Transport Category Research Articles

Performance evaluation of green logistics: Paving the way towards circular economy

The linear flow of production causes several problems, mainly concerning the environmental pillar of sustainability. In logistics, a more circular and green production system is linked to the implementation of Green Logistics (GL), which aims to reduce the emission of greenhouse gases, the use of fossil energy sources and the return of materials after their end-of-life. Given the need to reduce the environmental damage of plastic packaging used in the production system, the present study uses a tool to evaluate the performance of GL in the plastic sector to help improve environmental performance within organizations and reduce negative environmental impact. The Analytic Hierarchy Process (AHP) method was used with specialists to rank 27 green practices and indicators of the developed tool. Subsequently, the indicators were normalized to create a unified index of the GL in organizations. The tool was applied in two companies of the plastic packaging chain. Results show that some areas of green logistics are being overlooked when companies approach environmental sustainability, thus compromising the progress towards GL. In contrast, the green transportation category presents the worst results, followed by green stocking, green packaging and reverse logistics. Discussions and suggestions for future research on the subject are also drawn. This study presents a practical tool that will help practitioners easily evaluate companies' GL using a unified index.

ВИДИ МЕТРОЛОГІЧНИХ ХАРАКТЕРИСТИК І СКЛАДУ РОБІТ З ЇХ ВИЗНАЧЕННЯ НА ОСНОВНИХ СТАДІЯХ ІСНУВАННЯ КОМПОЗИТНИХ КОНСТРУКЦІЙ АГРЕГАТІВ ПОВІТРЯНИХ СУДЕН ТРАНСПОРТНОЇ КАТЕГОРІЇ

It is shown that the development of the concept of metrological support for the creation of composite structures of aircraft aggregates of the transport category and their support at all stages of the existence of an aircraft should be based on the formation of a complex criterion for the effectiveness of the use of polymer composite materials. It is noted that the effectiveness of a structure made of polymer composite materials is provided by various methods, methods and technical means of metrology. The structure of a complex of studies aimed at developing the concept of metrological support is discussed, the first point of which is to analyze the types of metrological characteristics and the scope of work to determine them at the main stages of the existence of composite structures of aircraft aggregates of the transport category. Based on the analysis of numerous publications on the problem of metrological support of the main stages of creating technical products, the main types of measurements of the metrological characteristics of composite structures of aircraft aggregates of the transport category have been established, and the composition of the nomenclature of works on metrological support of the main stages of the existence of these structures has been determined. 12 main types of measurements of parameters have been identified, on which the whole variety of production physical quantities and the description of the properties and characteristics of structures of aircraft aggregates made of polymer composite materials are based. The composition of the main works on the metrological support of the four stages of the existence of the aircraft is revealed: design, production, operation and disposal of composite structures formed into systems of sequential blocks for performing these works. It is shown that the tasks of metrological support at the facility manufacturers should be solved during the technological preparation of serial production and testing of the installation series of products, and also take into account the peculiarities of aircraft operation and disposal of composite structural elements in terms of work safety and economic efficiency of their results. An enlarged sequence has been established for organizing work on metrological support for measuring the properties of composite structures of aircraft aggregates at aviation enterprises. The results presented in the first approximation provide a solution to practically important aspects of the problem under discussion.

АНАЛІЗ МОЖЛИВОСТЕЙ РЕАЛІЗАЦІЇ МОДУЛЬНОГО ПРИНЦИПУ СТВОРЕННЯ МОДИФІКАЦІЙ ПОВІТРЯНИХ СУДЕН ТА ЇХ ЕФЕКТИВНОЇ ЕКСПЛУАТАЦІЇ В СИСТЕМІ ВІТЧИЗНЯНИХ АВІАПЕРЕВЕЗЕНЬ

