Signal Transmitter Research Articles

Broadband Optical Sources for Low-Cost WDM-MB-OFDM Networks

Multiband Orthogonal Frequency Division Multiplexing (MB-OFDM) signal transmission through a 10-km optical fiber link is experimentally demonstrated by using a broadband source. We propose the use of optical broadband sources in multiband OFDM signal transmitters as a low-cost and power fading free solution. The OFDM band is dynamically selected in the receiver by means of an Mach-Zehnder Interferometer (MZI). Therefore, MB-OFDM is demonstrated at 1.5 Gb/s per band in access networks, supporting up to 20 ONUs.

Visible light communication system based on spread spectrum technology for intelligent transportation

In recent years, with the rapid development of the solid state Light emitting diodes (LED’s) material, visible light communication has vast applications in transportation system. Generally, LED visible light communication refers to the communication technology which utilizes LED as a signal transmitter, the air as a transmission medium, and the photodiode as a signal receiving component. Visible light communication based on LED light source has been widespread concerned in intelligent transportation system (ITS). In particular, it is used to solve the communication problems between traffic lights and vehicles. However, signal source switching always puzzles the application of visible light communication based on LED in ITS. If signal source switching is not solved effectively, it will result in the interruption of information transmission. The paper proposes a visible light communication system using spread spectrum technology and pulse position modulation. When the vehicle is at the crossroads, the receiver on the vehicle receives signals from the four LED traffic lights at the same time. During the movement of the vehicle, the peak value of the four signals received by the receiver is constantly changing. The receiver detects the relevant peaks from the four traffic light signals and communicates with the traffic lights which have the maximum correlation peak. The problem of signal source switching is solved effectively. The experimental results show that the proposed system can achieve seamless switching between four-way LED traffic lights at the crossing, and the bit error rate of the system is 10−4–10−7.

Power allocation and range performance considerations for a dual-frequency EBPSK/MPPSK system

ABSTRACTExtended binary phase shift keying/M-ary position phase shift keying (EBPSK/MPPSK)-MODEM provides radar and communication functions on a single hardware platform with a single waveform. However, its range estimation accuracy is worse than continuous-wave (CW) radar because of the imbalance of power in two carrier frequencies. In this article, the power allocation method for dual-frequency EBPSK/MPPSK modulated systems is presented. The power of two signal transmitters is adequately allocated to ensure that the power in two carrier frequencies is equal. The power allocation ratios for two types of modulation systems are obtained. Moreover, considerations regarding the range of operation of the dual-frequency system are analysed. In addition to theoretical considerations, computer simulations are provided to illustrate the performance.

Simulation of intra-ciliary diffusion suggests a novel role of primary cilia as a cell-signaling enhancer.

Besides the role to generate a fluid flow in the surrounding medium, eukaryotic cilia have a crucial function in sensing external signals such as chemical or mechanical stimuli. A large body of work has shown that cilia are frequently found in various types of sensory cells and are closely related to many regulatory mechanisms in differentiation and development. However, we do not yet have a definitive answer to the fundamental question, "why cilia?" It has been a long-standing mystery why cells use cilia for sensing external signals. To shed light on this, we sought to describe the kinetics of signaling with theoretical approaches. Based on the results, here we propose a new role of cilia as a cell-signaling enhancer. The enhancing effect comes from restricted volume for the free intra-ciliary diffusion of molecules due to the cylindrical shape of cilia, which can facilitate quick accumulation of intracellular signaling molecules. Our simulations demonstrate that both the rate and amplitude of response in signal transduction depend on where the membrane receptors or channels are located along the ciliary shaft. In addition, the calculated transfer function of cilia regarded as a transmitter of external signals also suggests the properties of cilia as a signal enhancer. Since such unique composition of receptors and channels in cilia is found in various types of eukaryotic cells, signal enhancing is presumably one of the most essential and conserved roles of cilia.

