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Callens D. SP-0681 Immobilisation in the rapidly changing world of radiotherapy: Now and into the future. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)04005-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Chen B, Callens D, Campistron P, Moulin E, Debreyne P, Delaplace G. Monitoring cleaning cycles of fouled ducts using ultrasonic coda wave interferometry (CWI). Ultrasonics 2019; 96:253-260. [PMID: 30745025 DOI: 10.1016/j.ultras.2018.12.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 10/16/2018] [Accepted: 12/21/2018] [Indexed: 06/09/2023]
Abstract
Fouling in heat exchangers is the buildup of deposits on the solid surfaces. These deposits reduce the eco-efficiency of the processing equipment and increase the risk of subsequent surface contamination with the formation of biofilms. In the agro-food and water supplier sectors, which are our main concern, fouling on the hot walls of processing heat exchangers is a common occurrence and requires frequent cleaning cycles to ensure hygiene requirements are met. This results in a considerable ecological footprint. Sensors and diagnostic tools for monitoring fouling are thus of utmost importance to ensure the rational validation of the cleaning end-point and to decrease the environmental impact of the cleaning cycles. In this paper, a non-destructive ultrasonic monitoring technique using coda waves and the associated signal processing was tested to monitor the evolution over time of a deposit layer on a solid wall during cleaning. To ascertain the feasibility of the method, a piece of wax of controlled thickness was deposited to simulate the initial fouling state and a cleaning cycle was launched. The decorrelation coefficient was used as an indicator to monitor fouling. This article presents the principle of this unprecedented technique for measuring the degree of fouling. The results of the experiments show that this non-destructive monitoring technology is sensitive to changes in fouling and that the decorrelation coefficient curves are in agreement with the cleaning kinetics captured using a video camera, thus ascertaining the pertinence of the diagnostic tool proposed.
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Affiliation(s)
- B Chen
- IEMN UMR-CNRS 8520, Département Opto-Acousto-Electronique, 59313 Valenciennes, France
| | - D Callens
- IEMN UMR-CNRS 8520, Département Opto-Acousto-Electronique, 59313 Valenciennes, France
| | - P Campistron
- IEMN UMR-CNRS 8520, Département Opto-Acousto-Electronique, 59313 Valenciennes, France
| | - E Moulin
- IEMN UMR-CNRS 8520, Département Opto-Acousto-Electronique, 59313 Valenciennes, France.
| | - P Debreyne
- INRA UR638, Processus aux Interfaces et Hygiène des Matériaux, BP 20039, 59651 Villeneuve d'Ascq, France
| | - G Delaplace
- INRA UR638, Processus aux Interfaces et Hygiène des Matériaux, BP 20039, 59651 Villeneuve d'Ascq, France
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Collier N, Debreyne P, Delaplace G, Chen B, Callens D, Campistron P, Nongaillard B. Contribution of the shear wave ultrasonic reflectometry to the stickiness measurements. Ultrasonics 2018; 89:187-194. [PMID: 29860194 DOI: 10.1016/j.ultras.2018.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/28/2018] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Today, non-invasive quantification of the adhesion of a deposit to a surface is always a challenge and, unfortunately, few tools are available in this area. This is an obstacle, in several industrial processes, to the identification of conditions limiting the fouling and to the establishment of eco-efficient cleaning strategies. In this paper, a non-invasive ultrasonic technique was developed in the aim of characterizing the adhesion of viscoelastic fluids or solid deposited on a substrate. We adopted the idea that the more a deposit is difficult to clean the more adherent it is. From this point of view the value of the reflection coefficient of an ultrasonic shear wave informs us about the adhesion of the deposit on a surface. A large bibliography on the adhesion measurement is given. Then the principle of ultrasonic test is presented and cares required for the measurement of the reflection coefficient are widely discussed. The ultrasonic reflection coefficients obtained with different controlled samples covering a wide range of interfaces (liquid/substrate, solid/substrate) are presented and compared with other indicators of adhesion. All the data on various samples showed that the ultrasonic test is a tool to discriminate non-destructively a large range of interface quality, allowing ranking according to the adhesive strength.