It is known that an aircraft generates income for the operating airline only when it is in the air. Being on the ground, at the airport, airlines incur high costs for aerodrome maintenance of the aircraft. The longer the aircraft is stationary on the ground, the shorter the actual flight time of the aircraft. In this regard, the possibility of implementing one of the promising principles for the creation and effective operation of modifications of aircraft of the transport category - the modular principle - has been analyzed. The prospects for the implementation of modular modifications in domestic airlines in the context of further development of the market economy are considered. Modifications based on the implementation of the modular principle are classified into two types - created in the form of autonomous modules placed in the fuselage during aircraft operation and in the form of a removable modular compartment of the aircraft fuselage. A review and analysis of existing projects of these types of modular constructive and technological solutions, a comparison of their advantages and disadvantages in the technical and economic aspects of the prospects for their feasibility are carried out. The possibility of effective implementation of the modular principle of modifications of aircraft of the transport category was assessed, for which a generalized analysis of domestic and foreign information related to the state of the problem under discussion was carried out, on the basis of which an enlarged block diagram of a comprehensive methodology for analyzing the efficiency of operation of modular modifications in the air transportation system was synthesized in comparison with traditional (existing). The key aspects of the content of the main blocks of the scheme are revealed, including the main provisions of the maintenance and repair of aircraft in modern conditions of their operation, based on foreign experience, as well as the main aspects of the content of the blocks for accounting for weight losses in the design and implementation of traditional and modular modifications of aircraft. The generalized information related to the implementation of the synthesized block diagram, focused on subsequent addition, should form the basis of compliance methods and regulatory documentation in the design and implementation of promising domestic modifications of aircraft of the transport category.

ОЦІНКА ВПЛИВУ ЦЕНТРУВАННЯ НА АЕРОДИНАМІЧНУ ЯКІСТЬ, ПОЛЯРУ І ДАЛЬНІСТЬ ПОЛЬОТУ ЛІТАКА

The method of transport category airplane flight range estimation taking into account its center-of-gravity position variation in the process of fuel utilization at cruising flight mode is presented. The method structure includes the following models:– Interinfluence of main parameters on each other in the process of fuel utilization;– Estimation of CG position influence on lift-to-drag ratio in cruising mode;– Quantitative estimation of center-of-gravity position variation influence on airplane flight range.Simulation of the main parameters is based on authoring researches, establishing interinfluence among geometrical and aerodynamic parameters of wing, parameters of horizontal tail and center-of-gravity position variation caused by fuel utilization in cruise flight. Such model allows estimating airplane center-of-gravity influence on their values and relative position.Aerodynamic parameters variation caused by center-of-gravity shift resulted in necessity to take the influence into account, for required engine thrust variation; that is shown in the publication in the form of dependences allowing to take into account the required thrust variation and their influence on range variation.On the base of interinfluence model and taking into account required thrust variation (with center-of-gravity position shift), lift-to-drag variation has been obtained and analyzed in the form of dependences , for middle airplane of transport category.Expression for estimation of airplane flight range under variable values of its mass and center-of-gravity position is obtained on the base of these models; that allows to increase flight range by means of center-of-gravity position dedicated shift.On the example of mid-range transport airplane, it is shown, that at Mach number and center-of-gravity shift back from to , the increase of flight range makes .On the base of presented models, it is shown, that airplane center-of-gravity position influences lift-to-drag ratio, fuel efficiency and as a result on flight range at cruising flight mode.Application of aft center-of-gravity position allows to decrease engine required thrust (and to decrease fuel consumption), and increase lift-to-drag ratio and airplane flight range.

