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Bionic robots have great potential in healthcare, rescue, and surveillance. However, most soft actuators can only realize one or two deformation modes, which largely limit the application in complex environments. This study develops electric/Infrared (IR) light/magnetic multi‐field coupling soft actuators by combining liquid crystal elastomers (LCE), liquid metal (LM) and magnetic Ecoflex (Mecoflex). Originated from the synergistic effect of the differed thermal expansion and the liquid crystal phase transition, the actuator can realize outstanding large deformations (bending angle > 300°) at ultra‐low voltages (1.0 V). In addition, by designing the molecular orientation in the LCE layer and programming the magnetization in the Mecoflex layer, the bending or helical bending deformations can be controlled under electric/magnetic and IR light/magnetic coupling actuation. Based on the complex deformation capability, bionic climbing plants and two kinds of quadrupedal robots are developed. With the structural design of the quadrupedal robots, they can flexibly switch deformations to pass through complex environments by controlling the externally applied coupling fields, which demonstrates their broad potential in practical applications. [ABSTRACT FROM AUTHOR]

This review explores the Neapolitan pizza baking process in a traditional wood‐fired oven, employing visual color analysis and IR thermal scanning to detail heat exchange mechanisms. During cooking, the oven floor temperature in the pizza area decreased proportionally to the pizza's mass, whereas the free area maintained a constant temperature of 439 ± 3°C. An IR thermal camera indicated that the oven dome temperature reached approximately 480°C with a weak flame and 500°C with a strong flame. The pizza's bottom achieved a maximum temperature of 100 ± 9°C, facilitated by the Pizzaiolo's skill in lifting and rotating the pizza for uniform cooking. Top temperatures varied: up to 180°C for white pizza and 84°C and 67°C for tomato and Margherita pizzas, respectively. IRIS electronic eye analysis revealed more browning and blackening on the pizza's top compared to its bottom, with peaks of about 26% and 8% for white pizza, respectively. Rapid baking is pivotal in Neapolitan pizza‐making, necessitating precise heat and mass transfer management to influence sensory attributes. European Commission Regulation No. 97/2010 mandates wood‐fired ovens for true Neapolitan pizza, but environmental concerns prompted the Associazione Verace Pizza Napoletana to certify gas or electric ovens when wood‐fired ovens are impractical. Operating costs vary: liquefied petroleum gas ovens are the costliest, with costs ranging from €5.38 to €6.19/h, whereas natural gas and electric ovens have operating costs between €2.70 and €4.10/h. At €0.15/kg, firewood is the most economical, supporting traditionalist views. However, natural gas and electric ovens present competitive costs under stringent antipollution laws, making them viable alternatives. [ABSTRACT FROM AUTHOR]

Spinel ferrites are vital in developing next-generation technologies with potential applications covering the medical, electronic, and material industries. Nickel-cadmium spinel ferrites are soft magnetic materials having lots of applications ranging from electronics and magnetic to sensors industries. Herein, we developed cadmium-substituted spinel ferrites (Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4) and their nanocomposite with polymer polyvinyl alcohol (PVA). The results evidently indicate that the successfully developed Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4, which also confirmed the loading of PVA onto the Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4 materials. XRD results confirmed orthorhombic single-phase structure. The optimal particle size was 27.22 nm, and the minimum was 21.25 nm, respectively, as shown by Ba 0·5 Ni 0·1 Cd 0·4 Fe 2 O 4 (x = 0.4) and PVA composite of Ba 0·5 Ni 0·2 Cd 0·3 Fe 2 O 4 (x = 0.3). It was also observed that the composites showed lower particle size than nano-ferrites. Spectral analysis (Fourier Transform Infrared Spectroscopy) confirmed the formation of spinel ferrites by detecting the M − O bonds in the 400-800 cm−1 region. υ 1 and υ 2 were appeared in the range 560–609 cm−1 and 439-466 cm−1, corresponding to M-O. The average grain size of spinel ferrites was 0.55, 0.50, 1.03, and 1.31 μ m for Ba 0·5 Ni 0.5-x Cd x Fe 2 O 4 (x = 0.1, 0.2, 0.3, and 0.4) spinel ferrites. Dielectric parameters revealed that these materials are suitable for high-frequency devices due to their low dielectric loss, high quality factor, short relaxation time, and diverse responses. [ABSTRACT FROM AUTHOR]

