Passive Part Research Articles

Bacterial pathogen gene regulation: a DNA-structure-centred view of a protein-dominated domain.

The mechanisms used by bacterial pathogens to regulate the expression of their genes, especially their virulence genes, have been the subject of intense investigation for several decades. Whole genome sequencing projects, together with more targeted studies, have identified hundreds of DNA-binding proteins that contribute to the patterns of gene expression observed during infection as well as providing important insights into the nature of the gene products whose expression is being controlled by these proteins. Themes that have emerged include the importance of horizontal gene transfer to the evolution of pathogens, the need to impose regulatory discipline upon these imported genes and the important roles played by factors normally associated with the organization of genome architecture as regulatory principles in the control of virulence gene expression. Among these architectural elements is the structure of DNA itself, its variable nature at a topological rather than just at a base-sequence level and its ability to play an active (as well as a passive) part in the gene regulation process.

Hybrid vibration absorber with detached design for global vibration control

A new hybrid vibration absorber, with detached passive and active parts, is designed, analyzed and tested. This is an alternative approach in case the traditional bundled hybrid vibration absorber with collocated active and passive control elements cannot be applied. In fixed-free structures like buildings and towers, a passive dynamic vibration absorber is very popular for vibration control at or near the free ends. Active control may be introduced to improve performance, but space or weight may be limited in some applications. It may not be practical to attach an actuator near the passive part. The new approach provides more flexibility to retrofit a passive dynamic vibration absorber into a high performance hybrid vibration absorber by installing the actuator at a more suitable location than collocated with the passive part. The proposed hybrid vibration absorber is based on the pole-placement control strategy. Its controller is able to deal with a possible nonminimum-phase secondary path caused by noncollocated actuator sensors. This feature does not exist in a bundled hybrid vibration absorber with collocated actuator sensors. The performance of the new hybrid vibration absorber is analyzed in this study. Experimental and simulation results are used to verify the theoretical results and demonstrate the excellent performance of the new hybrid vibration absorber for vibration control at multiple points. A bundled hybrid vibration absorber with collocated passive and active elements is compared with the proposed hybrid vibration absorber with detached control elements, using experimental and simulation results. It was found that the vibration attenuation performance of the proposed hybrid vibration absorber can be better than the traditional bundled hybrid vibration absorber. The optimal actuator location, which is not necessarily the coupling point of the passive resonator, can be selected numerically by a proposed procedure. One could miss a better solution for vibration control if he/she only uses the bundled hybrid vibration absorber without considering the detached hybrid vibration absorber as a possible alternative.

Detonation propagation in thin explosive layers with inert partitions

This paper describes the experimental results in the study of detonation transfer in thin layers of a PVV-12M plastic-bonded explosive (90% of RDX and 10% of bond) through solid and perforated partitions. The critical thicknesses of steel or Plexiglas partitions, exceeding which makes detonation transfer impossible, are determined for the explosive layers with a thickness of 2–12 mm. It is shown that shock waves in the plates, which bound the explosive charge, can stay ahead of the initiating shock wave in the passive part of the explosive charge and load the explosive charge from the lateral surface. Thus, the peripheral desensitized layers of the explosives are formed, which reduce the layer thickness of the detonable explosive and complicate the detonation transfer. Detonation transfer through the partitions whose thickness is greater than the critical thickness can be carried out with the use of holes in the partition, closed by thin plates. The plate thicknesses at which detonation propagates through the hole either in forward and reverse directions or in the forward direction only, are determined.

不連続部への局所的な減衰要素の付与による波動伝播経路の設計

In order to perform vibration reduction of complex structures efficiently, a method of using Transfer Path Analysis (TPA) has become widespread. In this study, by fusing the TPA and wave analysis, a technique for intentionally changing a path of wave propagation was developed. As a first step, this paper deals with a design method of a path of wave propagation in the active part having vibration sources were considered. By attaching local damping elements to a discontinuity of an active part, the path of wave propagation was changed. The techniques can change the energy flow which is transmitted from active part to passive part by the wave. Therefore, it is considered to be useful in reducing vibration and noise of machinery.

Automatic Optimization of Single-Chip UHF RFID Tags

The automatic optimization is presented of the passive RF part of RFID, with special attention to single-chip UHF tags, and to the novel concept of RFID grids. The presented approach employs an optimization based on the Genetic Algorithm, and an efficient electromagnetic problem parameterization and novel solution strategy. A practical application example shows increase in overall performance.

