Silver oxide (AgO) thin films were prepared by using a cylindrical direct current reactive magnet... more Silver oxide (AgO) thin films were prepared by using a cylindrical direct current reactive magnetron sputtering system at 10 −5 torr initial pressure on BK7 glass substrate. Samples deposited for 3, 5 and 7 minutes. Surface characterization of AgO thin films in the nanometer scale can be accurately determined using the atomic force microscopy (AFM) and X-ray diffraction (XRD). The average roughness (R avg), maximum peak to valley height (R t) and root mean square (R rms) roughness are used to analyze the surface morphology of AgO films. The linear optical absorption data were measured in the visible-near infrared spectral regions and the nonlinear refractive index (n 2) of thin films is evaluated by the moiré deflectometery technique. The investigation indicates that, increase in AgO thickness leads to reduction in nonlinear refractive index.
Third conference on laser and its application, 2014
In this paper design and development of 780 nm stable tunable semiconductor laser is reported. Li... more In this paper design and development of 780 nm stable tunable semiconductor laser is reported. Littman configuration has been used in this work. The aim of this research is to find a suitable optical set-up for tuning semiconductor lasers without moving the output laser beam. To do so, a diffractive grating, a mirror, a cooling system, a power supply and opto-mechanical components have been used. The wavelength of the laser beam and the power of that have been measured using a spectrometer and a power meter respectively. Using the typical setup the laser was tuned 52 angstrom.
A cost-effective method employing a smartphone sensor to measure the laser-induced sound pressure... more A cost-effective method employing a smartphone sensor to measure the laser-induced sound pressure level (SPL) has been introduced for lens-to-sample distance (LTSD) adjustment in micro laser-induced breakdown spectroscopy (µLIBS).
Preparation of biological samples for further processing or analysis is generally performed manua... more Preparation of biological samples for further processing or analysis is generally performed manually by means of standard mechanical tools such as scalpels or biopsy punches. While this approach is uncomplicated and swift, it entails constraints such as low, operator-dependent cutting accuracy and reproducibility. Tissue segments surrounding the cut may further suffer mechanical and thermal damage due to shear forces and friction between tool and sample. These hindrances affect procedures both in the laboratory environment as well as within clinical settings. A system has been developed leveraging robotic positioning and laser light for precise, controlled, and contactless tissue ablation, and providing a concise and intuitive graphical user interface. Additionally, sterility of the process is demonstrated, a paramount element for clinical application. The proposed process does not require sterilization of the robotic components or the lasers, easing a prospective integration into existing workflows. In the context of this work, mainly cartilage repair surgery is targeted. The proposed system allows for highly accurate and reproducible shaping of the cartilage lesion area as well as its corresponding engineered cartilage graft, possibly leading to better and faster integration at the defect site. Promising results could be obtained in a first test series with human cartilage samples, validating the functionality of the preparation system and the feasibility of the sterility concept.
New Trends in Medical and Service Robotics. MESROB 2020. Mechanisms and Machine Science, 2021
Echelle spectrometers offer high-resolution (ca. one Angstrom or higher) and wide range (ca. half... more Echelle spectrometers offer high-resolution (ca. one Angstrom or higher) and wide range (ca. half a micron or wider), simultaneously, without having a mechanical moving part. However, they require a complicated optical setup as compared to conventional one-dimensional-dispersion/diffraction spectrometers, e.g., Czerny-Turner. Therefore, the simulation of the Echellogram is required before building the spectrometer. This paper aims to develop an application for visualizing the Echellogram using MATLAB App Designer followed by simulation of the optical aberrations by Zemax OpticStudio to optimize the spectrometer parameters. The developed application provides an interactive graphical interface with a user-friendly dashboard to control and monitor the required parameters. This spectrometer is being used in laser-induced breakdown spectroscopy (LIBS) system application lied of robot-guided laser ablation of biological tissues.
