Article
Engineering, Environmental
Shixiang Ma, Fengjing Cao, Xuelin Wen, Fanghao Xu, Hongwu Tian, Xinglan Fu, Daming Dong
Summary: The rapid and sensitive detection of heavy metal ions is crucial for environmental and human health. This study introduces a method utilizing laser-induced breakdown spectroscopy (LIBS) combined with filter paper modified with PtAg bimetallic nanoparticles (BNPs) for simultaneous and ultrasensitive detection of Hg2+, Cr3+, and Pb2+. The method shows highly efficient enrichment, rapid separation, and sensitive detection of heavy metal ions, making it a promising approach for detecting trace heavy metals in the environment.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Chemistry, Analytical
Megha Mohan, Jakub Buday, David Prochazka, Pavel Gejdos, Pavel Porizka, Jozef Kaiser
Summary: In recent years, Laser-Induced Breakdown Spectroscopy (LIBS) has been recognized as a powerful technique for elemental imaging of samples. However, analyzing heterogeneous samples with multiple matrices poses new challenges. In this study, the behavior of plasma plumes at the boundary of two well-defined matrices was investigated using a combination of three-dimensional plasma imaging, spectroscopy, and Mach-Zehnder interferometry. The findings provide valuable insights into the factors that need to be considered when mapping fine heterogeneous structures using LIBS.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2023)
Article
Chemistry, Analytical
Megha Mohan, Jakub Buday, David Prochazka, Pavel Gejdos, Pavel Porizka, Jozef Kaiser
Summary: Laser-Induced Breakdown Spectroscopy (LIBS) has become an important technique for elemental imaging of samples, but analyzing heterogeneous samples with multiple matrices presents new challenges. This study investigated the behavior of plasma plumes generated on the boundary of two well-defined matrices using three-dimensional imaging, spectroscopy, and interferometry. The effects of collection optic angles and slight misalignment of the optics on the elemental distribution and signal intensities were analyzed. The findings provide valuable insights into the behavior of plasma plumes at the boundary of matrices and factors to consider when mapping fine heterogeneous structures using LIBS.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2023)
Article
Thermodynamics
Brendan McGann, Timothy M. Ombrello, David M. Peterson, Ez Hassan, Stephen D. Hammack, Campbell D. Carter, Tonghun Lee, Hyungrok Do
Summary: Nanosecond-gated laser-induced breakdown spectroscopy (n-LIBS) was used to quantify fuel mole fraction in a high-speed combustor, showing unexpected results in low concentration fuel regions. An improved direct spectrum matching calibration matrix and comparison between different laser systems reduced measurement uncertainty and demonstrated insensitivity to specific lasers. Comparison between n-LIBS and numerical results provided good overall agreement, highlighting the importance of n-LIBS in diagnostic model testing.
COMBUSTION AND FLAME
(2021)
Article
Chemistry, Analytical
Wei Ke, Xiaohua Wang, Minyuan Chen, Huan Yuan, Aijun Yang, Jifeng Chu, Dingxin Liu, Mingzhe Rong
Summary: Laser-induced breakdown spectroscopy (LIBS) is a useful technique for quantitative detection based on the properties of laser-induced plasma (LIP) at local thermodynamic equilibrium (LTE). The influence of ambient pressure on the spatial-temporal evolution of LTE for LIP is still not well understood, and the mechanism of this influence remains unclear.
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
(2023)
Article
Optics
Farzaneh Ghazi-Maghrebi, Hamidreza Shirvani-Mahdavi, Seyede Zahra Shoursheini
Summary: This paper demonstrates the analysis of blood cholesterol using calibration curves derived from LIBS and FTIR techniques. By measuring the plasma emission spectrum and FTIR spectrum of the samples, calibration curves related to cholesterol concentration are obtained, which can be used to determine the target cholesterol concentration.
Article
Instruments & Instrumentation
David M. Surmick, Leon Taleh, Noureddine Melikechi
Summary: The impact of altering laser focusing conditions on laser-induced breakdown spectroscopy experiments was investigated in both ambient Earth laboratory and simulated Martian atmospheres. Results showed that the peak emissions of ionic species occur when the laser plasma is initiated with a focused spot within the sample in ambient Earth laboratory air, while atomic emissions have peak intensities several millimeters deeper into the sample. In simulated Martian atmospheres, atomic emissions peak when the laser is focused within the sample, while ionic emissions have peak intensities near the surface of the sample.
