Control with Micro Precision in Abrasive Machining through the Use of Acoustic Emission Signals

Fernando Torres,James Griffin 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

By using acoustic emission (AE) it is possible to control minuscule grit and workpiece interaction during micro and macro grindingprocesses. The single grit (SG) tests used in this work display that the intensities from approaching grit in air display an increasingintensity. As the grit interacts with the workpiece by forming a scratch, different intensities are recorded with respect to a changingmeasured depth of cut (DOC). It is these different recorded intensities of approaching touch (as the grit get closer the AE intensitiesincrease), touch (rubbing) and mechanisms with greater plastic deformation (ploughing and cutting) that need to be identified forgreater precision (especially approaching grit as this allows verification of CNC position). By extracting AE signals, correlated toboth elastic and plastic material removal mechanisms, this affords a robust and reactive setup for controlling micro machiningprocesses. Such control methods can be useful for grinding dressing ratios as well as against deviation errors. Two different aerospacematerials (CMSX4 and Titanium64) were used for the same SG tests to verify the control regime is robust and not just materialdependent. In addition, both Neural Networks (NN) and Classification and Regression Trees (CART) based rules were used toimplement a real-time simulation displaying how such a control system could be implemented.

Son Pyong-hui y el Movimiento del primero de Marzo

Torre, Fernando Torres de la 서울大學校 스페인中南美硏究所 1996 이베로아메리카硏究 Vol.7 No.-

La Charreri>a

Torre, Fernando Torres de la,Torres de la Torre, Fernando 한국외국어대학 서반아어과 1986 AULA Vol.4 No.1

Control with micro precision in abrasive machining through the use of acoustic emission signals

Fernando Torres,James Griffin 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.16 No.5

By using acoustic emission (AE) it is possible to control minuscule grit and workpiece interaction during micro and macro grinding processes. The single grit (SG) tests used in this work display that the intensities from approaching grit in air display an increasing intensity. As the grit interacts with the workpiece by forming a scratch, different intensities are recorded with respect to a changing measured depth of cut (DOC). It is these different recorded intensities of approaching touch (as the grit get closer the AE intensities increase), touch (rubbing) and mechanisms with greater plastic deformation (ploughing and cutting) that change needs to need to be identified for greater precision (especially approaching grit as this allows verification of CNC position). By extracting AE signals, correlated to both elastic and plastic material removal mechanisms, this affords a robust and reactive setup for controlling micro machining processes. Such control methods can be useful for grinding dressing ratios as well as against deviation errors. Two different aerospace materials (CMSX4 and Titanium64) were used for the same SG tests to verify the control regime is robust and not just material dependent. In addition, both Neural Networks (NN) and Classification and Regression Trees (CART) based rules were used to implement a real-time simulation displaying how such a control system could be implemented.

Growth performance, carcass traits, muscle fiber characteristics and skeletal muscle mRNA abundance in hair lambs supplemented with ferulic acid

( Edgar Fernando Peña-torres ),( Candelario Castillo-salas ),( Ismael Jiménez-estrada ),( Adriana Muhlia-almazán ),( Etna Aida Peña-ramos ),( Araceli Pinelli-saavedra ),( Leonel Avendaño-reyes ),( Cin 한국축산학회 2022 한국축산학회지 Vol.64 No.1

Ferulic acid (FA) is a phytochemical with various bioactive properties. It has recently been proposed that due to its phytogenic action it can be used as an alternative growth promoter additive to synthetic compounds. The objective of the present study was to evaluate the growth performance, carcass traits, fiber characterization and skeletal muscle gene expression on hair-lambs supplemented with two doses of FA. Thirty-two male lambs (n = 8 per treatment) were individually housed during a 32 d feeding trial to evaluate the effect of FA (300 and 600 mg d^-1) or zilpaterol hydrochloride (ZH; 6 mg d^-1) on growth performance, and then slaughtered to evaluate the effects on carcass traits, and muscle fibers morphometry from Longissimus thoracis (LT) and mRNA abundance of β2-adrenergic receptor (β₂-AR), MHC-I, MHC-IIX and IGF-I genes. FA increased final weight and average daily gain with respect to non-supplemented animals (p < 0.05). The ZH supplementation increased LT muscle area, with respect to FA doses and control (p < 0.05). Cross-sectional area (CSA) of oxidative fibers was larger with FA doses and ZH (p < 0.05). Feeding ZH increased mRNA abundance for β₂-AR compared to FA and control (p < 0.05), and expression of MHC-I was affected by FA doses and ZH (p < 0.05). Overall, FA supplementation of male hair lambs enhanced productive variables due to skeletal muscle hypertrophy caused by MHC-I up-regulation. Results suggest that FA has the potential like a growth promoter in lambs.

