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1.
Rev Gastroenterol Mex (Engl Ed) ; 89(1): 106-120, 2024.
Article in English | MEDLINE | ID: mdl-38485561

ABSTRACT

Immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized advanced cancer management. Nevertheless, the generalized use of these medications has led to an increase in the incidence of adverse immune-mediated events and the liver is one of the most frequently affected organs. Liver involvement associated with the administration of immunotherapy is known as immune-mediated hepatitis (IMH), whose incidence and clinical characteristics have been described by different authors. It often presents as mild elevations of amino transferase levels, seen in routine blood tests, that spontaneously return to normal, but it can also manifest as severe transaminitis, possibly leading to the permanent discontinuation of treatment. The aim of the following review was to describe the most up-to-date concepts regarding the epidemiology, diagnosis, risk factors, and progression of IMH, as well as its incidence in different types of common cancers, including hepatocellular carcinoma. Treatment recommendations according to the most current guidelines are also provided.


Subject(s)
Carcinoma, Hepatocellular , Hepatitis A , Hepatitis , Liver Neoplasms , Humans , Hepatitis/epidemiology , Hepatitis/etiology , Hepatitis/therapy , Carcinoma, Hepatocellular/etiology , Immunotherapy/adverse effects , Liver Neoplasms/complications
2.
Toxicon ; 237: 107549, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38061672

ABSTRACT

In Mexico occurs 25% of all worldwide cases of scorpion sting envenomation (SSE). An outbreak of SSE was identified in Villa Unión, Sinaloa, Mexico. The objective of this study is to describe the outbreak, and prevention and control strategies implemented. The design was a cross-sectional study. Eligibility criteria included confirmed cases (n = 425) identified from the date the outbreak was recognized (from November 08, 2023 to July 10, 2023). The cases from Villa Unión (n = 231) were included for the analysis of epidemiological and clinical findings. The research followed the recommendations of the Initiative Reporting of studies Conducted Using Observational Routinely collected Data (RECORD). Of the total cases (n = 425), 398 (93.6%) were from the municipality of Mazatlán, and 231 (58%) were from Villa Unión. The incidence rate was 13.64 per 1000 persons. The average cases per week was 51.5(SD ± 12). The male-to-female ratio was 3:4, the average age was 30.7(SD ± 19) years. Most of cases occurred in the 25-44 age group. The sting occurred mostly inside houses (n = 200, 86.5%). The predominant symptoms were local pain (95.2%), and local paresthesia (75.8%). The Case fatality rate was 0%. Implementation of prevention and control strategies based on field epidemiological research and scientific evidence are necessary to reduce the incidence and prevent fatal complications.


Subject(s)
Scorpion Stings , Scorpion Venoms , Animals , Male , Humans , Female , Adult , Scorpion Stings/epidemiology , Scorpion Stings/prevention & control , Mexico/epidemiology , Cross-Sectional Studies , Scorpions , Disease Outbreaks/prevention & control
3.
Community Dent Health ; 40(4): 242-247, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-37642340

ABSTRACT

OBJECTIVE: To examine the association between the level of marginalization and tooth loss in adults aged ≥50 years in Mexico. METHODS: A retrospective cross­sectional study was conducted on 2098 adults selected from communities presenting both high and medium levels of marginalization, with data obtained from the annual reports of the Epidemiological Surveillance System of Oral Pathologies 2019-2022. Analysis considered sociodemographic characteristics such as sex, age, and years of education. The prevalence of tooth loss was determined using the Decayed, Missing and Filled teeth (DMFT) index. Negative binomial regression was used to estimate rate ratio (RR) and 95% confidence intervals (CIs), using the presence of lost teeth as an outcome. RESULTS: Most (62.4%) participants had lost at least one tooth, of whom 60.3% had a medium level of marginalization, 28.8% a high level, and 10.9% a very high level. More adults who lived in high or very high marginalization communities had lost teeth [RR=1.19 (95% CI 1.08 - 1.30)] than those living in communities with a medium level of marginalization. More males [RR=1.19 (95% CI 1.09 - 1.31)], adults ≥70 years [RR=1.77 (95% CI 1.57 - 1.99)], people who were illiterate [RR=1.60 (95% CI 1.35 - 1.88)] or who had poor oral hygiene [RR=1.26 (95% CI 1.15 - 1.38)] had also lost teeth. CONCLUSION: High and very high marginalization was associated with tooth loss in adults ≥50 years in Mexico. Effective oral health strategies are required to prevent tooth loss, as are interventions to improve access to and quality of dental services for marginalized communities.