Electric discharge drilling (EDD) is a competent method for drilling hard-to-cut materials despite its drawbacks, including minimum material removal rate (MRR), excess tool wear rate (TWR), high surface roughness (Ra), and power consumption (PC). To address these issues, EDD's performance was explored by varying factors like tool electrode geometry (TEG), current (I), pulse-on-time (TON), and tool electrode speed (TES) to investigate the effect on MRR, TWR, Ra, and PC. Cu-6 produced the highest MRR of 36.26 mm³/min, surpassing Cu-7, Cu-8, and Cu-solid by 28.309%, 44.866%, and 51.843% respectively. Cu-solid revealed the lowest TWR of 4.397%, significantly lower than Cu-6, Cu-7, and Cu-8. Ra followed the trend: Cu-solid < Cu-8 < Cu-7 < Cu-6. Cu-solid consumed more power than hollow electrodes. Microscopic analysis attributed rough surfaces to high currents. Energy dispersive X-ray (EDX) analysis exhibits material migration from a workpiece and tool electrode on the machined surface.. [ABSTRACT FROM AUTHOR]

The increasing volume of personal motorized vehicles (PMVs) in cities has become a serious issue leading to congestion, noise, air pollution and high land consumption. To ensure the sustainability of urban transportation, it is imperative to transition the current transportation paradigm toward a more sustainable state. Transitions within socio-technical systems often arise from niche innovation. Therefore, this paper pursues the technical optimization of such a niche innovation by applying a technical sustainability perspective on an innovative mobility and logistics concept within a case study. This case study is based on a centrally managed connected, automated, shared and electric (CASE) vehicle fleet which might replace PMV use in urban city centers of the future. The key technical system components of the envisioned mobility and logistics concept are analyzed and optimized with regard to economic, ecological and social sustainability dimensions to maximize the overall sustainability of the ecosystem. Specifically, this paper identifies key challenges and proposes possible solutions across the vehicle components as well as the orchestration of the vehicles' operations within the envisioned mobility and logistics concept. Thereby, the case study gives an example of how different engineering disciplines can contribute to different sustainability dimensions, highlighting the interdependences. Finally, the discussion concludes that the early integration of sustainability considerations in the technical optimization efforts of innovative transportation systems can provide an important building block for the transition of the current transportation paradigm to a more sustainable state. [ABSTRACT FROM AUTHOR]

Developing technology and increasing population trigger the increasing of the energy demand. As a result, increase in energy demand has accelerated the studies in this field. Conventional energy sources were used currently as usual however it was desired to be limited due to the risk of depletion and negative environmental effects. Therefore, environmentally friendly and no risk of depletion renewable energy sources have created an alternative to conventional energy sources were the frequently studied topics recently. The use of biomass as a renewable energy source has led to development in agriculture and animal husbandry. Products that appear as waste in agriculture and animal husbandry will be evaluated and recycled. If animal feces remain in nature, the methane gas released creates a greenhouse effect and causes global warming. It becomes harmful to human health after mixing with water. For this reason, it is important to obtain electrical and heat energy and dispose of it recyclable. Within the scope of this study, the potential electrical energy that can be obtained from biogas was investigated, considering the collectability of animal feces in Ankara, Gaziantep and Kars provinces located in different regions of our country. In this context, it has been determined that 375,497.55 Mega Watt Hour Electricity (MWhe/year ) from Ankara, 115,452.27 MWhe/year from Gaziantep, and 198,691.4 MWhe/year from Kars have the potential to obtain electrical energy from biogas. [ABSTRACT FROM AUTHOR]

The present study refers to the maximization of self-consumption through the automation of a residential consumer that is or not fed from the low-voltage electrical network and from its own photovoltaic system. The level of self-consumption from photovoltaic sources in the residential sector is strictly dependent on the power installed in the own sources, as well as the load profile of the respective consumer. Two major directions are relevant regarding the possibility of increasing and optimizing self-consumption: the management of electrical energy storage systems (especially through the use of battery systems), respectively the implementation of load management systems, through the partial or total redistribution of their operation over time, but also through prioritization of critical consumers. [ABSTRACT FROM AUTHOR]

