CLUTCH OPERATING DEVICE WITH FRICTION LINING WEAR COMPENSATION ANALYSIS OF PROPERTIES AND UTILIZATION EFFICIENCY

In modern conditions of competition a lot of attention is paid to the comfort of driving. Control to driveline units is no exception. Application of clutch with the system of compensation of wear of friction overlays can not only enhance comfort, due to maintaining a stable effort on the pedal, but also improve the performance of the clutch. In the article a comparative analysis of the traditional design of the pneumohydraulic booster (PHB) and the design, which has a mechanism for compensat-ing the wear of friction plate of clutches. As a compensator for the wear of friction plate of clutches, a telescopic rod with a closed cavity is used, which is filled the brake fluid through a reverse valve. With the wear of friction clutches, the fluid has the ability to slowly flow out of the closed cavity of the rod due to the leakage of the reverse valve. A positive feature is the ability to implement the proposed de-sign within the framework of the traditional design of the pneumatic booster without changing the basic parts. As a result of the application of the proposed designs, it is expected to obtain such positive qualities as reducing the mass and material capacity of the product, maintaining high clutch performance regardless of the degree of wear of friction plates, reducing air consumption in operation (and, consequently, reducing fuel consumption), reducing the overall dimensions of the PHB. In order to confirm the new qualities, the consumption of air and fuel during the operation of both design of PHB on the typical urban route in the route bus is calculated. When calculating, the clutch exclusions taken into account are required during acceleration after each stop and traffic light. A reference to the investigation of the speed of the clutch control mechanism with new and worn friction plate of clutch is given. The properties of the proposed PHB design with the mechanism of compensation of the wear of the friction plate of the clutch are analyzed and the effect is shown not only in the manufacture of this design, but also from the application of this design in operation, which is expressed in fuel economy

Mineral oil certified reference materials for the determination of polychlorinated biphenyls from the National Metrology Institute of Japan (NMIJ)

Four mineral oil certified reference materials (CRMs), NMIJ CRM 7902-a, CRM 7903-a, CRM 7904-a, and CRM 7905-a, have been issued by the National Metrology Institute of Japan, which is part of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST), for the determination of polychlorinated biphenyls (PCBs). The raw materials for the CRMs were an insulation oil (CRM 7902-a and CRM 7903-a) and a fuel oil (CRM7904-a and CRM 7905-a). A solution of PCB3, PCB8, and technical PCB products, comprising four types of Kaneclor, was added to the oil matrices. The total PCB concentrations in the PCB-fortified oils (CRM 7902-a and CRM 7904-a) are approximately 6 mg kg−1. In addition, the mineral oils which were not fortified with PCBs were also distributed as CRMs (CRM 7903-a and CRM 7905-a). Characterization of these CRMs was conducted by the NMIJ/AIST, where the mineral oils and the PCB solution were analyzed using multiple analytical methods such as dimethylsulfoxide extraction, normal-phase liquid chromatography, gel permeation chromatography, reversed-phase liquid chromatography, and chromatography using sulfoxide-bonded silica; and/or various capillary columns for gas chromatography, and two ionization modes for mass spectrometry. The target compounds in the mineral oils and those in the PCB solution were determined by one of the primary methods of measurement, isotope dilution–mass spectrometry (ID-MS). Certified values have been provided for 11 PCB congeners (PCB3, 8, 28, 52, 101, 118, 138, 153, 180, 194, and 206) in the CRMs. These CRMs have information values for PCB homologue concentrations determined by using a Japanese official method for determination of PCBs in wastes and densities determined with an oscillational density meter. Because oil samples having arbitrary PCB concentrations between respective property values of the PCB-fortified and nonfortified CRMs can be prepared by gravimetric mixing of the CRM pairs, these CRMs can be used for validation of PCB analyses using various instruments which have different sensitivities

ANALYSIS OF ACTUATORS CONSTRUCTIONS FOR VEHICLE CLUTCH CONTROL

The most widely applied actuators of vehicle declutching are considered, and advantages and disadvantages of their operation are analyzed

Quantum coherence of multiple excitons governs absorption cross-sections of PbS/CdS core/shell nanocrystals

半導体ナノ粒子の光吸収効率の増加メカニズムを解明 --高効率な太陽電池や光検出器へ期待--. 京都大学プレスリリース. 2018-08-22.Multiple excitons in semiconductor nanocrystals have been extensively studied with respect to unique carrier dynamics including quantized Auger recombination and implementation in optoelectronic devices such as solar cells and photodetectors. However, the generation mechanism of multiple excitons still remains unclear. Here, we study instantaneous and delayed multiple exciton generation processes in PbS/CdS core/shell nanocrystals. The absorption cross-sections of biexcitons and triexcitons are identical to that of single excitons under instantaneous excitation with a single pulse. In contrast, the delayed excitation using double pulses shows a reduction of the biexciton and triexciton absorption cross-sections. Our theoretical analysis reveals that the excitonic coherence assists the generation of multiple excitons and that the reduction of multiple exciton absorption cross-sections is caused by the reduction of coherent excitation pathways. We clarify that exciton coherences play a key role in multiple exciton generation processes and seamlessly connect the identical and reduced multiple exciton absorption cross-sections