Product Design by Additive Manufacturing for Water Environments: Study of Degradation and Absorption Behavior of PLA and PETG

Additive manufacturing technologies are shifting from rapid prototyping technologies to end use or final parts production. Polymeric material extrusion processes have been broadly addressed with a specific definition of all parameters and variables for all different of technologies approaches and materials. Recycled polymeric materials have been studied due to the growing importance of the environmental awareness of the contemporary society. Beside this, little specific research has been found in product development applications for AM where the printed parts are in highly moisture environments or surrounded by water, but polymers have been for long used in such industries with conventional manufacturing approaches. This work focuses on the analysis and comparison of two different additively manufactured polymers printed by fused filament fabrication (FFF) processes using desktop-size printers to be applied for product design. The polymers used have been a recycled material: polyethylene terephthalate glycol (PETG) and polylactic acid (PLA). Degradation and water absorption behaviors of both materials are presented, analyzed and discussed in this paper, where different samples have been immersed in saturated solutions of water with maritime salt and sugar together with a control sample immersed in distilled water. The samples have been dimensionally and weight-controlled weekly as well as microscopically analyzed to understand degradation and absorption processes that appear in the fully saturated solutions. The results revealed how the absorption process is stabilized after a reduced number of weeks for both materials and how the degradation process is more remarked in the PLA material due to its organic nature

Lipoma intramuscular del músculo deltoides: Presentación de cuatro casos

Describimos cuatro casos de lipoma intramuscular del músculo deltoides en cuatro pacientes, dos mujeres y dos varones con una edad media de 62 años. Dos están situados en el lado derecho y dos en el izquierdo. Las tumoraciones tienen un tamaño que oscila entre 5 y 8 centímetros, produciendo un cuadro clínico de dolor y limitación funcional del hombro. En tres de los cuatro pacientes se realiza tratamiento definitivo con extirpación quirúrgica de la tumoración. Con un seguimiento mínimo de año y medio, no existe recidiva de la lesión y los pacientes muestran una recuperación clínica y funcional completa.We describe four intramuscular lipoma in the deltoids muscle, in four patients (two women and two men), 62 years old. Two of the tumors were localized in the right side and two in the left side. The tumor size was between 5 and 8 centimetres, causing pain and functional disability of the shoulder. Three of the four patients were treated by surgical extirpation of the tumors. 18 months after surgery, none of the tumors have recurred and all patients showed a total functional recovery

Hydrothermal CO2 conversion using zinc as reductant: Batch reaction, modeling and parametric analysis of the process

Producción CientíficaHydrothermal CO2 reduction using Zn as reductant was investigated. This process has the advantage of avoiding the use of hydrogen with all its safety and environmental concerns, and allows an easy integration with CO2 capture as NaHCO3. In this work, this reaction was studied in batch reactors at temperatures from 275 to 325 °C. Conversions up to 60% were obtained with 100% selectivity towards formic acid, at reaction times between 10 and 180 min. A mathematical model correlated with data from literature was developed and is able to correctly predict both experimental and literature data with an averaged error of 3.5%. Main variables of the process were analyzed: temperature, Zn/HCO3− ratio, heating rate, Zn particle size, pressure, etc. The optimum reaction conditions found were 300 °C with a rapid heating, and particle sizes of 10 μm. Zn excess dramatically improves the yield, but a lower excess can be compensated at high pressures.Ministerio de Economía, Industria y Competitividad (Project ENE2014-53459-R

Heridas craneales por proyectil de arma de fuego en población civil: análisis de la experiencia de un centro en Monterrey, México

