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This paper is concerned with the effects of the plasma surface treatment and the addition of CNT on the mechanical properties of carbon fiber/polytetrafluoroethylene (PTFE) composite. The tensile and flexural strength of composites containing CNT and plasma-treated carbon fibers improved. The flexural strength first decreases with respect to the CF content. The flexural strength increases to 179 MPa for the plasma-treated composite as compared with 167 MPa for the neat carbon fiber composites. The overall improvement is thus nearly 8%. [ABSTRACT FROM AUTHOR]

Methyl-CpG-binding protein 2 (MeCP2) is a transcriptional repressor that has been implicated in tumor onset and progression. Compared with normal and other tumorous tissue, MeCP2 is highly expressed in well-differentiated adenocarcinoma and mucinous adenocarcinoma tissues, particularly at the invasion site of colorectal cancer tissues. The aim of the present study was to evaluate the potential of MeCP2 for use as a therapeutic target for human colorectal cancer. The DLD-1 colorectal cancer cell line was subjected to lentivirus-mediated short hairpin RNA-induced knockdown of MeCP2 and the effects on cell growth, cell cycle progression and cell migration were assessed. It was confirmed that lentivirus-mediated RNA interference successfully suppressed MeCP2 expression in vitro, which was demonstrated to result in reduced cell viability, cell cycle arrest in G0/G1 phase and inhibition of cell migration. These results indicated that MeCP2 may serve as a potential target for gene therapy of colorectal cancer. [ABSTRACT FROM AUTHOR]

This paper presents a systematic method on how to design the coordinated lateral and longitudinal motion control system of autonomous four wheel drive (4WD) electric vehicles for platooning and trajectory tracking. First, mathematical models that perfectly describe the behaviors of autonomous 4WD vehicles are built-up, and the coupled effects in vehicle dynamic systems are given. Second, owing to the fact that autonomous vehicles are large-scale systems with strong coupling, nonlinearities, and uncertainties, a novel multi-objective hierarchical architecture used for coordinated lateral and longitudinal motion control is constructed, which is composed of a global cooperative control layer, a control allocation layer, and an action execution layer. A robust backstepping sliding mode controller (RBSMC) is presented in the cooperative control layer to provide the resultant forces/moment. The control allocation layer is designed using interior-point (IP) algorithm to determine the tire lateral and longitudinal forces, which result in the desired resultant forces/moment. The action execution layer consists of an inverse tire model, a slip ratio regulator for each wheel, and a slip angle regulator. Finally, simulation experiments are carried out under adverse driving conditions, and the results show that the proposed control architecture not only possesses excellent tracking performance but also enhances the riding comfort, stability, and safety of autonomous 4WD electric vehicles. [ABSTRACT FROM AUTHOR]

This work investigates commercial vehicle platoon predictive cruise control for highways. We propose a cloud-based platoon predictive cruise control method (CPPCC). A two-layered control architecture of the CPPCC is proposed as a platoon predictive cruise speed planning layer in the cloud and a platoon stabilization control layer. The CPPCC communication topology is proposed to achieve coupled control of the hierarchical architecture. The speed planning layer is a dynamic planning (DP) algorithm based on road slope in the rolling distance domain. The lower layer is a stability control algorithm to meet the stability requirements of vehicle platoon driving; the vehicle side is distributed model predictive control (DMPC). The CPPCC is validated by real road and vehicle data models, and comparative experiments with the traditional predecessor-leader following–cruise control (PLF-CC) platoon and predecessor following–cruise control (PF-CC) platoon. The speed error of the vehicle platoon was maintained at [−0.25, 0.30] (m=s) and the space error at [−0.13, 0.66] (m) in platoon stability. Against the comparison method, the CPPCC saved fuel by over 5.13% and achieved an overall operational efficiency improvement of 5.71%. [ABSTRACT FROM AUTHOR]

