Top Speed Research Articles

ANTHROPOMETRIC AND PHYSICAL QUALITIES OF SEMI-PROFESSIONAL RUGBY LEAGUE PLAYERS

AIM The aim of the current study was to investigate the physiological and anthropometric characteristics of semi-professional rugby league players across a typical season, including pre- and post-season data. METHODS Thirty-five semi-professional rugby league players, mean age 25.38 ± 2.35 years were measured for height, body mass, sum of skinfolds, and speed (20m sprint). Global positioning system (GPS) data, sampling at 10 Hz, were collected, two pre-season and eighteen Queensland Cup rugby league matches in the 2023 season for 10 players (backs and forwards). Data was categorized into total distance (km), sprint distance (m), power plays, energy expenditure (kcal), player load, and top speed (m/s). RESULTS Compared with forwards the backs had significantly lower body mass (99.4kg vs 90.8kg), and significantly greater speed during 20m sprint (3.00 vs 3.1sec). Sum of skinfolds, no differences between backs and forwards across the three time points, 104.2 vs 106.2mm, 103.9 vs 110.9mm and 93.8 vs 108.1mm. Reviewing the GPS data across the trial and cup games revealed a number of significant differences between backs and forwards, backs greater overall distance (6.63km vs 5.26km), sprint distance (467.53 vs 264.63m), power plays (37 vs 25), energy expenditure (1002.42 vs 778.90 kcal), player load (311.50 vs 275.16), top speed (8.02 vs 7.02m/s). CONCLUSION Retrospective analysis of our data has allowed us to understand the activity demands between match types and differences in activity demands between seasonal phases of training in semi-professional male rugby league players and will permit further specificity of training and improve performance. Determining the fitness and physiological profiles and how they relate to training and match demands will allow the coaching staff to develop more targeted training strategies in order to optimally develop the fitness characteristics that predominantly underpin match demands.

PERFORMANCE EVALUTION ON EV GO-KART

This study thoroughly evaluates the performance of an electric go-kart, covering acceleration, top speed, handling, energy efficiency, and driving experience. Real-world tests measure acceleration and top speed on a track, while expert drivers provide feedback on handling. Computational simulations analyze aerodynamics, structural integrity, and energy consumption. The study also considers subjective aspects like comfort and enjoyment through surveys and interviews. The results provide valuable insights for manufacturers, enthusiasts, and researchers, aiding the advancement of electric vehicles. Keywords: Acceleration, Energy efficiency, Computational fluid dynamics, Finite element analysis.

Method for the Experimental Identification of Variables and Configurations That Modify the Shape of the Macroscopic Fundamental Diagram

In this paper, we propose a method for establishing if a variable is capable of modifying the Macroscopic Fundamental Diagram (MFD) of a street network. The variables have many different configurations, and a simulation is performed for each one. Then, based on the output data of each simulation, the representative speed, density, and flow of the network are calculated. We use three metrics to establish if a variable affects the MFD: the first establishes a distance between the compared density and speed patterns, the second establishes a distance between capacities, and the third establishes a distance between critical densities. We select four variables to test our method: the precision of driving, the vehicles’ top speeds distribution, the procedure for selecting routes, and the procedure for selecting destinations; we determine whether each of these variables can modify the MFD shape. Additionally, we detect which configurations of a variable are able to reach and exceed the critical density (causing congestion) so we can establish which configurations are sustainable and which are not. The novelties of this work are twofold: (1) we introduce a method to detect if a variable modifies the MFD; (2) we establish if the selected variables modify the MFD.

The Impact of an 8-Week Resisted Sprint Training Program on Ice Skating Performance in Male Youth Ice Hockey Players.

