KPFM Study on the Charge Sign Reversal during Nanoscale Triboelectric Charging Induced by a Worn Tip and Sample Pretreatment

2021 ◽  
Author(s):  
Xuejie Bai ◽  
Hua Wei ◽  
Tian Qiu ◽  
Zhenxing Zhang ◽  
Yaqun He ◽  
...  
Keyword(s):  
Sample Pretreatment ◽  
Sign Reversal ◽  
Triboelectric Charging ◽  
Charge Sign

scholarly journals Selective Surface Charge Sign Reversal on Metallic Carbon Nanotubes for Facile Ultrahigh Purity Nanotube Sorting

ACS Nano ◽  
2016 ◽  
Vol 10 (3) ◽  
pp. 3222-3232 ◽  
Author(s):  
Jing Wang ◽  
Tuan Dat Nguyen ◽  
Qing Cao ◽  
Yilei Wang ◽  
Marcus Y.C. Tan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Surface Charge ◽  
Sign Reversal ◽  
Charge Sign

scholarly journals Effects of the solar wind termination shock and heliosheath on theheliospheric modulation of galactic and anomalous Helium

2004 ◽  
Vol 22 (8) ◽  
pp. 3063-3072 ◽  
Author(s):  
U. W. Langner ◽  
M. S. Potgieter
Keyword(s):  
Solar Wind ◽  
Cosmic Ray ◽  
Magnetic Polarity ◽  
Termination Shock ◽  
Shock Acceleration ◽  
Diffusive Shock Acceleration ◽  
Cosmic Ray Modulation ◽  
Low Energies ◽  
Solar Wind Termination Shock ◽  
Charge Sign

Abstract. The interest in the role of the solar wind termination shock and heliosheath in cosmic ray modulation studies has increased significantly as the Voyager 1 and 2 spacecraft approach the estimated position of the solar wind termination shock. The effect of the solar wind termination shock on charge-sign dependent modulation, as is experienced by galactic cosmic ray Helium (He++) and anomalous Helium (He+), is the main topic of this work, and is complementary to the previous work on protons, anti-protons, electrons, and positrons. The modulation of galactic and anomalous Helium is studied with a numerical model including a more fundamental and comprehensive set of diffusion coefficients, a solar wind termination shock with diffusive shock acceleration, a heliosheath and particle drifts. The model allows a comparison of modulation with and without a solar wind termination shock and is applicable to a number of cosmic ray species during both magnetic polarity cycles of the Sun. The modulation of Helium, including an anomalous component, is also done to establish charge-sign dependence at low energies. We found that the heliosheath is important for cosmic ray modulation and that its effect on modulation is very similar for protons and Helium. The local Helium interstellar spectrum may not be known at energies

scholarly journals Interface-induced sign reversal of the anomalous Hall effect in magnetic topological insulator heterostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fei Wang ◽  
Xuepeng Wang ◽  
Yi-Fan Zhao ◽  
Di Xiao ◽  
Ling-Jie Zhou ◽  
...  
Keyword(s):  
Hall Effect ◽  
Electric Fields ◽  
First Principles ◽  
Berry Phase ◽  
Condensed Matter ◽  
Anomalous Hall Effect ◽  
First Principles Calculations ◽  
Sign Reversal ◽  
Berry Curvature ◽  
Topological Materials

AbstractThe Berry phase picture provides important insights into the electronic properties of condensed matter systems. The intrinsic anomalous Hall (AH) effect can be understood as the consequence of non-zero Berry curvature in momentum space. Here, we fabricate TI/magnetic TI heterostructures and find that the sign of the AH effect in the magnetic TI layer can be changed from being positive to negative with increasing the thickness of the top TI layer. Our first-principles calculations show that the built-in electric fields at the TI/magnetic TI interface influence the band structure of the magnetic TI layer, and thus lead to a reconstruction of the Berry curvature in the heterostructure samples. Based on the interface-induced AH effect with a negative sign in TI/V-doped TI bilayer structures, we create an artificial “topological Hall effect”-like feature in the Hall trace of the V-doped TI/TI/Cr-doped TI sandwich heterostructures. Our study provides a new route to create the Berry curvature change in magnetic topological materials that may lead to potential technological applications.

scholarly journals Urine lipoarabinomannan in HIV uninfected, smear negative, symptomatic TB patients: effective sample pretreatment for a sensitive immunoassay and mass spectrometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anita G. Amin ◽  
Prithwiraj De ◽  
Barbara Graham ◽  
Roger I. Calderon ◽  
Molly F. Franke ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Sample Pretreatment ◽  
Positive Association ◽  
Proteinase K ◽  
Clinical Samples ◽  
Sputum Smear ◽  
Smear Negative ◽  
Tuberculostearic Acid ◽  
Negative Sputum ◽  
Adult Culture

