Front Panel Research Articles

A Study on Multimodal Behaviour of Plate Absorbers

Membrane absorbers, which are commonly used types of resonance absorbers, convert sound energy into thermal energy by exploiting vibrations that occur on oscillating panels. Those types of absorbers are generally tuned to be efficient in a very narrow frequency range. However, if plates are used as the front panel, it is possible to broaden the effective absorbing frequency bandwidth by exciting multiple modes. This study is devoted to investigating the multimodal behaviour of plate absorbers with closed back volumes in low-frequency range. In the numerical part of the study, the box-shaped plate absorbers are modelled using a combined BEM/FEM approach. The results are validated with measurements conducted in an anechoic chamber. In addition, the sound absorption characteristics of the plate absorbers are obtained from an experimental study conducted in a reverberation chamber. The obtained results reveal that the plate absorbers can be effective in wider frequency ranges.

Urban Birds Using Insects on Front Panels of Cars

Urbanization influences the food availability and quality for birds in many ways. Although a great amount of food for birds is provided incidentally or intentionally in urban areas, the quantity of insect-based food can be reduced in cities. We studied the role of one artificial food source, insects smashed on the front panels of cars, in Finland, and more specifically in the city of Rovaniemi, by conducting questionnaire research, searching for data from databases and performing a field study. Our results indicated that a total of seven bird species have been detected using insects on the front panels of cars in Finland. However, this behavior is not yet common since about 60% of responders to the questionnaire stated that this behavior is currently either rare or very rare. Most of the observations identified House Sparrows, followed by the White Wagtail or the Eurasian Jackdaw. Only a few observations identified the Eurasian Tree Sparrow, the Hooded Crow, the Great Tit and the Eurasian Magpie. The phenomenon was distributed quite widely across Finland, except in the case of the Eurasian Jackdaws, for which observations were restricted only to the southern part of the country. The first observation was made about the House Sparrow in 1971, followed by the White Wagtail (1975), Hooded Crow (1997), Eurasian Jackdaw (2006), Eurasian Tree Sparrow (2011), Eurasian Magpie (2019) and Great Tit (2022). The species using this food source are mainly sedentary urban exploiters, such as corvids and sparrows, that have been previously reported to have several different types of innovative behaviors. Most of the observations were conducted in urban parking sites of hypermarkets, and no observations were made in residential areas. Most of the foraging observations were made during the end phase of the breeding season, partly supporting the extra need for high-quality insect-based food for nestlings and fledglings. Our observations indicate that this behavior is not yet common and widespread among species.

Uniaxial compressive performance of an aramid and aluminum honeycomb sandwich structure

In recent years, explosion and impact resistance capacity of composite sandwich structures has been widely studied. However, the study of their basic mechanical properties is still lacking, which severely hinders the application of composite sandwich structures. This paper focuses on uniaxial compressive performance of a sandwich structure, so as to provide design guidance and promote application of such structures. Firstly, a novel aramid and aluminum honeycomb sandwich structure is proposed for explosion and impact resistance. Secondly, experimental and numerical studies on uniaxial compressive performance of the structure were conducted. Seven indices including yield compressive load were introduced to assess compressive behavior of the structure. A simulation framework to predict load-carrying capacity of the structure is proposed, in which the complex aluminum honeycomb was modeled as a cube with equivalent material properties. The mechanism of how the structure collapses under uniaxial compressive load was revealed. Thirdly, parametric sensitivity analysis was conducted. According to experimental and calculated results, the structure approximately undergoes five stages under progressive compression: uniform shrinkage in vertical direction, yielding at local regions of the weaker panel (rear panel), plastic deformation development on the rear panel, overall bending of the whole specimen, and fracture of localized welds. Front panel thickness and initial imperfection have little influence on compressive behavior of the structure, while thickness of the weaker panel (rear panel) is the decisive factor of compressive load-carrying capacity. Yield load, yield displacement, ultimate load, and elastic stiffness increase linearly with the increase of rear panel (316L) thickness, while ductility coefficient decreases linearly with the increase of rear panel (316L) thickness.

