To see the other types of publications on this topic, follow the link: Probe materiale.
Journal articles on the topic 'Probe materiale'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Probe materiale.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Odagiu, Iurie. "Colectarea mostrelor pentru cercetare comparativă: aspecte procesuale și de tactică criminalistică." LEGEA ŞI VIAŢA=LAW AND LIFE=ЗАКОН И ЖИЗНЬ . 4, 2024 (February 26, 2025): 40–52. https://doi.org/10.5281/zenodo.14930166.
Full textAbstract:
Articolul se referă la importanța mostrelor pentru cercetarea comparativă în cadrul procesului penal, subliniind rolul acestora în identificarea persoanelor și obiectelor implicate în infracțiuni. Mostrele sunt definite ca obiecte utilizate pentru compararea cu probele materiale, având scopul de a stabili legătura între suspect și fapta comisă. Deși nu sunt probe materiale în sensul tradițional, mostrele au un statut procesual independent și contribuie semnificativ la clarificarea circumstanțelor cazului. În articol se evidențiază distincția între mostre și probe materiale, subliniind că primele nu sunt direct legate de infracțiune, dar servesc ca instrumente de identificare. Participarea specialiștilor la procesul de colectare a mostrelor este esențială, în special pentru cele biologice, deoarece aceștia pot preveni erorile și asigura calitatea mostrelor. Procesul de obținere a mostrelor se desfășoară în trei etape: pregătirea, obținerea directă și fixarea rezultatelor. Fiecare etapă necesită o planificare atentă și respectarea cerințelor legale și tehnice.
2
Simion, Corina Anca, Maria Loredana Marin, Elena Alexandra Ispas, Cristian Mǎnǎilescu, Alexandru Rǎzvan Petre, and Eugen S. Teodor. "Datarea radiocarbon a unor probe de lemn şi derivaţi din lemn, ca urmare a unor tratamente termice. Un punct de vedere arheometric asupra unor eşantioane de la Mǎguricea Branului." Cercetări Arheologice 30, no. 2 (2023): 725–36. http://dx.doi.org/10.46535/ca.30.2.18.
Full textAbstract:
Datarea radiocarbon prin metoda spectrometriei de masǎ cu ioni acceleraţi AMS, folositǎ din 2012 la IFIN-HH Mǎgurele, a oferit recent cadrul ştiinţific pentru un studiu interdisciplinar, atât din punct de vedere arheologic cât şi arheometric, aplicat unor materiale din lemn sau derivaţi ai lemnului. Primele rezultate radiocarbon calibrate obţinute pe şase eşantioane prelevate la Mǎguricea Branului în 2021 au plasat majoritatea probelor într-un interval în jurul secolului al XIII-lea, unele diferenţe putând fi explicate pe baza unor parametri ce sunt prezentaţi în acest articol. Cele patru probe similare suplimentare rezultate din campania 2022 au oferit date radiocarbon calibrate foarte diferite de estimǎri, dar şi faţǎ de cele anterioare. Deşi aceste probe au justificat dezvoltarea în laborator a unei metode noi de pre-tratare, pentru „lemn carbonificat”, unele rezultate nu au putut fi explicate din punct de vedere tehnic prin încadrarea în cei trei parametri: terminus post quem, time-width, apparent ages, aplicabili materialelor din lemn şi derivaţi, şi deci nu au putut oferi date relevante din punct de vedere arheologic. Lucrarea poate fi de interes pentru arheologii care folosesc probe de lemn pentru datarea AMS.
3
HASEGAWA, SHUJI, ICHIRO SHIRAKI, FUHITO TANABE, et al. "ELECTRICAL CONDUCTION THROUGH SURFACE SUPERSTRUCTURES MEASURED BY MICROSCOPIC FOUR-POINT PROBES." Surface Review and Letters 10, no. 06 (2003): 963–80. http://dx.doi.org/10.1142/s0218625x03005736.
Full textAbstract:
For in-situ measurements of the local electrical conductivity of well-defined crystal surfaces in ultrahigh vacuum, we have developed two kinds of microscopic four-point probe methods. One involves a "four-tip STM prober," in which four independently driven tips of a scanning tunneling microscope (STM) are used for measurements of four-point probe conductivity. The probe spacing can be changed from 500 nm to 1 mm. The other method involves monolithic micro-four-point probes, fabricated on silicon chips, whose probe spacing is fixed around several μm. These probes are installed in scanning-electron-microscopy/electron-diffraction chambers, in which the structures of sample surfaces and probe positions are observed in situ. The probes can be positioned precisely on aimed areas on the sample with the aid of piezoactuators. By the use of these machines, the surface sensitivity in conductivity measurements has been greatly enhanced compared with the macroscopic four-point probe method. Then the conduction through the topmost atomic layers (surface-state conductivity) and the influence of atomic steps on conductivity can be directly measured.
4
Ramadi, Khalil B., and Michael J. Cima. "Materials and Devices for Micro-invasive Neural Interfacing." MRS Advances 4, no. 51-52 (2019): 2805–16. http://dx.doi.org/10.1557/adv.2019.424.
Full textAbstract:
ABSTRACTThere is widespread research and popular interest in developing micro-invasive neural interfacing modalities. An increasing variety of probes have been developed and reported in the literature. Newer, smaller probes show significant benefit over larger ones in reducing tissue damage and scarring. A different set of obstacles arise, however, as probes become smaller. These include reliable insertion and robustness. This review articulates the impact of various design parameters (material, geometry, size) on probe insertion mechanisms, chronic viability, and glial scarring. We highlight various emerging technologies utilizing novel form factors including micron-scale interfaces and bio-inspired designs for probe insertion and steering.
5
GÖRGÜN, Emre. "Investigation of the Effect of Ultrasonic Inspection Probe Diameters on Impact Echo Value." Karadeniz Fen Bilimleri Dergisi 12, no. 1 (2022): 381–89. http://dx.doi.org/10.31466/kfbd.1077386.
Full textAbstract:
The aim of this study is to investigate the relationship between the pulse echo value of the probes used in the ultrasonic examination method. Ultrasonic inspection method is known as one of the non-destructive inspection methods. Thanks to this method, discontinuities in the material can be detected without damaging the material to be examined. It works with the principle of sending the sound waves produced by piezoelectric materials to the material surface and reading the sound waves coming reversibly. As the general working principle, sound frequencies are used in the ranges that the human ear cannot hear. These frequency values vary according to the structure of the material and the environment to be examined, but generally vary between 1MHz and 4MHz. In our study, train wheels were preferred as material. Train wheels are produced from medium carbon steel material by forging method. Inspections of train wheels, which are exposed to dynamic stresses during operation, are of great importance. The method of drilling holes on the train wheels with 3mm artificial errors were created. Inspection was carried out with total probes with 3 different diameters and 3 different frequency values on the train wheels on which artificial defects were found. A spring mechanism has been prepared for the probes to contact the material surface with the same pressure force. Experimental groups and a data set was created of 9 tests were carried out with 6 different. The sound waves given from the probes were recorded as db unit. Although the frequency of the probes is seen as the basic parameter in the selection of probes in the literature, it has been observed that different probe diameters have an effect on the inspection sensitivity. IBk algorithm was used to determine the relationship between probe diameters and incoming sound waves. This algorithm is based on the principle of classifying objects based on the closest training examples in the feature space. In the model made using the IBk algorithm, a high correlation of 89% was found in the probe diameter and pulse echo value. This value is important in terms of showing the relationship between the probe diameters, which cannot be considered as the main parameter, and the pulse echo value.
6
Sun, Chuang, Yang Zhao, Xian De Yue, and Xin Lin Xia. "Sensitivity Analysis of Sensor Probe for Low Thermal Diffusivity Properties Measurement." Applied Mechanics and Materials 441 (December 2013): 364–67. http://dx.doi.org/10.4028/www.scientific.net/amm.441.364.
Full textAbstract:
Single probe and dual probes are always taken adopt to measure the material's thermal conductivity and thermal diffusivity. The measurement principle of the two kinds of probes is different and introduced in this article. Taken the material which has low thermal diffusivity for example, the single probe and dual probes are compared by the calculation accuracy and temperature response sensitivity. Numerical simulation results show that, under the same conditions, the thermal properties obtained by the dual probes are closer to the true value for the test material, but single probe has more sensitive at temperature response.