New Trends in Medical and Service Robotics. MESROB 2020. Mechanisms and Machine Science, 2021
The preparation of small-sized biological samples is traditionally performed manually utilizing m... more The preparation of small-sized biological samples is traditionally performed manually utilizing mechanical tools such as scalpels. The main drawbacks of such methods are a lack of accuracy and repeatability of the resulting cuts and damage to the surrounding tissue due to the high interaction forces and the accompanying mechanical stresses. One way to circumvent these issues is to substitute the mechanical tools for laser light. When used in conjunction with a high-accuracy positioning system, such a preparation procedure enables repeatable cutting of arbitrary geometries while largely preserving the integrity of the surrounding tissue. In this paper, a system leveraging the potential of laser-based ablation for bio-sample preparation is proposed. It integrates and synchronizes all key components with extensive safety features and an intuitive user interface, allowing novice operators to perform sample preparations easily. As a first application, the proposed system has been utilized to create microdamages in mouse tail tendon fascicles. Promising results could be obtained, but careful tuning of the laser parameters and further optimization of the mechanical setup is still required to attain the high repeatability striven for.
Minimally invasive laser surgeries that require the use of a flexible endoscope (flexiscope) coul... more Minimally invasive laser surgeries that require the use of a flexible endoscope (flexiscope) could benefit from high-energy nanosecond laser pulses delivered through fibers for real-time tissue characterization and phenotyping. The damage threshold of the fiber's glass material limits the maximum amount of deliverable peak power. To transmit high-energy pulses without damaging the fiber material, large-diameter fibers are typically used, leading to a limited bending radius. Moreover, in a large-core fiber, self-focusing can damage the fiber even if the tip remains intact. In this work, we tested a fused-end fiber bundle combined with a beam shaper capable of delivering more than 20 MW (>100 mJ/5 ns). The fiber bundle was tested over more than eight hours of operation, with different bending radiuses down to 15 mm. The results demonstrate, to the best of our knowledge, the highest peak power delivered through a flexible fiber, for a frequency-doubled Q-switched Nd:YAG laser.
Yb-doped: ytterbium-doped Zn: zinc μLIBS: micro laser-induced breakdown spectroscopy xiii Acknowl... more Yb-doped: ytterbium-doped Zn: zinc μLIBS: micro laser-induced breakdown spectroscopy xiii Acknowledgments Carrying out this study was only possible due to the contribution and cooperation of a number of people. I would like to take this opportunity to acknowledge them. First and foremost, I would like to express my sincere gratitude to my first thesis advisor, Prof. Dr. Azhar Zam, for the opportunity to work on this thesis with the Biomedical Laser and Optics Group (BLOG). It was very exciting to work on such an interesting project with BLOG. I learned about biomedical optics from Azhar, both in his course and also through our weekly meetings. Azhar's door was always open, even for daily discussion. I appreciate the time and the energy he spent on this thesis. I am also thankful to my second thesis advisor, Prof. Dr. Philippe C. Cattin. Philippe helped me regarding the required signal processing and data analysis. I learned about state-of-theart machine learning methods from Philippe, both from his course and also from our monthly meetings. Moreover, I am very grateful to Prof. Dr. Raphael Guzman, another advisor of this thesis, who guided me from a medical point of view. I appreciate the time that he spent during our meetings, despite his busy schedule. Raphael, a surgeon, guided me towards developing a device that would be intuitive and useful for the potential end-users (surgeons). In addition, I would like express gratitude to Prof. Dr. Georg Rauter. For part of the project, we worked together and shared equipment. Thanks to the opportunity to attend international conferences/schools, I was able to meet great researchers in the field, extend my network, and get inspired by my discussions with them. I appreciate those who helped me find the answers to my questions and gave me great ideas, especially Prof. Dr. Steven Jacques from the University of Washington. It was my pleasure to meet, discuss, and learn from Steven. I would like to acknowledge Prof. Dr. Conor L. Evans from Harvard University for kindly being the external expert/examiner of this thesis and evaluating this doctoral thesis. A great thanks also goes to Prof. Dr. Pablo Sinues, for chairing the defense. Additionally, I gratefully acknowledge funding from the Werner Siemens Foundation through the Minimally Invasive Robot-Assisted Computerguided LaserosteotomE (MIRACLE) project. For more than four years, I worked in the department of biomedical engineering (DBE) under the flagship project of the department, MIRACLE. There, I enjoyed working with other students, interns, postdoctoral research associates, and other colleagues from different groups, especially from BLOG (former and current members). Thank you all for the pleasant atmosphere in our working area. We shared facilities, labs, workshop, kitchen, dining area, classrooms, and so on. I enjoyed working in a multidisciplinary area while learning from all my colleagues, especially through our journal club, summer/winter school, retreat, and other meetings. The chance to work directly with a few master students gave me experience, joy, and additional insights, thanks to Antoine, Negin, and Matin. Last but not least, I would like to sincerely thank my friends and family for their generous support and never-ending motivation during my Ph.D.
