Academic literature on the topic 'Pulp detachment'
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Journal articles on the topic "Pulp detachment"
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KEMPPAINEN, KALLE, OSSI LAITINEN, MIKA KÖRKKÖ, MIRJA ILLIKAINEN, and JOUKO NIINIMÄKI. "Analysis of prewetting conditions for old magazine papers before pulping in deinking." June 2011 10, no. 6 (July 1, 2011): 7–15. http://dx.doi.org/10.32964/tj10.6.7.
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Recent research on deinking with an old newspaper (ONP)/old magazine (OMG) furnish and with a 100% ONP furnish demonstrates that the ink-substrate bond might not be sufficiently weakened within the short wetting time used in conventional pulping. If enough time for paper wetting is allowed before pulping, better ink detachment could be achieved when compared with conventional pulping. However, it has remained unclear how different prewetting conditions affect ink detachment and fragmentation when processing OMG-based furnish, such as supercalendered (SC) and lightweight coated (LWC) papers. In this study, we investigated the influence of prewetting time, temperature, and chemistry on the optical properties of rotogravure printed SC and heatset offset printed LWC-based pulps, when prewetting is performed without mechanical action before the actual pulping process. Different prewetting times (0-24 h) and temperatures (25°C-65°C) were tested with conventional alkaline soap chemistry and with reduced alkaline soap chemistry. The results for SC pulp support earlier findings and reveal that ink detachment can be improved by wetting SC paper with conventional deinking liquor before pulping. With SC paper, the longer the prewetting time, the lower the amount of attached ink after pulping. Ink that is printed on a coating (LWC paper) is easily detachable; therefore, its release cannot be improved by prewetting. Ink fragmentation was similar with and without prewetting treatment for SC- and LWC-based pulps.
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PAOLIELLO, FLAVIO. "Corrosion damage and in-service inspection of retractable sootblower lances in recovery boilers." October 2021 20, no. 10 (November 1, 2021): 655–62. http://dx.doi.org/10.32964/tj20.10.655.
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Several reports of accidents involving serious mechanical failures of sootblower lances in chemical recovery boilers are known in the pulp and paper industry. These accidents mainly consisted of detachment and ejection of the lance tip, or even of the entire lance, to the inside of the furnace, towards the opposite wall. At least one of these cases known to the author resulted in a smelt-water explosion in the boiler. In other events, appreciable damage or near-miss conditions have already been experienced. The risk of catastrophic consequences of the eventual detachment of the lance tip or the complete lance of a recovery boiler soot-blower has caught the attention of manufacturers, who have adjusted their quality procedures, but this risk also needs to be carefully considered by the technical staff at pulp mills and in industry committees. This paper briefly describes the failure mechanisms that prevailed in past accidents, while recommending inspection and quality control policies to be applied in order to prevent further occurrences of these dangerous and costly component failures. Digital radiography, in conjunction with other well known inspection techniques, appears to be an effective means to ensure the integrity of sootblower lances in chemical recovery boilers used in the pulp and paper industry.
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Chipili, Chitalu, and Clayton Bhondayi. "The role of the pulp-froth interface on particle detachment and selectivity." Advances in Colloid and Interface Science 287 (January 2021): 102296. http://dx.doi.org/10.1016/j.cis.2020.102296.
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Zhang, Songping, Olof Norrl�w, Joanna Wawrzynczyk, and Estera Szwajcer Dey. "Poly(3-Hydroxybutyrate) Biosynthesis in the Biofilm of Alcaligenes eutrophus, Using Glucose Enzymatically Released from Pulp Fiber Sludge." Applied and Environmental Microbiology 70, no. 11 (November 2004): 6776–82. http://dx.doi.org/10.1128/aem.70.11.6776-6782.2004.
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ABSTRACT Glucose, enzymatically released from pulp fiber sludge, was combined with inorganic salts and used as a growth medium for Alcaligenes eutrophus, a gram-negative strain producing poly(3-hydroxybutyrate) (PHB). By controlling the concentrations of the inorganic salts in the growth medium, almost 78% of the cell mass was converted to pure PHB. Efforts were made to find conditions for bacterial growth in the form of a biofilm on a cheap and reusable carrier. A number of positively charged carriers were tested, and the anion exchanger DEAE-Sephadex A-25 was chosen as a microcarrier for packed-bed biofilm cultures of A. eutrophus. Conditions for attachment, growth, and detachment were established. Biofilm formation on the microcarrier is strongly dependent on the ionic strength of the attachment medium. In order to achieve formation of the biofilm and its recovery from the microcarrier, the ionic strengths of the attachment and the detachment media were varied. Low ionic strength was tested for attachment, and high ionic strength was tested for detachment. Although biofilm formation in the packed-bed reactor is limited, the volumetric yield of cells based on the void volume of the packed bed is comparable with the batch culture yield.
