44 research outputs found
Qualitatively-improved identified parameters of prestressed concrete catenary poles using sensitivity-based Bayesian approach
Prestressed, spun-cast ultrahigh-strength concrete catenary poles have been used widely for electric train systems; for example, thousands of these poles have been installed along high-speed train tracks in Germany. Given the importance of the functionality of train systems, adequate attention has not been paid to catenary poles in research and the literature. Questions regarding the integrity of catenary poles still exist. This study contributes to identify the actual material properties of the poles of interest because the parameter identification is an essential process for any subsequent evaluation of the integrity of catenary poles. Accordingly, a sensitivity-based Bayesian parameter identification approach is developed to estimate the real material properties of the poles using measurements from multiple experiments and numerical models. This approach integrates the sensitivity of time-dependent measurements into the Bayesian inference, which improves the quality of inferred parameters considerably in comparison with classic Bayesian approaches applied in similar case of studies. Furthermore, the proposed approach combines observations of multiple experiments conducted on full-scale poles using a probabilistic uncertainty framework, which provides informative data used in the parameter identification process. Besides, Bayesian inference quantifies the uncertainty of inferred parameters and estimates the hyperparameters, such as the total errors of the observations. The proposed approach utilizes the efficiency of the transitional Markov Chain Monte Carlo algorithm for sampling from the posterior in both levels of Bayesian inference, namely, the unknown parameters and the hyperparameters. The results show the significant influence of the sensitivity concept in improving the quality of the posterior and highlight the importance of identifying the real material properties during the evaluation of the behavior of existing structures, rather than using the characteristic properties from the datasheet. Applying the proposed approach looks very promising when applied to similar applied case studies.publishe
Overexpression of transmembrane protein 168 in the mouse nucleus accumbens induces anxiety and sensorimotor gating deficit
Transmembrane protein 168 (TMEM168) comprises 697 amino acid residues, including some putative transmembrane domains. It is reported that TMEM168 controls methamphetamine (METH) dependence in the nucleus accumbens (NAc) of mice. Moreover, a strong link between METH dependence-induced adaptive changes in the brain and mood disorders has been evaluated. In the present study, we investigated the effects of accumbal TMEM168 in a battery of behavioral paradigms. The adeno-associated virus (AAV) Tmem168 vector was injected into the NAc of C57BL/6J mice (NAc-TMEM mice). Subsequently, the accumbal TMEM168 mRNA was increased approximately by seven-fold when compared with the NAc-Mock mice (controls). The NAc-TMEM mice reported no change in the locomotor activity, cognitive ability, social interaction, and depression-like behaviors; however, TMEM168 overexpression enhanced anxiety in the elevated-plus maze and light/dark box test. The increased anxiety was reversed by pretreatment with the antianxiety drug diazepam (0.3 mg/kg i.p.). Moreover, the NAc-TMEM mice exhibited decreased prepulse inhibition (PPI) in the startle response test, and the induced schizophrenia-like behavior was reversed by pretreatment with the antipsychotic drug risperidone (0.01 mg/kg i.p.). Furthermore, accumbal TMEM168 overexpression decreased the basal levels of extracellular GABA in the NAc and the high K+ (100 mM)-stimulated GABA elevation; however, the total contents of GABA in the NAc remained unaffected. These results suggest that the TMEM168-regulated GABAergic neuronal system in the NAc might become a novel target while studying the etiology of anxiety and sensorimotor gating deficits
Practitioners’ View on the Implementation Potential of Adaptive Façades with focus on The Netherlands
The adaptivity of façades is increasingly recognized as an important functional feature to be integrated with the state-of–the-art building technology. The aim is thereby to control its reversible system states in real-time to adapt to current indoor and outdoor conditions. Concepts reported elsewhere integrate two or more functions related to structural integrity, ventilation, heating and cooling, solar protection, as well as energy generation and storage. Although advantages are perceived obvious, the number of realized case studies remains limited. Triggered by this observation, the authors of this contribution report research findings from a literature study and interviews with stakeholders in the field, including contractors, building consultants and architects. The three key-findings suggest that (1) the functions daylighting and energy generation/storage are most commonly integrated into façades or façade components characterized as being adaptive, (2) interviewees are divided on the implementation potential of most of the designs/concepts and (3) the aesthetics of the design, (investment) costs, durability and required maintenance are critical for a widespread market uptake. Herewith, this paper contributes new knowledge to the discussion related to finding the right level of system integration in building technology