Optical Methods for Inspection, Characterization, and Imaging of Biomaterials IV, 2019
Anonymized social network graphs published for academic or advertisement purposes are subject to ... more Anonymized social network graphs published for academic or advertisement purposes are subject to deanonymization attacks by leveraging side information in the form of a second, public social network graph correlated with the anonymized graph. This is because the two are from the same underlying graph of true social relationships. In this paper, the maximum a posteriori (MAP) estimates of user identities for the anonymized graph are characterized and sufficient conditions for successful de-anonymization for underlying graphs with community structure are provided. The results generalize prior work that assumed underlying graphs of Erdős-Rényi type, and prove the optimality of the attack strategy adopted in the literature.
In this paper we report the preparation of silver nanoparticle thin films by cylindrical direct c... more In this paper we report the preparation of silver nanoparticle thin films by cylindrical direct current reactive magnetron sputtering (at 10-5 torr initial pressure) and characterization of their nonlinear optical properties. BK7 glasses were selected as substrate. Nonlinear optical response of silver nanoparticle thin films was measured by moiré deflectometry technique using 15 mW He-Ne laser illuminations. All fabricated silver nanoparticle thin films were evaluated using atomic force microscopy and spectrophotometry (from visible region to near infrared region).
In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properti... more In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properties of distilled water is studied. The distilled water was irradiated by a cold Argon plasma jet. The electrical conductivity, PH, and the absorbance of samples were measured before and after irradiation with various durations. The electrical conductivity of distilled water was increased with irradiation time, but its PH was decreased. An increase in the absorbance was observed after each irradiation time interval.
Optical Methods for Inspection, Characterization, and Imaging of Biomaterials IV, 2019
Anonymized social network graphs published for academic or advertisement purposes are subject to ... more Anonymized social network graphs published for academic or advertisement purposes are subject to deanonymization attacks by leveraging side information in the form of a second, public social network graph correlated with the anonymized graph. This is because the two are from the same underlying graph of true social relationships. In this paper, the maximum a posteriori (MAP) estimates of user identities for the anonymized graph are characterized and sufficient conditions for successful de-anonymization for underlying graphs with community structure are provided. The results generalize prior work that assumed underlying graphs of Erdős-Rényi type, and prove the optimality of the attack strategy adopted in the literature.
The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure... more The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure Argon plasma jet. When the plasma jet was directly irradiated onto a Methyl orange solution, the solution was decolorized. PH and absorbance of samples were measured before and after irradiation with various durations. Thus, non-thermal plasma jet irradiation is considered to be capable of decomposing, and can also be used for water purification.
In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properti... more In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properties of distilled water is studied. The distilled water was irradiated by a cold Argon plasma jet. The electrical conductivity, PH, and the absorbance of samples were measured before and after irradiation with various durations. The electrical conductivity of distilled water was increased with irradiation time, but its PH was decreased. An increase in the absorbance was observed after each irradiation time interval.
The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure... more The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure Argon plasma jet. When the plasma jet was directly irradiated onto a Methyl orange solution, the solution was decolorized. PH and absorbance of samples were measured before and after irradiation with various durations. Thus, non-thermal plasma jet irradiation is considered to be capable of decomposing, and can also be used for water purification.
