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Farm tractors have been applied in forest operations to carry out several tasks such as tree/felling/process-ing, forwarding, loading, skidding and cable yarding. Farm tractors can be equipped with special logging equipment that allows for their safe and efficient work in the harvesting of forest stands. This research is aimed to collect and review available literary sources on the productivity of farm tractors during skidding operations. The study results showed that work productivity of farm tractors for timber skidding has been studied by several researchers around the world. According to the results, the reported work productivity of skidding with farm tractors varied from 1.2 m3/PMH0 to 15.8 m3/PMH0 among international studies. Main variables impacting the work productivity of skidding included skidding distance, load volume, number of pieces per turn, tree diameter, tree length, slope of skid trails and engine power. Proper skid trail planning, applying suitable skidding equipment (e.g. winches, sulkies etc.), considering suitable engine size and prop-er safety standards can all help improving the work efficiency of the farm tractors during timber extracting. The information provided in this research can help the forest industry users and researchers gain proper knowledge on the work productivity of farm tractors applied for timber skidding. The study results can be also useful for planning and development purposes within small-scale forest operations.

The In-pipe Inspections robot (IPIR) are robots that run inside of pipelines and carry out the inspection work there. The pipelines develop certain anomalies like corrosion, cracks, dents, misalignments, etc. during their work cycle that needs to be rectified. Using IPIR eases the process of inspection that is difficult with the manual procedure that includes visual and some external non-destructive testings (NDTs). There are various types of robots in these fields including wheel-driven, track-driven, Pipe inspection gauge (PIG), walking type, and inchworm type. This paper will provide the specifications and design specialties of each type of robot. Each robot is designed considering certain parameters like maneuverability, pipeline diameter, adaptability, design structure, and more, and hence these are specific. There are certain limitations to each design at the end. Finally, this paper will help to select a specific robot for a particular requirement based on the comparison.

The paper deals with the simulation of selected activities in the warehouse. Routine logistics activities are the receipt of the goods, the control of the goods, and the goods’ storage in the warehousing system on the side of the entry into the warehouse. On the output side, these are activities such as picking, packing and shipping. The economy of warehouse operations depends on the efficiency of the logistics activities performed and on deployed the technical means. The paper’s main goal is to present a created simulation model for a selected warehouse activity—receipt of goods into the warehouse. This operation involves unloading the goods from the trucks, moving them to the physical receipt, where the quantitative and qualitative control of the goods is performed (acceptance of goods). An analysis of this activity preceded the creation of the simulation model under operating conditions. The research was performed by observing and measuring the forklift’s work cycle, which unloaded pallets from the trucks. The obtained data from the analysis were the input to the simulation model. The EXTENDSIM8 simulation system was used to create a simulation model. The several experiments were performed on the model after its creating and verifying the functionality. The paper evaluates 3 experiments and analyzes their results. The main benefit, novelty, of the article is the simulation of a selected activity for a specific company’s conditions. The experiments results are a reasonable basis for the creation of an operational tool for the company.

Increasing the efficiency of IC engines is a frequently discussed topic and one of the approaches taken is to modify the thermodynamic work cycle of the engine so that it resembles the ideal cycle more closely. This paper attempts to achieve that by altering the kinematics of the piston-crank mechanism by introducing an epicyclic non-circular gear train between the crank and the flywheel. The addition of the non-circular gears alters the work cycle by introducing a state of dwell during key points of the cycle. Possible gear shape solutions were calculated using a known, periodical function to express the gear transmission ratio. The final result was an epicyclic non-circular gear train that has a noticeable effect on the kinematics of the piston-crank mechanism which in turn increases the engine’s efficiency.

A possibility for machinery billet machining effectiveness increase at the expense of the use of high-speed grinding machines operated in an automated cycle of machining mode changes is considered. It allows performing operations of roughing and then finishing ensuring the required accuracy and quality of surfaces worked. The application of high-speed force grinding allows rejecting rough and finish preliminary milling and, in such a way, decreasing the number of machine equipment, hard-alloy cutters, production areas and increasing labor productivity.