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GOTO, SHISEI, HIROMICHI TSUJI, ISAO ONODERA, KEIGO WATANABE, and KATSUMASA ONO. "Cavitation-jet deinking: A new technology for deinking of recovered paper." September 2014 13, no. 9 (October 1, 2014): 9–17. http://dx.doi.org/10.32964/tj13.9.9.
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A new method and in-house device for treating secondary fiber were developed. The method is based on the fluid-jet cavitation technique. In this apparatus, pulp suspension was injected into the reacting vessel by using a high-speed jet that produced cavitation bubbles around the jet. The impact of the collapse of cavitation bubbles detached ink, binder, and other contaminants from fiber surfaces. The effects of the cavitating jet (CV-jet) treatment on deinking of the pulp from mixed office waste (MOW) and old newsprint/old magazines (ONP/OMG) mixture were studied. The basic experiments on cavitation control showed that the intensity and region of cavitation were controlled by the jet velocity and the pressure difference in the reacting vessel. The CV-jet generated broad ultrasound waves; the conventional ultrasonic apparatus generated an intrinsic frequency. The MOW test results showed that CV-jet, even without chemicals and high temperature, decreased dirt speckles and reached almost the same dirt reduction level as the mill kneader. Moreover, the CV-jet minimized fiber damage during the process. This yielded pulp handsheets giving much higher paper strength compared with pulp from the kneader. The ONP/OMG test revealed that CV-jet was superior to mill disperser in terms of ink detachment and stickies dispersion.
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van Deventer, J. S. J., D. Feng, and A. J. Burger. "Transport phenomena at the pulp–froth interface in a flotation column: II. Detachment." International Journal of Mineral Processing 74, no. 1-4 (November 2004): 217–31. http://dx.doi.org/10.1016/j.minpro.2003.11.002.
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GOTO, SHISEI, HIROMICHI TSUJI, ISAO ONODERA, KEIGO WATANABE, and KATSUMASA ONO. "Pilot-scale development of cavitation-jet deinking." September 2014 13, no. 9 (October 1, 2014): 19–25. http://dx.doi.org/10.32964/tj13.9.19.
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A new deinking method for paper recycling using a fluid-jet cavitation technique has been developed. An in-house, laboratory-scale device revealed that cavitation-jet treatment without deinking chemicals decreases ink and dirt content in deinked pulp. As the next step, a pilot-scale deinking device, 10 times larger than the laboratory device, was designed. The specifications of the pilot device were determined by experiments using the laboratory device. The pilot device was installed in a deinked pulp mill, and the effects of multijet nozzles within a reacting vessel, depending on consistencies of the deinked pulp, were investigated. The operation stability of the device was examined as well. The shape and size of an effective cavitation zone for ink detachment were changed by nozzle diameter and upstream pressure of the jet. The results from batch cavitation treatment of deinked pulp revealed that the device could treat the pulp with consistency up to 3.8% by weight and decrease attached ink, dirt specks, and macrostickies without addition of deinking chemicals. Hydrophobic colloidal materials, including microstickies after cavitation treatment, became more difficult to attach to hydrophobic surfaces. Continuous cavitation treatment gave similar results to those from batch treatment. Two types of multiple nozzle arrangements, parallel and cross-nozzle modes, decreased dirt specks to the same level as a mill disperser. On the other hand, the reductions of macrostickies by those modes were higher than with the disperser. Because treatment consistency increased more than 3%, treatment efficiency and device performance were significantly improved. This could be a big step toward practical use of cavitation treatment.
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Yuan, Rongcai, Ulrich Hartmond, and Walter J. Kender. "Physiological Factors Affecting Response of Mature `Valencia' Orange Fruit to CMN-Pyrazole. II. Endogenous Concentrations of Indole-3-Acetic Acid, Abscisic Acid, and Ethylene." Journal of the American Society for Horticultural Science 126, no. 4 (July 2001): 420–26. http://dx.doi.org/10.21273/jashs.126.4.420.
