933 resultados para MASS TRANSIT SYSTEM


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Incidents and rolling stock breakdowns are commonplace in rapid transit rail systems and may disrupt the system performance imposing deviations from planned operations. A network design model is proposed for reducing the effect of disruptions less likely to occur. Failure probabilities are considered functions of the amount of services and the rolling stock’s routing on the designed network so that they cannot be calculated a priori but result from the design process itself. A two recourse stochastic programming model is formulated where the failure probabilities are an implicit function of the number of services and routing of the transit lines.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In many major cities, fixed route transit systems such as bus and rail serve millions of trips per day. These systems have people collect at common locations (the station or stop), and board at common times (for example according to a predetermined schedule or headway). By using common service locations and times, these modes can consolidate many trips that have similar origins and destinations or overlapping routes. However, the routes are not sensitive to changing travel patterns, and have no way of identifying which trips are going unserved, or are poorly served, by the existing routes. On the opposite end of the spectrum, personal modes of transportation, such as a private vehicle or taxi, offer service to and from the exact origin and destination of a rider, at close to exactly the time they desire to travel. Despite the apparent increased convenience to users, the presence of a large number of small vehicles results in a disorganized, and potentially congested road network during high demand periods. The focus of the research presented in this paper is to develop a system that possesses both the on-demand nature of a personal mode, with the efficiency of shared modes. In this system, users submit their request for travel, but are asked to make small compromises in their origin and destination location by walking to a nearby meeting point, as well as slightly modifying their time of travel, in order to accommodate other passengers. Because the origin and destination location of the request can be adjusted, this is a more general case of the Dial-a-Ride problem with time windows. The solution methodology uses a graph clustering algorithm coupled with a greedy insertion technique. A case study is presented using actual requests for taxi trips in Washington DC, and shows a significant decrease in the number of vehicles required to serve the demand.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Summary There is concern about the health problems caused by pesticides in humans, which has led some grape producers to adopt organic procedures in their vineyards, and a certain amount of these grapes are directed to winemaking. Despite the approval awarded to this organic grape production by the certified organizations, there has been a demand to carry out a survey to determine the physicochemical composition of the wine derived from these products. Some of these wines were made from a single grape variety and others from more than one. For this survey, the samples consisted of five bottles of each type of wine, acquired from wineries and supermarkets in the Serra Gaúcha region, RS, Brazil. The analyses were carried out by physicochemical methods: volatile compounds by gas chromatography; minerals and trace elements by inductively coupled plasma optical emission spectrometry; and pesticide residues by liquid chromatography-mass spectrometry. The results showed that in general the physicochemical composition of these wines was within the limits established by Brazilian legislation. The mineral and trace element concentrations were very low and pesticide residues were not detected (MRL = 10 μg.kg?1) in any of the wines. Resumo: Há preocupação em relação a problemas causados por pesticidas no ser humano, o que levou uma parcela de viticultores a adotar procedimentos de agricultura orgânica em seus vinhedos. Assim, devido a essa preocupação, eles estão produzindo uva pelo sistema orgânico, sendo que uma parte dessa produção é direcionada à elaboração de vinho. Apesar de essas uvas terem sido aprovadas por entidades certificadoras, houve demanda para a realização de um levantamento para determinar a composição dos vinhos delas derivados. Portanto, cinco garrafas de cada tipo de vinho foram coletadas em vinícolas e supermercados da Serra Gaúcha, Rio Grande do Sul, sendo uma parte de vinhos varietais e outra, de cortes de diferentes variedades. As análises foram feitas por métodos físico-químicos: compostos voláteis, por cromatografia gasosa; minerais e elementos-traço, por espectrometria de emissão ótica com plasma acoplado indutivamente, e resíduos de pesticidas, por cromatografia líquida-espectrometria de massa. Os resultados mostram que a composição físico-química desses vinhos e dos minerais situou-se, em geral, dentro dos limites da legislação brasileira. As concentrações de minerais e de elementos-traço foram muito baixas, e não foram detectados resíduos de pesticidas (LMR = 10 μg.kg?1) em nenhum vinho.