Dietze-Hermosa, MS, Montalvo, S, Gonzalez, MP, and Dorgo, S. The impact of an 8-week, resisted, sprint training program on ice skating performance in male youth ice hockey players. J Strength Cond Res 38(5): 957-965, 2024-The purposes of this randomized control study were to (a) compare the effects of an on-ice versus an overground resisted sprint training intervention and a control condition and (b) identify changes in ice skating kinematics and kinetics after training intervention participation. Twenty-four youth ice hockey players were randomly allocated into 3 groups: (a) on-ice resisted sprint training (on-ice RST); (b) overground resisted sprint training (overground RST); and (c) body weight resistance training (control). During the 8-week intervention, the 2 RST groups engaged in sled towing methods, whereas the control group engaged in a body weight resistance training program twice a week. A series of individual, repeated-measures analysis of variances with post hoc pairwise comparisons were conducted for variables of interest. An interaction effect was noted for ice skating s-cornering agility drill completion time ( p = 0.01; ηp2 = 0.36), ice skating 30-m top speed completion time ( p = 0.04; ηp2 = 0.27), step length ( p = 0.04; ηp2 = 0.26), and knee angle at touchdown ( p = 0.03; ηp2 = 0.30). The on-ice RST group displayed superior improvements across ice skating tests compared with the control group. Data show that on-ice RST has the greatest transfer effect to ice skating metrics; however, improvements in certain ice skating metrics can be observed with overground training also.

Multi-Functional Nano-Doped Hollow Fiber from Microfluidics for Sensors and Micromotors.

Nano-doped hollow fiber is currently receiving extensive attention due to its multifunctionality and booming development. However, the microfluidic fabrication of nano-doped hollow fiber in a simple, smooth, stable, continuous, well-controlled manner without system blockage remains challenging. In this study, we employ a microfluidic method to fabricate nano-doped hollow fiber, which not only makes the preparation process continuous, controllable, and efficient, but also improves the dispersion uniformity of nanoparticles. Hydrogel hollow fiber doped with carbon nanotubes is fabricated and exhibits superior electrical conductivity (15.8 S m-1), strong flexibility (342.9%), and versatility as wearable sensors for monitoring human motions and collecting physiological electrical signals. Furthermore, we incorporate iron tetroxide nanoparticles into fibers to create magnetic-driven micromotors, which provide trajectory-controlled motion and the ability to move through narrow channels due to their small size. In addition, manganese dioxide nanoparticles are embedded into the fiber walls to create self-propelled micromotors. When placed in a hydrogen peroxide environment, the micromotors can reach a top speed of 615 μm s-1 and navigate hard-to-reach areas. Our nano-doped hollow fiber offers a broad range of applications in wearable electronics and self-propelled machines and creates promising opportunities for sensors and actuators.

Impact of Synthetic Textiles Emission in Sports Car Furnishing -An Overview

A sports automobile is one that is built with a focus on dynamic performance, including handling, acceleration, top speed, driving excitement, and the ability to race. Sports cars and other performance automobile categories, including muscle cars, are not always mutually exclusive; in fact, some cars can fit into more than one category. The automotive sector is the biggest consumer of technical textiles; each of the approximately 45 million cars produced globally each year uses around 20 kilograms of textiles. Undoubtedly, design and textiles will be crucial components in producing these unique homes. Not only do carpets and textile headliners enhance the general cosiness and aesthetics of the room, for high-pressure belts and hoses, reinforcing textile strands are necessary. Numerous air and oil filters, as well as bonnet liners, use non-woven materials. This essay addresses the issue of pollution caused by sports vehicle emissions of synthetic textiles and explores potential solutions. The use of synthetic materials in motor sports automobiles accounts for about 82% of all synthetic fabrics released into the atmosphere. Exhaust emissions account for 76% of the share of sports cars, evaporation for 22%, and refuelling for 2%. Human health issues resulting from emissions from synthetic textiles include cancer in cases of extended exposure and a host of other ailments in cases of shorter exposure. This paper gives an overview of the impact of man-made textile emissions on sports car furnishing and its source of reduction.