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Endogenous concentrations of IAA and ABA in the peel, pulp, seed, and abscission zone of mature `Valencia' oranges [Citrus sinesis (L.) Osbeck] were determined by high-performance liquid chromatography and enzyme-linked immunosorbent assay from early November 1998 to mid-June 1999. Ethylene production of mature `Valencia' oranges during the same period was determined by gas chromatography. IAA concentrations in the pulp and seed were three to five times lower than those in the peel over the 7-month observation period. IAA concentration in the abscission zone and peel was high from late April to mid-May, the period of less responsiveness to abscission chemicals. ABA concentration in the pulp was low over the entire observation period. ABA concentration in the abscission zone and peel was low during the less responsive period. Ethylene production was always low except for a slight increase during late December and early February. The IAA to ABA ratio was high in the fruit abscission zone during the less responsive period. Fruit detachment force of CMN-pyrazole-treated fruit was positively correlated with the ratio of endogenous IAA to ABA or endogenous IAA, but negatively to endogenous ABA in the fruit abscission zone. These data suggest the balance between IAA and ABA in the fruit abscission zone may be an important factor in determining sensitivity and thereby the response of mature `Valencia' orange fruit to abscission chemicals. Chemical names used: abscisic acid (ABA); indole-3-acetic acid (IAA); 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-pyrazole).
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Kang, Hoyeon, Yongkwon Chae, Koeun Lee, Hyo-seol Lee, Sungchul Choi, and Okhyung Nam. "Long-Term Outcome of Reattached Tooth Fragment in Permanent Anterior Teeth of Children and Adolescents." JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY 48, no. 1 (February 28, 2021): 42–49. http://dx.doi.org/10.5933/jkapd.2021.48.1.42.
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This study aimed to evaluate the long-term outcomes of teeth treated with reattachment technique in children and adolescents. Twenty seven permanent anterior teeth from 21 patients treated with fragment reattachment were evaluated. Clinical photos and medical records were used to assess treatment outcomes. Effect of pulp treatment and the ratio of fragment on success rate were statistically analyzed. Detachment of fragment was observed in 17 teeth, and their duration of retention was 21.41 ± 23.39 months. Repeated trauma was found to be the most frequent causes of failure. Pulp treatment before reattachment did not affect the success rate (<i>p</i> > 0.05). The mean ratio of fragment was 0.482 ± 0.147, and the success rate was affected by the ratio of fragment (<i>p</i> = 0.018). The median retention time of the teeth was 72 months if the ratio was under 0.5, and 8 months for that of the others. A significant correlation was found between the ratio of fragment and retention time (<i>p</i> = 0.003). Reattachment can be a predictable treatment option for crown fracture in anterior teeth in children and adolescents when a fracture involves less than 50% of the clinical crown.
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HUANG, KAIWU, KRIS STRICKLAND, AARON NOBLE, ROE-HOAN YOON, and CESAR BASILIO. "A new method of studying the fundamental mechanisms involved in pigment liberation from recycle papers." October 2022 21, no. 10 (November 1, 2022): 533–40. http://dx.doi.org/10.32964/tj21.10.533.
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Deinking flotation is the most efficient and widely used method of removing ink particles from printed papers to improve the recyclability. A prerequisite for successful deinking flotation is detachment of pigments from paper fibers, a subprocess known as liberation. The degree of liberation is usually determined via hyperwashing tests, which are costly and time consuming. Furthermore, they provide no information on the fundamental mechanisms controlling liberation. In the present work, we developed a new method in which potentials of the particles in a pulp are measured and analyzed. If pigments are not liberated from paper fibers, a frequency distribution plot gives a single peak, while two peaks appear when they are liberated. One can readily determine the degrees of liberation from the peak positions and peak heights. In addition, the potential data can be used to construct disjoining pressure isotherms using the DLVO theory that are useful to better understand the fundamental mechanisms involved and the roles of different reagents used to improve pigment liberation.
Dissertations / Theses on the topic "Pulp detachment"
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Forsström, Jennie. "Fundamental aspects on the re-use of wood based fibres : porous structure of fibres and ink detachment /." Stockholm, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-84.
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Laitinen, O. (Ossi). "Utilisation of tube flow fractionation in fibre and particle analysis." Doctoral thesis, Oulun yliopisto, 2011. http://urn.fi/urn:isbn:9789514294495.