The present study reports on an attempt to apply the principles of autonomous learning within the curriculum of an online course for teaching English to Iranian adult language learners. The contents of the course (i.e. general English) were delivered using work-cycles (Legenhausen, 2003) and were completed in the form of students’ projects. Each work-cycle started by setting personal learning goals in the planning and negotiation phase, deciding on the project in the decision-making phase, completing the actual project in the project phase, followed by an evaluation of the outcomes in the evaluation phase. Different phases of the cycle fitted autonomous learning framework, enabling the implementation of the principles of learner autonomy. Finally, after the actual implementation of the principles of learner autonomy through work-cycles, learners’ perceptions were assessed to estimate the efficiency of autonomous learning using work-cycles which revealed an overall positive pattern of beliefs. However, despite general success of work-cycles in implementing autonomous learning, a gap between learners’ autonomous beliefs and behaviors was observed which necessitates further preparation in the form of awareness-raising.

Employee performance is a reflection of employee work that determines the achievement of company goals. Performance optimization can be achieved through increasing motivation, competence, and work environment. This research is aimed at analyzing performance that is determined by motivation, competence, and work environment, both simultaneously and partially. The research design applies descriptive and verification approaches. Used multiple linear regression analysis, multiple correlation analysis, coefficient of determination analysis which is then tested by hypothesis. The results showed that motivation, competence, and work environment had a positive and real effect on employee performance. In contrast, partially motivation and competence had a positive and tangible impact on employee performance, except the work environment had no influence. It is recommended to appreciate the performance, communication skills, and work cycle activities that are oriented towards improving discipline.

Target of research of action go to school this is to improve performance and motivation learn SDN 150 Seluma pass activity of headmaster supervision. Its research type is research of school action. Activity of this research consist of step planning of action, execution of action, observation, and refleksi. Technique analyse data use technique of obeservasi. Instrumen observation the used is appliance assessment of ability of teacher in the form of instrument assessment of teacher performance and motivation . Result of research show finding that headmaster supervision of SDN 150 Seluma school year 2016 / 2017 can improve motivation work cycle of I equal to 29% becoming 86% mounting 57% and performance learn SDN 150 Seluma in cycle of I from 43% mounting to become 86% or there is make-up of equal to 43%Keywords: headmaster supervision, teacher motivation, teacher perform

the paper concerns the search for a reasonable calculation method to determine the energy consumption of a forklift. The effects of alternative pathways for determining energy consumption are summarised, including: VDI 2198, ISO 50001, MTM - and proprietary PZM test cycle. These tools are used to determine the energy consumption of logistical transport and storage systems. A single forklift is rarely operated; they more often occur in the form of “fleets”. Therefore, assuming the effect of scale, the precise determination of energy consumption gives a chance to significantly reduce emissions and operating costs, by defining in the next step precise costs (e.g. logistic costs); another aspect is optimum fleet and people management, as well as battery charging/refuelling. In addition to the traditional “pathways” of determining energy consumption (mentioned above) - the paper discusses a new PZM cycle (Pawel Zajac Method). The energy consumption in the PZM work cycle was verified in logistics centres and compared with the simulation results. Additionally, the results of energy consumption from computer simulations made for “economic” speed are included.

