Module System Research Articles

Topological origin of flat bands as pseudo-Landau levels in uniaxial strained graphene nanoribbons and induced magnetic ordering due to electron-electron interactions

Flat bands play a central role in the presence of correlated phases in moir\'e and other modulated two-dimensional systems. In this paper, flat bands are shown to exist in uniaxially periodic strained graphene. Such strain should be produced for example by a substrate. The model is thus mapped into a one-dimensional effective Hamiltonian and this allows to find the conditions for having flat bands, i.e., a long-wavelength modulation only on each one of the bipartite graphene sublattices, while having a tagged strain field between neighboring carbon atoms. The origin of such flat bands is thus tracked down to the existence of topological localized wavefunctions at domain walls separating different regions, each with a nonuniform Su-Schriffer-Hegger model (SSH) type of coupling. Thereafter, the system is mapped into a continuum model allowing to explain the numerical results in terms of the Jackiw-Rebbi model and of pseudo-Landau levels. Finally, the interplay between the obtained flat bands and electron-electron interaction is explored through the Hubbard model. The numerical results within the mean-field approximation indicate that the flat bands induce N\'eel antiferromagnetic and ferromagnetic domains even for a very weak Hubbard interaction, while the repulsive Hubbard interaction results in an effective electron-electron attraction. Thus this paper provides a simple, analytically solvable but realistic model to understand the physical origin of flat bands, pseudo-Landau levels and their effects on the effective electron-electron interaction.

HVLV ENGINEERING WITH MODULE SYSTEM(S), ETO AND LEAN DESIGN – STUDY ON PRACTITIONER INFORMATION NEEDS

AbstractThis research elaborates the engineering design of high value low volume (HVLV) artefacts (aka Capital goods, investment goods). Our goal is to describe what information needs the practitioners have when doing sales engineering and engineering in HVLV projects. The research approach uses Design Research Methodology with four company cases.Our findings are that engineering design of HVLV artefacts reuses several module systems, module libraries, technology catalogues, engineering-to-order and variety of design support systems, configurators, design guidelines, parametric models and lean-based design reasoning patterns etc. This poses major challenges for the engineers; how to use all relevant information and how to find it from different IT-systems.This study indicates that in HVLV context such engineering strategy is required, which guides and drives tactical and operational engineering decisions not only within a project delivery but across project deliveries. Operative and tactical engineering is done during the delivery project and value capture is not achieved in full potential if the engineering strategy is neglected or overruled. This is challenge for current modularisation and ETO-methods and tools.

Optimisation of Control Strategies for Power Shift Gearboxes

This study is based on the influence of power shift control on the smoothness of cotton picker shifts and proposes an optimization method for the smoothness of power shifts with different control strategies for the gearbox. Through the structural design of the power shift mechanism control module, the hydraulic power distribution of the hydraulic system of the hydraulic travel module and its control mode are analyzed, and a regional cooperative shift control strategy is proposed in conjunction with control theory. A model of cotton picker dynamics was built using AMESim simulation software. In addition, the traditional control strategy was simulated and compared with the Statement component automatic control strategy to analyze and discuss the control deficiencies in power shift smoothness. Then, a particle swarm genetic algorithm (PSGA) was constructed by integrating the PSO algorithm and the genetic algorithm to verify the effectiveness of the algorithm in improving the dynamic performance and shift smoothness of the gearbox. The algorithm was verified using bench tests, and the algorithm improved the harvesting quality and efficiency of the cotton picker.

Performance and energy loss mechanism of bifacial photovoltaic modules at a solar carport system

AbstractAs photovoltaic modules are increasingly used in renewable energy systems, ensuring energy efficiency by reducing the levelized cost of electricity has become the focus of current research. Herein, the 1‐year performances of both monofacial and bifacial photovoltaic modules were monitored, compared, and analyzed at a solar carport system in the Korean peninsula. The environmental parameters during the four seasons were investigated for both systems under ambient conditions. Irradiance was determined as the primary influencing parameter in the system. The energy yield of the bifacial module system was 3.08% higher than that of the monofacial system owing to rear‐side absorption during the study period. The loss mechanism for this lower yield was determined by investigating the irradiance effect. It was attributed to low bifaciality due to cell properties (optical and electrical properties, and the sorting effect) and module properties (shading effects from the junction box cable and frame design, and glass grid effect), design of the carport system, and the albedo effect. These analyses revealed that the photovoltaic energy yield can be increased further by reducing these loss parameters at the carport system. This study can contribute to achieving higher energy yield from photovoltaic systems during field applications.