ПРОЕКТУВАННЯ СТУЛКОВОГО ВІДСІКУ ХВОСТОВИХ ВАНТАЖНИХ ЛЮКІВ ЛІТАКІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

The method for determining the main parameters of the tail cargo doors of transport category aircraft is developed. There have been prepared initial data and described the methodology for finding them. An example based on an existing transport aircraft is considered. The basic nomenclature of transported cargoes of the designed aircraft, its dimensions and weight, methods of loading and mooring, additional loading equipment were taken as initial data. As well as such necessary design, operational and regulatory parameters and data as landing gear type, its “kneeling” system, rails of the upper loading equipment for loading and unloading, cargo trajectories during loading and landing, requirements of international regulatory organizations FAR, CS, AP. The principle of determining the dimensions of the cargo compartment, cargo floor and the hitting platforms in the form of ramp with pressure door, ladders is presented, based on the initial data. Taking into account the loading and unloading, landing operations described the dependence of the ramp length on the length of the cargo floor. The correct formation of these parameters is one of the most important tasks, from the solution of which directly depend the operational characteristics of the future transport aircraft. A method for designing cargo door fairings in the transport category aircraft fuselage tail part is also presented. There have been determined the main features of the fairings compartment, its main components and their varieties, depending on the scheme of the cargo door. At the stage of preliminary design, the principles for determining the main parameters of the fairings compartments based on their design purpose are outlined.Also provided information on the fairings compartment structural elements parameters selection: the axes of the fairings hinge, the selection of control cylinders and their installation, the parameters of the open and closed position locks, pressurization and sealing of the fairings compartment. Considered the design features of the fuselage tail section various theories fairings compartment - made in cross-section with one radius (in the shape of a cylinder) and given in cross-section with two radii (double-deck).

Transport category airplane flight range calculation accounting center-of-gravity position shift and engine throttling characteristics

A problem facing world commercial aviation is a provision of the flight range and an increase in the fuel efficiency of transport category airplanes using fuel trim transfer application, which allows for decreasing airplane trim drag at cruise flight. In the existing mathematical models, center-of-gravity position is usually assumed fixed, but with fuel usage, center-of-gravity shifts within the definite range of center-of-gravity positions. Until the fuel trim transfer was not used in airplanes, the center-of-gravity shift range was rather short, that allowed to use the specified assumption without any considerable mistakes. In case of fuel trim transfer use, center-of-gravity shifts can reach 15…20 % of mean aerodynamic chord, that requires considering the center-of-gravity actual position during the flight range calculation. Early made estimated calculations showed the necessity of following mathematical model improvement using accounting the real engine throttling characteristics. The goal of this publication is to develop a method of flight range calculation taking transport category airplane into account actual center-of-gravity position with fuel using and variation in engine-specific fuel consumption according to their throttling characteristics. On the basis of real data from engine maintenance manuals, formulas are obtained for approximation throttling characteristics of turbofan engines in the form of dimensionless specific fuel consumption (related to the specific fuel consumption at full thrust) dependence on the engine throttling coefficient. A mathematical model (algorithm and its program implementation using С language in Power Unit 11.7 R03 system) has been developed to calculate the airplane flight range accounting its actual center-of-gravity position shift with fuel usage and variation in specific fuel consumption according to engine throttling characteristics. Using comparison with known payload-range diagram, adequacy of developed mathematical model is shown. Recommendations to improve the mathematical model are also given.

Structural Analysis and Optimization of Wings Subjected to Dynamic Loads

Dynamic loads arising from the Title 14 Code of Federal Regulations (14 CFR; “Aeronautics and Space,” Federal Aviation Administration, U.S. Dept. of Transportation, Subchapter C Aircraft, Part 25 Airworthiness Standards: Transport Category Airplanes, https://ecfr.federalregister.gov/current/title-14/chapter-I/subchapter-C/part-25 [retrieved 23 August 2021]) are critical drivers of aircraft design. The aircraft structural design process is an iterative one involving computationally expensive simulations. Existing methods simplify the dynamic loads to equivalent static ones and design the structure using shell-based analysis. Other literature approaches use beam models for structural sizing but make assumptions on the geometry, material distribution, or both. In this work, the use of the Variational Asymptotic Method is explored to 1) systematically reduce the three-dimensional (3-D) wingbox to a one-dimensional (1-D) model, 2) solve the 1-D model using a nonlinear beam theory, and 3) recover the stress field on the wingbox. An adjoint-driven gradient-based structural optimization framework is developed to size the structure for dynamic loads subjected to strength-based failure considerations. The proposed structural analysis method is applied to the wingbox structural analysis and sizing of a novel hybrid-electric propulsion aircraft: NASA’s Parallel Electric-Gas Architecture with Synergistic Utilization Scheme (PEGASUS) concept. Results in the paper show that the sizing of aircraft wings for 14 CFR specified maneuvers 2.5 and static maneuvers using the proposed approach produces a 6% difference in weight compared to a shell-based method but with a speedup of 7.8 times, and it is efficient at sizing the wingbox structure for dynamic loads generated by gust maneuvers.

