2,110 research outputs found

    Influencia de pre tratamientos convencionales en el proceso de secado de banano y en las características físicas del producto final

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    This objective was to evaluate the effects of pre-drying treatments such as osmotic dehydration, antioxidants, and blanching using banana. A dry samples with different pre-treatments were performed to obtain the isotherms of the monolayer, which has a direct relationship with the shelf life. Once drying processes, it was determined the rate of drying where the product has the highest rate of drying is that which was not subjected to any pre-treatment, which is related to life. Subsequently, in addition to the experiment, we determined the shelf life, using the method of Theodore Labuza, proving the relationship and the value of the monolayers of the isotherms and the values of drying rate, which the sample without pre-treatment showed the highest value. Finally, we statistically analyzed the results, with a design of experiments, comparing the response variables with a significance level of 95%

    A TLA+ Formal Specification and Verification of a New Real-Time Communication Protocol

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    AbstractWe describe the formal specification and verification of a new fault-tolerant real-time communication protocol, called DoRiS, which is designed for supporting distributed real-time systems that use a shared high-bandwidth medium. Since such a kind of protocol is reasonably complex and requires high levels of confidence on both timing and safety properties, formal methods are useful. Indeed, the design of DoRiS was strongly based on formal methods, where the TLA+ language and its associated model-checker TLC were the supporting design tool. The protocol conception was improved by using information provided by its formal specification and verification. In the end, a precise and highly reliable protocol description is provided

    Influence of droplet clustering in sprays on liquid deposition rate on spherical targets

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    [EN] The origin of temporal fluctuations of liquid mass deposition rates, obtained from a spray of droplets impinging on a solid spherical target, was investigated by correlation with droplet clusters in the spray. The droplet clusters were quantified using a Voronoi analysis on instantaneous images of the droplets, to obtain the number of droplet clusters, the area of the clusters and the number of droplets in each cluster. It was found that the normalised area of the droplet clusters had a distribution with a peak around 10-1 and a right tail which followed a power law of exponent -1.8. As the number density of the droplets inside the clusters increased, the temporal fluctuations of the liquid mass deposition rates increased, as a greater variation of droplet sizes impinged the target. However, as the standard deviation of the distribution of the normalised droplet cluster areas was increased, the temporal fluctuations in the liquid mass deposition rates reduced, as variations to the droplet number density and droplet sizes inside the clusters were averaged out.We would like to acknowledge financial support from Procter and Gamble through an EPSRC industrial case studentship and EPSRC grant EP/K019732/1.Andrade, P.; Charalampous, G.; Hardalupas, Y. (2017). Influence of droplet clustering in sprays on liquid deposition rate on spherical targets. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 513-520. https://doi.org/10.4995/ILASS2017.2017.4673OCS51352

    A Dual-Mixed Approximation for a Huber Regularization of Generalized pp-Stokes Viscoplastic Flow Problems

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    In this paper, we propose a dual-mixed formulation for stationary viscoplastic flows with yield, such as the Bingham or the Herschel-Bulkley flow. The approach is based on a Huber regularization of the viscosity term and a two-fold saddle point nonlinear operator equation for the resulting weak formulation. We provide the uniqueness of solutions for the continuous formulation and propose a discrete scheme based on Arnold-Falk-Winther finite elements. The discretization scheme yields a system of slantly differentiable nonlinear equations, for which a semismooth Newton algorithm is proposed and implemented. Local superlinear convergence of the method is also proved. Finally, we perform several numerical experiments in two and three dimensions to investigate the behavior and efficiency of the method

    Dark Matter Subhalos and the X-ray Morphology of the Coma Cluster

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    Structure formation models predict that clusters of galaxies contain numerous massive subhalos. The gravity of a subhalo in a cluster compresses the surrounding intracluster gas and enhances its X-ray emission. We present a simple model, which treats subhalos as slow moving and gasless, for computing this effect. Recent weak lensing measurements by Okabe et al. have determined masses of ~ 10^13 solar masses for three mass concentrations projected within 300 kpc of the center of the Coma Cluster, two of which are centered on the giant elliptical galaxies NGC 4889 and NGC 4874. Adopting a smooth spheroidal beta-model for the gas distribution in the unperturbed cluster, we model the effect of these subhalos on the X-ray morphology of the Coma Cluster, comparing our results to Chandra and XMM-Newton X-ray data. The agreement between the models and the X-ray morphology of the central Coma Cluster is striking. With subhalo parameters from the lensing measurements, the distances of the three subhalos from the Coma Cluster midplane along our line of sight are all tightly constrained. Using the model to fit the subhalo masses for NGC 4889 and NGC 4874 gives 9.1 x 10^12 and 7.6 x 10^12 solar masses, respectively, in good agreement with the lensing masses. These results lend strong support to the argument that NGC 4889 and NGC 4874 are each associated with a subhalo that resides near the center of the Coma Cluster. In addition to constraining the masses and 3-d location of subhalos, the X-ray data show promise as a means of probing the structure of central subhalos.Comment: ApJ, in press. Matches the published versio

