Red Phase Research Articles

A Reason for the Earth Moving Away from the Sun and the Possibility to Escape Being Engulfed by a Red Giant Sun

Using the radar technology and the tracking technology of interplanetary spacecraft, scientists have calculated that the sun and Earth are gradually moving apart. But no one knows the reason why the Earth is moving away from the sun. So the author has analyzed various factors affecting Earth’s movement, and found that during the normal rotation of the Earth around the sun, the atmospheric pressure on the trailing hemisphere of the Earth is higher than the other hemisphere, effectively increasing its rotation speed, thus making the Earth gradually move away from the sun along a spiral line. Generally, any planet with thick atmosphere can move away from its parent star under the sunshine of its parent star. At the current speed of Earth’s moving away from the sun, the Earth can survive the sun's red giant phase.

Estimating Safety Effects of Green-Man Countdown Devices at Signalized Pedestrian Crosswalk Based on Cellular Automata

Safety effects of Green-Man Countdown Device (GMCD) at signalized pedestrian crosswalks are evaluated. Pedestrian behavior at GMCD and non-GMCD crosswalks is observed and analyzed. A microsimulation model is developed based on field observations to estimate safety performance. Simulation outputs allow analysts to assess the impacts of GMCD at various conditions with different geometric layout, traffic and pedestrian volumes, and the green time. According to simulation results, it is found that the safety impact of GMCD is affected by traffic condition as well as different time duration within green-man signal phase. In general, GMCD increases average walking velocity, especially during the last few seconds. The installation of GMCD improves safety performance generally, especially at more crowded crossings. Conflict severity is increased during last 10 s after GMCD installation. Findings from this study suggest that the current practice, which is to install GMCD at more crowded crosswalks or near the school zone, is effective. Moreover, at crosswalks with GMCD, longer all red signal phase is suggested to improve pedestrian safety during intergreen period.

Red Light Running at Heterogeneous Saturated Intersections in Mumbai, India: On the Existence of Two Regimes and Causal Factors

This paper presents an analysis of red light running (RLR) conducted at saturated intersections in the city of Mumbai, India, where the traffic is highly heterogeneous with respect to vehicle classes and driver behavior. When all vehicles are considered, almost one in 17 drivers is seen to be jumping red signals there. Unlike the RLR behavior that has been previously reported from intersections elsewhere, a peculiarity observed here is that, within a single red phase, two distinguishable segments of RLR behavior exist. The authors classified them into two regimes: Regime 1, just after the onset of red, and Regime 2, just before the onset of the next green. About one-third of RLR events occur in Regime 1 and the rest in Regime 2. The authors fit different distributions on the time distribution of RLR events. The Kolmogorov–Smirnov test suggests that, at all intersections, exponential distribution fits best for RLR behaviors in Regime 1, and extreme value distribution fits for Regime 2. In addition to those two regimes, RLR at a lower rate is observed in the period between those regimes, and normal distribution fits there. To analyze the causal factors of RLR behavior in the two regimes, the authors developed models at a mesoscopic level specific to vehicle class and regime. Although the red-to-green ratio and the presence of policing prove to be relevant factors affecting RLR in both the regimes, the relative time for which the conflict area is free affects RLR in Regime 2 but not in Regime 1.

Social Influence and Different Types of Red-Light Behaviors among Cyclists.

Accident analysis and studies on traffic revealed that cyclists’ violation of red-light regulation is one typical infringement committed by cyclists. Furthermore, an association between cyclists’ crash involvement and red-light violations has been found across different countries. The literature on cyclists’ psychosocial determinants of red-light violation is still scarce. The present study, based on the classification of cyclists’ red-light behavior in risk-taking (ignoring the red-light and traveling through the junction without stopping), opportunistic (waiting at red-lights but being too impatient to wait for green signal and subsequently crossing the junction), and law-obeying (stopping to obey the red-light), adopted an eye-observational methodology to investigate differences in cyclists’ crossing behavior at intersections, in relation to traffic light violations and the presence of other cyclists. Based on the social influence explanatory framework, which states that people tend to behave differently in a given situation taking into consideration similar people’s behaviors, and that the effect of social influence is related to the group size, we hypothesized that the number of cyclists at the intersection will have an influence on the cyclists’ behavior. Furthermore, cyclists will be more likely to violate in an opportunistic way when other cyclists are already committing a violation. Two researchers at a time registered unobtrusively at four different intersections during morning and late afternoon peak hour traffic, 1381 cyclists approaching the traffic light during the red phase. The 62.9% violated the traffic control. Results showed that a higher number of cyclists waiting at the intersection is associated with fewer risk-taking violations. Nevertheless, the percentage of opportunistic violation remained high. For the condition of no cyclist present, risk-taking behaviors were significantly higher, whereas, they were significantly lower for conditions of two to four and five or more cyclists present. The percentage of cyclists committing a red-light violation without following any other was higher for those committing a risk-taking violation, whereas those following tended to commit opportunistic violations more often.

