Experimental Study on the Crushing Properties of Corn Stalks in Square Bales

With the development of straw baling mechanization technology, straw is stored in the form of square baling or round baling. At present, hammer mill or the guilt-cutting and rubbing combined mill is widely used to crush square bales of straw. These two kinds of crushing equipment have disadvantages such as low productivity, large power consumption, and poor crushing effect. This paper aims to study and analyze the crushing characteristics of square baled straw after unbaling, and lay a theoretical foundation for the later research and development of a special square baled straw crusher with high productivity, low power consumption, good crushing effect, and the simulation of the square baled corn straw crushing process. For this purpose, this study carried out a corn bale crushing experiment on the Instron 8801 fatigue test machine, and studied the effects of blade angle, water content and loading speed on corn bale crushing force through the response surface method. Test results showed that the crushing process includes the compression stage and shearing stage; in terms of single factor effect, with the increase in water content and blade angle, the crushing force of the corn bale increased, but the loading speed had no significant effect on the crushing force of the corn bale. In terms of interaction effect, there was interaction effect between moisture content and blade inclination angle, when moisture content was 10%, with the increase in blade inclination angle, the incremental speed of the crushing force also increased gradually. When the blade inclination angle was 10°, with the increase in moisture content, the incremental speed of the crushing force also increased, and the interaction effect of them jointly acted on the crushing force of the corn bales.

Design of a Damping Controller Using a Metaheuristic Algorithm for Angle Stability Improvement of an SMIB System

Low frequency oscillations in large power systems may result in system instability under large disturbances. Power system stabilisers (PSS) play an effective role in damping these low frequency oscillations by injecting a modulating signal in the excitation loop of a synchronous machine. A new metaheuristic optimisation algorithm termed the sine cosine algorithm (SCA) was proposed for optimising PSS controller parameters to obtain an optimal solution with the damping ratio as an objective function. The SCA technique was examined on a single machine infinite bus (SMIB) system under distinct loading situations and matched with a moth flame optimisation technique and evolutionary programming to design a robust controller of PSS. The simulation was accomplished using a linearised mathematical model of the SMIB. The performance of a designed lead lag-controller of PSS was demonstrated using eigenvalue analysis with simulations, showing promising results. The dynamic performance was validated with respect to the damping ratio, the eigenvalue’s location in the s-plane and rotor angle deviation response to demonstrate system stability.

Large power spectrum and primordial black holes in the effective theory of inflation

We study the generation of a large power spectrum, necessary for primordial black hole formation, within the effective theory of single-field inflation. The mechanisms we consider include a transition into a ghost-inflation-like phase and scenarios where an exponentially growing mode is temporarily turned on. In the cases we discuss, the enhancement in the power spectrum results from either a swift change in some effective coupling or a modification of the dispersion relation for the perturbations, while the background evolution remains unchanged and approximately de Sitter throughout inflation. The robustness of the results is guaranteed thanks to a weakly broken galileon symmetry, which protects the effective couplings against large quantum corrections. We discuss how the enhancement of the power spectrum is related to the energy scale of the operators with weakly broken galileon invariance, and study the limits imposed by strong coupling and the validity of the perturbative expansion.

Generalized Newtonian flow analysis in the microchannel manufactured by SLA considering nano-scale stair effect

SLA (stereolithography), as a rapid and accurate additive manufacturing method, can be used to mold the microchannel. The stair effect is inevitable when the part is printed layer by layer, which has an important influence on the printing performance. In the current work, the power-law flow in the microchannel with nano-scale stairs manufactured by SLA is simulated and investigated. To improve the stability caused by the non-Newtonian behavior, a modified lattice Boltzmann method (LBM) is proposed and validated. Then, a series of simulations are conducted and analyzed, the results show that both the stair effect and power-law index are important factors. The stairs on the surface force the streamlines to be curved and increase the outlet velocity. In addition, different power-law indexes result in completely different flows. The small power-law index leads to a much larger velocity than other cases, while the large power-law index makes the outlet velocity unstable at the middle position.