Self-Powered Multi-Port UHF RFID Tag-Based-Sensor

In this paper, multi-port UHF RFID tag-based sensor for wireless identification and sensing applications is presented. Two RFID chips, one with attached sensor and the other without, are incorporated in a single tag antenna with two excitation ports. The chip with the integrated sensor (sensor port) transmits a signal impacted by the sensed temperature or humidity, while the other RFID chip serves as the reference signal (reference port) transmitter in the sensing process. The proposed tag-based sensor is fabricated and experimentally evaluated. The measured results demonstrate that the sensed data can be extracted using a commercial RFID reader by recording and comparing the difference in the reader output power required to power up the reference port and the power required to power the sensor ports. To improve the reading range of the proposed sensor, a dual-port solar powered RFID sensor is also presented. The reading range of the sensor is increased by two times compared to a similar prototype without solar energy harvesting. The experimental evaluation demonstrates that the proposed tag-based sensor can be easily integrated with a resistive humidity or temperature sensor for a low-cost solution to detect the heat or humidity exposure of sensitive items for several applications such as supply chains and construction structures.

Anemometric type flow transmitter using LM335 – A temperature sensing IC

In the present paper, an adapted anemometric type flow measurement technique has been designed and developed. To measure the flow rate of the fluid, a temperature sensing IC LM335 has been used in this technique as a flow sensor. The flow sensing IC is used to produce a change in output voltage of the flow transducer due to cooling effect of a flowing fluid on the metal cap of the IC sensor in contact with the fluid. In this transducer, the effect of fluid temperature is eliminated by using an identical IC sensor with its metal cap in contact with a stagnant part of the flowing fluid. Thus the difference of the outputs of the two identical transducers gives an output which depends only on fluid flow rate. The transducer along with signal conditioner and transmitter is designed and tested in the present work. The test results are reported in the paper. A characteristic equation of the proposed flow transducer has been derived and transducer characteristics obtained from experiment are found to follow this equation with good linearity, repeatability and small uncertainty of measurement. The signal conditioner and transmitter circuits used in this experiment are also found to have similar characteristics.

A novel dual-ratiometric-response fluorescent probe for SO2/ClO− detection in cells and in vivo and its application in exploring the dichotomous role of SO2 under the ClO− induced oxidative stress

Intracellular reactive sulfur species and reactive oxygen species play vital roles in immunologic mechanism. As an emerging signal transmitter, SO2 can be generated as the anti-oxidant, while SO2 is also a potential oxidative stress-inducer in organism. Aiming to elucidate in-depth the dichotomous role of SO2 under oxidative stress, we designed a dual-response fluorescent probe that enabled the respective or successive detection of SO2 and ClO-. The probe itself emits the red fluorescence (625nm) which can largely switch to blue (410nm) and green fluorescence (500nm) respectively in response to SO2 and ClO-, allowing the highly selective and accurate ratiometric quantification for both SO2 and ClO- in cells. Moreover the ultrafast (SO2: <60s; ClO-: within sec) and highly sensitive (detection limits: SO2: 3.5nM; ClO-: 12.5nM) detection were achieved. With the robust applicability, the developed probe was successfully used to quantify SO2 and endogenous ClO- in respectively the HeLa cells and the RAW 264.7cells, as well as to visualize the dynamic of SO2/ClO- in zebrafish. The fluorescent imaging studies and flow cytometry analysis confirmed the burst-and-depletion and meanwhile the oxidative-and-antioxidative effects of intracellular SO2 under the NaClO induced oxidative stress.

Success in the acquisition of Bombyx mori sperm motility is influenced by the extracellular production of nitric oxide (NO) in the presence of seminal fluid nitric oxide synthase (NOS)

A trypsin-like protease called initiatorin is known to initiate sperm motility in the silkworm, Bombyx mori, but little is known about the signaling events leading to sperm flagellar beating. The aim of this study was to investigate whether this mechanism of sperm motility activation involves the signaling transmitter nitric oxide (NO). NO is produced from the amino acid L-arginine by the enzyme action of nitric oxide synthase (NOS; EC 1.14.13.39). Simple treatment of quiescent sperm with an NO donor (SNAP or NOC7) in vitro did not lead to activation of motility. Nevertheless, initiatorin- or trypsin-induced motility was blocked by pretreatment of sperm with either the NOS inhibitor L-NAME or NO scavenger carboxy-PTIO. These observations suggested that NO may play important physiological roles in the acquisition of sperm motility under the in vitro condition used here. Then, we investigated whether NO synthesis would occur in the spermatophore, a capsule containing spermatozoa that is created by the contents of various male reproductive glands and is the site of sperm maturation. The amounts of NO2− and NO3−, stable metabolites of NO, reached maximum values after enclosure in the spermatophore, a time when apyrene spermatozoa acquire vigorous motility. Moreover, RT-PCR and Western blotting analyses of NOS indicated that it is abundantly expressed in glandula (g.) lacteola of the virgin male ejaculatory duct, from which it is secreted to the seminal fluid and transferred to the female during mating. Previous studies demonstrated that free L-arginine is supplied de novo by a specific proteolytic reaction in which initiatorin participates during spermatophore formation (Osanai et al., 1987c). Based on these results, it can be presumed that the mixing of seminal fluid contents from each male reproductive organ during ejaculation induced NO production outside of the spermatid, and exogenous NO stimulated a signaling pathway involved in the activation of silkworm apyrene sperm.