Since the impact of cyclical activity on fuel consumption by trucks in opencast mining is not considered in the literature, therefore, a method for assessing these effects is proposed. This study measured the fuel consumed in one cycle of a dump truck. The work cycle consists of the main stages: loading, maneuvering, transportation, unloading and return to the starting position. Each of the components of the cycle is associated with a certain fuel consumption. Therefore, the functional relationship between the components of the cycle (as independent variables) and the amount of fuel consumed per cycle (as a dependent variable) determines the share of each component in the total fuel consumption of the vehicle. Although dump truck manufacturers offer approximate estimates of fuel consumption for different truck models and sizes, there are significant uncertainties about actual fuel consumption due to specific operating conditions. Specific conditions (road quality, etc.) lead to significant deviations in the actual fuel consumption according to the manufacturer’s estimates. Insufficient assessment of quarry fuel needs leads to significant difficulties in deciding on an open-pit mine budget. In order to provide reliable and specific estimates of truck fuel consumption, this study processed statistics from the Omelyanovsk open-pit mine. This approach primarily takes into account variations in fuel consumption, which are due to specific conditions of production. This goal is achieved by using a sufficiently large database of fuel consumption statistics., Поскольку влияние циклической деятельности на потребление топлива грузовыми автомобилями при открытых горных работах в литературе не рассматривается, предлагается методика оценки этих эффектов. В этом исследовании измерялось топливо, потребленное за один цикл работы автосамосвала. Цикл работы состоит из основных этапов: погрузка, маневрирование, транспортировка, разгрузка и возврат в исходное положение. Каждый из компонентов цикла связан с определенным расходом топлива. Поэтому функциональная зависимость между компонентами цикла (как независимые переменные) и количеством потребляемого топлива за цикл (как зависимая переменная) определяет долю каждого компонента в общем расходе топлива автомобиля. Хотя производители автосамосвалов предлагают приблизительные оценки расхода топлива для разных моделей и размеров грузовиков, существуют значительные неопределенности по фактическим показателям потребления топлива, которые обусловлены специфическими условиями работы. Специфические условия (качество дорог и т. п.) приводят к значительным отклонениям в фактическом потреблении топлива в отношении оценок производителя. Недостаточная оценка потребности карьера в топливе приводит к большим трудностям в принятии решения о бюджете карьера. Для того чтобы дать достоверные и конкретные оценки потребления топлива для грузовиков, в этом исследовании обработаны статистические данные из Емельяновского щебеночного карьера. В этом подходе, в первую очередь, учитываются вариации потребления топлива, обусловленные конкретными условиями добычи. Эта цель достигается использованием достаточно обширной базы статистических данных о потреблении топлива., Оскільки вплив циклічної діяльності на споживання палива вантажними автомобілями при відкритих гірничих роботах у літературі не розглядається, тому пропонується методика оцінки цих ефектів. У цьому дослідженні вимірювалося паливо, яке було спожито за один цикл роботи автосамоскида. Цикл роботи складається з основних етапів: завантаження, маневрування, транспортування, розвантаження та повернення в вихідне положення. Кожен із компонентів циклу пов’язаний із певною витратою палива. Тому функціональна залежність між компонентами циклу (як незалежні змінні) та кількістю споживаного палива за цикл (як залежна змінна) визначає частку кожного компонента у загальній витраті палива автомобіля. Хоча виробники автосамоскидів пропонують приблизні оцінки витрат палива для різних моделей та розмірів вантажівок, існують значні невизначеності щодо фактичних показників споживання палива, які обумовлені специфічними умовами роботи. Специфічні умови (якість доріг тощо) призводять до значних відхилень у фактичному споживанні палива щодо оцінок виробника. Недостатня оцінка потреби кар’єру в паливі призводить до значних труднощів у прийнятті рішення про бюджет кар’єру. Для того, щоб надати достовірні та конкретні оцінки споживання палива для вантажівок, у цьому дослідженні оброблені статистичні дані з Омелянівського щебеневого кар’єру. У цьому підході, в першу чергу, враховуються варіації споживання палива, які обумовлені конкретними умовами видобутку. Ця мета досягається використанням достатньо великої бази статистичних даних про споживання палива.

