Recommendation of RILEM Technical Committee 250-CSM: Test method for Textile Reinforced Mortar to substrate bond characterization

Textile Reinforced Mortar (TRM), also known as Fabric Reinforced Mortar or Fabric Reinforced Cementitious Matrix, composites are an emerging technology for the external repair and strengthening of existing structures. For most applications, the effectiveness of the TRM reinforcement relies on its bond performance. This recommendation identifies the best practice to characterize the bond behaviour of TRM. A shear bond test method is proposed to determine the peak axial stress (associated with the maximum load that can be transferred from the structural member to the externally bonded TRM reinforcement), the stress–slip relationship and the failure mode that controls the TRM-to-substrate load transfer capacity. Guidelines on specimen manufacturing, experimental setup, test execution, and determination of test results are provided.     

Process optimization in the self-reacting friction stir welding of aluminum 6061-T6

Self-reacting friction stir welding (SR-FSW), also called bobbin-tool friction stir welding (BT-FSW), is a solid state welding process similar to friction stir welding (FSW) except that the tool has two opposing shoulders instead of the shoulder and a backing plate found in FSW. The tool configuration results in greater heat input and a symmetrical weld macrostructure. A significant amount of information has been published in the literature concerning traditional FSW while little has been published about SR-FSW. An optimization experiment was performed using a factorial design to evaluate the effect of process parameters on the weld temperature, surface and internal quality, and mechanical properties of self-reacting friction stir welded aluminum alloy 6061-T6 butt joints. The parameters evaluated were tool rotational speed, traverse speed, and tool plunge force. A correlation between weld temperature, defect formation (specifically galling and void formation), and mechanical properties was found. Optimum parameters were determined for the welding of 8-mm-thick 6061-T6 plate.     

Nanocrystalline Nd–Fe–B Anisotropic Magnets by Flash Spark Plasma Sintering

Flash spark plasma sintering (flash SPS) is an attractive method to obtain Nd–Fe–B magnets with anisotropic magnetic properties when starting from melt-spun powders. Compared to the benchmark processing route via hot pressing with subsequent die upsetting, flash SPS promises electroplasticity as an additional deformation mechanism and reduced tool wear, while maximizing magnetic properties by tailoring the microstructure—fully dense and high texture. A detailed parameter study is conducted to understand the influence of Flash SPS parameters on the densification and magnetic properties of commercial MQU-F powder. It is revealed that the presintering conditions and preheating temperature before applying the power pulse play a major role for tailoring grain size and texture in the case of hot deformation via Flash SPS. Detailed microstructure and magnetic domain evaluation disclose the texture enhancement with increasing flash SPS temperature at the expense of coercivity. The best compromise between remanence and coercivity (1.37 T and 1195 kA m⁻¹, respectively) is achieved through a combination of presintering at 500 °C for 120 s and preheating temperature of 600 °C, resulting in a magnet with energy product (BH)_max of 350 kJm⁻³. These findings show the potential of flash SPS to obtain fully dense anisotropic nanocrystalline magnets with high magnetic performance.     

Comparison between TRH-stimulated TSH and basal TSH measurement by a commercial immunoradiometric assay in the management of thyroid disease

