Metodología para la Automatización del Proceso de Barniz en Aerosol

T1-2019El método de aplicación de barniz en aerosol produce una capa uniforme rápida de aplicar y más estética que la aplicación por brocha, por lo que facilita el trabajo del operador a solo obligarlo a retocar cerca de las áreas que fueron cubiertas previamente con cinta adhesiva para evitar que se barnizaran. Debido a la alta demanda de tableros barnizados, Collins Aerospace planta Mexicali definió el método de aerosol automático, autospray, como el método preferido de aplicación para el proceso de barniz con la finalidad de disminuir defectos y aumentar la producción. Esto conlleva al análisis del proceso manual en aerosol, definición de requerimientos a replicar por medio de máquinas y la selección de dichos equipos que permitan automatizar completa o parcialmente el proceso, dando como resultado la metodología presentada en este proyecto.Maestrí

IDENTIFICATION OF CONCRETE FRACTURE PARAMETERS USING DIGITAL IMAGE CORRELATION AND INVERSE ANALYSIS

Concrete is one of the oldest materials used for construction, yet it still poses fundamental problems for engineers and researchers. The most critical problem is the propagation of cracks in concrete structures, but the mere presence of cracks does not necessarily mean that the concrete structure has reached the limit of its service life; however, instability caused by the propagation of these defects could result in the failure of a concrete structure. Thus, the focus of fracture mechanics is on assessing the stability of a structure, rather than detecting the presence of cracks. An accurate analysis of the progress of a fracture is required for assessing the integrity of a concrete structure and to predict its future performance. Accordingly, finite element analysis was used to model the performance of cracked concrete structures using available damage models, which require accurate evaluation of the mechanical and fracture properties. While concrete\u27s mechanical properties are well known, the identification of concrete\u27s fracture parameters poses an ongoing challenge. Concrete is a heterogeneous material with complicated fracture patterns. Therefore, sensors attached directly to the specimen to measure the crack opening do not provide accurate measures. The objective of this research is to develop a new methodology to study a cracked concrete structure\u27s performance using a non-contact technique to monitor the development of the fracture process zone without causing interference during fracture. Consequently, Digital Image Correlation was chosen and applied successfully to the Wedge Splitting Test to study a cracked structure\u27s response, represented by the mean of the load-crack tip opening displacement. Since the WST is an indirect fracture test, the experimental data was used to identify concrete fracture parameters by means of inverse analysis based on the cohesive crack model. The associated forward problem is based on the cracked hinge model, which is capable of accounting for the softening phenomenon. The use of Digital Image Correlation made it possible to study the dynamics of crack propagation. Experimental observations are thoroughly discussed, with special attention being placed on the monitoring of the crack\u27s evolution, and the variation of dissipated energy and tensile damage along the crack path

Man-in-the-barrel syndrome: Case report of ventral epidural abscess and review of the literature

Background: Man-in-the-barrel syndrome (MBS) is an uncommon clinical condition for which patients present with bilateral brachial diplegia but intact lower extremity strength. This syndrome is typically attributed to a cranial/cortical injury rather than a spinal pathology. Case Description: A 62-year-old diabetic male presented with bilateral upper extremity paresis attributed to a ventral cervical epidural abscess diagnosed on magnetic resonance imaging. Emergent cervical decompression resulted in slight improvement of upper extremity strength. However, he later expired due to sepsis and respiratory compromise. Conclusion: Establishing the correct diagnosis via clinical examination and proceeding with appropriate management of MBS attributed to a cervical epidural abscess is critical to achieve a good outcome

Reducing Superfluous Opioid Prescribing Practices After Brain Surgery: It Is Time to Talk About Drugs

BACKGROUND: Opioids are prescribed routinely after cranial surgery despite a paucity of evidence regarding the optimal quantity needed. Overprescribing may adversely contribute to opioid abuse, chronic use, and diversion. OBJECTIVE: To evaluate the effectiveness of a system-wide campaign to reduce opioid prescribing excess while maintaining adequate analgesia. METHODS: A retrospective cohort study of patients undergoing a craniotomy for tumor resection with home disposition before and after a 2-mo educational intervention was completed. The educational initiative was composed of directed didactic seminars targeting senior staff, residents, and advanced practice providers. Opioid prescribing patterns were then assessed for patients discharged before and after the intervention period. RESULTS: A total of 203 patients were discharged home following a craniotomy for tumor resection during the study period: 98 who underwent surgery prior to the educational interventions compared to 105 patients treated post-intervention. Following a 2-mo educational period, the quantity of opioids prescribed decreased by 52% (median morphine milligram equivalent per day [interquartile range], 32.1 [16.1, 64.3] vs 15.4 [0, 32.9], P \u3c .001). Refill requests also decreased by 56% (17% vs 8%, P = .027) despite both groups having similar baseline characteristics. There was no increase in pain scores at outpatient follow-up (1.23 vs 0.85, P = .105). CONCLUSION: A dramatic reduction in opioids prescribed was achieved without affecting refill requests, patient satisfaction, or perceived analgesia. The use of targeted didactic education to safely improve opioid prescribing following intracranial surgery uniquely highlights the ability of simple, evidence-based interventions to impact clinical decision making, lessen potential patient harm, and address national public health concerns

