Threat appeals in public service announcements: Effects of message framing and relationship norms.

Threat appeals have been widely utilized in numerous types of public service announcements (PSAs), and previous research has focused on the impact of the inherent messages in these announcements. By examining the research on the effects of framing PSAs in terms of the threat of the message to oneself or others, we proposed a clear conceptualization of "threat-target framing." The first two studies addressed the direct effects of threat-target framing and found that other-oriented threat appeals can evoke more guilt than can self-oriented threat appeals. Moreover, self-oriented threat appeals can evoke more fear and immediately direct recipients’ attention to the smoker than can other-oriented threat appeals. Study 3 reported that a contextual factor-relationship norms-was introduced as a potential moderating factor. Results showed that relationship norms had the potential to moderate the effect of threat-target framing on recipients’ fear response, but not the effect on recipients’ guilt and coping response. In sum, the results highlighted the importance of message framing of advertising copies and the placement context. Our findings may be useful in understanding the antecedents of the persuasiveness of PSAs

A single-end protection scheme for hybrid MMC HVDC grids considering the impacts of the active fault current-limiting control

In the hybrid modular multilevel converter (MMC) based high voltage direct current (HVDC) systems, the fault current can be actively suppressed by the converter itself, which endows a smaller requirement for current-limiting reactors (CLR) and a larger time margin for fault detection algorithms, comparing with the half-bridge MMC. But the robustness to fault resistance and noise disturbance of existing boundary protection schemes will be deteriorated with small CLRs. Moreover, the fast response of the fault current-limiting control will change the output DC voltage of hybrid MMC, which affects the fault characteristics and may cause mal-operation of existing protection algorithms. Thus, a single-end protection scheme considering the impacts of the active current-limiting control is proposed for the hybrid MMC based DC grids. The traveling-wave characteristics under different fault stages are analyzed to evaluate the impacts of the fault current-limiting control. In addition, a coordination protection strategy versus different fault conditions is adopted to improve reliability. Various cases in PSCAD/EMTDC are simulated to verify that the proposed method is robust to fault resistance, fault distance, power reversal, AC faults, and immune to noise

A novel HVDC circuit breaker for HVDC application

Hybrid high voltage direct current circuit breakers (DCCBs) are capable of interrupting fault current within a few milliseconds, but this technology has high capital cost, especially in a meshed HVDC grid. To increase the economic competitiveness of hybrid DCCBs, this paper proposes a capacitor commutated dc circuit breaker (CCCB). The CCCB mainly comprises an auxiliary branch with a fast dis-connector in series with semiconductor devices and the main branch with the series connection of a dc capacitor and diode valves. This paper provides a detailed depiction of the CCCB. The topology and operating principles are discussed. The impact of snubber circuits and stray inductances on the commutation process is analyzed. The general sizing method for the main components in the CCCB is detailed. Reclosing to transmission lines with different operating conditions is studied. Several extended topologies are proposed to further reduce the semiconductor cost and on-state operation power loss. The power loss and cost of CCCB are assessed. Extensive simulations on PSCAD/EMTDC verified the dc fault isolation and reclosing of the CCCB

Robust output regulation of linear system subject to modeled and unmodeled uncertainty

In this paper, a novel robust output regulation control framework is proposed for the system subject to noise, modeled disturbance and unmodeled disturbance to seek tracking performance and robustness simultaneously. The output regulation scheme is utilized in the framework to track the reference in the presence of modeled disturbance, and the effect of unmodeled disturbance is reduced by an $\mathcal{H}_\infty$ compensator. The Kalman filter can be also introduced in the stabilization loop to deal with the white noise. Furthermore, the tracking error in the presence/absence of noise and disturbance is estimated. The effectiveness and performance of our proposed control framework is verified in the numerical example by applying in the Furuta Inverted Pendulum system

3-Methyl-4-(3-methyl­phen­yl)-5-(2-pyridyl)-4H-1,2,4-triazole

In the mol­ecule of the title compound, C15H14N4, the triazole ring is oriented at dihedral angles of 30.8 (2) and 67.4 (2)° with respect to the pyridine and benzene rings, respectively. The crystal structure is stabilized by C—H⋯N hydrogen-bonding inter­actions, forming chains of mol­ecules along [01]

An adaptive fault current limiting control for MMC and its application in DC grid

This paper proposes an adaptive fault current limiting control (AFCLC) for modular multilevel converters (MMC). Without introducing extra current limiting devices, this control scheme enables fast fault current suppression during DC faults. The AFCLC will be triggered automatically once DC faults occur. By adaptively reducing the output DC voltages of MMCs, the fault current can be suppressed. Compared with the existing current limiting methods, the proposed AFCLC has a better performance on fault current limiting, since it only depends on the real-time operating condition and no fault detection delay is imposed. Firstly, the principle of the proposed AFCLC together with the mathematical analysis is disclosed. Then, the sensitivity analysis of the impact of key control parameters on the current limiting effect is investigated. Finally, the effectiveness of AFCLC is demonstrated in a four-terminal HVDC grid test model. The simulation results show that the proposed AFCLC can reduce the interrupted current and energy absorption of a DCCB from 10.39 kA and 38.24 MJ to 4.62 kA and 8.32 MJ, respectively. The simulation results also prove that the AFCLC will not affect the accuracy of the DC fault detection algorithms under DC faults

3-(2-Pyrid­yl)-5-(4-pyrid­yl)-4-(p-tol­yl)-1H-1,2,4-triazole

In the mol­ecule of the title compound, C19H15N5, the dihedral angles formed by the plane of the triazole ring with those of the 2-pyridyl, 4-pyridyl and p-tolyl rings are 28.12 (10), 34.62 (10) and 71.43 (9)°, respectively. The crystal structure is consolidated by C—H⋯π hydrogen-bonding inter­actions and by π–π stacking inter­actions, with a centroid–centroid distance of 3.794 (4) Å

A unidirectional DC-DC autotransformer for DC grid application

Conventional unidirectional DC-DC converters for DC grid application employ DC-AC-DC two-stage conversion technology and suffer from high converter cost and power loss. To solve these issues, a unidirectional step-up DC-DC autotransformer (UUDAT) and a unidirectional step-down DC-DC autotransformer (DUDAT) are studied. The UUDAT and DUDAT are composed of a series connection of diode bridges and voltage source converters. Topologies of UUDAT and DUDAT are detailed. The harmonic and un-controllability issues are discussed. Control and possible application scenarios for UUDAT and DUDAT are depicted. DC fault isolation mechanism and the methods of dimensioning the voltage and power ratings of the components in UUDAT and DUDAT are studied. Extensive simulations on power system level and experiments on a UUDAT and DUDAT prototype verified their technical feasibility