Effect of Sulfur‐Containing Compounds on Hydrogen Sulfide Production in THP‐1 Differentiated Macrophages

Hydrogen sulfide (H2S) is considered the third endogenous gaseous signaling transmitter. The H2S has been described as a target molecule for therapies on specific diseases, such as cardiovascular diseases and inflammatory processes. Garlic and glutathione (GSH) are examples of sulfur‐containing compounds that have been shown to modulate H2S production in erythrocytes and other specialized cells. However, such evidence has never been described in immune cells. Therefore, the aim of this study was to investigate the effect of aged garlic extract (AGE) and GSH on H2S production in macrophages. THP‐1 monocytes (0.7×106) were differentiated into macrophages using phorbol 12‐myristate 13‐acetate in a 96‐well plate. Once differentiated, the cells were pre‐incubated at 37°C in a humidified 5% CO2 atmosphere for 30 minutes with a fluorescent turn‐on H2S‐responsive probe (DP‐NBD – 150uM), synthesized according to Zhang et al. (2015). The cells were treated for 24 hours with GYY4137 (300uM), GSH (1mM), AGE (100mg/ml) or GSH+AGE. Cells were also treated for 24 hours with GSH and then 3 hours with AGE. The H2S production was identified using a fluorescent microscope and the fluorescence of DP‐NBD recorded. After the 24 hour incubation, GSH and AGE treatments alone had no effect on H2S production compared to non‐treated cells. Moreover, in the GSH (24 hours) + AGE (3 hours) treatment, the fluorescence intensity also did not differ from non‐treated cells. However, when the macrophages were incubated with GSH+AGE at the same time, the fluorescence was higher than non‐treated cells and comparable to the positive control. In conclusion, incubation with GSH and AGE together increased H2S production in THP‐1 differentiated macrophages after 24 hours of treatment, but this effect was not observed in the individual treatments. These results demonstrate a possible interaction between GSH and AGE in immune cells.Support or Funding InformationUF/IFAS Agriculture Experiment Station

Demonstration of a free-space optical communication system using a solar-pumped laser as signal transmitter

A free-space optical communication system with a sun light directly pumped laser as the signal transmitter was demonstrated. A 0.6 × 0.6 m Fresnel lens was used as the primary concentrator to collect the solar light. 6.8 W continuous wave laser power was obtained from a 4 mm diameter grooved Nd:YAG rod. The output intensity was modulated with a video signal via a LiNbO3 Mach–Zehnder optoelectronic modulator. The video signal with a resolution of 1920 * 1080/frame and the frame rate of 25 Hz was transmitted over five-meter free-space in real time with high fidelity. The transmission rate was 125 Mbps and bit error rate was lower than 10−6. This research shows the feasibility of applying a solar light directly pumped laser for free-space optical communication, which is significant for telecommunications between satellites.

Aptasensor with Expanded Nucleotide Using DNA Nanotetrahedra for Electrochemical Detection of Cancerous Exosomes

Exosomes are extracellular vesicles (50-100 nm) circulating in biofluids as intercellular signal transmitters. Although the potential of cancerous exosomes as tumor biomarkers is promising, sensitive and rapid detection of exosomes remains challenging. Herein, we combined the strengths of advanced aptamer technology, DNA-based nanostructure, and portable electrochemical devices to develop a nanotetrahedron (NTH)-assisted aptasensor for direct capture and detection of hepatocellular exosomes. The oriented immobilization of aptamers significantly improved the accessibility of an artificial nucleobase-containing aptamer to suspended exosomes, and the NTH-assisted aptasensor could detect exosomes with 100-fold higher sensitivity when compared to the single-stranded aptamer-functionalized aptasensor. The present study provides a proof-of-concept for sensitive and efficient quantification of tumor-derived exosomes. We thus expect the NTH-assisted electrochemical aptasensor to become a powerful tool for comprehensive exosome studies.