Polarity specific effects of cross-hemispheric tDCS coupled with approach-avoidance training on chocolate craving

Transcranial Direct Current Stimulation (tDCS) over the Dorsolateral Prefrontal Cortex (DLPFC) has already been shown to decrease craving for food. However, it remains unclear whether a single session of tDCS combined with a cognitive bias modification (CBM) task may affect explicit and implicit measures of craving for chocolate. Fifty-one healthy volunteers (38 females; mean age: 22.12 +/- 3.38) were randomly allocated to CBM training based on the Approach Avoidance task and either Sham, Right anodal-Left cathodal (RALC), or Left anodal-Right cathodal (LARC) tDCS. Results show that there was an increase in the explicit craving for chocolate, as assessed by the Visual Analog Scale [F(2, 46) = 3.239, p = 0.048], from the baseline to post-intervention. Participants which received LARC tDCS were explicitly self-reporting more craving for chocolate than those that received RALC tDCS (p = 0.023). Moreover, this effect was also observed on the implicit measure [F(2, 46) = 4.168, p = 0.022]. LARC tDCS significantly increased the implicit preference for chocolate when comparing to both RALC (p = 0.009) and Sham tDCS (p = 0.034). Previous studies have shown that RALC tDCS over the PFC is able to effectively decrease craving for food. Interestingly, the present data not only does not reproduce such result, but instead it suggests that LARC tDCS can actually increase the preference for chocolate. This result is compatible with recent models of brain laterality, in which cue craving seems to be more dependent on the left hemisphere. Thus, shifting the activity to the left hemisphere (while simultaneously reducing the activity over the homotopic region) may have led to this increased implicit as well as explicit preference for chocolate.This work was partially supported by Funded with National Funds through the Portuguese Foundation for Science and Technology (FCT) and co-funded through COMPETE 2020 - PO Competitividade e Internacionalizacao/Portugal 2020/Uniao Europeia, FEDER (Fundos Europeus Estruturais e de Investimento - FEEI) under the number: PTDC/PSI-ESP/30280/2017. SC was funded by the Portuguese Foundation for Science and Technology (FCT) with the Grant IF/00091/2015 and under FCT and COMPETE 2020 (PTDC/PSI-ESP/29701/2017). JL was funded also through FCT and COMPETE (P2020-PTDC/MHC-PCN/3950/2014) and from an internal grant from Portucalense University

Socioeconomic, demographic and socio-psychological predictors of carsharing

The aim of this bachelor thesis is to investigate how socioeconomic, demographic and socio-psychological factors influence individuals’ use of carsharing in Trondheim. Carsharing is a rapidly growing service which provides customers with short-term access to shared vehicles (Hjorteset & Böcker, 2020; Jain et al., 2021; Schaefers, 2013). By acquiring an overview on people’s preferences towards carsharing, the current study can help improve the carsharing market and gain insight into the environmental effects of carsharing. A cross-sectional design was utilized, alongside a self-administered anonymous questionnaire. The sample consisted of 384 participants, 217 women and 167 men. Principal Component Analysis (PCA) and hierarchical regression analysis was employed in the current study. The results indicated that younger people, males, highly educated people, and environmentally friendly individuals were the most likely to utilize carsharing. Income, geographics, financial considerations, social status, and social norms were also measured, but were insignificant predictors to carsharing. Additionally, limitations and suggestions for future research are discussed

Effects Of Dopamine Oxidation Products In Relation To Oxidative Stress And Parkinson\u27s Disease

The formation of low-potential, highly reactive dopamine oxidation products in the substantia nigra promotes cell death via mechanisms that have yet to be established. To identify the main pathway that is responsible for the cytotoxicity, extensive analysis of aminochrome and 5-cysteinyldopamine was done. It was found that aminochrome forms reactive oxygen species more readily than 5-cysteinyldopamine by redox-cycling with molecular oxygen. To be able to carry out experiments in vivo to efficiently test the low-potential products\u27 effects on cells and how they promote cell death, 3-methyl-5-anilino-1,2-benzoquinone (3-MAQ) was synthesized to act as an analogue of aminochrome and possibly also 5-cysteinyldopamine\u27s oxidation products. Experiments demonstrating the cytotoxicity of 3-MAQ were carried out in vivo using mouse embryonic fibroblasts. In conclusion, we have found that thiols such as cysteine protect against aminochrome\u27s formation, and we were able to synthesize a compound that can help in the study of aminochrome\u27s effects in vivo