Efficiency Of Mechanical Transmission Research Articles

Evaluating temporal bone column density for optimized bone conduction implant placement

IntroductionAn optimal placement of bone conduction implants can provide more efficient mechanical transmission to the cochlea if placed in regions with greater bone column density. The aim of this study was to test this hypothesis and to determine the clinical potential of preoperative bone column density assessment for optimal implant placement.MethodsFive complete cadaver heads were scanned with quantitative computed tomography imaging to create topographic maps of bone density based on the column density index (CODI). Laser Doppler vibrometry was used to measure cochlear promontory acceleration under bone conduction stimulation in different locations on the temporal bone, using a bone-anchored hearing aid transducer at frequencies ranging from 355 Hz to 10 kHz.ResultsWe found a statistically significant association between CODI levels and the accelerance of the cochlear promontory throughout the frequency spectrum, with an average increase of 0.6 dB per unit of CODI. The distance between the transducer and the cochlear promontory had no statistically significant effect on the overall spectrum.DiscussionWe highlight the importance of bone column density in relation to the mechanical transmission efficiency of bone conduction implants. It may be worthwhile to consider column density in preoperative planning in clinical practice.

Limited Capacity for Aedes aegypti to Mechanically Transmit Chikungunya Virus and Dengue Virus.

Mechanical transmission is an understudied mode of arbovirus transmission that occurs when a biting insect transmits virus among hosts by the direct transfer of virus particles contaminating its mouthparts. Multiple arboviruses have been shown to be capable of utilizing this transmission route, but most studies were conducted 40 to 70 years ago using dated methodologies. To gain a better understanding of this phenomenon, we used molecular techniques to evaluate the efficiency of mechanical transmission by Aedes aegypti mosquitoes for two evolutionarily divergent arboviruses, chikungunya virus (CHIKV) and dengue virus (DENV). Viral RNA and/or infectious DENV could be detected on 13.8% of mosquito proboscises sampled immediately after an infectious bloodmeal, but positivity rates declined within hours. CHIKV RNA and/or infectious virus was detected on 38.8% of proboscises immediately after feeding but positivity rates dropped to 2.5% within 4 hours. RNA copy numbers were low for both viruses, and we were unable to demonstrate mechanical transmission of CHIKV using an established animal model, suggesting that this mode of transmission is unlikely under natural conditions.

Multi-Objective Optimization and Test of a Tractor Drive Motor

The design objectives of the structural parameters of the tractor drive motor are diverse, and the constraints are complex. It is difficult to optimize the overall performance of the unit by using the empirical method and single-objective optimization method. This paper proposes a multi-objective optimization method for tractor drive motors based on an improved Non-dominated Sorting Genetic Algorithm II (NSGA-II). Constraints are formulated according to the inherent characteristics of the motor itself and the characteristics of the tractor’s working conditions. The objective function was established with the heat loss of the drive motor and the total efficiency of the drive system. Based on the designed solution process of NSGA-II algorithm, an example optimization was carried out, and the tractor electromechanical drive system was carried out with the single-objective optimization results of the optimal energy use efficiency of the drive motor and the optimal mechanical transmission efficiency of the transmission system as the control group. The test results show that compared with the control group, the proposed multi-objective optimization method can make the overall tractor system efficiency the highest, and the maximum and rated values of the total efficiency ηq of the drive system of the multi-objective optimization design scheme. Compared with the optimal design scheme with ηme as a single objective, it was increased by 2% and 1.4%, respectively, and compared with the optimal design scheme with ηtr as a single objective, it is improved by 26.5% and 73.6%, respectively. It can provide an effective calculation method for the motor design problem in the subsequent development of the tractor electromechanical drive system.

Tribology performance analysis of oil for wet drive axle

In order to solve the problems caused by the use of common gear oil in the wet drive axle, such as abnormal braking noise, excessive braking distance and severe wear of components, the special oil for the wet drive axle is developed in accordance with the new requirements for lubricating oil after the technical upgrade of the drive axle. Based on the actual braking condition of the wet brake, the oil tribology performance of the wet drive axle is tested and studied by using the brake test bench and increasing the energy density to improve the harshness of the braking condition. The results show that the method can distinguish oil with different tribology performance. The developed oil is superior to the reference oil in formulating smoothness, stability and mechanical transmission efficiency, providing better friction retention over long periods of use.