Red blood cell phase separation in symmetric and asymmetric microchannel networks: effect of capillary dilation and inflow velocity.

The non-uniform partitioning or phase separation of red blood cells (RBCs) at a diverging bifurcation of a microvascular network is responsible for RBC heterogeneity within the network. The mechanisms controlling RBC heterogeneity are not yet fully understood and there is a need to improve the basic understanding of the phase separation phenomenon. In this context, in vitro experiments can fill the gap between existing in vivo and in silico models as they provide better controllability than in vivo experiments without mathematical idealizations or simplifications inherent to in silico models. In this study, we fabricated simple models of symmetric/asymmetric microvascular networks; we provided quantitative data on the RBC velocity, line density and flux in the daughter branches. In general our results confirmed the tendency of RBCs to enter the daughter branch with higher flow rate (Zweifach-Fung effect); in some cases even inversion of the Zweifach-Fung effect was observed. We showed for the first time a reduction of the Zweifach-Fung effect with increasing flow rate. Moreover capillary dilation was shown to cause an increase of RBC line density and RBC residence time within the dilated capillary underlining the possible role of pericytes in regulating the oxygen supply.

Soft Radial Basis Cellular Neural Network (SRB-CNN) based robust low-cost truck detection using a single presence detection sensor

This paper does present a comprehensive concept for a robust and reliable truck detection involving solely one single presence sensor (e.g. an inductive loop, but also any other presence sensor) at a signalized traffic junction. Hereby, two operations modes are distinguished: (a) during green traffic light phases, and (b) a much challenging case, during red traffic light phases. First, it is shown how difficult the underlying classification task is, this mainly due to strongly overlapped classes, which cannot be easily separated by simple hyper-planes. Then, a novel soft radial basis cellular neural/nonlinear network (SRB-CNN) based concept is developed, validated and extensively benchmarked with a selection of the best representatives of the current related state-of-the-art classification concepts (namely the following: support vector machines with radial basis function, artificial neural network, naive Bayes, and decision trees). For benchmarking purposes, all selected competing classifiers do use the same features and the superiority of the novel CNN based classifier is thereby underscored, as it strongly outperforms the other ones. This novel SRB-CNN based concept does satisfactorily fulfill the hard industrial requirements regarding robustness, low-cost, high processing speed, low memory consumption, and the capability to be deployed in low cost embedded systems.

Fabrication of Helical Nanoribbon Polydiacetylene via Supramolecular Gelation: Circularly Polarized Luminescence and Novel Diagnostic Chiroptical Signals for Sensing.

Four kinds of commercially available diacetylene (DA) monomers with different chain length, diacetylene positions were fabricated into the organogels via mixing with a chaperone gelator, an amphiphilic l-histidine ester derivative LHC18 that can help the nongelator to form gels. Upon photo irradiation with a 254 nm UV light, the white gels underwent topochemical reaction and turned into red or blue gels, depending on the DA monomer structures. Through the gel formation, the molecular chirality of LHC18 can be transferred to the polydiacetylene (PDA) and helical nanoribbon structures were obtained. The blue gels showed a clear response to stimuli such as pH variation, heating, mechanical force and organic solvents, and turned into red gels. Interestingly, the blue gel showed strong supramolecular chirality, which could be turned off or changed into red phase CD signals. Such changes in chiroptical signals depended on the external heating and various organic solvents. In the case of heating, the blue gel changed into red one, which showed both strong CD signals and circularly polarized luminescence. In the case of organic solvents, although all the tested solvents made the blue gel to red, only some of them could keep the CD signals, thus providing additional sensing capacity of the PDA system. So far, the blue-to-red color change and the "fluorescence on" was widely used as colorimetric and fluorogenic diagnostic signals for PDA, here we showed an additional chiroptical diagnostic signal for a more precise sensing by using the helical PDA.