ПОКАЗНИК ЕФЕКТИВНОСТІ СТВОРЕННЯ МОДИФІКАЦІЙ ПОВІТРЯНИХ СУДЕН ТРАНСПОРТНОЇ КАТЕГОРІЇ ДЛЯ РЕАЛІЗАЦІЇ ЙОГО В ПРОЦЕСІ ВИРОБНИЦТВА

An analysis of the problem of the effectiveness of the creation of aircraft of the transport category was carried out and it was noted that the effectiveness indicator generally expresses the ratio of the operational effect of one aircraft for its service life as the target return in monetary terms to the cost of its creation is the essence of this concept as applied to its specific Implementation for any type of objects, including for modifications of aircraft of the transport category. Analysis of the features of applying an indicator of efficiency to the creation of aircraft modifications made it possible to interpret the operational efficiency for the entire period of operation of the aircraft modifications as the profit of the manufacturer's company, and the cost of manufacturing an object - as the amount of works of labor intensity of technological actions aimed at creating aircraft modifications to the relative cost of these actions, assigned to one norm-hour. Any technological actions include technological operations, processes, cycles, as well as organizational and technical measures, ensuring the effectiveness of creating aircraft modifications, including the cost of purchasing materials and aggregates. The process of forming a contract is considered to produce a series of modifications, in demand by the operator in the air transportation market, consistently acquisition in the initial delivery part of the series, followed by manufacturing and supply with a given sales ratio. The dependence of the total producer's total profit from the timing of the supply of modifications, its prices, production costs and sales coefficients, from which inequality should be determined by the level of permissible costs, as well as the profitability coefficients expressed by the ratio of profit to the sales volume. To find the maximum performance indicator, a technique was proposed for determining the minimum production costs and its implementation algorithm by minimizing the total costs in their set of all technological actions when limiting the regulated values. Recommendations are given to improve the efficiency of the contract in case of non-fulfillment of restrictive inequalities for industrial costs.

Формування областей основних параметрів модифікацій транспортного літака за умовами його базування

Along with the unique flight performance indicators and economic indicators that characterize heavy transport aircraft, the priority is also to ensure the basing for their heavier modifications at the airfields declared for the base aircraft. This problem arises at the very early stage of the modification creation, when its main parameters such as the gross mass at takeoff and thrust-to-weight ratio are formed. This is due to the very essence of creating a modification ‑ increasing its carrying capacity (which leads to increase in the gross mass at takeoff and flight range ) with an increased payload by increasing the mass of fuel on board. Ensuring growth of flight and hour , performance underlies the creation of all modifications of transport category aircraft. For heavier modifications than their base aircraft, it is further complicated by the fact that the base models are based on the runways of the second and first class airfields, which creates an insurmountable limitation on the available runway length. The second limitation is the value of the decision-making speed during takeoff, in case of failure of the critical engine during the takeoff run, which predetermines the required length of the runway. Since the takeoff masses of aircraft modifications of this type continue to increase, the problem of their basing on the runways of existing airfields arises by forming the takeoff weight relationship – decision-making speed in case of a critical engine failure ‑ thrust-to-weight ratio, providing the basing of a heavier modification at the airfield declared for the base aircraft . To implement this condition, a model for determining the speed , in which a safe termination of the takeoff run is possible in the event of a critical engine failure. The resulting model allows to take into account a number of restrictions due to the properties of heavy aircraft, such as the minimum and maximum thrust of the cruise engines, which makes it possible to make reasonable recommendations in the operating rules for aircraft of this type. Taking into account the expressions obtained to determine , a model has been formed to determine and assess the required thrust-to-weight ratio of a heavier modification by condition for modifications with a takeoff weight of more than 300 tons. It has been established that the required relative thrust-to-weight ratio should be within . Defining parameters such as , and is the basis for the implementation of other modification changes in the heavy transport aircraft.

