Transport is one of the factors influencing the development of metropolitan areas. However, for its efficient work, numerous optimizations are required. Main tasks are shortening travel time, improving service quality and increasing the number of passengers served. The author has presented current studies on the field in optimization of public transport, mainly ways to optimize the transport network construction, based on large data sets about the population and their communication behaviour. Methods of combining various types of public transport with each other are presented. In the paper also are presents authors studies on the communication accessibility within the city of Cracow. Estimated distances from buildings to various types of public transport stops. The results were presented in aggregated form. Calculated communication speed of three types of public transport functioning in Cracow has also been discussed.
Transportation networks respond differently to applied policies. The Tehran Metropolitan Area has one of the most complex networks with complex users, which has experienced many of these policies change within the past decades. In this study, some of these policies and their effect on air pollution is investigated. The goal is to pinpoint the variables which have the most effect on various transportation models and investigate how new policies should be focused. In order to do so, long-term variations of air pollution monitoring stations were analyzed. Results show that the most significant parameter that may affect air pollution is users' behavior due to the lack of a public transportation network and its level of comfort. The results of this study will be useful in developing new policies and evaluating their long-term consequences in appropriate models.
In the 1985 ablation season studies were made of the dynamics and size of the transport of suspended and dissolved material in a glaciated drainage basin (the Ebbaelva) and an unglaciated one (the Dynamiskbekken) in the central part of West Spitsbergen island. The dynamics of runoff, the exhaustion of sources of transportable suspended material, hysteretic effects during floods, the share of genetic type of water differing in the mineralisation level and chemical content, as well as the role of rain waters in mobilising soluble salts, are the principal factors of transport dynamics. The extremaly warm ablation season caused the extent of denudation to exceed the estimates made so far.
Traps to catch microfauna transported by wind were installed on already colonised by plants area, in the vicinity of the glacier. After 6-week-exposition 859 individuals of microfauna were caught, of which Nematoda constituted 71%, Tardigrada 22% and Rotifcra 7%. Number of microfauna individuals caught depended on distance from the already colonised areas and presence of plant parts, together with which animals can be transported more easily. Microfauna connected with vegetation, which is transferred together with plant parts, was transported in higher numbers. Probably these taxa (i.e. Diphascon within tardigrades and Dorylaimidae within nematodes) colonise new habitats at first, but other species dominate later in freshwater bodies.
This article sheds light on the advent of online platforms and the way it is reshaping urban enviroment, breaking down traditional axes of both social interaction and commercial power, shifting the structure of traditional services. The platform revolution is radically transforming an array of many functional cities’ areas, like transportation, accommodations and personal services. Thus current concerns as strong urbanization, industrialization and world population growth, enable sharing economy firms to flourish as a reaction against the frictions of urban life exploiting such exacerbation, in order to fulfill demand for appropriate services. After a critical analysis of these issues, the article deepens innovative transportation services, moving on to illustrate the Italian rulemaking process as a chance to provide a solution to the ongoing problem of striking the right balance between competing priorities, such as market access and preservation of sustainable mobility. It suggests to reflect upon the best approach able to face the complexity of urban transport systems, in order to break in a new culture for urban mobility, comply to EU legislation too.
Enhanced Traffic Management System (ETMS) stores all the information gathered by the Federal Aviation Administration (FAA) from aircraft flying in the US airspace. The data stored from each flight includes the 4D trajectory (latitude, longitude, altitude and timestamp), radar data and flight plan information. Unfortunately, there is a data quality problem in the vertical channel and the altitude component of the trajectories contains some isolated samples in which a wrong value was stored. Overall, the data is generally accurate and it was found that only 0.3% of the altitude values were incorrect, however the impact of these erroneous data in some analyses could be important, motivating the development of a filtering procedure. The approach developed for filtering ETMS altitude data includes some specific algorithms for problems found in this particular dataset, and a novel filter to correct isolated bad samples (named Despeckle filter). As a result, all altitude errors were eliminated in 99.7% of the flights affected by noise, while preserving the original values of the samples without bad data. The algorithm presented in this paper attains better results than standard filters such as the median filter, and it could be applied to any signal affected by noise in the form of spikes
Studies of the chemical composition of surface freshwaters of the Fugleberget drainage basin, Spitsbergen, were performed in the summer of 1979. It was found that activity of birds (little auk) is the main factor differentiating the chemical properties of waters of the drainage basin. The birds faeces cause the enrichment of waters with nutrients, fertilizing the environment. There is a dependence of the concentration of determined water chemistry parameters on the distance from the bird colony.