Research on adaptive control strategy of hydraulic mechanical continuously variable transmission of a cotton picker

Hydraulic mechanical continuously variable transmission has the advantages of good hydraulic stepless speed regulation performance and high efficiency of mechanical transmission, which can achieve the optimal matching of transmission system load and power source. In this article, an adaptive control strategy based on radial basis function neural network and proportional–integral–derivative control was proposed. The speed compound control method was used to solve the problems that the output speed of the hydraulic mechanical continuously variable transmission system was poor at the variable speed input and was difficult to control. The throttle opening and the engine speed were used as controller inputs. The pump–motor's displacement ratio and the output speed were used as controller outputs. Finally, the output speed of the cotton picker was stably controlled. Simulation and experimental results show that the transmission can quickly respond to the target speed and had little fluctuation based on different initial input speeds. The control strategy had good control precision and robustness. Compared with the traditional proportional–integral–derivative algorithm, the average steady-state error of the system output speed was controlled between ±0.0125%. The proposed algorithm based on radial basis function neural network proportional–integral–derivative adaptive control strategy had obvious control effect, and the stability of the speed output of the system was improved under the nonlinear input complex conditions. It provided research for the speed ratio adjustment and control of the hydraulic mechanical continuously variable transmission of the cotton picker.

Hydro-mechanical power split transmissions: Progress evolution and future trends

The hydro-mechanical power split transmission is an important form of hydraulic hybrid transmission, combining the stepless speed characteristics of hydraulic transmission and the high efficiency of mechanical transmission. Recently, the hydro-mechanical power split transmission, with its relatively large potential for energy recovery and improving the environment, and its low cost, has attracted many scholars from all over the world. Because there are many types of hydro-mechanical power split transmission, the different forms are complex, and researchers across the world are relatively dispersed, it has experienced a long and arduous development process. Therefore, it is important to summarize the types, developments, and achievements of this transmission. From the recent literature at home and abroad, this paper summarizes developments, key techniques and trends, analyses problems and difficulties in design and application, discusses the methods for solving these problems, and provides references for the development and application of hydro-mechanical power split transmission.

性能优异的纳米金刚石润滑油

用翔实的数据介绍了纳米金刚石作为极压抗磨剂的优越性。发动机台架试验表明，动力性、经济性、排放性、清净性和沉积物等均明显改善。钢磨损量可减少82%，油膜承载能力大幅提高，摩擦功耗和油温明显降低，传动机械效率提高，对摩擦副确有自修复功能。 The superiority of nano-diamond as extreme pressure anti-wear agent is introduced with in-formative data. Engine bench tests show that power, economy, emissions, cleanliness and sediment were significantly improved. Steel wear can be reduced by 82%. Oil film carrying capacity can be substantially increased. Frictional power consumption and oil temperature were significantly reduced. Mechanical transmission efficiency was enhanced. Nano-diamond engine oil does have self-repair function for the friction pairs.

Research on Mechanical Gearbox Transmission Efficiency Test

Automobile gearbox transmission efficiency is an important parameter which can directly reflect the gearbox design and manufacturing level . This paper analysis detailed the effect factors on measurement, test method, and data processing for transmission efficiency of automobile gearbox, summed up the actual test experience whereby the mechanical transmission efficiency measurement , plays a reference and guidance role on improving test precision.

Study on the Working Principle of a New Type of Power Transmission Mechanism for Gasoline Engine

This paper presents a new heat-work device, which chooses the gear-rack mechanism to realize the reciprocating motion of cylinder, and that applies swing rod rotation to transmit thermal energy, it changes the use of traditional engine crank-link mechanism and improves the mechanical transmission efficiency effectively. Using incomplete gear mesh, the length of displacement can change in the exhaust stroke, so that the combustion exhaust gas can discharge more. The premix gas is completed ahead of schedule two stroke earlier than traditional gasoline engine in the auxiliary cylinder, and mixture gas burn more thoroughly. To combine swing rod with overrunning clutch install on the output straight shaft, it can replace the crankshaft for output power.