ISOL module system for RAON ISOL facility

RAON (Rare Isotope Accelerator complex for ON-line experiments) heavy ion accelerator facility in Korea is preparing for producing rare isotopes using Isotope Separation On-line (ISOL) facility. Rare isotopes will be produced by a 70 MeV proton beam incident on the target system. Expecting the harsh radiation environment of the target area, the module system has been adopted. The module system in the ISOL facility consists of target ion source (TIS), rare isotope (RI) transport, and proton beam diagnostic modules. In order to handle and maintain the module system, the remote handling (RH) systems are developed and tested.

Force and deformation analysis on the fully recovered support system of pressure anchor cable and steel module

In order to overcome the technical defects of traditional foundation pit support technology, such as complex technology, serious pollution, waste of resources, and obstruction of the construction of surrounding underground structures, the fully recovered deep pit support system of pressure dispersion anchor cable and steel module is designed. The force of the compression anchor and the deformation of the modular is tested on-site. The test results show that: (1) The whole process of excavation to support slope roof immersion and stacking is safe, which verifies the correctness of the support design of pressure dispersion anchor cable and modular; (2) The soil restraint effect at the action of the recoverable pressure anchor cable is obvious, and the prestress loss is between 11.7% and 15% under continuous monitoring; according to the axial force of the anchor cable, the earth pressure acting on the module is calculated, and the results are consistent with the calculation results of the Terzaghi-Peck earth pressure mode; (3) According to the strain test acting on the module, the corresponding stress is calculated, and its stress value is consistent with the stress value of the plate fixed in the four corners under the action of earth pressure.

Optimal Design of Eigenvalues for the Full-Spectrum Modulated Nonlinear Frequency Division Multiplexing Transmission System

Nonlinear frequency division multiplexing (NFDM) system is an optional candidate to overcome the fiber nonlinearity limit. A full-spectrum modulated NFDM system, modulating data on combined continuous spectrum (CS) and discrete spectrum (DS) together, was proposed in recent years to improve the data rates and spectral efficiency (SE) by exploiting all the degrees of freedom offered in the nonlinear spectrum. However, the selection of discrete eigenvalues greatly affects the performance of both CS and DS. Designing appropriate eigenvalues of DS is an important issue to ensure the high SE and excellent performance of the system. In this paper, we discussed the selcection principle of eigenvalues and analyzed it from multiple perspectives, 11 eigenvalues with 64-quadrature amplitude modulation (64QAM) are selected for DS. Besides optimizing the eigenvalues at the transmitter, the linear minimum mean-square estimate (LMMSE) method was used at the receiver to furtherly improve the performance of DS. Through the numerical simulation, a 113 Gb/s (SE of 2.8 bits/s/Hz) full-spectrum modulated NFDM system was set up and transmitted 1120 km distance, where the Q-factors of both CS and DS are above the hard-decision forward error correction (HD-FEC) threshold. The results provide a way to design an efficiently full-spectrum modulated NFDM system.

The Simulation of the Terahertz Modulator by CMOS Process

The paper introduced the simulation of the terahertz modulator in complementary metal-oxide-semiconductor (CMOS) process. The modulator is composed of a metal split-ring resonator (SRR), CMOS, semiconductor dielectric layer and silicon substrate. The modulator can make different electromagnetic response to the transmitted terahertz wave between the connection state and the disconnection state of the gap in the SRR, which could be achieved by connecting CMOS in the gap. At 0.31THz, the simulation results show that the amplitude modulation depth of the modulator reached 28.8%. When the simulation keeped the modulator system in resonating state, the transmission coefficient was about 0.0018, while the conductive had reached 0.2895. If the design can pass the experimental verification in the future, it can make some references for further exploration of the high-speed and high modulation depth of the terahertz amplitude modulator.

THE ROLE AND IMPORTANCE OF INTERNATIONAL ORGANIZATIONS IN IMPROVING THE QUALITY OF HIGHER EDUCATION

This article talks about new methods of the family education system. Special emphasis is placed on new terms and concepts such as distance education, education export, borderless education, credit module system, horizontal and vertical movement of family education, different from traditional education. In addition, a comparative analysis of foreign experiences in the internationalization and internationalization of education aimed at quality assurance in the field of family education was made.

