Non-smooth contact dynamic approach for railway engineering: investigation of ballast behaviour under stabilisation process

Railway maintenance procedures include the stabilisation of ballasted tracks. The procedure of dynamic stabilisation which consists in vibrating laterally the rail while applying a vertical load is analysed using a discrete element code based on non-smooth contact dynamics. The ballast stones are modelled realistically using polyhedrons based on real ballast stones scans. The evolution of the compaction level and contact number between particles is analysed during the dynamic stabilisation process. A model is proposed to predict settlement. The results of simulation show the effectiveness of this maintenance procedure. It also points out the relevance of the model to predict settlement

Influencia del filtro tipo chimenea mediante modelamiento bidimensional para una presa de material homogéneo extraído de la cantera tres tomas

El tema a tratar en la presente tesis es acerca de la influencia que genera el uso del filtro tipo chimenea en una presa de material homogéneo, esto representado a través de la línea que genera la infiltración, el caudal infiltrado y la estabilidad de taludes de la presa. El principal interés es de dar solución a los fenómenos que ocurren al interior de una presa de material homogéneo y que afectan su subsistencia, también de buscar tecnologías que abaraten la construcción de una presa sin afectar la seguridad de la misma. Se empleó metodologías utilizadas en proyectos de gran envergadura como en Estados Unidos, Cuba entre otros, donde comparan por medio de programas y modelamientos físicos los benéficos que genera el uso de nuevas tecnologías. La finalidad del presente trabajo de investigación es cuantificar la influencia del uso del filtro tipo chimenea en una presa de material homogéneo, y dar a conocer sus beneficios o desventajas con lo que respecta a lo ya mencionado, la línea que genera la infiltración, el caudal infiltrado y la estabilidad de taludes de la presa. I. Introducción, se procedió a plantear los antecedentes, la problemática y la hipótesis de investigación, de igual manera el objetivo tanto general como específico. II. Metodología, se plantea el diseño de investigación a seguir, las variables, la población y muestra, las técnicas de recolección de datos y el método de análisis de los datos obtenidos. III. Resultados, se da a conocer el desarrollo de cada objetivo específico planteado al inicio de la investigación. IV. Discusión de los resultados, para poder dar un valor agregado a la investigación, se procedió a comparar los resultados obtenidos con otras investigaciones relacionadas al tema tratado. V. Conclusiones, se presentan los principales hallazgos como síntesis de la investigación realizada. VI. Recomendaciones, en este punto se da a conocer los aspectos a tomar en cuenta para su aplicabilidad de los procedimientos realizados. VII. Referencias, en este capítulo se ha realizado la enumeración de las citas realizadas a diversos autores. VIII. Anexos, se detalla en paso a paso para el cumplimiento de cada objetivo

INTERFERENTIAL MONOCHROMATOR FOR NEUTRAL ATOMS

Abstract When a so called "co-moving" magnetic field -i.e. a field moving at a velocity close to the atom ones -is used as a phase shifter in a Stern-Gerlach atom interferometer the resulting accumulated phase shift takes non negligible values for only those atomic velocities which are close to that of the field. The interferometer is then an adjustable interferential velocity filter. This effect has been demonstrated by means of a time-of-flight measurement on a metastable hydrogen atom beam the velocity distribution of which is wide (δv/v = 1). By scanning the field velocity, the velocity distribution of a continuous H* beam is readily obtained. Extension to accelerated magnetic fields and their application to gravimetry are proposed

Mobilized Peripheral Blood Stem Cells Versus Unstimulated Bone Marrow As a Graft Source for T-Cell-Replete Haploidentical Donor Transplantation Using Post-Transplant Cyclophosphamide.

Purpose T-cell-replete HLA-haploidentical donor hematopoietic transplantation using post-transplant cyclophosphamide was originally described using bone marrow (BM). With increasing use of mobilized peripheral blood (PB), we compared transplant outcomes after PB and BM transplants. Patients and Methods A total of 681 patients with hematologic malignancy who underwent transplantation in the United States between 2009 and 2014 received BM (n = 481) or PB (n = 190) grafts. Cox regression models were built to examine differences in transplant outcomes by graft type, adjusting for patient, disease, and transplant characteristics. Results Hematopoietic recovery was similar after transplantation of BM and PB (28-day neutrophil recovery, 88% v 93%, P = .07; 100-day platelet recovery, 88% v 85%, P = .33). Risks of grade 2 to 4 acute (hazard ratio [HR], 0.45; P \u3c .001) and chronic (HR, 0.35; P \u3c .001) graft-versus-host disease were lower with transplantation of BM compared with PB. There were no significant differences in overall survival by graft type (HR, 0.99; P = .98), with rates of 54% and 57% at 2 years after transplantation of BM and PB, respectively. There were no differences in nonrelapse mortality risks (HR, 0.92; P = .74) but relapse risks were higher after transplantation of BM (HR, 1.49; P = .009). Additional exploration confirmed that the higher relapse risks after transplantation of BM were limited to patients with leukemia (HR, 1.73; P = .002) and not lymphoma (HR, 0.87; P = .64). Conclusion PB and BM grafts are suitable for haploidentical transplantation with the post-transplant cyclophosphamide approach but with differing patterns of treatment failure. Although, to our knowledge, this is the most comprehensive comparison, these findings must be validated in a randomized prospective comparison with adequate follow-up