Lasers have become generally accepted devices in surgical applications, especially as a cutting t... more Lasers have become generally accepted devices in surgical applications, especially as a cutting tool, for cutting both soft and hard tissues including bone (laserosteotomy). It has been shown that applying lasers in osteotomy have important advantages over mechanical tools, including faster healing, more precise cut and functional cutting geometries as well as less trauma [1, 2]. However, the ability of detecting the type of tissue that being cut during surgery can extend the application and safety of laserosteotomes in practice. As a result, the laser could be stopped automatically in case of cutting a tissue that should be preserved. Authors have previously demonstrated that laser-induced breakdown spectroscopy (LIBS) is a potential candidate to differentiate surrounding soft tissue from the bone in ex vivo condition . In the current study, different machine learning classifiers were examined to find the best possible method to differentiate bone from soft tissues based on LIBS data. These methods include decision tree, K Nearest Neighbor (KNN), linear and quadratic Support Vector Machine (SVM) as well as linear and quadratic discriminant analysis. All classifiers were applied on LIBS data obtained from bone, muscle, and fat tissues using an Nd:YAG laser and an Echelle spectrometer. Confusion matrix and Receiver Operating Characteristic (ROC) curve were obtained for each classifier afterwards. Moreover, in order to estimate the model's performance on new data and also to protect the model against overfitting, cross-validation was applied. All mentioned examinations were performed with MATLAB (R2017b).
The 1st International Electronic Conference on Applied Sciences
This research study aims to decompose bromocresol green (C21H14Br4O5S) using direct irradiation o... more This research study aims to decompose bromocresol green (C21H14Br4O5S) using direct irradiation of a nonthermal atmospheric pressure plasma jet. The absorbance spectra of the bromocresol green solution were measured, as was its electrical conductivity and its pH before and after different durations of irradiation. The results showed that the lengths of conjugated systems in the molecular structure of bromocresol green decreased, and the bromocresol green solution was decolorized as a result of the decomposition of bromocresol green. This result indicates that cold atmospheric pressure plasma jet irradiation is capable of decomposing and can also be used for water purification.
Cold plasma is used as a novel and useful technique for sanitizing and antimicrobial applications... more Cold plasma is used as a novel and useful technique for sanitizing and antimicrobial applications. Although irradiation of plasma on fruits and vegetables can create desired properties, its long-time irradiation may decrease their life. The aim of this study is to evaluate the optimal irradiation time of cold argon plasma for maintaining freshness and safety of lettuce. Fluorescence spectroscopy is used to do so. Lettuce leaves have been induced using ultraviolet LED and their fluorescence spectra have been investigated before and after irradiation of plasma with various durations.
In this paper, design and developing of an optical spectra measuring instrument based on a diffra... more In this paper, design and developing of an optical spectra measuring instrument based on a diffraction grating and a CMOS webcam sensor – without using slit – has been described. The instrument is a slit free spectrometer. This cost effective spectrometer achieves real accuracy of 0.06 nm, suitable for resolving many spectral lines. This system has been tested for resolving the sodium doublet lines at 589 nm. The input of the instrument is a single mode optical fiber and the output of the instrument is a USB port. The software of the system is based on the LabVIEW program.
Silver oxide (AgO) thin films were prepared by using a cylindrical direct current reactive magnet... more Silver oxide (AgO) thin films were prepared by using a cylindrical direct current reactive magnetron sputtering system at 10 −5 torr initial pressure on BK7 glass substrate. Samples deposited for 3, 5 and 7 minutes. Surface characterization of AgO thin films in the nanometer scale can be accurately determined using the atomic force microscopy (AFM) and X-ray diffraction (XRD). The average roughness (R avg), maximum peak to valley height (R t) and root mean square (R rms) roughness are used to analyze the surface morphology of AgO films. The linear optical absorption data were measured in the visible-near infrared spectral regions and the nonlinear refractive index (n 2) of thin films is evaluated by the moiré deflectometery technique. The investigation indicates that, increase in AgO thickness leads to reduction in nonlinear refractive index.