Vzácné obalové vazby ve sbírkách Knihovny Národního muzea

Rare double-cover bindings in the collections of the National Museum Library Unlike contemporary embossed bindings, Gothic double-cover bindings are mostly undecorated, as priority was given to the binding’s useful function. Covered codexes were stored in a horizontal position and the wide overlaps on the front edge of the back panel were inserted between the front panel and the book block; after the fastening of the clasps, the parchment block was perfectly protected by this “packaging“ against the adverse effects of the surrounding environment. The originally Romanesque type of binding was used for larger format codexes and appeared practically throughout the Middle Ages, until the 16th century. In domestic literature, double-cover binding is wrongly included in the “shape and binding curiosities“ category; abroad, the terminology for describing and determining structural types of bindings with a secondary cover is not clear. During conservation research in the National Museum Library, a total of 45 Gothic double­-cover bindings was found in various states of preservation, from which we can determine a wide range of structural types and several methods of execution. A set of ten double-cover bindings published by Dr. Hamanová was expanded to include bindings from Augustinian monasteries

Simulation in the temperature parameters control in the yogurt manufacturing process

Industry 4.0 was born in the 2010 decade under the automotive sector, in what would be known as smart manufacturing, the fourth industrial revolution, and the industry digital transformation through the data acquisition in industrial processes. It was a change in the goods production methods and generated a new social-economic dynamics. For this reason, the objective of this research is the “Simulation in the temperature parameters control in the yogurt manufacturing process” by using the National Instruments’ LabView v20 software, which allows the control of temperature parameters in fermentation tanks for yogurt manufacture. The yogurt manufacture comprises operations such as pasteurization (80 to 85 °C), followed by cooling (45 °C) of milk, and bacterial fermentation of milk, which provides the texture and flavor that characterize yogurt. To achieve this, a controlled temperature is required between 42 and 45 °C, being 43 °C the optimal temperature (set point). After the fermentation, the yogurt is cooled to a temperature of 5-10 °C for storage. It was necessary to place the thermometer, graph indicator, LED diodes, speed adjustment dial, and stop button in the front panel; on the other hand, VI, random number, multiplier factor, scan rate timer, and the Constant Indicator were placed in the block diagram. The diodes for every temperature parameter in the manufacturing process were enabled (on-off). As a result, by means of the LabView software, the temperature parameters’ control could be simulated in the yogurt manufacturing stages, namely, pasteurization, cooling to 45 °C, fermentation, and yogurt cooling. With this simulation, graphs and numeric data on the yogurt manufacture could be obtained.

Design and Construction of a Digital Logic Training Module for Laboratory Experimentation

A Digital Logic Trainer is used to train students on experimental verification and implementation of basic logic gates. This research work describes a digital logic training (DLT) module designed and constructed using semiconductor components such as diodes, transistors, and integrated circuits. The DLT module can be used to verify logic gate theorems including Boolean expressions, combinational logic designs and Karnaugh’s reduction techniques for a given logic circuit. The front panel of the DLT module comprises of different Boolean symbols for easy logic gates identification and operates effectively on a 5 V DC rectified from a 220 V AC power supply. The DLT module performs favourably well when compared with commercially available types and comes at a lower production cost.

보물 백담사(百潭寺) 복장 저고리 직물 문양 고찰

This study examines the patterns on textiles used for the Jeogori originally placed and later discovered inside the wooden seated Amitabha housed at Baekdamsa temple. These patterns have been schematized more precisely on the basis of hyperspectral images, and the historical characteristics of each pattern have been analyzed on the basis of related records and artifact materials. A total of three types of textiles were used for the Jeogori. A satin textile is used for the Gil (front and back panels) of the Jeogori with a pattern incorporates chrysanthemums and orchids into a continuous Wan (swastika)-inspired background pattern. The combination of chrysanthemums and orchids signifies “spring orchids and autumn chrysanthemums” and is also frequently found on other excavated artifacts from the 17th century onward. Used for the Kkeutdong (cuffs) of the Jeogori is a satin fabric with a pattern where a small flower pattern is added to a continuous Gong-charactered pattern in the background. This is a rare type not found on other textile artifacts from the same era. Used for the Git (collar) and the Gyeonmagi (underarm outer patches) of the Jeogori is a satin fabric depicting a dragon and phoenix pattern. The dragon and phoenix pattern harmoniously combines elements of the dragon pattern and the phoenix pattern that were fashionable during this period, and the characteristics of the dragon and the phoenix, respectively, conform to the age as well. The textiles used for the Jeogori are characterized by a very clear demonstration of epochality yet also use types of patterns that are not found often on artifacts from the same era. Given the period from which this Jeogori originates is certain, the garment will serve as a good material for such characteristics to become epochal indices of patterns that will be newly excavated in the future.