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Abstract The tube flow fractionation method used in this thesis is one of the field flow separation processes, which can be used to fractionate particles over the entire size range of pulp particles (1–5000 µm) with high selectivity. The classification of particles in different size categories enables the fractional analysis of samples. According to this thesis, particle length is the most significant individual shape factor in particle classification for different size categories using tube flow fractionation. The fractional approach investigated in this thesis offers an interesting tool for investigating different pulp types more thoroughly than many other conventional laboratory methods such as the Bauer-McNett classification of pulp or the hyperwashing of DIP samples. The tube flow fractionator can be used to replace the Bauer-McNett device to determine the mass percentages of pulp sample fractions. Furthermore, pulp fractionation can be done quickly with the tube flow fractionation method and the results achieved are also comparable to the Bauer-McNett classification. The utilisation of recycled raw material in paper production is likely to continue to increase in the near future. This fact leads to even more heterogeneous raw material becoming one of the major challenges in deinked pulp production. Changes in the quality of raw material such as age or paper type have a notable effect on the deinkability of pulp. This creates a need to develop new methods for measuring DIP properties; in particular, information about the ink-releasing rate and ink particle size would be useful in controlling the deinking process. If DIP is fractionated with tube flow fractionation, it is possible to study the ink size distribution and ink content inside each fraction, thus obtaining fractional information on the ink release rate and ink particle size. A comparison of different DIP raw materials and process solutions can be performed with the fractional analysis presented in this thesis. It was noticed that aging had a negative effect on the slushing rate of LWC and SC raw material, but not on ONP. The ink detachment of LWC and SC was poorer when furnishes aged. However, the aging of LWC and SC did not result in a significant fragmentation of ink particles. In contrast, strong ink fragmentation is typical of aged ONP furnishes. The fractional approach gives new insight into deinking mechanisms, and could be essential for finding optimal deinking process conditions, for example in a pulping process or flotation environment. The method would also enable enhanced control of different DIP process stages and would contribute to creating a more efficient process with better waste management and improved final product qualityTiivistelmä Tässä työssä käytetyllä putkivirtausfraktioinnilla, joka on eräs kenttävirtausfraktioinnin sovellus, voidaan luokitella hyvin selektiivisesti erikokoisia (1–5000 µm) partikkeleita. Partikkeleiden luokittelu partikkelikooltaan erikokoisiin jakeisiin mahdollistaa näytteiden fraktionaalisen analyysin. Tässä työssä todettiin, että partikkelin pituus on tärkein yksittäinen muototekijä, joka vaikuttaa partikkelien fraktioitumiseen eri kokoluokkiin putkivirtausfraktioinnissa. Työssä tutkittu fraktionaalinen menetelmä mahdollistaa paljon syvällisemmän paperisulppujen analyysin kuin monet perinteiset laboratorioanalyysit, kuten Bauer McNett -luokittelu tai siistausmassojen hyperpesu. Putkivirtausfraktionaattorilla voidaan korvata Bauer McNett -luokittelu massasulppujen eri fraktioiden massaosuuksien määrityksessä. Lisäksi massojen fraktiointi putkivirtausfraktionaattorilla on nopea ja luotettava menetelmä, ja saadut tulokset ovat vertailukelpoisia Bauer McNett -luokittelulla saatujen tulosten kanssa. Kierrätyspaperiraaka-aineen kasvava hyödyntäminen paperin tuotannossa jatkunee lähivuosina. Tämä tarkoittaa, että siistausprosessissa hyödynnettävän raaka-aineen laatuvaihtelut aiheuttavat entistä suurempia haasteita. Muutokset raaka-aineen laadussa, kuten paperin ikä tai käytetty paperityyppi vaikuttavat huomattavasti massan siistattavuuteen. Näistä tekijöistä johtuen on tarvetta kehittää uusia mittausmenetelmiä määrittää siistausmassojen ominaisuuksia. Erityisesti musteen irtoaminen ja mustepartikkeleiden kokojen määritys voisi auttaa musteenpoistoprosessin ohjauksessa. Jos siistausmassa fraktioidaan putkivirtausfraktionaattorilla, on mahdollista tutkia mustekokojakaumia ja mustepitoisuuksia eri fraktioissa ja näin saadaan tietoa mustepartikkeleiden irtoamisesta ja mustepartikkelien koosta. Fraktionaalisella analyysilla on tässä työssä tutkittu eri siistausmassojen raaka-aineita ja prosessiratkaisuja. Työssä huomattiin, että LWC- ja SC-paperin ikääntymisellä on negatiivinen vaikutus paperin sulputtumisnopeuteen pulpperissa, mutta sanomalehtipaperilla vastaavaa ilmiötä ei huomattu. Musteen irtoaminen oli huonompaa LWC- ja SC-paperin ikääntyessä. Kuitenkaan ikääntyminen ei vaikuttanut LWC- ja SC-paperin mustepartikkeleiden pilkkoutumiseen merkittävästi. Sen sijaan sanomalehtipaperilla havaittiin voimakasta mustepartikkeleiden pilkkoutumista raaka-aineen ikääntyessä. Fraktionaalinen tutkiminen antaa uuden näkökulman musteenpoistomekanismeihin ja voisi olla hyödyllinen, kun etsitään optimaalisia musteenpoisto-olosuhteita esimerkiksi pulpperointiin tai flotaatioon. Menetelmä voisi mahdollistaa myös eri siistausprosessin osaprosessien säätämisen. Lisäsi menetelmän avulla voitaisiin saada tehostettua prosesseja ja parannettua laatua sekä saada prosesseista ympäristöystävällisempiä
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Olarte, Mantilla Sandra Milena. "Relationships between berry sensory assessment and wine quality in Vitis vinifera L. Shiraz." Thesis, 2015. http://hdl.handle.net/2440/100721.
