scholarly journals Lignin-Containing Coatings for Packaging Materials—Pilot Trials

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1595
Author(s):  
Asif Javed ◽  
Peter Rättö ◽  
Lars Järnström ◽  
Henrik Ullsten
Keyword(s):  
High Speed ◽  
Water Solubility ◽  
Transmission Rate ◽  
Kraft Lignin ◽  
Packaging Materials ◽  
Water Contact ◽  
Pilot Trials ◽  
Significant Difference ◽  
Ph Level ◽  
Ammonium Zirconium Carbonate

One severe weakness of most biopolymers, in terms of their use as packaging materials, is their relatively high solubility in water. The addition of kraft lignin to starch coating formulations has been shown to reduce the water solubility of starch in dry coatings. However, lignin may also migrate into aqueous solutions. For this paper, kraft lignin isolated using the LignoBoost process was used in order to examine the effect of pH level on the solubility of lignin with and without ammonium zirconium carbonate (AZC). Machine-glazed (MG) paper was coated in a pilot coating machine, with the moving substrate at high speed, and laboratory-coated samples were used as a reference when measuring defects (number of pinholes). Kraft lignin became soluble in water at lower pH levels when starch was added to the solution, due to the interactions between starch and lignin. This made it possible to lower the pH of the coating solutions, resulting in increased water stability of the dry samples; that is, the migration of lignin to the model liquids decreased when the pH of the coating solutions was reduced. No significant difference was observed in the water vapor transmission rate (WVTR) between high and low pH for the pilot-coated samples. The addition of AZC to the formulation reduced the migration of lignin from the coatings to the model liquids and led to an increase in the water contact angle, but also increased the number of pinholes in the pilot-coated samples.

Lignin-containing coatings for packaging materials

2018 ◽  
Vol 33 (3) ◽  
pp. 548-556
Author(s):  
Asif Javed ◽  
Henrik Ullsten ◽  
Peter Rättö ◽  
Lars Järnström
Keyword(s):  
Transmission Rate ◽  
Crosslinking Agent ◽  
Barrier Properties ◽  
Water Stability ◽  
Packaging Materials ◽  
Ph Adjustment ◽  
Water Vapour Transmission Rate ◽  
Starch Films ◽  
Ammonium Zirconium Carbonate ◽  
Coating Formulation

Abstract The mechanical properties and chemical stability in water of self-supporting films made from aqueous solutions of starch and lignin, and the barrier properties of paperboard coated with solutions of these polymers have been studied. The dissolution of starch from the starch-lignin films in contact with the model liquids was decreased significantly when lignin was added to the starch films. The addition of ammonium zirconium carbonate (AZC) to the formulations as a crosslinking agent substantially increased the storage modulus of the starch-lignin films, which indicated that crosslinking had occurred. The addition of AZC to the formulations also led to a decrease in dissolution of both starch and lignin from the starch-lignin films in contact with model liquids. The effect of AZC on the water stability of the films was greater when the pH of the starch-lignin-AZC solution was adjusted with ammonia rather than NaOH. The addition of NH4Cl solution as a presumed catalyst to the recipe when the pH adjustment was performed with NaOH did not improve the effect of AZC on the water stability of the films. The water vapour transmission rate of the coated paperboard decreased slightly when AZC was added to the coating formulation.

Maximum Temperature Through a Yttrium Stabilized Zirconia Ceramic After Er,Cr:YSGG Laser Irradiation

2020 ◽  
Vol 02 ◽  
Author(s):  
Laurel Stringer ◽  
Sarah Malley ◽  
Darrell M. Hutto ◽  
Jason A. Griggs ◽  
Susana M. Salazar Marocho
Keyword(s):  
High Speed ◽  
Potential Method ◽  
Maximum Temperature ◽  
Zirconia Ceramic ◽  
Tooth Pulp ◽  
Control Group ◽  
Stabilized Zirconia ◽  
Significant Difference ◽  
Power Setting ◽  
Group A

