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1.
This study aims at predicting Carbon monoxide (CO) emission rate as well as carboxyhaemoglobin (HbCO) levelsin Al-Ain City, United Arab Emirates (UAE). Also, several mathematical models are proposed for estimating both CO emission and HbCO levels. These models yield excellent agreements between observed and predicted data and can be easily coupled with atmospheric models. Carbon monoxide exposure from motor vehicles were measured over a 3-month period from September to December 1995 at three locations in the UAE. The study is based on a sample of 148 cars. The data revealed that the major characteristics of the cars surveyed were as follows: 69.5% of the cars were Japanese, 74.3% of the cars were 5 years old; 41% of the car was range rover or four-wheel-drive car, which indicates a higher proportion of powerful cars; 58.8% was used special fuel; 51.4% had regular maintenance for their cars and 52% of the cars had 4 cylinder engine capacity. Carboxyhaemoglobin (HbCO) levels in the UAE were predicted for 1-hour (1.720 ppm) and 8-hour (8.106 ppm) exposure times. Also, on an average driving of 80 km hr–1 per day, the CO emission rate was found to be 8.729 ppm. These findings indicate that the mean 1-hour and 8-hour Carboxyhaemoglobin (HbCO) levels do not exceed the permissible standards recommended by the WHO. Additionally, the results of stepwise multiple regression analyses revealed that the factors, such as, type of car, size of cylinder, size of car, and maintaining service of the car exerted the greatest influence on the amount and concentration of pollutant emission produced by car exhaust.  相似文献   

2.

Objectives

The aim of this study was to investigate the impact of motorcycle to car transitioning and urbanisation on traffic injury rates in Thailand.

Design

Analysis of two consecutive surveys of a large national cohort study.

Setting

Thailand.

Participants

The data derived from 57,154 Thai Cohort Study (TCS) participants who provided relevant data on both the 2005 and 2009 surveys.

Primary and secondary outcome measures

Motorcycle and car traffic crash injury self-reported in 2009, with twelve months’ recall.

Results

In 2009, 5608(10%) participants reported a traffic crash injury. Most crashes involved a motorcycle (74%). Car access increased and motorcycle use decreased between 2005 and 2009. Among those who used a motorcycle at both time points, traffic injury incidence was 2.8 times greater compared to those who did not use a motorcycle at either time point. Multivariable logistic regression models were used to test longitudinal and cross sectional factors associated with traffic crash injury: in the adjusted model, cars were negatively and motorcycles positively associated with injury. Living in an urban area was not injury protective in the adjusted model of traffic crash injury.

Conclusions

Ongoing urbanisation in Thailand can be expected to lead to further reductions in road traffic injuries based on transition from motorcycles to cars in urban areas. Cities, however, do not provide an intrinsically safer traffic environment. To accommodate a safe transition to car use in Thailand, traffic infrastructural changes anticipating the growing car density in urban areas is warranted.  相似文献   

3.
Traffic in one direction on a multilane highway is considered, and a general expression for the number of cars which pass a car travelling at a given velocity, as well as the number of cars which the given car passes, is derived for the case when the speeds of different cars are distributed in some arbitrary manner. Closed expressions are derived and discussed for a rectangular distribution. Each passing by another car or of another car is considered as a distracting stimulus which affects the reaction times of the driver. Using previously derived expressions for the safe speed as a function of reaction times, expressions for the safe average speed are derived, in terms of the volume of traffic and of the spread of the distribution of speeds.  相似文献   

4.
The changing material composition of cars represents a challenge for future recycling of end‐of‐life vehicles (ELVs). Particularly, as current recycling targets are based solely on mass, critical metals increasingly used in cars might be lost during recycling processes, due to their small mass compared to bulk metals such as Fe and Al. We investigate a complementary indicator to material value in passenger vehicles based on exergy. The indicator is called thermodynamic rarity and represents the exergy cost (GJ) needed for producing a given material from bare rock to the market. According to our results, the thermodynamic rarity of critical metals used in cars, in most cases, supersedes that of the bulk metals that are the current focus of ELV recycling. While Fe, Al, and Cu account for more than 90% of the car's metal content, they only represent 60% of the total rarity of a car. In contrast, while Mo, Co, Nb, and Ni account for less than 1% of the car's metal content, their contribution to the car's rarity is larger than 7%. Rarity increases with the electrification level due to the greater amount of critical metals used; specifically, due to an increased use of (1) Al alloys are mainly used in the car's body‐in‐white of electric cars for light‐weighting purposes, (2) Cu in car electronics, and (3) Co, Li, Ni, and rare earth metals (La, Nd, and Pr) in Li‐ion and NiMH batteries.  相似文献   

5.