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Berry sensory assessment (BSA) is a technique that can help grapegrowers and winemakers make decisions about harvest date and grape product allocation. BSA as a structured technique has been used by grapegrowers, winemakers and researchers for the last thirteen years. However the number of studies reporting results of the effect of viticultural practices on berry sensory characteristics and wine quality is limited. This thesis examined the BSA technique through four different studies. Study one is a combined review literature review and industry survey paper in which the methodology of Berry Sensory Assessment is presented and the research conducted using BSA is discussed. It also presents the results of a survey channeled to Australian grapegrowers and Australian and New Zealand winemakers about their experience using BSA, their perceptions on its use and their suggestions for improving the methodology. It was evident from the survey that 90% of grapegrowers and winemakers use BSA and they want to understand the link between BSA and wine quality. These results demonstrated the importance of BSA for wine producers and the need for further improvement. The aim of study number two was to determine if berry sensory attributes and berry compositional variables could predict wine sensory attributes, wine compositional variables and wine quality in Shiraz. The analyses of berry and wine sensory attributes, compositional measures and wine quality using partial least squares regression and Pearson’s correlations from two seasons identified several relationships between berry sensory attributes and wine sensory attributes and quality. A significant negative relationship was identified between seed bitterness and wine savoury spice flavour for the two seasons. The berry sensory attribute pulp detachment from the skin was identified as a predictor of various wine sensory attributes (eg. the harder to detach skin from the pulp the higher intensity for wine body colour, rim colour and dark berry aroma) and wine quality scores in the season 2011. The aim of study number three was to determine if berries stored at -20°C for three months could be used instead of fresh berries to conduct BSA. Being able to conduct BSA on frozen berries could help to reduce sensory fatigue in assessors by allowing them to evaluate samples over a longer time period and to schedule BSA away from the busy harvest period. The results of this study determined that sensory profile from Shiraz berries differed in five sensory attributes – pulp sweetness, pulp fresh fig flavour, skin colour extraction, skin bitterness and seed astringency - between fresh and frozen berries at three times of harvest, preventing the evaluation of these five sensory attributes in Shiraz frozen berries. Study number four aimed to determine the effect of three rootstocks on sensory and compositional differences of Shiraz grapes and wines in comparison to a nongrafted control. The trial was conducted over two seasons. Berry and wine sensory and compositional differences were found between the grafted treatments and the nongrafted control. PCA was able to discriminate the wines from the four treatments in three groups of aroma compounds (acetate esters, ethyl esters and higher alcohols) in both seasons. The results of wine quality scores from two seasons showed that the un-grafted treatment had the lowest quality and 110 Richter and Schwarzmann the highest. The findings from this study identified relationships between the sensory and compositional variables in berries and wines that are affecting wine quality. It also showed that that the use of rootstocks has an impact on berry and wine sensory and compositional characteristics.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Agriculture, Food and Wine, 2015.
Book chapters on the topic "Pulp detachment"
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Brinton, Daniel A., and Charles P. Wilkinson. "Pathogenesis, Epidemiology, and Natural Course of Retinal Detachment." In Retinal Detachment. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780195330823.003.0006.