Development of a Communication Aid App with iOS Devices to Support Children/Persons with Speech Disabilities Improvement in Obtaining Positioning Information with iBeacon as Near Field Radio Communication Technology

Communication has such a vital function as the foundation of human social life that speech disabilities can drastically deteriorate people’s quality of life. The author has developed a voice output communication aid (VOCA) to enable children/persons with speech disabilities to communicate with other people according to conversation situations with iOS devices with global positioning system (GPS), positional information acquiring technology (iBeacon), and a clock function installed. The developed technology is an application compatible with iOS (hereinafter, app) that displays a list of messages (hereinafter, VOCA interface) if any of them correspond to the information on the user’s location and time of use as acquired by users with a portable information device with a GPS function, iBeacon function, and clock function installed. Users can communicate by selecting the icons of required messages from VOCA interfaces to reproduce registered voice data instead of their own voices. We have named the developed technology “Friendly VOCA” because its intentions are that: (1) users can communicate with other people with as few operations involved as possible; (2) it should be easy for users to learn and to operate. This paper reports the development processes of the Friendly VOCA and defines the ratios of preregistered VOCA interfaces displayed (hereinafter, correct answer rates) in acquiring positional information with GPS and with iBeacon. In Research Task 1, we have conducted experiments to verify the correct answer rates of the GPS system in outdoor use of the Friendly VOCA and in Research Task 2 we have conducted experiments to verify the correct answer rates of the iBeacon system in indoor use of the Friendly VOCA. The research results show that both the GPS system and iBeacon system can specify user’s spatial information and display appropriate lists of messages. However, the experiments found that iBeacon signal transmitters can transmit signals over a distance of 50 m or more: to improve the correct answer rates of the iBeacon system, we may need to increase the distance between iBeacon signal transmitters or select devices with a shorter range of transmission.

Alpha-Tocopherol-Dependent Salt Tolerance is More Related with Auxin Synthesis Rather Than Enhancement Antioxidant Defense in Soybean Roots

In this paper, we describe the alleviated effects of alpha-tocopherol (α-T) on oxidative damage and its possible role as a signal transmitter in plants during salt stress. The results show that exogenously applied α-T under salt stress increased root length and weight, but reduced hydrogen peroxide (H2 O2), superoxide anion radical (O2.–) and malondialdehyde (MDA) content in soybean roots. The proline content was reduced by α-T treatment. Interestingly, endogenous auxin (IAA) level was significantly increased after α-T application as compared to salt stress alone. Moreover, α-T reduced significantly superoxide dismutase (SOD) enzyme and isoenzyme activity but upregulated peroxidase (POX) 2, 3 and glutathione-stransferase (GST) 1, 3 isoenzyme expression. However, ascorbate peroxidase (APX) enzyme activity was not affected at all. Consequently, the results show that α-T serves as a signal molecule under salinity from leaves to roots by increasing remarkably endogenous IAA levels and increasing partially antioxidant activity in roots.

