1,721,260 research outputs found
Modelling rotary diesel fuel injection equipment with rate control to reduce noise and emissions
No full textStringent legislation on vehicle noise and pollutant emissions has created increasingly severe demands on the fuel injection equipment fitted to automotive diesel engines. In particular, the use of high pressure across smaller nozzle holes to reduce particulate emissions has increased the effect of nonlinear compression of the fuel in the passages and volumes in the systems. Fuel cavitation has been increased by more vigorous wave action. Both of these nonlinear effects have been investigated and modelled by replacing the pressure with condensation, which is continuous across the fuel phase boundary. The nonlinearity in compression has been incorporated into the wave equations by using a nonlinear equation of state where the bulk modulus is assumed to change linearly with pressure. The cavitated pipe section is divided into liquid and mixture columns and modified momentum and mass conservation equations are applied separately. A more comprehensive injector model which considers the two loss factors at the needle seat and holes, sac volume, and viscous drag and leakage has been developed. The calculation methods for wave disturbances and losses have been reviewed and improved methods are presented. Rate modulation devices are becoming more popular as their potential is realised for reducing noise and emissions of unburned hydrocarbons and oxides of nitrogen. The split injection device, two-spring injector, and shuttle pilot service are described and modelled. The model has been validated with an over-the-nose pump, which was chosen to be one of the most difficult FIE specifications to model. The pump suffers from incidental pilot injection due to high amplitude of pressure waves in the pipe which is caused in turn by a high initial cam rate. Cavitation occurs in almost all operating conditions, and parametric losses occur in the volumes in the pump. Three different specifications have been chosen to validate the model. The model predictions are in accord with experimental results in all three cases.(DX182202)</p
Correlation of animal-based parameters with environment-based parameters in an on-farm welfare assessment of growing pigs
No full textNine pig farms were evaluated for the welfare quality in Korea using animal- and environment-based parameters (particularly air quality parameters) during the winter of 2013. The Welfare Quality(®) (WQ(®)) protocol consists of 12 criteria within four principles. The WQ(®) protocol classifies farms into four categories ranging from ‘excellent’ to ‘not classified’. Each of these criteria has specific measures for calculating scores. Calculations for the welfare scores were conducted online using the calculation model in the WQ(®) protocol. Environment-based parameters like microclimate (i.e., temperature, relative humidity, air speed, and particulate matter), bacteria (total airborne bacteria, airborne total coliform, and airborne total Escherichia coli), concentration of gases (carbon dioxide, ammonia, and hydrogen sulfide) were measured to investigate the relationship between animal- and environment-based parameters. Correlations between the results of animal- and environment-based parameters were estimated using spearman correlation coefficient. The overall assessments found that five out of nine farms were ‘acceptable’, and four farms were ‘enhanced’; no farm was ‘not classified’. The average score for the four principles across the nine farms, in decreasing order, were ‘good feeding’ (63.13 points) > ‘good housing’ (59.26 points) > ‘good health’ (33.47 points) > ‘appropriate behaviors’ (25.48 points). In the result of the environment aspect, the relative humidity of farms 2 (93.4%), 3 (100%), and 9 (98%) was much higher than the recommended maximum relative humidity of 80%, and four out of the nine farms had ammonia concentrations greater than 40 ppm. Ammonia had negative correlations with ‘positive social behaviors’ and positive emotional states: content, enjoying, sociable, playful, lively, happy and it had positive correlations with negative emotional states: aimless, distressed. The concentration of carbon dioxide had negative correlations with positive emotional states; calm, sociable, playful, happy and it had a positive correlation with negative emotional state; aimless. Our results indicate that the control of the environment for growing pigs can help improve their welfare, particularly via good air quality (carbon dioxide, ammonia, hydrogen sulfide)
Phylogenetic relationships between different raccoon dog (Nyctereutes procyonoides) populations based on four nuclear and Y genes