Do the European Data Portal Datasets in the Categories Government and Public Sector, Transport and Education, Culture and Sport Meet the Data on the Web Best Practices?

The European Data Portal is one of the worldwide initiatives that aggregates and make open data available. This is a case study with a qualitative approach that aims to determine to what extent the datasets from the Government and Public Sector, Transport, and Education, Culture and Sport categories published on the portal meet the Data on the Web Best Practices (W3C). With the datasets sorted by last modified and filtered by the ratings Excellent and Good+, we analyzed 50 different datasets from each category. The analysis revealed that the Government and Transport categories have the best-rated datasets, followed by Transportation and, lastly, Education. This analysis revealed that the Government and Transport categories have the best-rated datasets and Education the least. The most observed BPs were: BP1, BP2, BP4, BP5, BP10, BP11, BP12, BP13C, BP16, BP17, BP19, BP29, and BP34, while the least observed were: BP3, BP7H, BP7C, BP13H, BP14, BP15, BP21, BP32, and BP35. These results fill a gap in the literature on the quality of the data made available by this portal and provide insights for European data managers on which best practices are most observed and which ones need more attention.

Water Infrastructure: Does the US Need a National Policy?

Although its investment needs lag the dominant transportation category, water infrastructure addresses human needs at a foundational level because it plays public health and economic roles. Much of it is old and not likely to be replaced soon, so federal policy must focus on intergovernmental leadership to sustain vital dams, urban water systems, and natural systems. Fixing the federal responsibility requires attention to intergovernmental relations and the conflicting goals of investment and regulation. Regulatory reform is ongoing, and normally not amenable to political initiatives. Federal water policies for both investment and regulatory controls seem to be on a flat trajectory, which is expected because they have evolved over decades. These can be summarized as: maintain federal dams and levees, invest in small grants and leveraging funds for state and local governments, address water justice issues, and operate essential programs like flood insurance. Public health and safety concerns will continue to dominate, more than in other infrastructure sectors. The future of water investments will be to hold the course with occasional shifts to respond to emergencies and new opportunities, such as greater private sector involvement.

КЛАСИФІКАЦІЙНИЙ АСПЕКТ МЕТРОЛОГІЧНОГО ЗА-БЕЗПЕЧЕННЯ АВІАЦІЙНИХ КОНСТРУКЦІЙ З ПОЛІМЕРНИХ КОМПОЗИЦІЙНИХ МАТЕРІАЛІВ

An analysis of the classification aspect of metrological support of aviation structures from polymer composite materials was carried out.It is shown that the effectiveness of the objects under consideration is predetermined by their competitiveness in the global market for sales and services. One of the important components of the multidimensional efficiency of the use of polymer composite materials in the aircraft of the transport category is metrological support at all stages of creating composite structures.It was noted that the main objectives of the qualimetry of aviation structures made of polymer composite materials is to ensure the unity and accuracy, high quality products, reduce the cycle of its production, cost, reliability, and the same operation of operation.The achievement of the objectives of metrological support and challenges facing it is formed on the basis of a classification approach to the analysis of the main stages of the life cycle of the existence of composite structures, including an analysis of the effectiveness of aircraft constructions from polymer composite materials, which constitute the stage of their design and production, as well as tests, operation, disposal and forecast of perspectives Growth of the quality of products from polymer composite materials.A classifier of the stages of the life cycle of aircraft of the transport category of polymer composite materials were proposed, its top-level decomposition was carried out, including the composition of the species, classes, subclasses, groups and subgroups and their analysis was carried out. In the proposed classifier, starting with subclasses, previewed backup blocks, the need to use which may occur upon subsequent analysis of each stage.The proposed classification approach to the metrological support of composite structures and its further development on all the main stages of the life cycle of their existence, it is one of the most important components of the implementation of a high level of competitiveness of domestic aircraft transport categories in the global sales and services market.