APPLIED SPECTROSCOPY
(2021)
Article
Environmental Sciences
Xi Chen, Shujat Ali, Leiming Yuan, Fengyi Guo, Guangzao Huang, Wen Shi, Xiaojing Chen
Summary: This study quantified heavy metals contaminated microplastics samples using Laser-Induced Breakdown Spectroscopy (LIBS) and determined the sources of the contaminants based on the trace metals in microplastics. The findings demonstrated that LIBS is a promising and facile technique for rapid and non-destructive multi-metals detection in individual samples, making it suitable for the characterization of microplastics and analysis of heavy metals contaminants' sources in microplastics particles.
Article
Chemistry, Analytical
Maximilian Weiss, Zuzana Gajarska, Hans Lohninger, Martina Marchetti-Deschmann, Georg Ramer, Bernhard Lendl, Andreas Limbeck
Summary: The growing importance of fluoropolymers in high-tech applications and green technologies has led to an increased demand for their characterization. This study presents a novel approach for quantitative mapping of fluorine in fluoropolymer samples using laser-induced breakdown spectroscopy (LIBS). The approach is based on monitoring molecular emission bands arising from fluorine-containing molecules. The study evaluates two techniques - spray coating and sputter coating - for their effects on sensitivity and spatial resolution in elemental mapping.
ANALYTICA CHIMICA ACTA
(2022)
Article
Spectroscopy
Marina Martinez-Minchero, Laura Ulloa, Adolfo Cobo, Eugenio Bringas, Ma-Fresnedo San-Roman, Jose Miguel Lopez-Higuera
Summary: Chelating resins are effective in heavy metal recovery, with LIBS technology allowing for continuous monitoring. Calibration curves for single and bi-component resins show high correlation and accurate concentration prediction for copper and nickel.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2021)
Article
Optics
Jiang Xu, Xiao Wang, Mingyin Yao, Muhua Liu
Summary: This study establishes a detection model of polarization recognition rate by exploring the intensity formula of discrete spectral data, and investigates the polarization characteristics of plasma and the improvement mechanism of recognition rate under low energy density. The results show that increasing laser energy improves the recognition of characteristic spectral lines, and heavy-metal elements have a higher polarization recognition rate under low energy density.
Article
Chemistry, Analytical
Yue Li, Guoxia Zhang, Zhaoqing Cai, Zheng Wang
Summary: This study proposes a method to enhance the sensitivity of laser-induced breakdown spectroscopy (LIBS) using atmospheric pressure glow discharge, with further improvement achieved through cylindrical confinement. The technique was evaluated under laser energy of 30 mJ, resulting in significant enhancement of emission intensities and decrease in detection limits for various elements in soil samples. The possible mechanism of signal enhancement was explained by studying plasma electron temperature and density.
ANALYTICAL CHEMISTRY
(2022)
Article
Physics, Multidisciplinary
Wojciech Gromelski, Pawel Gasior
Summary: The time evolution of plasma electron temperature and density is crucial in various physics-related fields. The CF DP-LIBS method can minimize sample impact, optimize laser and spectral parameters, and enable real-time chemical analysis. By calculating electron temperature and density of plasma induced by double-pulse Nd:YAG laser with different inter-pulse delays, researchers can provide complementary calculations using methods like Stark broadening, Boltzmann plot, and Saha equation. The study focuses on tungsten samples, as tungsten is the preferred material for plasma-facing components in future fusion devices like ITER, where LIBS method will be used to monitor tritium retention.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Review
Spectroscopy
Giorgio S. Senesi, Russell S. Harmon, Richard R. Hark
Summary: This review discusses the application and performance comparison of laser-induced breakdown spectroscopy (LIBS) instrumentation in in situ measurement, as well as its practical applications in various industries. LIBS technology is important for meeting the demands of fast analysis and portability.
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
(2021)
Article
Materials Science, Multidisciplinary
Amir Fayyaz, Haroon Asghar, Tahani A. Alrebdi
Summary: The laser-induced breakdown spectroscopy (LIBS) technique was used to investigate green fluorite samples. It was found that the emission bands of the CaF diatomic molecule in the fluorite samples exhibited stronger optical emission compared to the fluorine atomic lines. Chemical composition analysis using CF-LIBS was in good agreement with results from the EDX technique. The validity of the CF-LIBS results was confirmed using the calibration curve method, and a principal component analysis (PCA) technique was utilized to classify the fluorite samples.