Subject(s)
Tooth Loss , Male , Adult , Humans , Aged , Tooth Loss/epidemiology , Mexico/epidemiology , Cross-Sectional Studies , Retrospective Studies , Oral Health
4.
Article in English | MEDLINE | ID: mdl-33998945

ABSTRACT

This research aims to provide an alternative eco-friendly way to obtain silver species and assess their bactericidal activity. This study reports the synthesis of Ag2O nanoparticles and Ag nanoparticles reduced with a green synthesis method, using a low-cost and commercial Aloe vera extract. The crystalline phases of Ag and Ag2O nanoparticles were analyzed by X-ray diffraction. The oxidation states for both species were determined by X-ray photoelectron spectroscopy. The optical properties of the material were studied through optical absorption, which resulted in well-defined band centered at 545 nm. This result is attributed to the morphology and size of the silver nanoparticles. In addition, antibacterial tests were performed on AgNPs biosynthesized with A. vera with the Kirby-Bauer protocol on Gram-negative and Gram-positive bacteria Escherichia coli and Staphylococcus aureaus, respectively. Moreover, antifungal tests were performed with various species from Candida.


Subject(s)
Aloe , Metal Nanoparticles , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests , Plant Extracts/pharmacology , Silver
5.
Rev Sci Instrum ; 89(10): 10B105, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30399752

ABSTRACT

In order to improve both the density and particularly the temporal resolution beyond previous dispersion interferometers (DIs), a heterodyne technique based on an acousto-optic (AO) cell has been added to the DI. A 40 MHz drive frequency for the AO cell allows density fluctuation measurements into the MHz range. A CO2 laser-based heterodyne DI (HDI) installed on DIII-D has demonstrated that the HDI is capable of tracking the density evolution throughout DIII-D discharges, including disruption events and other rapid transient phenomena. The data also show good agreement with independent density measurements obtained with the existing DIII-D two-color interferometer. The HDI line-integrated density resolution sampled over a 1 s interval is ∼9 × 1017 m-2. Density fluctuations induced by MHD instabilities are also successfully measured by the HDI.

6.
Rev Gastroenterol Mex (Engl Ed) ; 83(1): 31-40, 2018.
Article in English, Spanish | MEDLINE | ID: mdl-28506588

ABSTRACT

INTRODUCTION AND AIMS: Double-balloon enteroscopy has been improving the visualization of the entire intestine for more than a decade. It is a complementary method in the study of intestinal diseases that enables biopsies to be taken and treatments to be administered. Our aim was to describe its main indications, insertion routes, diagnostic/therapeutic yield, and complications. MATERIALS AND METHODS: All patients referred to our unit with suspected small bowel pathology were included. The insertion route (oral/anal) was determined through diagnostic suspicion. The variables measured were: insertion route, small bowel examination extent, endoscopic diagnosis/treatment, biopsy/histopathology report, complications, and surgical findings. RESULTS: The study included 28 double-balloon enteroscopies performed on 23 patients, of which 10 were women and 13 were men (mean age of 52.95 years). The oral approach was the most widely used (n=21), the main indication was overt small bowel bleeding (n=16), and the general diagnostic yield was 65.21%. The therapeutic intervention rate was 39.1% and the procedure was effective in all the cases. The most widely used treatment was argon plasma therapy (n=7). The complication rate was 8.6%; one patient presented with low blood pressure due to active bleeding and another had deep mucosal laceration caused by the argon plasma. CONCLUSIONS: Double-balloon enteroscopy is a safe and efficacious method for the study and management of small bowel diseases, with an elevated diagnostic and therapeutic yield.


Subject(s)
Double-Balloon Enteroscopy , Intestinal Diseases/diagnostic imaging , Intestinal Diseases/therapy , Intestine, Small/diagnostic imaging , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Double-Balloon Enteroscopy/adverse effects , Double-Balloon Enteroscopy/methods , Female , Humans , Male , Middle Aged , Treatment Outcome
7.
Curr Microbiol ; 74(6): 691-701, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28332163

