As non-operating room anesthesia (NORA) vastly increases, so does the complexity of both the patients and the procedures. Unfamiliar environment, remote locations, and limited access to resources are some of the many ...As non-operating room anesthesia (NORA) vastly increases, so does the complexity of both the patients and the procedures. Unfamiliar environment, remote locations, and limited access to resources are some of the many challenges faced by the anesthesiologist in this environment. Understanding the environmental factors such as the room layout, machine placement and patient positioning needs advanced planning in the COVID-19 patient to determine airway management, intravenous access and overall patient safety. Communication with the proceduralist and healthcare workers (HCW) is of essence as both the procedure and anesthetic requirements may need to be altered as the case progresses. Standard monitoring guidelines should apply to all patients regardless of depth of anesthesia. The COVID-19 patient adds to these challenges. Aerosol generating medical procedures (AGMP’s) need to be identified ahead of time in order to ensure the safety of both the staff and patients. This allows for planning and preparation required for transportation of the patient to the room. HCWs may need to be identified and be available to assist with the procedure. Time should be allocated for transportation, briefing, room preparation, personal protective equipment needs of the staff and donning and doffing procedures as per institutional protocol. Communication means with staff outside of the room should be discussed in advance should an emergent situation arise during the procedure. Debriefing should be performed at the end of every procedure to improve patient safety and outcomes.展开更多
Nowadays,there is considerable research interest in proposing modern permanent magnet(PM)electric machine structures for applications such as electric vehicles.Several radial and axial topologies with different arrang...Nowadays,there is considerable research interest in proposing modern permanent magnet(PM)electric machine structures for applications such as electric vehicles.Several radial and axial topologies with different arrangements of PM in the stator and rotor have been introduced for PM Vernier motors(PMVM)with the aim of increasing the performance characteristics such as power factor,efficiency,rotational torque torque density and wider constant torque-speed region.Meanwhile,the spoke PM arrangement has provided higher torque density than the surface and V-shaped arrangement.But in contrast,the V-shaped arrangement has a more sinusoidal flux and less cogging torque.In this paper,a 620 W,12-slot 16-pole Vernier PM motor with a fractional slot arrangement.Consequent K-shaped pole is introduced,which has the advantages of spoke and V-shaped magnetic arrangements.After presenting and confirming the concept of the proposed structure based on functional comparison with conventional structures,an analytical modeling based on the harmonic analysis method is introduced to accurately predict the performance of the machine,and finally the proposed structure is prototyped and the experimental results are simulated and modeling are compared.展开更多
Previous studies done elsewhere have shown that Eucalyptus poles treated with chromated copper arsenate (CCA) can last over 30 years. Kenya is exceptional because in some eco-regions, the Eucalyptus poles’ life span ...Previous studies done elsewhere have shown that Eucalyptus poles treated with chromated copper arsenate (CCA) can last over 30 years. Kenya is exceptional because in some eco-regions, the Eucalyptus poles’ life span has greatly reduced to 5 years. The current study was designed to evaluate wood deteriorating agents of CCA-treated Eucalyptus poles and variability in four eco-regions of Kenya, namely, dryland, coastal, highland and humid lake. A total of 360 Eucalyptus pole samples were used for this experiment. Three CCA treatments were used to treat transmission poles at 20 kg/cm3 fencing posts samples at 6 kg/cm3, and a control group. Results indicated that termites and wood-decay fungi attacks caused wood deterioration in the four eco-regions. The proportion of power transmission pole degradation by wood deteriorating agents varied across eco-regions, between treatments and control and between time after treatments. Dryland eco-regions had the highest termite-related degradation (41.82%) while wood-decay fungi attack was highest in the highland eco-regions (9.20%). Samples treated with 6 kg/cm3 recorded the lowest level of wood deterioration, manifested by minimal superficial termite and wood-decay fungi attack. Samples treated with 20 kg/cm3 were characterized by moderate termite and wood-decay fungi attacks observed around the heartwood region, unlike sapwood. This study concluded that the deterioration of Eucalyptus CCA-treated poles is a question of climatic variability and hence, to increase the poles’ lifespan, CCA treatment should be tailored according to the characteristics of the ecoregion of use. Further investigations will inform the diversity of termites and decay-fungi across different eco-regions.展开更多