Optimal Sizing, Gear Ratios, and Shifting Schedule of Battery‐Electric Mining Haul Trucks to Enhance Energy Efficiency

At present, mining haul trucks (MHTs) directly deploy the on‐road heavy‐duty trucks’ battery‐electric powertrain, as they can cut down costs and emissions in mining. However, the operating patterns of MHT are different, e.g., ultraduty, low‐speed, and continuous road slopes, resulting in a mismatch between the dynamic and economic performance of mining required and the MHT achieved. The powertrain design and control influence the dynamic and economic performance, which can be quantitatively measured by top speed, gradeability, and energy consumption. This study uses an improved differential evolutionary algorithm to develop an integrated optimization platform to obtain the components sizing, gear ratio, and shifting schedule for the dedicated battery‐electric MHT. Mathematical models are established and validated using on‐site experiment data. An integrated optimization platform is initiated by concurrently formulating the motor sizing, gear ratio, and shifting schedule and solved by the improved differential evolutionary algorithm. Optimization results indicate that the economic performance is enhanced by 10.82%, 11.08%, 11.18%, and 11.20%, respectively, while maintaining or slightly improving the dynamic performance. Besides, the achievable maximum speed at the most common grade is boosted by 11.82%, 6.52%, 7.44%, and 6.52%, respectively. The study provides an approach to developing a battery‐electric powertrain for MHT.

Rapid Decision-Making Tool for Electric Powertrain Sizing for Motorcycles during New Product Development

As part of the intergovernmental and public interventions to reduce carbon dioxide emissions, there are no existing regulations to ban the sale of petrol motorcycles (PM), but it is expected that motorcycle regulations will follow car regulations with several years of delay. There is an emerging trend in motorcycle uptake, which will lead to new development projects with existing brands, and new brands, and will clearly increase the need for development tools that satisfies design challenges specific to electric motorcycles (EM) and electric powertrains. There is significant importance in motorcycle design to quantify the vehicle-level performance indicators and specifications, which are not limited to total vehicle mass, range, acceleration performance, and top speed. Those performance indicators should be quantified for different powertrain configurations and component selections to identify the most suitable configuration for the specific motorcycle development. In this paper, an innovative powertrain sizing approach is proposed to provide solutions for EMs against the design challenges specific to electric motorcycles. The innovative approach is to apply the practice of design space exploration (DSE) in resilient system design (RSD) to EM development. As a proof of concept, a case study of battery sizing is presented, in which a powertrain sizing tool is used to identify battery pack sizing requirements using requirement-based design (RBD), sensitivity analysis and DSE. The case study shows that the RBD approach allows EM product developers to identify a single solution, while DSE clearly demonstrates the trade-off between different configurations, taking multiple design variables into account. The tool prioritises high accessibility and high confidence with limited information at the early phases of electric motorcycle powertrain component sizing and selection.

Trajectory Planning, Kinematics, and Experimental Validation of a 3D-Printed Delta Robot Manipulator

This paper presents the implementation, trajectory planning, kinematics, and experimental validation of an open-source 3D-printed delta robot manipulator. The robot’s hardware consists of three servo motors, an Arduino Uno microcontroller, and a Pulse Width Modulation (PWM) servo module. The software includes a trapezoidal velocity profile planner and an inverse and forward kinematics solver to calculate the motor angles required to achieve a desired end-effector position in task space. The 3D printed parts were obtained from an open-source Thingiverse project and assembled to form the robot’s kinematic structure. The robot’s performance was evaluated in terms of its accuracy, repeatability, and maximum speed for a pick-and-place task. Experimental results show that the robot can achieve a positioning accuracy of 2.2 mm, with a top speed of 0.4 m/s, 30 picks per minute, and load carrying capacity up to 200 g. These results are satisfactory, considering the ease of assembly and the cost-effectiveness of the robot. The comparison of the calculated motor angles with actual motor angles obtained through additional potentiometer wires soldering shows promising results. The proposed robot’s cost-effective characteristics, utilization of open-source additive manufacturing, and motion planning algorithms make it suitable for various applications, including education, research, and small-scale industrial applications.

