Optical Feedback Mechanism for Minimally Invasive Laserosteotome

Laserosteotomy has become a generally accepted method in surgical applications. However, the method still suffers from a lack of information about the type of tissue currently being ablated. Therefore, critical structures of the body near the focal spot of the laser beam are prone to inadvertent ablation. This issue can be solved by connecting the laserosteotome to an optical detection setup, which can differentiate various types of tissues, especially bone from soft connective tissues. This study examines the applicability of laser-induced breakdown spectroscopy (LIBS) as a potential technique to differentiate bone from surrounding soft tissue (fat and muscle). Additionally, the efficiency of the developed system to detect laser-induced thermal effects on the bone (dehydration and carbonization) has been investigated. In this experiment, fresh porcine femur bone, muscle, and fat were used. The beam of frequency-doubled Nd:YAG laser with nanoseconds pulse duration was used to ablate the tissue samples and generate the plasma. The plasma light emitted from the ablated spot, which is associated with the recombination spectra of ionized atoms and molecules, was collected with an optical fiber and sent to an Echelle spectrometer for resolving the atomic composition of the ablated sample. The results showed that LIBS is capable to differentiate between tissues and also detect laser-induced thermal damages with high accuracy

A Study on the Effect of Temperature in Synthesis and Magnetic Properties of W-Type Hexaferrites Barium Nanocomposites with Radar Wave Absorbing Properties

Absorption and attenuation of electromagnetic waves spread in air by radar or other equipments is considered as a main problem in military and industrial issues. With increasing development of radars and the raise of detection to solve the issue of camouflage, various methods have been offered including active removal, inactive removal, and absorbing materials and shaping deviate waves. To prepare absorbing materials used in aerospace industry, selecting a wide range of magnetic materials, conducting flow components and dielectric materials applied as matrix are regarded as deterministic factors. The present study attempts to investigate the effect of temperature in synthesis and magnetic properties of w-type hexaferrites barium Nano composites with radar wave absorbing properties. For this purpose, some salts such as cobalt, iron, and barium are employed to produce w-type hexaferrites barium Nano powder (Ba (CoxZn1+x)2 Fe16O27) using sol-gel auto-combustion via microwave. Compared to the other methods, the applied method has the advantages of more affordability, shorter synthesis time, pure specimen, lack of pollution, homogenized final phase, and lack of the need to high temperatures. The produced Nano powders are then analyzed through X-ray diffraction (XRD) in different temperatures revealing a close phase to W-type. A scanning electron microscope (SEM) is also used to determine the particles` size at Nano scale. Moreover, the vibrating magnetometer device is applied in order to depict the hysteresis loop of produced powders so that the rings are longer at the temperatures of 800 ° C and 950 ° C indicating higher magnetic saturation property

A Study on the Effect of Temperature in Synthesis and Magnetic Properties of W-Type Hexaferrites Barium Nanocomposites with Radar Wave Absorbing Properties

Absorption and attenuation of electromagnetic waves spread in air by radar or other equipments is considered as a main problem in military and industrial issues. With increasing development of radars and the raise of detection to solve the issue of camouflage, various methods have been offered including active removal, inactive removal, and absorbing materials and shaping deviate waves. To prepare absorbing materials used in aerospace industry, selecting a wide range of magnetic materials, conducting flow components and dielectric materials applied as matrix are regarded as deterministic factors. The present study attempts to investigate the effect of temperature in synthesis and magnetic properties of w-type hexaferrites barium Nano composites with radar wave absorbing properties. For this purpose, some salts such as cobalt, iron, and barium are employed to produce w-type hexaferrites barium Nano powder (Ba (CoxZn1+x)2 Fe16O27) using sol-gel auto-combustion via microwave. Compared to the other methods, the applied method has the advantages of more affordability, shorter synthesis time, pure specimen, lack of pollution, homogenized final phase, and lack of the need to high temperatures. The produced Nano powders are then analyzed through X-ray diffraction (XRD) in different temperatures revealing a close phase to W-type. A scanning electron microscope (SEM) is also used to determine the particles` size at Nano scale. Moreover, the vibrating magnetometer device is applied in order to depict the hysteresis loop of produced powders so that the rings are longer at the temperatures of 800 ° C and 950 ° C indicating higher magnetic saturation property