Experimental studies of using the digital control system in power conversion equipment of high-voltage power supply systems in spacecrafts with a hydrogen energy accumulator

Solar-hydrogen energy for spacecraft, space interplanetary stations, space bases on the planets of the solar system must reliably provide energy: spacecraft during peak periods (repairs at a space facility, energy-consuming experiments, cleaning of facilities, regeneration of waste to extract oxygen and hydrogen, etc. .d.) and bases on planets, especially where the night lasts for a long time.The onboard hydrogen module of the solar-hydrogen plant includes: a container with water; distiller; deionizer; water lines with adjustable shut-off valves; electrolyzer; cryogenic side tanks with hydrogen and oxygen; fuel cell, hydrogen safety sensor systems based on leakage and concentration sensors; level gauges; cryogenic and gas pipelines of hydrogen and oxygen; onboard cryo-refrigerator; automatic control system for the hydrogen module. The article presents the results of experimental studies of static, dynamic and mass-dimensional characteristics of power conversion equipment (hereinafter - PCE) in the power supply system (hereinafter - PSS) of the spacecraft (hereinafter - spacecraft) with a digital control system. The purpose of experimental research is to verify the theoretical results obtained earlier in the design of digital PCE control systems of high-voltage PSS spacecraft, including the study of static and dynamic characteristics. We developed and manufactured an experimental PCE sample with an output power of 2500W in this research. It includes: four voltage stabilization modules and the 100V load supply output bus filter. Each voltage stabilization module includes a battery energy conversion channel, a solar battery energy conversion channel and a digital control system unit. The power conversion channel of the accumulator battery is designed and made on the basis of a bridge volt-booster inverter-transformer circuit. Voltage control in energy converter of accumulator battery is based on phase shift in control pulses of transistors in adjustable inverter rack related to unregulated one. The power conversion channel of the solar battery is designed and made on the basis of a two-phase circuit of a direct voltage converter of an increasing type with switching throttles. The digital control system of the voltage stabilization module is designed on the basis of analogues in the modern electronic component base in the Space class and consists of four identical channels. Each channel of the control system controls its own voltage stabilization module. We obtained the following results during our experimental studies: some pulsations of the output voltage of the energy conversion equipment during operation on an active load, transient processes of the output voltage of the energy conversion equipment during pulsations of the load current without changing the mode of operation, transient processes of the output voltage of the energy conversion equipment when changing the modes of its operation and weight and size characteristics for different values of the output power. The obtained results of experimental studies confirm the previously obtained theoretical results, and also showed that the use of a distributed digital control system will increase the specific energy characteristics of the newly developed PSS spacecraft while ensuring the given static and dynamic characteristics of output voltage quality. The results of the work are designed to create a new on-board power conversion equipment for power supply systems of promising spacecraft. The area of application of the project results is space instrumentation.

Dynamic Context Awareness of Universal Middleware based for IoT SNMP Service Platform

This study focused on the Universal Middleware design for the IoT (Internet of Things) service gateway for the implementation module of the convergence platform. Recently, IoT service gateway including convergence platform could be supported on dynamic module system that is required mounting and recognized intelligent status with the remote network protocol. These awareness concepts support the dynamic environment of the cross-platform distributed computing technology is supported by these idea as a Universal Middleware for network substitution. Distribution system commonly used in recent embedded systems include CORBA (Common Object Request Broker Architecture), RMI (Remote Method Invocation), DCE (Distributed Computing Environment) for dynamic service interface, and suggested implementations of a device object context. However, the aforementioned technologies do not support each standardization of application services, communication protocols, and data, but are also limited in supporting inter-system scalability. In particular, in order to configure an IoT service module, the system can be simplified, and an independent service module can be configured as long as it can support the standardization of modules based on hardware and software components. This paper proposed a design method for Universal Middleware that, by providing IoT modules and service gateways with scalability for configuring operating system configuration, may be utilized as an alternative. This design could be a standardized interface provisioning way for hardware and software components as convergence services, and providing a framework for system construction. Universal Middleware Framework could be presented and dynamic environment standardization module of network protocols, various application service modules such as JINI (Apache River), UPnP (Universal Plug & Play), SLP (Service Location Protocol) bundles that provide communication facilities, and persistence data module. In this IoT gateway, management for based Universal Middleware framework support and available for each management operation, application service component could be cross-executed over SNMP (Simple Network Management Protocol) version 1, version 2, and version 3. The way of SNMP extension service modules are conducted cross-support each module and independent system meta-information that could be built life cycle management component through the MIB (Management Information Base) information unit analysis. Therefore, the MIB role of relation with the Dispatcher applied to support multiple concurrent SNMP messages by receiving incoming messages and managing the transfer of PDU (Protocol Data Unit) between the RFC 1906 network in this study. Results of the study revealed utilizing Universal Middleware that dynamic situations of context objects with mechanisms and tools to publish information could be consisted of IoT to standardize module interfaces to external service clients as a convergence between hardware and software platforms.