Aiming at the problem of high temperature and even demagnetization failure of permanent magnet (PM) due to PM eddy current loss in PM synchronous high-speed motors, this paper proposes a technique to lessen PM eddy cu...Aiming at the problem of high temperature and even demagnetization failure of permanent magnet (PM) due to PM eddy current loss in PM synchronous high-speed motors, this paper proposes a technique to lessen PM eddy current loss by cutting the angle of PM poles to change the shape of PM structure. Firstly, an analysis is conducted on the mechanism of PM synchronous high-speed motor eddy current loss production, the theoretical analytical model of PM eddy current loss is deduced, and it is theoretically proved that the magnetic pole shaving angle can reduce PM eddy current loss. Then, a 25 KW surface-type PM synchronous high-speed motor as an object, using two-dimensional time-step finite element method (FEM) to model and analyze PM eddy current loss. The results show that the smaller the PM pole shaving angle, the less its eddy current loss will be, it is possible to minimize the pole shaving angle of eddy current loss by 9.8% compared to the unshaved angle. Finally, the temperature field of the PM is calculated using a finite element method, and the outcomes demonstrate that the maximum temperature of the PM with a magnetic pole shaving angle can be reduced by about 5% compared with the unshaved angle.展开更多
Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed...Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed,while the magnitude of elastic potential energy depends on height.Therefore,the run-up speed determines the vaulter’s performance in pole vault to a certain extent.the horizontal speed of the pole-holding approach phase transitioning into vertical upward speed plays a crucial role in executing pole vault techniques,and the model of approaching speed establishes a theoretical foundation for vaulters to break through the pole limitation.In terms of specialized technical assistance in speed training,short-distance speed exercises are used in the approaching phase;in the swinging phase,gymnastic rings,single bar and suspension rope exercises are employed for suspension;in the stretch phase,trampoline exercises play a important role in rotation phase,etc.展开更多
The soft switching operation principle and operation performance of rugged resonant pole (RRP) is given. The applications of RRP in soft switching DC DC converter and soft switching inverter are discussed in detail. R...The soft switching operation principle and operation performance of rugged resonant pole (RRP) is given. The applications of RRP in soft switching DC DC converter and soft switching inverter are discussed in detail. RRP can constitute buck boost soft switching DC DC converter and isolated soft switching DC DC converter with the automatic limitation performance of output power. Partial series resonant DC DC converter with RRP can realize the zero voltage/zero current switching of power devices. RR...展开更多
A Mach-Zehnder(MZ) electro-optic(EO) modulator are real iz ed,with three optical layers as polymer materials.The functional layer is the co rona poled crosslinkable polyurethane.The ridge waveguide is fabricated by us...A Mach-Zehnder(MZ) electro-optic(EO) modulator are real iz ed,with three optical layers as polymer materials.The functional layer is the co rona poled crosslinkable polyurethane.The ridge waveguide is fabricated by using the spin-coating,poling,photolithography and oxygen reactive ion etching(RIE) techniques.The mode and the modulation properties of these devices are demonstra ted in a micron control system,while the light source works at the wavelength of 1 31 or 1 55 micron.展开更多
文摘As non-operating room anesthesia (NORA) vastly increases, so does the complexity of both the patients and the procedures. Unfamiliar environment, remote locations, and limited access to resources are some of the many challenges faced by the anesthesiologist in this environment. Understanding the environmental factors such as the room layout, machine placement and patient positioning needs advanced planning in the COVID-19 patient to determine airway management, intravenous access and overall patient safety. Communication with the proceduralist and healthcare workers (HCW) is of essence as both the procedure and anesthetic requirements may need to be altered as the case progresses. Standard monitoring guidelines should apply to all patients regardless of depth of anesthesia. The COVID-19 patient adds to these challenges. Aerosol generating medical procedures (AGMP’s) need to be identified ahead of time in order to ensure the safety of both the staff and patients. This allows for planning and preparation required for transportation of the patient to the room. HCWs may need to be identified and be available to assist with the procedure. Time should be allocated for transportation, briefing, room preparation, personal protective equipment needs of the staff and donning and doffing procedures as per institutional protocol. Communication means with staff outside of the room should be discussed in advance should an emergent situation arise during the procedure. Debriefing should be performed at the end of every procedure to improve patient safety and outcomes.
文摘Nowadays,there is considerable research interest in proposing modern permanent magnet(PM)electric machine structures for applications such as electric vehicles.Several radial and axial topologies with different arrangements of PM in the stator and rotor have been introduced for PM Vernier motors(PMVM)with the aim of increasing the performance characteristics such as power factor,efficiency,rotational torque torque density and wider constant torque-speed region.Meanwhile,the spoke PM arrangement has provided higher torque density than the surface and V-shaped arrangement.But in contrast,the V-shaped arrangement has a more sinusoidal flux and less cogging torque.In this paper,a 620 W,12-slot 16-pole Vernier PM motor with a fractional slot arrangement.Consequent K-shaped pole is introduced,which has the advantages of spoke and V-shaped magnetic arrangements.After presenting and confirming the concept of the proposed structure based on functional comparison with conventional structures,an analytical modeling based on the harmonic analysis method is introduced to accurately predict the performance of the machine,and finally the proposed structure is prototyped and the experimental results are simulated and modeling are compared.