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Retinal detachment does not result from a single, specific disease; rather, numerous disease processes can result in the presence of subretinal fluid. The three general categories of retinal detachments are termed rhegmatogenous, exudative, and tractional. Rhegmatogenous detachments are sometimes referred to as primary detachments, while both exudative and tractional detachments are called secondary or nonrhegmatogenous detachments. The three types of retinal detachments are not mutually exclusive. For example, detachments associated with proliferative vitreoretinopathy or proliferative diabetic retinopathy may exhibit both rhegmatogenous and tractional features. However, excluding the section on differential diagnosis in Chapter 5, the scope of this book is limited to rhegmatogenous retinal detachments. Accordingly, throughout the book, the term retinal detachment refers to the rhegmatogenous type, unless another type is specifically mentioned. Rhegmatogenous detachments (from the Greek rhegma, meaning rent, rupture, or fissure) are the most common form of retinal detachment. They are caused by a break in the retina through which fluid passes from the vitreous cavity into the subretinal space. The responsible break(s) can be identified preoperatively in more than 90% of cases, but occasionally the presence of a minute, unseen break must be assumed. Exudative detachments, also called serous detachments, are due to an associated problem that produces subretinal fluid without a retinal break. This underlying problem usually involves the choroid as a tumor or an inflammatory disorder. Tractional detachments occur when pathologic vitreoretinal adhesions or membranes mechanically pull the retina away from the pigment epithelium without a retinal break. The most common causes include proliferative diabetic retinopathy, cicatricial retinopathy of prematurity, proliferative sickle retinopathy, and penetrating trauma. Retinal breaks may subsequently develop, resulting in a combined tractional and rhegmatogenous detachment. The essential requirements for a rhegmatogenous retinal detachment include a retinal break and low-viscosity vitreous liquids capable of passing through the break into the subretinal space. Vitreous changes usually precede development of important defects in the retina. The usual pathologic sequence causing retinal detachment is vitreous liquefaction followed by a posterior vitreous detachment (PVD) that causes traction at the site of significant vitreoretinal adhesion with a subsequent retinal tear. Fluids from the vitreous cavity then pass through the tear into the subretinal space (Figure 2–1), augmented by currents within the vitreous cavity caused by rotary eye movements. Although a total PVD is usually seen, many detachments occur with partial vitreous detachment, and evidence of posterior vitreous detachment may not be seen.
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Kahook, Malik Y. "Descemet’s Membrane Detachment." In Complications of Glaucoma Surgery. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780195382365.003.0020.
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Corneal injury resulting from glaucoma surgery has been well described. Causes of injury can range from direct mechanical manipulation to the often more subtle pharmacologically induced injuries that occur with use of antifibrotic medications. Descemet’s membrane detachment (DMD) occurs uncommonly during or after intraocular surgery and has been linked with a variety of procedures ranging from simple clear cornea cataract extraction to deep lamellar keratoplasty. The corneal endothelium, which rests upon Descemet’s membrane, functions as a pump to keep the stroma from becoming swollen. Therefore, DMD results in focal corneal edema and possibly bullous keratopathy. If detachment of Descemet’s membrane extends far enough centrally, visual acuity may become sufficiently compromised to necessitate corneal transplantation surgery (either full-thickness penetrating keratoplasty [PKP] or Descemet’s stripping with automated endothelial keratoplasty [DSAEK]). In glaucoma surgery, DMD often results from the mechanical manipulation that occurs with creation of the cornealtrabecular meshwork opening. Knowing how to accurately diagnose and treat DMD can prevent disastrous consequences and preserve vision. Mackool and Holtz proposed separating DMD into 2 categories, planar and nonplanar, depending on the distance of separation between Descemet’s membrane and the posterior corneal stroma. Planar DMD involves less than 1 mm separation of Descemet’s membrane from the corneal stroma and may be limited to the periphery or extend from the periphery to central regions. Nonplanar DMD involves greater than 1 mm separation of Descemet’s membrane from the corneal stroma and may also be categorized as limited to the periphery or extending to central regions. The significance of this classification was the belief that planar DMD was more likely to spontaneously resolve while nonplanar DMD required surgical intervention. Assia and colleagues also split DMD into 2 categories: DMD with scrolling of tissue and DMD without scrolling of tissue. They believed this classification more accurately described potential for spontaneous resolution in that nonscrolled DMD was more likely to resolve without surgical intervention, even if its location was >1mm from the posterior corneal stroma. While useful as a general guide, these classification systems are not foolproof, and each case of DMD should be viewed independently.
Conference papers on the topic "Pulp detachment"
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Putignano, Carmine, Luciano Afferrante, Angelo Gentile, and Giuseppe Carbone. "Adhesion of Elastic Pre-Stressed Tapes." In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-38446.
