The self-sensing ability of materials, in particular carbon fiber polymer composites (SSCFPC), is a must-have requirement when designing a structural monitoring network for remote assessment of structural serviceability. This work presents a study using an Artificial Deep Neural Network (ADNN) wherein is evaluated the electrical resistance ( R) output of specimens subjected to an unchanged deformation state of 2.86% strain for prolonged periods of time. Six ADNN architectures are evaluated with varying numbers of neurons on pre-defined hidden layers, sharing the same four data inputs and one output. The dataset is based on 3276 data points collected during the experimental campaign of an innovative electrode design embedded in SSCFPC specimens. The effect of the number of iterations and the architecture of the neural network is investigated in proposed ADNN models. Simple moving average, and moving Standard Deviation, [Formula: see text], are determined and plotted in terms of z-score to assist in performance evaluation of proposed ADNN models. The optimal ADNN architecture is found among six proposed architectures and for each of the four SSCFPC mixtures. Results show the proposed model architectures are able to predict values of R with greater accuracy than traditional regression mathematical methods when traditional statistical coefficients are used. However, when analyzing data in a time-series manner, results show further research is needed to achieve optimal accuracy results. The analysis presented focused on the structural monitoring network infrastructure and hardware electronics compatibility for further development of this type of SSCFPC as a self-sensing composite material with ability of automatic calibration and suitable for real-time data acquisition and artificial intelligence modeling.

This article investigates the dependency of temperature on electrical resistance (R) change in micro carbon fiber polymer composites (MCFPC), for further development as an Internet of Things sensor from previous research works. Three mixtures were prepared using Dow Corning’s Silastic 145 as base polymer and made vary fiber content weight percentages: fiber diameter to length ratio ∅⁄l 0.13 and carbon fiber content of 13%; ∅⁄l:0.66 and carbon fiber contents of 40% and 50%. Composites tested were submitted to temperature loading, with a constant strain of 0.0%, for assessment of R when a change in the composite’s temperature occurs. The composite response was observed to follow an Arrhenius function, for temperatures ranging from −10°C to 40°C. The apparent activation energy was calculated to evaluate further differences between carbon fiber contents and the sensitivity factor, [Formula: see text] due to temperature is determined. The specimens were also tested with a constant strain of 2.86% to assess creep. It was found that creep and R, over the period of time in the analysis, best fit a discrete latent variable model. The sensitivity factor change is determined in regard to stress relaxation, [Formula: see text]. The properties of MCFPC investigated here can be used to establish relationships between electrical resistance outputs and environmental loading conditions for this type of composites, enabling the possibility of deployment as part of a management system network for structural monitoring with real-time data acquisition.

In order to develop a cost-effective carbon fiber reinforced polymer sensor for compressive strain monitoring, a study was carried out to assess electrical and piezoelectric properties of samples containing five different carbon fiber weight percentages. Testing focused on sensing ability throughout measurement of resistivity: (1) when submitted to uniaxial variable compressive strain; (2) to time prolonged relaxation at constant strain; (3) and influence of environment temperature on measurements. Results enabled the possibility of usage for live monitoring of samples by determining sensitivity values of each sample being tested. Electrical resistance measurements assessment test results, show real time resistivity change in respect to experienced strain. Further piezoelectric properties where determined. An exponential decay function was found in fractional resistance in respect to relaxation due to constant strain testing. The total amount of time needed for measurements to present an error less than 1% at the probes was determined and found to vary up to seven days. Strain reversibility of resistivity measurements varied according weight percentages of carbon fibers used in composite sample being tested. Samples were tested in situ for monitoring of displacement on foundations of a dwelling to be built, placed on foundation’s soil. The main objective here was to assess practical questions such as handling and how measurements could be made safely. Results demonstrated successful monitoring during construction phase with easy deployment on site, sensing each construction phase loading.