Background

Previous studies suggest that humans can acquire immunity to reinfection with schistosomes, most probably due to immunologic mechanisms acquired after exposure to dying schistosome worms.

Methodology/Principal Findings

We followed longitudinally two cohorts of adult males occupationally exposed to Schistosoma mansoni by washing cars (120 men) or harvesting sand (53 men) in Lake Victoria. Men were treated with praziquantel each time S. mansoni infection was detected. In car washers, a significant increase in resistance to reinfection, as measured by the number of cars washed between cure and reinfection, was observed after the car washers had experienced, on average, seven cures. In the car washers who developed resistance, the level of schistosome-specific IgE increased between baseline and the time at which development of resistance was first evidenced. In the sand harvesters, a significant increase in resistance, as measured by the number of days worked in the lake between cure and reinfection, was observed after only two cures. History of exposure to S. mansoni differed between the two cohorts, with the majority of sand harvesters being lifelong residents of a village endemic for S. mansoni and the majority of car washers having little exposure to the lake before they began washing cars. Immune responses at study entry were indicative of more recent infections in car washers and more chronic infections in sand harvesters.

Conclusions/Significance

Resistance to reinfection with S. mansoni can be acquired or augmented by adults after multiple rounds of reinfection and cure, but the rate at which resistance is acquired by this means depends on immunologic status and history of exposure to S. mansoni infection.  相似文献   

6.
OBJECTIVES--To examine whether road traffic in a big city has a direct effect on pulmonary function and respiratory symptoms in children. DESIGN--Cross sectional study. SETTING--Of all 7445 fourth grade children (aged 9-11 years) in Munich, 6537 were examined. Of the children with German nationality and the same residence during the past five years and known exposure data, 4678 questionnaires and 4320 pulmonary function tests could be analysed. MAIN OUTCOME MEASURES--Variables of pulmonary function by forced expiration and respiratory symptoms reported in a questionnaire; census data on car traffic collected in the school district. RESULTS--Density of car traffic ranged from 7000 to 125,000 cars per 24 hours. Multiple regression analysis of peak expiratory flow showed a significant decrease of 0.71% (95% confidence interval 1.08% to 0.33%) per increase of 25,000 cars daily passing through the school district on the main road. Maximum expiratory flow when 25% vital capacity had been expired was decreased by 0.68% (1.11% to 0.25%). In contrast, response to cold air challenge was not increased. The adjusted odds ratio for the cumulative prevalence of recurrent wheezing with the same exposure was 1.08 (1.01 to 1.16). Cumulative prevalence of recurrent dyspnoea was increased, with an odds ratio of 1.10 (1.00 to 1.20). Lifetime prevalence of asthma (odds ratio 1.04; 0.89 to 1.21) and recurrent bronchitis (1.05; 0.98 to 1.12) were not significantly increased. CONCLUSIONS--High rates of road traffic diminish forced expiratory flow and increase respiratory symptoms in children.  相似文献   

7.
The horizontally polarizing surface parts of shiny black cars (the reflection-polarization characteristics of which are similar to those of water surfaces) attract water-leaving polarotactic insects. Thus, shiny black cars are typical sources of polarized light pollution endangering water-leaving insects. A new fashion fad is to make car-bodies matt black or grey. Since rough (matt) surfaces depolarize the reflected light, one of the ways of reducing polarized light pollution is to make matt the concerned surface. Consequently, matt black/grey cars may not induce polarized light pollution, which would be an advantageous feature for environmental protection. To test this idea, we performed field experiments with horizontal shiny and matt black car-body surfaces laid on the ground. Using imaging polarimetry, in multiple-choice field experiments we investigated the attractiveness of these test surfaces to various water-leaving polarotactic insects and obtained the following results: (i) The attractiveness of black car-bodies to polarotactic insects depends in complex manner on the surface roughness (shiny, matt) and species (mayflies, dolichopodids, tabanids). (ii) Non-expectedly, the matt dark grey car finish is much more attractive to mayflies (being endangered and protected in many countries) than matt black finish. (iii) The polarized light pollution of shiny black cars usually cannot be reduced with the use of matt painting. On the basis of these, our two novel findings are that (a) matt car-paints are highly polarization reflecting, and (b) these matt paints are not suitable to repel polarotactic insects. Hence, the recent technology used to make matt the car-bodies cannot eliminate or even can enhance the attractiveness of black/grey cars to water-leaving insects. Thus, changing shiny black car painting to matt one is a disadvantageous fashion fad concerning the reduction of polarized light pollution of black vehicles.  相似文献   