Long-term outdoor performance of grid-connected photovoltaic power plant in a desert climate

In this paper, a 2.25 kWp grid integrated with the tied solar park has been implanted in the Renewable Energy Applied Research Unit (URAER) in a dry and harsh desert region. The PV plant uses micromorph thin-film solar modules (a-Si/μc-Si) technology. The photovoltaic module systems (PVS) were evaluated from May 2015 to December 2020 (around five and a half years of operation), and the electricity was injected into the internal network of the low-voltage power supply. Performance evolution has been conducted in this work as stated by the IEC61724 guideline. The monthly and annual performance indicators analyzed and assessed consist of reference yield, array yield, final yield, system losses, capture losses, PV module efficiency, system efficiency, inverter efficiency, capacity factor, and performance ratio. The annual electricity production is 3688.28 kWh, 3188.25 kWh, 3306.28 kWh, 3136.05 kWh, and 2952.81 kWh for 2016, 2017, 2018, 2019, and 2020 operating periods, respectively. The solar park's total produced energy yield over the monitored period and the quantity of CO2 emissions avoided are 16,271.67 kWh and 14.17 tons, respectively, which can significantly contribute to and help in purifying the environment from pollution. In addition, the energy results produced by the PVS were compared to those found by the four widely used PV simulation tools (PVsys, PVGIS, NREL's PVWatts® Calculator and Solar Med-Atlas). Furthermore, this work investigates and quantifies the degradation phenomenon of solar PVS power output after five years and a half years of outdoor exposure. There is around 0.22 % degradation per year. When this rate was compared to other studies conducted worldwide, it was shown to be highly appropriate. Technical-economic research was also conducted, revealing that the system's PVS period, which establishes its sustainability, is between 9 and 12 years. The results demonstrate that micromorph thin-film modules perform better and are more efficient under harsh real-world outdoor environmental conditions. Inventux modules preserve most of their better performance even with increasing module temperature. This kind of PV module technology is low-insensitive to the highest PV module temperature. Compared to the literature, micromorph thin-film technologies are better and preferable than crystalline modules under desert environmental conditions. The results also indicate that grid-connected solar park plants using this kind of technology are feasible in the hot arid climate to produce electricity and may participate in future energy projects in the country.

Neuromorphic Circuit Implementation of Operant Conditioning Based on Emotion Generation and Modulation

In this work, an operant conditioning (OC) model and memristive circuit implementation based on emotion generation and modulation is proposed, which is inspired by neural and psychological mechanisms to simulate human behavioral decisions guided by reinforcers and emotional changes during interaction with dynamically changing environments. The OC model consists of four main modules which are the cue-synapse-action module, the reward and punishment value systems, and the emotion system. Under four conditions of reward appearance or termination, and punishment appearance or termination, the memristive circuit designed according to the OC model can realize the process of exploration, acquisition, extinction, and recovery of OC (external phenomena), and also reflect the process of change of value signals and emotion signals (internal states). In addition, the phenomena of reward fatigue and punishment adaptation are considered so that value and emotion signals gradually diminish with the repetition of invariant reinforcers. The neuromorphic circuit is verified to have good robustness and device tolerance. This work enables multi-timescale OC tasks and is expected to be applied in an emotionally intelligent robot platform to achieve humanoid functions such as real-time dynamic decision-making for interaction with the environment and emotional companionship.