Get PDF© 2020, The Genetics Society of Korea.Background: The raccoon dog (Nyctereutes procyonoides), endemic to East Asia, is classified as six subspecies according to their geographical distribution including a population introduced to Europe. Studies on phylogenetic relationship or population genetics in both native and introduced areas have been carried out recently. Lately, opinions that Japanese raccoon dogs should be classified as a different species were asserted based on several studies using karyotypes, morphometric characters, mtDNA, and microsatellites analysis. However, no data pertaining to the nuclear DNA (nDNA) or Y chromosome are available. Objective: To estimate the relationship among the species using different genes is necessary in understanding of the history of this species. Method: Therefore, we investigated nDNA and Y chromosomes in our study to define relationships: (1) between continental raccoon dog populations, (2) between original and introduced groups, and (3) between continental and Japanese groups. Results: The analysis of four nuclear (CHRNA1, VTN, TRSP, WT1) and ZFY genes indicated that there had been no genetic differentiation among the continental populations. However, significant differences were observed between continental and Japanese raccoon dogs in VTN and ZFY genes implying genetic differentiation has been going between them. Conclusion: To better understand the phylogenetic relationship among raccoon dog populations, further study will be necessary.N
Diesel Spray Development from VCO Nozzles with Common-Rail
Get PDFThe authors would like to acknowledge the support of National Research Laboratory scheme, Korean governmen
High striped hyena density suggests coexistence with humans in an agricultural landscape, Rajasthan
No full textUnderstanding the mechanism of coexistence, where carnivores adapt to humans and vice versa in the shared landscape, is a key determinant of long-term carnivore conservation but is yet to be comprehensively examined. We explored the coexistence mechanism of striped hyena (Hyaena hyaena) and humans in the shared landscape of Sawai Mansingh Wildlife Sanctuary (SMS WLS), Rajasthan, from November 2019 to March 2021. We used data derived from motion sensors-based surveys, satellite remote sensing images, and household questionnaires to understand socio-ecological, environmental and anthropogenic factors facilitating hyena persistence in the shared landscape. The high density (12 individuals/100 km(2)) striped hyena in the landscape revealed the coexistence with humans. Being scavengers, they get subsidised food sources and are perceived as low-risk species by humans. Striped hyena minimised temporal activity during the daytime when human activity peaked. However, the highest activity overlap was observed in the agricultural area (Δ1 = 0.39), and likely depicts the high activity due to agricultural practices. While the human settlement was positively associated with the detection of hyenas, the probability of striped hyena captures increased with decreasing distance from human settlement, possibly influenced by high carcass availability, providing the easiest food resources to striped hyena, and allowing them to coexist with humans. This study demonstrates the coexistence of hyenas and humans in the shared landscape supported by mutual benefits, where hyenas benefit from anthropogenic food from scavenging, while humans benefit from waste removal and the non-lethal nature hyenas
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Comparison of point and roadside transect methods to evaluate the abundance and richness of diurnal raptors in the arid region of Rajasthan.
No full textDiurnal raptors show a wider distribution compared to other groups of birds including passerines, woodpeckers, and seriemas, but occur at lower-than-expected densities. Estimating the precise abundance is essential to achieve conservation goals but the methods used to estimate the populations of birds need to be appropriate to arrive at meaningful conclusions. We compared the two survey methods: roadside point count and strip transects, for estimating species richness and abundance of raptors in the arid landscape of Rajasthan. Roadside point counts and roadside strip transects were done on 50 transects between December 2019- February 2020 (with an average length of 20 km and a total distance of 3000 km) to assess the species richness and abundance of raptors. A total of 2954 observations of raptors belonging to 35 species were recorded using both methods. Mann Whitney U test result showed no significant difference in species richness and abundance estimates between both methods (p = 0.206). The point count method yielded a higher relative abundance of 2.79 individuals [10 km2]-1h-1 than the 1.90 individuals [10 km2]-1h-1 obtained during the strip transect. Also, the number of unidentified species were less for point counts. Extrapolation values indicated that both the methods do not differ much for the detection of unsampled species. The choice of survey method depends on the objectives of the study, but our results favor the use of point counts rather than strip transects to survey raptors in open habitats. The information generated from this study is expected to provide the most efficient method to study the abundance and distribution of raptors in similar landscapes
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