This paper offers a comprehensive exploration of the implementation of fully electric transportation systems within urban college campuses. Urbanization and environmental concerns have intensified the need for sustainable transportation solutions, and college campuses serve as ideal testbeds for innovative mobility initiatives. The paper begins by establishing the context through background research, which highlights the adverse effects of urban air pollution and the role of electric vehicles (EVs) in mitigating these issues. The driving forces behind the adoption of fully electric transportation systems are discussed, Benefits, challenges, and implications of implementing electric transportation systems are meticulously examined. The anticipated benefits encompass improvements in air and noise pollution, reduced operational costs, and enhanced campus reputation. Nevertheless, the challenges of infrastructure costs, charging management, and operational intricacies are acknowledged. The paper underscores that successful implementation goes beyond immediate advantages, positioning campus electric transportation systems as living laboratories for research and innovation in sustainable mobility. Additionally, these systems serve as models for neighboring communities and influence regional transportation policies. The paper concludes by laying the groundwork for forthcoming discussions. It highlights the subsequent sections' focus on planning, stakeholder engagement, technological integration, and operational management, which collectively shape the implementation. The paper will employ the application of Systems Thinking approaches, tools, and techniques in order to properly analyze and tackle the problem statement at hand. [ABSTRACT FROM AUTHOR]

Electric scooter (ES)-related injuries are increasing but poorly described. Clinicians need more information to be prepared for these patients. We supposed two prevalent patterns of patients: mildly injured (predominant upper-limb injuries) and severely injured (predominant head trauma). This study aims to understand the frequency of ES-related injuries and patients' characteristics despite the heterogeneity of data currently available. A systematic review with a proportion meta-analysis was conducted on studies with a multidisciplinary description of ES-related injuries in adult patients (PROSPERO-ID: CRD42022341241). Articles from inception to April 2023 were identified in MEDLINE, Embase, and Cochrane's databases. The risk of bias was evaluated using ROBINS-I. Twenty-five observational studies with 5387 patients were included in the meta-analysis, depending on reported data. Upper-limb (31.8%) and head (19.5%) injuries are the most frequent (25/25 studies included). When injured while riding, 19.5% of patients are intoxicated with drugs/alcohol, and only 3.9% use a helmet, increasing the possibility of severe injuries. About 80% of patients are victims of spontaneous falls. Half of the patients self-present to the ED, and 69.4% of cases are discharged directly from the ED. Studies' limitations include an overall moderate risk of bias and high heterogeneity. Electric scooter-related accidents are commonly associated with upper-limb injuries but often involve the head. Spontaneous falls are the most common mechanism of injury, probably related to frequent substance abuse and helmet misuse. This hot topic is not adequately investigated due to a lack of data. A prospective registry could fill this gap. [ABSTRACT FROM AUTHOR]

In this work, we examine the possibility of converting a light propeller-driven aircraft, powered by a spark-ignition, reciprocating piston, and internal combustion engine running on AVGAS, into one powered by an electric motor driven by a proton exchange membrane fuel cell stack running on hydrogen. Our studies suggest that storing hydrogen cryogenically is a better option than storing hydrogen under pressure. In comparison to cryogenic tanks, high-pressure tanks are extremely heavy and unacceptable for light aircraft. We show that the modified aircraft (including batteries) is no heavier than the original, and that the layout of the major components results in lower movement of the aircraft center-of-gravity as the aircraft consumes hydrogen. However, we acknowledge that our fuel cell aircraft cannot store the same amount of energy as the original running on AVGAS. Therefore, despite the fact that the fuel cell stack is markedly more efficient than an internal combustion engine, there is a reduction in the range of the fuel cell aircraft. One of our most important findings is that the quantity of energy that we need to dissipate to the surroundings via heat transfer is significantly greater from a fuel cell stack than from an internal combustion engine. This is particularly the case when we attempt to run the fuel cell stack at high current densities. To control this problem, our strategy during the cruise phase is to run the fuel cell stack at its maximum efficiency, where the current density is low. We size the fuel cell stack to produce at least enough power for cruise, and when we require excess power, we add the energy stored in batteries to make up the difference. [ABSTRACT FROM AUTHOR]

