Influence of Oxygenated Fuels on the Emissions from Three Pre-1985 Light-Duty Passenger Vehicles

Tailpipe and evaporative emissions from three pre-1985 passenger motor vehicles operating on an oxygenated blend fuel and on a nonoxygenated base fuel were characterized. Emission data were collected for vehicles operating over the Federal Test Procedure at 40,75, and 90°F to simulate ambient driving conditions. The two fuels tested were a commercial summer grade regular gasoline (the nonoxygenated base fuel) and an oxygenated fuel containing 9.5 percent methyl tert-butyl ether (MTBE), more olefins, and fewer aromatics than the base fuel. The emissions measured were total hydrocarbons (THCs), speciated hydrocarbons, speciated aldehydes, carbon monoxide (CO), oxides of nitrogen (NO_x), benzene, and 1,3-butadiene.

This study showed no pattern of tailpipe regulated emission reduction when oxygenated fuel was used. Tailpipe emissions from the 1984 Buick Century without a catalyst and the 1977 Mustang with catalyst decreased with the MTBE fuel. However, emissions from the 1984 Buick Century and the 1980 Chevrolet Citation, both fitted with catalysts increased. The vehicles emitted more 1,3- butadiene and, in general, more NO_x when operated with the base fuel.

THC, CO, benzene, and 1,3-butadiene emissions from both fuels and all vehicles, in general, decreased with increasing test temperature, whereas NO_x emissions, in general, increased with increasing test temperature. Formaldehyde, acetaldehyde, and total aldehydes also showed a decrease in emissions as test temperature increased. More formaldehyde was emitted when the MTBE fuel was used.

Evaporative, diurnal, and hot soak emissions from the base fuel were greater than those from the MTBE fuel. The evaporated emissions from both fuels increased with increasing test temperatures. Diurnal data indicate that canister conditioning (bringing the evaporative charcoal canister to equilibrium) is required before testing.     

Inspired to perform: A multilevel investigation of antecedents and consequences of thriving at work

Emerging research evidence across multiple industries suggests that thriving at work is critically important for creating sustainable organizational performance. However, we possess little understanding of how factors across different organizational levels stimulate thriving at work. To address this gap, the current study proposes a multilevel model that simultaneously examines contextual and individual factors that facilitate thriving at work and how thriving relates to positive health and overall unit performance. Analysis of data collected from 275 employees, at multiple time periods, and their immediate supervisors, representing 94 work units, revealed that servant leadership and core self‐evaluations are 2 important contextual and individual factors that significantly relate to thriving at work. The results further indicated that thriving positively relates to positive health at the individual level, with this relationship partially mediated by affective commitment. Our results also showed that collective thriving at work positively relates to collective affective commitment, which in turn, positively relates to overall unit performance. Taken together, these findings suggest that work context and individual characteristics play significant roles in facilitating thriving at work and that thriving is an important means by which managers and their organizations can improve employees' positive health and unit performance.     

The Challenges of Incorporating Cultural Ecosystem Services into Environmental Assessment

The ecosystem services concept is used to make explicit the diverse benefits ecosystems provide to people, with the goal of improving assessment and, ultimately, decision-making. Alongside material benefits such as natural resources (e.g., clean water, timber), this concept includes—through the ‘cultural’ category of ecosystem services—diverse non-material benefits that people obtain through interactions with ecosystems (e.g., spiritual inspiration, cultural identity, recreation). Despite the longstanding focus of ecosystem services research on measurement, most cultural ecosystem services have defined measurement and inclusion alongside other more ‘material’ services. This gap in measurement of cultural ecosystem services is a product of several perceived problems, some of which are not real problems and some of which can be mitigated or even solved without undue difficulty. Because of the fractured nature of the literature, these problems continue to plague the discussion of cultural services. In this paper we discuss several such problems, which although they have been addressed singly, have not been brought together in a single discussion. There is a need for a single, accessible treatment of the importance and feasibility of integrating cultural ecosystem services alongside others.     

Diffusive wave models for operational forecasting of channel routing at continental scale

Operational forecast models require robust, computationally efficient, and reliable algorithms. We desire accurate forecasts within the limits of the uncertainties in channel geometry and roughness because the output from these algorithms leads to flood warnings and a variety of water management decisions. The current operational Water Model uses the Muskingum-Cunge method, which does not account for key hydraulic conditions such as flow hysteresis and backwater effects, limiting its ability in situations with pronounced backwater effects. This situation most commonly occurs in low-gradient rivers, near confluences and channel constrictions, coastal regions where the combined actions of tides, storm surges, and wind can cause adverse flow. These situations necessitate a more rigorous flow routing approach such as dynamic or diffusive wave approximation to simulate flow hydraulics accurately. Avoiding the dynamic wave routing due to its extreme computational cost, this work presents two diffusive wave approaches to simulate flow routing in a complex river network. This study reports a comparison of two different diffusive wave models that both use a finite difference solution solved using an implicit Crank–Nicolson (CN) scheme with second-order accuracy in both time and space. The first model applies the CN scheme over three spatial nodes and is referred to as Crank–Nicolson over Space (CNS). The second model uses the CN scheme over three temporal nodes and is referred to as Crank–Nicolson over Time (CNT). Both models can properly account for complex cross-section geometry and variable computational points spacing along the channel length. The models were tested in different watersheds representing a mixture of steep and flat topographies. Comparing model outputs against observations of discharges and water levels indicated that the models accurately predict the peak discharge, peak water level, and flooding duration. Both models are accurate and computationally stable over a broad range of hydraulic regimes. The CNS model is dependent on the Courant criteria, making it less computational efficient where short channel segments are present. The CNT model does not suffer from that constraint and is, thus, highly computationally efficient and could be more useful for operational forecast models.     

