Effects of transit quality of service characteristics on daily bus ridership

This study explores how explicit transit quality of services (TQoS) measures including service frequency, service span, and travel time ratio, along with implicit environmental predictors such as topographic grade factor influence bus ridership using a case study city of Brisbane, Australia. The primary hypothesis tested was that bus ridership is higher within suburbs with high transit quality of service than suburbs that have limited service quality. Using Multiple Linear Regression (MLR) this study identifies a strong positive relationship between route intensity (bus-km/h-km2) and bus ridership, indicating that increasing both service frequency and spatial route density correspond to higher bus ridership. Additionally, travel time ratio (in-vehicle transit travel time to in-vehicle auto travel time) is also found to have significant negative association with ridership within a suburb, reflecting a decline in transit use with increased travel time ratio. Conversely, topographic grade and service span are not found to exert any significant impact on bus ridership in a suburb. Our study findings enhance the fundamental understanding of traveller behaviour which is informative to urban transportation policy, planning and provision.

Effects of transit quality of service characteristics on daily bus ridership

This study investigates whether an Australian city’s suburbs having high transit Quality of Service (QoS) are associated with higher transit ridership than those having low transit QoS •We explore how QoS measures including service frequency, service span, service coverage, and travel time ratio, along with implicit environmental predictors such as topographic grade factor influence bus ridership •We applied Multiple Linear Regression (MLR) to examine the relationship between QoS and ridership •Its outcomes enhance our understanding of transit user behavior, which is informative to urban transportation policy, planning, and provision

Effects of transit quality of service characteristics on daily bus ridership

A case study of Brisbane, the capital city of Queensland, Australia, explored how explicit measures of transit quality of service (e.g., service frequency, service span, and travel time ratio) and implicit environmental predictors (e.g., topographic grade factor) influenced bus ridership. The primary hypothesis tested was that bus ridership was higher in suburbs with high transit quality of service than in suburbs with limited service quality. Multiple linear regression, used to identify a strong positive relationship between route intensity (bus-km/h-km2) and bus ridership, indicated that both increased service frequency and spatial route density corresponded to higher bus ridership. Additionally, the travel time ratio (i.e., the ratio of in-vehicle transit travel time to in-vehicle automobile travel time) had a significant negative association with suburban ridership: transit use declined as travel time ratio increased. In contrast, topographic grade and service span did not significantly affect suburban bus ridership. The study findings enhance the fundamental understanding of traveler behavior, which is informative to urban transportation policy, planning, and provision.

多波分量地震资料处理解释方法

To deal with some key problems in multi-component seismic exploration, some methods are introduced in this thesis based on reading amounts of papers about multi-component seismic theories and methods. First, to find a solution for the detection of the fracture density and orientation in igneous, carbonate and shale reservoirs, a large amount of which exist in domestic oil fields with low exploration and development degree, a new fast and slow shear waves separation method called Ratio Method based on S-wave splitting theory is discussed in this thesis, through which the anisotropy coefficient as well as fracture parameters such as density and azimuthal angle can be acquired. Another main point in this thesis involves the application of seismic velocity ratio (Vp/Vs) to predict the Hthological parameters of subsurface medium. To deal with the unfeasibility of velocity ratio calculation method based on time ratio due to the usually low single-noise ratio of S-wave seismic data acquired on land, a new method based on detailed velocity analysis is introduced. Third, pre-stack Kirchhoff integral migration is a new method developed in recent years, through which both S and P component seismic data as well as amplitude ratio of P/S waves can be acquired. In this thesis, the research on untilizing the P and S wave sections as well as amplitude ratio sections to interpret low-amplitude structures and lithological traps is carried out. The fast and slow shear wave separation method is then be applied respectively to detect the density and azimuthal angle of fractures in an igneous rock gas reservoir and the coal formation in a coal field. Two velocity ratio-calculating methods are applied respectively in the lithological prediction at the gas and coal field after summarizing a large amount of experimental results draw domestically and abroad. P and S wave sections as well as amplitude ratio sections are used to identify low-amplitude structures and lithological traps in the slope area of a oil-bearing sedimentary basin. The calculated data concerning fracture density and azimuthal angle through the introduced method matches well with the regional stress and actual drilling data. The predicted lithological data reflects the actual drilling data. Some of the low-amplitude and lithological traps determined by Kirchhoff migration method are verified by the actual drilling data. These results indicate that these methods are very meaningful when dealing with complex oil and gas reservoir, and can be applied in other areas.