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose: To assess the efficacy of the BARD scoring system in Saudi non‐alcoholic fatty liver disease (NAFLD) patients attending Gizan General Hospital and to identify the clinical variables associated with advanced fibrosis. . Methods: The cross-sectional study involved 120 patients aged ≥ 18 years who attended the Ultrasound Department of Gizan General Hospital, Gizan, Saudi Arabia, during January – June 2013. BARD scoring system comprised the following variables: body mass index (BMI) ≥ 28 = 1 point, aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio ≥ 0.8 = 2 points, and type 2 diabetes mellitus = 1 point. Results: Patients with advanced fibrosis were older (55.0 years) than patients with no/mild fibrosis (48.6 years), albeit not significantly so. A higher BMI was associated with advanced fibrosis in males, females and all study participants (p = 0.013, 0.016 and 0.001, respectively). Advanced fibrosis was more common in older patients with a higher weight to height ratio. Logistic regression suggested that age ≥ 50 years was associated with a 2.52-fold increase in the risk of advanced fibrosis, but this did not have a significant clinical impact (p = 0.087). BMI > 28 was associated with a 26.73-fold increased risk of advanced fibrosis, while AST/ALT ≥ 0.8 was associated with an 18.46-fold increased risk of advanced liver fibrosis (p = 0.002 and 0.006, respectively). Conclusion: The major risk factors for advanced fibrosis using BARD scoring system in patients with NAFLD were old age, BMI > 28, and AST/ALT ≥ 0.8. In addition, grade 3 ultrasonographic fatty liver significantly correlated with advanced fibrosis.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose: To develop and validate a simple, efficient and reliable Liquid chromatographic-mass spectrometric (LC-MS/MS) method for the quantitative determination of two dermatological drugs, Lamisil® (terbinafine) and Proscar® (finasteride), in split tablet dosage form. Methods: Thirty tablets each of the 2 studied medications were randomly selected. Tablets were weighed and divided into 3 groups. Ten tablets of each drug were kept intact, another group of 10 tablets were manually split into halves using a tablet cutter and weighed with an analytical balance; a third group were split into quarters and weighed. All intact and split tablets were individually dissolved in a water: methanol mixture (4:1), sonicated, filtered and further diluted with mobile phase. Optimal chromatographic separation and mass spectrometric detection were achieved using an Agilent 1200 HPLC system coupled with an Agilent 6410 triple quadrupole mass spectrometer. Analytes were eluted through an Agilent eclipse plus C8 analytical column (150 mm × 4.6 mm, 5 μm) with a mobile phase composed of solvent A (water) containing 0.1% formic acid and 5mM ammonium formate pH 7.5, and solvent B (acetonitrile mixed with water in a ratio A:B 55:45) at a flow rate of 0.8 mL min-1 with a total run time of 12 min. Mass spectrometric detection was carried out using positive ionization mode with analyte quantitation monitored by multiple reaction monitoring (MRM) mode. Results: The proposed analytical method proved to be specific, robust and adequately sensitive. The results showed a good linear fit over the concentration range of 20 - 100 ng mL-1 for both analytes, with a correlation coefficient (r2) ≥ 0.999 and 0.998 for finasteride and terbinafine, respectively. Following tablet splitting, the drug content of the split tablets fell outside of the proxy USP specification for at least 14 halves (70 %) and 34 quarters (85 %) of FIN, as well as 16 halves (80 %) and 37 quarters (92.5 %) of TBN. Mean weight loss, after splitting, was 0.58 and 2.22 % for FIN half- and quarter tablets, respectively, and 3.96 and 4.09 % for TBN half- and quarter tablets,respectively. Conclusion: The proposed LC-MS/MS method has successfully been used to provide precise drug content uniformity of split tablets of FIN and TBN. Unequal distribution of the drug on the split tablets is indicated by the high standard deviation beyond the accepted value. Hence, it is recommended not to split non-scored tablets especially, for those medications with significant toxicity