7
Wang, Zheng, Ji Ma, Changlin Li, and Haichang Zhang. "Conjugated Aggregation-Induced Fluorescent Materials for Biofluorescent Probes: A Review." Biosensors 13, no. 2 (2023): 159. http://dx.doi.org/10.3390/bios13020159.
Full textAbstract:
The common fluorescent conjugated materials present weak or quenching luminescent phenomena in the solid or aggregate state (ACQ), which limits their applications in medicine and biology. In the last two decades, certain materials, named aggregation-induced emission (AIE) fluorescent materials, have exhibited strong luminescent properties in the aggregate state, which can overcome the ACQ phenomenon. Due to their intrinsic properties, the AIE materials have been successfully used in biolabeling, where they can not only detect the species of ions and their concentrations in organisms, but can also monitor the organisms’ physiological activity. In addition, these kinds of materials often present non-biological toxicity. Thus, AIE materials have become some of the most popular biofluorescent probe materials and are attracting more and more attention. This field is still in its early infancy, and several open challenges urgently need to be addressed, such as the materials’ biocompatibility, metabolism, and so on. Designing a high-performance AIE material for biofluorescent probes is still challenging. In this review, based on the molecular design concept, various AIE materials with functional groups in the biofluorescent probes are introduced, including tetrastyrene materials, distilbene anthracene materials, triphenylamine materials, and hexaphenylsilole materials. In addition, according to the molecular system design strategy, the donor–acceptor (D-A) system and hydrogen-bonding AIE materials used as biofluorescent probes are reviewed. Finally, the biofluorescent probe design concept and potential evolution trends are discussed. The final goal is to outline a theoretical scaffold for the design of high-performance AIE biofluorescent probes that can at the same time further the development of the applications of AIE-based biofluorescent probes.
8
Chang, Ming Kuen, Hua Sui Sun, and Jyun Cang Ciou. "Applying Ultrasonic Testing to Detect Hole Defect Near the Surface." Advanced Materials Research 194-196 (February 2011): 2054–57. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.2054.
Full textAbstract:
During materials manufacturing process will cause defects occasionally, if the defects located at near surface of material where the testing is not easy to implement. When the defects was stress by outside loading, it will grow up even become fracture, if the material apply ultrasonic testing then can increase material security to ensure structural safety. Practice material defect shape is variable and need complex product procedure. In this study, using wire cutting method to make practice defects specimen instead of the real flaws material, the specimen was made of medium carbon steel and aluminum alloy, defects away from the surface is 2-4 mm, defect shape including round shape hole and square shape hole, bore diameter was 1-3 mm. Using ultrasonic straight beam probe and delay line probe, straight beam probe have 5 MHz and 10 MHz frequency, and delay line probe have 5 MHz, 10 MHz frequency too, finally, compared the relationship between the accuracy and depth of flaws, pore size, flaw shape, material of specimen. Research results demonstrate that accuracy didn’t relate to the flaw shape, flaw size, depth of flaws and material of specimen. The accurately of 10 MHz delayed probe shown the depth of flaw smaller, the measurement than other probes.
9
Uhrmacher, Michael. "Can PAC Measurements be Used to Investigate Defects in Nano-Structures?" Defect and Diffusion Forum 311 (March 2011): 105–33. http://dx.doi.org/10.4028/www.scientific.net/ddf.311.105.
Full textAbstract:
The PAC-technique always claims to test the micro-surrounding of the probe atoms. Typically, the samples are macroscopic and more or less homogeneous and there is no debate about the usefulness of the method: substitutional sites, trapped vacancies or phase transitions are easily seen. Even the PAC-“fingerprint” of an amorphous material is known. In case of inhomogeneous samples, perhaps made out of different constituents, the question arises whether the PAC can contribute to the understanding of such materials or not. The article will show the different ways to introduce the probe atoms into the samples and discuss then the influence of these histories on the final site of the probe in the sample. In general, diffusion tends to place the probes into grain boundaries, whereas implantation reaches the bulk. This becomes important for nano-materials with their high fraction of internal surfaces. As a second, important difference for possible experiments the spatial distribution of the probes has to be considered. Implantation leads to a Gaussian shaped depth distribution of the probes. This corresponds – in a certain region – to a 3-dimensional distribution of probes in the sample, used e.g. when doping a semiconductor. In the production of special sensors (which apply e.g. the giant magnetoresistance (GMR) effect) one needs a different package, thin films (1-2 mono-layers). To apply PAC here, the probes have to be introduced during the fabrication of such a sensor. In these cases the probes have to be placed within a plane of nano-scale thickness.
10
Schneider, Jeffrey M., and Dante Fratta. "Time-domain reflectometry — parametric study for the evaluation of physical properties in soils." Canadian Geotechnical Journal 46, no. 7 (2009): 753–67. http://dx.doi.org/10.1139/t09-018.
Full textAbstract:
Time-domain reflectometry (TDR) has become a commonly used method in geotechnical engineering to measure the volumetric water content and electrical conductivity in soils. The ability of TDR to accurately determine soil properties depends on the proper understanding of the parameters that affect the propagation of an electromagnetic pulse along the TDR waveguide. The purpose of this paper is to document a parametric study and analyses aimed at gaining a better understanding of TDR measurements and to evaluate the limits in the measurement technique. A parametric study on TDR signals was performed by determining the effects of heterogeneities in the dielectric permittivity, conductivity, and magnetic permeability in sand and gravel specimens. Impedance differences in the probe head were found to contribute to inaccurate travel-time measurements that affect material dielectric permittivity calculations. The calculated relative dielectric permittivity may also be dependent on local changes in porosity near the probes. Tests performed in layered materials indicate that TDR can be used to find abrupt changes in material permittivity, such as the depth to saturation. However, problems in the determination of capillary rise may contribute to uncertainties in the proper determination of permittivity and thicknesses of layers. The presence of ferromagnetic materials was found to change the measured electromagnetic wave velocity. However, the properties of materials outside the radius defined by the probes and beneath the probes minimally affected the TDR results in the two-rod probe used.
11
Demura, Kazuya, Satoru Hirose, and Tohru Ihara. "Effect of Material Type and Tip Radius of AFM Probes on Nanosheets Groove Machining Accuracy." Advanced Materials Research 126-128 (August 2010): 835–42. http://dx.doi.org/10.4028/www.scientific.net/amr.126-128.835.
Full textAbstract:
This paper presents results of groove machining of potassium niobate nanosheets using an atomic force microscope (AFM). Groove machining operations are performed using recently developed diamond coating (DC) and super sharp silicon (sss) probes. The results obtained using these probes are compared to results obtained using a conventional silicon (Si) probe in order to examine the effects of the material type and the tip radius of the AFM probe on groove machining accuracy.
12
Wu, Meixian, Dongli Zhang, and Chuanglong Wang. "A new eddy current probe with deep penetrating field trajectories for the inspection of deep cracks in metal materials." Insight - Non-Destructive Testing and Condition Monitoring 62, no. 7 (2020): 402–7. http://dx.doi.org/10.1784/insi.2020.62.7.402.
Full textAbstract:
The detectability of deep cracks in metal materials is an important performance index of eddy current probes. However, because of the limitations of the skin effect of eddy currents, it is difficult to obtain deep crack information in materials using an ordinary probe. This paper proposes a new probe with deep penetrating field trajectories for the inspection of deep cracks. To optimise its performance, contributions of the coil radius, the pick-up position and the excitation frequency to penetration depth of eddy currents are studied. The results show that the capability of the new probe in the inspection of deep cracks is greatly improved when compared to traditional pancake probes.
13
Kalinin, Sergei. "Measuring Conductivity With Scanning Probe Microscopes." Microscopy Today 10, no. 2 (2002): 26–27. http://dx.doi.org/10.1017/s1551929500057837.
