Firearm shooting simulators are effective means for training the personnel in armed forces,police and shooting athletes.Shooter-weapon is a complex biomechanical system,therefore the best training quality is achieved ...Firearm shooting simulators are effective means for training the personnel in armed forces,police and shooting athletes.Shooter-weapon is a complex biomechanical system,therefore the best training quality is achieved when the process of a weapon shot is reconstructed in a training simulator and its training weapon mimics the(feeling) perception of the real weapon usage.Dynamics of motions of a handgun simulator held in the hand of a shooter by its grip during the shot is analysed theoretically and experimentally.Breech lock mechanism of the simulator is actuated pneumatically by supplying compressed air in pulses from external pressure source.Analysis of the obtained simulation results and experimentally recorded motion parameters of the training weapon body reveals that application of pneumatic drives is a reasonable option to simulate recoil perception of a pistol.展开更多
This paper addresses the syngas production and evaluation losses in high temperature gasification process using coffee husks. A fast and inexpensive way to evaluate the losses in gasification processes is by the appli...This paper addresses the syngas production and evaluation losses in high temperature gasification process using coffee husks. A fast and inexpensive way to evaluate the losses in gasification processes is by the application mathematical models which allow to predict the values needed in full scale. Hence, the quantification of gasifier’s losses at temperatures ranges of 800 K - 1400 K at an equivalence ratios of 0.3, 0.35 and 0.4 at 1 bar are revealed by using exergy model incorporating a chemical equilibrium model. The model evaluated the product syngas compositions, syngas heating values and degree of irreversibility values (losses). The results from the model showed that the production of H2 increased from 9.9% to 18.9% and the formation of CO2 ranges from 7.2% to 12.3%. CO production is from 21.8% to 17.2%. The irreversibility values obtained were less than 27%. Hence, reduction of losses protracts biomass resources to be used in energy generation.展开更多
This paper presents a study of the potential use of iron mining tailings as artificial pozzolan (metakaolin) after their submission to thermal treatment via calcination in a flash furnace. The research consists of the...This paper presents a study of the potential use of iron mining tailings as artificial pozzolan (metakaolin) after their submission to thermal treatment via calcination in a flash furnace. The research consists of the characterization of the tailings before and after calcination, chemical, mineralogical, thermogravimetric, and mechanical strength analyses were conducted. The results were compared with those for commonly used pozzolans, metakaolin, and similarities were identified. The study of the morphology of the particles before and after calcination was conducted through analyses of images obtained by scanning electronic microscope. The pozzolanic activity of the fine mining tailings calcined with flash technology was evaluated in uniaxial compression trials, which showed excellent results.展开更多
Writing an Editorial for a new journal provides a nice opportunity to express some ideas that normally would tend to lack space to be aired in public.I decided to concentrate on research ideas that I would welcome to ...Writing an Editorial for a new journal provides a nice opportunity to express some ideas that normally would tend to lack space to be aired in public.I decided to concentrate on research ideas that I would welcome to see pursued in the near future.展开更多
The authors studied diesel combustion improvement with a reformed fuel that mixed nano air-bubbles by using an EMNB （ejector-type micro-nano bubbler）. The EMNB performs adequately and is smaller （20 mm diameter, 34...The authors studied diesel combustion improvement with a reformed fuel that mixed nano air-bubbles by using an EMNB （ejector-type micro-nano bubbler）. The EMNB performs adequately and is smaller （20 mm diameter, 34 mm length） than other micro-nano bubblers. It is quite possible to install it in an actual engine. An experiment was performed using a single cylinder engine with a dish or square shaped combustion chamber cavity, and in order to compare the engine speed change, we also used a four cylinder engine with a turbo-charger. The results showed that an improvement in specific fuel consumption, a decrease in the density of the exhaust smoke and an improvement in charging efficiency etc. were achieved by mixing nano bubbles into gas oil under most conditions. It is confirmed that combustion was promoted and improved by a physical and chemical action through mixing the nano bubbles into gas oil.展开更多