A28: Biomechanical Analysis and Research in Rugby Speed Training

Purpose: Speed training is an essential and important part of rugby. Usually in confrontational events, strength will have a powerful effect, but good speed will be more than that plus works. Rugby speed drills can be complex or simple things that coaches choose. To the best of the speed required depends on the position, but every player on the field can be trained to get faster. Methods: Through the literature method, logic analysis and other related analysis of sports biomechanics of speed training in football, in order to provide some theoretical basis and reasonable suggestions for speed training, to improve the efficiency of speed training in football to make a contribution. Result: One of the most common scenes in football is when players speed up and slow down over and over again. Acceleration on the field can take many forms. Acceleration relies more on the quads and running at top speed relies more on the hamstrings and hip flexors. Acceleration depends on the strength of the buttocks, quadriceps, calves, and upper body (especially the anterior deltoid tract). Absolute strength, relative strength and running technique are also important. The process of deceleration is accomplished through centrifugal contraction of the legs, which creates the muscle elasticity to counter and mitigate impact and is a key element in the ability of athletes to perform rapid deceleration. To cushion such an impact, explosive force is absolutely essential, and the knee and hip joints also require a certain amount of flexion to effectively cushion the impact, a movement similar to the landing technique. But in actual speed training situations, a different scenario can occur, and many coaches directly relate disadvantage factors. Conclusion: First, speed training programs must be designed to meet the bioenergetic and biomechanical requirements encountered by athletes during competition and practice. Each position on the field needs to differentiate the composition of the training load to meet the different requirements that these players must meet during the game. Secondly, we should closely monitor the amount and time of speed training according to the actual situation and focus on the recovery of the body. Coaches should avoid the urge to rush, as athletes may practice incorrect sports biomechanics when they are tired. Finally, the coach should analyze the limiting factors of the disadvantageous elements, train the limiting factors of plasticity, and finally achieve the goal of improving the disadvantageous elements.

The relationship between off-ice testing and on-ice performance in male youth Ice hockey players.

Ice hockey demands a unique blend of physical fitness and skill, necessitating a comprehensive understanding of the factors influencing on-ice performance. The present study was designed to examine the relationship between off-ice and on-ice performance measures in male, youth, ice hockey players. Eleven minor hockey players (Age = 9.8 ± 1.1 years) participated in two testing days: (1) off-ice and (2) on-ice assessments. Off-ice assessments included maximal aerobic power, anaerobic fitness, muscular strength (handgrip and single leg squat), muscular endurance (curl-ups and push-ups), muscular power (standing long jump and vertical jump), and 30 m sprinting speed and acceleration. On-ice testing included a 15.2 m maximum speed test, a 6.1 m acceleration test with a continuation into a 47.9 m top speed test, an agility cornering S turn test, and a shot velocity test. Twenty-four out of 33 off-ice variables were significantly correlated with at least one of the 11 on-ice performance variables. From those 24, 10 were included as predictors for at least one of the on-ice performance variables. Each model was composed of either one or two predictors, where the most common predictors were 30 m Run - Split (6.1 m) Sprint time and 30 m Run - Total (30 m) Sprint Max speed (included in four out of 11 models each). The prediction formulas R2 and coefficient of variation ranged from 0.63% to 0.96% and 1.2% to 15.3%, respectively. Diverse off-ice measures of aerobic fitness, anaerobic power, muscular strength, power, and endurance, and sprinting speed, acceleration, and agility are predictive of on-ice performance. The insights gained from this study contribute to the refinement of assessment protocols, fostering a comprehensive approach to optimizing player performance and potential. Understanding the connection between objective off-ice testing and on-ice performance can support tailored training programs and player development in male youth ice hockey.

How Are E-Scooter Speed-Limiter Settings Associated with User Behavior? Observed Speeds and Road, Sidewalk, and Bike Lane Use in Austin, TX, and Washington, D.C.

