The enhancement of the biodegradability of phenolic solution using preozonation based on high ozone utilization

In this research, the effects of preozonation on the biodegradability of 4-cresol, 4-nitrophenol and 2-chlorophenol solutions were investigated using a new gas-inducing reactor with high ozone utilization rate. The extent of preozonation may be monitored by determining the characteristic ozonation behaviors of preozonized phenolic solutions, such as residual phenolic concentration, ADMI value and ozone gas outlet concentration. Experimental results showed that as the initial phenolic compounds decomposed completely, the ozone gas outlet concentration rapidly increases. In addition, at pH 7, a peak ADMI value appears during the preozonation of 4-cresol and 2-chlorophenol, while for 4-nitrophenol the ADMI value decreases monotonically. Based on the characteristic ozonation behaviors and the ozone utilization rate, three characteristic times were chosen in order to have better control on the extent of preozonation. The effect of preozonation on the biodegradability of preozonized phenolic solution was studied based on these characteristic times. The intermediate products during the preozonation were also identified. The variation of BOD5 is strongly dependent on the accumulation of intermediate products. It is suggested that the best characteristic time is as the rapid increase of ozone gas outlet concentration in this study. The biodegradability (BOD5/COD) of preozonized 4-cresol, 2-chlorophenol and 4-nitrophenol solutions increase to 0.18, 0.26 and 0.33, respectively, for the best characteristic time.     

Safety effects of street lighting on roadway segments: Development of a crash modification function

Objective: Nighttime crashes are overrepresented on the U.S. highway system. Roadway lighting, which provides additional visibility by supplementing vehicle headlights, has been identified as an effective countermeasure to improve nighttime safety. However, the existing literature does not provide a thorough understanding of the effects of street lighting photometric characteristics on nighttime crash occurrence on roadway segments. This study aimed to investigate the relationship between lighting photometric measures and nighttime crash risk on roadway segments and develop a crash modification function/factor (CMF).

Methods: The research team collected horizontal illuminance data on 440 roadway segments between 2 successive signalized intersections in Florida for 2012–2014 and matched 4 years of nighttime and daylight crash data (2011–2014). Random parameter negative binomial models were estimated for both nighttime and daylight crash frequencies. The expected night-to-day crash odds ratio, as an equivalent of CMF, was derived from the fitted models with the correction of estimation variances. The confidence intervals (CIs) of the developed CMF were estimated using the Cox method.

Results: The coefficient of the mean of horizontal illuminance is significantly negative in the nighttime model. The coefficients of the standard deviation of horizontal illuminance are significantly positive and normally distributed in both the nighttime and daylight models. The significance of the standard deviation in the daylight model captures the confounding effects—a high standard deviation correlates with high traffic exposures, poor safety design standards, and low maintenance quality. The CMF based on the expected daylight-to-day odds ratio was developed as an exponential function of the increments and the increment squares of the mean and the standard deviation of horizontal illuminance. Its 95% CIs indicate that the CMF is almost significant over the whole range. Other significant variables contributing to nighttime crash risk include annual average daily traffic, truck percentage, segment length, access density, undivided roads, and urban/city limits.

Conclusions: Horizontal illuminance characteristics have a significant impact on nighttime crash risk on roadway segments. An increase in the mean of horizontal illuminance, indicating an improvement in average lighting level, tends to decrease nighttime crash risk; an increase in the standard deviation, representing a poor uniformity of lighting pattern on a roadway segment, is more likely to raise nighttime crash risk. Because the 2 measures are strongly correlated in a low mean range (<0.44 fc), the 2 photometric measures need to be considered together to interpret the safety effects of lighting patterns. The standard deviation shows better performance in measuring lighting uniformity on a roadway segment than the traditional ratios (max-to-min and mean-to-min). However, a new photometric measure is needed to capture the true lighting pattern influencing driver vision at night.     

Tail loss compromises immunity in the many-lined skink, Eutropis multifasciata

Tail autotomy incurs energetic costs, and thus, a trade-off in resource allocation may lead to compromised immunity in lizards. We tested the hypothesis that tailless lizards will favor constitutive innate immunity responses over an energetically costly inflammatory response. The influence of fasting and colorful ornamentation was also investigated. We experimentally induced tail autotomy in the lizard Eutropis multifasciata and found that inflammation was suppressed by tail loss, but not further affected by fasting; the suppressive effect of colorful ornamentation was manifested only in males, but not in females. Constitutive innate immunity was not affected by any of these factors. As expected, only costly inflammation was compromised, and a less expensive constitutive innate immunity might be favored as a competent first-line defense during energetically demanding periods. After considering conventional trade-offs among tail regeneration and reproduction, further extending these studies to incorporate disease risk and how this influences escape responses to predators and future reproduction would make worthwhile studies.     

How can sports entrepreneurs achieve their corporate sustainable development goals under the COVID-19 epidemic?

Environmental Science and Pollution Research - The present study aimed to explore the opportunities for the sustainable development of professional sports enterprises and events from the...     

How to improve the problem of hotel manpower shortage in the COVID-19 epidemic environment? Exploring the effectiveness of the hotel practice training system

Environmental Science and Pollution Research - This study aimed to examine the role of effective employee training in the sustainable growth and corporate social responsibility of hotels during the...     

Water Resource Protection in Taiwan: An Evaluation of the Taipei Water Management Commission

/ This study evaluates the institutional capacity and performance of the Taipei Water Management Commission. The commission, which manages the Taipei Water Special Area-one of 95 such areas in Taiwan and the only one managed by a supervisory agency-has established a record of water conservation that suggests its utility as a model for managing other protected water resources areas in Taiwan. However, its present institutional structure limits its ability deliver on its mandate. The study identifies a number of problems related to the commission's current institutional structure that need to be addressed if the commission is to serve as a viable model for managing other protected water resource areas in Taiwan.KEY WORDS: Water resources management; Commissions; Institutional capacity; Taiwan