RESULTS IN PHYSICS
(2023)
Article
Automation & Control Systems
Aadil Sarwar Khan, Abdul Qayyum Khan, Naeem Iqbal, Ghulam Mustafa, Muhammad Asim Abbasi, Atif Mahmood
Summary: This paper presents a novel directional observer-based fault detection and isolation scheme for second-order networked control systems. The scheme utilizes a directional unknown input observer (UIO) to solve the problem of distributed fault detection and isolation (FDI). Two design schemes with global and partial/local network models are proposed. Thresholds for the schemes in a noisy environment are computed. The significant feature of the proposed schemes is achieving fault detection and isolation in a single step using a single observer. The schemes are validated with power system models and compared with existing FDI schemes, demonstrating their effectiveness in terms of computational requirements.
Article
Public, Environmental & Occupational Health
Madeeha Fatima, Aamna Habib, Saira Khan, Muhammad Hammad Butt, Tauqeer Hussain Mallhi, Yusra Habib Khan, Asifa Zaheer, Muhammad Umar Habib, Abdul Qayyum Khan, Muhammad Imran Khan, Azhar Iqbal, Malik Hassan Mehmood, Imran Masood
Summary: This study investigated the knowledge, attitude, and behavior of university students towards COVID-19. The results showed that the majority of students had good knowledge about the disease and had a positive attitude towards taking preventive measures. There was a correlation between knowledge, positive attitude, and preventive behavior.
DISASTER MEDICINE AND PUBLIC HEALTH PREPAREDNESS
(2022)
Article
Engineering, Electrical & Electronic
Muhammad Asim Shoaib, Abdul Qayyum Khan, Ghulam Mustafa, Sufi Tabbasum Gul, Owais Khan, Aadil Sarwar Khan
Summary: This study presents a nonlinear robust fault detection scheme for synchronous generators in power systems. The proposed scheme utilizes a nonlinear observer and is designed to be robust against disturbances, uncertainties, and faults. The effectiveness of the scheme is demonstrated through application to IEEE 9-bus and 3-machine systems.
IEEE TRANSACTIONS ON POWER SYSTEMS
(2022)
Article
Medicine, Research & Experimental
Hira Asif, Tahir Ali Chohan, Hafiz Muhammad Irfan, Mulazim Hussain Asim, Syed Nasir Abbas Bukhari, Waqas Younis, Yusuf S. Althobaiti, Aman Ullah, Abdul Qayyum Khan, Alqassem Y. Hakami, Alamgeer
Summary: This study investigated the vasorelaxation mechanisms of Mentha longifolia and found that its n-butanol fraction can induce endothelium-independent relaxation by inhibiting various PDEs and increasing cAMP and cGMP levels.
BIOMEDICINE & PHARMACOTHERAPY
(2022)
Correction
Public, Environmental & Occupational Health
Madeeha Fatima, Aamna Habib, Saira Khan, Muhammad Hammad Butt, Tauqeer Hussain Mallhi, Yusra Habib Khan, Asifa Zaheer, Muhammad Umar Habib, Abdul Qayyum Khan, Muhammad Imran Khan, Azhar Iqbal, Malik Hassan Mehmood, Imran Masood
DISASTER MEDICINE AND PUBLIC HEALTH PREPAREDNESS
(2022)
Article
Medicine, General & Internal
Mohammad Majid Paracha, Farah Sagheer, Abdul Qayyum Khan
Summary: This seven-year retrospective study examined the demography and clinical features of pemphigus at the Department of Dermatology, Lady Reading Hospital, Peshawar, from 2013 to 2020. Among the 148 patients included, 58% were females and 40% were males, with a female to male ratio of 1.46:1. The average age at onset of the disease was 38 +/- 12 years. The study found that severe pemphigus vulgaris was associated with multiple relapses, indicating poor prognosis. Patients who received Rituximab achieved complete remission on minimal therapy more frequently during five years of follow-up.
JOURNAL OF THE PAKISTAN MEDICAL ASSOCIATION
(2023)
Article
Mathematics
Atif Mahmood, Abdul Qayyum Khan, Nasim Ullah, Adil Sarwar Khan, Muhammad Asim Abbasi, Alsharef Mohammad, Abdulfattah Noorwali
Summary: This paper presents two new fault models for networked systems, which are more realistic and generalized in representing the effects of fault at the node and network levels. A new output feedback-based controller is proposed, considering network uncertainties and output measurements for gain calculation. Linear matrix inequality-based sufficient conditions are derived using robust control and stochastic stability tools. Simulation results verify the applicability of the presented fault-tolerant control against multiple simultaneous faults.