Evaluation of energy efficiency of a combined cooling system that uses night radiative cooling together with refrigerating machine with accumulation of cold without a phase transition and the supply of liquid coolant (propylene glycol) to the air cooler is performed based on the results of computer simulation. In the cooling system located in Kostanay (Kazakhstan), there are radiators (12 m2) that cool the coolant at night, as well as a conventional vapor compression refrigerating machine with a reciprocating compressor. The cooling system is used to maintain air temperature at the level of 0±1°C in a small refrigeration chamber (36 m3) with a low value of heat emission from stored products and the absence of other operational heat influx. It is found that 78,8 days a year the cooling system can maintain the required temperature due to the operation of radiators without turning on the refrigerating machine. This saves 242 kWh of electricity. Thus, the combined refrigeration system provides 7,6% reduced energy consumption, and also reduces physical deterioration of the refrigerating machine compressor for the annual cycle, which should reduce the financial costs for operating the refrigeration warehouse

The paper considers the specifics of gasification, mixing and burnout processes for propellant components in a combustion chamber featuring coaxial bicentrifugal injectors and operating in the liquid/liquid mode employing oxygen and the T-1 and T-6 kerosene types. Numerical simulation revealed that when using the T6 fuel, the structure of recirculation zones appearing in the leading region of the combustion chamber may provide more efficient oxygen and kerosene mixing and burnout as compared to a chamber running on the T-1 fuel

It is worth still working on the development of the internal combustion engine, because its time was not yet over. This was demonstrated by the author’s review of the literature, indicating at least the perspective of 2050 the universality of the engine as the primary propulsion or support in hybrid transport units. The presented considerations may have a broader perspective, when the thermodynamic problems of a thermal machine such as an internal combustion engine are indicated. This chapter deals with the issues of changing the swept volume known as downsizing/rightsizing. An equivalent swept volume was introduced, defined by the coefficients determining changes in the cylinder diameter and the stroke of the piston. An attempt was made to find the mutual relations to the efficiency of the work cycle and engine operating parameters. The research methodology was proposed as a mix of laboratory tests and theoretical analyses, on the basis of which it was established that while maintaining the same value of the downsizing index, despite the various permissible combinations of cylinder diameter and piston stroke changes, the cycle efficiency remains unchanged. The engine operating parameters are changing, resulting from the use of support systems for rightsizing geometric changes.

Este proyecto consistió en el diseño, implementación y calibración de un sistema de registro de variables del funcionamiento de un equipo de refrigeración. Se buscó contar con parámetros para el análisis de eficiencia y establecimiento óptimo del ciclo de trabajo. El sistema de medición se implementó en un circuito de refrigeración del Laboratorio de Termodinámica de la FACENA-UNNE, teniendo en cuenta las condiciones normales de trabajo.

Counting the number of work cycles per unit of time of earthmoving excavators is essential in order to calculate their productivity in earthmoving projects. The existing methods based on computer vision (CV) find it difficult to recognize the work cycles of earthmoving excavators effectively in long video sequences. Even the most advanced sequential pattern-based approach finds recognition difficult because it has to discern many atomic actions with a similar visual appearance. In this paper, we combine atomic actions with a similar visual appearance to build a stretching–bending sequential pattern (SBSP) containing only “Stretching” and “Bending” atomic actions. These two atomic actions are recognized using a deep learning-based single-shot detector (SSD). The intersection over union (IOU) is used to associate atomic actions to recognize the work cycle. In addition, we consider the impact of reality factors (such as driver misoperation) on work cycle recognition, which has been neglected in existing studies. We propose to use the time required to transform “Stretching” to “Bending” in the work cycle to filter out abnormal work cycles caused by driver misoperation. A case study is used to evaluate the proposed method. The results show that SBSP can effectively recognize the work cycles of earthmoving excavators in real time in long video sequences and has the ability to calculate the productivity of earthmoving excavators accurately.