Many cities limit the top speeds of shared e-scooters, but little is known about how these policies affect user behavior. This study measured speeds and observed use of roads, sidewalks, and bike lanes for 2,004 e-scooter riders in Washington, D.C., where shared e-scooters were equipped with speed governors that limited their speed to 10 mph, and Austin, TX, where the limit was 20 mph. At locations without bike lanes, riders in Washington were 51% more likely to ride on sidewalks than in Austin when accounting for environmental and rider characteristics. Over 80% of e-scooter users rode in bike lanes in both cities when they were available. Although the mean riding speed on sidewalks was not significantly higher in Austin than in Washington, demonstrating self-regulation of speed on sidewalks, the percentage of e-scooter riders traveling on sidewalks at speeds ≥10 mph (41% in Austin versus 17% in Washington) or ≥15 mph (9% in Austin versus <1% in Washington) was higher in Austin. Increased sidewalk riding associated with setting shared e-scooter speed limiters to 10 mph could potentially lead to more interactions with pedestrians, but lower e-scooter speeds at the high end of the distribution may mitigate injury risk to them. Bike lanes could provide space for e-scooters to ride where their speeds would more closely match other users. Future refinements to technology to identify sidewalk riding more accurately could potentially allow maximum e-scooter speeds to be adjusted to mix with pedestrians on sidewalks and cyclists in bike lanes.

Emergency obstacle avoidance system of sugarcane basecutter based on improved YOLOv5s

The basecutter collides with obstacles in the field while sugarcane harvesters operate, easily damaging the blades of the basecutter. The design of an emergency obstacle avoidance system with machine vision and deep learning for sugarcane basecutters was used to identify obstacles in the cane field. The embedded system then was used to control the lifting and lowering of the basecutter to complete the real-time obstacle avoidance work. The YOLOv5s target detection model was structurally optimized in a real field trial environment. With a weight file that is 8.4 M, 41.6 % smaller than the original model, and a detection speed increase of 7.98 fps, the improved detection model generally satisfies the real-time needs of the field detection tests. The detection model used on the Raspberry Pi in the field test can achieve better detection accuracy with an inference delay of just 0.2 s, ensuring both detection accuracy and speed while accounting for the size of the model memory. A better obstacle avoidance effect can be achieved under light to moderate occlusion conditions and the positive obstacle avoidance rate can be greater than 80 % when the harvester is moving at a speed between 0.25 m⋅s−1 and 0.35 m⋅s−1. The effect of obstacle avoidance is diminished when the harvester is moving at its general top speed and comes into contact with severe occlusion conditions, but it may still satisfy obstacle avoidance requirements in field work settings and fully protect the blade.

Performance Assessment of Battery Electric Vehicles Using the TOPSIS Method

Worldwide interest in "hybrid and battery electric vehicles" has increased recently as a result of their ability to save on fuel, lessen reliance on foreign oil, and reduce greenhouse gas emissions. The effectiveness of the sub-systems that these vehicles are built with determines their overall success in large part. It is necessary to estimate these subsystems' parameters with great accuracy to improve their performances. "Battery electric vehicles (BEVs)", an eco-friendly type of vehicle, are crucial given that the automotive industry contributes significantly to carbon emissions. Due to the recent quick growth of the BEV market, it has grown to be a substantial challenge to evaluate BEV alternatives fully from the perspective of the consumer. By examining the fundamental characteristics of each BEV, this evaluation can be made. The use of "multiple criteria decision making (MCDM)" techniques is a useful tool for making the best BEV buying choice. Therefore, six BEVs are selected as options in this work. These vehicles are then ranked using TOPSIS based on technical specifications, such as Battery capacity, Range, Top speed, Quick charge time, Acceleration and Purchasing price. In this study TOPSIS method analyses the rank of Mercedes-Benz EQS as first, Audi e-tron GT as fourth, Porsche Taycan as fifth, Audi e-tron as third, Audi RS e-tron GT as second and Mercedes-Benz EQC as sixth. So, the result from the TOPSIS method shows that Mercedes-Benz EQS is highlighted as the best choice of the selected battery electric vehicles followed by the Audi RS e-tron GT.

