Coherent summation of emission from relativistic Cherenkov sources as a way of production of extremely high-intensity microwave pulses

For relativistic Cherenkov devices, we investigate the process of high-power microwave pulse generation with its phase correlating to the sharp edge of an e-beam current pulse. Our theoretical consideration is referred to quasi-stationary and superradiative (SR) generation regimes when spontaneous emission of the e-beam edge serves as the seed for the development of further coherent oscillations. Phase correlation of the excited microwave pulses with the characteristics of the current pulse front and/or an initial external electromagnetic pulse has been additionally confirmed by particle-in-cell simulations. Pulse-to-pulse stability of the radiation phase within several percents of the oscillation period makes it possible to arrange multichannel schemes producing mutually coherent microwave pulses. In the experiments that have been carried out, the cathodes of independent generators were powered by identical accelerating pulses from strictly synchronized voltage modulators, or by splitting the pulse from a single powerful modulator. For the 2-ns regime with the power of each Ka-band backward-wave oscillator about 100 MW, we demonstrate quadratic growth of the power density in the interference maximum of the directional diagram. In a short pulse SR regime, with the peak power of 600 MW in a single channel, for a four-channel 2-D array, we attained a 16-fold radiation intensity gain

The complete nucleotide sequence of a Spanish isolate of <i>Citrus psorosis</i> virus: comparative analysis with other ophioviruses

The complete genomic sequence (11278 nt) of Citrus psorosis virus (CPsV), isolate P-121 from Spain, was determined and compared with those from isolate CPV-4 and from other ophioviruses. The three RNAs of P-121 had similar size and identical organization as those of CPV-4. The 24K and the RdRp proteins were potentially encoded in the viral complementary (vc) strand of RNA 1, the 54K protein potentially encoded in vcRNA 2 and the coat protein encoded in vcRNA 3. These four proteins from P-121 and CPV-4 had 87, 92, 93 and 94% amino acid identity, respectively, but only 22, 38, 25 and 33% identity with their homologous proteins from Mirafiori lettuce big vein virus (MLBVV), the only other ophiovirus completely sequenced. Biological and genetic differences between CPsV and MLBVV (and the other ophioviruses), would support their future allocation in different genera within a tentative family Ophioviridae.Instituto de Biotecnología y Biología Molecula

Simple Feedback System for Passive Mode Locked Gyro-Devices at 263 GHz

A promising new source to generate a periodic series of coherent, ultra-short pulses in the millimeter and submillimeter frequency range is based on the method of passive mode locking [1]. The basic principle is well known from laser physics [2]. A realization for millimeter and sub-millimeter waves consists of an amplifier and a saturable absorber coupled in a feedback loop. In this paper, a coupling system for two single-window vacuum electron tubes in a mode-locked microwave oscillator is presented. Based on full-wave simulations, the key components of the proposed feedback system at 263 GHz (typical DNP-NMR frequency) are designed

A Pilot Survey: Retention in Pain Medicine Among Fellowship Trained Anesthesiologists

BACKGROUND: We aim to explore the factors related to job satisfaction among pain physicians and identify the reasons why individuals minimize or stop practicing outpatient pain medicine. OBJECTIVES/STUDY DESIGN: This is a survey-based study with the primary goal to identify factors determining job satisfaction and dissatisfaction among pain medicine fellowship graduates who continue to practice and those who are no longer practicing interventional pain. A secondary goal is to elucidate reasons for anesthesiologists trained in pain medicine to leave pain medicine, despite an additional year of training, and to work as general anesthesiologists. METHODS: In this study, all 114 pain program directors listed on the Accreditation Council for Graduate Medical Education (ACGME) website, or their administrative assistants were directly contacted via email. All email addresses were obtained from the ACGME website. The survey opened in September 2021, with reminder emails sent before the closing of the survey in December 2021. A final reminder email was sent 4 weeks prior to the closing of the survey. RESULTS: Of all the respondents, 79 (89.77%) were currently practicing pain medicine, and 9 (10.23%) were no longer practicing pain medicine. LIMITATIONS: Our study has a major limitation as we are unable to determine the response rate and are limited in the data points gathered. CONCLUSION: We hope this study will allow for pain medicine fellowship program directors to improve recruitment and retention of pain fellows in the field while addressing the pros and cons of future career aspirations with anesthesiology residents prior to fellowship selection. A larger, more thorough study with an exact response rate can compare the various outcomes based upon different types of settings, such as private practice, partnership, and academia, as well as geographical locations