Full textAbstract:
There are two kinds of conductivity measurements possible with scanning probe microscopy (SPM). In the first case, the specific resistance of material directly below the tip is probed. In the second case, SPM probes local potential induced by the lateral current applied through macroscopic contacts, thus providing the information on the mesoscopic transport properties of the sample.The first set of techniques is invariably based on measuring tip-surface current in contact or intermittent tapping mode. If the tip-surface contact resistance is small (good contact), the current will be limited by the spreading resistance of the sample from which specific resistance can be calculated, assuming that the contact area is known.
14
Xie, Zipeng, Yongjie Li, Liguo Sun, Wentao Wu, Rui Cao, and Xiaohui Tao. "A Simple High-Resolution Near-Field Probe for Microwave Non-Destructive Test and Imaging." Sensors 20, no. 9 (2020): 2670. http://dx.doi.org/10.3390/s20092670.
Full textAbstract:
Non-destructive tests working at lower microwave frequencies have large advantages of dielectric material penetrability, lower equipment cost, and lower implementation complexity. However, the resolution will become worse as the work frequencies become lower. Relying on designing the structure of high field confinement, this study realizes a simple complementary spiral resonators (CSRs)-based near-field probe for microwave non-destructive testing (NDT) and imaging around 390 MHz (λ = 769 mm) whereby very high resolution (λ/308, 2.5 mm) is achieved. By applying an ingenious structure where a short microstrip is connected to a microstrip ring to feed the CSR, the probe, that is a single-port microwave planar circuit, does not need any extra matching circuits, which has more application potential in sensor arraying compared with other microwave probes. The variation of the electric field distribution with the standoff distance (SOD) between the material under test and the probe are analyzed to reveal the operation mechanisms behind the improved sensitivity and resolution of the proposed probe. Besides, the detection abilities of the tiny defects in metal and non-metal materials are demonstrated by the related experiments. The smallest detectable crack and via in the non-metal materials and the metal materials are of a λ/1538 (0.5 mm) width, a λ/513 (1.5 mm) diameter, a λ/3846 (0.2 mm) width and a λ/513 (1.5 mm) diameter, respectively. Moreover, to further evaluate the performance of the proposed probe, the defects under skin layer in the multilayer composite materials and the defects under corrosion in the carbon steel are inspected and imaged. Due to lower work frequency, high resolution, outstanding detection abilities of tiny defects, and large potentials in sensor arraying, the proposed probe would be a good candidate for microwave NDT and imaging.
15
Shahriari, D., J. Jodaki, V. Jandaghi Shahi, and J. Darban Falak. "Development of an Expert Engineering Module for Determination of Ultrasonic Probe Position on the Weld Joint of Plate." Advanced Materials Research 83-86 (December 2009): 1306–14. http://dx.doi.org/10.4028/www.scientific.net/amr.83-86.1306.
Full textAbstract:
Ultrasound based inspection techniques are used extensively throughout industry for detection of flaws in engineering materials. The range and variety of imperfections encountered is large and critical assessment of location, size, orientation and type is often difficult. The research presented in this paper has resulted in a knowledge-based engineering module, which was developed software for determining ultrasonic probe location precisely and detecting of the welded sections completely. The criteria for diagnosing these positions, which have been classified into different groups, included in type of material, thickness, geometry of welded section, couplant material, angle probes and etc. The expert system can display the limits that probe must be moved which caused an inspection welded section thoroughly. This study was conducted using three samples including different materials with V groove welded sections for verifying this expert system. Finally this module is very suitable in Q.C. labs and different industries for detection of flaws.
16
Machado, Miguel A. "Eddy Currents Probe Design for NDT Applications: A Review." Sensors 24, no. 17 (2024): 5819. http://dx.doi.org/10.3390/s24175819.
Full textAbstract:
Eddy current testing (ECT) is a crucial non-destructive testing (NDT) technique extensively used across various industries to detect surface and sub-surface defects in conductive materials. This review explores the latest advancements and methodologies in the design of eddy current probes, emphasizing their application in diverse industrial contexts such as aerospace, automotive, energy, and electronics. It explores the fundamental principles of ECT, examining how eddy currents interact with material defects to provide valuable insights into material integrity. The integration of numerical simulations, particularly through the Finite Element Method (FEM), has emerged as a transformative approach, enabling the precise modeling of electromagnetic interactions and optimizing probe configurations. Innovative probe designs, including multiple coil configurations, have significantly enhanced defect detection capabilities. Despite these advancements, challenges remain, particularly in calibration and sensitivity to environmental conditions. This comprehensive overview highlights the evolving landscape of ECT probe design, aiming to provide researchers and practitioners with a detailed understanding of current trends in this dynamic field.
17
Abetkovskaia, S. O., S. A. Chizhik, and Yu Guangbin. "Tapping mode of an atomic force microscope with a probe cantilever of a low spring constant." Proceedings of the National Academy of Sciences of Belarus. Physical-technical series 70, no. 1 (2025): 57–68. https://doi.org/10.29235/1561-8358-2025-70-1-57-68.
Full textAbstract:
The work presents mathematical simulation results of tapping interaction of an atomic force microscope (AFM) probe with low (0.1 N/m) spring constant of its cantilever with samples of materials with the Young moduli of 0.01; 0.1; 1; 10 GPa under varying the characterizing samples surface energy Hamaker constant, oscillation amplitude of a piezoelectric element, and also the quality factor of the probe. The Johnson–Kendall–Roberts model was used to describe contact between the probe and a sample. Non-contact interaction was taken into account using the Lennard–Jones potential. It was defined that at lower values of the Hamaker constant, higher quality factor of the AFM probe, and higher oscillation amplitude of the piezoelectric generator, conditions for transition from mixed mode of probe–sample interaction, which is undesirable for obtaining AFM images, to purely elastic mode occur. However, for materials with the Young moduli of 1 and 10 GPa abrupt changes in probe characteristics occur, which are associated not with influence of surface adhesion, but with late onset steady-state mode of probe oscillation. In order to avoid non-steady state oscillation of the probe in tapping AFM mode, it is proposed to use probes with higher spring constant to obtain high-quality AFM images of material surfaces with the Young modulus of 1 GPa and higher.
18
Kornev, K. G., X. Ren, and Y. Dzenis. "Controlling Liquid Release by Compressing Electrospun Nanowebs." Journal of Engineered Fibers and Fabrics 4, no. 3 (2009): 155892500900400. http://dx.doi.org/10.1177/155892500900400302.
Full textAbstract:
Electrospun nanowebs with pores ranging from nanometers to micrometers, constitute new materials with enhanced absorbency and ability to retain liquids in pores for a long period of time. These materials can be used as nanofluidic probes collecting minute amount of liquids. However, extraction of liquids from nanofibrous materials presents a problem: menisci in the interfiber pores create very high suction pressure which holds the liquid inside the material. This problem can be resolved if the probe is completely filled with the liquid: menisci at the probe edges become flat to establish a pressure equilibrium with the atmosphere. Therefore, one can take advantage of the nanoweb softness and extract liquid by mechanically deforming the nanowebs. We show that the liquid-saturated nanowebs follow the Voigt-type rheology upon loading. We theoretically explain this behavior and derive the relations between the Voigt phenomenological parameters, nanoweb permeability and compression modulus. We show that the limiting deformations follow the Hooke's law which assumes linear relation between the extracted volume of liquid and the applied load. Because of this predictable behavior, the nanoweb probes can be engineered to release minute liquid doses upon compression. The developed experimental methodology can be used for characterization of nanostructured materials which otherwise impossible to analyze by using the existing instruments.
19
WU Simin, 吴思敏, 张博涵 ZHANG Bohan, 郑彬 ZHENG Bin та 季敏标 JI Minbiao. "泵浦-探测显微镜在生物医学和材料科学领域的应用（特邀）". ACTA PHOTONICA SINICA 50, № 8 (2021): 0850211. http://dx.doi.org/10.3788/gzxb20215008.0850211.
Full text
20
Clark, Peter, Kate Maguire, Mattia Bulla, et al. "Probing the progenitors of Type Ia supernovae using circumstellar material interaction signatures." Monthly Notices of the Royal Astronomical Society 507, no. 3 (2021): 4367–88. http://dx.doi.org/10.1093/mnras/stab2038.