МЕТОД ІНТЕГРОВАНОГО ПРОЕКТУВАННЯ НОСОВОЇ ЧАСТИНИ ФЮЗЕЛЯЖУ ЛІТАКА ТРАНСПОРТНОЇ КАТЕГОРІЇ

Regulatory and technical documentation, design features and methods of fuselage transport category aircraft design was performed and identified the need to update design methods and calculate the characteristics of the fuselage using parametric models and integrated design systems CAD / CAM / CAE / PLM. The method of integrated fuselage design of transport category aircraft is developed and theoretically substantiated. Within the framework of the proposed method, parametric models of master geometry, aerodynamic flow and mass-inertial characteristics of the fuselage were created, taking into account the design features of transport aircraft.The proposed method was used to study the influence of geometric parameters of fuselage nose section on aerodynamic and mass characteristics of the fuselage, showing the efficiency of work with parametric models.The choice of parameters of the fuselage nose section in preliminary and sketch design of a promising aircraft for local airlines is justified, which allowed to implement and test the suitability of the proposed method for in new competitive aircraft designing process.The use of the method for integrated fuselage design for local aircraft allowed to determine the rational configuration of the nose section of the fuselage and increase the fuel efficiency of the aircraft by 6.4%, reduce the aerodynamic drag of the fuselage by 10%, increase the viewing angle from the cockpit by 10%. and ensure compliance with current regulatory and technical documentation, as well as determine the mass-inertial characteristics of the fuselage and its parts and form a list of cockpit equipment that will meet flight safety requirements, taking into account the operating conditions and modifications of the aircraft.The configuration of the nose section of the aircraft fuselage for local airlines has been developed, which allows to fit modern requirements for cockpit equipment and layout, low fuselage impedance and high aerodynamic quality and fuel efficiency in cruising mode at speeds up to 850 km / h (M = 0, 8). As a result of verification using other methods and parameters of existing aircraft, the accuracy of the results obtained using the proposed method at the level of 5% was confirmed.

Upstream oncology: identifying social determinants of health in a gynecologic oncology population

Introduction: Social determinants of health (SDoH) are the factors that affect a patient’s health quality and outcomes and contribute to health disparities. Evidence suggests that clinical care contributes only 20% to patients’ health outcomes, while the remainder is under the influence of upstream factors. The upstream approach to healthcare aims to address SDoH before they contribute to less ideal outcomes downstream. Several SDoH may contribute to outcomes for cancer patients. This Upstream Gynecologic Oncology Initiative seeks to identify which SDoH affect a population of patients with gynecologic malignancies. Hypothesis: This study hypothesizes that women receiving care for gynecologic malignancies are affected by specific SDoH among the categories of housing, food, transportation, finances, health literacy and social support. This study aims to identify the frequency of these six social factors among the outpatient gynecologic oncology population at the University of Iowa. Methods: This needs assessment is the first phase in a quality improvement project assessing the SDoH affecting women with gynecologic cancers. Two hundred twenty-two patients receiving outpatient care for gynecologic malignancies completed an anonymous needs assessment survey. Validated survey questions regarding housing, food, transportation, finances, health literacy and social support were used to identify needs. Responses were considered positive if any degree of need was reported. Results: Responses demonstrated the most substantial need in the categories of social support (32%), health literacy (28%) and financial stability (24%). Less need was reported in the categories of food (11%), transportation (5%) and housing (4%). Fifty-seven percent of women reported at least one social need among the six categories screened. Conclusion: Upstream SDoH, most notably social support, health literacy and financial stability are identified to be present and likely contributing to health quality, outcomes, and disparities within this gynecologic oncology patient population. Overall, these findings support the idea that SDoH should be assessed for each unique patient population - and for each patient receiving care for gynecologic cancer. While social support was the most frequently reported SDoH, many patients already received adequate help at home; suggesting that meaningful efforts should next be directed at improving health literacy in the population. Appreciation and assessment of SDoH potential to impact care and management should be used to design a routine screening tool for the study population and organize resources to address or mitigate the identified needs.