Preparation of air stable nanoscale zero valent iron functionalized by ethylene glycol without inert condition

Ruiz-Torres, Claudio Adrian,Araujo-Martí,nez, René,Fernando,Martí,nez-Castañ,ó,n, Gabriel Alejandro,Morales-Sá,nchez, J. Elpidio,Guajardo-Pacheco, Jesú,s Mar& Elsevier 2018 Chemical Engineering Journal Vol.336 No.-

<P><B>Abstract</B></P> <P>The use of nanoscale zero-valent iron has been widely studied in recent years for potential application in environmental engineering, due to its affinity for a large number of contaminants, which may be in aqueous or solid phase, and for its abundance, which makes it an attractive tool for environmental remediation. However, there exist some variables in the production of nZVI that complicate the generation of the material, such as the complex methodologies of synthesis and the cost of inert conditions like nitrogen or argon atmosphere, which have the purpose of preventing the oxidation and reducing the instability of the material under ambient conditions. As a simple and economical synthesis methodology, this work presents an optimized method to synthesize functionalized nanoscale zero-valent iron (nZVI) using ethylene glycol (EG) without need for inert conditions. The coordination of iron ions during the nZVI-EG synthesis and the functionalization mechanism of the nanoparticles were identified by UV–Vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). Functionalized nZVI showed increased dispersibility due to the effects of steric repulsion between the grafted polymers. Ethylene glycol functionalized nZVI showed stability against oxidation during dry atmospheric condition, while significant oxidation was observed in the case of unfunctionalized nZVI. This result was also correlated with actual capacity for contaminant reduction. Therefore, the possibility was verified of using ethylene glycol in an effective surface modification method to prepare air stable nZVI for environmental remediation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Air-stable nZVI could be prepared by ethylene glycol without inert condition. </LI> <LI> Smaller and narrower size distribution could be obtained by functionalization. </LI> <LI> The nZVI-EG exhibited a protection effect against oxidation in oxic conditions. </LI> <LI> The reaction kinetics was not hindered by the organic functionalization agent EG. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Assessment of a Simpler Friction Factor in an Algebraic Solution for Adiabatic Coiled Capillary Tubes

Thiago Torres Martins Rocha,Sara Isabel De Melo Resende,H elio Augusto Goulart Diniz,Fernando Antônio Rodrigues Filho,Raphael Nunes De Oliveira 대한설비공학회 2020 International Journal of Air-Conditioning and Refr Vol.28 No.4

In this work, the performance of an existing algebraic solution for adiabatic coiled capillary tubes, in subcritical cycles, is investigated. However, the C-M&N friction factor, commonly used, was replaced by Schmidt friction factor, which is less complex. Two existing dimensionless correlations were also evaluated for comparison. To assess the effect of altering the friction factor, experimental data collected in the literature were used as reference. Analyzing the present results and that with C-M&N friction factor, it was observed that adopting the Schmidt friction factor does not cause a relevant impact on the solution. The deviations of the predicted versus experimental mass flow rates were comprised in a range between –8% and 12%, with average deviation (AD), absolute average deviation (AAD) and root mean square (RMS) error of –0.1%, 2.7% and 3.4%, respectively. The empirical correlations presented unsatisfactory results, with maximum deviation around 40%. Therefore, it was concluded that using the Schmidt friction factor is adequate to reduce the complexity of the algebraic solution and to maintain the accuracy.

Intergenerational and Intragenerational Equity in the United States and their Implications for Korean Society

Kim Jung-Ki,Fernando Torres-Gil 韓國老年學會 2000 한국노년학 Vol.20 No.2

A cost-effective method to prepare size-controlled nanoscale zero-valent iron for nitrate reduction

Claudio Adrian Ruiz-Torres,Rene Fernando Araujo-Martinez,Gabriel Alejandro Martinez-Cas,J. Elpidio Morales-Sanchez,Tae-Jin Lee,Hyun-Sang Shin,Yuhoon Hwang,Abel Hurtado-Macias,Facundo Ruiz 대한환경공학회 2019 Environmental Engineering Research Vol.24 No.3

Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 ㎚), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 ㎚ and the predominance (> 90%) of particles with sizes < 6.10 ㎚. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.

Effects of Semen Processing on Sperm Function: Differences between Swim-Up and Density Gradient Centrifugation

Hernández-Silva Gabriela,López-Torres Aideé S.,Maldonado-Rosas Israel,Mata-Martínez Esperanza,Larrea Fernando,Torres-Flores Víctor,Treviño Claudia L.,Chirinos Mayel 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.4

Purpose: Andrology research has evolved notoriously in the latest years, particularly since male factor contribution to couple infertility has been undoubtedly demonstrated. However, sperm function investigations results are sometimes contradictory, probably as a result of the use of different sperm processing techniques. In this work, we underwent a systematic functional comparison of human sperm samples simultaneously processed by swim-up and density gradient centrifugation, which are the preferred sperm processing methods used in basic and clinical laboratories. Materials and Methods: To compare functional characteristics of sperm isolated by swim-up and density gradient centrifugation followed by incubation at different times under capacitating conditions. Results: Semen samples processed in parallel by these two procedures resulted in sperm preparations with significant differences in redox state, spontaneous intracellular calcium oscillations, hyperactivation, protein tyrosine phosphorylation, and acrosome reaction responsivity to calcium ionophore. Such differences showed time-dependent specific patterns for spontaneous intracellular calcium oscillations, hyperactivation and protein tyrosine phosphorylation. Sperm retrieved by density gradient centrifugation showed more hyperactivation and tyrosine phosphorylation than swim-up sperm, suggesting a higher degree of capacitation. Conclusions: Our results account for functional differences observed in spermatozoa processed with these two methods and therefore may contribute to a better interpretation of outcomes obtained in different laboratories as well as to improve experimental designs aimed to study sperm physiology and fertility potential.