Application of Laser Micromachining on Polymeric and Metallic Substrates

LASER (Light Amplification by Stimulated Emission of Radiation) has many applications in engineering, biology, biomedical etc. Recent years, laser micromachining has become a promising technology for mass production of surface texturing on various polymeric substrates and metals. However, excessive roughness of channel surface, lack of control of process parameters and no uniformity of channel geometry are the ongoing challenges. The goal of the study is to determine the effect of laser system parameters on the surface of different kinds of polymers (PMMA, PDMS and Glass) as well as metals (Titanium). There are two specific objectives in this study. The first objective was to determine the effect of laser parameters on different kinds of polymers. A commercial MUSE laser system was used for machining three widely used microfluidic substrates to create microfluidic channels, which consists of a 45W laser tube with three degree of freedom (lateral, longitudinal and vertical). Four laser system parameters - speed, power, focal distance and number of passes are varied to fabricate straight microchannel on glass, PDMS and PMMA. The results show that higher speed produces lower depth while higher laser power produces deeper channel regardless of the substrate materials. The out-of-focus laser cut produces wider but shallower channel. However, for same speed and power, PDMS channel had the roughest surface and PMMA had smoother surface. In PMMA, a uniform and wider channel was produced with the number of passes, which when increased can control the bulging phenomenon. This comprehensive experimental investigation can provide guidance for the substrate material-based mass production of microchannels. The second objective was to investigate the effect of nitriding on a laser textured titanium surface to improve its optical properties for application in solar thermo photovoltaic. Nitriding of titanium alloy samples were carried out in plasma nitriding furnace after laser engraving. Full spectrum high power laser machine was used to make grooves on titanium alloy. The study found that laser textured nitride titanium has better surface properties and increased optical properties when compared to those of non-nitride titanium. For better understanding of the TiN on Ti , X-ray photoelectron spectroscopy (XPS) was carried out before and after plasma treatment. XPS analysis found nitriding has positive influence on the surface characteristics. Nitriding makes the laser grooved Ti surface more reflective compared to those of non-nitriding Ti surface