Not if,but when we need resilience in the workplace

Workplace resilience is a necessity for organizations and employees given it assists them in overcoming adversity and ultimately succeeding. However, organizational scholars have largely overlooked this construct. In this Incubator, we briefly summarize extant research on workplace resilience to highlight opportunities for theory building and advancement of empirical research. Copyright © 2015 John Wiley & Sons, Ltd.     

A protocol for eliciting nonmaterial values through a cultural ecosystem services frame

Stakeholders’ nonmaterial desires, needs, and values often critically influence the success of conservation projects. These considerations are challenging to articulate and characterize, resulting in their limited uptake in management and policy. We devised an interview protocol designed to enhance understanding of cultural ecosystem services (CES). The protocol begins with discussion of ecosystem‐related activities (e.g., recreation, hunting) and management and then addresses CES, prompting for values encompassing concepts identified in the Millennium Ecosystem Assessment (2005) and explored in other CES research. We piloted the protocol in Hawaii and British Columbia. In each location, we interviewed 30 individuals from diverse backgrounds. We analyzed results from the 2 locations to determine the effectiveness of the interview protocol in elucidating nonmaterial values. The qualitative and spatial components of the protocol helped characterize cultural, social, and ethical values associated with ecosystems in multiple ways. Maps and situational, or vignette‐like, questions helped respondents articulate difficult‐to‐discuss values. Open‐ended prompts allowed respondents to express a diversity of ecosystem‐related values and proved sufficiently flexible for interviewees to communicate values for which the protocol did not explicitly probe. Finally, the results suggest that certain values, those mentioned frequently throughout the interview, are particularly salient for particular populations. The protocol can provide efficient, contextual, and place‐based data on the importance of particular ecosystem attributes for human well‐being. Qualitative data are complementary to quantitative and spatial assessments in the comprehensive representation of people's values pertaining to ecosystems, and this protocol may assist in incorporating values frequently overlooked in decision making processes.     

Ergonomic evaluation of a new truck seat design: a field study

A postural evaluation of commercial licensed truck drivers was conducted to determine the ergonomic benefits of a truck seat prototype in comparison with an industry standard seat. Twenty commercially licensed truck drivers were recruited to perform a 90-min driving task. Postures were assessed using accelerometers and a backrest and seat pan pressure mapping system. Subjective discomfort measurements were monitored using two questionnaires: ratings of perceived discomfort (RPD) and the automotive seating discomfort questionnaire (ASDQ). Participants reported significantly higher discomfort scores when sitting in the industry standard seat. Participants sat with more lumbar lordosis and assumed a more extended thoracic posture when seated in the prototype. Pairing the gluteal backrest panel with the adjustable seat pan also helped reduce the average sitting pressure on both the seat pan and the backrest. The prototype provided several postural benefits for commercially certified truck drivers, as it did for a young and healthy population.     

Chemotherapy of bacterial plasmids

Pharmacological approaches to plasmid chemotherapy are: 1) discovery of novel antibacterial drugs against which plasmids do not carry resistance genes, 2) molecular modification of existing drugs to render them non-susceptible to plasmid-encoded enzymes, 3) development of drugs which are selective inhibitors of plasmid DNA replication, 4) development of drugs which inhibit phenotypic expression of plasmid genes, and 5) development of drugs which are inhibitors of drug-inactivating enzymes that are plasmid gene products.     

Habitat association studies in conjunction with adaptive cluster samples

Habitat association studies investigate the relationships between habitat characteristics and animal usage of study regions. These studies are often conducted in conjunction with surveys designed primarily to estimate population totals. This paper shows that habitat association studies may proceed from surveys using adaptive cluster sampling. The manner in which units appear in the sample turns out not be relevant to the habitat association study, which proceeds as though the units came from a simple random sample. However, it is also shown that the information about the habitat association parameters is greater than one would expect from a simple random sample of the same general size.     

Interspecific aggression in Leucorrhinia dragonflies: a frequency-dependent discrimination threshold hypothesis

Summary Male Leucorrhinia dragonflies defend territories from conspecific and heterospecific intruders. Defense against heterospecifics is surprising, as mating and oviposition are the only activities that occur on the territories, and heterospecific males are not expected to pose a reproductive threat. L. frigida and L. intacta males respond aggressively with equal frequency and intensity against intrusions by conspecifics and heterospecifics. In contrast, L. proxima males respond more aggressively against conspecifics. The apparent lack of species discrimination shown by L. frigida and L. intacta males may result because territorial males that assess intruders (as do L. proxima) suffer a tactical disadvantage from hesitating when an intruder flies in. This assessment process may lead to reduced fighting success by the territorial male. Thus there is a tradeoff between assessment cost incurred when the intruder is a conspecific and benefit gained from avoiding conflict when the intruder is a heterospecific. Given this assessment cost, males of species that only rarely encounter conspecific intruders are more likely to evolve species discrimination than males of species that commonly encounter conspecific intruders.