Physical Working Principle Research Articles

Bina Kabuğunda Isı Ve Ses Yalıtım Performansı Optimizasyonu: Antalya 100.Yıl Bulvarı Üzerinde Bir Bina Örneği

The most important point to be considered in terms of ‘sustainability’ and ‘energy conservation’ in a building is the design of the building envelope. Although the importance of thermal and sound insulation in the envelope has increased in Turkey, various problems are experienced due to regulations that have not been strictly implemented. In particular, the fact that people spend most of their time at home due to the COVID 19 pandemic has increased the importance of indoor comfort conditions. In order to increase user comfort, the first thing to do is to take the necessary measures for sound and thermal insulation, which have different physical working principles and parameters on the facades of existing buildings. It is important to design optimal facades that will meet the needs of both types of insulation. In this study, the existing building stocks that emerged as a result of the deficiencies in the zoning plans within the settlement pattern of Antalya 100. Yıl Boulevard are examined. Necessary improvement suggestions are presented in order to increase the performance, depending on the envelope. Within the scope of the study, both insulation performances of the facades are compared and solutions for the optimal envelope design were revealed.

Remediation of emerging metal pollutants using environment friendly biochar- Review on applications and mechanism

Bioremediation of heavy metals has become a major environmental concern due to their bio resistant nature and tendency to accumulate. Application of various technologies, involving physical and chemical working principles are applied and passive uptake using sorption involving eco-friendly substrates gained significant attention. Biochar, a cheaper and efficient material, offers good potential due to the greater ease of production, treatment and disposal. This review focuses on the effective application of biochar to treat water contaminated by three specific heavy metals: chromium, lead and arsenic. The on-field applications like soil amendment, industrial wastewater treatment and groundwater treatment using biochar are highlighted. The review article describes the feedstock available for biochar production, various production processes and the importance of optimum conditions like pyrolysis temperature, rate and retention time for various feedstocks reported in literature. The energy requirement of the production process can be supplied by its own energy output. Various modifications that are suitable for the biochar from distinct feedstocks are also discussed. The removal performance of biochar at different working conditions like pH, initial concentration of pollutant and adsorbent dose are consolidated. The highest removal efficiencies reported were by coconut shell biochar (Cr – 99.9%), canola straw biochar (Pb – 100%) and perilla leaf biochar (As – 100%). The adsorption mechanism is explained with reference to kinetics, isotherms, and molecular dynamics. Adsorption mechanism of most of the biochars was found to fit either Freundlich or Langmuir isotherm.

Recent Progress on Ultrathin Metalenses for Flat Optics.

SummaryAs technology advances, electrical devices such as smartphones have become more and more compact, leading to a demand for the continuous miniaturization of optical components. Metalenses, ultrathin flat optical elements composed of metasurfaces consisting of arrays of subwavelength optical antennas, provide a method of meeting those requirements. Moreover, metalenses have many other distinctive advantages including aberration correction, active tunability, and semi-transparency, compared to their conventional refractive and diffractive counterparts. Therefore, over the last decade, great effort has been focused on developing metalenses to investigate and broaden the capabilities of metalenses for integration into future applications. Here, we discuss recent progress on metalenses including their basic design principles and notable characteristics such as aberration correction, tunability, and multifunctionality.

Miniaturised Wireless Power Transfer Systems for Neurostimulation: A Review.

In neurostimulation, wireless power transfer is an efficient technology to overcome several limitations affecting medical devices currently used in clinical practice. Several methods were developed over the years for wireless power transfer. In this review article, we report and discuss the three most relevant methodologies for extremely miniaturised implantable neurostimulators: ultrasound coupling, inductive coupling and capacitive coupling. For each powering method, the discussion starts describing the physical working principle. In particular, we focus on the challenges given by the miniaturisation of the implanted integrated circuits and the related ad-hoc solutions for wireless power transfer. Then, we present recent developments and progresses in wireless power transfer for biomedical applications. Last, we compare each technique based on key performance indicators to highlight the most relevant and innovative solutions suitable for neurostimulation, with the gaze turned towards miniaturisation.

Piezoresponse amplitude and phase quantified for electromechanical characterization

Piezoresponse force microscopy (PFM) is a powerful characterization technique to readily image and manipulate the ferroelectric domains. PFM gives an insight into the strength of local piezoelectric coupling and polarization direction through PFM amplitude and phase, respectively. Converting measured arbitrary units into units of effective piezoelectric constant remains a challenge, and insufficient methods are often used. While most quantification efforts have been spent on quantifying the PFM amplitude signal, little attention has been given to the PFM phase, which is often arbitrarily adjusted to fit expectations. This is problematic when investigating materials with unknown or negative sign of the probed effective electrostrictive coefficient or strong frequency dispersion of electromechanical responses, because assumptions about the PFM phase cannot be reliably made. The PFM phase can, however, provide important information on the polarization orientation and the sign of the effective electrostrictive coefficient probed by PFM. Most notably, the orientation of the PFM hysteresis loop is determined by the PFM phase. Moreover, when presenting PFM data as a combined signal, the resulting response can be artificially lowered or asymmetric if the phase data have not been correctly processed. Here, we explain the PFM amplitude quantification process and demonstrate a path to identify the phase offset required to extract correct meaning from the PFM phase data. We explore different sources of phase offsets including the experimental setup, instrumental contributions, and data analysis. We discuss the physical working principles of PFM and develop a strategy to extract physical meaning from the PFM amplitude and phase.

