Voltammetric response of ferroceneboronic acid to diol and phenolic compounds as possible pollutants

A voltammetric determination of possible organic pollutants such as diol and phenolic compounds in water was studied using ferroceneboronic acid (FBA) as a redox-active marker. A cyclic voltammogram of FBA exhibited a pair of oxidation and reduction peaks at 230 and 170 mV at pH 7.0, respectively, while another pair of redox peaks was observed in the presence of diol or phenolic compounds tested. The results were rationalized based on the formation of boronate esters of FBA with the added compounds. The changes in the redox peak currents were dependent on the concentration of the additives, suggesting a usefulness of FBA in the electrochemical determination of these compounds in water.     

Research for MSW flow analysis in developing nations

Developing nations have various problems regarding municipal solid waste (MSW). Therefore, to carry out a systematic review of the MSW problems in the target area and to formulate a well-considered management plan, it is extremely important to understand the present MSW flow in the region. One of the authors participated in the nine solid waste management (SWM) studies in developing nations undertaken under the technical cooperation program of the Japan International Cooperation Agency (JICA). Based on these studies, this paper reviews the results of research in developing countries regarding different MSW streams, the factors that cause the differences, and the elements considered to have the most impact on those streams. This research identifies several issues regarding MSW streams in developing nations. The MSW generation rate per capita in developing countries is generally said to grow in proportion to the GNP. However, the findings of this research show no correlation between the two; instead, there is a relationship between the GNP and the collection rate. To formulate proper future MSW management plans in countries with low collection rates, it is very important to forecast the rates of self-disposed and recycled waste, and their fluctuations. These are affected by urban structure, collection services, etc. Received: January 27, 2000 / Accepted: July 19, 2000     

Point-of-use water disinfection using UV light-emitting diodes to reduce bacterial contamination

The treatment process described in this research explores the impact of exposing water samples containing fecal coliforms to the radiation produced by single ultraviolet (UV) light-emitting diodes (LEDs) operating at 265 nm. UV LEDs are long lasting, compact in size and produce more efficient light output than traditional mercury-vapour bulbs, making them ideal for application in point-of-use disinfection systems, such as in remote areas. In this study, contaminated water samples containing either a pure culture of Escherichia coli or tertiary effluent from the City of Regina Wastewater Treatment Plant were used to study the application and efficiency of using UV LEDs for water disinfection. The results indicate that bacterial inactivation was achieved in a time-dependent manner, with 1- and 2.5-log E. coli reductions in water following 20 and 50 min of UV LED exposure, respectively. Ultraviolet radiation was less effective in reducing coliform bacteria in wastewater samples due to the elevated turbidity levels. Further work remains to be completed to optimize the application of UV LEDs for point-of-use disinfection systems; however, the results from this study support that bacterial inactivation using UV LEDs is possible, meriting further future technological development of the LEDs.     

Systematic Biases in Measured PM10 Values with U.S. Environmental Protection Agency-Approved Samplers at Owens Lake,California

ABSTRACT

From 1993 through 1998, Wedding or Graseby high-volume PM₁₀ samplers were collocated with tapered element oscillating microbalance (TEOM) samplers at three sites at Owens Lake, CA. The study area is heavily impacted by windblown dust from the dry Owens Lake bed, which was exposed as a result of water diversions to the city of Los Angeles. A dichotomous (dichot) sampler and three collocated Partisol samplers were added in 1995 and 1999, respectively. U.S. Environmental Protection Agency (EPA) operating procedures were followed for all samplers, except for a Wedding sampler that was not cleaned for the purpose of this study. On average, the TEOM and Partisol samplers agreed to within 6%, and the dichot, Graseby, and Wedding samplers measured lower PM₁₀ concentrations by about 10, 25, and 35%, respectively. Surprisingly, the “clean” Wedding sampler consistently measured the same concentration as the “dirty” Wedding sampler through 85 runs without cleaning. The finding that the Graseby and Wedding high-volume PM₁₀ samplers read consistently lower than the TEOM, Partisol, and dichot samplers at Owens Lake is consistent with PM₁₀ sampler comparisons done in other fugitive dust areas, and with wind tunnel tests showing that sampler cut points can be significantly lower than 10 um under certain conditions. However, these results are opposite of the bias found for TEOM samplers in areas that have significant amounts of volatile particles, where the TEOM reads low due to the vaporization of particles on the TEOM's heated filter. Coarse particles like fugitive dust are relatively unaffected by the filter temperature. This study shows that in the absence of volatile particles and in the presence of fugitive dust, a different systematic bias of up to 35% exists between samplers using dichot inlets and high-volume samplers, which may cause the Graseby and Wedding PM₁₀ samplers to undermeasure PM₁₀ by up to 35% when the PM₁₀ is predominantly from coarse particulate sources.     