Impact resistance of composite circular corrugated core sandwich structures

In this study, we used HyperMesh and LS-DYNA software, based on the MAT54 model and Chang-Chang failure criterion, to establish a finite element model of composite corrugated sandwich structures, and introduced a progressive damage model. The impact resistance of the corrugated sandwich structure was studied by analysing the residual velocity of the projectile, the impact force of the target plate, and the failure mode. The impact resistance of the corrugated sandwich structure was analysed when four types of composite materials were used as the front and back panels of the corrugated sandwich structure. The results showed that, compared with the metal aluminium panel, the impact resistance of the structure was high when ultra-high molecular weight polyethylene (UHMWPE) fibres were used as the positive panel. When the composites were used as the back panel, although the residual velocity was lower than metal aluminium, the impact force was higher than metal aluminium, with more serious damage form of the target plate. Thus, the impact resistance of composite front panel/metal aluminium core/metal aluminium back panel sandwich structure was better than the all-metal aluminium corrugated sandwich structures. The results of this paper can provide a reference for the design of novel lightweight multifunctional structures.

USER EXPERIENCE DESIGN AND ARCHITECTURE – AN APPLICATION WITH ARDUINO

User experience design, which provides the emergence of user-oriented designs, while meeting the needs of users functionally, also deals with their emotions and perceptions. With this interactive design approach, personalized design alternatives can be offered in accordance with the expectations of the users. At the same time, the flexibility with changing conditions, demands and pleasures ensures that designs are sustainable. Architecture is one of the disciplines where user experience design can effectively use. The inability of changing of buildings in traditional architecture causes another inability that to respond user’s current needs and demands. Thus, in modern architecture many researchers and designers investigate for a solution to create different spaces. Moving, flexible and interactive spaces, which are shaped with demands and needs of the users, give importance to the user experience. In this context, a tent was designed as a temporary shelter with caring the user experience and changes depending on the demands and needs of the user, by using the Arduino Uno microcontroller development board. The prototype experiments of the tent design, which was modeled with SketchUp and rendered with Lumion, were made with the Fritzing program. Arduino Uno, sensors, lamp, relay module and servo motors were used in the tent design and the space was enabled to interact with the user's different senses. Two different sensors, temperature-humidity and sound were used in the study. The temperature-humidity sensor interacts with both the user and the environment. Since precipitation occurs when the relative humidity in the air reaches 100%, the program is coded to turn off the panel on the top of the tent when the humidity in the air reaches 70%. With the help of the sound sensor, predetermined colors are lit on the front panel of the tent with the user's hand clap. In the study, it is aimed to create different experiences by providing the interaction between the body and the space.

Experimental vs. Numerical Computation of Acoustic Analyses on the Thickness Influence of the Multilayer Panel

Sound-absorbing panels made with a perforated front and a sound-absorbing material on the back have been used in many forms of construction for a long time. It is a reasonably efficient system, obtaining high values of sound absorption at a specific resonant frequency, depending on the design of the structure of the sound-absorbing multilayer panel. The present work considers an acoustic panel in two constructive types, consisting of four layers: a front panel made of perforated sheet, polyethylene foam foil, basalt wool board with two different thicknesses, and a back panel of the non-perforated sheet. Due to the different thicknesses of the basalt wool board, for the multilayer structure of the acoustic panel, differences in acoustic impedance and acoustic absorption can be highlighted, experimentally determined with an impedance tube, using the transfer function method (TFM) based on EN ISO 10534-2 in the frequency range 100–3200 Hz. In the meantime, a method was developed to predict the sound absorption coefficient, namely the prediction of sound absorption coefficient using the transfer matrix method (PSAC-TMM). This computational model of the multilayer acoustic panel is introduced considering the internal geometry of the multilayer panel, as well as the computation of the acoustic impedance of each layer, all gathered through the transfer matrix method (TMM). Comparative analyses between experimental data and predictive results using PSAC-TMM were performed, validating the PSAC-TMM as a predictive method to estimate the sound absorption coefficient for acoustic multilayer panels.