Third conference on laser and its application, 2014
In this paper design and development of 780 nm stable tunable semiconductor laser is reported. Li... more In this paper design and development of 780 nm stable tunable semiconductor laser is reported. Littman configuration has been used in this work. The aim of this research is to find a suitable optical set-up for tuning semiconductor lasers without moving the output laser beam. To do so, a diffractive grating, a mirror, a cooling system, a power supply and opto-mechanical components have been used. The wavelength of the laser beam and the power of that have been measured using a spectrometer and a power meter respectively. Using the typical setup the laser was tuned 52 angstrom.
A cost-effective method employing a smartphone sensor to measure the laser-induced sound pressure... more A cost-effective method employing a smartphone sensor to measure the laser-induced sound pressure level (SPL) has been introduced for lens-to-sample distance (LTSD) adjustment in micro laser-induced breakdown spectroscopy (µLIBS).
Preparation of biological samples for further processing or analysis is generally performed manua... more Preparation of biological samples for further processing or analysis is generally performed manually by means of standard mechanical tools such as scalpels or biopsy punches. While this approach is uncomplicated and swift, it entails constraints such as low, operator-dependent cutting accuracy and reproducibility. Tissue segments surrounding the cut may further suffer mechanical and thermal damage due to shear forces and friction between tool and sample. These hindrances affect procedures both in the laboratory environment as well as within clinical settings. A system has been developed leveraging robotic positioning and laser light for precise, controlled, and contactless tissue ablation, and providing a concise and intuitive graphical user interface. Additionally, sterility of the process is demonstrated, a paramount element for clinical application. The proposed process does not require sterilization of the robotic components or the lasers, easing a prospective integration into existing workflows. In the context of this work, mainly cartilage repair surgery is targeted. The proposed system allows for highly accurate and reproducible shaping of the cartilage lesion area as well as its corresponding engineered cartilage graft, possibly leading to better and faster integration at the defect site. Promising results could be obtained in a first test series with human cartilage samples, validating the functionality of the preparation system and the feasibility of the sterility concept.
New Trends in Medical and Service Robotics. MESROB 2020. Mechanisms and Machine Science, 2021
Echelle spectrometers offer high-resolution (ca. one Angstrom or higher) and wide range (ca. half... more Echelle spectrometers offer high-resolution (ca. one Angstrom or higher) and wide range (ca. half a micron or wider), simultaneously, without having a mechanical moving part. However, they require a complicated optical setup as compared to conventional one-dimensional-dispersion/diffraction spectrometers, e.g., Czerny-Turner. Therefore, the simulation of the Echellogram is required before building the spectrometer. This paper aims to develop an application for visualizing the Echellogram using MATLAB App Designer followed by simulation of the optical aberrations by Zemax OpticStudio to optimize the spectrometer parameters. The developed application provides an interactive graphical interface with a user-friendly dashboard to control and monitor the required parameters. This spectrometer is being used in laser-induced breakdown spectroscopy (LIBS) system application lied of robot-guided laser ablation of biological tissues.
New Trends in Medical and Service Robotics. MESROB 2020. Mechanisms and Machine Science, 2021
The preparation of small-sized biological samples is traditionally performed manually utilizing m... more The preparation of small-sized biological samples is traditionally performed manually utilizing mechanical tools such as scalpels. The main drawbacks of such methods are a lack of accuracy and repeatability of the resulting cuts and damage to the surrounding tissue due to the high interaction forces and the accompanying mechanical stresses. One way to circumvent these issues is to substitute the mechanical tools for laser light. When used in conjunction with a high-accuracy positioning system, such a preparation procedure enables repeatable cutting of arbitrary geometries while largely preserving the integrity of the surrounding tissue. In this paper, a system leveraging the potential of laser-based ablation for bio-sample preparation is proposed. It integrates and synchronizes all key components with extensive safety features and an intuitive user interface, allowing novice operators to perform sample preparations easily. As a first application, the proposed system has been utilized to create microdamages in mouse tail tendon fascicles. Promising results could be obtained, but careful tuning of the laser parameters and further optimization of the mechanical setup is still required to attain the high repeatability striven for.