8.
A multi-car elevator system is an elevator system that has more than one car installed in each elevator shaft. This system enables us to improve the transportation capability without increasing the occupied floor space. The primary purpose of this study is to consider the group control problem of operating cars efficiently without collision nor reversal in a multi-car elevator system, based on a detailed and realistic model where floor stoppage time of cars cannot be known in advance. In the context of elevator systems, reversal means that a car travels in the direction opposite to the desired direction of on-board passengers, which is prohibited because it makes passengers uncomfortable. We first propose an optimization-based collision and reversal avoidance method to operate cars in the same shaft. Next, we construct simple methods to allocate calls to individual cars under immediate and delayed guidance policies. Under the immediate guidance policy a call is allocated to a car immediately after it is registered, while under the delayed guidance policy the allocation may be changed until it is actually served. The effectiveness of the proposed group control method is examined by computer simulation.  相似文献   

9.
Stone martens (Martes foina) commonly climb into car engine compartments, where they may tear up heat and noise insulation mats or bite into rubber or plastic components. This brings martens into conflict with humans. Although various hypotheses have been suggested as to why martens damage cars once inside them, it is not known what makes martens associate with cars in the first place. We radio-tracked 13 urban stone martens over a 2-year period in Luxembourg to determine the context in which martens visit parked cars at night. Martens associated with cars most frequently in spring and early summer, when their activity on roads was highest and when they systematically patrolled and scent-marked cars. Most visits to cars were of short duration. We suggest, therefore, that the main factor promoting marten–car contact is territorial behaviour, rather than either the thermal benefits to be gained from proximity to recently used engines or the need for a safe environment for resting, hiding or food consumption.  相似文献   

10.
Three hundred and seventy-five families replied to a questionnaire about the use of their disabled children''s wheelchairs. Many problems were found, such as difficulty in folding the chair and placing it in the car boot and difficulty in using pulbic transport. These families need adequate guidance to anticipate and deal with the problems. Provision of a wheelchair does not solve the mobility problems. The parents are faced with the task of transporting both the disabled child and the wheelchair whenever they want to use their own car or public transport. Ease of folding and lightness are important criteria for wheelchairs carried by cars. Parents need careful guidance about selecting suitable cars and also need to be shown how to lift the chairs without endangering their backs. Such advice should be provided by every wheelchair clinic and assessment and rehabilitation certre.  相似文献   

11.
幸丽君  杜赛南  仝照民  张蕾 《生态学报》2023,43(13):5370-5382
从环境正义视阈出发,重点关注选择步行和私家车出行的居民群体,采用高斯两步移动搜索(2SFCA)模型和基尼系数测度2000-2018年武汉市中心城区公园绿地可达性和公平性的时空差异,并运用梯度提升决策树(GBDT)模型进一步探析交通因素、用地因素和社会经济因素对公园绿地可达性的非线性影响及其阈值效应,以期为公平导向下的城市绿地规划提供相关参考。结果表明:(1)研究时段内公园绿地供给与需求均呈现较快的增长,居民出行成本在逐渐降低;(2)居民选择两种交通方式出行的公园绿地可达性高值区域均呈现扩大趋势,主要分布在长江两岸、湖泊和大型风景区周围,但是不同时期步行方式可达性低值区域均多于车行;同时,基尼系数显示研究时段内两种交通出行的居民享受公园绿地服务的机会均不公平,且步行可达不公平程度远大于车行;(3)用地结构和社会经济因素对不同时期公园绿地服务可达性存在协同性影响,而交通因素是不同交通方式出行可达性存在差异的主要原因;(4)非线性关系图显示关键变量的阈值效应能够为城市绿地精细化规划与管理提供量化参考。  相似文献   

12.
We study a simple traffic model with a non-signalized road intersection. In this model the car arriving from the right has precedence. The vehicle dynamics far from the crossing are governed by the rules introduced by Nagel and Paczuski, which define how drivers behave when braking or accelerating. We measure the average velocity of the ensemble of cars and its flow as a function of the density of cars on the roadway. An additional set of rules is defined to describe the dynamics at the intersection assuming a fraction of drivers that do not obey the rule of precedence. This problem is treated within a game-theory framework, where the drivers that obey the rule are cooperators and those who ignore it are defectors. We study the consequences of these behaviors as a function of the fraction of cooperators and defectors. The results show that cooperation is the best strategy because it maximizes the flow of vehicles and minimizes the number of accidents. A rather paradoxical effect is observed: for any percentage of defectors the number of accidents is larger when the density of cars is low because of the higher average velocity.  相似文献   