DEVELOPMENT OF FUNCTIONAL ELEMENTS FOR THE ELECTRONIC DESIGNER «TAPANDA»

Expanding the capabilities of intelligent electronic designers and reducing the cost of production of various functional elements for them is an urgent scientific and practical task. The aim of the work was to develop smart elements of an electrical circuit on the MSP430 microcontroller, simulating the operation of various electronic components, for the circuit designer «Tapanda». The firmware for the microcontroller has been developed and tested, printed circuit boards and front panels of various elements of the electrical circuit of the controlled devices have been designed. Based on the results of the work, a package of design documentation was formed for the production of the developed functional elements.

Crashworthiness analysis and design of a sandwich composite electric bus structure under full frontal impact

The transition toward sustainable transportation includes adopting ecofriendly electric vehicles in public transport, which reduces greenhouse gas emissions and increases energy efficiency. One of the critical features in fuel economy improvement of electric vehicles lies in lightweight structural design. Nevertheless, the crashworthiness of the structures of the vehicles and the safety of passengers must be guaranteed in the attempt of mass reduction because the crash of large vehicles such as buses usually costs many lives. This paper, therefore, aims to present an in-depth analysis of the impact behavior of a lightweight monocoque sandwich composite microbus body under full-frontal crash conditions. The bus structure, made of a high-density polyurethane foam core and woven glass fabric-epoxy face sheets, was modeled and simulated via LS-DYNA dynamic analysis using strength-based Chang-Chang criteria to characterize the failure mechanism of the structure and investigate intrusion into the passenger survival space. Under front collision, the front panel, A-pillars, and front sidewalls of the original bus were found to be extensively damaged in the compressive fiber mode. Based on the 50th percentile male dummy anthropometric parameters, injury indices of 0-5 intervals were proposed to evaluate occupant injury risks. The maximum front and side intrusion into the specified safety space under a maximum impact speed of 50 km/h is 208 mm at the front panel and 221 mm at the sidewall, indicating high injury indices of 3.59 and 4.81, respectively. The effects of stiffeners reinforced in the front panel and foam core thicknesses in the sidewalls, floor, and bottom parts on crashworthiness improvement were thoroughly discussed. The improved bus design can significantly enhance the safety of the occupants with a minimal increase in structural weight of merely 35.6 kg. An effective vehicle safety design under full frontal collision is presented.

Optimization of the Hydrodynamic Performance of a Double-Vane Otter Board Based on Orthogonal Experiments

An orthogonal experiment was conducted to study the effects of the aspect ratio, camber of the fore wing, and gap ratio of front and rear wing panels on the hydrodynamic performance of double-vane otter boards. The design of the orthogonal experiment comprised three factors (each having three levels), namely the aspect ratio (1.0, 1.5, and 2.0), camber (0.12, 0.14, and 0.16), and gap ratio (0.25, 0.30, and 0.35), the drag coefficient Cx and the lift coefficient Cy of nine otter board models obtained in a wind tunnel experiment, and the lift–drag ratio K obtained by calculation. The lift–drag ratio for a working angle of attack of 30° was selected as the inspection index, and the experimental data were analyzed in an orthogonal design-direct analysis. Analysis of each factor revealed that the optimal level combination of factors was A3B3C3 and that the decreasing order of the effects of the factors was A (aspect ratio) > B (gap ratio) > C (camber). The orthogonal experiment thus obtained an optimal otter board in terms of the aspect ratio (2.0), fore wing camber (0.16), and gap ratio (0.35), with the aspect ratio having the greatest effect on performance. The hydrodynamic performances of the otter board with the optimized structure and another otter board model were compared in numerical simulation, which verified the correctness of the analysis results. The experimental results provide a reference for the optimal design of the double-vane otter board.