Hybrid tracked vehicles are common in construction, agriculture, and military applications. Most use a series hybrid powertrain with large motors and operate at a relatively low efficiency. Although some researchers have proposed power-split powertrains, most of these would require an additional mechanism to achieve skid steering. To solve this problem and enhance drivability, a single-mode power-split hybrid powertrain for tracked vehicles with two outputs connected to the left and right tracks is proposed. The powertrain with three planetary gears (PGs) would then be able to control the torque on the two tracks independently and achieve skid steering. This powertrain has three degrees-of-freedom (DOF), allowing for control of the output torques and the engine speed independently from the vehicle running speed. All design candidates with three PGs are exhaustively searched by analyzing the dynamic characteristics and control to obtain the optimal design. Efficient topology design selection with parameter sizing and component sizing is accomplished using the enhanced progressive iteration approach to achieve better fuel economy using downsized components. [ABSTRACT FROM AUTHOR]

Tracked vehicles have been widely used in construction, agriculture, and the military. Major problems facing the industry, however, are high emissions and fuel consumption. Hybrid electric tracked vehicles have thus become increasingly popular because of their improved fuel economy and reduced emissions. While the series hybrid system has drawn the most attention and has been applied in most cases, the low efficiency caused by energy conversion losses and large propulsion motors has limited its development. A novel multi-mode powertrain with two output shafts controlling each side of the track independently is first proposed. The powertrain is a three-planetary-gear power-split system with one engine, three motors, and an ultracapacitor pack. Compared with the existing technologies, the proposed powertrain can realize skid steering without an extra steering mechanism, and significantly improve the overall efficiency. To demonstrate the advantages of the novel powertrain, a topology-control-size integrated optimization problem is solved based on drivability, fuel economy, and cost. Final simulation results show that the optimized design with downsized components can produce about a 30% improvement in drivability and a 15% improvement in fuel economy compared with the commonly used series hybrid benchmark. Moreover, the optimized design is verified to be much more economical taking cumulative cost into account, which is very attractive for potential industrial applications in the future. [ABSTRACT FROM AUTHOR]

This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control. [ABSTRACT FROM AUTHOR]

1-Aminocyclopropane-l-carboxylate (ACC) deaminase is a pyridoxal 5'-phosphate (PLP) dependent enzyme which catalyzes the opening of the cyclopropane ring of ACC to give α-ketobutyric acid and ammonia. In an early study of this unusual C[sub α]-C[sub β] ring cleavage reaction, 1-amino-2methylenecyclopropane-l-carboxylic acid (2-methylene-ACC) was shown to be an irreversible inhibitor of ACC deaminase. The sole turnover product was identified as 3-methyl-2-oxobutenoic acid. These results provided strong evidence supporting the ring cleavage of ACC via a nucleophilic addition initiated process, thus establishing an unprecedented mechanism of coenzyme B[sub 6] dependent catalysis. To gain further insight into this inactivation, tritiated 2-methylene-ACC was prepared and used to trap the critical enzyme nucleophiles. Our results revealed that inactivation resulted in the modification of an active site residue, Ser-78. However, an additional 5 equiv of inhibitor was also found to be incorporated into the inactivated enzyme after prolonged incubation. In addition to Ser-78, other nucleophilic residues modified include Lys-26, Cys-41, Cys-162, and Lys-245. The location of the remaining unidentified nucleophile has been narrowed down to be one of the residues between 150 and 180. Labeling at sites outside of the active site is not enzyme catalyzed and may be a consequence of the inherent reactivity of 2-methylene-ACC. Further experiments showed that Ser-78 is responsible for abstracting the α-H from D-vinylglycine and may serve as the base to remove the β-H in the catalysis of ACC. However, it is also likely that Ser-78 serves as the active site nucleophile that attacks the cyclopropane ring and initiates the fragmentation of ACC, while the conserved Lys-51 is the base required for β-H abstraction. Clearly, the cleavage of ACC to α-ketobutyrate by ACC deaminase represents an intriguing conversion beyond the common scope entailed by... [ABSTRACT FROM AUTHOR]

1-Amino-2,2-difluorocyclopropane-1-carboxylicacid (DFACC)is of interest in the study of 1-aminocyclopropane-1-carboxylicacid (ACC) deaminase due to the increased reactivity of its cyclopropylfunctionality. It is shown that DFACC is unstable under near-physiologicalconditions where it primarily decomposes via specific-base catalysisto 3-fluoro-2-oxobut-3-enoic acid with a rate constant of 0.18 ±0.01 min–1. Upon incubation with ACC deaminase,DFACC is found to be a slow-dissociating inhibitor of ACC deaminasewith submicromolar affinity. [ABSTRACT FROM AUTHOR]