Background: Immediate hypersensitivity reactions (IHR) to iodinated contrast media (ICM) have traditionally been considered nonallergic; however, the increasingly frequent reporting of positive skin test and basophil activation test results suggests a specific allergic mechanism in some patients. Skin tests have been proposed as a useful tool for diagnosis, although their sensitivity and predictive values remain to be determined. The role of controlled challenge testing has not been assessed.Objective: We aimed to evaluate the role of controlled challenge testing in skin test-positive IHR to ICM.Patients and Methods: We evaluated 106 patients with IHR to ICM by performing skin tests with the agent that caused the reaction. Patients with a positive result were selected. Skin tests were extended to a series of 8 ICMs; 5 patients underwent controlled challenge test with an alternative skin test-negative ICM; a further 2 patients underwent computed tomography with an alternative skin test-negative ICM. No premedication was administered.Results: Intradermal test results were positive to the ICM that caused the reaction in 11 out of 106 patients (10.4%). Five of the 11 patients tolerated a controlled challenge test with an alternative skin test negative ICM. The 2 patients who underwent computed tomography with an alternative skin test-negative ICM tolerated the medium.Conclusions: Skin tests are useful for the diagnostic workup in patients with an allergic IHR to ICM. Since ICM cannot be avoided in many patients because they are irreplaceable in some diagnostic or therapeutic techniques, an alternative safe ICM should be investigated for future procedures. We propose the use of controlled challenge tests based on skin test results to address this need in skin test-positive reactions in order to identify an alternative non-cross-reactive ICM.

Quantification of baseline serum tryptase levels in patients who had anaphylaxis may be useful to detect cases of underdiagnosed mastocytosis. We aimed to determine the prevalence of increased baseline tryptase levels in these patients and to relate them to the severity of the episode. A prospective study was performed at the Emergency Room (ER) of a third level Hospital in Madrid, from June 2009 to May 2010. All patients over 15 years old with clinical criteria of anaphylaxis (NIAID 2006) were referred to the Allergy Department to be studied. 107,225 patients attended at the ER. 119 were diagnosed with anaphylaxis. 62 finished the allergy workup, in 42 of whom baseline tryptase was measured. In these patients, the mean age was 47.28 years (SD=18.39), 59.5% were women, and 21.4% were atopic. 26.2% had shown criteria for severe anaphylaxis (Brown, 2004). These data did not differ from those patients in which no tryptase was measured. Mean baseline tryptase measured 5.67 (SD=3,59) ug/L. No significant differences were found by gender, age, atopy antecedents, causal agent, or severity of the anaphylaxis. One patient had elevated baseline tryptase level (22.6 and 24.3μg/L in 2 separate determinations), and is being studied with a suspicion of mastocytosis. She had an anaphylactic shock (grade 3) without a confirmed trigger. Mean baseline levels of tryptase did not correlate with the severity of the anaphylaxis. Increased baseline serum tryptase is uncommon among patients who suffer anaphylaxis, but its determination could be useful as a screening of mast cell disorders.

Food allergy is a growing concern, and recognition of symptoms, knowledge of common food allergens, and management of reactions are important for patients and practitioners. Symptoms of a classic IgE-mediated food allergy vary in severity and can include any combination of laryngeal edema, wheezing, nausea, vomiting, diarrhea, urticaria, angioedema, and hypotension. Many foods can induce an allergic reaction, but the most commonly implicated foods include cow's milk, egg, peanut, tree nut, soy, wheat, fish, and shellfish. Milk and egg allergy generally develop and are outgrown in childhood. Peanut and tree nut allergy can occur during childhood or adulthood, are less likely to be outgrown, and tend to cause more fatal reactions. Given the possibility of life-threatening reactions, it is important to recognize the potential for cross-reactivity among food groups. Diagnosis of food allergy includes skin prick testing, specific serum IgE testing, and oral food challenges. Management is centered on avoidance of allergenic and cross-reacting foods and early recognition and immediate treatment of reactions. Treatment protocols to desensitize patients to food are currently under investigation.