AbstractOur study sought to determine whether urine lipoarabinomannan (LAM) could be validated in a sample cohort that consisted mainly of HIV uninfected individuals that presented with tuberculosis symptoms. We evaluated two tests developed in our laboratory, and used them on clinical samples from Lima, Peru where incidence of HIV is low. ELISA analysis was performed on 160 samples (from 140 adult culture-confirmed TB cases and 20 symptomatic TB-negative child controls) using 100 μL of urine after pretreatment with Proteinase K. Two different mouse monoclonal antibodies-CS35 and CHCS9-08 were used individually for capture of urine LAM. Among cases, optical density (OD450) values had a positive association with higher bacillary loads. The 20 controls had negative values (below the limit of detection). The assay correctly identified all samples (97–100% accuracy confidence interval). For an alternate validation of the ELISA results, we analyzed all 160 urine samples using an antibody independent chemoanalytical approach. Samples were called positive only when LAM surrogates—tuberculostearic acid (TBSA) and d-arabinose (d-ara)—were found to be present in similar amounts. All TB cases, including the 40 with a negative sputum smear had LAM in detectable quantities in urine. None of the controls had detectable amounts of LAM. Our study shows that urinary LAM detection is feasible in HIV uninfected, smear negative TB patients.

Sign reversal of anomalous Hall effect derived from the transformation of scattering effect in cluster-assembled Ni0.8Fe0.2 nanostructural films

Nanoscale ◽  
2021 ◽  
Author(s):  
Ning Jiang ◽  
Bo Yang ◽  
Yulong Bai ◽  
Yaoxiang Jiang ◽  
Shifeng Zhao
Keyword(s):  
Hall Effect ◽  
Anomalous Hall Effect ◽  
Sign Reversal ◽  
Surface And Interface ◽  
Scattering Effect ◽  
Single Substance ◽  
Interface Scattering ◽  
Hall Effects

Both surface and interface scattering induced a sign reversal of anomalous Hall effects (AHE) in a few heterostructures. The sign reversal exiting in a single-substance can clarify the role of...

Factors influencing the triboelectric charging of granular plastics in a new multi-cylinder type device

2020 ◽  
Author(s):  
Imed Eddine Achouri ◽  
Gontran Richard ◽  
Thami Zeghloul ◽  
Karim Medles ◽  
Mohamed Fodil Boukhoulda ◽  
...  
Keyword(s):  
Factors Influencing ◽  
Type Device ◽  
Triboelectric Charging

Applying Probe Electrospray Ionization Mass Spectrometry to Cytological Diagnosis: A Preliminary Study by Using Cultured Lung Cancer Cells

2021 ◽  
pp. 1-10
Author(s):  
Yuki Morimoto ◽  
Takeshi Oya ◽  
Mayuko Ichimura-Shimizu ◽  
Minoru Matsumoto ◽  
Hirohisa Ogawa ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Squamous Cell ◽  
Cultured Cells ◽  
Sample Pretreatment ◽  
Cell Types ◽  
Diagnostic Tools ◽  
Ionization Mass ◽  
Diagnostic Modality ◽  
Probe Electrospray Ionization

<b><i>Objectives:</i></b> Cytology and histology are 2 indispensable diagnostic tools for cancer diagnosis, which are rapidly increasing in importance with aging populations. We applied mass spectrometry (MS) as a rapid approach for swiftly acquiring nonmorphological information of interested cells. Conventional MS, which primarily rely on promoting ionization by pre-applying a matrix to cells, has the drawback of time-consuming both on data acquisition and analysis. As an emerging method, probe electrospray ionization-MS (PESI-MS) with a dedicated probe is capable to pierce sample and measure specimen in small amounts, either liquid or solid, without the requirement for sample pretreatment. Furthermore, PESI-MS is timesaving compared to the conventional MS. Herein, we investigated the capability of PESI-MS to characterize the cell types derived from the respiratory tract of human tissues. <b><i>Study Design:</i></b> PESI-MS analyses with DPiMS-2020 were performed on various type of cultured cells including 5 lung squamous cell carcinomas, 5 lung adenocarcinomas, 5 small-cell carcinomas, 4 malignant mesotheliomas, and 2 normal controls. <b><i>Results:</i></b> Several characteristic peaks were detected at around m/z 200 and 800 that were common in all samples. As expected, partial least squares-discriminant analysis of PESI-MS data distinguished the cancer cell types from normal control cells. Moreover, distinct clusters divided squamous cell carcinoma from adenocarcinoma. <b><i>Conclusion:</i></b> PESI-MS presented a promising potential as a novel diagnostic modality for swiftly acquiring specific cytological information.

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