Steep terrain harvesting can only be implemented by a limited set of operational alternatives, therefore, it is important to be efficient in such conditions, in order to avoid incurring high costs. Harvesting abiotically-disturbed forests (salvage harvests caused by wet snow), which is becoming common these days, can significantly impact the operational efficiency of extraction operations. This study was implemented in order to evaluate the performance of truck-mounted uphill cable yarding operations in salvage logging deployed in coniferous stands. A time study was used to estimate the productivity and yarding costs, and predictive models were developed in order to relate the time consumption and productivity to the relevant operational factors, including the degree of wood damage. The average operational conditions were characterized by an extraction distance of 101 m and a lateral yarding distance of 18 m, resulting in a productivity rate of 20.1 m3 h−1. In response to different kind of delays, the productivity rate decreased to 12.8 m3 h−1. Under the prevailing conditions, lateral yarding accounted for 32% of the gross work cycle time, and for 50% of the delay-free work cycle time of the machine. Decreasing the lateral yarding distance and increasing the payload volume to the maximum capacity of the machine would eventually lead to a yarding productivity of close to 30 m3 per SMH (scheduled machine hour). The calculation of the gross costs of uphill yarding showed that the labor costs (35.7%) were slightly higher than the fixed costs (32.9%), and twice as high compared to the variable costs (17.7%). The remote control of the carriage, mechanical slack-pulling mechanisms, and radio-controlled chokers are just some of the improvements that would have led to increments in operational efficiency.

We derive an analytic expression for the mechanical pressure of a generic one-dimensional model of confined active Brownian particles (ABPs) that is valid for all values of Peclet number Pe and all confining scenarios. Our model reproduces the known scaling of bulk pressure with Pe^2 while in strong confinement pressure scales with Pe. Our analytic results are very well reproduced by simulations of ABPs in 2D. We use the pressure formula to calculate both the work performed by an active engine and its efficiency. In particular, efficiency is maximized for work cycles with finite period and not in the limit of infinitely slow cycles as in thermodynamic engines.

In this paper, we present an integrated multi-objective framework of a single machine for a single cutting tool problem. Our maintenance policy is based on performing minimal repairs in case of a minor failure and Preventive Maintenance (PM) to avoid a major failure that results in the replacement of the tool. This framework allows simultaneous optimization of the two conflicting time and cost objectives. A redundant system is proposed as a part of the model to assist the production line under a major failure. In addition, the tool’s preventive maintenance time is synchronized with the completion of the machine tool’s work cycle to reduce the machine’s set-up time. The model was optimized using a customized Non-dominated Sorting Genetic Algorithm (NSGA-II). An experimental study based on real-market data was conducted and the results were compared with the ones obtained from classical methods.

Increasing the efficiency of IC engines is a frequently discussed topic, and one of the approaches taken is to modify the thermodynamic work cycle of the engine so that it resembles the ideal cycle more closely. This paper attempts to achieve that by altering the kinematics of the piston-crank mechanism by introducing an epicyclic non-circular gear train between the crank and the flywheel. The addition of the non-circular gears alters the work cycle by introducing a state of dwell during key points of the cycle. Possible gear shape solutions were calculated using a known, periodic function to express the gear transmission ratio. The final result was an epicyclic non-circular gear train that has a noticeable effect on the kinematics of the piston-crank mechanism resulting in an increase of the engines work cycle efficiency.