Radiation defect dynamics in Si at room temperature studied by pulsed ion beams

The evolution of radiation defects after the thermalization of collision cascades often plays the dominant role in the formation of stable radiation disorder in crystalline solids of interest to electronics and nuclear materials applications. Here, we explore a pulsed-ion-beam method to study defect interaction dynamics in Si crystals bombarded at room temperature with 500 keV Ne, Ar, Kr, and Xe ions. The effective time constant of defect interaction is measured directly by studying the dependence of lattice disorder, monitored by ion channeling, on the passive part of the beam duty cycle. The effective defect diffusion length is revealed by the dependence of damage on the active part of the beam duty cycle. Results show that the defect relaxation behavior obeys a second order kinetic process for all the cases studied, with a time constant in the range of ∼4–13 ms and a diffusion length of ∼15–50 nm. Both radiation dynamics parameters (the time constant and diffusion length) are essentially independent of the maximum instantaneous dose rate, total ion dose, and dopant concentration within the ranges studied. However, both the time constant and diffusion length increase with increasing ion mass. This demonstrates that the density of collision cascades influences not only defect production and annealing efficiencies but also the defect interaction dynamics.

Thermomechanical properties and performance of ceramic resonators for wireless pressure reading at high temperatures

This paper reports on the design, fabrication, and thermomechanical study of ceramic LC resonators for wireless pressure reading, verified at room temperature, at 500 °C and at 1000 °C for pressures up to 2.5 bar. Five different devices were fabricated from high-temperature co-fired ceramics (HTCC) and characterized. Alumina green tape sheets were screen printed with platinum paste, micromachined, laminated, and fired. The resulting samples were 21 mm × 19 mm with different thicknesses. An embedded communicator part was integrated with either a passive backing part or with a pressure-sensing element, including an 80 µm thick and 6 mm diameter diaphragm. The study includes measuring thermally and mechanically induced resonance frequency shifts, and thermally induced deformations. For the pressure sensor device, contributions from changes in the relative permittivity and from expanding air trapped in the cavity were extracted. The devices exhibited thermomechanical robustness during heating, regardless of the thickness of the backing. The pressure sensitivity decreased with increasing temperature from 15050 ppm bar−1 at room temperature to 2400 ppm bar−1 at 1000 °C, due to the decreasing pressure difference between the external pressure and the air pressure inside the cavity.

Study on a Mechanical Semi-Active Heave Compensation System of Drill String for Use on Floating Drilling Platform.

There are some disadvantages for existing heave compensation systems of drill string used for the Floating Drilling Platform (FDP), including high energy consumption, large and complex structure, and expensive manufacturing and maintenance costs. In view of the above, we present a streamlined mechanical semi-active heave compensation system (MSAHC) in this study. This system consists of active compensation part with the pinion and rack and passive compensation part. In order to evaluate system performance of the MSAHC, we establish its simulation model with AMEsim software. In the process of simulation, displacement of rotary hook and energy consumption is regarded as performance parameters of the system. And the change rule of two performance parameters are analyzed by changing these design parameters including gear radius of the pinion and rack, scale coefficient of PID, rotary hook load, heave height and heave period of the FDP, and accumulator volume. Then, based on the simulation results of the MSAHC system performance, we have selected out a best set of design parameters from them. Moreover, the feasibility of the design scheme of the MSAHC is effectively verified by comparison with the existing three heave compensation system. The result shows that the energy consumption of the MSAHC is lower than the active heave compensation system (AHC) and the semi-active heave compensation system (SAHC) when achieving a same compensation effect as well as the accumulator volume of MSAHC is half of the passive heave compensation system (PHC). Therefore, the new designed MSAHC not only ensure compensation effect but also lower energy consumption, and its structure is simplified by adopting the simple mechanical structure to decrease manufacturing cost, maintenance cost and floor space.