Background: The most common approach to remove yttria stabilized zirconia (YSZ) fixed-dental prostheses (FDPs) is by means of diamond burs attached to a high-speed handpiece. This process is time-consuming and destructive. The use of lasers over mechanical instrumentation for removal of FDPs can lead to efficient and predictable restoration retrievability. However, the heat produced might damage the tooth pulp (>42˚C). Objective: The purpose of this study was to determine the maximum temperature (T) reached during the use of different settings of the erbium, chromium:yttrium-scandium-gallium-garnet Er,Cr:YSGG laser through a YSZ ceramic. Methods: YSZ slices (1 mm thick) were assigned into 7 groups. For the control group, a diamond bur was used to cut a 1 mm groove into the YSZ slices. For the 6 experimental groups, the laser was operated at a constant combination of 33% water and 66% air during 30 s with two different power settings (W) at three frequencies (PPS), as follows (W/PPS): 2.5/20, 2.5/30, 2.5/45, 4.5/20, 4.5/30, 4.5/45. The T through the YSZ slice was recorded in degrees Celsius by using a digital thermometer with a K thermocouple. Results: The median T of the control group was 26.5˚C. The use of 4.5 W resulted in the median T (˚C) of 44.2 at 20 PPS, 53.3 at 30 PPS, and 58.9 at 45 PPS, while 2.5 W showed 34.6, 31.6, and 25.0 at 20, 30, and 45 PPS, respectively. KruskalWallis one-way ANOVA showed that within each power setting, the T was similar. The high power and lowest frequency (4.5/20) showed no significant difference from the 2.5 W settings and the control group. Conclusion: The lower power setting (2.5 W) is a potential method for the use of the Er,Cr:YSGG laser to debond YSZ structures. The higher power (4.5 W) with high frequencies (30 and 45 PPS) is unsuitable.

scholarly journals Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1745
Author(s):  
Tamaki Hada ◽  
Manabu Kanazawa ◽  
Maiko Iwaki ◽  
Awutsadaporn Katheng ◽  
Shunsuke Minakuchi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Sorption ◽  
Water Solubility ◽  
Flexural Modulus ◽  
Manufacturing Method ◽  
Heat Curing ◽  
Significant Difference ◽  
Cad Cam ◽  
Curing Method

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

Investigation on the mechanical properties of press-hardened boron steel sheets using the conductive heating technique

2020 ◽  
Vol 234 (8) ◽  
pp. 1084-1098
Author(s):  
O Kocar ◽  
H Livatyalı
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Boron Steel ◽  
Fast Heating ◽  
Heating Method ◽  
Conductive Heating ◽  
Press Hardening ◽  
High Speed Impact ◽  
Significant Difference ◽  
Structural Parts

An aluminized 22MnB5 (Boron) steel sheet, used for structural parts in the automotive industry, was subjected to press-hardening followed by austenitizing, both in a conventional furnace and via the conductive (electric resistance) heating method, an innovative technique based on the Joule’s principle for fast heating of the sheet metal. Conductive heating presents a number of advantages over the in-furnace heating method. These include a more efficient use of energy, as well as the requirement of less time and space for heating, thus lowering costs. After press-hardening was performed using both methods, the microstructural and mechanical characterizations of both specimens were examined for optical microscopy, hardness, tensile strength, and high-speed impact tests. The results showed that the press-hardening process transformed the ferritic–pearlitic microstructure in the as-received state into martensite after die quenching and caused a substantial increase in hardness and strength at the expense of ductility and impact toughness. On the other hand, no significant difference was observed in either the microstructure or mechanical properties with respect to the heating method used. The results obtained in the present investigation concur with the findings of current literature.

Betadine has a ciliotoxic effect on ciliated human respiratory cells

2014 ◽  
Vol 129 (S1) ◽  
pp. S45-S50 ◽  
Author(s):  
J H Kim ◽  
J Rimmer ◽  
N Mrad ◽  
S Ahmadzada ◽  
R J Harvey
Keyword(s):  
Epithelial Cells ◽  
High Speed ◽  
Imaging System ◽  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Positive Control ◽  
Clinical Dose ◽  
Significant Difference ◽  
Sinonasal Mucosa ◽  
Ciliary Beat