Full textAbstract:
ABSTRACT This work aims to study different probes of Type Ia supernova (SN Ia) progenitors that have been suggested to be linked to the presence of circumstellar material (CSM). In particular, we have investigated, for the first time, the link between narrow blueshifted Na i D absorption profiles and the presence and strength of the broad high-velocity Ca ii near-infrared triplet absorption features seen in SNe Ia around maximum light. With the probes exploring different distances from the SN; Na i D > 1017cm, high-velocity Ca ii features < 1015cm. For this, we have used a new intermediate-resolution X-shooter spectral sample of 15 SNe Ia. We do not identify a link between these two probes, implying either that, one (or both) is not physically related to the presence of CSM or that the occurrence of CSM at the distance explored by one probe is not linked to its presence at the distance probed by the other. However, the previously identified statistical excess in the presence of blueshifted (over redshifted) Na i D absorption is confirmed in this sample at high significance and is found to be stronger in SNe Ia hosted by late-type galaxies. This excess is difficult to explain as being from an interstellar-medium origin as has been suggested by some recent modelling, as such an origin is not expected to show a bias for blueshifted absorption. However, a circumstellar origin for these features also appears unsatisfactory based on our new results, given the lack of link between the two probes of CSM investigated.
21
Ionita, Codrina, Roman Schrittwieser, Guosheng Xu, et al. "Diamond-Coated Plasma Probes for Hot and Hazardous Plasmas." Materials 13, no. 20 (2020): 4524. http://dx.doi.org/10.3390/ma13204524.
Full textAbstract:
Plasma probes are simple and inexpensive diagnostic tools for fast measurements of relevant plasma parameters. While in earlier times being employed mainly in relatively cold laboratory plasmas, plasma probes are now routinely used even in toroidal magnetic fusion experiments, albeit only in the edge region, i.e., the so-called scrape-off layer (SOL), where temperature and density of the plasma are lower. To further avoid overheating and other damages, in medium-size tokamak (MST) probes are inserted only momentarily by probe manipulators, with usually no more than a 0.1 s per insertion during an average MST discharge of a few seconds. However, in such hot and high-density plasmas, their usage is limited due to the strong particle fluxes onto the probes and their casing which can damage the probes by sputtering and heating and by possible chemical reactions between plasma particles and the probe material. In an attempt to make probes more resilient against these detrimental effects, we tested two graphite probe heads (i.e., probe casings with probes inserted) coated with a layer of electrically isolating ultra-nano-crystalline diamond (UNCD) in the edge plasma region of the Experimental Advanced Superconducting Tokamak (EAST) in Hefei, People’s Republic of China. The probe heads, equipped with various graphite probe pins, were inserted frequently even into the deep SOL up to a distance of 15 mm inside the last closed flux surface (LCFS) in low- and high-confinement regimes (L-mode and H-mode). Here, we concentrate on results most relevant for the ability to protect the graphite probe casings by UNCD against harmful effects from the plasma. We found that the UNCD coating also prevented almost completely the sputtering of graphite from the probe casings and thereby the subsequent risk of re-deposition on the boron nitride isolations between probe pins and probe casings by a layer of conductive graphite. After numerous insertions into the SOL, first signs of detachment of the UNCD layer were noticed.
22
Xu, Ke, and Yuzhe Liu. "Studies of probe tip materials by atomic force microscopy: a review." Beilstein Journal of Nanotechnology 13 (November 3, 2022): 1256–67. http://dx.doi.org/10.3762/bjnano.13.104.
Full textAbstract:
As a tool that can test insulators' surface morphology and properties, the performance index of atomic force microscope (AFM) probes is the most critical factor in determining the resolution of microscopy, and the performance of probes varies in various modes and application requirements. This paper reviews the latest research results in metal, carbon nanotube, and colloidal probes and reviews their related methods and techniques, analyses the advantages and disadvantages of the improved probes compared with ordinary probes by comparing the differences in spatial resolution, sensitivity, imaging, and other performance aspects, and finally provides an outlook on the future development of AFM probes. This paper promotes the development of AFM probes in the direction of new probes and further promotes the broader and deeper application of scanning probe microscope (SPM).
23
Kilias, Antje, Yu-Tao Lee, Ulrich P. Froriep, et al. "Intracortical probe arrays with silicon backbone and microelectrodes on thin polyimide wings enable long-term stable recordings in vivo." Journal of Neural Engineering 18, no. 6 (2021): 066026. http://dx.doi.org/10.1088/1741-2552/ac39b7.
Full textAbstract:
Abstract Objective. Recording and stimulating neuronal activity across different brain regions requires interfacing at multiple sites using dedicated tools while tissue reactions at the recording sites often prevent their successful long-term application. This implies the technological challenge of developing complex probe geometries while keeping the overall footprint minimal, and of selecting materials compatible with neural tissue. While the potential of soft materials in reducing tissue response is uncontested, the implantation of these materials is often limited to reliably target neuronal structures across large brain volumes. Approach. We report on the development of a new multi-electrode array exploiting the advantages of soft and stiff materials by combining 7-µm-thin polyimide wings carrying platinum electrodes with a silicon backbone enabling a safe probe implantation. The probe fabrication applies microsystems technologies in combination with a temporal wafer fixation method for rear side processing, i.e. grinding and deep reactive ion etching, of slender probe shanks and electrode wings. The wing-type neural probes are chronically implanted into the entorhinal-hippocampal formation in the mouse for in vivo recordings of freely behaving animals. Main results. Probes comprising the novel wing-type electrodes have been realized and characterized in view of their electrical performance and insertion capability. Chronic electrophysiological in vivo recordings of the entorhinal-hippocampal network in the mouse of up to 104 days demonstrated a stable yield of channels containing identifiable multi-unit and single-unit activity outperforming probes with electrodes residing on a Si backbone. Significance. The innovative fabrication process using a process compatible, temporary wafer bonding allowed to realize new Michigan-style probe arrays. The wing-type probe design enables a precise probe insertion into brain tissue and long-term stable recordings of unit activity due to the application of a stable backbone and 7-µm-thin probe wings provoking locally a minimal tissue response and protruding from the glial scare of the backbone.
24
Wang, Zhankun, Yanqiu Hu, Xiaoxuan Zhou, and Yuguang Lv. "Construction of mercury ion fluorescence system in water samples and art materials and fluorescence detection method for rhodamine B derivatives." Green Processing and Synthesis 11, no. 1 (2022): 987–95. http://dx.doi.org/10.1515/gps-2022-0085.
Full textAbstract:
Abstract At present, the research on fluorescent molecular probe has become a hot topic in the field of environmental science, chemical materials, medicine, and other fields. Therefore, the detection of industrial mercury-containing wastewater (Hg2+) is of great significance. In this article, the fluorescent probe is used to detect mercury ions, and when compared with the traditional detection method, the fluorescent probe has the advantage of operation such as the effect of simplicity is evident. The experiments first synthesized rhodamine B derivatives and then the synthesized rhodamine B derivative fluorescent molecular probes were constructed and used to detect the mercury ions in water sample and oil paints. It was demonstrated that rhodamine B-derived probes have been constructed by UV and fluorescence spectroscopy. The different metal ions and rhodamine B-derived fluorescent molecular probes were compounded, resulting in the appearance of fluorescence peak centered at 583 nm only after the addition of metallic mercury ions with almost no response from other ions. The mercury ion rhodamine B derivative is more responsive to metallic mercury ions.
25
Freitas, Teresa Stingl, Ana Sofia Guimarães, Staf Roels, Vasco Peixoto de Freitas, and Andrea Cataldo. "Is the Time-Domain Reflectometry (TDR) Technique Suitable for Moisture Content Measurement in Low-Porosity Building Materials?" Sustainability 12, no. 19 (2020): 7855. http://dx.doi.org/10.3390/su12197855.