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In this paper, we discuss the mechanism of detachment of thin pre-stressed films from a flat smooth rigid substrate. Indeed, we develop an analytical solution in closed form which shows how the critical value of the pull-off force strongly depends on the press-stress P0. In detail, the critical pull-off force needed to detachment is shown to be higher for pre-stressed tapes. Furthermore, we notice that, when a high pre-stress is present, tapes may behave in different manner and spontaneously detach from the rigid substrate.
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Teodorescu, Mircea, and Homer Rahnejat. "Nano-Scale Contact Model for Microfiber Tip Attachment, Detachment and Friction." In STLE/ASME 2008 International Joint Tribology Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ijtc2008-71220.
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The paper investigates the forces that can contribute to the attachment and detachment of the tip of a synthetic fiber to a substrate in normal atmosphere. The contact is subjected to a number of competing forces, which together with the localized contact deflection can promote equilibrium. The pull-off force is predicted as a function of the angle of approach of the fiber toward a substrate and an initial fiber preload.
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Ramezani, Asghar, Aria Alasty, and Javad Akbari. "Pull-In Parameters of Cantilever Type Nanomechanical Switches in Presence of Casimir Force." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95316.
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In this paper, the influence of the Casimir force on two main parameters describing an instability point of cantilever type nanomechanical switches, which are the pull-in voltage and deflection are investigated by using a distributed parameter beam model. The nonlinear differential equation of the model is transformed into the integral form by using the Green’s function of the cantilever beam. The integral equation is solved analytically by assuming an appropriate shape function for the beam deflection. The detachment length and the minimum initial gap of the cantilever type switches are given, which are the basic design parameters for NEMS switches. The pull-in parameters of micromechanical electrostatic actuators are also investigated as a special case of our study by neglecting the Casimir effect.
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Ramezani, Asghar, Aria Alasty, and Javad Akbari. "Influence of van der Waals Force on the Pull-In Parameters of Cantilever Type Nanoscale Electrostatic Actuators." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95068.
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In this paper, the influence of the van der Waals force on two main parameters describing an instability point of cantilever type nanomechanical switches, which are the pull-in voltage and deflection are investigated by using a distributed parameter beam model. The nonlinear differential equation of the model is transformed into the integral form by using the Green’s function of the cantilever beam. The integral equation is solved analytically by assuming an appropriate shape function for the beam deflection. The detachment length and the minimum initial gap of the cantilever type switches are given, which are the basic design parameters for NEMS switches. The pull-in parameters of micromechanical electrostatic actuators are also investigated as a special case of our study by neglecting the van der Waals force.
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Xie, Chao, Xuan Wu, and Xiaojie Wang. "A Three-Row Opposed Gripping Mechanism With Radial Configuration for Wall-Climbing Robots." In ASME 2019 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/smasis2019-5549.
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Abstract This paper presents a three-row opposed gripping mechanism with radial configuration for wall-climbing robots inspired by the structure of the gripper of LEMUR IIB. The mechanism builds upon a kind of microspines for climbing robots. This work utilizes an opposed spoke configuration with 3 rows of 31 microspines on each linkage array, splayed around a central bracket. A single motor drives the 3 linkage arrays by a set of gears to achieve attachment and detachment procedures, and the trajectory of each linkage array tip makes the miniature spines easy to penetrate in and pull off the surfaces. The mechanism designed as a foot of climbing robots can vertically resist at least 1kg of load on rough surface. The findings provide a foundation for constructing a system for a rough-wall-climbing robot.
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Killion, Jesse D., and Srinivas Garimella. "Simulation of Pendant Droplets and Falling Films in Horizontal Tube Absorbers." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60302.
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Recent literature suggests that the droplets that form in horizontal-tube, falling-film absorbers play a major role in the absorption process. The performance of such absorbers is critical to the performance of many absorption heat pump systems. The simulation of droplets of aqueous Lithium Bromide pendant from horizontal tubes was performed by numerically solving the equations of motion on a fixed 3-D grid. The so-called volume of fluid method was used to handle the interface between the liquid and vapor phase. Results are compared with simplified axisymmetric models and with high speed video taken during flow visualization experiments. The results show that simplified axisymmetric models do not satisfactorily represent the evolution of the droplets under horizontal tubes, and that the 3-D numerical model appears to accurately match the important characteristics of droplet formation, detachment and impact observed in the experiments.