Previsão da temperatura e do desempenho do gerador fotovoltaico flutuante a partir de suas características elétricas medidas em reais condições ambientais

Este trabalho apresenta uma metodologia para a estimativa da temperatura de módulos fotovoltaicos quando em condições ambientais reais de operação e os resultados obtidos no caso da Usina Fotovoltaica Flutuante da Hidroelétrica de Sobradinho-BR (-9°35’; -40°50'). Utiliza dadosexperimentais locais medidos, em tempo real, por oito meses, das características elétricas e as temperaturas do módulo e seu flutuador, simultaneamente, com parâmetros climatológicos. Os resultados comprovam a forte dependência da temperatura de operação, portanto, da potência gerada com as condições climáticas locais, determinantes nas perdas térmicas do módulo. Para os sistemas flutuantes destaca-se a troca de calor módulo - flutuador por convecção, as quais representam o maiorpercentual, 67% da perda total e podem ser fortemente impactadas pela possibilidade ou não de aeração na região entre o módulos e seu flutuador. A escolha do tipo de flutuador é, portanto, de grande relevância no projeto de sistemas FV flutuantes

Sedimentation of bentonite suspensions under the influence of low molecular weight polymers based on amino ester salts

Among the available technologies for treating natural and wastewater from clay materials, coagulation/flocculation is the most common method due to its high efficiency, simplicity, and cost-effectiveness. Inorganic coagulants such as aluminum sulfate and ferric chloride, widely used as destabilizing agents for colloidal particles, have several significant drawbacks: low efficiency and toxicity. Organic reagents of both natural and synthetic origin are a good alternative. This work is devoted to the evaluation of the flocculation action of new reagents, which are low molecular weight polymers based on amino ester salts on clay suspensions, as well as the selection of their optimal concentration, providing the maximum sedimentation rate. Studies have shown that amino ester salts can be effectively used for the treatment of water-clay suspensions. An important factor is the nature of the anion used, which has a significant influence on the oagulation ability of esters. Thus, 40–50 % (wt.) aqueous solutions of amino ester chlorides added to clay suspensions in an amount not exceeding 0.1% (vol.) can be used to thicken clay suspensions. At the same time, aqueous solutions of amino ester bromides regardless of the concentration, introduced into bentonite suspensions of 0.1–0.4 % (vol.), contribute to improved sedimentation, reducing viscosity, and increasing filtration capacity. These results allow us to recommend the use of amino ester chlorides as a thickener in the preparation of drilling muds for strengthening the walls of wells during drilling, and bromides – for flocculation of bentonite suspensions in oil productio

Antiracist Feminism and the Politics of Solidarity in Neoliberal Times

The chapter analyses the establishment and expansion of antiracist feminism in the last decade throughout the Nordic region, with new groups, media sites, and public events organised, especially in the large cities. Keskinen examines antiracist feminist and queer of colour activism in which the main or sole actors belong to groups racialised as non-white or ‘others’ in Nordic societies. A fundamental argument developed in the chapter is the central role and potential of these emerging social movements in the reconfiguring of political agendas and tackling pressing societal issues, due to its capacity to overlap and connect the borders of antiracist, feminist, and (to some extent) class-based politics. The chapter further argues for the usefulness of theorising the neoliberal turn of racial capitalism as the societal condition in which feminist activism takes place.Peer reviewe