and 1.5 mM) under varied irrigation water salinities (0, 7, 14, and 21 dS m(−1)). Salinity decreased shoot and root growth, potassium (K(+)) concentration, and potassium to sodium ratio (K/Na) and increased sodium (Na(+)) and chlorine (Cl(−)) concentrations in both cultivars. Calcium (Ca(2+)) and magnesium (Mg(2+)) concentrations increased in 7 dS m(−1) but decreased in higher salinities. The growth and salinity tolerance of Giza1 were higher, while the growth of Giza1 increased and of Titicaca decreased in high salinity. Salicylic acid at 0.75-mM concentration increased shoot and root growth and improved the ions concentration in favor of the plant, while the 1.5-mM concentration either had no significant effect or had a negative impact. The ions distribution estimated by K/Na selectivity and storage factor (SF) indicated quinoa accumulated more ions in roots under saline conditions. Salicylic acid increased NaSF, ClSF, and MgSF and decreased KSF and CaSF, meaning less Na(+), Cl(−), and Mg(2+) and more K(+) and Ca(2+) transferred to shoots in SA-treated plants. Importantly, Giza1, as the more tolerant cultivar, had higher NaSF and ClSF and lower KSF, CaSF, and MgSF. In general, the concentrations of ions in roots were higher than in shoots. The results indicated more ions accumulation in the root could be one of the most important mechanisms of salinity tolerance in quinoa, and the more tolerant cultivar (Giza1) transferred less Na(+) and Cl(−) and more K(+) and Ca(2+) and Mg(2+) to the shoot

Shelter models for consequence and risk assessment of CO2 pipelines

Pipelines are acknowledged as one of the most efficient and cost-effective methods for transporting large volumes of various fluids over long distances and therefore the majority of proposed schemes for Carbon Capture and Storage (CCS) involve high pressure pipelines transporting carbon dioxide (CO2). In order to be able to design and route pipelines safely, it is a code requirement that a separation distance, or safety zone, is defined between the pipeline and any habitable dwellings along the route. Safety zones are generally defined on the basis of a Quantitative Risk Assessment (QRA). The purpose of a QRA is to assess the risks posed by a pipeline failure to people in the vicinity and to ensure that consistent levels of risk are applied along the pipeline route. The risk levels are normally calculated along a transect drawn perpendicular to the pipeline. These levels are then compared with defined acceptance criteria to determine the safety zone i.e. the distance from the pipeline within which the risk to the public from a pipeline failure is considered to be unacceptable. The calculation of the risk level requires the determination of both the probability of a failure occurring in the pipeline and the consequences of that failure to the population. For natural gas pipelines, existing and accepted QRA techniques can be implemented to define the consequences of failure based on the thermal hazards. However for CO2 pipelines, the consequences of failure need to be considered differently, as they relate to a toxic hazard rather than a thermal hazard. Therefore in order to conduct a consequence analysis, what is required is a determination of the concentration of CO2 to which an individual may be exposed during a release event. This type of data can be generated either using dispersion models. These models will produce a profile of the change in CO2 concentration with time at various distances from the release, see for example [1, 2], that can then be used in the QRA to determine the toxic dose and therefore the level of harm experienced by an individual. However, none of these approaches consider the effect of shelter on the dose experienced by an individual who is within a building at the time of the release or is outside and enters a building to seek shelter. The work described in this paper seeks to address this gap and describes the application of two models ̶ an analytical and a Computational Fluid Dynamics (CFD) model ̶ that can be used to determine the effects of shelter on the toxic dose received by an individual during a pipeline release event. The motivation behind this work was: i) to develop a validated and computationally efficient shelter model, which had been tested against experimental data and CFD models, ii) to use both CFD and analytical models to demonstrate how shelter should be considered as part of the QRA procedure for a CO2 pipeline. A description of the analytical model has been published previously [3]. Therefore, the current paper concentrates on an explanation of the development and application of the CFD model. Using a case study scenario for a single roomed building, engulfed by a transient cloud of CO2, comparisons are made between the output of the analytical models and the CFD models for the same scenario. A sensitivity analysis indicates the input parameters that most affect the resultant toxic effects within the building. The paper further demonstrates how both models can be extended to investigate the effects of partial coverage of the building with the cloud of CO2 and the impact of partitions within the building. Predictions of toxic dose are made for both models and it is demonstrated how these results can be used in a QRA analysis. This work has been funded by the UK Carbon Capture and Research Centre within the framework of the S-Cape project (Shelter and Escape in the Event of a Release of CO2 from CCS Transport Infrastructure UKCCSRC-C2-179). References [1] M. Molag, C. Dam, Modelling of accidental releases from a high pressure CO2 pipelines, in:  10th International Conference on Greenhouse Gas Control Technologies, Amsterdam, 2011, pp. 2301-2307. [2] J. Koornneef, M. Spruijt, M. Molag, A. Ramírez, W. Turkenburg, A. Faaij, Quantitative risk assessment of CO2 transport by pipelines - A review of uncertainties and their impacts, Journal of Hazardous Materials, 177 (2010) 12-27. [3] C.J.Lyons, J.M.Race, H.F.Hopkins, P Cleaver, Prediction of the consequences of a CO2 pipeline release on building occupants. in Hazards 25: Edinburgh International Conference Centre, Edinburgh; United Kingdom; 13 May 2015 through 15 May 2015. vol. 160, Institution of Chemical Engineers Symposium Series, Red Hook, Hazards 25, Edinburgh, 201