This research investigates the soil conditioning effect of sugar cane fields with biochar produced from sugarcane bagasse.Its influence on the physicochemical and microbiological conditions of the soil and the agronom...This research investigates the soil conditioning effect of sugar cane fields with biochar produced from sugarcane bagasse.Its influence on the physicochemical and microbiological conditions of the soil and the agronomic performance of sugarcane seedlings was verified.To this end,the biochar from sugarcane bagasse was produced by pyrolysis in a double drum oven and mixed with soil at rates of 0,1%,3%,and 5%(in weight).The experiment was installed in a greenhouse with two evaluation periods(30 days and 60 days)and five replicates.Each pot received a pre-sprouted cane seedling,and the analysis of colony-forming units(bacteria and fungi),physicochemical characteristics of the soil,and growth and development of sugarcane were performed per pot.The biochar showed a high fixed carbon content(72%)and a specific surface area estimated by the adsorption of methylene blue of 50 m2 g−1.Furthermore,its structure is porous and contains important nutrients(e.g.,CaO,K2O,and P2O5).In the periods evaluated,the applications of the 3%and 5%(in weight)rates of biochar reduced most of the soil fertility parameters.However,the chemical analyses indicated that the sugarcane field soil collected already possessed high fertility.The microbiota was influenced,but only the application of the 3%(in weight)rate at 60 days after planting showed a significant positive effect on the number of bacteria forming units,with an increase of approximately 385%.On the other hand,no significant positive effect on sugarcane development was found.Therefore,biochar application in high-fertility sugarcane plantation soil did not result in gains for sugarcane development in the periods evaluated.展开更多
Investigation on vibration of laminated composite beam(LCB)is an important issue owing to its wide use as fundamental component.In the present work,we study the free vibration of arbitrarily LCB with generalized elast...Investigation on vibration of laminated composite beam(LCB)is an important issue owing to its wide use as fundamental component.In the present work,we study the free vibration of arbitrarily LCB with generalized elastic boundary condition(BC)by using Haar wavelet discretization method(HWDM).Timoshenko beam theory is utilized to model the free vibration of LCB.The LCB is first split into several segments,and then the displacement for each segment is obtained from the Haar wavelet series and their integral.Hamilton’s principle is applied to construct governing equations and the artificial spring boundary technique is adopted to obtain the general elastic boundary and continuity conditions at two ends of LCB.The vibration characteristics of beam with different fiber orientations and lamina numbers is investigated and its displacements are compared with those in previous works.Numerical results are shown graphically and demonstrate the validation of our method.展开更多
In this paper we present relevant contributions and important features related to the study of the retroreflectivity performance of pavement markings.The contribution of this paper is threefold.First,we propose an art...In this paper we present relevant contributions and important features related to the study of the retroreflectivity performance of pavement markings.The contribution of this paper is threefold.First,we propose an artificial scheme to allow some randomization of the treatments owing to several restrictions imposed on the choice of the experimental units.It is an experiment involving one fixed factor(three types of materials)in a randomized block design executed on a high-traffic-volume highway.Under this condition,the traffic volume works as a stress factor and the degradation of the retroreflectivity of pavement markings is faster than the degradation on rural roads or streets.This is related to the second contribution:the possibility of a reduction of experimental time.The current experiment spent 20 weeks to collect the data.And finally a mixed linear model considering three random effects and several fixed effects is fitted and the most relevant effects pointed out.This study can help highway managers to improve road safety by scheduling the maintenance of pavement marks at the appropriate time,choosing adequate material for the pavement markings and applying the proposed artificial scheme in future studies.展开更多
In recent years,rapid urbanization,population growth,and increasing concerns about climate change have led to a growing demand for innovative and sustainable transportation solutions.As we strive to meet these challen...In recent years,rapid urbanization,population growth,and increasing concerns about climate change have led to a growing demand for innovative and sustainable transportation solutions.As we strive to meet these challenges,the development of next-generation smart transportation systems has emerged as a critical focus for researchers,industry leaders,and policymakers worldwide.These advanced systems have the potential to revolutionize the way we move people and goods,integrating cutting-edge technologies or concepts such as artificial intelligence,electrification,connected and automated driving,and advanced aerial mobility.This special issue aims to provide a platform for the exchange of ideas,research findings,and best practices,fostering a deeper understanding of the opportunities and challenges presented by this paradigm shift in transportation.By exploring the diverse aspects of carbon neutrality,connectivity,intelligence,equity,and verticalization,we hope to foster a multidisciplinary dialogue and shed a light on the development of sustainable,efficient,and equitable transportation solutions for the future.展开更多
基金This research was funded by the grant from Research Council of Lithuania.Grant No.S-MIP-17-94.
