Demonstration of the Benefits of SAE 30 Stationary Gas Engine Oil in Full Scale Engine Tests

This paper evaluates the benefits of an SAE 30 monograde stationary gas engine oil (SGEO) in comparison with SAE 40 monograde SGEOs with the focus on two main areas. First, to demonstrate and quantify the positive impact of lower viscosity on the fuel consumption rate, and second to demonstrate the faster lubrication of hard to reach points in the engine during startup. The current industry recognized fuel efficiency test methods for passenger car and on-road diesel engine sectors are not suitable for evaluating the fuel efficiency performance of a gas engine oil because of the significant differences in fuel type, engine operating conditions, and oil formulations. This paper, therefore, describes comparative studies of three different gas engine oils in a modern MAN E3262 E302 gas engine that was carefully adapted and fully instrumented. The performance of each oil with respect to fuel efficiency was assessed in an extensive program comprising endurance testing, stationary tests on various load/speed points and dynamic tests running the engine fired as well as non-fired (motored). Another part of the test program explores the lubrication of hard to reach points in the engine, e.g. valve guide. The paper describes how the SAE 30 monograde oil results in faster lubrication of these parts during startup in comparison with the SAE 40 oils.

Technique for Profiling the Cycling-Induced Oxide Trapped Charge in NAND Flash Memories

NAND Flash memories have gained tremendous attention owing to the increasing demand for storage capacity. This implies that NAND cells need to scale continuously to maintain the pace of technological evolution. Even though NAND Flash memory technology has evolved from a traditional 2D concept toward a 3D structure, the traditional reliability problems related to the tunnel oxide continue to persist. In this paper, we review several recent techniques for separating the effects of the oxide charge and tunneling current flow on the endurance characteristics, particularly the transconductance reduction (ΔGm,max) statistics. A detailed analysis allows us to obtain a model based on physical measurements that captures the main features of various endurance testing procedures. The investigated phenomena and results could be useful for the development of both conventional and emerging NAND Flash memories.

Comprehensive analysis of existing endurance testing methods of flexible dowel crutches of composite reinforced concrete road bridges according to the standards of a number of countries

In the article, the author considers the verification issue of the endurance of the venture elements of steel-reinforced concrete spans of bridges, in particular, flexible dowel crutches («Nelson’s anchors»). According to the existing domestic regulatory framework, the endurance test of the flexible dowel crutches for road bridges is not required; at the same time, the survey’s results of the operated superstructures indicate the presence of problems associated with the insufficient endurance of these elements. The article presents comprehensive (qualitative and quantitative) comparative analysis results of the world’s existing approaches to testing the endurance of the venture elements. At the stage of qualitative analysis, the author considered methods of checking the endurance of elements in general according to the norms of 8 countries and regions (Russia, the European Union, the USA, Ukraine, Australia, Canada, Japan, China) and highlighted a basic set of methods for checking the endurance of the venture elements (Russia, the European Union, USA, Ukraine). The models of the basic set were subjected to a detailed qualitative analysis according to the criteria of the models used and the parameters included in them. The quantitative analysis of the selected basic set techniques, carried out in relation to the existing bridge, included an analysis of the effects of moving loads on the venture elements, direct elements verification using the considered methods, as well as the design damage comparison of the elements obtained by the Palmgren-Miner linear summation hypothesis. Based on the obtained values of design damage, the values of the use of endurance reserves were determined and analyzed for each of the considered methods and the conditional load model. Based on the results of the qualitative and quantitative analysis, the author draws conclusions based on the comparison of various methods and highlights the rational directions for improving the existing domestic methodology.