The landscape of open science in behavioral addiction research: Current practices and future directions

Open science refers to a set of practices that aim to make scientific research more transparent, accessible, and reproducible, including pre-registration of study protocols, sharing of data and materials, the use of transparent research methods, and open access publishing. In this commentary, we describe and evaluate the current state of open science practices in behavioral addiction research. We highlight the specific value of open science practices for the field; discuss recent field-specific meta-scientific reviews that show the adoption of such practices remains in its infancy; address the challenges to engaging with open science; and make recommendations for how researchers, journals, and scientific institutions can work to overcome these challenges and promote high-quality, transparently reported behavioral addiction research. By collaboratively promoting open science practices, the field can create a more sustainable and productive research environment that benefits both the scientific community and society as a whole

MODELAMIENTO FÍSICO BIDIMENSIONAL DE UNA PRESA DE TIERRA CON FILTRO TIPO CHIMENEA Y SU INFLUENCIA EN EL DRENAJE INTERNO

Actualmente surge la necesidad de estudiar el funcionamiento de una presa de tierra con material homogéneo pues el uso de este tipo de presas es muy común a nivel mundial debido a los menores costos que genera su construcción y por el aprovechamiento del material en la zona donde se va a construir, entonces para proyectar una estructura de tales características es necesario considerar un sistema de filtración y drenaje que permita transportar un determinado caudal de infiltración hacia aguas abajo de la presa; sin embargo, no se sabe los cambios originados por la alteración de sus principales criterios de diseño tales como la composición granulométrica y los grados de compactación. En las diferentes investigaciones relacionadas que se han realizado se ha demostrado que un mejor estudio se logra a través de un modelamiento físico bidimensional y por esta razón se evaluó la influencia del filtro tipo chimenea en el drenaje interno del cuerpo de la presa de tierra. Los ensayos se realizaron con el equipo tanque – filtración en una sección trasversal de presa previemente dimensionado, el cual permitió obtener la línea de saturación, los caudales de infiltración y las lecturas piezométricas. Finalmente la estabilidad de taludes, el comportamiento del drenaje, los porcentajes de compactación y los valores de densificación de la presa nos indican resultados muy satisfactorios para este tipo de filtro cumpliendo los parámetros requeridos en todas las condiciones de funcionamiento

SY-MIS Project: Biomedical Design of Endo-Robotic and Laparoscopic Training System for Surgery on the Earth and Space

Despite the location (Earth or Space), surgical simulation is a vital part of improving technical skills and ensuring patients' safety in the real procedure. The purpose of this study is to describe the Space System for Minimally Invasive Surgery (SY-MIS©) project, which started in 2016 under the supervision of the Center for Space Systems (C-SET). The process connects the best features of the following machines: Biomedik Surgeon, Space Biosurgeon, SP-LAP 1, and SP-LAP 2, which were defined using the VDI 2221 guidelines. This research uses methods based on 3 standards: i) Biomedical design: ISO 9001-13485 / FDA 21 CFR 820.30 / ASTM F1744-96(2016); ii) Aerospace human factors: HF-STD-001; iii) Mechatronics design: VDI 2206. The results depict the conceptual biomedical design of a novel training system named Surgical Engineering and Mechatronic System (SETY©), which integrates the use of 2 laparoscopic tools and 2 anthropomorphic mini-robotic arms (6 DOF). It has been validated by the Evaluation of Technical Criteria, getting a total score of 90% related to clinical assessment, machine adaptability, and robustness. The novelty of the research lies in the introduction of a new procedure that covers the simultaneous use of laparoscopic and robotic systems, named Hybrid Cyber-Physical Surgery (HYS©). In conclusion, the development of SY-MIS© promotes the use of advanced technologies to improve surgical procedures and human-machine medical cooperation for the next frontier of habitability on other planets. Doi: 10.28991/ESJ-2024-08-02-01 Full Text: PD

Impact Factor: outdated artefact or stepping-stone to journal certification?

A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

2,4-Diaminopyrimidines as Potent Inhibitors of Trypanosoma brucei and Identification of Molecular Targets by a Chemical Proteomics Approach

The protozoan parasite Trypanosoma brucei is the causative agent of human African trypanosomiasis (HAT) or sleeping sickness, a fatal disease affecting nearly half a million people in sub-Saharan Africa. Current treatments for HAT have very poor safety profiles and are difficult to administer. There is an urgent need for new, safe and effective treatments for sleeping sickness. This work describes the discovery of 2,4-diaminopyrimidines, exemplified by 4-[4-amino-5-(2-methoxy-benzoyl)-pyrimidin-2-ylamino]-piperidine-1-carboxylic acid phenylamide or SCYX-5070, as potent inhibitors of T. brucei growth in vitro and also in animal models for HAT. To determine the parasite proteins responsible for interaction with SCYX-5070 and related compounds, affinity pull-downs were performed followed by sequence analysis and parasite genome database searching. The work revealed that mitogen-activated protein kinases (MAPKs) and cdc2-related kinases (CRKs) are the major proteins specifically bound to the immobilized compound, suggesting their potential participation in the pharmacological effects of 2,4-diaminopyrimidines against trypanosomatid protozoan parasites. These data strongly support the use of 2,4-diminipyrimidines as leads for the development of new drug candidates for the treatment of HAT