Non-Linear Evaluation Model to Analyze Saturation Flow under Weak-Lane-Disciplined Mixed Traffic Stream

Saturation flow is an essential parameter for the performance evaluation and signal cycle design of an intersection. However, in a weak-lane-disciplined mixed traffic stream, vehicles (mainly motorized two- and three-wheelers) are more interested in forming queues with the behavior of creeping and infiltration through the larger vehicles for a quick dispersion. Consequently, a high rate of discharge can be found in the first few seconds of green, followed by a wavering discharge pattern to the end of the green period. In this context, the present study frames a non-linear evolutionary model (NLEM) to analyze passenger car unit (PCU) and saturation flow value by minimizing the vehicle encroachment and wavering in discharge for mixed traffic stream. Field traffic data was collected from 10 signalized intersections from three different cities of India. The NLEM considers the vehicle discharge during the saturated green interval in the optimization process to analyze PCU and saturation flow value. The result indicates an appropriate estimation of PCU and saturation flow concerning the Highway Capacity Manual. The discharge profile obtained using the proposed model also specifies the model’s aptness in analyzing the effect of vehicle encroachment and wavering throughout the green period. Thus, the proposed NLEM is probably suitable for analyzing the PCU and saturation flow of an intersection where vehicle interaction is sensitive because of a mixed scenario.

Impact of Countdown Ground LED Lights on Traffic Flow Efficiency at Signalized Intersections: A Driving Simulator study

Unnecessary stopping at signalized intersections during yellow interval reduces traffic flow efficiency. The aim of this driving simulator study was to investigate the impact of an advanced countdown system on traffic flow efficiency during yellow interval at signalized intersections. The experiment was conducted using a driving simulator at Qatar Transportation and Traffic Safety Centre, Qatar University. Sixty-seven volunteers with a valid Qatari driving license participated in the study. Three signalized intersections for three scenarios were designed with the north bound of the Corniche road in the city of Doha as the real-life reference context. The control scenario was an untreated typical signalized intersection (default) with the signal order of green-yellow-red. The signal order was changed to green-flashing green-yellow-red in the condition with 3 seconds advanced flashing. In the third scenario, green LED lights were used as an advanced countdown system and was compared with a default traffic signal with order green-yellow-red and a flashing green traffic signal with order green-flashing green-yellow-red. The LED lights were installed over a 100 m stretch of the road surface with spacing of 5m. More specifically, these ground lights were integrated in the pavement marking strips indicating lane division and edge lines. Light units were flashed green, 3 seconds prior to the yellow interval, and then turned off one by one in sequential order towards the intersection at a predetermined speed. The system was aimed at providing advanced information and visualizing the inter-green period by means of a countdown system as a way to improve traffic flow efficiency. Study results showed that compared to the other two scenarios, drivers’ utilized the yellow interval in a better way in the scenario with green LED lights. Furthermore, results from binary logistic regression showed that probability of crossing the intersection was 30 and 2.6 times higher in the scenario with green LED lights compared to the flashing green and control scenarios, respectively. Regarding the red light running occurrences, there was no significant differences between the scenarios. Taking into account the results from this study, we recommend jurisdictions to further evaluate G-LED as a potentially effective treatment for increasing traffic flow efficiency during the inter-green period at signalized intersections.

Effect of Winter Temperature Increase on Prolonging Green Period of Lawn

Taking mixed lawn of Festuca elata Keng ex E. Alexeev and Poa pratensis L. as the research object, through the comparison of the electric heating, covering by non-woven fabric or electric heating and non-woven fabric treatment group with the control group, exploring the effects of winter temperature increase on prolonging the green period of lawn. The results show that: compared with the control group, different temperature increasing measures have different effects on prolonging the green period of the lawn. The test group using only electric heating or only covering the non-woven fabric was completely yellow in mid-January, which was about 10 days longer than the green period of the control group. The effect of using electric heating and non-woven fabric was the best. During the research period, the lawn of this group did not appear completely yellow. Compared with the control group, the green period was prolonged by about 53 days.