Electromyography-based Fatigue Assessment During Endurance Testing by Different Vibration Training Protocols

Objectives: This study presents a method of assessing muscle fatigue during endurance testing at 50% maximal voluntary contraction (MVC) using electromyography (EMG) information as indirect indices of fatigability in the forearm muscles, namely, flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi ulnaris (ECU) and extensor carpi radialis brevis (ECRB)." This study presents a method of assessing muscle fatigue during endurance testing at 50% maximal voluntary contraction (MVC) using electromyography (EMG) information as indirect indices of fatigability in the forearm muscles, namely, flexor digitorum superficialis (FDS); flexor carpi ulnaris (FCU); extensor carpi ulnaris (ECU) and extensor carpi radialis brevis (ECRB). Methods: A randomized comparative experimental design was used during endurance test with 8 VT protocols; based on different combinations of vibration frequency (35 & 45 Hz), amplitude (3±0.5g & 9±0.5g), and exposure duration (30 & 60 seconds), i.e., were given to the study participants for 4 days. A random sampling of participants was conducted from two groups (n=56/group), as follows: individuals with a Sedentary Lifestyle (SL) and a group of Construction Workers (CW). Results: Multivariate Analysis of Variance (MANOVA) results indicated a significant increase in EMG rms, median frequency, waveform length, mean absolute value (P<0.001), and the variance of EMG signal (P<0.05) (except in ECU for the SL group and ECRB for the CW group on the variance of EMG signal) after VT in all muscles of both research groups. Therefore, an increase in the EMG parameter value after a grip endurance task revealing an elevation in EMG signal amplitude is indicative of muscle fiber fatigue. Furthermore, the strongest correlation was found between grip endurance and WL (r=0.471, P<0.001), and EMG rms (r=0.401, P<0.001) of the ECU muscle in the SL group only. Discussion: The patterns of EMG signal represented the amplitude and spectral parameters of the signal, enabling real-time fatigue analysis. Additionally, surface EMG information is useful for indirectly evaluating performance fatigue during the endurance test.

Muscle Endurance Testing Using an Isokinetic Dynamometer and A Recumbent Stepper: A Correlation Study

Purpose: A lack of objective and validated clinical measures to assess Quadriceps muscle endurance (ME) currently exists. The Transitt model of the NuStep recumbent stepper has the capability to measure ME but has not been validated. Therefore, the aim of this study was to investigate the association between ME measures on the NuStep and the isokinetic dynamometer (ID). Methods: 30 healthy individuals were recruited to participate. On both the NuStep (70°/90° knee flexion) and ID (70° knee flexion), the participants were instructed to hold a submaximal isometric unilateral knee extension contraction until exhaustion. Descriptive statistics, inferential statistics and correlation analyses were used with significance set at p<0.05. Results: There was excellent correlation (r between 0.813 to 0.840, p<0.001) between the average force generated by the individuals on the ID and the NuStep. There was a fair correlation (r between 0.331 to 0.413, p<0.05) for the ME measures between the ID and the NuStep. Conclusions: The NuStep shows excellent agreement for average force measurements. Future studies are needed to validate the NuStep as an objective measure of ME in both healthy and clinical populations.

Analisis Indeks Kelelahan dan Daya Tahan Anaerobic Atlet Futsal SMA Institut Indonesia Semarang

While futsal is a pre dominant anaerobic endurance sport. Problem research of how the anaerobic endurance ability o extracurricular participants at the Semarang Indonesia Institute High School. The purpose of this study was to determine the anaerobic endurance of extracurricular participants at the Semarang Indonesia Institute High School.This research method uses a descriptive qualitative survey research design. The sample consisted of 16 male students participating in the extracurricular at the Semarang Indonesia Institute High School. The research instrument used the RAST (Running Anaerobic Sprint Test).The result of the study are based on the RAST Test. The test result show that the sample that has an index of fatigue is said to be tired as many as 12 samples (75%) while the samples that have said to be tired are as many as 4 samples (25%). An athlete’s physical condition can be predicted using the right test instrument.Based on data analysis and discussion, it can be concluded that the fatigur index an anaerobic endurance ability of futsal extracurricular participants at the Indonesia Institute of High School Semarang is tired. Test recommendations or endurance testing for futsal sports using Running Anaerobic Sprint Test (RAST)