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Affiliation(s)
- N Collier
- INRA UR638, Processus aux Interfaces et Hygiène des Matériaux, BP 20039, 59651 Villeneuve d'Ascq, France
| | - P Debreyne
- INRA UR638, Processus aux Interfaces et Hygiène des Matériaux, BP 20039, 59651 Villeneuve d'Ascq, France
| | - G Delaplace
- INRA UR638, Processus aux Interfaces et Hygiène des Matériaux, BP 20039, 59651 Villeneuve d'Ascq, France
| | - B Chen
- IEMN UMR-CNRS 8520, Département Opto-Acoustique Electronique, 59313 Valenciennes, France
| | - D Callens
- IEMN UMR-CNRS 8520, Département Opto-Acoustique Electronique, 59313 Valenciennes, France
| | - P Campistron
- IEMN UMR-CNRS 8520, Département Opto-Acoustique Electronique, 59313 Valenciennes, France.
| | - B Nongaillard
- IEMN UMR-CNRS 8520, Département Opto-Acoustique Electronique, 59313 Valenciennes, France
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Carlier J, Toubal M, Li S, Campistron P, Callens D, Thomy V, Senez V, Nongaillard B. High Frequency Acoustic Reflectometry for Solid/Liquid Interface Characterization: Application to Droplet Evaporation. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.phpro.2015.08.285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Li S, Carlier J, Lefebvre F, Campistron P, Callens D, Nassar G, Nongaillard B. Optimization of high Frequency 45̊ Acoustic Mirrors for Lab on Chip Applications. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.phpro.2015.08.190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Callens D, Sarrazyn R, Evens W. Signum, a new fungicide for control of leaf diseases in outdoor vegetables. Commun Agric Appl Biol Sci 2005; 70:199-207. [PMID: 16637178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
During three years, the new fungicide Signum, containing 6.7% pyraclostrobine + 26.7 % boscalid and developed by BASF. has been evaluated in leek, carrots and cabbages in several outdoor field experiments under practical conditions and during one year in outdoor lettuce. In leek, Phytophthora porri is one of the major leaf diseases causing lesions on differ ent places on the leaves, resulting in at least extra labour costs for trimming or even worse sometimes resulting in complete crop loss. So far, crop protection consists of repeated applications of fungicides especially during autumn and winter. Pyraclostrobin + boscalid has been evaluated in comparison with the fungicides mancozeb, mancozeb + metalaxyl-M and azoxystrobin. The progress of the disease during the growth season is discussed. For all parameters evaluated, pyraclostrobin + boscalid gave comparable or even better results than reference products. Especially during 2003, a small drop of the activity of benalaxyl against P. porri has been observed after repeated applications. In carrots, Erisiphe heraclei and Alternaria dauci are both the most common leaf diseases causing yield and quality loss. During periods of very high pressure of A. dauci, pyraclostrobin + boscalid, applied in a three weeks interval, revealed a superior activity compared with triazole references or compared with azoxystrobin. Against E. heraclei, a good control but also a clear dose response activity have been observed with pyraclostrobin + boscalid. Yield gain was approximately 30 ton /ha compared wih untreated. In Brussels sprouts, good efficacy was obtained against Mycosphaerella spp., Albugo candida and Alternaria spp. In outdoor lettuce Botrytis cinerea and Sclerotinia sclerotiorum are the most important diseases causing crop damage and reducing the quality of the heads. Pyraclostrobin + boscalid was evaluated in comparison with the standard fungicide iprodione. The plant protection was better with the new fungicide pyraclostrobin + boscalid.