文摘Firearm shooting simulators are effective means for training the personnel in armed forces,police and shooting athletes.Shooter-weapon is a complex biomechanical system,therefore the best training quality is achieved when the process of a weapon shot is reconstructed in a training simulator and its training weapon mimics the(feeling) perception of the real weapon usage.Dynamics of motions of a handgun simulator held in the hand of a shooter by its grip during the shot is analysed theoretically and experimentally.Breech lock mechanism of the simulator is actuated pneumatically by supplying compressed air in pulses from external pressure source.Analysis of the obtained simulation results and experimentally recorded motion parameters of the training weapon body reveals that application of pneumatic drives is a reasonable option to simulate recoil perception of a pistol.
文摘This paper addresses the syngas production and evaluation losses in high temperature gasification process using coffee husks. A fast and inexpensive way to evaluate the losses in gasification processes is by the application mathematical models which allow to predict the values needed in full scale. Hence, the quantification of gasifier’s losses at temperatures ranges of 800 K - 1400 K at an equivalence ratios of 0.3, 0.35 and 0.4 at 1 bar are revealed by using exergy model incorporating a chemical equilibrium model. The model evaluated the product syngas compositions, syngas heating values and degree of irreversibility values (losses). The results from the model showed that the production of H2 increased from 9.9% to 18.9% and the formation of CO2 ranges from 7.2% to 12.3%. CO production is from 21.8% to 17.2%. The irreversibility values obtained were less than 27%. Hence, reduction of losses protracts biomass resources to be used in energy generation.
文摘This paper presents a study of the potential use of iron mining tailings as artificial pozzolan (metakaolin) after their submission to thermal treatment via calcination in a flash furnace. The research consists of the characterization of the tailings before and after calcination, chemical, mineralogical, thermogravimetric, and mechanical strength analyses were conducted. The results were compared with those for commonly used pozzolans, metakaolin, and similarities were identified. The study of the morphology of the particles before and after calcination was conducted through analyses of images obtained by scanning electronic microscope. The pozzolanic activity of the fine mining tailings calcined with flash technology was evaluated in uniaxial compression trials, which showed excellent results.
文摘Writing an Editorial for a new journal provides a nice opportunity to express some ideas that normally would tend to lack space to be aired in public.I decided to concentrate on research ideas that I would welcome to see pursued in the near future.
文摘The authors studied diesel combustion improvement with a reformed fuel that mixed nano air-bubbles by using an EMNB （ejector-type micro-nano bubbler）. The EMNB performs adequately and is smaller （20 mm diameter, 34 mm length） than other micro-nano bubblers. It is quite possible to install it in an actual engine. An experiment was performed using a single cylinder engine with a dish or square shaped combustion chamber cavity, and in order to compare the engine speed change, we also used a four cylinder engine with a turbo-charger. The results showed that an improvement in specific fuel consumption, a decrease in the density of the exhaust smoke and an improvement in charging efficiency etc. were achieved by mixing nano bubbles into gas oil under most conditions. It is confirmed that combustion was promoted and improved by a physical and chemical action through mixing the nano bubbles into gas oil.