The main goal of the considered work is to adjust mathematical modeling for mass transfer, to specific conditions resulting from presence of chemical surface reactions in the flow of the mixture consisting of helium and methanol. The thermocatalytic devices used for decomposition of organic compounds incorporate microchannels coupled at the ends and heated to 500 ◦C at the walls regions. The experiment data were compared with computational fluid dynamics results to calibrate the constants of the model’s user defined functions. These extensions allow to transform the calculations mechanisms and algorithms of commercial codes adapting them for the microflows cases and increased chemical reactions rate on the interphase between fluid and solid, specific for catalytic reactions. Results obtained on the way of numerical calculations have been calibrated and compared with the experimental data to receive satisfactory compliance. The model has been verified and the performance of the thermocatalytic reactor with microchannels under hydrogen production regime has been investigated.
The aim of this work was to evaluate the use of the naphthalic anhydride safener on the protection of common bean cultivars BRS-Estilo (carioca) and BRS-Esplendor (black) from negative effects of herbicides. Two experiments were conducted, one for each cultivar in a complete randomized design with five replications, in a 6 × 3 factorial scheme, with six herbicide treatments: bentazon, fluazifop-P + fomesafen, bentazon + imazamox, fomesafen, cloransulam, and control without application, and three naphthalic anhydride treatments: without application, foliar application, and application via seed treatment. Visible injuries at 7, 14 and 21 days after application, photosystem II electron transport rate, and plant dry weight were evaluated. The naphthalic anhydride applied via foliar, and seed treatment reduced significantly the visible injuries in relation to the control when using the herbicides bentazon, fluazifop-P + fomesafen, bentazon + imazamox, and cloransulam. The photosystem II electron transport rate was protected by anhydride applied via foliar and seed treatment when using the herbicides bentazon, fluazifop-P + fomesafen and bentazon + + imazamox. The application of naphthalic anhydride via seed treatment protected the BRS-Estilo and BRS-Esplendor common bean cultivars, with no reductions in the plant dry weight when using the herbicides fluazifop-P + fomesafen, and fomesafen. The use of naphthalic anhydride via seed treatment and foliar application protected BRS-Estilo and BRSEsplendor common bean cultivars, from the negative effects of fluazifop-P + fomesafen and fomesafen herbicides. Thus, this practice has potential to be used in common beans.
Three commercially available intercooled compression strategies for compressing CO2 were studied. All of the compression concepts required a final delivery pressure of 153 bar at the inlet to the pipeline. Then, simulations were used to determine the maximum safe pipeline distance to subsequent booster stations as a function of inlet pressure, environmental temperature, thickness of the thermal insulation and ground level heat flux conditions. The results show that subcooled liquid transport increases energy efficiency and minimises the cost of CO2 transport over long distances under heat transfer conditions. The study also found that the thermal insulation layer should not be laid on the external surface of the pipe in atmospheric conditions in Poland. The most important problems from the environmental protection point of view are rigorous and robust hazard identification which indirectly affects CO2 transportation. This paper analyses ways of reducing transport risk by means of safety valves.
In recent time, as the Chinese consumption level increases, the consumption quantity of high-value fruits, vegetables and seafood products have been increasing year by year. As a consequence, the traffic volume of refrigerated products also increases yearly and the popularization degree of the cold-chain transportation enhances. A low-temperature environment should be guaranteed during transportation, thus there is about 40% of diesel oil should be consumed by the refrigerating system and the cold-chain transportation becomes very costly. This study aimed to explore methods that could reduce the cost of transport packages of refrigerated products. On the basis of the heat transfer theory and the fluid mechanics theory, the heat exchanging process of corrugated cases during the operation of refrigerating system was analyzed, the heat transfer process of corrugated cases and refrigerator van was theoretically analyzed and the heat balance equation of corrugated cases was constructed.