Metabolomic profiling of the astaxanthin accumulation process induced by high light in Haematococcus pluvialis

The growth of Haematococcus pluvialis exposed to high light was divided into three pigmentation phases: a green phase, a yellow phase and a red phase. Classification was based on astaxanthin and chlorophyll content and cell morphology. Metabolic profiling of the three pigmentation phases was performed. A total of 81 metabolites were identified and quantified by gas chromatography–mass spectrometry, including 23 amino acids, 19 sugars, 15 organic acids, 8 alcohols, 7 amines, 4 nucleic acids and 5 others. These were subdivided into four groups according to their changes during the three phases. The clustering of metabolites was revealed, and potential biomarkers were identified by principal component analysis, partial least squares analysis and hierarchical clustering analysis, suggesting details of the metabolic pathways of cells. The contents of some cytoprotective metabolites were increased in the yellow phase, such as sucrose, proline and glutamic acid. The precursors of these metabolites are the intermediates of the Calvin cycle and the TCA cycle, indicated those two cycles provided more precursors for the synthesis of the cytoprotective metabolites. A hypothetical metabolic regulation model of H. pluvialis exposed to high light was proposed. Our study provides the first metabolomics view of the astaxanthin accumulation process that is induced by high light in H. pluvialis.

Studying critical pedestrian behavioral changes for the safety assessment at signalized crosswalks

Pedestrian-vehicle conflicts are one of the most important safety concerns at signalized intersections especially in urban areas. Conflicting vehicles and pedestrians select their maneuvers by predicting the other user behavior. Sudden behavioral changes of pedestrians such as sudden speed change (acceleration or deceleration) cannot be predicted by drivers, which can lead to safety hazards especially if these sudden behavioral changes occur near conflict areas. In this study, continuous pedestrian speed profiles were analyzed at signalized crosswalks to investigate the existence of such behavioral changes. A methodology is proposed to identify significant sudden changes of pedestrian speeds. The locations and timings of these sudden speed change events were analyzed, and the influencing factors such as crosswalk geometry and signal timing were studies and evaluated. Five signalized crosswalks at three intersections in Nagoya City were videotaped for analysis. Individual pedestrian maneuvers were extracted with image processing software. Empirical analysis showed that sudden acceleration events were observed at the entrance points to the pedestrian-vehicle conflict area, which highlights the significance of these events to pedestrian-vehicle conflict analysis. A multinomial logit model was developed to estimate the probability of a pedestrian making a sudden speed change as a function of different influencing factors. The results implied that the entering speed, necessary speed to finish crossing before the onset of the pedestrian signal red phase, and crosswalk length have a significant impact on speed change choices. This paper presents important suggestions to understanding pedestrian maneuvers in detail from the viewpoint of safety.

Quantitative phase imaging by single-shot Hilbert-Huang phase microscopy.

We propose a novel single-shot Hilbert-Huang transform-based algorithm applied to digital holographic microscopy (DHM) for robust, fast, and accurate single-shot quantitative phase imaging in on-axis and off-axis configurations. Fringe pattern with possible defects and closed fringes are adaptively filtered and accurately phase demodulated using local fringe direction estimation. Experimental validation of the proposed techniques is presented as the DHM study of microbeads and red blood cells phase samples. Obtained results compare very favorably with the Fourier approach (off-axis) and temporal phase shifting (on-axis).

Skeletal muscle growth dynamics and the influence of first-feeding diet in Atlantic cod larvae (Gadus morhua L.).