Full textAbstract:
Measuring moisture content in building materials is essential both for professional practice and for research. However, this is a very complex task, especially when long-term minor destructive measurements are desired. The time-domain reflectometry (TDR) technique is commonly used for soil moisture measurements, but its application in construction materials is considered a relatively new method, particularly for low-porosity building materials. The major obstacles to its current use in construction materials are (1) the difficulty of ensuring good contact between the TDR probe and the material, and (2) the lack of appropriate conversion functions between the measured relative permittivity and the moisture content of building materials. This paper intends to contribute to overcoming these difficulties by explaining in detail all the required steps to monitor moisture content in real-scale limestone walls. For that, a device is presented to guarantee the correct installation of the TDR probes on the walls, and a calibration procedure through the gravimetric method is proposed to avoid the use of an unsuitable calibration function developed for soil moisture measurements. In addition, the importance of the individual probe calibration is discussed, as well as TDR advantages and disadvantages for construction materials. The results obtained so far reveal that the TDR technique is suitable to detect moisture content variations in limestone, which is a low-porosity building material.
26
Tiefenbacher, Patrick, Norbert I. Kömle, Wolfgang Macher, and Günter Kargl. "Influence of probe geometry on measurement results of non-ideal thermal conductivity sensors." Geoscientific Instrumentation, Methods and Data Systems 5, no. 2 (2016): 383–401. http://dx.doi.org/10.5194/gi-5-383-2016.
Full textAbstract:
Abstract. The thermal properties of the surface and subsurface layers of planets and planetary objects yield important information that allows us to better understand the thermal evolution of the body itself and its interactions with the environment. Various planetary bodies of our Solar System are covered by so-called regolith, a granular and porous material. On such planetary bodies the dominant heat transfer mechanism is heat conduction via IR radiation and contact points between particles. In this case the energy balance is mainly controlled by the effective thermal conductivity of the top surface layers, which can be directly measured by thermal conductivity probes. A traditionally used method for measuring the thermal conductivity of solid materials is the needle-probe method. Such probes consist of thin steel needles with an embedded heating wire and temperature sensors. For the evaluation of the thermal conductivity of a specific material the temperature change with time is determined by heating a resistance wire with a well-defined electrical current flowing through it and simultaneously measuring the temperature increase inside the probe over a certain time. For thin needle probes with a large length-to-diameter ratio it is mathematically easy to derive the thermal conductivity, while this is not so straightforward for more rugged probes with a larger diameter and thus a smaller length-to-diameter ratio. Due to the geometry of the standard thin needle probes they are mechanically weak and subject to bending when driven into a soil. Therefore, using them for planetary missions can be problematic. In this paper the thermal conductivity values determined by measurements with two non-ideal, ruggedized thermal conductivity sensors, which only differ in length, are compared to each other. Since the theory describing the temperature response of non-ideal sensors is highly complicated, those sensors were calibrated with an ideal reference sensor in various solid and granular materials. The calibration procedure and the results are described in this work.
27
Cheng, Zhao, Lei Zheng, Fei Liang, Hao He, Hao Xu, and Long Pang. "Rhodamine probes for Fe3+: theoretical calculation for specific recognition and instant fluorescent bioimaging." Future Medicinal Chemistry 11, no. 15 (2019): 1859–69. http://dx.doi.org/10.4155/fmc-2019-0077.
Full textAbstract:
Aim: To overcome the existing difficulty in distinguishing Fe(III) from Fe(II), rhodamine-containing Fe3+ probes, giving off different fluorescence responses to ferric and ferrous ions, were synthesized. Materials & methods: Color change in Fe3+ recognition, accompanying spirolactam opening–closing, could be used for ‘naked-eye’ detection. Theoretical calculations revealed the possible Fe3+-probe combination mechanism. Results: Apart from the probes’ specific response toward Fe3+, the Fe3+-probe demonstrated highly quantitative relationships in fluorescence titration, instant labeling and dynamic tracking of intracellular Fe3+ in bioimaging. Conclusion: Cytotoxity and bioimaging in living L929 suggested the probes’ future applications as real-time detection methods for Fe3+ in clinical diagnosis. Instant and time-lapse imagings, based on fluorescence-time stability of Fe3+-probe, enables the dynamic labeling and tracking of Fe3+ in living systems.
28
Jin, Yuxin, Bingli Jiang, Huajian Song, et al. "Monophenyl luminescent material with dual-state emission and pH sensitivity for cell imaging." RSC Advances 14, no. 16 (2024): 10942–52. http://dx.doi.org/10.1039/d4ra01422g.
Full textAbstract:
A novel probe, called DMSS-AM, has been synthesized to be pH-sensitive and target lysosomes. It exhibits efficient emission in both solution and solid states, overcoming the limitations of AIE and ACQ fluorescent probes.
29
Lin, Riqiang, Jiaming Zhang, Wen Gao, et al. "A Miniature Multi-Functional Photoacoustic Probe." Micromachines 14, no. 6 (2023): 1269. http://dx.doi.org/10.3390/mi14061269.
Full textAbstract:
Photoacoustic technology is a promising tool to provide morphological and functional information in biomedical research. To enhance the imaging efficiency, the reported photoacoustic probes have been designed coaxially involving complicated optical/acoustic prisms to bypass the opaque piezoelectric layer of ultrasound transducers, but this has led to bulky probes and has hindered the applications in limited space. Though the emergence of transparent piezoelectric materials helps to save effort on the coaxial design, the reported transparent ultrasound transducers were still bulky. In this work, a miniature photoacoustic probe with an outer diameter of 4 mm was developed, in which an acoustic stack was made with a combination of transparent piezoelectric material and a gradient-index lens as a backing layer. The transparent ultrasound transducer exhibited a high center frequency of ~47 MHz and a −6 dB bandwidth of 29.4%, which could be easily assembled with a pigtailed ferrule of a single-mode fiber. The multi-functional capability of the probe was successfully validated through experiments of fluid flow sensing and photoacoustic imaging.
30
Huber, Silvia, Mariusz Wicinski, and Achim Walter Hassel. "Suitability of Various Materials for Probes in Scanning Kelvin Probe Measurements." physica status solidi (a) 215, no. 15 (2017): 1700952. http://dx.doi.org/10.1002/pssa.201700952.
Full text
31
Spychalski, Maciej, E. Fortuna-Zalesna, Joanna Zdunek, et al. "Tungsten Langmuir probes from JET-with the ITER-Like Wall: Assessment of mechanical properties by nano-indentation." Physica Scripta 96, no. 12 (2021): 124072. http://dx.doi.org/10.1088/1402-4896/ac3dbb.
Full textAbstract:
Abstract Tungsten Langmuir probes retrieved from the JET tokamak with the ITER-Like Wall (JET-ILW) after the second ILW campaign were examined by nano-indentation, microscopy and x-ray diffraction in order to determine changes in mechanical properties and phase composition. Not-exposed probe served as a reference material. Two regions were studied: (i) recrystallized region below the tip and, (ii) the lower probe structure, called ‘support structure’. A large difference between the hardness in the tip and the other region has been found: 5 GPa versus 15 GPa, respectively. The measured values of the Young’s modulus in both zones of exposed probe are at the same level of 260 GPa. From the force-displacement curves, it can be concluded that the material in the tip has a smaller range of elastic deformations compared to that characteristic for the support structure. The values obtained for the material in its initial state are consistent with the available literature data for tungsten. With x-ray diffraction and microscopy only tungsten has been detected in the probe tip. It remained clean and free from impurities and undesirable compounds, which could have a negative impact on the probes electrical properties.
32
Zanetti, Chiara, Liang Li, Rafael Di Lazaro Gaspar, et al. "Susceptibility of the Different Oxygen-Sensing Probes to Interferences in Respirometric Bacterial Assays with Complex Media." Sensors 24, no. 1 (2024): 267. http://dx.doi.org/10.3390/s24010267.