Study on dechlorination technology for municipal waste plastics containing polyvinyl chloride and polyethylene terephthalate

It is necessary to remove chlorine efficiently from municipal waste plastics (MWP) that contain polyvinyl chloride (PVC) and other plastics containing chlorine. In this article we consider thermal degradation liquefaction technology. In Japan, the chlorine content of reclamation oil products must be kept below 100 ppm owing to the quality standard for pyrolysis oil. Liquefaction dechlorination technology for MWP is still an important issue to study. The twin-screw extruder that has been developed as dechlorination technology for blast furnaces and coke ovens has a shorter residence time for dechlorination than other dechlorination technologies. In this article, we used a single-screw extruder for the dechlorination process because it also has a short residence time. Experiments on the dechlorination process were carried out by using a single-screw extruder to assess its dechlorination performance. Practical use of the single-screw was demonstrated by the operation of a commercial oil reclamation plant operated by Sapporo Plastic Recycle Co., Ltd. (SPR). Moreover, an investigation of cascade recycling was carried out in 2008 in which material recycle wastes were mixed with MWP and processed by chemical recycling (liquefaction). It was demonstrated that cascade recycling is an efficient recycling combination and contributes to local feedstock recycling. However, it was shown that MR wastes affect the quality of the reclamation oil when they make up more than 40% of the feed mix. If the quantity of MR wastes is kept below 40%, the reclamation oil is able to meet the quality standard. The SPR plant can be operated safely and in a stable manner.     

Improvement of driver active interventions during automated driving by displaying trajectory pointers—A driving simulator study

Abstract

Objective: The handover of vehicle control from automated to manual operation is a critical aspect of interaction between drivers and automated driving systems (ADS). In some cases, it is possible that the ADS may fail to detect an object. In this event, the driver must be aware of the situation and resume control of the vehicle without assistance from the system. Consequently, the driver must fulfill the following 2 main roles while driving: (1) monitor the vehicle trajectory and surrounding traffic environment and (2) actively take over vehicle control if the driver identifies a potential issue along the trajectory. An effective human–machine interface (HMI) is required that enables the driver to fulfill these roles. This article proposes an HMI that constantly indicates the future position of the vehicle.

Methods: This research used the Toyota Dynamic Driving Simulator to evaluate the effect of the proposed HMI and compares the proposed HMI with an HMI that notifies the driver when the vehicle trajectory changes. A total of 48 test subjects were divided into 2 groups of 24: One group used the HMI that constantly indicated the future position of the vehicle and the other group used the HMI that provided information when the vehicle trajectory changed.

The following instructions were given to the test subjects: (1) to not hold the steering wheel and to allow the vehicle to drive itself, (2) to constantly monitor the surrounding traffic environment because the functions of the ADS are limited, and (3) to take over driving if necessary.

The driving simulator experiments were composed of an initial 10-min acclimatization period and a 10-min evaluation period. Approximately 10?min after the start of the evaluation period, a scenario occurred in which the ADS failed to detect an object on the vehicle trajectory, potentially resulting in a collision if the driver did not actively take over control and manually avoid the object.