文摘Previous studies done elsewhere have shown that Eucalyptus poles treated with chromated copper arsenate (CCA) can last over 30 years. Kenya is exceptional because in some eco-regions, the Eucalyptus poles’ life span has greatly reduced to 5 years. The current study was designed to evaluate wood deteriorating agents of CCA-treated Eucalyptus poles and variability in four eco-regions of Kenya, namely, dryland, coastal, highland and humid lake. A total of 360 Eucalyptus pole samples were used for this experiment. Three CCA treatments were used to treat transmission poles at 20 kg/cm3 fencing posts samples at 6 kg/cm3, and a control group. Results indicated that termites and wood-decay fungi attacks caused wood deterioration in the four eco-regions. The proportion of power transmission pole degradation by wood deteriorating agents varied across eco-regions, between treatments and control and between time after treatments. Dryland eco-regions had the highest termite-related degradation (41.82%) while wood-decay fungi attack was highest in the highland eco-regions (9.20%). Samples treated with 6 kg/cm3 recorded the lowest level of wood deterioration, manifested by minimal superficial termite and wood-decay fungi attack. Samples treated with 20 kg/cm3 were characterized by moderate termite and wood-decay fungi attacks observed around the heartwood region, unlike sapwood. This study concluded that the deterioration of Eucalyptus CCA-treated poles is a question of climatic variability and hence, to increase the poles’ lifespan, CCA treatment should be tailored according to the characteristics of the ecoregion of use. Further investigations will inform the diversity of termites and decay-fungi across different eco-regions.
文摘Aiming at the problem of high temperature and even demagnetization failure of permanent magnet (PM) due to PM eddy current loss in PM synchronous high-speed motors, this paper proposes a technique to lessen PM eddy current loss by cutting the angle of PM poles to change the shape of PM structure. Firstly, an analysis is conducted on the mechanism of PM synchronous high-speed motor eddy current loss production, the theoretical analytical model of PM eddy current loss is deduced, and it is theoretically proved that the magnetic pole shaving angle can reduce PM eddy current loss. Then, a 25 KW surface-type PM synchronous high-speed motor as an object, using two-dimensional time-step finite element method (FEM) to model and analyze PM eddy current loss. The results show that the smaller the PM pole shaving angle, the less its eddy current loss will be, it is possible to minimize the pole shaving angle of eddy current loss by 9.8% compared to the unshaved angle. Finally, the temperature field of the PM is calculated using a finite element method, and the outcomes demonstrate that the maximum temperature of the PM with a magnetic pole shaving angle can be reduced by about 5% compared with the unshaved angle.
文摘Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed,while the magnitude of elastic potential energy depends on height.Therefore,the run-up speed determines the vaulter’s performance in pole vault to a certain extent.the horizontal speed of the pole-holding approach phase transitioning into vertical upward speed plays a crucial role in executing pole vault techniques,and the model of approaching speed establishes a theoretical foundation for vaulters to break through the pole limitation.In terms of specialized technical assistance in speed training,short-distance speed exercises are used in the approaching phase;in the swinging phase,gymnastic rings,single bar and suspension rope exercises are employed for suspension;in the stretch phase,trampoline exercises play a important role in rotation phase,etc.
文摘The soft switching operation principle and operation performance of rugged resonant pole (RRP) is given. The applications of RRP in soft switching DC DC converter and soft switching inverter are discussed in detail. RRP can constitute buck boost soft switching DC DC converter and isolated soft switching DC DC converter with the automatic limitation performance of output power. Partial series resonant DC DC converter with RRP can realize the zero voltage/zero current switching of power devices. RR...
文摘A Mach-Zehnder(MZ) electro-optic(EO) modulator are real iz ed,with three optical layers as polymer materials.The functional layer is the co rona poled crosslinkable polyurethane.The ridge waveguide is fabricated by using the spin-coating,poling,photolithography and oxygen reactive ion etching(RIE) techniques.The mode and the modulation properties of these devices are demonstra ted in a micron control system,while the light source works at the wavelength of 1 31 or 1 55 micron.