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Electrical Bus Rapid Transit (eBRT) is a charging electrical public transport which brings a clean, high performance, and affordable cost alternative from the conventional traffic vehicles which work with combustion and hybrid technology. These buses charge the battery in every bus stop to arrive at the next station. But, this charging system needs an appropriate infrastructure called pantograph, and it requires a high precision bus location to maintain battery lifetime, energy saving and charging time. To overcome this issue Vicomtech and Datik has planned a project based on computer vision to help to the driver to locate the vehicle in the correct place. In this document, we present a mono camera bus driver guided fast algorithm because these vehicles embedded computers do not support high computation and precision operations. In addition to the frequent lane sign, there are more accurate geometric beacons painted on the road to bring metric information to the vision system. This method uses segmentation to binarize the image discriminating the background space. Besides it detects, tracks and counts different lane mark contours in addition to classify each special painted mark. Besides it does not need any calibration task to calculate longitudinal and cross distances because we know the lane mark sizes.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The use of ultra high strength steels (UHSS) in the automotive industry presents a significant opportunity for continued vehicle light-weighting, due to possible strength-to-weight improvements of three to four times that of conventional sheet steel grades. This performance benefit is achievable whist maintaining most of the advantages of low-cost mass-production associated with the cold stamping of sheet steel for automotive body components. However, the introduction of UHSS can result in significantly increased wear of the stamping tools, which is difficult to predict at the design stage and can lead to unexpected process failure during mass-production. Therefore, there is a need to be able to monitor and predict the onset of severe wear, such that the best course of condition-based maintenance can be scheduled and unscheduled stoppages due to tool wear eradicated. This paper describes a novel active monitoring system that is being developed by researchers at Deakin University, The Australian National University and Ford Motor Company, Asia Pacific and Africa. The aim of the active monitoring system is to detect the initial onset of a change of state, such as wear, through the measurement of variables such as punch force and audio signals. A semi-industrial stamping process, using a progressive die setup and high strength steel sheet with hardened tool steel tooling, is the experimental basis for the initial model and system development.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: To examine associations of public transport system accessibility with walking, obesity, metabolic syndrome and diabetes/impaired glucose regulation. Methods: Associations of public transport accessibility with self-reported walking for transport or recreation and measured biomarkers of chronic disease risk were estimated in 5241 adult residents of 42 randomly selected areas in Australia in 2004/05, drawn from the second wave of a population-based cohort study (AusDiab). Public transport accessibility was objectively measured using an adaptation of the Public Transport Accessibility Levels (PTAL) methodology, comprising both GIS derived spatial and temporal accessibility measures. Logistic regression models were adjusted for individual and environmental level covariates and clustering within areas. Results: Above median public transport accessibility was positively associated with a walking time of more than the median 90 min per week (OR=1.28, 95%CI 1.03, 1.60) and walking above the recommended 150 min per week (OR=1.35, 95%CI 1.11, 1.63). There were no associations of public transport accessibility with obesity (OR=1.05, 95%CI 0.85, 1.30), the metabolic syndrome (OR=1.09, 95%CI 0.91, 1.31) nor diabetes/impaired glucose regulation (OR=1.11, 95%CI 0.94, 1.30). Findings were similar for a subgroup reporting no vigorous recreational physical activity. Conclusions: In this Australian sample, public transport accessibility was positively associated with walking at recommended levels, including for people who are not otherwise vigorously active. Significance: Walking is crucial for increasing physical activity levels and population health, as well as maximising public transport system efficiency. Building evidence on public transport accessibility and walking will enable governments to exploit this important synergy.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: Left ventricular (LV) hypertrophy is a risk factor for cardiovascular death, but the genetic factors determining LV size and predisposition to hypertrophy are not well understood. We have previously linked the quantitative trait locus cardiac mass 22 (Cm22) on chromosome 2 with cardiac hypertrophy independent of blood pressure in the spontaneously hypertensive rat. From an original cross of spontaneously hypertensive rat with F344 rats, we derived a normotensive polygenic model of spontaneous cardiac hypertrophy, the hypertrophic heart rat (HHR) and its control strain, the normal heart rat (NHR).

