Study of Viscoelastic Rubber Mounts on Vehicle Suspensions with In-Wheel Electric Motors.

Rubber bushings and mounts are vastly used in automotive applications as support and interface elements. In suspension systems, they are commonly employed to interconnect the damping structure to the chassis. Therein, the viscoelastic nature of the material introduces a desirable filtering effect to reduce mechanical vibrations. When designing a suspension system, available literature often deals with viscoelastic mounts by introducing a linear or nonlinear stiffness behavior. In this context, the present paper aims at representing the rubber material using a proper viscoelastic model with the selection of different in-wheels motors. Thus, the mount dynamic behavior's influence in a suspension is studied and discussed thoroughly through numerical simulations and sensitivity analyses. Furthermore, guidelines are proposed to orient the designer when selecting these elements.

Processing of ultra-high molecular weight polyethylene/graphite composites by ultrasonic injection moulding: Taguchi optimization.

Ultrasonic injection moulding was confirmed as an efficient processing technique for manufacturing ultra-high molecular weight polyethylene (UHMWPE)/graphite composites. Graphite contents of 1 wt%, 5 wt%, and 7 wt% were mechanically pre-mixed with UHMWPE powder, and each mixture was pressed at 135 °C. A precise quantity of the pre-composites mixtures cut into irregularly shaped small pieces were subjected to ultrasonic injection moulding to fabricate small tensile specimens. The Taguchi method was applied to achieve the optimal level of ultrasonic moulding parameters and to maximize the tensile strength of the composites; the results showed that mould temperature was the most significant parameter, followed by the graphite content and the plunger profile. The observed improvement in tensile strength in the specimen with 1 wt% graphite was of 8.8% and all composites showed an increase in the tensile modulus. Even though the presence of graphite produced a decrease in the crystallinity of all the samples, their thermal stability was considerably higher than that of pure UHMWPE. X-ray diffraction and scanning electron microscopy confirmed the exfoliation and dispersion of the graphite as a function of the ultrasonic processing. Fourier transform infrared spectra showed that the addition of graphite did not influence the molecular structure of the polymer matrix. Further, the ultrasonic energy led oxidative degradation and chain scission in the polymer.

Cuatro casos de exantema periflexural asimétrico. ¿se diagnostica poco esta entidad clínica? / Four cases of asymmetric periflexural exanthema. An underdiagnosed entity?

Introducción. Diagnosticar una enfermedad que cursacon exantema no siempre es fácil, es preciso la valoraciónde los antecedentes, las manifestaciones iniciales, las propiascaracterísticas del exantema y la clínica extracutáneaacompañante.En el caso del exantema periflexural asimétrico de lainfancia, las características cutáneas son el elemento clavepara establecer el diagnóstico.A pesar de que es una enfermedad antigua, probablementees poco reconocida por el pediatra en el momentode establecer los diagnósticos. Su benignidad clínica probablementeha hecho que se infravalore y no se hagandiagnósticos precisos de la misma y se incluya dentro deexantemas inespecíficos y viriasis.Observación clínica. Se presentan cuatro casos diagnosticadosdurante la primavera, de niñas en edades entre18 meses y 3 años con mínimas manifestaciones prodrómicasde 1-2 días de duración con febrícula y manifestacionescatarrales mínimas de vías respiratorias. El exantema fuediagnosticado entre la primera y la cuarta semana de evolución,con duración total entre 4 y 6 semanas. La distribuciónfue unilateral con alguna zona de confluencia y en uncaso con extensión a la espalda. Los estudios serológicosfueron negativos.Comentarios. El perfecto conocimiento de esta enfermedadfavorecerá el diagnóstico y su diferenciación conotras entidades clínicas, como la dermatitis de contacto, lapitiriasis rosada, otros exantemas, sudamina o reaccionesmedicamentosas.La infravaloración del diagnóstico puede ser debida avarios factores: el desconocimiento de la enfermedad; labenignidad evolutiva, que provoca que tampoco preocupeen exceso el establecimiento exacto del diagnóstico; la variabilidadsegún el momento de la visita, junto a la inexperiencia.Además, se acostumbra a desviar el caso al dermatólogopensando que se trata sólo de una enfermedadcutánea.Probablemente se trata de una reacción cutánea a diferentesetiologías

Background. The diagnosis of exanthematic diseases isnot easy; a careful evaluation of the prior history, the initialsymptoms, the characteristics of the exanthem, andthe extracutaneous manifestations must be performed. Inthe case of asymmetric periflexural exathem, the cutaneousfeatures are diagnostic. This disease has been recognizedfor a long time, although general pediatricians usuallyare not familiar with its features. Its benign clinical coursehas probably resulted in its underdiagnosis, as it is usuallyincluded in the diagnosis of non-specific extanthems andviral illnesses.Case reports. We describe four girls diagnosed withasymmetric periflexural exanthem during the spring. Theage at diagnosis was between 18 months and 3 years, thepatients had very mild prodromes, with 1 – 2 days of lowgradefever and upper respiratory symptoms. The exanthemwas diagnosed between the first and the fourthweek, and the total duration of symptoms was 4 to 6weeks. All cases had unilateral involvement, with someconfluent areas and, in one case, spread to the back. Allserology studies were negative.Comments. The better knowledge of this disease willfacilitate its diagnosis and its differentiation from otherclinical entities, such as contact dermatitis, pityriasis roseaor other viral exanthems, sweat rashes, and drug reactions.The probable underdiagnosis of this entity is due to thelack of knowledge of it clinical features and its benignclinical course. Often times, these cases are referred todermatology specialists. While the etiology of this diseaseis unclear, it is thought to represent a cutaneous reactionto different causes