13.
OBJECTIVE--To define usual colour and site of storage of visiting bags in general practitioners'' cars and to investigate effect of these variables on temperature inside bag. DESIGN--Questionnaire to general practitioners; serial temperature measurements from paired black visiting bags at different storage sites and from bags of different colour. SETTING--South Devon coastal town during May and June. SUBJECTS--200 general practitioners, of whom 145 returned legible questionnaires. MAIN OUTCOME MEASURES--Bag colour, duration and site of storage, temperature inside black bags at defined storage sites, and effects of bag colour on internal temperature. RESULTS--111 (77%) of the general practitioners carried a black visiting bag, and 76 kept their bag in their car all day. The bag was coolest in the car boot, but irrespective of storage site, maximum internal temperature of the bag was always over 25 degrees C and reached up to 80 degrees C. Spraying a black bag silver significantly reduced the bag''s internal temperature (mean difference 8.37 degrees C (95% confidence interval 6.68 to 9.86 degrees C) df = 59, t = 10.29, P < 0.001). CONCLUSIONS--General practitioners should use a silver coloured visiting bag; when visiting, they should store it in their car boot; at other times they should remove it to a cooler site.  相似文献   

14.
Understanding the influence of consumer behavior on the life cycle of products can provide further insights into effective mitigation strategies. Here, we developed a stochastic model to quantify the influence of consumer behavior on midpoint and endpoint impacts of European passenger car tires. The life cycle included resource extraction, production, use, and end-of-life stages of a passenger car tire with a functional unit of driving 50,000 km. The combined influence of variability in the lifetime, rolling resistance, size and inflation pressure of the tire, and mass and engine efficiency of the car on a range of environmental footprints was assessed via Monte Carlo simulations. We found that differences in consumer behavior can change the environmental impacts of tires with a factor 1.6 to 2.1 (95th/5th percentile). Environmental savings over the life cycle of tires are effectively achievable by stimulating the use of smaller cars and fuel-efficient tires with longer lifetimes. We found that a shift in consumer behavior specifically related to tires can result in mitigations of the tire's life cycle impacts ranging from 13% for human toxicity to 26% for climate change. Our findings show that a detailed variability analysis can provide case-specific and realistic recommendations to mitigate environmental footprints.  相似文献   

15.

Background

A woman of reproductive age often harbors a small number of foreign cells, referred to as microchimerism: a preexisting population of cells acquired during fetal life from her own mother, and newly acquired populations from her pregnancies. An intriguing question is whether the population of cells from her own mother can influence either maternal health during pregnancy and/or the next generation (grandchildren).

Methodology/Principal Findings

Microchimerism from a woman''s (i.e. proband''s) own mother (mother-of-the-proband, MP) was studied in peripheral blood samples from women followed longitudinally during pregnancy who were confirmed to have uncomplicated obstetric outcomes. Women with preeclampsia were studied at the time of diagnosis and comparison made to women with healthy pregnancies matched for parity and gestational age. Participants and family members were HLA-genotyped for DRB1, DQA1, and DQB1 loci. An HLA polymorphism unique to the woman''s mother was identified, and a panel of HLA-specific quantitative PCR assays was employed to identify and quantify microchimerism. Microchimerism from the MP was identified during normal, uncomplicated pregnancy, with a peak concentration in the third trimester. The likelihood of detection increased with advancing gestational age. For each advancing trimester, there was a 12.7-fold increase in the probability of detecting microchimerism relative to the prior trimester, 95% confidence intervals 3.2, 50.3, p<0.001. None of the women with preeclampsia, compared with 30% of matched healthy women, had microchimerism (p = 0.03).