Efectos de la posición corporal y la sedación en la calidad de la voz

En el ámbito de la Otorrinolaringología, existe una situación en donde la voz juega un papel importante para tomar una decisión intraoperatoria: durante la cirugía de tiroplastia de medialización de la cuerda vocal. Tras la realización de numerosas tiroplastias de medialización con anestesia local y sedación en nuestro Servicio de Otorrinolaringología, sospechamos que el test de voz intraoperatorio no era fiable ya que la voz obtenida durante el mismo no era la misma que la obtenida por el paciente al cabo de varios días de la intervención. Para tener una prueba objetiva de la fiabilidad o no del test de la voz hemos decidido realizar la comparación de la calidad de la voz del paciente en las mismas condiciones quirúrgicas: en posición decúbito supino y bajo los efectos de la sedación. Nuestro objetivo es estudiar si existe influencia de la sedación y la postura en la calidad de la voz y, de ser así, cuantificar dicha influencia. Concretamente pretendemos analizar las características acústicas de la voz de los pacientes en la posición sentada, en decúbito supino y decúbito supino con sedación. Para ello se realizará análisis acústico en las tres condiciones. Se realizará igualmente un estudio subjetivo de la voz bajo los efectos de la sedación. Materiales y Método: Se realiza un estudio prospectivo de un total de 3 muestras de voz por paciente sin patología vocal. Para el registro de la voz se utiliza una grabadora digital con un micrófono unidireccional de alta resolución frecuencial que se coloca a 10 cm de la boca del paciente. Los pacientes dicen su nombre, la posición en la que se encuentra, una frase “al que madruga Dios le ayuda” para el estudio de fraseo, de la claridad articular y del ajuste del tono e intensidad; y luego dicen la vocal /a/ de forma sostenida para el análisis acústico. La grabación se realiza en posición sentada, en decúbito supino sin sedación y en decúbito supino con administración de fármacos sedantes. Los fármacos sedantes utilizados por el anestesista son: Midazolam (0,02-0,05mg/kg 3-5min antes de la prueba de fonación); Fentanilo (0,5-1 µg/kg); y dosis crecientes de Propofol 1% hasta alcanzar el estado de conciencia deseado (0,3-0,5mg/kg). El estado hemodinámico y respiratorio son vigilados; y el nivel de sedación fue monitorizado con 3 sistemas de medida: dos escalas observacionales de sedación: Escala de Ramsay y Escala de Evaluación de Alerta/Sedación por el Observador Modificada; y el Índice Biespectral. Los datos de voz recogidos fueron sometidos a un análisis acústico mediante la aplicación PRAATS. Se realizó una comparación interpersonal de la frecuencia fundamental, los valores de jitter, shimmer y HNR de las 3 posiciones estudiadas realizando un análisis estadístico utilizando las medidas repetidas ANOVA. Los resultados fueron confirmados por la prueba no paramétrica correspondiente (test de Friedman). Resultados: Se han estudiado los datos de 30 pacientes: 17 hombres y 13 mujeres. El rango de edad fue de 18 a 54 años, con una media de 33,4 años. Un único logopeda ha realizado una valoración subjetiva de las muestras de voces de los pacientes bajo los efectos de la sedación y ha encontrado las siguientes características: el habla de todos los pacientes sedados muestra una bradilalia y el tono está descendido en comparación con el paciente sin sedación; además, se observó un patrón articulatorio cercano a lo observado en la disartria atáxica, lo que se conoce como habla de beodo caracterizado por una voz monótona y débil, imprecisión consonántica y ritmo irregular y lento. Los resultados del análisis acústico de la vocal sostenida fueron: POSICIÓN SENTADA: F0= 191 Hz, F0 masculino=140 Hz, F0 femenino= 233 Hz, jitter local=0.23%, jitter rap=0.12%, shimmer local=0.94%, shimmer apq3=0.51%, HNR=32.6 dB. POSICIÓN DECÚBITO SUPINO: F0=189 Hz, F0 masculino=129 Hz, F0 femenino=240 Hz, jitter local=0.25%, jitter rap=0.13%, shimmer local=0.96%, shimmer apq3=0.52%, HNR=32.1 dB. POSICIÓN DECÚBITO SUPINO CON SEDACIÓN: F0=161.1 Hz, F0 masculino=120 Hz, F0 femenino=213Hz, jitter local=0.84%, jitter rap=0.40%. shimmer local=2.6%, shimmer apq3=1.39%, HNR=25.2dB. En el estudio estadístico no se observaron diferencias significativas en los datos acústicos de los grupos de pacientes con respecto a la posición. Los datos del grupo de pacientes sentados y en decúbito supino fueron similares. Se observó que la variable “sedación” afecta significativamente a todos los valores estudiados: descenso en la frecuencia fundamental, aumento del jitter y shimmer, y descenso en el HNR. Por otra parte, los valores de los parámetros promediados: jitter rap y shimmer apq3, mostraron resultados coherentes con los valores del jitter local y shimmer local respectivamente. Conclusiones: 1. Los fármacos Midazolam, Fentanilo y Propofol en la fonación, producen cambios significativos en todos los parámetros estudiados: Descenso en la F0 y aumento en jitter, shimmer locales y suavizados, y un descenso en HNR mean. 2. La posición supina no tiene influencia en los parámetros que caracterizan la voz. En efecto, los datos promedios de análisis acústicos de paciente en decúbito supino sin sedación son similares a los encontrados en pacientes sentados. 3. La sedación produce bradilalia y descenso del tono, además produce un patrón articulatorio cercano a lo observado en la disartria atáxica. 4. Ante la dificultad para evaluar la voz bajo los efectos de la sedación, se plantea la realización de tiroplastia de medialización bajo anestesia general monitorizando la glotis durante el procedimiento. 5. Como una alternativa al uso de anestesia general, el uso de nuevos fármacos sedantes con una influencia menor sobre la fonación debe ser tenido en cuenta. 6. La anestesia local sin sedación puede ser utilizada en pacientes seleccionados

Combination of Machine Learning Algorithms with Concentration-Area Fractal Method for Soil Geochemical Anomaly Detection in Sediment-Hosted Irankuh Pb-Zn Deposit, Central Iran