ResumenAntecedentesLas heridas por proyectil de arma de fuego en población civil mexicana eran excepcionales. Actualmente los conflictos entre grupos de delincuencia organizada son con armas consideradas en México como de uso exclusivo del ejército.ObjetivosDescribir nuestra experiencia y compartir el resultado de factores clínicos y radiológicos de influencia en el pronóstico de los pacientes.Material y métodosEstudio observacional, retrospectivo de pacientes con herida craneal por proyectil de arma de fuego penetrando duramadre, tratados de enero de 2009 a enero de 2013, considerando variables: demográficas, escala de coma de Glasgow al ingreso, estado pupilar, tipo de operación y tamaño de descompresión, escala de resultados de Glasgow al egreso y a los 6 meses.ResultadosDe 68 pacientes excluimos a aquellos en los que no hubo penetración de duramadre, quedando 52. Edad promedio de 28.7 años, hombres un 80.8%, todos intervenidos quirúrgicamente y con mortalidad general del 8%. La mortalidad del grupo con escala de coma de Glasgow de 3-5 fue del 43%, de 6-8 fue del 6%, y nula con 9-15. En los pacientes con ambas pupilas fijas, anisocóricas e isocóricas, la mortalidad fue del 67, 7 y 3%, respectivamente. Una trayectoria del proyectil bihemisférica, multilobar y unihemisférica más compromiso ventricular se relacionó con escala de resultados de Glasgow en el momento del egreso≤3 en el 90.9% de los casos.ConclusionesEscala de coma de Glasgow al ingreso y estado pupilar son los factores con mayor influencia en el pronóstico. Pacientes con escala de coma de Glasgow>8 y<13 puntos al ingreso, respuesta pupilar normal y sin compromiso ventricular se pueden beneficiar con tratamiento quirúrgico agresivo temprano.AbstractBackgroundGunshot wounds in civilian population of México were quite rare. Currently, conflicts amongst organized crime groups are carried out with weapons, which are considered as exclusive use by the natiońs army.ObjectivesDescribe the experience of our institution and share results of clinical and radiological factors influencing the prognosis of the patients.Material and methodsObservational and retrospective study of patients with cranial gunshot wounds (GSW), which penetrated the duramater, treated from January 2009 - January 2013. We considered several demographic variables, Glasgow Coma Scale (GCS), upon admission, state of pupils, type of surgery and size of decompression, Glasgow Outcome Score (GOS) upon discharge, and after 6 months.ResultsOf 68 patients, we excluded those whose duramater was not penetrated, leaving 52 patients. The average age was 28.7 years, and 80.8% were males. All were surgically intervened, with 8% of general mortality. Mortality in the GCS 3 to 5 points group was 43%, from the 6 to 8 points it was 6%, and no deaths in the 9 to 15 points. In patients with both pupils fixed, anisocoric and isocoric, mortality was 67%, 7%, and 3%, respectively. Bihemispheric, multilobar and unihemispheric trajectory of the bullet plus ventricular compromise was related to a Glasgow Outcome Score ≤ 3 upon discharge in 90.9% of the cases.ConclusionsGCS upon admission and state of the pupils are the most influential factors in the prognosis. Patients with a GCS > 8 < 13 points upon admission, normal pupillary response, without ventricular compromise can benefit with early and aggressive surgical treatment

High-performance liquid chromatography and UV-visible measurements to optimize the storage of volume holograms in hydrogels

The storage of time-stable holographic gratings in photohydrogels when the material is immersed in liquid media represents a great challenge at present. A very important stage in the process of storing holograms in photohydrogels are the washing stages to eliminate the remains of the components that have not reacted in the photochemical reaction. The main goal of this work is focusing on the study of the optimization of the washing stages of the photohydrogels based on acrylamide and N,N’-methylenebis(acrylamide) once unslanted transmission holograms have been stored. For the purpose of determining the compositions of the wash solutions, High-Performance Liquid Chromatography and UV-visible measurements have been employed in our system. PBST and DMSO:H2O 6:4 (v/v) are used as solvents in the washing stages. The diffraction efficiencies are measured during the washing stages and after the storing of the holograms during several days in PBST. Maximum diffraction efficiencies of 38.0 and 27.6% are reached when PBST and DMSO:H2O 6:4 are employed, respectively.Work funded by Ministerio de Ciencia e Innovación, Spain, under project PID2019-106601RB-I00; by Generalitat Valenciana under projects GRISOLIAP/2019/143, CIDEXG/2022/60, PROMETEO/2021/006, PROMETEO/2020/094 and IDIFEDER/2021/014 (co-funded by European Union through the FEDER Program), Spain. K. Berramdane thanks to the government of Algeria for her scholarship offered to develop her thesis in the Holography and Optical Processing Group at the University of Alicante (Spain). M. I. Lucío acknowledges her Juan de la Cierva Incorporación grant (IJC 2018-035355-I) funded by MCIN/AEI/10.13039/501100011033

Do Products Respond to User Desires? A Case Study. Errors and Successes in the Design Process, under the Umbrella of Emotional Design

This article introduces a methodological approach to the evaluation of different industrial products according to Norman's approach and dimensions, focusing on a specific case study. The study also shows different possibilities to guide industrial designers during the design process in order to create products with high emotional value. For those, the case study was done with 330 target specific users, submitting nine prototypes (designed for different targets) to the user experience evaluation and product perception analysis. The evaluated proposals were selected from a total of 45. The results show the visceral, behavioural and reflective levels perceived by those users to whom each product is intended, as well as the target deviation within the design process. In this sense, the emotional response reveals the asymmetric character of perception according to Norman's dimensions

Barrera protectora de las ventiscas

Barrera protectora de las ventiscas, para instalar cerca de rutas de comunicación con el objeto de evitar la acumulación de la nieve o arena en la vía. La barrera se constituye por la unión de varias pantallas formadas por un conjunto de lamas que se colocarán en sentido horizontal, superpuestas entre sí a distancias regulares, vinculadas con postes verticales mediante el anclaje de sus extremos a unas placas rectangulares que se introducen en el poste vertical por un anillo que presenta la placa.Solicitud: 200803250 (10.11.2008)Nº Pub. de Solicitud: ES2341211A1 (16.06.2010)Nº de Patente: ES2341211B1 (14.02.2011