Asymptotic approach for the nonlinear equatorial long wave interactions

In the present work we use an asymptotic approach to obtain the long wave equations. The shallow water equation is put as a function of an external parameter that is a measure of both the spatial scales anisotropy and the fast to slow time ratio. The values given to the external parameters are consistent with those computed using typical values of the perturbations in tropical dynamics. Asymptotically, the model converge toward the long wave model. Thus, it is possible to go toward the long wave approximation through intermediate realizable states. With this approach, the resonant nonlinear wave interactions are studied. To simplify, the reduced dynamics of a single resonant triad is used for some selected equatorial trios. It was verified by both theoretical and numerical results that the nonlinear energy exchange period increases smoothly as we move toward the long wave approach. The magnitude of the energy exchanges is also modified, but in this case depends on the particular triad used and also on the initial energy partition among the triad components. Some implications of the results for the tropical dynamics are disccussed. In particular, we discuss the implications of the results for El Nĩo and the Madden-Julian in connection with other scales of time and spatial variability. © Published under licence by IOP Publishing Ltd.

Assesment of the TEI index of myocardial performance in dogs with doxorubicin-induced cardiomiopathy

The development of a dose-dependent cardiomyopathy is the main limitation for the use of doxorubicin in chemotherapy protocols in both humans and animals. In this setting, the global myocardial function may be compromised resulting in signs of congestive heart failure. In this study, we investigated the ability of the Tei index of myocardial performance to identify myocardial dysfunction in healthy dogs receiving doxorubicin to a cumulative dose of 210 mg/m(2) over 147 days, comparing it with other standard echocardiographic indicators of systolic and diastolic function. Our results indicated that the Tei index, the isovolumic relaxation time, pre-ejection period and the pre-ejection period-to-left ventricular ejection time ratio were able to identify the cardiotoxic effects of doxorubicin on cardiac function when only 60 mg/m(2) had been administered, while the standard systolic and diastolic parameters, including left ventricular diameter at systole, ejection fraction, and fractional shortening needed at least 120 mg/mg(2) to deteriorate. We concluded that prolonged anthracycline therapy compromises both systolic and diastolic functions, which may be documented earlier by including the Tel index evaluation to the standard echocardiographic assessment of animals receiving doxorubicin.

Synthese und Charakterisierung von Poly(tert-butylacrylat)- und Polyacrylsäure-Sternpolymeren

Sternpolymere aus Poly(tert.-butylacrylat)-Armen und einem Mikrogel-Core aus Ethylenglykoldimethacrylat wurden nach der arm-first Strategie hergestellt. Diese weisen eine enge Armzahlverteilung auf. Mit sinkender Precursorlänge, mit steigendem Verhältnis [bifunktionelles Monomer]/[Initiator], sowie mit zunehmender Reaktionszeit und Gesamtkonzentration nimmt die mittlere Armzahl fn zu. Die Sternbildung verläuft ähnlich einer Polykondensation. Die Molekulargewichte wurden mittels GPC gekoppelt mit einem online-Viskosimeter und einem online-Vielwinkellichtstreudetektor (MALLS) bestimmt.Die intrinsischen Viskositäten der Sternpolymere sind sehr niedrig. Für Armzahlen f ca. 8 erhält man ein Maximum in der doppellogarithmischen Auftragung der intrinsischen Viskosität und des Molekulargewichts. Die Trägheitsradien nehmen nur wenig mit dem Molekulargewicht zu. Die erhaltenen Koeffizienten liegen im von Daoud und Cotton vorhergesagten Bereich. Die Schrumpfungsfaktoren sinken auf g ca. 0,2 bzw. g' ca. 0,25. Aus den Poly(tert.-butylacrylat)-Sternpolymeren wurden durch Verseifung mit HBr in Methanol Polyacrylsäure-Sternpolymere hergestellt, welche ebenfalls mittels GPC-Viskosimetrie und GPC-MALLS charakterisiert wurden. Für die ionischen Sternpolymere findet man deutlich höhere Schrumpfungsfaktoren, kein Maximum in der intrinsischen Viskosität und höhere Exponenten als von Daoud und Cotton vorhergesagt. Erklärt wurde dies mit der hohen Segmentdichte in Sternpolymeren, die bei den ionischen Sternpolymeren zu einer hohen Ladungsdichte führt. Dadurch müssen sich die Arme stärker strecken als bei nicht-ionischen Sternen und es resultieren größere Moleküldimensionen.