Design of Steering Wheel Control System of Tracked Vehicle of Hydro-Mechanical Differential Turning

The hydro-mechanical differential turning mechanism is the new type of double power flow turning mechanism of tracked vehicle. The hydraulic stepless speed regulation and the high efficiency of mechanical transmission are integrated into the turning mechanism. The stepless turning of tracked vehicle can be achieved. Basing on hydro-mechanical differential turning theory, the scheme design of steering wheel control system of tracked vehicle of hydro-mechanical differential turning is finished. By establishing model of steering wheel control system, its working stability and following characteristic is simulated and analyzed in this paper. The demand of hydro-mechanical differential turning of tracked vehicle can be realized by the steering wheel control system designed through the simulation results.

Modeling and Simulation of a Screw-Worm Gear Mechanical Transmission to Achieve its Optimal Design under Imposed Constraints

This work deals with the modeling and simulation of a screw-worm gear mechanical transmission (worm gear screw jack), abbreviated WGSJ, to achieve its optimal design under imposed constraints. Optimal design is sought under two different conditions: to maximize the efficiency of WGSJ, for energy saving, and to minimize the overall size of WGSJ, for compact design. Several different models of buckling for the screwed shaft are taken into account by introducing a variable coefficient of fixity. Different strength theories of failure for the screwed shaft are taken into account, according to the type of material used, by introducing a variable weighting coefficient of the shear stress relative to the normal stress in evaluation of the equivalent stress. Variation of the mechanical transmission's efficiency and its overall size versus the coefficient of fixity and the shear stress weighting coefficient are presented and discussed.

Evolution of dyskinetoplastic trypanosomes: how, and how often?

Evolution of dyskinetoplastic trypanosomes: how, and how often?

Adaptation of plum pox virus to a herbaceous host (Pisum sativum) following serial passages.

Plum pox virus (PPV) populations from peaches are able to adapt consistently to herbaceous hosts, characterized by a reduction in time to symptom development, increases in inoculation efficiency and increased titres. PPV adaptation was studied by using pea (Pisum sativum) as an alternative host. Two isolates of PPV from peaches were inoculated and passaged in peas ten times using either aphid or mechanical inoculation, generating four independent passage lines. Mechanical-transmission efficiency from peach to pea improved from 3 % at passage 1 to 100 % by serial passage 4 on peas. Inoculation using aphid vectors required six to ten serial passages in pea to reach a peak of 50-60 % transmission efficiency. Sequence analyses of all four PPV population lines inoculated sequentially to pea identified a specific mutation occurring consistently in the NIb gene when compared with the same PPV isolates passaged in parallel in peach. The mutation allowed PPV to replicate up to 20 times faster in the new host. Pea-adapted strains of PPV at every passage were also tested for their ability to infect the original host, peach. Regardless of the number of previous passages, all pea-adapted PPV strains consistently infected peach at low levels using aphid inoculation.

Nicotiana megalosiphon, a Highly Susceptible, New, and Useful Host for Potato Virus A.

