Low-Noise Design of Medium-Range Aircraft for Energy Efficient Aviation

Promising low-noise aircraft architectures have been identified over the last few years at DLR. A set of DLR aircraft concepts was selected for further assessment in the context of sustainable and energy-efficient aviation and was established at the TU Braunschweig in 2019, the Cluster of Excellence for Sustainable and Energy-Efficient Aviation (SE2A). Specific Top-Level aircraft requirements were defined by the cluster and the selected DLR aircraft designs were improved with focus on aircraft noise, emissions, and contrail generation. The presented paper specifically addresses the reduction of aviation noise with focus on noise shielding and modifications to the flight performance. This article presents the state of the art of the simulation process at DLR and demonstrates that the novel aircraft concepts can reduce the noise impact by up to 50% in terms of sound exposure level isocontour area while reducing the fuel burn by 6%, respective to a conventional aircraft for the same mission. The study shows that a tube-wing architecture with a top-mounted, forward-swept wing and low fan pressure ratio propulsors installed above the fuselage at the wing junction can yield significant noise shielding at improved low-speed performance and reduce critical fuel burn and emissions.

Performance verification of heavy-duty motorcycles adjusting intake and exhaust timing

Heavy-duty locomotives with large exhaust vehicles have become a common means of transportation for Taiwanese. However, for car owners to increase power output, improve efficiency, and reduce fuel use, the original factory has designed demand settings for cost, environmental protection, and regulations. This leads to the sacrifice of the performance of the original car design, so the RC2 Super ECU is used to replace the original injection computer, and the air-fuel ratio, ignition angle and exhaust pipe are modified. Without the need to change the structure of the heavy locomotive, the horsepower of the heavy locomotive is improved. It is pointed out that the modification of these three original factory settings has greatly improved the overall speed performance of the heavy-duty locomotive horsepower. Therefore, it is proposed that “heavy locomotive performance verification by changing the timing of intake and exhaust” is mainly to verify the performance benefits and performance brought about by modifying the air-fuel ratio, ignition angle and exhaust pipe.

Frailty and Processing Speed Performance at the Cusp of Midlife in CATSLife

Frailty is an important multi-domain measure of health status and aging. Processing speed (PS) performance may be predictive of later frailty among older adults, but the interrelation between frailty and PS at the cusp of mid-adulthood is unclear. Using data from the ongoing Colorado Adoption/Twin Study of Lifespan Behavioral Development and Cognitive Aging (CATSLife; N = 1213; Mean age = 33.22 years; SD = 5.0), we constructed a 24-item frailty sum score across anthropomorphic, objective health, and perceived health and engagement measures based on the Accumulation of Deficits model. PS was measured using the Colorado Perceptual Speed (CPS) and WAIS-III Digit Symbol (DS) tests. All mixed-effects regression models accounted for clustering among siblings, and covariates included sex, age, race, ethnicity, and educational attainment. Intraclass correlations (ICCs) [95% CI] for frailty among siblings, adjusted for sex and age, ranged from near zero for siblings in adoptive families, .13 [.08-.30] for nonadoptive siblings/fraternal (DZ) twins, and .44 [.40-.48] for identical (MZ) twins, suggesting possible heritable influences. Poorer PS performance was associated with higher frailty, but was significant for DS only (B: DS = -0.43, p =.005). Furthermore, the DS-frailty association was magnified by age (B: DSxAge = -0.06, p =.025), suggesting that the associations between processing speed and frailty may increase with age. These findings help elucidate the interrelationship between indicators of frailty and cognitive performance for adults approaching midlife, a salient and understudied period within lifespan development.

