74 research outputs found
Spatial profiles of collimated laser Compton-scattering -ray beams
The intensity and energy spatial distributions of collimated laser Compton
scattering (LCS) -ray beams and of the associated bremsstrahlung beams
have been investigated as functions of the electron beam energy, electron beam
phase space distribution, laser optics conditions and laser polarization. We
show that the beam halo is affected to different extents by variations in the
above listed parameters. In the present work, we have used laser Compton
scattering simulations performed with the \texttt{eliLaBr} code
(https://github.com/dan-mihai-filipescu/eliLaBr) and real LCS and
bremsstrahlung -ray beams produced at the NewSUBARU synchrotron
radiation facility. A 500~m MiniPIX X-ray camera was used as beamspot
monitor in a wide -ray beam energy range between 1.73~MeV and 38.1~MeV
Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study
BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223
Le rôle du variant d'histone cenp-a et de son chaperon hjurp dans la propagation des centromères et la tumorigenèse chez la souris
Les centromères contribuent à garantir la distribution égale de l'ADN en mitose. Leur identité n'est pas codifiée par la séquence d'ADN, mais de manière épigénétique par le variant de l'histone H3 CENP-A. Dans des lignées cellulaires humaines transformées, CENP-A est incorporé au centromère par son chaperon HJURP, au début de la phase G1. Pendant ma thèse, j'ai utilisé le modèle murin pour étudier les particularités de la chromatine centromérique et son dysfonctionnement dans le cancer. J'ai montré que CENP-A est maintenu sur le génome paternel au cours de la spermatogenèse, contrairement aux autres histones, et peut constituer une marque transgénérationnelle du centromère. Nous avons généré une souris KO pour HJURP pour l'étudier in vivo, et avons détecté son amplification dans de multiples souches de souris. En parallèle, nous avons étudié l'interaction entre la dynamique des variants d'histone et la structure d'ordre supérieur de la chromatine centromèrique. Nous avons découvert que la réorganisation de l'hétérochromatine péricentrique au cours du cycle cellulaire contrôle les deux modes distinctifs d'incorporation des variants d'H2A et la stoechiométrie de CENP A. Pour explorer le lien entre la tumorigenèse et la surexpression de CENP A/HJURP dans des cancers humains, nous avons utilisé un modèle de transformation de fibroblastes murins embryonnaires. Dans le fond génétique nul pour p53 de ces cellules, la surexpression exogène des deux facteurs n'apportait pas un avantage prolifératif mesurable, mais leur accumulation était une conséquence de la transformation. Actuellement, nous analysons si cette surexpression contribue à augmenter la capacité de transformation.Centromeres are genomic loci ensuring equal distribution of the two sets of chromosomes in mitosis. Their identity is not encoded in the underlying DNA sequence but specified epigenetically by the histone H3 variant CENP-A. In transformed human cell lines, CENP A is deposited at centromeres by the histone chaperone HJURP in a distinct window of the cell cycle. During my PhD I have taken advantage of the mouse model to address cell cycle and developmental features of centromeric chromatin, as well as its dysfunction in cancer.Using an organism-level approach, I could observe that contrary to most histones, CENP-A is retained on the paternal genome during spermatogenesis, acting as a transgenerational mark of the centromere. To study the role of HJURP in vivo, we generated a knockout mouse and discovered that its genomic locus underwent amplification in several mouse subspecies.In parallel, we addressed the crosstalk between histone variant dynamics and higher-order chromatin structure at the centromere, and revealed that the dynamic reorganization of pericentric heterochromatin during the cell cycle controls the distinct incorporation of H2A variants and CENP-A stoichiometry.Finally, to explore the connection between tumorigenesis and CENP-A/HJURP overexpression, recorded in a number of human cancers, we used a mouse embryonic fibroblast model of transformation. We determined that whereas their overexpression did not confer a measurable proliferative advantage in a p53-deficient background, CENP-A/HJURP upregulation was a consequence of transformation. Whether their accumulation has a functional role to enhance tumorigenesis in this system was further investigated
Multifunctional Technology of Flexible Manufacturing on a Mechatronics Line with IRM and CAS, Ready for Industry 4.0
A communication and control architecture of a multifunctional technology for flexible manufacturing on an assembly, disassembly, and repair mechatronics line (A/D/RML), assisted by a complex autonomous system (CAS), is presented in the paper. A/D/RML consists of a six-work station (WS) mechatronics line (ML) connected to a flexible cell (FC) equipped with a six-degree of freedom (DOF) industrial robotic manipulator (IRM). The CAS has in its structure two driving wheels and one free wheel (2 DW/1 FW)-wheeled mobile robot (WMR) equipped with a 7-DOF robotic manipulator (RM). On the end effector of the RM, a mobile visual servoing system (eye-in-hand VSS) is mounted. The multifunctionality is provided by the three actions, assembly, disassembly, and repair, while the flexibility is due to the assembly of different products. After disassembly or repair, CAS picks up the disassembled components and transports them to the appropriate storage depots for reuse. Technology operates synchronously with signals from sensors and eye-in-hand VSS. Disassembling or repairing starts after assembling and the final assembled product fails the quality test. Due to the diversity of communication and control equipment such as PLCs, robots, sensors or actuators, the presented technology, although it works on a laboratory structure, has applications in the real world and meets the specific requirements of Industry 4.0