Compliment del tractament tuberculostàtic entre la població visitada a l’Hospital del Mar de Barcelona. 10 anys de control / Cumplimiento del tratamiento tuberculostático entre la población atendida en el Hospital del Mar de Barcelona. 10 años de seguimiento / Compliance with tuberculostatic therapy among patients seen at Hospital del Mar in Barcelona. Ten-year follow up

Fonament. L’èxit terapèutic tuberculostàtic es fonamenta en el correcte compliment. Objectiu. Valorar el compliment del tractament tuberculostàtic. Mètode. 109 infants. Metodologia: 1) verbalització, preguntes directes i indirectes; 2) comprovació colorimè- trica de presència de rifampicina i isoniazida a orina. Resultats. Malaltia tuberculosa: 36 casos (3 perduts); 27 fan totes visites. Compliment a totes visites 23 (71.8%); irregular 4. Taxa de compliment 81.25%. Infecció tuberculosa: 45 casos (2 perduts); 30 fan totes visites. Compliment correcte 24 (55.8%); irregular 13. Taxa de compliment 77.08%. Quimioprofilaxi primària: 28 casos. Compliment correcte 15; irregular 8. Conclusions. 1) El compliment terapèutic és fonamental per minvar malaltia. El millor mètode és el tractament directament observat, no sempre factible. 2) Les taxes de compliment (81.25 i 77.08%) són acceptables, però millorables. 3) La metodologia per a la valoració no és idònia, però és innòcua, fàcil, pràctica i de baix cost; 4) És imprescindible que el pediatre mentalitzi i eduqui en la importància de la malaltia i el compliment terapèutic. 5) Mantenir el mateix equip metge-infermeria pot afavorir adherències. 6) En tractaments curts és més fàcil el compliment (AU)

Fundamento. El éxito terapéutico tuberculostático se basa en el correcto cumplimiento. Objetivo. Valorar el cumplimiento de los tratamientos tuberculostáticos. Métodos. 109 niños. Metodología: 1) verbalización, preguntas directas e indirectas; 2) comprobación colorimétrica de la presència de rifampicina e isoniazida en orina. Resultados. Enfermedad tuberculosa: 36 casos (3 perdidos); 27 asisten a todas las visitas. Cumplimiento terapéutico en todas 23 (71.8%), irregular 4. Tasa de cumplimiento 81.25%. Infección tuberculosa: 45 (2 perdidos); 30 asisten a todas las visitas. Cumplimiento correcto 24 (55.8%); irregular 13. Tasa de cumplimiento 77.8%. Quimioprofilaxis primaria: 28. Cumplimiento correcto 15; irregular 8. Conclusiones. 1) El cumplimiento terapéutico es fundamental para la reducción de la tuberculosis. El mejor método es el tratamiento directamente observado, no siempre factible. 2) Las tasas de cumplimiento (81.25 y 77.8%) son aceptables pero mejorables. 3) La metodología para la valoración no es idónea, pero es inócua, fácil y de bajo costo. 4) Es imprescindible que el pediatra mentalice y eduque en la importancia de la enfermedad y el cumplimiento terapéutico. 5) Mantener el mismo equipo médico-enfermeria favorece la adherencia. 6) Con tratamientos cortos el cumplimiento es más fácil (AU)

Background. The success of tuberculostatic therapy correlates directly with compliance. Objective. To evaluate the compliance with tuberculostatic treatment among a group of children seen at a single institution. Method. 109 children receiving different tuberculostatic regimens were evaluated for compliance. The methods used included: 1) disclosure in response to direct and indirect questions; 2) colorimetric test for the presence of rifampin and isoniazid in urine. Results. Among the 36 cases of pulmonary tuberculosis, 3 patients were lost to follow-up and 27 patients have complied with all the follow-up visits. Of those, good therapeutic compliance was documented in 23 patients (71.8%), and it was estimated to be irregular in 4 patients. Thus, the overall compliance rate for patients with pulmonary tuberculosis was 81.25%. Among the 45 cases of latent tuberculosis infection, 2 patients were lot to follow-up, and 30 patients complied with all the follow-up visits. Of those, therapeutic compliance was good in 24 patients (55.8%), and it was irregular in 13 patients. Thus, the overall compliance rate for patients with latent tuberculosis infection was 77.8%. Among the 28 patients receiving primary chemoprophylaxis, therapeutic compliance wasgood in 15 patients, and irregular in 8 patients. Conclusions. 1) A good therapeutic compliance is very important to decrease the prevalence of tuberculois. The best method to improve compliance is direct supervision, which is not always feasible. 2) The compliance rates in our population (81.25% and 77.8%) are satisfactory, but could be improved. 3) The methodology used in our study is not optimal, but it is harmless, cheap and easy to perform. 4) It is essential that the primary pediatrician educates the patients on the severity of the disease and the importance of a good therapeutic compliance. 5) A stable health-care team facilitates the therapeutic compliance. 6) Short regimens are associated with better compliance (AU)