Minimally invasive laser surgeries that require the use of a flexible endoscope (flexiscope) coul... more Minimally invasive laser surgeries that require the use of a flexible endoscope (flexiscope) could benefit from high-energy nanosecond laser pulses delivered through fibers for real-time tissue characterization and phenotyping. The damage threshold of the fiber's glass material limits the maximum amount of deliverable peak power. To transmit high-energy pulses without damaging the fiber material, large-diameter fibers are typically used, leading to a limited bending radius. Moreover, in a large-core fiber, self-focusing can damage the fiber even if the tip remains intact. In this work, we tested a fused-end fiber bundle combined with a beam shaper capable of delivering more than 20 MW (>100 mJ/5 ns). The fiber bundle was tested over more than eight hours of operation, with different bending radiuses down to 15 mm. The results demonstrate, to the best of our knowledge, the highest peak power delivered through a flexible fiber, for a frequency-doubled Q-switched Nd:YAG laser.
Yb-doped: ytterbium-doped Zn: zinc μLIBS: micro laser-induced breakdown spectroscopy xiii Acknowl... more Yb-doped: ytterbium-doped Zn: zinc μLIBS: micro laser-induced breakdown spectroscopy xiii Acknowledgments Carrying out this study was only possible due to the contribution and cooperation of a number of people. I would like to take this opportunity to acknowledge them. First and foremost, I would like to express my sincere gratitude to my first thesis advisor, Prof. Dr. Azhar Zam, for the opportunity to work on this thesis with the Biomedical Laser and Optics Group (BLOG). It was very exciting to work on such an interesting project with BLOG. I learned about biomedical optics from Azhar, both in his course and also through our weekly meetings. Azhar's door was always open, even for daily discussion. I appreciate the time and the energy he spent on this thesis. I am also thankful to my second thesis advisor, Prof. Dr. Philippe C. Cattin. Philippe helped me regarding the required signal processing and data analysis. I learned about state-of-theart machine learning methods from Philippe, both from his course and also from our monthly meetings. Moreover, I am very grateful to Prof. Dr. Raphael Guzman, another advisor of this thesis, who guided me from a medical point of view. I appreciate the time that he spent during our meetings, despite his busy schedule. Raphael, a surgeon, guided me towards developing a device that would be intuitive and useful for the potential end-users (surgeons). In addition, I would like express gratitude to Prof. Dr. Georg Rauter. For part of the project, we worked together and shared equipment. Thanks to the opportunity to attend international conferences/schools, I was able to meet great researchers in the field, extend my network, and get inspired by my discussions with them. I appreciate those who helped me find the answers to my questions and gave me great ideas, especially Prof. Dr. Steven Jacques from the University of Washington. It was my pleasure to meet, discuss, and learn from Steven. I would like to acknowledge Prof. Dr. Conor L. Evans from Harvard University for kindly being the external expert/examiner of this thesis and evaluating this doctoral thesis. A great thanks also goes to Prof. Dr. Pablo Sinues, for chairing the defense. Additionally, I gratefully acknowledge funding from the Werner Siemens Foundation through the Minimally Invasive Robot-Assisted Computerguided LaserosteotomE (MIRACLE) project. For more than four years, I worked in the department of biomedical engineering (DBE) under the flagship project of the department, MIRACLE. There, I enjoyed working with other students, interns, postdoctoral research associates, and other colleagues from different groups, especially from BLOG (former and current members). Thank you all for the pleasant atmosphere in our working area. We shared facilities, labs, workshop, kitchen, dining area, classrooms, and so on. I enjoyed working in a multidisciplinary area while learning from all my colleagues, especially through our journal club, summer/winter school, retreat, and other meetings. The chance to work directly with a few master students gave me experience, joy, and additional insights, thanks to Antoine, Negin, and Matin. Last but not least, I would like to sincerely thank my friends and family for their generous support and never-ending motivation during my Ph.D.
