Synthesis new fused and non-fused chromene [I] derivatives derived from 2-amino-4-[4-(dimethylamino)phenyl]-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile

A new series of pyrano-chromene and pyrimido pyrano-chromene derivatives were synthesized starting from 2-amino-4-[4-(dimethylamino)phenyl]-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile (5). The structures of the synthesized compounds were elucidated by spectral data. Key words: Chromenes, Pyrano-chromene

DC Fault Current Analyzing, Limiting, and Clearing in DC Microgrid Clusters

A new DC fault current limiter (FCL)-based circuit breaker (CB) for DC microgrid (MG) clusters is proposed in this paper. The analytical expressions of the DC fault current of a bidirectional interlink DC/DC converter in the interconnection line of two nearby DC MGs are analyzed in detail. Meanwhile, a DC fault clearing solution (based on using a DC FCL in series with a DC circuit breaker) is proposed. This structure offers low complexity, cost, and power losses. To assess the performance of the proposed method, time-domain simulation studies are carried out on a test DC MG cluster in a MATLAB/Simulink environment. The results of the proposed analytical expressions are compared with simulation results. The obtained results verify the analytical expression of the fault current and prove the effectiveness of the proposed DC fault current limiting and clearing strategy

Opportunities for improving interfaces between railway engineering analysis tools

Railways are complex systems, which utilize many engineering disciplines in order to ensure their safe and efficient operation. Railway engineers make use of ever improving analysis tools to control the performance of various parts of the railway system. Often these tools have become efficient but highly specialized. For example, vehicle engineers use powerful dynamic simulation packages but the information these provide are not always fully utilized in work carried out by infrastructure engineers who are using their own software tools. The EPSRC funded TRAINS project is studying the Railway System as a whole. As part of this the Rail Technology Unit at MMU is investigating the links between tools used by different engineering disciplines in the railway field. An overview of the TRAINS project is given in [1]. A database of tools has been set up and is being used to establish links between tools and, more importantly, gaps where tools are not interfacing as they could. The structure of the database is outlined in this paper. This project provides an opportunity to investigate the interaction between design, maintenance and operation of the vehicle and the effect on the track. In this paper we show how a sample system model is being set up which links some of the identified tools to demonstrate the interfaces. This system tool is then used to establish the effects of changes in one part of the system (such as the wheel-rail interface) on other parts of the system (such as interaction with the infrastructure)

Effects of Blood Flow Restriction and Exercise Intensity on Aerobic, Anaerobic, and Muscle Strength Adaptations in Physically Active Collegiate Women

The purpose of this study was to compare the effects of different combinations of blood flow restriction (BFR) pressure and exercise intensity on aerobic, anaerobic, and muscle strength adaptations in physically active collegiate women. Thirty-two women (age 22.8 ± 2.9 years; body mass index 22.3 ± 2.7 kg/m2) were randomly assigned into four experimental training groups: (a) increasing BFR pressure with constant exercise intensity (IP-CE), (b) constant partial BFR pressure with increasing exercise intensity (CPp-IE), (c) constant complete BFR pressure with increasing exercise intensity (CPC-IE), and (d) increasing BFR pressure with increasing exercise intensity (IP-IE). The participants completed 12 training sessions comprised of repeated bouts of 2 min running on a treadmill with BFR interspersed by 1-min recovery without BFR. Participants completed a series of tests to assess muscle strength, aerobic, and anaerobic performances. Muscle strength, anaerobic power, and aerobic parameters including maximum oxygen consumption (VO2max), time to fatigue (TTF), velocity at VO2max (vVO2max), and running economy (RE) improved in all groups (p ≤ 0.01). The CPC-IE group outscored the other groups in muscle strength, RE, and TTF (p < 0.05). In summary, participants with complete occlusion experienced the greatest improvements in muscle strength, aerobic, and anaerobic parameters possibly due to increased oxygen deficiency and higher metabolic stress

Blood Flow Restriction During Futsal Training Increases Muscle Activation and Strength

The aim of this study was to investigate the effect of leg blood flow restriction (BFR) applied during a 3-a-side futsal game on strength-related parameters. Twelve male futsal players were randomly assigned into two groups (n = 6 for each group) during 10 training sessions either with or without leg BFR. Prior to and post-training sessions, participants completed a series of tests to assess anabolic hormones and leg strength. Pneumatic cuffs were initially inflated to 110% of leg systolic blood pressure and further increased by 10% after every two completed sessions. In comparison with baseline, the resting post-training levels of myostatin (p = 0.002) and IGF-1/MSTN ratio (p = 0.006) in the BFR group changed, whereas no change in the acute level of IGF-1 and myostatin after exercise was observed. Peak torque of knee extension and flexion increased in both groups (p &lt; 0.05). A trend of increased neural activation of all heads of the quadriceps was observed in both groups, however, it was statistically significant only for rectus femoris in BFR (p = 0.02). These findings indicated that the addition of BFR to normal futsal training might induce greater neuromuscular benefits by increasing muscle activation and augmenting the hormonal response