ABSTRACTDynamics between hypertrophy (increase in cell size) and hyperplasia (increase in cell numbers) of white and red muscle in relation to body size [standard length (SL)], and the influence of the first-feeding diets on muscle growth were investigated in Atlantic cod larvae (Gadus morhua). Cod larvae were fed copepod nauplii or rotifers of different nutritional qualities from 4 to 29 days post hatching (dph), Artemia nauplii from 20 to 40 dph and a formulated diet from 36 to 60 dph. The short period of feeding with cultivated copepod nauplii had a positive effect on both muscle hyperplasia and hypertrophy after the copepod/rotifer phase (19 dph), and a positive long term effect on muscle hypertrophy (60 dph). The different nutritional qualities of rotifers did not significantly affect muscle growth. We suggest here a model of the dynamics between hyperplasia and hypertrophy of red and white muscle fibre cells in relation to cod SL (4 to 30 mm), where the different red and white muscle growth phases clearly coincided with different metamorphosis stages in cod larvae. These shifts could be included as biomarkers for the different stages of development during metamorphosis. The main dietary muscle effect was that hypertrophic growth of red muscle fibres was stronger in cod larvae that were fed copepods than in larvae that were fed rotifers, both in relation to larval age and size. Red muscle fibres are directly involved in larval locomotory performance, but may also play an important role in the larval myogenesis. This can have a long term effect on growth potential and fish performance.

Star-planet interactions

Context. Fast rotating red giants in the upper part of the red giant branch have surface velocities that cannot be explained by single star evolution. Aims. We check whether tides between a star and a planet followed by planet engulfment can indeed accelerate the surface rotation of red giants for a sufficient long time in order to produce these fast rotating red giants. Methods. Using rotating stellar models, accounting for the redistribution of the angular momentum inside the star by different transport mechanisms, for the exchanges of angular momentum between the planet orbit and the star before the engulfment and for the deposition of angular momentum inside the star at the engulfment, we study how the surface rotation velocity at the stellar surface evolves. Results. We show that the surface velocities reached at the end of the orbital decay due to tidal forces and planet engulfment can be similar to values observed for fast rotating red giants. This surface velocity then decreases when the star evolves along the red giant branch but at a sufficiently slow pace for allowing stars to be detected with such a high velocity. More quantitatively, star-planet interaction can produce a rapid acceleration of the surface of the star, above values equal to 8 km s$^{-1}$, for periods lasting up to more than 30% the red giant branch phase. The changes of the surface carbon isotopic ratios produced by the dilution of the planetary material into the convective envelope is quite modest. Much more important might be the increase of the lithium abundance due to this effect. However lithium may be affected by many different, still uncertain, processes. Conclusions. The acceleration of the stellar surface to rotation velocities above limits that depend on the surface gravity does appear at the moment as the clearest signature of a star-planet interaction.[abridged]

Investigating the gender differences on bicycle-vehicle conflicts at urban intersections using an ordered logit methodology

In the literature, a crash-based modeling approach has long been used to evaluate the factors that contribute to cyclist injury risk at intersections. However, this approach has been criticized as crashes are required to occur before contributing factors can be identified and countermeasures can be implemented. Moreover, human factors related to dangerous behaviors are difficult to evaluate using crash-based methods. As an alternative, surrogate safety measures have been developed to address the issue of reliance on crash data. Despite recent developments, few methodologies and little empirical evidence exist on bicycle-vehicle interactions at intersections using video-based data and statistical analyses to identify associated factors. This study investigates bicycle-vehicle conflict severity and evaluates the impact of different factors, including gender, on cyclist risk at urban intersections with cycle tracks. A segmented ordered logit model is used to evaluate post-encroachment time between cyclists and vehicles. Video data was collected at seven intersections in Montreal, Canada. Road user trajectories were automatically extracted, classified, and filtered using a computer vision software to yield 1514 interactions. The discrete choice variable was generated by dividing post-encroachment time into normal interactions, conflicts, and dangerous conflicts. Independent variables reflecting attributes of the cyclist, vehicle, and environment were extracted either automatically or manually. Results indicated that an ordered model is appropriate for analyzing traffic conflicts and identifying key factors. Furthermore, exogenous segmentation was beneficial in comparing different segments of the population within a single model. Male cyclists, with all else being equal, were less likely than female cyclists to be involved in conflicts and dangerous conflicts at the studied intersections. Bicycle and vehicle speed, along with the time of the conflict relative to the red light phase, were other significant factors in conflict severity. These results will contribute to and further the understanding of gender differences in cycling within North America.