Mobile Visual Servoing Based Control of a Complex Autonomous System Assisting a Manufacturing Technology on a Mechatronics Line
The main contribution of this paper is the modeling and control for a complex autonomous system (CAS). It is equipped with a visual sensor to operate precision positioning in a technology executed on a laboratory mechatronics line. The technology allows the retrieval of workpieces which do not completely pass the quality test. Another objective of this paper is the implementation of an assisting technology for a laboratory processing/reprocessing mechatronics line (P/RML) containing four workstations, assisted by the following components: a complex autonomous system that consists of an autonomous robotic system (ARS), a wheeled mobile robot (WMR) PeopleBot, a robotic manipulator (RM) Cyton 1500 with seven degrees of freedom (7 DOF), and a mobile visual servoing system (MVS) with a Logitech camera as visual sensor used in the process of picking, transporting and placing the workpieces. The purpose of the MVS is to increase the precision of the RM by utilizing the look and move principle, since the initial and final positions of the CAS can slightly deviate from their trajectory, thus increasing the possibility of errors to appear during the process of catching and releasing the pieces. If the processed piece did not pass the quality test and has been rendered as defective, it is retrieved from the last station of the P/RML and transported to the first station for reprocessing. The control of the WMR is done using the trajectory-tracking sliding-mode control (TTSMC). The RM control is based on inverse kinematics model, and the MVS control is implemented with the image moments method
Communication and Control of an Assembly, Disassembly and Repair Flexible Manufacturing Technology on a Mechatronics Line Assisted by an Autonomous Robotic System
This paper aims to describe modeling and control in what concerns advanced manufacturing technology running on a flexible assembly, disassembly and repair on a mechatronic line (A/D/RML) assisted by an Autonomous Robotic System (ARS), two robotic manipulators (RM) and visual servoing system (VSS). The A/D/RML consists of a six workstations (WS) mechatronics line (ML) connected to a flexible cell (FC) equipped with a 6-DOF ABB industrial robotic manipulator (IRM) and an ARS used for manipulation and transport. A hybrid communication and control based on programmable logic controller (PLC) architecture is used, which consists of two interconnected systems that feature both distributed and centralized topology, with specific tasks for all the manufacturing stages. Profinet communication link is used to interconnect and control FC and A/D/RML. The paper also discusses how to synchronize data between different field equipment used in the industry and the control systems. Synchronization signals between the master PLC and ARS is performed by means of Modbus TCP protocol and OPC UA. The structure of the ARS consists of a wheeled mobile robot (WMR) with two driving wheels and one free wheel (2DW/1FW) equipped with a 7-DOF RM. Trajectory tracking sliding-mode control (TTSMC) is used to control WMR. The end effector of the ARS RM is equipped with a mobile eye-in-hand VSS technology for the precise positioning of RM to pick and place the workparts in the desired location. Technology operates synchronously with signals from sensors and from the VSS HD camera. If the workpiece does not pass the quality test, the process handles it by transporting back from the end storage unit to the flexible cell where it will be considered for reprocessing, repair or disassembling with the recovery of the dismantled parts. The recovered or replaced components are taken over by the ARS from disassembling location and transported back to the dedicated storage warehouses to be reused in the further assembly processes
Prediction of prompt neutron spectra of the photon induced reactions on
The processing of experimental data for the photon induced reactions on 238U and 232Th investigated by quasi-monochromatic γ-ray beams (produced in Laser Compton scattering at the NewSUBARU facility) needs the prediction of prompt neutron spectra. They are obtained using reliable models and systematics, i.e. the most employed and well validated approach of the most probable fragmentation with input parameters provided by a recent systematic and fission chance probabilities based on nuclear reaction calculations performed with the EMPIRE code
Digital Twin for a Multifunctional Technology of Flexible Assembly on a Mechatronics Line with Integrated Robotic Systems and Mobile Visual Sensor—Challenges towards Industry 5.0