In order to assess the current diagnostic role of the TRH test following the introduction of more sensitive "second generation" TSH assays, we studied a series of 259 outpatients, 237 women and 22 men, mean age 44.7 years (range 12-82), 91 of whom (35%) with untreated simple goiter, 133 (51%) with simple nodular goiter on steady state I-thyroxine treatment, 18 (7%) with overt or subclinical hyperthyroidism and 17 (7%) with overt or subclinical hypothyroidism, compared to a control group of 26 euthyroid healthy subjects. Serum TSH was measured by a commercial immunoradiometric assay (clinical sensitivity 0.1 microU/ml). TSH response to TRH was evaluated 30 minutes after giving 200 micrograms TRH i.v. bolus, the results being analyzed both as absolute increase (delta-TSH=stimulated TSH minus basal TSH) and as relative increase (R-TSH stimulated TSH/basal TSH). Using cut-off values of 0.3-3.2 microU/ml, basal TSH measurement was able to detect hypothyroidism (specificity = 100%) and to exclude hyperthyroidism (sensivity = 96.9%), but failed to accurately prove hyperthyroidism (specificity = 93.4%) and, above all, to exclude hypothyroidism (sensitivity = 35.3%) in our ambulatory patients. The delta-TSH values showed a basal TSH dependent linear increase (r = + 0.87, p < 0.001) both including only patients (n = 139) with basal TSH level in the euthyroidism range and including all patients (n = 223) having TSH responsive to TRH. All the patients with detectable basal TSH level displayed detectable TSH response to TRH, as did 19 (= 23.5%) of 81 patients with undetectable (< 0.1 microU/ml) basal value. In particular: a) for subnormal but detectable basal TSH ranging between 0.1 and 0.2 microU/ml, TSH was always hyporesponsive (delta-TSH < or = 2.5 microU/ml), while between 0.2 and 0.3 microU/ml TSH was hyporesponsive in 72.2% and normoresponsive (delta-TSH > 2.5 and < or = 11.9 microU/ml) in the remaining 27.8%; b) for basal TSH values within the normal range (0.3-3.2 microU/ml). TSH was hyporesponsive in 13.7%, normoresponsive in 74.8% and hyperresponsive in 11.5%; c) for high basal TSH values TSH was always hyperresponsive. The analysis of R TSH showed relatively constant values in the range of euthyroidism and hypothyroidism (m +/- SD: 7.4 +/- 2.3 and 7.7 +/- 3.1, respectively), and a marked differentiation of hyperthyroid patients whose R-TSH values were significantly lower (4.2 +/- 3.4) but had a wide individual variability. Linear regression analysis of basal or stimulated TSH and circulating thyroid hormones showed a close negative relationship, being highly significant between delta-TSH and T4 (r = 0.57, p < 0.001) and delta-TSH and FT4 (r = 0.46, p < 0.001). In conclusion, after the introduction of current second generation TSH immunoradiometric assay, the diagnostic role of the TRH test is greatly limited but not to be excluded: it can provide additional information to that obtained with simple basal TSH measurement in the diagnosis of subclinical hypothyroidism and in the precise evaluation of the degree of TSH suppression in patients with a subnormal basal TSH, either for endogenous thyrotoxicosis or I.-thyroxine treatment.     

Segmentation of the carotid intima-media region in B-mode ultrasound images

This paper proposes a new approach for the segmentation of both near-end and far-end intima-media regions of the common carotid artery in ultrasound images. The method requires minimal user interaction and is able to segment the near-end wall in arteries with large, hypoechogenic and irregular plaques, issues usually not considered previously due to the increased segmentation difficulty.     

Preserving correctness during business process model configuration

A configurable process model captures a family of related process models in a single artifact. Such models are intended to be configured to fit the requirements of specific organizations or projects, leading to individualized process models that are subsequently used for domain analysis or solution design. This article proposes a formal foundation for individualizing configurable process models incrementally, while preserving correctness, both with respect to syntax and behavioral semantics. Specifically, assuming the configurable process model is behaviorally sound, the individualized process models are guaranteed to be sound. The theory is first developed in the context of Petri nets and then extended to a process modeling notation widely used in practice, namely Event-driven Process Chains.     

Pseudo Bond Graph modelling and on-line estimation of unknown kinetics for a wastewater biodegradation process

This paper deals with the problem of modelling and on-line estimation of kinetics for a biomethanation process. This bioprocess is in fact a wastewater biodegradation process with production of methane gas, which takes place inside a Continuous Stirred Tank Bioreactor. The reaction scheme and the analysis of biochemical phenomena inside the bioreactor are used in order to obtain a nonlinear dynamic model of the bioprocess, by means of the pseudo Bond Graph method. Two nonlinear estimation strategies are developed for the identification of unknown kinetics of the bioprocess. First, an estimator is developed by using a state observer based technique. Second, an observer based on high-gain approach is designed and implemented. Several numerical simulations are performed in order to analyse and compare the behaviour and the performance of the proposed estimators.     

APROMORE: An advanced process model repository

Business process models are becoming available in large numbers due to their widespread use in many industrial applications such as enterprise and quality engineering projects. On the one hand, this raises a challenge as to their proper management: how can it be ensured that the proper process model is always available to the interested stakeholder? On the other hand, the richness of a large set of process models also offers opportunities, for example with respect to the re-use of existing model parts for new models. This paper describes the functionality and architecture of an advanced process model repository, named APROMORE. This tool brings together a rich set of features for the analysis, management and usage of large sets of process models, drawing from state-of-the art research in the field of process modeling. A prototype of the platform is presented in this paper, demonstrating its feasibility, as well as an outlook on the further development of APROMORE.