Potato virus A (PVA; genus Potyvirus, family Potyviridae) occurs wherever potatoes are grown and may reduce tuber yields as much as 40%. Its host range consists of six experimental hosts (Lycopersicon pimpinellifolium (Jusl.) P. Mill., Nicandra physalodes (L.) Gaertn., Nicotiana tabacum L., Solanum demissum Lindl., S. demissum × S. tuberosum [2], and Nicotiana debneyi Domin.) and two natural hosts (S. tuberosum L. and S. betaceae (Cav.) Sendt.) (2). Aphids transmit PVA in a stylet-born manner. Its difficult mechanical transmission, caused by a low virus concentration in potato and other hosts (1), has constrained pathological research on the virus. In routine studies to identify virus isolates from the field, we discovered that N. megalosiphon Van Heurck & Mull. Agr. is a superior host of PVA that markedly facilitated diagnosis, selection for resistance to PVA, and other research applications. The efficiency of mechanical transmission of PVA to potato (5 duplicated assays and 10 plants per assay) ranged from 0 to 10% with PVA-infected potato as the virus source, 0 to 30% with Nicandra physalodes, 10 to 30% with N. tabacum cv. Samsun, and 20 to 80% with N. megalosiphon as the source of virus. The efficiency of mechanical transmission to four systemic hosts of PVA with potato (cv. Russet Burbank) as the source of virus (5 duplicated assays and 10 plants per assay) ranged from 0 to 20% to potato, 0 to 30% to Nicandra physalodes, 10 to 40% to N. tabacum cv. Samsun, and 80 to 100% to N. megalosiphon. The superiority of N. megalosiphon as a host and source of PVA was associated with a high virus concentration in tissues. Infected potato leaves yielded 0.32 to 0.54 mg of virus per kg of infected leaves, Nicandra physalodes yielded 0.37 to 0.66 mg per kg, N. tabacum cv. Samsun yielded 0.78 to 1.22 mg per kg, and N. megalosiphon yielded 5.16 to 9.39 mg per kg of infected leaves in five different purification experiments. These yields are based on the amount of virus isolated in sucrose gradients subjected to rate-zonal centrifugation as the last step in purification (3). The virus antigen concentrations of the original PVA-infected tissues measured using quantitative enzyme-linked immunosorbent assay ranked virus concentrations in the same relative order as purification but were nearly 2 times higher than were the purification yields. Similarly, local lesion assays on S. demissum A leaves (4) ranked infectious virus concentrations in the same order as did purification. Efficiency of aphid transmission from the four hosts was not assayed. Infected N. megalosiphon plants survived and served as sources of PVA for at least 1 year in a greenhouse. N. megalosiphon is an important new host of PVA because it facilitates the routine transmission of the virus and other manipulations essential for efficient research on control of the virus disease.

Functional replacement of Wheat streak mosaic virus HC-Pro with the corresponding cistron from a diverse array of viruses in the family Potyviridae

Helper component-proteinase (HC-Pro) of Wheat streak mosaic virus strain Sidney 81 (WSMV-Sidney 81) was systematically replaced with the corresponding cistron derived from four strains of WSMV (Type, TK1, CZ, and El Batán 3), the tritimovirus Oat necrotic mottle virus (ONMV), the rymoviruses Agropyron mosaic virus (AgMV) and Hordeum mosaic virus (HoMV), or the potyviruses Tobacco etch virus (TEV) and Turnip mosaic virus (TuMV). These HC-Pro proteins varied in amino acid sequence identity shared with HC-Pro of WSMV-Sidney 81 from high (strains of WSMV at ∼86–99%) to moderate (ONMV at 70%) to low (rymoviruses and potyviruses at ∼15–17%). Surprisingly, all chimeric viral genomes examined were capable of systemic infection of wheat upon inoculation with RNA transcripts produced in vitro. HC-Pro replacements derived from tritimoviruses did not alter host range relative to WSMV-Sidney 81, as each of these chimeric viruses was able to systemically infect wheat, oat, and corn line SDp2. These results indicate that differences in host range among tritimoviruses, including the inability of ONMV to infect wheat or the inability of WSMV strains Type and El Batán 3 to infect SDp2 corn, are not determined by HC-Pro. In contrast, all chimeric viruses bearing HC-Pro replacements derived from rymoviruses or potyviruses were unable to infect SDp2 corn and oat. Collectively, these results indicate that HC-Pro from distantly related virus species of the family Potyviridae are competent to provide WSMV-Sidney 81 with all functions necessary for infection of a permissive host (wheat) and that virus–host interactions required for systemic infection of oat and SDp2 corn are more stringent. Changes in symptom severity or mechanical transmission efficiency observed for some chimeric viruses further suggest that HC-Pro affects virulence in WSMV.

Efficiency of Mechanical Transmission of Citrus Tristeza Virus

Efficiency of Mechanical Transmission of Citrus Tristeza Virus