Full textAbstract:
Respirometric microbial assays are gaining popularity, but their uptake is limited by the availability of optimal O2 sensing materials and the challenge of validating assays with complex real samples. We conducted a comparative evaluation of four different O2-sensing probes based on Pt-porphyrin phosphors in respirometric bacterial assays performed on standard time-resolved fluorescence reader. The macromolecular MitoXpress, nanoparticle NanO2 and small molecule PtGlc4 and PtPEG4 probes were assessed with E. coli cells in five growth media: nutrient broth (NB), McConkey (MC), Rapid Coliform ChromoSelect (RCC), M-Lauryl lauryl sulfate (MLS), and Minerals-Modified Glutamate (MMG) media. Respiration profiles of the cells were recorded and analyzed, along with densitometry profiles and quenching studies of individual media components. This revealed several limiting factors and interferences impacting assay performance, which include probe quenched lifetime, instrument temporal resolution, inner filter effects (mainly by indicator dyes), probe binding to lipophilic components, and dynamic and static quenching by media components. The study allowed for the ranking of the probes based on their ruggedness, resilience to interferences and overall performance in respirometric bacterial assays. The ‘shielded’ probe NanO2 outperformed the established MitoXpress probe and the small molecule probes PtGlc4 and PtPEG4.
33
Li, Fu Sheng, Xiao Chu Liu, Li Yao, et al. "Research of Sensing Probe Material in Wet and Dry Soil." Advanced Materials Research 807-809 (September 2013): 1715–18. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.1715.
Full textAbstract:
Soil moisture sensor probe is the basic and key part of the automated water-saving irrigation equipment. It can measure soil moisture accurately and in real-timely, while metal probes have a serious problem of corrosion and passivation as working in the soil which is a severe environment of the soil of high humidity and complex chemical compositions. Graphite gelling of different content of graphite composite material under both wet and dry conditions, the experimental study, by testing the experimental data of its resistivity contrast to identify the proportion of the composite material of graphite content suitable for the production of a new probe.
34
Gommes, Cedric J. "Small-angle scattering and scale-dependent heterogeneity." Journal of Applied Crystallography 49, no. 4 (2016): 1162–76. http://dx.doi.org/10.1107/s1600576716007810.
Full textAbstract:
Although small-angle scattering is often discussed qualitatively in terms of material heterogeneity, when it comes to quantitative data analysis this notion becomes somehow hidden behind the concept of correlation function. In the present contribution, a quantitative measure of heterogeneity is defined, it is shown how it can be calculated from scattering data, and its structural significance for the purpose of material characterization is discussed. Conceptually, the procedure consists of using a finite probe volume to define a local average density at any point of the material; the heterogeneity is then quantitatively defined as the fluctuations of the local average density when the probe volume is moved systematically through the sample. Experimentally, it is shown that the so-defined heterogeneity can be estimated by projecting the small-angle scattering intensity onto the form factor of the chosen probe volume. Choosing probe volumes of various sizes and shapes enables one to comprehensively characterize the heterogeneity of a material over all its relevant length scales. General results are derived for asymptotically small and large probes in relation to the material surface area and integral range. It is also shown that the correlation function is equivalent to a heterogeneity calculated with a probe volume consisting of two points only. The interest of scale-dependent heterogeneity for practical data analysis is illustrated with experimental small-angle X-ray scattering patterns measured on a micro- and mesoporous material, on a gel, and on a semi-crystalline polyethylene sample. Using different types of probes to analyse a given scattering pattern enables one to focus on different structural characteristics of the material, which is particularly useful in the case of hierarchical structures.
35
Oesterschulze, E. "Novel probes for scanning probe microscopy." Applied Physics A: Materials Science & Processing 66, no. 7 (1998): S3—S9. http://dx.doi.org/10.1007/s003390051089.
Full text
36
Sporea, Ioan, Roxana Șirli, Ruxandra Mare, Alina Popescu, and Siegfried Cristian Ivașcu. "Feasibility of Transient Elastography with M and XL probes in real life." Medical Ultrasonography 18, no. 1 (2016): 7. http://dx.doi.org/10.11152/mu.2013.2066.181.xsi.
Full textAbstract:
Aim: Reliable liver stiffness measurement (RLSM) using Transient Elastography (TE) with the standard M probe are difficult to obtain in overweight (BMI≥25kg/m2) and obese (BMI>30kg/m2) patients. The aim of our paper was to assess the feasibility of TE in daily practice using both M and XL probes. Material and method: We studied retrospectively 3235 patients with chronic liver disease assessed by TE first by the M probe (standard probe – transducer frequency 3.5 MHz), and if the measurements were unreliable, with the XL probe (transducer frequency 2.5 MHz). Reliable measurements were defined as the median of 10 valid measurements with a success rate ≥ 60% and an interquartile range < 30%. Results of liver elasticity were expressed in kiloPascals (kPa). Results: RLSM by M probe were obtained in 62.2% (2015/3235) patients, and by XL probe in 1011/1220 (80%) of patients with unreliable measurements by M probe; thus we obtained RLSM in 93.5% of 3235 cases.In overweight patients we obtained RLSM in 89.9% (1039/1156) cases: in 63.1% (729) by M probe and in 26.8% (310) by XL probe. In obese patients we obtained RLSM in 83.8% (746/890): in 18.4% (164) by M probe and in 65.4% (582) by XL probe. Thus, by using both probes, RLSM were obtained in 1785 (87.2%) of overweight and obese patients. Conclusion: The feasibility of the M probe was 62.2% in our Department. Reliable measurements using M or XL probe allowed the evaluation of liver stiffness in 93.5% of cases. By using both M and XL probes, reliable LSM by TE can be obtained in the majority of obese and overweight patients (87.2%).
37
Oberdorfer, Christian, and Guido Schmitz. "On the Field Evaporation Behavior of Dielectric Materials in Three-Dimensional Atom Probe: A Numeric Simulation." Microscopy and Microanalysis 17, no. 1 (2010): 15–25. http://dx.doi.org/10.1017/s1431927610093888.
Full textAbstract:
AbstractAs a major improvement in three-dimensional (3D) atom probe, the range of applicable material classes has recently been broadened by the establishment of laser-assisted atom probes (LA-3DAP). Meanwhile, measurements of materials of low conductivity, such as dielectrics, ceramics, and semiconductors, have widely been demonstrated. However, besides different evaporation probabilities, heterogeneous dielectric properties are expected to give rise to additional artifacts in the 3D volume reconstruction on which the method is based. In this article, these conceivable artifacts are discussed based on a numeric simulation of the field evaporation. Sample tips of layer- or precipitate-type geometry are considered. It is demonstrated that dielectric materials tend to behave similarly to metals of reduced critical evaporation field.
38
Lees, Alistair J. "New Phosphorescence Probes for Monitoring the Kinetics of Thermal and Photochemical Polymerization." Engineering Plastics 6, no. 3 (1998): 147823919800600. http://dx.doi.org/10.1177/147823919800600301.
Full textAbstract:
Several organometallic complexes have recently been demonstrated to act as spectroscopic probes of kinetic changes taking place on polymer network formation. This review summarizes the recent development of these phosphorescence probe molecules in both thermal polymerization and photo-initiated processes. Polymers based on epoxy and aromatic cyanate ester thermosetting materials and epoxy and acrylate photosensitive resins are discussed. Most attention is focused on fac-ClRe(CO)3(where 4,7-Ph2-phen) (4,7-Ph2-phen = 4,7-diphenyl-1,10-phenanthroline), and on closely related complexes, as they are strongly luminescent in the visible region and appear to offer considerable promise in probe applications. These spectroscopic probes are shown to be sensitive to viscosity changes of over five orders of magnitude within the polymer network. The luminescence features of these organometallic probe complexes are compared to that of other organic probe molecules.
39
Lees, Alistair J. "New Phosphorescence Probes for Monitoring the Kinetics of Thermal and Photochemical Polymerization." Polymers and Polymer Composites 6, no. 3 (1998): 121–31. http://dx.doi.org/10.1177/096739119800600301.
Full textAbstract:
Several organometallic complexes have recently been demonstrated to act as spectroscopic probes of kinetic changes taking place on polymer network formation. This review summarizes the recent development of these phosphorescence probe molecules in both thermal polymerization and photo-initiated processes. Polymers based on epoxy and aromatic cyanate ester thermosetting materials and epoxy and acrylate photosensitive resins are discussed. Most attention is focused on fac-ClRe(CO)3(where 4,7-Ph2-phen) (4,7-Ph2-phen = 4,7-diphenyl-1,10-phenanthroline), and on closely related complexes, as they are strongly luminescent in the visible region and appear to offer considerable promise in probe applications. These spectroscopic probes are shown to be sensitive to viscosity changes of over five orders of magnitude within the polymer network. The luminescence features of these organometallic probe complexes are compared to that of other organic probe molecules.