Colorimetric detection of endogenous hydrogen sulfide production in living cells

Hydrogen sulfide (H2S) has received great attention as a third gaseous signal transmitter, following nitric oxide and carbon monoxide. In particular, H2S plays an important role in the regulation of cancer cell biology. Therefore, the detection of endogenous H2S concentrations within biological systems can be helpful to understand the role of gasotransmitters in pathophysiology. Although a simple and inexpensive method for the detection of H2S has been developed, its direct and precise measurement in living cells remains a challenge. In this study, we introduced a simple, facile, and inexpensive colorimetric system for selective H2S detection in living cells using a silver-embedded Nafion/polyvinylpyrrolidone (PVP) membrane. This membrane could be easily applied onto a polystyrene microplate cover. First, we optimized the composition of the coating membrane, such as the PVP/Nafion mixing ratio and AgNO3 concentration, as well as the pH of the Na2S (H2S donor) solution and the reaction time. Next, the in vitro performance of a colorimetric detection assay utilizing the silver/Nafion/PVP membrane was evaluated utilizing a known concentration of Na2S standard solution both at room temperature and at 37°C in a 5% CO2 incubator. As a result, the sensitivity of the colorimetric assay for H2S at 37°C in the incubator (0.0056Abs./μM Na2S, R2=0.9948) was similar to that at room temperature (0.0055Abs./μM Na2S, R2=0.9967). Moreover, these assays were less sensitive to interference from compounds such as glutathione, l-cysteine (Cys), and dithiothreitol than to the H2S from Na2S. This assay based on the silver/Nafion/PVP membrane also showed excellent reproducibility (2.8% RSD). Finally, we successfully measured the endogenous H2S concentrations in live C6 glioma cells by s-(5′-adenosyl)-l-methionine stimulation with and without Cys and l-homocysteine, utilizing the silver/Nafion/PVP membrane. In summary, colorimetric assays using silver/Nafion/PVP-coated membranes can be simple, robust, and reliable tools for the detection of H2S that can avoid the complicated and labor-intensive analytical approach used in conventional biology. In addition, we expect that this assay will demonstrate a powerful ability to study pathophysiological pathways that involve H2S.

Cytosolic GAPDH: a key mediator in redox signal transduction in plants

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) serves not only as a key enzyme in glycolysis, but also as a multifunctional protein in other biological processes, especially in response to abiotic stresses in plants. Cytosolic GAPDH (GAPC) is a typical redox protein with selected catalytic cysteine, which undergoes reversible redox post-translational modifications (RPTMs) on its thiol group by reacting with hydrogen peroxide and nitric oxide related species. Moreover, the modified GAPC may interact with certain signal transmitters such as phosphatidic acid, phospholipase D, and osmotic stress-activated protein kinase. All these observations suggest that GAPC serve as a key mediator in redox signal transduction in plants. In this review, we provide an up-to-date insight into molecular mechanisms after H2O2- and NO-dependent oxidation of GAPC. We also discuss GAPC catalytic functions and potential functions as a modified protein by RPTMs.

SLVS Transmitter and Receiver for CBM MUCH ASIC

Scalable Low Voltage Signaling (SLVS) Transmitter (Tx) and Receiver (Rx) IP blocks are designed in the UMC 180 nm CMOS technology as component of the readout ASIC for the muon chambers (MUCH) of the Compressed Baryonic Matter (CBM) experiment at FAIR (Darmstadt, Germany). These blocks are a prototype of the physical layer of the e-link interface that is used for ASIC-GBTx connection. The experimental results at 320 Mbit/s are presented.

Design and analysis of high-spectral resolution lidar discriminator

An accurate aerosol optical property can be obtained by a high spectral resolution lidar (HSRL) technique, which employs a narrow spectral filter to suppress Mie scattering in the lidar return signal. The ability for filter to suppress Rayleigh scattering is critical for the HSRL. In the HSRL system, Rayleigh scattering signal is obtained and aerosol scattering is suppressed at least by a factor of 10-5 through using the narrow filter. Usually, an atomic absorption filter can reach this level. While, the gaseous absorption lines do not exist at many convenient laser wavelengths, thus restricting the development of multi-wavelength HSRL instrument. A new and practical filtering method is proposed to realize the precise detection of atmospheric optical parameters by using the reflection field of Fabry-Perot (FP) interferometer. An optical splitting system with high spectral resolution is designed and its spectral characteristics are analyzed. Based on the characteristic of hyper-spectral lidar detection signal, the variations of spectral separation ratio and Rayleigh signal transmittance with reflectivity and cavity length are discussed. Spectral separation ratio is the transmittance ratio of aerosol scattering signal to molecular scattering signal through the spectral filter. With the increases of FP cavity length and surface reflectivity, the spectral separation ratio decreases and the Rayleigh signal transmission increases. The high spectral separation ratio and Rayleigh signal transmittance can be achieved by the reflection field of FP interferometer when the FP cavity length and reflectivity parameter can be chosen reasonably. We design an FP interferometer with a cavity length of 36 mm and reflectivity of 0.4. Its spectral separation ratio is affected by the echo divergence and incidence angle. The spectral separation ratio keeps unchanged when the beam divergence angle is within 3 mrad and the incident angle of the beam is within 0.5 mrad. In addition, a simulation analysis model is established based on the error propagation. An observed actual Mie-scattering profile is used for analyzing the errors. Moreover, the influences of the divergence angle and the incident angle of the echo beam on detection results are also discussed. The results show that the proposed FP interferometer can achieve fine spectral separation of Mie and Rayleigh scattering signal, and the error of detection result is not sensitive to laser divergence angle. Fine aerosol optical parameters can be achieved when the divergence and incidence angles are controlled within 10 mrad and 1.5 mrad, respectively.

