Development and Physical Characterization of a Composite Laminate Aramid/Epoxy Manufactured by the Vacuum Bag Method

Carlos Andres Espinosa Dominguez,Honorio Ortiz Hernández,Helvio Mollinedo,Orlando Susarrey Huerta,Hilario Hernández Moreno 한국고분자학회 2023 폴리머 Vol.47 No.1

The manufacturing process of composite materials is crucial in determining their final quality and mechanical and physical properties. Although manufacturing defects affecting mechanical properties cannot be entirely eliminated, some process parameters can be improved to reduce them, and solutions without increasing manufacturing costs are sought. Currently, research on aramid fibers and epoxy resin is booming; thus, this study aims to apply the vacuum bag process with epoxy matrix and aramid fiber reinforcement, focusing on the manufacturing process parameters. Herein, a procedure for the hand lay-up of aramid impregnated with resin and the vacuum bag method for a composite laminate is described. Some variations and improvements in the vacuum bag technique were applied, improving the breathable layers in the mold to enhance the extraction of gases and promote a homogenous pressure distribution. ASTM procedures were performed to obtain the density and constituent content of the composite material, resulting in a fiber volume fraction of 0.606, a resin volume fraction of 0.294, and a porosity volume fraction of 0.098.

Real-time Embedded Architecture for improving Pervasive Robot Services

Carlos Dominguez,Houcine Hassan,Alfons Crespo 보안공학연구지원센터 2008 International Journal of Software Engineering and Vol.2 No.1

The integration of embedded real-time control systems with the physical world via sensors and actuators (pervasive computing systems) is creating a nascent infrastructure for a technical, economic and social revolution. Service robots have to execute tasks that have different criticality, flexible timing constraints and variable execution time, because they perform their activities in dynamic and unpredictable environments, they share resources and have to cooperate to fulfill the objectives. The environmental conditions have influence in the variability of the system load. For instance, the computational requirements of recognition tasks are variable and dependent on the number of objects perceived in scenes. To tackle the computational variability of pervasive robots a real-time architecture is proposed in this paper.

Incorporation of ZnO Nanoparticles on Solution Processed Zinc Oxide Thin-Film Transistors

Miguel A. Dominguez,Javier Martinez,Karim Monfi l-Leyva,Susana Soto,Netzahualcoyotl Carlos,Mario Moreno 한국전기전자재료학회 2018 Transactions on Electrical and Electronic Material Vol.19 No.6

In this work, a simple, low-cost and reliable method for deposition of solution-processed Zinc oxide fi lms with embeddedZnO nanoparticles (np-ZnO) at low deposition temperature is presented. The np-ZnO fi lms are obtained by ultrasonic spraypyrolysis technique at 200 °C. The np-ZnO precursor solution is prepared at diff erent nanoparticles content. After deposition,the np-ZnO fi lms do not require any additional treatment. The np-ZnO fi lms were characterized by Fourier transforminfrared spectroscopy, X-ray diff raction and fi eld emission scanning electron microscope. Moreover, a comparison of ZnOand np-ZnO based thin-fi lm transistors (TFTs) is presented. The extracted fi eld-eff ect mobility was 0.01 cm 2 /Vs for ZnOTFTs and 0.05 cm 2 /Vs for np-ZnO TFTs.

Flexible Real-time Embedded Architecture for Advanced Service Robots

David Ramada,Carlos Dominguez,Houcine Hassan,Alfons Crespo 보안공학연구지원센터 2008 International Journal of Smart Home Vol.2 No.4

In most advanced real-time control applications such as service robots, the tasks have different criticality, flexible timing constraints and variable execution time. For instance, autonomous service robots perform their activities in dynamic environments, share resources and have to cooperate to fulfill their objectives. These changing environmental conditions produce a variability of the system load. Firstly, the computational requirements of recognition tasks are variable and dependent on the number of objects perceived in scenes. Secondly, the application processes are executed at different frequencies with varying periods and deadlines that are dependent on robot speeds. To tackle these aspects a flexible real-time architecture is implemented in rt-linux in this paper. Moreover, the architecture permits to extract the slack time, enabled in the system due to load variability, and to invest it in improving the communication performances of the robots. Experimental evaluations of the architecture have been carried out with real autonomous robots.