The Construction and Realization of the Precise Funding Platform for Impoverished Students in Colleges and Universities Driven by Computer Intelligence Technology

At present, the state’s financial aid for students from financially disadvantaged families is increasing, and the number of students receiving financial aid is also increasing substantially. Poor students have to run back and forth to submit various materials while busy with their own studies, which causes a lot of inconvenience to students and teachers. The development of the poverty-stricken student precision funding platform frees teachers from tedious and low-end work and engages in core affairs, which improves the overall efficiency of school affairs and the controllability of information. In this context, this paper uses computer intelligence technology to realize the construction of the precise funding platform for impoverished students in colleges and universities (CAU) and completes the following tasks: (1) the research status of precise funding for impoverished students in CAU at home and abroad is introduced. (2) The SSI frame structure diagram of the funding information management platform is designed and the specific function description and detailed design of the relevant modules are given. (3) The module function test and system function test of the platform designed in this paper are completed through experiments. The results show that the system is very stable, and the functions are perfectly realized.

Frequency-Selective Surface Based on Negative-Group-Delay Bismuth–Mica Medium

Negative group delay may be observed in dispersive media with anomalous dispersion in a certain frequency range. The fact that an outgoing wave packet precedes an incoming one does not violate the causality principle but is only a consequence of a waveform reshaping. This effect is observed in media such as photonic crystals, hyperbolic and epsilon-near-zero metamaterials, undersized waveguides, subwavelength apertures, side-by-side prisms, and resonant circuits at various frequencies. The current work is devoted to the design of a simple negative-group-delay medium with tunable properties in the THz frequency range. This medium consists of a bismuth-based frequency-selective surface on a dielectric substrate and may be tuned both statically and dynamically. While a geometry variation defines a main form of an effective permittivity dispersion and group delay/group velocity spectra, an external voltage allows one to adjust them with high precision. For the configuration proposed in this work, all frequency regions with noticeable change in group delay/group velocity lie within atmospheric transparency windows, which are to be used in 6G communications. This medium may be applied to THz photonics for a tunable phase-shift compensation, dispersion management in systems of THz signal modulation, and for encoding in next-generation wireless communication systems.

DDPG-based controlling algorithm for upper limb prosthetic shoulder joint

ABSTRACT The development of intelligent prostheses has effectively improved the life of amputees. However, the current prosthetics mainly focus on restoring the basic mobility of amputees, without considering the use habits of the wearer and the diversity of arm movements, which makes the unknown interference and complex control requirements in daily life an obstacle to the use of prosthetics. To solve this problem, this paper proposes a combination method of adaptive control algorithms of bionic arm shoulder joint based on DDPG to realise intelligent control of the shoulder joint of upper limb prosthesis. Based on using adaptive control to reduce the interference of external variables, the accuracy of the joint module system is improved through reinforcement learning. The results show that the controller has a good effect on improving the dynamic performance of the mechanical system and can be widely used in bionic mechanical control.

Photovoltaic powered operational scale Membrane Capacitive Deionization (MCDI) desalination with energy recovery for treated domestic wastewater reuse

An operational scale Membrane Capacitive Deionization (MCDI) desalination system was trialled for water reuse applications in Western NSW, Australia. The 6 electrode module system had an average current efficiency of 74 %, water recovery of 84 % (77 % including pre-treatment) and delivered 1.0 m3/h of treated water with an electrode energy consumption of 0.35 kWh/m3 (including energy recovery) and total energy consumption of 1.28 kWh/m3 (using mains power) or 1.05 kWh/m3 (using photovoltaics to power the electrodes). No performance decline was noted over an operational period of 3 months that included reverse current stopped flow desorption and regular cleaning with sodium hypochlorite. The use of photovoltaics for the electrode power supply enabled an average power saving of 27 %. The inclusion of energy recovery devices on the electrode control system facilitated a 40 % reduction in electrode energy consumption. The system demonstrated that MCDI desalination is a feasible option for treated domestic wastewater reuse and can be easily coupled with photovoltaics supply to the electrodes. As one of the first larger scale MCDI operations, we demonstrate that performance trends found in bench scale studies do translate to larger units, however control constraints of the operational units may require optimisation trade-offs between performance parameters.