Results: The collision avoidance rate of the HMI that constantly indicated the future position of the vehicle was higher than that of the HMI that notified the driver of trajectory changes, χ² = 6.38, P < .05. The steering wheel hands-on and steering override timings were also faster with the proposed HMI (t test; P < .05).

Conclusions: This research confirmed that constantly indicating the position of the vehicle several seconds in the future facilitates active driver intervention when an ADS is in operation.     

Influence of oxygen flow rate and compost addition on reduction of organic matter in aerated waste layer containing mainly incineration residue

Landfilling municipal solid waste incineration (MSWI) residue alkalizes the waste layer, causing a subsequent decrease in microbial activity and a delay in the decomposition of organic matter. In this study, efficiencies of neutralization of the leachate and organic matter decomposition in the waste layer in a column filled with MSWI residue using aeration and compost addition were evaluated.Total organic carbon (TOC) reduction in the waste layer is large at high oxygen flow rate (OFR). To effectively accelerate TOC reduction in the waste layer to which compost was added, a high OFR exceeding that by natural ventilation was required. At day 65, the pH of the leachate when OFR was above 102mol-O2/(day·m3) was lower than that when OFR was below 101mol-O2/(day·m3). At the same OFR, the pH of waste sample was lower than that of waste sample with compost. Although leachate neutralization could be affected by compost addition, TOC reduction in the waste layer became rather small. It is possible that humic substances in compost prevent the decomposition of TOC in MSWI residue.     

Damselfly females prefer hot males: higher courtship success in males in sunspots

Males of some territorial calopterygid damselflies show an elaborate courtship display that involves high-frequency wing-beats directed toward an incoming female. Although it has been suggested that female mate preference is based on some characteristics of male’s courtship display, it is unclear whether the courtship display varies between males or is influenced by environmental conditions. We combined two recent technologies, thermographic imaging and high-speed digital videography, to show that the wing-beat frequency during courtship (i.e., courtship intensity) in a damselfly, Mnais costalis, is correlated with thorax temperature. Our data indicated that (1) male thorax temperature was associated with solar exposure in his territory, (2) environmentally derived thermal gain enhanced courtship intensity, (3) hotter males were more likely to copulate than others, and (4) female thorax temperature during oviposition within a territory was associated with solar exposure. Males with territories that have longer exposure to sun spots are expected to attain higher thorax temperatures for longer and so are able to successfully court more females. We suggest that females benefit from mating with hot males because they will be on a warmer territory while ovipositing. Hot males might also have greater mate guarding ability, and/or eggs may develop faster in warmer territories.     

Carbamoyl phosphate synthetase I deficiency: molecular genetic findings and prenatal diagnosis

We report a Japanese boy who died at Day 28 of life because of severe carbamoyl phosphate synthetase I (CPS1) deficiency that was proven by enzyme assay. By analysis of cDNA and genomic DNA, he was shown to be a compound heterozygote with two point mutations of the CPS1 gene, 840G>C leading to an aberrant splicing and 1123C>T (predicting Q375X). The 840G>C was a mutation described in another Japanese family. Since his parents carried each mutation heterozygously, we performed prenatal diagnosis at 16 weeks of his mother's next gestation by multiplex PCR and melting curve analysis in a single capillary containing two-color fluorescent (LC-Red 640 and LC-Red 705) probes on LightCycler. We analyzed genomic DNA extracted from amniotic cells and found that the fetus was homozygous for the wild-type alleles. At term a healthy girl was born without hyperammonemia. Copyright © 2001 John Wiley & Sons, Ltd.     

Spider silk has an ice nucleation activity

Several ice nucleating substances have been identified, which exist in vivo or can be extracted from biological materials. Spider silk, which has a strong ability for water condensation, has also been found to possess an ice nucleation activity. The freezing temperature of water droplets was higher in the presence than in the absence of spider silk. Moreover, by means of environmental scanning electron microscopy, it was observed that the activity is not due to foreign matter attached to the silk but to the silk fibroin itself.