A commercially available ASPEN PLUS simulation using a pipe model was employed to determine the maximum safe pipeline distances to subsequent booster stations as a function of carbon dioxide (CO2) inlet pressure, ambient temperature and ground level heat flux parameters under three conditions: isothermal, adiabatic and with account of heat transfer. In the paper, the CO2working area was assumed to be either in the liquid or in the supercritical state and results for these two states were compared. The following power station data were used: a 900 MW pulverized coal-fired power plant with 90% of CO2recovered (156.43 kg/s) and the monothanolamine absorption method for separating CO2from flue gases. The results show that a subcooled liquid transport maximizes energy efficiency and minimizes the cost of CO2transport over long distances under isothermal, adiabatic and heat transfer conditions. After CO2is compressed and boosted to above 9 MPa, its temperature is usually higher than ambient temperature. The thermal insulation layer slows down the CO2temperature decrease process, increasing the pressure drop in the pipeline. Therefore in Poland, considering the atmospheric conditions, the thermal insulation layer should not be laid on the external surface of the pipeline.
Integration of transport subsystems in transfer nodes of public transport in Poznań based on city railway stations, Poznań, being one of the strongest urban centers in the country, has a significant zone of impact (functional area). A natural consequence of this development model are significant communication issues caused by dynamic development of the suburban area. The solution of those issues is assumed to be basing the public communication system on a railway junction and, on its basis, creating the Poznań Metropolitan Railway. However, to ensure efficient functioning of such a system the need arises to integrate it with other systems of transport using transfer nodes. The aim of this article is to illustrate the potential of creating a polycentric system of multi-modal transfer nodes, based on existing city railway stations (district stations). The study focuses on the perspective of the passenger and the primary research method is the in-depth interview. This enabled to learn the opinion and identify the needs of passengers who use the facilities which are the subject of this study. The study also concentrated on analyzing thee communication behaviors of passengers and analyzing thee functioning of city stations themselves. Additionally, information was also acquired regarding the approximate destination of the passengers’ travel, which further allowed to specify the hypothetical impact range of individual city stations. Results of the study allowed to develop a range of recommendations intended to optimize the functioning of selected city railway stations, from a technical, as well as organization and management perspective. They have the potential to become a basis for developing a concept of sustainable public transport with a metropolitan reach.
Measurements of pollutants scavenged from air masses over southern Svalbard in summer precipitation are presented. Rainfall was sampled in July and August 2002 at Calypsobyen, Bellsund. Specific conductivity (SpC) and pH were measured and ion concentrations were determined by ion chromatography. Ions of marine origin were subtracted, assuming that all chlorides were of marine origin. The FLEXTRA trajectory model was applied to discover the sources of air masses arriving at Svalbard and track the paths of pollutant transport. Average (v/w) rainfall pH was 4.94, mean SpC amounted to 34.8 µS cm-1. Total dissolved solids concentration (TDS) ranged from 12.6 to 67 mg L-1, with ions of marine origin (Cl-, Na+, Mg2+) prevailing. Rains with the highest percentage of marine salts occurred with winds from the East at above average velocities. Non-sea salt (nss) sulphate concentrations ranged from 0.5 µeq L-1 to 23 µeq L-1, (v/w) average was 17 µeq L-1. Nitrate concentrations ranged from 0 to 24 µeq L-1. The highest concentrations of nss-SO42- and NO3- were measured on 25 August, when the highest rainfall occurred (27 mm) and pH was the lowest (4.65). Rainfall at Calypsobyen deposited 194 kg km-2 of acidifying anions and 263 kg km-2 of base cations over the recording period. The polluted air masses were mostly from northern and central Europe. Rainfalls scavenging air masses formed over Greenland and Norwegian Seas displayed similar concentrations, being probably polluted by SOx and NOx from ship emissions.
Scientific research discussed in the present article is focused on the determination of the vertical conveyance capacity in the process of mining minerals, while applying a mathematical calculation and verification of the calculation results by simulation. Input parameters for the capacity calculation include the transport cycle time. The article presents the results of measuring a transport cycle during the operation and a calculation of the transport cycle while using known formulas. On the basis of the observed findings, two methods of increasing the hoisting machine capacity were proposed. The first method is increasing the velocity from the original value of 6 m.s–1 to the velocity of 7 m.s–1. In this case, we achieved the daily capacity increase in 2-2.5%. The second method consisted in changing the hoisting machine acceleration and deceleration modes by which we achieved as much as 9% increase in the daily capacity. The article also describes a transport cycle simulation model, with its output being the number of work cycles parameter. The obtained parameter was used again in the capacity calculation. The simulation model was used in experiments for both, the current status as well as proposed solutions. The simulation model serves also for calculation verification.