This work covers a numerical analysis of the design and optimization of a thermoelectric cooler (TEC) operated by a thermoelectric generator (TEG). The aim of the work was to design the optimum mini refrigerator for tractors and also to provide cooling using the energy produced in the TEG used in the tractor. Thanks to the TEC powered with the TEG system, farmers will be able to preserve their food during working hours without additional fuel consumption. When the literature is examined, no study has been found in which cooling is done by using the compressor air of turbocharged systems. Therefore, this work will make an important contribution to the literature. According to the numerical results obtained, while the electrical power requirement was 34.78 W at an outdoor temperature of 30 °C, it was 26.54 W at an outdoor temperature of 15 °C. In other words, while the coefficient of performance was obtained as 0.301 at 15 °C, it was determined as 0.219 at 30 °C. In addition, while the electrical power value produced by the TEG system used in the tractor for an outdoor temperature of 15 °C was 50.71 W, it was 38.84 W at an outdoor temperature of 30 °C. [ABSTRACT FROM AUTHOR]

The paper proposes an explanation of the physicochemical processes occurring during the electric-arc plasma-chemical synthesis of carbon nanomaterials. A diagram of the action of forces on charged particles and a diagram of forces acting on the motion of ions in an arc in the presence of a magnetic field for the plasma-chemical synthesis of carbon nanomaterials are presented and considered. The levels of organization of matter in an arc discharge during the formation of carbon vapour with an increase in temperature are considered. A comparative characterization and a conditional scheme for the formation of various carbon nanostructures during plasma-chemical synthesis are proposed. The sequence of carbon transformations during the formation of carbon nanomaterials and the conditional levels of organization of matter with the types of processes occurring on each of them during structure formation, as the classification of carbon structures by size levels under conditions of temperature decrease from plasma temperature to room one are established. Carbon nanomaterials are synthesized by the plasma-chemical method, and the analysis of the obtained and processed carbon nanostructures is carried out by the following methods: scanning electron microscopy, transmission electron microscopy, Raman spectral analysis, UV–VIS spectroscopy, spectrophotometric analysis. The presence of fullerenes in the products of plasma-chemical synthesis is established, and fullerenes are extracted from the synthesized wall soot. [ABSTRACT FROM AUTHOR]

In this work, it was proposed to introduce non-stoichiometric nano cadmium sulfide (CdS1-x) nanoparticles into polyvinyl chloride (PVC) polymer using simple, environmentally friendly and low-cost techniques. Undoped and doped PVC polymers with non-stoichiometric CdS1-x were formed using casting and thermolysis procedures. Rietveld refinement was applied to identify the phases formed and microstructure parameters in non-stoichiometric CdS1-x. Different techniques were used to investigate the structure, morphology, optical properties and dielectric of polymer films. The direct and indirect optical band gap (Eg) values of the undoped PVC film are 5.63 eV and (5.22, 4.49, 3.51) eV. As the sulfur concentration in the nanofiller increased to 97%, the direct and indirect Eg values of the CdS1-x doped polymers decreased to (5.21, 4.07, 2.44) eV and (4.18, 2.3, 2.03) eV, respectively. The optical dielectric constant and optical conductivity reached their maximum values as the amount of sulfur reached 97% in CdS1-x. Doped polymers are effective materials against UVA, UVB, and UVC spectra and work very well as solar cell absorber materials. The CIE 1931 chromaticity diagram revealed that PVC shifted from blue color to green-yellow and yellow-orange regions under excitation wavelengths of 317 and 380 nm, respectively. The electrical dielectric constant reached its maximum value when the sulfur content of the nanofiller reached 95%. AC conductivity has its maximum value when PVC is loaded with CdS0.9. The manageable optical and electrical features show that PVC/CdS1-x polymers could be potential optical materials in the development of futuristic flexible-type optoelectronic devices. [ABSTRACT FROM AUTHOR]