THE LEED-COMMERCIAL INTERIORS (V4) PROJECTS IN CALIFORNIA

ABSTRACT This study analyzed the Leadership in Energy and Environmental Design for Commercial Interior Certified, Silver, and Gold projects version 4.0 (LEED-CIv4) in California for the period 2015‒2020. Nonparametric tests were used to assess category and credit achievement, i.e., the difference between possible and achieved points and the correlation between associated credits. The results show that most of the credits in the location and transportation category and the indoor environmental quality categories had a high level of achievement, a few credits in the energy and atmosphere and materials and resources categories had a high level of achievement, and all of the credits in the water efficiency category had a low level of achievement. Some associated credits, such as surrounding density and quality transit, had a high level of achievement and a positive correlation, whereas other associated credits, such as life-cycle impact reduction and environmental product declarations, had a low level of achievement and a positive correlation. If LEED-CIv4 credits meet the requirements of the California Green Building Standards Code 2016 (CGBSC 2016), then these credits typically have a medium/high level of achievement. If LEED-CIv4 credits exceed the requirements of CGBSC 2016, then these credits have a low level of achievement. Therefore, to improve the next version of LEED-CI, it is necessary to improve the local green codes.

Порівняльна оцінка модифікацій літаків транспортної категорії за частковими та інтегральними показниками ефективності

The subject of the article is a method for evaluating the effectiveness of modifications of transport category aircraft by partial and integrated indicators, including the marketing cost of the flight and the cost of aircraft hours of air transportation, the amounts of which provide the relationship of economic indicators and parameters used in the design. The aim is to increase the efficiency of modifications of transport category aircraft relative to the basic ones. Objectives: to develop models for estimating modification changes according to integrated cost indicators; to carry out a comparative assessment of different modifications of the transport category aircraft in terms of partial and integrated cost indicators. The methods used are analysis and synthesis of research indicators, mathematical approaches for their evaluation based on the solution of systems of equations. The following results were obtained. According to the analysis and synthesis, the shortcomings of the above partial cost-effectiveness indicators were identified, Optimization of modifications on this indicator gives the maximum economic effect. Taking into account this circumstance, to assess the cost-effectiveness of modifications of transport aircraft, models have been developed that allow determining the cost of LC modifications with a variant change of the modified parameters, such as takeoff mass, flight performance, declared resource, etc., which are laid before modification. making conceptual decisions when creating it. Five modifications of a light transport aircraft are considered, in which such parameters as take-off mass and flight performance were changed. It is accepted that the change in takeoff mass is associated with an increase in the transported cargo, and the change in flight performance - with an increase in range from 2000 to 4000 km. Based on mathematical approaches for estimating existing partial and newly introduced integrated indicators, these five possible modifications of light transport aircraft are analyzed. There is a clear inadequacy in assessing the effectiveness of the developed options for partial and integrated indicators of their effectiveness. Conclusions. The scientific novelty of the obtained results is as follows: a method for estimating the total cost of LC modifications of transport category aircraft, taking into account the characteristic parameters of the modification: flight performance in the form of the characteristic "cargo - range"; the declared resource of modification, and also partial criteria, such as cost of air-hour of air transportation; the cost of transportation of 1 ton of cargo per 1 kilometer; full cost per flight of a transport category aircraft. The proposed method has significantly expanded the information based on which decisions can be made on the competitiveness of various modifications.

Detailing the impact structure of the participants of the complex transport service

During the reforms underway in the railway industry, the consolidation of companies and vehicles, the formation of new models of transportation services is achieved through the creation and implementation of integrated high-tech information systems. In this case, a holistic approach to the effective management of the production system should determine the extent of their responsibility. The article illustrates the main aspects of quality management of customer service as one of the key factors of transportation company efficiency in the segment of freight transportation. The procedure of quality estimation of the transportation service is presented in the Target model of the complex transport service by each of its parties in the different transportation categories. Specification of the impact structure of the parties of the complex transport service on its quality level through calculation of a responsibility ratio has been made.