Modular and Scalable Powertrain for Multipurpose Light Electric Vehicles

Light electric vehicles are best suited for city and suburban settings, where top speed and long-distance travel are not the primary concerns. The literature concerning light electric vehicle powertrain design often overlooks the influence of the associated driving missions. Typically, the powertrain is initially parameterized, established, and then evaluated with an ex-post-performance assessment using driving cycles. Nevertheless, to optimize the size and performance of a vehicle according to its intended mission, it is essential to consider the driving cycles right from the outset, in the powertrain design. This paper presents the design of an electric powertrain for multipurpose light electric vehicles, focusing on the motor, battery, and charging requirements. The powertrain design optimization is realized from the first stages by considering the vehicle’s driving missions and operational patterns for multipurpose usage (transporting people or goods) in European urban environments. The proposed powertrain is modular and scalable in terms of the energy capacity of the battery as well as in the electric motor shaft power and torque. Having such a possibility gives one the flexibility to use the powertrain in different combinations for different vehicle categories, from L7 quadricycles to light M1 vehicles.

Speed and Nighttime Usage Restrictions and the Incidence of Shared Electric Scooter Injuries

Electric scooter (e-scooter) crashes have become a serious health issue worldwide. The need for effective e-scooter regulations has been established in numerous instances. To investigate the association of restrictions on top speed and nighttime usage on the incidence of e-scooter-related injuries. A retrospective comparative cohort study of all patients with an injury related to shared e-scooter riding sustained in Helsinki, Finland. Data were collected from the electric patient database from 3 trauma hospitals representing all public hospitals treating patients with acute trauma in Helsinki. Shared e-scooter injuries from 2 periods were compared: an unrestricted period (January 1 to August 31, 2021) and a restricted period (January 1 to August 31, 2022). Data were analyzed from September 2022 to September 2023. The restrictions established for shared e-scooters during the restricted period were: (1) the daytime top speed of 20 km/h, as opposed to the previous top speed of 25 km/h, (2) the use of shared e-scooters was prohibited on Friday and Saturday nights between 12 am and 5 am, and (3) the nighttime top speed was decreased to 15 km/h from Sunday to Thursday between 12 am and 5 am, as opposed to 25 km/h. The incidence of e-scooter injuries compared with the total trips made by e-scooters. There were 528 e-scooter injuries requiring hospital care during the unrestricted period and 318 injuries during the restricted period of similar length. The median (IQR) age of the patients in the study periods was 25 (21-32) and 28 (22-37), respectively; 308 (58%) and 191 (60%) were male, respectively. The incidence of e-scooter injuries was 19 (95% CI, 17-20) for every 100 000 rides during the unrestricted period and 9 (95% CI, 8-10) per 100 000 rides during the restricted period. In the risk analysis, the odds ratio for shared e-scooter injuries was 0.5 (95% CI, 0.4-0.6) for the restricted period when adjusted for hourly temperature, rain amount, wind speed, and visibility. After introducing the restrictions, the number of e-scooter injuries decreased significantly between 11 pm and 5 am. The number of injuries decreased after implementing restrictions on the top speed and nighttime usage of e-scooters. Similar restrictions in cities with shared e-scooter services should be explored.

Measuring skill via player dynamics in football dribbling

Although a myriad of studies have been conducted on player behavior in football, in-depth studies with structured theory are rare due to the difficulty in quantifying individual player skills and team strategies. We propose a physics-based mathematical model that describes football players’ movements during dribbling situations, parameterized by the attacker aggressiveness, the defender hesitance and the top speed of both players. These player- and situation-specific parameters are extracted by fitting the model to real player trajectories from Major League Soccer games, and enable the quantification of player dribbling attributes and decisions beyond classical statistics. We show that the model captures the essential dribbling dynamics, and analyze how differences between parameters in varying game situations provide valuable insights into players’ behavior. Lastly, we quantitatively study how changes in the player’s parameters impact dribbling performance, enabling the model to provide scientific guidance to player training, scouting and game strategy development.

