Quality Factor Enhancement of 650 MHz Superconducting Radio-Frequency Cavity for CEPC

Medium-temperature (mid-T) furnace baking was conducted at 650 MHz superconducting radio-frequency (SRF) cavity for circular electron positron collider (CEPC), which enhanced the cavity unloaded quality factor (Q0) significantly. In the vertical test (2.0 K), Q0 of 650 MHz cavity reached 6.4 × 1010 at 30 MV/m, which is remarkably high at this unexplored frequency. Additionally, the cavity quenched at 31.2 MV/m finally. There was no anti-Q-slope behavior after mid-T furnace baking, which is characteristic of 1.3 GHz cavities. The microwave surface resistance (RS) was also studied, which indicated both very low Bardeen–Cooper–Schrieffer (BCS) and residual resistance. The recipe of cavity process in this paper is simplified and easy to duplicate, which may benefit the SRF community.

Development and Vertical Tests of CEPC 650-MHz Single-Cell Cavities with High Gradient

A circular electron positron collider (CEPC) will adopt hundreds of 650-MHz superconducting cavities with high quality factor (Q) and accelerating gradient (Eacc). Two 650-MHz single-cell cavities made of fine-grain niobium were first treated via buffered chemical polishing (BCP), which was easy and convenient. However, the vertical test results could not meet the specification of the CEPC (4 × 1010 at 22 MV/m). Therefore, electro-polishing (EP) of 650-MHz single-cell cavities was conducted, which was complicated but remarkably effective. Both 650-MHz single-cell cavities achieved state-of-the-art gradients of 35 MV/m after the EP process, which is extremely high for large elliptical cavities (frequency < 1 GHz). One cavity achieved an intrinsic quality factor (Q0) of 4.5 × 1010 at 22.0 MV/m, which was higher than the CEPC spec. The other cavity obtained a lower Q0 of 3.4 × 1010 at 22.0 MV/m, which may have resulted from the cancellation of high-temperature annealing.

CHASSIS FRAME DESIGN AND ANALYSIS BASED ON FORMULA SAE JAPAN

Formula Society of Automotive Engineers (FSAE) is a competition where the students design, build, and race the formula-style car. In this competition, the regulation stringent for the safety of participants. Chassis is one of the regulated parts among the other parts. This paper examines design process followed by chassis analysis by using Solidworks 2018 and Abaqus/CAE 6.14 software. The analysis process is carried out with Static Vertical Test, Torsional Stiffness Test, and Crash Impact Test using a safety standard in the form of a safety factor that must be more than 1 (SF> 1) to ensure the safety of the driver. The aim is to obtain an optimum final design based on FSAE Japan regulation as a reference for the Universitas Sriwijaya electric car team, namely Sriwijaya Eco in making the framework for the upcoming electric formula car.

Estado nutricional y fuerza de tren inferior: diferencias entre sexo y área geográfica entre niños y niñas. (Nutritional status and lower train force: differences between gender and geographical area between boys and girls)

El presente estudio transversal pretende determinar y establecer la asociación entre las variables de estado nutricional y fuerza en el segmento inferior entre estudiantes Chilenos correspondientes a la región de la Araucanía, pertenecientes a un sector urbano en contraste con estudiantes de un sector rural. La muestra fue de 120 escolares, divididos en 60 niños y 60 niñas cuyas edades fluctuaron entre los 10 y 11 años . Se realizó medición del IMC (Kg/H^2) para luego clasificar su estado nutricional y también la prueba de salto vertical Test de Sargent (fuerza de tren inferior) en la población escolar. Los grupos fueron comparados con la prueba estadística Chi-cuadrado con intervalos de confianza del 95 %. Para los resultados del test de Sargent se realizó correlación de Pearson. Se encontró una alta prevalencia de niñas de ambos sectores, encasilladas en el rango de sobrepeso y obesidad. Así mismo, presentan similitud en la prueba de salto vertical (test de Sargent) en donde no existieron diferencias significativas al momento de correlacionar entre sexo y área geográfica. Abstact. The present cross-sectional study aims to determine an establish the association between the variables of nutritional status and lower segment in Chilean students from Araucanía Region an urban sector in contrast to students from a rural sector. The sample was 120 schoolchildren, divided into 60 boys and 60 girls whose ages fluctuated between 10 and 11 years of age. BMI (Kg / H ^ 2) was measured to later classify their nutritional status and also the Sargent vertical jump test (lower body strength) in the school population. The groups were compared with the statistical T-student test for independent samples with 95% confidence intervals. Pearson's correlation was performed for the results of the Sargent test. A high prevalence of girls from both sectors was found, classified as overweight and in the obesity range. Likewise, there are more overweight children in the urban sector than in the rural sector. Presenting similarity in the vertical jump test (Sargent test) where there were no significant differences when correlating between sex and geographic area.