Thermal characterization of a photovoltaic panel under controlled conditions

To avoid large variability in environmental factors, the thermal and electrical behavior of a 310 W PV panel exposed to a 6 kW halogen light source was studied in a 48 m3 climatic room. The physical quantities measured were panel temperature (front and back), radiation illuminating the panel, ambient temperature, air speed, panel current and panel voltage. Under these conditions, it was possible to estimate the thermal constant of the panel at 9 minutes. The effect of forced convection on the panel temperature was quantified using a fan. The results obtained confirm that the panel temperature decreases exponentially with air speed. The part of the incident radiation that is converted into electricity and therefore does not contribute to the heating of the panel was quantified. The results show that the front panel temperature decreases by about 3°C and the rear panel temperature by about 3.7°C when the system produces electricity. The Maximum Power Point from I–V and P–V characteristics was studied for different PV temperatures to confirm the linear decay of the electrical efficiency with increasing cell temperature.

New Products

Pickering has added two new matrix modules to their line of PXI/PXIe instruments. The 40-724-021-L (PXI) and 42-724-021-L (PXIe) are 32x8 RF matrix modules with y-axis loop-thru and are suitable for switching frequencies up to 150 MHz. Having a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$50\Omega$</tex> characteristic impedance and front panel SMB connectors, these modules provide a simple and scalable bidirectional matrix for RF and are intended for the easy construction of high performance switching systems.

Development of an Energy-Sensitive Detector for the Atom Probe Tomography.

A position and energy-sensitive detector has been developed for atom probe tomography (APT) instruments in order to deal with some mass peak overlap issues encountered in APT experiments. Through this new type of detector, quantitative and qualitative improvements could be considered for critical materials with mass peak overlaps, such as nitrogen and silicon in TiSiN systems, or titanium and carbon in cemented carbide materials. This new detector is based on a thin carbon foil positioned on the front panel of a conventional MCP-DLD detector. According to several studies, it has been demonstrated that the impact of ions on thin carbon foils has the effect of generating a number of transmitted and reflected secondary electrons. The number generated mainly depends on both the kinetic energy and the mass of incident particles. Despite the fact that this phenomenon is well known and has been widely discussed for decades, no studies have been performed to date for using it as a means to discriminate particles energy. Therefore, this study introduces the first experiments on a potential new generation of APT detectors that would be able to resolve mass peak overlaps through the energy-sensitivity of thin carbon foils.

Block programming to develop interactive activities in the analysis of passive filters using an RC circuit for distance classes

Block programming was developed for interactive activities in the analysis of a passive low pass filter using a RC circuit for distance classes. On a breadboard, was integrated an Arduino development board, a potentiometer and a visual indicator (a light emitting diode LED). The development of the programming was carried out using the software LabVIEW to generate an interactive front panel that allows us to manipulate and visualize the calculations, the graphic expressions and at the same time vary at least one passive element. A graphical interface was obtained that allows iterations and immediate calculations for the missing parameters to see the behavior of the filter and also generates a display for the mathematical expression and its Bode plot, the resistance allows us vary the values and make a sweep to locate the angular frequency and activate the light emitting diode connected on the development board. In the programming a web camera was implemented to visualize the circuit in real time at the moment of manipulating a graphical interface.