Highly sensitive aptasensor based on synergetic catalysis activity of MoS2-Au-HE composite using cDNA-Au-GOD for signal amplification

Single or few-layer nanosheets of MoS2 (MoS2 nanosheets) and a composite composed of MoS2 nanosheets, Au nanoparticles (AuNPs) and hemin (HE) (denoted as MoS2-Au-HE) were prepared. The composites possessed high synergetic catalysis activity towards the electroreduction of hydrogen peroxide. Furthermore, glucose oxidase (GOD) and AuNPs were used as marker of the complementary DNA (cDNA) strand of kanamycin aptamer to prepare a conjugate (reffered as cDNA-Au-GOD) that was designed as the signal probe. Both cDNA-Au-GOD and MoS2-Au-HE were applied to fabricate aptasensor for kanamycin. MoS2-Au-HE acted as solid platform for kanamycin aptamer and signal transmitters. AuNPs were employed as the supporter of cDNA and GOD which catalyze dissolved oxygen to produce hydrogen peroxide in the presence of glucose. Then cathodic peak current of H2O2 was recorded by differential pulse voltammetry (DPV). The electrochemical reduction of H2O2 was catalyzed by MoS2-Au-HE that was modified onto the surface of a glassy carbon electrode (GCE). The cathodic peak current of H2O2 was highly linearly decreased with an increase of kanamycin concentrations from 1.0ng/L to 1.0×105ng/L, with a detection limit of 0.8ng/L. This aptasensor can be used to detect kanamycin in milk with high specificity, sensitivity and selectivity.

Fluorescence-based rapid measurement of sphingosine-1-phosphate transport activity in erythrocytes

Sphingosine-1-phosphate (S1P) is present in the blood plasma and acts as a pivotal intercellular signal transmitter in the immune system by recruiting lymphocytes from the thymus and secondary lymphoid tissues. The plasma S1P concentration is maintained by the supply of S1P from erythrocytes. Previously, we showed that S1P release from erythrocytes is mediated by an ATP-dependent transporter. In this study, we attempted to establish a rapid and reliable method for measuring the S1P transport activity in erythrocytes by using a fluorescent S1P analog, 7-nitro-2-1,3-benzoxadiazol-4-yl (NBD)-labeled S1P. NBD-S1P was released from erythrocytes in a time-dependent manner. The NBD-S1P release was reduced after exposure to glyburide, which is an inhibitor of the S1P transporter in erythrocytes. Moreover, the release of NBD-S1P and S1P from erythrocytes was competitively inhibited by intracellular S1P and NBD-S1P, respectively. These results showed that the erythrocyte S1P transporter exports NBD-S1P. We optimized the sample-preparation conditions and lipid extraction to increase the sensitivity of the assay. Furthermore, we successfully measured NBD-S1P release without lipid extraction by decreasing the concentration of BSA in the assay buffer to 0.1%. This method will be useful for the high-throughput screening of S1P transporter inhibitors using conventional fluorometers.

Effect of the variation of the gating system on the magnetic properties of injection molded pole-oriented rings

Abstract The demand for contactless and wear-free sensor systems for the measurement of different physical values, such as angle, position, or speed has increased over the past years and opened up new application areas for magnetically sensitive sensors. Polymer bonded magnets can be used as signal transmitters in these sensor applications. In general, a high precision and good repeatability of the magnetic field is required, whereas in particular, a high peak flux density and accurate pole length of each pole is demanded for precise measurement. These polymer bonded magnets can be produced economically using the injection molding process with an integrated magnetization of the particles, such that a second magnetization step is unnecessary. This article addresses the influences of the gating system on the magnetic properties of multipolar bonded rings. Further, the particle orientation as well as filler content at different locations, and along the pathway are investigated. It was evaluated that the gating system significantly influences the pole length accuracy, as well as the peak flux density. However, differences in the filler orientation and content cannot be analyzed quantitatively.