Prediction of geochemical concentration values is essential in mineral exploration as it plays a principal role in the economic section. In this paper, four regression machine learning (ML) algorithms, such as K neighbor regressor (KNN), support vector regressor (SVR), gradient boosting regressor (GBR), and random forest regressor (RFR), have been trained to build our proposed hybrid ML (HML) model. Three metric measurements, including the correlation coefficient, mean absolute error (MAE), and means squared error (MSE), have been selected for model prediction performance. The final prediction of Pb and Zn grades is achieved using the HML model as they outperformed other algorithms by inheriting the advantages of individual regression models. Although the introduced regression algorithms can solve problems as single, non-complex, and robust regression models, the hybrid techniques can be used for the ore grade estimation with better performance. The required data are gathered from in situ soil. The objective of the recent study is to use the ML model’s prediction to classify Pb and Zn anomalies by concentration-area fractal modeling in the study area. Based on this fractal model results, there are five geochemical populations for both cases. These elements’ main anomalous regions were correlated with mining activities and core drilling data. The results indicate that our method is promising for predicting the ore elemental distribution

Body composition and three indices of physical fitness in freshmen: exercise is of no effect?

Grip strength. back strength, standing trunk flexion and skinfold thickness were measured on 314 freshmen (mean 18.6 years). Body composition was estimated by the method of measuring skinfold thickness. The subjects were asked whether they had belonged to athletic clubs in junior and/or senior high schools or not, and they were divided into four groups with regard to their answers. Of the groups, group A is composed of 94 students who belonged to athletic clubs both in junior and senior high schools and group B is composed of 117 students who did not. The values of groups A and B were compared. The results were as follows: 1) The mean value of fat storage rate (% fat) of all subjects was 21% and 44 per cent of them were judged to be obese. 2) The % fat of growp A was smaller than that of group B. 3) Group A indicated significantly bigger Lean Body Mass (LBM) and LBM/Height-index than group B (P < 0.01). 4) The grip strength and back strength of group A were significantly better than those of group B (P < 0.01). 5) There was no statistical difference in standing trunk flexion between groups A and B. From these results, it seems that exercise in adolescence keeps % fat small. promotes the development of muscle and enhances muscular strength

Geochemical Anomaly Detection in the Irankuh District Using Hybrid Machine Learning Technique and Fractal Modeling

Prediction of elemental concentrations is essential in mineral exploration as it plays a vital role in detailed exploration. New machine learning (ML) methods, such as hybrid models, are robust approaches infrequently used concerning other methods in this field; therefore, they have not been examined properly. In this study, a hybrid machine learning (HML) method was proposed based on combining K-Nearest Neighbor Regression (KNNR) and Random Forest Regression (RFR) to predict Pb and Zn grades in the Irankuh district, Sanandaj-Sirjan Zone.. The aim of the proposed study is to employ the hybrid model as a new method for grade distribution. The KNNR-RFR hybrid model results have been applied for the Pb and Zn anomalies classification. The hybrid (KNNR-RFR) method has shown more accurate prediction outputs based on the correlation coefficients than the single regression models with 0.66 and 0.54 correlation coefficients for Pb and Zn, respectively. The KNN-RF results were used to classify Pb and Zn anomalies in the study area. The concentration-area fractal model separated the main anomalous areas for these elements. The Pb and Zn main anomalies were correlated with mining activities and core drilling data. The current study demonstrates that the hybrid model has a substantial potential for the ore elemental distribution prediction. The presented model expresses a promising result and can predict ore grades in similar investigations

Characteristics of body composition in male students with inactive life

This study was made to find the characteristics of body composition, aerobic capacity, and grip strength in male students with inactive life. For the purpose above, we studied those of three groups; male students with inactive life, male students belonging to a college tennis club and male personnel with sedentary life. Body composition was estimated by a method of measuring skinfold thickness. Aerobic capacity was measured by carrying out submaximal work with Isopower Ergometer in a bicycle shape. The results were as follows 1) The indices of aerobic capacity represented well the usual exercise-levels by figures 2) LBM influenced aerobic capacity for inactive men without distinction of the two ages 3) As the value of LBM increased，all subjects had a tendency to put forth grip strength further 4) A positive correlation was found between LBM and BFM of. inactive students (Pく0.05) 5) Only inactive students had a significant correlation between aerobic capacity and BFM(P <0.05) From the above, we indicated that inactive students were in a poor state of exercise. As this result, for inactive students, BFM was found to be rather large, and aerobic capacity also was found to be on low level. Aerobic capacity, however, was within the permitted limit. Moreover, we could conclude the following: For the male students with inactive life, the function of BFM on cardiorespiratory system would be weight for providing them with a certain exercise intensity, not having a time for exercise in particular form. Thus it was considered that BFM has an effect on aerobic capacity

