Juan Manuel

Hospital Juárez de México, Mexico City 07760, Mexico Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico City 54090, Mexico

Departamento de Producción Agraria, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Avenida Puerta de Hierro, 4, 28040 Madrid, Spain

The maintenance of betalains and the color of extracts from the peel of red beetroot (RBAC), golden beetroot (YBAC), and purple prickly pear (PBAC) were evaluated, describing the capacity of their use as natural pigments and in the formulation of attractive and functional foods. Betalain extracts were prepared as juices from frozen and dehydrated peel, adding organic acids and concentrating for water reduction. Extracts were evaluated and applied on cottage cheese, measuring the capacity of betalains retention and pigmentation, during 10 days of storage of closed and opened products. Extracts of RBAC showed the highest betacyanin concentration, followed by YBAC with betaxanthins and PBAC with less betacyanin content. The pH stability for the extracts was pH4–7; RBAC and PBAC were stables at 125 °C. Extracts were constant during 10 days under oxygen and light exposure; however, YBAC exhibited low resistance in this environment. With cottage cheese, extracts exposed no changes in betalains and color on closed products (10 days of storage at 4 °C). In opened products, PBAC maintained the maximum betalains and color at 90%, PBAC at 75%, and YBAC at 60%. The obtained data contributed to use of agro-industrial residues, betalain extraction and conservation, and their potential use in food coloration and stabilization.

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Machining titanium alloys, particularly Ti6Al4V, pose significant challenges in manufacturing engineering. The combination of high strength and low thermal conductivity makes Ti6Al4V a particularly difficult material to machine. One of these difficulties is the rapid wear and short tool life of cutting tools, which substantially increases manufacturing costs. To address this issue, the texturing of cutting tools, especially using laser-based techniques, has garnered significant attention due to its potential to enhance the tribological performance of textured surfaces. In this paper, by means of a groove design applied to a tungsten carbide (WC) disc by laser surface texturing (LST), its behavior and wear have been evaluated after subjecting it to tribological pin-on-flat tests by confronting it with Ti6Al4V pins with different reciprocating times (250 s, 500 s, 750 s and 1000 s) in lubricated and dry conditions. In addition, these same tests have been replicated without textures for comparison. Through conducting this research, we expect to gain new insights into texturing processes and their influence on friction and sliding behavior under lubricated conditions. Additionally, the study aims to evaluate how lubricant retention capacity varies to reduce friction and wear across different testing durations. The results show better behavior with textures, reaching a higher rate of volume loss in the titanium pins. The main conclusions obtained after these tests are that textures offer a better performance in tests up to 800 s. In addition, after this time, the lubricant begins to lose its properties, becoming an abrasive paste.

Instituto de Investigación en Micología y Micotoxicología (IMICO), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad

Loading web-font Gyre-Pagella/DoubleStruck/Regular Departamento de Matemática Aplicada, Universidad de Zaragoza, 50018 Zaragoza, Spain

Today, transportation plays a crucial role in economic development and establishing strong social relationships. Primary mobility challenges in cities include high levels of traffic, accidents, and pollution. Improvements in road infrastructure, technological advancements at traffic light intersections, and the adoption of electric or hybrid vehicles are insufficient to resolve these issues. Maximizing the use of public transit and shared transportation is essential for this purpose. Strategies aimed at reducing the number of private vehicles on city roads are beneficial in this regard. Ridesharing, particularly carpooling, is an effective strategy to achieve such a reduction in vehicle numbers. However, safety concerns related to carpooling tools present a significant barrier to the growth of this mode of transportation. The measures implemented in these tools often lack appropriate technology for the authentication process, which is crucial for enhancing safety for both passengers and drivers. This proposed research explores the benefits of improving the authentication processes for passengers and drivers within a shared transportation system to minimize information security risks. A thorough literature review was conducted on shared transportation, user registration, authentication processes within these systems, and technologies that could enhance security, such as blockchain. Subsequently, considering the identified criteria in the literature review, a proposal was developed for creating a registration and authentication module based on blockchain that could be applied across various systems. Finally, an analysis was conducted on how this module could be integrated into a carpooling application and the benefits it would provide regarding safety and increased user adoption. The findings from the review were organized and assessed to identify key aspects for improving user authentication in a system based on intelligent transportation systems (ITSs) and utilizing blockchain, recognized for its security and data integrity. The registration and authentication module developed in this work allows increased security, scalability, and user adoption for any type of application, e.g., carpooling.

The increasing demand for higher resolution and faster machinery in silicon wafer inspection is driven by the rise in electronic device production and the decreasing size of microchips. This paper presents the design and implementation of a device capable of accurately measuring the surface of silicon wafers using the stitching technique. We propose an optical system design for measuring the surface profile, specifically targeting the roughness and nanotopography of a silicon wafer. The device achieves a lateral resolution of 7.56 μm and an axial resolution of 1 nm. It can measure a full 300-mm wafer in approximately 60 min, acquiring around 400 million data points. The technique utilized is a wavefront phase sensor, which reconstructs the surface shape using two images displaced a certain distance from the conjugate plane in the image space of a 4f system. The study details the calibration process and provides a method for converting local measurement coordinates to global coordinates. Quantitative phase imaging was obtained by using the wave front intensity image algorithm. The conclusive results validate the method different metrics over a wafer with bonded dies. In addition, the device demonstrates the ability to distinguish different dies that are thinned along with die-to-wafer bonding onto a carrier wafer to obtain the difference in coplanarity between the die and its surroundings as well as to detect defects during the die-to-wafer bonding. Lastly, the residual stress in the thin film deposited over the die is obtained using the Stoney model.

This study aimed to determine the dynamics of dormancy using triphenyl tetrazolium chloride (TTC) and asymbiotic germination in Laelia speciosa (Kunth) Schltr. seeds stored for three years and one year at different temperatures. This is the first report of a circannual rhythm in L. speciosa seeds under controlled storage conditions. Two experiments were carried out: (a) with seeds from wild populations of L. speciosa collected at two different times and dehydrated to 4% relative humidity (RH) and stored for three years at 25 °C, 6 °C, −20 °C, and −80 °C, and (b) with seeds from six fruits stored in liquid nitrogen (LN2; −196 °C) at 25 °C for 12 months. The germination conditions were 25 ± 1 °C with 16 h of light (23 μmol m−2 s−1) and 8 h of darkness for both trials. Because they have a rudimentary embryo, orchids are attributed a morphological latency; however, the staining of the embryo with TTC (>92%) in all the evaluations carried out throughout a year and the decrease in asymbiotic germination in the intermediate evaluations record a circannual biological cycle or clock, under temperature and humidity control (4% RH).