40
Popa, Radu C., Cosmin-Andrei Serban, Andrei Barborica, et al. "Functional Enhancement and Characterization of an Electrophysiological Mapping Electrode Probe with Carbonic, Directional Macrocontacts." Sensors 23, no. 17 (2023): 7497. http://dx.doi.org/10.3390/s23177497.
Full textAbstract:
Electrophysiological mapping (EM) using acute electrode probes is a common procedure performed during functional neurosurgery. Due to their constructive specificities, the EM probes are lagging in innovative enhancements. This work addressed complementing a clinically employed EM probe with carbonic and circumferentially segmented macrocontacts that are operable both for neurophysiological sensing (“recording”) of local field potentials (LFP) and for test stimulation. This paper illustrates in-depth the development that is based on the direct writing of functional materials. The unconventional fabrication processes were optimized on planar geometry and then transferred to the cylindrically thin probe body. We report and discuss the constructive concept and architecture of the probe, characteristics of the electrochemical interface deduced from voltammetry and chronopotentiometry, and the results of in vitro and in vivo recording and pulse stimulation tests. Two- and three-directional macrocontacts were added on probes having shanks of 550 and 770 μm diameters and 10–23 cm lengths. The graphitic material presents a ~2.7 V wide, almost symmetric water electrolysis window, and an ultra-capacitive charge transfer. When tested with clinically relevant 150 μs biphasic current pulses, the interfacial polarization stayed safely away from the water window for pulse amplitudes up to 9 mA (135 μC/cm2). The in vivo experiments on adult rat models confirmed the high-quality sensing of LFPs. Additionally, the in vivo-prevailing increase in the electrode impedance and overpotential are discussed and modeled by an ionic mobility-reducing spongiform structure; this restricted diffusion model gives new applicative insight into the in vivo-uprisen stimulation overpotential.
41
Cooney, Thomas F., H. Trey Skinner, and S. M. Angel. "Comparative Study of Some Fiber-Optic Remote Raman Probe Designs. Part I: Model for Liquids and Transparent Solids." Applied Spectroscopy 50, no. 7 (1996): 836–48. http://dx.doi.org/10.1366/0003702963905592.
Full textAbstract:
We have developed models describing the sensitivity and sampling volume of various remote fiber-optic Raman probes—single-fiber, lensed, dual-fiber beveled-tip, dual-fiber flat-tipped, and multi-fiber flat-tipped. The models assume clear samples and incorporate radii, separation, bevel angle, and numerical aperture of the fibers; overlap geometry of illumination and excitation light cones; and refractive index of immersion medium. For the Raman spectra of solid samples in air, single-fiber and lensed probes are predicted to yield the highest Raman signal. Beveled probes should provide greater Raman signal strength than do flat-tipped probes because beveled probes can collect light from a restricted volume closer to the probe end. Although multiple collection fibers improve Raman signal strength, progressively distant concentric fiber rings contribute less and sample material further from the probe.
42
Guihard, Vincent, Frédéric Taillade, Jean-Paul Balayssac, Barthélémy Steck, and Julien Sanahuja. "Permittivity measurement of cementitious materials and constituents with an open-ended coaxial probe: combination of experimental data, numerical modelling and a capacitive model." RILEM Technical Letters 4 (July 10, 2019): 39–48. http://dx.doi.org/10.21809/rilemtechlett.2019.77.
Full textAbstract:
The study presents the development of a new two-dimensional FEM numerical model describing the operation of two large open-ended coaxial probes designed to investigate the permittivity of concrete, and its constituents. This numerical simulation, combined with a capacitive approach describing the behaviour of the probes, enabled to prove the suitability of such device to determine the permittivity of dispersive dielectrics. Finding back the permittivity of a specified material by calculation of the S parameters, change of the reference plane and use of the capacitive model is the key to the proof. Measurements performed onto different materials show good similarities with the numerical simulations. Special considerations are mentioned concerning the size of the probe and its ability to measure the permittivity of heterogeneous materials made of large inclusions. Combination of such numerical tool and measuring device can be used as a non-destructive testing technique to assess the near surface permittivity of concrete structures or as a calibration technique for GPR measurements.
43
Zheng, Xinyu, Jing Huang, and Ningzhao Luo. "Enhanced Nondestructive Testing Using Pulsed Eddy Current and Electromagnetic Ultrasonic Techniques." Applied Sciences 14, no. 15 (2024): 6488. http://dx.doi.org/10.3390/app14156488.
Full textAbstract:
Owing to the challenging working conditions aboard ships, equipment may develop various defects that traditional nondestructive testing methods cannot fully detect. This study proposes a combined approach using pulsed eddy current and electromagnetic ultrasonic testing for enhanced probe detection. Utilizing COMSOL 6.2 finite-element software, a two-dimensional model of the probe was developed to optimize the probe’s design. Based on these findings, a composite probe was designed and structurally optimized, resulting in improved energy conversion efficiency. An experimental platform was established to evaluate the detection capabilities of the composite detection probes. The results indicate that the composite detection probe, as designed and optimized in this study, is effective in testing materials with various artificial defects and enhances the detection of near-surface defects in materials.
44
Zhou, Dan, Lei Zhou, Xiaoyan Hu, Yan Hu, and Ping Hu. "Detection and Imaging Application of miRNA in Cells and Living Organisms with Nano-Fluorescent Probes Made by Novel Synthesis Materials." Science of Advanced Materials 11, no. 12 (2019): 1806–15. http://dx.doi.org/10.1166/sam.2019.3724.
Full textAbstract:
As a kind of rare earth fluorescent material, the rare earth upconversion nanomaterial can be applied in various fields such as biological detection and imaging, solar cells, and safe positioning, which has attracted wide concerns. In this study, the novel material is applied to the preparation of biological nano-fluorescent probes. Due to its broad UV absorption spectrum, cobalt oxyhydroxide is selected and used as a quencher for upconversion nanomaterials. Once the cobalt oxyhydroxide is placed on upconversion nanomaterials, the surface reaction can effectively remove the fluorescence reaction of the upconversion nanomaterial. In terms of the molecular miRNA tests for cells and living organisms, the nano-fluorescent probe can reduce the fluorescence intensity of miRNA, while the control group can finish the normal fluorescence reaction. The designed fluorescent probe can adjust the contents of cobalt oxyhydroxides and cells to regulate the fluorescence intensity. In terms of the miRNA sensitivity tests, the fluorescence intensity detected by the nano-fluorescent probe is significantly lower than that in the control group, which can be observed through the fluorescence recovery tests of the chemical system. After the addition of miRNA obtained from cells or living organisms, the fluorescent probe has apparently changed the fluorescence intensity of miRNA in cells/living organisms. Also, the detection range of miRNA is effectively expanded, i.e., the different concentrations of miRNA can be detected by adjusting the ratio of the components of the fluorescent probes, which indicates the excellent sensitivity of the fluorescent probe in detecting miRNA in cells and living organisms. In terms of the miRNA tests for cells, different degrees of cancer cells are selected. The fluorescent probe can discriminate the concentration of cancer cells according to fluorescence imaging of cancer cells, thereby further explaining that the fluorescent probe has high-sensitivity in bio-detection.
45
Leake, Mark C., and Steven D. Quinn. "A guide to small fluorescent probes for single-molecule biophysics." Chemical Physics Reviews 4, no. 1 (2023): 011302. http://dx.doi.org/10.1063/5.0131663.
Full textAbstract:
The explosive growth of single-molecule techniques is transforming our understanding of biology, helping to develop new physics inspired by emergent biological processes, and leading to emerging areas of nanotechnology. Key biological and chemical processes can now be probed with new levels of detail, one molecule at a time, from the nanoscopic dynamics of nature's molecular machines to an ever-expanding range of exciting applications across multiple length and time scales. Their common feature is an ability to render the underlying distribution of molecular properties that ensemble averaging masks and to reveal new insights into complex systems containing spatial and temporal heterogeneity. Small fluorescent probes are among the most adaptable and versatile for single-molecule sensing applications because they provide high signal-to-noise ratios combined with excellent specificity of labeling when chemically attached to target biomolecules or embedded within a host material. In this review, we examine recent advances in probe designs, their utility, and applications and provide a practical guide to their use, focusing on the single-molecule detection of nucleic acids, proteins, carbohydrates, and membrane dynamics. We also present key challenges that must be overcome to perform successful single-molecule experiments, including probe conjugation strategies, identify tradeoffs and limitations for each probe design, showcase emerging applications, and discuss exciting future directions for the community.
