Analytical Performance of Low Noise Amplifier Using Single-Stage Configuration for ADS-B Receiver

Automatic dependent surveillance-broadcast (ADS-B) is an equipment of a radar system to reach difficult areas. For radar applications, an ADS-B requires a low noise amplifier (LNA) with high gain, stability, and a low noise figure. In this research, to produce an LNA with good performance, an LNA was designed using a BJT transistor 2SC5006 with DC bias, VCE = 3 V, and current Ic = 10 mA, also a DC supply with VCC = 12 V, to achieve a high gain with a low noise figure. The initial LNA impedance circuit was simulated using 2 elements and then converted into 3 elements to obtain parameters according to the target specification through the tuning process, impedance matching circuit was used to reduce return loss and voltage standing wave ratio (VSWR) values. The LNA sequence obtains the working frequency of 1090 MHz, return loss of -52.103 dB, a gain of 10.382, VSWR of 1.005, a noise figure of 0.552, stability factor of 0.997, and bandwidth of 83 MHz. From the simulation results, the LNA has been successfully designed according to the ADS-B receiver specifications.

Estimation of ergonomic indicators of special purpose clothing for patients with thermal injuries

This article discusses the determination of the optimal design allowances for a full factorial experiment in the development of special-purpose clothing for patients with thermal injuries in a hospital. To assess the ergonomic performance of special-purpose clothing, was used of pressure exerted by clothing on the human body. Based on the results of the study, a mathematical model was developed based on a full factorial experiment. In accordance with the presented mathematical models, the minimum values of contact pressures are obtained for the following values of construction parameters: for a cut with a sewn-in sleeve Warmhole = 15 cm, Ifa = 5,0 cm, Ic = 9 cm, Hse = 10 cm; for a cut with a raglan sleeve Warmhole = 15 cm, Ifa = 6 cm, Ic = 10 cm; for a cut with a one-piece sleeve Warmhole = 16 cm, Ifa = 6 cm, Ic = 11 cm.

TRANSFORMACIÓN PRODUCTIVA AGROECOLÓGICA CON IDENTIDAD CULTURAL EN LA PROVINCIA DE IMBABURA

Esta investigación identifica los factores que inciden en la transformación productiva agroecológica (TPA) con identidad cultural en la provincia de Imbabura – Ecuador y cuáles son los más importantes para diseñar un sistema de producción de alimentos sanos. El sistema actual perjudica al ambiente por la contaminación de los recursos naturales, a los consumidores por los efectos adversos en la salud y a los pequeños productores por la baja rentabilidad. Cambiar esta situación demanda de un alto grado de innovación a partir de las ventajas competitivas existentes en el territorio, éstas deben articular una estrategia que facilite la transición basada en cuatro variables o componentes. (Identidad Cultural IC, Gestión Empresarial GE, Innovación Institucional II y Desarrollo Tecnológico DT). Se investigó 34 dimensiones de las variables (7.IC, 10.GE, 11.II y 6.DT), a 1312 agricultores de los territorios rurales de la provincia y mediante un modelo de regresión logística se logró identificar la relación que tienen con la TPA siendo estas; 1.- la eliminación del analfabetismo y el mejoramiento del nivel de escolaridad, 2.- la asociatividad en procura de cantidad y la calidad, 3.- los ingresos extra agropecuarios, 4.- conectividad 5.- los servicios técnicos como el riego. Mediante un análisis de efectos marginales, se identificó aquellas que tienen mayor probabilidad de impacto en la TPA siendo: 1.- riego tecnificado (17,42%), 2.- ingresos extra agropecuarios (11,26%), 3.- conectividad (10,28%), 4.- crédito (10,26%) 5.- cobertura telefónica (7,03%), de menor impacto son la vialidad, el nivel de educación y el tamaño de la Unidad de Producción Agropecuaria UPA. El desarrollo tecnológico y la gestión empresarial son las variables que más influyen en la transformación productiva agroecológica de esta importante actividad económica en el territorio.

Bowel function after laparoscopic right hemicolectomy: a randomized controlled trial comparing intracorporeal anastomosis and extracorporeal anastomosis