ABSTRACT

The aim of this study was to evaluate the fermentation of dietary fiber from green bean (Phaseolus vulgaris) and prickly pear shell (Opuntia ficus-indica) by Lactobacillus acidophilus LA-5 and Bifidobacterium bifidum 450B growing as mono-culture and co-culture, the fermentation products, and proteins expressed during this process. The analysis of the fermentation profile showed a major growth of bacteria in the culture media of each dietary fiber supplemented with glucose, and particularly B. bifidum 450B at 48 h showed the highest growth. In the case of the co-culture, the growth was lower indicating the possible negative interaction between L. acidophilus LA-5 and B. bifidum 450B and may be due to the less amount of carbohydrates and the high content of non-soluble fiber that affected the nutrients availability for the bacterial strains. The pH changes indicated the presence of short-chain fatty acids (SCFAs), being acetate (46-100%) the main SCFA. Changes in the proteome concerned proteins that are involved in carbohydrate and other carbohydrate pathways. The characterization of the bacteria according to the growth, metabolites, and proteins expressed allows understanding the response to the change of environmental conditions and could be useful to understand L. acidophilus LA-5 and B. bifidum 450B strains' adaptation to specific applications.


Subject(s)
Bifidobacterium bifidum/metabolism , Dietary Fiber/metabolism , Lactobacillus acidophilus/metabolism , Opuntia/metabolism , Phaseolus/metabolism , Environmental Microbiology , Fatty Acids, Volatile/metabolism , Fermentation/physiology
8.
Med Vet Entomol ; 31(1): 36-43, 2017 03.
Article in English | MEDLINE | ID: mdl-27759176

ABSTRACT

The acaricidal effects of 55 strains of Metarhizium anisopliae (Metschnikoff) Sorokin, 1883 (Hypocreales: Clavicipitaceae) isolated from paddocks of cattle farms were evaluated in two Rhipicephalus microplus (Canestrini 1887) (Ixodida: Ixodidae) populations, of which one was multi-resistant and one was susceptible to chemical acaricides. Percentage mortality and reproductive efficiency indices in R. microplus were evaluated by adult immersion tests at a dose of 1 × 108 conidia/mL for each fungal strain. Some strains were selected to calculate lethal concentrations to kill 50% (LC50 ) and 99% (LC99 ) of engorged ticks. Strains MaV22, MaV26 and MaV55 induced 100% mortality in R. microplus on day 14. Strains MaV05, MaV09 and MaV22 caused mortality of >90% from day 12 onward in both tick populations. The most effective acaricidal fungal strain, MaV55, inhibited egg laying by 54.86 and 55.86% in acaricide-resistant and -susceptible R. microplus populations, respectively. None of the fungal strains had statistically significant effects on larval hatching. In conclusion, nine strains of M. anisopliae demonstrated high acaricidal effects against R. microplus and reduced its egg laying. No differences in acaricidal effects were observed between the two populations of ticks tested.


Subject(s)
Cattle Diseases/prevention & control , Metarhizium/physiology , Pest Control, Biological , Rhipicephalus/microbiology , Tick Infestations/veterinary , Animals , Cattle , Cattle Diseases/parasitology , Female , Larva/growth & development , Larva/microbiology , Male , Metarhizium/genetics , Mexico , Rhipicephalus/growth & development , Rhipicephalus/physiology , Tick Control , Tick Infestations/parasitology , Tick Infestations/prevention & control
9.
Rev Sci Instrum ; 87(12): 123502, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28040946

ABSTRACT

A heterodyne detection scheme is combined with a 10.59 µm CO2 laser dispersion interferometer for the first time to allow large bandwidth measurements in the 10-100 MHz range. The approach employed utilizes a 40 MHz acousto-optic cell operating on the frequency doubled CO2 beam which is obtained using a high 2nd harmonic conversion efficiency orientation patterned gallium arsenide crystal. The measured standard deviation of the line integrated electron density equivalent phase resolution obtained with digital phase demodulation technique, is 4 × 1017 m-2. Air flow was found to significantly affect the baseline of the phase signal, which an optical table cover was able to reduce considerably. The heterodyne dispersion interferometer (DI) approach is found to be robustly insensitive to motion, with measured phase shifts below baseline drifts even in the presence of several centimeters of retroreflector induced path length variations. Plasma induced dispersion was simulated with a wedged ZnSe plate and the measured DI phase shifts are consistent with expectations.