文摘This research investigates the soil conditioning effect of sugar cane fields with biochar produced from sugarcane bagasse.Its influence on the physicochemical and microbiological conditions of the soil and the agronomic performance of sugarcane seedlings was verified.To this end,the biochar from sugarcane bagasse was produced by pyrolysis in a double drum oven and mixed with soil at rates of 0,1%,3%,and 5%(in weight).The experiment was installed in a greenhouse with two evaluation periods(30 days and 60 days)and five replicates.Each pot received a pre-sprouted cane seedling,and the analysis of colony-forming units(bacteria and fungi),physicochemical characteristics of the soil,and growth and development of sugarcane were performed per pot.The biochar showed a high fixed carbon content(72%)and a specific surface area estimated by the adsorption of methylene blue of 50 m2 g−1.Furthermore,its structure is porous and contains important nutrients(e.g.,CaO,K2O,and P2O5).In the periods evaluated,the applications of the 3%and 5%(in weight)rates of biochar reduced most of the soil fertility parameters.However,the chemical analyses indicated that the sugarcane field soil collected already possessed high fertility.The microbiota was influenced,but only the application of the 3%(in weight)rate at 60 days after planting showed a significant positive effect on the number of bacteria forming units,with an increase of approximately 385%.On the other hand,no significant positive effect on sugarcane development was found.Therefore,biochar application in high-fertility sugarcane plantation soil did not result in gains for sugarcane development in the periods evaluated.
文摘Investigation on vibration of laminated composite beam(LCB)is an important issue owing to its wide use as fundamental component.In the present work,we study the free vibration of arbitrarily LCB with generalized elastic boundary condition(BC)by using Haar wavelet discretization method(HWDM).Timoshenko beam theory is utilized to model the free vibration of LCB.The LCB is first split into several segments,and then the displacement for each segment is obtained from the Haar wavelet series and their integral.Hamilton’s principle is applied to construct governing equations and the artificial spring boundary technique is adopted to obtain the general elastic boundary and continuity conditions at two ends of LCB.The vibration characteristics of beam with different fiber orientations and lamina numbers is investigated and its displacements are compared with those in previous works.Numerical results are shown graphically and demonstrate the validation of our method.
文摘In this paper we present relevant contributions and important features related to the study of the retroreflectivity performance of pavement markings.The contribution of this paper is threefold.First,we propose an artificial scheme to allow some randomization of the treatments owing to several restrictions imposed on the choice of the experimental units.It is an experiment involving one fixed factor(three types of materials)in a randomized block design executed on a high-traffic-volume highway.Under this condition,the traffic volume works as a stress factor and the degradation of the retroreflectivity of pavement markings is faster than the degradation on rural roads or streets.This is related to the second contribution:the possibility of a reduction of experimental time.The current experiment spent 20 weeks to collect the data.And finally a mixed linear model considering three random effects and several fixed effects is fitted and the most relevant effects pointed out.This study can help highway managers to improve road safety by scheduling the maintenance of pavement marks at the appropriate time,choosing adequate material for the pavement markings and applying the proposed artificial scheme in future studies.
文摘In recent years,rapid urbanization,population growth,and increasing concerns about climate change have led to a growing demand for innovative and sustainable transportation solutions.As we strive to meet these challenges,the development of next-generation smart transportation systems has emerged as a critical focus for researchers,industry leaders,and policymakers worldwide.These advanced systems have the potential to revolutionize the way we move people and goods,integrating cutting-edge technologies or concepts such as artificial intelligence,electrification,connected and automated driving,and advanced aerial mobility.This special issue aims to provide a platform for the exchange of ideas,research findings,and best practices,fostering a deeper understanding of the opportunities and challenges presented by this paradigm shift in transportation.By exploring the diverse aspects of carbon neutrality,connectivity,intelligence,equity,and verticalization,we hope to foster a multidisciplinary dialogue and shed a light on the development of sustainable,efficient,and equitable transportation solutions for the future.
