The hybrid drive effects of green innovation in Chinese coal enterprises: an empirical study

Purpose The purpose of this study is to explore the green innovation evolution in coal enterprises in China and the various driving mechanisms influenced by government regulations, enterprise resource capability and supply chain integration. Design/methodology/approach This paper uses the innovation data of coal enterprises in China for constructing a model to infer how enterprises achieve green innovation (the “hybrid drive effect model”). Findings This paper shows that various driving modes of green innovation in an enterprise are influenced by government regulations, enterprise resource and capability, supply chain integration and the interaction effects between any two actors. Originality/value By examining the evolution process of green innovation in a specific industry from the perspectives of exploitative and exploratory innovation, the paper touches a relatively novel view on green innovation.

Direct Driven Hydraulic Drive: Effect of Oil on Efficiency in Sub-Zero Conditions

Direct driven hydraulic drives (DDH) have the advantages of compact high power density in hydraulic systems and flexible control of electric motors. These advantages can benefit non-road mobile machinery (NRMM) applications. However, maintaining high efficiency while working in sub-zero conditions with NRMM is challenging. Therefore, this paper investigates the effect of hydraulic oil on the efficiency of a DDH in a cold environment for an NRMM application. In the DDH setup, the speed and position control of a double-acting cylinder was implemented directly with an electric motor drive in a closed-loop system without the conventional control valves. Efficiency measurements of the DDH setup with two oils (conventional multi-grade and high-performance) were conducted under different operating conditions (speed and payload) and environmental conditions (temperature in °C). The paper provides an evaluation of the electro-hydraulic system and a discussion on the usage of hydraulic oil by non-road mobile working machines in sub-zero conditions. An experimental investigation demonstrated an improvement in efficiency of 5%-unit at 22 °C, from 2%-unit to 5%-unit at 3 °C, and of almost a 10%-unit at temperatures below zero (−10 °C) by changing oil.

Experiment on the Influence of Vertical Heterogeneity of Reservoir on the Steam Drive Effect

This paper carried out experimental studies on the influence of vertical heterogeneity of reservoir on the steam drive effect after multiple-round steam stimulations. Taking the actual productive process of a heavy oil reservoir as an example, a physical model for the vertical heterogeneity was established. First, under the initial reservoir conditions, conduct multiple rounds of steam stimulations to obtain the initial reservoir conditions of steam drive, and then carry out physical simulation of steam drive, including the simulation of the horizontal reservoir and the tilted one. The development of temperature field and the oil-water output changes indicate that when the steam drive is conducted after the steam stimulations, the steam advances along the high permeability layer with better steam stimulation effect, once it gets a breakthrough, the swept volume will not change. For the tilted reservoir, due to the beneficial effects of the gravity drainage, its displacement effect is better than the horizontal one, which provides an important basis for the adjustment of layers and the section of methods of gas injection when the steam simulation is converted into steam drive.

Center Distance Change of Silent Chain Drive Effect on Sprocket Tooth Profile Modification

The principle of modified gear was applied to silent chain transmission, and tooth profile equation of the involute sprocket was derived, then method of processing gear using imaginary rack cutter solved modification coefficient of involute sprocket. When Center distance of silent chain drive changed smaller, processing method of sprocket modification coefficient and range of modification coefficient values were analysed. The method by changing the modification coefficient of involute sprocket solves the problem that the chain links are increased or decreased in the actual application to be unable to meet the requirements of specific center distance, thus improve transmission performance of silent chain.

Characteristics of Fluid Flow Between Single Rigid Body and Wall of Small-Diameter Tube

A multibody system that moves with fluid inside a small-diameter tube is applied to some parts of industry such as a PIG and it is also expected to be developed for future engineering applications. As a first step to considering a multibody system, this study focused on elucidating the flow characteristics around a single rigid body and understanding the effect of a bypass hole. The model considered has been a single rigid body moving at a constant velocity in a narrow tube. Assuming that the flow is steady axisymmetric laminar flow, the fluid flow around the body has been experimentally observed and numerically analyzed. A Rankine’s combined vortex was observed around the body and it was also observed that a layer of fluid near the top wall has characteristics of the boundary layer. Furthermore, a minimum allowable thickness of a bypass hole to cause the successful front-drive effect was obtained.

Failure and its Relationship to the Social Facilitation Effect: Evidence for a Learned Drive Interpretation of the Social Facilitation Effect

Social facilitation theory states that an audience functions as a conditioned stimulus for generalized drive and that this drive effect is learned through classical conditioning. In the present study an attempt was made to condition classically an aversive drive to an audience by having a subject fail a task in front of an audience. A sample of 61 subjects took part in a 2 × 2 factorial design. Half of the subjects did not perform a first task but only a complex motor task. Half of these subjects performed in the presence of an audience, half without an audience present. Of those subjects exposed to failure on the first task, half performed a second complex motor task in the presence of the same audience. Results indicated that performance of subjects who failed a first task in the presence of an audience and then performed the second task in the presence of that audience was significantly poorer than all of the other groups. The findings were taken as evidence that the social facilitation effect may be based on an aversive learned drive.