Conclusions/Significance

These results show that microchimerism from a woman''s own mother is detectable in normal pregnancy and diminished in preeclampsia, supporting the previously unexplored hypothesis that MP microchimerism may be a marker reflecting healthy maternal adaptation to pregnancy.  相似文献   

16.
This article sets out an approach to researching sociocultural aspects of product service systems (PSSs) consumption in consumer markets. PSSs are relevant to industrial ecology given that they may form part of the mix of innovations that move society toward more‐sustainable material and energy flows. The article uses two contrasting case studies drawing on ethnographic analysis: Harley Davidson motorcycles and the Zipcar car club. The first is a case of consumption involving ownership; the second is one of consumption without ownership. The analysis draws on consumer culture theory to explicate the sociocultural, experiential, symbolic, and ideological aspects of these case studies, focusing on product ownership. The article shows that ownership of Harley Davidson motorcycles enables riders to identify with a brand community and to define themselves. Owners appropriate their motorcycles through customization. In contrast, Zipcar users resist the company's attempts to involve them in a brand community, see use of car sharing as a temporary fix, and even fear contamination from shared use of cars. We conclude that iconic products such as Harley Davidson motorcycles create emotional attachment and can challenge PSS propositions. But we also suggest that somewhat standardized products may present similar difficulties. Knowing more about sociocultural aspects of PSSs may help designers overcome these difficulties.  相似文献   

17.
Previous studies have shown that a female dunnock Prunella modularis increases her reproductive success on average by copulating with more than one male resident on her territory and thereby obtaining extra help in raising offspring. Here we document behavior by females that affects which males copulate with them. During her period of receptivity to copulation, a female in a territory shared by two males often left the dominant (or alpha) male, which guarded her most of the time, and approached the subordinate (or beta) male when he sang. A female's responses to individual males thus tend to increase her own reproductive success by increasing her chances for copulation with both males sharing her territory. Playbacks of tape-recorded songs in the field showed that females approached only songs of resident males, not neighbors. They can therefore discriminate individual males by their songs alone, a capability not previously established for female songbirds. Despite intensive guarding of females by males, mating success among male dunnocks depends in part on female choice.  相似文献   

18.
AIMS: To describe the tall stature and its possible underlying mechanism in a Caucasian girl (age 12 years and 10 months) with 46,XX (28%)/47,XXX (72%) mosaicism and to identify the parental origin of her extra X chromosome. METHODS: The fasting glucose-to-insulin ratio was studied. The karyotypes of the girl and her parents as well as the presence of SHOX copies and the parental origin of her extra X chromosome were assessed. RESULTS: Clinical examination revealed a tall stature and severe acne, and endocrinological/metabolic assessment revealed insulin resistance. Fluorescence in situ hybridization cytogenetic analysis depicted the presence of three SHOX genes in the 47,XXX cell line of the patient. Karyotyping of her parents showed a normal 46,XX karyotype in the mother and 46,XY(93%)/47,XXY(7%) Klinefelter mosaicism in the father. However, DNA analysis unequivocally showed maternal origin of the extra X chromosome of the patient. CONCLUSIONS: This report suggests that SHOX gene triplication may produce a tall stature, even in the presence of preserved ovarian function. X triplication might predispose to insulin resistance and behavioral disorders.  相似文献   

19.
All deaths from road accidents in certain areas and periods were studied. Analysis of 224 deaths to car occupants from collisions between cars and lorries showed that such accidents were the commonest cause of death for car occupants on motorways and link roads. The impacts were such that relatively poor protection could be given by occupant restraint systems. Collisions of cars into the rear of lorries caused the most severe injuries; most of these accidents occurred at night.The traffic characteristics of cars and lorries are largely incompatible and increase the likelihood of collisions and of extremely severe injuries to car occupants. Some reduction in deaths may be expected from making lorries more conspicuous and eliminating the rear overhang. More fundamental measures are segregation of lorries from cars and return of traffic to railways.  相似文献   

20.
An important issue in autonomous vehicle development is the transition phase between autonomous and manual driving. Here, we focused on a vibrotactile signal that warns the driver 1 min before they must take over. Our goal was to design a signal detectable by, and satisfactory for, all drivers. After listing parameters defining a vibrotactile signal, we performed a design‐of‐experiments study to select 16 signals for evaluation by 80 participants of different ages, body mass indexes, and genders. In a car on the road, autonomous driving conditions were simulated with the participant in the front passenger seat, who performed a task unrelated to driving. Whenever the participant detected a signal, they gave a satisfaction score. Modeling enabled us to evaluate the effects of the signal parameters and participant characteristics on satisfaction and detection. Moreover, we obtained specifications for the design of a tactile signal according to our two criteria.

Practical applications

To the best of our knowledge, this is the first study to focus on the sensory aspect of a tactile signal in a car environment. Both functional (i.e., signal detection) and hedonic aspects are important. We investigated the influence of gender, age, and body mass index of the participants on signal detection and satisfaction score, and optimized the satisfaction score under detection constraints. We use a 3‐point method to reach those two goals:
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