    A new model for the formation of microbial polygons in a coastal sabkha setting

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    The stratigraphic record of microbially induced sedimentary structures spans most of the depositional record. Today, microbes continue to generate, bind and modify sediments in a vast range of depositional environments. One of the most cited of these settings is the coastal microbial mat system of the Persian/Arabian Gulf. In this setting, an extensive zone of microbial mat polygons has previously been interpreted as resulting from desiccation‐related contraction during episodic drying. This study employs 15 years of field‐based monitoring of the interaction between environmental factors and the development and evolution of polygon morphologies to test the desiccation model in this setting. On the basis of these observations, a new model is proposed that accounts for the genesis and development of microbial polygons without the need for desiccation‐induced shrinkage. Conversely, the formation, development and erosion of microbial polygons is a direct result of the production of large amounts of organic matter in a healthy, yet spatially limited, microbial community. The recognition of microbial polygons has previously been applied as a diagnostic tool for the reconstruction of ancient depositional environments. The present study calls these interpretations into doubt. It is inferred that preservation of the microbial polygons as a recognizable form would be rare. Biological degradation and compaction will reduce polygons to produce the ‘wispy’ laminae that are a common feature of ancient sabkha lithofacies

    Identification of novel stem cell markers using gap analysis of gene expression data

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    A method for the detection of marker genes in large heterogeneous collections of gene expression data is described and applied to DNA microarray data generated from 83 mouse stem cell-related samples

    A self-management programme to reduce falls and improve safe mobility in people with secondary progressive MS: the BRiMS feasibility RCT

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    This is the final version, also available from NIHR journals library via the DOI in this record.Abstract Background Balance, mobility impairments and falls are common problems for people with multiple sclerosis (MS). Our ongoing research has led to the development of Balance Right in MS (BRiMS), a 13-week home- and group-based exercise and education programme intended to improve balance and encourage safer mobility. Objective This feasibility trial aimed to obtain the necessary data and operational experience to finalise the planning of a future definitive multicentre randomised controlled trial. Design Randomised controlled feasibility trial. Participants were block randomised 1 : 1. Researcher-blinded assessments were scheduled at baseline and at 15 and 27 weeks post randomisation. As is appropriate in a feasibility trial, statistical analyses were descriptive rather than involving formal/inferential comparisons. The qualitative elements utilised template analysis as the chosen analytical framework. Setting Four sites across the UK. Participants Eligibility criteria included having a diagnosis of secondary progressive MS, an Expanded Disability Status Scale (EDSS) score of between ≥ 4.0 and ≤ 7.0 points and a self-report of two or more falls in the preceding 6 months. Interventions Intervention – manualised 13-week education and exercise programme (BRiMS) plus usual care. Comparator – usual care alone. Main outcome measures Trial feasibility, proposed outcomes for the definitive trial (including impact of MS, mobility, quality of life and falls), feasibility of the BRiMS programme (via process evaluation) and economic data. Results A total of 56 participants (mean age 59.7 years, standard deviation 9.7 years; 66% female; median EDSS score of 6.0 points, interquartile range 6.0–6.5 points) were recruited in 5 months; 30 were block randomised to the intervention group. The demographic and clinical data were broadly comparable at baseline; however, the intervention group scored worse on the majority of baseline outcome measures. Eleven participants (19.6%) withdrew or were lost to follow-up. Worsening of MS-related symptoms unrelated to the trial was the most common reason (n = 5) for withdrawal. Potential primary and secondary outcomes and economic data had completion rates of > 98% for all those assessed. However, the overall return rate for the patient-reported falls diary was 62%. After adjusting for baseline score, the differences between the groups (intervention compared with usual care) at week 27 for the potential primary outcomes were MS Walking Scale (12-item) version 2 –7.7 [95% confidence interval (CI) –17.2 to 1.8], MS Impact Scale (29-item) version 2 (MSIS-29vs2) physical 0.6 (95% CI –7.8 to 9) and MSIS-29vs2 psychological –0.4 (95% CI –9.9 to 9) (negative score indicates improvement). After the removal of one outlier, a total of 715 falls were self-reported over the 27-week trial period, with substantial variation between individuals (range 0–93 falls). Of these 715 falls, 101 (14%) were reported as injurious. Qualitative feedback indicated that trial processes and participant burden were acceptable, and participants highlighted physical and behavioural changes that they perceived to result from undertaking BRiMS. Engagement varied, influenced by a range of condition- and context-related factors. Suggestions to improve the utility and accessibility of BRiMS were highlighted. Conclusions The results suggest that the trial procedures are feasible and acceptable, and retention, programme engagement and outcome completion rates were sufficient to satisfy the a priori progression criteria. Challenges were experienced in some areas of data collection, such as completion of daily diaries.National Institute for Health Research (NIHR
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