The development of air transport affects elements of the aviation fuel market. In recent years an increase in both the number of passengers and the number of passenger operations has been observed. This phenomenon also concerns passengers and the number of operations served by Polish airports which translates into more and more fuel consumption in Poland. The authors of the study tried to approximate the characteristics of aviation fuels used in various types of aircrafts. The most important of them, from the perspective of the Polish aviation sector, include Jet. This type of fuel plays a key role in civil aviation. In the article, the enterprises operating in the analyzed sector were also reviewed. The empirical part of the article is devoted, in turn, to the analysis of changes in air passenger transport in Poland and changes in Jet fuel prices on the Polish fuel markets. The conducted research shows that the dynamics of changes in the number of passengers, as well as the number of passenger operations at Polish airports were characterized by an upward trend, and the increase in the number of passengers was driven not only by a larger number of available flights, but also by such factors as: increasing the capacity of aircraft and increasing the fill rate for seats. The authors have also attempted to examine the strength of dependence between the number of passengers deciding to use Polish airports and Jet fuel prices, which in recent years have undergone significant fluctuations. For this purpose, the value of Pearson’s linear correlation coefficient was used and the analyzed period covered the years 2011–2017. The data on passenger traffic used in the study came mainly from periodic reports prepared by the Civil Aviation Office (ULC).
The article is an attempt to present circumstances that nowadays determine negotiating, conclusion and performance of a multimodal transport contract in Poland. Author focuses in particular on parties’ approach, their business and legal conscience in this respect, as well as their decisions’ practical consequences. Doctrinal aspects of a multimodal transport contract are taken into account only as long as it is essential in examining the most common practices of the parties to the contract. Due to particular character of this publication, the method of author’s views presentation is as brief as possible.
The paper refers to planning deliveries of food products (especially those available in certain seasons) to the recipients: supermarket networks. The paper presents two approaches to solving problems of simultaneous selection of suppliers and transportation modes and construction of product flow schedules with these transportation modes. Linear mathematical models have been built for the presented solution approaches. The cost criterion has been taken into consideration in them. The following costs have been taken into account: purchase of products by individual recipients, transport services, storing of products supplied before the planned deadlines and penalties for delays in supply of products. Two solution approaches (used for transportation planning and selection of suppliers and selection of transportation modes) have been compared. The monolithic approach calls for simultaneous solutions for the problems of supplier selection and selection of transportation modes. In the alternative (hierarchical) solution approach, suppliers are selected first, and then transportation companies and their relevant transportation modes are selected. The results of computational experiments are used for comparison of the hierarchical and monolithic solution approaches.
In intra-enterprise logistics and automation of manufacturing processes general a rising productivity by high flexibility is required. Existing transportation systems exclusively use two-dimensional track sections, because they can be served with standard drives. Because of these simple structures the transport speed is limited and thereby also the throughput. In this paper now a modular transportation system is presented which could reach higher speeds with a direct drive and the use of centrifugal force compensating curves. Simultaneously the system also can change the altitude. All this succeeds with the integration of three-dimensional track sections. Therefore a two piped guiding system with a long stator linear motor was designed. To combine the linear motor with the three dimensional track special stator elements were developed which allow a bending of the stator to follow the route course. The current work deals with the implementation of a mechanical passive switch, which is operated by the electromagnetic forces of the linear motor. So no additional mechanical actors or a separate electromagnetic system are necessary.
The paper presents differences between technical states and technical operation states of haul trucks in the technical operation process. The specification and analysis of operational parameters of technological vehicles used in surface mining is possible only due to more and more frequently used diagnostic – telemetric systems. While a detailed analysis of machines operation data can result in the more effective management of mining plant operations and the mining process itself. The determination of operational state indices and their individual components allows preventive actions to be commenced, resulting in improving the work organization of the entire mine machinery system. Moreover, the future technical state of machines operated in surface mining is strictly related to the current state and also depends on the events that occurred in the extraction system. A set of parameter values of individual state characteristics, which allow the haul trucks technical and operational state to be characterized, is a direct effect of a telemetric – diagnostic system operation.