Optical Methods for Inspection, Characterization, and Imaging of Biomaterials IV, 2019
Anonymized social network graphs published for academic or advertisement purposes are subject to ... more Anonymized social network graphs published for academic or advertisement purposes are subject to deanonymization attacks by leveraging side information in the form of a second, public social network graph correlated with the anonymized graph. This is because the two are from the same underlying graph of true social relationships. In this paper, the maximum a posteriori (MAP) estimates of user identities for the anonymized graph are characterized and sufficient conditions for successful de-anonymization for underlying graphs with community structure are provided. The results generalize prior work that assumed underlying graphs of Erdős-Rényi type, and prove the optimality of the attack strategy adopted in the literature.
In this paper we report the preparation of silver nanoparticle thin films by cylindrical direct c... more In this paper we report the preparation of silver nanoparticle thin films by cylindrical direct current reactive magnetron sputtering (at 10-5 torr initial pressure) and characterization of their nonlinear optical properties. BK7 glasses were selected as substrate. Nonlinear optical response of silver nanoparticle thin films was measured by moiré deflectometry technique using 15 mW He-Ne laser illuminations. All fabricated silver nanoparticle thin films were evaluated using atomic force microscopy and spectrophotometry (from visible region to near infrared region).
In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properti... more In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properties of distilled water is studied. The distilled water was irradiated by a cold Argon plasma jet. The electrical conductivity, PH, and the absorbance of samples were measured before and after irradiation with various durations. The electrical conductivity of distilled water was increased with irradiation time, but its PH was decreased. An increase in the absorbance was observed after each irradiation time interval.
Optical Methods for Inspection, Characterization, and Imaging of Biomaterials IV, 2019
Anonymized social network graphs published for academic or advertisement purposes are subject to ... more Anonymized social network graphs published for academic or advertisement purposes are subject to deanonymization attacks by leveraging side information in the form of a second, public social network graph correlated with the anonymized graph. This is because the two are from the same underlying graph of true social relationships. In this paper, the maximum a posteriori (MAP) estimates of user identities for the anonymized graph are characterized and sufficient conditions for successful de-anonymization for underlying graphs with community structure are provided. The results generalize prior work that assumed underlying graphs of Erdős-Rényi type, and prove the optimality of the attack strategy adopted in the literature.
The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure... more The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure Argon plasma jet. When the plasma jet was directly irradiated onto a Methyl orange solution, the solution was decolorized. PH and absorbance of samples were measured before and after irradiation with various durations. Thus, non-thermal plasma jet irradiation is considered to be capable of decomposing, and can also be used for water purification.
In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properti... more In this work the effect of the Argon atmospheric-pressure plasma jet irradiation on some properties of distilled water is studied. The distilled water was irradiated by a cold Argon plasma jet. The electrical conductivity, PH, and the absorbance of samples were measured before and after irradiation with various durations. The electrical conductivity of distilled water was increased with irradiation time, but its PH was decreased. An increase in the absorbance was observed after each irradiation time interval.
The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure... more The aim of this paper is decolorization of a Methyl orange solution using an atmospheric pressure Argon plasma jet. When the plasma jet was directly irradiated onto a Methyl orange solution, the solution was decolorized. PH and absorbance of samples were measured before and after irradiation with various durations. Thus, non-thermal plasma jet irradiation is considered to be capable of decomposing, and can also be used for water purification.
