Impact of grade separator on pedestrian risk taking behavior

Pedestrians on Delhi roads are often exposed to high risks. This is because the basic needs of pedestrians are not recognized as a part of the urban transport infrastructure improvement projects in Delhi. Rather, an ever increasing number of cars and motorized two-wheelers encourage the construction of large numbers of flyovers/grade separators to facilitate signal free movement for motorized vehicles, exposing pedestrians to greater risk. This paper describes the statistical analysis of pedestrian risk taking behavior while crossing the road, before and after the construction of a grade separator at an intersection of Delhi. A significant number of pedestrians are willing to take risks in both before and after situations. The results indicate that absence of signals make pedestrians behave independently, leading to increased variability in their risk taking behavior. Variability in the speeds of all categories of vehicles has increased after the construction of grade separators. After the construction of the grade separator, the waiting time of pedestrians at the starting point of crossing has increased and the correlation between waiting times and gaps accepted by pedestrians show that after certain time of waiting, pedestrians become impatient and accepts smaller gap size to cross the road. A Logistic regression model is fitted by assuming that the probability of road crossing by pedestrians depends on the gap size (in s) between pedestrian and conflicting vehicles, sex, age, type of pedestrians (single or in a group) and type of conflicting vehicles. The results of Logistic regression explained that before the construction of the grade separator the probability of road crossing by the pedestrian depends on only the gap size parameter; however after the construction of the grade separator, other parameters become significant in determining pedestrian risk taking behavior.     

Optimum dispersion map profile for a stable DM soliton system

This paper investigates the optimum dispersion map profile for stable DM soliton formation and propagation. Results of numerical analysis suggest that anomalous–normal–normal–anomalous (A-N-N-A) profile is the most suitable one for a dispersion map with perfect dispersion compensation. DM soliton stability and propagation behavior has been further explored for an undercompensated A-N-N-A profile which increases the distance for stable propagation but requires a positive initial chirp. The stability region has been identified for such DM links in the parametric space of residual dispersion and initial chirp. The study of DM soliton interaction and collision dynamics indicates that a DM soliton formed in such stable parametric space offers improved spectral efficiency as compared to the fundamental solitons.     

A Cost-Effective Method of Aerosolizing Dry Powdered Nanoparticles

The ability to produce nanoscale aerosols from dry powdered material is needed for studies of the toxicity and environmental transformation and fate of manufactured nanoparticles. Wet aerosol generation methods can alter particle chemistry, while dry methods often cannot produce truly nanoscale aerosols. We have developed a cost-effective dry dispersion technique for manufactured nanoparticles and have demonstrated its use with C₆₀ fullerene, TiO₂, and CeO₂. The system disperses dry powders to create aerosols with mode diameters below 100 nm. Average mode and median diameters for each of the tested manufactured nanoparticles are 91 and 107 nm for C₆₀, 65 and 77 nm for TiO₂, and 40 and 43 nm for CeO₂. All aerosols exhibit right-skewed unimodal distributions and irregular morphology. Aerosol mass concentrations produced by the dispersion system vary linearly with the mass of nanomaterial loaded into it and are of a magnitude appropriate for inhalation nanotoxicology studies. This work demonstrates the ability of a simple device to produce nanoscale aerosols from powdered engineered nanoparticles.

Copyright 2013 American Association for Aerosol Research     

用微波和声波发生器加紫草根根部树皮进行非常规天然染色

1　前　言　　天然染料是一种从植物物质和动物剩余物中提取的染料。它们被认为是一种媒染染料 ,需要包含一种或多种金属盐 ,如 :铝、铁、铬、铜、锡和其他金属以保证在日照和洗涤条件下有理想的颜色牢度。这些金属盐结合染料形成染料聚集物 ,它不能很容易地从织物上去除。这些天然染料被认为是有环境亲和力的 ,采用的金属盐通常是安全的 ,而不是铜或铬。随着合成染料的出现 ,合成染料的不利因素 ,影响到染料领域。在 1 9世纪中叶就开始使用天然染料。第一次由于合成染料的出现 ,人和自然间的亲情遭到了破坏。除了在很小的地方使用外 ,天然…     