合金化溶融亜鉛めっきホットスタンプ鋼板の耐食性およびクラック形成挙動に関する研究

信州大学(Shinshu university)博士（工学）この博士論文は、次の学術雑誌論文を一部に使用しています。 / Materials Transactions 64(1) :252-259(2023); doi:10.2320/matertrans.MT-C2022004 © 2022 Japan Society of Corrosion Engineering/ 材料と環境 70(5) :170-176(2021); doi:10.3323/jcorr.70.170 © 2021 公益社団法人 腐食防食学会Thesis小成　佳史. 合金化溶融亜鉛めっきホットスタンプ鋼板の耐食性およびクラック形成挙動に関する研究. 信州大学, 2023, 博士論文. 博士（工学）, 甲第805号, 令和05年03月20日授与.doctoral thesi

白内障患者水晶体における臨床的因子と蛋白質メチル化酵素

It has been suggested that protein carboxyl-o-methyltransferase (PCMT) [EC. 2. 1. 1. 24] is involved in removal of abnormal accumulation of amino acids (D-Asp, L-isoasp) in longlived protein, e.g., lens protein, resulted from spontaneous racemization and deamidation by aging. To study the relationship of PCMT activities and cataractogenesis, the PCMT activities were determined in 24 lenses obtained from 22 cataract patients and compared with several clinical factors. The activity of PCMT (pmol/mg protein/min) was distributed from 0.48 to 1.62 (mean 0.99). No significant difference in the activities was observed among age, sex, preoperative visual acuity, and cataract type. However, systemic complications (DM; diabetes mellitus, HT; hypertension) seemed to effect significantly on the activity. That is, the lens enzyme activities in DM or HT group were lower than those in normal group. These results suggest that the decrease in the PCMT activity of cataractous lens in patients with systemic disease (HT and/or DM) may promote the age-associated accumulation of atypical aspartyl residues in aged lens proteins

DAMPING ANALYSIS TO IMPROVE THE PERFORMANCE OF SHUNT CAPACITIVE RF MEMS SWITCH

This paper describes the significance of the iterative approach and the structure damping analysis which help to get better the performance and validation of shunt capacitive RF MEMS switch. The micro-cantilever based electrostatic ally actuated shunt capacitive RF MEMS switch is designed and after multiple iterations on cantilever structure a modification of the structure is obtained that requires low actuation voltage of 7.3 V for 3 µm deformation. To validate the structure we have performed the damping analysis for each iteration. The low actuation voltage is a consequence of identifying the critical membrane thickness of 0.7 µm, and incorporating two slots and holes into the membrane. The holes to the membrane help in stress distribution. We performed the Eigen frequency analysis of the membrane. The RF MEMS switch is micro machined on a CPW transmission line with Gap-Strip-Gap (G-S-G) of 85 µm - 70 µm - 85 µm. The switch RF isolation properties are analyzed with high dielectric constant thin films i.e., AlN, GaAs, and HfO2. For all the dielectric thin films the RF MEMS switch shows a high isolation of -63.2 dB, but there is shift in the radio frequency. Because of presence of the holes in the membrane the switch exhibits a very low insertion loss of -0.12 dB

制作モデルの表象にみる子供のインテリア観について

In this study, we tried to extract children's view of interior space through modeling of a room. As a result, the investigation revealed the fact that children understand interior space gradually from nearby things to the whole room. There is a sex difference in the view of interior that girls understand practically, while boys do fancifully. On the whole, the first-year students of an elementary school don't know how to understand interior, the second years begins to be interested in color and figures and the third and forth years in patterns. And in the third and forth years students deepen their understanding of ceiling, in the fifth they get to think much of the formation of windows and in the junior high school days, the three-dimensional understanding of space is though to be almost completed