Consequential Impacts of Tobacco Use on Cognitive Performance

Tobacco use represents a pernicious lifestyle factor that may influence processes of aging, including cognitive functioning. As individuals tend to start smoking before adulthood, it may serve as an important factor in cognitive development and maintenance. We explored smoking history-cognition associations in a sample approaching midlife. Study data was derived from the Colorado Adoption/Twin Study of Lifespan behavioral development and cognitive aging (CATSLife 1; N = 1195 [53% F]; x̄age = 33.2 years, SD = 5.0). All cognitive measures were t-scored covering working memory, spatial reasoning, processing speed (WAIS-III Digit Span, Block Design, and Digit Symbol, and Colorado Perceptual Speed) and episodic memory domains (Picture Memory, immediate and delayed). Tobacco use measures included ever-smokers, current-smokers, and log-transformed packyears. Mixed-effects regression models were applied, accounting for sex, age, race, ethnicity, and clustering among siblings. Tobacco use was associated with worse episodic memory, spatial and speed performance, but not working memory. When educational attainment was included, patterns remained consistent though attenuated. Results suggested current-smokers scored 0.27 to 0.36 SD lower than non-smokers on speed and spatial reasoning tasks. Episodic memory performance was reduced by approximately 0.07 to 0.1 SD per log packyear. In a sample approaching midlife, the harmful impacts of tobacco use on cognitive performance may be already apparent with cumulative impacts of packyears on episodic memory and current smoking associated with spatial and speed performance. This work helps to elucidate the temporal associations of an important lifestyle factor that may influence cognitive functioning prior to midlife.

Examination of Acceleration and Speed Performances According to Different Foot Sole Sizes in Sedentary Women

In this study, it was aimed to examine the acceleration and speed performances of sedentary women according to their different foot sole length. 60 women that recide in Gaziantep and live sedentary life has participated voluntarily. The subjects were divided into 4 groups in terms of foot sole length and metatarsus width. The average age of the subjects that are participated in the study is determined as 15.8±0.76 for the 1st group, 16.1±1.13 for the 2nd group, 15.9±1.12 for the 3rd group and 15.7±1.33 for the 4th group. Foot sole, metatarsus measurements, acceleration and speed performance values of the subjects were taken in accordance with the measurement technique. All data that is obtained in the study were compared with each other and analyzed in terms of groups while using the SPSS 20.0 software package. When we evaluate the results of the analysis; it can be seen that there are significant differences that is detected between the 1st, 3rd and 4th groups in terms of acceleration performance in terms of foot sole length and metatarsus width; however, no significant difference was found between the 2nd group and the other groups. Although small differences were detected between the groups when it comes to sprint performance, these differences were not statistically significant. As a result, it was observed that there were differences between the groups in terms of acceleration performance, but there was no significant difference in terms of speed performance.

Effects of velocity based training vs. traditional 1RM percentage-based training on improving strength, jump, linear sprint and change of direction speed performance: A Systematic review with meta-analysis

Background There has been a surge of interest on velocity-based training (VBT) in recent years. However, it remains unclear whether VBT is more effective in improving strength, jump, linear sprint and change of direction speed (CODs) than the traditional 1RM percentage-based training (PBT). Objectives To compare the training effects in VBT vs. PBT upon strength, jump, linear sprint and CODs performance. Data sources Web of science, PubMed and China National Knowledge Infrastructure (CNKI). Study eligibility criteria The qualified studies for inclusion in the meta-analysis must have included a resistance training intervention that compared the effects of VBT and PBT on at least one measure of strength, jump, linear sprint and CODs with participants aged ≥16 yrs. and be written in English or Chinese. Methods The modified Pedro Scale was used to assess the risk of bias. Random-effects model was used to calculate the effects via the mean change and pre-SD (standard deviation). Mean difference (MD) or Standardized mean difference (SMD) was presented correspondently with 95% confidence interval (CI). Results Six studies met the inclusion criteria including a total of 124 participants aged 16 to 30 yrs. The differences of training effects between VBT and PBT were not significant in back squat 1RM (MD = 3.03kg; 95%CI: -3.55, 9.61; I2 = 0%) and load velocity 60%1RM (MD = 0.02m/s; 95%CI: -0.01,0.06; I2 = 0%), jump (SMD = 0.27; 95%CI: -0.15,0.7; I2 = 0%), linear sprint (MD = 0.01s; 95%CI: -0.06, 0.07; I2 = 0%), and CODs (SMD = 0.49; 95%CI: -0.14, 1.07; I2 = 0%). Conclusion Both VBT and PBT can enhance strength, jump, linear sprint and CODs performance effectively without significant group difference.