46
Queiroz, Ana Luiza P., Brian M. Kerins, Jayprakash Yadav, et al. "Investigating microcrystalline cellulose crystallinity using Raman spectroscopy." Cellulose 28, no. 14 (2021): 8971–85. http://dx.doi.org/10.1007/s10570-021-04093-1.
Full textAbstract:
AbstractMicrocrystalline cellulose (MCC) is a semi-crystalline material with inherent variable crystallinity due to raw material source and variable manufacturing conditions. MCC crystallinity variability can result in downstream process variability. The aim of this study was to develop models to determine MCC crystallinity index (%CI) from Raman spectra of 30 commercial batches using Raman probes with spot sizes of 100 µm (MR probe) and 6 mm (PhAT probe). A principal component analysis model separated Raman spectra of the same samples captured using the different probes. The %CI was determined using a previously reported univariate model based on the ratio of the peaks at 380 and 1096 cm−1. The univariate model was adjusted for each probe. The %CI was also predicted from spectral data from each probe using partial least squares regression models (where Raman spectra and univariate %CI were the dependent and independent variables, respectively). Both models showed adequate predictive power. For these models a general reference amorphous spectrum was proposed for each instrument. The development of the PLS model substantially reduced the analysis time as it eliminates the need for spectral deconvolution. A web application containing all the models was developed. Graphic abstract
47
Stingl Freitas, Teresa, Ana Sofia Guimarães, Staf Roels, Vasco Peixoto de Freitas, and Andrea Cataldo. "Time Domain Reflectometry (TDR) technique – A solution to monitor moisture content in construction materials." E3S Web of Conferences 172 (2020): 17001. http://dx.doi.org/10.1051/e3sconf/202017217001.
Full textAbstract:
Measuring moisture content in building materials is crucial for the correct diagnosis of buildings’ pathologies and for the efficiency evaluation of the treatment solution applied. There are several different techniques available to measure the moisture content in construction materials. However, perform long-term minor-destructive measurements is still a great challenge. The TDR – Time Domain Reflectometry – technique is commonly used for moisture content measurements in soils, but is considered a relatively new method with regard to its application in construction materials. In the present state of research, the current use of the TDR technique for monitoring moisture content in all types of consolidated porous building materials is not possible yet. Indeed, the empirical conversion functions proposed for soils are mostly not suitable for building materials. Furthermore, to successfully use the TDR technique, a good contact between the TDR probe and the material under study is required, which may be difficult to achieve in hard materials. In this paper, the TDR technique was implemented in two limestone walls constructed in the lab to test experimentally the efficiency of a wall-base ventilation channel to speed up drying after a flood. Each wall was equipped with four two-rod TDR probes for continuous monitoring the moisture content in both situations: with and without the ventilation channel. All the equipment used, procedures followed during the drilling until the probes’ final installation, as well as the individual calibration required for each probe are explained in detail. Instead of using unsuitable functions proposed for soils, the evaluation of the moisture content from the apparent relative dielectric permittivity measured was established using as reference method the gravimetric method. The results obtained suggest that the TDR technique is suitable for moisture content monitoring in consolidated porous building materials.
48
Kuroda, Akio. "Research on advanced asbestos testing using asbestos-binding proteins and fluorescence." Impact 2023, no. 2 (2023): 12–15. http://dx.doi.org/10.21820/23987073.2023.2.12.
Full textAbstract:
It was discovered in the 1970s that asbestos fibre inhalation can cause lung cancer and other lethal lung conditions, and its use is therefore banned in many countries. However, large quantities of asbestos containing materials remain in old buildings and it is also found in natural materials such as talc. Professor Akio Kuroda, Graduate School of Integrated Sciences for Life, Hiroshima University, is focused on the importance of fast and accurate asbestos testing. He and his team have been developing testing techniques to accurately pinpoint the presence of asbestos, including a fluorescent microscopy (FM) method that offers increased sensitivity, accuracy and convenience, and an asbestos-specific protein probe combined with a fluorescent marker that allows users to easily visualise asbestos fibres under a fluorescent microscope. Kuroda has also used engineered peptides, to develop a highly specific probe that binds to asbestos fibres and flags the presence of even minute fibres of the material. He and the team have used proteins based on samples from the Escherichia coli cellular protein library to develop probes that cover different types of asbestos.
49
Li, M., P. Gong, H. Zhang та ін. "Research on multi-probe energy response compensation for X/γ dose rate meter". Journal of Instrumentation 19, № 01 (2024): P01005. http://dx.doi.org/10.1088/1748-0221/19/01/p01005.
Full textAbstract:
Abstract Dose rate meters operating in pulse counting mode usually encounter the problem of uneven energy response. While current methods of coating a single probe with a metal layer can effectively improve the flatness of the energy response, the energy range of the flat response is limited. In this research, a multi-probe energy response compensation method was proposed to solve the problem of uneven energy response of a CsI(Tl) dose rate meter. In this method, different relative energy response curves were obtained by adding different hardware compensations to a probe. Then, two to four relative energy response curves were selected and weighted to obtain a flatter response within the energy region of interest. Specifically, first, 51 compensation schemes were obtained by changing the geometry and material parameters of the CsI(Tl) probe compensation layer. Second, the relative energy response curves of CsI(Tl) probes with 51 compensation schemes were obtained by MCNP simulation. Finally, the weight coefficient of each relative energy response curve was determined by overdetermined equations, and the combination with the smallest relative energy response deviation was selected. Within the energy range of 80–1500 keV, the optimal two-probe compensation scheme was selected from one to three probe compensation schemes. After the dual probe combination compensation, the relative energy response deviation ranged from -23.0% to 5.0%. Within the energy range of 50–3000 keV, the compensation schemes of one to four probes were traversed. The optimal three-probe compensation schemes were selected. After combined compensation, the relative energy response deviation ranged from -27.3% to 15.3%. Furthermore, the compensation effect of multiple probes was better than that of single probes in both energy regions of interest. Simulation results demonstrated that our proposed method can significantly improve the flatness of the energy response of dose rate meters based on CsI(Tl).
50
Toifur, Moh, Moh Irma Sukarelawan, and Okimustava Okimustava. "Home Made Four-Point Probe: Case Studies of the Wobbly A and B Probes." Indonesian Review of Physics 6, no. 1 (2023): 56–62. http://dx.doi.org/10.12928/irip.v6i1.8362.
Full textAbstract:
A simulation on the effect of probe deviation on sheet resistivity value (Rs) of Cu/Ni thin film was carried out in a home-made four-point probe (HM-FPP) type. This began by solving the Rs formula for normal probes, and then for wobbly probe when it was either A, or both A and B. The formula was implemented on a thin layer of Cu/Ni, which was a low temperature sensor material obtained from electrodeposition for 60s assisted by a 200G magnetic field at a current density of 0.07A/mm2. An electric current of 0.20118A was flown from probe A to D in order to produce a potential difference between probe C and D of 0.0005 volts. Furthermore, the distance between the probes was 5 mm and the deviation of each probe A and B were simulated from -0.5 mm to 0.5 mm. The maximum allowable limit for the relative error of Rs or SRs is 5%. The results showed that the ideal Rs value was 0.113 ohm/sq. Furthermore, for HM-FPP in which the wobbly probe only A, there is no problem encountered with the variation of the deviation because all SRs are less than 5%. For wobbly probes A and B, if they are on the same side of the center point of each probe, the maximum allowable deviation is 0.3 mm. The SRs for this case were 4.6%. However, if they are on different sides of the center point of each probe, the maximum allowable deviation is 0.1 mm with SRs of 2.9%. With these results, HM-FPP craftsmen must be more careful in making the size of the probe hole.