AbstractObjective:This study investigated the effect of Betadine on ciliated human respiratory epithelial cells.Methods:Epithelial cells from human sinonasal mucosa were cultured at the air–liquid interface. The cultures were tested with Hanks' balanced salt solution containing 10 mM HEPES (control), 100 µM ATP (positive control), 5 per cent Betadine or 10 per cent Betadine (clinical dose). Ciliary beat frequency was analysed using a high-speed camera on a computer imaging system.Results:Undiluted 10 per cent Betadine (n = 6) decreased the proportion of actively beating cilia over 1 minute (p < 0.01). Ciliary beat frequency decreased from 11.15 ± 4.64 Hz to no detectable activity. The result was similar with 5 per cent Betadine (n = 7), with no significant difference compared with the 10 per cent solution findings.Conclusion:Betadine, at either 5 and 10 per cent, was ciliotoxic. Caution should be applied to the use of topical Betadine solution on the respiratory mucosal surface.

scholarly journals Influence of Two Innovative Packaging Materials on Quality Parameters and Aromatic Fingerprint of Extra-Virgin Olive Oils

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 929
Author(s):  
Stefano Farris ◽  
Susanna Buratti ◽  
Simona Benedetti ◽  
Cesare Rovera ◽  
Ernestina Casiraghi ◽  
...  
Keyword(s):  
Shelf Life ◽  
Storage Temperature ◽  
Transmission Rate ◽  
Virgin Olive Oil ◽  
Quality Parameters ◽  
Packaging Materials ◽  
Transparent Plastic ◽  
Virgin Olive Oils ◽  
Oxygen Transmission Rate ◽  
Olive Oils

The performance of two innovative packaging materials was investigated on two Sardinian extra-virgin olive oils (Nera di Gonnos and Bosana). In particular, a transparent plastic film loaded with a UV-blocker (packaging B) and a metallized material (packaging C) were compared each other and to brown-amber glass (packaging A). During accelerated shelf-life tests at 40 and 60 °C, the evolution of quality parameters (i.e., acidity, peroxide value, K270, and phenolic content) was monitored, together with the aromatic fingerprint evaluated by electronic nose. Packaging B resulted in the best-performing material in protecting oil from oxidation, due to its lower oxygen transmission rate (0.1 ± 0.02 cm3/m2 24 h) compared to packaging C (0.23 ± 0.04 cm3/m2 24 h). At the end of storage, phenolic reduction was on average 25% for packaging B and 58% for packaging C, and the aromatic fingerprint was better preserved in packaging B. In addition, other factors such as the sanitary status of the olives at harvesting and the storage temperature were demonstrated to have a significant role in the shelf life of packaged extra-virgin olive oil.

Venom flow in rattlesnakes: mechanics and metering

2001 ◽  
Vol 204 (24) ◽  
pp. 4345-4351
Author(s):  
Bruce A. Young ◽  
Krista Zahn
Keyword(s):  
Functional Morphology ◽  
Delivery System ◽  
Flow Rate ◽  
High Speed ◽  
Distal Portion ◽  
Retrograde Flow ◽  
Crotalus Atrox ◽  
Direct Recording ◽  
Significant Difference ◽  
Digital Videography

SUMMARY The functional morphology of venom injection in Crotalus atrox was explored using high-speed digital videography combined with direct recording of venom flow using perivascular flow probes. Although venom flow was variable, in most strikes the onset of venom flow was coincidental with fang penetration, and retrograde flow (venom suction) was observed prior to fang withdrawal. The duration of venom flow was consistently less than the duration of fang penetration. The occurrence of retrograde flow, ‘dry bites’ (which accounted for 35 % of the strikes) and unilateral strikes all support a hypothesis for venom pooling in the distal portion of the venom-delivery system. No significant difference in temporal or volumetric aspects of venom flow were found between defensive strikes directed at small and large rodents. With the species and size of target held constant, the duration of venom flow, maximum venom flow rate and total venom volume were all significantly lower in predatory than in defensive strikes.