Can infant lung function predict respiratory morbidity during the first year of life in preterm infants?

Compared with term-born infants, preterm infants have increased respiratory morbidity in the first year of life. We investigated whether lung function tests performed near term predict subsequent respiratory morbidity during the first year of life and compared this to standard clinical parameters in preterms.The prospective birth cohort included randomly selected preterm infants with and without bronchopulmonary dysplasia. Lung function (tidal breathing and multiple-breath washout) was measured at 44 weeks post-menstrual age during natural sleep. We assessed respiratory morbidity (wheeze, hospitalisation, inhalation and home oxygen therapy) after 1 year using a standardised questionnaire. We first assessed the association between lung function and subsequent respiratory morbidity. Secondly, we compared the predictive power of standard clinical predictors with and without lung function data.In 166 preterm infants, tidal volume, time to peak tidal expiratory flow/expiratory time ratio and respiratory rate were significantly associated with subsequent wheeze. In comparison with standard clinical predictors, lung function did not improve the prediction of later respiratory morbidity in an individual child.Although associated with later wheeze, noninvasive infant lung function shows large physiological variability and does not add to clinically relevant risk prediction for subsequent respiratory morbidity in an individual preterm.

Anticoagulation Management Practices and Outcomes in Elderly Patients with Acute Venous Thromboembolism: A Clinical Research Study.

Whether anticoagulation management practices are associated with improved outcomes in elderly patients with acute venous thromboembolism (VTE) is uncertain. Thus, we aimed to examine whether practices recommended by the American College of Chest Physicians guidelines are associated with outcomes in elderly patients with VTE. We studied 991 patients aged ≥65 years with acute VTE in a Swiss prospective multicenter cohort study and assessed the adherence to four management practices: parenteral anticoagulation ≥5 days, INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulation, early start with vitamin K antagonists (VKA) ≤24 hours of VTE diagnosis, and the use of low-molecular-weight heparin (LMWH) or fondaparinux. The outcomes were all-cause mortality, VTE recurrence, and major bleeding at 6 months, and the length of hospital stay (LOS). We used Cox regression and lognormal survival models, adjusting for patient characteristics. Overall, 9% of patients died, 3% had VTE recurrence, and 7% major bleeding. Early start with VKA was associated with a lower risk of major bleeding (adjusted hazard ratio 0.37, 95% CI 0.20-0.71). Early start with VKA (adjusted time ratio [TR] 0.77, 95% CI 0.69-0.86) and use of LMWH/fondaparinux (adjusted TR 0.87, 95% CI 0.78-0.97) were associated with a shorter LOS. An INR ≥2.0 for ≥24 hours before stopping parenteral anticoagulants was associated with a longer LOS (adjusted TR 1.2, 95% CI 1.08-1.33). In elderly patients with VTE, the adherence to recommended anticoagulation management practices showed mixed results. In conclusion, only early start with VKA and use of parenteral LMWH/fondaparinux were associated with better outcomes.

Desenvolvimento de novos biolubrificantes hidráulicos derivados dos óleos de maracujá e de moringa in natura e epoxidados