The manipulation of single particles remains a topic of interest with many applications. Here we characterize the impact of selected parameters on the motion of single particles thanks to dielectrophoresis (DEP) induced by visible light, in a technique called Light-induced Dielectrophoresis, or LiDEP, also known as optoelectronic tweezers, optically induced DEP, and image-based DEP. Baker's yeast and Candida cells are exposed to an electric field gradient enabled by shining a photoconductive material with a specific pattern of visible light, and their response is measured in terms of the average cell velocity towards the gradient. The impact on cell velocity when varying the shape and color of the light pattern, as well as the distance from the cell to the pattern, is presented. The experimental setup featured a commercial light projector featuring digital light processing (DLP) technology but mechanically modified to accommodate a 40× microscope objective lens. The minimal resolution achieved on the light pattern was 8 µm. Experimental results show the capability for single cell manipulation and the possibility of using different shapes, colors, and distances to determine the average cell velocity. [ABSTRACT FROM AUTHOR]

The energy mix determines the external costs of transport and the benefits from investments in the drive systems perceived as more environmentally friendly, such as electric vehicles.

Light is a potent circadian entraining agent. For many people, daily light exposure is fundamentally dysregulated with reduced light during the day and increased light into the late evening. This lighting schedule promotes chronic disruption to circadian physiology resulting in a myriad of impairments. Developmental changes in sleep-wake physiology suggest that such light exposure patterns may be particularly disruptive for adolescents and further compounded by lifestyle factors such as early school start times. This narrative review describes evidence that reduced light exposure during the school day delays the circadian clock, and longer exposure durations to light-emitting electronic devices in the evening suppress melatonin. While home lighting in the evening can suppress melatonin secretion and delay circadian phase, the patterning of light exposure across the day and evening can have moderating effects. Photic countermeasures may be flexibly and scalably implemented to support sleep-wake health; including manipulations of light intensity, spectra, duration and delivery modality across multiple contexts. An integrative approach addressing physiology, attitudes, and behaviors will support optimization of light-driven sleep-wake outcomes in adolescents.

Copyright of Egyptian Journal of Agricultural Sciences is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To date, asteroid trajectory modification techniques employ the "big bang" approach. An impulsive deflection is imparted by slamming one or more high-speed kinetic impactor spacecraft into the object or by detonation of a nuclear device in its proximity. This is a "hit it once and hope for the best" approach. Instead of relying on this restrictive method, centrifugal propulsion offers an alternative, where a centrifuge and power supply land on a threatening asteroid to collect and incrementally project portions of the asteroid, using momentum transfer of the recoil to gradually adjust the trajectory away from Earth. This process sequentially allows "ejection, measurement, and repetition" to gradually fine-tune the trajectory needed for course correction. This offers flexible operation parameters that can be varied for convenience and optimization, including the location of the landing site, weight of each ejected payload, launch speed, direction, cadence, timing of successive ejections, and the relationship to the asteroid's velocity vector and spin axis. Once landed on an asteroid, the centrifugal system requires no consumables. Operating entirely on electrical power, it can operate indefinitely without additional support. This approach addresses aspects of Goal 3 of the 2018 U S. government's "National Near-Earth Object (NEO) Preparedness Strategy and Action Plan"—"Develop Technologies for NEO Deflection and Disruption Missions." The centrifuge approach adds a sustainable and repeatable slow-push tool to the planetary defense toolbox, mitigating the risk and uncertainty of single-impulse methods. An on-site centrifuge could deflect Chelyabinsk and Tunguska-sized asteroids to miss Earth within a few weeks' operation. The asteroid Bennu could be deflected in a few years of continuous spinner operation, depending upon the parameters chosen, which would be sufficient to eliminate a potential collision with Earth in the late 22nd century. The innovation of a self-contained power and kinetic launch capability without consumables opens new vistas for cost-effective asteroid deflection and other commercial, scientific, government, and international space missions. • Serial asteroid material ejection is an economic alternative to impulsive deflection. • Serial asteroid material ejection is a controlled trajectory modification method. • Centrifugal asteroid deflection evades "hit it once and hope for the best" methods. • Centrifugal electrical asteroid material ejection system requires no consumables. • Centrifugal asteroid deflection is a sustainable slow-push planetary defense tool. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Cukurova University Institute of Social Sciences is the property of Cukurova University Institute of Social Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Tecnológica Ciencia y Educación Edwards Deming is the property of Instituto Corporativo Edwards Deming and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Minimizing electric losses is critical to the success of battery-powered small unmanned aerial systems (SUASs) that weigh less than 25 kgf (55 lb). Losses increase energy and battery weight requirements which hinder the vehicle's range and endurance. However, engineers do not have appropriate models to estimate the losses of a motor, motor controller, or battery. The aerospace literature often assumes an ideal electrical efficiency or describes modeling approaches that are more suitable for controls engineers. The electrical literature describes detailed design tools that target the motor designer. We developed SUAS powertrain models targeted for vehicle designers and systems engineers. The analytical models predict each component's losses using high-level specifications readily published in SUAS component datasheets. We validated the models against parametric experimental studies involving novel powertrain flight data from a specially instrumented quadcopter. Given propeller torque and speed, our integrated models predicted a quadcopter's battery voltage within 5% of experimental data for a 5+ min mission despite motor and controller efficiency errors up to 10%. The models can reduce development costs and timelines for different stakeholders. Users can evaluate notional or existing powertrain configurations over entire missions without testing any physical hardware. [ABSTRACT FROM AUTHOR]