METHODS AND RESULTS: To identify the genes and molecular mechanisms underlying spontaneous LV hypertrophy we sequenced the HHR genome with special focus on quantitative trait locus Cm22. For correlative analyses of function, we measured global RNA transcripts in LV of neonatal HHR and NHR and 198 neonatal rats of an HHR × NHR F2 crossbred population. Only one gene within locus Cm22 was differentially expressed in the parental generation: tripartite motif-containing 55 (Trim55), with mRNA downregulation in HHR (P < 0.05) and reduced protein expression. Trim55 mRNA levels were negatively correlated with LV mass in the F2 cross (r = -0.16, P = 0.025). In exon nine of Trim55 in HHR, we found one missense mutation that functionally alters protein structure. This mutation was strongly associated with Trim55 mRNA expression in F2 rats (F = 10.35, P < 0.0001). Similarly, in humans, we found reduced Trim55 expression in hearts of subjects with idiopathic dilated cardiomyopathy.

CONCLUSION: Our study suggests that the Trim55 gene, located in Cm22, is a novel candidate gene for polygenic LV hypertrophy independent of blood pressure.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Estimating un-measurable states is an important component for onboard diagnostics (OBD) and control strategy development in diesel exhaust aftertreatment systems. This research focuses on the development of an Extended Kalman Filter (EKF) based state estimator for two of the main components in a diesel engine aftertreatment system: the Diesel Oxidation Catalyst (DOC) and the Selective Catalytic Reduction (SCR) catalyst. One of the key areas of interest is the performance of these estimators when the catalyzed particulate filter (CPF) is being actively regenerated. In this study, model reduction techniques were developed and used to develop reduced order models from the 1D models used to simulate the DOC and SCR. As a result of order reduction, the number of states in the estimator is reduced from 12 to 1 per element for the DOC and 12 to 2 per element for the SCR. The reduced order models were simulated on the experimental data and compared to the high fidelity model and the experimental data. The results show that the effect of eliminating the heat transfer and mass transfer coefficients are not significant on the performance of the reduced order models. This is shown by an insignificant change in the kinetic parameters between the reduced order and 1D model for simulating the experimental data. An EKF based estimator to estimate the internal states of the DOC and SCR was developed. The DOC and SCR estimators were simulated on the experimental data to show that the estimator provides improved estimation of states compared to a reduced order model. The results showed that using the temperature measurement at the DOC outlet improved the estimates of the CO , NO , NO2 and HC concentrations from the DOC. The SCR estimator was used to evaluate the effect of NH3 and NOX sensors on state estimation quality. Three sensor combinations of NOX sensor only, NH3 sensor only and both NOX and NH3 sensors were evaluated. The NOX only configuration had the worst performance, the NH3 sensor only configuration was in the middle and both the NOX and NH3 sensor combination provided the best performance.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Oscillometric blood pressure (BP) monitors are currently used to diagnose hypertension both in home and clinical settings. These monitors take BP measurements once every 15 minutes over a 24 hour period and provide a reliable and accurate system that is minimally invasive. Although intermittent cuff measurements have proven to be a good indicator of BP, a continuous BP monitor is highly desirable for the diagnosis of hypertension and other cardiac diseases. However, no such devices currently exist. A novel algorithm has been developed based on the Pulse Transit Time (PTT) method, which would allow non-invasive and continuous BP measurement. PTT is defined as the time it takes the BP wave to propagate from the heart to a specified point on the body. After an initial BP measurement, PTT algorithms can track BP over short periods of time, known as calibration intervals. After this time has elapsed, a new BP measurement is required to recalibrate the algorithm. Using the PhysioNet database as a basis, the new algorithm was developed and tested using 15 patients, each tested 3 times over a period of 30 minutes. The predicted BP of the algorithm was compared to the arterial BP of each patient. It has been established that this new algorithm is capable of tracking BP over 12 minutes without the need for recalibration, using the BHS standard, a 100% improvement over what has been previously identified. The algorithm was incorporated into a new system based on its requirements and was tested using three volunteers. The results mirrored those previously observed, providing accurate BP measurements when a 12 minute calibration interval was used. This new system provides a significant improvement to the existing method allowing BP to be monitored continuously and non-invasively, on a beat-to-beat basis over 24 hours, adding major clinical and diagnostic value.