10.
Ultrasonics ; 54(6): 1575-80, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24794506

ABSTRACT

The progress of malolactic fermentation in red wines has been monitored by using ultrasonic techniques. The evolution of ultrasonic velocity of a tone burst 1MHz longitudinal wave was measured, analyzed and compared to those parameters of oenological interest obtained simultaneously by analytical methods. Semi-industrial tanks were used during measurements pretending to be in real industrial conditions. Results showed that the ultrasonic velocity mainly changes as a result of the conversion by lactic acid bacteria of malic acid into lactic acid and CO2. Overall, the present study has demonstrated the potential of the ultrasonic technique in monitoring the malolactic fermentation process.


Subject(s)
Fermentation , Lactic Acid/analysis , Malates/analysis , Ultrasonics , Wine/analysis , Food Technology , Volatilization
11.
Rev Sci Instrum ; 84(4): 043501, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23635190

ABSTRACT

One of the systems planned for the measurement of electron density in ITER is a multi-channel tangentially viewing combined interferometer-polarimeter (TIP). This work discusses the current status of the design, including a preliminary optical table layout, calibration options, error sources, and performance projections based on a CO2/CO laser system. In the current design, two-color interferometry is carried out at 10.59 µm and 5.42 µm and a separate polarimetry measurement of the plasma induced Faraday effect, utilizing the rotating wave technique, is made at 10.59 µm. The inclusion of polarimetry provides an independent measure of the electron density and can also be used to correct the conventional two-color interferometer for fringe skips at all densities, up to and beyond the Greenwald limit. The system features five chords with independent first mirrors to reduce risks associated with deposition, erosion, etc., and a common first wall hole to minimize penetration sizes. Simulations of performance for a projected ITER baseline discharge show the diagnostic will function as well as, or better than, comparable existing systems for feedback density control. Calculations also show that finite temperature effects will be significant in ITER even for moderate temperature plasmas and can lead to a significant underestimate of electron density. A secondary role TIP will fulfill is that of a density fluctuation diagnostic; using a toroidal Alfvén eigenmode as an example, simulations show TIP will be extremely robust in this capacity and potentially able to resolve coherent mode fluctuations with perturbed densities as low as δn∕n ≈ 10(-5).

12.
Rev Sci Instrum ; 83(10): 10D707, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23126881

ABSTRACT

A new scintillator-based fast-ion loss detector (FILD) installed near the outer midplane of the plasma has been commissioned on DIII-D. This detector successfully measures coherent fast ion losses produced by fast-ion driven instabilities (≤500 kHz). Combined with the first FILD at ∼45° below the outer midplane [R. K. Fisher, et al., Rev. Sci. Instrum. 81, 10D307 (2010)], the two-detector system measures poloidal variation of losses. The phase space sensitivity of the new detector (gyroradius r(L) ∼ [1.5-8] cm and pitch angle α ∼ [35°-85°]) is calibrated using neutral beam first orbit loss measurements. Since fast ion losses are localized poloidally, having two FILDs at different poloidal locations allows for the study of losses over a wider range of plasma shapes and types of loss orbits.

13.
Rev Sci Instrum ; 82(2): 023114, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21361580

ABSTRACT

Charge exchange spectroscopy is one of the standard plasma diagnostic techniques used in tokamak research to determine ion temperature, rotation speed, particle density, and radial electric field. Configuring a charge coupled device (CCD) camera to serve as a detector in such a system requires a trade-off between the competing desires to detect light from as many independent spatial views as possible while still obtaining the best possible time resolution. High time resolution is essential, for example, for studying transient phenomena such as edge localized modes. By installing a mask in front of a camera with a 1024 × 1024 pixel CCD chip, we are able to acquire spectra from eight separate views while still achieving a minimum time resolution of 0.2 ms. The mask separates the light from the eight spectra, preventing spatial and temporal cross talk. A key part of the design was devising a compact translation stage which attaches to the front of the camera and allows adjustment of the position of the mask openings relative to the CCD surface. The stage is thin enough to fit into the restricted space between the CCD camera and the spectrometer endplate.

14.
Environ Technol ; 31(8-9): 957-66, 2010.
Article in English | MEDLINE | ID: mdl-20662384

ABSTRACT

Extremophiles are microorganisms that possess application possibilities in several industrial fields, including agricultural, chemical, laundry, pharmaceutical, food, petroleum and bioremediation. This work reports the isolation of 19 thermophilic, alkalitolerant and halotolerant bacterial strains from two thermal sites in Veracruz, México: El Carrizal thermal pool and Los Baños hot spring. These strains belong to the Geobacillus, Anoxybacillus and Aeribacillus genera. The strains produce lipases, proteases, and amylases under thermophilic conditions. They may have good potential for application in microbial enhanced oil recovery, since they are thermophilic and halotolerant, produce exopolymers (up to 11.8 mg/mg) and acids, show emulsifying activity (E24 up to 7.5%), and are able to grow in kerosene as carbon source; these strains may also be used in biodesulphurization since they can grow in dibenzothiophene producing 2-hydroxybiphenyl under thermophilic conditions (up to 2.9 mg/L).