A digital twin for a multifunctional technology for flexible manufacturing on an assembly, disassembly, and repair mechatronics line (A/D/RML), assisted by a complex autonomous system (CAS), is presented in the paper. The hardware architecture consists of the A/D/RML and a six-workstation (WS) mechatronics line (ML) connected to a flexible cell (FC) and equipped with a six-degree of freedom (DOF) industrial robotic manipulator (IRM). The CAS has in its structure two driving wheels and one free wheel (2DW/1FW)-wheeled mobile robot (WMR) equipped with a 7-DOF robotic manipulator (RM). On the end effector of the RM, a mobile visual servoing system (eye-in-hand MVSS) is mounted. The multifunctionality is provided by the three actions, assembly, disassembly, and repair, while the flexibility is due to the assembly of different products. After disassembly or repair, CAS picks up the disassembled components and transports them to the appropriate storage depots for reuse. Disassembling or repairing starts after assembling, and the final assembled product fails the quality test. The virtual world that serves as the digital counterpart consists of tasks assignment, planning and synchronization of A/D/RML with integrated robotic systems, IRM, and CAS. Additionally, the virtual world includes hybrid modeling with synchronized hybrid Petri nets (SHPN), simulation of the SHPN models, modeling of the MVSS, and simulation of the trajectory-tracking sliding-mode control (TTSMC) of the CAS. The real world, as counterpart of the digital twin, consists of communication, synchronization, and control of A/D/RML and CAS. In addition, the real world includes control of the MVSS, the inverse kinematic control (IKC) of the RM and graphic user interface (GUI) for monitoring and real-time control of the whole system. The “Digital twin” approach has been designed to meet all the requirements and attributes of Industry 4.0 and beyond towards Industry 5.0, the target being a closer collaboration between the human operator and the production line
Space Technology for Reduction of Desert Areas on Earth and Weather Control
In precedent papers the authors presented the idea of a space system composed of two opposite parabolic mirrors (large and small) having the same focal point. This system is able to concentrate solar power in a strong light beam having irradiance of hundreds or thousands of times stronger than the solar irradiance on Earth's orbit. The system can be placed on a Sun synchronous orbit around the Earth or on the Earth’s orbit around the Sun at a distance of several hundred km from ground. When the concentrated light beam is directed toward the Earth surface it can locally melt, vaporize or decomposes tones of ground in its elements. This is happening because when the ground is hit by the light beam, ground temperature can reach thousands of degrees Celsius. At such temperatures the matter is decomposed into constitutive elements. For example, the silicate oxides which are frequently found in the composition of desert ground are decomposed into oxygen and silicon. Similarly, other oxides release oxygen and other type of oxides or constitutive elements. A network of deep and large channels can be dug in this way in hot deserts as Sahara. When these channels are connected with the seas & oceans, a network of water channels is created in those deserts. In this way, the local climate of deserts will change because channel water is vaporized during daytime when air temperature reaches 50ºC and condenses during nighttime when air temperature is around 0ºC. Presence of clouds over the hot deserts can lead to a reduction of ground temperature and rain follows. The channel water can be desalinized for producing drinking water and for irrigation using simple equipment. In addition to these advantages, channel deserts can be a solution for melting of polar ice calottes and flooding of seaside areas that are inhabited areas. On the other hand, the system composed of two opposite mirrors can be used for strength decreasing or deviation of hurricanes and tornados. The power of these meteorological phenomena increased in the last time due to global warming producing disasters of tens of billions of dollars.
The hurricane is a thermal engine working in Carnot cycle. Due to this fact, although the difference between the cold source temperature (temperature of high atmosphere) and hot source temperature (temperature of ocean surface) is of only 100 °C, the thermal efficiency is ηt=0.333 leading to increasing of hurricane's total energy at extremely high levels.
The cold source can be heated through vaporizing the system of clouds of hurricane formed in the high atmosphere by the concentrated light beam directed from space. In this way the energy of hurricane or tornado no longer increases and damages produced at ground level are limited. Another possibility is to vaporize locally the hurricane's eye-wall for its deviation far away of dense populated areas
Passenger Spaceplanes and Airplanes that Have Variable Configuration for Sonic Boom Reduction
In the last time, the interest for passenger space plane, supersonic passenger aircraft and supersonic business jets is increasing. For reducing sonic boom effects at ground level, some companies proposed airplanes having fuselage with small traversal section or having curved fuselage.
This paper presents a new practical method for exciting vibrations in the leading edge of wing, tail and airplane's nose surfaces in order to scatter the shock wave and to reduce the sonic boom impact at ground level. The leading edges of wing, tail and airplane nose are covered with thin elastic fairings made of carbon fiber composite material which are separated through small gaps by the adjacent surfaces of wing, tail and nose. When the aircraft flies over populated areas, compressed air bleed from the engine compressors excites the vibration of carbon fiber fairings. The air is released through calibrated nozzles and directly impinges on the fairing surface generating their vibration. Thus, the shock waves are scattered and the impact of sonic boom on ground is much reduced
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