The time constant of phase II pulmonary oxygen uptake kinetics ( $${\dot{\text{V}}\text{O}}_{2} \, \tau_{{\text{p}}}$$ ) is increased when high-intensity exercise is initiated from an elevated baseline (work-to-work). A high-intensity priming exercise (PE), which enhances muscle oxygen supply, does not reduce this prolonged $${\dot{\text{V}}\text{O}}_{2} \, \tau_{{\text{p}}}$$ in healthy active individuals, likely because $${\dot{\text{V}}\text{O}}_{2} \, \tau_{{\text{p}}}$$ is limited by metabolic inertia (rather than oxygen delivery) in these individuals. Since $${\dot{\text{V}}\text{O}}_{2} \, \tau_{{\text{p}}}$$ is more influenced by oxygen delivery in type 2 diabetes (T2D), this study tested the hypothesis that PE would reduce $${\dot{\text{V}}\text{O}}_{2} \, \tau_{{\text{p}}}$$ in T2D during work-to-work cycle exercise. Nine middle-aged individuals with T2D and nine controls (ND) performed four bouts of constant-load, high-intensity work-to-work transitions, each commencing from a baseline of moderate-intensity. Two bouts were completed without PE and two were preceded by PE. The rate of muscle deoxygenation ([HHb + Mb]) and surface integrated electromyography (iEMG) were measured at the right and left vastus lateralis, respectively. Subsequent to PE, $${\dot{\text{V}}\text{O}}_{2} \, \tau_{{\text{p}}}$$ was reduced (P = 0.001) in T2D (from 59 ± 17 to 37 ± 20 s) but not (P = 0.24) in ND (44 ± 10 to 38 ± 7 s). The amplitude of the $${\dot{\text{V}}\text{O}}_{{2}}$$ slow component ( $${\dot{\text{V}}\text{O}}_{2} \, \tau_{{\text{p}}}$$ 2 As) was reduced (P = 0.001) in both groups (T2D: 0.16 ± 0.09 to 0.11 ± 0.04 l/min; ND: 0.21 ± 0.13 to 0.13 ± 0.09 l/min). This was accompanied by a reduction in ΔiEMG from the onset of $${\dot{\text{V}}\text{O}}_{{2}}$$ slow component to end-exercise in both groups (P

In this article, a study of supersonic airflow through a channel with various cross-section is presented. The channel is namely a heatproof nozzle which is used in a pneumatic pulsator system. The system utilizes a pneumatic impact to destruct or to avoid of the creation of unfavourable phenomena which comes from cohesion forces. The pneumatic pulsator system is driven by compressed air and a high-velocity airflow is induced by the difference between internal and external air pressure. This flow changes its characteristics during a work cycle of the pulsator from subsonic to supersonic conditions. It causes a very dynamic gas conversion and may produce additional heat inside the pulsator and its nozzle. The article presents a method for calculating the value of the heat which can be generated inside the heatproof nozzle. The results of the study shows that the small amount of energy is lost during the airflow which can generate an increment of heatproof nozzle wall temperature.

The increasing demand for highly customized products requires flexible, reactive and adaptive manufacturing systems. Accurate and up-to-date information about the processes is a strict requirement to meet these needs. Real-time data capturing technologies, such as RFID, have already been used for some years in manufacturing environments, mainly for inventory management, planning and quality control. However, these systems fail to generate information on the performance of the operator in the system. This paper presents a video-based system that automates the analysis of manual assembly line work stations and generates near real-time information to support workers in their pursuit of continuous improvement. A work cycle classification method was developed to detect anomalous and problematic situations in the work flow. Besides the classification of work cycles, the method also generates performance indicators to analyze the performance of the operator in the system. These performance indicators are visualized in an operational dashboard, which reveals the improvement potential of the work station.

The authors describe a technical approach to validating efficient regimes and process flow charts for draglines in open pit mining in permafrost zone; the approach integrates modeling data on temperature conditions of permafrost treated by blasting, geometrical parameters of a dragline face and interaction of work cycle time and face rock temperature in different seasons. It is shown that a dragline has the appreciably reduced productivity in slice-by-slice handling of broken-rock disintegration having negative temperature.

This paper is an experience report about the educational actions developed in a children´s hospital by an undergraduate student from the Nursing course at the State University of Feira de Santana. The actions were part of the outreach program called Identification and analysis of drug interactions in medical prescriptions in a specialized hospital in Feira de Santana. The aim of this paper was to demonstrate the student´s experience in educational actions for health professionals and the community. Lectures about themes related to work cycle were offered to health professionals whereas as waiting rooms were offered to the community with the participation of around 20 people in each presentation. It was concluded that health professionals need to be stimulated more and more, emphasizing that they play a very relevant role for the institution and the community. The study also demonstrated that the community still lack meaningful information about health. education; continuing education; health professional; community.