The development of advanced construction technology cannot be separated from welding, as it plays an important role in constructing and repairing metal structures. At present, the construction of metal structures involves a lot of welding elements, especially in the field of good quality design. Based on the background, the problem can be formulated, namely, the effect of current strength on strength of Aisi 4340 steel joints after SMAW welding treatment. The research method used is the impact test method to see the results of the influence of strong currents in steel joints. The results of this study are the value of impact toughness at a current variation of 80 Ampere, the first specimen is 0.56080 J/mm2, the second specimen is 0.54811 J/mm2, and the third is 0.51724 J/mm2. The impact toughness value at 95 amps variation of the first sample is 0.01869 J/mm2, the second is 0.05481 J/mm2, and the third is 0.05172 J/mm2. From the test data, it can be seen that the average value of the average impact toughness in the variation of current strength of 80 Ampere and 95 Ampere is 80 Ampere current average impact toughness value of 0.54205 J/mm2 and 95 Ampere current average impact toughness value of 0.04174 J/m2. That the 80 ampere current variation is better and more efficient because it produces a higher toughness value than the 95 ampere current variation. [ABSTRACT FROM AUTHOR]

This research tested the energy consumption and efficiency of five electric tabletop appliances (cooktops) used in home cooking, specifically induction, infrared, resistance plate, resistance coil, and electric pot. The water boiling test with a cold start was used to determine the energy consumption and the efficiency for each appliance with variable volumes of water—500, 1000, 1500, and 2000 mL—and two pot sizes of 3 and 5 quarts. The effect of cold vs. hot start was evaluated with one water volume, 1000 mL, on all appliances. The electric pot was studied with and without insulation to determine if it is worth insulating the pot that comes un-insulated from the factory. Also, the appliances were subjected to simulated simmering tests to determine which device was more efficient in slow cooking. Of the five appliances tested, the induction cooktop and the electric pot were the most energy efficient and took the least time to boil water. Moreover, the energy efficiency and heating time were similar for the induction matched with the smaller pot and the electric pot. Induction lost efficiency by approximately ten percentage points when used with the large pot, thus reinforcing the importance of matching the pot size with the heating element. During the simmering experiments, induction proved easier than resistance coil to control the temperature in the culinary simmering band, from 85 to 100 °C; however, the energy consumption difference between induction and resistance coil was unclear. [ABSTRACT FROM AUTHOR]

The energy mix determines the external costs of transport and the benefits from investments in the drive systems perceived as more environmentally friendly, such as electric vehicles. The aim of this article was to present a methodology to determine the environmentally preferable urban bus drive systems (electric, hydrogen, CNG, hybrid, plug-in hybrid, and diesel) depending on CO2 emission factors related to the production of electricity in a given country. The developed methodology was exemplified by the Polish energy system. The results indicate the environmentally preferable types of urban bus drive systems, taking into account vehicle exploitation. The results obtained can inform the decision-making process and, in particular, enable state administrations in EU countries to define a support mechanism for public transport (e.g., through subsidies) that is appropriate to the environmental benefits of operating particular types of vehicles under country-specific energy mix conditions. [ABSTRACT FROM AUTHOR]