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Dadvar, Shima, Sanjeev Chandra, Nasser Ashgriz, and Stephan Drappel. "Adhesion of Wax Droplets to Porous Substrates." In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72060.
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The adhesion of solid wax ink droplets to porous polyethylene and Teflon substrates was studied experimentally. Wax droplets with a diameter of 3 mm and an initial temperature of 110°C were dropped onto test surfaces from heights varying from 20–50 mm. The Teflon surfaces had holes drilled in them to create idealized porous surfaces while the porous polyethylene sheets had mean pore sizes of either 35 or 70 μm. The force required to remove the wax splats from the substrates was measured by a pull test. The detachment force increased with droplet impact velocity. A simple analytical model is proposed to predict the force attaching the wax splat to the surface: it has an adhesive component, calculated by multiplying the contact area between the splat and substrate by the strength of adhesion; and a cohesive component, calculated by multiplying the area of the pores into which wax penetrates by the ultimate tensile strength of wax. Predictions from the model agreed reasonably well with measurements.
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Bergonzini, E., G. Bolelli, B. Bonferroni, L. Lusvarghi, T. Varis, U. Kanerva, T. Suhonen, J. Oksanen, O. Söderberg, and S. P. Hannula. "Wear Behaviour of HVOF-Sprayed Nanostructured WC-CoCr Coatings." In ITSC2011, edited by B. R. Marple, A. Agarwal, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima, and A. McDonald. DVS Media GmbH, 2011. http://dx.doi.org/10.31399/asm.cp.itsc2011p0590.
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Abstract HVOF-sprayed WC–10wt%Co–4wt.%Cr coatings were obtained using experimental feedstock powders (manufactured by spray-drying + sintering), containing nanometric carbide particles. Three reference coatings were also deposited using commercially-available powders containing sub-micrometric carbide particles. The coatings obtained from nanostructured powders, although affected by decarburisation phenomena, contained very fine carbide particles (~200 nm size). Those obtained from commercially-available powders simultaneously exhibited sub-micrometric (~400 nm size) and micrometric carbide particles, and were much less decarburised. Sliding wear tests performed at room temperature against sintered Al2O3 balls showed the occurrence of brittle fracture wear (detachment of near-surface material by local brittle cracking) on the nanostructured coatings, which were embrittled by decarburisation. The reference coatings, by contrast, exhibited either ductile wear behaviour (plastic deformation, pull-out of single carbide particles) or a mix of both ductile and brittle wear mechanisms. When the decarburisation of the nanostructured coatings was not too extensive, their wear loss was comparable to that of the reference ones. At 500 °C, the wear behaviour of all coatings was dominated by abrasive grooving, on account of thermal softening. The most decarburised nanostructured coatings, however, still experienced brittle cracking as well.
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Wang, Haiyu, Weidong Shi, Desheng Zhang, Ling Zhou, and Dazhi Pan. "Numerical Investigations of Scale Effect on Cavitation Around Hydrofoils." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21881.
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Although scale effects on cavitation have been studied, there seems to be no experimental or numerical work has been done on scale effects on cavitation regimes for hydrofoils. The present study was motivated by the prediction uncertainty of cavitation performance in scaling an axial flow pump, which is also an indispensable step in the design and application of hydraulic machineries. Hydrofoil NACA66 was adopted in this paper to represent the general characteristics of hydrofoils. Three hydrofoils with similar boundary conditions were simulated and analyzed, i.e. the initial hydrofoil, the hydrofoil models scaled down 0.5 and 0.25 times, respectively. High quality hexahedral mesh was established based on three-dimensional geometry of the hydrofoils. The monitoring points were arranged at the same locations relative to the boundary in each case. Computations were conducted on these three-dimensional hydrofoils, based on Detached Eddy Simulation (DES) turbulence model and Zwart cavitation model, which is a homogeneous model of cavitation, considering vapor/water mixture as one phase. In order to validate the practicability of numerical method and configuration employed in this paper, the numerical calculation of the initial hydrofoil was compared with experimental results provided by previous researchers, including the evolution of cavitation and pressure fluctuation on suction surface of the hydrofoil. According to the comparisons of the simulation results of the initial case and the other two scaled down models, we found the boundary layer suppresses the reentrant jet, which plays a critical role in cavitation detachment. Consequently, it influences the evolution of cavitation from the initial bubble, sheet cavitation, cloud cavitation and bubble breakup. Meantime, cavity evolution, cavity lengths, as well as cloud shedding periods were analyzed and discussed.