English

From the hypothesis that during the development of sugarcane, the water regime affects the morphological performance and this affects the productivity. The objective of this work was to evaluate the growth, development, productivity and yield of sugarcane during the cycle the planting sugarcane (variety SP83-5073), under different water replacements. The experiment was established in the Boa Vista mill located in Quirinopolis – GO, Brazil, on a distroferric Red Latosol cerrado phase. The experimental design was a randomized complete block, analyzed in a split plot scheme with four replications. Irrigation was carried out by a hose-drawn traveller sprinkler systems coupled to an irrigation bar. The evaluated variables were plant height, stem diameter, number of leaves and leaf area of two plants located in the useful area of each plot. The results were submitted to analysis of variance by F test at 5% probability, and in cases where significant difference were observed, regression analysis was performed on the water replacement levels and the evaluation dates, using the statistical software SISVAR. The growth of sugarcane was influenced positively by water replacement, depending on the season and applied blade, for plant height variables, stem diameter, leaf number and leaf area. The sugarcane yield obtained maximum increases of 61.07% and 81.52 t ha-1 on the blade 86.16% of water replacement with a productivity of 133.5 t ha-1. Key words: Irrigation depth, biometry, water deficit, yield.

Temporo-spatial cell-cycle kinetics in HeLa cells irradiated by Ir-192 high dose-rate remote afterloading system (HDR-RALS).

BackgroundIntracavitary irradiation plays a pivotal role in definitive radiotherapy for cervical cancer, and the Ir-192 high dose-rate remote afterloading system (HDR-RALS) is often used for this purpose. Under this condition, tumor tissues receive remarkably different absorption doses, with a steep gradient, depending on distance from the radiation source. To obtain temporo-spatial information regarding cell-cycle kinetics in cervical cancer following irradiation by Ir-192 HDR-RALS, we examined HeLa cells expressing the fluorescence ubiquitination-based cell cycle indicator (Fucci), which allowed us to visualize cell-cycle progression.MethodsHeLa-Fucci cells, which emit red and green fluorescence in G1 and S/G2/M phases, respectively, were grown on 35-mm dishes and irradiated by Ir-192 HDR-RALS under normoxic and hypoxic conditions. A 6 French (Fr) catheter was used as an applicator. A radiation dose of 6 Gy was prescribed at hypothetical treatment point A, located 20 mm from the radiation source. Changes in Fucci fluorescence after irradiation were visualized for cells from 5 to 20 mm from the Ir-192 source. Several indices, including first green phase duration after irradiation (FGPD), were measured by analysis of time-lapse images.ResultsCells located 5 to 20 mm from the Ir-192 source became green, reflecting arrest in G2, in a similar manner up to 12 h after irradiation; at more distant positions, however, cells were gradually released from the G2 arrest and became red. This could be explained by the observation that the FGPD was longer for cells closer to the radiation source. Detailed observation revealed that FGPD was significantly longer in cells irradiated in the green phase than in the red phase at positions closer to the Ir-192 source. Unexpectedly, the FGPD was significantly longer after irradiation under hypoxia than normoxia, due in large part to the elongation of FGPD in cells irradiated in the red phase.ConclusionUsing HeLa-Fucci cells, we obtained the first temporo-spatial information about cell-cycle kinetics following irradiation by Ir-192 HDR-RALS. Our findings suggest that the potentially surviving hypoxic cells, especially those arising from positions around point A, exhibit different cell-cycle kinetics from normoxic cells destined to be eradicated.Electronic supplementary materialThe online version of this article (doi:10.1186/s13014-016-0669-8) contains supplementary material, which is available to authorized users.

Design and Predeployment Assessment of an Integrated Intersection Dilemma Zone Protection System