Lasers have become generally accepted devices in surgical applications, especially as a cutting t... more Lasers have become generally accepted devices in surgical applications, especially as a cutting tool, for cutting both soft and hard tissues including bone (laserosteotomy). It has been shown that applying lasers in osteotomy have important advantages over mechanical tools, including faster healing, more precise cut and functional cutting geometries as well as less trauma [1, 2]. However, the ability of detecting the type of tissue that being cut during surgery can extend the application and safety of laserosteotomes in practice. As a result, the laser could be stopped automatically in case of cutting a tissue that should be preserved. Authors have previously demonstrated that laser-induced breakdown spectroscopy (LIBS) is a potential candidate to differentiate surrounding soft tissue from the bone in ex vivo condition . In the current study, different machine learning classifiers were examined to find the best possible method to differentiate bone from soft tissues based on LIBS data. These methods include decision tree, K Nearest Neighbor (KNN), linear and quadratic Support Vector Machine (SVM) as well as linear and quadratic discriminant analysis. All classifiers were applied on LIBS data obtained from bone, muscle, and fat tissues using an Nd:YAG laser and an Echelle spectrometer. Confusion matrix and Receiver Operating Characteristic (ROC) curve were obtained for each classifier afterwards. Moreover, in order to estimate the model's performance on new data and also to protect the model against overfitting, cross-validation was applied. All mentioned examinations were performed with MATLAB (R2017b).
The 1st International Electronic Conference on Applied Sciences
This research study aims to decompose bromocresol green (C21H14Br4O5S) using direct irradiation o... more This research study aims to decompose bromocresol green (C21H14Br4O5S) using direct irradiation of a nonthermal atmospheric pressure plasma jet. The absorbance spectra of the bromocresol green solution were measured, as was its electrical conductivity and its pH before and after different durations of irradiation. The results showed that the lengths of conjugated systems in the molecular structure of bromocresol green decreased, and the bromocresol green solution was decolorized as a result of the decomposition of bromocresol green. This result indicates that cold atmospheric pressure plasma jet irradiation is capable of decomposing and can also be used for water purification.
Cold plasma is used as a novel and useful technique for sanitizing and antimicrobial applications... more Cold plasma is used as a novel and useful technique for sanitizing and antimicrobial applications. Although irradiation of plasma on fruits and vegetables can create desired properties, its long-time irradiation may decrease their life. The aim of this study is to evaluate the optimal irradiation time of cold argon plasma for maintaining freshness and safety of lettuce. Fluorescence spectroscopy is used to do so. Lettuce leaves have been induced using ultraviolet LED and their fluorescence spectra have been investigated before and after irradiation of plasma with various durations.
In this paper, design and developing of an optical spectra measuring instrument based on a diffra... more In this paper, design and developing of an optical spectra measuring instrument based on a diffraction grating and a CMOS webcam sensor – without using slit – has been described. The instrument is a slit free spectrometer. This cost effective spectrometer achieves real accuracy of 0.06 nm, suitable for resolving many spectral lines. This system has been tested for resolving the sodium doublet lines at 589 nm. The input of the instrument is a single mode optical fiber and the output of the instrument is a USB port. The software of the system is based on the LabVIEW program.
During the past half-century, laser osteotomy has been studied for a broad range of lasers, which... more During the past half-century, laser osteotomy has been studied for a broad range of lasers, which almost covers the entire range of available laser systems in the market, from early unsuccessful experiments with CW lasers to newly developed ultrashort pulse lasers. Although a large variety of laser parameters including wavelength, pulse energy, pulse duration, and repetition rate have been investigated to find an optimum laser system as an alternative osteotomy tool, there is not a universal agreement on a specific type of laser to replace conventional mechanical saws. The only universal agreement is on the speed of cutting (ablation rate) which went to long-pulse Er:YAG and CO2 lasers. Microsecond pulse Er:YAG and CO2 lasers perform osteotomy by inducing efficient photothermal effect to the bone with the help of high absorption peak of water in the bone. However, having a speedy cut is not the only effective parameter to pave the way for transferring lasers to the operating room. Other parameters including cutting with the lowest thermal damage, ability for deep cutting, and compatibility with integrating sensors are among the other determinant parameters. Moreover, being able to be delivered through the fiber optic and as a consequence fit inside the endoscope channel could extend their application from the open surgery to minimally invasive ones. This chapter besides proving the necessary information on the physics behind the laser–bone interaction provides a short review on the history of bone surgery with laser and state-of-the-art studies in this field.
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Papers by Hamed Abbasi