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Affiliation(s)
- D Callens
- Provincial Onderzoeks- en Voorlichtingscentrum voor Land- en Tuinbouw, Ieperseweg 57, BE-8800 Rumbeke, Belgium
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Myrdycz A, Callens D, Kot K, Monchau F, Radziszewski E, Lefebvre A, Hildebrand HF. Cells under stress: a non-destructive evaluation of adhesion by ultrasounds. Biomol Eng 2002; 19:219-25. [PMID: 12202186 DOI: 10.1016/s1389-0344(02)00035-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The adhesion process plays a major role in the development of osteoblastic cells on various substrates used in orthopaedic applications such as metals, bioceramics, or glass. High frequency and low power ultrasounds seem to be an appropriate tool for an evaluation of interface mechanical properties. Is it a non-destructive method? We investigated osteoblastic cell cultures, maintained in their medium with high frequency, bulk longitudinal waves. The influence of both acoustical frequency and acoustical power on cell adhesion is evaluated by cell detachment ratio and re-adhesion ratio. We demonstrate the existence of a power threshold depending on the frequency, allowing optimal cellular detachment and re-adhesion. Finally, a qualitative study of the detachment phenomena is performed by use of scanning electron microscopy (SEM), Confocal Laser Scanning Microscopy and cytochemical labelling.
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Affiliation(s)
- A Myrdycz
- Department of Opto-Acousto-Electronics (UMR CNRS 8520), North Institute of Electronics and Microelectronics (IEMN), University of Valenciennes, Le Mont Houy, 59313 Valenciennes Cedex 9, France
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Abstract
The aim of this paper is to present the potentialities of ultrasounds to investigate the mechanical properties of a cell/substrate interface. The adhesion process plays a major role in the development of osteoblastic cells on various substrates used in orthopedic applications such as metals, bioceramics, etc. Particularly, cell adherence appears to be a critical factor in the colonization process. High-frequency and low-power ultrasounds seem to be an appropriate tool for a nondestructive evaluation of interface properties. First, we present the results obtained with bulk longitudinal and shear waves under an arbitrary incidence over an aluminum-adhesive interface. This study was performed for an industrial application of bonding. The results clearly show the sensitivity of shear waves for the evaluation of the adhesion quality owing to the shear solicitations at the interface they induce. A model of ultrasound interactions with a boundary subject to varying degrees of adhesion has been developed and compared to the experiments. Second, we investigated osteoblastic cell cultures with a high-frequency acoustic microscope working at 50 MHz. The images obtained in the shear mode reveal a better contrast than those obtained in the longitudinal mode. For the time being, these results are qualitative, and theoretical models have to be developed according to the point of view of biologists.
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Affiliation(s)
- A Myrdycz
- Institut d'Electronique et de Microélectronique du Nord, Département d'Opto-Acousto-Electronique, University of Valenciennes, France.
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Rouchaud J, Neus O, Callens D, Bulcke R. Isoxaflutol herbicide soil persistence and mobility in summer corn and winter wheat crops. Bull Environ Contam Toxicol 1998; 60:577-584. [PMID: 9557195 DOI: 10.1007/s001289900664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- J Rouchaud
- Laboratory of Phytopharmacy, Catholic University of Louvain, Louvain-la-Neuve, Belgium
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Rouchaud J, Neus O, Bulcke R, Callens D, Dekkers T. Isoxaben soil biodegradation in pear tree orchard after repeated high dose application. Arch Environ Contam Toxicol 1997; 33:247-251. [PMID: 9353201 DOI: 10.1007/s002449900250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
During the past nine years, each of the plots of a pear tree orchard were treated annually with the same herbicide treatment. The following herbicide treatments were compared, each being made by application of a mixture of two or three herbicides: 1a, no herbicide at all, weeds being hoed (control 1a); 2, diuron + paraquat 3 + 1 kg/ha; 3, simazine + paraquat 2 + 1 kg/ha; 4, isoxaben + diuron + paraquat 0.5 + 1.6 + 1 kg/ha; and 5, isoxaben + simazine + paraquat 0.5 + 1.25 + 1 kg/ha. In March 1996, one year after the final orchard herbicide treatment, isoxaben could not be detected in the soils of any field plots; isoxaben was incorporated at 0.74 mg/kg in the loamy soils sampled separately in each of the field plots, and the soils were incubated in the laboratory. Isoxaben soil half-lives were 92 days in the soils treated previously with herbicide treatments 1a, 2, or 3 and 42 days in the soils treated with herbicide treatments 4 and 5. The repeated isoxaben treatments applied in the past thus enhanced the isoxaben soil biodegradation; diuron, simazine, and paraquat had no influence on this rate enhancement. On the other hand, herbicide treatments 4 and 5 were applied in the orchard in April 1996 on the corresponding plots treated in this manner for the last nine years. Isoxaben + paraquat 0.5 + 1 kg/ha was applied simultaneously on other plots (control 1b) not treated in the past with isoxaben. During the growth season in the orchard, the isoxaben soil half-lives in the control plots 1b was 101 days, and 41 days in the plots where herbicide treatments 4 or 5 were applied.