SIMULATION AND EXPERIMENTAL INVESTIGATION OF DUAL THREE-PHASE BLDC MOTOR OPERATION AT IMBALANCED MODULAR LOADING

Electric machines built according to the modular principle – with several three-phase windings on a stator – are a new direction of modern electromechanics, because they have a number of advantages compared to traditional single-winding machines. Among these benefits, the most important are increased efficiency and fault tolerance, which is especially important for self-powered electric vehicles. However, the presence of a mutual magnetic coupling between the modules, as well as their unequal electrical load, amplify the electromagnetic torque ripple inherent in one or another electric drive system. In this work, the electromagnetic torque ripples in a dual three-phase (DTP) brushless DC motor (BLDCM) under different loads of its modules were investigated for the cases of absence and presence of mutual magnetic coupling between armature winding sets and in the cases of the drive operation in open and closed control systems. The research was carried out by means of simulation in the Matlab/Simulink environment on a circular model of real mock-up sample of DTP permanent magnet machine developed based on the results of its magnetic field simulation using the finite element method. Adequacy of simulation results is confirmed by experimental investigation. The results of the DTP BLDCM simulation studies showed an increase in the relative electromagnetic torque ripples of individual modules due to both the presence of magnetic coupling between winding sets and the deviation from their equal loading. However, at the level of the whole DTP BLDCM, a significant mutual compensation the electromagnetic torque ripples of the modules is shown, especially if they are magnetically coupled. The presence of closed-loop control systems of individual modules significantly reduces the electromagnetic torque ripples caused by different loading of the modules, especially in the case of magnetically uncoupled modules. References 26, figures 7, tables 3.

Dual-functional MOFs-based hybrid microgel advances aqueous lubrication and anti-inflammation

This paper demonstrates the hybridization of copolymer microgel with drug-loaded metal–organic frameworks nanoparticles that can achieve excellent aqueous lubricating performance and anti-inflammatory effect for synergistic treatment of osteoarthritis (OA). Poly(ethylene glycol)-graft-poly(N-isopropylacrylamide) (PEG-g-PNIPAm) microgel layer is grown on the MIL-101(Cr) surface via one-pot soap-free emulsion polymerization method. The lower critical solution temperature of the MIL-101(Cr)@PEG-g-PNIPAm hybrid is raised significantly by incorporating PEG chains into the PNIPAm microgel matrix, which greatly enhances the high-temperature aqueous dispersion stability. The hybrid microgel demonstrated reversibly thermo-sensitive swelling-collapsing behavior to modulate the optical properties and hydrodynamic size. Using as aqueous lubricating additives, the hybrid reduces over 64% and 97% in friction coefficient and wear volume. Also, the hybrid supports desirable temperature-controlled lubrication modulation due to their reversible thermo-responsive behavior, which is benefit to joint lubrication of OA. After encapsulating anti-inflammatory diclofenac sodium (DS), the DS-MIL-101(Cr)@PEG-g-PNIPAm shows thermo-responsive drug release in aqueous media, which can improve the drug-delivery efficiency. By co-culturing the DS-loaded hybrid with human normal chondrocytes, we demonstrate good biocompatibility and anti-inflammatory effect on the chondrocytes with inflammation by regulating the expression of OA-related genes and proteins. Our work establishes multifunctional MOFs-based hybrid microgel systems for advanced colloids modulation and biomedical application.

Double dissociation of perirhinal nicotinic acetylcholine receptors and dopamine D2 receptors in modulation of object memory consolidation by nicotine, cocaine and their conditioned stimuli

There are indications that drug conditioned stimuli (CS) may activate neurochemical systems of memory modulation that are activated by the drugs themselves. To directly test this hypothesis, a cholinergic nicotinic receptor antagonist (mecamylamine; MEC: 0, 10 or 30 µg/side) and a dopamine D2 receptor antagonist (l-741,626: 0, 0.63, 2.5 µg/side) were infused in the perirhinal cortex (PRh) to block modulation of object recognition memory consolidation induced by 0.4 mg/kg nicotine, 20 mg/kg cocaine, or their CSs. To establish these CSs, male Sprague-Dawley rats were confined for 2 h in a chamber, the CS+, after injections of 0.4 mg/kg nicotine, or 20 mg/kg cocaine, and in another chamber, the CS−, after injections of vehicle. This was repeated over 10 days (5 drug/CS+ and 5 vehicle/CS− pairings in total). It was found that the memory enhancing action of post-sample nicotine was blocked by intra-PRh infusions of both MEC doses, and 30 µg/side MEC also blocked the memory enhancing action of the nicotine CS. Interestingly, intra-PRh MEC did not block the memory enhancing effect of cocaine, nor that of the cocaine CS. In contrast, the memory enhancing action of post-sample cocaine administration was blocked by both l-741,626 doses, and 2.5 µg/side also blocked the effect of the cocaine CS, but not the memory effects of nicotine or of the nicotine CS. This functional double dissociation strongly indicates that drug CSs modulate memory consolidation by activating neural systems that are activated by the drugs themselves.