With the increasing environmental awareness, maximizing biodegradability and minimizing ecotoxicity is the main driving force for new technological developments. Thus, can be developed new biodegradable lubricants for use in environmentally sensitive areas. The aim of this study was to obtain new bio-lubricants from passion fruit (Passiflora edulis Sims f. flavicarpa Degener) and moringa (Moringa oleifera Lamarck) epoxidized oils and develop a new additive package using experimental design for their use as a hydraulic fluid. In the first stage of this work was performed the optimization of the epoxidation process of the oils using fractional experimental design 24-1 , varying the temperature, reaction time, ratio of formic acid and hydrogen peroxide. In the second step was investigated the selectivity, thermodynamics and kinetics of the reaction for obtaining the two epoxides at 30, 50 and 70 °C. The result of the experimental design confirmed that the epoxidation of passion fruit oil requires 2 hours of reaction, 50 °C and a ratio H2O2/C=C/HCOOH (1:1:1). For moringa oil were required 2 hours reaction, 50 °C and a ratio of H2O2/C=C/HCOOH (1:1:1.5). The results of the final conversions were equal to 83.09% (± 0.3) for passion fruit oil epoxide and 91.02 (±0,4) for moringa oil epoxide. Following was made the 23 factorial design to evaluate which are the best concentrations of corrosion inhibitor and anti-wear (IC), antioxidant (BHA) and extreme pressure (EP) additives. The bio-lubricants obtained in this step were characterized according to DIN 51524 (Part 2 HLP) and DIN 51517 (Part 3 CLP) standards. The epoxidation process of the oils was able to improve the oxidative stability and reduce the total acid number, when compared to the in natura oils. Moreover, the epoxidized oils best solubilized additives, resulting in increased performance as a lubricant. In terms of physicochemical performance, the best lubricant fluid was the epoxidized moringa oil with additives (EMO-ADI), followed by the epoxidized passion fruit oil with additives (EPF-ADI) and, finally, the passion fruit in natura oil without additives (PFO). Lastly, was made the investigation of the tribological behavior under conditions of boundary lubrication for these lubricants. The tribological performance of the developed lubricants was analyzed on a HFRR equipment (High Frequency Reciprocating Rig) and the coefficient of friction, which occurs during the contact and the formation of the lubricating film, was measured. The wear was evaluated through optical microscopy and scanning electron microscopy (SEM). The results showed that the addition of extreme pressure (EP) and anti-wear and corrosion inhibitor (CI) additives significantly improve the tribological properties of the fluids. In all assays, was formed a lubricating film that is responsible for reducing the coefficient of metal-to-metal wear. It was observed that the addition of EP and IC additives in the in natura vegetable oils of passion fruit and moringa did not favor a significant reduction in wear. The bio-lubricants developed from passion fruit and moringa oils modified via epoxidation presented satisfactory tribological properties and shown to be potential lubricants for replacement of commercial mineral-based fluids.

Análise tribo-termodinâmica da aplicação de nanopartículas de Al2O3 como aditivo lubrificante em compressor hermético de refrigeração

The thermodynamic performance of a refrigeration system can be improved by reducing the compression work by a particular technique for a specific heat removal rate. This study examines the effect of small concentrations of Al2O3 (50 nm) nanoparticles dispersion in the mineral oil based lubricant on the: viscosity, thermal conductivity, and lubrication characteristics as well as the overall performance (based on the Second Law of Thermodynamics) of the refrigerating system using R134a or R600a as refrigerants. The study looked at the influences of variables: i) refrigerant charge (100, 110, 120 and 130 g), ii) rotational speed of the condenser blower (800 and 1100 RPM) and iii) nanoparticle concentration (0.1 and 0.5 g/l) on the system performance based on the Taguchi method in a matrix of L8 trials with the criterion "small irreversibility is better”. They were carried pulldown and cycling tests according to NBR 12866 and NBR 12869, respectively, to evaluate the operational parameters: on-time ratio, cycles per hour, suction and discharge pressures, oil sump temperature, evaporation and condensation temperatures, energy consumption at the set-point, total energy consumption and compressor power. In order to evaluate the nanolubricant characteristics, accelerated tests were performed in a HFRR bench. In each 60 minutes test with nanolubricants at a certain concentration (0, 0.1 and 0.5 g/l), with three replications, the sphere (diameter 6.00 ± 0.05 mm, Ra 0.05 ± 0.005 um, AISI 52100 steel, E = 210 GPa, HRC 62 ± 4) sliding on a flat plate (cast iron FC200, Ra <0.5 ± 0.005 um) in a reciprocating motion with amplitude of 1 mm, frequency 20 Hz and a normal load of 1,96 N. The friction coefficient signals were recorded by sensors coupled to the HFRR system. There was a trend commented bit in the literature: a nanolubricant viscosity reduction at the low nanoparticles concentrations. It was found the dominant trend in the literature: increased thermal conductivity with increasing nanoparticles mass fraction in the base fluid. Another fact observed is the significant thermal conductivity growth of nanolubricant with increasing temperature. The condenser fan rotational speed is the most influential parameter (46.192%) in the refrigerator performance, followed by R600a charge (38.606%). The Al2O3 nanoparticles concentration in the lubricant plays a minor influence on system performance, with 12.44%. The results of power consumption indicates that the nanoparticles addition in the lubricant (0.1 g/L), together with R600a, the refrigerator consumption is reduced of 22% with respect to R134a and POE lubricant. Only the Al2O3 nanoparticles addition in the lubricant results in a consumption reduction of about 5%.