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Affiliation(s)
- J Rouchaud
- Laboratory of Phytopharmacy, Catholic University of Louvain, 3, Place Croix du Sud, SCI 15D, 1348 Louvain-la-Neuve, Belgium
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Rouchaud J, Neus O, Callens D, Bulcke R. Enhanced soil biodegradation of prosulfocarb herbicide in barley crop. Bull Environ Contam Toxicol 1997; 58:752-757. [PMID: 9115138 DOI: 10.1007/s001289900397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- J Rouchaud
- Laboratory of Phytopharmacy, Catholic University of Louvain, Belgium
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Wyndaele JJ, Van Eetvelde B, Callens D. Comparison in young healthy volunteers of 3 different parameters of constant current stimulation used to determine sensory thresholds in the lower urinary tract. J Urol 1996; 156:1415-7. [PMID: 8808885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE We compared different parameters of constant current stimulation used for evaluation of sensation in the lower urinary tract. MATERIALS AND METHODS In 24 healthy male and 9 healthy female volunteers (mean age 24 years) sensory thresholds were determined at the same site on the bladder, urethra and skin with 3 different parameters of constant current stimulation (2.5, 20 and 95 Hz. at pulses 1, 1 and 0.5 msec., respectively) given at random. RESULTS Thresholds were highly reproducible at all sites and with the 3 currents. Thresholds obtained with 2.5 Hz. were significantly greater than those obtained with 20 Hz. at all sites or 95 Hz. at the bladder and male urethra. No significant difference was found between thresholds in the bladder or urethra with 20 and 95 Hz. In 2 volunteers no bladder sensation was elicited with 2.5 Hz. even at 33 mA. A reproducible elevated threshold was found with 20 and 95 Hz. No intravesical pressure increase occurred during stimulation. CONCLUSIONS Absolute values of sensory thresholds vary in relation to the site of stimulus and stimulation parameters in healthy young subjects. Low frequency current (2.5 Hz.) is less easily perceived and, therefore, would seem less suitable for evaluation of electrical sensation in the lower urinary tract. Thresholds obtained with frequences of 20 and 95 Hz. were not statistically different.
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Affiliation(s)
- J J Wyndaele
- Department of Urology, University Hospital Antwerp, Belgium
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Wyndaele J, Eetvelde VB, Callens D. Comparison in Young Healthy Volunteers of 3 Different Parameters of Constant Current Stimulation Used to Determine Sensory Thresholds in the Lower Urinary Tract. J Urol 1996. [DOI: 10.1016/s0022-5347(01)65604-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- J.J. Wyndaele
- Department of Urology, University Hospital Antwerp, Antwerp, Belgium
| | - Van B. Eetvelde
- Department of Urology, University Hospital Antwerp, Antwerp, Belgium
| | - D. Callens
- Department of Urology, University Hospital Antwerp, Antwerp, Belgium
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Rouchaud J, Thirion A, Callens D, Bulcke R. Soil dissipation of the post-emergence herbicide sulcotrione in maize crops treated with organic fertilizers. Bull Environ Contam Toxicol 1996; 57:398-405. [PMID: 8672065 DOI: 10.1007/s001289900204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- J Rouchaud
- Laboratory of Phytopharmacy, Catholic University of Louvain, 3, Place Croix du Sud, SCI. 15D, 1348 Louvain-la-Neuve, Belgium
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