Subject(s)
Bacillaceae/isolation & purification , Biodegradation, Environmental , Hot Springs/microbiology , Phylogeny , Amylases/metabolism , Bacillaceae/enzymology , Bacillaceae/metabolism , Base Sequence , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Lipase/metabolism , Mexico , Molecular Sequence Data , Peptide Hydrolases/metabolism , Polymerase Chain Reaction , RNA, Ribosomal, 16S/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Alignment , Sequence Analysis, DNA
15.
Ultrasonics ; 46(3): 270-6, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17462688

ABSTRACT

Within the baking industry, the control of dough properties is required to achieve final product quality and consistency. Traditional methods for dough testing are slow and off-line and do not provide fundamental rheological information. There is therefore a need for the development of fast and on-line instruments capable of providing relevant data for baking. Ultrasonics provide a non-destructive, rapid and low cost technique for the measurement of physical food characteristics. In this work, the water content of dough is investigated using ultrasonic techniques. The capability of ultrasound measurements for discriminating flours for different purposes is also studied. Doughs from more than 30 flours were characterised rheologically using a Chopin Alveograph and a Brabender Extensograph. Ultrasound measurements on the doughs prepared from these flours were also performed. The measurements were correlated, showing that ultrasound was an alternative measurement method to discriminate types of flours for different purposes.


Subject(s)
Algorithms , Flour/analysis , Food Analysis/methods , Image Interpretation, Computer-Assisted/methods , Ultrasonography/methods , Water/analysis , Reproducibility of Results , Sensitivity and Specificity
16.
Appl Opt ; 46(3): 307-11, 2007 Jan 20.
Article in English | MEDLINE | ID: mdl-17228374

ABSTRACT

We report an ultra-widely tunable long-period holey-fiber grating, which combines the wide-range single-mode behavior and transverse strain sensitivity of the holey fibers with the advantages of mechanically induced long-period fiber gratings. We obtain a versatile widely tunable long-period holey-fiber grating with attractive transmission spectral characteristics for optical communications, fiber-based amplifiers, and lasers. The mechanically induced long-period holey-fiber grating shows a continuous tuning range over 500 nm, more than 12 dB depth notches with less than 0.75 dB out-of-band losses, and bandwidth control from 10 to 40 nm.

17.
Ultrasonics ; 44 Suppl 1: e1077-82, 2006 Dec 22.
Article in English | MEDLINE | ID: mdl-16806365

ABSTRACT

In Lamb waves inspection, an air-coupled transmitter transducer is oriented at a specific angle such that it generates a pure Lamb mode which propagates along the structure and interacts with any existing defects. For this inspection system, amplitude losses appears when small inclinations of the tested structure occurs. An important factor which affects directly these losses has been observed, it consists of the Lamb waves beam (LWB) deviation due to this bad alignment. In this work, a simple expression of LWB deviation has been deduced. This expression includes the test structure angle, phase velocity of generated Lamb mode, and the phase velocity of waves propagating in the coupled medium. A(0) Lamb mode is generated and detected in 1 mm thick aluminium plate sample using 1 MHz PZ27 piezoelectric transducers of 20 mm of diameter. Experimental LWB deviation angles are measured for different inclination angles of the test sample. A comparative study is released with theoretical results. For 1 degree of misalignment in the aluminium plate inclination, and transducers separation distance of 35 mm, LWB deviation angle is around 7 degrees and the amplitude is reduced by around 11%. Then, for a large separation distance, we must move the receiver transducer to detect the deviated LWB. It is shown that, for both theoretical and experimental studies, the LWB deviation and its measured amplitude are very sensitive to the alignment of the tested structure with respect to the transmitter-receiver transducers plane. In metal plates it is most satisfactory to use A(0) mode compared with S(0) mode since it is easy to excite and has a large amplitude and small deviation beam angles.