Análise tribo-termodinâmica da aplicação de nanopartículas de Al2O3 como aditivo lubrificante em compressor hermético de refrigeração

The thermodynamic performance of a refrigeration system can be improved by reducing the compression work by a particular technique for a specific heat removal rate. This study examines the effect of small concentrations of Al2O3 (50 nm) nanoparticles dispersion in the mineral oil based lubricant on the: viscosity, thermal conductivity, and lubrication characteristics as well as the overall performance (based on the Second Law of Thermodynamics) of the refrigerating system using R134a or R600a as refrigerants. The study looked at the influences of variables: i) refrigerant charge (100, 110, 120 and 130 g), ii) rotational speed of the condenser blower (800 and 1100 RPM) and iii) nanoparticle concentration (0.1 and 0.5 g/l) on the system performance based on the Taguchi method in a matrix of L8 trials with the criterion "small irreversibility is better”. They were carried pulldown and cycling tests according to NBR 12866 and NBR 12869, respectively, to evaluate the operational parameters: on-time ratio, cycles per hour, suction and discharge pressures, oil sump temperature, evaporation and condensation temperatures, energy consumption at the set-point, total energy consumption and compressor power. In order to evaluate the nanolubricant characteristics, accelerated tests were performed in a HFRR bench. In each 60 minutes test with nanolubricants at a certain concentration (0, 0.1 and 0.5 g/l), with three replications, the sphere (diameter 6.00 ± 0.05 mm, Ra 0.05 ± 0.005 um, AISI 52100 steel, E = 210 GPa, HRC 62 ± 4) sliding on a flat plate (cast iron FC200, Ra <0.5 ± 0.005 um) in a reciprocating motion with amplitude of 1 mm, frequency 20 Hz and a normal load of 1,96 N. The friction coefficient signals were recorded by sensors coupled to the HFRR system. There was a trend commented bit in the literature: a nanolubricant viscosity reduction at the low nanoparticles concentrations. It was found the dominant trend in the literature: increased thermal conductivity with increasing nanoparticles mass fraction in the base fluid. Another fact observed is the significant thermal conductivity growth of nanolubricant with increasing temperature. The condenser fan rotational speed is the most influential parameter (46.192%) in the refrigerator performance, followed by R600a charge (38.606%). The Al2O3 nanoparticles concentration in the lubricant plays a minor influence on system performance, with 12.44%. The results of power consumption indicates that the nanoparticles addition in the lubricant (0.1 g/L), together with R600a, the refrigerator consumption is reduced of 22% with respect to R134a and POE lubricant. Only the Al2O3 nanoparticles addition in the lubricant results in a consumption reduction of about 5%.

Antitumor effect and mechanism of action of polysaccharides extracted from Polygonum perfoliatum L whole plant in human lung carcinoma A549 cell line

Purpose: To optimize the extraction conditions of polysaccharides from Polygonum perfoliatum L. (PSDP) and to evaluate their anti-tumor activities on A549 cell line. Methods: Extraction of PSDP was optimized using Box-Behnken design (BBD). Three factors of response surface methodology (RSM) including extraction time, ratio of water to raw material and number of extractions were employed to optimize the yield of PSDP. The cytotoxic effect of PSDP on human lung carcinoma A549 cell line was evaluated in vivo, while its effects on expressions of caspase3, caspase-9, Bcl-2 and Bax were determined by western blot assay. Result: BBD was significant and applicable to PSDP extraction. Based on the contour plots, response surface plots and variance analysis, it predicted that the optimum conditions for PSDP extraction were: 1.58 h (extraction time); 30.18 mL/g (ratio of water to raw material); and 2.02 (number of extractions). PSDP had significant inhibitory effect on the growth of A549 cells in a concentration- and timedependent manner (p < 0.05). After treatment with PSDP, caspase-3, caspase-9 and Bax were significantly up-regulated (p < 0.05), whereas Bcl-2 was down-regulated, all concentration-dependently. Conclusion: RSM analysis is an appropriate method to optimize PSDP extraction. The results also indicate that PSDP has significant anti-tumor effect against A549 cells, most likely via inducing mitochondria-mediated apoptosis.