A Switching Control Strategy Based on Switching System Model of Three-Phase VSR Under Unbalanced Grid Conditions

The power electronic converters are typical nonlinear systems. The conventional linearized modeling methods cannot accurately describe the working process of the converter. The control strategies based on the linearized model can only achieve good performance near the working point. By considering the switching nonlinear system nature of the converters, the main contributions of this article are as follows: a current error switching model is developed for the three-phase voltage source rectifiers (VSRs) under unbalanced grid for the first time; and an improved stability analysis theorem is proved for the switching control of the three-phase VSRs under unbalanced grid condition. These contributions are used to design a simple current switching controller for VSRs. The main advantages of the proposed modeling and control strategy are as follows. The switching model of the converter is built without any approximation. It accurately describes the physical working principle of the three-phase VSR under unbalanced grid condition. The proposed current switching controller has a very simple control structure. The switching states of the converter are directly produced according to the switching rule. There are no control parameters, no complicated rotation transformation, and no voltage vector modulation in the proposed switching controller. The proposed switching controller is not sensitive to the circuit parameters. The robustness of the control system is improved without any extra compensators or observers. Simulation and experiment verifies the correctness, the effectiveness, and the superiority of the proposed theory and methodology.

Intelligent Surfaces for 6G Wireless Networks: A Survey of Optimization and Performance Analysis Techniques

This paper surveys the optimization frameworks and performance analysis methods for large intelligent surfaces (LIS), which have been emerging as strong candidates to support the sixth-generation wireless physical platforms (6G). Due to their ability to adjust the behavior of interacting electromagnetic (EM) waves through intelligent manipulations of the reflections phase shifts, LIS have shown promising merits at improving the spectral efficiency of wireless networks. In this context, researchers have been recently exploring LIS technology in depth as a means to achieve programmable, virtualized, and distributed wireless network infrastructures. From a system level perspective, LIS have also been proven to be a low-cost, green, sustainable, and energy-efficient solution for 6G systems. This paper provides a unique blend that surveys the principles of operation of LIS, together with their optimization and performance analysis frameworks. The paper first introduces the LIS technology and its physical working principle. Then, it presents various optimization frameworks that aim to optimize specific objectives, namely, maximizing energy efficiency, sum-rate, secrecy-rate, and coverage. The paper afterwards discusses various relevant performance analysis works including capacity analysis, the impact of hardware impairments on capacity, uplink/downlink data rate analysis, and outage probability. The paper further presents the impact of adopting the LIS technology for positioning applications. Finally, we identify numerous exciting open challenges for LIS-aided 6G wireless networks, including resource allocation problems, hybrid radio frequency/visible light communication (RF-VLC) systems, health considerations, and localization.

Design and evaluation of a new bioelectrical impedance sensor for micro-surgery: application to retinal vein cannulation.

Nowadays, millions of people suffer from retinal vein occlusion, a blind-making eye disease. No curative treatment currently exists for this vascular disorder. However, a promising treatment consists in injecting a thrombolytic drug directly inside the affected retinal vessel. Successfully puncturing miniature vessels with diameters between 50 and 400[Formula: see text] remains a real challenge, amongst others due to human hand tremor, poor visualisation and depth perception. As a consequence, there is a significant risk of double-puncturing the targeted vessel. Sub-surfacic injection of thrombolytic agent could potentially lead to severe retinal damage. A new bio-impedance sensor has been developed to visually display the instant of vessel puncture. The physical working principle of the sensor has been analysed, and a representative electrical model has been derived. Based on this model, the main design parameters were derived to maximise the sensor sensitivity. A detailed characterisation and experimental validation of this concept were conducted. Stable, repeatable and robust impedance measurements were obtained. In an experimental campaign, 35 puncture attempts on ex vivo pig eyes vessels were conducted. A confusion matrix shows a detection accuracy of 80% if there is a puncture, a double puncture or no puncture. The 20% of inaccuracy most probably comes from the limitations of the employed eye model and the experimental conditions. The developed bio-impedance sensor has shown great promise to help in avoiding double punctures when cannulating retinal veins. Compared to other puncture detection methods, the proposed sensor is simple and therefore potentially more affordable. Future research will include validation in an in vivo situation involving vitreoretinal surgeons.