Multiport impedance quantization

With the increase of complexity and coherence of superconducting systems made using the principles of circuit quantum electrodynamics, more accurate methods are needed for the characterization, analysis and optimization of these quantum processors. Here we introduce a new method of modeling that can be applied to superconducting structures involving multiple Josephson junctions, high-Q superconducting cavities, external ports, and voltage sources. Our technique, an extension of our previous work on single-port structures (Solgun, 2014), permits the derivation of system Hamiltonians that are capable of representing every feature of the physical system over a wide frequency band and the computation of T1 times for qubits. We begin with a “black box” model of the linear and passive part of the system. Its response is given by its multiport impedance function Zsim(ω), which can be obtained using a finite-element electromagnetics simulator. The ports of this black box are defined by the terminal pairs of Josephson junctions, voltage sources, and 50Ω connectors to high-frequency lines. We fit Zsim(ω) to a positive-real (PR) multiport impedance matrix Z(s), a function of the complex Laplace variable s. We then use state-space techniques to synthesize a finite electric circuit admitting exactly the same impedance Z(s) across its ports; the PR property ensures the existence of this finite physical circuit. We compare the performance of state-space algorithms to classical frequency domain methods, justifying their superiority in numerical stability. The Hamiltonian of the multiport model circuit is obtained by using existing lumped element circuit quantization formalisms (Burkard et al., 2004; Burkard, 2005). Due to the presence of ideal transformers in the model circuit, these quantization methods must be extended, requiring the introduction of an extension of the Kirchhoff voltage and current laws.

Trapping of interacting propelled colloidal particles in inhomogeneous media.

A trapping mechanism for propelled colloidal particles based on an inhomogeneous drive is presented and studied by means of computer simulations. In experiments this method can be realized using photophoretic Janus particles driven by a light source, which is partially blocked by a shading mask. This leads to an accumulation of particles in the passive part. An equation for an accumulation parameter is derived using the effective inhomogeneous diffusion constant generated by the inhomogeneous drive. The impact of particle interaction on the trapping mechanism is studied, as well as the interplay between passivity-induced trapping and the emergent self-clustering of systems containing a high density of active particles. The combination of both effects makes the clusters more controllable for applications.

Performance Benefits of Using Inerter in Semiactive Suspensions

This brief investigates the performance benefits of using inerter in semiactive suspensions. A novel structure for semiactive suspensions with inerter, which consists of a passive part and a semiactive part, is proposed. Six semiactive suspension struts, each of which employs an inerter in the passive part and a semiactive damper in the semiactive part, are introduced. Two suboptimal control laws named clipped optimal control and steepest gradient control laws are derived to control the damping coefficient in the semiactive part. Extensive simulations with respect to different choices of weighting factors and suspension static stiffnesses are conducted based on both a quarter car model and a full car model. The results show that, compared with the conventional semiactive suspension strut, the overall suspension performance can be significantly improved using inerters, including ride comfort, suspension deflection, and road holding. Comparative studies between these two suboptimal control laws and between these semiactive struts are also carried out to facilitate future practical application of the proposed semiactive suspensions with inerter.

Time constant of defect relaxation in ion-irradiated 3C-SiC

Above room temperature, the buildup of radiation damage in SiC is a dynamic process governed by the mobility and interaction of ballistically generated point defects. Here, we study the dynamics of radiation defects in 3C-SiC bombarded at 100 °C with 500 keV Ar ions, with the total ion dose split into a train of equal pulses. Damage–depth profiles are measured by ion channeling for a series of samples irradiated under identical conditions except for different durations of the passive part of the beam cycle. Results reveal an effective defect relaxation time constant of ∼3 ms (for second order kinetics) and a dynamic annealing efficiency of ∼40% for defects in both Si and C sublattices. This demonstrates a crucial role of dynamic annealing at elevated temperatures and provides evidence of the strong coupling of defect accumulation processes in the two sublattices of 3C-SiC.