RATIONALE: To determine the prevalence of allergy to topical drugs in a drug allergy unit (DAU) and describe the most common causal agents.METHODS: A prospective and descriptive study was led. Six hundred and sixty-six patients were referred to our DAU in a period of 7 months. Topical drugs hypersensitivity was suspected in 37 (5.5%), 31 female (83.9%), 6 male (16.1%), mean age 61.13 (range 22-82) years. Previous history: atopy (10), contact dermatitis (4), drug allergy (2). Suspected drugs were eye drops (24), antiseptics (5), antibiotics (3), corticosteroids (2), NSAID (1), estrogens (1), chemotherapics (1). Patch-test was performed in all of them. If patch test turned negative, single blind challenge test was performed.RESULTS: Eleven patients were diagnosed of allergy (9 after a positive patch-test, 2 followed a challenge test), 5 are yet under study. Ten patients (83.3%) were allergic to eye drops (6 phenylephrine, 1 travoprost, 1 polymyxin B, 1 tobramycin, 1 benzalkonium chloride and 1 thiomersal). Betamethasone was the causative drug in 1 patient. Only 1 patient had previous allergic history (contact dermatitis to nickel).CONCLUSIONS: Allergy to topical drugs represents a small part of adverse drug reactions (ADR) in a DAU. Eye drops are the main cause of topical ADR, of which phenylephrine is the first causal agent. Patch-test is a very sensitive tool in diagnosis, false negatives are rare. We have not found any relationship to previous history of atopy, contact dermatitis or other drug allergy. RATIONALE: To determine the prevalence of allergy to topical drugs in a drug allergy unit (DAU) and describe the most common causal agents. METHODS: A prospective and descriptive study was led. Six hundred and sixty-six patients were referred to our DAU in a period of 7 months. Topical drugs hypersensitivity was suspected in 37 (5.5%), 31 female (83.9%), 6 male (16.1%), mean age 61.13 (range 22-82) years. Previous history: atopy (10), contact dermatitis (4), drug allergy (2). Suspected drugs were eye drops (24), antiseptics (5), antibiotics (3), corticosteroids (2), NSAID (1), estrogens (1), chemotherapics (1). Patch-test was performed in all of them. If patch test turned negative, single blind challenge test was performed. RESULTS: Eleven patients were diagnosed of allergy (9 after a positive patch-test, 2 followed a challenge test), 5 are yet under study. Ten patients (83.3%) were allergic to eye drops (6 phenylephrine, 1 travoprost, 1 polymyxin B, 1 tobramycin, 1 benzalkonium chloride and 1 thiomersal). Betamethasone was the causative drug in 1 patient. Only 1 patient had previous allergic history (contact dermatitis to nickel). CONCLUSIONS: Allergy to topical drugs represents a small part of adverse drug reactions (ADR) in a DAU. Eye drops are the main cause of topical ADR, of which phenylephrine is the first causal agent. Patch-test is a very sensitive tool in diagnosis, false negatives are rare. We have not found any relationship to previous history of atopy, contact dermatitis or other drug allergy.

RATIONALE: Delayed adverse reactions to iodinated contrast media (ICM) were studied to explore type IV hypersensitivity mechanism through skin-tests and/or controlled challenge test (CCT). Cross-reactivity among different ICM and the tolerance of alternative ICM was evaluated.METHODS: Twenty three patients were studied (43.5% male, 56.3% female), mean age 60 years. The latent period, clinical symptoms and the causative ICM were registered. Intradermal-test (IDT) with delayed lecture and patch-test were performed with 6 ICM. If skin tests turned negative, intravenous CCT was performed with the causative ICM. If skin tests were positive CCT was performed with a skin-tests negative alternative ICM.RESULTS: The ICM involved were iopamidol 43.3%, ioversol 39.1%, iodixanol 4.3%, meglumine and sodium ioxaglate 4.3% and meglumine and sodium amidotrizoate 4.3%. Clinical symptoms were maculopapular exanthema 47.8%, desquamative erythrodermia 26.1%, face and neck erythema 13%, eczema 4.3%, angioedema 4.3% and purpura 4.3%. Latent period varied between 3-72 hours. IDT diagnostic sensitivity was 84.6% for IDT and 27.3% for patch-test. Negative predictive value was 81.8% for IDT and 60% for patch-test. Overall, type IV hypersensitivity was confirmed in 13 patients (59.1%). Reactivity to more than 1 ICM was detected in 85% of cases and to more than 2 ICM in 46% of cases. Good tolerance to an alternative ICM was obtained in 4 out of 6 patients.CONCLUSIONS: A high percent of delayed-type ICM reactions are due to a type IV mechanism. The ID test is a valid diagnostic method. An allergologic study should be performed in these patients to select an alternative ICM. RATIONALE: Delayed adverse reactions to iodinated contrast media (ICM) were studied to explore type IV hypersensitivity mechanism through skin-tests and/or controlled challenge test (CCT). Cross-reactivity among different ICM and the tolerance of alternative ICM was evaluated. METHODS: Twenty three patients were studied (43.5% male, 56.3% female), mean age 60 years. The latent period, clinical symptoms and the causative ICM were registered. Intradermal-test (IDT) with delayed lecture and patch-test were performed with 6 ICM. If skin tests turned negative, intravenous CCT was performed with the causative ICM. If skin tests were positive CCT was performed with a skin-tests negative alternative ICM. RESULTS: The ICM involved were iopamidol 43.3%, ioversol 39.1%, iodixanol 4.3%, meglumine and sodium ioxaglate 4.3% and meglumine and sodium amidotrizoate 4.3%. Clinical symptoms were maculopapular exanthema 47.8%, desquamative erythrodermia 26.1%, face and neck erythema 13%, eczema 4.3%, angioedema 4.3% and purpura 4.3%. Latent period varied between 3-72 hours. IDT diagnostic sensitivity was 84.6% for IDT and 27.3% for patch-test. Negative predictive value was 81.8% for IDT and 60% for patch-test. Overall, type IV hypersensitivity was confirmed in 13 patients (59.1%). Reactivity to more than 1 ICM was detected in 85% of cases and to more than 2 ICM in 46% of cases. Good tolerance to an alternative ICM was obtained in 4 out of 6 patients. CONCLUSIONS: A high percent of delayed-type ICM reactions are due to a type IV mechanism. The ID test is a valid diagnostic method. An allergologic study should be performed in these patients to select an alternative ICM.