Background The laparoscopic right hemicolectomy is the standard surgical treatment for right-sided colon cancer. The continuity of the digestive tract is restored through ileocolic anastomosis which can be performed extracorporeally or intracorporeally. The study aimed to compare both anastomotic techniques in laparoscopic right hemicolectomy. Materials and methods A single-blinded two-armed randomized control trial with 1:1 parallel allocation carried out from 2016 to 2020 in a single center. The follow-up period was 30 days. Compared interventions involved extracorporeal and intracorporeal ileocolic anastomosis in laparoscopic right hemicolectomy. The main outcome of the study was bowel recovery measured as the time to the first stool. Other outcomes involved the time to the first flatus, morbidity, and duration of surgery. Results One hundred and seventeen patients undergoing a laparoscopic right hemicolectomy with curative intent were eligible for the trial. Eight patients refused to participate. One hundred and two patients were analyzed, 52 in the intracorporeal group and 50 in the extracorporeal group. The groups did not differ in terms of cancer stage or body mass index, but did differ in age and sex. Intracorporeal anastomosis was associated with a shorter time to the first stool than extracorporeal, 32.8 h (26.0–43.7) vs. 41.7 (35.9–50.0), p = 0.017. There was no significant difference in the time to the first flatus, 30 h (23.2–42.3) vs. 26.6 h (21.8–37.3), p = 0.165. Similarly, overall complications did not differ (EC 12/50 vs. IC 10/52, p = 0.56). There were no differences in length of surgery, 190 min (150–230) and 190 min (180–220), p = 0.55. Conclusion Intracorporeal ileocolic anastomosis following laparoscopic right hemicolectomy results in slightly faster bowel recovery, with no differences in morbidity and duration of surgery.

Estrutura Interna da Versão Brasileira do Questionário de Estresse Traumático Secundário

Resumo O Estresse Traumático Secundário caracteriza-se por um conjunto de sintomas e condutas que se manifestam após a exposição indireta ao trauma. Profissionais que cuidam de pessoas traumatizadas estão susceptíveis ao transtorno. Este estudo examinou a estrutura interna da versão brasileira do Cuestionario de Estrés Traumático Secundario. Participaram 624 profissionais da saúde, acessados on-line. Para realização das análises fatoriais, a amostra foi dividida em dois grupos. Na análise exploratória, foram retidos 12 componentes, com cargas fatoriais entre 0,312 e 0,999. Os resultados da análise confirmatória revelaram que o modelo de doze fatores para 50 itens forneceu o melhor ajuste possível para os dados (RMSEA = 0,044; IC = 10%-90%; CFI = 0,949; TLI = 0,904) e índice de consistência interna geral do modelo foi de 0,91. Esses doze fatores foram distribuídos em quatro escalas (Antecedentes, Síndrome de Trauma Secundário, Personalidade e Consequências), com índices psicométricos relativamente baixos e uma nova organização dos itens das escalas do QETS, em contraste com a versão teórica original do instrumento. Sugere-se que novos estudos psicométricos analisem as escalas do questionário, separadamente, e investiguem outras categorias profissionais, especialmente na área dos serviços de emergências, além de estudos comparativos com amostras clínicas.

Abdominal migraines: Variations in diagnosis and care between pediatric gastroenterologists and neurologists

Introducción: La migraña abdominal (MA) es infrecuente y poco estudiada. Nuestro objetivo fue investigar el diagnóstico y tratamiento de niños y adolescentes con MA y compararlos entre gastroenterólogos y neurólogos pediatras.Pacientes y Método: Todos los cuadros de MA (1-18 años) de un hospital de EE. UU, con diagnóstico de MA o sus variantes (ICD-9 346.2 o IC-10 G43.D, G43.D0, G43.D1) entre 2011-2017 fueron revisados. La información sobre diagnóstico, intervalo desde inicio de síntomas, criterios diagnósticos, pruebas diagnósticas, tratamiento y resultado se analizaron.Resultados: Sesenta y nueve historias médicas fueron identificadas. La edad media al diagnóstico fue 9,7 años. El 48% de los pacientes fueron del sexo femenino. Cincuenta (72,4%) pacientes fueron tratados solo por gastroenterólogos pediatras, y 10/69 (14,5%) por neurológos pediatras exclusivamente. 6/69 (8,7%) fueron inicialmente evaluados por gastroenterología y posteriormente referidos a neurología, y 2/69 (2,9%) fueron inicialmente evaluados por neurología y luego referidos a gastroenterología. 3/10 (30%) de las MA diagnosticadas por neurólogos no mencionaban que el paciente tuviera dolor abdominal, sin embargo, todos los diagnósticos realizados por gastroenterólogos presentaron dicho síntoma (p=0,0035). 5/50 (10%) de las historias médicas de gastroenterología y ninguna de las historias de neurología mencionaban los criterios de Roma.Conclusiones: La mayoría de los niños fueron diagnosticados por pediatras gastroenterólogos. Los gastroenterólogos rara vez utilizaron los criterios de Roma. Pacientes evaluados por neurología son frecuentemente diagnosticados con MA, incluso sin presentar dolor abdominal (criterio necesario para el diagnóstico). Se recomienda educación para el correcto y oportuno diagnóstico de la migraña abdominal.