FUZZY REGULATOR OF THE ROD SUPPLY SYSTEM OF ARDUINO-BASED CROSS-WEDGE ROLLING MILL IN LABVIEW ENVIRONMENT

The main purpose of scientific work is to develop a regulator based on fuzzy logic for an electronic control system for the supply of bar billets in automated cross-wedge rolling complexes.&#x0D; Cross-wedge rolling belongs to the advanced energy-saving technologies where technological processes based on metal cutting are replaced by economic processes of plastic forming of details. The analysis showed that coefficient increase of metal utilization requires loss decrease arising from the supply inaccuracy of the bar workpiece to the length of the part. The task is to reproduce the given law of motion of the actuator, i.e. to ensure maximum speed, smooth acceleration and braking with the possibility of a shockless stop at the end of the stroke. The solution of this problem is proposed to be carried out by entering the fuzzy control unit into the structure of the system for controlling the supply..&#x0D; The hardware basis of the control system in this work is the Arduino hardware and software complex based on the Atmel AVR microcontroller. The software model of the control system is developed in the graphical programming environment LabVIEW, which is widely used as a standard tool for data collection and control of devices in industry, education and research laboratories. The construction of a fuzzy regulator and its implementation are considered using Fuzzy Logic Designer.&#x0D; On the basis of systematized knowledge about the object of research, its characteristics and features, linguistic input and output variables were selected, as well as membership functions and a fuzzy production model of knowledge was formulated. The configuration of the control system depends on the number of controlled outputs and controlled input data and in this case the MISO information structure is applied. The paper presents the front panel of the virtual device developed by LabVIEW, which is designed to display information about the current state of the system. The purpose of the developed fuzzy regulator model is to output the value of the initial air pressure in the cavity of the actuating pneumatic cylinder, which will create an air cushion in the process of advancing the piston, which has properties similar to those of a normal spring. Smooth stopping of the piston is provided by the coordinated choice of rigidity of a pneumatic spring taking into account length of a detail and weight of a rod and allows us to reduce kinetic energy in an end point of positioning that increases accuracy of supply.&#x0D; The analysis of research results confirmed the efficiency and adequacy of the model used and the developed set of operation rules of the fuzzy regulator. Testing of the control system on parts of different lengths confirmed a reduction in total losses and an increase in the utilization of the metal.

A prototype optical link board with redundancy design for the ATLAS liquid argon calorimeter Phase-2 upgrade

A prototype optical-link board has been developed for the ATLAS Liquid Argon Calorimeter Phase-2 upgrade. The board consists of 24 lpGBT chips and 8 VTRx+ modules and demonstrates the full optical link design of the future front-end board. The board has 22 simplex optical links to transmit detector data, which are emulated in FPGAs and injected through 6 FMC connectors, to the off-detector electronics. The board implements 2 duplex optical links for clocks, control, and monitoring with redundant design to improve the system reliability. Data transmission and all redundant designs have been verified. A fiber routing scheme, in which 2 or 3 VTRx+ modules are re-connected to the front panel with an MPO connector, has been prototyped.

Automated system for regulating the thermal parameters of cord heat treatment furnaces with optimization of the gas-to-air ratio at a certain value

The system of automation which allows to control autonomous use of gas with preserva-tion of quality of technological process is resulted. The given algorithm, corresponding programs, technical means of automation system carry out regulation of air expenses at any values of quantity of fuel (gas). The gas-to-air ratio is determined experimentally from the analysis of exhaust gases for a specific type of furnace. The control algorithm is implemented using a microprocessor controller, and includes: PID control - law (proportional-integral-differential), linearization, which processes the input values of gas and air and reduces measurement errors of flow sensors and especially in the initial part of the sensor range; piecewise linear approximation, which allows: to implement the specified dependence of the ratios, flexibility and the ability to adjust and change the parameters of the control circuits, which adapts the control system to specific production conditions. The controllers can be configured both at the lower level of the distributed ACS TP and communicate with the upper level through the digital serial communication channel, and used as a stand-alone device. The meter of the measured and calculated parameters of the corresponding physical quantities displays them on the matrix board of its front panel. A computer with a printer located on the panel shop is connected to the meters. Devel-oped programs that implement control algorithms written in Delphi 3.0 using BDE (Bor-landDatabaseEnqine). Technological programs and a set of documentation for the operation of the system have also been developed. The system is focused on daily work in conjunction with meter gauges. Instrument read-ings are taken at intervals of one to one hundred and twenty minutes, depending on the settings made on the front panel. Information from the meters is stored in the database "Infoterm.db", as well as in the archival database "Archive.db". Moreover, the database "Infoterm.db" is released from the data every day before the launch of system programs. The technological program for heat meters is made on the basis of preliminary calcula-tions of measuring diaphragms from the manufacturer with observance of metrological and technological conditions (metrological certification, etc.). If necessary, the software is configured.