A Passive Front End of Radio Transceivers for LTE Bands

ABSTRACT Software defined radio implementation is required for LTE radio transceivers. An SDR consists of an rf front end and a digital processor platform DSP. This paper is devoted to the design and implementation of the passive part of the front end; the antennas and bandpass filters. It presents the design of two microstrip patch antennas and a third order parallel coupled band pass filter with defected ground structure that can be used in cellular communication applications, especially in LTE . The two antennas cover LTE network bands 1, 2, 3, 4, 9, 10, 23, 25, 33, 34, 35, 36, 37, and 39[1]. The antennas and filter were printed using FR-4 substrate material with dielectric constant of ɛ r =4.4, thickness of h = 1.6 mm and loss tangent tan δ = 0.025. The overall dimensions of the first antenna is 39 mm * 37mm * 1.6 mm with 50 Ω impedance. This antenna operates between 1666 MHz and 2239.5MHz for return loss of less than - 6 dB and covers LTE network bands 1, 2, 3, 4, 9, 10, 23, 25, 33, 34, 35, 36, 37, and 39. The simulation results suggest that the antenna gain and directivity value are 1.7dB and 2.5 dBi with omnidirectional radiation pattern. The overall dimension of the second antenna is 25 mm * 21mm * 1.6 mm with 50 Ω impedance. This antenna operates between 1896MHz and 2015.8MHz for return loss of less than - 6dB and covers LTE network bands 1, 2, 25, 33, 36, and 37. The simulation results suggest that the antenna gain and directivity value are 1.4dB and 1.7dBi with omnidirectional radiation pattern. The parallel coupled filter with over all dimensions of 45 mm * 25 mm achieves centers frequency of 1.95 GHz and band width of 80 MHz and covers LTE network bands 36 or 1. The order of the proposed band pass filter is three and three defected ground structure are used. The devices are analyzed using Computer Simulation technology (CST) and Zeland IE3D. They are fabricated with photolithographic techniques and their scattering parameters are measured by using Vector Network Analyzer (VNA) E8719A. Measurements and simulations show good agreement.

A new robust adaptive controller for vibration control of active engine mount subjected to large uncertainties

This work presents a new robust model reference adaptive control (MRAC) for vibration control caused from vehicle engine using an electromagnetic type of active engine mount. Vibration isolation performances of the active mount associated with the robust controller are evaluated in the presence of large uncertainties. As a first step, an active mount with linear solenoid actuator is prepared and its dynamic model is identified via experimental test. Subsequently, a new robust MRAC based on the gradient method with σ-modification is designed by selecting a proper reference model. In designing the robust adaptive control, structured (parametric) uncertainties in the stiffness of the passive part of the mount and in damping ratio of the active part of the mount are considered to investigate the robustness of the proposed controller. Experimental and simulation results are presented to evaluate performance focusing on the robustness behavior of the controller in the face of large uncertainties. The obtained results show that the proposed controller can sufficiently provide the robust vibration control performance even in the presence of large uncertainties showing an effective vibration isolation.

Muscle and tendon stiffness assessment using the alpha method and ultrafast ultrasound

The alpha method enables the dissociation of the passive (i.e., tendinous tissues) and active (i.e., fascicles) part of muscle-tendon stiffness. It is based on two main assumptions (i.e., a constant tendon stiffness and a muscle stiffness proportional to the torque produced), which have not been approved in vivo. The purpose of this study was to validate these two assumptions using ultrafast ultrasound, and to compare fascicle and tendon stiffness as determined by both methods. Ten healthy males performed a fast-stretch experiment on the ankle plantar flexors. The mathematical model of the alpha method allowed to estimate the stiffness of muscle and tendinous tissues on the basis of the assumptions associated to the behaviors of muscle fascicles and tendinous tissues. Muscle and tendon stiffness of the gastrocnemius medialis were also calculated from ultrafast ultrasound measurements. Muscle stiffness measured by the ultrasound method increased from 217 ± 83 to 720 ± 265 N/mm with an increasing level of force (from 30 to 90 % MVC). Tendinous stiffness measured by the ultrasound method remained constant across the force level (P < 0.001). However, the stiffness values obtained with both methods were significantly different (P < 0.001). In conclusion, these findings validate the two main assumptions underlying the alpha method using ultrasound. Differences in stiffness values obtained with alpha and ultrasound methods could be associated with physiological and geometrical differences between the whole plantar flexors muscles characterized by the alpha method and the gastrocnemius medialis assessed with the ultrasound method.

High thermal performance lithium-ion battery pack including hybrid active–passive thermal management system for using in hybrid/electric vehicles

In this study, a novel Li-ion battery pack design including hybrid active–passive thermal management system is presented. The battery pack is suitable for using in hybrid/electric vehicles. Active part of the hybrid thermal management system uses distributed thin ducts, air flow and natural convection as cooling media while the passive part utilizes phase change material/expanded graphite composite (PCM/EG) as cooling/heating component to optimize the thermal performance of the proposed battery pack. High melting enthalpy of PCM/EG composite together with melting of PCM/EG composite at the temperature of 58.9 °C remains the temperature distribution of the battery units in the desired temperature range (below 60 °C). The temperature and voltage distributions in the proposed battery pack design consisting of battery units, distributed thin ducts and PCM/EG composite are calculated by numerical solving of the related partial differential equations. Simulation results obtained by writing M-files code in Matlab environment and plotting the numerical data are presented to validate the theoretical results. A comparison between the thermal and physical characteristics of the proposed battery pack and other latest works is presented that explicitly proves the battery pack performance.