Design Considerations of Low Bypass Ratio Mixed Flow Turbofan Engines with Large Power Extraction

The possibility of extracting large amounts of electrical power from turbofan engines is becoming increasingly desirable from an aircraft perspective. The power consumption of a future fighter aircraft is expected to be much higher than today’s fighter aircraft. Previous work in this area has concentrated on the study of power extraction for high bypass ratio engines. This motivates a thorough investigation of the potential and limitations with regards to performance of a low bypass ratio mixed flow turbofan engine. A low bypass ratio mixed flow turbofan engine was modeled, and key parts of a fighter mission were simulated. The investigation shows how power extraction from the high-pressure turbine affects performance of a military engine in different parts of a mission within the flight envelope. An important conclusion from the analysis is that large amounts of power can be extracted from the turbofan engine at high power settings without causing too much penalty on thrust and specific fuel consumption, if specific operating conditions are fulfilled. If the engine is operating (i) at, or near its maximum overall pressure ratio but (ii) further away from its maximum turbine inlet temperature limit, the detrimental effect of power extraction on engine thrust and thrust specific fuel consumption will be limited. On the other hand, if the engine is already operating at its maximum turbine inlet temperature, power extraction from the high-pressure shaft will result in a considerable thrust reduction. The results presented will support the analysis and interpretation of fighter mission optimization and cycle design for future fighter engines aimed for large power extraction. The results are also important with regards to aircraft design, or more specifically, in deciding on the best energy source for power consumers of the aircraft.

GraphAttack

Graph structures are a natural representation of important and pervasive data. While graph applications have significant parallelism, their characteristic pointer indirect loads to neighbor data hinder scalability to large datasets on multicore systems. A scalable and efficient system must tolerate latency while leveraging data parallelism across millions of vertices. Modern Out-of-Order (OoO) cores inherently tolerate a fraction of long latencies, but become clogged when running severely memory-bound applications. Combined with large power/area footprints, this limits their parallel scaling potential and, consequently, the gains that existing software frameworks can achieve. Conversely, accelerator and memory hierarchy designs provide performant hardware specializations, but cannot support diverse application demands. To address these shortcomings, we present GraphAttack, a hardware-software data supply approach that accelerates graph applications on in-order multicore architectures. GraphAttack proposes compiler passes to (1) identify idiomatic long-latency loads and (2) slice programs along these loads into data Producer/ Consumer threads to map onto pairs of parallel cores. Each pair shares a communication queue; the Producer asynchronously issues long-latency loads, whose results are buffered in the queue and used by the Consumer. This scheme drastically increases memory-level parallelism (MLP) to mitigate latency bottlenecks. In equal-area comparisons, GraphAttack outperforms OoO cores, do-all parallelism, prefetching, and prior decoupling approaches, achieving a 2.87× speedup and 8.61× gain in energy efficiency across a range of graph applications. These improvements scale; GraphAttack achieves a 3× speedup over 64 parallel cores. Lastly, it has pragmatic design principles; it enhances in-order architectures that are gaining increasing open-source support.

Design o f Wireless Ad Hoc System u sing Adaptive Multi Hop Link State Optimal Routing Protocol

Now a days for the radio network communication multi-hop routing is used. This multi-hop routing technique covers larger coverage area. Therefore to reach at specific location data is transferred in form of packets from one node to other node. But for the transmission of radio signals over the large distance, large number of transreceivers are required and these transreceivers requires large power to operate. As a result, multi-hop routing can saves energy over separate routing. Therefore it is necessity to design a cost effective multi-hop routing technique for successful transmission of ratio packet data. In this paper a hop by hop adaptive link state optional routing (HALO) is explained. It is the first packet transmitting solution with hop by hop and link state routing, which reduces the cost of transporting data across a packet switch network[3]. The triple model is designed for multi hop packet routing. In this work each node of network iteratively and separately improves the small part of traffic bound. This algorithm finds the shortest path of specific location for every iteration and it is calculated by the marginal cost of the various links of network. The marginal link cost is used to calculate the shortest path between the node and the destination location. This marginal link cost is gathered from link state updates. The various networks changes are automatically identified by the adaptive method which is used in this paper. Due to this the exchange between the packets on wrong node is reduced over the overhead traffic. To validate these theoretical results the experimental evaluations and mathematical calculations are also reported in this work. Net beans java is the programmed use in this proposed project.

Reaction Sintering of Ca3Co4O9 with BiCuSeO Nanosheets for High-Temperature Thermoelectric Composites

Ceramic composites composed of oxide materials have been synthesized by reaction sintering of Ca3Co4O9 with BiCuSeO nanosheets. In situ x-ray diffraction and thermogravimetric analyses of the compound powders were conducted to understand the phase transformations during heating up to 1173 K. Further thermogravimetric analyses investigated the thermal stability of the composites and the completion of reaction sintering. The microstructure of the formed phases after reaction sintering and the composition of the composites were investigated for varying mixtures. Depending on the amount of BiCuSeO used, the phases present and their composition differed, having a significant impact on the thermoelectric properties. The increase of the electrical conductivity at a simultaneously high Seebeck coefficient resulted in a large power factor of 5.4 $$\mu $$ μ W cm−1 K−2, more than twice that of pristine Ca3Co4O9.