Comparative Study on the Use of a Portable Alternative Method for Measuring High Jump in Men's Volleyball Game

"Hight jump is a very important skill in the modern volleyball game. The height of the vertical detachment can be measured in a variety of ways, from the most sophisticated (jumping platform, jumping mats) to those available to all (Sargent test, and Vertec). Through this study we followed the comparative analysis of an alternative method for measuring detachment on the spot, using the G-Vert device, with a device known and currently used by several federations for measuring vertical detachment. Following the application of the Counter-movement jump Test (CMJ) or Static Vertical Test (SVT) and Approach Vertical Test (AVT), the values obtained were recorded, analyzed, and compared using the Microsoft Xcel and IBM SPSS statistical processing and analysis programs. The results of the analysis show small differences between them, which attests to the G-Vert device, as a reliable device for measuring vertical detachment. The G-Vert device, in addition to the ability to record vertical detachment, gives us information about the gravitational force that is exerted on the body during the jump, and the force with which the detachment is performed on the spot, information that can be obtained by the jumping platform. Keywords: G-Vert, high jump, measurements, tests."

Development of a Model for Stormwater Runoff Prediction on Vertical Test Panels Coated with Plaster and Mortar

Leaching outdoor tests (LOT) are commonly used to assess the leaching of substances from construction materials. In this context, the amount of stormwater in contact with the surface material is of special interest for analyzing the runoff loads of substances from building façades. A numerical model was developed in MATLAB on the basis of previous analytical models to calculate the collected stormwater runoff volumes from the vertical test panels (VTP) during LOT. In the model, wind-driven rain (WDR) is considered to be the main mechanism for determining the amount of water impinging on the VTP, so it is a crucial factor in the modeling for the façade runoff. The new model makes it possible to simulate the runoff volumes from VTP that are covered with a wide variety of plaster and mortar. Using the new model, it was possible to relate the VTP runoff volumes obtained during an 18-month sampling period for LOTs performed at the Fraunhofer Institute for Building Physics in Valley, Germany. When comparing the simulation results with the field test accumulated runoffs, the model exhibited a difference of no more than 3.5% for each of the analyzed materials. The simulation results are satisfying, and the paper demonstrates the feasibility of the modelling approach for the runoff assessment of VTP covered with a variety of plaster and mortar.

Subjective Visual Vertical Testing in Patients With Chronic Suppurative Otitis Media

Objective To analyze the results of the subjective visual vertical test using the “bucket method” in patients with chronic suppurative otitis media (CSOM). Study Design Cross-sectional, controlled study. Setting Outpatient otology clinic in a tertiary care hospital. Subjects and Methods Patients had CSOM, defined as the presence of chronic infection or inflammation of the middle ear cleft, associated with a perforation of the tympanic membrane, frequent or intractable middle ear suppuration, with or without cholesteatoma. Controls were selected using a nonprobability, purposive sampling method. We excluded patients with neurologic or metabolic diseases, cognitive deficits, otosclerosis, vestibular migraine, Ménière’s disease, past use of ototoxic medication, or head and neck cancer. The volunteers were subjected to the subjective visual vertical test using the “bucket method.” The results obtained in our study and control groups were analyzed using nonparametric tests. Results Our study comprised 51 patients with CSOM and 50 controls. In the CSOM group, we observed that 72.5% of the patients had vestibular symptoms in the past year, and 70.5% had abnormalities identified in at least 1 vestibular function test. The subjective visual vertical test revealed that patients with CSOM (with and without cholesteatoma) had significantly higher deviations of the true vertical as compared with controls (CSOM, 3.66°; controls, 0.76°; P < .001). Conclusion Our results revealed that CSOM was associated with high rates of vestibular symptoms, abnormal vestibular function tests, and abnormal subjective vertical visual results.