Assessment of the applicability of failure frequency models for dense phase carbon dioxide pipelines

In Carbon Capture, Usage and Storage (CCUS) schemes, Carbon Dioxide (CO2) is captured from large scale industrial emitters and transported to geological sites for storage. The most efficient method for the transportation of CO2 is via pipeline in the dense phase. CO2 is a hazardous substance which, in the unlikely event of an accidental release, could cause people harm. To correspond with United Kingdom (UK) safety legislation, the design and construction of proposed CO2 pipelines requires compliance with recognised pipeline codes. The UK code PD-8010-1 defines the separation distance between a hazardous pipeline and a nearby population as the minimum distance to occupied buildings using a substance factor. The value of the substance factor should be supported by the results of a Quantitative Risk Assessment (QRA) approach to ensure the safe design, construction and operation of a dense phase CO2 pipeline. Failure frequency models are a major part of this QRA approach and the focus of this paper is a review of existing oil and gas pipeline third-party external interference failure frequency models to assess whether they could be applied to dense phase CO2 pipelines. It was found that the high design pressure requirement for a dense phase CO2 pipeline typically necessitates the use of high wall thickness linepipe in pipeline construction; and that the wall thickness of typical dense phase CO2 pipelines is beyond the known range of applicability for the pipeline failure equations used within existing failure frequency models. Furthermore, even though third party external interference failure frequency is not sensitive to the product that a pipeline transports, there is however a limitation to the application of existing UK fault databases with to onshore CO2 pipelines as there are currently no dense phase CO2 pipelines operating in the UK. Further work needs to be conducted to confirm the most appropriate approach for calculating failure frequency for dense phase CO2 pipelines, and it is recommended that a new failure frequency model suitable for dense phase CO2 pipelines is developed that can be readily updated to the latest version of the fault database

The main factors affecting heat transfer along dense phase CO2 pipelines

Carbon Capture and Storage (CCS) schemes will necessarily involve the transportation of large volumes of carbon dioxide (CO2) from the capture source of the CO2 to the storage or utilisation site. It is likely that the majority of the onshore transportation of CO2 will be through buried pipelines. Although onshore CO2 pipelines have been operational in the United States of America for over 40 years, the design of CO2 pipelines for CCS systems still presents some challenges when compared with the design of natural gas pipelines. The aim of this paper is to investigate the phenomenon of heat transfer from a buried CO2 pipeline to the surrounding soil and to identify the key parameters that influence the resultant soil temperature. It is demonstrated that, unlike natural gas pipelines, the CO2 in the pipeline retains its heat for longer distances resulting in the potential to increase the ambient soil temperature and influence environmental factors such as crop germination and water content. The parameters that have the greatest effect on heat transfer are shown to be the inlet temperature and flow rate, i.e. pipeline design parameters, that are within the control of the pipeline operator rather than environmental parameters. Consequently, by carefully controlling the design parameters of the pipeline it is possible to control the heat transfer to the soil and the temperature drop along the pipeline