Despite the fact that both traffic researchers and highway agencies have devoted considerable efforts over the past few decades to improving intersection safety, the development of effective strategies remains a challenging task. This research presents an integrated dilemma zone protection system (DZPS) for contending with the safety issues caused by the presence of a dilemma zone, a primary factor contributing to the rear-end collisions or side-angle crashes at intersections, especially at those experiencing high-speed traffic flows. The entire paper includes three parts: (1) development of an integrated system for protecting vehicles within the dilemma zone; (2) procedures to calibrate those key system parameters with field data at a candidate intersection; and (3) design of a per-deployment assessment process for evaluating such a design prior to its field deployment. The proposed DZPS, developed with a target intersection’s traffic characteristic data and geometric constraints, consists of three principal modules: variable message sign (VMS) for advanced warning or speed display, wide-range sensors to track individual vehicles in the dilemma zone, and a decision module to execute the all-red extension function. Based on a proactive design notion, the proposed DZPS can first use the VMS to inform the approaching drivers of a yellow or red phase ahead and prepare to stop, or to display the speed of the discharging traffic flows from the stop line during a green phase. The information will help compliant drivers to adjust their speeds in a timely manner so as to avoid rear-end collisions. For those aggressive/noncompliant vehicles, the DZPS system’s wide-range sensors will track the evolution of their speeds and locations within the dilemma zone at the interval of every 0.1 s, and then determine whether or not an all-red extension call shall be granted to prevent such vehicles from incurring potential side-angled crashes with vehicles from the side street. Recognizing that reliable evaluation of a deployed DZPS’s effectiveness needs the field data over a sufficiently long period, this study has presented the process for conducting a predeployment assessment with well-calibrated simulation experiments. The effectiveness of the proposed system, demonstrated with the results of the case study at the intersection of highway U.S. 301 at Croom Station Road, Upper Marlboro, Maryland, has also been summarized in this paper. Overall, the proposed system, from both the proactive and reactive perspectives to protect drivers, exhibits quite promising properties for use in practice.

Preface

Stellar mass loss is now widely recognized to have a significant impact on stellar evolution. Mass loss on the asymptotic giant branch (AGB) allows stars with initial masses under 8 solar masses to avoid the fate of going supernovae. Over 95% of stars in our Galaxy will evolve through the planetary nebulae phase to end up as white dwarfs instead of neutron stars or black holes. Massive stars undergo mass loss both in the blue and red phases of evolution and create new classes of stars such as Wolf-Rayet stars and luminous blue variables. The circumstellar matter ejected by these mass loss processes becomes new laboratories to study the physical and chemical processes of interstellar matter. The interaction between different phases of mass loss (with variable mass loss rates, ejection speeds, and directions) leads to spectacular morphological transformation of the circumstellar nebulae. The circumstellar nebulae are also sites of molecular and solid-state synthesis. Close to 100 molecular species and a variety of solids, including minerals and complex organics, have been detected in circumstellar envelopes. Since the dynamical time scale of the ejection puts an upper limit on the chemical time scale, we are witnessing a rapid synthesis of chemical species in an extremely low-density environment, creating new challenges to our understanding of chemical reactions.Effects of mass loss are not limited to single stars. Mass loss by one component of a binary system allows mass transfer to occur at separations beyond the Roche Lobe limit. Accreted wind materials on the surface of a degenerate star can lead to periodic outbursts through H-shell burning. When both components are losing mass, we have interesting dynamical systems such as symbiotic novae.The theme of this conference is “Physics and Chemistry of the Late Stages of Stellar Evolution”. We try to bring together experts in different fields to exchange ideas in the hope of solving the many unsolved problems in the late stages of stellar evolution. The size of the conference was limited to about 100 participants to allow for sufficient time for discussions and personal exchanges of opinions. Although the conference is part of the Pacific Rim series, astronomers from Asia, Europe, North and South America participated in the conference. We hope that these proceedings will serve as a record of our current understanding of the late stages of stellar evolution and be a useful resource for future generation of scientists working in the field.

Low radio frequency observations and spectral modelling of the remnant of Supernova 1987A

We present Murchison Widefield Array observations of the supernova remnant (SNR) 1987A between 72 and 230 MHz, representing the lowest frequency observations of the source to date. This large lever arm in frequency space constrains the properties of the circumstellar medium created by the progenitor of SNR 1987A when it was in its red supergiant phase. As of late-2013, the radio spectrum of SNR 1987A between 72 MHz and 8.64 GHz does not show any deviation from a non-thermal power-law with a spectral index of $-0.74 \pm 0.02$. This spectral index is consistent with that derived at higher frequencies, beneath 100 GHz, and with a shock in its adiabatic phase. A spectral turnover due to free-free absorption by the circumstellar medium has to occur below 72 MHz, which places upper limits on the optical depth of $\leq$ 0.1 at a reference frequency of 72 MHz, emission measure of $\lesssim$ 13,000 cm$^{-6}$ pc, and an electron density of $\lesssim$ 110 cm$^{-3}$. This upper limit on the electron density is consistent with the detection of prompt radio emission and models of the X-ray emission from the supernova. The electron density upper limit implies that some hydrodynamic simulations derived a red supergiant mass loss rate that is too high, or a wind velocity that is too low. The mass loss rate of $\sim 5 \times 10^{-6}$ $M_{\odot}$ yr$^{-1}$ and wind velocity of 10 km s$^{-1}$ obtained from optical observations are consistent with our upper limits, predicting a current turnover frequency due to free-free absorption between 5 and 60 MHz.