18.
Ultrasonics ; 44 Suppl 1: e1051-5, 2006 Dec 22.
Article in English | MEDLINE | ID: mdl-16797637

ABSTRACT

The viscoelastic properties of dough are of great interest in the baking industry as they affect the quality of the final product. In this work, the viscoelastic properties of dough were investigated using ultrasonic techniques and then compared with traditional methods. It has been shown that ultrasonics provides a non-destructive, rapid and low cost technique for the measurement of physical food characteristics. A common protocol for dough preparation was used for each type of measurement. Experimental results on more than 30 different flour quality and dough processing were presented. The measurements were correlated and compared with traditional dough quality tests. In addition, the capability of ultrasound measurements for discriminating flours for different purposes was also studied, showing the potential of ultrasound as an alternative measurement method to discriminate types of flours for different purposes.


Subject(s)
Flour/analysis , Food Analysis/methods , Food Handling/methods , Image Interpretation, Computer-Assisted/methods , Materials Testing/methods , Ultrasonography/methods , Water/chemistry , Algorithms , Elasticity , Flour/classification , Reproducibility of Results , Sensitivity and Specificity , Viscosity , Water/analysis
19.
Ultrasonics ; 44 Suppl 1: e667-72, 2006 Dec 22.
Article in English | MEDLINE | ID: mdl-16797644

ABSTRACT

Air coupled piezoelectric ultrasonic array transducers are a novel tool that could lead to interesting advances in the area of non-contact laminar material testing using Lamb wave's propagation techniques. A key issue on the development of such transducers is their efficient coupling to air media (impedance mismatch between the piezoelectric material and air is 90 dB or more). Adaptation layers are used in order to attain good matching and avoid possible serious signal degradation. However, the introduction of these matching layers modify the transducer surface behaviour and, consequently, radiation characteristics are altered, making the usual idealization criteria (of uniform surface movement) adopted for field simulation purposes inaccurate. In our system, we have a concave linear-array transducer of 64 elements (electrically coupled by pairs) working at 0.8 MHz made of PZ27 rectangular piezoceramics (15 mm x 0.3 mm) with two matching layers made of polyurethane and porous cellulose bonded on them. Experimental measurements of the acoustic aperture of single excited array elements have shown an increment on the geometrical dimensions of its active surface. A sub-millimeter vibrometer laser scan has revealed an extension of the aperture beyond the supposed physical single array element dimensions. Non-uniform symmetric apodized velocity surface vibration amplitude profile with a concave delay contour indicates the presumed existence of travelling wave phenomena over the surface of the outer array matching layer. Also, asymptotic propagation velocities around 2500 m/s and attenuation coefficient between 15 and 20 dB/mm has been determined for the travelling waves showing clear tendencies. Further comparisons between the experimental measurements of single array element field radiation diagram and simulated equivalent aperture counterpart reveal good agreement versus the ideal (uniform displaced) rectangular aperture. For this purpose an Impulse Response Method (IRM) has been used.

20.
Ultrasonics ; 44 Suppl 1: e1093-100, 2006 Dec 22.
Article in English | MEDLINE | ID: mdl-16797654

ABSTRACT

This work presents an ultrasonic sensor for on-line batter monitoring with low-noise design considerations. The density and the compressibility of the batter vary as a function of mixing time and are strongly related to the quality of the final product. Traditionally, a batter sample of a fixed volume is removed and weighted in order to determine its density. This is a time consuming process. Benefits to the industry of on-line measuring techniques include better control of product quality, improving processing efficiencies and reduction in wastage. In this paper low-noise design considerations are accounted for an ultrasonic sensor based on a piezoceramic disk mounted between two reference buffer rods of acrylic resin to measure the acoustic impedance of the batter. Measuring the acoustic impedance changes of the batter its compressibility and density can be monitored. Spurious echoes generated at different parts of the buffer rods boundary strongly affect accuracy and reliability of the measurements, and are considered as noise. The influence of buffer rods geometry on noise level is studied using simulations and afterwards justified experimentally. Design aspects such as buffer rods length and radius, piezoceramic disk frequency and radius are discussed and their influence on noise level is shown. Finally, strategies for optimum geometry design of the ultrasonic sensor are given.


Subject(s)
Computer-Aided Design , Food Analysis/instrumentation , Image Interpretation, Computer-Assisted/methods , Materials Testing/methods , Models, Theoretical , Transducers , Ultrasonography/instrumentation , Computer Simulation , Equipment Design , Equipment Failure Analysis , Image Enhancement/instrumentation , Image Enhancement/methods , Reproducibility of Results , Sensitivity and Specificity , Ultrasonography/methods
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