‘They Collected Money and Used Hammer to Remove My Front teeth’: ‘One-Chance’ Criminality and Victimisation Experiences in Lagos Transport Corridors

ABSTRACT “One-chance” criminality has become public transport threat in Lagos State where passengers are trapped through deceit, robbed, and victimized by individuals or groups pretending to offer public transportation services. Understanding the strategies and victimization experiences may help illuminate this phenomenon toward developing preventive cues and appropriate institutional response. This study, therefore examines “one-chance” strategies and the victimization experiences of passengers in Lagos public transportation corridors. The Routine Activities Theory (RAT) is used to explain the phenomenon using exploratory research design. The snowball technique was used to reach victims of one-chance robbery who responded to in-depth interview guide questions which probed into the strategies, victimization experiences and coping strategies. Findings show that timing, disguise/deception, taking unusual routes, tampering with the vehicle central lock, reworking the seatbelt, and winding up glasses are methods adopted by the one-chance robbery perpetrators to victimize. Physical assaults (beating with all kinds of weapons, sexual assaults, and forced pushing out of the vehicle at top speed which could lead to the victim’s disability or death) and loss of valuables (dispossession of jewelleries, monies, and phones). Participants increased vigilance before boarding, hailing a private taxi and instrumentalised religion for protection as coping strategies. The study provokes mapping of “one-chance” hot-spots by law enforcement authorities and routine adjustment for commuters.

FLASHING: Project overview

Abstract This paper describes an overview of the FLASHING (Finest Legacy Acquisitions of SiO-/H2O-maser Ignitions by the Nobeyama Generation) project promoted using the 45 m telescope of Nobeyama Radio Observatory, which aims to intensively monitor H2O (at 22 GHz) and SiO (at 43 GHz) masers associated with so-called “water fountain” sources. Here we show scientific results based on the data taken in the first five seasons of FLASHING, from 2018 December to 2023 April. We show the evolution of the H2O maser spectra, discovering new spectral components that break the record of the jet’s top speed and/or systematic velocity drifts in the spectrum indicating acceleration or deceleration of the maser gas clumps. For the 43 GHz SiO maser emission, we newly detect it in one source and find that it is no longer present in another source. This implies that the jets from these water fountains can be accelerated or decelerated, and show how circumstellar envelopes are destroyed.

Pengaruh muatan dan kecepatan kendaraan terhadap hasil emisi gas buang

The government is promoting the enforcement of over-dimensional and over-loading vehicles. Overloaded vehicles usually require a lot of power so it affects the results of exhaust emissions. This study aims to determine the results of emission tests by providing variations in load and speed on gasoline motorized vehicles, namely the Daihatsu Granmax Pick-Up 1.5 produced in 2014. The method used is experimental to determine the effect of independent variables (variations of load and speed) on the dependent variable (emissions exhaust gas). Variations of payload used are 0 kg, 735 kg, and 1200 kg with variations in speed of 0 km/hour, 10 km/hour, 20 km/hour, 30 km/hour, and 40 km/hour. The result of the experiment is that when the vehicle is unladen, with variations in speed, the Carbon monoxide (CO) and Hydro Carbon (HC) levels will be higher with a CO value of 0.83% and HC 121 ppm at a speed of 40 km/hour. When the vehicle is loaded according to GVW and given a variety of speeds, CO and HC levels increase with a CO value of 1.43% and HC 362 ppm at a speed of 40 km/hour. Meanwhile, if the vehicle is given a variation of speed with overload, the CO value rises to 3.30% and HC becomes 516 ppm at a top speed of 40 km/hour. So it can be concluded that the load variable and speed variations affect exhaust emissions and the largest exhaust emissions occur in overloaded vehicles.