The red, purple and blue modifications of polymeric unsymmetrical hydroxyalkadiynyl-N-arylcarbamate derivatives in Langmuir-Schaefer films

Solid topochemical photopolymerization (STP) of Langmuir-Schaefer films of a new class of unsymmetrical diynes, containing N-arylcarbamate groups in the hydrophobic part and hydroxymethylene groups in the hydrophilic part of the molecules was examined. In addition, the monomeric Langmuir monolayer formation was studied by Brewster angle microscopy and the surface morphology of monomer and polymer films on solid substrates were studied by scanning electron microscopy and atomic force microscopy. Three phases of polydiacetylene (PDA) (red, purple and blue) were observed after UV-light polymerization of above-mentioned films of alcohol diacetylene (DA) derivatives. The substitution of MeO group in the aryl ring substituent by hydrogen atom and the variation of the methylene group number in the hydrophobic part from 5 to 6 changed significantly the result of STP: instead of blue phase PDA observed for diynes with MeO group, the red phase PDA was observed for DA with H-atom from the very beginning of diyne film UV irradiation. For two other diynilic N-arylcarbamates of identical chemical structures except of the substituents in the aryl ring of hydrophobic parts of the molecules, no changes in the efficiency of polymerization or the position and shape of absorption bands were observed. This indicated the formation of the purple phase PDA. For these molecules, the number of methylene groups in hydrophobic and hydrophilic parts of the molecules was 9 and 2, respectively.

Pedestrian Road Crossing Behavior Under Mixed Traffic Conditions: A Comparative Study of an Intersection Before and After Implementing Control Measures

Traffic accidents involving pedestrians have become a major safety problem in most of the developing countries like India due to rapid urbanization, increase in vehicular growth and lack of adherence to traffic regulations by both drivers and pedestrians. The existing roads design does not provide adequate facilities for pedestrians and hence, there exists a constant conflict between the pedestrians and the vehicles in sharing the limited space available on a road. At intersections, pedestrian crossing behavior is even more complex since the vehicles have very little response time to control the vehicles, particularly in urban areas. All these issues are pointing towards the research work required for studying the road crossing behavior of pedestrians at urban intersections. The main motivation of this study is to investigate the changes in pedestrian road crossing behavior of an intersection under mixed traffic conditions before and after signal installation. For this purpose, traffic and pedestrian data were collected from an intersection located in Mangalore city. Different parameters like age, gender, crossing patterns, crossing times, waiting times and crossing speeds of pedestrians, speed and types of vehicles and vehicular flows were extracted from the videos. The study analysis shows that majority of the pedestrians chooses one-step crossing after signal installation since they get sufficient gap to cross the road during the red phase of the signal provided for vehicles. The waiting times of the pedestrians were increased after installation of the signal since pedestrians have to wait for gaps until the vehicles get dissipated during the green phase. The 15th percentile crossing speed of pedestrians for both the scenarios were lesser than the crossing speed (1.2 m/s) used in pedestrian facility design as per Indian Road Congress (IRC 103). Critical gap of pedestrians has reduced marginally due to the decrease in crossing speeds of pedestrians after installation of the signal. A model was developed considering pedestrian gap size as the dependent variable and pedestrian and traffic characteristics as the independent variables using multiple linear regression (MLR) technique. A total of 468 and 333 accepted gaps of pedestrians were used for modeling the before and after scenarios, respectively. It was found that pedestrian jaywalking behavior is reduced after installation of the signal. The study concludes that after signal installation the factors such as traffic volume, average speed of vehicles and age-group play a predominant role in estimating the pedestrian gap acceptance. This study will be useful for understanding the complex pedestrian road crossing behavior at intersections under mixed traffic conditions. The findings of this paper have great implications for designing pedestrian facilities and also, for devising traffic management measures for pedestrian safety.