Evaluation of the Role of the Peers in the Communication with Pupils Who Represent Aggressive Behaviour in the Classroom Environment

Aim: The aim of this article is to evaluate the role of peers/ school friends during the adaption phase in the school environment of children aggressive behaviour, aged 11-14 with. The article aims at identifying how the other children perceive the aggressive behaviour and how they react towards this behaviour. Methods: This is a qualitative research. The methods used are: analysing the secondary data and also information gathered by semi-structured interviews with pupils. The Interviews are part of the general research made for the PHD-theses. This study includes a sample of 20 pupils who are part of the same classrooms identified with high level of aggressive behaviour. The questions of the semi-structured interviews tend to explore how the aggressive behaviour of some children in the class affects the emotional comfort of other children.The analysis of secondary data is based on the existing literature of national and international studies and policies related to the field of aggressivity and in the high schools. Results: in general, the situation of conflicts with the expressed disruptive behaviour is seen in an resilient point of view from the peer group. They reflect conformism in some situations where they are passive part of a conflict. Most of the pupils interviewed emphasize how essential is the intervention of the teachers or an adult in cases when the conflict involves them directly. Some cases were successful just because the classmates created a comfortable environment for the aggressive children inside the classroom. The intervention of a teacher was important to resolve difficult situations in the classroom environment.Conclusions: If we contribute to have a positive environment in the classroom with the support of the teachers than we can have better quality of the emotional wellbeing of all children in the classroom.

Integrated Active Filter for Differential-Mode Noise Suppression

This letter presents a novel integrated structure for electromagnetic interference (EMI) active filter. This approach integrates an active filter with a passive one to form a hybrid EMI filter. The chosen active filtering circuit is integrated on the printed board circuit embedding the integrated EMI choke. Theoretical and realization results show the integration compatibility between the active part and the passive part. Then, EMI measurements show that the proposed integrated hybrid filter can greatly reduce the noise at high and low frequencies while reducing the overall bulkiness.

Selected characteristics of gait in women of different ages

In our research we have attempted to find out and compare force and time characteristics of gait in women. We measured and compare women in two age groups - 18-30 (group 1) a 46-60 (group 2). The average height of both groups was same, 167 cm, while the average weight and average body mass index were different (group 1 - weight 62 kg, BMI 22,3, group 2 - weight 68 kg, BMI 24,6). For measuring, pressure shoe insoles were used (Pedar Mobile, Novel Munich, 99 sensors,100 Hz). Each person had three attempts: two trial attempts, the third one was measured. For observation, we selected three stances of each leg, always between the third and eighth stride. We measured force characteristics F1, F2, F3 and time characteristics t, t1, t2, t3. Significant differences between both groups were found in t3 on the left leg (time between peak force in active part of stance and peak force in passive part of stance). With applied force (F1, F2, F3) during stance, after recalculating per a kilogram of weight, no statistically significant differences were found.

BOND-GRAPHS AND GENETIC ALGORITHMS FOR DESIGN AND OPTIMIZATION OF ACTIVE DYNAMIC SYSTEMS

The aim of this work is to propose a methodology of sizing in a frame of the conception of mechatronic systems in particular and active dynamic ones, in general. This methodology w ill support conceptual design step [1]. We propose a collaborative design approach based on Bond Graph tool and Genetic algor ithms. Mechatronic systems have a passive part and active part. In our approach we establish a hard interaction between pa ssive and active parts. This interaction will be ma terialized in taking into account of control criteria in the evolution (synthesis) ph ase of passive part. This initiative treats functional aspects, both structural and behavioral; while respecting interactions between p assive and active parts. In our approach we treat functional, structural and behavioral aspects in order to validate a post-pro ject solution. Optimization needs Behavioral models which are systematically deducted from bond-graph structural models. Thus, retained bond graph elements which constitute passive part will be obtained, done by o ptimization Genetic Algorithms procedure. In this p rocedure Gramians of controllability and of observability represent the fitness function. The proposed method will be appli ed to an automatic transmission of a scooter and validated by a dynamic simulation.