Green Period Characteristics and Foliar Cold Tolerance in 12 Iris Species and Cultivars in the Yangtze Delta, China

Iris (Iris sp.) is a popular and widely planted herbaceous perennial. However, most iris species go dormant without any aesthetic quality for 5–6 months in the transition zone between the temperate and subtropical climates. To investigate the effects of species/cultivars, leaf shape, and air temperature conditions on the ability to stay green, 12 popular species and cultivars in the transition zone were evaluated. Iris tested included the following species: roof iris (I. tectorum), japanese iris (I. japonica), long leafed flag (I. halophila), yellow flag (I. pseudacorus), blood iris (I. sanguinea), japanese water iris (I. ensata), and small-flower iris (I. speculatrix) and the following cultivars: ‘Chinensis’ milky iris (I. lactea var. chinensis), ‘Bryce Leigh’ louisiana iris (I. hexagonae), ‘Black Swan’ german iris (I. germanica), ‘Careless Sally’ siberian iris (I. sibirica), and ‘Loyalty’ japanese water iris (I. ensata). We conducted a 2-year field study on mature iris populations and evaluated the percentage of green leaves during winter retention and spring recovery using a digital image analysis (DIA). Green period during this study was calculated using predicted sigmoid curves based on the percentage of green leaves. The present study revealed that iris species/cultivars and air temperatures had considerable influence on the duration of the green period. Both evergreen and deciduous iris phenotypes exist with three different leaf shapes, among which the average green period of fan-shaped leaf iris species and cultivars was the longest. Because there was no significant (P = 0.205) relationship between green period during this period and leaf lethal temperature (LT50), new cultivars with long green periods may be achieved without a simultaneous loss of cold tolerance in iris.

Agromorphological Characterisation of Foxtail Millet (Setaria italica L. Beauv) at Rampur, Chitwan, Nepal

Ten foxtail millet accessions were collected from different parts of Nepal and were characterized for different agro morphological traits at Institute of Agriculture and Animal Science, Rampur, Chitwan. Ten accessions were experimented in Randomized Complete Block Design with three replications. Observations were taken for quantitative traits i.e. days to heading, days to anthesis, days to maturity, peduncle length, plant height, flag leaf length, flag leaf breadth, flag leaf length breadth ratio and stay green period and yield attributing traits i.e. panicle length, panicle exertion, number of panicle per square meter, hundred grain weight, five panicle weight and yield per plant. The mean performance was obtained and correlation analysis was performed between grain yield and other traits. Observations were also taken for qualitative traits i.e. tip of first leaf, anthocyanin at leaf base, lobe compactness, length of bristles, anthocyanin presence, leaf blade altitude, flag leaf color, lobe in panicles, panicle lodging, inflorescence compactness, overall color, panicle anthocyanin, panicle shape and growth habit. Significant differences were observed among the accessions for many characters. Based on quantitative and yield attributing traits, Humla-149 was considered the best performing accession. The UPGMA clustering and PCA analysis revealed three distinct clusters of the studied accessions. Most closely related accessions were Co-1896 and Co-5645 and most distantly related accessions were Co-1896 and Humla-522.Int J Appl Sci Biotechnol, Vol 4(3): 298-307

Research on the Changes of Vegetation Coverage in Turks County Based on NDVI

24 periods of 10-day hierarchy schemes of the vegetation coverage of Turks County within 3 years are obtained through inversion, and annual change and interannual change of the vegetation coverage of Turks County are analyzed. The result demonstrates that the average vegetation coverage of the whole county is about 40%~45% during the returning green period, the peak value of the vegetation coverage appears in the last ten days of July, and the highest vegetation coverage of the three years is as high as 60% or above. During the past 12 years, the vegetation change of Turks County is stable-based that accounts for 39.6% of the total area of the county, the area of grassland slightly recovered equals to that of grassland slightly degraded, and the total of both lands is 39.1% of the whole county while the area of grassland significantly degraded accounts for only 8.7%.