Rheological Properties of Sonicated Guar,Xanthan and Pectin Dispersions

The influence of high intensity ultrasound on the rheological characteristics of guar, xanthan, and pectin dispersions was investigated. Guar 1%, xanthan 1% and pectin 2% (w/v) dispersions were sonicated at varying intensity levels of 3.7, 6.3, 8.1, and 10.1 W/cm² for 5 min at 25^oC. Significant differences were observed in the rheological characteristics of each sonicated hydrocolloid dispersion studied. Sonication affected the consistency index (k), flow behaviour index (n) and complex power law constants (a and b). No recovery was observed in the structure breakdown after a 24-h storage period. Changes in the rheological properties of guar and pectin dispersions were significantly higher than that of xanthan dispersions.     

Solar heating of a fluid through a semi-transparent plate: A simple transient analysis

A straightforward transient analysis for the heating of a fluid through a semi-transparent plate is presented in this note. It is concluded that the present theory also validates the experimental results of Lumsdaine.     

Enhancement of daily yield in a double basin solar still

A straightforward transient analysis of a double basin solar still has been presented, incorporating the effect of water flow over the glass cover and flow of hot water in the lower basin by a flat plate collector. It is concluded that, for higher daily yield, the collector should be disconnected from the still during off-sunshine hours.     

Distributed AEC databases for collaborative design

The Architecture, Engineering and Construction (AEC) design process for a facility involves participation of many design specialists. These participants are architects, engineers (structural, mechanical and electrical) and contractors, who may be independent design professionals or design teams within an organization. From the viewpoint of information processing, two characteristic features distinguish the AEC design process from many other design domains. Firstly, there is a massive volume of design data involved in the design of each of its component specialties. Secondly, the specialization of the disciplines themselves warrant substantial autonomy. For design automation, this autonomy should be realized without sacrificing the collaborative nature of the multidisciplinary AEC design process. We propose autonomous AEC databases to deal with the first issue, and a global constraint maintenance mechanism for the second. Autonomous design databases can support the existing local applications in architectural, structural and mechanical engineering, and construction domains. However, a set of inter-disciplinary constraints needs to be enforced to ensure spatial and functional consistency of the design. A global constraint checking mechanism frees designers from the burden of keeping track of various design changes that may result in cross-functional conflicts. In this paper, we discuss the relevant issues for constraint management on distributed AEC databases. Although specific AEC examples will be used, the presentation is general enough to be applicable to other design domains, such as VLSI and manufacturing.     

Potential applications of polymeric microsphere suspension as subcutaneous depot for insulin

The objective of this investigation was to develop an injectable, depot-forming drug delivery system for insulin based on microparticle technology to maintain constant plasma drug concentrations over prolonged period of time for the effective control blood sugar levels. Formulations were optimized with two well-characterized biodegradable polymers namely, poly(DL-lactide-co-glycolide) and poly-epsilon-caprolactone and evaluated in vitro for physicochemical characteristics, drug release in phosphate buffered saline (pH 7.4), and evaluated in vivo in streptozotocin-induced hypoglycemic rats. With a large volume of internal aqueous phase during w/o/w double emulsion solvent evaporation process and high molecular weight of the polymers used, we could not achieve high drug capture and precise control over subsequent release within the study period of 60 days. However, this investigation revealed that upon subcutaneous injection, the biodegradable depot-forming polymeric microspheres controlled the drug release and plasma sugar levels more efficiently than plain insulin injection. Preliminary pharmacokinetic evaluation exhibited steady plasma insulin concentration during the study period. These formulations, with their reduced frequency of administration and better control over drug disposition, may provide an economic benefit to the user compared with products currently available for diabetes control.