LIBS for Smart Laserosteotomy

Over the past several years laserosteotomes have become a generally accepted device in various surgical applications. In laserosteotomy, the type of tissue being cut has to be identified, otherwise critical structures of the body under or near the focal spot of the laser beam are prone to inadvertently ablation. Laser-Induced Breakdown Spectroscopy (LIBS) is a potential tool for detecting the type and properties of the ablating tissue. This study examines the applicability of LIBS as a potential technique to differentiate bone from surrounding soft tissue (fat, muscle and bone marrow). Moreover, LIBS has been evaluated to detect the bone carbonization during the ablation process. In these experiments, fresh porcine femur tissues were used as samples. A beam of a nanosecond frequency-doubled Nd:YAG laser was used to ablate the tissue samples and generate the plasma. The plasma light emitted from the ablated spot, which corresponds to the recombination spectra of ionized atoms and molecules, was collected with a collection optic (including a reflective light collector and a UV-enhanced fiber optic) and was sent to an Echelle spectrometer to resolve the atomic composition of the ablated sample. Several spectra from different points of different samples of each group were collected. Then, to determine the elemental composition of the ablated tissues, the atomic emissions in the recorded LIBS spectra of all classes were compared to known spectra of atoms available in the NIST atomic emission database. Afterward, Discrimination Function Analysis (DFA) was employed to classify different groups of the samples. Finally, the Receiver Operating Characteristic (ROC) was performed, and the Area Under Curve (AUC) were calculated. Differences in the recorded spectra of the results are potentially enabled a real-time tissue classification in smart laserosteotomy

Investigating the effects of green marketing on development of brand fascination

This paper investigates the effects of different green marketing on brand fascination for a south Korean electronic producer, Samsung. The proposed study designs two questionnaires, one for measuring the effects of green marketing and the other for brand fascination in Likert scale. Cronbach alphas for green marketing and brand fascination are calculated as 0.72 and 0.79, respectively. The study has been implemented among 385 regular customers of Samsung’s electronic devices. Using Spearman correlation ratio as well as stepwise regression analysis, the study has concluded that two components of green marketing including green product and green promotion influence positively on brand fascination, positively

Investigating the effects of different levels of CRM investment on development of brand equity

This paper investigates the effects of different marketing strategies including basic marketing, reactive marketing, accountable marketing, proactive marketing and partnership marketing on brand equity. The proposed study uses two questionnaires, one for measuring the effects of different marketing strategies and the other for brand equity in Likert scale. Cronbach alphas for brand equity and marketing strategies are calculated as 0.71 and 0.86, respectively. The study has been implemented among 385 regular customers of a Picnic Gas distributer in city of Karaj, Iran. Using Spearman correlation ratio as well as stepwise regression analysis, the study has detected that there were positive and meaningful relationship between marketing strategies and brand equity

The Impact of Individualized Homework Assignment on Iranian Intermediate EFL Learners’ Motivation

This study was designed to investigate the effectiveness of applying individualized homework assignments on Iranian intermediate level EFL learners’ motivation. To achieve this objective, 60 learners in the 16-21 age range who were studying at two private language institutes in Rasht, Iran, were selected from 122 participants based on their performance on QPT. The participants were randomly assigned to experimental and control groups. A pretest piloted before with an accepted reliability index was administered to both groups. Next, the experimental group received the treatment for 20 sessions (doing homework materials specifically designed based on each learner’s interests and preferred learning style). Meanwhile, the control group received a placebo which was the use of exercises in the workbook of the coursebook American English File 3 (Second Edition) as homework assignments. The posttest of motivation was then administered to both groups. The results showed significantly higher scores on motivation test for experimental group at the end of the course. Based on the findings of this study, language teachers can utilize individualized homework assignments to motivate their learners for doing their homework more willingly

Gold Nanoparticles: Synthesising, Characterizing and Reviewing Novel Application in Recent Years

AbstractIn this paper we report the synthesis of gold nanoparticles during laser ablation of a metal gold plate in distilled water. The experiments were performed with a first harmonic (1064nm, 6ns, 10Hz) output of a Nd:YAG laser varying the operative fluency between 5Jcm-2 and 15Jcm-2. The results indicate that gold nanoparticles are synthesized at room temperature.In this paper we give an overview of the properties of gold relevant to its potential application in molecular-scale devices absorption spectroscopy and Transmission Electron Microscopy (TEM) were employed to determine the optical properties and size of gold nanoparticles. And novel applications of gold nanoparticles have been studied in various fields

Threatened fishes of the world: Paracobitis vignai Nalbant and Bianco, 1998 (Nemacheilidae)

Paracobitis vignai is a Nemacheilid loach endemic to the Sistan basin. It occurs in Helmand River and its related reservoirs in Sistan-va-Baluchistan Province in southeastern Iran and probably in Afghanistan. This species is currently endangered due to habitat loss or degradation, damming and droughts. Therefore, this paper reviews the available data on taxonomy and distribution of P. vignai, provides its morphometric features, and recommends actions for its conservation

LIF Spectroscopy of Fruits: Study of Excitation Wavelength Independence

In fluorescence spectroscopy, fluorescence emissiongenerally occurs from the excited state with the lowest energy. This is known as "Kasha's rule" and is a general principle with only a few rare exceptions. As a consequence,the emission wavelength is independent of the excitation wavelength. In order to select an appropriate excitation source in fluorescence spectroscopy,it is very important to know the relation between the excitation source wavelength and the emission wavelength. The aim of this paper isto study the excitation-wavelength-independent fluorescence emission of some fruits. To do so, a fluorescence spectrometer controlled by labVIEW software was developed forcollecting the fluorescence spectra ofsome famous fruits.A semiconductor laser and light emitting diodes with different wavelengths was used as the excitation sources