Measurement of the Melt Pool Length During Single Scan Tracks in a Commercial Laser Powder Bed Fusion Process

2017 ◽  
Author(s):  
J. C. Heigel ◽  
B. M. Lane
Keyword(s):  
Laser Power ◽  
High Speed ◽  
Infrared Camera ◽  
Powder Bed Fusion ◽  
Single Track ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Melt Pool ◽  
Significant Difference ◽  
Scan Speed

This work presents high speed thermographic measurements of the melt pool length during single track laser scans on nickel alloy 625 substrates. Scans are made using a commercial laser powder bed fusion machine while measurements of the radiation from the surface are made using a high speed (1800 frames per second) infrared camera. The melt pool length measurement is based on the detection of the liquidus-solidus transition that is evident in the temperature profile. Seven different combinations of programmed laser power (49 W to 195 W) and scan speed (200 mm/s to 800 mm/s) are investigated and numerous replications using a variety of scan lengths (4 mm to 12 mm) are performed. Results show that the melt pool length reaches steady state within 2 mm of the start of each scan. Melt pool length increases with laser power, but its relationship with scan speed is less obvious because there is no significant difference between cases performed at the highest laser power of 195 W. Although keyholing appears to affect the anticipated trends in melt pool length, further research is required.

Performance changes of venous valves following tissue treatment with novel in vitro system

2018 ◽  
Vol 34 (5) ◽  
pp. 347-354
Author(s):  
Garrett Easson ◽  
Megan Laughlin ◽  
Hanna Jensen ◽  
Kevin Haney ◽  
Marc Girardot ◽  
...  
Keyword(s):  
High Speed ◽  
In Vitro Model ◽  
Closing Time ◽  
Venous Valve ◽  
Orifice Area ◽  
Treatment Methods ◽  
Venous Valves ◽  
Significant Difference ◽  
Vitro Model

Objectives The purpose of this study is to test venous valve performance and identify differences between native tissue and replacement devices developed with traditional tissue treatment methods using a new in vitro model with synchronized hemodynamic parameters and high-speed valve image acquisition. Methods An in vitro model mimicking the venous circulation to test valve performance was developed using hydrostatic pressure driven flow. Fresh and glutaraldehyde-treated vein segments were placed in the setup and opening/closing of the valves was captured by a high-speed camera. Hemodynamic data were obtained using synchronized hardware and virtual instrumentation. Results Geometric orifice area and opening/closing time of the valves was evaluated at the same hemodynamic conditions. A reduction in geometric orifice area of 27.2  ± 14.8% (p < 0.05) was observed following glutaraldehyde fixation. No significant difference in opening/closing time following chemical fixation was observed. Conclusions The developed in vitro model was shown to be an effective method for measuring the performance of venous valves. The observed decrease in geometric orifice area following glutaraldehyde treatment indicates a decrease in flow through the valve, demonstrating the consequences of traditional tissue treatment methods.

scholarly journals Impact of cleaning regimes on dental water unit contamination

2011 ◽  
Vol 9 (4) ◽  
pp. 647-652 ◽  
Author(s):  
Soad A. Abdallah ◽  
Ahmed I. Khalil
Keyword(s):  
High Speed ◽  
Tap Water ◽  
Daily Basis ◽  
Dental Chair ◽  
Dental Clinics ◽  
Significant Difference ◽  
Before And After ◽  
Hand Piece ◽  
Viable Bacteria ◽  
Dental Unit Waterlines

Microorganisms that have been identified in dental unit waterlines (DUWLs) are of concern because they can cause infections, especially in immunocompromised patients. This study aimed to assess the incidence of microbial contamination in DUWLs before and after intervention to reduce contamination, and to investigate the presence of coliforms, Escherichia coli and Pseudomonas aeruginosa. Water samples were collected aseptically from the waterlines. The high-speed hand-piece and dental chair units were served by one distillation apparatus, which was fed by the potable tap water of four dental clinics. Different interventions were used: chlorination, flushing before clinics and between patients, draining at the end of the day, and freshly distilled water on a daily basis. There was a significant difference between the level of contamination in the high-speed hand-piece (1.5–2.7 log CFU/ml) and dental chair unit water (2.0–3.5 log CFU/ml). Coliforms (0.9%) E. coli (0.9%) and Pseudomonas (1.8%) were detected during 2008. This study indicates the need to monitor water quality regularly and prevent stagnation in DUWLs to reduce the number of viable bacteria to &lt;100 CFU/ml. We recommend flushing the DUWL for 2 min before the first patient and for 10–20 s between patients, flushing the dental unit at the end of the day and draining it overnight to reduce the development of biofilms, and chlorination of the DUWLs.

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