Shaping light spectra and field profiles in metal-coated monolayers of etched microspheres

Hybrid colloidal plasmonic-photonic crystals (HPPCs) are known for their interesting optical properties, which are relevant both fundamentally and for their applicative potential. The optical response of HPPCs is easily tunable from the visible to the infrared spectral range, while their fabrication, based on colloidal self-assembly, keeps production costs rather low. Both arguments make HPPCs a class of attractive functional materials. Here, we explore the optical properties of HPPCs obtained by gradual etching of a hexagonal close-packed monolayer of polystyrene microspheres, subsequently covered by a thin metal layer. We analyze the optical transmission characteristics of these etched colloidal crystals and HPPCs as a function of the etching degree. Finite-difference time-domain simulations allowed us to explain the correlations between the observed optical response and morphology. The transmission gap in bare colloidal crystals can be blue-shifted up to at least 50 nm, and its depth increased by more than 20%. In HPPCs on the other hand, it is possible to tune not only the wavelength of the enhanced plasmonic fields, but also their locations within the nanostructure. Thus, both spectra and near-field profiles can be fine-tuned in a controlled manner by plasma etching in these hybrid plasmonic-photonic structures, expanding the current understanding of the physical working principles of HPPCs and their applications.

Model and Control of a Compact Long-Travel Accurate-Manipulation Platform

Stick-slip accurate manipulator (composed of piezo and slider) is widely applied in scanning electron microscope (SEM). However, for its positioning control in SEM, conventional displacement sensors are hard to be used because of their big physical dimensions or magnetic working principles. To solve these problems, this paper proposes to use strain gauge as the accurate manipulator's positioning sensor and develops a displacement-prediction method to achieve a long-travel accurate positioning (positioning error no more than 2% of the traveling range) in SEM. The slider's feedback displacement is obtained indirectly, which is calculated and predicted by the LS friction model and the piezo's motion statements obtained from the strain gauge. Meanwhile, the application of strain gauge can minimize the manipulator's geometric dimension guarantee a nonmagnetic working environment and avoid the thermal radiation caused by sensor in SEM. An LS friction model with the main friction characteristics is developed to provide the friction calculation between the slider and the piezo. Feedforward PID control method is employed to improve the system's dynamic characteristics. Experiments are carried out to validate the effectiveness of displacement-prediction control applying on the positioning platform.

Material Loadings during Electrochemical Machining (ECM) - A First Step for Process Signatures

Properties of workpieces, like residual stress in the rim zone, cannot be predicted for manufacturing technologies reproducible in advance. This lack of predictability shall be solved by a new approach, called Process Signatures. These Process Signatures will combine the material loadings forced by the manufacturing process with the change of state variables, e. g. the variation of residual stress in the surface layer. As the Process Signatures shall achieve comparability for different processes with same physical working principle, it is necessary to describe the transition from material loadings to the change of material properties in a uniform way. Consequently an energy based approach is chosen that considers these transitions by the dissipation of the several kinds of energy brought into the manufacturing process and especially in the respective working area.A first step for the development of such Process Signatures is the identification of all process specific material loadings. This paper presents several material loadings generated during the electrochemical sinking process. In a further step the contribution of the individual material loadings to the material removal process are estimated. Finally first approaches for the combination of the main material loadings and the change of material properties are presented.

Smart3 – Smart Materials for Smart Applications

Smart Materials are designed materials that have one or more properties that can be significantly changed in a controlled fashion by an externally applied field value such as stress, temperature and electric or magnetic fields. This behavior is reversible and consequently enables these materials to fulfill actuation and sensing functions in one component. Compared to conventional systems such actuators are rather high integrated. They can be applied not just to be a discrete part of the system; they are the system itself combining sensing, actuation and mechanical functions. Certain actuating properties of Smart Materials are far beyond the ones of conventional actuating principles. These advantages possess to use them in special application areas such as lightweight construction, active vibration control or the development of highly dynamic systems for instance.The design of Smart Materials in highly integrated components is technically more advanced and requires interdisciplinary knowledge. In this paper we present three groups of Smart Materials: piezoceramics, shape memory alloys and dielectric elastomers and their specific characteristics. That covers their physical working principle, their mechanical behavior, the actuation and sensing properties. Especially the interdisciplinary design approach required for developing highly integrated components is exemplarily clarified on Shape Memory Alloys. To enable designers to use Smart Materials without having this special knowledge smart tools for smart design are presented.

Controlling mode instabilities by dynamic mode excitation with an acousto-optic deflector

We demonstrate an approach to actively stabilize the beam profile of a fiber amplifier above the mode instability threshold. Both the beam quality and the pointing stability are significantly increased at power levels of up to three times the mode instabilities threshold. The physical working principle is discussed at the light of the recently published theoretical explanations of mode instabilities.