Epidemiological Aspects of Osteosarcoma, Giant Cell Tumor and Chondrosarcoma Musculoskeletal Tumors - Experience of the National Rehabilitation Institute, Mexico City

DelaGarza-Montano, P,Estrada-Villasenor, E,Dominguez Rubio, R,Martinez-Lopez, V,Avila-Luna, A,Alfaro-Rodriguez, A,Garciadiego-Cazares, D,Carlos, A,Hernandez-Perez, AD,Bandala, C Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: Primary bone neoplasms are rare, contributing only 0.2% of the global burden of all human malignancies. Osteosarcoma (OS) and chondrosarcoma (CS) are the most common malignancies of bone. The giant cell tumor of bone (GCTb) is a benign tumor with behavior characterized by osteolytic bone destruction. The OS, CS and GCTb affect both sexes, all races and generally have incidence peaks regarding the age of the patient which vary according to the tumor type. We analyzed the incidences of OS, CS and GCTb and their relations with gender and age in patients treated in the National Rehabilitation Institute (INR, for its acronym in Spanish) over a period of nine years. Materials and Methods: In the study period, clinic pathological data for 384 patients were obtained with clinical, radiological and histopathological diagnosis for OS, GCTb and CS. Data analysis was performed using the chi-square and Fisher's exact tests. Results: From 2006 to 2014 were recorded 384 cases of bone malignancies in the database of INR. The GCTb had the highest incidence (53.1%), followed by OS (31.3%) and finally the CS (15.6%). The overall average age was $33.6{\pm}15.8$ years and the overall frequency of gender had a ratio of 1/1.03 male/female. The states with the highest incidence were Distrito Federal and Estado de Mexico with 29.2% and 25.3% respectively. Malignant neoplasms of bone assessed in the course of nine years show three significant increases in 2008, 2011 and 2014 (p=0.14). We found association between sex and tumor type (p=0.03), GCTb and CS predominated in females (54.9% and 56.6% respectively), while for the OS males were most affected (59.1%). Age was different in relation with tumor type (p=0.0001), average age was $24.3{\pm}11.2$ years for OS, $34.5{\pm}13$ years for GCTb and $49.2{\pm}18.5$ years for CS. Furthermore, associations of tumor type with topographic location of the primary tumor (P=0.0001) were found. Conclusions: In this study we can see that incidence of musculoskeletal tumor in our population is continuously increasing and in nine years an approximately 200% increase of musculoskeletal tumor cases was observed.

Adult pancreatoblastoma: A rare malignant tumor of the pancreas

German Esteban Sanchez Morales,Hillary Lizarraga Payan,Roberto Andre Moguel Valladare,Ismael Dominguez Rosado,Carlos Chan 한국간담췌외과학회 2021 Annals of hepato-biliary-pancreatic surgery Vol.25 No.3

Pancreatoblastoma (PB) is a rare malignant tumor in adults. It has an overall incidence of 0.004 per 100,000 inhabitants. Its diagnosis with fine-needle aspiration (FNA) is difficult due to multiple differentiation lines present on PB that overlap with other tumors. A 76-year-old male patient presented with jaundice, weight loss of 10 kg in 6 months, and appetite loss. Abdominal computed tomography scan showed a tumor in the pancreas head. Transendoscopic ultrasound with FNA biopsy revealed a malignant epithelial neoplasia compatible with PB with immunohistochemistry CK19 (+), P63(+), synaptophysin (–), and Ki67 50%. The patient underwent surgical resection and adjuvant chemotherapy. Currently, the patient is in follow-up with the latest imaging showing no evidence of disease at 32 months after his initial diagnosis. PB is an uncommon malignant neoplasia with an aggressive behavior. Its diagnostic and therapeutic protocols are unclear. Its preoperative diagnosis may be difficult since its imaging features and serological markers are non-specific. However, FNA may be useful in some situations. Surgical resection is currently the recommended treatment that is associated with the best long-term survival.