Аэродинамический профиль в трансзвуковом потоке газа

The subject of investigation in this article is transonic flow. This is a condition in which local speeds of sound are appears on the wing surface, even at the subsonic speed of the nonturbulent flow. As a result, at a certain speed of the incoming flow, the flow regime around the aerodynamic surface will change sharply, which in turn changes the aerodynamic characteristics. Aerodynamic surfaces of the most transport category airplane experience transonic airflow during flight. The goal of the investigation is to study aerodynamic characteristics using numerical methods. The use of numerical methods in the design of aircraft structures is used more and more often to determine the optimal parameters for given operating conditions. This contributes to obtaining a more optimal and perfect design. In this article, we carried out a numerical analysis of the aerodynamic characteristics of airfoils in the transonic flow case using the CAE system CFD ANSYS. As a result of the research, the distributions of the pressure coefficients over the profile surface were obtained. The nature of the flow is obtained, which is similar to the picture of the pressure coefficients for transonic flow in the published sources of this topic. In the area of the middle of the profile, a shock-wave is observed. As a result, the flow around the airfoil changes, which contributes to a change in aerodynamic characteristics. The behavior of the aerodynamic drag and lift coefficients depending on the speed of the Mach number is considered. Also, the position of the center of pressure was analyzed at various velocities of the nonturbulent flow. The calculation was carried out at the cruising altitude of a medium-range aircraft of 11 km. For the calculations, we used the characteristics of the air temperature, the pressure of a given height from the table of the standard atmosphere.

Ion Transporters and Osmoregulation in the Kidney of Teleost Fishes as a Function of Salinity.

Euryhaline teleosts exhibit major changes in renal function as they move between freshwater (FW) and seawater (SW) environments, thus tolerating large fluctuations in salinity. In FW, the kidney excretes large volumes of water through high glomerular filtration rates (GFR) and low tubular reabsorption rates, while actively reabsorbing most ions at high rates. The excreted product has a high urine flow rate (UFR) with a dilute composition. In SW, GFR is greatly reduced, and the tubules reabsorb as much water as possible, while actively secreting divalent ions. The excreted product has a low UFR, and is almost isosmotic to the blood plasma, with Mg2+, SO42–, and Cl– as the major ionic components. Early studies at the organismal level have described these basic patterns, while in the last two decades, studies of regulation at the cell and molecular level have been implemented, though only in a few euryhaline groups (salmonids, eels, tilapias, and fugus). There have been few studies combining the two approaches. The aim of the review is to integrate known aspects of renal physiology (reabsorption and secretion) with more recent advances in molecular water and solute physiology (gene and protein function of transporters). The renal transporters addressed include the subunits of the Na+, K+- ATPase (NKA) enzyme, monovalent ion transporters for Na+, Cl–, and K+ (NKCC1, NKCC2, CLC-K, NCC, ROMK2), water transport pathways [aquaporins (AQP), claudins (CLDN)], and divalent ion transporters for SO42–, Mg2+, and Ca2+ (SLC26A6, SLC26A1, SLC13A1, SLC41A1, CNNM2, CNNM3, NCX1, NCX2, PMCA). For each transport category, we address the current understanding at the molecular level, try to synthesize it with classical knowledge of overall renal function, and highlight knowledge gaps. Future research on the kidney of euryhaline fishes should focus on integrating changes in kidney reabsorption and secretion of ions with changes in transporter function at the cellular and molecular level (gene and protein verification) in different regions of the nephrons. An increased focus on the kidney individually and its functional integration with the other osmoregulatory organs (gills, skin and intestine) in maintaining overall homeostasis will have applied relevance for aquaculture.

Benefits for Greek Regional Airports Through Innovative Approach Technology Using an LPV to GLS Converter: A Case Study for Corfu and Thessaloniki

Required navigation performance procedures are a cost-effective and accurate solution for aircraft instrument approaches, especially when combined with a final approach segment utilizing satellite based augmentation. However, transport category aircraft are currently not equipped with the satellite based augmentation for precision guidance. An existing converter technology can provide this final approach segment to aircraft equipped with the GPS landing system. Then, as an added bonus, an automatic landing at pilots discretion is possible after the presented approach. Here, we study Thessaloniki and Corfu airports, both accommodating a large number of transport category aircraft, with many ground infrastructure constraints. Both were recently equipped by the Hellenic air navigation service provider with RNP approaches. We successfully flight tested the satellite based augmentation to GPS landing system converter and show that both airports could benefit from a permanent installation of such a system by having fewer diversions.