Article
Computer Science, Information Systems
Hira Sana, Ghulam Mustafa, Owais Khan, Nouman Ashraf, Abdul Qayyum Khan, Muhammad Abid, Haroon Ur Rashid Khan
Summary: This study addresses the issue of secure control design for cyber-physical systems (CPS) against denial of service (DoS) attacks. We propose an efficient procedure to compute an upper bound on the performance degradation brought on by the DoS attack using the linear matrix inequality approach. We also redesign the controller to minimize this performance degradation. Simulation results demonstrate the effectiveness of the designed controller in maintaining the performance and stability of the feedback loop under attack.
Article
Computer Science, Information Systems
Sheraz Shafique, Ghulam Mustafa, Nouman Ashraf, Owais Khan, Abdul Qayyum Khan, Muhammad Abid
Summary: This paper presents a novel sampled-data approach to design event-triggered asynchronous H-8 filters for networked switched systems, ensuring the global asymptotic stability and H∞ performance level.
Article
Computer Science, Information Systems
Faizan E. Mustafa, Abdul Qayyum Khan, Abdus Samee, Ijaz Ahmed, Muhammad Abid, Mohammad M. Alqahtani, Muhammad Khalid
Summary: Industrial processes are complex and nonlinear, making it difficult to identify and isolate defects. This study investigates the use of Principal Component Analysis (PCA), Fisher Discriminant Analysis (FDA), Kernel Fisher Discriminant Analysis (KFDA), and Sequential quadratic programming (SQP) for fault detection and isolation in industrial processes. The findings suggest that FDA, KFDA, and SQP are effective in identifying and isolating faults, while PCA has limitations. Data-driven design approaches offer higher reliability and efficiency compared to PCA-based methods in complicated industrial processes.
Article
Engineering, Electrical & Electronic
Muhammad Asim Shoaib, Abdul Qayyum Khan, Sufi Tabassum Gul, Ghulam Mustafa, Muhammad Abid, Muhammad Abubakar, Adil Khan
Summary: In this study, the problem of accurately locating transmission line faults is addressed by proposing a solution based on sparse current and voltage measurements along with a resistive superconducting fault current limiter (RSFCL). The proposed technique improves fault location accuracy by limiting the effect of CT saturation and is robust against fault impedance and load variation.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Psychiatry
Abdul Qayyum Khan, Lukas Thielen, Gwenaelle Le Pen, Marie-Odile Krebs, Oussama Kebir, Adrian Groh, Maximilian Deest, Stefan Bleich, Helge Frieling, Kirsten Jahn
Summary: Schizophrenia is influenced by both genetic and environmental factors, with adolescence being a critical period for symptom manifestation. This study focused on the interaction between DNA methylation and mRNA expression, using the MAM animal model to study neurodevelopmental disruptions and behavioral deficits. The results showed reduced expression levels of Drd2 and high alterations of methylation rates in co-factor genes under MAM treatment during pre-adolescence.
Proceedings Paper
Computer Science, Artificial Intelligence
Muhammad Haris Rehman, Sajjad Asghar, Muhammad Abid, Abdul Qayyum Khan
Summary: This study explores the guidance and control of high spin rate artillery shells using roll coupled guidance fuze. By developing a mathematical model and implementing a guidance algorithm, the accuracy and precision of the shells can be improved.
2022 17TH INTERNATIONAL CONFERENCE ON EMERGING TECHNOLOGIES (ICET'22)
(2022)
Article
Computer Science, Information Systems
Muhammad Asim Shoaib, Abdul Qayyum Khan, Ghulam Mustafa, Owais Khan, Nasimullah, Muhammad Abid, Muhammad Arif, Sufi Tabassum Gul, Lukas Prokop, Vojtech Blazek, Stanislav Misak
Summary: This paper presents a robust dynamic fault detection filter for synchronous generators, which is robust against model uncertainties and process disturbances while being sensitive to faults.
Article
Plant Sciences
Abdul Qayyum Khan, Berhanu Lemma, Amare Girma, Cherinet Kasahun
Summary: A collection of 27 bread wheat varieties from Ethiopia was evaluated for physico-chemical quality characteristics. The varieties showed significant differences in quality traits. The findings suggest that certain varieties could be suitable for different food products and utilized in breeding programs to improve quality.
INDIAN JOURNAL OF GENETICS AND PLANT BREEDING
(2022)