Halbleiter-basierte Hochleistungsgeneratoren für Breitbandpuls-Abstrahlung

Abstract. Irradiated DS pulses beneath HPM and UWB are capable of disturbing the signal processing or even destroying the semiconductor structure. This paper presents the History of DS sources and their physical and electronic working principle, their technology and the potential application fields.

The Generic Mechatronic Transducer Model – A Unified System Modeling Approach

The current paper presents a unified lumped parameter modeling approach for deriving generic analytical system models of reciprocal electromechanical (mechatronic) transducers for various physical working principles (e.g. electrostatic, piezoelectric, electromagnetic, electrodynamic). Starting from constitutive physical relations representing natural laws, the model hierarchy comprises energy based nonlinear EULER-LAGRANGE behavior models, linearized electromechanical two-port models forming constitutive transducer equations and MIMO transfer function models describing the causality based signal flow behavior to be used for control system design and analysis purposes. It is shown that the models describe in a generic way the unified behavior of reciprocal transducers under different operating conditions, e.g. voltage vs. current control. Moreover the models allow in a straightforward way the generic discussion, i.e. independent from the concrete physical working principle, of important transducer operational concepts such as impedance feedback or self-sensing.

Completely mechanical quick changeable joints for multipurpose explosive ordnance disposal robots

SUMMARYThis paper is an investigation of completely mechanical quick changeable joints for multipurpose explosive ordnance disposal (EOD) robots. With the assistance of a quick changeable joint, an ordinary EOD robot becomes a multipurpose robot with an end effector which can be switched during the task. This exchangeable end effector permits the robot to perform more complex duties. Making the joint completely mechanical increases its capacity and decreases its complexity of control and risk of failure. In this paper, the design, manufacturing, and testing stages are explained for four quick changeable joints each possessing different physical working principles. The test results reveal the best design for a multipurpose EOD robot and give ideas for other uses of quick changeable joints. Employing the quick changeable joints in other mobile robot applications can increase a robot's capacity and efficiency.

Physical working principles of semiconductor disk lasers

The physical working principles of whispering gallery mode semiconductor disk lasers are examined. A new method is proposed for measuring the single-pass gain. The theory of cylindrical waveguides is considered. The spectral characteristics of whispering gallery mode lasers is investigated experimentally in the temperature range 4–300K. It is shown that lasers of this kind are very promising as potential laser radiation sources operating at room temperature.

Point Laser Measurements for Particle Characterisation

In this contribution two novel techniques for particle characterisation in dispersed, multiphase flows will be discussed: the time-shift technique and the rainbow technique using femtosecond laser pulses. Both methods are rather new and each offers some very distinct advantages for specific applications. The purpose of this contribution is to briefly outline the physical working principles of each technique and to outline their specific features. This information is meant to stimulate use of these techniques for hitherto inaccessible applications and measurement quantities.

Numerical simulation of heat and fluid flow in basic pulse tube refrigerator

PurposeTo clarify the physical working principle of refrigeration in basic pulse tube refrigerators (BPTRs).Design/methodology/approachA numerical simulation was performed. Transient compressible NS equation was solved utilizing the TVD scheme coupled with energy equation.FindingsThe periodic flow and temperature field were obtained. The movement of the gas particles and heat transfer between the gas particles and wall were analyzed. These numerical results explained the mechanism of surface heat pumping (SHP) which is known as the working principle of refrigeration in BPTR.Research limitations/implicationsPulse tube refrigerator (PTR) is classified into the third generation. BPTR is the first generation. It is needed to clarify the working principle of refrigeration in the second and third generation by analyzing heat and fluid flow in the tube.Practical implicationsA very useful source of information to understand the physical working principle of refrigeration in BPTR.Originality/valueThe mechanism of SHP was shown by analyzing the heat exchange between the gas particles and pulse tube wall.

C04 ベーシック型パルス管冷凍機に関する熱流動数値シミュレーション

Purpose – To clarify the physical working principle of refrigeration in basic pulse tube refrigerators (BPTRs).Design/methodology/approach – A numerical simulation was performed. Transient compressible NS equation was solved utilizing the TVD scheme coupled with energy equation.Findings – The periodic flow and temperature field were obtained. The movement of the gas particles and heat transfer between the gas particles and wall were analyzed. These numerical results explained the mechanism of surface heat pumping (SHP) which is known as the working principle of refrigeration in BPTR.Research limitations/implications – Pulse tube refrigerator (PTR) is classified into the third generation. BPTR is the first generation. It is needed to clarify the working principle of refrigeration in the second and third generation by analyzing heat and fluid flow in the tube.Practical implications – A very useful source of information to understand the physical working principle of refrigeration in BPTR.Originality/value –...