Physical parameters of red supergiants in dwarf irregular galaxies in the Local Group

Context. Increasing the statistics of evolved massive stars in the Local Group enables investigating their evolution at different metallicities. During the late stages of stellar evolution, the physics of some phenomena, such as episodic and systematic mass loss, are not well constrained. For example, the physical properties of red supergiants (RSGs) in different metallicity regimes remain poorly understood. Thus, we initiated a systematic study of RSGs in dwarf irregular galaxies (dIrrs) in the Local Group. Aims. We aim to derive the fundamental physical parameters of RSGs and characterize the RSG population in nearby dIrrs. Methods. The target selection is based on 3.6 μm and 4.5 μm photometry from archival Spitzer Space Telescope images of nearby galaxies. We selected 46 targets in the dIrrs IC 10, IC 1613, Sextans B, and the Wolf-Lundmark-Melotte (WLM) galaxy that we observed with the GTC–OSIRIS and VLT–FORS2 instruments. We used several photometric techniques together with a spectral energy distribution analysis to derive the luminosities and effective temperatures of known and newly discovered RSGs. Results. We identified and spectroscopically confirmed 4 new RSGs, 5 previously known RSGs, and 5 massive asymptotic giant branch (AGB) stars. We added known objects from previous observations. In total, we present spectral classification and fundamental physical parameters of 25 late-type massive stars in the following dIrrs: Sextans A, Sextans B, IC 10, IC 1613, Pegasus, Phoenix, and WLM. This includes 17 RSGs and 8 AGB stars that have been identified here and previously. Conclusions. Based on our observational results and PARSEC evolutionary models, we draw the following conclusions: (i) a trend to higher minimum effective temperatures at lower metallicities and (ii) the maximum luminosity of RSGs appears to be constant at log(L/L⊙)≈5.5, independent of the metallicity of the host environment (up to [Fe/H] ≈ −1 dex).

H i observations of IC 10 with the DRAO synthesis telescope

ABSTRACT H i observations of the nearby blue compact dwarf galaxy IC 10 obtained with the Dominion Radio Astrophysical Observatory synthesis telescope, for a total integration of ∼1000 h, are presented. We confirm the NW faint 21 cm H i emission feature discovered in Green Bank Telescope (GBT) observations. The H i feature has an H i mass of 4.7 × 105 M⊙, which is only ∼0.6 ${{\ \rm per\ cent}}$ of the total H i mass of the galaxy (7.8 × 107 M⊙). In the inner disc, the rotation curve of IC 10 rises steeply, then flattens until the last point where it rises again, with a maximum velocity of 30 km s−1. Based on our mass models, the kinematics of the inner disc of IC 10 can be described without the need of a dark matter halo. However, this does not exclude the possible presence of dark matter on a larger scale. It is unlikely that the disturbed features seen in the outer H i disc of IC 10 are caused by an interaction with M 31. Features seen from our simulations are larger and at lower surface density than can be reached by current observations. The higher velocity dispersions seen in regions where several distinct H i features meet with the main core of IC 10 suggest that there is ongoing accretion.

TV Cassiopeiae with Chandra and XMM–Newton X-ray Observations

TV Cassiopeia (TV Cas) is a well-known eclipsing Algol-type binary comprising a B9V primary and F7 IV secondary in an orbit with a period of 1.81 days, together with a purported low-mass companion in a wide orbit. Despite the considerable attention TV Cas has received in optical and UV bands, no X-ray analysis has been reported. Chandra has detected TV Cas six times and XMM–Newton observed it twice, all serendipitously during observations of the starburst galaxy IC 10. We have put all the X-ray data together to investigate its coronal morphology and spectral properties. We use the X-ray light curves and eclipses to probe the emitting geometry and the X-ray spectra at different epochs to investigate the activity mechanisms and test speculation that TV Cas undergoes significant mass transfer episodes.

High-energy neutrino flux from individual blazar flares

ABSTRACT Motivated by the recently reported evidence of an association between a high-energy neutrino and a γ-ray flare from the blazar TXS 0506+056, we calculate the expected high-energy neutrino signal from past, individual flares, from 12 blazars, selected in declinations favourable for detection with IceCube. To keep the number of free parameters to a minimum, we mainly focus on BL Lac objects and assume the synchrotron self-Compton mechanism produces the bulk of the high-energy emission. We consider a broad range of the allowed parameter space for the efficiency of proton acceleration, the proton content of BL Lac jets, and the presence of external photon fields. To model the expected neutrino fluence, we use simultaneous multiwavelength observations. We find that in the absence of external photon fields and with jet proton luminosity normalized to match the observed production rate of ultrahigh-energy cosmic rays, individual flaring sources produce a modest neutrino flux in IceCube, $N^{\mathrm{IC,10 \,yr}}_{\nu _{\mu },{\mathrm{\gt 100~TeV}}} \lesssim 10^{-3}$ muon neutrinos with energy exceeding 100 TeV, stacking 10 yr of flare periods selected in the >800 MeV Fermi energy range, from each source. Under optimistic assumptions about the jet proton luminosity and in the presence of external photon fields, we find that the two most powerful sources in our sample, AO 0235+164, and OJ 287, would produce, in total, $N^{\mathrm{IC \times 10,10 \,yr}}_{\nu _{\mu }, \rm all~flares, \gt 100~TeV} \approx 3$ muon neutrinos during Fermi flaring periods, in future neutrino detectors with total instrumented volume ∼10 times larger than IceCube, or otherwise, constrain the proton luminosity of blazar jets.