Functional interface micromechanics of 11 en-bloc retrieved cemented femoral hip replacements

Contains fulltext : 88556.pdf (publisher's version ) (Open Access)BACKGROUND AND PURPOSE: Despite the longstanding use of micromotion as a measure of implant stability, direct measurement of the micromechanics of implant/bone interfaces from en bloc human retrievals has not been performed. The purpose of this study was to determine the stem-cement and cement-bone micromechanics of functionally loaded, en-bloc retrieved, cemented femoral hip components. METHODS: 11 fresh frozen proximal femurs with cemented implants were retrieved at autopsy. Specimens were sectioned transversely into 10-mm slabs and fixed to a loading device where functional torsional loads were applied to the stem. A digital image correlation technique was used to document micromotions at stem-cement and cement-bone interfaces during loading. RESULTS: There was a wide range of responses with stem-cement micromotions ranging from 0.0006 mm to 0.83 mm (mean 0.17 mm, SD 0.29) and cement-bone micromotions ranging from 0.0022 mm to 0.73 mm (mean 0.092 mm, SD 0.22). There was a strong (linear-log) inverse correlation between apposition fraction and micromotion at the stem-cement interface (r(2) = 0.71, p < 0.001). There was a strong inverse log-log correlation between apposition fraction at the cement-bone interface and micromotion (r(2) = 0.85, p < 0.001). Components that were radiographically well-fixed had a relatively narrow range of micromotions at the stem-cement (0.0006-0.057 mm) and cement-bone (0.0022-0.029 mm) interfaces. INTERPRETATION: Minimizing gaps at the stem-cement interface and encouraging bony apposition at the cement-bone interface would be clinically desirable. The cement-bone interface does not act as a bonded interface in actual use, even in radiographically well-fixed components. Rather, the interface is quite compliant, with sliding and opening motions between the cement and bone surfaces.1 juni 201

Suitability and optimisation of analytical indoor shelter model used for infiltration of carbon dioxide for typical dwellings

Carbon Capture Utilisation and Storage (CCUS) schemes involve transporting large quantities of carbon dioxide (CO2). A release of CO2 from CCUS transportation infrastructure could cause severe consequences for the surrounding population if the risk is not appropriately managed. Following a release of CO2, people in the surrounding environment could move away and seek shelter. The CO2 plume could drift past buildings causing the concentration of CO2 inside these buildings to build up. How much CO2 accumulates inside the buildings is key to the safety of their occupants. Previously an analytical infiltration model, based on wind and buoyancy driven ventilation, and a CFD infiltration model were created which can be used to predict the effect of CO2 exposure on building occupants following a release from an onshore CO2 pipeline [1]. These models can be used to determine the consequences of failure the dispersion behaviour of CO2 and the infiltration rate of a plume of CO2 into buildings and can form part of a Quantitative Risk Assessment (QRA) process for a CO2 pipeline. The models were validated against an experimental test of CO2 infiltration into a small enclosure. Comparisons were made between the analytical model, CFD model and experimental data for the build-up of CO2 in the enclosure and the changes in internal temperature. This paper investigates the suitability of the analytical model for buildings geometries more closely resembling domestic abodes and against a wider range of conditions by comparing its results to those of the CFD model for a set of representative case studies. It also tunes the parameters used in the model. Thirty test cases were created which explore the key parameters affecting the CO2 ventilation rate: wind speed, the area and height of the openings, internal temperature and building height, width and length. The analytical model’s predictions of the accumulation of CO2 inside a building are shown to be extremely close to the CFD results for all cases except one, where it makes an over prediction of the level of CO2. Furthermore, it is recommended that the analytical infiltration model is used with the tuned set of coefficients identified in this paper

Intelligent diagnostic feedback for online multiple-choice questions

When students attempt multiple-choice questions (MCQs) they generate invaluable information which can form the basis for understanding their learning behaviours. In this research, the information is collected and automatically analysed to provide customized, diagnostic feedback to support students’ learning. This is achieved within a web-based system, incorporating the snap-drift neural network based analysis of students’ responses to MCQs. This paper presents the results of a large trial of the method and the system which demonstrates the effectiveness of the feedback in guiding students towards a better understanding of particular concepts