Depuis la création de l'université autonome de Barcelone, notre groupe a mené une recherche à la fois théorique et expérimentale sur les rayonnements cosmiques et leur détection au moyen de détecteurs passifs. La connaissance acquise sur le processus d'enregistrement des détecteurs solides de traces et les caractéristiques de ces détecteurs ont permis au groupe d'étendre sa recherche vers d'autres applications et d'autres types de détecteurs. Nous présentons nos travaux principaux de recherche sur ce thème en prenant en compte les résultats les plus significatifs dans cette étude.

The objective pursued with this work includes the evaluating of the strength and the total energy absorption capacity (toughness) of reinforced concrete beams using different amounts of steel-bar reinforcement. The experimental campaign deals with the evaluation of the threshold load prior collapse, ultimate load and deformation, as well as the beam total energy absorption capacity, using a three point bending test. The beam half span displacement was measured using a displacement transducer, and the applied force was monitored using a load cell. The tested samples consists on a set of ten reinforced concrete beams having three different levels of steel-bar-reinforcement percentages and four different concrete compositions (i.e., giving rise to a different values of concrete strength). It was observed that the most influential parameter in the beams energy absorption capacity is the amount of steel-bar reinforcement. The results have presented good agreement between themselves. In fact, for beams with a given concrete compressive strength, a decrease in beam’s deformation was measured for higher steel-bar-reinforcement percentages. Moreover, the results had shown that for a particular steel-bar-reinforcement percentage, the concrete compressive strength have also influence in the total energy absorption capacity of the beams.

The objective of this work is to determine experimentally the damping properties of concrete reinforced beams under mechanical vibrations. This is a very important property in earthquake engineering once damping provides structure energy dissipation during moderate or strong earthquake motions. The experimental campaign used the pseudo-dynamic (PsD) method to analyse the beam dynamic behaviour. Essentially the PsD test method is a hybrid computer-driven testing procedure where a numerical algorithm and experimental step are used and combined on-line in order to solve a dynamic problem. The implementation of the method is not expensive and has the leading advantage of offering the operator a total control of any intermediate structure state during the test still keeping the realism of a real dynamic testing. In this analysis the dynamic model was assumed as single degree-of-freedom system (SDOF). For the calculation of the structural damping factor, the structure stiffness was determined prior the set-up of the time integration algorithm; thereafter a pseudo-dynamic process dealing with a free and a forced vibration scheme, where this last was achieved with an external harmonic load, led to the definition of the structure response where the dissipative effect of the damping properties of reinforced concrete beams was evidenced.

In some Spanish nuclear power plants of pressurised water reactor (PWR) type, albedo thermoluminescence dosemeters are used for personal dosimetry while survey meters, based on a thermal-neutron detector inside a cylindrical or spherical moderator, are used for dose rate assessment in routine monitoring. The response of both systems is highly dependent on the energy of the existing neutron fields. They are usually calibrated by means of ISO neutron sources with energy distributions quite different from those encountered at these installations. Spectrometric measurements with a Bonner sphere system (BSS) allow us to determine the reference dosimetric values. The UAB group, under request from the National Coordinated Research Action, was in charge of characterising the neutron fields and evaluating the response of personal dosemeters at several measurement points inside the containment building of the Catalan Nuclear Power Plant Vandellòs II. The neutron fields were characterised at five places using the UAB-BSS and a home made unfolding code called MITOM. The results obtained confirm the presence of low-energy components in the neutron field in most of the selected points. Moreover, we have found no influence of the nuclear fuel burning on the shape of the spectrum.