Re-Design of Machine Tool Joint Components Based on Polymer Fillings for High-Speed Performance

In this paper, we report the results of an experimental study of a re-design approach using filling polymers and particulate composites with a polymer matrix, thus creating a macroscopic hybrid structure. The re-design is focused on the joint of a textile machine. It is a re-design of already existing machine parts of a joint in order to increase the damping of components, reduce the amplitudes of high-frequency vibrations and acoustic emission for high-speed operation of textile rotors, and to compare individual structural modifications of the rotor housing body and absorber of high-speed textile rotor in a spinning unit with respect to dynamic properties of that measured mechanical system. The experiments included a bump test, determination of logarithmic decrement, measurement of vibration acceleration, a wavelet analysis, and measurement of acoustic emission. When excited by high frequency signal amplitudes up to 5 g, the benefits of polymer filling were manifested by an approximately 50% reduction in amplitude vibrations, a 66% reduction in acoustic emission amplitude, and an 85% reduction of the maximum peak in the acoustic emission FFT spectrum. In the area above 10 g, the stiffness of the component dominated to reduce the magnitude of vibrations.

An Analysis of Acceleration and Speed Performances Through the Positions in Handball

This research was conducted in order to compare the acceleration and speed performances of handball players according to their positions. A total of 60 male handball players that includes 5 goalkeepers, 15 middle playmakers, 7 right playmakers, 8 left playmakers, 7 right wingers, 8 left wingers and 10 pivots who actively play handball in the 2nd league of the Turkish handball federation has participated in the study voluntarily. Average age of the subjects participating in the study is determined as 19.5±1.43 for the goalkeepers, 19.3±1.35 for the right-left playmakers, 18.7±1.29 for the right-left wingers, 19.1±1.89 for the pivot players. Acceleration and speed performances of the subjects were measured in accordance with the measurement technique and all the data obtained were analyzed in the SPSS 20.0 software package program. Results that is obtained is examined, it is seen that the best values in terms of acceleration and speed performance were the performance values of right-left playmakers and right-left wing players, while the worst performance values belonged to pivot players. As a result of our study, it was observed that athletes have different physical performances in handball according to their playing positions.

Evaluation and Comparative Analysis of Speed Performance of Brushless DC Motor using Digital Controllers

This paper presents modeling, performance evaluation, and comparative analysis of speed performance of brushless DC motor (BLDCM) by using digital controllers. Speed performance analysis is carried out by using time response specifications which are useful for determining the effectiveness of the digital controllers. The wide spread of BLDCM in many areas due to the advantages of BLDCM over the conventional widely used motors such as induction motor and brushed DC motor. Advantages of BLDCM include higher efficiency, lower maintenance, longer life, reduced losses, single excitation, etc. Controllers are used to improve the transient and steady state speed response of the BLDCM. In many applications conventional PID controller is widely used to control the speed of the BLDCM but the main issue with the conventional PID controller is that it requires manual tuning of the parameters such as proportional, integral, and derivative gain constant. Even though the autotuning methods are available with the PID controller it is not adaptive itself to handle the conditions such as variations in parameters, disturbances in load, etc. In this Paper the Fuzzy-PID controller is used to control the speed of the BLDCM and Transient and steady state speed performance analysis is carried out using conventional PID controller and Fuzzy-PID to showcase the comparative analysis between two controllers. MATLAB/SIMULINK environment is used for modeling of the BLDCM and its drive/control system. Keywords: Brushless DC Motor (BLDCM), Fuzzy Logic Controller (FLC), Modeling of BLDC drive/control system, of PID controller, Transient and steady state analysis