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Cassava contributes significantly to biobased material development. Conventional approaches for its bio-derivative-production and application cause significant wastes, tailored material development challenges, with negative environmental impact and application limitations. Transforming cassava into sustainable value-added resources requires redesigning new approaches. Harnessing unexplored material source, and downstream process innovations can mitigate challenges. The ultimate goal proposed an integrated sustainable process system for cassava biomaterial development and potential application. An improved simultaneous release recovery cyanogenesis (SRRC) methodology, incorporating intact bitter cassava, was developed and standardized. Films were formulated, characterised, their mass transport behaviour, simulating real-distribution-chain conditions quantified, and optimised for desirable properties. Integrated process design system, for sustainable waste-elimination and biomaterial development, was developed. Films and bioderivatives for desired MAP, fast-delivery nutraceutical excipients and antifungal active coating applications were demonstrated. SRRC-processed intact bitter cassava produced significantly higher yield safe bio-derivatives than peeled, guaranteeing 16% waste-elimination. Process standardization transformed entire root into higher yield and clarified colour bio-derivatives and efficient material balance at optimal global desirability. Solvent mass through temperature-humidity-stressed films induced structural changes, and influenced water vapour and oxygen permeability. Sevenunit integrated-process design led to cost-effectiveness, energy-efficient and green cassava processing and biomaterials with zero-environment footprints. Desirable optimised bio-derivatives and films demonstrated application in desirable in-package O2/CO2, mouldgrowth inhibition, faster tablet excipient nutraceutical dissolutions and releases, and thymolencapsulated smooth antifungal coatings. Novel material resources, non-root peeling, zero-waste-elimination, and desirable standardised methodology present promising process integration tools for sustainable cassava biobased system development. Emerging design outcomes have potential applications to mitigate cyanide challenges and provide bio-derivative development pathways. Process system leads to zero-waste, with potential to reshape current style one-way processes into circular designs modelled on nature's effective approaches. Indigenous cassava components as natural material reinforcements, and SRRC processing approach has initiated a process with potential wider deployment in broad product research development. This research contributes to scientific knowledge in material science and engineering process design.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Introducción: La diverticulosis es la condición más frecuentemente encontrada en la colonoscopia, condición asintomática, con un alto costo para el sistema de salud. Diversos factores han demostrado estar en relación con la aparición de la enfermedad. En nuestra población, esta información se desconoce; el objetivo del estudio es la caracterización de la población con diverticulosis y su relación con la frecuencia de la ingesta de fibra. Materiales y Métodos: Estudio observacional prospectivo de corte transversal con componente analítico. Realizado a todas las personas que asistieron al HUS a realización de colonoscopia entre Noviembre de 2015 y Abril de 2016. Se recolectaron datos de la frecuencia de fibra ingerida a través de entrevistas basadas. Resultados: Se estudiaron 278 personas, 55.7% mujeres. La prevalencia de diverticulosis fue de 21.58%, siendo más frecuente en mujeres ( 66,7%), 31% entre los 71-80 años, 2,16% tenían antecedente familiar de diverticulosis; principal sitio de afectación fue colon sigmoide en las mujeres y el colon descendente en los hombres. En las personas con diverticulosis el consumo de harina de trigo fue mayor (91,67% vs 86,7%), mientras el consumo de frutas fue mayor en las personas que no presentaron diverticulosis (83,49% vs 78,33%). Conclusiones: La prevalencia de diverticulosis es similar a lo reportado en la literatura. Así mismo se encontró un mayor consumo de fibra en la población sin divertículos lo que hace pensar que a pesar de que esta condición es multifactorial , el consumo de mayores cantidades de fibra puede prevenir la aparición de la misma

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper is on a wind energy conversion system simulation of a transient analysis due to a blade pitch control malfunction. The aim of the transient analysis is the study of the behavior of a back-to-back multiple point clamped five-level full-power converter implemented in a wind energy conversion system equipped with a permanent magnet synchronous generator. An alternate current link connects the system to the grid. The drive train is modeled by a three-mass model in order to simulate the dynamic effect of the wind on the tower. The control strategy is based on fractional-order control. Unbalance voltages in the DC-link capacitors are lessen due to the control strategy, balancing the capacitor banks voltages by a selection of the output voltage vectors. Simulation studies are carried out to evaluate not only the system behavior, but also the quality of the energy injected into the electric grid.